Abstract: A tandem drive axle mechanical shift assembly including a first shift rail assembly having a first shift rail actuated via a first pneumatic actuator, and a shift fork having a first end coupled with the first shift rail and a second end coupled with an engagement selector. A second shift rail assembly having a second shift rail actuated via a second pneumatic actuator, and a second shift fork having a first end coupled with the second shift rail and a second end coupled with an inter-axle differential lock-up clutch. First and second primary valves in fluid communication with a reservoir, and a secondary valve in fluid communication with the reservoir and in selective fluid communication with the second pneumatic actuator. A first actuation valve operated by the first shift rail and in selective fluid communication with the first and second primary valves, and the first and second pneumatic actuators.

Abstract: A tandem drive axle mechanical shift assembly including a first shift rail assembly having a first shift rail actuated via a first pneumatic actuator, and a shift fork having a first end coupled with the first shift rail and a second end coupled with an engagement selector. A second shift rail assembly having a second shift rail actuated via a second pneumatic actuator, and a second shift fork having a first end coupled with the second shift rail and a second end coupled with an inter-axle differential lock-up clutch. First and second primary valves in fluid communication with a reservoir, and a secondary valve in fluid communication with the reservoir and in selective fluid communication with the second pneumatic actuator. A first actuation valve operated by the first shift rail and in selective fluid communication with the first and second primary valves, and the first and second pneumatic actuators.

Abstract: A tandem axle system has a forward axle system and a rear axle system. A method of selectively driving one or both of the axle systems is described.

Abstract: A tandem axle system has a forward axle system and a rear axle system. A method of selectively driving one or both of the axle systems is described.

Abstract: Simulated or “mock” continuously variable transmission shift strategies are used in an electromechanically actuated automotive transmission having reduced ratios steps in its upper ratio ranges. In one described embodiment, a 12-speed truck transmission consists of a five-speed main section and an auxiliary section that includes splitter and range sub-sections to provide the 12 ratios. Separate shift strategies are directed to fuel economy and power optimization modes; driver throttle demand determines the mode. Both strategies are targeted to the upper gear ratios, which represent the ratios subject to approximately ninety percent (90%) of vehicular operation. In the described embodiment, the applicable affected ratios are gears 7-12. In the described embodiments, the shift strategies are carried out by embedded software subject to the command of an electronic power train control module.

Abstract: Simulated or “mock” continuously variable transmission shift strategies are used in an electromechanically actuated automotive transmission having reduced ratios steps in its upper ratio ranges. In one described embodiment, a 12-speed truck transmission consists of a five-speed main section and an auxiliary section that includes splitter and range sub-sections to provide the 12 ratios. Separate shift strategies are directed to fuel economy and power optimization modes; driver throttle demand determines the mode. Both strategies are targeted to the upper gear ratios, which represent the ratios subject to approximately ninety percent (90%) of vehicular operation. In the described embodiment, the applicable affected ratios are gears 7-12. In the described embodiments, the shift strategies are carried out by embedded software subject to the command of an electronic power train control module.

Abstract: A ground strap and vibration mount assembly (10) effectively mechanically isolates an electronic component from vibration while also providing an electrically conductive path to ground potential. The assembly (10) includes a vibration dampener (16) mounted through an opening (28) formed in a tab (12) projecting from the housing of the vibration sensitive electronic component. An insert (18) is provided therein and a mounting bolt (54) is positioned through a suitable opening (36) formed through the insert (18). An electrically conductive ground strap (40) is wrapped partially around the tab (12). An aperture (52) is formed in one portion (50) of the strap (40) and the bolt (54) passed therethrough. Opposing ends (42) of the electrically conductive connector (40) are secured to the tab (12).

Abstract: The shift quality of an automated mechanical transmission is improved and transmission wear is reduced by controlling the armature current of the motor driving the transmission shifting mechanism. The current is monitored by a microcontroller to determine if the shifting mechanism has encountered a snag or has stalled during a shift operation. The microcontroller is programmed to control the duty cycle of a pulse width modulated (PWM) voltage signal, applied to the motor, in accordance with an algorithm which provides both proportional and derivative control of the error between the measured current and a target current. The rapid reduction in current spikes through PWM control reduces the force applied to the shifting mechanism and thus the sliding clutch and transmission gearing.

Abstract: A parking brake system is provided which includes a dual solenoid operated valve located in series with the emergency brake control valve of a hydraulically operated brake system. The dual solenoid valve is operable to either one of two mechanical detent positions so that positioning of the valve is retained in the event of loss of power. The dual solenoid valve is controlled by the vehicle operator from the transmission console and removes fluid pressure from the brakes when actuated to a PARK position. An electronic control unit is provided for sensing the speed of the vehicle and the pressure in the hydraulic line to the brakes and provides a PARK enabling signal when the vehicle speed is below a predetermined amount. When a gear is selected at the console the dual solenoid valve is actuated to a position permitting fluid pressure to be applied to the brakes and effectively returns control of the brakes to the emergency brake control device.

Abstract: An X-Y shifting mechanism (25) is disclosed for controlling the shifting of a shift rail (17) in a first (Y-Y) transverse direction. The mechanism includes a shift finger assembly (39) including a shift finger (23). A lever member (57) is pivotable about the axis (A) of rotation. When the lever member (57) is pivoted, the movement is transmitted through a spring (91) to rotate a spring seat member (73), thus causing pivotal movement of the shift finger (23). During a non-synchronous engagement, kick-out movement causes pivotal movement of the shift finger in the opposite direction, compressing the spring (91) rather than damaging the shifting mechanism. The disclosed mechanism also enables preselection of neutral, compressing the appropriate one of the springs (91), such that the preloaded spring will move the shift finger and shift rail to the neutral position as soon as a torque break occurs.

Abstract: Apparatus is provided for isolating a sensor from a vibrating surface. The sensor has first and second spaced surfaces, a bore extending between the surfaces and a groove in the second surface. The apparatus includes a flanged sleeve adapted to extend through the bore to the vibrating surface. The sleeve is sufficiently long when extending through the bore to provide a first gap between the vibrating surface and the second surface of the sensor and sufficiently narrow when extending through the bore to provide a second gap between the sleeve and the sensor. The flange overlays the first surface of the sensor and the second gap. The apparatus also includes a bolt, which extends through the bore and into engagement with the vibrating surface, for attaching the sleeve to the vibrating surface. The apparatus also includes a first O-ring positioned between the first surface of the sensor and the sleeve flange and a second O-ring positioned in the groove of the second surface.

Abstract: For use with an automated mechanical transmission system including an electrically actuated shift mechanism having a motor, a method of controlling the shift mechanism is provided for shifting the transmission out of gear during a reduced torque shift window by quickly detecting motor motion. The shift mechanism is first energized with a low effective voltage signal to minimize power consumption and avoid overheating the motor, and then with a high effective voltage signal upon detection of motor motion, to quickly shift the transmission out of gear.

Abstract: A control method/system (200) for a control system (104) for semi-automatically executing automatically selected upshifts and downshifts of a mechanical transmission system (10) is provided. The control system includes a central processing unit (106) for receiving input signals indicative of transmission input shaft (16) and output shaft (90) speeds (IS, OS) and processing the same in accordance with predetermined logic rule to issue command output signals to a transmission actuator (112, 70, 96) to implement the selected shifts by automatic shifting into neutral upon a naturally or manually caused torque reversal of the transmission and remaining in neutral until the vehicle operator causes substantially synchronous conditions to occur.

Abstract: A position-feedback-control servomechanism for shifting the transmission of a vehicle has both an adaptive proportional-integral-differential controller to compensate for manufacturing variations, etc, and a voltage-compensation system that senses the battery voltage and prevents the gain of a servomechanism drive motor from varying significantly when the battery voltage changes. The motor is preferably a permanent-magnet type to whose terminals the battery voltage is switched on and off. The switching is done by electronic switches that are under the control of a pulse-width-modulated signal. The width of the pulses of the pulse-width-modulated signal is controlled by both a closed-loop position-error signal and a signal derived from an open-loop measurement of the battery voltage.

Abstract: A position-feedback-control servomechanism for shifting the transmission of a vehicle has a control algorithm that adjusts the loop gains in a proportional-integral-differential controller to compensate for manufacturing variations in the apparatus as well as for temperature changes and wear. The resulting control system moves the shifting servomechanism into the selected positions accurately and as quickly as possible without permitting excessive overshooting or resonance.

Abstract: An electrically actuated shift mechanism (100) is provided that is mountable upon a manual mechanical change gear transmission and operable to move a shift finger (20) in an (X--X) direction into registration with a selected shift rail and then move the shift rail in a (Y--Y) direction to effect the gear shift is response to either a selected operator input signal (S.sub.1) or a speed signal (S.sub.2).

Abstract: A vehicle electronic transmission control system (10) having a servo control loop is disclosed. During the selection of a new gear, a countershaft (27) and transmission input drive shaft (13) are declutched from an engine crankshaft (11) and decoupled from a transmission output shaft (15). An error signal e is calculated representative of the difference between a desired speed related to input shaft speed (w.sub.1) and actual output shaft speed (w.sub.2). The error signal e is utilized to provide a servo control signal C having a first proportional term related to the square of the error signal, but having the polarity of the error signal, a second term related to the integral of the error signal multiplied by the absolute magnitude of the error signal and a third term related to the derivative of the error signal.

Abstract: A power synchronizer assembly (10) for selectively increasing the rotational speed of a mechanical change gear transmission (12) input shaft (22), main section countershaft (58) and ratio gears (82, 84, 86, and 88) independently of the rotational speed of the drive engine (14) is provided. The power synchronizer assembly includes a sun gear shaft (174) drivingly associated with the main section countershaft and carrying a sun gear (176) fixed thereto which is in constant engagement with the planet gears (180) of a planet gear carrier (178) rotatably driven by the transmission output shaft (28). A ring gear (182) surrounds and is in constant engagement with the planet gears and is selectively frictionally coupled for rotation with the transmission housing (68) by means of a band brake and band brake operating mechanism (186 and 188).