US3884038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for a prime mover connected to a stepless transmission
Assignee: Linde GmbH
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Filing: 1974-01-30
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Granted: 1975-05-20
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Expires: 1994-01-30
Abstract
Abstract A torque-responsive device is provided between the output shaft of a prime mover such as an internal-combustion engine or electric motor, and the input (driven) shaft of a stepless transmission (e.g. a hydrostatic drive) and controls the prime mover so that, when the loading of the prime mover reaches a limiting value, the ratio of the stepless transmission is varied to reduce its output speed.
Inventors
- 👤 Franz Forster
- 👤 Hans-Waldemar Stuhr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:07
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/47; B; B60; B60W; B60W30/00; B60W30/18; B60W30/184; B60W30/1846; F16H61/468; F16H59/00; F16H59/14; F16H59/16
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
108 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for directly detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission.
Claim 2
Independent Claim
108 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for directly detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission.
Claim 3
Dependent Claim
38 words
The system defined in claim 1 wherein said transmission is a hydrostatic drive and said means responsive to the torque-measuring means includes a comparator having a selective set-point input establishing a threshold corresponding to said predetermined limiting value.
Claim 4
Dependent Claim
21 words
The system defined in claim 1 wherein said limiting value is determined by a threshold directly set at said torque-measuring means.
Claim 5
Dependent Claim
38 words
The system defined in claim 1 wherein said prime mover has means for controlling the energy input thereto, said system further comprising means for establishing said limiting value and for operating said means for controlling said energy input.
Claim 6
Dependent Claim
42 words
The system defined in claim 1, further comprising means for controlling the energy input to said prime mover whereby said speed of the output shaft of said transmission is adjusted only upon the attainment of maximum energy input to said prime mover.
Claim 7
Independent Claim
139 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said transmission being a hydrostatic drive and said means responsive to the torque-measuring means including a hydraulic control valve, said torque-measuring means including a torsion spring twistable for operation of said valve.
Claim 8
Independent Claim
139 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said transmission being a hydrostatic drive and said means responsive to the torque-measuring means including a hydraulic control valve, said torque-measuring means including a torsion spring twistable for operation of said valve.
Claim 9
Independent Claim
136 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission; and a further load coupled to said output shaft of said prime mover, said torque-measuring means being provided between said prime mover and both said transmission and said further load.
Claim 10
Independent Claim
136 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission; and a further load coupled to said output shaft of said prime mover, said torque-measuring means being provided between said prime mover and both said transmission and said further load.
Claim 11
Independent Claim
144 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said torque-measuring means including a pair of relatively rotatable members connected respectively to the output shaft of said prime mover and the input shaft of said transmission for generating a signal upon relative rotation of said members.
Claim 12
Independent Claim
144 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said torque-measuring means including a pair of relatively rotatable members connected respectively to the output shaft of said prime mover and the input shaft of said transmission for generating a signal upon relative rotation of said members.
Claim 13
Independent Claim
121 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said torque-measuring means including a twistable shaft having a strain gauge strip mounted thereon.
Claim 14
Independent Claim
121 words
A system comprising a prime mover having an output shaft; a steplessly adjustable transmission having an input shaft operatively connected to said output shaft of said prime mover, and an output shaft operatively connectible to a load, and control means for varying the speed ratio between the input and output shafts of said transmission; torque-measuring means between said prime mover and said transmission for detecting the torque at the output shaft of said prime mover; and means responsive to the torque-measuring means for operating said control means upon the measured torque attaining a predetermined limiting value to reduce the speed of the output shaft of said transmission, said torque-measuring means including a twistable shaft having a strain gauge strip mounted thereon.
Claim 15
Dependent Claim
68 words
In a control device for a stepless transmission connected to a load and driven by a shaft connected to a prime mover wherein the transmission ratio is altered in a direction reducing the output speed upon approaching maximum loading of the prime mover, the improvements which comprise means for directly measuring the torque in said shaft; and means responsive to the torque-measuring means for controlling said transmission ratio.
Claim 16
Dependent Claim
68 words
In a control device for a stepless transmission connected to a load and driven by a shaft connected to a prime mover wherein the transmission ratio is altered in a direction reducing the output speed upon approaching maximum loading of the prime mover, the improvements which comprise means for directly measuring the torque in said shaft; and means responsive to the torque-measuring means for controlling said transmission ratio.
Claim 17
Dependent Claim
39 words
The improvement defined in claim 10 wherein said control device includes means for comparing a measurement derived from said torque-measuring means with a predetermined threshold value and varying said transmission ratio upon the measured torque exceeding said threshold value.
Claim 18
Dependent Claim
14 words
The improvement defined in claim 11, further comprising means for varying the threshold value.
Claim 19
Dependent Claim
17 words
The improvement defined in claim 12 wherein the threshold value is adjustable directly on said torque-measuring means.
Claim 20
Dependent Claim
33 words
The improvement defined in claim 12 wherein said means for comparing comprises a comparator for a set point value and a measured value, said threshold value being introduced as said set point value.
Claim 21
Dependent Claim
29 words
The improvement defined in claim 12 wherein said prime mover is adjustable, further comprising means for modifying said threshold value in accordance with the adjustment of said prime mover.
Claim 22
Dependent Claim
18 words
The improvement defined in claim 10 wherein said transmission has a setting device unaffected by said torque-measuring means.
Claim 23
Dependent Claim
19 words
The improvement defined in claim 10, further comprising means for selectively varying said ratio independently of said torque-measuring means.
Claim 24
Dependent Claim
48 words
The improvement defined in claim 10 wherein said control device has a control characteristic whereby, upon attaining a threshold value of said torque at which said ratio is adjusted, first the prime mover is set at maximum output and thereafter at said maximum output, said ratio is adjusted.
Claim 25
Dependent Claim
37 words
The improvement defined in claim 10 wherein a second load is connected to said shaft, the torque-measuring means being provided between said prime mover and the point at which said second load is connected to said shaft.
Claim 26
Dependent Claim
35 words
The improvement defined in claim 10 wherein said transmission is a hydrostatic transmission having a pressure-responsive device including a control valve responsive to said torque-measuring means for adjusting the pressure supplied to the latter device.
Claim 27
Dependent Claim
21 words
The improvement defined in claim 10 wherein said torque-measuring means includes a twisted portion of said shaft provided with torque-measuring strips.
Claim 28
Dependent Claim
24 words
The improvement defined in claim 10 wherein said torque-measuring means includes a lever arm acting upon a force-measuring element and connected to said shaft.
Claim 29
Dependent Claim
23 words
The improvement defined in claim 10 wherein said torque-measuring means includes a force-measuring element disposed between two threadedly interconnected portions of said shaft.
Claim 30
Dependent Claim
19 words
The improvement defined in claim 10 wherein said torque-measuring means includes a torsion spring acting upon a pressure-relief valve.
Claim 31
Dependent Claim
37 words
The improvement defined in claim 10 wherein said torque-measuring means includes a clutch having a pair of relatively rotatable portions and means responsive to relative rotation of said portions for producing an output representing the measured torque.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |