Hydraulically actuated detent mechanism

Claim 2

A hydraulic detent mechanism in a control valve having an elongated spool axially movable in a bore of a valve body for regulating fluid communication with a motor means, comprising a portion of the spool forming axially spaced apart depressions, the valve body forming a plurality of circumferentially spaced apart, radial bores communicating at their inner ends with the valve bore and at their outer ends with a common pressurized fluid conduit, a detent plunger slidably arranged in each of the radial bores, the detent plungers tending to be urged into balanced detent engagement with the depressions in the spool by fluid pressure in the outer ends of the radial bores.

Claim 3

The detent mechanism of claim 1 further comprising detent kickout means operable for selectively communicating fluid pressure into the inner ends of the radial bores and thereby tending to urge the detent plungers out of engagement with the spool.

Claim 4

The detent mechanism of claim 2 further comprising means for providing fluid drainage from the inner ends of the radial bores other than when the detent kickout means is communicating fluid pressure thereto.

Claim 5

The detent mechanism of claim 2 wherein the control valve comprises a centering mechanism tending to urge the spool into a selected position within the valve bore, common fluid inlet means communicating fluid at substantially the same pressure to the outer ends of the radial bores and to the kickout means for selective communication to the inner ends of the radial bores.

Claim 6

The detent mechanism of claim 2 wherein the motor means is a hydraulic jack having a piston movable within a cylinder, the kickout means being associated the the jack and responsive to movement of the piston toward a preselected position in the cylinder.

Claim 7

A pilot operated valve assembly for regulating operation of a hydraulic motor, with a main control valve for selectively communicating fluid to the motor and a pilot valve for selectively communicating pilot fluid from a pilot inlet to the main control valve, the pilot valve comprising a valve body forming a bore, a spool arranged in the bore for axial movement to selectively regulate fluid flow from the pilot inlet to the main contRol valve, means coupled with the spool for axially positioning it in the bore, and a hydraulic detent mechanism including a portion of the pilot valve spool with axially spaced apart depressions formed therein, a plurality of circumferentially spaced apart, radial bores communicating at their inner ends with the pilot valve bore and at their outer ends with the pilot fluid inlet and a detent plunger slidably arranged in each of the radial bores, the detent plungers tending to be urged into balanced engagement with the depressions in the pilot valve spool by pilot inlet fluid pressure.

Claim 8

A pilot operated valve assembly for regulating operation of a hydraulic motor, with a main control valve for selectively communicating fluid to the motor and a pilot valve for selectively communicating pilot fluid from a pilot inlet to the main control valve, the pilot valve comprising a valve body forming a bore, a spool arranged in the bore for axial movement to selectively regulate fluid flow from the pilot inlet to the main contRol valve, means coupled with the spool for axially positioning it in the bore, and a hydraulic detent mechanism including a portion of the pilot valve spool with axially spaced apart depressions formed therein, a plurality of circumferentially spaced apart, radial bores communicating at their inner ends with the pilot valve bore and at their outer ends with the pilot fluid inlet and a detent plunger slidably arranged in each of the radial bores, the detent plungers tending to be urged into balanced engagement with the depressions in the pilot valve spool by pilot inlet fluid pressure.

Claim 9

The pilot operated valve assembly of claim 6 further comprising kickout valve means for limiting operation of the motor, the kickout valve means selectively communicating inlet pilot fluid pressure to the inner ends of the radial bores.

Claim 10

A pilot control valve for selectively communicating pilot fluid pressure through first and second conduits to a main control valve for regulating operation of a double-acting hydraulic motor, comprising a valve body defining a valve bore, an elongated spool including resilient centering means tending to position the spool in a neutral condition, the spool being axially movable in opposite directions for communicating a source of fluid pressure with the first and second conduits respectively, the valve body forming a plurality of circumferentially spaced apart, radial bores communicating at their inner ends with the valve bore and at their outer ends with a common pressurized fluid conduit, and a detent plunger slidably arranged in each of the radial bores for balanced detent engagement with the spool under the influence of fluid pressure in the outer ends of the radial bores, a portion of the spool forming a plurality of a depressions, the depressions being axially spaced from each other to receive the detent plungers when the spool is positioned to communicate fluid to either of the first and second conduits and detent kickout means operable for selectively communicating fluid pressure into the inner ends of the radial bores.

Claim 11

A pilot control valve for selectively communicating pilot fluid pressure through first and second conduits to a main control valve for regulating operation of a double-acting hydraulic motor, comprising a valve body defining a valve bore, an elongated spool including resilient centering means tending to position the spool in a neutral condition, the spool being axially movable in opposite directions for communicating a source of fluid pressure with the first and second conduits respectively, the valve body forming a plurality of circumferentially spaced apart, radial bores communicating at their inner ends with the valve bore and at their outer ends with a common pressurized fluid conduit, and a detent plunger slidably arranged in each of the radial bores for balanced detent engagement with the spool under the influence of fluid pressure in the outer ends of the radial bores, a portion of the spool forming a plurality of a depressions, the depressions being axially spaced from each other to receive the detent plungers when the spool is positioned to communicate fluid to either of the first and second conduits and detent kickout means operable for selectively communicating fluid pressure into the inner ends of the radial bores.