Two axis position sensor using sloped magnets to generate a variable magnetic field and hall effect sensors to detect the variable magnetic field

• US 6,175,233 B1
• Filed: 02/02/1998
• Issued: 01/16/2001
• Est. Priority Date: 10/18/1996
• Status: Expired due to Fees

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Jarrard, Craig A., McCurley, Jeffrey L., Zdanys, John Jr., Olson, Thomas R., White, James E., Nonnenmacher, Ronald C.
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US08/999,585
• Time in Patent Office: 1,079 Days
• Field of Search: 324/207.2, 324/207.21, 324/207.22, 324/207.23, 324/207.24, 338/32.R, 338/32.H, 744/71.XY
• US Class Current: 324/207.2
• CPC Class Codes: F16H 59/68 Inputs being a function of gearing status
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01B 7/004 for measuring coordinates of points
• CPC Class Codes: G01B 7/023 for measuring distance between sensor and object G01B7/082 and G01B7/102 take precedence
• CPC Class Codes: G01D 2205/775 Tapered profiles
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: Y10T 74/20201 Control moves in two planes

Abstract

A dual-axes position sensor 10 having an outer housing 12, an actuator 40, a linear Hall effect sensor assembly 20 for detecting position changes along a first (y) axis, and a linear Hall effect sensor assembly 30 for detecting position changes along a second (x) axis is disclosed. The housing 12 is preferably made out of a non-magnetic material such as plastic. Actuator 40 is rod shaped and coupled to a movable device or shaft (not shown) that is to have its position sensed. The linear Hall effect sensor assembly 20 is unattachably positioned to set on lip 52 of the housing 12, and includes a magnetically conducting pole piece 26, a magnet assembly 24 comprising an upper magnet 21 and a lower magnet 23 that are separated by an air gap 25. Magnet assembly 24 and pole piece 26 are positioned around a Hall sensor device support 14 in a“U” shaped configuration or form. Hall sensor device support 14 is fixedly attached to housing 12 via attachment area 54. Linear Hall effect sensor assembly 20 also includes a positionally fixed Hall effect sensor element 22 attached to Hall sensor device support 14 on surface 15. Linear Hall effect sensor assembly 30 is positioned approximately 90 degrees from and to linear Hall effect sensor assembly 20.

Claims

1. A sensor for determining the linear position of a movable body along two different axes, comprising:

a) a housing being fixed in position against relative movement of a the body;

b) an actuator, positioned in the housing and coupled to the movable body for receiving reciprocating motion;

c) first linear sensing means, positioned within the housing and coupled to the actuator, for sensing the linear position of the actuator along a first axis wherein the first linear sensing means includes a first sloped magnet means and a first pole piece slidably engaged with the actuator to move with the linear position of the actuator;

d) second linear sensing means, positioned within the housing and coupled to the actuator, for sensing the linear position of the actuator along a second axis wherein the second linear sensing means includes a second sloped magnet means and a second pole piece slidably engaged with the actuator to move with the linear position of the actuator;

e) the first linear sensor having a first slide with a first slot thereon for slidably engaging the first linear sensor to the actuator; and

f) the second linear sensor having a second slide with a second slot thereon for slidably engaging the second linear sensor to the actuator.

2. The sensor of claim 1, wherein the movable body is a shifter that is coupled to the actuator.

3. The sensor of claim 1, wherein the first pole piece forms a U-shape, where the first magnet means includes first and second magnets that are placed upon opposite legs of the first pole piece forming a gap between therebetween.

4. The sensor of claim 3, wherein the first linear sensor includes a first Hall effect sensing element positioned within the gap to sense magnetic flux changes indicative of a relative position of the body.

5. The sensor of claim 1, wherein the second pole piece forms an U-shape where the second magnet means includes third and fourth magnets placed upon opposite legs of the second pole piece forming a void therebetween.

6. The sensor of claim 1, wherein the second linear sensor includes a second Hall effect sensing element positioned within the void to sense magnetic flux changes indicative of a relative position of the body.

7. A sensor for determining a linear position of a movable body along two different axes, comprising:

a) a housing;

b) an actuator coupled to the movable body, the actuator including;

b1) a shaft extending into the housing;

b2) a first slide located within the housing;

b3) a second slide located within the housing and positioned adjacent the first slide, the shaft coupled to the first and second slides;

c) a first magnetic field generator, coupled to the first slide, for generating a first magnetic field as the body moves along a first axis, the first magnetic field generator including a pair of sloped permanent magnets held opposed by a pole piece and mounted to the first slide;

d) a first magnetic field sensor affixed to the housing and located proximate the first magnetic field generator for sensing the first magnetic field, the first magnetic field sensor generating a first electrical signal corresponding to the position of the movable body along the first axis;

e) a second magnetic field generator, coupled to the second slide, for generating a second magnetic field as the body moves along a second axis, the second magnetic field generator including a pair of sloped permanent magnets held opposed by a pole piece and mounted to the second slide; and

f) a second magnetic field sensor affixed to the housing and located proximate the first magnetic field generator for sensing the second magnetic field, the second magnetic field sensor generating a second electrical signal corresponding to the position of the movable body along the second axis.

8. The sensor according to claim 7, wherein the first and second magnetic field sensors each are hall effect devices.

9. The sensor according to claim 8, wherein the first and second slides have a slot through which the shaft extends for slidably engaging the actuator.

10. The sensor according to claim 9, wherein the opposed magnets form an air gap.

11. The sensor according to claim 10, wherein the movable body is a transmission shift rod that is coupled to the actuator using a ball and socket connection.

12. A sensor for determining the position of a movable body along first and second orthogonal axes, comprising:

a) a housing being fixed in position against relative movement of a the body;

b) an actuator, positioned in the housing and coupled to the movable body, the actuator having a shaft extending therefrom;

c) a first slide, positioned adjacent the actuator for movement along the first axis, the first slide having a first slot therein, the shaft extending through the first slot;

d) a second slide, positioned adjacent the first slide for movement along the second axis, the second slide having a second slot therein, the shaft further extending through the second slot;

e) a first tapered magnet attached to the first slide for generating a first variable magnetic field;

f) a second tapered magnet attached to the second slide for generating a second variable magnetic field;

g) a first magnetic field sensor affixed to the housing and located proximate the first magnet for sensing a first magnetic flux, the first magnetic field sensor generating a first electrical signal corresponding to the position of the movable body along the first axis; and

h) a second magnetic field sensor affixed to the housing and located proximate the second magnet for sensing a second magnetic flux, the second magnetic field sensor generating a second electrical signal corresponding to the position of the movable body along the second axis.

13. The sensor according to claim 12, wherein the first and second magnets each are a pair of sloped permanent magnets held opposed by a pole piece.

14. The sensor according to claim 13, wherein the first and second magnetic field sensors each are hall effect devices.

15. The sensor according to claim 13, wherein the opposed magnets form an air gap.

16. The sensor according to claim 13, wherein the movable body is a transmission shift rod that is coupled to the actuator using a ball and socket connection.