US4263988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed control system for a motor
Assignee: Hitachi Ltd
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Filing: 1978-11-03
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Granted: 1981-04-28
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Expires: 1998-11-03
Abstract
Abstract A speed control system for an elevator motor, comprising a D. C. motor for driving an elevator, a device which generates a speed command signal for the elevator, a speed dynamo which generates a speed signal corresponding to a speed of the elevator, a speed control device which adjusts an applied voltage to the motor according to the speed deviation between the speed command signal and the speed signal, an emergency stop device which subjects the elevator to braking when the speed deviation has exceeded a predetermined value, and a blind sector device which provides an output when the speed signal has exceeded a predetermined value and which negatively feeds it back to the speed control device.
Inventors
- 👤 Hiromi Inaba
- 👤 Seiya Shima
- 👤 Takeki Ando
- 👤 Toshiaki Kurosawa
- 👤 Hiroaki Kuroha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:13
CPC Classifications
B; B66; B66B; B66B5/00; B66B5/02; B66B5/04; B66B5/06; H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/34; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/906
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
126 words
A speed control system for an elevator comprising: a motor for driving an elevator; a magnet brake for holding said motor in a stop state; means for generating a speed command signal for said elevator; means for generaging a speed signal corresponding to a speed of said elevator; speed control apparatus which controls a speed of said motor according to a deviation between the speed command signal and the speed signal; and a blind sector device which is electrically connected between said speed signal generating means and said speed control apparatus and provides a feed-back signal which suppresses an output of said speed control apparatus when said speed signal exceeds a predetermined value which is set to be higher than a rated speed of the elevator.
Claim 2
Dependent Claim
126 words
A speed control system for an elevator comprising: a motor for driving an elevator; a magnet brake for holding said motor in a stop state; means for generating a speed command signal for said elevator; means for generaging a speed signal corresponding to a speed of said elevator; speed control apparatus which controls a speed of said motor according to a deviation between the speed command signal and the speed signal; and a blind sector device which is electrically connected between said speed signal generating means and said speed control apparatus and provides a feed-back signal which suppresses an output of said speed control apparatus when said speed signal exceeds a predetermined value which is set to be higher than a rated speed of the elevator.
Claim 3
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 1, wherein said motor is a D.C. motor, and said speed control apparatus includes a D.C. dynamo which is in the Ward-Leonard connection with said D.C. motor.
Claim 4
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 1, wherein said motor is a D.C. motor, and said speed control apparatus includes a thyristor converter which supplies power to an armature of said D.C. motor.
Claim 5
Dependent Claim
62 words
The speed control system for an elevator as defined in claim 3, wherein said thyristor converter is constructed so as to cause current to flow through said armature of said D.C. motor in only one direction, and said speed control apparatus includes means for causing currents to flow through a field winding of said D.C. motor in both positive and negative directions.
Claim 6
Dependent Claim
49 words
The speed control system for an elevator as defined in claim 4, wherein said speed control apparatus comprises an armature current-control device which controls the armature current to be constant, and a field winding current-control device which adjusts the field winding current of said motor according to said deviation.
Claim 7
Dependent Claim
93 words
The speed control system for an elevator as defined in claim 4, wherein said speed control apparatus includes an armature current-control device which holds the armature current constant when the deviation is at most a predetermined value and which adjusts the armature current according to the deviation when said deviation exceeds said predetermined value, and a field winding current-control device which adjusts the field winding current according to the deviation when said deviation is at most said predetermined value and which holds the field winding current when the deviation exceeds said predetermined value.
Claim 8
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 5, wherein said speed control apparatus includes a preamplifier which enters the speed command signal, the speed signal and the feedback signal into said current control devices.
Claim 9
Dependent Claim
20 words
The speed control system for an elevator as defined in claim 7, wherein said preamplifier includes a proportional integration element.
Claim 10
Dependent Claim
24 words
The speed control system for an elevator as defined in claim 6, wherein the feed-back signal is negatively entered into said armature current-control device.
Claim 11
Dependent Claim
54 words
The speed control system for an elevator as defined in claim 9, wherein said blind sector device is an absolute-value blind sector element which, when the speed signal exceeds the positive or negative predetermined value, provides a feed-back signal of the same polarity and which negatively feeds it back to said armature current-control device.
Claim 12
Dependent Claim
141 words
A speed control system for an elevator comprising: a motor for driving an elevator; a magnet brake for holding said motor in a stop state; means for generating a speed command signal for said elevator; means for generating speed corresponding to a speed of said elevator; speed control apparatus which controls a speed of said motor according to a deviation between the speed command signal and the speed signal; emergency stop apparatus which actuates said magnet brake when said deviation exceeds a first predetermined value; and a blind sector device which is electrically connected between said speed signal generating means and said speed control apparatus and provides a feed-back signal which suppresses an output of said speed control apparatus when the speed signal exceeds a second predetermined value which is set to be higher than a rated speed of the elevator.
Claim 13
Dependent Claim
141 words
A speed control system for an elevator comprising: a motor for driving an elevator; a magnet brake for holding said motor in a stop state; means for generating a speed command signal for said elevator; means for generating speed corresponding to a speed of said elevator; speed control apparatus which controls a speed of said motor according to a deviation between the speed command signal and the speed signal; emergency stop apparatus which actuates said magnet brake when said deviation exceeds a first predetermined value; and a blind sector device which is electrically connected between said speed signal generating means and said speed control apparatus and provides a feed-back signal which suppresses an output of said speed control apparatus when the speed signal exceeds a second predetermined value which is set to be higher than a rated speed of the elevator.
Claim 14
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 11, wherein said motor is a D.C. motor, and said speed control apparatus includes a D.C. dynamo which is in the Ward-Leonard connection with said D.C. motor.
Claim 15
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 11, wherein said motor is a D.C. motor, and said speed control apparatus includes a thyristor converter which supplies power to an armature of said D.C. motor.
Claim 16
Dependent Claim
62 words
The speed control system for an elevator as defined in claim 13, wherein said thyristor converter is constructed so as to cause current to flow through said armature of said D.C. motor in only one direction, and said speed control apparatus includes means for causing currents to flow through a field winding of said D.C. motor in both positive and negative directions.
Claim 17
Dependent Claim
49 words
The speed control system for an elevator as defined in claim 14, wherein said speed control apparatus comprises an armature current-control device which controls the armature current to be constant, and a field winding current-control device which adjusts the field winding current of said motor according to the deviation.
Claim 18
Dependent Claim
93 words
The speed control system for an elevator as defined in claim 14, wherein said speed control apparatus includes an armature current-control device which holds the armature current constant when the deviation is at most a predetermined value and which adjusts the armature current according to the deviation when said deviation exceeds said predetermined value, and a field winding current-control device which adjusts the field winding current according to the deviation when said deviation is at most said predetermined value and which holds the field winding current when the deviation exceeds said predetermined value.
Claim 19
Dependent Claim
38 words
The speed control system for an elevator as defined in claim 15, wherein said speed control apparatus includes a preamplifier which enters the speed command signal, the speed signal and the feed-back signal into said current control devices.
Claim 20
Dependent Claim
20 words
The speed control system for an elevator as defined in claim 17, wherein said preamplifier includes a proportional integration element.
Claim 21
Dependent Claim
24 words
The speed control system for an elevator as defined in claim 16, wherein the feed-back signal is negatively entered into said armature current-control device.
Claim 22
Dependent Claim
54 words
The speed control system for an elevator as defined in claim 19, wherein said blind sector device is an absolute-value blind sector element which, when the speed signal exceeds the positive or negative predetermined value, provides a feed-back signal of the same polarity and which negatively feeds it back to said armature current-control device.
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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |