Direct acting rotary actuator cylinder

A direct acting rotary actuator cylinder with an initial linear movement comprising in combination:

• (a) a cylinder including a first circular cylindrical cavity with a first end wall having a centrally disposed circular hole and a second end wall with a centrally disposed circular hole;
• (b) a rod with a circular cross section coaxially disposed in said first circular cylindrical cavity with one extremity rotatably and slidably engaging and extending through the circular hole centrally disposed through said first end wall in an air-tight manner and the other extremity engaging and extending through the circular hole centrally disposed through said second end wall, said rod having a noncircular cross section over a mid-portion of its length wherein the minimum diametrical dimension of said noncircular cross section is greater than the diameter of said circular cross section;
• (c) a first slidable partitioning body slidably disposed adjacent to said first end wall in said first circular cylindrical cavity and dividing said first circular cylindrical cavity into a first compartment adjacent to said first end wall and a second compartment in an air-tight manner, said first slidable partitioning body pierced by and rigidly affixed to said rod in an air-tight manner;
• (d) a second slidable partitioning body slidably disposed adjacent to said second end wall in said first circular cylindrical cavity and dividing said first circular cylindrical cavity into said second compartment intermediate said first and second slidable partitioning bodies, and a third compartment adjacent to said second end wall in an air-tight manner, said second slidable partitioning body including;
• (1) a first cylindrical member having a centrally located noncircular hole slidably and nonrotatably engaged by the noncircular portion of said rod at least in part and having a plurality of helical grooves of common pitches disposed on the outer cylindrical surface of said first cylindrical member, said plurality of helical grooves slidably engaged by a plurality of guide means affixed to the cylindrical wall of said first circular cylindrical cavity;
• (2) at least one second cylindrical member having a centrally located circular hole slidably and rotatably engaged by the circular portion of said rod in an air-tight manner, said at least one second cylindrical member slidably engaging said first circular cylindrical cavity in an air-tight manner wherein said at least one second cylindrical member is kinematically linked to said first cylindrical member;
• (e) a fluid passage disposed through said rod with one end open to said first compartment and the other end emerging through the cylindrical surface of said rod and into a seal ring affixed to said cylinder with a slit open to said third compartment wherein said other end of said fluid passage lines up with said slit included in said seal ring only when sad rod is fully rotated to one extreme angular position;
• (f) a first port with a check valve disposed adjacent to said first end wall and open to said first compartment, said check valve allowing the flow into said first compartment and preventing the flow out of said first compartment;
• (g) a second port disposed adjacent to said first end wall and open to said second compartment;
• (h) a third port disposed adjacent to said second end wall and open to said third compartment;
• whereby, the pressurization of said second compartment and the venting of said third compartment moves said rod first to said one extreme angular position and then to one extreme linear position, and the venting of said second compartment and the pressurization of said first and third compartments moves said rod to the other extreme linear position opposite to said one extreme linear position and to the other extreme angular position opposite to said one extreme angular position.

An air-spring return direct acting rotary actuator cylinder with an initial linear movement comprising in combination;

• (a) a cylinder including;
• (1) a first circular cylindrical cavity with a first end wall having a centrally disposed circular hole and a second end wall having a centrally disposed circular hole;
• (2) a second circular cylindrical cavity with a third end wall having a centrally disposed circular hole, said second circular cylindrical cavity disposed coaxially to and separated from said first circular cylindrical cavity by said second end wall;
• (3) a third circular cylindrical cavity with a fourth end wall having a centrally disposed circular hole, said third circular cylindrical cavity disposed coaxially to and separated from said second circular cylindrical cavity by said third end wall;
• (b) a rod with a circular cross section coaxially disposed through said first, second and third circular cylindrical cavities and rotatably and slidably engaging and extending through the circular holes centrally disposed through said first, third and fourth end walls in an air-tight manner and through the circular hole centrally disposed through said second end wall with a substantial clearance, said rod having a noncircular cross section over a mid-portion of its length disposed within sid first circular cylindrical cavity wherein the minimum diametrical dimension of said noncircular cross section is greater than the diameter of said circular cross section;
• (c) a first slidable partitioning body slidably disposed adjacent to said first end wall in said first circular cylindrical cavity and dividing said first cylindrical cavity into a first compartment adjacent to said first end wall and a second compartment in an air-tight manner, said first slidable partitioning body piereced by and rigidly affixed to said rod in an air-tight manner;
• (d) a second slidable partitioning body slidably disposed in said first circular cylindrical cavity and dividing said first circular cylindrical cavity into said second compartment intermedate said first and second slidable partitioning bodies and a third compartment adjacent to said second end wall in air-tight manner, said second slidable partitioning body including;
• (1) a first cylindrical member having a centrally located noncircular hole slidable and nonrotatably engaged by the noncircular portion of said rod at least in part and having a plurality of helical grooves of common pitches disposed on the outer cylindrical surface of said first cylindrical member, said plurality of helical grooves slidably engaged by a plurality of guide means affixed to the cylindrical wall of said first circular cylindrical cavity;
• (2) at least one second cylindrical member having a centrally located circular hole slidably and rotatably engaged by the circular portion of said rod in an air-tight manner, said second cylindrical member slidably engaging said first circular cylindrical cavity in an air-tight manner wherein said at least one second cylindrical member is kinematically linked to said first cylindrical member;
• (e) a third slidable partitioning body slidably disposed in said second circular cylindrical cavity and dividing said second circular cylindrical cavity into a fourth compartment adjacent to said second end wall and a fifth compartment adjacent to said third end wall in an air-tight manner, said third slidable partitioning body including a centrally located circular hole rotatably and slidably engaged by the circular portion of said rod in an air-tight manner wherein said third slidable partitioning body is spaced away from said second slidable partitioning body by a hollow circular cylinder slidably engaged by the circular portion of said rod in an air-tight manner and slidably engaging and extending through the circular hole disposed through said second end wall in air-tight manner;
• (f) a fourth slidable partitioning body pierced by and rigidly affixed to the circular portion of said rod in an air-tight manner and dividing said third circular cylindrical cavity into a sixth compartment adjacent to said third end wall and a seventh compartment adjacent to said fourth end wall;
• (g) a first port disposed adjacent to said first end wall and open to said first compartment;
• (h) a second port with a check valve disposed adjacent to said first end wall and open to said second compartment, said check valve allowing the flow into and preventing the flow out of said second compartment;
• (i) a third port disposed adjacent to said second end wall and open to said third compartment;
• (j) a fourth port disposed adjacent to said second end wall and open to said fourth compartment;
• (k) a fifth port disposed adjacent to said third end wall and open to said fifth compartment;
• (l) a sixth port disposed adjacent to said fourth end wall and open to said seventh compartment;
• (m) a fluid passage disposed through said rod with one end open to said first compartment and the other end open to said sixth compartment, said fluid passage including a branch opening emerging through the cylindrical surface of said rod and into a seal ring affixed to said cylinder, said seal ring including a slit open to said fifth compartment wherein said branch opening of said fluid passage lines up with said slit including in said seal ring only when said rod is fully rotated to one extreme angular position;
• whereby, the pressurization of said first, second, third and fifth compartments moves said rod to the other extreme linear position and to the other extreme angular position opposite to said one extreme angular position, and the venting of said first, third and fifth compartments automatically moves said rod first to said one extreme angular position and then to one extreme linear position opposite to said other extreme linear position.