Deere + Company

Dieter Nobis

Reinhard Schwarz

Volker D Huckler

Heinz Stuhrmann

Helmut Schafer

Volker Hueckler

Eugen Sonns

A drive arrangement for a selectively engageable wheelset includes a clutch and a freewheel arranged in series, one behind the other, between a transmission and the selectively engageable wheelset. The clutch is designed as an overload release clutch, so that overloading of the drive to the selectively engageable wheelset is avoided when the freewheel is engaged. In addition, the clutch will permit interruption of the drive to the selectively engageable wheelset completely and as long as desired. The freewheel can be locked as a function of various operating conditions or upon demand.

Drive engagement for a selectively engageable wheelset

A drive arrangement for a four wheel drive vehicle is equipped with a planetary gear set for driving the front wheels which can operate in either direct drive or with a speed increase and which is shifted according to the steering angle .beta. sensed at the front pair of wheels. To avoid an excessively high jump in speed during the transition from direct drive to the increased speed mode, the planetary gearset is gradually shifted, i.e., the planetary gear clutch and/or brake are allowed to slip in proportion to the steering angle .beta..

Drive arrangement for a four wheel drive vehicle

A drive system for a four-wheel drive motor vehicle, in particular an agricultural tractor, includes a gradually lockable differential for the front wheels, a gradually lockable differential for the rear wheels, and a gradually lockable center differential in the drive to the front and rear differential gears. The degree of locking of the respective differentials is controlled by a control circuit based upon their relative rotational speeds, the steering angle and the temperature in the center differential. In an alternative embodiment, brakes on each wheel and on the shafts connecting the center differential to the front and rear differential are used to supplement or replace the differential locks.

Drive system for two pairs of wheels

A procedure for shifting a transmission composed of several gear units in which a number of synchronizer linkages are provided, is so designated that during a gear ratio change in the last gear unit, that is in that unit to which the speed of all preceding gear units must be brought, all shift linkages are initially released. Following this, the shift linkages are re-established beginning with the last gear unit. By this means unnecessary rotating inertias are decoupled, and the shift linkages, and particularly any synchronizing devices, can be reduced in size.

Procedure for shifting a transmission composed of several gear units

A vehicle, such as a tractor, has a main change-speed gear with an associated clutch and a load shift gear coupled to a selector rod. The load shift gear can be shifted under load between a normal position and an under-speed position which produces increased tractive effort by reducing the speed by about 20%. This load shift gear can be operated by the same lever as operates the main change speed gear. In order to prevent simultaneous operation of the main gear and the load change gear, with corresponding interference with the synchronization of the main gear, an interlock device is provided. The interlock device includes a bellows which is connected into the hydraulic circuit for the clutch and, when the clutch pedal is depressed, the bellows holds a plunger in interlocking engagement with one of two grooves in the selector rod which is mechanically coupled to the load change gear. In other embodiments, a mechanical linkage between the clutch pedal and the interlock device is provided.

Gear shift arrangement for a vehicle

A gear change mechanism for a tractor is designed so that a single shift lever only is used both for gear and 'Hi-lo' selection. When the lever is in a gear selected position, it can be swung sideways, bringing with it its associated pivotally mounted shift lever quadrant (12) to make the 'Hi-lo' change. A stop (26, 26a) is provided to prevent such a change in neutral.

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Lonsee-Halzhausen, Germany

Dieter Nobis