Abstract: A gun silencer and muzzle protector utilizes a hollow housing mounted on a gun barrel with expandable release doors being positioned within the housing. The release doors are pivotally mounted within the housing and are normally retained together in a cone-shaped abutting relationship through the use of a circumferentially extending spring positioned about the doors. A lining employed in the housing silences a gunshot and several different types of adapters may be utilized to mount the housing and associated doors to the gun barrel. The adapters include a first type which is threadably attachable to a gun barrel, a second type which utilizes a split sleeve construction to clamp the adapter to a gun barrel, and a third type which utilizes a radially extending clamp member to clamp the adapter to the gun barrel with the third type of adapter being used in conjunction with any type and caliber of gun.

Abstract: The sliding deadbolt of a security door lock internally mounts a latching device engageable with the coupling element on the end of a flexible guard element retracted within a jamb-mounted, strike housing into which the deadbolt is projected for door locking purposes. Retraction of the deadbolt permits opening of the door to a limited extent by extension of the guard element from the strike housing in the jamb. Continued retraction of the deadbolt effects release of the latch device and retraction of the guard element.