Electric fail-safe actuator

• US RE30,135 E
• Filed: 10/29/1975
• Issued: 11/06/1979
• Est. Priority Date: 02/09/1973
• Status: Expired due to Term

• Current Assignee: Frederick W. Lowe, Madelyn Y. Lowe Lowe
• Original Assignee: Amelia Incorporated
• Inventors: Fitzwater, deceased, John H., Fitzwater, executrix, by Amelia
• Primary Examiner(s): Scott, Samuel
• Assistant Examiner(s): Turner, R. C.
• Application Number:
  US05/626,723
• Time in Patent Office: 1,469 Days
• Field of Search: 74/2, 74/625, 251/66, 251/68, 251/69, 251/70, 251/71
• US Class Current: 74/2
• CPC Class Codes: F16K 17/36 actuated in consequence of extraneous circumstances, e.g. shock, change of position
• CPC Class Codes: F16K 31/043 characterised by mechanical means between the motor and the valve, e.g. lost motion means reducing backlash, clutches, brakes or return means
• CPC Class Codes: F16K 31/563 for rotating or pivoting valves
• CPC Class Codes: Y10T 74/11 Tripping mechanism

Abstract

An electrically operated fail-safe valve actuator employs a spring which is wound to store energy during operation of the electric drive motor, an electric clutch operable to disengage the drive motor from the actuator output shaft in response to loss of power from the electrical supply whereby the spring drives the valve in the opposite direction.

Claims

3. winding and said spring means..]. .[.14. In an electric valve actuator of the type wherein electric motor means is connectible to an electrical supply and mechanically connectible to a valve by way of the motor output shaft, the improvement therein of fail-safe means comprising:

spring motor means interposed between the electric motor means and the valve and operated to store energy upon driving of the valve by the electric motor means; and

electric clutch means connectible with the electric motor means to the electrical supply and energizible with the electric motor means to engage the electric motor means and said spring motor means and deenergizible upon a loss of power from the electrical supply to disengage the electric motor means and said spring motor means, whereupon said spring motor means is operable to drive the valve in the direction opposite to that driven by the electric motor means..]. .[.15. The improvement set forth in claim 14, wherein said spring motor means comprises;

a rotatably mounted actuator output shaft for connection to the valve; and

a spring having a fixed end and an end connected to said rotatable actuator

4. output shaft..]. .[.16. The improvement set forth in claim 15, wherein said electric clutch means comprises:

an electromagnetic coil;

a clutch armature attracted upon energization of said coil and mounted on said actuator output shaft for relative rotary and fixed axial movement with respect to said shaft; and

a clutch spring disposed about the output shaft of the electric motor means and said actuator output shaft and urged by said clutch armature to engage the two shafts for mutual rotation in response to energization of said electromagnetic coil..]. .[.17. An electric fail-safe valve actuator for connection to a valve, comprising;

an electric motor for driving the valve in one direction;

a spring motor, wound by said electric motor, for driving the valve in the opposite direction; and

an electric clutch energized with said electric motor for engaging said electric and spring motors and deenergized with said electric motor for disengaging said motors and permitting said spring motor to drive the valve..]. .[.18. An electric fail-safe actuator according to claim 17, comprising;

a housing including

an intermediate wall dividing said housing into two compartments,

said electric motor mounted in one of said compartments, and

spring motor and said electric clutch mounted in the other compartment..].

5. [.19. An electric fail-safe valve actuator according to claim 18, wherein said spring motor comprises:

a rotatably mounted output shaft for connection to the valve; and

a spring mounted about said spring motor output shaft, said spring having a first end fixed to said housing and a second end fixed to said output shaft..]. .[.20. An electric fail-safe valve actuator according to claim 18, wherein said electric motor comprises;

a rotatably mounted output shaft;

said spring motor comprises;

a rotatably mounted output shaft; and

a spring disposed about said spring motor output shaft including a first end fixed to said housing and a second end fixed to said spring motor output shaft; and

said electric clutch comprises;

an electromagnetic coil; and

means responsive to the energization of said coil to engage said two output

6. shafts..]. .[.21. An electric fail-safe actuator according to claim 20

wherein said electric motor output shaft and said spring motor output shaft are axially aligned;

wherein said means responsive to the energization of said coil comprises

an armature carried about said spring motor output shaft for axial movement therealong; and

a clutch spring carried by said electric motor output shaft and disposed about both of said motor shafts, said clutch spring being urged by said armature to couple said shafts for mutual rotation upon energizaton of said coil..]. .[.22. An electric fail-safe valve actuator according to claim 21, wherein said electric motor output shaft comprises;

an axial bore extending through said shaft;

said spring motor output shaft comprises;

an axial bore extending at least partially into said shaft; and

wherein said actuator further comprises;

a cam shaft fixed in said bore of said spring motor output shaft and rotatably received through said electric motor output shaft, said cam shaft extending from said other compartment into said one compartment;

at least one cam mounted on said cam shaft; and

a limit switch disposed in said one compartment for operation by said cam when said valve is at a predetermined setting, said limit switch electrically connected between said electric motor and the electrical

7. supply..]. .[.23. An electric fail-safe valve actuator according to claim 17, comprising:

a brake mounted on said electric motor including a brake solenoid electrically connected to said motor for simultaneous energization therewith, said brake operated to a non-braking condition upon energization..]. .[.24. An electric fail-safe valve actuator according to claim 23, wherein said brake comprises;

a brake drum mounted on said electric motor shaft;

a brake band about said brake drum biased to a braking condition; and

a mechanical linkage connected between said solenoid and said brake band..]. .[.25. An electric fail-safe valve actuator according to claim 24, wherein said solenoid is mounted on the side of said electric motor and includes an extensible member connected to said linkage..]. .[.26. An electric fail-safe valve actuator according to claim 25, wherein said mechanical linkage comprises;

a first plate fixed to one end of said electric motor adjacent said brake drum;

a second plate pivotally carried on said first plate, said second plate including means connected to the ends of said brake band;

a third plate pivotally carried on said first plate and pivotally connected to said extensible member and pivotal to pivot said second plate; and

a bias spring connected between said first and second plates to bias said

8. second plate to tighten said band about said drum..]. .[.27. An electric fail-safe valve actuator according to claim 26, wherein said first plate includes an arm extending at a right angle to the plate generally parallel to the side of said electric motor and pivotally mounting said third plate..]. .[.28. An electric fail-safe valve actuator according to claim 27, wherein said first plate includes a second arm extending therefrom and mounting one end of said bias spring..]. .[.29. An electric fail-safe valve actuator for connection to a valve, comprising:

an electric motor for driving the valve in one direction;

spring motor, wound by said electric motor, for driving the valve in the opposite direction; and

an electric clutch energized with said electric motor for engaging said electric and spring motors and deenergized with said electric motor for disengaging said motors and permitting said spring motor to drive the valve, said spring motor including a prewound spring having energy stored therein before being wound by said electric motor..]. .[.30. An electrically operated actuator for operating a device from one position to another, comprising;

an electric motor for connection to an electrical supply;

means for connecting said motor to the device for driving the device in one direction, including electric clutch means for connection to the electrical supply and normally energized to connect said motor in driving engagement with the device and deenergized in response to loss of power from the electrical supply to disengage the device from said motor; and

energy storage means for connection to the device responsive to the operation of said motor to store energy and responsive to disengagement of said motor from the device to drive the device in the opposite direction..]. .[.31. In an actuator of the type having an electric motor for connection to and driving a device toward a first predetermined position and a limit switch for opening the powering circuit of the motor when the device has reached the first predetermined position the improvement comprising;

coupling means for connection to the power supply for the motor and interposed between the motor and the device said coupling means including means normally engaged between the device and the motor and responsive to a loss of power from the power supply to disengage the motor and the device; and

energy storage means for connection to the device and engaged with the motor by said means which normally causes engagement between the motor and the device, said energy storage means storing energy upon driving of the device toward the first predetermined condition and responsive to disengagement to drive the device toward a second predetermined

9. position..]. .Iadd. 32. An electrically operated valve actuator, comprising:

an electric motor for connection to an electrical supply;

means for connecting said motor to a valve for driving the valve in one direction, including electric clutch means for connection to the electrical supply and normally energized to connect said motor in driving engagement with the valve and deenergized in response to loss of power from the electrical supply to disengage the valve from said motor;

energy storage means for connection to the valve responsive to the operation of said motor to store energy and responsive to disengagement of said motor from the valve to drive the valve in the opposite direction;

switch means operated in response to a predetermined number of revolutions of said motor to disconnect said motor from the electrical supply; and

brake means operated in response to the operation of said switch means to hold the valve in the position driven by said motor,

said electric clutch means including a pair of axially aligned shaft means, an electromagnetic coil disposed about one of said shaft means, a clutch armature disposed about said one shaft means and axially movable toward the other shaft means, a torsion spring disposed about said other shaft means and having one end connected to said other shaft means and the other end disposed adjacent said armature, and means on said armature for gripping the other end of said torsion spring to cause a tightening of said torsion spring about said pair of shaft means to couple said shaft means together when said electric motor is energized to drive the

10. valve..Iaddend..Iadd. 33. An electrically operated valve actuator according to claim 32, wherein said brake means includes an electromagnetic device for connection to the electrical supply and normally energized with said motor to a non-braking condition..Iaddend..Iadd. 34. An electrically operated valve actuator, comprising:

electric motor means for connection to an electrical supply to drive a valve, said motor means including an electric motor, an output shaft and switch means including contacts connected between said motor and the electrical supply, said switch means including a switch operating shaft coupled to said output shaft and operated upon a predetermined number of revolutions thereof to disconnect said motor from the electrical supply;

electric brake means for connection to the valve and electrically connected to said switch means, said brake means operated in response to the operation of said switch means to hold the valve in the position driven by said motor;

energy storage means for connection to the valve and operated to store energy upon the operation of the valve in one direction; and

electric clutch means connected between said motor and the valve and electrically connected to the electrical supply, said clutch means operable to disengage said motor from the valve in response to loss of power from the electrical supply whereupon said energy storage means becomes effective to drive the valve in the opposite direction. .Iaddend..Iadd. 35. An electrically operated valve actuator, comprising;

electric motor means for connection to an electrical supply to drive a valve, said motor means including an electric motor, an output shaft and switch means including contacts connected between said motor and the electrical supply, said switch means coupled to said output shaft and operated upon a predetermined number of revolutions thereof to disconnect said motor from the electrical supply;

electric brake means for connection to said motor and electrically connected to said switch means, said brake means operated in response to the operation of said switch means to hold the valve, via said motor, in the position driven by said motor;

energy storage means for connection to the valve and operated to store energy upon operation of the valve in one direction;

electric clutch means connected between said motor and the valve and electrically connected to the electrical supply, said clutch means operable to disengage said motor from the valve in response to loss of power from the electrical supply whereupon said energy storage means becomes effective to drive the valve in the opposite direction; and

an actuator output shaft for connection to the valve, said actuator output shaft axially aligned with said motor output shaft,

said electric clutch means including a clutch winding for connection to the electrical supply, a clutch armature mounted for axial movement with respect to said motor output shaft and said actuator output shaft upon energization and deenergization of said clutch winding, and spring means carried by one of said shafts and disposed about both of said shafts, said spring means urged by said clutch armature to frictionally embrace the other of said shafts for driving engagement with said one shaft upon

1. the position driven by said motor..]. .[.3. An electrically operated valve actuator according to claim 2, wherein said brake means includes an electromagnetic device for connection to the electrical supply and normally energized with said motor to a non-braking condition..]. .[.4. In a valve actuator of the type having an electric motor for connection to and driving a valve toward a first predetermined condition and a limit switch for opening the powering circuit of the motor when the valve has reached the first predetermined condition, the improvement comprising:

coupling means for connection to the power supply for the motor and interposed between the motor and the valve, said coupling means including means normally engaged between the valve and the motor and responsive to a loss of power from the power supply to disengage the motor and the valve; and

energy storage means for connection to the valve and engaged with the motor by said means which normally causes engagement between the motor and the valve, said energy storage means storing energy upon driving of the valve toward the first predetermined condition and responsive to disengagement to drive the valve toward a second predetermined condition..]. .[.5. An electrically operated valve actuator, comprising;

electric motor means for connection to an electrical supply to drive a valve, said motor means including an electric motor, an output shaft and switch means including contacts connected between said motor and the electrical supply, said switch means coupled to said output shaft and operated upon a predetermined number of revolutions thereof to disconnect said motor from the electrical supply;

electric brake means for connection to the valve and electrically connected to said switch means, said brake means operated in response to the operation of said switch means to hold the valve in the position driven by said motor;

energy storage means for connection to the valve and operated to store energy upon operation of the valve in one direction; and

electric clutch means connected between said motor and the valve and electrically connected to the electrical supply, said clutch means operable to disengage said motor from the valve in response to loss of power from the electrical supply whereupon said energy storage means becomes effective to drive the valve in the opposite direction..]. .[.6. An electrically operated valve actuator according to claim 5, comprising;

an actuator output shaft for connection to the valve, said actuator output shaft axially aligned with said motor output shaft;

said electric clutch means including a clutch winding for connection to the electrical supply, a clutch armature mounted for axial movement with respect to said motor output shaft and said output shaft upon energization and deenergization of said clutch winding, and spring means carried by one of said shafts and disposed about both of said shafts, said spring means urged by said clutch armature to frictionally embrace the other of said shafts for driving engagement with said one shaft upon energization of

2. said clutch winding..]. .[.7. An electrically operated valve actuator according to claim 6, wherein said clutch armature includes a central bore which receives said actuator output shaft therethrough and a surface disposed at an angle to the axis of said actuator output shaft to engage and urge said spring means axially and radially inwardly against said actuator output shaft..]. .[.8. An electrically operated valve actuator according to claim 6, wherein said clutch winding includes a central bore receiving said actuator output shaft therethrough, and said surface of said clutch armature is disposed between said clutch winding and said spring means..]. .[.9. An electrically operated valve actuator according to claim 8, wherein said clutch armature includes a bearing carried on and slidable axially along said actuator output shaft, a first armature portion mounted at one end of said bearing and a second armature portion mounted at the other end of said bearing and carrying said surface for engagement with said spring means..]. .[.10. An electrically operated valve actuator, comprising:

an actuator housing including first and second end walls, sidewalls and compartment wall dividing said housing into a motor compartment and a clutch compartment;

electric motor means mounted in said motor compartment for connection to an electrical supply to drive a valve, said motor means including an electric motor, a motor output shaft and switch means including contacts interposed between said motor and the electrical supply, said switch means coupled to said motor output shaft and operated upon a predetermined number of revolutions thereof to disconnect said motor from the electrical supply;

an actuator output shaft extending through said clutch compartment for connection to a valve to be actuated;

energy storage means mounted in said clutch department and connected between said actuator housing and said actuator output shaft, said energy storage means operated to store energy upon operation of the valve in one direction; and

electric clutch means mounted in said clutch compartment for connecting said motor output shaft to said actuator output shaft, said electric clutch means electrically connected to the electrical supply and operable to disengage said motor output shaft and said actuator output shaft in response to loss of power from the electrical supply whereupon said energy storage means drives the valve in the opposite direction..]. .[.11. An electrically operated valve actuator according to claim 10, wherein said actuator output shaft and said motor output shaft are mounted for rotation and have the same axis of rotation, and wherein said electric clutch means includes a clutch winding for connection to the electrical supply, a clutch armature mounted for movement along the axis of rotation of said shafts, and spring means carried about said motor output shaft and said actuator output shaft for causing engagement and disengagement between said shafts in response to movement of said clutch armature..]. .[.12. An electrically operated valve actuator according to claim 11, wherein said clutch armature includes a bore for receiving said actuator output shaft therethrough, and having at least one surface disposed at an angle to the axis of said shafts to engage and urge said spring means axially and radially inwardly with respect to said shafts..]. .[.13. An electrically operated valve actuator according to claim 11, wherein said clutch winding is fixed to one of said walls within said clutch compartment and includes a bore for receiving said actuator output shaft therethrough, and wherein at least a portion of said clutch armature is disposed between said clutch

11. energization of said clutch winding. .Iaddend..Iadd. 36. An electrically operated valve actuator according to claim 35, wherein said clutch armature includes a central bore which receive said actuator output shaft therethrough and a surface disposed at an angle to the axis of said actuator output shaft to engage and urge said spring means axially and radially inwardly against said actuator output shaft. .Iaddend. .Iadd. 37. An electrically operated valve actuator according to claim 35, wherein said clutch winding includes a central bore receiving said actuator output shaft therethrough, and said surface of said clutch armature is disposed between said clutch winding and said spring means. .Iaddend..Iadd. 38. An electrically operated valve actuator according to claim 37, wherein said clutch armature includes a bearing carried on and slidable axially along said actuator output shaft, a first armature portion mounted at one end of said bearing and a second armature portion mounted at the other end of said bearing and carrying said surface for engagement with said spring means. .Iaddend..Iadd. 39. An electrically operated valve actuator, comprising:

an actuator housing including first and second end walls, sidewalls and a compartment wall dividing said housing into a motor compartment and a clutch compartment;

electric motor means mounted in said motor compartment for connection to an electrical supply to drive a valve, said motor means including an electric motor, a motor output shaft, switch means including contacts interposed between said motor and the electrical supply, and switch actuating means including cam means for engaging said switch means and a cam shaft connected to and rotatable with said motor output shaft, said switch means operated upon a predetermined number of revolutions of said motor output shaft to disconnect said motor from the electrical supply;

brake means mechanically connected to said electric motor and electrically connected to said switch means and responsive to the operation of said switch means to hold the valve in the condition driven by said electric motor;

an actuator output shaft extending through said clutch compartment for connection to a valve to be actuated;

energy storage means mounted in said clutch compartment and connected between said actuator housing and said actuator output shaft, said energy storage means operated to store energy upon operation of the valve in one direction of the valve in one direction; and

electric clutch means mounted in said clutch compartment for connecting said motor output shaft to said actuator output shaft, said electric clutch means electrically connected to the electrical supply and operable to disengage said motor output shaft and said actuator output shaft in response to loss of power from the electrical supply whereupon said energy storage means drives the valve in the opposite direction. .Iaddend..Iadd. 40. An electrically operated valve actuator according to claim 39, wherein said actuator output shaft and said motor output shaft are mounted for rotation and have the same axis of rotation, and wherein said electric clutch means includes a clutch winding for connection to the electrical supply, a clutch armature mounted for movement along the axis of rotation of said shafts, and spring means carried about said motor output shaft and said actuator output shaft for causing engagement and disengagement between said shafts in response to movement of said clutch armature. .Iaddend. .Iadd. 41. An electrically operated valve actuator according to claim 40, wherein said clutch armature includes a bore for receiving said actuator output shaft therethrough, and having at least one surface disposed at an angle to the axis of said shafts to engage and urge said spring means axially and radially inwardly with respect to said shafts. .Iaddend..Iadd. 42. An electrically operated valve actuator according to claim 40, wherein said clutch winding is fixed to one of said walls within said clutch compartment and includes a bore for receiving said actuator output shaft therethrough, and wherein at least a portion of said clutch armature is disposed between said clutch winding and said spring means. .Iaddend..Iadd. 43. In an electric valve actuator of the type wherein electric motor means is connectible to an electrical supply and mechanically connectible to a valve by way of the motor output shaft, the improvement therein of fail-safe means comprising;

spring motor means interposed between the electric motor means and the valve and operated to store energy upon driving of the valve by the electric motor means; and

electric clutch means connectible with the electric motor means to the electrical supply and energizable with the electric motor means to engage the electric motor means and said spring motor means and deenergizable upon a loss of power to disengage the electric motor means and said spring motor means, whereupon said spring motor means is operable to drive the valve in the direction opposite to that driven by the electric motor means,

said spring motor means comprising a rotatably mounted actuator output shaft for connection to the valve, and a spring having a fixed end and another end connected to said rotatable actuator output shaft,

and said electric clutch means comprising an electromagnetic coil, a clutch armature attracted upon energization of said coil and mounted on said actuator output shaft for relative rotary and axial movement with respect to said actuator output shaft, and a clutch spring disposed about the output shaft of the electric motor means and said actuator output shaft and urged by said clutch armature to engage the two shafts from mutual rotation in response to energization of said electromagnetic coil.

12. Iaddend..Iadd. 44. An electric fail-safe actuator for connection to a valve, comprising:

an electric motor for driving the valve in one direction;

a spring motor, wound by said electric motor, for driving the valve in the opposite direction,

an electric clutch energized with said electric motor for engaging said electric and spring motors and deenergized with said electric motor for disengaging said electric and spring motors and permitting said spring motor to drive the valve;

a housing including an intermediate wall dividing said housing into two compartments, said electric motor mounted in one of said compartments, and said spring motor and said electric clutch mounted in the other compartment,

said electric motor comprising a rotatably mounted output shaft,

said spring motor comprising a rotatably mounted output shaft for connection to the valve, and a spring mounted about said spring motor output shaft, said spring having a first end fixed to said housing and a second end connected to said output shaft,

said electric clutch comprising an electromagnetic coil, and means responsive to the energization of said coil to engage said two output shafts,

said electric motor output shaft and said spring motor output shaft being axially aligned, and

said means responsive to the energization of said coil comprising an armature carried about said spring motor output shaft for axial movement therealong, and a clutch spring carried by said electric motor output shaft and disposed about both of said motor shafts, said clutch spring being urged by said armature to couple said shafts for mutual rotation

13. upon energization of said coil. .Iaddend..Iadd. 45. An electric fail-safe valve actuator according to claim 44, wherein said electric motor output shaft comprises an axial bore extending through said shaft;

said spring motor output shaft comprises an axial bore extending at least partially into said shaft, and said actuator further comprises a cam shaft fixed in said bore of said spring motor output shaft and rotatably received through said electric motor output shaft, said cam shaft extending from said other compartment into said one compartment;

at least one cam mounted on said cam shaft; and

a limit switch disposed in said one compartment for operation by said cam when said valve is at a predetermined setting, said limit switch electrically connected between said electric motor and the electrical supply. .Iaddend. .Iadd. 46. An electric fail-safe valve actuator for connection to a valve, comprising;

an electric motor for driving the valve in one direction;

a spring motor, wound by said electric motor, for driving the valve in the opposite direction;

an electric clutch energized by said electric motor for engaging said electric and spring motors and deenergized with said electric motor for disengaging said electric and spring motors and permitting said spring motor to drive the valve; and

a brake mounted on said electric motor including a brake solenoid electrically connected to said motor for simultaneous energization therewith, said brake operated to a non-braking condition upon energization, a brake drum mounted on said electric motor shaft, a brake band disposed about said brake drum and biased to a braking condition, and a mechanical linkage connected between said solenoid and said brake band. .Iaddend..Iadd. 47. An electric fail-safe valve actuator according to claim 46, wherein said solenoid is mounted on the side of said electric motor and includes an extensible member connected to said linkage. .Iaddend..Iadd. 48. An electric fail-safe valve actuator according to claim 47, wherein said mechanical linkage comprises;

a first plate fixed to one end of said electric motor adjacent said brake drum;

a second plate pivotally carried on said first plate, said second plate including means connected to the ends of said brake band;

a third plate pivotally carried on said first plate and pivotally connected to said extensible member and pivotal to pivot said second plate; and

a bias spring connected between said first and second plates to bias said second plate to tighten said band about said drum. .Iaddend..Iadd. 49. An electric fail-safe valve actuator according to claim 48, wherein said first plate includes an arm extending at a right angle to the plate generally parallel to the side of said electric motor and pivotally mounting said third plate. .Iaddend..Iadd. 50. An electric fail-safe valve actuator according to claim 49, wherein said first plate includes a second arm extending therefrom and mounting one end of said bias spring. .Iaddend.