Spring bolt combination lock

A combination lock comprising a lock housing, a spring biased bolt having a locking free end, said bolt being spring biased for sliding movement so that said locking free end moves out of said housing, a manually operable combination element outside said housing for operating a combination mechanism to assume a predetermined condition within said housing, bolt retracting cam means operable from outside said housing;

• a bolt retracting element secured to said bolt and engageable by said bolt retracting cam means, when said combination mechanism is operated to said predetermined condition, for retracting said locking free end in said housing by displacing and holding said cam means, disengagement means to disengage said bolt retracting element from said retracting cam means after said locking free end is retracted in said housing to a predetermined position and said cam means is no longer held, a timer mechanism having a time adjustment means disposed on a side of said lock housing opposite the side having said manually operable combination element to set the timer for a predetermined time of operation, a displaceable cam element continuously displaceable by said timer when operative;
• a lock mechanism disengaging member having an engagement end to hold said bolt retracting element inoperative, a cam activated end displaceable by said displaceable cam whereby said bolt retracting element is held inoperative for a predetermined time set by said adjustment means, said disengaging means being a pivoted link arm, and a cam follower element in displaceable engagement with said cam element and engaging said cam activated end.