Position adjustable see-through headrest

Claim 1

An angular position adjustable see-through headrest adapted to be mounted on a seatback of a seat, comprising: stays extending from said seatback; a lower frame shaft extending across said stays and secured to the same; a pivotal reversed U-shaped structure pivotally connected to said lower frame shaft so as to be pivotal about the axis of said lower frame shaft between first and second extreme angular positions; a position adjusting mechanism arranged between said pivotal reversed U-shaped structure and said lower frame shaft, said mechanism being operable to lock said pivotal reversed U-shaped structure to a selected one of the angular positions relative to the fixed lower frame shaft; a cover member covering said mechanism so as to conceal the same from the exterior of the cover member without affecting the function of the mechanism; and a pad member covering substantially entire of a unit including said lower frame shaft, said pivotal reversed U-shaped structure and said mechanism, wherein said pivotal reversed U-shaped structure comprises: a reversed U-shaped upper frame; and two base plates respectively secured to leg portions of said upper frame, and wherein said position adjusting mechanism comprises: a ratchet plate secured to a selected one of said base plates with its teeth facing toward said lower frame shaft; a pawl member selectively engageable with said teeth of the ratchet plate, said pawl member having a first pawl section practically engageable with said teeth and a second pawl section; a pawl carrying plate secured to the fixed lower frame shaft and pivotally carrying said pawl member through a pivot pin; first biasing means for biasing said pawl member in a direction to meshingly engage with the teeth of the ratchet plate; a lock cancelling plate rotatably disposed on said lower frame shaft, said plate having a projection which is engageable with said second pawl section of said pawl member; stopper means for suppressing extreme rotation of said look cancelling plate in a given direction; and second biasing means for biasing said lock cancelling plate in said given direction.