Deere + Company

Robert James Johnston

Thomas Daryl Bebernes

David Henry Diebold

John Lewis Rukgaber

Alan Joseph Novak

Larry Allen Workman

A vehicle has a pair of opposite drive wheels driven by a dual path hydrostatic transmission. Steering and speed/direction controls are effected by changing the displacement and/or direction of fluid flow through the pair of reversible, variable displacement pumps that are respectively coupled to fixed displacement ground wheel drive motors. The control mechanism for accomplishing steering and/or speed/direction control includes a steering rack that is caused to pivot about a fixed post in response to steering wheel movement. A first crank arm is coupled for pivoting in concert with the rack and a second crank arm is coupled for pivoting in concert with a pivot plate about a second axis, the pivot plate having a pair of connection points respectively coupled to control arms of the pair of pumps by a pair of pump control rods. The pivotal motion of the steering rack is transmitted to the pivot plate by a tie-rod coupled between the first and second crank arms. This tie-rod is parallel to a pivot support bar that swings about the fixed post in response to fore-and-aft movement of a speed/direction control lever, the pivot plate being pivotally mounted to the free end of the pivot support bar. Thus, the pivot support bar, first and second crank arms and the tie-rod cooperate to define a four-bar linkage that causes the pivot plate to retain its pivoted position about the second axis during speed/direction control so that such control is made independently of steering, and vice-versa.

Steering and ground speed control mechanism of a dual-path hydrostatic drive system

A self-propelled windrower includes an engine compartment containing an engine-driven fan for pulling cooling air through a screen covering a circular air inlet leading into the compartment. The fan also is coupled for creating a suction in an air duct extending diametrically across the air inlet, the duct in turn being coupled to the center of a channel-like vacuum wand mounted for sweeping the exterior of the screen and removing airborne debris collected by the screen. Provided for rotatably supporting a drive shaft for the wand is a bearing support member including a cylindrical portion having an end fixed to a mounting plate secured to the air duct, the cylindrical portion having an interior end section receiving an outer race of a roller bearing having an inner race receiving and being fixed to the wand drive shaft. An electric drive motor is located within said compartment and mounted to said air duct at a side thereof remote from said screen. The electric motor is, for example, of a type normally used for driving windshield wiper blades and includes a main body disposed at a right angle to an output shaft coupled to the wand shaft by a wedge fit formed by respective frusto-conical surfaces of the motor output shaft and the wand drive shaft. The motor output shaft projects through a hole provided in the mounting plate of the bearing support member, the hole having an axially short pilot portion to accurately position the motor output shaft relative to the wand drive shaft to minimize misalignments, and secondly to minimize the binding of the motor shaft.

Mounting for drive mechanism of heat exchanger screen cleaning wand

A steering and ground speed control mechanism of a vehicle equipped with a dual-path hydrostatic drive system includes a pivot plate fixed to a vertical pivot post at a location between and equidistant from a pair of locations respectively linked to a pair of pump displacement control arms of a pair of pumps respectively coupled for delivering fluid to right- and left-hand drive motors coupled to right- and left-hand ground wheels. A train of elements for transferring steering inputs from a steering wheel to the pivot plate includes a timed belt and sprocket set with one of the sprockets being fixed to the pivot post and the other mounted to a fixed post together with a quadrant-shaped steering rack for pivotal movement about the fixed post in concert with the rack. Pivoting the pivot plate in opposite directions from a centered position causes different displacements of the pumps and, hence, in the two drive motors being driven at different speeds. A train of elements for transferring speed inputs from a speed control lever to shift the pivot plate back and forth in a nearly straight path includes a push-pull cable coupled between the lever and an arm having the pivot post pivotally mounted in one end thereof, with the arm being mounted for pivoting about the fixed post exclusive of the rack and sprocket. A spring-applied, hydraulically released latch is provided for latching the steering wheel and speed control lever in their respective 'centered' and 'neutral' positions when hydraulic pressure is absent and a 'neutral' start switch is positioned for being activated for completing a vehicle starting circuit only when the steering wheel and speed control lever are in these positions.

Growing community of inventors

Oskaloosa, IA, United States of America

Robert James Johnston