| 摘要 |
PURPOSE:To make it possible to reduce operating sound and to construct with inexpensive parts without using expensive parts such as splines by composing a variable speed motor of an electromagnetic controller and bearings for axially moving a rotational shaft. CONSTITUTION:A current in response to a depressing stroke of a pedal of a sewing machine is supplied to a stator 21, and a rotor 22 rotates at the prescribed speed. When the pedal is then returned to a neutral position, a current is so flowed as to apply a reverse rotation to the stator 21, the speed of a rotor 25 is abruptly decelerated, and a current is supplied from a control unit to a brake coil 30. Thus, an electromagnetic force is acted, a rotary plate 34 is attracted, a shaft 25 is moved rightward, the plate 34 is pressed on a lining 33, and a brake force is generated. |
