Automatic transmission parking brake mechanism

Claim 1

A transmission parking brake for anchoring a transmission power output shaft to a relatively stationary transmission housing comprising: a parking gear carried by and rotatable with said power output shaft, said parking gear having external teeth; a parking pawl lever mounted on said housing for oscillation about a first axis, said pawl lever having a pawl adapted to engage said teeth when said pawl lever is oscillated in one direction, means for moving said pawl lever in the opposite direction, said pawl lever having a cam follower thereon; a detent plate mounted on a second axis spaced from said first axis; a cam plate mounted on said second axis adjacent said detent plate, a support shaft for supporting said detent plate and said cam plate for oscillation about said second axis, said detent plate and said cam plate having engageable parts that are engaged, one with respect to the other; a cam surface on said cam plate adapted to engage a follower portion of said pawl lever; spring means engageable with said detent plate and said cam plate to urge them into mutual engagement; means for adjusting said detent plate and said cam plate in said one direction whereby said cam surface forces said pawl into locking engagement with said gear; and said means for moving said pawl lever in said opposite direction comprising a tail portion on said pawl lever, said cam plate being adapted to engage said tail portion when said cam plate is moved out of the gear locking position, said cam plate and said tail portion being located generaly in a common plane of movement.