PRESET QUANTITY FLUID DELIVERY APPARATUS

摘要

Apparatus for delivering constant quantities of fluid, comprises a chamber, a piston (6) reciprocally movable within the chamber, a fluid inlet (3) to the chamber on one side of the piston, and a fluid outlet (5) from the chamber on the other side of the piston (6). A valve (12) through the piston (6) includes a valve stem (11) extending through the outlet side of the chamber to the fluid outlet (5). Spring means (10) and subsidiary spring means (16) urges respectively the piston (6) and valve (12) through the piston (6) towards the inlet side of the chamber, such that fluid pressure on the inlet side of the chamber will cause the piston (6) to move to eject a predetermined quantity of fluid from the outlet side, and on the return stroke fluid will flow through the valve (12) in the piston (6) to refill the outlet side for the subsequent piston delivery stroke.