| 摘要 |
An edge follower for sensing and following a selected edge (24) a workpiece (2) so as to control the path of a metal working tool such as a welding torch (12) includes a light source for illuminating a small area of the workpiece (2) and a photocell for generating a signal corresponding to the amount of light entering the cell after reflection from the workpiece. Means in the forms of a synchronous stepping motor and a carriage (16) is provided to move the light source and photocell incrementally transversely to the edge (24) being followed in accordance with the amplitude of the signal from the photocell to keep the signal at a predetermined level. |
