Charge control valve and piston assembly for diaphragm pump
AssigneeGraco Inc.
InventorVernon K. Quarve
Life of this patent
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Abstract
An apparatus for reciprocating a piston in a diaphragm pump wherein the piston alternately pressurizes and relieves an oil filled chamber having a diaphragm separating the chamber from a liquid pumping chamber, the invention comprising a bearing shoe interposed between the piston and driving crank shaft, wherein the shoe has oil ports for lubricating and for relieving excess fluid volume from the oil chamber during each piston stroke.
Claims10
In a diaphragm pump of the type having a reciprocating piston for alternately pressurizing and relieving an oil-filled chamber having a diaphragm separating said chamber from a liquid pumping chamber, the improvement in piston reciprocating drive and oil volume control, comprising:
- a. a rotatable crankshaft with an axially offset cam;
- b. a bearing shoe fitted on said cam and having a bearing surface for contacting said piston, said bearing shoe having an oil groove along its surface fitted on said cam and having an oil port between said groove and said piston bearing surface;
- and
- c. a piston oil port passing through said piston and opening to said piston surface contacting said bearing surface, whereby said piston oil port and said bearing shoe oil port come into coincidence during each piston reciprocating stroke.
A diaphragm pump apparatus of the type having a mechanically-reciprocated piston in an oil-filled chamber, one end of which chamber is defined by a flexible diaphragm, comprising:
- a. a rotatable crankshaft for providing the reciprocating driving means for said piston;
- b. a bearing shoe shaped to fit said crankshaft and having an oil groove along its surface mated to said crankshaft, said bearing shoe having a second surface contacting said piston in reciprocating and sliding relationship;
- c. a first port through said piston communicating between said bearing shoe second surface and said oil-filled chamber;
- and
- d. a second port through said bearing shoe communicating between said bearing shoe second surface on said oil groove.
Dependencies are inferred from the claim text.