Bi-stable pin actuator

Patent metadata

Field	Value
Publication number	US-10297376-B2
Application number	US-201715714119-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 25, 2017
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A bi-stable pin actuator includes a soft magnetic core and having a first central portion and a second central portion spaced apart from the first central portion. The first central portion has a first passage extending there-through and the second portion has a second passage extending there-through which is coaxial with the first passage. A first coil is wound about the first central portion and a second coil is wound about the second central portion. A pair of permanent magnets are located in the space between the first central portion and second central portion and attached to the core. An armature is movably positioned between and spaced apart from the permanent magnets. A pin is attached to the armature and extends into the first passage and second passages such that movement of the armature results in movement of the pin within the first passage and second passage. The armature moves between a first position wherein the armature is adjacent to the first central portion of the core and a second position wherein the armature is adjacent to the second central portion of the core. The armature is in one stable state when in the first position and in another of the stable state when in the second position. The magnets generate magnetic flux having a magnetic flux density sufficient to hold the armature in either of the stable states when neither of the coils is energized. When the armature is in the first stable state, only a first end of the pin protrudes from the core. When the armature is in the second stable state, only an opposite second end of the pin protrudes from the core. Energizing at least one of the coils generates a magnetic flux in one section of the actuator that opposes the magnetic flux holding the armature in a current stable state and supplements the magnetic flux in another section of the actuator so as to shift the armature into another stable state.

First claim

What is claimed is:

1. A bi-stable pin actuator comprising:
a core made from soft magnetic material and including a first central portion and a second central portion that is separated from the first central portion by a space, the first central portion having a first passage extending there-through and the second portion having a second passage extending there-through;
a first conductive coil wound about the first central portion of the core and configured to be energized with an electrical current;
a second conductive coil wound about the second central portion of the core and configured to be energized with an electrical current;
a first permanent magnet located within the space between the first central portion and second central portion and attached to the core;
a second permanent magnet located within the space between the first central portion and second central portion and attached to the core, the second permanent magnet being positioned across from the first permanent magnet;
wherein the first and second permanent magnets each have horizontally oriented North (N) and South (N) poles and like poles of the first and second permanent magnets face each other;
an armature made of soft magnetic material and movably positioned within the space between the first central portion and the second central portion, the armature being positioned between and spaced apart from the first permanent magnet and the second permanent magnet, the armature being movable between a first position wherein the armature is adjacent to the first central portion of the core and the first conductive winding and a second position wherein the armature is adjacent to the second central portion of the core and the second conductive winding, wherein the armature is in one stable state when in the first position and in another stable state when in the second position, the first permanent magnet and the second permanent magnet generating magnetic flux having a magnetic flux density sufficient to hold the armature in either the first stable state or the second stable state when neither coil is energized;
a pin member having a first end and an opposite second end and being attached to the armature, the pin extending into the first passage of the first central portion of the core and into the second passage of the second central portion of the core so that movement of the armature causes the pin to longitudinally move within the first passage and the second passage, wherein only the first end of the pin member protrudes from the core when the armature is in one stable state and only the opposite second end of the pin member protrudes from the core when the armature is in another stable state; and
wherein energizing at least one of the conductive coils generates in a first section of the bi-stable pin actuator a magnetic flux that opposes the magnetic flux holding the armature in a current stable state and supplements the magnetic flux in a second section of the bi-stable pin actuator so as to shift the armature into another stable state.

2. The bi-stable pin actuator according to claim 1 wherein the core comprises a first core section and a second core section attached to the first core section.

3. The bi-stable pin actuator according to claim 1 wherein the first core section and second core section are bolted together.

4. The bi-stable pin actuator according to claim 1 wherein the second passage is coaxial with the first passage.

5. The bi-stable pin actuator according to claim 4 wherein the armature includes a third passage that is coaxial with the first passage and the second passage, the pin being disposed in the third passage and attached to the armature.

6. The bi-stable pin actuator according to claim 2 wherein the first core section and second core section are identically constructed.

7. The bi-stable pin actuator according to claim 6 wherein the first core section includes the first central portion and further comprises:
a widthwise end portion;
a first generally “L” shaped leg portion that extends from the widthwise end portion;
a second generally “L” shaped leg portion that extends from the widthwise end portion; and
wherein the first central portion extends from the widthwise end portion and is located between and spaced apart from the first generally “L” shaped leg portion and the second generally “L” shaped leg portion, the first central portion extending to an end.

8. The bi-stable pin actuator according to claim 6 wherein the second core section includes the second central portion and further comprises:
a widthwise end portion;
a first generally “L” shaped leg portion that extends from the widthwise end portion;
a second generally “L” shaped leg portion that extends from the widthwise end portion; and
wherein the second central portion extends from the widthwise end portion and is located between and spaced apart from the first generally “L” shaped leg portion and the second generally “L” shaped leg portion, the second central portion extending to an end.

9. The bi-stable pin actuator according to claim 1 further including a first spool mounted on the first central portion, wherein the first conductive coil is wound about the first spool.

10. The bi-stable pin actuator according to claim 9 further including a second spool mounted on the second central portion, wherein the second conductive coil is wound about the second spool.

11. The bi-stable pin actuator according to claim 10 wherein the first spool and second spool are made from fiberglass.

12. The bi-stable pin actuator according to claim 1 wherein the first permanent magnet and the second permanent magnet are rare-earth magnets.

13. The bi-stable pin actuator according to claim 1 wherein the first permanent magnet and the second permanent magnet are bonded to the core.

14. The bi-stable pin actuator according to claim 1 wherein the core includes a plurality of thru-holes for receiving fastener devices for attaching the bi-stable pin actuator to a structure or apparatus.

Assignees

• Nasa

Inventors

• Church Joseph C

Classifications

• H01F2007/1692

  Electromagnets or actuators with two coils · CPC title

• H01F2007/1669

  Armatures actuated by current pulse, e.g. bistable actuators · CPC title

• H01F7/1615 Primary

  Armatures or stationary parts of magnetic circuit having permanent magnet · CPC title

• H01F7/1646 Primary

  Armatures or stationary parts of magnetic circuit having permanent magnet · CPC title