Coupling for negative pressure fluid dispese systems

CONNECTOR FOR NEGATIVE PRESSURE LIQUID DISTRIBUTION SYSTEMS

ROYAL PACKAGING INDUSTRIES VAN LEER BV, Amstelveen, NL Inventor: WILLINGHAM John Denis Engineer, Hull, GB International filing date: 28.10.1993.

International Application Number: PCT / GB93 / 02222

International Publication Date: 11/05/1994

International Publication Number: WO 94/10081

Priority: 30.10.1992 (922886.5), GB

BACKGROUND OF THE INVENTION The present invention relates to a coupling device for use with negative pressure fluid delivery systems, in particular, but not limited to, containers for hazardous chemicals and the like.

81412-3656 / MJ

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-2 In one group of dispensing systems for liquids and other fluids, expensive or hazardous liquid chemicals are dispensed from the storage tank under negative pressure, i.e., suction. The reservoir is provided with a dispensing valve assembly which is connected to a coupling head by which the fluid can be pumped out of the reservoir. Such a connector is described, for example, in PCT Patent Publication No. WO 88/06693 (Applicant: The Mogul Corporation). In this case, the coupling device is not provided with an air valve and is arranged on a threaded cover to close the container.

At first glance, it may seem obvious and inexpensive to use a coupling device for negative pressure dispensing systems, such as positive pressure salt dispensers. An example of the latter is the Target 2000 Closed Refund System (a system sold by Micromatic A / S in Denmark). In this arrangement, air inlet is provided in the coupling head, and seals are arranged between the sliding element and the body of the coupling head below and above the air intake. An additional seal is provided between the coupling head housing and the metering valve flange. Thus, in this arrangement, air can enter the tank only through the air inlet port of the coupling head. Note, however, that after careful study of the requirements for use with negative pressure dosing, especially after testing with hazardous chemical liquids, ···· ·

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The inventors of the present case have realized that special, ie targeted development of coupling devices is the most effective solution.

It is an object of the present invention to provide an improved coupling device for negative pressure liquid dispensing systems where the dispensing assembly can be simply replaced with an existing container lid.

Thus, the object of the present invention has been solved by a coupling device having a metering assembly connected to the liquid container and a coupling head associated therewith. It is an object of the present invention that the dispensing assembly is formed as a dispensing lid sealed to the fluid container, and is provided with an air inlet control valve and a fluid outlet control fluid valve; the coupling head being sealed in communication with the fluid valve; the dispensing lid and the coupling head are provided with releasably engaging coupling means; the fluid valve is connected to the coupling head assembly and is open in the coupling head and dosing cover coupled position.

GB-1-348-654. U. S. Patent No. 4,194,125 to The Perlick Company Inc., discloses a conventional gas-pressure metering system wherein the coupling head is pivotally engaged with the barrel valve. The coupling head is screwed to the barrel valve, and the inner valve members form two sealed passages when open, one of which is for pressurized gas inlet. ............

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-4, and the other is for spilling beer. The coupling head in this arrangement is not provided with an air duct.

US 4'388-997. A hand-held spray gun known from US Patent No. Thomas E. Grime, which is capable of spraying paint from a paint container by suction. This specification does not include a reference to the fluid outlet blocking device and any additional elements on the dispensing cap that can be engaged by the coupling head by relative rotation of the coupling head and the dispensing cap. When the coupling head and the dispensing lid are connected, no structural unit is engaged here which engages and opens the fluid outlet blocking unit.

In a preferred embodiment of the coupling device according to the present invention, the metering lid and the coupling head are provided with screw threads which are connected to one another.

In a further embodiment of the invention, the dispensing lid and the coupling head are bayonetically connected to each other.

In a further preferred embodiment of the present invention, the fluid drainage blocking unit is configured as a diaphragm and the front portion of the coupling head is configured to receive the diaphragm. With this arrangement, the membrane can be opened by screwing the coupling head into the dispensing head, thereby creating a flow passage for the fluid to be dispensed.

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In yet another exemplary embodiment of the invention, the fluid spill prevention device is configured as a fluid valve having an axially displaceable valve member and the front portion of the coupling head being configured to engage with said valve member. The valve member can thus be displaced axially, thereby opening the fluid valve by screwing the coupling head into the coupling cap, thereby creating a free cross-section for the fluid to be dispensed.

It is also possible to design the coupling device according to the invention in which the fluid spill prevention device is designed as a fluid valve having a pivotable valve member thereby engaging a properly formed front end of the coupling head. Thus, in this arrangement, the fluid valve can be opened by rotating the valve member when the nozzle is screwed into the dispensing lid, thereby allowing free flow of the fluid to be dispensed.

Preferably, the air valve is formed as a one-way valve in the metering lid, completely separated from the valve preventing the discharge of liquid.

It is also possible, according to a further feature of the present invention, that the air inlet control air valve is formed as a one-way valve in the metering lid, coaxially with the fluid outlet valve.

The invention will be described in more detail with reference to the accompanying drawing, in which some exemplary embodiments of the present invention are illustrated. In the drawing:

Figure 1 is a side elevational view, partly in section, of a first embodiment of a coupling device according to the invention;

Figure 2 shows the solution of Figure 1 in a connected state;

Figure 3 is a fragmentary side elevational view of a second exemplary embodiment, partly in section;

Figure 4 illustrates the solution of Figure 3 in a connected state;

Figure 5 is a side view, partly in section, of the third embodiment in an expanded state;

Figure 6 is a diagram of the solution of Figure 5 in a connected state.

The coupling device according to Figures 1 and 2 consists essentially of two parts, namely a dispensing cover 10 and a coupling head 12 connected thereto. The dispensing lid 10 is in the form of a conventional lid, in this case by injection molding of plastic. The dispensing lid 10 has an internal threaded collar 14 attached to the head portion 16 and is provided with a sealing ring 18 which lies on the rim of the opening neck of a liquid storage barrel (not shown) (e.g.

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-7 type of plastic barrel). The head part 16 is provided with a central recess 20 in which in this case a one-way air valve 22 and a valve valve 24 are arranged side by side.

The air valve 22 is arranged in a bore 26 provided with a passage 28 in the bottom portion. Through the passage 28, the valve stem 30 of the flexible material valve valve extends. The valve head 32 of the air valve 22 rests sealingly on the underside of the central recess 20 of the metering lid 10.

The liquid valve 24 is provided in the present case in the form of a threaded bore coupling member 34 having a cylindrical valve body 36 extending downward from its base. The valve body 36 includes a spring-loaded valve seat 38 which rests sealably on the valve seat 40 in its closed position at the top of the valve body 36. The inlet formed in the bottom portion of the valve body 36 is in this case connected to a plastic pipe 42, the lower end of which reaches the bottom of the barrel (not shown).

The coupling head 12 has a substantially cylindrical housing 62 with radial wings, which in this case is formed by injection molding of plastic. The front portion thereof is formed as a coupling member 44, the outer thread of which engages the inner threaded coupling member 34 of the dispenser lid 10. The coupling head 12 has a central through hole which ends in a larger diameter bore 46. The passageway bore 48 is provided with a tube 48 having a

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The front end is closed by a lid 50 and is provided with lateral passages at the front end (Fig. 2). The bore 46 is provided with a spring-loaded valve having a cylindrical valve member 52 disposed about the tube 48 and axially displaceable therein. The valve member 52 is pressed against the sealing ring 56 by a spring 54, which in turn closes the lateral passages.

In use, the coupling member 44 of the coupling head 12 is screwed into the coupling 34 of the dispensing lid 10, which is a threaded hole (the direction of rotation is indicated by an arrow R in Figure 2). During screwing, the tabs 62 of the coupling head 12 are gripped. This screwing is performed until the lid 50 is in contact with the spring loaded valve plate 38. In this case, when the coupling head 12 is slightly further screwed in, the valve plate 38 moves axially downward until the end of the tube 48 passes through the valve seat 40 of the fluid valve 24. Thus, the fluid valve 24 is opened. Since the valve in the coupling head 12 is not a non-return valve, the valve member 52 is raised from the end of the tube 48, while the sealing ring 56 exposes the lateral passages at the bottom of the coupling member 34. By means of a rotary connection 58, an outlet tube 60 can be connected to the coupling head 12 in a manner known per se. This is advantageously secured after screwing the coupling head 12 into the dispensing lid 10, since this avoids twisting the outlet 60.

A pump can be connected to the outlet 60 to carry the barrel

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The liquid content is aspirated along the path indicated by arrows in FIG. 2, i.e., fluid passes through tube 42, through a passageway in the lower portion of valve body 36, into tube 48 and laterally through outlet port 60 through lateral passages of coupling head 12. The pressure in the barrel will decrease as the liquid flows out, so the air valve 22 will automatically open and release air into the upper space of the barrel, also marked with an arrow.

Second FIG.

The periphery 14 of the lid 10 may optionally be provided with an anti-theft ring 64 in a manner known per se, and the threaded bore of the lid 10 provided as a coupling member 34 may optionally be provided with a temporary stopper 66 for sealing.

Figures 3 and 4 show a second exemplary embodiment of a coupling device according to the invention. It has a dispensing cover 70 and a coupling head 72 which can be connected thereto. Again, the dispensing lid 70 is formed in a conventional manner by injection molding plastic. The inner threaded skirt 74 of the dispensing lid 70 is attached to the head 76 and is provided with a seal 78. A conical hub 80 is sealed into the upper portion of the dispensing lid 70 and is coaxially arranged. The hub 80 is provided with a radially outwardly extending flange 82 on its upper portion which engages the head 76 of the dispensing lid 70. The hub 80 is provided with a central recess 84 and further has a bore 86 that extends from the lower portion of the recess 84 to the inner end 88 of the hub 80. The lower part of the bore 86 has an enlarged diameter as shown in Figure 3, in which the end of the tube 90 is fixed. The lower end of the tube 90 reaches the bottom of the barrel (not shown). The tube 90 in this case secures a fluid valve 92 formed as a membrane at the shoulder portion of the bore 86. The purpose of the fluid valve 92 is to close the central bore 86 of the hub 80.

The bores 86 have circular air holes 94. These axial air holes 94 are able to conduct air under the flange 82. A groove 98 is formed on the outer periphery of the hub 80 with a membrane-like air valve 96 made of a resilient material in the form of a ring. The air valve 96, when installed, is arranged to seal the space at the lower part of the flange 82 and consequently maintain the air holes 94 in a sealed position. The recess 84 in this case is also provided with inwardly extending flanges which act as bayonet lock-like coupling members.

The coupling head 72 in this case also has an injection molded and wing housing made of plastic. Its front end 102 is provided with flange-like coupling members 104 which are configured to provide a bayonet-like engagement with the coupling members 100 of the dispenser cover 70. The coupling head 72 has a continuous bore 106 which ends in a larger diameter bore. In this larger diameter lower part, a spring-loaded fluid valve 108 is provided, the valve body 110 of which has an apex ending in a bore.

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-11ges ending in 112. A sealing ring 114 is disposed around the valve body 110, which is sealed against the end face of the dispensing cover 70 when the coupling head 72 is screwed. The upper end 116 of the coupling head 72 is provided with an external thread for connecting the suction pipe (not shown).

The coupling head 72 is connected to the dispensing cover 70 by inserting the front end 102 of the coupling head 72 into the hub 80 of the dispensing cover 70 and then rotating the coupling head 72 relative to the dispensing cover 70 so that the coupling members 104 of the coupling head 72 100 switches. The coupling members 100 and 104 may optionally be provided with a slight slant in the axial direction so that the coupling head 72 remains in the dispensing lid 70 in a self-locking condition.

As soon as the end of the coupling head 72 enters the hub 80 of the dispensing head 70, the projection 112 extends into the bore 86, extends through the membrane-like fluid valve 92 and clamps the sealing ring 114 to the bottom of the recess 84, thereby sealing the projection The liquid can then be pumped out of the barrel, which passes through the tube 90 through the liquid valve 92, enters the central cavity of the projection 112, raises the ball of the liquid valve 108, and spills over the top of the bore 106 (as shown in Figure 4). As soon as the suction is reduced in the barrel, air enters the interior of the barrel through the air holes 94 formed at the front end 102 of the coupling head 72, but the air pressure difference is: •: ···: ···.

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the diaphragm-like air valve 96 is lifted from the lower part of the flange 82 as indicated by the arrow in FIG. In this embodiment, therefore, no pivoting connection is required, since the coupling head 72 need only be rotated slightly to be connected to the dispensing cover 70 by means of a bayonet-like connection.

Figures 5 and 6 show a third exemplary embodiment of a coupling device according to the invention. Here, the dispenser lid 120 is substantially the same as the dispenser lid 70. The only difference is that here the membrane-like fluid valve 90 is replaced by a fluid valve 122 formed as a rotary valve, the rotary valve member of which is designated 124. The other parts are the same, and are therefore denoted by the reference numbers used in Figures 3 and 4. The pivotable valve member 124 has an inverted cup shape having radial passageways 126 (FIG. 6). These radial passageways 126 are formed in the sidewall 128. The valve member 124 may be rotated about a vertical axis on a support member 130 that is part of a hub 80. Figure 5 shows that the hub 80 is provided with radial passages 132 that pass through the bore 86. The valve member 124 may be rotated such that its passageways 126 engage the passageways 132 of the support member 130, thereby causing the fluid valve 122 to open (Fig. 6). Fluid valve 122 closes when rotating valve member 124 to a position where passages 132 and 126 are not in communication with each other (Figure 5). The valve member 124 is provided with a transverse recess 134 on its upper surface.

In this embodiment, the coupling head 136 is substantially the same as the dosing head 72. The only difference is that the valve body 110 has been replaced in this case by a much shorter central cross-shaped projection 130. Further, the coupling head 136 has non-protruding portions 138 provided with axial passageways 140 which engage the ball valve 108.

The coupling head 136 is connected to the dispensing lid 120 by inserting the front end 102 into the hub 80 and then rotating the coupling head 136 slightly relative to the dispensing lid 120 so that the coupling members 104 engage with the coupling members 100 of the dispensing lid 120. When the coupling head 136 is inserted into the hub 80, the projection 138 engages in a form-locking engagement with the cross-shaped recess 134. The coupling head 136 is then rotated slightly so that the valve member 124 is also pivoted from its closed position to its open position. The sealing ring 114 is then pressed against the upper end face of the hub 80, thereby creating a sealed connection over the dispensing lid 120 and the coupling head 136 (Fig. 6).

The fluid can then be pumped out of the barrel (not shown) as it passes through pipe 90, passageways 132 and 126, axial passageways 140, then passes through fluid valve 108 and through outlet port 136 as shown by arrow 6).

As soon as the pressure drops in the barrel, air may flow through the air holes 94 into the interior of the barrel at the front end 102 of the coupling head 136. As a result of the differential pressure, the membrane-like air valve 96 rises from the lower surface of the flange 82 (as indicated by the arrow in Figure 6).