| 摘要 |
A safety belt retractor reel which is automatically locked against belt extraction under emergency conditions or with the withdrawal of a predetermined length of belt is provided with a mechanism for releasing and locking the reel against belt retraction operated in response to respective successive short sequential extraction and retraction of the belt. The mechanism includes a supplementary ratchet wheel affixed to the reel shaft and a pawl spring biased into engagement with the ratchet wheel to lock the reel against belt retraction. A pair of first and second cam discs are rotatably supported by the shaft and individually slip drive coupled thereto. One of the cam discs functions to releasably retain the pawl in its ratchet disengage position and the other cam disc functions to urge the pawl toward the retainer disc against its spring bias with the belt extraction rotation of the reel. Transfer of the pawl from either its ratchet engage or disengage position to its opposite position is effected by a predetermined extraction of the belt followed by retraction thereof. |
