Measuring device for determination of rotary angle

• US 5,175,497 A
• Filed: 10/29/1990
• Issued: 12/29/1992
• Est. Priority Date: 01/20/1990
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Dobler, Klaus, Hachtel, Hansjorg
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US07/606,055
• Time in Patent Office: 792 Days
• Field of Search: 324/207.11, 324/207.13, 324/207.15, 324/207.16, 324/207.17, 324/207.18, 324/207.19, 324/207.22, 324/207.25, 336/75, 336/77, 336/79, 336/134, 336/135, 336/200, 340/870.31, 340/870.32, 340/870.33, 340/870.34, 340/870.35
• US Class Current: 324/207.25
• CPC Class Codes: G01D 5/2006 by influencing the self-induction of one or more coils G01D5/22 takes precedence

Abstract

A measuring device for contactless determination of a rotary angle has two movable members which are rotatable relative to one another and two sensor coils whose resistance value to alternating current is varied by relative changes of values of regions of the members associated with the coils. One of the bodies members has a region corresponding to a number of the coils. At least one of the coils formed as a wire coil is arranged on the region. At least one second of the members is arranged on both end sides of the first member.

Claims

1. A measuring device for contactless determination of a rotary angle, comprising two movable members which are rotatable relative to one another;

coil means whose resistance value to alternating current is varied by relative changes of values of regions of said members associated with said coil means, one of said members having a region corresponding to said coil means, said coil means being formed as a wire coil being arranged on said region, at least one second of said members being arranged on both end sides of said first member, said second member having a region composed of a ferromagnetic material selected from the group consisting of a material which is ferromagnetic and electrically conductive and a material which is ferromagnetic, and another region composed of a material which is non-ferromagnetic and electrically conductive.

2. A measuring device as defined in claim 1, wherein one such second member is arranged at both end sides of said first member.

3. A measuring device as defined in claim 1, wherein said second members arranged at both end sides of said first member are approximately identical and arranged opposite to one another.

4. A measuring device as defined in claim 1, wherein said first member is composed of a material selected from an electrically conductive material and ferromagnetic material.

5. A measuring device as defined in claim 4, wherein the regions of said second members composed of same materials are located opposite to one another.

6. A measuring device as defined in claim 1, wherein said first body has an approximately D-shaped cross-section.

7. A measuring device as defined in claim 1, wherein said second members are formed as disc and extend over an angular region corresponding to said coil.

8. A measuring device of contactless determination of a rotary angle, comprising two movable members which are rotatable relative to one another;

coil means including two symmetrical, oppositely located sensor coils whose resistance value to alternating current is varied by relative changes of values of regions of said members associated with said coils, one of said members having a region corresponding to a a number of said coils, at least one of said coils formed as a wire coil being arranged on said region, at least one second of said members being arranged on both end sides of said first member, said second member being formed as disc composed of a material selected from the group consisting of a material which is ferromagnetic and electrically conductive and a material which is ferromagnetic and extend over an angular region greater than said coil.

9. A measuring device as defined in claim 8, wherein one such second member is arranged at both end sides of said first member.

10. A measuring device as defined in claim 8, wherein said second members arranged at both end sides of said first member are approximately identical and arranged opposite to one another.

11. A measuring device for contactless determination of a rotary angle, comprising two movable members which are rotatable relative to one another;

two coil means including symmetrical, oppositely located sensor coils whose resistance value to alternating current is varied by relative changes of values of regions of said members associated with said coils, one of said members having a region corresponding to a number of said coils, at least one of said coils formed as a wire coil being arranged on said region, at least one second of said members being arranged on both end sides of said first member, said second member being formed as disc composed of a material selected from the group consisting of a material which is ferromagnetic and electrically conductive and a material which is ferromagnetic and extend over an angular region greater than said coil, said second member having a region composed of a ferromagnetic material selected from the group consisting of a material which is ferromagnetic and electrically conductive, and a material which is ferromagnetic, and another region composed of a material which is non-ferromagnetic and electrically conductive.

12. A measuring device as defined in claim 11, wherein the regions of said second members composed of same materials are located opposite to one another.