| 摘要 |
A linear motor provides stepwise, incremental advance of a movable member. The linear motor includes an electric coil surrounded by a magnetic core. A magnetic movable pole member is coaxially aligned with a magnetic plunger member and extends through the core and coil. Opposed faces of the movable pole member and the plunger are separated by an air gap. An incremental advance member is fixedly attached to the plunger and extends outward from the movable pole member. A biasing spring is connected between the incremental advance member and the pole member to bias the pole member away from the plunger when electric current has been removed from the coil to re-establish the air gap between the pole member and the plunger. Latches are associated with the pole member and the plunger to provide unidirectional movement only of the pole member and the plunger when a magnetic field induced in the core when current is applied to the coil causes advance of the plunger into contact with the pole member and an incremental advance of the incremental advance member a distance equal to the original air gap. When current is removed from the coil, the magnetic field collapses and the biasing spring urges the pole member away from the plunger re-establishing the air gap for the next sequential energization of the coil.
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