Self-locking electronic lock

An electrically operated spring bolt lock for a door, comprising:

• a lock housing, a cam bolt and a spring means for normally biasing said bolt outwardly of said door;
• an electrically driven means for moving said bolt inwardly of said door against the bias of said spring means for a given time interval to allow opening of said door and for releasing said bolt after the expiration of said time interval, said electrically driven means comprising a lost motion connection with said cam bolt, a reversible electric motor having a motor shaft connected via said lost motion connection with said cam bolt, and a circuit board, said cam bolt being movable inwardly of said door to allow closing of said door when released by said electrically driven means, rotation of said motor in a first direction withdrawing said bolt inwardly of said door and subsequent reverse rotation in a second direction releasing said bolt to be free to move under its spring bias inwardly and outwardly of said door as said door is closed against an associated door jamb;
• a code entry means for actuating said electrically driven means upon entry therein of a predetermined code;
• mounting means for mounting said electrically driven means, cam bolt and spring means within said housing, said cam bolt being movable to protrude from said housing and door, said circuit board being electrically connected to said code entry mean and to said electric motor, said circuit board sending a motor operating signal to said motor to move said bolt when said predetermined code is entered on said code entry means, said signal is provided to first operate said motor in a first bolt withdrawal mode to cause movement of said bolt inwardly of said housing, then in a second mode wherein said motor is in a dwell condition, and then in a third mode wherein said motor is reversed.