Patent US3668487A successfully refreshed from Google Patents.
US3668487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic actuated detent apparatus
Assignee: International Business Machines Corp
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Filing: 1970-12-31
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Granted: 1972-06-06
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Expires: 1990-12-31
Abstract
Abstract Locking and release for rotation of a threaded drive shaft or lead screw are selectively achieved by a detent apparatus, which includes an actuator element that is bidirectionally movable by a voice coil motor (VCM). A toothed detent wheel attached to the rotary drive shaft is engaged by detent pawls for locking. The detent wheel is released to allow rotation of the drive shaft by retraction of the actuator element, that is responsive to the VCM and that pulls the pawls out of engagement with the detent wheel. Stops limit the path of travel of the actuator element. A pulse generating circuit, in combination with a center-tapped coil of the VCM, provides an inhibit pulse to minimize bounce of the movable actuator element and associated mechanical members.
Inventors
- 👤 David E Cuzner
- 👤 Leo J Rigbey
- 👤 George M Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:05
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/035; H02K41/0352; H02K41/0354; H02K41/0356; G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; H01; H01F; H01F7/00; H01F7/06; H01F7/066; H01F7/08; H01F7/18; H01F7/1872; H02K33/00; H02K33/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A detent apparatus for controlling the movement of a mechanical member comprising: a drive shaft; mechanical detent means for selectively holding said shaft in a fixed position, and alternatively releasing said shaft for movement; an electromagnetic actuator having a coil mounted in a magnetic field; circuit means for pulsing said coil to provide bidirectional movement of said actuator; stop means for limiting such movement of said actuator; means for detecting the bounce of said detent means and said actuator whenever the limiting stop means is impacted; and means responsive to said detecting means for pulsing the coil of said electromagnetic actuator to inhibit bounce of said detent means and said actuator.
Claim 2
Dependent Claim
111 words
A detent apparatus for controlling the movement of a mechanical member comprising: a drive shaft; mechanical detent means for selectively holding said shaft in a fixed position, and alternatively releasing said shaft for movement; an electromagnetic actuator having a coil mounted in a magnetic field; circuit means for pulsing said coil to provide bidirectional movement of said actuator; stop means for limiting such movement of said actuator; means for detecting the bounce of said detent means and said actuator whenever the limiting stop means is impacted; and means responsive to said detecting means for pulsing the coil of said electromagnetic actuator to inhibit bounce of said detent means and said actuator.
Claim 3
Dependent Claim
39 words
A detent apparatus as in claim 1, wherein said coil is center-tapped, one-half of said coil being energizable to drive the actuator towards the stop, and the other half being energizable to drive the actuator away from the stop.
Claim 4
Dependent Claim
15 words
A detent apparatus as in claim 2, wherein said detent means comprises a bifurcated yoke.
Claim 5
Dependent Claim
57 words
A detent apparatus as in claim 3, wherein said drive shaft is a rotary shaft, and said detent means includes a toothed wheel, rigidly attached to said shaft, a pair of spring-loaded detent pawls for engaging said wheel for detent action, and means associated with said yoke for retracting said pawls to release said shaft for rotation.
Claim 6
Dependent Claim
26 words
A detent apparatus as in claim 3, wherein said stop means includes first and second stops that define the limits of longitudinal travel of said yoke.
Claim 7
Dependent Claim
41 words
A detent apparatus as in claim 5, wherein the means for detecting bounce of the yoke includes a circuit responsive to the change in electromotive forCe produced in the coil upon impact of the yoke with the first or second stop.
Claim 8
Dependent Claim
50 words
A detent apparatus as in claim 6, wherein said circuit detects at the moment of impact the change in electromotive force produced in the half of the coil not being driven, and supplies an arresting pulse to the driven half of the coil to inhibit the bounce of the yoke.
Claim 9
Dependent Claim
29 words
A detent apparatus as in claim 1, wherein the voltage pulse supplied to the coil consists of an initial portion of higher amplitude than the remainder of the pulse.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |