Pump displacement control

Claim 2

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. a fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. a first conduit connected to function as a pump outlet on displacement of the pump in one direction and as a pump inlet on displacement of the pump in the opposite direction, c. a second conduit connected to function as a pump inlet on displacement of the pump in said one direction and as a pump outlet on displacement in said opposite direction, d. means providing a source of control fluid under pressure, e. directional valve means for directing control fluid to opposite sides of the displacement varying means, f. means defining an adjustable orifice creating a pressure drop in one of said conduits during flow in either direction through the conduit, g. means for sensing the pressure drop across the orifice during flow in either direction through the orifice defining means to control the displacement varying means to provide a constant flow rate for each orifice setting, and h. means for adjusting the orifice defining means to vary the size of the orifice to vary the rate of flow delivered by the pump.

Claim 3

A control as defined in claim 1, including a single manual control for operating the directional valve and the orifice defining means.

Claim 4

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. a fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. a conduit connected to function as a pump outlet on displacement of the pump in one direction and as a pump inlet on displacement of the pump in the opposite direction, c. a conduit connected to function as a pump inlet on displacement of the pump in said one direction and as a pump outlet on displacement in said opposite direction, d. means providing a source of control fluid under pressure, e. directional valve means for directing control fluid to opposite sides of the displacement varying means, f. an orifice creating a pressure drop in one of said conduits, g. means for sensing the pressure drop across the orifice to control the displacement varying means during flow in either direction through the orifice, h. a single manual control for operating the directional valve means and the orifice varying means, and i. means responsive to the control to first operate the directional valve means to put the pump in stroke and then operate the orifice varying means to select the rate of flow.

Claim 5

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. a fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. a conduit connected to function as a pump outlet on displacement of the pump in one direction and as a pump inlet on displacement of the pump in the opposite direction, c. a conduit connected to function as a pump inlet on displacement of the pump in said one direction and as a pump outlet on displacement in said opposite direction, d. means providing a source of control fluid under pressure, e. directional valve means for directing control fluid to opposite sides of the displacement varying means, f. an orifice creating a pressure drop in one of said conduits, g. means for sensing the pressure drop across the orifice to control the displacement varying means during flow in either direction through the orifice, h. a single manual control for operating the directional valve means and the orifice varying means, and i. means responsive to the control to first operate the directional valve means to put the pump in stroke and then operate the orifice varying means to select the rate of flow.

Claim 6

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a first conduit connnected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a second conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. means defining an adjustable orifice creating a pressure drop in one of said conduits during flow in either direction through the conduit, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice defining means to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. manually operable means for adjusting the orifice defining means to vary the orifice to vary the flow rate.

Claim 7

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a first conduit connnected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a second conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. means defining an adjustable orifice creating a pressure drop in one of said conduits during flow in either direction through the conduit, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice defining means to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. manually operable means for adjusting the orifice defining means to vary the orifice to vary the flow rate.

Claim 8

A control as defined in claim 4 wherein the adjustable orifIce includes a movable valve member in a valve bore, means biasing the valve member to a position closing the orifice, and a manual control for moving the valve member selectively in varying amounts to vary the size of the orifice to vary the rate of flow.

Claim 9

A control as defined in claim 4 wherein the directional valve includes a valve member movable in a valve bore, means biasing the valve member to a neutral central position blocking flow of control fluid to the displacement varying means, and a manually operable control for moving the valve member in opposite directions from neutral to selectively direct control fluid to one side or the other of the displacement varying means.

Claim 10

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, i. means for directing fluid from the downstream side of the orifice to the displacement control valve to increase displacement, and j. means for directing fluid from the upstream side of the orifice to the displacement control valve to decrease displacement.

Claim 11

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, i. means for directing fluid from the downstream side of the orifice to the displacement control valve to increase displacement, and j. means for directing fluid from the upstream side of the orifice to the displacement control valve to decrease displacement.

Claim 12

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve member for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, i. manually operable means for moving the valve member in opposite directions from neutral to selectively direct control fluid to one side or the other of the displacement varying means, j. valving on the directional valve member for directing fluid from the downstream side of the orifice to the displacement control valve to increase displacement regardLess of the direction of valve member movement, and k. valving on the directional valve member for directing fluid from the upstream side of the orifice to the displacement control valve to decrease displacement regardless of the direction of valve member movement.

Claim 13

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve member for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, i. manually operable means for moving the valve member in opposite directions from neutral to selectively direct control fluid to one side or the other of the displacement varying means, j. valving on the directional valve member for directing fluid from the downstream side of the orifice to the displacement control valve to increase displacement regardLess of the direction of valve member movement, and k. valving on the directional valve member for directing fluid from the upstream side of the orifice to the displacement control valve to decrease displacement regardless of the direction of valve member movement.

Claim 14

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. said variable orifice comprising a valve stem movable in a valve bore, means biasing the valve stem to a neutral central position closing the orifice, and means for moving the valve stem selectively in opposite directions from neutral in varying amounts to vary the size of the orifice to vary the rate of flow.

Claim 15

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to function as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. said variable orifice comprising a valve stem movable in a valve bore, means biasing the valve stem to a neutral central position closing the orifice, and means for moving the valve stem selectively in opposite directions from neutral in varying amounts to vary the size of the orifice to vary the rate of flow.

Claim 16

A control as defined in claim 9, wherein the directional valve comprises a valve stem movable in a valve bore, means biasing the valve member to a neutral central position blocking flow of control fluid to the displacement varying means, means for moving the valve stem in opposite directions from neutral to selectively direct control fluid to one side or the other of the displacement varying means, and stop means limiting movement of the valve stem in opposite directions.

Claim 17

A control as defined in claim 10 including valving on the directional valve stem for directing fluid from the downstream side of the orifice to the displacement control valve to increase displacement regardless of the direction of displacement and the direction of flow through the orifice, and valving on the directional valve stem for directing fluid from the upstream side of the orifice to the displacement control valve to decrease displacement regardless of the direction of displacement and the direction of flow through the orifice.

Claim 18

A control as defined in claim 10 including a single manually operable control lever connected for operating the directional valve and the variable orifice.

Claim 19

A control as defined in claim 12 including means pivotally connecting the lever to the directional valve stem, means pivotally connecting the lever to the orifice valve stem, relatively weak spring means centering the directional valve stem, and relatively strong spring means centering the orifice valve stem, so that operation of the lever first effects movement of the directional valve stem to put the pump in stroke, and after the directional valve stem stop is encountered, then effects movement of the orifice valve stem to vary the rate of flow.

Claim 20

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to functioN as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. a single manually operable control lever for operating the directional valve and the variable orifice.

Claim 21

A control for a variable displacement pump adapted to supply a reversible load device, comprising, a. reversible fluid operable means for varying the displacement of the pump in opposite directions from neutral, b. means yieldably biasing the displacement varying means toward neutral, c. a conduit connected to functioN as a pump outlet to the load on displacement of the pump in one direction from neutral and as a pump inlet from the load on displacement of the pump in the opposite direction from neutral, d. a conduit connected to function as a pump inlet from the load on displacement of the pump in said one direction from neutral and as a pump outlet to the load on displacement of the pump in said opposite direction from neutral, e. means providing a source of control fluid under pressure, f. a directional valve for directing control fluid to opposite sides of the displacement varying means, g. a variable orifice creating a pressure drop in one of said conduits, h. a displacement control valve responsive to the pressure drop across the orifice during flow in either direction through the orifice to increase displacement of the pump on decrease of the pressure drop and decrease displacement on increase of the pressure drop thereby to maintain a constant flow rate for a given orifice setting, and i. a single manually operable control lever for operating the directional valve and the variable orifice.

Claim 22

A control as defined in claim 14 including means pivotally connecting the lever to the directional valve, means pivotally connecting the lever to the variable orifice, relatively weak means resiliently resisting movement of the directional valve, relatively strong means resiliently resisting variation of the orifice, whereby operation of the control lever first operates the directional valve and then operates the variable orifice.