Fluid motor control system with manual and self-cycling modes of operation

Claim 2

A control system for a fluid pressure operated motor having a first port which may be pressurized to produce motor operation in one direction and having a second port which may be pressurized to produce motor operation in an opposite direction, comprising: a motor control valve having a pressurized fluid inlet and drain means and first and second outlets for connection to said first and second motor ports respectively, said control valve further having a valving element shiftable between at least three positions including a first position at which both of said outlets are closed and a second position at which said first outlet is communicated with said inlet and a third position at which said second outlet is communicated with said inlet, means for manually shifting said valving element between said positions thereof, an actuator means having a bore therein and having first and second fluid passages communicated with said bore, a valving element extension connected to said valving element of said control valve for movement therewith and extending into said bore of said actuator means, a piston in said actuator means shiftable by pressurized fluid admitted to said first passage thereof and having means for engaging said valving element extension, to force said valving element to said second position thereof only after said piston has travelled relative to said valving element a distance at least equal to the movement needed to shift said valving element from said first to said second position thereof, second means in said actuator means shiftable in an opposite direction in response to pressurization of said second passage of said actuator means and having means for engaging said valving element extension to force said valving element to said third position thereof only after said second means has travelled relative to said valving element a distance at least equal to the movement required for shifting said valving element from said first to said third position thereof, and means for alternately pressurizing said first and second passages of said actuator means to cause said control valve to cyclically reverse the direction of operation of said motor.

Claim 3

A control system as defined in claim 1 further comprising first resilient means urging said valving element towards said first position thereof.

Claim 4

A control system as defined in claim 2 further comprising second resilient means acting on said piston for urging said piston in a direction opposite to that along which said pressurized fluid shifts said piston.

Claim 5

A control system as defined in claim 3 wherein said piston has a bore therethrough and wherein said valving element extension extends into said bore at one end of said piston, and wherein said second means comprises a plunger extending into the other end of said piston and being slidably supported therein, the end of said plunger which is most distant from said valving extension being exposed to pressurized fluid received through said second passage of said actuator means.

Claim 6

A control system as defined in claim 4 wherein said motor control vaLve is a spool valve having a housing with a bore and wherein said valving element is a spool disposed coaxially in said bore for axial movement therein and wherein said valving element extension extends axially from one end of said spool, said actuator means having a second housing with said bore thereof being substantially coaxial with said bore of said control valve housing to receive said valving element extension, said piston being a stepped cylinder disposed coaxially in said actuator means bore and said plunger being mounted coaxially in said piston.

Claim 7

A control system as defined in claim 5 wherein the end of said piston closest to said control valve has an inside diameter substantially greater than the outside diameter of said valving element extension and has an outside diameter substantially smaller than the inside diameter of said actuator means bore whereby slight misalignment of said control valve housing bore and said actuator means bore does not interfere with operation of said control valve and said actuator means, further comprising a cylindrical sleeve disposed coaxially within said bore of said actuator means and encircling said closest end of said piston in radially spaced relationship therewith, an annular seal element disposed coaxially on said piston adjacent said sleeve, and means carried on said piston for causing said sleeve to maintain pressure on said seal element.

Claim 8

A control system as defined in claim 1 wherein said means for alternately pressurizing said first and second passages of said actuator means comprises a first flow conduit for connection to said first port of said motor, first pressure sensing means for transmitting pressurized fluid to said first passage of said actuator means in response to a predetermined pressure rise at said first flow conduit, a second flow conduit for connection to said second port of said motor, and second pressure sensing means for transmitting pressurized fluid to said second passage of said actuator means in response to a predetermined pressure rise at said second flow conduit.

Claim 9

A control system as defined in claim 1 wherein said means for alternately pressurizing said first and second passages of said actuator means comprises a source of pressurized fluid, a pilot operated reversing valve connected between said source and said first and second passages of said actuator means and having a first position at which fluid from said source is transmitted to said first passage while said second passage is vented and having a second position at which fluid from said source is transmitted to said second passage while said first passage is vented, a first sequencing valve connected to said source and said reversing valve and having first pilot means for connection to said first motor port and having means for piloting said reversing valve to said first position thereof in response to a predetermined pressure rise at said first pilot means, and a second sequencing valve connected to said source and said reversing valve and having second pilot means for connection to said second motor port and having means for piloting said reversing valve to said second position thereof in response to a predetermined pressure rise at said second pilot means.

Claim 10

A control system as defined in claim 8 wherein said source of pressurized fluid is communicated with said reversing valve and said first and second sequencing valves through a fluid supply conduit, further comprising an on-off valve connected between said source and said fluid supply conduit and having a first position at which said supply conduit is vented and a second position at which said source is communicated with said supply conduit.

Claim 11

In a control system for a reversible fluid pressure operated motor, the combination comprising: a motor control valve having a housing with a bore therein and a fluid inlet situated between a pair of fluid outlets and drain means, said control valve having a spool disposed in said bore for axial movEment therein between a first centered position at which both of said outlets are closed and a second position at which said inlet is communicated with a first of said outlets while the other of said outlets is communicated with said drain means and a third position at which said inlet is communicated with said other outlet while said first outlet is communicated with said drain means, said spool having an axially directed extension at one end thereof, first resilient means urging said spool towards said centered position thereof, manually operated means for selectively forcing said spool to either of said second and said third positions thereof, actuator housing means disposed adjacent said control valve housing and having a bore extending substantially coaxially with respect to said bore of said control valve with said spool extension being received in a first end of said bore of said actuator housing means, said actuator housing means having a closure at the other end of said bore thereof and having a first control fluid passage communicating with an intermediate region of said bore thereof and a second control fluid passage communicating with said other end thereof, a hollow stepped piston disposed coaxially in said bore of said actuator means and having a bore with a step therein through which spool extension extends, second resilient means urging said piston towards a first position at which said step is spaced from the end of said spool extension a distance at least equal to the distance that said spool must be manually moved to shift from said first to said second position thereof, means for causing fluid pressure at said intermediate region of said actuator means bore to force said piston towards said other end thereof, means on said spool extension end positioned to be contacted by said step of said piston after said piston has travelled said distance whereby further piston travel shifts said spool to said first position thereof, and a plunger mounted in said piston for axial movement relative thereto between a first position at which an end of said plunger is spaced from said end of said spool extension by a distance at least equal to the distance that said spool must be manually moved to shift from said first to said third position thereof and a second position at which said end of said plunger has contacted said end of said spool extension and forced said spool to said third position thereof, the other end of said plunger being exposed to fluid pressure within said other end of said actuator means bore.

Claim 12

In a control system for a reversible fluid pressure operated motor, the combination comprising: a motor control valve having a housing with a bore therein and a fluid inlet situated between a pair of fluid outlets and drain means, said control valve having a spool disposed in said bore for axial movEment therein between a first centered position at which both of said outlets are closed and a second position at which said inlet is communicated with a first of said outlets while the other of said outlets is communicated with said drain means and a third position at which said inlet is communicated with said other outlet while said first outlet is communicated with said drain means, said spool having an axially directed extension at one end thereof, first resilient means urging said spool towards said centered position thereof, manually operated means for selectively forcing said spool to either of said second and said third positions thereof, actuator housing means disposed adjacent said control valve housing and having a bore extending substantially coaxially with respect to said bore of said control valve with said spool extension being received in a first end of said bore of said actuator housing means, said actuator housing means having a closure at the other end of said bore thereof and having a first control fluid passage communicating with an intermediate region of said bore thereof and a second control fluid passage communicating with said other end thereof, a hollow stepped piston disposed coaxially in said bore of said actuator means and having a bore with a step therein through which spool extension extends, second resilient means urging said piston towards a first position at which said step is spaced from the end of said spool extension a distance at least equal to the distance that said spool must be manually moved to shift from said first to said second position thereof, means for causing fluid pressure at said intermediate region of said actuator means bore to force said piston towards said other end thereof, means on said spool extension end positioned to be contacted by said step of said piston after said piston has travelled said distance whereby further piston travel shifts said spool to said first position thereof, and a plunger mounted in said piston for axial movement relative thereto between a first position at which an end of said plunger is spaced from said end of said spool extension by a distance at least equal to the distance that said spool must be manually moved to shift from said first to said third position thereof and a second position at which said end of said plunger has contacted said end of said spool extension and forced said spool to said third position thereof, the other end of said plunger being exposed to fluid pressure within said other end of said actuator means bore.