US3918312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulically operated transmission system for automotive vehicles
Assignee: Robert Bosch GmbH
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Filing: 1974-06-07
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Granted: 1975-11-11
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Expires: 1994-06-07
Abstract
Abstract An automatic transmission system for use in automotive vehicles wherein the engine shaft drives an output shaft through a medium of a reversing gear and the output shaft carries a disk-shaped clutch element which can drive one flange of a variable-pitch sheave on the output shaft. The sheave forms part of a belt drive the other sheave of which drives one or more wheels. The flanges of the sheave on the output shaft are rotatable relative to the output shaft and are movable axially of the output shaft with and relative to each other by a piston which is reciprocable in a cylinder of the output shaft. A helical spring urges the sheave on the output shaft to a position in which the one flange is disengaged from the clutch element. When the cylinder receives pressurized fluid from a hydraulic regulating unit, the piston causes the one flange to engage the clutch element so that the belt drive rotates the wheel or wheels. A further increase of fluid pressure in the cylinder causes the other flange of the sheave on the output shaft to move toward the one flange and to thus change the speed ratio of the belt drive. The regulating unit has a pressure regulating valve which is controlled by an electromagnet. The latter can be influenced by the speed of the engine shaft, by the position of the gas and/or brake pedal, by the position of the kickdown switch and/or by a device which is actuated when the vehicle travels on a sloping road surface.
Inventors
- 👤 Helmut Espenschied
- 👤 Georg Rothfuss
- 👤 Hans-Dietrich Smentek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:08
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/66; F16H61/662; F16H61/66254; F16H61/66259; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86879
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
272 words
In a transmission system for automotive vehicles or the like, a combination comprising a driven output shaft; a belt drive having a plurality of speed ratios and including two variablepitch sheaves and an endless flexible element trained over said sheaves, one of said sheaves including two flanges axially movably and rotatably mounted on said output shaft, one of said flanges being movable axially of the other of said flanges; a clutch element mounted on and driven by said output shaft, said clutch element being adjacent to said other flange; means for moving said flanges with and relative to each other and comprising a hydraulic motor having a reciprocable piston constituting a shifting member and displaceable between a first position in which said other flange is disengaged from said clutch element so that said output shaft and said one sheave can rotate relative to each other, a second position in which said other flange is driven by said clutch element when said output shaft rotates, and a plurality of third positions in each of which said one flange is located at a different distance from said other flange so that each third position of said piston corresponds to a different speed ratio of said belt drive; and means for displacing said piston and comprising a single valve having a valve member movable between a plurality of positions each corresponding to a different fluid pressure in said motor and a plurality of devices each of which is arranged to influence the position of said valve member and therewith the pressure of hydraulic fluid in said motor to thus change the position of said piston.
Claim 2
Dependent Claim
272 words
In a transmission system for automotive vehicles or the like, a combination comprising a driven output shaft; a belt drive having a plurality of speed ratios and including two variablepitch sheaves and an endless flexible element trained over said sheaves, one of said sheaves including two flanges axially movably and rotatably mounted on said output shaft, one of said flanges being movable axially of the other of said flanges; a clutch element mounted on and driven by said output shaft, said clutch element being adjacent to said other flange; means for moving said flanges with and relative to each other and comprising a hydraulic motor having a reciprocable piston constituting a shifting member and displaceable between a first position in which said other flange is disengaged from said clutch element so that said output shaft and said one sheave can rotate relative to each other, a second position in which said other flange is driven by said clutch element when said output shaft rotates, and a plurality of third positions in each of which said one flange is located at a different distance from said other flange so that each third position of said piston corresponds to a different speed ratio of said belt drive; and means for displacing said piston and comprising a single valve having a valve member movable between a plurality of positions each corresponding to a different fluid pressure in said motor and a plurality of devices each of which is arranged to influence the position of said valve member and therewith the pressure of hydraulic fluid in said motor to thus change the position of said piston.
Claim 3
Dependent Claim
27 words
A combination as defined in claim 1, wherein said valve includes electromagnet means for moving said valve member, said plurality of devices cooperating with said electromagnet means.
Claim 4
Dependent Claim
24 words
A combination as defined in claim 1, wherein said displacing means includes resilient means arranged to bias said shifting member to said first position.
Claim 5
Dependent Claim
17 words
A combination as defined in claim 1, wherein one of said devices includes a movable brake pedal.
Claim 6
Dependent Claim
44 words
A combination as defined in claim 4, wherein said one device further includes a switch which is actuated in response to engagement of said pedal preparatory to movement of said brake pedal from an idle position to one of a plurality of braking positions.
Claim 7
Dependent Claim
29 words
A combination as defined in claim 1, wherein said motor further comprises a portion of said shaft and said portion of said shaft defines a cylinder for said piston.
Claim 8
Dependent Claim
20 words
A combination as defined in claim 6, further comprising motion transmitting means interposed between said piston and said one flange.
Claim 9
Dependent Claim
49 words
A combination as defined in claim 7, wherein said shaft has at least one axially parallel slot and said motion transmitting means comprises a follower having a portion extending into and movable lengthwise of said slot so that said follower rotates with and is movable axially of said shaft.
Claim 10
Dependent Claim
22 words
A combination as defined in claim 8, wherein said displacing means comprises a spring arranged to bias said follower against said piston.
Claim 11
Dependent Claim
25 words
A combination as defined in claim 8, wherein said motion transmitting means further comprise an antifriction bearing interposed between said follower and said one flange.
Claim 12
Dependent Claim
56 words
A combination as defined in claim 2, wherein said electromagnet means comprises a winding and a core connected with said valve member and movable relative to said winding in response to changes in the magnitude of current flowIng in said winding, each of said plurality of devices being actuatable to change the magnitude of said current.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |