US4688902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-backlash cam
Assignee: Qioptiq Ltd
•
Filing: 1985-11-19
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Granted: 1987-08-25
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Expires: 2005-11-19
Abstract
Abstract A zoom lens cam mechanism has two cam follower bearings mounted on a common shaft and arranged so that they engage against and roll on opposite sides of a cam groove or slot so as to reduce backlash.
Inventors
- 👤 Allan Gardam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:35
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/04; G02B7/10; F; F16; F16H; F16H25/00; F16H25/18; F16H25/186; F16H53/00; F16H53/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
An optical lens incorporating a scroll cam mechanism for effecting controlled movement of a lens element, said cam mechanism comprising a cam member having a cam groove or slot and a cam follower having two bearings mounted on a common shaft and arranged so that the bearings engage against and roll on respective opposite sides of the groove or slot.
Claim 2
Dependent Claim
60 words
An optical lens incorporating a scroll cam mechanism for effecting controlled movement of a lens element, said cam mechanism comprising a cam member having a cam groove or slot and a cam follower having two bearings mounted on a common shaft and arranged so that the bearings engage against and roll on respective opposite sides of the groove or slot.
Claim 3
Dependent Claim
25 words
A lens according to claim 1 in which the groove or slot has an asymmetric cross-sectional shape such that the bearings engage respective opposite sides.
Claim 4
Dependent Claim
26 words
A lens according to claim 2 in which the groove or slot has stepped walls on both sides to accommodate two bearings of the same diameter.
Claim 5
Dependent Claim
27 words
A lens according to claim 2 in which the groove or slot has a stepped wall on one side only to accommodate bearings of different respective diameters.
Claim 6
Dependent Claim
25 words
A lens according to claim 2 in which the groove or slot walls have an angled part for engagement by a corresponding angled bearing periphery.
Claim 7
Dependent Claim
26 words
A lens according to claim 1 in which the groove or slot has plain walls and one bearing is eccentrically mounted with respect to the other.
Claim 8
Dependent Claim
18 words
A lens according to claim 6 in which said one bearing is mounted on an eccentric shaft portion.
Claim 9
Dependent Claim
16 words
A lens according to claim 1 in which one of the bearings has a resilient part.
Claim 10
Dependent Claim
17 words
A lens according to claim 8 in which said resilient part is an inner or outer tire.
Claim 11
Dependent Claim
17 words
A lens according to claim 1 in which the groove or slot has an enlarged end opening.
Claim 12
Dependent Claim
11 words
A lens according to claim 1 incorporated into a zoom lens.
Claim 13
Dependent Claim
9 words
A mechanically compensated zoom lens according to claim 11.
References Cited (Backward Citations)
GB254261A
Cited
GB1112917A
Cited
GB1320861A
Cited
GB1458779A
Cited
GB1575725A
Cited
US4322151A
Cited
WO1982003889A1
Cited
US4533218A
Cited
US4548471A
Cited
EP0112805A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |