Abstract: A centrifugal clutch assembly includes a clutch cover attachable to a rotatable input member. Friction plates are clamped between pressure plates in response to rotation of the clutch assembly. Rotation of the clutch assembly causes at least one centrifugal weight to move radially outward to force the pressure plates against the friction plates. The radial position of the centrifugal weights is modified to tailor clutch actuation. This modification of centrifugal weight position causes a corresponding change to engagement characteristics of the clutch assembly allowing clutch actuation to be tailored to operating conditions.

Abstract: A vehicle power train system includes an engine, a transmission, and a centrifugal clutch assembly that selectively couples an engine output shaft to a transmission input shaft in response to an operator input. An operator selects a desired vehicle-operating mode by actuating a shift lever or shift switch from a gear selection device. The gear selection device indicates many different operating modes and includes a low-speed maneuvering mode that is selected for low-speed operations such as coupling a truck to a trailer, or positioning a truck and/or trailer in relation to a loading dock area. Once the low-speed maneuvering mode is selected, a control unit controls at least one of engine speed and engine torque to indirectly effect clutch slippage, which results in improved vehicle speed control at low-speed operations.

Abstract: A clutch assembly includes a reaction surface that provides several disengagement surfaces that cause axial movement of a front plate to reduce torque transmission at rotational speeds above an engagement speed. The disengagement surfaces reduce torque to break torque lock at rotational speeds corresponding to desired gear changes. The clutch assembly is controlled to tailor the relationship between clutch torque and engine speed to current vehicle operating conditions to provide consistent vehicle performance over different operating conditions.

Abstract: A master clutch includes a pressure plate adjacent to a friction disc. A centrifugal weight forces the pressure plate and friction disc into engagement when in a desired install position. A locking device retains the centrifugal weight in the desired installed position. A controller sends an electronic command to a system component, such as an engine, to disengage the locking device. In one example, the electronic command may be an engine speed command that is above an engine speed limit in a normal vehicle operating mode. Commanding the engine to run at a speed greater than the typical engine speed limit moves the centrifugal weight out of the desired installed position making the master clutch operational.

Abstract: A centrifugal clutch assembly includes movable centrifugal weight reaction surfaces that provide for actuation at varying rotational speeds. A radially movable front plate with a ramped surface changes the radial position at which the centrifugal weight begins moving the front plate axially to compress a clamp spring and begin clutch actuation. An axially movable back plate moves axially to change the magnitude of compression caused by axial movement of the front plate. The changes to clamping force corresponding to movement of the reaction surfaces of the centrifugal weight change the rotational speed required to beginning and maintain actuation of the clutch assembly.

Abstract: A normally open clutch assembly includes a device holding a centrifugal weight in a position causing axial movement of pressure plates and thereby a clamping force between pressure plates and the friction disks. The clamping force holds the friction disks in a desired aligned position during assembly.

Abstract: A vehicle transmission system includes a transmission component that has an engaged condition where torque can be transferred from a vehicle engine to a drive component, and a non-engaged condition where torque is prohibited from being transferred to the drive component. A controller generates control signals to control whether the transmission component is in the engaged or non-engaged condition. The controller also identifies when a vehicle start maneuver is a coast start based on vehicle conditions existing just prior to or during the vehicle start maneuver. When a coast start is identified, the controller generates a control signal to either disengage the transmission component or to maintain the transmission component in the non-engaged condition until engine speed generally matches transmission component speed. The controller can directly control engagement by automatically actuating a movable transmission member or can indirectly control engagement by controlling engine speed.

Abstract: An improved shift input module may be moved to a stowed position where it is out of the way of a vehicle operator. This allows the operator to move easily about the cab of the vehicle. The module also carries the cruise control buttons, such that they are easily accessible.

Abstract: A clutch brake assembly includes a clutch and a transmission shaft for transmitting rotational motion from the clutch to the transmission. A brake disc is rotatably driven by and slideably disposed on the transmission shaft. A clutch release member is also slideably disposed on the shaft. Brake pads are non-rotatably and removably attached to the release member and a bearing retainer on the transmission for dissipating braking energy. Each of the brake pads include a backing plate and friction material secured to the backing plate. During operation, the release member frictionally sandwiches the brake disc between the release member and the bearing retainer for reducing rotation of the shaft. The inventive brake pads are configured to facilitate replacement of the pads without disconnection of the transmission.

Abstract: A system for automatically effecting a range shift between high and low ranges in a multi-speed transmission includes a control that monitors the output speed of both the engine and the transmission. The ratio of the two speeds is compared to available ratios in a look-up table such that the control is constantly determining the engaged gear. In one embodiment, a driver provides an intention of the next gear to be selected to the control. Should the intended gear shift require a range shift from the engaged gear, the control actuates the range shift once the transmission has been moved to neutral. In a second embodiment, no driver intention is provided to the controller. Instead, the control compares the engine output speed to threshold values. If the threshold values predict a gear shift that would require a range shift to be effected from the currently engaged gear, then the range shift will be effected once the transmission has been moved to neutral.

Abstract: An improved switch system is incorporated into a multi-speed transmission and engine combination. The switch system provides a positive electronic signal to an electronic control unit for the engine of both when the transmission is in a neutral state and when the transmission is in a gear-engaged state. In one embodiment, a switch plunger rides within a switch housing between two extreme positions. The switch plunger is at one axial position when the transmission is in neutral, and at the other axial position when the transmission is in a gear-engaged state. At either position, an electric circuit is completed and a signal is sent to an electronic control unit. The electronic control unit is thus provided with positive position feedback for the transmission.

Abstract: An operator input control system assists shifting between gears in a multi-speed transmission without clutching. A single switch allows an operator to provide an indication of the next gear that is to be selected, and further allows the operator the option of requesting torque elimination when moving the transmission to neutral. In one embodiment, the switch includes a rotatable switch body that is held in either an upshift or downshift intent position. The operator is able to move the switch a slight additional rotational amount beyond the intent position to request torque elimination. Once the operator releases the switch, it returns to the upshift or downshift indicated position. The inventive switch reduces the complexity of operator input in an overall system for assisting an operator in shifting transmission speeds without clutching.

Abstract: A system for automatically effecting a range shift between high and low ranges in a multi-speed transmission includes a control that monitors the output speed of both the engine and the transmission. The ratio of the two speeds is compared to available ratios in a look-up table such that the control is constantly determining the engaged gear. In one embodiment, a driver provides an intention of the next gear to be selected to the control. Should the intended gear shift require a range shift from thee engaged gear, the control actuates the range shift once the transmission has been moved to neutral. In a second embodiment, no driver intention is provided to the controller. Instead, the control compares the engine output speed to threshold values. If the threshold values predict a gear shift that would require a range shift to be effected from the currently engaged gear, then the range shift will be effected once the transmission has been moved to neutral.

Abstract: An improved switch system is incorporated into a multi-speed transmission and engine combination. The switch system provides a positive electronic signal to an electronic control unit for the engine of both when the transmission is in a neutral state and when the transmission is in a gear-engaged state. In one embodiment, a switch plunger rides within a switch housing between two extreme positions. The switch plunger is at one axial position when the transmission is in neutral, and at the other axial position when the transmission is in a gear-engaged state. At either position, an electric circuit is completed and a signal is sent to an electronic control unit. The electronic control unit is thus provided with positive position feedback for the transmission.

Abstract: A vehicle drive incorporates a speed control that assists an operator in shifting the transmission without requiring the clutch, or synchronization of engine speed. An operator is provided with a single switch that allows a prediction of the next shift direction, and also a request for torque elimination to begin a gear shift. The electronic control unit modifies the engine fueling to a predicted value to achieve a zero torque load, thus allowing the operator to move the transmission to neutral. The transmission is provided with a neutral switch that provides a positive signal to the electronic control unit of when the transmission is in neutral and when it is engaged. Once the electronic control receives the neutral signal, it begins to modify the engine speed to achieve the desired synchronization speed. The operator is thus able to engage the new gear. Once the new gear is engaged, control over the engine returns to the operator.

Abstract: An improved system for synchronizing the output speed of an engine with that necessary at the next expected gear to achieve a desired speed ratio updates and monitors the currently engaged gear. In this way, the system improves upon prior systems that attempted to "count" to determine the currently engaged gear. Moreover, the system provides an operator with a shift intent switch that allows the operator to predict an upshift or a downshift as the next shift. The system calculates what the next expected gear will be based upon this indication. Once the next expected gear is known, the speed ratio at that gear is determined. Once the transmission is moved to neutral, the synchronization speed for the engine is then determined by multiplying the current transmission output speed with that next speed ratio. The engine control drives the engine speed to achieve synchronization speed ratio. The determination is updated as the transmission speed changes. The operator completes the shift with a manual stick shift.