VALVE RING FOR A DOUBLE VALVE

Abstract: A valve ring (2) is used in a double valve (1) for a pressure container (4) serving for distributing a liquid, e.g. beer, under pressure of a gas, e.g. CO<2>. In open condition, the double valve has a gas passage (7) between a valve seat (8) in the valve and a valve face (9) in the valve ring, and a liquid passage (10) between a valve plug (11) and a valve-ring seat (12) in the centre opening (13) of the valve ring. The valve can be closed partly by pushing the valve face of the valve ring to abut on the valve seat under the influence of a first compression spring, partly by pushing the valve plug to abut on the valve-ring seat under the influence of a second compression spring. The valve ring comprises an elastomeric first ring (25) and a solid second ring (26) fixed on the outside of first ring along a part of the surface of this ring. The connection between the two rings is made sure by a purely mechanical engagement which, contrary to conventional valve ring surface joinings, is indifferent to the strong chemicals and high temperatures used in cleaning the container and its valve between each casking.

Description: Valve ring for a double valve The invention concerns a valve ring for closing a double valve of the kind used in a pressure container for distributing a liquid, e.g. beer, under pressure of a gas, e.g. C0 2 and which, in open condition, has a gas passage around the valve ring and a liquid passage through the centre opening of the valve ring. Transportable pressure containers are largely used for distributing beverages, such as beer, to be served in portions in e.g. a restaurant. When the container is to be used, its valve is mounted with a coupling head with connections for a pressure bottle or cartridge containing a pressure gas, normally C0 2 , and a barrel tap for drawing the beverage. In the coupling head is a spindle for opening the valve by displacement with a grip. In order for the beverage to be able to keep fresh during transportation and storage, it is necessary that the gas pressure is maintained, and that the valve therefore always keeps completely tight in closed condition. Conventional valve rings are therefore made of elastomer materials, such as rubber which can be elastically deformed to abut tightly on the gas passage and the liquid passage, respectively, under the influence of at least one compression spring. A safe sealing presupposes that the valve ring is acted upon by relatively great forces which the elastomer material hardly can absorb without the ring being buckled, whereby the gas and/or liquid passage will be inclined to leak, and the valve ring can be forced out of its position in the valve. The elastomer material of said conventional valve ring is therefore strengthened by a plate-shaped strengthening ring of a strong, solid material, for example stainless steel. A fixing agent is applied to the ring at the manufacturing and it is cast together with the elastomer material to an integrated unit. Normally, a part of the strengthening ring will be completely embedded in the elastomer material, while another part has a free surface for, at the opening of the valve, absorbing the load from the spindle of the coupling head and thereby sparing the soft elastomer material from being damaged. Between each casking, the pressure container and valve are as a body cleaned with strong cleaning materials at very high temperatures, e.g. 130° C. It has in many cases turned out that this hard treatment degrades the fixing agent between the elastomer and solid material, and that the two materials come apart especially in those places where the surface of the two materials pass into each other. The cracks, made in this way, are likely to gradually open so much that the valve ring no longer will be able to keep neither the gas passage nor the liquid passage completely tight. The object of the invention is to provide a valve ring of the kind mentioned in the opening paragraph which, without being damaged, can stand repeatedly being subjected to cleaning processes in which strong cleaning materials and high temperatures are used. The novel and unique features according to the invention whereby this is achieved, is the fact that the valve ring comprises an elastomeric first ring and a solid second ring which is fixed around the first ring along a part of the surface of this first ring. The second ring functioning as a strengthening ring is not joined to the elastomer material merely by a surface joining, as is the case in conventional valve rings, but instead by a purely mechanical engagement between the two materials. The mechanical engagement is proof against even strong chemical agents and high temperatures . To make sure that the valve ring can effectively keep the valve tight, the second ring can advantageously be fixed on the outside of the first ring along an area outside the active seal face of the valve ring. The mechanical engagement between the elastomer and solid material will be especially durable when the tangents to the inner side of the second ring - seen in cross section - at the inner and outer marginal zone respectively, form an angle which is equal to or smaller than 90°, and when the elastomer material of the first ring is in a prestressed condition in an area comprising at least the areas beneath and/or at the marginal zones of the second ring. The second ring can in itself function as a reinforcement ring to the valve ring, but an especially solid and durable valve ring is obtained when there also is a third ring made of a solid material, such as stainless steel, and which, completely or partly, is embedded into the first ring. Preferably, the third ring is completely embedded in the elastomer material, but with the inner marginal zone extending to or out of the material around the opening of the elastomeric ring. At this spot, the inner marginal zone of the second ring can advantageously be beaded around the inner marginal zone of the third ring, whereby the mechanical engagement between the second ring and the elastomer material is further secured. The third ring can furthermore have holes for making a bridge between the elastomer material on both sides of the ring, so that the elastomer material is kept together even if the joint between the third ring and the elastomer material fails. The invention also concerns a method of manufacturing a valve ring of the above-mentioned kind of an elastomeric ring with a fixed-on second ring and an embedded third ring. The novel and unique features of this method is, according to the invention, that the third ring is made of a metallic material, such as stainless steel, that a fixing agent is applied onto the third ring, that the first ring is cast-in around the third ring of an elastomer material, such as rubber, that the second ring is made of a metallic material, such as stainless steel, and that the second ring is fixed onto the first ring, at least partially compressing the elastomer material of this ring and beading the inner marginal zone of the third ring. The invention will be explained in greater details below, describing only exemplary embodiments with reference to the drawing, in which fig. 1 is a cross-sectional view of a double valve with a valve ring according to the invention, fig. 2 shows a solid strengthening ring for embedment in the valve ring shown in fig. 1, fig. 3 shows the strengthening ring shown in fig. 2, embedded in an elastomer material forming the elastomeric part of the valve ring, fig. 4 shows the finished valve ring with a solid clamping ring clamped onto the outer side of the elastomeric part of the valve ring, and fig. 5 shows a conventional valve ring. In fig. 1 is seen a double valve 1 with a valve ring 2 according to the invention. The valve is releasably mounted in a connection piece 3 which is welded onto a transportable pressure container 4 shown only in fragments in the figure. Transportable containers of this kind are used for distributing beverages, such as beer, cola, soft drinks, and wine, under pressure of C0 2 . However, the containers can also be used for many other liquids, just as the gas can be another than C0 2 . The containers do not have to be transportable, but can just as well be stationary. The double valve can be shaped as shown, but there are also many other designs of such double valves . The embodiment shown in fig. 1 is therefore only used in the below description to exemplify the invention, and as the structure is known per se, it will only be described in broad outline. The valve consists primarily of a valve body 5 and a riser pipe 6, only fragmentarily shown, which is displaceably fitted in the body. The left side of the figure shows the valve in open position, while the right side shows the valve in closed position. The valve ring 2 is also shown in fig. 2, 3 and 4 on an enlarged scale. When the valve is open, as shown in the left side of the figure, there is a gas passage 7 between a valve seat 8 in the valve body 5 and a valve face on the valve ring 2. There is furthermore a liquid passage 10 between a valve plug 11 and a valve-ring seat 12 in the centre opening 13 of the valve ring. When the valve is to be closed, as shown in the right side of the figure, the ascension pipe 6 is displaced with the valve ring 2 by a first compression spring 14 until the valve face 9 of the valve ring abuts on the valve seat 8. Thereby, the gas passage 7 is closed. At the same time, the valve plug 11 is displaced by a second compression spring 15 to abut on the valve-ring seat 12, so that the liquid passage 10 is also closed. When the container 4 is to be used, its valve 1 is releasably mounted with a coupling head (not shown) with a displaceable, tubular spindle 16, of which the bottom part is seen in fig. 1. The spindle treads with its bottom part on the valve plug 11 and the valve ring 2, which both are removed from their seats 8; 12, so that the valve is opened when the spindle is displaced downwards in the figure by operating a grip (not shown) on the coupling head. The gas is supplied to the double valve and the container via the coupling head which, in operation, is connected with a pressure bottle or cartridge containing a pressure gas (not shown) . Similarly, the liquid is led out via the double valve and the tubular spindle 16 of the coupling head, said spindle is connected with a barrel tap at the place of drawing (not shown) . The spindle 16 and the two compression springs 14 and 15 load the valve ring 2 with forces which would make a plain elastomeric ring buckle, so that the valve would leak. It is therefore necessary to strengthen the elastomeric ring with a solid ring of e.g. stainless steel. Such a strengthening is seen in fig. 5 which shows a conventional valve ring 17 constructed of an elastomeric ring 18 and a solid ring 19. In connection with the manufacture of this valve ring, the solid ring 19 is applied with a fixing agent to make sure that the surfaces of the two materials are stuck securely together. The solid ring 19 is then embedded in the material of the elastomeric ring 18 with a tongue 20, while a second part 21 of the solid ring is extending along the surface of the opening 22 of the elastomeric ring. This second part 21 serves for absorbing the compressive force of the spindle 16 of the coupling, when the valve is to be opened. The relatively soft material of the elastomeric ring 18 would in itself not be strong enough to stand this load. The above-mentioned structure of the valve ring 17 means that the surfaces of the two rings 18; 19 pass into each other in two places 23 and 24. In practice, it has turned out that the surface joining between the elastomer and solid material is degraded by the hard treatment which the valve ring is subjected to, when it, between each casking, is cleaned with strong chemicals at high temperatures. The surface joining between the two materials can therefore not keep the two materials tightly joined together in the long run, and at the transitions 23 and 24, cracks can therefore be made which can lead to the valve becoming leak. The above-mentioned disadvantages of the conventional valve rings are eliminated by means of the specific structure of the valve ring according to the invention as shown in fig. 2, 3 and 4. This valve ring, also shown in fig. 1, consists of an elastomeric first ring 25, a solid second ring 26, and a solid third ring 27. The valve ring is made in the following way. The third ring 27, shown in fig. 2, is stamped out of a plate of e.g. stainless steel and is surfaced with a fixing agent. In the shown example, the ring is furthermore given a number of holes 28. In fig. 3, the third ring 27 is then embedded in the elastomer material of the first ring 25, said material can typically be rubber which is vulcanized. The elastomer on the two sides of the third ring is interconnected with elastomer material which forms a bridge through the holes 28 of the third ring for strengthening the bond between the first and third ring. In embedded condition, the inner marginal zone of the third ring is extending to the centre opening 13 of the valve ring. The second ring 26 is also stamped out of a plate of e.g. stainless steel. As shown in fig. 4, the second ring is then fixed onto the first ring 25, and in the shown case, with its inner marginal zone 30 beaded around the inner marginal zone 29 of the third ring in order to make the second ring be firmly fixed on the first ring. It is to be noticed that the valve ring 2, within the scope of the invention, also can be arranged so that the third ring is not extending freely into the centre opening 13 of the valve ring, and that the inner marginal zone of the second ring then merely is fixed into the elastomer material of the first ring. Now, the joint between the first and second ring is not due to surface joinings, as is the case in conventional valve rings, which can be degraded by chemicals and heat, but to a purely mechanical engagement which is indifferent to the chemicals and the intense heat used during the cleaning of the container and its valve between each casking. The second ring can preferably be fixed onto the first in such a way that the elastomer material is compressed at least at the inner and outer marginal zones 30 and 31 of the second ring. Thereby, the engagement between the two rings 25 and 26 is strengthened, by means of which the compressed elastomer material is tightened to the solid second ring. As shown in fig. 4, the tangents form, at the inner side of the second ring at its marginal zones, 30 and 31 respectively, an angle α which is smaller than 90°. Thereby, the second ring obtains to be interlocked in engagement with the first ring. When the engagement is interlocked in this way, the two rings 25 and 26 cannot or only by means of considerable tractive forces which do not occur in practice, be torn apart. In the embodiment of the valve ring according to the invention shown in fig. 2, 3 and 4, there is a third ring 27 ' which is embedded in the elastomer material of the first ring 25 and sealed at the inner marginal zone 29 by beading the inner marginal zone 30 of the second ring 26. The second and third ring, 26 and 27 respectively, perform in combination the same tasks as the solid ring 19 of the conventional valve ring 17, which has to both strengthen the elastomeric ring 18 and absorb the load of the spindle 16 of the coupling head when the valve is opened. In a second embodiment according to the invention, there is only the second ring 26 which then alone serves to strengthen the elastomeric first ring 25 and absorb the load of the spindle 16 when the valve is opened. This structure is especially simple and inexpensive. It has been mentioned above that the second ring is fixed onto the first ring while simultaneously compressing its elastomer material. To further secure the connection between the two rings, the second ring can advantageously be applied with a fixing agent and be stuck or vulcanized onto the first ring.

Claims: C l a i m s 1. A valve ring for closing a double valve of the kind used in a pressure container for distributing a liquid, e.g. beer, under pressure of a gas, e.g. CO 2 , and which in open condition has a gas passage around the valve ring and a liquid passage through the centre opening of the valve ring, characterized in that the valve ring comprises an elastomeric first ring and a solid second ring fixed on the outside of the first ring along a part of the surface of this ring. 2. A valve ring according to claim 1, characterized in that the second ring is fixed on the outside of the first ring along an area outside the active seal face of the valve ring. 3. A valve ring according to claim 1 or 2 , characterized in that the tangents to the inner side of the second ring - seen in cross section - at the inner and outer marginal zone respectively form an angle equal to or smaller than 90°. 4. A valve ring according to claim 1, 2 or 3 , characterized in that the elastomer material of the first ring is in a prestressed/compressed condition in an area comprising at least the areas beneath and/or at the marginal zones of the second ring. 5. A valve ring according to each of the claims 1 - 4, characterized in that it comprises a solid third ring which is, completely or partly, embedded in the first ring. 6. Valve ring according to each of the claims 1 - 5, characterized in that the inner marginal zone of the second ring is beaded around the inner marginal zone of the third ring. 7. A valve ring according to each of the claims 1 - 6, characterized in that the third ring has one or more through holes . 8. A valve ring according to each of the claims 1 - 7, characterized in that the first ring is made of an elastomer, such as rubber, and that the second and third ring are plate shaped and are made of a metallic material, such as stainless steel . 9. A method of manufacturing a valve ring for closing a double valve of the kind used in a pressure container for distributing a liquid, e.g. beer, under pressure of a gas, e.g. C0 2 , and which, in open condition, has a gas passage around the valve ring and a liquid passage through the centre opening of the valve ring, characterized in that - the first ring is cast of an elastomer material, such as rubber , the second ring is made of a metallic material, such as stainless steel, and the second ring is fixed onto the first ring at least partially compressing the elastomer material of this ring. 10. Method according to claim 9, where the valve ring comprises a solid third ring which is, completely or partly, embedded in the first ring, characterized in that - the third ring is made of a metallic material, such as stainless steel, a fixing agent is applied onto the third ring, the first ring is cast-in around the third ring of an elastomer material, such as rubber, the second ring is made of a metallic material, such as stainless steel, and the second ring is fixed onto the first ring, at least partially compressing the elastomer material of this ring and beading the inner marginal zone of the third ring.

Inventors: IPSEN BERNT, IPSEN, BERNT
Applicants: IPSEN BERNT, MICRO MATIC AS, IPSEN, BERNT, MICRO MATIC A/S
Application year: 1997
Main classification: B67D1
IPC codes: B67D1