Patent ID: 6860177

Claim:
A screw for the anti-fraud locking of a throttle or clamp lever of the control rod of a shutter of a valve or stopcock, the screw comprising: an at least partially threaded shank having a polygonal head surmounted by a truncated-cone shaped dome, a base of said dome extending over an edge of a perimeter surface of said polygonal head, wherein said dome is free to turn around said shank above said polygonal head; a housing defining a recess, said polygonal head and said dome are spaced from an inside of said recess of said housing, said housing and said polygonal head define a tool space; and a tool including a base and a lock jaw, said lock jaw being elastically connected to said base in order to slide over and past said dome into said tool space, said lock jaw having a shape to engage with said polygonal head and rotate said polygon head.