Electrohydraulic valve having dual-action right-angle pilot actuator
AssigneeCaterpillar Inc.
InventorDennis Ray BARBER
Life of this patent
Estimating the term…
Abstract
A pilot actuator is disclosed for use with a valve. The pilot actuator may have a cage with a base end and a tip end, and a pilot bore formed in the cage. The pilot actuator may also have a supply port, a drain port, a first end port, and a second end port each formed in the cage and intersecting with the pilot bore. The pilot actuator may further have a pilot spool slidingly disposed in the pilot bore and movable to selectively connect the supply port and the drain port with the first and second end ports, a follower separate from the cage and disposed at the tip end of the cage, and at least one spring operatively connecting the follower to the cage and to the pilot spool.
Claims20
A pilot actuator for a valve, comprising:
- a cage having a base end and a tip end;
- a pilot bore formed in the cage;
- a supply port formed in the cage and intersecting with the pilot bore;
- a drain port formed in the cage and intersecting with the pilot bore;
- a first end port formed in the cage and intersecting with the pilot bore;
- a second end port formed in the cage and intersecting with the pilot bore;
- a pilot spool slidingly disposed in the pilot bore and movable to selectively connect the supply port and the drain port with the first and second end ports;
- a follower separate from the cage and disposed at the tip end of the cage;
- and
- at least one spring operatively connecting the follower to the cage and to the pilot spool.
A valve, comprising:
- a valve body;
- a central bore formed in the valve body;
- an actuator passage formed in the valve body and intersecting with the central bore;
- at least one of a supply passage and a drain passage formed in the valve body and intersecting with the central bore;
- a control spool slidingly disposed in the central bore and movable to selectively connect the actuator passage and the at least one of the supply passage and the drain passage, the control spool having a base end and a tip end;
- and
- a pilot actuator located at the tip end of the control spool, the pilot actuator operable to selectively direct pressurized fluid to one of the base end and the tip end of the control spool and to receive mechanical force feedback from the tip end.
A hydraulic circuit, comprising:
- an actuator;
- a primary pump;
- a pilot pump
- a sump;
- and
- a valve disposed between the actuator, the primary pump, and the sump, the valve including:
- a valve body;
- a central bore formed in the valve body;
- an actuator passage formed in the valve body and intersecting with the central bore;
- at least one of a supply passage and a drain passage formed in the valve body and intersecting with the central bore;
- a control spool slidingly disposed in the central bore and movable to selectively connect the actuator passage and the at least one of the supply passage and the drain passage, the control spool having a base end and a tip end with a tapered outer surface;
- a spring located at the tip end of the control spool and configured to center the control spool within the central bore;
- and
- a dual-action pilot actuator located at the tip end of the control spool, the dual-action pilot actuator operable to selectively direct pilot fluid to one of the base end and the tip end of the control spool, to selectively direct fluid from a remaining one of the base end and the tip end to the sump, and to receive mechanical force feedback from the tapered outer surface at the tip end of the control spool.
Dependencies are inferred from the claim text.