US 5,682,955 AGranted

Blade control system for an earthmoving blade

AssigneeCaterpillar Inc.

InventorsSteven L. Groth, Richard A. Arstein, Randall A. Harlow, David P. Smith, Richard J. Skiba

Life of this patent

Estimating the term…

Loading patent…

Abstract

A blade control system includes a directional control valve, a fluid regeneration valve and a selector valve for selectively controlling fluid flow between a pump and first and second hydraulic cylinders and between the cylinders. With the valves positioned at preselected operative positions, pressurized fluid from the pump is directed to the head end chamber of the first cylinder, fluid expelled from the rod end chamber of the first cylinder is diverted to the head end chamber of the second cylinder, and fluid expelled from the rod end chamber of the second cylinder is combined with the fluid being directed to the head end chamber of the first cylinders to provide two stages of fluid regeneration for increasing the extension speed of the cylinder.

Claims5

Dependent claims

A blade control system for an earthmoving blade pivotally mounted on a machine so that the blade can be tipped fore and aft comprising:

a tank;
a pump;
first and second hydraulic cylinders each having a head end chamber and a rod end chamber, the cylinders being disposed on opposite sides of the machine between the machine and the blade;
a directional control valve connected to the pump and the tank and having first and second control ports, the directional control valve having an operative position communicating the pump with the first control port;
a fluid regeneration valve connected to the first and second control ports of the directional control valve and having a cylinder port connected to the head end of the first cylinder and a valve port, the regeneration valve having an operative position at which the first control port of the directional control valve and the valve port communicate with the cylinder port;
and
a selector valve connected to the valve port of the regeneration valve and having a second cylinder port connected to the rod end chamber of the first cylinder, a third cylinder port connected to the rod end chamber of the second hydraulic cylinder, and a fourth cylinder port connected to the head end chamber of the second cylinder, the selector valve having an operative position communicating the rod end of the first hydraulic cylinder with the head end of the second hydraulic cylinder and the rod end of the second hydraulic cylinder with the valve port of the regeneration valve.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/707,830Filed 6 Sep 1996
Granted: 4 Nov 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

F15B 11/024
Systems essentially incorporating special features for controlling the speed or the actuating force of an output member: by means of differential…
E02F 3/844
Drives or control devices therefor , e.g. hydraulic drive systems: for positioning the blade, e.g. hydraulically
E02F 9/2203
Hydraulic or pneumatic drives: arrangements for controlling the attitude of actuators, e.g. speed, floating function
F15B 2211/30525
Characterised by the type of valves: directional control valves, e.g. 4/3-directional control valve