Dispensers for syrups and like commodities

Claim 1

A LIQUID DISPENSER OF THE KIND INDICATED COMPRISING A CONTAINER FOR LIQUID THE INTERIOR OF WHICH IS SUBJECT TO ATMOSPHERIC PRESSURE, A DIAPHRAGM HOUSING INCLUDING A BASE PORTION AND A HEAD PORTION, AN INLET PORT IN SAID BASE PORTION COMMUNICATING WITH THE INTERIOR OF SAID CONTAINER FOR RECEPTION OF LIQUID THEREFROM, AN OUTLET PORT IN SAID BASE PORTION, A DISPENSING HEAD, CONDUIT MEANS CONNECTING SAID OUTLET PORT OF SAID DISPENSING HEAD, A RESTRICTED OUTLET ORIFICE LOCATED IN SAID DISPENSING HEAD ABOVE THE MAXIMUM LIQUID LEVEL IN THE CONTAINER, A FLEXIBLE DIAPHRAGM UNIT INCLUDING A SUBSTANTIALLY HEMISPHERICAL DIAPHRAGM WITH A RADIALLY OUTWARDLY EXTENDING CONTINUOUS LOCATING FLANGE CLAMPED BETWEEN SAID HEAD AND BASE PORTIONS, THE DIAPHRAGM DEFINING WITH SAID BASE PORTION A DISCHARGE CHAMBER THE VOLUME OF WHICH INCREASES AND DECREASES UPON EXPANSION AND CONTRACTION RESPECTIVELY OF THE DIAPHRAGM, SAID DIAPHRAGM UNIT FURTHER INCLUDING A FLEXIBLE FLAP VALVE DEPENDING FROM SAID DIAPHRAGM LOCATING FLANGE TO OVERLIE SAID INLET PORT, SAID FLAP VALVE YIELDING UNDER PRESSURE OF LIQUID IN SAID CONTAINER WHEN SAID DIAPHRAGM IS EXPANDED TO PERMIT PASSAGE OF LIQUID INTO SAID DIAPHRAGM HOUSING THROUGH THE INLET PORT, BUT CLOSING SAID INLET PORT UNDER PRESSURE OF LIQUID IN THE DIAPHRAGM HOUSING UPON CONTRACTION OF SAID DIAPHRAGM TO PREVENT BACKFLOW OF LIQUID FROM THE DISCHARGE CHAMBER TO THE CONTAINER, PRESSURE CONTROLLED MEANS TO MOVE SAID DIAPHRAGM BETWEEN EXPANDED AND CONTRACTED POSITIONS, MEANS FOR LIMITING MOVEMENT OF SAID DIAPHRAGM TO PROVIDE A SELECTED CONSTANT, PREDETERMINED CHANGE OF VOLUME OF THE DISCHARGE CHAMBER BETWEEN SAID EXPANDED AND CONTRACTED POSITIONS OF THE DIAPHRAGM, SPRING MEANS URGING SAID CONTROL MEANS TO RETAIN SAID DIAPRAGM IN ITS EXPANDED POSITION CORRESPONDING TO THE MAXIMUM VOLUME OF THE DISCHARGE CHAMBER, SAID DISPENSING HEAD INCLUDING AN INLET OPENING HAVING AN ASSOCIATED VALVE SEATING AND COMMUNICATING WITH SAID CONDUIT MEANS, NONRETURN VALVE MEANS IN THE FORM OF A VALVE UNIT OF FLEXIBLE MATERIAL HAVING A BODY PORTION SECURED WITHIN THE DISPENSING HEAD AND A DISPLACEABLE PORTION INTEGRAL WITH THE BODY PORTION AND COOPERATING WITH SAID VALVE SEATING, WHEREBY UPON OPERATION OF SAID PRESSURE CONTROL MEANS TO CONTRACT THE DIAPHRAGM, THE DISPLACEABLE PORTION OF THE VALVE UNIT IN THE DISPENSING HEAD IS UNSEATED TO PERMIT EJECTION OF SAID PREDETERMINED VOLUME OF LIQUID THROUGH SAID RESTRICTED OPENING AND UPON REMOVAL OF PRESSURE FROM SAID CONTROL MEANS, THE DISPLACEABLE PORTION OF THE VALVE UNIT IS CAUSED, BY VIRTUE OF THE PRESSURE DIFFERENCE SET UP ON OPPOSITE SIDES THEREOF, TO SEAT ON SAID VALVE SEATING TO MINIMIZE BACK FLOW TO LIQUID TO THE DISCHARGE CHAMBER.