US3601227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emergency brake control system for elevators
Assignee: Doosan Bobcat North America Inc
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Filing: 1970-06-15
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Granted: 1971-08-24
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Expires: 1990-06-15
Abstract
Abstract An emergency brake control system for elevator cars is disclosed. The system is adapted to be carried in its entirety on the elevator car and requires no external source of energization. An electrical generator is operatively connected between the elevator car and frame for developing a voltage corresponding to the speed of the car. Control means is connected to the generator and is responsive to a predetermined voltage for applying brakes to the car. A permanent magnet direct current generator is used with a control means including a unidirectionally conductive voltage responsive device such as a silicon controlled rectifier so that the brakes are applied only when the polarity of the generator voltage corresponds to downward travel of the elevator car.
Inventors
- 👤 Arthur R Burch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:06
CPC Classifications
B; B66; B66B; B66B5/00; B66B5/02; B66B5/16; B66B5/18; B66B5/20; B66B5/04; B66B5/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
76 words
An emergency brake control system for an elevator car movable relative to a frame, an electric generator adapted to be operatively connected between the car and the frame for developing an electrical quantity corresponding to the speed of said car, brake means for said car including a brake actuator, and control means connected between said brake actuator and said generator and being responsive to a predetermined value of said electrical quantity for applying said brake means.
Claim 2
Dependent Claim
76 words
An emergency brake control system for an elevator car movable relative to a frame, an electric generator adapted to be operatively connected between the car and the frame for developing an electrical quantity corresponding to the speed of said car, brake means for said car including a brake actuator, and control means connected between said brake actuator and said generator and being responsive to a predetermined value of said electrical quantity for applying said brake means.
Claim 3
Dependent Claim
26 words
The invention as defined in claim 1 wherein said actuator is electrically operated and said control means is operative to connect said generator to said actuator.
Claim 4
Dependent Claim
36 words
The invention as defined in claim 1 wherein said electrical generator is a permanent magnet direct current generator and said control means is polarity responsive thereby preventing energization of said actuator in one direction of travel.
Claim 5
Dependent Claim
62 words
The invention as defined in claim 3 wherein said control means comprises a controlled rectifier with its anode and cathode connected serially between the generator and the actuator and having its gate connected through voltage dividing means to said generator, said controlled rectifier being poled to conduct in a forward direction when said car reaches a predetermined overspeed in the downward direction.
Claim 6
Dependent Claim
45 words
The invention as defined in claim 1 wherein said electrical generator is adapted to generate a voltage magnitude corresponding to the speed of said car and wherein said control means is responsive to a voltage of a predetermined magnitude for actuation of said brake means.
Claim 7
Dependent Claim
26 words
The invention as defined in claim 5 wherein said control means includes unidirectionally conductive means and voltage-responsive means for connection of said generator to said actuator.
Claim 8
Dependent Claim
114 words
An emergency brake control system for an elevator comprising; an elevator frame, a car movable within the frame and lift means interconnecting said car and said frame, an electrical generator mounted on said car with its rotor connected through rotative drive means to said frame whereby said rotor is rotatably driven in a direction and at a speed corresponding to the motion of said car, brake means mounted on said car and including a brakeshoe adapted to coact with said frame, an electrical actuator for said brakeshoe on said car, and control means connected between said generator and said actuator and being responsive to a predetermined value of voltage for actuating said brake means.
Claim 9
Dependent Claim
114 words
An emergency brake control system for an elevator comprising; an elevator frame, a car movable within the frame and lift means interconnecting said car and said frame, an electrical generator mounted on said car with its rotor connected through rotative drive means to said frame whereby said rotor is rotatably driven in a direction and at a speed corresponding to the motion of said car, brake means mounted on said car and including a brakeshoe adapted to coact with said frame, an electrical actuator for said brakeshoe on said car, and control means connected between said generator and said actuator and being responsive to a predetermined value of voltage for actuating said brake means.
Claim 10
Dependent Claim
36 words
The invention as defined in claim 7 wherein said electrical generator is a permanent magnet direct current generator and said control means is polarity responsive thereby preventing energization of said actuator in one direction of travel.
Claim 11
Dependent Claim
62 words
The invention as defined in claim 7 wherein said control means comprises a controlled rectifier with its anode and cathode connected serially between the generator and the actuator and having its gate connected through voltage dividing means to said generator, said controlled rectifier being poled to conduct in a forward direction when said car reaches a predetermined overspeed in the downward direction.
Claim 12
Dependent Claim
26 words
The invention as defined in claim 7 wherein said control means includes unidirectionally conductive means and voltage-responsive means for connection of said generator to said actuator.
Claim 13
Dependent Claim
50 words
The invention as defined in claim 7 wherein said actuator comprises keeper means engaging said brakeshoe and retaining it in disengaged position, retractor means connected with said keeper means and a solenoid connected with said retractor means for operation thereof to initiate engagement of said brakeshoe with said frAme member.
Claim 14
Dependent Claim
37 words
The invention as defined in claim 7 wherein said actuator means comprises a spring-loaded operating means for causing engagement of said brake means and a solenoid actuated release means connected between said generator and said operating means.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |