EP0628016B1

EP0628016B1 - A coupling arrangement for coupling a dispenser head to a container valve

Info

Publication number: EP0628016B1
Application number: EP93906466A
Authority: EP
Inventors: Per Kurt Augustinus; Birger Moller Wollesen
Original assignee: Micro Matic AS
Current assignee: Micro Matic AS
Priority date: 1992-03-04
Filing date: 1993-03-03
Publication date: 1996-06-12
Anticipated expiration: 2013-03-03
Also published as: GB2280176B; DE4390855T1; WO1993017954A1; DE4390855C2; DK29192A; EP0628016A1; GB2280176A; NL194121C; NL9320028A; DK29192D0; GB9417838D0; DK169814B1; NL194121B

Abstract

A coupling arrangement serves to couple a dispenser head (1) to a valve (2) which is mounted in a connecting piece (3) on a container (4) for a liquid, such as beer under pressure from a gas, e.g. CO2. Sealing between the two parts (1, 2) takes place by means of a sealing ring (16) which is arranged axially slidably in a recess (17) in the dispenser head. The head moreover contains a slide (9) which can be moved vertically up and down with a handgrip (10) to close and open the container and the pressure gas inlet, respectively. The slide downwardly has a first outwardly directed collar (28) to lift the sealing ring clear of the valve when the container is to be closed and the dispenser head to be removed. The slide moreover has a second outwardly directed collar (29) to cause the sealing ring to engage the valve before the slide opens the valve and the gas inlet. To ensure effective sealing and easy removal the sealing ring (16) has a relatively large, annular rib (19) of triangular cross-section on the underside. By means of the coupling arrangement a dispenser head can easily and without any difficulty be mounted on a valve in a pressure container for a liquid under pressure from a gas and be removed from it. Further, the operating staff will not be splashed with liquid when the container is opened.

Description

The invention concerns a coupling arrangement for coupling a dispenser head to a valve mounted in a connecting piece on a container for a liquid, such as beer under pressure from a gas, e.g. CO₂, said dispenser head comprising; a gas inlet; a hollow slide slidable by means of a handgrip between a lower position in which the valve is open and the liquid can flow out through the hollow slide, and an upper position in which the valve is closed; an elastomeric sealing ring which, co-axial with the slide, is arranged axially slidably in a recess downwardly in the dispenser head and serves to form a seal between said head and the valve upon coupling; and a first outwardly directed collar so provided on the slide that the collar tries to lift the sealing ring clear of the valve when the slide is moved towards its upper position.
In the most widely used dispenser head types for coupling arrangements of the above-mentioned type the sealing ring is retained in the dispenser head by means of a ring-shaped rib which is provided on the inner side of the recess and engages a corresponding groove in the sealing ring. This therefore just has a very small or frequently almost no freedom of movement in an axial direction. When the valve is closed by pulling the slide up to its upper position, a cavity in the dispenser head above the sealing ring is blocked. However, this cavity will still be filled with pressure gas, which keeps the sealing ring so hard against the valve that it is extremely difficult to remove the dispenser head from the valve when the container e.g. is to be replaced by a new one. In particular, the problem has been found to be serious in connection with the structures where coupling takes place by moving the dispenser head transversely over an outwardly protruding flange on the valve.
The British patent specification 2 185 470 describes a coupling arrangement in which it has been attempted to solve the above-mentioned problem of removing the dispenser head. In this case the sealing ring is mounted to be somewhat axially slidable in the recess of the dispenser head, and the slide is downwardly provided with an outwardly directed collar which lifts the sealing ring slightly clear of the upper side of the valve when the slide is moved up toward its upper position by applying an upward pull to the handgrip of the dispenser head. The confined pressure gas in the cavity of the dispenser head will then escape below the sealing ring and relieve the pressure on it, following which the dispenser head can be removed without any difficulty.
The force required to lift the sealing ring depends upon the pressure to which it is subjected. Initially, the collar on the slide lifts the innermost end of the sealing ring, seen in cross-section, while the still confined gas keeps the outermost end pressed down against the valve. The force thus required to twist and deform the sealing ring increases as ever greater parts of the sealing ring are lifted clear of the valve. In order that the individual who is to replace the container shall not put unduly much strength into the job of pulling up the handgrip and lifting the slide, the underside of the sealing ring is formed with a plurality of radial grooves which terminate on the outer side of the ring and extend somewhat inwardly below it. As soon as the bending of the sealing ring, seen in cross-section, has reached these grooves, an open communication is formed between the cavity in the dispenser head and the atmosphere. The confined gas therefore rapidly escapes and relieves the pressure on the sealing ring, which can now be lifted completely clear of the valve easily and without any difficulty.
The radial grooves reduce the force necessary to lift the sealing ring clear of the valve to an acceptable size, but on the other hand they form pits which can collect dirt and be a hotbed of fermentation and putrefactive processes which are not compatible with the requirements of hygiene that food product containers of this type must satisfy. Furthermore, the grooves reduce the active gasket area of the sealing ring and, when the upper side of the valves is uneven, may cause a leaky connection between the dispenser head and the valve.
The upper side of the sealing ring described in the above-mentioned British patent specification is formed with a plurality of small upwardly extending pins which are pressed elastically together against the bottom of the recess when the slide is pulled up to its upper position. According to the patent specification these pins are to serve to press the sealing ring down to engage the upper side of the valve before the slide has reached so far in its downward movement as to open the valve and the gas inlet. However, it has been found in practice that the sealing ring remains in the recess in which it must necessarily form a tight fit, and this entails that liquid inacceptably splashes out through the gap between the dispenser head and the valve before the slide has been pressed home. A possible remedy to this drawback might consist in increasing the dimensions of the pins and thereby their spring force. However, this would simultaneously increase the force necessary to lift the sealing ring clear of the valve for removal.
The object of the invention is to provide a coupling arrangement of the type mentioned in the opening paragraph which, upon activation of the dispenser head, remains tight with certainty before the slide has managed to open the valve and the gas inlet, and which can moreover easily be removed without having to apply much force.
The novel and unique features according to the invention are that the slide is formed with a second outwardly directed collar which has a larger diameter than the bore of the sealing ring and is so positioned on the slide in an axial direction that when being moved toward its lower position the slide, by engagement between the collar and the sealing ring, carries along the sealing ring down to engage the valve before the slide opens the valve and the gas inlet. This arrangement effectively prevents unintentional liquid splash while the operator presses the handgrip of the dispenser head down to open the container.
The slide function of closing and opening the gas inlet and the valve, respectively, entails that the slide must have a relatively long travel between its upper and lower positions. The sealing ring, on the other hand, only has to be lifted slightly to get clear of the valve for removal. The second outwardly directed collar of the slide will therefore be pulled up and down through the sealing ring during the movements of the slide between its extreme positions, and for the correct function to be achieved in this connection this collar has a slightly larger diameter than the bore of the sealing ring and, in cross-section, has the shape of a triangle whose vertex faces outwardly so that the collar can suitably easily pass through the sealing ring.
A particularly advantageous embodiment is obtained when the sealing ring is formed with a plurality of inwardly directed noses and the slide with a third outwardly directed collar which is arranged at a distance below the second collar of the slide corresponding to the height of the noses, and that the diameter of the slide between the two collars has a diameter corresponding to the diametrical distance between the noses. When the dispenser head is in its free, unmounted state, the noses of the sealing ring tend to be caught in the space between the second and third collars of the slide by activation of the slide with the handgrip. The sealing ring therefore acts as a pump piston in the recess when the handgrip is repeatedly moved up and down, and this function can advantageously be used for cleaning the interior parts of the dispenser head, which may optionally be partly immersed in a suitable cleaning liquid in this operation.
Moreover, to ensure an effective and lasting seal in use a ring-shaped disc may be arranged in the recess of the dispenser head above the sealing ring and a breast on the slide which is so axially positioned on the slide that when engaged with the disc the breast causes the disc to compress the sealing ring axially when the slide is in its lower position.
To avoid the drawbacks associated with the radial grooves, which are provided in the underside of the sealing ring described in the above-mentioned British patent specification 2 185 470, the inner side of the sealing ring may moreover be formed with a lower annular rib between the inner and outer sides of the sealing ring, said rib in cross-section having the shape of a triangle with a downwardly facing vertex which extends further down than the rest of the underside of the sealing ring in the unloaded state of the sealing ring. In use this rib is in a highly compressed state, and it has been found that the rib is capable of forming an extremely effective seal even in the cases where the upper side of the valve is very uneven or damaged by scratches extending transversely of the rib.
During the operation of removal the compressed rib initially contributes to the force which serves to lift the sealing ring clear of the valve. But, when the bending of the sealing ring has reached the area at the rib and has begun to lift it, the rib will be more and more unstable because of its triangular cross-section and at a certain time it can no longer withstand the load from the confined pressure gas. The rib therefore collapses and permits the confined pressure gas to blow past below the rib. This completely relieves the pressure on the sealing ring, which can now be lifted freely. During this process it has at no point been necessary to subject the sealing ring to an upwardly directed force which corresponds to the relatively great downwardly directed force from the total pressure gas load of the sealing ring.
To ensure the effective seal of the lower annular rib additionally even against an uneven surface on the valve, a plurality of shoulders may moreover advantageously be provided above the lower rib on the upper side of the sealing ring which rise above the rest of the upper side of the sealing ring. When the ring-shaped disc in the recess of the dispenser head is pressed down towards the sealing ring by the breast of the slide upon opening of the valve, the disc applies a downwardly directed force to the sealing ring which is transferred to a considerable extent via the shoulders to the lower rib, which is therefore pressed down into all scratches and irregularities in the surface of the valve with certainty.
In an expedient embodiment of the sealing ring, said sealing ring may be formed with a lip along the periphery which touches the ring face of the recess, thereby instantaneously sealing the space above the sealing ring as soon as the gas inlet is opened.
The seal achieved by the lip may be improved additionally by means of a labyrinth seal along the periphery of the sealing ring below the lip, and this labyrinth seal may advantageously consist of a plurality of annular outer ribs, each of which has the shape of half an 0-ring in cross-section.
The invention will be explained more fully by the following description of an embodiment, which just serves as an example, with reference to the drawing, in which

fig. 1 is a partially sectional view of a coupling arrangement according to the invention, said arrangement being in a closed position in the left half and in an open position in the right half,
fig. 2 shows a sealing ring for the coupling arrangement shown in fig. 1,
fig. 3 is a top view of the same, and
fig. 4 is a bottom view of the same.

Fig. 1 shows a coupling arrangment having a dispenser head which is generally designated by the reference numeral 1, and a valve which is generally designated by the reference numeral 2. The valve, of which only the uppermost part is shown, is threadedly secured in a connecting piece 3 which is welded upwardly on a container 4, which is only shown in fraction. The valve is provided with an axially slidable gasket 5 which is affected by an upwardly directed force from a compression spring 6. A down pipe 7 extends down into the liquid, e.g. beer, which is to be dispensed.
The dispenser head 1 comprises a housing 8, a slide 9 slidable up and down in the housing as well as a handgrip 10 which serves to slidably move the slide. The handgrip is pivotally journalled about pivots 11 and can pivot between an upper position shown in dotted line in the figure, and a lower position shown in solid line. The dispenser head is moreover provided with a connection 12 which serves to connect the dispenser head with a pressure gas source (not shown), e.g. CO₂ in a bottle or a cartridge. The slide 9 has an axially extending channel 13 through which the liquid to be dispensed is conveyed out to the location of consumption (not shown).
The valve upwardly has a flange 14, and the dispenser head an inwardly directed edge 15 gripping firmly below the flange 14 when the dispenser head is coupled to the valve. The inwardly directed edge 15 only extends semi-circularly along the lower periphery of the dispenser head, which can therefore by moved transversely across the flange of the valve for coupling. The seal between the dispenser head and the valve is provided by means of a sealing ring 16 which is mounted axially slidably in a recess 17 in a housing 8.
As shown to the left of fig. 1, the valve 2 is closed when the slide 9 is in its upper position, and as shown to the right of fig. 1, the valve is open when the slide is in its lower position, where it has pressed the gasket 5 down so that the liquid can be conveyed out to the location of consumption via the down pipe 7, a plurality of openings 18 in it and the channel 13 in the slide. The slide has simultaneously opened the gas inlet 12.
Figs. 2, 3 and 4 show the sealing ring 16 on an enlarged scale. The sealing ring is made of an elastomeric material, which may e.g. be rubber of a suitable hardness. As shown, the underside of the sealing ring is formed with a relatively large lower, annular rib 19 having a triangular profile in cross-section. The rib 19 is spaced from the outer periphery of the sealing ring. Further, two smaller annular ribs 20 are provided between the sealing ring and the rib 19, which likewise have a triangular profile in cross-section. A labyrinth seal is provided along the actual periphery, consisting of three 0-ring halves, and a lip 22 is provided above this labyrinth seal, said lip serving to form a seal against the inner side of the recess 17 as soon as the gas inlet is opened. A plurality of shoulders 23 are provided on the upper side of the sealing ring in an area present above the lower annular rib 19, said shoulders being arranged with mutual spaces 24 and rising above the rest of the upper side of the sealing ring. A plurality of inwardly directed noses 25, which are mutually separated by vertical openings 26, are provided along the inner side of the sealing ring. Further, a ring-shaped plane face 27 is provided downwardly on the sealing ring at the inner side.
The slide 9 is downwardly formed with a first outwardly directed collar 28 having an upper face mating with the ring-shaped plane face 27 downwardly on the sealing ring 16. A second outwardly directed collar 29 is arranged at a distance above the first collar 28 corresponding to the height of the sealing ring at the inner side, said second collar 29 in cross-section having a triangular profile with a vertex which has a slightly larger diameter than the bore of the sealing ring. Additionally, a third outwardly directed collar 30 is provided at a distance below the second collar 29 which corresponds to the height of the noses 25.
A ring-shaped disc 31, which has a downwardly directed edge 32 of the same diameter as the noses 25 of the sealing ring and a plurality of holes 33, is arranged in the recess 17 above the sealing ring 16. The slide is moreover provided with a breast 34 in the form of e.g. a ring. The breast 34 has a larger diameter than the inside diameter of the ring-shaped disc 31.
As mentioned before, in the coupling operation the dispenser head is moved transversely over the flange 14 of the valve 2 and is then retained on it by the inwardly directed edge 15 downwardly on the housing 8. During this operation the handgrip 10 is pulled up to its upper position and the slide 9 is correspondingly present in its upper position, where is has pulled the sealing ring 16 slightly into the recess 17 of the housing with its first collar 28. The dispenser head is moreover connected to a gas source (not shown) and a location of consumption (not shown), respectively.
When the slide 9 is moved downwardly by means of the handgrip 10, the slide with its second outwardly directed collar 29 initially carries the sealing ring 16 along and causes it to engage the valve flange 14, even before the slide has opened the gas inlet and the valve. Therefore, liquid cannot unintentionally splash out of the container when this is opened e.g. the first time, as is the case in the known coupling arrangement of this type.
During its further downward movement the second collar 29 passes through the opening of the sealing ring 16 because of its triangular shape, and the slide can therefore continue to the lower position shown to the right in fig. 1 in which the valve 2 and the gas inlet 12 are opened. In this state the breast 34 on the slide has pressed the ring-shaped disc 31 in the recess 17 down against the sealing ring so that the downwardly directed edge 32 of the disc rests on the shoulders 23 of the sealing ring with a predetermined force, which is transferred to a considerable extent via the shoulders to the lower annular rib 19, which is thereby caused to effectively seal even an irregular surface on the flange 14. The lip 22 of the sealing ring simultaneously ensures that the space above the sealing ring is tight from the moment the gas pressure is first admitted. The labyrinth seal, which consists of the 0-ring halves 21, simultaneously ensures the lasting durability of the seal, because they engage the inner side of the recess and at the same time support the sealing ring against the radially acting pressure from the gas. The coupling arrangement can now be used until the container has been emptied or is to be replaced for some other reason.
The valve and the gas inlet are then closed by pulling the handgrip 10 up to its upper position, whereby the slide 9 simultaneously moves upwardly. During this movement the slide engages the ring-shaped plane face 27 downwardly on the sealing ring with its first upwardly directed collar 28, and the sealing ring is therefore affected by an upwardly directed force trying to lift the sealing ring clear of the valve 2 against the pressure of the gas which is confined in the cavity above the sealing ring. The sealing ring hereby bends at the innermost end, seen in cross-section, while the outermost end is still pressed down against the valve by the gas pressure. Initially the spring force from the highly compressed large, lower rib 19 acts in the same direction as the lifting force of the slide, which is thereby reduced correspondingly. When, seen in cross-section, the bending of the ring has reached the area at the lower rib 19, this is gradually lifted so much that, because of its triangular profile, it no longer has the necessary strength and stability to resist the pressure from the confined pressure gas. The lower rib 19 therefore collapses and permits the gas to escape to the atmosphere. The sealing ring is then completely unloaded and can be lifted freely. The structure of the sealing ring entails that at no time of the complete lifting operation has it been necessary to use a lifting force which is just as great as the force by which the confined pressure gas affects the sealing ring.
By means of the coupling arrangement of the invention a dispenser head mounted on a valve in a pressure container can be removed easily and without any difficulty when the container is e.g. to be exchanged. The reason is that the sealing ring is not fixed against the valve by the pressure of the confined gas above the sealing ring, since this is relieved completely when the handgrip of the dispenser head is pulled up to close the container. This only requires a modest effort from the operating staff. Further, the operating staff and the surroundings will not be splashed with liquid when the container is opened.

Claims

A coupling arrangement for coupling a dispenser head to a valve which is mounted in a connecting piece on a container for a liquid, such as beer under pressure from a gas, e.g. CO₂, said dispenser head comprising: a gas inlet; a hollow slide slidable by means of a handgrip between a lower position in which the valve is open and the liquid can flow out through the hollow slide, and an upper position in which the valve is closed; an elastomeric sealing ring which, co-axial with the slide, is arranged axially slidably in a recess downwardly in the dispenser head and serves to form a seal between said head and the valve upon coupling; and a first outwardly directed collar so provided on the slide that the collar tries to lift the sealing ring clear of the valve when the slide is moved toward its upper position, characterized in that the slide is provided with a second outwardly directed collar which has a larger diameter than the bore of the sealing ring and is so positioned on the slide in an axial direction that when moving toward its lower position the slide, by engagement between the collar and the sealing ring, carries along the sealing ring down to engage the valve before the slide opens the valve and the gas inlet.
A coupling arrangement according to claim 1, characterized in that the second outwardly directed collar has a slightly larger diameter than the bore of the sealing ring and, in cross-section, the shape of a triangle whose vertex faces outwardly.
A coupling arrangement according to claim 1 or 2, characterized in that the sealing ring is provided with a plurality of inwardly directed noses and the slide with a third outwardly directed collar which is arranged at a distance below the second collar of the slide corresponding to the height of the noses, and that the diameter of the slide between the two collars has a diameter corresponding to the diametrical distance between the noses.
A coupling arrangement according to claim 1, 2 or 3, characterized in that a ring-shaped disc is arranged in the recess of the dispenser head above the sealing ring, and a breast is arranged on the slide, said breast being so axially positioned on the slide that when engaged with the disc it causes the disc to compress the sealing ring axially when the slide is in its lower position.
A coupling arrangement according to one or more of claims 1-4, characterized in that the inner side of the sealing ring is formed with a lower annular rib between the inner and outer sides of the sealing ring, said rib in cross-section having the shape of a triangle with a downwardly facing vertex which extends further down than the rest of the underside of the sealing ring in the unloaded state of the sealing ring.
A coupling arrangement according to one or more of claims 1-4, characterized in that a plurality of shoulders are arranged on the upper side of the sealing ring substantially vertically above the lower annular rib on the underside, said shoulders rising above the rest of the upper side of the sealing ring.
A coupling arrangement according to one or more of claims 1-6, characterized in that the sealing ring is peripherally formed with a lip which touches the ring face of the recess.
A coupling arrangement according to claims 1-7, characterized in that the sealing ring is peripherally formed with a plurality of annular outer ribs, each of which has the shape of half an 0-ring in cross-section.