Compressed air-operated fastener driving tool with release safety means

Claim 1

Compressed air-operated fastener driving tool comprising a pilot valve controlled by a manually operated release lever, a control valve the pressure bias of which is controlled by the pilot valve and which for its part control the supply of compressed air to a working cylinder, and a release barrier actuated by the workpiece by means of which in common with the release lever placed in the working position the actuation of the pilot valve is adapted to be controlled; and in addition to said pilot valve and control valve a third manually operable release organ movably fitted at the fastener driving tool casing outside the gripping region of the operator's hand actuating the release lever which is effective on a movable valve element of the pilot valve via an opening in the fastener driving tool casing in such a manner that the pilot valve is capable of being moved into the working position only if the other hand of the operator actuates the third release organ, said third release organ being a lever pivotally supported at the fastener driving tool casing which with the aid of a projection over the casing opening is effective on the valve element of the pilot valve and with the aid of a spring is constantly urged in a direction towards the valve element, the force of the spring being greater than the actuating force at the valve element of the pilot valve.