Back-rest angle adjusting apparatus

摘要

Irrespective of limitation of a back-rest operating speed of a in a normal angle range, a raising speed of the back-rest in the case where the back-rest is greatly raised forward beyond the angle adjusting range is made faster. A back-rest angle adjusting apparatus 1 for a seat of a cylinder type in which an enlarged diameter portion 37 is constituted in an inner wall portion of a cylinder 2 opposed to a piston 16 in the vicinity of said back-rest angle adjusting apparatus 1, a bypass passage 38 is formed between the inner wall of the cylinder 2 and the outer periphery of the piston 16 when the enlarged diameter portion 37 on the cylinder 2 side is opposed to the piston 16, and a rod side chamber R and a head side chamber H within the cylinder 2 defined by the piston 16 are caused to communicate with each other by said bypass passage 38.