Patent ID: 6456791
Filing Date: 2002-09-24
Classification: G03B

Abstract:
A moving mechanism comprising:a first helicoid thread on an inner surface of a first cylinder, a second helicoid thread threadedly engaging the first helicoid thread on an outer surface of a second cylinder, wherein when one of the first and second cylinders is rotated with respect to the other, the other is moved relative to the cylinder that is rotated, and a moving mechanism including: a projection on the outer surface of the second cylinder, and a groove in the inner surface of the first cylinder for engaging the projection, wherein the groove is parallel to the first helicoid thread in a range where the first and second helicoid threads threadedly engage each other upon movement of the first and second cylinders relative to each other, and has a nonparallel region not parallel to at least the first helicoid thread within a range where the first and second helicoid threads do not threadedly engage each other.