Abstract: A method of controlling an activation load applied to a clutch pedal. A first load is applied to the clutch pedal that has a first reaction force in a first phase of pedal movement. A switch is activated at the end of the first phase. When the switch is activated, a second load that is greater than the first load is applied to the pedal that provides a second reaction force in a second phase of pedal movement.

Abstract: A method of controlling an activation load applied to a clutch pedal. A first load is applied to the clutch pedal that has a first reaction force in a first phase of pedal movement. A switch is activated at the end of the first phase. When the switch is activated, a second load that is greater than the first load is applied to the pedal that provides a second reaction force in a second phase of pedal movement.

Abstract: An external activation clutch brake that is controlled by a switch is actuated when a clutch pedal is depressed. A compression spring, torsion spring or hydraulic valve may be used to simulate engagement of a standard clutch brake in which clutch brake squeeze is sensed by the driver. The clutch pedal has first and second phases of movement with the load required to compress the clutch pedal in a first phase being less than the load required to further compress the clutch pedal in a second phase.

Abstract: An embodiment provides a drive train for a medium duty truck. The drive train includes an engine having an engine output member, and a centrifugal clutch. The clutch has a plurality of swing weights and a driving member. The driving member generally defines an axis and is rotatable with the engine output member. The clutch also includes a ramp portion having a generally planar ramped surface portion in selective engagement with at least a portion of the swing weights, and a clutch disk portion for transferring torque from the driving member to a driven member. The clutch is operable between an engaged condition and a disengaged condition. The swing weights are radially moveable with respect to the axis. Radial movement of the swing weights causes axial movement of at least a portion of the clutch between a disengaged position and an engaged position. The swing weights engage only the ramped surface portion when the at least a portion of the clutch is not in the disengaged position.

Abstract: A release bearing assembly has a roller bearing, an enclosure and a slinger. The enclosure has first and second flange portions. The slinger has a body portion sized for radial disposition within an inner diameter of the first flange portion. A lip portion extends from the body portion and defines a channel between itself and the enclosure.

Abstract: A dual friction clutch assembly for a multiple-ratio transmission comprises separate friction disks of the assembly separately connected to each of two torque input shafts for the transmission. Two torque flow paths for the torque input shafts are defined in part by pre-engaged transmission clutches.

Abstract: A centrifugal clutch assembly is provided that includes a cover module having a pressure plate for applying a clamping force against a friction plate, a moveable plate adapted to rotate with the cover module, but axially displaceable with respect thereto to apply an axial force on the pressure plate through a preloaded plate spring, a fixed plate secured for rotation with the cover module, and a plurality of weights positioned between the moveable plate and the fixed plate that are adapted to move outward under the effects of centrifugal force to cause axial movement in the movable plate and a clamping force on the friction plate. The cover module also includes at least one return spring configured to apply a return force on the weights through the moveable plate, the return force being generally parallel to the axis of rotation of the cover module and independent of weight position.

Abstract: A friction clutch is provided that includes a clutch cover, an intermediate plate that is spaced apart from an engine flywheel, a first friction disk positioned between the flywheel and the intermediate plate, a pressure plate spaced apart from the intermediate plate and a second friction disk positioned between the intermediate plate and the pressure plate. The clutch further includes a first drive strap for applying a load to the intermediate plate, a second drive strap for applying a load to the pressure plate and a separator arm attached to the intermediate plate. The separator arm engages the second drive strap such that axial movement of the intermediate plate relative to the clutch cover is a fraction of the corresponding axial movement of the pressure plate during engagement and disengagement of the clutch.

Abstract: A friction torque device includes an adjustment mechanism for adjusting the device in response to wear on a friction surface within the device, and an adjustment limiting member for controlling adjustment thereof. In one embodiment, the adjustment mechanism includes a first cam ring rotatable relative to both a pressure plate and a cover, and a second cam ring engaging the first cam ring on a side of the first cam ring opposite the cover and rotatably fixed relative to the cover. The first cam ring is rotatable with respect to the second cam ring such that ramped surfaces cam against each other to increase the axial displacement of the first and second cam rings, whereby the axial displacement compensates for wear on the friction surface. The adjustment limiting device is selectively engagable with the first cam ring to inhibit rotation thereof.

Abstract: An installation device for a centrifugal clutch is disclosed. In an embodiment of the invention, the centrifugal clutch includes a clutch cover, a pressure plate for applying a clamping force against a friction plate, and at least one flyweight that moves radially outward under the effects of centrifugal force to cause the pressure plate to exert a clamping force against the friction plate. The installation device includes an installation hub moveable relative to the clutch cover between a first position, wherein the installation hub is engaged with the flyweight to force the engaged flyweight to move radially outward, and a second position, wherein the installation hub is disengaged from the flyweight. A resilient member biases the installation hub toward the second position and is selectively engaged with the clutch cover to inhibit movement of the installation hub toward the first position.

Abstract: An installation device for a centrifugal clutch is disclosed. In an embodiment of the invention, the centrifugal clutch includes a clutch cover, a pressure plate for applying a clamping force against a friction plate, and at least one flyweight that moves radially outward under the effects of centrifugal force to cause the pressure plate to exert a clamping force against the friction plate. The installation device includes an installation hub moveable relative to the clutch cover between a first position, wherein the installation hub is engaged with the flyweight to force the engaged flyweight to move radially outward, and a second position, wherein the installation hub is disengaged from the flyweight. A resilient member biases the installation hub toward the second position and is selectively engaged with the clutch cover to inhibit movement of the installation hub toward the first position.

Abstract: A friction torque device includes an adjustment mechanism for adjusting the device in response to wear on a friction surface within the device, and an adjustment limiting member for controlling adjustment thereof. In one embodiment, the adjustment mechanism includes a first cam ring rotatable relative to both a pressure plate and a cover, and a second cam ring engaging the first cam ring on a side of the first cam ring opposite the cover and rotatably fixed relative to the cover. The first cam ring is rotatable with respect to the second cam ring such that ramped surfaces cam against each other to increase the axial displacement of the first and second cam rings, whereby the axial displacement compensates for wear on the friction surface. The adjustment limiting device is selectively engagable with the first cam ring to inhibit rotation thereof.

Abstract: A clutch driven disc assembly includes a hub and an annular spring plate fixed to the hub. A friction disc assembly is mounted concentric with an axis of rotation of the hub and is rotatably relative to the spring plate. A plurality of drive springs are operably disposed between the spring plate and the friction disc assembly. The friction disc assembly further includes a reinforcing plate and a substantially annular disc fixed to the reinforcing plate. A friction material button is fixed to the substantially annular disc. The friction material button has a friction material cookie and a backer plate. The backer plate is fixed to the friction material cookie. The backer plate is substantially the same size and shape as the friction material cookie. A laser weld bead joins the substantially annular disc and the backer plate, in turn fixing the friction material button to the substantially annular disc.

Abstract: A dual mass flywheel and clutch system for minimizing torsional vibration levels during engine start-up and during low speed engine operation where the rotational moment of inertia of a clutch input assembly is minimized to raise the torsional natural frequency of the dual mass clutch system above the engine firing frequency when the clutch is disengaged to reduce the level of torsional vibration during engine start-up. After engine start-up, the dual mass clutch system is engaged and the torsional natural frequency of the clutch system returns to a lower frequency due to the rotation of the clutch output assembly thereby effectively reducing the torsional vibration levels in the vehicle driveline in a normal manner.

Abstract: A control system/method for controlling a vehicle drive-train system including an internal combustion engine, a transmission and a centrifugal clutch for drivingly coupling an engine output to a transmission input shaft. A system controller issues command output signals for controlling engine speed in order to prevent damage and/or overheating of the clutch during periods of prolonged operation of the clutch in a partially engaged state.

Abstract: A friction clutch is provided that includes a clutch cover, an intermediate plate that is spaced apart from an engine flywheel, a first friction disk positioned between the flywheel and the intermediate plate, a pressure plate spaced apart from the intermediate plate and a second friction disk positioned between the intermediate plate and the pressure plate. The clutch further includes a first drive strap for applying a load to the intermediate plate, a second drive strap for applying a load to the pressure plate and a separator arm attached to the intermediate plate. The separator arm engages the second drive strap such that axial movement of the intermediate plate relative to the clutch cover is a fraction of the corresponding axial movement of the pressure plate during engagement and disengagement of the clutch.

Abstract: A centrifugal master friction clutch having an installation device is provided that includes a cover assembly fixed for rotation with an engine flywheel and at least one friction plate fixed for rotation with a transmission input shaft. The cover assembly includes a pressure plate for applying a clamping force against the friction plate and a plurality of flyweights that rotate outward under the effects of centrifugal force to cause the pressure plate to exert a clamping force against the friction plate. The clutch installation device includes a first member rotatably disposed in the cover assembly radially inward of the flyweights. A portion of the first member is configured to engage at least one of the flyweights to force the engaged flyweight to rotate outward. A second member is included for engagably limiting the degree of rotation of the first member. A method of installing a centrifugal clutch is also described.

Abstract: A fluid pressure operated actuator mechanism for a friction clutch is provided that includes a housing having a generally annular piston disposed therein that is operatively engaged with a resilient member that is pivotably connected to a clutch throw-out bearing. The piston is reciprocally received in a cylinder that possesses a longitudinal axis coaxial with a longitudinal axis of a clutch output shaft. The cylinder is in communication with a plurality of ducts formed in the housing that supply fluid pressure to the piston. The piston, when pressurized, causes the resilient member to pivot about a fulcrum member to redirect the force generated by the piston. The redirected force of the piston causes the bearing and a connected clutch spring to move in a direction away from the friction clutch to disengage the clutch.

Abstract: A centrifugal master friction clutch having an installation device is provided that includes a cover assembly fixed for rotation with an engine flywheel and at least one friction plate fixed for rotation with a transmission input shaft. The cover assembly includes a pressure plate for applying a clamping force against the friction plate and a plurality of flyweights that rotate outward under the effects of centrifugal force to cause the pressure plate to exert a clamping force against the friction plate. The clutch installation device includes a first member rotatably disposed in the cover assembly radially inward of the flyweights. A portion of the first member is configured to engage at least one of the flyweights to force the engaged flyweight to rotate outward. A second member is included for engagably limiting the degree of rotation of the first member. A method of installing a centrifugal clutch is also described.

Abstract: A drive reaction plate for insertion between a ramp plate and a centrifugal actuation module of a centrifugally actuated vehicular clutch. The annular body of the reaction plate is secured to the ramp plate, while an interior diameter of the reaction plate includes drive straps for resilient attachment to the centrifugal module. The straps are adapted to flex upon clutch engagement, to unflex upon clutch release, and to dampen torsional vibrations between the clutch ramp plate and the centrifugal actuation module. The reaction plate includes openings for ramp segments of the ramp plate, and the ramp segments extend into the plate openings to maintain angular locations of the segments relative to cooperating rollers of the centrifugal module. The reaction plate is formed of thin spring metal, and is bolted or riveted directly to the ramp plate to avoid misalignment of the reaction plate during the useful life of the clutch.