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US 4,378,710 AGranted
Variable-speed transmission for motor cars
AssigneeGetrag Getriebe-und Zahnradfabrik GmbH
InventorGunter Knodel
Life of this patent
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AssigneeGetrag Getriebe-und Zahnradfabrik GmbH
InventorGunter Knodel
Estimating the term…
The invention relates to a variable-speed transmission for motor cars, in particular a manual gear-box in the form of a synchronized lay-shaft transmission having several forward speeds and one reverse motion, in which the gears of the reverse motion (11, 12) are also constantly meshing and in which the pairs of gears are selectively shifted into the flux of forces by means of a shifting clutch (13). In order to permit low-noise shifting into the reverse motion, the latter (11, 12) is provided with a synchronizer unit (17, 23). Considering, however, that this creates the risk that the reverse gear may be put in while the car is moving forward, a stop (9, 23) can be moved into the path of transmission of motion between a shift lever to be actuated by the driver and the shifting clutch (13) for the reverse motion, which stop occupies the engaged position when a predetermined traveling speed is exceeded and acts in this engaged position to block the actuation of the shifting clutch (13) for the reverse motion (11, 12) (FIG. 1). The stop is incorporated into the shifting clutch for the reverse gear.
A multi-step reduction gear for motor vehicles, comprising a transmission of the countershaft type of construction, having several forward gear sets and one reverse gear set in which at least the reverse gear set is synchronized and constantly engaged with each other, at least one gear set of the forward speeds and reverse speed is engaged for the transmission of power by a clutch having an axially sliding member, said clutch serving to actuate the reverse gear being blocked against engagement therewith by a stop actuated by centrifugal force when a given speed is exceeded, said stop being built into the clutch and engaging the axially movable member positively when engaged to prevent movement thereof into engagement with the gear set for reverse motion.
A variable speed transmission for motor cars, comprising a manually operable transmission having a drive shaft, a driven shaft and at least one forward speed and a reverse motion being effected respectively by synchronized gear sets constantly driven by the drive shaft and a shifting clutch for selective shifting of said sets into engagement with the driven shaft, said shifting clutch comprising a guiding sleeve fixed to the driven shaft, gearshift sleeve connected to rotate with the guiding sleeve, said gearshift sleeve being axially displaceable from a central neutral position to a selected one of opposed axial directions in association with at least one of said gear sets for forward speed and said gear set for reverse motion, a clutch body mounted between said gearshift sleeve and each of said associated gear sets to rotate with the associated gear set, the toothing of the said gearshift sleeve being adapted to mesh with the toothing of the associated clutch body on axial movement of said gearshift sleeve and stop means located within the guiding sleeve movable to engage the gearshift sleeve when the speed of said driven shaft exceeds a predetermined speed for blocking the axial movement of the gearshift sleeve toward the clutch body associated with the reverse motion gear set and thereby prevent actuation of reverse motion.
Dependencies are inferred from the claim text.