Pinch clamp for flexible tubing

1. A pinch clamp for restricting flow or metering in a flexible tube or hose comprising:

a pair of substantially semi-circular pinching members having cooperating elongated pinching surfaces pivotally connected at one end; and

a tightening assembly pivotally secured at the opposite end of one of the pinching members for selectively securing the pinching members in a closed position when the pinching members are pivoted toward each other;

the elongated pinching surfaces on the pinching members have cooperating projections having inclined sides and substantially flat engaging surfaces for engaging the flexible tube or hose to restrict flow;

the projections positioned on the pinching members to be directly opposed to each other and substantially parallel when the clamp is closed.

2. The pinch clamp of claim 1 , wherein the tightening assembly includes a threaded screw mounted on one pinching member.

3. The pinch clamp of claim 1 , wherein the pair of pinching members are pivotally connected with a pin.

4. The pinch clamp of claim 2 , wherein the tightening assembly includes a conical formation on the second pinching member and a nut with recesses to engage the formation to restrain the lugs from separating under load as the nut is tightened.

5. The pinch clamp of claim 1 , formed of a polysulphone.

6. A pinch clamp for metering or restricting flow in a flexible tube or hose comprising:

a pair of substantially semi-circular pinching members having cooperating elongated pinching surfaces pivotally connected at one end, where the pinching members have cooperating projections for engaging the flexible tube or hose to restrict flow therein;

each projection having inclined sides and substantially flat engaging surface;

a pin for pivotally connecting one end of the pinching members; and

a tightening assembly pivotally secured at the opposite end of the pinching members for selectively securing the pinching members in a closed position when the pinching members are pivoted toward each so that the flat engaging surfaces are substantially parallel to each other; and

one of the pinching members having an opening with a crossbar for limiting angular displacement of the tightening assembly.

7. The pinch clamp of claim 6 , wherein the tightening assembly includes a nut and screw.

8. The pinch clamp of claim 7 , wherein the screw has a cross-head for engaging in an opening of one of the pinching members.

9. The pinch clamp of claim 8 , wherein the opening is defined by two lugs with a recess in which the cross-head clips.

10. The pinch clamp of claim 9 , wherein the nut engages with a conical formation on the recess to restrain the lugs from separating under load as the nut is tightened.

11. A pinch clamp for restricting flow in a flexible tube or hose comprising:

a pair of substantially semi-circular pinching members having cooperating elongated pinching surfaces pivotally connected at one end, where the pinching members have cooperating projections for engaging the flexible tube or hose to restrict flow therein;

each projection having inclined sides and a substantially flat engaging surface;

a pin for pivotally connecting one end of the pinching members; and

a screw and nut at the opposite end of the pinching members for detachably connecting the pinching members in a closed position when the pinching members are pivoted toward each and the flat engaging surfaces substantially parallel to each other; and

one of the pinching members has an opening with a crossbar for limiting angular displacement of the screw.

12. The pinch clamp of claim 11 , wherein the screw has a cross-head for engaging in an opening of one of the pinching members.

13. The pinch clamp of claim 12 , wherein the opening is defined by two lugs with a recess in which the cross-head clips.

14. The pinch clamp of claim 11 , wherein the nut engages with a conical formation on the recess to restrain the lugs from separating under load as the nut is tightened.

15. A clamp, comprising:

a pair of substantially semi-circular pinching members hinged together at one end and connectable together at the other end by a screw and nut;

the pinching members having mating faces with cooperating projections formed with inclined sides a flat pinching face to pinch a tube and an opening for receiving the screw;

the flat pinching faces being substantially parallel when the clamp is closed;

the screw having a cross-head for engaging in the opening of one of the pinching members; and

the opening having a cross-bar distal of the pinching member for limiting angular displacement of the screw.

16. The pinch clamp of claim 15 , wherein the opening in the member is defined by two lugs having a recess into which the cross-head clips.