Patent ID: 7669797

Claim:
A boarding ramp device for an aircraft, the aircraft comprising: a body; a door opening provided in the body; a door for opening and closing the door opening; a main wing; and a fairing for covering a connecting portion between the body and the main wing, the fairing bulging in a lower face of the body; wherein the boarding ramp device comprises a foldable boarding ramp which connects the door opening to the ground, and which is stored inside the fairing in a folded state, and further comprising interlocking means for connecting together the door and the boarding ramp so that the foldable boarding ramp is deployed in association with opening of the door, and wherein the interlocking means comprises a clutch mechanism provided at an upper portion of the door opening for releasing interlocking between the door and the foldable boarding ramp, wherein said interlocking means further includes a driving pulley provided at the upper portion of the door opening, a driven pulley operatively connected to said boarding ramp and a cable being operatively connected to said driven pulley and said driving pulley for deploying said foldable boarding ramp as said door is opened, wherein said driving pulley includes a support shaft operatively mounted to a bracket, the driving pulley and a clutch ring are rotatably supported on an outer circumference of the support shaft independently from each other, a portion of a driven arm is mounted through a key groove and a key in the outer circumference of the clutch ring with the clutch ring being non-rotatably mounted relative to said support shaft, said clutch ring being slidably mounted relative to said support shaft with recess portions being formed on said clutch ring that mate with projections formed on an upper surface of the driving pulley, and further including a clutch shaft slidably fitted within the support shaft and being biased downwardly by a biasing member under compression and being disposed between a clutch shaft and an end plate mounted to an upper end of the support shaft, a pin secured to said clutch shaft is disposed within an aperture in the clutch ring, a lever is fitted in a slit formed in a lower end of the support shaft, said lever being pivotally supported by a pin for oscillation, a contact portion formed at a base end of the lever being in contact with the lower end of the clutch shaft, said clutch ring, said clutch shaft, said biasing member and said lever forming the clutch mechanism at the upper portion of the door opening.