Abstract: A system for locking a Park device in a transmission in an out-of-Park mode of operation includes a valve body that defines a bore, a solenoid connected to the valve body, a lock feature disposed in the valve body and interconnected with the solenoid, and a servo piston disposed within the bore of the valve body. The servo piston has a detent and the servo piston is interconnected to the Park device and is moveable between a first position and a second position. The detent is radially aligned with the lock feature when the servo piston is in the first position. Activation of the solenoid locks the lock feature into the detent of the servo piston to lock the Park device of the transmission in the no-Park mode.

Abstract: A parking pawl actuation assembly for a transmission includes a shaft, a hub member rotatably supported by the shaft, a cam plate and lever plate rotatably supported by the hub member, a first resilient member disposed between the cam plate and the lever plate, and wherein the resilient member applies a rotational force on the cam plate in a first rotational direction when the lever plate is rotated in the first rotational direction, an actuator configured to selectively rotate the lever plate to one of a plurality of positions, and a parking pawl member configured to engage the cam plate and the parking gear of the transmission.

Abstract: A hydraulic control system for a transmission is provided. The hydraulic control system includes a source of pressurized hydraulic fluid that communicates with a discrete electronic transmission range selection (ETRS) subsystem. The hydraulic control system includes first and second mode valves located downstream of a hydraulic fluid pressure source. The mode valves are supplied with fluid via one or more solenoid valves or other valves. The mode valves have a plurality of ports configured to transfer pressurized hydraulic fluid. The first mode valve transfers pressurized hydraulic fluid from the source to the second mode valve. The second mode valve transfers pressurized hydraulic fluid from the first mode valve to one of drive or reverse. An electro-hydraulic circuit for pulling the transmission out of park and putting the transmission into park is also provided. A park sensor assembly including a Hall Effect sensor switch is also provided.

Abstract: A parking pawl actuation assembly for a transmission includes a shaft, a hub member rotatably supported by the shaft, a cam plate and lever plate rotatably supported by the hub member, a first resilient member disposed between the cam plate and the lever plate, and wherein the resilient member applies a rotational force on the cam plate in a first rotational direction when the lever plate is rotated in the first rotational direction, an actuator configured to selectively rotate the lever plate to one of a plurality of positions, and a parking pawl member configured to engage the cam plate and the parking gear of the transmission.

Abstract: A system for locking a Park device in a transmission in an out-of-Park mode of operation includes a valve body that defines a bore, a solenoid connected to the valve body, a lock feature disposed in the valve body and interconnected with the solenoid, and a servo piston disposed within the bore of the valve body. The servo piston has a detent and the servo piston is interconnected to the Park device and is moveable between a first position and a second position. The detent is radially aligned with the lock feature when the servo piston is in the first position. Activation of the solenoid locks the lock feature into the detent of the servo piston to lock the Park device of the transmission in the no-Park mode.

Abstract: A hydraulic control system for a transmission is provided. The hydraulic control system includes a source of pressurized hydraulic fluid that communicates with a discrete electronic transmission range selection (ETRS) subsystem. The hydraulic control system includes first and second mode valves located downstream of a hydraulic fluid pressure source. The mode valves are supplied with fluid via one or more solenoid valves or other valves. The mode valves have a plurality of ports configured to transfer pressurized hydraulic fluid. The first mode valve transfers pressurized hydraulic fluid from the source to the second mode valve. The second mode valve transfers pressurized hydraulic fluid from the first mode valve to one of drive or reverse. An electro-hydraulic circuit for pulling the transmission out of park and putting the transmission into park is also provided. A park sensor assembly including a Hall Effect sensor switch is also provided.

Abstract: A Park inhibition solenoid assembly for preventing the undesirable shifting of a transmission from an out-of-Park mode to a Park mode includes a follower and an armature slidably disposed within a valve body/housing and within a solenoid. The follower is moveable between an out-of-Park position and a Park position and the armature is moveable between an unlocked position and a locked position. The follower and armature include detents for supporting a bearing. The armature and bearing prevent the follower from moving from the out-of-Park position to the Park position when the armature is held in place in the lock position by the solenoid.

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: A solenoid control system for implementation with an electronic range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. A first solenoid assembly is operable to control a fluid valve to supply pressurized fluid to urge a valve spool toward a first position. A second solenoid assembly is operable to control a fluid valve to supply pressurized fluid to urge said valve spool toward a second position. A control module selectively energizes one of the first and second solenoids based on a transmission fluid temperature.

Abstract: A servo system includes pressurized fluid, and one or more fluid control devices (FCD) such as a valve or actuator, with at least one FCD having an element with a variable property that varies in response to a stimulus. The FCD controls a flow rate or pressure transmission of the fluid within the servo system. The element may include an active return spring having a variable stiffness. The servo system may operate as an interlock system for a transmission. A method for moving an output load using a servo system includes providing a first FCD with an active element, connecting an output load to a second FCD, activating the active element with a stimulus to vary a property of the active element, transmitting a force from the pressurized fluid to the second FCD, and moving the output load from a first position to a second position in response to the force.

Abstract: A servo system includes pressurized fluid, and one or more fluid control devices (FCD) such as a valve or actuator, with at least one FCD having an element with a variable property that varies in response to a stimulus. The FCD controls a flow rate or pressure transmission of the fluid within the servo system. The element may include an active return spring having a variable stiffness. The servo system may operate as an interlock system for a transmission. A method for moving an output load using a servo system includes providing a first FCD with an active element, connecting an output load to a second FCD, activating the active element with a stimulus to vary a property of the active element, transmitting a force from the pressurized fluid to the second FCD, and moving the output load from a first position to a second position in response to the force.

Abstract: A Park inhibition solenoid assembly for preventing the undesirable shifting of a transmission from an out-of-Park mode to a Park mode includes a follower and an armature slidably disposed within a valve body/housing and within a solenoid. The follower is moveable between an out-of-Park position and a Park position and the armature is moveable between an unlocked position and a locked position. The follower and armature include detents for supporting a bearing. The armature and bearing prevent the follower from moving from the out-of-Park position to the Park position when the armature is held in place in the lock position by the solenoid.

Abstract: A solenoid control system for implementation with an electronic range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. A first solenoid assembly is operable to control a fluid valve to supply pressurized fluid to urge a valve spool toward a first position. A second solenoid assembly is operable to control a fluid valve to supply pressurized fluid to urge said valve spool toward a second position. A control module selectively energizes one of the first and second solenoids based on a transmission fluid temperature.

Abstract: An electronic transmission range selection (ETRS) system for shifting a transmission range of a transmission includes an electro-mechanical park inhibit assembly that operates to disallow the ETRS system from shifting from an Out-of-Park mode to a Park mode under certain circumstances. The park inhibit assembly includes a follower having a recess defined thereon and slidably disposed within a follower bore. In one embodiment a selectively energizable solenoid assembly is mounted substantially perpendicular to the follower and operates to bias a ball into the recess when energized thereby locking the ETRS system in the Out-of-Park mode. In another embodiment the park inhibit assembly includes a selectively energizable motor assembly mounted substantially perpendicular to the follower. The motor assembly operates to enforce the Park and Out-of-Park mode of the ETRS system.

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: A detent lever assembly for implementation with an electronic transmission range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. The detent lever assembly includes a shaft rotatably supported by a housing and a detent lever rotatably supported by the shaft and rotatable between a first position and a second position. In a first mode, the detent lever is rotatable about the shaft and in a second mode the detent lever is rotatable with the shaft.

Abstract: A hydraulic servo assembly includes a piston slidably disposed within a housing and a pin extending from the piston. The pin is interconnected with a servo link rod of the ETRS system. A port enables inlet of hydraulic fluid to induce movement of the piston and the pin from a first position to a second position to pull the servo link rod thereby shifting the transmission range to the out-of-park position. When in the first position the pin biases a forward-reverse enable (FRE) valve of the ETRS system in a first position. When in the second position a bias force of the pin is relieved from the FRE valve enabling the FRE valve to shift to a second position.

Abstract: A solenoid assembly for implementation with an electronic transmission range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. The solenoid assembly includes an extension arm biased against a member of the ETRS system. The extension arm is movable to an extended position to maintain the member in the out-of-park position. A solenoid is interconnected with the extension arm. The solenoid is operable to selectively move the extension arm between the extended position and a retracted position to selectively retain the member in the out-of-park position.

Abstract: An electronic transmission range selection (ETRS) system for shifting a transmission range of a transmission includes a park servo valve movable between a first position to inhibit a first flow of pressurized fluid and a second position to enable the first flow of pressurized fluid. A hydraulic servo assembly is movable between a first position and a second position based on the first flow of pressurized fluid. An actuator arm is interconnected to the hydraulic servo assembly. When the hydraulic servo assembly moves to the second position the actuator arm shifts the transmission range from a Park position to an Out-of-Park position.

Abstract: A detent lever assembly for implementation with an electronic transmission range selection (ETRS) system that shifts a transmission range between a park position and an out-of-park position. The detent lever assembly includes a shaft rotatably supported by a housing and a detent lever rotatably supported by the shaft and rotatable between a first position and a second position. In a first mode, the detent lever is rotatable about the shaft and in a second mode the detent lever is rotatable with the shaft.