Patent ID: 7854082

Claim:
An opening and closing device for rolling block firearms comprising a rolling block, at least one barrel and a receiver, said receiver being attached to the barrel and hinged to the rolling block; the device being associated with the rolling block and receiver so as to allow reciprocal rotation of the rolling block and of the receiver to open and reciprocal end locking between the rolling block and the receiver to close; the device comprising a key that is hinged by a tube to the upper part of the rolling block, and a bolt that is actuated by a shaped end of the key and is slidably mounted on the rolling block in such a way that it can be moved from a rectracted, open position in which the bolt is entirely inside the rolling block, and an advanced, closed position in which the bolt protrudes from the front of the rolling block with two arms designed to lock by friction two matching mortises made in the receiver; the arms extending from the ends of a shoulder of the bolt; the shaped end of the key having a first cam designed to exert a pushing action on the central portion of the shoulder in order to disengage the arms from the mortises; the first cam acting in conjuction with a central protrusion on the shoulder so as to disengage the arms from the mortises; the shaped end of the key having a second cam designed to act in conjunction with a hollow in one of the arms in order to move the bolt to the retracted, open position; and the first and the second cam, the protrusion and the hollow being positioned and shaped in such a way that, as the bolt moves from the advanced, closed position to the retracted, open position, first the protrusion is engaged by the first cam and then the hollow is engaged by the second cam.