Feed and proportioning pump

Claim 2

A feed and proportioning pump for delivering two different liquids in a given proportion by flow volume and in particular delivering fuel and oil to a mixture-lubricated combustion engine, having two interconnected displacement members executing their suction strokes simultaneously and their delivery strokes simultaneously and arranged in individual pumping chambers each communicating with a separate suction line and a common delivery line by way of opposing acting check valves, one of said displacement members being a diaphragm and forming a portion of one of said pumping chambers, a motor chamber on the opposite side of said first diaphragm, a second diaphragm connected to the first mentioned diaphragm and dividing the motor chamber into two spaces capable of being connected to a common source of pressure or suction, said two diaphragms having different effective areas, a bistable valve capable of being actuated by the second diaphragm at the end of each stroke of the displacement members, one of the spaces being between the diaphragms and being continuously connected to the source of pressure or suction during operation of the pump, said bistable valve establishing communication of the other space to the source of pressure or suction at the end of one stroke of the displacement members and interrupting such comMunication and establishing communication of that space with the atmosphere at the end of the counterstroke.

Claim 3

A pump according to claim 1 wherein the chamber space between the two diaphragms is in communication with the atmosphere by way of a negative pressure valve.

Claim 4

A pump according to claim 1 wherein the chamber space between the two diaphragms is in communication with the source of suction by way of a throttling means.

Claim 5

A feed and proportioning pump for delivering two particular liquids in a given proportion by flow volume and in particular delivering fuel and oil to a mixture-lubricated combustion engine, having two interconnected displacement members executing their suction strokes simultaneously and their delivery strokes simultaneously and arranged in individual pumping chambers each communicating with a separate suction line and a common delivery line by way of opposing acting check valves, one of said displacement members being a diaphragm and forming a portion of one of said pumping chambers, a motor chamber on the opposite side of said first diaphragm, a second diaphragm connected to the first mentioned diaphragm and dividing the motor chamber into two spaces capable of being connected to a common source of pressure or suction, one of the spaces being between the diaphragms and being continuously connected to the source of pressure or suction during operation of the pump, said two diaphragms having different effective areas, a U-shaped snap spring attached to the second diaphragm, a bistable valve capable of being actuated by the spring at the end of each stroke of the displacement members, a cam mounted on the bistable valve, the spring having bends directed toward each other near its ends to cooperate with the cam mounted on the bistable valve to move the valve between two positions, said bistable valve establishing communication of the other of said spaces to the source of pressure or suction at the end of one stroke of the displacement members and interrupting such communication and establishing communication of that space with the atmosphere at the end of the counterstroke.

Claim 6

A feed and proportioning pump for delivering two particular liquids in a given proportion by flow volume and in particular delivering fuel and oil to a mixture-lubricated combustion engine, having two interconnected displacement members executing their suction strokes simultaneously and their delivery strokes simultaneously and arranged in individual pumping chambers each communicating with a separate suction line and a common delivery line by way of opposing acting check valves, one of said displacement members being a diaphragm and forming a portion of one of said pumping chambers, a motor chamber on the opposite side of said first diaphragm, a second diaphragm connected to the first mentioned diaphragm and dividing the motor chamber into two spaces capable of being connected to a common source of pressure or suction, one of the spaces being between the diaphragms and being continuously connected to the source of pressure or suction during operation of the pump, said two diaphragms having different effective areas, a U-shaped snap spring attached to the second diaphragm, a bistable valve capable of being actuated by the spring at the end of each stroke of the displacement members, a cam mounted on the bistable valve, the spring having bends directed toward each other near its ends to cooperate with the cam mounted on the bistable valve to move the valve between two positions, said bistable valve establishing communication of the other of said spaces to the source of pressure or suction at the end of one stroke of the displacement members and interrupting such communication and establishing communication of that space with the atmosphere at the end of the counterstroke.