Abstract: The driven pulley is used in a variable-speed belt drive. It includes a clutch for transferring torque from the belt to the main shaft of the driven pulley. The clutch is alternatively movable between a disengaged position where the belt can still be in movement without transferring torque, and an engaged position where the torque is transferred to the main shaft. The clutch is controlled by the winding diameter of the belt. A plurality of rods is also provided for keeping the flanges from rotating relative to each other and for transferring torque from the flanges to a movable plate at the back of the clutch. This driven pulley reduces the wear of the belt, decreases the response time and increases the maximum torque that can be transferred compared with the conventional driven pulleys.

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on an annular-conical surface located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the annular-conical surface and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: A pulley mounted at the output of a drive shaft is used in a variable-speed belt drive in which pairs of generally cylindrical toothed flyweights engage toothed racks in order to vary the winding diameter of the pulley by varying the centrifugal force. A V-belt is placed around the pulley. As a result of using the pulley, a more accurate adjustment of the diameter is achieved, maximum engine power is maintained under conditions of severe loading, and the response time of the diameter varying system is reduced in the case of an abrupt load change.

Abstract: The driving pulley is used in a variable-speed belt drive, which includes, in particular, two radially converging ramps facing each other and coaxial to a shaft, one ramp being rigidly attached to a movable flange and the other ramp being rigidly attached to the shaft in spaced relationship with the movable flange. A plurality of sliding flyweights are symmetrically located around the shaft and radially movable between the ramps. The improvement in the driving pulley is that each ramp includes a contact surface on which the flyweights are in contact wherein at least one movable ramp contact surface is curved. Each flyweight also includes a lateral knob engaged with the curved contact surface for ensuring that the contact point of the sliding flyweights with a curved contact surface does not substantially change as the flyweights slide.

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on a conical ring located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the conical ring and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on an annular-conical surface located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the annular-conical surface and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: A driving pulley used in a variable speed transmission is adapted to receive a trapezoidal belt by which power is transmitted from the driving pulley to a driven pulley. The driving pulley is provided with radial pins connected to the shaft and movable inside respective apertures delimited by ramps for limiting sliding and rotating movements of the movable flange within predetermined limits with respect to the shaft and for imposing a specific mechanical behavior to the movable flange. It allows additional control of the engine speed under full throttle, reducing the overrun and helping the transmission return to its smallest ratio during a quick vehicle slowdown.

Abstract: A speed variator pulley provided with reduced flexion removable rings is used in a variable speed transmission of the V pulley type, provided with a trapezoidal belt. Transmissions of this type are, for example, used in snow scooters, motorcycles, utilitarian or pleasure vehicles or cars without permit or of the TQM type. The pulley of the invention has an arrangement which makes it possible to reduce the axial friction forces which are the cause of a hysteresis effect in the operation of the pulley.

Abstract: A driving pulley of a variable speed transmission having a drive shaft and two coaxial cheeks facing one another and defining a v-shaped groove which receives a trapezoidal belt. One of the cheeks is axially movable relative to the other cheek and has two housings distributed around its axis. The housings have a linear oblique ramp secured thereto and side wings which act as radial translation guides for inertia blocks which bear against the ramps and against a reaction cup attached to a hub of the driving pulley. The movable cheek is made solid in rotation with the drive shaft by a rubber membrane having a bow shape which is connected to the reaction cup. As the drive shaft rotates, the inertia blocks are subject to centrifugal forces which cause the movable cheek to move toward the other cheek. A return spring provides a force opposing the movement of the movable cheek.

Abstract: In a variable speed transmission of the pulley type, one of the pulley cheeks is movable axially with respect to the other which is stationary. The movable cheek faces a reaction cup which is solid with the stationary cheek. The cup and the movable cheek are formed with converging cam surfaces which define between them a chamber into which are disposed centrifugal weights having ends sliding on the cam surfaces. When the pulley and reaction cup rotate, the weights are thrown outward and force the movable cheek toward the stationary one. According to the invention, the cam surface of the reaction cup is concave, having a radius of curvature of predetermined length. On the other hand, the end edges of the centrifugal weights slidable on the cam surface of the reaction cup are convex and have a radius of curvature shorter than said predetermined length so that the ends of the weights bear only on a limited part of the cam surface of the reaction cup.