Cask for drawing off liquids under the effect of pressure

Description of the invention

The invention relates to a disposable plastic barrel for transporting, storing and spilling drinks by the action of pressure, as well as a container for producing such a barrel and a method of manufacturing such a barrel. The barrel according to the invention is intended in particular for carbonated beverages such as beer, etc. It is intended for retailers and / or consumers.

In order to simplify the description, the invention will be presented with reference to a beer keg, but it is obvious that this use does not limit the scope of the invention. In fact, the invention can be applied to any fluid that is removed from the container by the own pressure of the fluid within the barrel and / or by the gas pressure introduced into the barrel later during emptying, such as during emptying, for example. bottling wine using pressurized nitrogen.

Patent FR-A 2,719,285 describes a container for a pressurized fluid, consisting of a fluid storage chamber, an outer housing defining a space in the chamber, and a material filling the space. According to the operating embodiments of the invention, the material of which the outer casing is made and the material filling said space may be identical and, moreover, they may be made in the form of a one-piece casting. The evacuation of the fluid from the container can be done in a conventional manner by means of a commonly known plunger tube having an opening for the introduction of the gas used to empty the container, the fluid exiting the container also exiting the plunger tube.

EP-A 0,162,117 describes containers which can be used as washable reusable beer kegs, the containers consisting of two halves made by injection molding and welded together along a circumferential center line to thereby form barrel way. Said barrel has a hinged flange forming an element supporting the head of the discharge pipe, which either forms one piece with the upper part of the barrel, in which case all parts of the tube head must be firmly attached to the upper part of the barrel, which creates the risk of deformation and loss of tightness, or is an element of attached with glue or by heat welding, in which case the tube head assembly must be secured from the inside, before welding the two halves of the barrel together.

Patent FR-A 2,776,637 describes a disposable container with a drain tube in which the chamber for storing the liquid and the device for filling / emptying the barrel form a single unit. The tube is in this case not placed inside the container. It is attached to the neck of the container during hot rolling, and due to the shrinking of the neck during cooling, the connection is tight.

There is therefore a need to provide a container, in particular one that can be used as a beer keg, with a simple structure that reduces manufacturing costs and having a means for filling and / or emptying the contents of the container. There is also a need to develop a disposable beer keg, i.e. a keg that cannot be reused and is made of recyclable materials.

The subject of the invention is a disposable plastic barrel for transporting, storing and pouring drinks under the action of pressure, characterized in that it comprises a profiled housing or an insert forming a container, consisting of at least two asymmetrical, complementary parts welded together, each of which parts have a boss or circumferential rim, one of the parts has an opening with an outer neck, extending inward in the form of a cylindrical portion which has at its lower end a reduced diameter member forming an end defining a restricted diameter passage for holding a device for emptying the container, the end having at least one opening allowing liquid to flow during filling of the barrel; and gases when emptying this liquid from the container.

Preferably, the lower part has a lower lug or a circumferential rim ending with protrusions matching the projections made in the end part of the upper rim of the upper part, allowing the barrels to be stacked one on top of the other.

Preferably, the barrel is made of a thermoplastic material by injection molding.

PL 204 089 B1

Preferably, the housing or insert is made of a material selected from the group consisting of high-density polyethylene, high-density polypropylene, PVC and ABS.

In a preferred variant of the invention, the barrel also has an outer coating made by hot-dip coating.

Advantageously, the barrel according to the invention has a structure designed for transporting, storing and pouring beer.

Preferably, the container has a plunger tube with a heat-sealed head.

In another, preferred embodiment of the invention, the container has a plunger tube provided with a head attached by threaded connection, and has at least one gasket and / or at least one vent in the outer neck portion of the container opening.

The invention also relates to a container for producing a disposable plastic barrel for transporting, storing and bottling drinks by the action of pressure, characterized in that it comprises a container as defined above.

Moreover, the subject of the invention is a method of manufacturing a barrel as defined above, characterized in that it comprises injection molding the barrel parts, optionally making at least one cutout forming a handle, as well as a head adapted to the type of plunger tube used, welding the barrel parts together, optional application of a coating to all or some of the outer surfaces of the container by means of hot metallization, mounting a plunger tube, peripheral seal, spring, and support member by guiding them to the neck of the part, and welding or screwing the head to the exterior of the neck of the container opening.

The head or peripheral rim of the container portion provided with its filling / emptying aperture may have a height at least equal to the outer height of the portion of the above-mentioned container filling / emptying device, and possibly sufficient to provide a cutout forming the handle.

The subject of the invention in an exemplary embodiment is shown in the drawing in which Fig. 1 shows a schematic longitudinal section of a container according to the invention; Fig. 2 is a schematic longitudinal section of another variant of the container according to the invention; Fig. 3 is a schematic longitudinal section of another embodiment of the container according to the invention shown in Fig. 1; Fig. 4 is a schematic longitudinal section of another embodiment of the container according to the invention shown in Fig. 2; fig. 5 - a partial longitudinal schematic section of a further variant of the container according to the invention; and Fig. 6 is a schematic longitudinal sectional view of yet another embodiment of the container according to the invention shown in Fig. 2.

Identical or very similar parts (at least from a utility point of view) have been marked with the same numbers in the drawings.

With reference to Fig. 1, a container 1 according to the invention is described which comprises a housing or an insert preferably made of thermoplastic material. It is recommended that the material be approved for contact with foodstuffs. Otherwise, or additionally, said housing may be lined with substances giving it the properties required for contact with foodstuffs.

The material of the housing is preferably compact enough so that there is no or practically no possibility for gas to pass through it. Moreover, the material should preferably be impermeable to light and / or UV radiation so that it can be used for protection against UV radiation if necessary or recommended.

Non-limiting examples of preferred housing materials are thermoplastic polymers selected from the group consisting of high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), and polyacrylonitrile / butadiene / styrene ( ABS).

In one embodiment, the barrel or container 1 according to the invention also has an outer covering to improve gas tightness, in particular. It has been found that, in fact, under certain extreme conditions, the materials of the containers may be porous to some extent. Without wishing to be bound by any theory, it can be assumed that air is under pressure4

(Typically consisting of nitrogen, oxygen, carbon dioxide, water vapor, argon, noble gases and microscopic airborne dust) can pass through the walls of the container from the outside to the inside and come into contact at this pressure. with other gaseous constituents that may be present inside the container, arising from the use of the container or from the materials from which the container is made. The external pressure exerted in this way tends to entrain with the air these components of the container material and the components mentioned above. This may cause a reaction or many chemical reactions that may adversely affect the smell inside the container 1.

In one embodiment of the invention, this phenomenon is eliminated by creating an outer barrier around the container 1, preferably made by hot-spraying a metal powder on all outer surfaces of the container 1, creating a coating of sufficient thickness and density to be sealed to eliminate the pressure effects described above. atmospheric. This coating avoids the formation and development of undesirable odors in the container 1, which is called the "Dalton effect" in plastics technology.

Those skilled in the art can determine the most advantageous metal coating performance parameters, and in particular select the metal and its physical form, coating thickness and density, as well as coating application method and temperature, and if necessary, they can perform a series of standard tests for this purpose.

Two preferred embodiments of the housing described are shown in longitudinal section in Figs 1-5 and 6, respectively.

The housing forming the container 1 is preferably made by injection molding or some other equivalent method. An essential feature of the casing produced in this way is that the dimensions are sufficiently constant and continuous, so that the welding of the two casing parts and the attachment of auxiliary elements, in particular the devices for filling / emptying the keg, can be carried out easily.

In the embodiment shown in Figs. 1-5, the housing consists of mutually complementary parts 1a and 1b which are intended to be welded or otherwise suitably connected to each other to obtain the container 1.

The two housing parts 1a and 1b are preferably connected to each other by a weld 2 or any other equivalent element. Thus, the parts 1a and 1b, separately made by injection molding, are connected to each other along the respective contact surface or the weld surface 2.

The housing may have walls of constant or varying thickness. With the help of appropriate preliminary tests, specialists in the field are able to check and determine for each specific case what thickness and possible changes in wall thickness will lead to the best results. According to one preferred embodiment of the invention, the thickness is constant for the entire set of parts 1a and 1b of the container 1, except for the two edge areas where the walls are reinforced to form outer beads that can serve as rolling elements when the barrel is turned 90 ° to roll it over. on the ground. The beads are therefore spaced apart and arranged symmetrically with respect to the barrel's center of gravity. It is furthermore preferred that one of the beads and / or the rolling elements coincide with the surface area of ​​the weld of one of the portions 1a or 1b, so that the bead additionally joins the portions 1a and 1b together.

Optionally, the container 1 may consist of more than two parts joined together by welding or by any equivalent method. However, for economic reasons, it is preferable to limit the number of parts joined by welding to two.

In one embodiment, the neck of the opening of the container 1 according to the invention may be a separate piece attached by a suitable method such as welding or the like to the part 1a of the container. Said part 1a must therefore have the appropriate shape and dimensions.

The container 1 is an essential part of the barrel, but to be functional it must also have a plunger tube 3, also known as a filling / emptying tube.

In the exemplary container according to the invention shown in Figs. 1-5, the plunger tube 3 is further provided with a head 4, 18, a peripheral seal 5 in close proximity to it, at least one spring 6, and a user-controlled support 7 compressing the return spring and /. or alternately closing and opening outlets through which the liquid stored in the container 1 flows.

PL 204 089 B1

The plunger tube 3 allowing the emptying of the liquid from the container 1 has an opening at the submerged end up to the bottom of the container 1 and at least one opening, preferably lateral, at the top end, this opening being at the level of the above-mentioned seal 5.

In the embodiments shown in Figures 1, 2 and 5, the container 1 has a plunger tube 3 provided with a non-detachable head 4 attached, for example, by a weld 8.

In the embodiments shown in Figures 3, 4 and 5 the container 1 has a plunger tube 3 provided with a screw-on head 4, 18, in which case the upper part of the neck of the opening of the container 1 must have a thread (not shown here) corresponding to the thread of the above-mentioned head.

In the embodiment shown in Fig. 5, the container has a plunger tube 3 the same as the fluid container disclosed in patent WO 95/31671.

Figures 1 and 3 show a plunger tube 3 provided with a flat head 4, while the head 18 with which the containers of figures 2, 4, 5 and 6 are provided is concave. Both types of plunger or trigger tube heads are well known to those skilled in the art.

In this embodiment of the plunger tube it has a collar 12 that rests against the bottom of the cover formed by the inner part of the neck of the container 1 and the concave part of the above-mentioned part.

In the container 1 according to the invention, the inner neck portion 9 of the opening preferably has, at or near its inner end, a concave portion forming the bottom end 10, in which an opening is centrally made large enough for the plunger tube 3 to pass through it, the play being the hole should be sufficient to allow them to be displaced by a translational movement. The end 10 of the concave neck portion of the container 1 has at least one opening 11, the principal function of which is to allow the flow of liquid when filling the container with liquid and gases during emptying the container from this liquid. Said openings 11 may have any shape, for example round or oval.

In the embodiments shown in Figures 1 and 3, the plunger tube 3 abuts against the bottom of the neck of the opening of the container 1 via a collar 12.

The above-mentioned gasket 5 has a shape that allows the barrel to be sealed, as well as emptied by means of a drain valve of any type known in the state of the art, in practice drain valves designed specifically for this type of application are used. The seal 5 is held in the correct position by the spring 6.

The upper, outer part of the barrel (when the barrel is standing on its bottom) has a part called the upper rim or circumferential rim 13, in which there are preferably notches, thanks to which the parts of the rim located above them can be used as handles 14 to facilitate the handling of the barrel.

In one preferred embodiment, the part forming the bottom of the container also has a rim or circumferential rim 15, which may or may not be provided with cutouts for easy handling. The lower boss or peripheral rim 15 preferably ends with protrusions 16 matching the protrusions 17 made in the end portion of the upper rim or peripheral rim 13, whereby it is possible to place the barrel according to the invention in a vertical position and stack at least two barrels on top of each other.

In the embodiments shown in Fig. 3 5, in which the plunger tube is screwed into the neck of the container 1, preferably having at least one seal 19, it is particularly advantageous to provide at least one vent 20 in the area of ​​the neck thread of the container 1 and / or in the area of ​​the thread of the head 4, with which the pressure can be reduced. the contents of the barrel before starting the plunger disconnection, thus preventing the head from being ejected by the overpressure.

The embodiments shown in Figures 1, 2 and 6 employ a non-detachable, welded plunger tube.

The plunger tube 3 according to the invention can thus be designed specifically for use in the container 1 and made in the same way as the container 1.

In the embodiments of the barrels according to the invention shown in Figures 1 and 3 a plunger tube is shown equipped with a so-called flat head, while Figures 2, 4, 5 and 6 show a plunger tube equipped with a so-called concave head.

The implementation of the barrel according to the invention may consist of the following steps: manufacturing by injection molding the parts 1a and 1b, and optionally the head 4, 18, depending on the plunger tube used, welding the above-mentioned parts 1a and 1b together,

The plunger tube 3, the peripheral seal 5, the spring 6 and the support 7 are mounted on the neck of the plunger tube 3, 1a, and the head 4, 18 are welded or screwed to the outside of the neck of the container opening 1.

The container is made by injection molding and by welding and / or screwing the elements, which guarantees perfect geometry and proper distribution of resistance to the pressure of the finished barrel.

In this way, external shapes are easy to obtain, which has the advantage of being able to use the same production lines for filling kegs as currently used kegs made of stainless steel.

The barrel according to the invention has the significant advantage that it is compatible with existing keg filling and emptying systems. In cafes, bars and restaurants where drinks are poured from kegs, two types of release valve are used, both of which are widely used. These are so-called "flat head" and "concave head" valves which have the above-described (see Figs. 1 and 3 and 2, 4 and 5, respectively) types of plunger head. Thus, the differing embodiments of the invention provide full compatibility with existing drain valves, and the invention has at least one embodiment corresponding to each system with which an existing bottling device may be equipped.

Moreover, as described above with reference to the accompanying drawings, the barrel for emptying the barrel is preferably one of two types: shown in Figures 1 and 3 or shown in Figures 2, 4, 5 and 6.

The pressurization system and other components complementing the keg emptying system are of the standard type and are therefore well known to those skilled in the art.

When the invention is used as disposable barrels, it has the additional advantage of being able to choose whether the elements for emptying the barrel are welded to it or detachable. Even though the concept of disposable containers is preferred, the same product may be regenerated, washed, dried and refilled, but only if it is compatible with an embodiment using a detachable plunger tube.

However, as described above, the neck of the container according to the invention has a particular shape that makes washing and drying of the reused container impossible or very slow, ultimately rendering it not in line with the productivity requirements for products of this type.

Due to the abovementioned features, the product according to the invention has the undeniable advantage that, compared to similar existing solutions, it is only single-use.

Such a single-use keg, also known as a disposable keg, allows you to eliminate the costs of storing, repairing and buying re-used kegs that are associated with currently used kegs made of stainless steel.

The barrel according to the invention, instead of being thrown away after use, which is costly and pollutant, can be recycled; that is, after optionally separating the plunger tube, if it is made of a material that requires separate processing, the barrel can be recovered from the user and transported to a landfill into recyclable materials.

In the embodiment with top and bottom rims and the above-described protrusions, the barrels according to the invention have the advantage of being stackable, which is not possible with currently used barrels made of stainless steel, which must be stacked on pallets in single strings, which requires much larger warehouse space.

The preferred materials from which the barrels of the invention are made can absorb the impact energy that often occurs during the handling and transportation of such barrels. This allows the barrels to regain their original shape and size by the action of resilience, which is not possible with the currently used barrels made of stainless steel, and therefore their use is associated with high losses and the risk of their contents escaping.