Patent ID: 7676976

Claim:
Auxiliary apparatus for attachment to a firearm including a barrel having a longitudinal axis, comprising the combination of: a fixture operatively configured to be attached to the muzzle of the barrel coaxially therewith and including an annular ridge; an auxiliary device including a bore for coaxially receiving said fixture, a collar having an outer surface eccentric about said bore, and a ring having an annular wall rotatably and threadedly secured to said outer surface of said collar, said ring including a radial wall having a circular opening eccentric relative to said annular wall, said opening being concentric relative to said bore at a first rotational position of said ring for permitting said ring to pass over said ridge, said opening being eccentric relative to said bore at a second rotational position of said ring for causing said radial wall to block passage of said ring over said ridge; and a locking device for releasably locking said ring in said second rotational position.