Patent attributes
A chain lock includes a top part pivotably connected to a bottom part. An engaging member is located in the bottom part. A lock cylinder, a rotary member and a rod are connected to each other. A torsion spring is biased between the lock cylinder and the rotary member. The torsion spring, the lock cylinder, the rotary member and the rod are located in a movable member to which a compression spring is mounted. Both of the movable member and the compression spring are received in the top part. A chain is secured in a first radial slot of the top part by the movable member, and the other end is inserted in the second radial slot of the bottom part. The chain lock is locked without using the key, and the key is required to unlock the chain lock.
