Abstract: The present invention provides a control system for a dual clutch automatic transmission having a torque converter. The transmission provides seven forward speeds or gear ratios and reverse. The control system includes a hydraulic pump, a pressure regulator assembly and control valves that provide and release pressurized hydraulic fluid to the torque converter, a pair of input clutches and eight synchronizer clutches. A first pair of control valves are high flow rate valves which are capable of rapidly engaging and disengaging the input clutches. A second pair of high flow rate valves, control valves and spool valves provide a branching control circuit which controls engagement and disengagement of the synchronizer clutches. A control valve linked to the shift lever blocks hydraulic fluid flow to the first pair of high flow rate valves to inhibit input clutch activation when the shift lever is in Park or Neutral.

Abstract: A shift fork actuation system includes an actuator housing defining a piston cavity and a piston assembly having three pistons with three different surface areas responsive to fluid pressure to establish positions of the piston assembly within the piston cavity. A stopping mechanism, such as a shoulder formed by the actuator housing at the interface of different bores in the piston cavity, interferes with one of the surface areas to prevent movement of one of the pistons past the stopping mechanism. A neutral position of a shift fork is established by interference of the piston assembly with the stopping mechanism. A slot in the piston assembly captures a finger extension from the shift rail to act as an anti-rotation feature, ensuring that a magnet embedded in the piston assembly as part of a sensor assembly is properly positioned.

Abstract: The present invention provides a control system for a dual clutch automatic transmission having a torque converter. The transmission provides seven forward speeds or gear ratios and reverse. The control system includes a hydraulic pump, a pressure regulator assembly and control valves that provide and release pressurized hydraulic fluid to the torque converter, a pair of input clutches and eight synchronizer clutches. A first pair of control valves are high flow rate valves which are capable of rapidly engaging and disengaging the input clutches. A second pair of high flow rate valves, control valves and spool valves provide a branching control circuit which controls engagement and disengagement of the synchronizer clutches. A control valve linked to the shift lever blocks hydraulic fluid flow to the first pair of high flow rate valves to inhibit input clutch activation when the shift lever is in Park or Neutral.

Abstract: A shift fork actuation system includes an actuator housing defining a piston cavity and a piston assembly having three pistons with three different surface areas responsive to fluid pressure to establish positions of the piston assembly within the piston cavity. A stopping mechanism, such as a shoulder formed by the actuator housing at the interface of different bores in the piston cavity, interferes with one of the surface areas to prevent movement of one of the pistons past the stopping mechanism. A neutral position of a shift fork is established by interference of the piston assembly with the stopping mechanism. A slot in the piston assembly captures a finger extension from the shift rail to act as an anti-rotation feature, ensuring that a magnet embedded in the piston assembly as part of a sensor assembly is properly positioned.

Abstract: A solenoid control valve for use in actuation of a manual hydraulic clutch in a vehicle. The solenoid control valve has an electronically operated solenoid with armature and actuator rod displaced through a channel in the solenoid. A spool valve has a valve body that is coupled at one end to the solenoid. A spool is slidably disposed in the control channel. A first and second dampener chambers are located at the two ends of the spool. The dampeners function to improve the stability in the control system and balance the transient flow forces of the hydraulic fluid as it moves through the valve member. The spool also has a control portion located between the first end and the second end of the spool. The control portion allows the control portion to communicate with a supply, control and exhaust passages in the valve body.

Abstract: A brake band shifting mechanism for an automatic transmission. The brake band shifting mechanism includes a brake band encircling a brake drum of the transmission. A first end of the brake band is mounted to a secured portion of the transmission by a first linkage and a second end of the brake band is mounted to a two-stage servo by a second linkage. The servo provides selective apply and release pressure to the second linkage to control the compression or expansion of the brake band. In operation, the brake band is quickly compressed to the brake drum during the first stage of the servo, and then fine adjustments are made to control the speed of the brake drum during the second stage of the servo, where inputs from position and speed sensors in the transmission are used to control the adjustment of the brake band.

Abstract: A solenoid control valve for use in actuation of a manual hydraulic clutch in a vehicle. The solenoid control valve has an electronically operated solenoid with armature and actuator rod displaced through a channel in the solenoid. A spool valve has a valve body that is coupled at one end to the solenoid. A spool is slidably disposed in the control channel. A first and second dampener chambers are located at the two ends of the spool. The dampeners function to improve the stability in the control system and balance the transient flow forces of the hydraulic fluid as it moves through the valve member. The spool also has a control portion is located between the first end and the second end of the spool. The control portion allows the control portion to communicate with a supply, control and exhaust passages in the valve body.

Abstract: A solenoid control valve for use in actuation of a manual hydraulic clutch in a vehicle. The solenoid control valve has an electronically operated solenoid with armature and actuator rod displaced through a channel in the solenoid. A spool valve has a valve body that is coupled at one end to the solenoid. A spool is slidably disposed in the control channel. A first and second dampener chambers are located at the two ends of the spool. The dampeners function to improve the stability in the control system and balance the transient flow forces of the hydraulic fluid as it moves through the valve member. The spool also has a control portion is located between the first end and the second end of the spool. The control portion allows the control portion to communicate with a supply, control and exhaust passages in the valve body.

Abstract: A brake band shifting mechanism for an automatic transmission. The brake band shifting mechanism includes a brake band encircling a brake drum of the transmission. A first end of the brake band is mounted to a secured portion of the transmission by a first linkage and a second end of the brake band is mounted to a two-stage servo by a second linkage. The servo provides selective apply and release pressure to the second linkage to control the compression or expansion of the brake band. In operation, the brake band is quickly compressed to the brake drum during the first stage of the servo, and then fine adjustments are made to control the speed of the brake drum during the second stage of the servo, where inputs from position and speed sensors in the transmission are used to control the adjustment of the brake band.