Patent ID: 7108401

Claim:
A specialized lighting fixture of the type comprising a lamp housing enclosing a source of illumination and a plurality of framing shutters for shaping and confining a light beam emitted by said fixture, wherein (a) said framing shutters are mounted in said housing for radial and/or tilting adjustment with respect to said housing and have first portions extending outward from said housing and hand grip portions at outer ends of said first portions for manually gripping and adjusting said framing shutters, (b) said housing includes friction elements engaging said framing shutters and permitting said framing shutters to be adjusted by an operator, and tending to retain said shutters in adjusted positions in which they are set by the operator, and which further includes (c) first and second locking plates, independent of and separate from said friction elements, generally surrounding said housing and positioned respectively on opposite sides of the outwardly extending first portions of said framing shutters and arranged to bear against said portions, and (d) releasable locking elements engaging said locking plates for causing said locking plates to apply clamping pressure to said outwardly extending first portions and thereby locking said framing shutters against movement from their adjusted positions with respect to said housing.