Slam-style safety lock

Claim 1

An improved slam-style safety lock for enclosed environments allowing egress from the interior when the exterior lock has been actuated, comprising: a. a retractable bolt b. means for housing the bolt, the housing having an opening, to allow passage of the bolt therefrom c. means to secure the housing means to a door allowing access into the environment d. keeper means on the door jamb in alignment with and receiving a portion of the bolt in its normal extended position when the door is closed e. means mounted on the housing means for actuating the bolt between its engagement position with the keeper means to which it is normally yieldingly biased and its retracted position, out of engagement with the keeper means f. the bolt having an aperture, cam means within said aperture g. hand grip and spindle means movably mounted on the door inside the environment, the spindle means passing through the door and engaging the cam means for retracting the bolt from inside the environment without utilizing the actuating means, h. a locking plate positioned inwardly of the bolt, the plate having an outwardly extending forward portion, the bolt having a lip adjacent the forward portion i. Means urging the plate outwardly and particularly the forward portion into the path of travel of the bolt and engagement with the lip j. locking means positioned within the housing and extending inwardly toward the locking plate, the locking means in its locking position being free of the locking plate which prevents opening of the lock from the exterior, and the locking means having a second position which pushes the locking plate out of the path of travel of the bolt so that the lock may be actuated from the exterior k. and means operable only from inside the environment for pushing the locking plate inwardly to a position free of said lip, thus allowing unobstructed rearward movement of the bolt by actuation of the hand grip and spindle means even when such movement is precluded from the exterior.