Abstract: A control system/method for controlling engine (12) output torque in a vehicular powertrain system (10) including an electronically controlled engine and a torque load limited drivetrain system (11) is provided. The control will sense values of a control parameter (GR, OS) indicative of potential overloading of the drivetrain at maximum engine output torque and will cause engine output torque to be limited to a value less than the maximum value thereof.

Abstract: A control system/control method for controlling the jaw clutch engagement and at least partially automated multiple speed change gear mechanical transmission (10) is provided. The control includes a central processing unit (106) for receiving signals indicative of transmission input shaft (16) speed, transmission output shaft (90) speed and of a selected ratio to be engaged. The control unit initiates/permits engagement of the jaw clutch members associated with the selected ratio upon sensing that the rotational speed of the input shaft falls within a calculated synchronous window. The control unit senses vehicle start from stop conditions and/or degraded clutch operation during vehicle start from stop conditions and responds thereto by enlarging the synchronous window.

Abstract: Manual override apparatus (38) for use in a vehicle having an automated mechanical transmission (10) or similar transmission, that enables limited driving of the vehicle in the event of a malfunction of the transmission's automatic electronic control system (30). The override apparatus includes a semi-manual arrangement (42, 44, 50, 58) for putting the transmission (10) in gear (46), disabling the electronic logic circuits (48), and actuating the clutch operator (22) from a manual lever-controlled valve (56, 40) in the cab. Another manual device (58) in the cab selectively enables and prevents manual control by the lever-controlled valve of the clutch operator (22).

Abstract: A compound change gear semi-blocked transmission (10) of the splitter type is provided. The transmission comprises a multi-speed main section (12) connected in series with an multi-speed auxiliary section (14). The main section utilizes manually engaged, non-blocked, nonsynchronized jaw clutch assemblies (56, 58, 60) while the auxiliary section utilizes resiliently shifted blocked jaw clutch assemblies (114, 116, 118, 120). The blocked jaw clutch assemblies are provided with ramps (176, 178, 180, 182) which will cause unblocking during a clutching operation if the main section is not engaged.

Abstract: The compound detent mechanism (104) for a manual change gear transmission (10) of the type wherein engagement and disengagement reverse gear is controlled by a first shift rail (58) and engagement and disengagement of the lowest forward speed is controlled by an adjacent second shift rail (56) is provided. Detent mechanism (104) is carried by the shift block assembly (88) associated with the first shift rail and includes a first piston (132) resiliently blocking transverse alignment of a shift element with the contact surfaces (96, 98) associated with the second shift rail (56) associated with the lowest forward speed and a second piston element (114) resiliently blocking shifter element transverse alignment with the contact surfaces (100 and 102) associated with the first shift rail (58) associated with the reverse speed ratio.

Abstract: An automatic clutch control system for controlling a vehicle master clutch (14) drivingly interposed a throttle controlled engine (12) and a change gear transmission (10) having a clutch protection portion (70) to prevent the clutch from destructively overheating due to excessive slipping is provided. The clutch protection portion (70) includes a device for maintaining a variable parameter simulating clutch operating temperature (110) and devices (104 and 116) for causing said variable parameter to be increased and decreased, respectively, at first and second rates selected to simulate clutch heating and cooling rates, respectively. A signal generating device (126) is responsive to the simulated value exceeding a predetermined limit to generate a clutch protection output singal (84) effective to cause the clutch to be operated in a non-slipping, preferably fully engaged, mode of operation.

Abstract: An improved control for an automatic transmission, preferably an automatic mechanical transmission (10), is provided. The improved control includes an operator selectable mode of operation (D.sub.1) for off-road and other higher resistance vehicle operating conditions. In the off-road mode of operation, the central processing unit (30) will generate upshift commands in accordance with an upshift shift point profile (OHU) such that, assuming constant output shaft speed and throttle position, the engine (12) output power following an upshift will be at least as great as the engine output power prior to the upshift.

Abstract: A throttle modulation mechanism (10) is disposed between a throttle pedal (18) and a fuel control device (12) for an unshown engine. Mechanism (10) is operable during shifting modes of an unshown transmission driven by the engine to dip and boost fuel delivery to the engine for synchronizing the transmission and/or reducing shifting shocks. Mechanism (10), which is controlled by a transmission logic (14), includes a lever (16) pivotally connected at one end (16a) to link (28), at the other end (16c) to a throttle dip actuator (20), and in the middle (16b) to the fuel control via a link (30) and to a throttle boost actuator (22) via a piston rod (32). The actuators are positioned by fluid pressure in response to logic signals applied to solenoid valves (24, 26). A second embodiment of the modulation device includes a slotted connector (101a) which negates mechanical and force feedback to the throttle pedal independent of all throttle pedal positions.

Abstract: A shift control mechanism for a change speed transmission, or a change speed transmission section, having selectively axially movable gears, the selective axial movement of which is effective to cause engagement and disengagement of the axially moved gear, is provided. The shift control mechanism is utilized for a four speed transmission, or transmission section, and comprises a first shift fork fixed to a first shift rail, a second shift fork fixed to a second shift rail and a third shift fork fixed to a third shift rail. The shift rails are independently axially movable, the first and second shift rails are concentrically received in a first bore of a housing, the third shift rail is received in the second bore of a housing, and positive interlock means are provided to prevent simultaneous displacement of any two or more of the shift rails.