Device for dispensing metered quantities of liquid

Claim 1

A DEVICE FOR DISPENSING LIQUIDS COMPRISING A BASE MEMBER, A SUBSTANTIALLY CYLINDRICAL HOLLOW BODY MEMBER UPSTANDING FROM SAID BASE MEMBER, LIQUID INLET PORT MEANS AND LIQUID OUTLET PORT MEANS CARRIED BY SAID BASE MEMBER, MEANS FOR SELECTIVELY PLACING EITHER ONE OF SAID PORT MEANS IN COMMUNICATION WITH THE INTERIOR OF SAID BODY MEMBER AND FOR SIMULTANEOUSLY PREVENTING COMMUNICATION BETWEEN THE OTHER OF SAID PORT MEANS AND THE INTERIOR OF SAID BODY MEMBER, A COVER MEMBER CLOSING THE UPPER END OF SAID BODY MEMBER, A PISTON IN SAID BODY MEMBER IN AXIALLY SPACED RELATION ABOVE SAID PORT MEANS, AN AXIALLY EXTENDING THREADED MEMBER EXTENDING THROUGH SAID COVER MEMBER AND SUPPORTING SAID PISTON MEMBER WITHIN SAID HOLLOW BODY MEMBER, SAID THREADED MEMBER HAVING A VERTICAL KEY-WAY IN ITS OUTER SURFACE, A VERTICALLY DISPOSED KEY FIXED TO SAID COVER EXTENDING INTO SAID KEY-WAY TO PREVENT ROTATION OF SAID THREADED MEMBER WITH RESPECT TO SAID COVER, NUT MEANS HAVING A PERIPHERAL GROOVE IN ITS OUTER SURFACE THREADEDLY ENGAGING SAID AXIALLY EXTENDING THREADED MEMBER, A RETAINER STRAP MOUNTED WITH ONE END ATTACHED TO SAID COVER AND ITS OTHER END RIDING IN SAID GROOVE TO PREVENT AXIAL TRAVEL OF SAID NUT MEANS WHEREBY ROTATION OF SAID NUT MEANS ON SAID AXIALLY THREADED MEMBER IS EFFECTIVE TO IMPART AXIAL MOVEMENT TO SAID THREADED MEMBER AND TO SAID PISTON SUPPORTED THEREBY, SAID PISTON BEING THEREBY AXIALLY MOVABLE TO AN ADJUSTED POSITION TO PROVIDE A METERING CHAMBER OF PREDETERMINED VOLUME IN SAID BODY MEMBER BETWEEEN SAID PORT MEANS AND SAID PISTON.