Automatic release and centering device

Claim 2

An automatic release and centerinG device for automatically returning a control valve for a hydraulic cylinder to a null position; said device comprising a housing having a chamber; an actuating rod mounted for reciprocal motion in said chamber and being connected to the valve; a first detent member connected to move in one direction with said rod; a second detent member connected to move in the other direction with said rod; a spring biasing said detent members to an initial position; means for engaging one of said detent members on movement of said actuating rod in either direction to an actuated position and means for releasing said engaging means from said detent members whereby said engaged detent member is returned to the initial position by the bias of the spring, said engaging means including a piston mounted for radial movement in said housing and a spring for biasing said piston to a position to engage said one of said detent members.

Claim 3

The device according to claim 1 wherein said releasing means includes a fluid pressure passage in said housing communicating with said piston and a valve in said passage connected to respond to a signal to pressurize said passage and move said piston radially outwardly to release said piston from the detent member.

Claim 4

The device according to claim 1 including a second detent assembly in one of said detent members and a tubular member connected to said actuating rod, said tubular member having a pair of spaced annular grooves positioned to engage said detent assembly and being movable through said one of said detent members.

Claim 5

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing having a chamber, an actuating member and extending through said chamber, means for connecting said actuating member to said valve, means in said chamber for biasing said member to a neutral position with respect to said valve; said biasing means including a floating detent member mounted on said actuating member at each end of the chamber, means for connecting each of said detent members in one direction with said actuating member, and a spring positioned to bias said detent members to a neutral position at each end of the chamber; means mounted in said housing for holding said actuating member in an actuated position in said chamber; said holding means including a bore in said housing, a piston mounted for movement in said bore radially toward said actuating member, a piston rod connected to said piston and positioned in the path of motion of said detent members and a spring positioned to bias said piston toward said detent members; and means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral.

Claim 6

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing having a chamber, an actuating member and extending through said chamber, means for connecting said actuating member to said valve, means in said chamber for biasing said member to a neutral position with respect to said valve; said biasing means including a floating detent member mounted on said actuating member at each end of the chamber, means for connecting each of said detent members in one direction with said actuating member, and a spring positioned to bias said detent members to a neutral position at each end of the chamber; means mounted in said housing for holding said actuating member in an actuated position in said chamber; said holding means including a bore in said housing, a piston mounted for movement in said bore radially toward said actuating member, a piston rod connected to said piston and positioned in the path of motion of said detent members and a spring positioned to bias said piston toward said detent members; and means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral.

Claim 7

The device according to claim 4 wherein said releasing means comprises a fluid passage in said housing connected to said bore, a source of fluid pressure connected to said passage and a valve in said passage to control the flow of fluid through said passage to said bore in response to the position of the piston in the cylinder.

Claim 8

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing mounted on the amplifier and having a chamber, an actuating member operatively connected to said amplifier and extending through said chamber, means in said chamber for biasing said member to a neutral position with respect to said amplifier, means mounted in said housing for holding said actuating member in an actuating position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, and means connected to said piston and cylinder assembly for providing a signal indicating the preset limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of fluid valves and a fluid actuator connected to respond to fluid pressure in said valves.

Claim 9

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing mounted on the amplifier and having a chamber, an actuating member operatively connected to said amplifier and extending through said chamber, means in said chamber for biasing said member to a neutral position with respect to said amplifier, means mounted in said housing for holding said actuating member in an actuating position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, and means connected to said piston and cylinder assembly for providing a signal indicating the preset limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of fluid valves and a fluid actuator connected to respond to fluid pressure in said valves.

Claim 10

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing mounted on the amplifier and having a chamber, an actuating member operatively connected to said amplifier and extending through said chamber, means in said chamber for biasing said member to a neutral position with respect to said amplifier, means mounted in said housing for holding said actuating member in an actuated position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, and means connected to said piston and cylinder assembly for providing a signal indicating the present limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of micro switches and a hydraulic solenoid valve connected to said switches for hydraulically releasing said releasing means.

Claim 11

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing mounted on the amplifier and having a chamber, an actuating member operatively connected to said amplifier and extending through said chamber, means in said chamber for biasing said member to a neutral position with respect to said amplifier, means mounted in said housing for holding said actuating member in an actuated position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, and means connected to said piston and cylinder assembly for providing a signal indicating the present limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of micro switches and a hydraulic solenoid valve connected to said switches for hydraulically releasing said releasing means.

Claim 12

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing and having a chamber, an actuating member and extending through said chamber, means for connecting said actuating member to said valve, means in said chamber for biasing said member to a neutral position with respect to said valve, means mounted in said housing for holding said actuating member in an actuated position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, means connected to said piston and cylinder assembly for providing a signal indicating the preset limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of fluid valves, and a fluid actuator connected to respond to fluid pressure said said valves.

Claim 13

In a hydraulically actuated mechanism having a hydraulic piston and cylinder assembly controlled by a three position control valve, an automatic centering device connected to return said control valve to neutral when the piston reaches a predetermined limit, said device comprising: a housing and having a chamber, an actuating member and extending through said chamber, means for connecting said actuating member to said valve, means in said chamber for biasing said member to a neutral position with respect to said valve, means mounted in said housing for holding said actuating member in an actuated position in said chamber, means responsive to a signal from the piston and cylinder assembly for releasing said holding means, whereby said actuating member automatically returns to neutral, means connected to said piston and cylinder assembly for providing a signal indicating the preset limits of travel of said piston and cylinder assembly to said releasing means, said providing means including a pair of fluid valves, and a fluid actuator connected to respond to fluid pressure said said valves.