Pneumatic actuator system and method

Claim 2

In combination: a generally elongated housing having a pair of separate, internal, elongated chambers therewithin; a linearly shiftable mechanical output member mounted for reciprocation within one of said chambers; a rotary, bi-directional, pneumatic vane motor operably disposed in the other said chambers; a power output shaft operably coupled to said motor and mounted for rotation within said housing, said output shaft extending substantially parallel to said linear member; gearing means operably extending transversely across said housing between said output shaft and said output member for effecting linear shifting of said member in response to rotation of said output shaft, said output shaft being rotatable in opposite directions to effect corresponding opposite shifting of said output member; elongated sensing means disposed in said one chamber for sensing the linear position of said output member; a source of pressurized gas; conduit means for communicating said source with said motor to effect rotation thereof; and directional flow control means operably disposed in said conduit means and operably associated with said sensing means for controlling motor operation in relation to said sensed position of the output member.

Claim 3

A combination as set forth in claim 1 wherein said control means are mounted upon said housing.

Claim 4

A combination as set forth in claim 1, further including pneumatically operated detent means mounted to said housing and cooperable with said transmission means for locking the latter to prevent displacement of said member, said conduit means communicating with said detent means for actuating the latter to release said detent means.

Claim 5

A combination as set forth in claim 1, wherein said transmission means includes Acme screw gearing operably associated with said output shaft and said member for translating said rotary motion of the shaft into linear motion of said element.

Claim 6

A combination as set forth in claim 1, wherein said source is located remotely from said housing, and further including pressure regulator means operably communicating with said conduit means and located remotely from said housing for regulating pressurized gas delivered through said conduit means to said housing to a constant, preselected pressure level.

Claim 7

A combination as set forth in claim 1, wherein said sensing means are electrically operated, and said flow control means are responsive to an electrical input signal, said system further including an electrical command control system responsive to a command input signal indicative of a desired position of said member for actuating said flow control means to shift said member to said desired position.

Claim 8

A combination as set forth in claim 6, wherein said sensing means includes a linear variable differential transformer.

Claim 9

An actuator system comprising: a source of pressurized gas; a rotary, bi-directional, pneumatic vane motor; conduit means communicating said source with said motor to effect rotation of the latter; a rotary power output shaft driven by said motor; a linearly displaceable power output member; transmission means operably coupling said output shaft with said member for effecting linear shifting of said member in response to rotation of said power output shaft; electrical sensor means for sensing the linear position of said member; electrically actuated pneumatic flow control means disposed in said conduit means and operably coupled with electrical sensing means for controlling operation of said motor to position said member; said motor including a housing having an axially elongated internal chamber, a centrally located exhaust port communicating with said chamber, and a pair of gas receiving ports disposed on opposite sides of said central exhaust port communicating with said chamber; a rotor rotatably mounted within said chamber, said rotor having axially elongated, radially extending slots, said rotor rotatable about a central longitudinal axis; a vane reciprocally disposed within each of said radial slots of the rotor and extending from said rotor radially outward to cooperate with the wall of said chamber to define gas carrying interspaces between adjacent vanes and the chamber wall, said chamber being symmetrically configured about a plane extending through said central exhaust port, said chamber including circular sections extending between each of said receiving ports and said central exhaust port, said wall of the chamber in said circular sections being configured to prevent radial reciprocation of said vanes while rotating within said circular sections, said chamber further defining port sections respectively extending along the length of each of said receiving ports, said wall of the chamber in said port sections being configured to permit radial shifting of said vanes as the latter rotate through said port sections while assuring that interspaces on opposite sides of vanes positioned in said port sections communicate with the corresponding port, whereby said vanes are pressure balanced while reciprocating radially within said port sections, said flow control means including a pair of closed center, double acting poppet valves for controlling communication of each of said receiving ports with said conduit means and a low pressure exhaust, each of said poppet valves including a movable poppet cooperable in first and second positions to respectively engage and disengage a cooperating first seat on said first housing to interrupt and permit communication between the associated receiving port and said conduit means, and each of said poppets including a central through passage therewithin having one end communicating with said associated receiving port at all positions of said poppet, the opposite end of said passage defining a second seat, each of said poppet valves further including a ball engageable and disengageable with said seat respectively in said second and first positions to permit and interrupt communication between the associated receiving port and said low pressure exhaust through said central through passage.

Claim 10

An actuator system comprising: a source of pressurized gas; a rotary, bi-directional, pneumatic vane motor; conduit means communicating said source with said motor to effect rotation of the latter; a rotary power output shaft driven by said motor; a linearly displaceable power output member; transmission means operably coupling said output shaft with said member for effecting linear shifting of said member in response to rotation of said power output shaft; electrical sensor means for sensing the linear position of said member; electrically actuated pneumatic flow control means disposed in said conduit means and operably coupled with electrical sensing means for controlling operation of said motor to position said member; said motor including a housing having an axially elongated internal chamber, a centrally located exhaust port communicating with said chamber, and a pair of gas receiving ports disposed on opposite sides of said central exhaust port communicating with said chamber; a rotor rotatably mounted within said chamber, said rotor having axially elongated, radially extending slots, said rotor rotatable about a central longitudinal axis; a vane reciprocally disposed within each of said radial slots of the rotor and extending from said rotor radially outward to cooperate with the wall of said chamber to define gas carrying interspaces between adjacent vanes and the chamber wall, said chamber being symmetrically configured about a plane extending through said central exhaust port, said chamber including circular sections extending between each of said receiving ports and said central exhaust port, said wall of the chamber in said circular sections being configured to prevent radial reciprocation of said vanes while rotating within said circular sections, said chamber further defining port sections respectively extending along the length of each of said receiving ports, said wall of the chamber in said port sections being configured to permit radial shifting of said vanes as the latter rotate through said port sections while assuring that interspaces on opposite sides of vanes positioned in said port sections communicate with the corresponding port, whereby said vanes are pressure balanced while reciprocating radially within said port sections, said flow control means including a pair of closed center, double acting poppet valves for controlling communication of each of said receiving ports with said conduit means and a low pressure exhaust, each of said poppet valves including a movable poppet cooperable in first and second positions to respectively engage and disengage a cooperating first seat on said first housing to interrupt and permit communication between the associated receiving port and said conduit means, and each of said poppets including a central through passage therewithin having one end communicating with said associated receiving port at all positions of said poppet, the opposite end of said passage defining a second seat, each of said poppet valves further including a ball engageable and disengageable with said seat respectively in said second and first positions to permit and interrupt communication between the associated receiving port and said low pressure exhaust through said central through passage.

Claim 11

A system as set forth in claim 8, wherein each of said poppet valves includes biasing means urging the associated poppet valves toward said first positions thereof.

Claim 12

A system as set forth in claim 9, wherein said flow control means includes a single, pivotal beam link engageable with said poppet valves for shifting the latter in unison in opposite directions.

Claim 13

A system as set forth in claim 10 wherein said flow control means further includes a proportional electrical solenoid operably engaging said beam link to effect pivoting thereof.

Claim 14

A system as set forth in claim 11, further including a spring engaging said beam link to urge the latter to pivot in a direction shifting one of said poppet valves to its first position and shifting the other poppet valve to its second position.