WO2005012158A1

WO2005012158A1 - A spear valve with a blow-out preventing device

Info

Publication number: WO2005012158A1
Application number: PCT/DK2004/000515
Authority: WO
Inventors: Benny Dahl; Morten Larsen; Per Kurt Augustinus
Original assignee: Micro Matic A/S
Priority date: 2003-08-01
Filing date: 2004-07-29
Publication date: 2005-02-10

Abstract

The present invention relates to an extractor tube with a safety device to be used in an outlet opening of a beverage container, such as for instance a beer keg, in which the beverage is under pressure. The extractor tube comprises a skirt surrounding a down tube, an external pressure spring, at least one safety pawl designed in such a way that during operation of the beverage container it passes beyond the outlet opening, so that the safety pawl prevents the extractor tube from being ejected from the beverage container, and during removal of the extractor tube from the beverage container it lies mainly inside the skirt, as well as a locking plate fitted around the upper part of the down tube. The extractor tube is new and characterised in that the safety pawl is pivotally secured in the locking plate or in the skirt.

Description

A SPEAR VALVE WITH A BLOW-OUT PREVENTING DEVICE

Technical field of the invention The invention relates to an extractor tube with a safety arrangement used in an outlet opening of a beverage container, such as a beer keg in which the beverage may be under pressure. The extractor tube comprises a skirt which surrounds a down tube, which has an upper part with a larg-. diameter, said upper part is situated inside the skirt, a lower part with a small diameter, said lower part is situated outside the skirt, and a conical extension between the upper and lower parts, an external pressure spring arranged around the upper part of the down tube inside the skirt. Moreover the extractor tube comprises at least one safety pawl, which is designed such as during operation of the beverage container it passes beyond the outlet opening, so that the safety pawl prevents the extractor tube from being ejected from the beverage container, and during removal of the extrac- tor tube from the beverage container it lies mainly inside the skirt, and a locking plate arranged around the upper part of the down tube .

Background art of the invention Today many liquids are kept and dispensed in movable containers, such as beverages in kegs pressurized by a propelling gas. For this objective each container is provided with a valve arrangement with two passages, one for gas inlet and one for pressing the liquid out of the con- tainer by the gas pressure. This valve arrangement, in the following called an extractor tube, is normally arranged into a neck secured in an outlet opening in the container. The valve arrangement is often fitted in the con- tainer through a threaded part. But this embodiment can lead to serious damage during use, since it is possible to screw it out of the thread without complete degassing of the container, and so it will be ejected from the outlet opening at a high speed and force as soon as the threads are not mutually engaged. In addition, recent years have shown a general tendency towards the beverage suppliers' request for safety at higher and higher pressures (10 - 15 bar) , which again increases the risk of the valve arrangement being ejected at a big force during incorrect handling of the con- tainer. In order to prevent such disadvantages the technicians have provided the valve arrangements with safety devices that prevent the valve arrangements from being ejected from the container during unprofessional han- dling. These safety devices are widely different and rather complicated to produce, fit, use and dismantle. From EP 680 453, for instance, is known a safety arrangement for a valve insert of the type described in the introduction. However, the drawback of this valve insert is that it is difficult to assemble and dismantle, as it consists of several loose parts. In particular during disassembly of the valve insert, for example in connection with regular inspection and cleaning, the fitter can leave out or forget to fit the safety arrangement in the shape of the safety element into the valve insert . This can of course have serious consequences, since in that case there is no security at all during use. The next fitter who handles the containers with the valve insert will believe that the security is present, which obviously can be a false security.

Summary of the invention The object of the present invention is to provide an extractor tube with a safety arrangement which solves the above mentioned disadvantages and problems related with the prior art . An additional object is to provide an extractor tube which cannot be fitted without the safety arrangement. Another object of the present invention is to provide an extractor tube, which can easily be incorporated into existing conventional containers. The extractor tube is new and characterised in that the safety pawl is pivotally secured in the locking plate or in the skirt . Hereby is obtained a simple design of the safety ar- rangement, wherein the safety pawl is pivotally secured in the locking plate or the skirt, leaving the extractor tube with a permanent security during disassembly and assembly, seeing that it is not possible to fit the safety pawl wrongly, and it will never disappear. The term "secured" means that the safety pawl cannot be separated from the locking plate or the skirt, i.e. although a separate element it is still an integrated part of the locking plate or the skirt . According to a first embodiment of the invention the safety pawl may be secured in the skirt by a snap fixation. In a preferred embodiment of the invention the pressure spring may abut a plurality of spring supports, which are arranged in connection with a deactivation ele- ment, which are arranged around the upper part of the down tube. Hereby is obtained that the pressure spring with its upper end through the spring supports and the deactivation element exerts a force on a sealing element. Furthermore the spring supports define a room on top of the pressure spring, in which it is possible for the safety pawl to enter, for instance during removal of the extractor tube from the beverage container. Advantageously the deactivation element may comprise at least one safety pawl releaser. The operation of which is described in details in connection with the drawings. Furthermore the deactivation element may comprise a guiding part for guidance of the deactivation element during assembly/dismantling. According to a preferred embodiment of the invention the safety pawl is arranged with a spring force that affects the safety pawl such as it is kept in the safety position outside the skirt. This ensures permanent safety for the extractor tube in a suitable way, and an additional operation (for instance with a special tool) will be required to remove the safety. This increases the security of the extractor tube. The safety pawl may advantageously be made of spring steel . According to another embodiment of the invention the safety pawl may project essentially vertically through a recess of the locking plate, and the pressure spring at its lower end may abut the safety pawl, so that the safety pawl utilizes the spring effect of the pressure spring during use. When fitted, the extractor tube now utilizes the spring force of the pressure spring to force the safety pawl out into safety position. According to a preferred embodiment at least one projection may be arranged on the safety pawl at each side of the locking plate. Thus ensuring in a simple way that the safety pawl is secured in the recess of the locking plate, and it cannot be removed from the locking plate by unauthorized handling. In order to take higher pressures in the beverage container three safety pawls may advantageously be ar- ranged, substantially equally spaced along the circumference of the skirt or the locking plate. Thus ensuring that the safety arrangement may absorb the increasingly higher pressures in the beverage containers . In another advantageous embodiment of the invention the safety pawl may be pivotally connected to the locking plate or the skirt by a hinge. Brief description of the drawings The invention is described in details below with reference to particularly preferred embodiments and drawing wherein Fig. 1 shows an extractor tube with a safety arrangement in a second embodiment of the invention partly in section, Fig. 2 shows an extractor tube according to the invention, in which the skirt has been removed, Figs. 3 and 4 show fitting of the skirt on the other elements of the extractor tube, Fig. 5 shows an extractor tube with a safety device according to a first embodiment of the invention partly in section, Fig. 6 shows an enlarged area of the area E indicated in Fig. 5, Fig. 7 shows an embodiment of the deactivation element according to the invention, Fig. 8 shows an extractor tube according to the in- vention seen from the top, Fig. 9 shows a sectional view of the extractor tube from Fig. 8 taken along cut A-A, Fig. 10 shows an embodiment of a locking plate, and Fig. 11 shows an embodiment of a safety pawl accord- ing to the invention. All figures are highly schematised and not necessarily to measures, and they only illustrate the parts required to visualize the invention, while the remaining parts have been left out or are only indicated. The same reference number is used in all figures for identical or matching details.

Detailed description of the invention Fig. 1 shows an extractor tube 1 in a second embodi- ment of the invention partly shown in section. Extractor tube 1 comprises a skirt 2 surrounding a down tube 3 that has an upper part 4 with a large diameter, said upper part 4 is situated inside the skirt 2, a lower part 5 with a small diameter, said lower part 5 is situated outside the skirt 2, and a conical extension 6 between upper part 4 and lower part 5. Furthermore an external pressure spring 7 is arranged around the upper part 4 of the down tube 3 inside the skirt 2. At its upper end the pressure spring 7 abuts a sealing element 8. In this embodiment the pressure spring 7 is shown as a helical spring. In the shown embodiment two safety pawls 10 will be seen. The idea of the invention is that any number of safety pawls may be fitted, but minimum one. The safety pawl 10 is designed in such a way that during operation of the beverage container (not shown) it passes beyond the outlet opening (not shown) , so that the safety pawl 10 prevents the extractor tube 1 from being ejected from the beverage container, and during removal of extractor tube 1 from the beverage container it mainly lies within the skirt. The functioning of the safety pawls 10 is de- scribed in details below. In this embodiment of the invention the safety pawl 10 is designed as a triple angle piece, so that the safety pawl 10 consists of a projecting flap 10a, first middle part 10b and another middle part 10c as well as an internal projection lOd. The angle α between the projecting flap 10a and the first middle part 10b of the safety pawl 10 exceeds 90°. The first middle part 10b is preferably essentially horizontal, so it is of major importance that the angle α is bigger than 90°, since the effect of a smaller angle would be that the projecting flap 10a of the safety pawl 10 will not project past the skirt 2 during operation of the extractor tube 1, with consequent lack of safety for the extractor tube. It has proved advantageous if the an- gle α lies between 95° and 135°, so that during operation the projecting flap 10a can protrude past the skirt 2, and during disassembly it can be inside the skirt 2. Consequently it is vital according to the invention that sequently it is vital according to the invention that the angle α is not too big, since in that case the safety pawl 10 will not be able to function. In addition the extractor tube 1 comprises a locking plate 11 arranged around upper part 4 of the down tube 3. According to this embodiment the safety pawl 10 projects essentially vertically through a recess of the locking plate 11, and at the same time the safety pawl 10 is pivotally secured into the locking plate 11. This se- curing of the safety pawl 10 will be explained later in connection with Fig. 2. At its lower end the pressure spring 7 abuts the first middle part 10b of the safety pawl 10. Consequently the safety pawl 10 utilizes the spring effect of the pressure spring 7 during use. In other words, this spring fixation of the safety pawl 10 functions as a hinged joint during relocation of the safety pawl. And during operation of the safety arrangement the spring fixation of the safety pawls will provide locking of the first middle part 10b of safety pawl 10 towards the bottom of a recess 12 in the skirt 2, while at the same time the locking plate 11 also presses against the skirt 2. Peak load during use caused by the high pressure in the beverage container will be reduced when the locking plate 11 and the safety pawl 10, respectively, go downwards in an elastic movement, before the skirt 2 absorbs the full loading from the pressure in the beverage container. This ensures that the safety arrangement can absorb a higher pressure in the beverage container than the known safety arrangements . In particular if the safety device comprises three safety pawls 10, the external pressure spring 7 provides a good support, which pressure spring extends around the upper part of the down tube 3, and abuts with all the safety pawls 1. Hereby the pressure spring does not "tilt" during loading with subsequent wedging. Furthermore it is vital that the safety pawls 10 are made of a material which may absorb big pressure forces without deformation, such as for instance metal. Fig. 2 shows the extractor tube 1 without the skirt. In this embodiment of the invention an example of the securing of the safety pawls 10 on the locking plate 11 is shown. Two projections 13, 14 have been arranged on the safety pawls 10 at each side of the locking plate 11. These projections 13, 14 ensure that the safety pawls 10 are secured to the locking plate, since the projections 13 and 14 are protruding further than the recesses of locking plate 11, which they are projecting through. The projections 13 and 14 are now locking the safety pawl vertically, thus preventing disassembly and removal from the locking plate 11. Pivoting is ensured through the recesses of the locking plate 11 at each side of the safety pawls 10 designed with a small play, thus enabling the safety pawls 10 to move a little in the recesses. In another not shown embodiment of the invention the safety pawls 10 may be pivotally secured to the locking plate 11 by a hinge. Fig. 2 shows clearly that the pressure spring 7 abuts safety pawls 10, and thereby dividing the spring force evenly through projections 13 on the safety pawls 10 down to the locking plate 11. Figs. 3 and 4 show fitting of the skirt 2 to the other elements of the extractor tube 1. The skirt 2 is here shown with several recesses. Recess 12 is meant to hold the protruding flap of the safety pawl, and is arranged such as there is sufficient room for the flap to move without hitting the very skirt 2. The other shown recess 15 is intended for flow of the beverage, ensuring that the right amount of liquid flows to the extractor tube. Fig. 3 shows how the protruding flaps 10a of the safety pawls 10 are pressed towards pressure spring 7, so that the skirt 2 can be led down over them, which is visualized more clearly in Fig. 4. It is also evident from Figs. 3 and 4 that the internal projection lOd of the safety pawls 10 are lifted out from the down tube 3. Consequently, the length of these projections lOd must not be too big, seeing that too big length will prevent the protruding flap 10a from extending beyond the skirt 2. In order to finally fix the locking plate 11 in the skirt 2 a special tool is required (not shown) . With this tool the fitter pushes at the underside of the locking plate 11, so that the safety pawl 10 presses the pressure spring 7 upwards into the skirt 2. One or several projections on the locking plate (not shown) is now led up into one or several grooves 16 or recesses in the skirt 2. After a little while the locking plate 11 can be turned into a horizontal groove 17 of the skirt 2, which also has a projection. When the projection of the locking plate 11 has been turned completely into the horizontal groove 17, the loading on the special tool is removed, and through the spring force of the pressure spring 7 the projection of locking plate 11 is pressed down through the recess with subsequent fixation in the skirt 2. The same method is used in reverse order for disassembly of the extractor tube 1. During operation of the beverage container the safety arrangement of the extractor tube 1 is in use. In this situation the protruding flaps of the safety pawls 10 are extending beyond the skirt, and so the safety pawls 10 will be able to prevent the extractor tube from being ejected from the container in case of unauthorised handling. In this situation the conical extension 6 of the down tube 3 is located a little above the internal projection lOd of the safety pawl 10. During operation, i.e. when the liquid in the container shall be portioned out, the down tube moves downwards to allow the liquid to pass. So during operation the opening displacement of the down tube made through a normal dispense head fitted on the extractor tube is smaller than the distance between the conical extension 6 on the down tube 3 and the internal projection lOd of the safety pawl 10. For disassembly of the extractor tube 1 a special dismounting tool is required. By this dismounting tool the conical extension 6 of the down tube 3 is pressed downwards until it hits and now forces the internal projection lOd of the safety pawl 10 out. Now the protruding flap 10a of the safety pawl 10 swings into the recess 12 of the skirt 2, and it disappears completely behind the skirt. After that it is possible in a simple way to screw the extractor tube out of the container when the container or the extractor tube needs cleaning or the con- tainer needs refilling. Fig. 5 shows another embodiment of the extractor tube 21 of the invention, partly shown in section. Basically the extractor tube 21 is built up in the same way as the extractor tube 1 described above in connection with Fig. 1 - 4, so no further details will be described here . In this embodiment the extractor tube 21 comprises a deactivation element 50, placed between the sealing element 8 and the pressure spring 7. The very design of the deactivation element 50 will be described in details in connection with Fig. 7, but the function of the deactivation element is shown in connection with Fig. 6 and will also be described later. In addition Fig. 5 shows the skirt 22 in which the safety pawl 30 is pivotally secured. The left part of Fig. 5 shows the skirt 22 seen from outside. The right part shows a cut of the extractor tube, from which the securing of the safety pawl 30 clearly appears. In this embodiment the safety pawl 30 is secured through a snap fixture. By "snap fixture" is meant that the safety pawl 30 is made of for instance spring steel, and designed with a certain inherent flexibility, which allows snap location between two recesses of the skirt 22. Furthermore, the safety pawl 30 holds a spring force that affects the safety pawl 30 in such a way that it is kept in the safety position outside the skirt 22, as shown in Fig. 5. The very design of the safety pawl 30 will be described in details in connection with Fig. 11. Fig. 5 shows an encircled area E around the upper part of the safety pawl 30, enlargement of which can be seen in Fig. 6, showing deactivation of the safety pawl 30. The deactivation element (not shown) comprises at least one safety pawl releaser 51, adjusted for internal engagement, i.e. it moves down between the inner side of the skirt 22 and the safety pawl 30, with the upper part of the safety pawl 30. The longer the safety pawl re- leaser 51 moves downwards, the more the upper part of the safety pawl 30 is forced into the skirt 22, thus following the part of the safety pawl placed outside the skirt also into a recess of the skirt with consequent deactivation of the safety arrangement, after which it is possible to remove the extractor tube from the beverage container in the usual way. This downwards displacement of the safety pawl re- leaser 51 may be made for instance with a special dismounting tool in the same way as described above. Fig. 7 shows an embodiment of the deactivation element 50 seen in perspective. In this execution the deactivation element is shaped as a ring, adjusted to fit around the upper part of the down tube. The deactivation element 50 comprises three safety pawl releasers 51 and three spring supports 52, almost equally spaced around the circumference of the element 50. From this figure it is evident that there is a dis- tance, i.e. a room, between the spring supports 52 and the ring itself 54. This room is made in such a way that the upper part of the safety pawl has sufficient space for being displaced towards the down tube. In other words : The room appears on top of the pressure spring by placing the spring supports 52 at some distance from the ring 54. Furthermore the spring supports 52 transfer the spring force from the pressure spring to the sealing element via the ring 54. Another point is that a good support of the external pressure spring 7 is achieved when the deactivation element comprises three spring supports 52, seeing that in this situation the pressure spring 7 will not "tilt" during loading with subsequent wedging, at the same time providing an even and uniform force along the whole circumference of the sealing element. Advantageously for the safety pawl releasers 51 are shaped with a slope out and away from the very ring 54. One aspect is that the end of the safety pawl releaser will more easily engage with the upper part of the safety pawl, another that the slope will force the safety pawl more quickly inwards during the downward movement of the safety pawl releaser. In addition the ingoing movement of the upper part of the safety pawl is achieved with a smaller movement of the sloping safety pawl releaser. In addition, one spring support is illustrated on a guiding part 53. Guiding part 53 is used for assembly and disassembly of the extractor tube. For instance during assembly of this embodiment the deactivation element is placed at first around the upper part of the down tube, after which the pressure spring is placed in such a way that it rests on the spring supports of the deactivation element. Furthermore the pressure spring lies on the inner side of the guiding part. Now the locking plate is placed around the down tube, and at the same time the guiding part is placed at a recess (not shown) of the locking plate. After this all parts are placed inside the skirt, and with a special tool the fitter can press the locking plate, so that the pressure spring is compressed, and projection on the locking plate can be engaged with recesses of the skirt as described above for the embodiment shown in Fig. 1 - 4. Simultaneously with the projection of the locking plate getting in engagement with the skirt, for instance in order to achieve a bayonet locking, the deactivation element is also turned by means of the guiding part, so that the safety pawl releasers are placed into position exactly above the upper parts of the safety pawls. Disassembly is made in reverse order. If one of the parts is left out or forgotten during assembly of the extractor tube, such as for instance the deactivation element, the secured safety pawls in the skirt will provide the required safety, so the safety will always be present. However, in this situation it will be difficult, not to say impossible to remove the extractor tube from the container. Another point is that if the deactivation element is missing, it will not be possible to compress the pressure spring owing to the longer distance between the locking plate and the sealing element with consequent malfunction of the extractor tube . Fig. 8 shows the extractor tube 21 seen from above. Section A-A in Fig. 8 is shown in Fig. 9, where the inner side of the skirt 22 is shown. Furthermore it appears clearly from Fig. 9 how the safety pawl 30 is secured to the skirt 22. Fig. 10 shows an embodiment of the locking plate 31 seen in perspective. In this embodiment the locking plate 31 is designed such as parts 33 of the plate will be placed below the skirt when fitted, in order to achieve better flow properties of the beverage during filling into the container. Furthermore this design allows the special tool for assembly and disassembly to engage with the plate 31 to make it turnable . Fig. 11 shows an embodiment of the safety pawl 30 seen in perspective. The safety pawl 30 is preferably made of spring steel and it comprises three parts. The first upper part 41, which is arranged to extend up to the inner side of the skirt. The end of the upper part 41 is angled a little (a better view appears from the enlarged part in Fig. 6) to provide space for the safety pawl releaser. The passage 42 between the upper part 41 and the middle part 43 is substantially horizontal, and this surface 42 will hit the outlet opening, if the safety device comes into use. The middle part 43 comprises also two flanges 44 in its prolongation, and the safety pawl 30 is consequently strengthened considerably, and thus able to absorb a big force. The lower area 45 of the middle part is adjusted to get engaged with a groove in the skirt and is in close contact with the skirt, allowing transfer of a potential force from the safety pawl 30 to the skirt. The lower part 46 of the safety pawl 30 provides both the snap fixation to the skirt and the inherent spring force in the safety pawl that affects the middle part of the safety pawl, so that it stays in the safety position outside the skirt. Like the embodiment described above the safety pawl can be secured pivotally by a hinge. A common feature for the embodiments described is that they can easily be incorporated in existing ordinary extractor tubes, if improved safety is wanted. This is carried out by exchanging the individual parts during service operations or cleaning. This is an easy way to upgrade safety of older extractor tubes that might be used in connection with beverage containers, where safety for higher pressures (10 - 15 bars) is required. Furthermore we have seen from tests with containers exposed to 10 bar pressure that the safety arrangements of the invention could be used at least 10 times without losing the safety function of the extractor tube. Furthermore the invention relates to a skirt for an extractor tube, said skirt comprising at least one safety pawl that is pivotally secured in the skirt. The invention also relates to a locking plate for an extractor tube, said locking plate comprising at least one safety pawl that is pivotally secured in the locking plate . Even if the invention has been described in connection with preferred embodiments of the invention, it is obvious to a skilled person that more modifications and improvements would be possible without deviating from the idea of the invention that is defined by the following claims.

Claims

Patent claims

1. An extractor tube (1, 21) with a safety arrangement used in an outlet opening of a beverage container, such as a beer keg, wherein the beverage is under pressure, said extractor tube (1, 21) comprises a skirt (2, 22) which surrounds a down tube (3) , which has an upper part (4) with a large diameter, said upper part (4) is situated inside the skirt (2, 22), a lower part (5) with a small diameter, said lower part (5) is situated outside the skirt (2, 22), and a conical extension (6) between the upper part (4) and the lower part (5) ; an external pressure spring (7) arranged around the upper part (4) of the down tube (3) inside the skirt (2, 22), at least one safety pawl (10, 30), designed such as during operation of the beverage container it extends beyond the outlet opening, so that the safety pawl (10, 30) prevents the extractor tube (1, 21) from being ejected from the beverage container, and during removal of the extractor tube (1, 21) from the beverage container it lies mainly inside the skirt (2, 22); and a locking plate (11, 31) arranged around the upper part (4) of the down tube (3); characterised in that said safety pawl (10, 30) is pivotally fixed in the locking plate (11) or in the skirt (22) .

2. An extractor tube according to claim 1, wherein the safety pawl (30) is secured in the skirt (22) by a snap fixation. 3. An extractor tube according to claim 1 or 2 , wherein the pressure spring (7) abuts a plurality of spring supports (52) , which are arranged in connection with a deactivation element (50) , which are arranged around the upper part of the down tube (3) .

4. An extractor tube according to claim 3, wherein the deactivation element (50) further comprises at least one safety pawl releaser (51) . 5. An extractor tube according to claim 3 or 4 , wherein the deactivation element (50) comprises a guiding part (53) .

6. An extractor tube according to any one of the preceding claims, wherein the safety pawl (30) is arranged with a spring force that affects the safety pawl (30) such as it is kept in the safety position outside the skirt (22) . . An extractor tube according to claim 6, wherein the safety pawl (30) is made of spring steel.

8. An extractor tube according to claim 1, wherein the safety pawl (10) essentially projects vertically through a recess of the locking plate (11) , and the pressure spring (7) at its lower end abuts the safety pawl (10) , so that the safety pawl (10) utilizes the spring effect of the pressure spring during use. 9. An extractor tube according to claim 8, wherein at least one projection (13, 14) of the safety pawl (10) is arranged at each side of the locking plate (11) .

10. An extractor tube according to any one of the preceding claims, wherein three safety pawls (10, 30), substantially equally spaced around the circumference of the skirt (22) or the locking plate (11) .

11. An extractor tube according to claim 1, wherein the safety pawl (10, 30) is pivotally connected to the locking plate (11) or the skirt (22) by a hinge.

12. A skirt (22) for the extractor tube according to claims 1 - 7, characterised in that the skirt (22) comprises at least one safety pawl (30) pivotally secured in the skirt (22) .

13. A locking plate for the extractor tube according to claims 8 - 9, characterised in that the locking plate (11) comprises at least one safety pawl (10) pivotally secured in the locking plate (11) .