US 8,297,586 B1 · Proportional control pneumatic cylinder

Abstract

A proportional control pneumatic cylinder as an air actuator device for a hydraulic pump valve having a valve spool moving in a bore in a valve housing. The device having an actuator housing attachable to the valve housing and having a bore carrying a piston coaxially secured to an end of the valve spool. The device provided with spaced openings in the actuator housing which communicate with the bore therein to introduce air to act on opposite sides of the piston, and factory pretensioned biasing means for normally urging the piston and spool to a center closed position. Surface areas on opposite sides of the piston are approximately equal so that piston movement is approximately proportional to movement of an actuating lever of an air supplying pneumatic control valve over the majority of the range of travel of the actuating lever for both raised and lowered positions.

Claims20

Dependent claims

A proportional control pneumatic cylinder comprising:

a housing having a bore provided therein that includes first and second portions having different diameters, a first port that communicates with the first portion of the bore, and a second port that communicates with the second portion of the bore;
a piston disposed within the housing and defining first and second air spaces within the first and second portions of the bore, respectively, of the housing, the piston having a first surface area that is exposed to the first air space, the piston having a second surface area that is exposed to the second air space and that is approximately equal to the first surface area, the piston being movable relative to the housing between a first position, a second position, and a center position located between the first and second positions;
and
a mechanism biasing the piston in the center position.

1 more element

A combined hydraulic pump valve and proportional control pneumatic cylinder comprising:

a hydraulic pump valve including a valve housing supporting a hydraulic valve associated with a hydraulic pump, the hydraulic valve including a valve spool that is movable between a first position, a second position, and a center position located between the first and second positions for controlling the operation of the hydraulic pump;
and
a proportional control pneumatic cylinder including a cylinder housing having a bore provided therein that includes first and second portions having different diameters, a first port that communicates with the first portion of the bore, and a second port that communicates with the second portion of the bore;
a piston connected for movement with the valve spool and disposed within the cylinder housing and defining first and second air spaces within the first and second portions of the bore, respectively, of the cylinder housing, the piston having a first surface area that is exposed to the first air space, the piston having a second surface area that is exposed to the second air space and that is approximately equal to the first surface area, the piston being movable relative to the cylinder housing between a first position, a second position, and a center position located between the first and second positions;
and a mechanism biasing the piston in the center position.

2 more elements

Dependencies are inferred from the claim text.

Proportional control pneumatic cylinder

Life of this patent

Proportional control pneumatic cylinder

Life of this patent

Abstract

Claims20