A small and compact rotation transmitter includes a torque limiter and an angular position holding apparatus. An outer race member is installed in a housing, and a coil spring is mounted on the outer peripheral surface thereof. Inside the outer race member, an internal space is formed, and an inner race member is installed concentrically with the outer race member. In the annular space between the outer and inner race members, a thin-plate elastic piece is pressed against the outer and inner race members, and either the outer or inner race member is connected to an input-side device while the other is connected to an output-side device. Even without rotation torque, the position of the output-side device is held by the coil spring. When the rotation torque from the input-side device becomes excessive, slippage occurs on the thin-plate elastic piece, whereby the outer and inner race members are disconnected.

A small and compact rotation transmitter includes a torque limiter and an angular position holding apparatus. An outer race member is installed in a housing, and a coil spring is mounted on the outer peripheral surface thereof. Inside the outer race member, an internal space is formed, and an inner race member is installed concentrically with the outer race member. In the annular space between the outer and inner race members, a thin-plate elastic piece is pressed against the outer and inner race members, and either the outer or inner race member is connected to an input-side device while the other is connected to an output-side device. Even without rotation torque, the position of the output-side device is held by the coil spring. When the rotation torque from the input-side device becomes excessive, slippage occurs on the thin-plate elastic piece, whereby the outer and inner race members are disconnected.

A centrifugal brake mechanism for a controlled descent device, and a drum device employing it, are described. The mechanism comprises a circular wheel configured and operable to rotate about an axis of rotation thereof, an axle extending along and rotatable about the axis inside a central cavity of the wheel and having two or more parallel shaft rods extending inside the cavity substantially perpendicular to the axis of rotation, a gear system for transferring rotations of the wheel into counter-rotations of the axle, one or more brake elements each having pass-through bores for slidably mounting over the two or more parallel shaft rods, springs mounted over the parallel shaft rods between the brake element and the axle, and a friction enhancement mechanism for increasing friction forces between the brake elements and the inner wall the wheel responsive to increase in angular velocity of the wheel.

An adjustable friction brake assembly may adjust a variable amount of frictional force required to translate or rotate a shaft, rather than merely locking or unlocking the shaft. The brake assembly includes a housing for internally receiving the shaft, the external portion of the housing including external threading leading into circumferentially spaced fingers extending axially and oriented radially inward to engage the shaft. The brake assembly includes a rotatable adjuster having an internally threaded throughbore for engaging the housing and directing the fingers radially inward to engage the shaft, thereby increasing the required frictional force. For example, by rotating the adjuster clockwise, the required force can be increased; similarly, by rotating the adjuster counterclockwise, the required force can be decreased.

An adjustable friction brake assembly may adjust a variable amount of frictional force required to translate or rotate a shaft, rather than merely locking or unlocking the shaft. The brake assembly includes a housing for internally receiving the shaft, the external portion of the housing including external threading leading into circumferentially spaced fingers extending axially and oriented radially inward to engage the shaft. The brake assembly includes a rotatable adjuster having an internally threaded throughbore for engaging the housing and directing the fingers radially inward to engage the shaft, thereby increasing the required frictional force. For example, by rotating the adjuster clockwise, the required force can be increased; similarly, by rotating the adjuster counterclockwise, the required force can be decreased.

A band brake actuator is for actuating a band brake on a planetary gearset. The band brake actuator comprises a actuator shaft; an output finger; and a linkage assembly. The linkage assembly connects the actuator shaft to the output finger such that rotation of the actuator shaft in a first rotation direction causes the output finger to engage the band brake on the planetary gearset, and such that rotation of the actuator shaft in an opposite, second rotation direction causes the output finger to disengage the band brake from the planetary gearset. Engagement of the band brake and the planetary gearset shifts the planetary gearset into one of a forward and a reverse gear and wherein disengagement of the band brake and the planetary gearset shifts the planetary gearset into a neutral gear.

A torque transfer apparatus and method of use is described. The apparatus comprises a plurality of elements assembled together to form a ring structure oriented in a plane around a longitudinal axis. The ring structure defines a first engagement surface. A structure defining a second engagement surface is rotatable with respect to the ring structure. The ring structure is operable to be moved between a collapsed condition and an expanded condition by movement of the plurality of elements, and movement between the collapsed condition and the expanded condition engages or disengages the first and second engagement surfaces. The apparatus can be configured to transfer a driving torque (e.g. a clutch) or a braking force (e.g. a torque brake).

A torque transfer apparatus and method of use is described. The apparatus comprises a plurality of elements assembled together to form a ring structure oriented in a plane around a longitudinal axis. The ring structure defines a first engagement surface. A structure defining a second engagement surface is rotatable with respect to the ring structure. The ring structure is operable to be moved between a collapsed condition and an expanded condition by movement of the plurality of elements, and movement between the collapsed condition and the expanded condition engages or disengages the first and second engagement surfaces. The apparatus can be configured to transfer a driving torque (e.g. a clutch) or a braking force (e.g. a torque brake).

A rotary actuator has a rotatable platform rotatably supported on a base. The rotatable platform has a friction surface. An actuator band is operated by a band clamp so as to be selectively frictionally engageable with the friction surface. A motion actuator is coupled between the base and the actuator band such that change in length of the motion actuator causes corresponding movement of the actuator band. A brake band is operated by a brake band actuator so as to be selectively frictionally engageable with the friction surface, the brake band anchored to the base.

A rotary actuator has a rotatable platform rotatably supported on a base. The rotatable platform has a friction surface. An actuator band is operated by a band clamp so as to be selectively frictionally engageable with the friction surface. A motion actuator is coupled between the base and the actuator band such that change in length of the motion actuator causes corresponding movement of the actuator band. A brake band is operated by a brake band actuator so as to be selectively frictionally engageable with the friction surface, the brake band anchored to the base.