Dispensing device

Claim 1

A LIQUID DISPENSING APPARATUS FOR DISPENSING PREDETERMINED QUANTITIES OF LIQUID AT REGULAR INTERVALS COMPRISING A HOLLOW CYLINDER HAVING OPEN ENDS DEFINING A CHAMBER OF PREDETERMINED VOLUME, A PISTON-LIKE VALVE MEMBER MOUNTED AT EACH OF SAID OPEN ENDS, SAID VALVE MEMBERS FACING ONE ANOTHER SO AS TO COOPERATE WITH THE OPEN ENDS OF THE HOLLOW CYLINDER, SHAFT MEANS INTERCONNECTING SAID VALVE MEMBERS AND SPACING THEM AT A DISTANCE LESS THAN THE LENGTH OF SAID HOLLOW CYLINDER, MEANS ADJACENT SAID HOLLOW CYLINDER FOR REGULARLY ACTUATING SAID SHAFT MEANS IN TWO DIRECTIONS TO CLOSE ONE VALVE AND OPEN THE OTHER IN THAT ORDER AS THE SHAFT MEANS MOVE IN ONE DIRECTION AND TO OPEN SAID ONE VALVE AND CLOSE SAID OTHER VALVE IN THAT ORDER AS THE SHAFT MEANS MOVES IN THE OTHER DIRECTION, HOUSING MEANS ENCLOSING SAID HOLLOW CYLINDER, VALVE MEMBERS, AND SHAFT MEANS, SAID HOUSING MEANS DEFINING A SUPPLY RESERVIOR FOR SUPPLYING LIQUID TO ONE END OF THE CHAMBER AND A DISCHARGE RECEIVER FOR LIQUID DISCHARGED FROM THE OTHER END OF THE CHAMBER, DISCHARGE MEANS OPERATIVELY COMMUNICATING WITH THE DISCHARGE RECEIVER FOR DISCHARGING LIQUID FROM THE DISCHARGE RECEIVER, AND VENT MEANS IN THE HOUSING MEANS ABOVE THE DISCHARGE RECEIVER COMMUNICATING THE DISCHARGE CHAMBER WITH THE ATMOSPHERE, SAID VENT MEANS BEING CONSTRUCTED AND ARRANGED TO PREVENT LOSS OF ANY OF THE PREDETERMINED QUANTITY OF LIQUID DISCHARGED FROM THE HOLLOW CYLINDER INTO THE DISCHARGE RECEIVER.