Planetary gearbox system

(canceled)

A limit position safety device for establishing upper and lower limit positions of a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction, said device comprising two electrical limit switches each actuatable to reflect when an associated limit position of the rolling door has been reached;

• actuators movable to selectively actuate one of the limit switches at associated upper or lower limits positions of the rolling door;
• and direct drive gear means coupled to the shaft for moving said actuators in response to movements of the rolling door horizontal shaft, whereby said direct drive gear means always provides a direct physical connection or link between the rolling door shaft and said actuators to provide reliable indications of the position of the rolling door.

A power transfer device for an operator having a pair of drive gears comprising a bridge gear box having a drive shaft suitable for being coupled to an external drive;

• an idle spur gear fixed to said drive shaft;
• a pair of spur gears coupled to said idle spur gear to rotate in response to rotations of said idle spur gear;
• and spur gear shafts coupled to said spur gears and arranged to be coupled to the drive gears of the operator, whereby rotation of said drive shaft by an external drive is translated to simultaneous rotations of the drive gears of the operator.