US4520343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lift control system
Assignee: Fujitec Co Ltd
•
Filing: 1981-12-15
•
Granted: 1985-05-28
•
Expires: 2001-12-15
Abstract
Abstract A lift control system includes a spatial filter producing a signal having various features, a discriminator for discriminating one or more features of the signal, and for producing a control signal when at least one of the features discriminated falls in a predetermined range, and active devices connected to the discriminator. The active devices are made active upon receipt of the control signal.
Inventors
- 👤 Hiroshi Koh
- 👤 Junichi Hirota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:07
CPC Classifications
G; G08; G08B; G08B19/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
139 words
In a lift system including a cage for carrying passengers up and down in a shaft and a mechanically-driven door at each floor the cage is to stop to allow ingress and egress of passengers, a control system for at least controlling operation of the mechanical door in response to passengers desiring to load on the lift, said control system comprising: a spatial filter inside the cage of the lift, said spatial filter including a fence reticle with the reticle stripes oriented in a parallel relationship to the movement of the mechanical door; discriminating means for discriminating between signals below and above a predetermined level as received from said spatial filter, and for producing a control signal when the signals are above the predetermined level; and active means connected to said discriminating means for controlling closure of said door.
Claim 2
Dependent Claim
139 words
In a lift system including a cage for carrying passengers up and down in a shaft and a mechanically-driven door at each floor the cage is to stop to allow ingress and egress of passengers, a control system for at least controlling operation of the mechanical door in response to passengers desiring to load on the lift, said control system comprising: a spatial filter inside the cage of the lift, said spatial filter including a fence reticle with the reticle stripes oriented in a parallel relationship to the movement of the mechanical door; discriminating means for discriminating between signals below and above a predetermined level as received from said spatial filter, and for producing a control signal when the signals are above the predetermined level; and active means connected to said discriminating means for controlling closure of said door.
Claim 3
Dependent Claim
32 words
A lift control system as claimed in claim 1 wherein said spatial filter comprises a plurality of stripes of silicon solar cells aligned in parallel to each other with a predetermined pitch.
Claim 4
Dependent Claim
69 words
A lift control system as claimed in claim 1 wherein said discriminating means also discriminates between the amplitude of a wanted pulsating signal and produces a control signal when said amplitude of the wanted pulsating signal exceeds a predetermined high level or falls below a predetermined low level for the indication that an object moving or flickering in the field is brighter or darker than an average brightness, respectively.
Claim 5
Dependent Claim
57 words
A lift control system as claimed in claim 1 wherein said discriminating means also discriminates between the frequency of a wanted pulsating signal and produces a control signal when the frequency of the wanted pulsating signal exceeds a predetermined frequency for the indication that an object moving in the field is moving faster than an average speed.
Claim 6
Dependent Claim
41 words
A lift control system as claimed in any one of claims 3 or 4, wherein said active means further includes any one of or a combination of an alarm device, a display device, a broadcast device and/or a lift drive device.
Claim 7
Dependent Claim
53 words
A lift control system as claimed in claim 1 wherein said discriminating means also detects the amplitude of a background signal and produces a control signal when said amplitude of said background signal falls below a predetermined level for the indication that the background of the field is darker than a predetermined level.
Claim 8
Dependent Claim
31 words
A lift control system as claimed in claim 6, wherein said active means further includes an auxiliary light control for controlling power supply to an auxiliary light provided in the cage.
Claim 9
Dependent Claim
41 words
The lift control system of claim 1 wherein said discriminating means comprises: a differential amplifier and automatic gain control means receiving signals from the spatial filter for eliminating background signals generated by lights in the field angle of the spatial filter.
Claim 10
Dependent Claim
38 words
The lift control system of claim 8 wherein said discriminating means further comprises: a level detector means receiving signals from said automatic gain control means for generating a control signal when the received signal exceeds a predetermined level.
Claim 11
Dependent Claim
63 words
The lift control system of claim 9 further comprising: a second level detector means responsive to signals from said spatial filter for generating a control signal when the received signal is below a predetermined level; and means responsive to the control signal from said control signal generating means for actuating an auxiliary light to illuminate the area in front of the mechanically-driven door.
Claim 12
Dependent Claim
59 words
The lift control system of claim 1 further comprising: means responsive to signals from the spatial filter for generating a control signal when the received signal is below a predetermined level; and means responsive to the control signal from said control signal generating means for actuating an auxiliary light to illuminate the area in front of the mechanically-driven door.
Claim 13
Dependent Claim
55 words
The lift control system of claim 1 wherein said discriminator means comprises: a differential amplifier means receiving signals from said spatial filter for generating a signal free from background signals; and a level detector means receiving signals from said differential amplifier means for generating a control signal when the received signal exceeds a predetermined level.
References Cited (Backward Citations)
US2198725A
Cited
US3168164A
Cited
US3444544A
Cited
US3824392A
Cited
US3803572A
Cited
US3972021A
Cited
US4052616A
Cited
US4258255A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |