초록 ▼

A brake mechanism includes a reduction gear train, a motor structure, and a braking means. The reduction gear train transmits at least a rotation force in a first rotational direction supplied from a drive source. The reduction gear train is imparted with a returning tendency in a second rotational

A brake mechanism includes a reduction gear train, a motor structure, and a braking means. The reduction gear train transmits at least a rotation force in a first rotational direction supplied from a drive source. The reduction gear train is imparted with a returning tendency in a second rotational direction opposite to the first rotational direction. The motor structure has an output shaft rotatably connected to the reduction gear train. The braking means has field magnets, an armature coil, a braking circuit, and either one of a fixed resistor, a variable resistor, a rectifying diode, a Zener diode, a varister, a constant-current diode, a light-emitting diode, and a lamp bulb. The braking means generates a torque in the first rotational direction to the output shaft which, upon being disconnected from the drive source, rotates to return in the second rotational direction through the reduction gear train in accordance with the returning tendency, thereby suppressing a returning rotation speed of the reduction gear train.

대표청구항 ▼

[ What is claimed is:] [1.] A power actuator comprising:an operating member supported for rotation;a drive source having a holding torque when power is not supplied;a rotation transmitting mechanism for transmitting a rotation force from said drive source to said operating member;a power clutch for

[ What is claimed is:] [1.] A power actuator comprising:an operating member supported for rotation;a drive source having a holding torque when power is not supplied;a rotation transmitting mechanism for transmitting a rotation force from said drive source to said operating member;a power clutch for separating between said operating member and driving source as not to transmit a rotation force from said drive source to said operating member, when a power failure occurs;a return spring for imparting said operating member with a returning tendency to return the said operating member to rotating limit; anda brake mechanism having a rotator which rotates by a return force of said operating memberwherein return rotation of said rotator is damped by an induced current generated during the return operation of said rotator, when a power failure occurs.