Fluid power piston actuators

• US 4,056,043 A
• Filed: 10/28/1975
• Issued: 11/01/1977
• Est. Priority Date: 10/28/1975
• Status: Expired due to Term

• Current Assignee: Johnson Service Company
• Original Assignee: Johnson Controls, Inc. (Johnson Controls International plc)
• Inventors: Brzezinski, Donald E., Sriramamurty, Durvasula V.
• Primary Examiner(s): Cohen, Irwin C.
• Application Number:
  US05/625,823
• Time in Patent Office: 735 Days
• Field of Search: 92/13.2, 92/13.41, 92/13.6, 92/99, 92/98 D, 92/118, 92/119, 92/161, 403/131, 403/122
• US Class Current: 92/13.2
• CPC Class Codes: F15B 15/02 Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member
• CPC Class Codes: F15B 15/10 the motor being of diaphragm type
• CPC Class Codes: Y10T 403/32704 Stud extends into ball

Abstract

A pneumatic actuator includes a cup-shape cylinder body housing a piston and having a generally flat base with a mounting hub projecting outwardly. A piston rod is slidably mounted in the hub and connects to a load such as a damper in an air mixing box. The base is formed with a bearing recess or depression means encircling the hub. The recess defines a spherical sector offset from the center of a complete sphere of the same radius. An annular swivel ring includes an inner diameter adapted to loosely fit over the hub and includes an outer periphery which is generally spherically shaped and defines a central spherical sector having a maximum planar diameter slightly larger than that of the sector defined by recess. The swivel ring is a two-part member having interconnecting slot and projection elements providing a snap joint connection, with the mounting plate firmly clamped therebetween. The swivel ring with the attachment plate fits over the mounting hub. A clamping nut means is secured to the hub with a bearing recess generally corresponding to that formed in the base. An outer head is secured to the cylinder by a suitable snap joint with a peripherial head of a diaphragm rigidly clamped therebetween. A cup-shaped piston is connected to a piston rod by a snap joint which permits free rotation of the rod within the piston. The piston opens into the cylinder and provides a guide for a clamp spring which acts between the piston and the base of the cylinder. The diaphragm ovelies the face of the piston and extends downwardly therebetween to develop a rolling diaphragm construction.

Claims

1. In a fluid power actuator, an outer body portion having a mounting wall with an opening, an operator projecting through said mounting wall opening, a fluid driven member in said body portion and connected to said operator, said mounting wall further including an annular recess encircling said opening, said recess defining a spherical chordal section having a spherically shaped sidewall with an outer circular opening to the recess of a diameter less than the diameter of a sphere generated by the full development of the spherically shaped sidewall, an annular mounting means clamped within said recess and having a central opening for the operator and an outer periphery defining a central sector of said sphere, said central opening having a diameter greater than the operator and being spaced from said operator and permitting movement of the mounting means independently of the body portion and the operator, a clamping means secured to said body portion in spaced relation to said mounting wall, said clamping means having a spherical chordal sector generally corresponding to and coaxially aligned with said spherical chordal sector defined by said recess and operable to firmly clamp the mounting means in position for supporting of the actuator, wherein said annular mounting means is a two-piece member having a pair of similar ring members with internal slot and projections defining a snap-joint connection of the ring members.

2. In the fluid actuator of claim 1 wherein said fluid driven member is a piston means slidably mounted within said body portion, said piston means dividing the body portion into a pair of opposite piston-positioning chambers, at least one of said chambers having an input signal means for receiving of a fluid signal for positioning of said piston means, said operator is a piston rod slidably mounted within the mounting wall opening, said mounting wall having an operator hub including said opening, and said clamping means being releasably secured to said hub.

3. In the actuator of claim 2 wherein said piston means includes a central hub portion, said piston rod projecting into said hub portion, said hub portion and said piston rod having complementing slots and projection means defining a snap-joint connection of the rod to the hub portion.

4. The actuator of claim 1, wherein said body portion includes a cup-shaped cylindrical body member having said mounting wall integrally formed to define the base portion of said member, a cup-shaped head member having an annular sidewall adapted to telescope with the outer end of said cylindrical body member, the opposing telescoped surfaces of said cylindrical body member and said cup-shaped head member including complementing parts of a snapjoint connector.

5. The actuator of claim 4 wherein said connector includes an annular slot and a mating projection, said telescoping members having inclined camming surface means to facilitate the telescoping movement of the members to align said snap connecting slot and projection.

6. In a fluid power actuator, an outer body portion having a mounting wall with an opening, an operator projecting through said mounting wall opening, a fluid driven member in said body portion and connected to said operator, said mounting wall further including an annular recess encircling said opening, said recess defining a spherical chordal section having a spherically shaped sidewall with an outer circular opening to the recess of a diameter less than the diameter of a sphere generated by the full development of the spherically shaped sidewall, an annular mounting means clamped within said recess and having a central opening for the operator and an outer periphery defining a central sector of said sphere, said central opening having a diameter greater than the operator and being spaced from said operator and permitting movement of the mounting means indepedently of the body portion and the operator, a clamping means secured to said body portion in spaced relation to said mounting wall, said clamping means having a spherical chordal sector generally corresponding to and coaxially aligned with said spherical chordal sector defined by said recess and operable to firmly clamp the mounting means in position for supporting of the actuator, said body portion includes a tubular housing, said driven member being a piston member, a plurality of similar circumferentially distributed stop means, each of said stop means including a longitudinally extended slot in the sidewall of the member, a generally L-shaped stop member having a mounting leg and a stop leg of a length greater than the length of the slot, said stop member being located in said slot with the mounting leg extending generally radially of the housing and secured within said slot by a snap-joint means, each slot including a plurality of snap-joint means, said stop leg extending generally axially of the housing and said stop leg being longer than said slot whereby in all positions of said stop member the outer end of the stop leg overlaps the edge in the slot to hold the stop member in position in the path of said fluid driven member.

7. The actuator of claim 6 wherein said mounting leg includes an outer locating portion engaging the exterior wall of the body portion and an inner tapered cam portion terminating in spaced relation to the outer locating portion, and a latching offset portion between said cam portion and said outer locating portion.

8. In a pneumatic piston actuator having a piston member slidably mounted within a tubular member, a diaphragm overlying said piston member and dividing the tubular member into a pair of opposite piston-positioning chambers, at least on of said chambers having an input signal means for receiving of a pneumatic signal for positioning of the diaphragm and piston member, a piston rod secured to the piston member, said tubular member having a mounting wall with a mounting hub projecting outwardly of the wall, said mounting wall further including an annular recess encircling said hub, said recess defining a spherical chordal sector, a clamping member having means for releasably securing said clamping member on said hub in spaced relation to said mounting wall to define a clamping gap therebetween, said clamping member having a recess defining a spherical chordal sector generally corresponding to the spherical chordal sector of said recess, and a multiple part swivel member having an outer surface complementing said recesses and fixedly clamped within said recesses by said clamping member on said hub and having separable interconnecting means and operable for clamping a mounting wall therebetween.

9. The actuator of claim 8 wherein said swivel member is a ring having an outer spherically shaped surface, said ring including a pair of similar annular half-ring members each of which includes a plurality of circumferentially spaced resilient arms projecting axially into the opposite half-ring member, each of said rings having recesses between said arms with a slightly smaller diametrical spacing to establish an interference fit with said arms.

10. The actuator of claim 9 wherein said recesses and arms having chamfered edges to facilitate assembly of the half-ring members.

11. The actuator of claim 8 wherein said tubular member includes a cup-shaped cylindrical body having said mounting wall integrally formed to define the base portion of said body, a shallow cup-shaped head member having an outer sidewall adapted to telescope over the outer end wall of said cylindrical body member, the exterior surface of said cylindrical body member and the inner surface of said sidewall including a complementing recess and projection defining a connector, said telescoped walls having inclined camming surfaces to facilitate the telescoping movement of the members to align said snap connecting recess and projection.

12. In the actuator of claim 11, wherein said tubular member includes a plurality of similar circumferentially distributed stop means, each of said stop means including a longitudinally extended slot in the side wall of the member, a generally L-shaped stop member having a mounting leg and a depending stop leg, said stop member being located into said opening with the mounting leg extending generally radially and the stop leg extending generally axially of the tubular member, said stop leg being longer than said opening whereby in all positions of said stop member the outer end of the stop leg is extended beyond the edge of the opening, said mounting leg including being generally T-shaped with an outer locating cross-bar portion and a stem having an inner tapered cam portion terminating in spaced relation into the outer cross-bar portion with an inset latching portion included between said cam portion and said cross-bar in an interference fit with the edges of the opening.

13. The pneumatic actuator of claim 12 wherein said tubular member is a cup-shaped cylinder having an integral mounting wall, a shallow cup-shaped head member having an outer sidewall adapted to telescope over the outer end wall of said cylindrical body member, the exterior surface of said cylindrical body member and the inner surface of said sidewall including a complementing recess and projection, defining a connector, said telescoped walls having inclined camming surfaces to facilitate the telescoping movement of the members to align said snap connecting recess and projection.

14. The actuator of claim 13 wherein said swivel member is a ring having an outer spherically shaped surface, said ring including a pair of similar annular half-ring members each of which includes a plurality of circumferentially spaced resilient arms projecting axially into the opposite half-ring member, each of said rings having recesses between said arms with a slightly smaller diametrical spacing to establish an interference fit with said arms.

15. The actuator of claim 14 wherein said diaphragm is clamped between the cylinder and head, said diaphragm including a convolution location between the piston and the cylinder to define a rolling diaphragm construction.

16. In combination, a load device having a housing with a mounting opening in said housing, a fluid power actuator having a body portion with an integral actuator mounting wall adjacent said mounting opening, an integral hub member projecting from said mounting wall through said opening, an operator slidably journaled in said integral hub member, a fluid driven member in said body portion and connected to said operator, said mounting wall further including an annular recess encircling said opening, said recess defining a spherical chordal sector having a spherically shaped sidewall with an outer circular opening to the recess of a diameter less than the diameter of a sphere generated by the full development of the spherically shaped sidewall, said actuator being located with the mounting wall adjacent said housing and said hub projecting through said opening in said housing, an annular two piece mounting member having a pair of similar ring members with internal slot and projections defining a snap-joint connection of the ring members for clamping within said mounting opening, said ring members having an outer periphery defining a central sector of the sphere including said spherical chordal sector, and clamping means including a nut member with a spherical chordal sector generally corresponding to and coaxially aligned with said spherical chordal sector defined by said annular recess in said body portion to firmly clamp the body portion to the ring members for swivel mounting.

17. In combination, a load device having a housing with a mounting opening in said housing, a fluid power actuator having a body portion with an integral actuator mounting wall adjacent said mounting opening, an integral hub member projecting from said mounting wall through said opening, an operator slidably journaled in said integral hub member, a fluid driven member in said body portion and connected to said operator, said mounting wall further including an annular recess encircling said opening, said recess defining a spherical chordal sector having a spherically shaped sidewall with an outer circular opening to the recess of a diameter less than the diameter of a sphere generated by the full development of the spherically shaped sidewall, said actuator being located with the mounting wall adjacent said housing and said hub projecting through said opening in said housing, said hub being threaded, a threaded nut for releasable attachment to said hub with a tight fit between the threads of the hub and nut to firmly hold the nut on the hub for clamping of said actuator to said housing, a mounting member having a central opening for said operator and an outer periphery defining a central sector of the sphere, said mounting member being located over said hub, said nut includes a spherical chordal sector generally corresponding to and coaxially aligned with said spherical chordal sector defined by said annular recess in said body portion for clamping of the mounting member within the annular recesses in said nut and said mounting wall.

18. A pneumatic piston-diaphragm actuator comprising a cylinder having an end mounting wall, said base wall including an outwardly axially extending mounting hub with the outer end exteriorly threaded, a cup-shaped piston reciprocally mounted within said cylinder and having a coaxial hub, a piston rod extended into said hub and connected to the hub by an annular snap-joint, a coil spring encircling the piston rod within said cylinder and acting between the inner base wall of the cylinder and the base of the cup-shaped piston, a diaphragm overlying said piston and having an outer peripheral portion abutting the outer edge of the cylinder, a cup-shaped head telescoped over the cylinder and a cup-shaped head having a flange telescoped over the outer wall of the cylinder and connected thereto by a snap-joint, said head including an inner clamping ledge abutting the outer wall of the diaphragm and clamping the diaphragm between the cylinder and the head with a fluid-type joint, said diaphragm being a generally cup-shaped member having the sidewall formed into the shape of a convolution extending between the wall of the piston and the interior wall of the cylinder whereby said diaphragm rolls between the walls of the cylinder and the sidewall of the piston as said piston moves axially of the cylinder, the sidewalls of said cylinder including a pair of diametrically located stop slots extending longitudinally of the cylinder, a pair of L-shaped stop members located one within each of said slots, each of said L-shaped stop members including a mounting leg extending through the slot with an outer cross-bar abutting the outer surface of the cylinder, the stem of the leg including an inner tapered portion defining a camming member having an innermost end smaller than said slot and laterally enlarged to a recessed latching portion, said latching portion tapering inwardly to the outer stop portion whereby said member is lodged with the locking portion aligned with the cylinder wall to define an interference fit, each of said stops including a depending stop leg, said leg being longer than the slot whereby the outer end of the leg is located beneath the outermost edge of the slot in the assembled relation, a plurality of ledge members on the outer wall of the cylinder located in longitudinally spaced relation along the side of the slot, said cross-bar being located in adjacent relation to one of said ledges to hold the stop member in any one of a plurality of positions defined by said ledges, and said head having a fluid connector for interconnection to an incoming pneumatic signal line.