Self-releasing ratchet-type seat adjustment

In a seat comprising a relatively stationary frame element and a seat element which is swingable in opposite adjustment directions between a pair of defined limits about an adjustment axis that is fixed in relation to the frame element and which is normally urged in one of said directions by its support of an occupant of the seat, adjustment means comprising ratchet means consisting of a ratchet member cooperable with a pawl member for holding said seat element against swinging in said one direction out of each of a plurality of defined adjustment positions to which it can be swung in the opposite adjustment direction, and a latch member cooperating with said ratchet means to provide for substantially free swinging of the seat element in said one direction to one of said limits in consequence of its being swung in said opposite direction to the other of said limits, said adjustment means being characterized by:

• A. one of said members of the ratchet means being fixed to one of said elements;
• B. the other of said members of the ratchet means
• (1) being confined to movement relative to the other of said elements in opposite ratcheting directions towards and from said one member that are substantially transverse to said adjustment directions, and
• (2) being biased in the ratcheting direction towards said one member for ratcheting engagement with it;
• and
• C. said latch member being carried by said other of said elements and confined to motion relative thereto in substantially said adjustment directions between defined latching and release positions;
• D. said latch member having means fixed thereon defining a first pair of abutments and said one of said elements having means fixed thereon defining a second pair of abutments, said abutments of each pair being arranged to cooperate with those of the other pair in defining a lost motion connection between said latch member and said one of said elements whereby the latch member is moved to a release position and to a latching position, respectively, by movement of the seat element to its said one limit and to its said other limit;
• E. said latch member and said other member of the ratchet means having cooperating driving surfaces
• (1) which are spaced apart when the latch member is in its release position,
• (2) which are engaged during motion of the latch member to its latching position, and
• (3) through which the latch member by that motion drives said other member of the ratchet means to a disabled position in which it is spaced from said one member of the ratchet means;
• and
• F. cooperating latch member restraining means on said latch member and on a part carried by said other of said elements, said latch member restraining means being arranged
• (1) to be disengaged when the latch member is out of its latching position, but
• (2) to be engaged under the bias of said other member of the ratcheting means when the latch member is in its latching position, and
• (3) when engaged to releasably restrain the latch member against movement out of its latching position while the latch member retains said other member of the ratcheting means in its disabled position.