To provide a lowering device for an evacuation ladder having a simple structure, installed at a low cost, having a secure action, and capable of securing safety by controlling the lowering speed of the evacuation ladder with both a constant-torque spiral spring and a centrifugal brake.
An evacuation ladder 1 is stored in a hatch in the folded state, and a pawl is meshed with a ratchet gear 2 1 to hold the storage state. The pawl is released from the ratchet gear 21 at the time of an evacuation, the ladder 1 is extended by the tare weight, and a lowering wire 9 is delivered. A spool 14 arranged with the winding section 20 of the wire 9 is rotated, the winding section 15 of a constant-torque spiral spring 7 is rotated, and the constant-torque spiral spring 7 on a winding shaft 12 is wound up. The winding of the constant-torque spiral spring 7 gives the lowering resistance to the ladder 1, the quick descent by the tare weight of the ladder 1 is suppressed, and the ladder 1 is lowered and extended at a slow speed. The lower end of the ladder 1 is brought into contact with a veranda on the lower stage, and the ladder 1 can be set to the stable and safe evacuation state.
KOITABASHI MASATOSHI
TOMARU YUKINOBU
