US3747472A — Flexible cable hydraulic control means

Claim 1

Independent Claim 196 words

A hydraulic control system for controlling the flow of hydraulic fluid from a fluid pressure source to a plurality of hydraulic piston and cylinder assemblies from a remote point comprising, main valves for selectively connecting each of the cylinder assmeblies to the fluid pressure source, a yoke pivotally connected to each of said valves, first means including a manual input lever operably connected for moving each of said main valves to an open position, said first means including a fixed guide and a flexible cable passing through said fixed guide and being attached to one end of said yoke, and second means connected to said piston and cylinder assemblies for moving each of said main valves in the reverse direction to the direction of movement imparted by said manual input lever a distance equal to the distance of movement of the lever to close the valves, said second means including a second fixed guide and a second flexible cable passing through said second cable and being attached to the other end of said yoke, whereby the amount of movement of the piston and cylinder assemblies is directly related to the amount of movement of the lever.

Claim 2

Dependent Claim 196 words

A hydraulic control system for controlling the flow of hydraulic fluid from a fluid pressure source to a plurality of hydraulic piston and cylinder assemblies from a remote point comprising, main valves for selectively connecting each of the cylinder assmeblies to the fluid pressure source, a yoke pivotally connected to each of said valves, first means including a manual input lever operably connected for moving each of said main valves to an open position, said first means including a fixed guide and a flexible cable passing through said fixed guide and being attached to one end of said yoke, and second means connected to said piston and cylinder assemblies for moving each of said main valves in the reverse direction to the direction of movement imparted by said manual input lever a distance equal to the distance of movement of the lever to close the valves, said second means including a second fixed guide and a second flexible cable passing through said second cable and being attached to the other end of said yoke, whereby the amount of movement of the piston and cylinder assemblies is directly related to the amount of movement of the lever.

Claim 3

Dependent Claim 181 words

The control system of claim 1 wherein each of said main valves includes a spool valve slidably received in a housing having inlet-outlet ports communicating with one of said piston and cylinder assemblies, and pressure and tank ports, metering lands on said spool valve normally closing said ports, said spool valve having opposed first and second end surfaces defining first and second chambers respectively with the ends of said housing, the area of said first end surface being half that of said second end surface, said first chamber being in constant communication with said pressure source, a pilot valve coaxial with and slidably received in an axial bore in said spool valve and operably connected to said first and second means, first and second passageways communicating with second chamber with said pressure source and with a reservoir at tank pressure respectively, said pilot valve extending across said passageways and selectively communicating said second chamber with said pressure source and reservoir to cause movement of one of said piston and cylinder assemblies in rEsponse to movement of said first and second cables.

Claim 4

Dependent Claim 136 words

The control system of claim 2 wherein said pilot valve has third and fourth lands normally closing both said first and second passageways respectively when said spool is in the balanced or null position and wherein the axial spacing between said metering lands is equal to the axial spacing between said passageways, said lands defining a third chamber therebetween, a third passageway constantly communicating said second chamber with said third chamber, and whereby said pilot valve is shifted axially to uncover one of said passageways in response to movement of said first means thereby changing the pressure in said second chamber relative to said constantly pressurized first chamber and causing movement of said spool valve relative to said pilot valve until said first and second passageways are again covered by the lands of said pilot valve.

Claim 5

Dependent Claim 31 words

The system according to claim 1 including a proportional force amplifier operatively connected to said main valve, said amplifier including a pilot valve, said yoke being connected to said pilot valve.

Claim 6

Dependent Claim 95 words

The system according to claim 1 including, a proportional force amplifier operatively connected to said main valve, said amplifier including a housing having a cylindrical chamber, a double faced piston mounted for axial movement in said chamber and having a central passage, said piston separating said chamber into a pressure chamber and a control chamber, first and second passages in said piston connecting said pressure and control chambers to said central passage, and a pilot valve mounted for axial movement in said central piston passage for selectively connecting said pressure chamber to said control chamber.

Claim 7

Dependent Claim 35 words

The system according to claim 5 wherein said pilot valve includes a central bore in communication with each end of said valve whereby the fluid pressure action on each end of the valve is equal.

Claim 8

Dependent Claim 124 words

A hydraulic control system for controlling the flow of fluid under pressure to a plurality of hydraulic piston and cylinder assemblies from a remote point comprising, a normally closed main valve for each of said assemblies, each main valve including a housing having a central bore and a spool valve slidably received in said bore in saId housing, a proportional force amplifier connected to control said spool valve, a universally movable manual input lever connected to actuate said amplifier and open said main valve to actuate the corresponding piston and cylinder assembly, and means connected to said amplifier for returning said spool valve to the closed position, said returning means being connected to respond to the movement of the corresponding piston and cylinder assembly.

Claim 9

Dependent Claim 124 words

A hydraulic control system for controlling the flow of fluid under pressure to a plurality of hydraulic piston and cylinder assemblies from a remote point comprising, a normally closed main valve for each of said assemblies, each main valve including a housing having a central bore and a spool valve slidably received in said bore in saId housing, a proportional force amplifier connected to control said spool valve, a universally movable manual input lever connected to actuate said amplifier and open said main valve to actuate the corresponding piston and cylinder assembly, and means connected to said amplifier for returning said spool valve to the closed position, said returning means being connected to respond to the movement of the corresponding piston and cylinder assembly.

Claim 10

Dependent Claim 116 words

The control system of claim 7 wherein said spool valve includes first and second ends defining first and second chambers with the end walls of the bore in said housing, said first end being of approximately twice the cross sectional area of said second end, the fluid pressure source being in constant communication with said second chamber to provide static pressure therein, and said amplifier including a pilot valve selectively communicating said first chamber to the pressure source and reservoir to vary the pressure therein and to thereby cause the movement of said spool valve, the direction of movement being a function of differential pressures in said chambers and the difference in areas of said surfaces.

Claim 11

Dependent Claim 148 words

The control system of claim 7 wherein said amplifier includes a double-faced actuator piston connected to said spool valve, a housing having a bore for receiving said piston, said bore being divided into first and second chambers by said piston, the faces of said piston being of different cross sectional areas such that the area of the face presented to said first chamber is approximately twice that of the face presented to said second chamber, a fluid pressure source in constant communication with said second chamber To provide static pressure therein, a pilot valve in said piston selectively communicating said first chamber to the pressure source to vary the pressure therein and to thereby cause the movement of said actuator piston and said main valve, the direction of movement being a function of the differential pressures in said chambers and the difference in areas of said piston faces.

Claim 12

Dependent Claim 52 words

The control system of claim 9 wherein said piston has an axial bore therein and said pilot valve is slidably received in said axial bore, a reservoir in communication with said axial bore, said piston has passageways for communicating said first chamber with said pressure source and reservoir through said pilot valve.

Claim 13

Dependent Claim 36 words

The system according to claim 7 including, a yoke connected to said amplifier, said lever being connected to one end of said yoke and said returning means being connected to the other end of said yoke.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-07-23	1977-01-22	1977-07-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-07-23	1981-01-22	1981-07-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-07-23	1985-01-22	1985-07-24	$7700.00	Window Closed / Lapsed

Flexible cable hydraulic control means

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