Apparatus for dispensing a predetermined quantity of fluid

Claim 1

APPARATUS FOR INJECTING A MEASURED AMOUNT OF MATERIAL INTO A MIXING CHAMBER COMPRISING, A CYLINDER HAVING AT A DELIVERY END AN INLET FOR MATERIAL AND A DELIVERY EXTENSION OF SMALLER DIAMETER THAN THAT OF SAID CYLINDER HAVING ONE END OPEN TO SAID CYLINDER AND EXTENDING FROM SAID DELIVERY END AXIALLY OF SAID CYLINDER AND HAVING AT ITS OTHER END AN OUTLET TO DELIVER MATERIAL TO THE MIXING CHAMBER, A PISTON IN SAID CYLINDER SLIDABLE FLUID-TIGHTLY THEREIN AXIALLY TOWARD AND FROM SAID DELIVERY END, AN EXTENSION OF SAID PISTON EXTENDING AXIALLY OF AND TOWARD SAID DELIVERY EXTENSION AND POSITIONED TO EXTEND INTO SAID DELIVERY EXTENSION TOWARDS THE OUTLET THEREOF WHEN SAID PISTON MOVES FORWARDLY TOWARDS SAID DELIVERY END OF SAID CYLINDER ON A FORWARD DELIVERY STROKE OF SAID PISTON SAID PISTON EXTENSION BEING WITHDRAWN CLEAR OF SAID DELIVERY EXTENSION AND INTO SAID CYLINDER TO PERMIT FREE FLOW OF MATERIAL FROM SAID CYLINDER INTO SAID DELIVERY EXTENSION ON THE RETURN STROKE OF SAID PISTON, AN OUTLET VALVE ON THE OUTLET OF SAID DELIVERY EXTENSION TO CLOSE SAID OUTLET, FLUID ACTUATED MEANS TO OPEN AND CLOSE SAID OUTLET VALVE AND MEANS TO ADMIT PRESSURE FLUID TO THE OPPOSITE END OF SAID CYLINDER AND SIMULTANEOUSLY TO SAID FLUID ACTUATED MEANS TO OPEN SAID VALVE ON THE FORWARD STROKE OF SAID PISTON AND ALTERNATIVELY TO EXHAUST PRESSURE FLUID FROM SAID OPPOSITE END OF SAID CYLINDER AND TO REVERSE THE SUPPLY OF PRESSURE FLUID TO SAID FLUID ACTUATED MEANS TO CLOSE SAID OUTLET VALVE ON THE RETURN STROKE OF SAID PISTON.