Patent ID: 7237449
Filing Date: 2007-07-03
Classification: B23Q,F16H,Y10T

Abstract:
1. A drive mechanism interposed between two members to make said two members move relatively with respect to each other, at least one of said two members being guided to move linearly in a linear moving direction, said drive mechanism comprising: a plurality of rolling cam followers that are rotatably supported on one of said two members, that are arranged in said linear moving direction, and that are spaced from each other; and a cam that is rotatably supported on the other one of said two members and that is provided in its circumference with a cam groove in which said rolling cam followers engage, said cam groove being defined by a pair of inner side surfaces opposing each other and a bottom surface connecting said side surfaces, the rotation axis of said cam being arranged in the direction of said linear moving direction; wherein said two members are made to move relatively with respect to each other by driving said cam to rotate and making said rolling cam followers engage successively in said cam groove and move in the direction of said rotation axis, two adjacent rolling cam followers being engaged in said cam groove simultaneously, and wherein said rolling cam followers are arranged at alternate long pitches and short pitches, the difference in length between said long pitches and said short pitches being substantially two times a gap formed between side surfaces of the cam groove and the cam followers of said drive mechanism so that said two adjacent rolling cam followers roll on said opposed inner side surfaces of said cam groove.