Patent US3759350A successfully refreshed from Google Patents.
US3759350A
Expired / Lapsed
US
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Elevator system
Assignee: Westinghouse Electric Corp
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Filing: 1972-05-30
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Granted: 1973-09-18
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Expires: 1992-05-30
Abstract
Abstract An elevator system which automatically reduces the rate of change of acceleration when an elevator car is requested to decelerate before the car reaches the end of its normal acceleration mode. When a stop request is initiated while the car is still accelerating, a modification circuit changes the normal acceleration schedule to reduce the rate of rise of the speed pattern signal. A delay circuit delays the operation of the modification circuit to insure that the modification circuit does not substantially lengthen the time required for the car to reach the landing at which it is to stop.
Inventors
- 👤 W Caputo
- 👤 W Ostrander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:38
CPC Classifications
B; B66; B66B; B66B1/00; B66B1/34; B66B1/46; B66B1/52
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
172 words
An elevator system, comprising: an elevator car, a structure having spaced landings to be served by said car, motive means for moving the car relative to said structure to serve the landings, car control means providing a speed pattern reference signal for said motive means which directS the movement mode of said car, said car control means including acceleration means which provides an acceleration mode, accelerating the car according to a first predetermined acceleration schedule, call means operable to provide a stop request signal when said car is to stop at a landing, modification means responsive to a stop request signal initiated during a predetermined terminal portion of said first acceleration schedule to modify the speed pattern reference signal to provide a second predetermined acceleration schedule, and delay means operative when a stop request is initiated during the first acceleration schedule but prior to the predetermined terminal portion thereof, said delay means delaying the modification of the speed pattern reference signal until said terminal portion of the first acceleration schedule is reached.
Claim 2
Dependent Claim
172 words
An elevator system, comprising: an elevator car, a structure having spaced landings to be served by said car, motive means for moving the car relative to said structure to serve the landings, car control means providing a speed pattern reference signal for said motive means which directS the movement mode of said car, said car control means including acceleration means which provides an acceleration mode, accelerating the car according to a first predetermined acceleration schedule, call means operable to provide a stop request signal when said car is to stop at a landing, modification means responsive to a stop request signal initiated during a predetermined terminal portion of said first acceleration schedule to modify the speed pattern reference signal to provide a second predetermined acceleration schedule, and delay means operative when a stop request is initiated during the first acceleration schedule but prior to the predetermined terminal portion thereof, said delay means delaying the modification of the speed pattern reference signal until said terminal portion of the first acceleration schedule is reached.
Claim 3
Dependent Claim
62 words
The elevator system of claim 1 wherein the voltage across the acceleration means during the acceleration mode is inversely proportional to the speed of the car, with the delay means being responsive to the voltage across the acceleration means, said delay means preventing the modification of the speed pattern reference signal when the voltage across the acceleration means exceeds a predetermined magnitude.
Claim 4
Dependent Claim
81 words
The elevator system of claim 1 wherein the car control means includes rectifier means and a source of alternating potential, and the acceleration means includes a pair of back-to-back connected switching devices connected in series with said rectifier means and said source of alternating potential, and control means for firing said switching devices to provide an output voltage from said rectifier means which provides the desired acceleration schedule, with the delay means being responsive to the voltage across said switching devices.
Claim 5
Dependent Claim
49 words
The elevator system of claim 3 wherein the acceleration means increases the voltage applied to the rectifier means substantially linearly, reducing the voltage drop across the switching devices substantially linearly, said delay means preventing the operation of the modification means while the voltage drop is above a predetermined magnitude.
Claim 6
Dependent Claim
37 words
The elevator system of claim 4 wherein the delay means includes a relay responsive to the voltage across the switching devices, and impedance means which elavates the drop out voltage of said relay to the desired level.
Claim 7
Dependent Claim
40 words
The elevator system of claim 5 including means rendering said impedance means for elevating the drop out voltage effective only when a stop request signal is initiated, facilitating the pick-up of said relay at the start of the acceleration mode.
Claim 8
Dependent Claim
54 words
The elevator system of claim 5 wherein the relay, when it drops out at its elevated drop out voltage modifies the control means to slow down the rate of rise of pattern current to reduce the rate of change of acceleration as the speed pattern changes from an acceleration mode to a deceleration mode.
Claim 9
Dependent Claim
22 words
The elevator system of claim 7 wherein the control means is modified to provide a zero rate of rise of pattern current.
Claim 10
Dependent Claim
51 words
The elevator system of claim 4 including means providing a different slope of the linear voltage drop curve for different lengths of short runs, to enable the elevator car to reach a high speed on a larger run than on a shorter run, before the voltage drop reaches the predetermined magnitude.
Claim 11
Dependent Claim
169 words
An elevator system, comprising: an elevator car, a structure having spaced landings to be served by said car, motive means for moving the car relative to said structure to serve the landings, car control means providing a speed pattern reference signal for said motive means which directs the movement mode of said car, said car control means including acceleration means which provides an acceleration mode, accelerating the car according to a first predetermined acceleration schedule, said acceleration means operating such that the voltage drop across it is reduced as the elevator car increases in velocity, call mEans operable to provide a stop request signal when said car is to stop at a landing, modification means effective when the elevator car initiates deceleration in response to a stop request, prior to the completion of said first acceleration schedule, to provide a second predetermined acceleration schedule, and delay means preventing the modification of the speed pattern reference signal when the voltage drop across said acceleration means is above a predetermined magnitude.
Claim 12
Dependent Claim
169 words
An elevator system, comprising: an elevator car, a structure having spaced landings to be served by said car, motive means for moving the car relative to said structure to serve the landings, car control means providing a speed pattern reference signal for said motive means which directs the movement mode of said car, said car control means including acceleration means which provides an acceleration mode, accelerating the car according to a first predetermined acceleration schedule, said acceleration means operating such that the voltage drop across it is reduced as the elevator car increases in velocity, call mEans operable to provide a stop request signal when said car is to stop at a landing, modification means effective when the elevator car initiates deceleration in response to a stop request, prior to the completion of said first acceleration schedule, to provide a second predetermined acceleration schedule, and delay means preventing the modification of the speed pattern reference signal when the voltage drop across said acceleration means is above a predetermined magnitude.
Claim 13
Dependent Claim
78 words
The elevator system of claim 10 wherein the voltage drop across the acceleration means during the acceleration mode is substantially linear, with the slope of the voltage drop curve being responsive to the length of the run, when deceleration of the car is initiated prior to the end of the first acceleration schedule, to lengthen the time required for the voltage across the acceleration means to drop to the predetermined magnitude as the length of the run increases.
References Cited (Backward Citations)
US3526300A
Cited
US3552524A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |