Patent US3626264A successfully refreshed from Google Patents.
US3626264A
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Velocity servosystem
Assignee: Information Storage Systems Inc
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Filing: 1969-08-20
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Granted: 1971-12-07
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Expires: 1989-08-20
Abstract
Abstract A velocity servocircuit for retracting the access mechanism of a disk storage drive independently of the normal position servo, including a summing amplifier connected to deliver a motor drive signal to the access motor, means providing a velocity command input to the amplifier from a signal source and means providing a velocity feedback to the amplifier derived from the back EMF of the motor.
Inventors
- 👤 Martin O Halfhill
- 👤 Frank J Sordello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:59
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/02; G11B21/12; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/46; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1409; G05D3/1445; G05D3/1463; H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/2855; H02P7/288; H02P7/2885; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/91
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
163 words
A velocity servosystEm for a reversible access mechanism drive motor, comprising: a summing amplifier having an output connected to deliver a motor drive signal to the drive motor in the event of an emergency power failure; power failure detecting means providing a velocity command signal to the summing amplifier upon the occurrence of a power failure for operating said motor in a reverse direction thereby generating a motor back EMF which is proportional to the velocity of movement of said motor; means electrically connected uninterruptedly to said motor for applying said generated back EMF to said summing amplifier; and emitter follower means receiving said velocity command signal and said back EMF for halting the reverse movement of said motor and producing a forward drive signal effecting movement of said motor in the forward direction; said forward drive signal continuing without interruption to drive said motor in the forward direction until said velocity command signal balances the back EMF being generated by said motor.
Claim 2
Dependent Claim
163 words
A velocity servosystEm for a reversible access mechanism drive motor, comprising: a summing amplifier having an output connected to deliver a motor drive signal to the drive motor in the event of an emergency power failure; power failure detecting means providing a velocity command signal to the summing amplifier upon the occurrence of a power failure for operating said motor in a reverse direction thereby generating a motor back EMF which is proportional to the velocity of movement of said motor; means electrically connected uninterruptedly to said motor for applying said generated back EMF to said summing amplifier; and emitter follower means receiving said velocity command signal and said back EMF for halting the reverse movement of said motor and producing a forward drive signal effecting movement of said motor in the forward direction; said forward drive signal continuing without interruption to drive said motor in the forward direction until said velocity command signal balances the back EMF being generated by said motor.
Claim 3
Dependent Claim
30 words
A velocity servosystem as set forth in claim 1, wherein: said power failure detecting means includes a signal source and means for providing a predetermined voltage signal to the amplifier.
Claim 4
Dependent Claim
50 words
A velocity servosystem as set forth in claim 1, wherein: said power failure detecting means includes a fixed voltage source and circuitry for providing a constant predetermined voltage to the summing amplifier for providing a constant predetermined voltage to the summing amplifier for driving the voltage at a limited velocity.
Claim 5
Dependent Claim
47 words
A velocity servosystem as set forth in claim 1, wherein: said emitter follower means is driven by the common mode level of the summing amplifier inputs, and a differential amplifier is connected to the output of the summing amplifier and the output of the emitter follower means.
Claim 6
Dependent Claim
45 words
A velocity servosystem as set forth in claim 4, wherein: said power failure detecting means includes means for applying a voltage to activate the differential amplifier and to generate a current and to switch the current into the summing amplifier as said velocity command signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |