Abstract: A transmission system for a straddle vehicle offers an automatic mode based on preprogrammed values for consistent shifting each time certain engine conditions are encountered. A variety of preset shifting parameters may be provided to allow different shifting modes. By this, an operator can select the degree of aggressiveness of the transmission. The automatic transmission may be modulated so that a preset shifting delay is provided to allow the operator to experience the sensation of shifting.

Abstract: A transmission system for a straddle vehicle which provides two operating modes, namely semi-automatic and automatic. With the semi-automatic transmission system, an operator only uses a switching means mounted on a sheeting bar of the vehicle for activating a clutch actuator and a shift actuator. The clutch actuator disengages a transmission clutch while the shift actuator operates a shifter for changing the transmission ratio. With the automatic transmission system, an Electronic Control Unit reads inputs signals such as speed of the engine (RPM), speed of the vehicle, opening of a throttle valve and position of a shifter and accomplishes a smooth shifting by activating a clutch actuator, a shift actuator and a modulated controlling valve.

Abstract: Disclosed is an all terrain vehicle with an improved engine and power train. The engine is located under the seat and the hingably seat provides for ready access to the engine for maintenance and repair. The engine is placed in the vehicle such that the crankshaft is parallel to the line of travel; that is to say that the crankshaft is in line with the longitudinal axis of the vehicle. The engine has a split output shaft; that is to say, two output shafts. One shaft extends forwardly of the engine to a front transmission on the front axle and the second extends rearwardly to a rear transmission on the rear axle. The output shafts run directly to the transmissions in a straight line. The front and rear output shafts are connected by gears which enables different ratios of revolution between the front and rear axle if necessary. The all terrain vehicle is also equipped with a unique parking gear which essentially locks the two output shafts to the transmission housing.

Abstract: An all terrain vehicle includes an engine located under a hingably mounted seat, the seat providing ready access to the engine for maintenance and repair. The vehicle includes an engine having a clutch housing and a clutch cover sealably connected to the clutch housing. At least one of the clutch housing and the clutch cover include a bottom wall having at least one coolant-fillable cooling channel within the thickness of the bottom wall provided to cool oil above the clutch housing and the clutch cover. The vehicle also includes a frame having a plurality of engine mounting points. The engine is supportable by the frame and includes a crankcase and a plurality of mounting points adapted to engage the plurality of engine mounting points on the frame. The plurality of mounting points include at least one uppermost mounting point, wherein the at least one uppermost mounting point is positioned on the crankcase.

Abstract: A transmission system for a straddle vehicle offers an automatic mode based on preprogrammed values for consistent shifting each time certain engine conditions are encountered. A variety of preset shifting parameters may be provided to allow different shifting modes. By this, an operator can select the degree of aggressiveness of the transmission. The automatic transmission may be modulated so that a preset shifting delay is provided to allow the operator to experience the sensation of shifting.

Abstract: A system reduces the amount of work exerted by an ATV operator to change transmission gears. The system includes a foot lever assembly with a mechanical portion, such as a mechanical linkage, attached to an automated portion, such as an electrical switch. When the ATV operator applies a predetermined amount of force to the foot lever assembly, a clutch assembly and a gear box are actuated in a single motion, assisted by the automated portion of the foot lever assembly. Thus, the operator is able to exert less work in order to change the gears.

Abstract: Disclosed is an all terrain vehicle with an improved engine and power train. The engine is located under the seat and the hingably seat provides for ready access to the engine for maintenance and repair. The engine is placed in the vehicle such that the crankshaft is parallel to the line of travel; that is to say that the crankshaft is in line with the longitudinal axis of the vehicle. The engine has a split output shaft; that is to say, two output shafts. One shaft extends forwardly of the engine to a front transmission on the front axle and the second extends rearwardly to a rear transmission on the rear axle. The output shafts run directly to the transmissions in a straight line. The front and rear output shafts are connected by gears which enables different ratios of revolution between the front and rear axle if necessary. The all terrain vehicle is also equipped with a unique parking gear which essentially locks the two output shafts to the transmission housing.

Abstract: A suspension system for an ATV is provided that includes a torsion control mechanism having a left connecting structure and a right connecting structure. The torsion control mechanism defines an axis of rotation passing through the left and right connecting structures. A left swing arm is fixedly connected to the left connecting structure and a right swing arm is fixedly connected to the right connecting structure, such that the right and left swing arms are pivotable about the rotation axis defined by the torsion control mechanism.

Abstract: A transmission system for a straddle vehicle which provides two operating modes, namely semi-automatic and automatic. With the semi-automatic transmission system, an operator only uses a switching means mounted on a sheeting bar of the vehicle for activating a clutch actuator and a shift actuator. The clutch actuator disengages a transmission clutch while the shift actuator operates a shifter for changing the transmission ratio. With the automatic transmission system, an Electronic Control Unit reads inputs signals such as speed of the engine (RPM), speed of the vehicle, opening of a throttle valve and position of a shifter and accomplishes a smooth shifting by activating a clutch actuator, a shift actuator and a modulated controlling valve.

Abstract: An all terrain vehicle comprises an engine located under a hingably mounted seat, the seat providing ready access to the engine for maintenance and repair. The engine is placed in the vehicle such that the crankshaft is parallel to the line of travel and the crankshaft is in line with the longitudinal axis of the vehicle. The engine has two output shafts. The front output shaft extends forwardly of the engine to a front differential on the front axle and the rear output shaft extends rearwardly to a rear differential on the rear axle. The front and rear output shafts are in communication with one another by gears which enables different ratios of revolution between-the front and rear axle. The all terrain vehicle is also equipped with a parking gear which locks the two output shafts and prevents rotation with respect to the transmission housing.

Abstract: A transmission system for a straddle vehicle which provides two operating modes, namely semi-automatic and automatic. With the semi-automatic transmission system, an operator only uses a switching means mounted on a steering bar of the vehicle for activating a clutch actuator and a shift actuator. The clutch actuator disengages a transmission clutch while the shift actuator operates a shifter for changing the transmission ratio. With the automatic transmission system, an Electronic Control Unit reads inputs signals such as speed of the engine (RPM), speed of the vehicle, opening of a throttle valve and position of a shifter and accomplishes a smooth shifting by activating a clutch actuator, a shift actuator and a modulated controlling valve.

Abstract: A system for reversing the direction of a two-stroke, internal combustion engine provided with a spark ignition system, the engine having at least one cylinder and a piston reciprocating therein and connected to drive a rotary crankshaft, the system comprising: a manually operable inverse command button; trigger means located proximate a rotary member driven by the crankshaft, a cooperating member carried on the rotary member and cooperating with the trigger means as the rotary member rotates to generate a train of pulses; means detecting the direction of rotation of the crankshaft and generating a direction signal indicative of direction of rotation; a microprocessor control unit receiving the train of pulses, the direction signal and an output from the inverse command button and connected to control the spark ignition system, the microprocessor monitoring the speed and direction of rotation of the rotary member on the basis of the train of pulses and the direction signal, the microprocessor operable when th

Abstract: This invention relates to an improved snowmobile drive train configuration arrangement that incorporates a fixed ratio speed reduction mechanism directly coupled to the engine crankshaft. This mechanism is in turn coupled to the driving pulley of a variable ratio belt drive system, the driven pulley of which is mounted on the axle of the sprocket wheels that drive the snowmobile track. Interposing the reduction drive between the engine and the belt drive system reduces the operational speed of both the pulleys and the belt, which proves beneficial from several aspects: the mechanical efficiency of the global system is increased, the dynamic response of the transmission to throttle modulation is improved; aerodynamic losses are reduced; the bending vibrations of the crankshaft are no longer transmitted to the drive clutch; and the engine can be run at higher RPM without decreasing the efficiency of the belt drive system.

Abstract: In a snowmobile drive train the variable ratio belt drive is not directly coupled to the engine crankshaft as in the prior art, but rather the driving pulley of the variable ratio belt drive is carried on one end of a jackshaft and the engine power is applied to the opposite end of the jackshaft. The jackshaft is supported in a fixed bearing in the vehicle frame, this bearing being immediately adjacent to the driving pulley so that the influence on the belt drive of vibrations generated by the engine is vastly diminished. Therefore the engine mounts can be arranged to fully absorb vibrations of the engine. Previously, when the driving pulley was directly coupled to the engine crankshaft it was necessary to include a tie restraint to limit movements of the engine housing in the direction of separation between the axes of the driving and driven pulleys.