Abstract: An arresting mechanism to prevent a nail gun from cocking and firing when there are no nails in its magazine. A trigger includes a retaining part organized to prevent the trigger from cocking to fire. A cotter is arranged for sliding engagement in the trigger mechanism. The cotter is provided along an axial length with a convex portion. A swingable sensing component is pivotally mounted outwardly of the housing with a magazine end projecting into the magazine and pushed outwardly by nails therein. Consequently the other end of the sensing component is pushed on to and holds the cotter during normal operation so that it does not activate the retaining part. When no nail is in the magazine the magazine end of the sensing component is no longer pushed outwardly so the cotter is moved by a spring to position its convex portion to activate the retaining part so as to jam the trigger whereby it can not cock and shoot.

Abstract: A structure of an arresting mechanism for a nail gun, wherein the nail gun is composed of a nailing device. The nail gun further comprises a trigger, which is fastened between two pin plates of the nailing device and can be cocked to shoot nails. The arresting mechanism contains a reciprocating cotter pierced through the two pin plates; at lease one retaining part disposed on the trigger; a swinging sensing component, which is fastened together with the magazine, with its first end in the location corresponding to the magazine and further extending into the magazine to reach the nail and the second end reaching the head of the cotter. Accordingly to foregoing structure, when there is no nail loaded in the magazine, the trigger cannot be cocked by the users; contrarily, when nails are loaded in the magazine, the trigger can be cocked.