Patent US3921818A successfully refreshed from Google Patents.
US3921818A
Expired / Lapsed
US
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Crane suspension control apparatus
Assignee: Toshiba Corp
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Filing: 1974-03-28
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Granted: 1975-11-25
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Expires: 1994-03-28
Abstract
Abstract A system for controlling a suspension type crane which moves transversely while suspending a load by a rope. The crane is accelerated at least two times to a predetermined maximum speed during an acceleration period, the swing of the rope is minimized when a predetermined maximum speed is reached, the crane is moved at the predetermined maximum speed for a predetermined interval, the crane is decelerated from the maximum speed at least two times during the deceleration period, and the crane is stopped when the swing of the rope is reduced to a minimum, and the areas of the acceleration and deceleration periods of the crane are made equal.
Inventors
- 👤 Toshio Yamagishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:40
CPC Classifications
B; B66; B66C; B66C13/00; B66C13/18; B66C13/22; B66C13/04; B66C13/06; B66C13/063; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/904
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A control system for a suspension type crane running in the transverse direction, the improvement comprising means for providing a start command signal, means responsive to said start command signal for determining a maximum transverse running speed of said crane corresponding to the distance between the starting position and a predetermined target position of said crane, means for generating a deceleration command signal when said crane reaches a point a predetermined distance before said target position, which is determined by said maximum transverse running speed, and means responsive to said start command signal or said deceleration command signal for providing a predetermined acceleration-deceleration pattern signal corresponding to said maximum transverse running speed, whereby the transverse running speed of said crane is controlled so as to stop said crane at said target position.
Claim 2
Dependent Claim
132 words
A control system for a suspension type crane running in the transverse direction, the improvement comprising means for providing a start command signal, means responsive to said start command signal for determining a maximum transverse running speed of said crane corresponding to the distance between the starting position and a predetermined target position of said crane, means for generating a deceleration command signal when said crane reaches a point a predetermined distance before said target position, which is determined by said maximum transverse running speed, and means responsive to said start command signal or said deceleration command signal for providing a predetermined acceleration-deceleration pattern signal corresponding to said maximum transverse running speed, whereby the transverse running speed of said crane is controlled so as to stop said crane at said target position.
Claim 3
Dependent Claim
48 words
The control system according to claim 1 wherein said crane includes a transversely running trolley operated by an electric motor and suspends a load by means of a rope, and said control system further comprises a speed controller responsive to said acceleration-deceleration pattern signal for controlling said motor.
Claim 4
Dependent Claim
36 words
The control system according to claim 2 which further comprises means for generating a speed signal proportional to the speed of said motor and means for negativeLy feeding back said speed signal to said speed controller.
Claim 5
Dependent Claim
38 words
The control system according to claim 3 which further comprises means for applying a signal corresponding to the swing angle of said rope at a point immediately prior to the stop of said trolley to said speed controller.
Claim 6
Dependent Claim
34 words
The control system according to claim 4 which further comprises means for applying to said speed controller a signal corresponding to the distance between said target position and the present position of said trolley.
Claim 7
Dependent Claim
69 words
The control system according to claim 1 wherein said deceleration command signal generating means includes means for comparing the distance S between a point at which deceleration of said crane is commenced and said target position with the deviation Delta L of the present position of said crane from said target position for generating said deceleration command signal when said deviation Delta L becomes equal to said distance S.
Claim 8
Dependent Claim
45 words
The control system according to claim 1 wherein said means for providing said acceleration-deceleration pattern signal comprises an integrator which is connected to integrate said maximum transverse running speed or a reference signal in accordance with the operation of said deceleration command signal generating means.
Claim 9
Dependent Claim
17 words
The control system according to claim 7 wherein said integrator includes means to reverse said pattern signal.
Claim 10
Dependent Claim
81 words
The control system according to claim 2 which further includes a switching time computer comprising means responsive to the operation of a controller for said trolley and the speed of said trolley driving motor for producing a signal Vmax where Vmax represents a predetermined maximum transverse running speed of said trolley; means for producing a signal (a Vmax +0 b1 + c), where a, b and c are constants, and 1 the length of the rope; means for producing a signal
Claim 11
Dependent Claim
97 words
The control system according to claim 9 which further comprises means for detecting the polarity of a signal V1 - V2, where V1 represents a constant voltage start signal applied by said trolley controller and V2 the actual transverse running speed of said trolley; means responsive to the operation of said polarity detecting means for applying a signal + Alpha or - Alpha to one input of said third integrator, and means responsive to the operation of said first and second relay means for applying a signal 2 Alpha to the other input of said third integrator.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |