NEEDLE POSITIONER FOR A SEWING MACHINE

摘要

A needle positioner for a sewing machine having an electric motor, including electrical circuitry for driving the electric motor at a uniform low speed and at variable speeds greater than the low speed, a dynamic braking circuit connected to the motor and adapted to be energized when the motor is de-energized to reduce the speed of the motor, automatic electric controls for de-energizing the dynamic braking circuit and re-energizing the motor when the speed of the motor has decreased to the low speed, a switch element responsive to the up or down position of the needle and adapted to energize controls for simultaneously de-energizing the motor and actuating braking means to stop the motor when the needle is in the desired up or down position.