The invention relates to an actuating device for an internal shoe brake, including an automatic adjusting device with an adjusting lever which includes a guide track in the form of a guiding slot with two opposing track surfaces which cooperate with opposing sides of a housing-fixed guide element in order to convert a displacement of the adjusting lever relative to the housing-fixed guide element into pivoting movements of the adjusting lever.

Electric parking brake devices are configured such that a parking lever is driven by an electric actuator. The electric actuator is provided with: an electric motor drivable in a forward/reverse direction and operationally controlled by a motor control unit according to rotational loads; a conversion mechanism capable of converting a rotational motion into a linear motion, moving the parking lever from a return position toward an operating position through forward rotation of the electric motor, and moving the parking lever from the operating position toward the return position through the reverse rotation of the electric motor; and a load applying mechanism (a stopper and a disc spring assembly) for applying a predetermined rotational load to the electric motor by driving a constituent member of the conversion mechanism after the parking lever is moved from the operating position to the return position through the reverse rotation of the electric motor.

Electric parking brake devices are configured such that a parking lever is driven by an electric actuator. The electric actuator is provided with: an electric motor drivable in a forward/reverse direction and operationally controlled by a motor control unit according to rotational loads; a conversion mechanism capable of converting a rotational motion into a linear motion, moving the parking lever from a return position toward an operating position through forward rotation of the electric motor, and moving the parking lever from the operating position toward the return position through the reverse rotation of the electric motor; and a load applying mechanism (a stopper and a disc spring assembly) for applying a predetermined rotational load to the electric motor by driving a constituent member of the conversion mechanism after the parking lever is moved from the operating position to the return position through the reverse rotation of the electric motor.

The reverse input cutoff clutch comprises a pressed member having a pressed surface, an input member arranged coaxially with the pressed surface and having an input-side engaging portion arranged radially inside the pressed surface, an output member arranged coaxially with the pressed surface and having an output-side engaging portion arranged more radially inside than the input-side engaging portion, and an engaging element arranged radially inside the pressed surface and having a pressing surface facing the pressed surface, an input-side engaged portion that engages with the input-side engaging portions, and an output-side engaged portion that engages with the output-side engaging portion. The output-side engaged portion is configured by a recessed portion, and the interior surface of the recessed portion has a pair of guided surfaces. The output-side engaging portion has a pair of guide surfaces facing the pair of guided surfaces.

The reverse input cutoff clutch comprises a pressed member having a pressed surface, an input member arranged coaxially with the pressed surface and having an input-side engaging portion arranged radially inside the pressed surface, an output member arranged coaxially with the pressed surface and having an output-side engaging portion arranged more radially inside than the input-side engaging portion, and an engaging element arranged radially inside the pressed surface and having a pressing surface facing the pressed surface, an input-side engaged portion that engages with the input-side engaging portions, and an output-side engaged portion that engages with the output-side engaging portion. The output-side engaged portion is configured by a recessed portion, and the interior surface of the recessed portion has a pair of guided surfaces. The output-side engaging portion has a pair of guide surfaces facing the pair of guided surfaces.

A cable-pull actuation system for a parking brake may have a body which houses an electric motor device. A rod, adapted to operate along an actuation direction, at a first end thereof, an actuation member of a drum brake and/or of a parking brake. A transmission device may operatively connect the electric motor device to a second end of the rod which is translationally integral with a screw. The screw may be engaged with a nut screw rotationally actuated by the transmission device. A pre-loading device may act in contrast on the screw. The pre-loading device may be compressively pre-loaded to exert a pre-load traction on the rod to offset variations of load on the rod. The pre-loading device may be configured to exert a thrust action on the rod following the annulment of axial clearances for an incremental compression of the pre-loading device with respect to the pre-load value.

A cable-pull actuation system for a parking brake may have a body which houses an electric motor device. A rod, adapted to operate along an actuation direction, at a first end thereof, an actuation member of a drum brake and/or of a parking brake. A transmission device may operatively connect the electric motor device to a second end of the rod which is translationally integral with a screw. The screw may be engaged with a nut screw rotationally actuated by the transmission device. A pre-loading device may act in contrast on the screw. The pre-loading device may be compressively pre-loaded to exert a pre-load traction on the rod to offset variations of load on the rod. The pre-loading device may be configured to exert a thrust action on the rod following the annulment of axial clearances for an incremental compression of the pre-loading device with respect to the pre-load value.

The rotation transmission state switching device comprises a clutch device comprising a first rotating member having a first-rotating-member-side engaging portion, a second rotating member having a second-rotating-member-side engaging portion, a third rotating member having a third-rotating-member-side engaging portion; and an engaging element having an engaging-element-side first engaging portion engaging with the first-rotating-member-side engaging portion, an engaging-element-side second engaging portion engaging with the second-rotating-member-side engaging portion, and an engaging-element-side third engaging portion engaging with the third-rotating-member-side engaging portion; and a restriction device configured to switch between allowing and restricting rotation of the first rotating member, allowing or preventing torque transmission between the second rotating member and the third rotating member.

A cable-pull actuation system for a parking brake may have a body which houses an electric motor device. A rod, adapted to operate along an actuation direction, at a first end thereof, an actuation member of a drum brake and/or of a parking brake. A transmission device may operatively connect the electric motor device to a second end of the rod which is translationally integral with a screw. The screw may be engaged with a nut screw rotationally actuated by the transmission device. A pre-loading device may act in contrast on the screw. The pre-loading device may be compressively pre-loaded to exert a pre-load traction on the rod to offset variations of load on the rod. The pre-loading device may be configured to exert a thrust action on the rod following the annulment of axial clearances for an incremental compression of the pre-loading device with respect to the pre-load value.

A cable-pull actuation system for a parking brake may have a body which houses an electric motor device. A rod, adapted to operate along an actuation direction, at a first end thereof, an actuation member of a drum brake and/or of a parking brake. A transmission device may operatively connect the electric motor device to a second end of the rod which is translationally integral with a screw. The screw may be engaged with a nut screw rotationally actuated by the transmission device. A pre-loading device may act in contrast on the screw. The pre-loading device may be compressively pre-loaded to exert a pre-load traction on the rod to offset variations of load on the rod. The pre-loading device may be configured to exert a thrust action on the rod following the annulment of axial clearances for an incremental compression of the pre-loading device with respect to the pre-load value.