Taps for controlling liquid flow

1. A tap ( 10 ) for controlling liquid flow having a tube ( 14 ) with first ( 16 ) and second ( 18 ) opposite open ends, an inlet opening ( 20 ) leading into the tube between the first and second open ends, an outlet opening ( 16 ) defined by the first open end ( 16 ), which outlet opening ( 16 ) serves as an outlet from the tube ( 14 ), the tap ( 10 ) being characterized thereby that it is adapted for use in bag-in-box containers containing consumable liquids and that it includes a first valve seat ( 36 ) formed between the inlet opening ( 20 ) and the outlet opening ( 16 ); a second valve seat ( 38 ) formed between the inlet opening ( 20 ) and the second open end ( 18 ); a closure member ( 42 ) sealingly slidably movable in the tube ( 14 ); a first circumferential sealing edge ( 60 ) provided on and integrally formed with the closure member ( 42 ), the first sealing edge ( 60 ) being adapted to removably abut against the first valve seat ( 36 ); and a second circumferential sealing edge ( 66 ) provided on and integrally formed with the closure member ( 42 ), the second sealing edge ( 66 ) being adapted to removably abut against the second valve seat ( 38 ).

2. A tap as claimed in claim 1 , characterized thereby that the closure member ( 42 ) is displaceable internally along the tube ( 14 ) to cause the first sealing edge ( 60 ) to move across the inlet opening ( 20 ) from between a first or closed position, in which the first sealing edge ( 60 ) of the closure member ( 42 ) cooperates with the first valve seat ( 36 ) to close off the inlet opening ( 20 ) from the outlet opening ( 16 ) and the second sealing edge ( 66 ) cooperates with the second valve seat ( 38 ), into a second or open position in which the first ( 60 ) and second ( 66 ) sealing edges are spaced away from the first ( 36 ) and second ( 38 ) valve seats to permit liquid flow through the inlet opening ( 20 ) into the tube ( 14 ) and out through the outlet opening ( 16 ), and for closure of the outlet opening ( 16 ) the reverse procedure taking place to cause the closure member ( 42 ) to be moved back into the first or closed position.

3. A tap as claimed in claim 1 , characterized thereby that the first valve seat ( 36 ) and the first sealing edge ( 60 ) are adapted to deflect the closure member ( 42 ) outwardly against the tube ( 14 ), when the closure member ( 42 ) is in the closed position.

4. A tap as claimed in claim 1 , characterized thereby that the first ( 36 ) and second ( 38 ) valve seats are convexly curved.

5. A tap as claimed in claim 1 , characterized thereby that the first valve seat ( 36 ) is provided with a convexly curved circumferential protuberance ( 64 ) extending approximately half-way across the first valve seat ( 36 ).

6. A tap as claimed in claim 5 , characterized thereby that the protuberance ( 64 ) is spaced away from an inner wall ( 30 ) of the tube ( 14 ).

7. A tap as claimed in claim 1 , characterized thereby that the first ( 60 ) and second ( 66 ) sealing edges are convexly curved.

8. A tap as claimed in claim 1 , characterized thereby that the first sealing edge ( 60 ) is provided with a convexly curved circumferential protuberance ( 62 ) extending approximately half-way across the first sealing edge ( 60 ).

9. A tap as claimed in claim 8 , characterized thereby that the protuberance ( 62 ) is located near to an outer wall ( 52 ) of the closure member ( 42 ).

10. A tap as claimed in claim 1 , characterized thereby that the first ( 60 ) and second ( 66 ) sealing edges are adapted to have a small contact area with the first ( 36 ) and second ( 38 ) valve seats respectively.

11. A tap as claimed in claim 1 , characterized thereby that the closure member ( 42 ) and the tube ( 14 ) are both resilient, but that the closure member ( 42 ) is less resilient to deformation than the tube ( 14 ).

12. A tap as claimed in claim 1 , characterized thereby that a skirt ( 61 ) extends from the first sealing edge ( 60 ) of the closure member ( 42 ) towards the open end ( 16 ).

13. A tap as claimed in claim 12 , characterized thereby that the skirt ( 61 ) is adapted to be in flush contact with a section ( 30 . 1 ) of the inner wall ( 30 ) of the tube ( 14 ) when the closure member ( 42 ) is in a closed position.

14. A tap as claimed in claim 1 , characterized thereby that the closure member ( 42 ) forms part of a plunger knob ( 40 ).

15. A tap as claimed in claim 1 , characterized thereby that it includes guiding means ( 32 , 34 , 48 , 50 ) for rotatably guiding the plunger knob ( 40 ) along a spiral path.

16. A tap as claimed in claim 15 , characterized thereby that the guiding means ( 32 , 34 , 48 , 50 ) includes at least one spiral groove ( 32 , 34 ) in the tube ( 14 ) and at least one protrusion ( 48 , 50 ) from the plunger knob ( 40 ) slidingly engaged in the spiral groove(s) ( 32 , 34 ).

17. A tap ( 10 ) for controlling liquid flow having a tube ( 14 ) with first ( 16 ) and second ( 18 ) opposite open ends, an inlet opening ( 20 ) leading into the tube ( 14 ) between the first ( 16 ) and second ( 18 ) open ends, an outlet opening ( 16 ) defined by the first open end ( 16 ), which outlet opening ( 16 ) serves as an outlet from the tube ( 14 ), the tap ( 10 ) being characterized thereby that it includes a valve seat ( 36 ) formed between the inlet opening ( 20 ) and the outlet opening ( 16 ); a closure member ( 42 ) sealingly slidably movable in the tube ( 14 ); a circumferential sealing edge ( 60 ) provided on the closure member ( 42 ), the sealing edge ( 60 ) being adapted to removably abut against the valve seat ( 36 ); and the valve seat ( 36 ) and the sealing edge ( 60 ) being adapted to deflect the closure member ( 42 ) outwardly against the tube ( 14 ), when the closure member ( 42 ) is in a closed position.

18. A tap as claimed in claim 17 , characterized thereby that the closure member ( 42 ) is displaceable internally along the tube ( 14 ) to cause the sealing edge ( 60 ) to move across the inlet opening ( 20 ) from between a first or closed position, in which the sealing edge ( 60 ) of the closure member ( 42 ) cooperates with the valve seat ( 36 ) to close off the inlet opening ( 20 ) from the outlet opening ( 16 ), into a second or open position in which the sealing edge ( 60 ) is spaced away from the valve seat ( 36 ) to permit liquid flow through the inlet opening ( 20 ) into the tube ( 14 ) and out through the outlet opening ( 16 ), and for closure of the outlet opening ( 16 ) the reverse procedure taking place to cause the closure member ( 42 ) to be moved back into the first or closed position.

19. A tap as claimed in claim 17 , characterized thereby that it includes a second valve seat ( 38 ) formed between the inlet opening ( 20 ) and the second open end ( 18 ) and a second circumferential sealing edge ( 66 ) provided on the closure member ( 42 ) being adapted to removably abut against the second valve seat ( 38 ).

20. A tap as claimed in claim 19 , characterized thereby that the first ( 36 ) and second ( 38 ) valve seats are convexly curved.

21. A tap as claimed in claim 17 , characterized thereby that the first valve seat ( 36 ) is provided with a convexly curved circumferential protuberance ( 64 ) extending approximately half-way across the first valve seat ( 36 ).

22. A tap as claimed in claim 21 , characterized thereby that the protuberance ( 64 ) is spaced away from an inner wall ( 30 ) of the tube ( 14 ).

23. A tap as claimed in claim 19 , characterized thereby that the first ( 60 ) and second ( 66 ) sealing edges are convexly curved.

24. A tap as claimed in claim 17 , characterized thereby that the first sealing edge ( 60 ) is provided with a convexly curved circumferential protuberance ( 62 ) extending approximately half-way across the first sealing edge ( 60 ).

25. A tap as claimed in claim 24 , characterized thereby that the protuberance ( 62 ) is located near to an outer wall ( 52 ) of the closure member ( 42 ).

26. A tap as claimed in claim 19 , characterized thereby that the first ( 60 ) and second ( 66 ) sealing edges are adapted to have a small contact area with the first ( 36 ) and second ( 38 ) valve seats respectively.

27. A tap as claimed in claim 17 , characterized thereby that the closure member ( 42 ) and the tube ( 14 ) are both resilient, but that the closure member ( 42 ) is less resilient to deformation than the tube ( 14 ).

28. A tap as claimed in claim 17 , characterized thereby that a skirt ( 61 ) extends from the first sealing edge ( 60 ) of the closure member ( 42 ) towards the open end ( 16 ).

29. A tap as claimed in claim 28 , characterized thereby that the skirt ( 61 ) is adapted to be in flush contact with a section ( 30 . 1 ) of the inner wall ( 30 ) of the tube ( 14 ) when the closure member ( 42 ) is in a closed position.

30. A tap as claimed in claim 17 , characterized thereby that the closure member ( 42 ) forms part of a plunger knob ( 40 ).

31. A tap as claimed in claim 17 , characterized thereby that it includes guiding means ( 32 , 34 , 48 , 50 ) for rotatably guiding the plunger knob ( 40 ) along a spiral path.

32. A tap as claimed in claim 31 , characterized thereby that the guiding means ( 32 , 34 , 48 , 50 ) includes at least one spiral groove ( 32 , 34 ) in the tube ( 14 ) and at least one protrusion ( 48 , 50 ) from the plunger knob ( 40 ) slidingly engaged in the spiral groove(s) ( 32 , 34 ).