Cyclic adjustable volume dispensing apparatus

Claim 1

APPARATUS FOR DISPENSING ACCURATELY RELATIVELY SMALL QUANITITES OF FLUID COMPRISING, IN COMBINATION: A FLUID COMPARTMENT HAVING ONE WALL CLOSED BY A DIAPHRAGM HAVING AN AXIS, SAID DIAPHRAGM BEING CAPABLE OF AN AXIAL DISTENDING MOVEMENT BETWEEN A FIXED FIRST POSITION CORRESPONDING TO MINIMUM COMPARTMENT VOLUME AND A SECOND POSITION CORRESPONDING TO MAXIMUM COMPARTMENT VOLUME, RESILIENT MEANS NORMALLY URGING SAID DIAPHRAGM TO SAID FIRST POSITION, SAID RESILIENT MEANS ADAPTED TO YIELD TO SUFFICIENT FLUID PRESSURE WITHIN SAID COMPARTMENT TO DISTEND SAID DIAPHRAGM TO THE SECOND POSITION THEREBY TO ADMIT A QUANTITY OF FLUID INTO SAID COMPARTMENT TO BE DISPENSED, ADJUSTABLE MEANS FOR SELECTIVELY ESTABLISHING SAID SECOND POSITION, THEREBY TO VARY THE QUANTITY OF FLUID DISPENSED FROM SAID COMPARTMENT BY SAID RESILIENT MEANS IMMEDIATELY UPON THE CESSATION OF SAID SUFFICIENT FLUID PRESSURE, AND A FLOATING FOLLOWER PLATE ABUTTING SAID ADJUSTABLE MEANS, SAID RESILIENT MEANS, AND AW SUBSTANTIAL PORTION OF SAID DIAPHRAGM, THEREBY TO ACCURATELY CONTROL THE DIAPHRAGM DISTENSION AND HENCE THE QUANTITY OF DISPENSED FLUID.