Patent ID: 6916068

Claim:
An armrest apparatus comprises: a fixed shaft fixed to a seat frame; a rotation plate integrally connected to an armrest body and having a tubular portion into which the fixed shaft is inserted, so that the tubular portion is rotatably supported on the fixed shaft; a lock spring wound tightly on outer peripheral surfaces of a part of the fixed shaft and the tubular portion of the rotation plate in a free condition, one end of the lock spring being formed into a fixing-side hook retained by the rotation plate, while the other end thereof being formed into a free-side hook; a cancellation block rotatably mounted on a pivot shaft, the pivot shaft being fixedly mounted on the rotation plate in parallel to the fixed shaft, and is disposed adjacent to the free-side hook; and a cam unit mounted on a distal end of the fixed shaft and including a lock-canceling cam portion and a re-lock cam portion, wherein while the armrest body being pivotally moved in a storing direction, the free-side hook abuts against the lock-canceling cam portion through the cancellation block, and the lock-canceling cam portion expands the lock spring in an unwinding direction to enlarge its diameter to cancel a locked condition of the armrest body, the re-lock cam portion is spaced from the lock-canceling cam portion in a direction of rotation of the cam member, while the armrest body being pivotally moved in an opening direction, the free-side hook abuts against the re-lock cam portion through the cancellation block, and the re-lock cam portion causes the lock spring to spring back in a diameter-reducing direction to lock the armrest body, and when the armrest is stored, the armrest further rotates in a direction which is opposite to the opening direction, the canceling block and the free side hook of the lock spring move internally along with the lock-canceling cam portion.