Gauge pointer with integrated shape memory alloy actuator

• US 7,082,890 B2
• Filed: 05/03/2004
• Issued: 08/01/2006
• Est. Priority Date: 05/02/2003
• Status: Expired due to Fees

• Current Assignee: Alfmeier Prã¤Zision AG Baugruppen und Systemlã¶Sungen
• Original Assignee: Alfmeier Prã¤Zision AG Baugruppen und Systemlã¶Sungen
• Inventors: Szilagyi, Andrei, MacGregor, Roderick
• Primary Examiner(s): SMITH, RICHARD A
• Application Number:
  US10/838,644
• Publication Number:
  US 20040261688A1
• Time in Patent Office: 820 Days
• Field of Search: 116/284, 116/285, 116/290, 116/291, 116/292, 116/299, 116/221, 116/303, 605/27, 605/28, 74/25, 74/891.8, 340/815.78, 340/815.86, 702/94, 702/95, 702150-154, 374/187, 374/204, 374/205
• US Class Current: 116/284
• CPC Class Codes: F03G 7/065 using a shape memory element
• CPC Class Codes: G01D 13/22 Pointers, e.g. settable pointer
• CPC Class Codes: G01D 2213/10 Drivers for gauges

Abstract

An actuated gauge pointer that includes a shape memory alloy element configured to move the gauge pointer when activated is provided. The actuated gauge pointer includes a first shape memory alloy element disposed within the perimeter of the gauge pointer housing. Additionally, the actuated gauge pointer may include a second shape memory alloy element to provide temperature compensation, and a bias member to return the gauge pointer to an initial condition.

Claims

1. A shape memory alloy actuated indicator movably attached to a base, comprising:

an indicator having a housing surrounded by a perimeter, the housing being movably attachable to the base; and

a shape memory alloy element being no larger than the perimeter of said housing, said shape memory alloy element being attached to said housing within said perimeter,

wherein activation of said shape memory alloy element causes movement of said housing of said indicator relative to the base.

2. The shape memory alloy actuated indicator of claim 1, further comprising a second shape memory alloy element disposed within said perimeter of said indicator housing configured in an antagonistic arrangement to said shape memory alloy element.

3. The shape memory alloy actuated indicator of claim 1, further comprising a pin coupled to said indicator housing configured to provide a current to said shape memory alloy element.

4. The shape memory alloy actuated indicator of claim 1, further comprising an epicyclic gear mechanism disposed within said perimeter of said indicator housing and coupled to said shape memory alloy element such that activation of said shape memory alloy element moves said epicyclic gear mechanism which in turn moves said indicator.

5. The shape memory alloy actuated indicator of claim 1, further comprising a lever disposed within said perimeter of said housing and coupled to said housing, said shape memory alloy element coupled to said lever so that activation of said shape memory alloy element moves said lever and said housing.

6. The shape memory alloy actuated indicator of claim 5, wherein said lever is disposed entirely within said perimeter of said housing.

7. The shape memory alloy actuated indicator of claim 1, further comprising a bias member disposed within said perimeter of said housing such that when said shape memory alloy element is deactivated said bias member extends said shape memory alloy element and moves said housing to an initial condition.

8. The shape memory alloy actuated indicator of claim 7, wherein said bias member is disposed entirely within said perimeter of said housing.

9. A shape memory alloy actuated gauge pointer movably attachable to a base, comprising:

a gauge pointer housing having a perimeter; and

first and second shape memory alloy elements disposed within said perimeter of said gauge pointer housing and configured such that activation of said first shape memory alloy element causes movement of said gauge pointer housing relative to the base in a first direction, and activation of said second shape memory alloy element causes movement of said gauge pointer housing relative to the base in a second direction.

10. The actuated gauge pointer of claim 9, wherein said direction is opposite said first direction.

11. The actuated gauge pointer of claim 9, further comprising a pin coupled to said gauge pointer housing configured to provide current to each of said first and second shape memory alloy elements.

12. The actuated gauge pointer of claim 9, further comprising a epicyclic gear mechanism disposed within said perimeter of said gauge pointer housing and coupled to said first and second shape memory alloy elements such that activation of either said first or second shape memory alloy element moves said epicyclic gear mechanism which in turn moves said gauge pointer housing.

13. The actuated gauge pointer of claim 9, further comprising:

a lever disposed within said perimeter of said gauge pointer housing and coupled to said gauge pointer housing; and

said first and second shape memory alloy elements each coupled to said lever and said gauge pointer housing such that activation of either said first or second shape memory alloy elements moves said lever which in turn moves said gauge pointer housing.

14. The actuated gauge pointer of claim 13, wherein said lever is disposed entirely within said perimeter of said gauge pointer housing.

15. An actuated gauge pointer, comprising:

a fixed housing;

a gauge pointer coupled to said fixed housing via a pin;

a lever pivotably coupled to said fixed housing at a pivot point spaced from said pin and coupled to said gauge pointer; and

a shape memory alloy element coupled to said fixed housing and said lever configured such that activation of said shape memory alloy element causes movement of said lever relative to the fixed housing, thereby rotating the pin and the gauge pointer.

16. The actuated gauge pointer of claim 15, further comprising a second shape memory alloy element coupled to said fixed housing configured in an antagonistic arrangement to said shape memory alloy element.

17. The actuated gauge pointer of claim 15, further comprising a bias member coupled to said fixed housing such that when said shape memory alloy element is deactivated said bias member extends said shape memory alloy element and moves said gauge pointer to an initial condition.

18. A system for controlling a position of a gauge indicator movably attachable to a base, comprising:

a gauge indicator having a perimeter and being movably attachable to the base;

a shape memory alloy element disposed entirely within said gauge indicator perimeter and configured in that shape memory element activation results in gauge indicator movement relative to the base;

a position sensor that indicates said position information of said gauge indicator after shape memory alloy actuation; and

a condition responsive device adapted to control the activation of said shape memory alloy element in response to said position information provided by said position sensor and in accordance with a remote condition-indicating signal.

19. The system for controlling said position of a gauge indicator according to claim 18 wherein said position sensor is one of a resistive position sensor, a capacitive position sensor and an optical position sensor.

20. A method for positioning a gauge indicator, comprising:

applying a power signal within a housing of a gauge indicator;

actuating a shape memory alloy (“

SMA”

) element disposed entirely within said gauge indicator perimeter in response to said power signal; and

rotating a lever-type member,

wherein the rotating of said lever-type member causes a pin to rotate, thereby causing said housing to rotate.

21. The method for controlling said position of a gauge indicator according to of claim 20 further comprising:

sensing a position of said gauge pointer;

generating a position signal including information indicating the position of said gauge indicator; and

modifying said power signal if said information indicates said position differs from an expected position.

22. A shape memory alloy rotary actuator comprising:

a first anchor point, a second anchor point and a lever pivot point;

a rotatable shaft configured to rotate about an axis spaced from said lever point;

a flexible mechanical link having one end coupled to said rotatable shaft;

a lever having a first end coupled to said lever pivot point and a second end coupled to another end of said flexible mechanical link, said lever configured to rotate about said lever pivot point; and

a shape memory alloy element having a first end and a second end coupled to said first anchor point and said second anchor point, respectively, said second anchor point being disposed on said lever.

wherein the activation of said shape memory alloy element causes rotation of said rotatable shaft.

23. The shape memory alloy rotary actuator of claim 22, wherein said flexible mechanical link is tangentially coupled to said rotatable shaft by being wrapped around a portion of said rotatable shaft.

24. The shape memory alloy rotary actuator of claim 22, further comprising a second shape memory alloy element having a first end and a second end coupled to said first anchor point and a third anchor point disposed on said lever, respectively, wherein said second shape memory alloy is configured in an antagonistic arrangement to said shape memory alloy element.

25. The shape memory alloy rotary actuator of claim 22, further comprising a bias member having a first end attached to a third anchor point disposed on said lever and a second end configured to move said rotatable shaft to an initial condition when said shape memory alloy element is deactivated, said bias member thereby extending said shape memory alloy element.

26. A shape memory alloy rotary actuator, comprising:

a first anchor point, a second anchor point and a pivot point;

a planet gear;

a rotatable shaft disposed within said planet gear and coupled to said planet gear so both rotate about an axis simultaneously, said axis spaced from the pivot point;

a ring gear;

a member having a first portion including said ring gear configured to enmesh with said planet gear and a second portion coupled to said pivot point, said member configured to rotate about said pivot point; and

a shape memory alloy element having a first end and a second end coupled to said first anchor point and said second anchor point, respectively, said second anchor point being disposed on said member,

wherein the activation of said shape memory alloy element causes rotation of said rotatable shaft.

27. The shape memory alloy rotary actuator of claim 26, further comprising a second shape memory alloy element having a first end and a second end coupled to said first anchor point and a third anchor point disposed on said member, respectively, wherein said second shape memory alloy is configured in an antagonistic arrangement to said shape memory alloy element.

28. The shape memory alloy rotary actuator of claim 26, wherein said member, said ring gear and said planet gear form an epicyclic gear mechanism coupled to said shape memory alloy element such that activation of said shape memory alloy element moves said epicyclic gear mechanism which in turn rotates said rotatable shaft.

29. A shape memory alloy rotary actuator, comprising:

a first anchor point, a second anchor point and a pivot point;

a first flexible mechanical link and a second flexible mechanical link;

a rotatable shaft rotatable around an axis spaced from said pivot point and coupled tangentially to a first end of said first flexible mechanical link to rotate said rotatable shaft in a first direction of rotation and coupled tangentially to a first end of said second flexible mechanical link to rotate said rotatable shaft in a second direction of rotation;

a member having a first portion coupled to a second end of said first flexible mechanical link, a second portion coupled to a second end of said second flexible mechanical link, and a third portion coupled to said pivot point, said member configured to rotate about said pivot point; and

a shape memory alloy element having a first end and a second end coupled to said first anchor point and said second anchor point, respectively, said second anchor point being disposed on said member,

wherein the activation of said shape memory alloy element causes rotation of said rotatable shaft.

30. The shape memory rotary actuator of claim 29, further comprising a second shape memory alloy element having a first end and a second end coupled to said first anchor point and a third anchor point disposed on said member, respectively, wherein said second shape memory alloy is configured in an antagonistic arrangement to said shape memory alloy element.