Liquid source switch-over device

1. A liquid source switch-over device comprising:

a valve chamber having first and second inlets in communication with first and second sources of liquid and having an outlet;

a valve member disposed within the valve chamber and being moveable from a first position in which communication between the first inlet and the outlet is promoted and communication between the second inlet and the outlet is inhibited, to a second position in which communication between the second inlet and the outlet is promoted and communication between the first inlet and the outlet is inhibited; and

a catch apparatus shaped to inhibit displacement of the valve member when the catch apparatus is in fluid communication with the liquid from one of the sources of liquid.

2. The device as claimed in claim 1 wherein the catch apparatus is shaped inhibit displacement of the valve member from the first position thereof when the catch apparatus is in fluid communication with the liquid from the first source of liquid.

3. The device as claimed in claim 1 wherein the catch apparatus is shaped inhibit displacement of the valve member from the second position thereof when the catch apparatus is in fluid communication with the liquid from the second source of liquid.

4. The device as claimed in claim 1 wherein the catch apparatus is resiliently-biased to remain free from the valve member.

5. The device as claimed in claim 1 wherein the catch apparatus is resiliently-biased to remain free from the valve member when communication between the catch apparatus and the liquid from the first and second sources of liquid is inhibited.

6. The device as claimed in claim 1 wherein the catch apparatus includes a catch disposed within the valve chamber and biased to abut the valve member when the catch is in fluid communication with the liquid from one of the sources of liquid.

7. The device as claimed in claim 6 wherein the valve member includes spaced-apart first and second recesses, with the catch engaging the first recess when the valve member is in the first position and the catch engaging the second recess when the valve member is in the second position.

8. The device as claimed in claim 7 wherein the catch and the recesses are triangular in part in side section and wherein the recesses are v-shaped in side section.

9. The device as claimed in claim 6 further including a piston coupled to the catch, said one of the sources of liquid exerting pressure on said piston and causing the catch to abut the valve member when the piston is in fluid communication with said one of the sources of liquid.

10. The device as claimed in claim 1 wherein the catch apparatus includes a hold-down piston.

11. The device as claimed in claim 10 wherein the piston has a cross-sectional area that is equal to or greater than twice that of the valve member.

12. The device as claimed in claim 10 wherein the piston has a cross-sectional area that is equal to or greater than three times that of the valve member.

13. The device as claimed in claim 1 further including a float member, whereby when the first source of liquid is depleted, the float member lowers and inhibits communication between the first source of liquid and the valve chamber, and the valve member moves to the second position thereby.

14. The device as claimed in claim 1 , the sources of liquid being pressurized, wherein the device includes first and second float chambers in fluid communication with the first inlet and the second inlet, respectively, and wherein the device further includes first and second float members disposed within respective ones of the float chambers, whereby,

when the first source of liquid is depleted, the first float member abuts a float seat of the first float chamber and inhibits communication between the first source of liquid and the valve chamber, and pressure from the second source of liquid causes the valve member to move to the second position of the valve member thereafter, and

when the first source of liquid is replenished and the second source of liquid is depleted, the second float member abuts a float seat of the second float chamber and inhibits communication between the second source of liquid and the valve chamber, and pressure from the first source of liquid causes the valve member to move to the first position of the valve member thereafter.

15. The device as claimed in claim 1 wherein the first source of liquid and the second source of liquid are pressurized.

16. The device as claimed in claim 1 , further including the first and second sources of liquid, wherein the first and second sources of liquid comprise pressurized beer.

17. A valve assembly comprising:

a valve member moveable within the valve assembly along a first longitudinal axis, shaped to both enable communication between a first inlet and an outlet of the valve assembly and inhibit communication between a second inlet and the outlet when in a first position, and shaped to both enable communication between the second inlet and the outlet and inhibit communication between the first inlet and the outlet when in a second position; and

a catch apparatus moveable within the valve assembly along a second longitudinal axis and shaped to inhibit movement of the valve member when the catch apparatus is in communication with flowable material flowing through one of the inlets.

18. The valve assembly as claimed in claim 17 wherein the first longitudinal axis thereof extends in perpendicular to the second longitudinal axis thereof.

19. The device as claimed in claim 17 , further including a wall mount for the valve assembly, the valve assembly including a pair of conduits each having a lower portion and an upper portion coupled thereto, the lower portions of the conduits having cross-sectional areas smaller than cross-sectional areas of the upper portions of the conduits, and the wall mount comprising: a base connectable to a wall, the base having a pair of spaced-apart recesses each shaped to receive a respective one of the lower portions of the conduits, with the upper portions of the conduits abutting the base thereafter; and a pair of resilient members coupled to and extending outwards from the base, each of the resilient members being biased towards and abutable against a respective one of the lower portions of the conduits.

20. A valve assembly having a first inlet connectable to a first source of flowable material, having a second inlet connectable to a second source of flowable material and having an outlet, the device comprising:

a switching cylinder in fluid communication with the inlets;

a spool moveable within the switching cylinder, whereby pressure differences between the sources of flowable material position the spool in a first position that promotes flow of flowable material from a first one of the sources through a first one of the inlets and to the outlet; and

a catch apparatus in fluid communication in part with the outlet and which, when in communication with the flowable material from said first one of the sources, inhibits movement of the spool,

whereby when said first one of the sources is depleted, the switching cylinder is depressurized at said first one of the inlets and said outlet, thereby releasing the catch apparatus, and

pressure of flowable material from a second one of the sources at said second one of the inlets causes the spool to move thereafter to a second position that promotes flow of the flowable material from the second one of the sources through a second one of the inlets and to the outlet, with the catch apparatus now in communication with the flowable material from said second one of the sources and inhibiting movement of the spool once more.