Dispenser for fluid and semi-fluid materials

Claim 1

IN A DISPENSER FOR LIQUID AND SEMI-LIQUID MATERIALS, A DISPENSER BODY, A PRODUCT CONTAINER MOUNTED ON THE BODY, THE PRODUCT CONTAINER HAVING A VERTICAL AXIS AND A LOWER WALL GENERALLY TRANSVERSE TO THE AXIS, AND A NECK DEPENDING FROM THE MIDDLE OF THE LOWER WALL, AND MEANS TO SECURE THE BODY TO A WALL OR THE LIKE SUPPORT, THE BODY HAVING AN UPWARDLY FACING SURFACE WITH AN INLET OPENING THROUGH THE MIDDLE THEREOF; THE BODY HAVING A MEANS TO ENGAGE THE LOWER WALL OF THE CONTAINER AT DISTANCES SUBSTANTIALLY OUTWARD FROM THE INLET AND LEAVING ALSO A CONTINUOUS RECEPTACLE-RECEIVING RECESS AROUND THE OPENING; THE PRODUCT CONTAINER BEING THUS SUPPORTED ON THE BODY AND ITS NECK HAVING A DEPENDING WALL ENGAGED IN SAID RECESS IN SEALING RELATIONSHIP WITH THE BODY TO PREVENT LEAKAGE AROUND THE WALL, AND TO DISPOSE THE PRODUCT OVER THE OPENING; THE BODY HAVING A VENT THROUGH FROM WITHIN THE RECESS TO THE OUTSIDE OF THE DISPENSER BODY, TO CONNECT THE AREA ADJACENT THE RECESS TO THE OUTSIDE, AND MEANS TO OPEN AND CLOSE SAID VENT, WHEREBY TO RELIEVE AIR PRESSURE IN THE DISPENSER AS DESIRED; A DISPENSING CHAMBER IN THE HOUSING, THE INLET OPENING LEADING THEREINTO, AND AN OUTLET OPENING LEADING THEREFROM AND PROVIDING A DISCHARGE ORIFICE; MECHANISM PROVIDING METERING DISCHARGE OF PRODUCT FROM THE CONTAINER, INCLUDING A PISTON SLIDABLE IN THE CHAMBER IN A SUCTION STROKE DIRECTION TO DRAW MATERIAL FROM THE RECEPTACLE INTO SAID CHAMBER AND MOVABLE IN THE OPPOSITE DIRECTION TO EXPEL MATERIAL FROM THE CHAMBER; AND MEANS TO PREVENT INGRESS TO THE CHAMBER THROUGH THE OUTLET ON THE SUCTION ON THE OPPOSITE STROKE.