| 摘要 |
An inductive position detector 10 comprises a longitudinally extending scale 20 and a transducer 30 movable along the scale. The scale 20 comprises a tube 21 of non-magnetic material housing a train of magnetic balls 22. The transducer surrounds the tube 21 and comprises transmission and pick up coils. The transmission coils induce a magnetic field along the line of the balls 22 and the pick up coils detect variation in the field as the balls 22 move relative to a pick-up coils. Positional information is found from this variation. The transducer 30 is couped to the ball tube 21 by a thread (40, figure 2). A magnetic marker 23 may be used to act as a datum point. A tool head may mounted on the threaded tube (which forms a lead screw) and may be integral with the transducer. |
