US 5,692,541 AGranted

Hydraulic joystick

AssigneeCaterpillar Inc.

InventorDavid J. Brown

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Abstract

The present invention includes a single joystick for the simultaneous control of three spool valves for use on a construction machine. A first portion of the joystick is moved in a first direction which causes a cam to selectively depress a first pair of plungers to control the first spool valve. Movement of the first portion in the second direction causes the cam to selectively depress a second pair of plungers thereby controlling the movement of the second spool valve. A handle of a second portion of the joystick rotates about an axis causing a plate to rotate in a corresponding manner. The corresponding rotation of the plate causes a link member to rotate about the axis causing a pair of lugs to selectively depress a third pair of plungers to control the third spool valve. The mechanism for depressing the third plungers works independently of the position of the first portion so that the control of the third spool valve is independent of the control of the first and second spool valves.

Claims9

Dependent claims

A hydraulic joystick for controlling three hydraulic spool valves, comprising:

a first portion for controlling two of the spool valves, the first portion being pivotable about first and second axes, whereby movement about each axes in a first direction and a second direction opposite the first direction displaces a respective plunger which is arranged to transmit a hydraulic signal to a respective end of a respective spool valve to displace the spool valve proportionately to the displacement of the joystick;
and
a second portion pivotally connected to and operatively associated with the first portion for movement therewith about the first and second axes for controlling the two spool valves, the second portion controlling the third spool valve and being rotatable about a third axis independent of the position and movement of the first portion, whereby movement about the third axis in a first direction and a second direction opposite the first direction displaces a respective plunger which is arranged to transmit a hydraulic signal to a respective end of the third spool valve to displace the spool valve proportionately to the displacement of the joystick.

Dependencies are inferred from the claim text.