Dispenser mixing module and method of assembling and using same

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DESCRIPTION

Dispenser mixer module, method of assembly and use.

Field of the invention

The present invention relates to a method and apparatus for dispensing material such as foam for use, for example, in the formation of foam buffer bags or in a more direct application of the dispensed foam, such as in a packaging protection process. foam in position or injection of foam material within a confined area such as in an insulation injection process.

Background of the invention

Various material dispensers have been developed over the years including those aimed at dispensing foamable material such as urethane foam. For example, when certain chemicals are mixed together, they form polymeric products that simultaneously generate gases such as carbon dioxide and water vapor. If the chemicals are selected to harden after generation, for example, of carbon dioxide and water vapor, they can be used to form "hardened" polymeric foams (eg, a cushion grade in an appropriate fully expanded state ) in which the mechanical foaming action is produced by gaseous carbon dioxide and water vapor exiting the mixture.

In some techniques, synthetic foams consist of liquid organic resins and polyisocyanates in a mixing chamber (for example, a liquid form of isocyanate, which is often referred to in the industry as the "A" chemical, and a liquid mixture of components such as that which includes polyurethane resin to produce polyurethane foam, which is often referred to in the industry as "B" chemical). The mixture can be dispensed into a receptacle, such as a packet or foam bag in place (see, for example, U.S. Patent Nos. 4,674,268,4,800,708 and 4,854,109 which are incorporated by reference), where it reacts to form the foam.

A particular problem associated with some foams, such as polyurethane foams, is that once mixed, the organic resin and the polyisocyanate generally react quickly so that the resulting produced foam tends to accumulate in all the holes it passes through, including foam backing in holes the components passed through prior to mixing. Also, some of the most useful polymers that form foamable compositions are adhesives. As a result, the foamable composition, which is often dispensed as a somewhat viscous liquid, tends to adhere to objects it collides with and then harden into place. Many of these foamable adhesive compositions adhere tenaciously to the interface making removal especially difficult.

Solvents are often used in an effort to remove the hardened foamable composition from non-contact surfaces, but even with solvents (particularly when considering the limitations of the type of solvents suitable for operator contact or exposure), this can result a difficult task. Undesirable adhesion can take place in the general region where chemicals A and B first come into contact (for example, a mixing dispensing chamber) or an upward position as in individual injection ports in light of the quality of expansion of the mixture, or downwards such as a dispensing gun or, in realization, anywhere near the dispensing device, for example, after misdirection, improper application or leakage (for example, a foam bag with a leaking end or edge seal). For example, "foaming" in a bag dispenser, where the mixed material is not adequately confined within a receiving bag, can result in the foam hardening in every nook and cranny of the dispensing system making extraction reasonably unattainable. particularly complete if the configuration of prior art systems is considered. A misdirected stream from a hand held gun outlet can also result in numerous unwanted surfaces being covered.

Because of this adhesion characteristic, measures have been taken in the prior art to try to avoid contact of chemicals A and B in unwanted positions, as well as to prevent the passage of chemicals A / B mixed into unwanted areas. or staying in areas such as the discharge passage used when directing the A / B chemical mix. Examples of injection systems for such foamable compositions and their operation are described in US Patent Nos. 4,568,003 and 4,898,327, and incorporated herein in their entirety by reference. As disclosed in these two patents, in a typical dispensing cartridge, the mixing chamber for the foam precursors is a cylindrical core having a hole extending longitudinally therethrough. The core is typically formed from a fluorinated hydrocarbon polymer such as polytetrafluoroethylene ("PTFE" or "TFE"), fluorinated ethylene propylene ("FEP"), or perfluoroalkoxy ("PFA"). Polymers of this type are available in large quantities from various companies, and one of the more familiar names for such materials is "Teflon", the trademark used by DuPont for such materials. For the sake of convenience and familiarity, such materials will be referred to herein as "Teflon," although it will be understood that materials available from companies other than DuPont and others may also be used if appropriate.

In such systems, a plurality of holes (generally two) are arranged in the core in communication with the hole to supply the organic resin and polyisocyanate to the hole, which acts as a mixing chamber.

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A combination bleed rod and valve is positioned to slide into a tight tolerance fit, "interference", within the hole or mixing chamber to control the flow of organic resin and polyisocyanate from the openings to the hole and subsequent discharge. cartridge foam.

With hand held and bag foam dispensing apparatus, A / B chemicals are typically supplied from their respective sources (typically a large reservoir such as a 55 gallon drum for each respective chemical) in the desired state (for example, desired flow rate, volume, pressure, and temperature). Thus, even with a new brand dispenser, trying to achieve a desired foam product involves additional requirements. Various pumping techniques have emerged in the present state of the art such as individual pumps designed for introduction directly to the source containers of chemicals coupled with a controller arranged in an effort to maintain the desired flow rate characteristics by controlling the flow rate. bomb.

Figure 1 illustrates a prior art handheld two component (electric) dispensing system 20. System 20 includes chemical drums 22, 24 for the two chemical components "A" and "B" to be mixed in order to produce a dispensed foam. Pumps 26, 28 extend into drums "A" and "B", each pump having a combined tachometer and a set of DC motors (27, 29). The pumps 26, 28 are connected to a control console 30. The chemical lines 32, 34 extend from the pumps, through the hanging support structure 36 and are connected to the hand dispenser 38. In each of the lines 32, 34 there are coils of heating wires to control the temperature. of the chemical, and electrical lines 31, 33 extend from the control console and are electrically connected to the heating wire coils in the conduits. Electrical line 35 extends from the control console to the dispenser valve rod alternating electric motor. Adjacent to the dispenser 38 is a bracket 40 to support the box 42 and a dispenser sleeve 44. Dispenser system 20 is a closed-loop control system with positive displacement pumps that attempt to maintain the "ratio" supply of each dispenser "shot" by continuously monitoring and adjusting the temperature, pressure, and speed of the pump.

Figure 2 provides an exploded view of a prior art handheld dispenser 38 that includes a handle 46 having a handgrip extension 48 and a mounting base 50 that supports the valve rod reciprocating motor 52. , a mix cartridge "bottom" bracket 54 and a mix cartridge "top" bracket 56. Brackets 54 and 56 are designed to retain the mix cartridge assembly 58 in place. Top bracket 54 also functions as a manifold for chemicals received via hose adapters 60, 62 and receives valve control plugs 64, 66, filter assemblies 68, 70, and O-rings 71, 73 to prevent product leakage chemical between the outlet of the lower support (72 shown) and the housing holes of the cartridge assembly (74 shown). The chemical mixing cartridge 58 is secured between the lower bracket 54 and the upper bracket 56, which are secured by fasteners 76, while cartridge position set screws 78 extend to fixing cavities 80, 80 'in the cartridge set 58.

Figures 3A and 3B provide an illustration of the interior of the prior art mixing cartridge assembly 58 (see US Patent No. 4,898,327) that shares similarities with that depicted in Figure 2. As depicted, the prior art cartridge assembly 58 includes a housing 82 with accessible rear end 84 (C-Clip), perforated front end 86, Teflon mixing chamber 88 defining chemical mixing zone 89 (the " "actual mixing chamber"), chemical mixing port elements A and B 90, 92 (FIG. 3B) receiving chemical from the housing port inlets 91,93, and a valve rod 94. In an effort to maintain a sealing relationship with the valve stem, a stack of Belleville washers 96 pushes against the intermediate disc 98 to keep the Teflon material compressed. After packaging, the open rear end is closed by means of a special pressing tool (not shown) that allows the end cap 91 and clip 84 to be fitted.

Despite great effort in the art (see, for example, U.S. Patent Nos. 4,463,251, 4,867,346, 5,211,311, 5,090,814, 5,180,082, 5,709,317), mixing cartridges of The prior art have to be maintained and replaced very frequently, resulting in a corresponding large amount of downtime and operator frustration.

In these prior art devices the actual mixing takes place in the cylindrical hole or cavity that is drilled through the central axis of the Teflon cylinder. Thus, the mixing region chamber is actually a hole surrounded by the inside diameter of the relatively thick-walled Teflon cylinder (it is noted that the term "mixing chamber" is often used in the art in a broader sense, so as to include the chamber formation structure). The cavity or hole is where both urethane components A and B collide, mix and start the reaction process that creates foam.

Prior art functional foam dispensers employing a Teflon mixing chamber, such as those listed above, are often made of various grades of Teflon, because of their excellent non-stick properties. Mixing chambers, such as those in the patents listed above, are generally cylindrical in shape and compress against the front of the housing. Desirable characteristics of a mixing chamber in most environments include (i) maximizing mixing efficiency; (ii) providing a laminar outlet stream; (iii) have valves without leaks in the flow of chemicals.

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Prior art mixing chambers are generally designed to provide mechanical support to shock ports used to direct the expelled chemical. One purpose of these chemical ports is to focus the flow of high speed shock liquid precursors in an effort to improve efficiency. The nozzles that chemicals pass through before entering the mixing chamber itself are commonly referred to as orifices in the industry. These orifices help to minimize the cross-sectional area of ​​the outlet jet, maximizing the flow velocity, and thereby maximizing the shock pressure when the two streams collide. The outlet diameter of the orifice nozzle opening is designed in these systems with the idea that the opening should not be less than the desired outlet capacity of the pumping system (for example, in the range of (200) 1, 38 MPa at (300 psi) 2.07 M Pa which could be considered a comfortable operating level, with a range of 2.76 to 3.45 MPa (400 to 500 psi) representative of a maximized pressure level of a practical system of the prior art). Mixing can possibly be improved by using additional mechanical mixing elements in the system, but these can add significant complexity to the design, which can often outweigh the possible advantage of mixing.

For greater efficiency (and foam quality), keeping both ports clean and unobstructed helps maintain initial production environments. Maintaining the holes properly aligned for impact in the desired position such as on the center line of the mixing chamber is also generally considered desirable in the prior art system.

With respect to a laminar outlet stream, the length of the mixing chamber channel provides a means of damping the turbulence of the chemical flow immediately after the collision. If the turbulence is adequately damped, a laminar quality is given to the flow of chemical (mixing) exiting the receiving chamber (mixing). A laminar outflow, commonly called a "pencil pour," is easier to direct and much cleaner to work with than a turbulent or centrifugal outflow. However, if the length to diameter ratio of the mixing chamber is too small, the output current can be highly erratic. This can be confusing to the operator, and is an indication that chemicals are mixed poorly.

In addition, it is generally considered in the industry that mixing can be improved in systems that have a longer downtime at the confines of a mixing chamber since confinement helps keep chemicals in close proximity for a longer time. length. On the other hand, if the mixing chamber is too long, the axial force required to withdraw the valve rod increases significantly, leading to an increase in the size and weight of the associated drive mechanism. Large size and large weight requirements are generally unacceptable for practical application, eg, in hand packaging systems (eg, the user has to comfortably hold the weight of a hand dispenser).

Another source of the development of non-laminar or erratic flow in prior art systems is to prevent chemicals from colliding on the centerline of the inside diameter of the mixing chamber, because rotational moment can be imparted to the flow stream. in such prior art systems. This rotational moment can manifest itself in an outlet stream centrifuge, which appears as a spray pattern and can cause a number of problems.

The mixing chamber in most systems also provides a means for the valve rod to shut off the flow of liquid precursors and open to allow flow and mixing to take place. Thus, in prior art systems an effort is made to maintain valve devices that prevent the formation of highly troublesome exhaust paths that can allow chemical A to mix with chemical B at undesirable times and positions. However, since Teflon is a marginal sealing material, it is quite difficult to provide the necessary seal in the typical pressure range of interest (eg, 1.38 to 3.45 MPa (200 to 500 psi)). The compression of Teflon can potentially improve its function as a watertight gasket. For example, compression with a load in psi three to four times the pressure of the fluid being sealed. A stack of Belleville washers has been used at the rear of the housing to provide this load.

In addition, Teflon gaskets have the potential to improve with time under load, since over time Teflon material can cold flow to microscopic surface imperfections that are possible leak paths along the face of a sealing surface. Teflon material is more prone to cold flow than most other designer plastics because the polymer chains in the material do not adhere to each other. Because of this, the Teflon material zones can freely slide past one another to a greater extent than most other designer plastics, making the Teflon material a useful non-stick surface. Although this cold flow distortion of Teflon can be beneficial (for example, allowing the material to form around surfaces intended to be sealed), it is also the cause of several problems, including the possible loss of fit between the hole and the valve rod. as well as the fit between the holes (eg, holes) through which the separated precursors enter the hole for mixing and subsequent dispensing. In many of the prior art systems using Teflon, the Teflon core is mounted to the cartridge under a certain degree of stress in order to help prevent leakage in the way that a gasket is mounted under stress for the same purpose. This stress also promotes the creep of the Teflon at intervals or other holes that may be next to it, which can be good or bad depending on the movement and the surface contacted or whose contact is interrupted in view of the cold flow.

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However, in these prior art systems, the quality of the seal is lost over time, at least to some extent, allowing an initial build-up of the curable material, which can lead to a cycle of seal degradation and deterioration. from build-up of hardened material. In turn, this can lead to various problems including partial blocking of chemical inlet ports such that the desired flow mix is ​​disturbed and the quality of the foam produced is degraded. In other words, in typical injection cartridges, the separated foam precursors enter the hole through separate inlet holes. Polyurethane foam tends to accumulate in the area where the precursor exits the hole and enters the mixing chamber. Such accumulations cause splashing in the outlet stream and dispensing of the mixture in an inappropriate ratio. Accumulation of hardened material can also result in partial blockage of the dispenser outlet causing misalignment of the dispensed flow in contact with a desirable surface (eg, the operator or various nooks and crannies in the dispenser).

The build-up of hardened / adhesive material over time causes additional problems such as the valve rod sticking so far within its region of alternate sealing / non-sealing travel that the actuator mechanism is able to move the rod (resulting in the generation of a stop signal in many common prior art systems) or a component breaks along the drive train, which is often the valve rod latching position relative to some prior art designs. Furthermore, if the movement of the Teflon sealing element is forced after it has solidified in a given position, the quality of the seal, as explained in more detail below, will degrade until the Teflon can solidify in the new position.

A disturbance to any of the upstream mixing chamber functions will necessitate servicing or replacement of the mixing module, with the resulting downtime, inconvenience, and expense. Anything that can eliminate or reduce the occurrence of these problems will greatly improve the reliability of the mixing module.

As a result of studying such problems and difficulties associated with the prior art, the inventors believe that one source of many of the difficulties and problems associated with prior art devices is the tendency of the mixing chamber to move within the housing of the mixing chamber. mixing chamber. Thus, according to the present invention, the tendency of the chamber to "move" within the confining cylinder of the housing of the mixing chamber has been studied. The effects of this movement have been observed by changes in the position of the stainless steel chemical orifices of prior art devices (for example, looking through the two flow holes radially drilled through the outer metal housing ). These housing inlet holes provide a clear view of the chemical holes that are located radially in the Teflon mixing chamber body. It has been observed that after a few thousand cycles, the orifices will generally rotate appreciably relative to the inlet holes of the mixing chamber housing and that the displacement tends to worsen with a greater number of cycles. It has been determined that this movement problem manifests itself in the movements of the mixing chamber in both axial and radial directions.

Some examples of problems that are considered to exist as a result of displacement of the mixing chamber within its housing unit include:

I. Movement of the chemical orifices from the ideal position

to. Mixing chamber displacement, even a small increment, causes the holes to deviate from their ideal (design and mounting) position.

b. If the A and B chemical ports are displaced from a desired shock position, the foam quality may be affected.

c. The outgoing stream of reacted chemicals from the outlet of the mixing module may be pulverized due to rotation of the outgoing stream produced by the displaced holes.

d. If the rotation is severe, the orifices may move so misaligned from the flow holes in the housing that chemical flow is severely restricted, and the system will shut down as a result.

II. Chemical leak

to. Displacement of the mixing chamber, even a small increase, can seriously degrade its sealing ability, causing chemical A and / or B to leak into positions where they can mix and react with each other and cause various problems.

b. Leaks that produce urethane deposits near the exit areas of the chemical orifices can cause the outlet stream of the mix module to be sprayed, or even total flow blockage.

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c. If a leak is large enough it can lead to what is known as a massive crossover, where large amounts of urethane are produced on the A and / or B sides of the dispenser manifold. The massive crossover in the dispenser manifold is difficult to clean, and often results in the replacement of many expensive components.

d. Chemical leaks can also cause the valve rod to stick to the mixing chamber. Urethane that forms on the inside diameter of the mixing chamber will over time have a tendency to clog a prior art mechanism. Where the drive mechanism can no longer move the rod, a stopped system or equipment breakage is detected as a broken rod connector.

and. Chemical leakage to a solvent source such as a solvent chamber at the rear of a mix module reduces the effectiveness of solvent venting, and greatly reduces the life of the mix module.

III. Premature wear of the mixing chamber

to. Most mixing modules are based on relatively tight tolerances and fairly critical snap fits. Thus, any tolerance deviation caused by exhaust movements can lead to related failures.

b. If these fittings are not maintained, the mixing chamber, in addition to leaking, will also be subject to damage due to movement of the valve rod. Damage may not be visible to the naked eye, but deformations, even microscopic, can have observable effects.

c. Any damage or wear to the Teflon mixing chamber will exacerbate the leakage problems listed above.

d. Damage to the ID surface of the mixing chamber will also create fissures, gouges, and scratch marks that are nucleation sites for urethane build-up. Once urethane build-up begins, it will attract more urethane, increasing in size until it causes a mix module to fail.

The sequence of events is considered according to the present invention as described below (although it is not the intention of the present invention to specifically delimit or be limited in any way by the ideas (e.g., analysis and conclusions) in the development of the present application), using the explanation given in relation to a typical embodiment of the prior art compression with Belleville washers:

1. The mix module begins life in an aligned condition, with the holes in the mix chamber in proper alignment with the through holes in the mix module housing. When using the mix module, urethane naturally builds up on the inside diameter of the mix chamber.

2. The slow build-up of urethane on the inside diameter of the mixing chamber gradually increases the adhesion force between the valve rod and the mixing chamber.

3. At some point, when the bond strength increases to a critical level, the act of removing the valve rod causes the mixing chamber to return to the Belleville washers that hold it from behind. Indeed, the Belleville washer stack is a powerful spring with a short stroke.

Four. The valve rod will move the chamber in the forward direction, which compresses the Belleville stack. This will increase the force pushing the mix chamber forward until the urethane bond between the mix chamber and the valve rod is broken.

5. After the joint is broken, the Belleville washer pushes the mixing chamber forward, close to its original position.

6. If all these movements were "perfect", the mixing chamber would not rotate and would return to its original position. However, the forces in this situation are considered not perfectly balanced, and the mixing chamber tends to rotate as it is pushed back, or when it tries to return to its initial position.

7. The mixing chamber tends to rotate a tiny amount with each cycle. After a large number of cycles, the sum of these minute rotations manifests as a significant change in the radial position of the orifice within the mixing chamber housing.

8. These stresses in the chamber also cause it to distort, which may explain the movement of the orifice that is evident in the axial direction with respect to the flow holes of the housing.

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A further problem associated with the prior art is the difficulty of accessing the mixing chamber to correct the aforementioned problems that arise. For example, as seen in Figures 3A and 3B, prior art mixing modules have been assembled using retaining rings on the back plug or compression plug. To install the retaining ring, the back plug is pushed into the stack of Belleville washers, an action that requires approximately 0.89KN (2001bf) to perform. Thus, the prior art mounting method requires the use of machines such as boring presses and some special holding and aligning accessories to join the prior art mixing module. This type of design is difficult to assemble and disassemble, since the retaining ring can be difficult to install and remove when heavy loads are involved.

A further problem associated with prior art designs that include a housing integrated front end plug is the tendency of the front end plug to warp or bulge due to the load exerted by the stack of Belleville washers on the mixing chamber and , in turn, on the front end plug that contacts the mixing chamber. The prior art front plug stamped onto the housing design does not have especially high strength and is subject to deformation. This deformation can cause reliability problems and lead to problems such as those outlined above when the mixing chamber moves its position.

The prior art designs also have the difficulty of assembly. For example, the typical assembly process includes inserting the mixing chamber from the rear end and attempting to align the chemical holes before adding the Belleville washers, compression plug, and C-clip. This alignment can be difficult and, even if properly accomplished, the activity associated with locking the C-clip can easily cause misalignment problems. In such cases, the user has to perform a difficult C-clip removal and alignment sequence. Difficult assembly and disassembly also makes prior art devices unsuitable for on-site repairs and on-site retrofits, instead requiring their return to the service center and technical service intervention.

A further problem associated with the prior art design is the difficulty of adequately filling the solvent chamber with solvent. It can be a cumbersome and complicated procedure to fill prior art mixing modules with solvent. For example, in a prior art design the solvent has to be dispensed to the rear of the mixing module, just before using a boring press to compress the washers. In addition to the spillage produced during this process, it is difficult to know if the mixing module is sufficiently filled with solvent (for example, since the viscosity of the solvent is quite high at room temperature, it is easy for air to be trapped in the mixing chamber, giving a false impression of solvent filling). Once assembled, a solvent check cannot be performed in the prior art design without going through a difficult disassembly process. Considering that the duration of the mix module is typically proportional to the amount of solvent, the presence of trapped air and low levels of solvent can seriously degrade the life of the mix module.

Once the C-clip is mounted and locked, the solvent vent within it can degrade or degrade the seals over time, thus making the prior art design unsuitable for harsh climates and / or prolonged storage. as often happens in military applications.

US 5950875, US 5791522, US 3144210 and US 4377256 describe other examples of mixing modules of the prior art.

Summary of the invention

Accordingly, the present invention is concerned with reducing or obviating at least some of said difficulties and problems associated with the prior art. That is, with the help of the above ideas, various problems have been solved according to the present invention including those related to said movement of the mixing chamber, and, under one embodiment of the invention, a mixing chamber has been developed that includes a locking device that prevents the mixing chamber from backing up with a valve rod to the compression means (eg a stack of Belleville washers). Thus, in one embodiment of the present invention, blocking means are provided to prevent movement of material from the mixing chamber in cold flow, which is not beneficial, relative to its supporting housing or confining means. By providing a mixing chamber with position locking means, relative to, for example, the reciprocating movement of the valve rod, any movement (preferably both axial and radial movement is excluded) of the chamber is prevented or at least minimized. of the present invention after an adhesion relationship is formed between the rod and mixing chamber while the rod is pushed back into the compression means.

The locking means of the present invention preferably function using the housing as a fixed base, which housing is preferably fixed in position relative to the dispenser (eg, a hand housing or frame that supports the mixing module assembly). A mechanical interlocking between the mixing chamber housing or confinement means and the mixing chamber is preferred, as it provides for locking and removal of the mixing chamber when desired. The locking means is preferably applied around the entire circumference or a significant percentage (eg, 30% or more continuously or serially spaced) of the mixing chamber to provide an equal degree of retention force around a portion. significant or the entire circumference or periphery of the mixing chamber. For example, a preferred locking means (which also have the advantage of facilitating manufacture and insertion and removal of the mixing module), is a

2 294 516 T3 enlarging the outer diameter of the distal end of the mixing chamber to match an enlarged inner diameter of the mixing module housing. This “mushroom” configuration in the mixing chamber (for example, a stepped annular boss on a block of cold-flow Teflon material), is designed to resist the forces inherent in the dispensing mechanism, and avoid or at least minimize all tendency of the mixing chamber to return or move with the rod.

Additional embodiments of the locking means include an inversion of the relative components of locking by extension or exit and receiving or recessing or a mixture of both techniques. Again, it is preferable to have an entire periphery continuous protrusion or protrusions arranged circumferentially significantly completely by avoiding mixing chamber movement and undesirable cold flow distribution of material from the mixing chamber while the mixing chamber it is under the compression of the compression media. For example, in an inverted arrangement, the mixing chamber is provided with one or more receiving zones that receive element (s) extending radially inward or formed in the housing itself such as an integral protrusion or a added locking extension or extensions that extend from or through the housing (for example, pins arranged in series, an annular ring or the like that are sufficiently circumferential to provide a coherent locking force against the force of the spring or compression means operating against the locking means). The axial positioning of the "inverted" or non-inverted means of preventing movement of the mixing chamber of the present invention is performed in order to make the projection (s) engage a sufficient axial amount of the mixing chamber. mix to lock chamber in axial position during reciprocating valve movement. The housing boss (s) in the "inverted" embodiment or the housing receiving area (s) in the non-inverted embodiment are based on a monolithic housing design (eg, a single molded unit , machined or formed) or composed of a plurality of assembled components (for example, inserted pin elements or compressible annular sleeve or fixation arrangement or a cylindrical sleeve inserted in the non-inverted embodiment to retain the distal end of an axially intermediate projection of the mixing chamber). Consequently, instead of or in addition to the aforementioned expanded or mushroom-shaped distal end (the end where the free end of the rod exits), the locking means of the present invention can be placed in an intermediate or opposite locking position. (near end). As will become more apparent below (eg, the description of the loading of a mixing chamber under the new housing design of the mixing module at the front end of the housing), the "non-inverted" embodiment of "mushroom" placed is preferred. distal.

The design of the preferred embodiment of the invention also includes a front end plug and a rear plug that are releasably attached to respective open ends of the mixing module housing. In a preferred embodiment, the releasable fixation is made by means of threaded connections at respective ends of the housing such as an internal thread at the compression end which is preferably the rear end according to the present invention and an external thread at the front end, the front end being preferably arranged for insertion and removal by finger grip of a front plug and at the rear end a simple tool that screws or unscrews the rear plug.

This union of the front plug and rear plug to an open front and rear end housing design allows for on-site service and retrofit. Furthermore, in accordance with the design of the present invention, the front plug can be manufactured separately from the housing and made of a strong material and construction. In addition, the design of the present invention allows for loading and handling through the front end of the mixing chamber prior to attachment of the leading end plug which allows for exact alignment of the chemical orifices in the mixing chamber with that of the mixing chamber. accommodation before closing the front end plug (which may take place after or before fixing the rear plug, but preferably before inserting the rear plug, using the introduction of the back plug in the direction of a compression plug preferably performed as the final assembly step (except for the optional activity associated with adding solvent through a solvent plug hole and fixing the plug of solvent as described immediately below)). Orifice pins or the like can be used to facilitate position maintenance during the final assembly process.

The inclusion of a detachable and attachable solvent cap and its placement in the housing provides the advantage that solvent filling takes place after all other components of the mixing module are fully assembled without the spillage problems associated with the prior art, and the design makes it easier to properly carry the solvent chamber from the beginning since air entrapment problems can be more easily avoided and solvent level monitoring can be easily performed after the entire assembly.

Despite being an easily accessible solvent introduction design, solvent containment is ensured with the solvent plug, even with the added certainty provided by placing a watertight gasket, such as an O-ring, between the solvent plug. and housing threads which also prevent potential leakage during shipping. Plus, ready access allows for extended solvent-free storage and on-site filling when desired. In addition, when going from use to a state of prolonged storage, the solvent can be easily removed and later refilled at the time of reuse.

A preferred embodiment of the invention includes a dispensing module including a housing, a fluid receiving chamber received within the housing and having a rod passage formed therein and at least one chemical passage orifice in fluid passage communication. with the rod passage, a rod received in the rod passage, and locking means to prevent adjustment of the fluid receiving chamber in conjunction with an alternative adjustment of the position of the rod.

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A preferred embodiment of the invention also includes a dispensing module in the form of a mixing module where the fluid receiving chamber is a mixing chamber that receives at least two different chemicals, it is formed by a block of cold flow material. , such as Teflon material, and has a through hole formed in it to define the rod pitch. The mixing module further includes compression means (for example, a stack of Belleville washers) to impose compression forces on the mixing chamber and the rod is dimensioned relative to the mixing chamber such that, in practice, even though a stick-to-chamber adhesion relationship is likely (assumed to occur at some point during use), the mixing chamber retains a pre-adhesion position despite the design of the compression means which is adjustable in configuration or position when subjected to compression.

In the dispensing module, the locking means preferably includes a projection / recess arrangement or relationship formed between the housing and the mixing chamber and providing a generally consistent peripheral or circumferential locking force between the mixing module and the housing. For example, the projection / recess relationship preferably includes an annular projection in one of the housing and mixing module, and a receiving recess formed in the corresponding one of said housing and mixing module. A preferred embodiment has the projection formed closer to a first end of the mixing chamber than a second end, and the first end being a forward discharge end of the mixing chamber. The boss is also preferably formed in a forward end portion of the mixing chamber. The compression means is also preferably designed so that it is continuously in compression mode at all times when the mixing module is mounted.

A preferred embodiment has the mixing chamber with the projection and the housing with the corresponding recess, and the projection extending over at least most of the periphery of the mixing chamber, such as that which extends continuously without interruption around the periphery of the mixing chamber. A projecting annular ring that extends across the entire periphery of the mixing chamber from the front end to the rear to a limited longitudinal degree is illustrative of a suitable configuration. The boss also preferably extends radially out of a main cylindrical body of the mixing chamber, the boss and the main body being formed as an integrated monolithic unit, and preferably representing the radial extension (considering both ends of the diametrical extensions) of 5 at 25% of a maximum diameter of the mixing chamber, 10 to 15% being sufficient for most applications (half the amount above being the radial annular distance or one of the two extensions along a circumferential flange diameter.

In an alternative embodiment of the mixing module of the present invention, the mixing chamber has a projection that extends around a peripheral area of ​​the mixing chamber and the projection includes multiple projecting elements disposed around the peripheral area of ​​the mixing chamber. mixture.

The present invention also includes a dispensing module where the wand is dimensioned to seal an exit hole in the chemical product hole upon reciprocating movement of the wand through said exit hole, and where there are at least two chemical product holes extending radially formed in the mixing chamber, and the rod passage is represented by an axial passage in a cold flow block of the material that forms the mixing chamber. In addition, in a preferred embodiment the wand functions as both a valve wand and a bleed wand, and the fluid receiving chamber includes two chemical inlet ports that open to the mixing wand passage when the wand is in. a withdrawn state, and the rod is dimensioned to seal the chemical inlet ports when in a non-withdrawn state.

The dispensing module preferably has two or more chemical mixing inlets formed in a main housing and further includes, in a preferred axial series, a rear housing closure member, compression means, fluid receiving chamber or mixing chamber formed of a cold flow material (and which also preferably has at least two chemical inlet ports that open to the passage of rod), and a front closure element. The front and rear closure elements of the housing are preferably releasably attached to the housing, the housing having an open front end and an open rear end, and the front and rear closure elements being attached to or over the holes so as to close the front holes. and rear of the housing. The front and rear closure elements are preferably releasably attached using, for example, a threaded engagement with the housing. In addition, the fluid receiving chamber is preferably formed of cold flow Teflon material and includes two chemical inlet ports that open to the rod passage and the housing has chemical feed ports aligned with the inlet ports. of chemicals.

A preferred embodiment of the invention also includes a mixing module for a two-component chemical dispensing system, including a housing having a receiving cavity and front and rear ends, a mixing chamber formed of a cold flow material and received in the housing, and the mixing chamber having first and second chemical ports and a rod passage formed therein, as well as a rod received in the rod passage, a compression device that is positioned within the housing in compression ratio with the mixing chamber (preferably continuously), a front closure plug detachably attached to the front of the housing and having a chemical discharge cavity formed in the front closure plug, and a rear closure plug releasably attached to the rear of the housing and having a rod receiving cavity formed in the rear closure plug. A "safe" relationship from this

ES 2 294 516 T3 embodiment means to be able to retain the relative position on the basis of interlocking means, such as threads, despite the external forces acting on them, not including any external forces indicated any specifically designed external extraction force, such as unscrewing forces, but includes maintaining position despite continuous axial force from compression means at the ends directly or indirectly.

Preferably, at least one of the front and rear closure caps are in threaded engagement with the housing, with a preferred embodiment each of the front and rear closure caps having releasably attached such that each is in threaded engagement with a respective end. of the accommodation. Preferably the front closure plug is attached to the housing such that it can be removed by hand without tools and where the rear closure plug has tool hooking means to facilitate removal of the tool from the rear closure plug from the housing, or vice versa.

The mixing module of the indicated embodiment has a mixing chamber that includes sticking movement prevention means of the rod to prevent movement of the mixing chamber with the rod as a unit relative to the compression means when the rod is attached to the mixing chamber during operation. A preferred means of preventing stick sticking includes male / female locking elements associated with the mixing chamber and / or the housing and which are positioned to exclude axial movement of the mixing chamber as a whole within the housing. In addition, the male locking member may include an annular forward extension disposed in the mixing chamber that is received within an annular female recessed section of a forward region of the housing, which recessed section defines a locking wall relative to a direction of rotation. movement of the mixing chamber opposite to the direction of the compression action imposed on the mixing chamber.

The housing preferably also includes a solvent fill port that opens to the housing and a threaded solvent port cover that is releasably attached to the housing to facilitate filling and solvent removal. A sealing element is also provided to facilitate sealing of the solvent orifice in conjunction with the orifice cover.

The present invention further includes a mixing module that includes a housing, a mixing chamber formed of a cold-flow material and having a chemical inlet port and rod passage, and a rod received within the chamber. mixing as well as a set of Belleville washers within the housing and in a compression ratio with the mixing chamber, and the mixing chamber and housing being in a male / female locking relationship by means of a male annular projection on one of the housing and the mixing module and a corresponding female recess receiving the male projection on the other of the housing and the mixing module. An example of a suitable male / female locking relationship includes the mixing chamber having an enlarged front end forming a male locking element, and the housing having a recess formed in a leading end to receive the enlarged front end of the mixing module. . In addition, the mixing module of the present invention preferably includes a housing having front and rear open ends, and front and rear closure plugs are provided which are designed to releasably secure (eg, threads) to the housing.

The present invention also includes a method of mounting a mixing module that includes inserting into a housing (i) compression means, (ii) an alternative rod, (iii) a mixing chamber, the latter receiving the rod and placing it in a compression state by the compression means, and releasably attaching to the front and rear open ends of the housing respective front and rear end plugs, the front and rear plugs having a rod through hole formed therein. The method further includes arranging for the locking means to lock between the mixing chamber and the housing to prevent movement of the mixing chamber despite an adhesion relationship of the rod between the rod and the mixing chamber. The method also preferably includes mounting the device such that a front face of the mixing chamber abuts the inner surface of the front plug and the blade plug is screwed on after inserting the front plug into the front end of the housing.

A preferred method further includes supplying solvent to a solvent hole formed in the mixing module housing and closing the hole with a solvent hole plug. The preferred method includes the introduction of solvent (for example, warmed above room temperature or above 37.8 ° C (100 ° F), for example, at 54.4 ° C (130 ° F)) after of closing the front plug and the rear plug by a former detachable joint of the front end rear plugs.

The present invention also includes a method of dispensing including preventing relative movement of a mixing chamber and the housing receiving said mixing chamber despite joint adhesion of an alternative valve rod within the mixing chamber and despite the possibility of movement of compression means compressing the mixing chamber if not for the blocking means, and the compression means continuously imposing compressive forces on the mixing chamber after assembly and the locking forces being designed to prevent non-uniform application relative to the periphery of the mixture.

ES 2 294 516 T3

Brief description of preferred embodiments

Many aspects of the invention can be better understood with reference to the following drawings, emphasis being placed on illustrating the principles of the present invention. Furthermore, in the drawings, like reference numerals designate corresponding parts throughout the various views.

Figure 1 depicts a prior art two-component handheld dispensing system for dispensing foam.

Figure 2 provides an exploded view of the dispenser used in the system in Figure 1.

Figure 3A depicts a cross-sectional view of a prior art mixing chamber cartridge used in a handheld dispenser.

Figure 3B depicts a cross-sectional view taken along cross-section line 3B3B-III in Figure 3A.

Figure 4 depicts a cross-sectional view of a mixing module of the present invention taken along cross-sectional line IV-IV in Figure 5.

Figure 5 represents a cross-sectional view of the mixing module of Figure 4 taken along the cross-sectional line VV in Figure 4.

Figure 5A is an enlarged view of the referenced front area of ​​the mixing module shown in Figure 5.

Figure 6 provides a front elevational end view of the mixing module of the present invention.

Figure 7 provides a cross-sectional view of the mixing module taken along cross-section line VII-VII in Figure 4.

Figures 8A and 8B provide different perspective views of the mixing chamber of the present invention.

Figure 8C provides a partial front view illustration of a non-continuous multiple protrusion locking means in accordance with the present invention.

Figure 8D provides a cutaway perspective illustration of the female recessed portion of the locking arrangement of Figure 8C.

Figure 9 provides a cross-sectional view of the mixing chamber of the present invention taken along cross-section line IX-IX in Figure 11.

Figure 10 depicts a rear end elevational view of the mixing chamber in Figure 9.

Figure 11 depicts a cross-sectional view of the mixing chamber taken along cross-sectional line XI-XI in Figure 9.

Figure 12 depicts a cross-sectional view of the mixing chamber taken along cross-section line XII-XII in Figure 11.

Figure 13 depicts a cross-sectional view of the mixing chamber taken along cross-sectional line XIII-XIII in Figure 11.

Figure 14 depicts a top-front perspective end view of the mixing chamber housing of the present invention.

Figure 15 depicts a top-rear end and side perspective view of the mixing module housing of the present invention.

Figure 16 represents a bottom perspective view of the housing of the mixing module of the present invention.

Figure 17 depicts a cross-sectional view of the mixing module housing of the present invention taken along a vertical axis bisecting the illustration in Figure 14.

Figure 18 depicts a cross-sectional view of the housing of the mixing module of the present invention taken along a horizontal plane extending between edges E1 and E2 of the housing and looking downward.

ES 2 294 516 T3

Figure 19 represents an interior or rear side perspective view of the front cap of the mixing module.

Figure 20 represents an exterior or front perspective view of the front cap of the mixing module.

Figure 21 represents a vertical bisector cross-sectional view of the front plug in Figure 20.

Figure 22 depicts a cross-sectional view of the rear cap of the mixing module taken along the cross-sectional line AA in Figure 24.

Figure 23 depicts a cross-sectional view of the rear cap of the mixing module taken along the cross-sectional line EE in Figure 24.

Figure 24 represents a perspective view of the rear cap of the mixing module.

Figure 25 represents a rear and side perspective view of the mixing module of the present invention.

Figure 26 represents a front and top perspective of the mixing module of the present invention.

Figure 27 represents a front and side perspective view of the spacer of the mixing module of the present invention.

Figure 28 represents a rear and side perspective view of said spacer.

Figures 29A-29G show in side-to-top rotary illustrative sequence the chemical orifice of the present invention from the point of view of a first origin.

Figures 30A-30G show a similar rotational illustrative sequence of the chemical orifice from the point of view of a second origin.

Figures 31A-31F show an illustrative rotary sequence from the side to the bottom of the chemical orifice.

Figures 32A-32C show additional perspective views of the chemical orifice.

Figure 33 depicts a cross-sectional view of the chemical orifice taken along cross-sectional line FF in Figure 29A.

Figure 34 depicts a cross-sectional view of the chemical orifice taken along the cross-sectional line GG in Figure 30A.

Detailed description of preferred embodiments

Figures 4-7 illustrate the mixing module 100 of the present invention that includes the housing 102 having a "front" (open) end 104 and a "rear" (open) end 106 with an associated front end plug 108 and a rear plug 110. Plugs 108, 110 retain in operative position mixing chamber 112, slotted cup spacer 114 and stack of Belleville washers 116 (the preferred form of compression means). The front plug 108, mixing chamber 112, spacer 114, stack of washers 116, and rear plug 110 each have an axial passage for receiving a valve and / or bleed rod (hereinafter "rod") 118. Mixing module 100 also preferably has a solvent chamber 122 with spacer 114 and back plug 110 preferably formed with solvent receiving pockets or pockets (123, 124). Stacked Belleville washers 116 are also depicted with an annular clearance (see Figures 5 and 7) that facilitates solvent flow or presence along the received portion of rod 118.

As explained in more detail below, the solvent cap 126 is threaded (or otherwise easily releasable attached with associated tooling or manual gripping means such as a finger grip protrusion (not shown) or the most recessed recess). tool introduction preferred 216). Its sealing portion may be secured to housing 102 to close solvent access hole 128 formed on one side of multi-sided housing 102 (eg, see hexagonal wall arrangement of FIG. 4). Solvent plug 126 is preferably positioned so as to axially overlap part of stack of Belleville washers 116 and spacer 114 positioned between compression means 116 and Teflon block mixing chamber 112. The stack of Belleville washers 116 is also preferably arranged in opposing pairs (e.g., 8 pairs of washers, each set of pairs having opposing washers) that provide a preferred level of force, e.g., 150 to 250 lbf (200 lbf being preferred). for many uses of the invention) in relation to the spacer contact with the mixing chamber and the corresponding contact of the mixing chamber with the inside face of the front plug 108.

It should be noted that no indication of dimension or range (including the above and below) presented in the present application is intended to be limiting, but is offered for illustrative purposes to better appreciate the various aspects of the present invention.

ES 2 294 516 T3

As also depicted in Figures 5 and 7, valve rod 118 has an alternate media capture perforated end 130 (eg, a motorized rod alternator attachment end) and extends axially fully through the housing and is depicted passing through respective front and rear plugs 108 and 110. Rod 118 also includes an annular limit ring 132 to prevent unintended complete removal of rod 118 from the mixing module. A rod contact sealing element 134 such as an O-ring inserted into an O-ring receiving cavity formed in the back plug 110 is also preferably provided. Housing 102 is also depicted in Figures 7 and 16 including locating recesses 136, 138 for securing the housing in position relative to a hand-held bracket or non-hand-held dispensing system (e.g., the bagging system with mixing module fixed in position). It should be noted that although a preferred embodiment includes the mixing module associated with a handheld dispenser, the mixing module is not limited to handheld dispensers or foam systems, but is usable in any environment where a mixing module operates. . For example, reference is made to the bagged foam dispenser assembly and associated systems described in the AO provisional applications listed in the table on page 2 of this application, and each of the listed provisional applications being incorporated herein by reference.

Housing 102 also further includes chemical passage inlet holes 140, 142 formed, for example, at mid-peripheral points through side walls 144 and 146 (FIG. 4) and within the front axial half of housing 102 (by example, a position about 1/3 back from the front end). The walls 144, 146 are positioned on opposite sides of the intermediate side wall 148 in the preferred hexagonal configuration housing 102. Wall 148 is preferably diametrically opposite wall 150 in which position cavities 136, 138 are formed. Chemical inlets 140, 142 and they are shown positioned at the preferred 120 ° chemical inlet spacing at the walls 144, 146.

Reference is made to Figures 5A, 8A, 8B, 8C, and 9-13 for further explanation of mixing chamber 112 with means for blocking or preventing stick movement of rod 158. Figures 8A and 8B provide views in A perspective of a preferred embodiment of mixing chamber 112 which is preferably formed of a low friction material such as one having cold flow capability, with TEFLON brand material being a preferred material.

Mix chamber 112 has a first end (eg, spacer sleeve contact end) 152 and a second end (eg, front) 154 that is positioned in contact with the inner surface of the like configuration of the front plug once installed in housing 102. As depicted in Figures 12 and 13, the axial rod passage (or through hole) 156 extends through the central axis of the mixing chamber 112 so as to open at the first and second ends.

Figures 12 and 13 illustrate the preferred configuration of passage 156 which is a continuous diameter passage of diameter Da (a range of 2.54 to 12.7 mm (0.1 to 0.5 inch) illustrative of a range of diameter suitable Da, with 3.55 to 7.62 mm (0.15 to 0.3 inch) being a more preferred subrange and 4.75 mm (1.87 inch) being a preferred value for Da). Figures 8A and 8B also illustrate means for blocking or preventing the sticking movement of the rod 158 in the form of a locking projection 158, which in a preferred embodiment is an annular projection having a leading edge 160 (Figure 8A) that coincides with the outer radial edge of the front face 154, and the trailing edge 162 define an inner axial edge of the peripheral surface 164. An inclined surface 161 extending between trailing edge 163 and adjacent edge 163 provides on locking boss 158 a trailing chamfered edge portion that facilitates proper positioning within the housing during assembly. Locking boss 158 is preferably integral with main body portion 166 (eg, the entire mixing chamber is formed as a monolithic body and also preferably from a common material such as Teflon). As illustrated, the stepped wall ring inner radial edge 168 extends from the forward region of the main body portion 166. The rear end 152 of the main body portion 166 also preferably includes a chamfered peripheral edge 151 defined between the trailing edge 153 and an adjacent edge 155 to facilitate initial insertion of mixing chamber 112 into housing 102. The slope of the chamfered edge 161 is preferably the same as that of the chamfered edge 151.

The locking means 158 can take various configurations in accordance with the present invention (eg, peripherally continuous or interrupted with protrusion (s) of common or different lengths / heights around the periphery of the mixing chamber) as well as a variety of axial lengths. and a variety of radial lengths (for example, a radial distance R (Figure 13) between the surface 164 and the outer exposed surface of the main body 166 of 0.64 to 2.54 mm (0.025 to 0.1 inches), being 0.89 to 1.27 mm ( 0.035 to 0.05 inch) a suitable subrange). Length R includes a combination of wall 168 and chamfered edge 161, the latter representing a small percentage of the radial distance R (eg, inclined surface 161 represents 25 to 50% of the overall radial distance R). The axial length and radial extent utilized of the locking boss 158 are designed to provide a sufficient locking function in place (despite sticking of the rod due to the static friction / adhesion relationship between the rod and the mixing chamber expected during normal operation) with efficient material use.

Figures 8C and 8D provide a partial front view of the locking relationship and a cutaway perspective view of the male protrusion component of the male / female multiple protrusion / recess arrangement of an alternate embodiment of the locking means 158 'herein. invention. As seen there, there is a circumferentially serial non-continuous set of projections / recesses 159 of the mixing chamber for locking means 158 'which

ES 2 294 516 T3 is different from the male / female locking relationship of the first described embodiment of continuous projections (the dashed reference numerals correspond generally to those of the first embodiment). Figures 8C and 8D further illustrate the housing's intermeshing projection / recess assembly (167, 167 ') (female recesses 169 receiving male projections 191 in the illustrated embodiment) extending axially forward from a continuous reinforcing wall 168 'in mixing module 112' and wall surface 190 'in housing 102'. The combination provides an axial stop in association with the circumferential interlock as well as a rotational lock (although axial lock that excludes "axial sticking of the rod" movement is considered to be all that is required in practice).

Figures 5A, 8B, and 12 illustrate preferred continuous annular protrusion locking means 158 that includes stepped wall 168 extending from main body 166 (preferably with a curved fill or smaller sloped transition wall 170), the overall diameter of the locking projection Dp preferably 6.35 to 25.4 mm (0.125 to 1.0 inch), with a preferred value of 14.22 mm (0.56 inch). The diameter Dm of the rear end of the main body 166 (Figure 12) or the average width, if any, other than a cylindrical cross section of the main body 166 is preferably 8.89 to 19.05 mm (0.35 to 0 .75 inch) or more preferably a value of 12.45 mm (0.49 of an inch), the difference (Dp-Dm = R) representing about 5 to 15% Dp. In addition, a preferred diameter Da for rod passage 156 is 2.54 to 10.16 mm (0.1 to 0.4 inch) or 3.81 to 7.62 mm (0.15 to 0.3 inch) as an intermediate preferred range, with 4.7 mm (0.19 inch) being a preferred value. The radial annular wall thickness of the portion of the main body that forms its annular ring (its inner surface defining the chemical mixing zone) is preferably 2.54 to 12.7 mm (0.1 to 0.5 inch), with 3.81 mm (0.15 inch) preferred.

Furthermore, although a two-component system is a preferred embodiment of the present invention, the present invention is also suitable for use with a single or more than two chemical component systems where there is a potential problem of adhesion and movement of the compression means. into a mixing or dispensing chamber of a dispenser and a wand that is received into it.

In Figures 8A, 8B, chemical holes 174, 176 are depicted that are formed through the radial thickness of the main body portion 166 and are depicted circumferentially spaced and in a common transverse plane (a preferred arrangement as opposed to axially deviated). The central axis of each hole 174, 176 is designed to be common with a respective central axis of passage of the inlet holes 140, 142 in housing 102 (Figures 4, 5) and each intersecting the central axis of passage 156.

Furthermore, the holes 174, 176 preferably have a passage configuration with a large outer receiving cavity 178 and a smaller inner cavity 180, and an annular passage wall 181 with a sloped or chamfered transition wall 179 is formed in between. The step configuration is dimensioned to accommodate chemical ports 182, 184 (Figure 4) which are preferably stainless steel ports designed to produce streams of chemicals exiting the ports colliding, for example, at an angle of 120 ° to avoid chemical crosslinking problems in the mixing chamber cavity. As shown in Figures 4.12 and 13, the diameters Db and Dc are dimensioned in association with the dimensioning of holes 182, 184, it being preferable to have the input end of holes 182 and 184 of a common diameter and aligned relative to to the outlet end of the housing inlets 140, 142. The holes 182, 184 are depicted with an upwardly tapered introducer section and an outlet cylindrical section representing approximately 50% of the axial length of the hole. The dimension Db is preferably 2.54 to 7.62 mm (0.1 to 0.3 inch), 4.52 mm (0.17 inch) being a preferred representative value and the dimension Dc is preferably 1.27 at 1.91 mm (0.05 to 0.075 inch), with 1.65 mm (0.065 inch) representing a preferred value.

Figures 13 illustrate longitudinal dimension lines L1 to L4 for mixing chamber 112, with L1 representing the entire axial length of mixing chamber 112 or the distance from the rear outer edge to the leading edge (preferably 12.7 to 50.08 mm (0.5 to 2 inches), with 25.4 mm (1 inch) being a preferred representative value). L2 represents the axial distance from the rear end 152 to the peripheral edge 160 of the locking boss 158 (the reduction in length L1 being due to the inward slope (e.g., 5 to 15 ° from vertical, with 10 ° preferred) of the front face of the mixing chamber and the length L2 being preferably 10.92 to 45.72 mm (0.43 to 1.8) (or 0.51 to 1.78 mm (0.02 to 0.07 inch ) less than the length L1), with 24.13 mm (0.95) (or 1.27 mm (0.05 inch) less than L1) being a preferred illustrative value. L3 represents the axial length between the trailing edge 152 to the inner edge of the locking projection 162 of the surface 164 (preferably 12.7 to 25.4 mm (0.5 to 1.0 inch), where 18.8 mm (0 , 74 inch) a preferred value). L4 represents the distance from the trailing edge 152 to the central axis of the closest chemical passage such as the smallest interior cavity 180 (preferably 2.54 to 7.62 mm (0.1 to 0.3 inch), where 4 is, 57 mm (0.18 inch) a preferred value).

Figures 5 and 5A illustrate the forward end 104 of the mixing module housing 102 having a larger diameter recess 186 tapering to a smaller diameter housing recess 188. Figure 5A depicts the stepped wall 190 formed between the larger and smaller diameter housing recesses 186, 188 which is dimensioned to correspond to the stepped wall rim 168 of the locking boss 158 to provide a means for preventing axial movement with relative to the alternating rod 118. The bearing relationship establishes a non-axial movement locking relationship between mixing chamber 112 and housing 102 when the mixing module is in an assembled state (see below) and without such movement both axial and rotational displacement can be prevented. in mixing chamber despite temporary stick adhesion

ES 2 294 516 T3 in the mixing chamber and the possibility that the compression means compress if it were not for the blocking means 158. Thus, the mixing chamber is not subjected to the sticking movement of the rod and avoids the problems previously mentioned associated with this movement, such as misalignment of the holes.

The configuration of the housing is best illustrated in Figures 5, 5A, 7 and 14-18, the latter providing perspective and cross-sectional views of the housing 102 alone. Figures 15 and 18 illustrate a preferred stepped wall configuration 190 formed between large diameter recess 186 and interior recess 188 that is radially transverse or oblique (e.g., conically convergent in a front-to-back direction although a ratio of level vertical non-oblique wall contact). For example, referring to Figure 18, housing 102 has a radial thickness T1 defining the diameter of recess D1 at its forward end (for example) from 2.54 to 5.08 mm (0.10 to 0.20 inch) (for example 3.81 mm (0.15 inch)) for T1, and 12.7 to 19.05 mm (0.5 to 0.75 inch) for D1, D1 being preferably equal to 14.22 mm (0.56) to the thickness T2 of 5.08 to 7.62 mm (0.2 to 0.3 inch) 6.35 mm (0.25 inch) preferred) with a common outer circumference such that a reduced diameter housing cavity 188 is formed defining the diameter of the housing recess D2 10.16 to 15.24 mm (0.4 to 0.6 inch), with 17.45 mm being preferred (0.49)) and is bridged by stepped wall 190. As best seen in FIG. 5A, step wall 190 preferably includes a forward more axial abutment wall section 190 'followed axially at the rear by a sloped wall section 190 ". As shown, wall section 190 'is oriented more vertically than wall section 190 ", with wall section 190' preferably extending transverse to the axial center line of housing 102. Wall section 190 'also preferably represents the greater or greater part of the transverse length relative to wall section 190', the axial extent of wall section 190 'preferably being greater than its radial elevation. Sloped wall 190 "allows easier insertion of mixing module 112 (eg, sliding of chamfer 151 onto sloped surface 190" while wall section 190 'is of sufficient radial length to perform the contact / contact function. blocking). Figure 5A also illustrates the outer surface of the main body that is in sliding frictional contact with surface 188 of housing 102.

Rearward of the recess 188 defining the housing surface a slight step 194 is provided (eg, a 0.18 to 0.25 mm (0.007 to.01 inch) rise from D2 to D3). With a preferred common outer wall surface, the different inner diameters are formed by a different wall thickness than T3 and T4 and / or differences in the diameter of the recess. As seen in Figures 17 and 5, the minor step 194 provides a leading boundary for the Belleville stack, although the spacer sleeve 124 preferably (in conjunction with the rear end plug 110) keeps the washer stack compressed and axially spaced. of step 194. Expansion of cavity 188 to a rear cavity 193 also provides additional radial clearance to accommodate compression fits of the Belleville stack. Spacer 124 has an outer diameter generally conforming to D2 and axially bridges step 194.

As seen in FIG. 7, the main body portion 166 of the mixing chamber 112 is preferably fully received in the housing recess 188 while the stack of Belleville washers 116 is fully received in the housing recess 193 defined by the thickness T4. Spacer 124 preferably extends to opposite sides of step 194, and at the rear end of housing 102 is preferably provided a rear plug receiving recess 192 of diameter, for example, 12.7 to 15.24 mm (0 , 5 to 0.6 inch), with 12.7 mm (0.50 inch) preferred) and thickness T5 (for example 5.08 to 7.62 mm (0.2 to 0.3 inch), with 7 , 11mm (0.28)).

The recess 198 is designed in the rear receiving plug 110, with the plug 110 sized to occupy the recess area 198 and extend inward to the recess 186 and into contact with compression means 116. In this regard reference is made to Figure 7 where L5 illustrates the axial length from the rear end of the housing to the rear end of the compression means (in an assembled but non-operational state) 116 (eg 7.62 to 15, 24 mm (3 to 0.6 inch) or 11.43 mm (0.45 inch) representing approximately 10 to 30% or more preferably 20% of the entire axial length of the mixing module 100, 0% being at the rear end). L6 illustrates the axial length from the rear end to the central axis of the solvent access hole 128 which is also preferably generally proportional to the front end of the compression means 116 and the rear end of the compression of the spacer 114 (e.g. 22 , 86 to 35.56 mm (0.9 to 1.4 inches) or 40 to 60%, with 50 ± 5% being preferable, back end being 0%); L7 represents the contact interface between the front end of the spacer sleeve and the rear end of the mixing chamber 112 (for example, 27.94 to 38.11 mm (1.1 to 1.5 inches) or 50 to 65 %); L8 (Figure 5) represent the distance from the rear end 106 of the housing and the center axis of the housing inlet 140 (for example, 33.02 to 48.26 mm (1.3 to 1.9 inches) or 55 to 85%) and L9 represents the entire axial length of housing 102.

The receiving recess 192 includes means for axially locking the rear plug 110, which means are preferably those that allow removal of the rear plug without the need for special support devices such as a boring press upon release of the compression force and that is they can be tightened with a simple tool to an operating position that compresses the compression means to the desired level of force. In a preferred embodiment, a threaded recess 192 is provided having fine threads (for example, 625-32 UN-class 2B for the rear and somewhat coarser 750-32 UN-23 threads for the front cap) to facilitate locking. in the axial position of the rear plug 110 in a position that induces a desired compression.

Housing 102 also preferably includes another rear end recess (eg further rearward) 195 that rises to a larger diameter D5 (eg 0.51mm (0.02 inch) expansion) that provides a sloping annular ridge. 197 (which facilitates the assembly of the rear plug 110).

ES 2 294 516 T3

As noted above, ordinary prior art packaging foam mix cartridges are mounted using retaining rings on the back of a compression plug (see Figure 3). To install the retaining ring, the back plug must be pushed into the stack of Belleville washers, an action that requires approximately 200 lbf (0.89MN) to perform. This prior art method of assembling mixing cartridges requires the use of machines such as boring presses and some special holding and aligning accessories to fit a mixing cartridge, making the process difficult. Furthermore, the assembly of prior art mixing cartridges such as that in Figure 3 cannot be accomplished with the hand tools normally contained in a tool kit. These prior art designs are difficult to assemble, and even more difficult to disassemble, since the retaining rings can be difficult to remove with the heavy spring load exerted on the back plug.

In view of this, the mixing module 100 of the present invention has been designed to be easier to assemble and disassemble. Furthermore, under the compression forces of the Belleville stack imposed on the cartridges and mixing chambers of the prior art as shown in Figure 3, they also tended to deform the front face of the housing when considering the desirable thickness relative to the stroke. the passage of the front face of the bleed rod. This deformation can occur in prior art assemblies even after only moderate use in situ. That is, the front cover of prior art mixing chambers is often stamped onto the housing and the design is not always strong enough to fully handle the imposed load without flexing. This deformation can cause various mix cartridge reliability problems.

A preferred embodiment of the present invention includes the feature of having non-permanent resolvable fixation means; A preferred embodiment includes threads (TH represents threads throughout the figures and MTH represents an indication of meshing of the threads) disposed in the rear plug receiving recess 198 or some other releasable fastening means, for example, a key / key hitch. groove. The threads on the rear plug receiving recess are designed to mate with threads on the rear plug 110 while the threads on the front end housing are designed for threaded engagement with the front plug. Thus, a releasable locking relationship similar to that of the rear end is provided at the front end with a preferred embodiment including threads disposed, for example, on the outer surface 200 at the front end of the housing 102 for threaded engagement with internal threads. of the front plug 102 (see Figures 19-21). This relationship at the front and rear of the mix chamber allows a mechanic with minimal knowledge, without special or exotic tools, to mount and remove the mix module 100.

The "snap-fit" mounting technique of the present invention (eg, threaded construction) also has several other advantages. For example, the clamp construction is much easier to assemble without the retaining ring that holds the back plug in position against the pressure of the Belleville stack. The present invention also allows for easier on-site disassembly (for example, an ordinary foam production facility) since the locking construction makes it easier to remodel or reconstitute in the foam production environment without sending it to a foam production center. special service with special equipment and similar for remodeling or reconstitution.

The present invention helps to avoid this prior art tendency for the front housing plug to warp or bulge due to the force imposed by the stack of Belleville washers on the front face of the mixing chamber relative to the sloped front face. 154 that is in contact with the corresponding inclined inner surface 207 of the front plug 108 and the front end 104 of the housing 102 that is in contact with another wall section (preferably transverse to the central axial axis of the plug) 209.

The attachment and construction of the front plug 108 at the front end of the housing 102 provides a more robust construction of the front plug. That is, because of the releasable connection means, the front plug can be designed in such a way as to avoid distortion under load. The present invention is thus designed in order to avoid such problems associated with stamped front end plugs, including the difficulty of proper installation and alignment of the mixing chamber, strength parameters that are difficult to predict, and the tendency to deformation under high load. The ease of assembly and disassembly of the mixing module design of the present invention at the production site also facilitates assembly and disassembly both on site and at a separate service location.

With the arrangement of the present invention, it is easier to install the mixing chamber from the front, rather than from the rear of the mixing module housing. In a preferred embodiment of the present invention that includes mixing chamber locking means 158 at the forward end of the mixing chamber and a detachable front fixing plug 108, the advantage of being able to install a mixing chamber from the front is provided. front of the mixing module housing compared to the more difficult rear installation of the prior art housing design. For example, the front loading capability makes it much easier to orient the holes in the mix chamber to the correct alignment with the through holes in the mix module housing compared to leaving a mix chamber within easy reach once released. in the camera.

In addition, to facilitate assembly and disassembly of the mixing module of the present invention, the front cap 108 is preferably provided with a knurled circumferential facing for preferred finger contact by squeezing it into position only and is released for access (cap tightening rear provides the highest level load in the final stages of assembly). In an alternative embodiment, the diametrically opposite peripheral surfaces of the front plug are smooth for contact with a key and final tightening or release as in situations where

ES 2 294 516 T3 external forces make removal with a key or the like easier due, for example, to hardened foam accumulating in the region.

Figures 19 through 21 provide three-dimensional views of the front or front plug 108 without full threads TH shown for convenience. Front plug 108 is shown including threaded inner surface 109 that threads into housing 102 along threaded surface 111 provided as exposed surface 200 and provides the forward boundary of the mixing chamber. The hole 204 in the center is the outlet for the liquid reaction precursor mixture and also receives the forward end of the valve rod when in its most forward state. As seen in Figures 5A, 8A, and 13, the front face 206 of the mixing chamber 112 includes a conical taper on its inner surface with a preferred slope of angle β (eg, 5 ° to 15 °) and preferably of 10 °. Thus, the edge 208 in the leading end passage 156 represents the forward most portion of the mixing chamber 112 and the forward face slopes back up to the forward most peripheral edge 160 of the locking boss 158. With reference to Figures 5A and 19, it can be seen that the taper 207 formed on the inner surface of the mixing chamber 154 corresponds to the taper on the inner surface of the front face 206 of the mixing chamber 112 (preferably at the initial contact , but certainly after compression against said face by the compression means). The taper in the front face of the plug 108 allows the thickness of the front plug 108 at the center hole to be reduced, without sacrificing structural integrity. It is desirable to reduce this thickness to reduce the urethane bond zone, since the Teflon material in mixing chamber 112 cannot spread there. For example, Figure 5A depicts the inclined front plug having a thinner portion 211 on the surface 204, an intermediate thickness section 289 due to the sloping wall the angle β, and then the thicker outer region (preferably the axial thickness at surface 204 is 0.033 and thickness at 211 is 0.027).

The front plug 108 is preferably made of stainless steel, and is designed to minimize deflection caused by the force generated by the Belleville washer in the mixing module. The tolerances in the front plug 108 and the housing itself are preferably kept at a relatively high standard tolerance compared to what is possible with the stamped approach used by the mixing chamber depicted in FIG. 3. The hole in the center of the front plug 108 is made correspondingly very concentric to the inside diameter of the housing, which means that the valve rod will remain centered in the hole in the front plug 108.

As seen in Figures 5, 7 and 22-24, the rear end of housing 102 provides rear plug 110. Compression plug or rear plug 110 is screwed into rear threaded recess 210 in rear end 106 of the housing 102 (figure 7), after all the internal components are in position (although there is also the possibility of closing the front plug in the last stage since both ends are accessible). The through hole 212 extending along the center axis of the back plug 110 has a notched sealing groove 134 to receive the rear end O-ring 214 in order to seal the solvent in the chamber when the valve rod 118 enters. and comes out.

Figures 22-24 further illustrate the rear plug 110 having two smaller knockouts 216, 218 on each side of the center of the plug 110 that are used to rotate the plug as it is screwed into the rear of the housing. In a preferred embodiment, a key (not shown) is provided for mounting and dismounting of the rear cap relative to the housing. The wrench has a correctly spaced two pin engagement end to engage the two holes 216, 218 and a rear clamping handle. Compression plug 208 compresses the stack of Belleville washers as it is screwed into the housing. This action generates the compressive loads on the mixing module and generally involves a fairly high level of torque, so that the wrench is strong. As shown in Figure 5 and Figure 24, the back plug 110 has a cylindrical inner portion 217 dimensioned for contact with the rear end of the compression means. A larger diameter intermediate section 219 is included which is threaded for threaded connection with the threaded section of the corresponding housing 221. Between the threaded section 219 and the inner portion 217 is an indented section 223. On the opposite side of the section 219, there is an annular recess 225.

Figures 25 and 26 provide a view of an assembled mixing module 100 depicting front plug 108, rear fill plug 110, opposite rod ends 118, and housing inlets 140, and 142. Figure 25 also depicts key receiving holes 216, 218, compression plug 110, and a full view of capture loop 130 of rod 118, which has been configured for attachment to a ball screw used in current systems. hand-held, although alternative designs, such as an expanded cylindrical rear end as described in one embodiment in said United States Patent Application No. 10 / 623,858 filed July 22, 2003 and entitled Dispenser System and Method of Making and Using It with Dispenser Tip Management, which incorporated herein by reference, are also representative of an alternative means of engagement with the mixing module of the present invention and with a suitably shaped alternator. Figure 25 also depicts the two conical point placement holes 136, 138 that are used to place the mixing module in the dispenser manifold of an existing hand holding system sold by Omni Packaging Inc. of Oklahoma, USA. America.

Figure 26 illustrates the solvent fill plug 126 (with an integral gasket 217 as depicted in Figure 7) which offers significant advantages over older designs where it is easier to introduce the solvent after mounting the module. mixture. It can be an embarrassing and complicated procedure to fill out

ES 2 294 516 T3 solvent chamber in prior art mixing module designs such as those in Figure 3A with rear end loading where solvent has to be dispensed to the rear of the mixing module, just prior to using a boring press to compress the Belleville Washer enough to install an ID retaining ring in the rear of the housing. This is not an easy or clean procedure, and it is difficult to know how much solvent is still inside after the job is done. A cross-sectional view of the solvent plug 126 is shown in Figure 7 depicting how the solvent chamber is formed by the solvent recesses 122, 124, formed in the opposite rear plug 110 and spacer sleeve 114, and the free space of the housing 102 not occupied by the compression means positioned in the solvent chamber and between the spacer and the back plug.

According to the present invention, the mixing module 100 can be fully assembled, and access to the solvent port is still possible based on the relative positional relationship between, for example, the access port to the solvent plug and the recessed areas of the spacer sleeve (described in more detail later). This ability to fully assemble the mixing module 100 and subsequently introduce the solvent via the solvent plug 126 and the coordinate placement of the solvent chamber and the solvent chamber forming component portions is advantageous, for example, by allowing easy, reliable and solvent-free ventilation to take place after complete assembly. It is also easy to open the solvent cap for an initial solvent level check and / or, less preferably, the back cap can be easily removed for a solvent check after fully mounting the mix module. In prior art systems, it often happens that there is significantly less solvent than originally thought. For example, a solvent chamber may appear full after the initial fill operation, but there may be a significant amount of air trapped in the solvent chamber, since the viscosity of commonly used solvents can be quite high at room temperature. , preventing full filling of prior art systems. To help solve the problem of incomplete fill, the solvent can be heated to around 130 ° F (for example, above room temperature at 48.9 to 65.6 ° C (120-150 ° F)) before that filling represents a preferred step.

Thus, according to the present invention with the solvent access plug 126 of large diameter (for example, 7.62 to 15.24 mm (0.3 to 0.6 inch) and preferably 10.80 mm (0.425 inch) )) (relative to a 2.3 inch housing length, for example), strategically positioned relative to the solvent chamber to provide means of access to the solvent chamber, Complete filling of the chamber is easy to achieve without air bubbles or overflow problems associated with prior art solvent chambers. Since the solvent access threaded hole allows for easy filling, there is less chance of trapping air pockets when the chamber is sealed. Since the life of the mix module is proportional to the amount of solvent, removing trapped air in the solvent chamber can extend the life of the mix module. Easy filling into the solvent chamber is possible without special tools using the solvent fill screw plug 126 which can be easily removed with a small screwdriver applied to slot 216 any time you want to check the conditions inside the module mixing. Therefore, the solvent chamber can be easily filled with solvent, and the plug can be installed again. As shown in FIG. 7, the O-ring 217 is provided on the solvent plug to help prevent solvent leakage even during shipping.

Additionally, less leakage means longer life, and the sealed plug can be opened and resealed many times with minimal degradation in seal quality. With the solvent access means of the present invention, the mixing module can be initially constructed and assembled in a solvent-free factory or assembly facility if long-term storage is required. There are applications that require long-term storage of the system mix modules in warehouses and / or the placement of mix modules in harsh climates. In these situations, the solvent mix module, and the elastomeric gaskets in contact with the solvent, can degrade over time if they are pre-installed in the initial assembly. The present invention allows no solvent introduction at the time of assembly or easy access to replace the old solvent and seals after a prolonged period. This storage feature can be an advantage, for example, in some military applications, as well as other storage environments and / or requirements.

Additionally, the solvent plug 126 can be opened and resealed many times with minimal degradation of seal quality and the mixing module can also be provided without solvent if long-term storage is required for use in applications that require high-end storage. long term of system parts including mixing modules, in warehouses or even in harsh climates. Prior art mixing chambers containing solvent and elastomeric seals in contact with solvent will degrade over time. Thus, the ability of the present invention to post-manufacture the solvent supply or pour-and-fill capability of the present invention makes the present invention advantageous for use in harsh environments or in a long-term storage condition in military applications.

Figures 27 and 28 provide different perspective views of the spacer sleeve 114, which includes a solid cylindrical front section 218 that is integral with a compression contact front face 220 that is in contact with the rear end of the mixing modules, having a valve rod receiving hole 224, and at its rear end 223 (or contact end of the compression means) is provided one or more spacer slots 228 defined between spacers 226. At least one spacer slot 228 is preferably aligned with access hole (s) to the housing of solvent 128. In a preferred embodiment, there are multiple spacers 226 (eg 3-10, 6 being preferred) separated by arcuate slots 228 that allow easy

ES 2 294 516 T3 solvent hole access 128 to receiving cavity 122 of the solvent sleeve. The size of the solvent hole 128 (see supra) and / or the dimensional circumferential width and axial depth of the spacer grooves 228 are designed to allow solvent introduction access into the solvent chamber. Since spacer sleeve 114 is loaded by compression means, spacer 226 (and the remaining surfaces as well) has a thickness and configuration designed to handle such loads. Furthermore, the inner side edges 227, 729 of the grooves preferably diverge from one another by radially inward direction.

Figures 29A through 34 provide various views illustrating the geometry of a preferred chemical introduction port (such as 182 and 184 depicted in Figure 4) designed to allow exact injection of chemical and to provide a configuration that matches the geometry of the receiving holes 174, 176, the outer surface of the mixing chamber, and the surface of the mixing chamber cavity in the cross section of the holes. Figures 29A to 29G illustrate the rotary sequence (at 15 ° angle intervals) with a front elevation view in Figure 29A, and Figure 29G provides a top plan view with a 90 ° rotation relative to a view. end in axial direction of the elongation of the mixing chamber. Figure 30A provides a view similar to Figure 29A, but with the orifice rotated 45 ° along its central axis of elongation to present a front elevational view of the orifice from an end view of the mixing chamber.

Figure 33 provides a cross-sectional view of hole 182 (or 184, preferably of the same configuration and formed, for example, of a stainless steel) taken along cross-sectional line FF in Figure 30A. Figure 34 provides a cross-sectional view of hole 182 taken along cross-sectional line GG in Figure 29A. Figure 34 illustrates an upwardly convex surface of radius RA2 having a radius of curvature (for example, 0.246) designed to match the radius of curvature of the outer circumference of mixing module 100 (for example, having a diameter of approximately 2.7 mm (0.5 inches) (+/- 2.54 mm (0.1) in order to avoid any discontinuity in the surface until it enters the edge at 231 of the section Tapered Bore 230 having a depth Hi of approximately 1.68 mm (0.066) at 30 to 60% H₂ (the maximum height of hole 182 which is preferably about 3.84mm (0.151 inch) and more preferably about 40%). As seen in the various views, the annular upper edge 232 undergoes a rise and fall sequence as it passes from a first generally raised convex area or (eg, a quadrant) 234, to the first lowered concave area (eg, the quadrant). 236, second raised convex area (eg, the quadrant) 238 and the second lowered concave area (eg, quadrant) 240 with a continuous smooth curvature as one passes the next along the entire annular edge.

Comparison of Figures 33 and 34 shows that edge 231 is essentially midway between the top point of height H₃ (which is the maximum height reached by the edge of the conical section 230 that conforms to the maximum height of annular edge 232 and is preferably approximately 1.83 (0.072 inch)) and the top point of the height H5 (for example 1 , 47mm (0.058 inch)) which is the minimum height level of the annular edge. The height H4 is preferably about 2.00 mm (0.079 inch). As seen by the comparison of Figures 33 and 34, the annular edge 232 transitions from a horizontal orientation and gradually changes orientation from horizontal to slope from a higher inner end to a lower outer end. The edge 231 of the conical hole section 230 has a maximum inlet diameter D₁ approximately 2.70 mm (0.114 in.), for example, tapering (for example, angle B₂ 25 to 35 ° tilt and more preferably 30 °) to cylindrical pitch diameter D₂ about 0.76 mm (0.03 inch) for example. The diameter of the passage is preferably made as small as possible to maximize the outlet velocity, the limiting factor being the operating pressure of the system and the capacity of the pump.

Fig. 33 depicts the conical hole section 230 with a concave conical edge portion 242 having a compound curve configuration RA1 that matches the configuration of the. Figures 33 and 34 and perspective figures such as Figure 31A show a rotation of the hole 182 (or 184) from a front elevation view to a bottom plan view depicting the curve or slope of the lower annular edge 242 of the hole 182. The upper annular edge 232 has a preferred minimum width W1 of 0.51 to 0.76 mm (0.02 to 0.03 inch) (or 0.64 mm (0.025 inch)), for example, a preferred enlarged width W2 0.61 to 0.86 mm (0.024 to 0.034) 0.74 mm (0.029), for example, while the lower annular edge W3 0.41 to 0.86 mm (0.016 to 0.026 inch) 0, 47 mm (0.016 inch) preferred) for example, with W3 being a horizontal orientation. Moving from the orientation of Figure 33 to that of Figure 34 including two inclined edge sections 244, 246 the angle A2 approximately 15 ° (± 5 °) preferably with a height H7 (for example 0.13 mm (0.005 inch ) for extension from the upper edge of the outlet 235 of the hole 1 82 to the lower edge of said outlet. As illustrated, the downstream end of the tapered bore section 230 opens to the cylindrical passage 233 approximately at the transition from the larger head 239 to the extent of the bore 237. Between the sloped sections 244 and 246 is the flat section 245, the outlet port extending fully through flat section 245 and partially into sloped section 244, 246 with the combination of flat surfaces represented by RA3.