Non-reopening locking pinch clamp for tubing

1. A tube clamp having:

first and second opposed jaws joined by a first hinge,

the jaws movable between open and closed positions, the tube clamp adapted to attach to a flexible plastic tube so that the tube passes between the jaws, whereby the flow of fluid through the tube is permitted when the jaws are open but is blocked when the jaws are brought together to the closed position to pinch closed the tube there-between, and

locking mechanism to effect substantially permanent and irreversible locking of the jaws in the closed position, the locking mechanism comprising:

a stud on the first jaw comprising a post and a head comprising two arms extending sideways from the post in opposite directions, and

a corresponding aperture on the second jaw positioned and adapted to accept the stud, the aperture located in a first wall having a proximal side facing the first jaw,

and being proportioned so that the head of the stud can be forced through the aperture from proximal side by deflecting, bending or folding the two arms inwards towards the post of the stud and so that, after passing through the aperture the two arms spring irreversibly outwards and overlay the distal side of the first wall to lock the jaws together.

2. A tube clamp as claimed in claim 1 including a guard adjacent the aperture on its distal side that prevents or limits access to the head when the clamp is in the closed position.

3. A tube clamp as claimed in claim 1 wherein the distal side of the aperture is surrounded or substantially surrounded by an upstanding second wall.

4. A tube clamp as claimed in claim 3 wherein, in the closed position, the two arms engage the second wall.

5. A tube clamp as claimed in claim 1 wherein the aperture is located in a base of a recess on the distal side of the second jaw.

6. A tube clamp as claimed in claim 5 , wherein the recess has a side wall or walls, and wherein in the closed position, the two arms engage the side wall or walls of the recess.

7. A tube clamp as claimed in claim 5 wherein the recess has a size less than the maximum size of the head.

8. A tube clamp as claimed in claim 5 wherein if, in the closed position, the jaws are moved apart the two arms engage the side wall or walls of the recess.

9. A tube clamp as claimed in claim 1 wherein the two arms are configured to deflect, bend or fold outwards if, in the closed position, the jaws are moved apart.

10. A tube clamp as claimed claim 1 wherein each arm has a first section that extends generally perpendicular to the post and a second section, depending from the first section, which extends outwards and towards the first jaw.

11. A tube clamp as claimed in claim 10 wherein the junction of the first and second sections comprises a resilient second hinge.

12. A tube clamp as claimed in claim 11 wherein a first arm extends towards the first hinge and a second arm extends away from the first hinge.

13. A tube clamp as claimed in claim 1 wherein the two arms engage the aperture and the distal side of the first wall is configured so that the two arms pass through the aperture and spring outwards substantially simultaneously.

14. A tube clamp as claimed in claim 1 wherein at least part of the distal side of the first wall is chamfered to present a surface extending at an angle to the aperture.

15. A tube clamp as claimed in claim 1 wherein the distal side of the first wall nearest to the first hinge is chamfered to present a surface extending at an angle to the aperture.

16. A tube clamp having:

first and second opposed jaws joined by a hinge,

the jaws movable between open and closed positions, the tube clamp adapted to attach to a flexible plastic tube so that the tube passes between the jaws, whereby the flow of fluid through the tube is permitted when the laws are open but is blocked when the jaws are brought together to the closed position to pinch closed the tube there-between, and

a locking mechanism to effect substantially permanent and irreversible locking of the jaws in the closed position, the locking mechanism comprising:

a first leg extending from one of the jaws and a second leg extending from one of the jaws, the legs extending generally parallel to each other, at least one of the legs having a barb, and

at least one corresponding aperture on the other of the laws positioned and adapted to accept the legs, the at least one aperture being proportioned so that passage of the barb or barbs through the respective aperture occurs by deflecting, bending or folding at least a portion of the respective leg sideways and so that, after at least the barb or barbs has passed through the aperture, the leg or legs spring irreversibly sideways to position the barbs over the surface of the jaw defining the respective aperture to lock the laws together, and

wherein one of the legs has a barb extending generally sideways to the leg and the other leg does not have a barb.

17. A tube clamp as claimed in claim 16 wherein both legs extend from the same jaw.

18. A tube clamp as claimed in claim 16 wherein a separate aperture is provided for each leg.

19. A tube clamp as claimed in claim 16 wherein the leg without a barb is a snug fit in the corresponding aperture.

20. A tube clamp as claimed in claim 16 including a guard adjacent the at least one aperture on its distal side that prevents or limits access to the barb or barbs when the clamp is in the closed position.

21. A tube clamp as claimed in claim 16 wherein the distal side of the least one aperture is surrounded or substantially surrounded by an upstanding second wall.

22. A tube clamp as claimed in claim 16 wherein, in the closed position, at least part of the periphery of the head engages the second wall.

23. A tube clamp as claimed in claim 16 wherein the at least one aperture is located in a base of a corresponding recess on the distal side of the second jaw.