Abstract: A structural fastener for blind fixing to a member with an elongate slot comprising a stud within an elongate head which allows the head to be inserted through the slot, the stud then being rotated to move the head out of register with the slot preventing withdrawal of the stud. The shank of the stud has a threaded portion in which a nut is mounted, and further includes a region between the head and the threaded portion which is non-circular and permits limited rotation of the stud after the head has been inserted through the slot, and thereafter engages the sides of the slot to prevent further rotation of the stud in the same direction, thus allowing tightening of the nut to clamp one or more items between the head and the nut.

Abstract: A locking device suitable for use in a gun to prevent unauthorized use of the gun includes a key operated lock (3) operable to expand a ring (8) into locking engagement with the gun chamber. In order to prevent removal of the device by applying force to the muzzle end of the device locking pins (14) are mounted in radial bores (11) to be driven radially outwardly by a tapered piston (18) if the piston is driven away from the muzzle end. An explosvie cartridge (23) is detonated by a firing pin (25) if force is applied to an end plate (26) thereby driving the piston in the desired manner.