Patent ID: 7417809

Claim:
An optical assembly, comprising: a first tubular member having a first end, a second end opposite the first end, a longitudinal passage extending between the first and the second ends along a longitudinal axis of the first tubular member, and a pitched bearing surface proximate the second end, the pitched bearing surface disposed about the longitudinal axis of the first tubular member such that the pitched bearing surface of the first tubular member is not perpendicular to the longitudinal axis of the first tubular member; a second tubular member having a first end, a second end opposite the first end, a longitudinal passage extending between the first and the second ends along a longitudinal axis of the second tubular member, and a pitched bearing surface proximate the second end, the pitched bearing surface disposed about the longitudinal axis of the second tubular member such that the pitched bearing surface of the second tubular member is not perpendicular to the longitudinal axis of the second tubular member; a coupling tubular member having a first end, a second end opposite the first end, a longitudinal passage extending between the first and the second ends along a longitudinal axis of the coupling tubular member, the coupling tubular member fixedly coupled to the second tubular member for rotation therewith about the longitudinal axis of the second tubular member, the coupling tubular member rotatably and slideably coupled to the first tubular member, with at least a portion of the pitched bearing surface of the first tubular member in engaging contact with at least a portion of the pitched bearing surface of the second tubular member, such that rotation of the first tubular member with respect to the second tubular member varies a distance between the first end of the first tubular member and the first end of the second tubular member; and an optical element received in the longitudinal passage of at least one of the first, the second or the coupling tubular members.