Patent US4086983A successfully refreshed from Google Patents.
US4086983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elevator control system
Assignee: Mitsubishi Electric Corp
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Filing: 1975-08-06
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Granted: 1978-05-02
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Expires: 1995-08-06
Abstract
Abstract A direct current motor for an elevator car includes an armature and an interpole winding or a series field winding serially connected to the armature and controlled by a static Ward-Leonard device. A filter includes the interpole or series field winding and a series combination of a capacitor, a resistor, a reactor and a fuse with or without a series reactor.
Inventors
- 👤 Nobuo Anzai
- 👤 Eiki Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:18
CPC Classifications
B; B66; B66B; B66B1/00; B66B1/24; B66B1/28; B66B1/30; H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/281
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
An elevator control system comprising a direct current motor including an armature and a selected one of an interpole winding and a series field winding serially connected to said armature to operate an elevator car, static Ward-Leonard means coupled to said motor for controlling said motor, said static Ward-Leonard means being capable of generating current ripples, and series resonance filter means having a resonance frequency at least extremely close to the fundamental frequency of said current ripples from said static Ward-Leonard means, said series resonance filter means being connected across said armature of said direct current motor to reduce noise produced from said direct current motor.
Claim 2
Dependent Claim
106 words
An elevator control system comprising a direct current motor including an armature and a selected one of an interpole winding and a series field winding serially connected to said armature to operate an elevator car, static Ward-Leonard means coupled to said motor for controlling said motor, said static Ward-Leonard means being capable of generating current ripples, and series resonance filter means having a resonance frequency at least extremely close to the fundamental frequency of said current ripples from said static Ward-Leonard means, said series resonance filter means being connected across said armature of said direct current motor to reduce noise produced from said direct current motor.
Claim 3
Dependent Claim
109 words
An elevator control system comprising a direct current motor including an armature and a selected one of an interpole winding and a series field winding serially connected to said armature, a static Ward-Leonard means coupled to said motor for controlling said motor, said static Ward-Leonard means being capable of generating current ripples, and filter means connected across said winding of said direct current motor to form a parallel resonance circuit, said parallel resonance circuit having a parallel resonance frequency selected to be at least extremely close to the fundamental frequency of said current ripples from said static Ward-Leonard means thereby to reduce noise produced by said direct current motor.
Claim 4
Dependent Claim
109 words
An elevator control system comprising a direct current motor including an armature and a selected one of an interpole winding and a series field winding serially connected to said armature, a static Ward-Leonard means coupled to said motor for controlling said motor, said static Ward-Leonard means being capable of generating current ripples, and filter means connected across said winding of said direct current motor to form a parallel resonance circuit, said parallel resonance circuit having a parallel resonance frequency selected to be at least extremely close to the fundamental frequency of said current ripples from said static Ward-Leonard means thereby to reduce noise produced by said direct current motor.
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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |