Abstract: The invention relates to an interface system for a vehicle having a starter motor and a transmission control lever. There is a need for such an interface system which senses control lever position and prevents starter motor operation unless the control lever is in a park position. The interface system includes a plurality of magnet members generating magnetic fields, and a plurality of magnetic sensors or Hall effect switches mounted to the lever so that movement of the lever causes the magnetic sensors to move through the magnetic fields. An interface circuit is connected to the starter motor and to the magnetic sensors. The interface circuit and the sensors cooperate to generate lever position signals. The interface circuit and the sensors also cooperate to prevent activation of the starter motor unless the lever is in its park position. Thus, the same lever position sensors are used by the transmission control system and are used to control operation of the starter.

Abstract: The invention relates to a vehicle with coordinated steering. There is a need for a vehicle wherein Ackerman steered front wheels are coordinated with differentially steered and driven rear wheels. Such a vehicle includes Ackerman steerable front wheels and differentially driven left and right rear wheels. A steered wheel angle sensor is coupled to the front wheels and generates a steered wheel angle value. A front steering unit steers the front wheels and a differential drive unit drives the rear wheels. A control unit is coupled to the steering input sensor, to the steered wheel angle sensor, and to the front steering unit and the differential drive unit. The control unit generates the front steering control signal and the rear drive/steering control signal, and coordinates the steering operation of the front wheels with the differential steering/driving of the rear wheels.

Abstract: The invention relates to an interface system for a vehicle having a starter motor and a transmission control lever. There is a need for such an interface system which senses control lever position and prevents starter motor operation unless the control lever is in a park position. The interface system includes a plurality of magnet members generating magnetic fields, and a plurality of magnetic sensors or Hall effect switches mounted to the lever so that movement of the lever causes the magnetic sensors to move through the magnetic fields. An interface circuit is connected to the starter motor and to the magnetic sensors. The interface circuit and the sensors cooperate to generate lever position signals. The interface circuit and the sensors also cooperate to prevent activation of the starter motor unless the lever is in its park position. Thus, the same lever position sensors are used by the transmission control system and are used to control operation of the starter.

Abstract: The invention relates to a vehicle with coordinated steering. There is a need for a vehicle wherein Ackerman steered front wheels are coordinated with differentially steered and driven rear wheels. Such a vehicle includes Ackerman steerable front wheels and differentially driven left and right rear wheels. A steered wheel angle sensor is coupled to the front wheels and generates a steered wheel angle value. A front steering unit steers the front wheels and a differential drive unit drives the rear wheels. A control unit is coupled to the steering input sensor, to the steered wheel angle sensor, and to the front steering unit and the differential drive unit. The control unit generates the front steering control signal and the rear drive/steering control signal, and coordinates the steering operation of the front wheels with the differential steering/driving of the rear wheels.

Abstract: The invention relates to an engine cooling system monitoring system. There is a need for a cooling system monitoring system for an engine system wherein the coolant is maintained at a precise temperature. Thus, a cooling system monitoring system is provided for an engine system having internal combustion engine, a fan driven by a variable speed fan drive, and a radiator for cooling coolant circulating through the engine. The monitoring system includes a fan speed sensor generating a fan speed signal, a control unit and a display device controlled by the control unit. The control unit generates a cooling system status signal as a function of the fan speed signal and a maximum fan speed value. The display device has visible position range associated with a normal engine operating temperature, and has an indicator movable within said position range in response to the cooling system status signal to indicate a status of the engine cooling system.

Abstract: The invention relates to an engine cooling system monitoring system. There is a need for a cooling system monitoring system for an engine system wherein the coolant is maintained at a precise temperature. Thus, a cooling system monitoring system is provided for an engine system having internal combustion engine, a fan driven by a variable speed fan drive, and a radiator for cooling coolant circulating through the engine. The monitoring system includes a fan speed sensor generating a fan speed signal, a control unit and a display device controlled by the control unit. The control unit generates a cooling system status signal as a function of the fan speed signal and a maximum fan speed value. The display device has visible position range associated with a normal engine operating temperature, and has an indicator movable within said position range in response to the cooling system status signal to indicate a status of the engine cooling system.

Abstract: A control lever assembly having a moveable lever and a knob mounted on an end of the lever. The knob has a hollow housing which is removably attached to a cylindrical base. The housing has a cylindrical side wall which forms an opening. A wheel is received in and partially enclosed by the housing for rotation therein. A portion of the housing completely surrounds an outer surface of one end of the wheel. A rotary encoder generates a rotary position signal and is coupled to the wheel by a stiff wire or shaft. The shaft extends through the wheel to a first end which is received by an alignment recess formed on an inner surface of the housing and to a second end which is coupled to the encoder. The shaft extends through a bore in the base and through a bore in the lever.

Abstract: A hitch control system controls a vehicle hitch to which implements can be attached. The hitch control system includes a spring-centered primary command lever which is manually moveable from a centered position to deflected positions, and which automatically returns to the centered position when released from a deflected position. A control unit generates a hitch command signal in part as a function of the lever position. The control unit has a closed-loop control mode wherein the valve command signal is generated in response to parameter, such as position and draft force, and the hitch command signal. The control unit moves the hitch in a step-wise manner by a predetermined amount in response to momentary deflection of the command lever to one of the deflected positions, and the amount of hitch movement is independent of an amount and duration of deflection of the command lever if the duration is not more than a predetermined duration.

Abstract: A rotary multi-position magnetic detent device includes an inner member having an outer cylindrical surface and an outer member receiving the inner member. The outer member has an inner cylindrical surface and the outer member rotates relative to the inner member. A plurality of inner magnets are disposed in the outer surface and distributed regularly and peripherally around the outer surface. The inner magnets have radially oriented magnetic poles, and alternate adjacent ones of said inner magnets have alternate radially outwardly directed north and south poles. A plurality of outer magnets are disposed in the inner surface and distributed regularly and peripherally around the inner surface. The outer magnets have radially oriented magnetic poles, and alternate adjacent ones of the outer magnets have alternate radially inwardly directed north and south poles.

Abstract: The entire right, title and interest in and to this application and all subject matter disclosed and/or claimed therein, including any and all divisions, continuations, reissues, etc., thereof are, effective as of the date of execution of this application, assigned, transferred, sold and set over by the applicant(s) named herein to Deere & Company, a Delaware corporation having offices at Moline, Ill. 61265, U.S.A., together with all rights to file, and to claim priorities in connection with, corresponding patent applications in any and all foreign countries in the name of Deere & Company or otherwise.

Abstract: A control lever assembly for a vehicle transmission includes a housing which supports a guide plate having a slot and a recess formed in a central portion of the slot. A carrier member is pivotally coupled to the housing about a pivot pin. A lever has a shaft which is supported by the carrier and which is rotatable and axially movable relative to the carrier. The lever has a knob which is mounted on an end of the shaft and which is received by the slot. A spring is coupled between the shaft and the carrier and is biased to rotate the knob and to urge the lever towards the pivot pin. When the knob is in the slot and outside of the recess, the slot walls prevent rotation of the knob and maintain the lever in a first rotary orientation. When the knob is moved into the recess, the spring is automatically able to rotate the knob and lever into a second rotary orientation.

Abstract: A sensor mounting assembly includes a housing having a sensor bore formed therein. An annular groove is formed in a surface of the sensor bore. A retainer is mountable in the sensor bore. The retainer has a C-shaped body and an end of the body has a lip projecting radially outwardly therefrom. A plurality of spaced apart fingers extend axially away from the C-shaped body and away from the lip. Each finger has a plurality of retainer teeth formed thereon. The lip is received by the groove as the retainer is moved axially into the sensor bore. The sensor has a cylindrical sensor body on which are formed teeth for interlocking with the finger teeth. The sensor body is inserted into the retainer when the retainer is mounted in the sensor bore, and the sensor body engages the retainer body to hold the lip within the groove, and the sensor teeth interlock with the retainer teeth to releasable hold the sensor in a mounted position within the retainer and within the sensor bore.

Abstract: A sensor mounting assembly includes a housing having a sensor bore formed therein. An annular groove is formed in a surface of the sensor bore. A retainer is mountable in the sensor bore. The retainer has a C-shaped body and an end of the body has a lip projecting radially outwardly therefrom. A plurality of spaced apart fingers extend axially away from the C-shaped body and away from the lip. Each finger has a plurality of retainer teeth formed thereon. The lip is received by the groove as the retainer is moved axially into the sensor bore. The sensor has a cylindrical sensor body on which are formed teeth for interlocking with the finger teeth. The sensor body is inserted into the retainer when the retainer is mounted in the sensor bore, and the sensor body engages the retainer body to hold the lip within the groove, and the sensor teeth interlock with the retainer teeth to releasable hold the sensor in a mounted position within the retainer and within the sensor bore.

Abstract: A tracked vehicle has an electrohydraulic drive/steering system having an engine driven variable displacement hydraulic steering pump which drives a hydraulic steering motor which is coupled to a differential track drive mechanism via a transmission with multiple gear ratios. A steering wheel is coupled to a variable friction device which produces a variable friction force which resists rotation of the steering wheel. A control system is responsive to a position of the steering wheel and controls the steering pump displacement and controls the friction device. The control system sets the variable friction device to its high friction level when a limit of the steering pump displacement is reached when the transmission is in a higher one of its gear ratios.

Abstract: A control system controls a tracked vehicle drive/steering system which has an engine driven hydraulic steering pump which drives a hydraulic steering motor. In one embodiment, the control system operates to gradually reduce the magnitude of the steering pump control signals if the vehicle is stationary, the clutch is engaged and these conditions persist for at least a certain time period, and to further or more rapidly reduce the magnitude if the vehicle seat is not occupied. In an alternate embodiment, the control system operates to limit the magnitude of the steering pump control signals as a function of the acceleration of wheel speed. In another alternate embodiment, the control system operates to quickly reduce the magnitude of the steering pump control signals if the vehicle is stationary, the clutch is engaged and the transmission is commanded to be in a non-neutral gear, between the time the ear is commanded and the vehicle motion begins.

Abstract: A control device for an infinitely variable transmission includes a control lever that is movable along a guide slot and whose position within the slot indicates the commanded speed and direction. The control lever is moved forward from a zero speed position to a maximum forward speed position. Between the zero speed position and maximum forward speed position is a set point position corresponding to a set point speed. A set speed adjuster, such as a potentiometer, enables the operator to adjust the set point speed that is commanded when the control lever is placed in the set point position. The speed for positions of the control lever between the zero and the set point positions varies proportionally between zero and the set point speed. Likewise, the speed for positions of the control lever between the set point position and the maximum forward speed position varies proportionally between the set point speed and the maximum forward speed.

Abstract: A control system is provided for a tracked vehicle drive/steering system which has an engine driven hydraulic steering pump which drives a hydraulic steering motor. The steering pump is responsive to steering pump control signals, and an operator manipulated steering wheel generates steering command signals. A steering motor provides an input to a differential track drive mechanism which responds to manipulation of the steering wheel and drives left and right tracks, turning the vehicle. The control system includes a steering wheel position sensor, a steering motor position sensor and a wheel speed sensor. The control system generates a motor displacement value as a function of the steering wheel position and the wheel speed. The control system also generates a motor target position value as a function of the motor displacement, and generates a motor desired position value as a function of the target position value.

Abstract: A tracked vehicle includes an engine driven variable displacement steering pump which drives hydraulic steering motor. The steering motor drives a differential drive mechanism which drives left and right track drive wheels. A steering control system senses the position of a non-spring centered steering wheel, vehicle speed, engine speed, steering motor speed, whether or not the transmission is in gear or in neutral, and whether the clutch is engaged or disengaged. In order to prevent a self-perpetuating turn situation, the control system gradually decreases the steering motor speed if the transmission is in neutral or the clutch is not engaged, and the steering motor speed divided by the vehicle speed is greater than a threshold, and the vehicle speed is less than a reference level.

Abstract: A vehicle steering input device includes a fixed housing, a steering input shaft rotatable relative to the housing by a vehicle operator, a hub non-rotatably mounted on the input shaft, a friction member frictionally engaging the hub, a resilient member biased to maintain the friction member in engagement with the hub member, a movable locking ring meshingly coupled to the friction member, and an electromagnet. When the electromagnet is energized it moves the locking ring into meshing engagement with the housing, thus limiting rotation of the friction member and creating an additional friction force which makes it more difficult to rotate the hub and the input shaft. The magnitude of this friction force depends on the bias of the resilient member and is not limited by the strength of the electromagnet.

Abstract: A powershift transmission includes a plurality of hydraulically operated clutch packs which are selectively engaged and disengaged to enable various gear ratios. A control circuit for such a transmission includes a system pressure source, a fluid reservoir, a control gallery, a plurality of control valves and a plurality of latching valves. Each control valve and each latching valve is connected with a corresponding one of the clutch packs, and is communicated with each other, with the system pressure source, with the reservoir and with the control gallery. The control valves, latching valves and the control gallery cooperate to prevent pressurization of any one of the clutch packs before all the clutch packs are filled with hydraulic fluid. The control valves and the latching valves also cooperate to maintain disengaged clutch packs at reservoir pressure, and to maintain engaged clutch packs at system pressure.