Anti-jam hydraulic servo valve

Claim 2

A control system for controlling the flow of fluid under pressure to a controllable device, said control system comprising: a housing having a supply port for receiving fluid under pressure and a return port for returning the fluid from the housing, said housing having first and second ports for supplying the fluid to the device and for receiving fluid from the device; first valve means mounted for movement in said housing and including a first slide movable for controlling the flow of fluid from the supply port to said first and second ports and from said first and second ports to said return port; a second slide mounted for movement in said housing; input means for moving both of said slides in said housing during normal operation of the control system; said input means including detent means responsive to the jamming of either of said slides for permitting the input means to drive the other of said slides; and jam responsive means for sensing the jamming of either of said slides and providing a signal in response thereto.

Claim 3

A control system as defined in claim 1 including means for providing an indication in response to said signal.

Claim 4

A control system as defined in claim 1 including second valve means at least partially on said second slide and drivable by said input means for controlling the flow of fluid from said supply port to said first and second ports and from said first and second ports to said return port whereby said second valve means can at least partially control the device if the first valve means jams.

Claim 5

A control system as defined in claim 1 including means responsive to said signal for shutting off the supply of fluid to said device from the housing.

Claim 6

A control system as defined in claim 1 wherein said input means moves said second slide in a predetermined phase relationship relative to the first slide during normal operation of the control system, said predetermined phase relationship being altered by the jamming of either of said slides, and said jam responsive means is responsive to the altering of said predetermined phase relationship for providing said signal.

Claim 7

A control system as defined in claim 5 including spring means for biasing each of said slides.

Claim 8

A control system as defined in claim 1 wherein said jam responsive means includes cooperating surface means driven by said slides and responsive to the jamming of either of said slides for porting fluid under pressure to a predetermined location to provide said signal.

Claim 9

A control system as defined in claim 1 wherein said second slide is an inner slide and said first slide is an outer slide, said inner slide being mounted for movement in said outer slide.

Claim 10

A control system as defined in claim 8 wherein said input means moves said slides in opposite directions during normal operation of the control system.

Claim 11

A control system as defined in claim 9 wherein said jam responsive means includes cooperating surface means driven by at least one of said slides and responsive to the jamming of either of said slides for porting fluid under pressure to a predetermined location to provide said signal.

Claim 12

A control system as defined in claim 1 wherein said input means moves said slides relative to the housing and relative to each other during normal operation of the control system.

Claim 13

A control system as defined in claim 1 wherein said input means moves said slides in opposite directions during normal operation of the control system.

Claim 14

A control system for controlling the flow of fluid under pressure to a controllable device, said control system comprising: a housing connectable to a source of the fluid under pressure; first valve means movable in said housing for controlling the flow of fluid under pressure to the device; a slide mounted for movement in said housing; input linkage means for moving both of said first valve means and said slide in said housing during normal operation of the control system; said input linkage means including detent means responsive to the jamming of either of said first valve means or said slide for permitting the input linkage means to drive the other of said first valve means and said slide; and jam responsive means for sensing the jamming of either of said first valve means or said slide and for providing a signal in response thereto.

Claim 15

A control system for controlling the flow of fluid under pressure to a controllable device, said control system comprising: a housing connectable to a source of the fluid under pressure; first valve means movable in said housing for controlling the flow of fluid under pressure to the device; a slide mounted for movement in said housing; input linkage means for moving both of said first valve means and said slide in said housing during normal operation of the control system; said input linkage means including detent means responsive to the jamming of either of said first valve means or said slide for permitting the input linkage means to drive the other of said first valve means and said slide; and jam responsive means for sensing the jamming of either of said first valve means or said slide and for providing a signal in response thereto.

Claim 16

A control system as defined in claim 13 wherein said slide is an inner slide, said first valve means includes an outer slide movable in said housing for controlling the flow of fluid under pressure to the device, said inner slide being movable within said outer slide, said input linkage means includes a first input linkage section for moving said outer slide and a second input linkage section for moving said inner slide, said detent means being in said first input linkage section.

Claim 17

A control system as defined in claim 13 wherein said input linkage means includes a first input linkage section for moving the first valve means and a second input linkage section for moving said slide, and said jam responsive means includes first means responsive to either of said input linkage sections being open for providing said signal.

Claim 18

A control system as defined in claim 15 wherein said slide is a first slide and said first valve means includes a second slide, said first means includes means for moving at least one of said slides to a predetermined position with respect to the other of the slides in response to the associated linkage section being open.

Claim 19

A control system as defined in claim 13 wherein said first valve means includes a second slide movable in said housing for controlling the flow of fluid under pressure to the device and said linkage means includes means for moving said slides in opposite directions from each other during normal operation of the control system.

Claim 20

A control system as defined in claim 13 wherein said jam responsive means includes means driven by at least one of said slide and said first valve means responsive to the jamming of either of said slide or said first valve means for porting fluid under pressure to a predetermined location to provide said signal.

Claim 21

A control system comprising: a housing connectable to a source of fluid under pressure; an actuator; first slide valve means movable in said housing for controlling the flow of fluid under pressure to and from the actuator; a second slide mounted for movement in said housing; input linkage means responsive to an input command and feedback from the actuator for driving both the slide valve means and the slide in said housing during normal operation of the control system; said input linkage means including detent means responsive to the jamming of either of the first slide valve means or said second slide for permitting the input linkage means to drive the other of said first slide valve means and said second slide; and cooperating surface means movable by said first slide valve means and said second slide and responsive to the jamming of either of said first slide valve means or said second slide for porting fluid in a particular manner to provide a signal.

Claim 22

A control system comprising: a housing connectable to a source of fluid under pressure; an actuator; first slide valve means movable in said housing for controlling the flow of fluid under pressure to and from the actuator; a second slide mounted for movement in said housing; input linkage means responsive to an input command and feedback from the actuator for driving both the slide valve means and the slide in said housing during normal operation of the control system; said input linkage means including detent means responsive to the jamming of either of the first slide valve means or said second slide for permitting the input linkage means to drive the other of said first slide valve means and said second slide; and cooperating surface means movable by said first slide valve means and said second slide and responsive to the jamming of either of said first slide valve means or said second slide for porting fluid in a particular manner to provide a signal.

Claim 23

A control system as defined in claim 19 wherein said input linkage means drives said slide valve means and said slide in a predetermined phase relationship during normal operation of the valve, said phase relationship being altered by the jamming of either of said slide valve means or said slide, and said cooperating surface means being responsive to the altering of said predetermined phase relationship for porting fluid to provide said signal.

Claim 24

A control system as defined in claim 20 wherein said predetermined phase relationship is in opposite directions.

Claim 25

A control system for controlling the flow of fluid under pressure to a controllable device, said control system comprising: a housing connectible to a source of fluid under pressure; first valve means for controlling the flow of fluid under pressure to the device; said first valve means including first and second slides mounted for movement in said housing; a first input linkage section for moving said first slide during normal operation of the control system; a second input linkage section for moving said second slide during normal operation of the control system; said linkage sections moving said slides in opposite directions from each other during normal operation of the control system; first means responsive to either of said linkage sections being open for providing a corrective function with respect to the control system; said first means including means for moving at least one of said slides to a predetermined position with respect to the other of the slides in response to the associated linkage section being open, the movement of said one slide to said predetermined position altering the phase relationship of said slides; and said first means being responsive to the altering of the phase relationship to provide said corrective function.

Claim 26

A control system for controlling the flow of fluid under pressure to a controllable device, said control system comprising: a housing connectible to a source of fluid under pressure; first valve means for controlling the flow of fluid under pressure to the device; said first valve means including first and second slides mounted for movement in said housing; a first input linkage section for moving said first slide during normal operation of the control system; a second input linkage section for moving said second slide during normal operation of the control system; said linkage sections moving said slides in opposite directions from each other during normal operation of the control system; first means responsive to either of said linkage sections being open for providing a corrective function with respect to the control system; said first means including means for moving at least one of said slides to a predetermined position with respect to the other of the slides in response to the associated linkage section being open, the movement of said one slide to said predetermined position altering the phase relationship of said slides; and said first means being responsive to the altering of the phase relationship to provide said corrective function.