Dale B Childress

US Patent:

6030183, Feb 29, 2000

Filed:

Apr 30, 1998

Appl. No.:

9/070296

Inventors:

Dale B. Childress - Plainfield IL

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F04B 4908

US Classification:

4172221

Abstract:

A variable margin pressure control for a variable displacement load sensing pump comprises a body having a bore therein and a valve spool slidably disposed in the bore defining a chamber in continuous communication with a discharge passage in the body. The valve spool is movable in a first direction for communicating the discharge passage with a control port in the body and in a second direction for communicating the control port with an exhaust flow path. The valve spool is biased in the first direction by discharge fluid pressure in the chamber. A spring mechanism biases the valve spool in the second direction against the force generated by the discharge pressure with a biasing force sufficient to establish a predetermined margin pressure. A remotely controllable variable biasing force is applied against the valve spool by a device so that the margin pressure can be selectively varied in response to receiving a pressure signal. Another devices applies a load pressure generated biasing force against the valve spool in the second direction so that the margin pressure is maintained throughout the pressure operating range of the pump.

US Patent:

56736061, Oct 7, 1997

Filed:

Aug 22, 1996

Appl. No.:

8/701418

Inventors:

Charles E. Rose - Morris IL
Dale B. Childress - Plainfield IL

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F01B 300

US Classification:

92 122

Abstract:

A swash plate actuating device for an axial piston unit has a swash plate tiltably mounted within the housing. A pair of axially aligned actuating chambers defined in the housing slidably receive the opposite ends of an elongate actuator and are disposed on opposite sides of a distal end portion formed on an actuator lever connected to the swash plate. A connector has a mounting portion spanning a transverse slot in the actuator and seated on a planar surface of the actuator. A guide portion of the connector is disposed within the transverse slot and has a bearing slot slidably receiving the distal end portion of the actuator lever.

US Patent:

55671233, Oct 22, 1996

Filed:

Sep 12, 1995

Appl. No.:

8/526830

Inventors:

Dale B. Childress - Plainfield IL
Noah D. Manring - Roland IA

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F04B 4908

US Classification:

4172221

Abstract:

A pump displacement control for a variable displacement pump includes a torque control valve disposed between a variable torque limiter and a force applying device disposed in axial alignment within a common bore. A sleeve and a valve spool are movable relative to each other to establish a first condition communicating discharge pressure into an actuator chamber to move a swashplate toward a minimum displacement position against the bias of a spring or a second condition communicating the actuating chamber with an exhaust passage to allow the spring to move the swashplate toward its maximum displacement position. A torque control piston disposed between opposing springs resiliently bias the valve spool in a direction to establish the second condition when control fluid is directed into a control chamber. Pump discharge pressure communicated into a pressure chamber exerts a force against the valve spool proportional to the discharge pressure so that the valve spool moves in a second direction to establish the first condition when the control force exceeds the biasing force exerted by the torque limiter.