Patent US3638781A successfully refreshed from Google Patents.
US3638781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conveyor belt-tensioning means
Assignee: Anderson Strathclyde PLC
•
Filing: 1971-01-29
•
Granted: 1972-02-01
•
Expires: 1991-01-29
Abstract
Abstract An endless conveyor has belt-tensioning means comprising two devices adapted and arranged to sense and signal variations in the tensions in the working and return runs of the belt respectively due to change of load conditions, a drum around which the return run of the belt passes and which is displacable so as to vary the tensions in the belt, speed-variable driving gear adapted to effect said displacement of the drum, and means adapted to effect actuation of said driving gear in response to signals emitted by said devices when said tensions are not at a predetermined ratio, and to effect variation in the speed of said gear, and hence of the displacement of the drum, in accordance with the signal characteristics which vary in accordance with the rate at which tension change in the belt takes place due to variation in load conditions.
Inventors
- 👤 Peter Donald Heywood Comley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:17
CPC Classifications
B; B65; B65G; B65G23/00; B65G23/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
145 words
An endless conveyor having belt tensioning means comprising, two devices adapted and arranged to sense and signal variations in the tensions in the working and return runs of the belt respectively due to change of load conditions, a drum around which the return run of the belt passes and which is displaceable so as to vary the tensions in the belt, speed-variable driving gear adapted to effect said displacement of the drum, and means adapted to effect actuation of said driving gear in response to signals emitted by said devices when said tensions are not at a predetermined ratio, and to effect variation in the speed of said gear, and hence of the displacement of the drum, in accordance with the signal characteristics which vary in accordance with the rate at which tension change in the belt takes place due to variation in load conditions.
Claim 2
Dependent Claim
145 words
An endless conveyor having belt tensioning means comprising, two devices adapted and arranged to sense and signal variations in the tensions in the working and return runs of the belt respectively due to change of load conditions, a drum around which the return run of the belt passes and which is displaceable so as to vary the tensions in the belt, speed-variable driving gear adapted to effect said displacement of the drum, and means adapted to effect actuation of said driving gear in response to signals emitted by said devices when said tensions are not at a predetermined ratio, and to effect variation in the speed of said gear, and hence of the displacement of the drum, in accordance with the signal characteristics which vary in accordance with the rate at which tension change in the belt takes place due to variation in load conditions.
Claim 3
Dependent Claim
33 words
An endless conveyor having belt-tensioning means as claimed in claim 1 wherein, said driving gear includes a swashplate pump of which the tilt of the swashplate is controlled by said signal responsive means.
Claim 4
Dependent Claim
49 words
An endless conveyor having belt-tensioning means as claimed in claim 2 wherein, the arrangement is such that when the ratio of the tensions is that predetermined, the signals are of equal magnitude, and the degree of tilt of the swashplate increases with the degree of imbalance between the signals.
Claim 5
Dependent Claim
31 words
An endless conveyor having belt-tensioning means as claimed in claim 3 wherein, the movement of said drum is effected by a winch driven by a hydraulic motor fed by said pump.
Claim 6
Dependent Claim
26 words
An endless conveyor having belt-tensioning means as claimed in claim 4 wherein, each of said devices may be a load cell of hydroelastics or electrical form.
Claim 7
Dependent Claim
33 words
An endless conveyor having belt-tensioning means as claimed in claim 5 wherein, said devices are actuated by pivotal frames carrying rollers around which the working and return runs of the belt pass respectively.
Claim 8
Dependent Claim
39 words
An endless conveyor having belt-tensioning means as claimed in claim 6 wherein, the amplified signal from the load cells of positive or negative form is employed to operate an electrohydraulic servovaLve in which the electrocontrol may be a servomotor.
References Cited (Backward Citations)
US3275126A
Cited
US3537573A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |