Shaft rotary position sensor

• US 5,300,918 A
• Filed: 02/04/1993
• Issued: 04/05/1994
• Est. Priority Date: 03/06/1992
• Status: Expired due to Term

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Becker, Manfred
• Primary Examiner(s): Lateef, Marvin M.
• Application Number:
  US08/014,302
• Time in Patent Office: 425 Days
• Field of Search: 338/196, 338/162, 338/176, 338/DIG. 1
• US Class Current: 338/196
• CPC Class Codes: G01B 7/30 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01D 5/04 using levers; using cams; using gearing
• CPC Class Codes: G01D 5/165 by relative movement of a point of contact or actuation and a resistive track
• CPC Class Codes: Y10S 338/01 Worm gear drive

Abstract

A position sensor assembly for sensing the rotary position of a rockshaft of a hitch mechanism includes a rotary potentiometer coupled to the rockshaft. The rockshaft is enclosed in a rockshaft housing and a sensor housing is attached to the rockshaft housing. The potentiometer is attached to an outside surface of the sensor housing and has a sensor shaft which extends through a portion of the sensor housing. The position sensor has a first set of gear teeth on the rockshaft meshing with a second set of gear teeth on the sensor shaft. The sensor housing at least partially encloses the second set of gear teeth. The first and second sets of gear teeth are preferably configured as gear segments. The sensor shaft is supported for rotation by the sensor housing. The potentiometer is preferably a spring-pre-loaded potentiometer. A second spring is mounted on the second set of gear teeth and is engagable with a wall of the sensor housing to define an assembly position.

Claims

1. In an assembly including a rotatable main shaft enclosed in a main shaft housing, a position sensor assembly for sensing the rotary position of the main shaft, the assembly including a rotary potentiometer coupled to the main shaft, characterized by:

a sensor housing attached to the main shaft housing; and

the potentiometer is attached to an outside surface of the sensor housing, and the potentiometer having a sensor shaft which extends through a portion of the sensor housing and which is rotatably coupled to the main shaft.

2. The position sensor of claim 1 characterized by:

a first set of gear teeth on the main shaft meshing with a second set of gear teeth on the sensor shaft, the sensor housing at least partially enclosing the second set of gear teeth.

3. The position sensor of claim 2, wherein:

the first and second sets of gear teeth are configured as gear segments.

4. The position sensor of claim 1, wherein:

the sensor shaft is supported for rotation by the sensor housing.

5. The position sensor of claims 1 wherein:

the potentiometer is a spring-pre-loaded potentiometer.

6. The position sensor of claim 2, wherein:

the sensor shaft can be rotated from a first limit position to a second limit position; and

a gear segment spring is mounted on the second set of gear teeth, the spring having an arm which is engagable with the sensor housing when the sensor shaft is rotated one of the limit positions.

7. The position sensor of claim 6, wherein:

the potentiometer is a spring-pre-loaded potentiometer; and

the gear segment spring is at least twice as stiff as that of the potentiometer spring.

8. The position sensor of claim 6, wherein:

the gear segment spring arrangement is configured as a flat spring which is attached to the second set of gear teeth and which extends approximately radially from a central portion of thereof.