Abstract: A dynamic and event-dependent determination of a rest point of a clutch. The rest point being an actuation path shortly before a slipping region of the clutch in which the clutch still does not transmit an appreciable amount of torque but which allows very rapid attainment of a clutch position in which an appreciable torque can be transmitted. The rest point can be determined by proceeding from a basic test point by allowing for various offset or correction values. A control device determines, at favorable event-dependent times, these correction values depending on specific parameters. Then a clutch actuator is actuated such that the friction clutch is engaged up to this rest point. In this manner, increased wear of the clutch and the shifting time required to achieve the slipping region of the clutch can be minimized depending on the specific parameters.

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 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 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 centrifugal clutch assembly includes a sleeve movable to selectively engage the clutch assembly independent of rotational speed. The clutch assembly includes centrifugal weights that move radially responsive to rotation of the clutch assembly. The centrifugal weights move pressure plates between clamped and open positions in response to a desired rotational speed. The sleeve is movable to selectively engage the pressure plate independent of rotational speed of the clutch assembly.

Abstract: The proposal is to compare determined measurement values in the form of the actual engagement position to a set engagement speed of the clutch apparatus with a set position and a set engagement speed so that, upon the attainment of a known set-position and the presence of a defined deviation or a trend toward a diversion in the concept of an over-stepping of the set engagement speed, the set engagement speed of the clutch apparatus is braked to a predetermined engagement speed which prevents an undesired engagement impact of the clutch apparatus or at least alleviates an excessive engagement speed.

Abstract: A control for a transmission and a clutch monitors conditions to determine when a vehicle associated with the clutch and transmission is likely in a stationary state. If the vehicle appears to be stationary, with the transmission engaged and the clutch open, then the control determines that the transmission should be moved to a neutral position. Upon movement to the neutral position, the control then closes the clutch. It is preferable for a vehicle remaining stationary to have its clutch closed and its transmission in neutral than to have its transmission engaged and its clutch open. In a further aspect of this invention, the neutral state is verified by testing the ability to move one of the transmission shift components. If the transmission shift component can move beyond a predetermined amount, this is indicative that the transmission is in neutral.

Abstract: A control for a transmission and a clutch monitors conditions to determine when a vehicle associated with the clutch and transmission is likely in a stationary state. If the vehicle appears to be stationary, with the transmission engaged and the clutch open, then the control determines that the transmission should be moved to a neutral position. Upon movement to the neutral position, the control then closes the clutch. It is preferable for a vehicle remaining stationary to have its clutch closed and its transmission in neutral than to have its transmission engaged and its clutch open. In a further aspect of this invention, the neutral state is verified by testing the ability to move one of the transmission shift components. If the transmission shift component can move beyond a predetermined amount, this is indicative that the transmission is in neutral.

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 heavy vehicle transmission is provided with an interlock that prevents movement from neutral into an engaged speed ratio if the vehicle is under start from stop conditions. The interlock ensures that the operator does desire to engage a gear prior to effecting the engagement. The method is also incorporated into a control for the transmission. The method and control are most preferably incorporated into a type of automatic transmission which has an automatic clutch that does not require any operator input.

Abstract: A system and method of controlling an automatic clutch to prevent a motor vehicle engine from stalling is disclosed. The method includes the steps of determining an engine stall threshold, detecting accelerator pedal actuation, detecting current engine speed, and comparing current engine speed to the engine stall threshold. If the engine speed is below the engine stall threshold, a controller detects and compares vehicle acceleration to predetermined threshold acceleration such that the automatic clutch is actuated only when the vehicle acceleration is below the threshold acceleration. The system includes the step of detecting foot brake position such that the automatic clutch is only actuated if the foot brake is properly actuated. The controller will then actuate the automatic clutch to proportionally decouple the engine from the transmission to prevent engine stall. The automatic clutch will remain open until detecting a predetermined clearing condition.

Abstract: A system and method of controlling an automatic clutch to prevent a motor vehicle engine from stalling is disclosed. The method includes the steps of determining an engine stall threshold, detecting accelerator pedal actuation, detecting current engine speed, and comparing current engine speed to the engine stall threshold. If the engine speed is below the engine stall threshold, a controller detects and compares vehicle acceleration to predetermined threshold acceleration such that the automatic clutch is actuated only when the vehicle acceleration is below the threshold acceleration. The system includes the step of detecting foot brake position such that the automatic clutch is only actuated if the foot brake is properly actuated. The controller will then actuate the automatic clutch to proportionally decouple the engine from the transmission to prevent engine stall. The automatic clutch will remain open until detecting a predetermined clearing condition.

Abstract: Engine braking in a vehicle driveline during transmission upshifts is controlled to provide more efficient and accurate speed synchronization. The physical limitations on the engine brake components are taken into account to determine a delay between an off request and the actual time that the engine brake turns off. This delay is factored into the time when the engine brake off request is made prior to a predicted time when the actual engine speed will meet a desired engine speed. By accounting for such delay, overshoot and undershoot during speed synchronization is avoided.

Abstract: Engine braking in a vehicle driveline during transmission upshifts is controlled to provide more efficient and accurate speed synchronization. The physical limitations on the engine brake components are taken into account to determine a delay between an off request and the actual time that the engine brake turns off. This delay is factored into the time when the engine brake off request is made prior to a predicted time when the actual engine speed will meet a desired engine speed. By accounting for such delay, overshoot and undershoot during speed synchronization is avoided.

Abstract: A method of engaging and disengaging transmission gears in a vehicle is provided. An intent switch is actuated for preparing the transmission to engage or disengage the transmission gears. An engine speed synchronization (ESS) controller processes an input torque parameter representing torque from an engine and an output torque parameter representing torque at a transmission output shaft. The input torque parameter may include such inputs as friction torque while the output torque parameter may include such inputs as vehicle torque load. The input torque parameter is adjusted to approximate the output torque parameter for achieving a zero torque load between the engine and transmission output shaft to facilitate engaging and disengaging transmission gears.

Abstract: A method of engaging and disengaging transmission gears in a vehicle is provided. A controller processes an initial torque representing an engine torque and an estimated zero torque representing an estimate of a transmission output shaft torque. The controller also sets a high and low band torque about the estimated zero torque. Once the above torques have been determined, the controller compares the initial torque to the high band torque. If the initial torque is below the high band torque, the controller increases the engine torque to the high band torque. If the initial torque is greater than the high band torque, then no preliminary adjustments to the engine torque need be made. At least one shift valve is energized when the engine torque is equal to or greater than the high band torque. The engine torque is decayed by the controller to the low band torque to facilitate engaging and disengaging transmission gears.