US4075478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Floating head encoder
Assignee: MOTION SYSTEMS COMPANY Inc
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Filing: 1976-06-03
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Granted: 1978-02-21
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Expires: 1996-06-03
Abstract
Abstract An optical encoder design is disclosed which maintains a constant fixed air gap between the commutator and light sensors. The encoder head is mounted on a partially compressed hollow bellows or other spring member biasing snubber posts adjacent to the light sensors against tracks on the commutator. The height of the snubber posts above the light sensors defines the air gap.
Inventors
- 👤 Ralph Eldridge Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:24
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/264; G01D5/32; G01D5/34; G01D5/347; G01D5/34707; G01D5/34715
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
An improved optical encoder for generating an electrical signal representative of the rotational position of a shaft, of the type having a non-rotating optical head including light sources and light sensors connected by light paths, a commutator including a coded pattern thereon mounted for rotation with the shaft through the light paths, wherein the improvement comprises: snubber means mounted to the optical head for contact with the commutator to maintain a constant air gap between the coded pattern and the optical head, and means for urging the commutator and snubber posts into contact with each other.
Claim 2
Dependent Claim
96 words
An improved optical encoder for generating an electrical signal representative of the rotational position of a shaft, of the type having a non-rotating optical head including light sources and light sensors connected by light paths, a commutator including a coded pattern thereon mounted for rotation with the shaft through the light paths, wherein the improvement comprises: snubber means mounted to the optical head for contact with the commutator to maintain a constant air gap between the coded pattern and the optical head, and means for urging the commutator and snubber posts into contact with each other.
Claim 3
Dependent Claim
23 words
The improved optical encoder claimed in claim 1 wherein the snubber means comprises: snubber posts projecting above the light sensors a predetermined distance.
Claim 4
Dependent Claim
24 words
The improved optical encoder claimed in claim 2 wherein the snubber posts are constructed of a plastic material including a substantial percentage of graphite.
Claim 5
Dependent Claim
25 words
The improved optical encoder claimed in claim 2 wherein the commutator includes on one surface thereof clear tracks for sliding contact with the snubber posts.
Claim 6
Dependent Claim
39 words
The improved optical encoder claimed in claim 1 wherein the means for urging comprises: a partially compressed spring member for supporting the optical head, the spring member permitting axial motion while minimizing tangential and radial deflection of the head.
Claim 7
Dependent Claim
16 words
The improved optical encoder claimed in claim 5 wherein the spring member is a hollow bellows.
Claim 8
Dependent Claim
16 words
The improved optical encoder claimed in claim 6 wherein the bellows has a round cross section.
Claim 9
Dependent Claim
29 words
The improved optical encoder claimed in claim 6 wherein the bellows has an elliptical cross section, the short axis of the ellipse being along a radial of the shaft.
References Cited (Backward Citations)
US3770971A
Cited
US3815125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |