Electromagnetically actuated bistable magnetic latching pin lock

• US 7,408,433 B1
• Filed: 01/12/2007
• Issued: 08/05/2008
• Est. Priority Date: 01/12/2007
• Status: Expired due to Fees

• Current Assignee: Saia-Burgess Limited
• Original Assignee: Saia-Burgess Limited
• Inventors: Irwin, James C.
• Primary Examiner(s): Barrera; Ramon M.
• Application Number:
  US11/652,622
• Publication Number:
  US 20080169890A1
• Time in Patent Office: 571 Days
• Field of Search: 335228-234, 335/272
• US Class Current: 335/228
• CPC Class Codes: E05B 15/0053 means providing a stable, i.e. indexed, position of lock parts
• CPC Class Codes: E05B 47/0002 with electromagnets
• CPC Class Codes: E05B 47/0005 said core being rotary movable
• CPC Class Codes: E05B 47/0006 having a non-movable core; with permanent magnet
• CPC Class Codes: E05B 47/026 the bolt moving rectilinearly
• CPC Class Codes: H01F 7/122 by permanent magnets H01F7/1615, H01F7/1646 take precedence
• CPC Class Codes: H01F 7/14 Pivoting armatures H01F7/17 takes precedence
• CPC Class Codes: H01F 7/1615 Armatures or stationary parts of magnetic circuit having permanent magnet

Abstract

A pin lock is movably mounted for linear movement along a longitudinal axis. A magnet, preferably a permanent magnet, is mounted for limited rotation between the pin extended and pin retracted positions. An electromagnet provides a controllable electromagnetic field which encompasses at least a portion of the permanent magnet. A ferromagnetic latch is located within the magnetic field of the mounted magnet in each of the pin extended and pin retracted positions. A mechanical interconnection between the pin lock and the permanent magnet for moving the pin lock when the permanent magnet is rotated wherein the movement extends or retracts the pin lock between its pin extended and pin retracted positions. Reversing the electromagnetic field of the electromagnet serves to rotate the magnet so that the pin lock moves from one to the other of the two positions.

Claims

1. An electromagnetically actuated, bistable magnetic latching pin lock, said lock comprising:

a pin lock moveably mounted for linear movement along a longitudinal axis between a pin extended position and a pin retracted position;

a magnet having two pole ends, said magnet mounted for limited rotation about between said pin extended and pin retracted positions;

an electromagnet having first and second ends and electromagnetically actuated in one of said pin extended and pin retracted positions to provide one orientation of magnetic field and in the other of said pin extended and said pin retracted positions to provide a second orientation of magnetic field, said second orientation of magnetic field substantially the reverse of the first orientation of magnetic field, wherein actuation of said electromagnet biases said permanent magnet towards a field alignment rotation;

a ferromagnetic latch located within the magnetic field of said mounted magnet to latch the magnet into at least one of said pin extended and pin retracted positions in the absence of actuation of said electromagnet; and

a mechanical interconnection between said pin lock and said magnet for moving said pin lock from said pin extended position when said magnet is in said pin extended position to said pin retracted position when said magnet is in said pin retracted position, said magnet is located in the magnetic field of said electromagnet and moveable between said magnet pin extended and pin retracted positions in dependence on the orientation of said electromagnet magnetic field.

2. An electromagnetically actuated pin lock according to claim 1, wherein said magnet is a permanent magnet.

3. An electromagnetically actuated pin lock according to claim 2, wherein said permanent magnet is comprised of at least one of ceramic, samarium cobalt and neodymium.

4. An electromagnetically actuated pin lock according to claim 1, wherein said rotational movement of said magnet comprises substantially 90 degrees from said pin extended position to said pin retracted position.

5. An electromagnetically actuated pin lock according to claim 1, wherein said ferromagnetic latch comprises ferromagnetic material positioned closer to one pole end of said magnet when the magnet is in the pin extended position and closer to the other pole end of said magnet when the magnet is in the pin retracted position and magnetic attraction between at least one pole end of the magnet and the ferromagnetic material latches the magnet in at least one of said two magnet positions.

6. An electromagnetically actuated pin lock according to claim 5, wherein the magnet and the ferromagnetic material latches the magnet in both of said two magnet positions.

7. An electromagnetically actuated pin lock according to claim 1, wherein said mechanical interconnection between said pin lock and said magnet comprises:

a cam rotatable with said magnet; and

a cam follower associated with said pin lock, wherein when said cam is pivoted to said extended position, said cam moves said cam follower and said pin lock to said pin extended position and when said cam is pivoted to said pin retracted position, said cam moves said cam follower and said pin lock to said retracted position.

8. An electromagnetically actuated pin lock according to claim 7, wherein said cam has an area of substantially constant radius of curvature portion located on at least one end of the cam surface such that continued rotation of the cam does not result in additional longitudinal movement of the pin.

9. An electromagnetically actuated pin lock according to claim 7, wherein the cam has an area of substantially constant radius of curvature portion located on both ends of the cam surface such that continued rotation of the cam does not result in additional longitudinal movement of the pin at either end of the cam rotation.

10. An electromagnetically actuated pin lock according to claim 1, wherein said magnet has a longitudinal axis and said pin lock has a longitudinal axis, and said magnet axis is substantially transverse to said pin lock axis midway between said pin extended and pin retracted positions of said magnet.

11. An electromagnetically actuated pin lock according to claim 1, wherein said mechanical interconnection between said pin lock and said magnet comprises:

a sleeve connected to said magnet, said sleeve having a helical slot;

a mount for the pin lock, said mount permitting pin lock movement along its longitudinal axis and preventing rotation around said longitudinal axis; and

said pin lock including a follower located in said slot, wherein rotation of said magnet causes rotation of said sleeve, said slot in turn causing said follower to move in the pin lock longitudinal direction between extended and retracted positions.

12. An electromagnetically actuated pin lock according to claim 11, wherein said helical slot has a non-helical flat portion flat on one end such that continued rotation of the sleeve does not result in additional longitudinal movement of the pin lock in at least one of the pin retracted and pin extended positions.

13. An electromagnetically actuated pin lock according to claim 11, wherein said helical slot has a non-helical flat portion on both ends such that continued rotation of the sleeve does not result in additional longitudinal movement of the pin lock in both the pin retracted and pin extended positions.

14. An electromagnetically actuated pin lock according to claim 1, wherein said magnet has an axis of rotation and said pin lock has a longitudinal axis, and said magnet axis is substantially parallel to said pin lock axis.

15. An electromagnetically actuated, bistable magnetic latching pin lock, said lock comprising:

a pin lock moveably mounted for linear movement along a longitudinal axis between a pin extended position and a pin retracted position;

a permanent magnet having north and south pole ends, said magnet pivotally mounted for limited rotation about an axis which is substantially transverse to said pin lock longitudinal axis, said rotation is between said pin extended and pin retracted positions;

an electromagnet having first and second ends and electromagnetically actuated in one of said pin extended and pin retracted positions to provide a first orientation of magnetic field and in the other of said pin extended and pin retracted positions to provide a second orientation of magnetic field, said electromagnet magnetic field at least partially encompassing said magnet, wherein actuation of said electromagnet biases said permanent magnet towards a field alignment rotation;

a ferromagnetic latch located within the magnetic field of said pivotally mounted magnet to latch the magnet into at least one of said pin extended and pin retracted positions in the absence of actuation of said electromagnet;

a cam rotatable by said permanent magnet between pin extended and pin retracted positions; and

a cam follower engaging said cam and associated with said pin lock, said cam follower for moving said pin lock from one of said pin extended and pin retracted positions to the other of said pin extended and pin retracted positions, wherein said permanent magnet is located in the magnetic field of said electromagnet and is moveable between said magnet pin extended and pin retracted positions in dependence on the orientation of said electromagnet magnetic field.

16. An electromagnetically actuated pin lock according to claim 15, wherein said cam has an area of substantially constant radius of curvature portion located on at least one end of the cam surface such that continued rotation of the cam does not result in additional longitudinal movement of the pin.

17. An electromagnetically actuated pin lock according to claim 15, wherein the cam has an area of substantially constant radius of curvature portion located on both ends of the cam surface such that continued rotation of the cam does not result in additional longitudinal movement of the pin at either end of the cam rotation.

18. An electromagnetically actuated, bistable magnetic latching pin lock, said lock comprising:

a pin lock moveably mounted for linear movement along a longitudinal axis between a pin extended position and a pin retracted position;

a permanent magnet having pole ends, said magnet pivotally mounted for limited rotation about an axis substantially parallel with said longitudinal axis, said rotation is between said pin extended and pin retracted positions;

an electromagnet having first and second ends and electromagnetically actuated in one of said pin extended and said pin retracted positions to provide a first orientation of magnetic field and the other of said pin extended and pin retracted positions to provide a second orientation of magnetic field, said second orientation of magnetic field substantially the reverse of the first orientation of magnetic field, wherein actuation of said electromagnet biases said permanent magnet towards a field alignment rotation;

a ferromagnetic latch located within the magnetic field of said pivotally mounted magnet to latch the magnet into at least one of said pin extended and pin retracted positions in the absence of actuation of said electromagnet; and

a sleeve connected to said magnet, said sleeve having a helical slot;

a mount for the pin lock, said mount permitting pin lock movement along its longitudinal axis and preventing rotation around said longitudinal axis; and

said pin lock including a follower located in said helical slot, wherein rotation of said magnet causes rotation of said sleeve, said slot in turn causing said follower to move in the pin lock longitudinal direction between extended and retracted positions, wherein said permanent magnet is located in the magnetic field of said electromagnet and is moveable between said magnet pin extended and pin retracted positions in dependence on the orientation of said electromagnet magnetic field.

19. An electromagnetically actuated pin lock according to claim 18, wherein said helical slot has a flat on one end such that continued rotation of the sleeve does not result in additional longitudinal movement of the pin lock in at least one of the pin retracted and pin extended positions.

20. An electromagnetically actuated pin lock according to claim 18, wherein said helical slot has a flat on both end such that continued rotation of the sleeve does not result in additional longitudinal movement of the pin lock in both the pin retracted and pin extended positions.