| 摘要 |
<p>An apparatus and method is disclosed for centering a pattern wheel (8) of a modular optical shaft encoder (2) and setting a predetermined gap distance between the pattern wheel (8) and a mask (26) and photodetector (32). The apparatus is built in to the encoder (2) and facilitates aligning and gapping of the pattern wheel (8) with respect to the mask (26) and photodetector (32) during installation of the encoder (2) about a rotatable shaft (14). The apparatus consists of a slidable linear cam (36) which cooperatively engages a centering collar (42) to urge the collar against a pattern wheel (8), the pattern wheel (8) is in turn urged into a predetermined position. The collar (42) is retractable from contact with the pattern wheel (3) after the pattern wheel (8) is mounted in position on the rotatable shaft (14) to allow rotation of the wheel (8) and the shaft (14).</p> |
