Pump and method of driving same

Claim 2

A driven fluid pump device adapted to be throttled and stopped without throttling or stopping the driving input which comprises, means defining a pumping chamber and a driven fluid chamber, a fluid propelling member separating said chambers, a driving fluid in said driving fluid chamber actuating said member and composed of liquid and gas, driving means for alternately pressure loading and unloading said driving fluid, means for releasing some of said driving fluid when loaded above a predetermined pressure to provide a reduced driving volume for reduced actuation of said propelling member, and means maintaining minimum pressure on the driving fluid above the vapor pressure of said fluid whereby any expansion of the reduced driving volume upon unloading will be accommodated by the remaining liquid and gas released therefrom.

Claim 3

The device of claim 1 wherein the driving fluid is a liquid having a gas dissolved therein which is released therefrom according to the law of Henry.

Claim 4

The device of claim 2 wherein the liquid is a lubricant and the gas is air.

Claim 5

The device of claim 1 wherein the fluid propelling member is a diaphragm.

Claim 6

The device of claim 1 wherein the driving means is a piston.

Claim 7

The device of claim 5 wherein the piston has a uniform stroke.

Claim 8

The device of claim 5 wherein the piston is driven by an eccentric member.

Claim 9

The pump device of claim 1 wherein the fluid propelling member receives pumpage on one side and said driving fluid on the other side and an inlet valve controls flow of pumpage to maintain a dead space on the pumpage side of said fluid propelling member accommodating movement of the member to lessen reduction of the driving volume of said driving fluid during standby operation when no flow of pumpage occurs.

Claim 10

The device of claim 8 wherein the fluid propelling member is a diaphragm having a pumpage chamber on one side and a driving fluid chamber on the other side, an inlet valve controls flow of pumpage into the pumpage chamber, a check valve controls flow out of the pumpage chamber, and said two valves cooperate to prevent the pumpage chamber from being completely filled to maintain a dead space of compressible fluid accommodating movement of the diaphragm into the pumpage chamber during throttling or stopping of the pumping.

Claim 11

The device of claim 1 including a supply chamber for driving fluid and a spring loaded valve controlling release of driving fluid to said supply chamber.

Claim 12

The device of claim 10 wherein a passageway selectively connects the supply chamber with the driving fluid chamber ahead of the driving means for replenishing said chamber.

Claim 13

A driven pump adapted to be throttled or stopped without throttling or stopping the driving imput comprising a housing defining a pumping chamber and a driving liquid chamber, a fluid propelling member separating said chambers, driving means acting on liquid in the driving liquid chamber to actuate said propelling member for pumping fluid through the pumping chamber, a relief valve controlling maximum pressure in said driving liquid chamber and releasing excess liquid from the chamber to accommodate throttled movement of the diaphragm, and means controlling the driving means to maintain pressure on the remaining liquid in the driving liquid chamber above the vapor pressure of the liquid.

Claim 14

A driven pump adapted to be throttled or stopped without throttling or stopping the driving imput comprising a housing defining a pumping chamber and a driving liquid chamber, a fluid propelling member separating said chambers, driving means acting on liquid in the driving liquid chamber to actuate said propelling member for pumping fluid through the pumping chamber, a relief valve controlling maximum pressure in said driving liquid chamber and releasing excess liquid from the chamber to accommodate throttled movement of the diaphragm, and means controlling the driving means to maintain pressure on the remaining liquid in the driving liquid chamber above the vapor pressure of the liquid.

Claim 15

The pump of claim 12 having a source of driving liquid containing gas dissolved therein communicating with said relief valve to receive excess driving liquid from the driving liquid chamber, and means connecting said source with the driving liquid chamber to replenish the chamber whenever pressure therein is below the pressure of the source.

Claim 16

The pump of claim 12 wherein the pumping chamber is fed through an inlet valve biased to closed position to maintain a dead space accommodating movement of the fluid propelling member into the pumping chamber even when the chamber is closed.

Claim 17

The pump of claim 12 wherein the fluid propelling member is a diaphragm and the driving means is a constant stroke piston.

Claim 18

A driven diaphragm pump adapted to be throttled and stopped without throttling or stopping the driving input which comprises a housing having a diaphragm chamber, a diaphragm in said housing spanning said chamber and dividing the chamber into a pumping chamber and an opposed driving liquid chamber, a spring biased inlet valve for admitting pumpage to said pumping chamber, an outlet valve controlling flow of pumpage from said pumping chamber, a source of lubricating liquid having air dissolved therein, means bleeding liquid from said source to said driving chamber, a relief valve controlling flow of liquid from the driving chamber back to the source, a piston acting on liquid in said driving chamber to load and unload said liquid for reciprocating said diaphragm to draw pumpage through the inlet valve into said pumping chamber and to discharge pumpage from the pumping chamber through the outlet valve, means driving said piston through a stroke to act through the liquid for forcing a full stroke of the diaphragm whenever pressure in the pumping chamber is below the pressure of the driving liquid, said relief valve releasing driving liquid from the driving chamber back to the source when pressure in the pumping chamber exceeds pressure on the driving liquid, the spring load on said inlet valve to the pumping chamber being effective to maintain a dead space in the pumping chamber accommodating movement of the diaphragm into the pumping chamber even when the outlet valve is closed thereby minimizing release of driving liquid through the relief valve upon throttled operation of the pump, and means limiting the stroke of the piston to maintain the driving liquid volume less than a volume occupied by the liquid and available air from the liquid to always sustain the liquid above its vapor pressure whereby reduced throttled diaphragm strokes are accommodated by reducing the volume of driving liquid and releasing air from the reduced volume of liquid to prevent vaporization of the liquid.

Claim 19

A driven diaphragm pump adapted to be throttled and stopped without throttling or stopping the driving input which comprises a housing having a diaphragm chamber, a diaphragm in said housing spanning said chamber and dividing the chamber into a pumping chamber and an opposed driving liquid chamber, a spring biased inlet valve for admitting pumpage to said pumping chamber, an outlet valve controlling flow of pumpage from said pumping chamber, a source of lubricating liquid having air dissolved therein, means bleeding liquid from said source to said driving chamber, a relief valve controlling flow of liquid from the driving chamber back to the source, a piston acting on liquid in said driving chamber to load and unload said liquid for reciprocating said diaphragm to draw pumpage through the inlet valve into said pumping chamber and to discharge pumpage from the pumping chamber through the outlet valve, means driving said piston through a stroke to act through the liquid for forcing a full stroke of the diaphragm whenever pressure in the pumping chamber is below the pressure of the driving liquid, said relief valve releasing driving liquid from the driving chamber back to the source when pressure in the pumping chamber exceeds pressure on the driving liquid, the spring load on said inlet valve to the pumping chamber being effective to maintain a dead space in the pumping chamber accommodating movement of the diaphragm into the pumping chamber even when the outlet valve is closed thereby minimizing release of driving liquid through the relief valve upon throttled operation of the pump, and means limiting the stroke of the piston to maintain the driving liquid volume less than a volume occupied by the liquid and available air from the liquid to always sustain the liquid above its vapor pressure whereby reduced throttled diaphragm strokes are accommodated by reducing the volume of driving liquid and releasing air from the reduced volume of liquid to prevent vaporization of the liquid.

Claim 20

The pump of claim 16 wherein the piston closes the bleeding means except at the end of its suction stroke.

Claim 21

The pump of claim 16 wherein the piston is spring biased against a wobble plate providing the driving input.

Claim 22

The pump of claim 16 wherein the outlet valve is in a spraygun receiving pumpage from the pumping chamber.

Claim 23

A diaphragm pump comprising a housing defining a chamber for a source of lubricating liquid containing dissolved air, a driving chamber for said liquid and a pumping chamber, a diaphragm separating said driving and pumping chambers, a piston separating said source and driving chambers, means reciprocating said piston to load and unload liquid in said driving chamber, a passageway venting the source chamber to the driving chamber only when the piston unloads the liquid in the driving chamber, a relief valve releasing liquid from the driving chamber to the source chamber when pressure in the pumping chamber exceeds pressure in the driving chamber, means biasing the piston in an unloading direction to reduce pressure in the driving chamber following release of liquid therefrom, and means limiting the unloading stroke of the piston to maintain a volume in the driving chamber filled only by the liquid therein and the air released from said liquid.

Claim 24

A diaphragm pump comprising a housing defining a chamber for a source of lubricating liquid containing dissolved air, a driving chamber for said liquid and a pumping chamber, a diaphragm separating said driving and pumping chambers, a piston separating said source and driving chambers, means reciprocating said piston to load and unload liquid in said driving chamber, a passageway venting the source chamber to the driving chamber only when the piston unloads the liquid in the driving chamber, a relief valve releasing liquid from the driving chamber to the source chamber when pressure in the pumping chamber exceeds pressure in the driving chamber, means biasing the piston in an unloading direction to reduce pressure in the driving chamber following release of liquid therefrom, and means limiting the unloading stroke of the piston to maintain a volume in the driving chamber filled only by the liquid therein and the air released from said liquid.

Claim 25

The diaphragm pump of claim 20 having an inlet valve limiting liquid flow into the pumping chamber on the suction stroke of the diaphragm to maintain a dead space in the pumping chamber accommodating some movement of the diaphragm into the pumping chamber even when said pumping chamber is closed.

Claim 26

The diaphragm pump of claim 20 wherein the means limiting the unloading stroke of the piston maintains a pressure in the driving chamber substantially above the vapor pressure of the liquid therein so that any air released from said liquid folLows the law of Henry.