Patent US4804893A successfully refreshed from Google Patents.
US4804893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric braking control
Assignee: FMC Corp
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Filing: 1987-05-11
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Granted: 1989-02-14
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Expires: 2007-05-11
Abstract
Abstract An apparatus for an electric drive vehicle which provides linear deceleration via electrical braking. The apparatus monitors vehicle speed and adjusts the duty cycle of a chopper circuit according to look-up tables. These table correlate vehicle speed and desired deceleration rate to braking torque, thereby enabling the apparatus to maintain a preselected deceleration through the entire stopping distance and to precisely position the vehicle.
Inventors
- 👤 Grant C. Melocik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:31
CPC Classifications
B; B60; B60L; B60L15/00; B60L15/20; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64; Y02T10/72
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
238 words
An apparatus for providing substantially constant deceleration of an electric drive work vehicle, comprising: a battery; an electric drive motor having a field and armature winding; switching means for controllably interconnecting the battery and drive motor windings in response to receiving a control signal; means for sensing work vehicle speed and delivering a signal correlative to the work vehicle speed; means for detecting plugging of the drive motor and delivering a signal in response thereto; means for calculating a desired vehicle stopping distance in response to receiving the plugging signal and delivering a signal having a magnitude responsive to the desired vehicle stopping distance; means for receiving the work vehicle speed signal and the desired vehicle stopping distance signal, calculating a desired linear deceleration rate responsive to the magnitudes of the received signals, and delivering a signal responsive to the magnitude of the desired linear deceleration rate; a plurality of look up tables each having a plurality of control signal duty cycle values corresponding to a plurality of vehicle speed values, each of the look up tables corresponding to a preselected unique deceleration rate; means for accessing the look up table corresponding to the desired linear deceleration rate and retrieving the control signal duty cycle value corresponding to the magnitude of the work vehicle speed signal; and means for delivering the control signal to the switching means having a duty cycle responsive to the retrieved duty cycle value.
Claim 2
Independent Claim
238 words
An apparatus for providing substantially constant deceleration of an electric drive work vehicle, comprising: a battery; an electric drive motor having a field and armature winding; switching means for controllably interconnecting the battery and drive motor windings in response to receiving a control signal; means for sensing work vehicle speed and delivering a signal correlative to the work vehicle speed; means for detecting plugging of the drive motor and delivering a signal in response thereto; means for calculating a desired vehicle stopping distance in response to receiving the plugging signal and delivering a signal having a magnitude responsive to the desired vehicle stopping distance; means for receiving the work vehicle speed signal and the desired vehicle stopping distance signal, calculating a desired linear deceleration rate responsive to the magnitudes of the received signals, and delivering a signal responsive to the magnitude of the desired linear deceleration rate; a plurality of look up tables each having a plurality of control signal duty cycle values corresponding to a plurality of vehicle speed values, each of the look up tables corresponding to a preselected unique deceleration rate; means for accessing the look up table corresponding to the desired linear deceleration rate and retrieving the control signal duty cycle value corresponding to the magnitude of the work vehicle speed signal; and means for delivering the control signal to the switching means having a duty cycle responsive to the retrieved duty cycle value.
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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) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |