Method and apparatus for converting digital input signals into distinct output positions or velocities

Claim 2

A fluid actuated control system for converting a sequence of digital input signals into output positions of a fluid actuated working element (5) in a fluid actuated system having a pump (11) and reservoir (12) comprising: an impulse valve means (2) for directing the fluid power to first (6'', 8'') and second (7'', 9'') sets of output ports, each set having a pump connected port (6'', 7'') and a reservoir connected port (8'', 9''); a servo valve (3,4) having spaced input ports (6, 7, 8, 9), said input ports connected to the two sets of output ports (6'', 7'', 8'', 9'') of the said impulse valve means (2), the first set pump connected impulse valve output port (6'') being connected to a first one (6) of said input servo valve ports (6, 7, 8, 9), the second set pump connected impulse valve output port (7'') being connected to a second one (7) of said input servo valve ports (6, 7, 8, 9), the first set reservoir connected impulse valve output port (8'') being connected to a third one (8) of said input servo valve ports (6, 7, 8, 9), the second set reservoir connected impulse valve port (9'') being connected to a fourth one (9) of said input servo valve ports (6, 7, 8, 9), the servo valve ports being spaced around the servo valve in the order of first input port, second input port, third input port and fourth input port, said servo valve having a slide (3) therein having closure members thereon which are spaced to cover every other input port in the servo valve and forming two sets of interconnected chambers, one set of chambers being connected to one port (15 or 16) of the fluid actuated work element (5) and the other set of chamberS to the other port (16 or 15) of the fluid actuated work element, and one of said servo valve input ports (6, 7, 8 or 9), said slide valve being physically connected (17) to the mechanical output of the work element such that as the work element moves it advances the slide valve to cause each closure element to cover the next input port whereby the work element is incrementally advanced with each change of position of the impulse valve.

Claim 3

A fluid actuated control system for converting a sequence of digital input signals into output positions of a reversible fluid actuated working element (5) in a fluid actuated system having a pump (11) and reservoir (12) comprising: a directional control valve means (1) for directing the fluid to control valve output ports therein, said valve selectively connecting the control valve outlet ports to either the pump or reservoir, respectively; an impulse valve means (2) connected to the output of the directional control valve means (1) for directing the fluid to first (6'', 8'') and second (7'',9'') sets of output ports, each set having a pump connected port (6'',7'') and a reservoir connected port (8'',9''); a servo valve (3,4) having spaced input ports (6, 7, 8, 9), said input ports connected to the two sets of output ports (6'', 7'', 8'', 9'') of the said impulse valve means (2), the first set pump connected impulse valve output port (6'') being connected to a first one (6) of said input servo valve ports (6, 7, 8, 9), the second set pump connected impulse valve output port (7'') being connected to a second one (7) of said input servo valve ports (6, 7, 8, 9), the first set resevoir connected impulse valve output port (8'') being connected to a third one (8) of said input servo valve ports (6, 7, 8, 9), the second set resevoir connected impulse valve port (9'') being connected to a fourth one (9) of said input servo valve ports (6, 7, 8, 9), the servo valve ports being spaced around the servo valve in the order of first input port, second input port, third input port and fourth input port, said servo valve having a slide (3) therein having closure members thereon which are spaced to cover every other input port in the servo valve and forming two sets of interconnected chambers, one set of chambers being connected to one port (15 or 16) of the reversible fluid actuated work element (5) and one of said servo valve input ports (6,7,8 or 9) and the other set of chambers to the other port (15 or 16) of the reversible fluid actuated work element and an input port, said slide valve being physically (17) connected to the mechanical output of the work element such that as the work element moves it advances the slide valve to cause each closure element to cover the next input port whereby the work element is incrementally advanced with each change of position of the impulse valve and the direction of the movement of the work element is controlled by the directional control valve.

Claim 4

A fluid actuated control system for converting a sequence of digital input signals into output positions of a reversible fluid actuated working element (5) in a fluid actuated system having a pump (11) and reservoir (12) comprising: a directional control valve means (1) for directing the fluid to control valve output ports therein, said valve selectively connecting the control valve outlet ports to either the pump or reservoir, respectively; an impulse valve means (2) connected to the output of the directional control valve means (1) for directing the fluid to first (6'', 8'') and second (7'',9'') sets of output ports, each set having a pump connected port (6'',7'') and a reservoir connected port (8'',9''); a servo valve (3,4) having spaced input ports (6, 7, 8, 9), said input ports connected to the two sets of output ports (6'', 7'', 8'', 9'') of the said impulse valve means (2), the first set pump connected impulse valve output port (6'') being connected to a first one (6) of said input servo valve ports (6, 7, 8, 9), the second set pump connected impulse valve output port (7'') being connected to a second one (7) of said input servo valve ports (6, 7, 8, 9), the first set resevoir connected impulse valve output port (8'') being connected to a third one (8) of said input servo valve ports (6, 7, 8, 9), the second set resevoir connected impulse valve port (9'') being connected to a fourth one (9) of said input servo valve ports (6, 7, 8, 9), the servo valve ports being spaced around the servo valve in the order of first input port, second input port, third input port and fourth input port, said servo valve having a slide (3) therein having closure members thereon which are spaced to cover every other input port in the servo valve and forming two sets of interconnected chambers, one set of chambers being connected to one port (15 or 16) of the reversible fluid actuated work element (5) and one of said servo valve input ports (6,7,8 or 9) and the other set of chambers to the other port (15 or 16) of the reversible fluid actuated work element and an input port, said slide valve being physically (17) connected to the mechanical output of the work element such that as the work element moves it advances the slide valve to cause each closure element to cover the next input port whereby the work element is incrementally advanced with each change of position of the impulse valve and the direction of the movement of the work element is controlled by the directional control valve.

Claim 5

A valve control system for converting digital input signals into a plurality of intermediate output positions of a fluid actuated work element supplied by a pump through said control valve system comprising: impulse valve means for receiving one of said input signals and in response thereto initiating flow from the pump to the work element; servo valve means for intermittently directing flow from the pump to the work element, said servo valve having a plurality of spaced ports for receiving said flow and a slide valve having a plurality of spaced closure elements for closing said ports, said slide being rigidly connected to the output of said work element whereby said work element moves until the closure elements on the said slide moved by the said work element close the next encountered control ports whereupon blocking the flow from the pump to the work element and the work element remains at a standstill until a new input signal is transmitted to the impulse valve.

Claim 6

A valve control system for converting digital input signals into a plurality of intermediate output positions of a fluid actuated work element supplied by a pump through said control valve system comprising: impulse valve means for receiving one of said input signals and in response thereto initiating flow from the pump to the work element; servo valve means for intermittently directing flow from the pump to the work element, said servo valve having a plurality of spaced ports for receiving said flow and a slide valve having a plurality of spaced closure elements for closing said ports, said slide being rigidly connected to the output of said work element whereby said work element moves until the closure elements on the said slide moved by the said work element close the next encountered control ports whereupon blocking the flow from the pump to the work element and the work element remains at a standstill until a new input signal is transmitted to the impulse valve.

Claim 7

The valve control system of claim 3 wherein the impulse valve means is two solenoid valves in tandem.

Claim 8

The valve control system of claim 4 wherein the servo valve is a rotary slide valve, the control ports being in a valve casing and the closure members being on the rotary slide.