A fire door operator for a rolling door includes a housing defining an axis. An outer main gear in the form of an annular ring is mounted within the housing for rotation about the axis and formed with exterior gear teeth and radially inwardly spaced interior teeth. Planet gears are meshed with the interior teeth and a sun gear is meshed with the planet gears for rotation about the axis. A carrier is secured to the planetary gears and coupled to the shaft. A lock normally locks the main gear in relation to the housing. A drive selectively rotates the sun gear and the carrier to transmit rotational power to a rolling door shaft when secured to the carrier. A releasing device selectively releases the lock to allow free rotation of the main gear and the carrier to allow a rolling door to be lowered under its own weight.

A power transfer device for a fire door operator having a pair of drive gears includes a bridge gear box having a drive shaft suitable for being coupled to an external drive. An idle spur gear is fixed to the drive shaft. A pair of spur gears are coupled to the idle spur gear to rotate in response to rotations of the idle spur gear. Spur gear shafts are coupled to the spur gears and arranged to be coupled to the drive gears of the operator so that rotation of the drive shaft by an external drive is translated to simultaneous rotations of the drive gears of the operator.

A fire door operator for a rolling door includes a housing defining an axis. An outer main gear in the form of an annular ring is mounted within the housing for rotation about the axis and formed with exterior gear teeth and radially inwardly spaced interior teeth. Planet gears are meshed with the interior teeth and a sun gear is meshed with the planet gears for rotation about the axis. A carrier is secured to the planetary gears and coupled to the shaft. A lock normally locks the main gear in relation to the housing. A drive selectively rotates the sun gear and the carrier to transmit rotational power to a rolling door shaft when secured to the carrier. A releasing device selectively releases the lock to allow free rotation of the main gear and the carrier to allow a rolling door to be lowered under its own weight.

A power transfer device for a fire door operator having a pair of drive gears includes a bridge gear box having a drive shaft suitable for being coupled to an external drive. An idle spur gear is fixed to the drive shaft. A pair of spur gears are coupled to the idle spur gear to rotate in response to rotations of the idle spur gear. Spur gear shafts are coupled to the spur gears and arranged to be coupled to the drive gears of the operator so that rotation of the drive shaft by an external drive is translated to simultaneous rotations of the drive gears of the operator.

A locking device includes a lever turnably provided relative to a lid member, and switched from an initial state to an operating state against an urging force or self-weight; a lock rod sliding in association with turning of the lever; and a braking device. The locking device locks the lid member in a main member side through the lock rod, and switches the lid member to be unlocked by turning of the lever. The braking device is a rotation damper including a braking shaft with a gear, and placed to approximately conform to a turning center of the lever relative to the lever to damp the lever and the lock rod. The rotation damper includes an operation gear disposed to engage the gear of the rotation damper, associate the gear with sliding of the lock rod, and rotate the gear in a direction opposite to the turning of the lever.