| 摘要 |
<p>1,182,563. Sewing-machines. SINGER CO. 18 April, 1968 [1 May, 1967], No. 18354/68. Heading D1G. In a lockstitch sewing machine having high and low speed drives, the needle is positioned in the up or down position by the low speed drive and auxiliary devices such as thread cutters are operated only on the correct and appropriate position of the needle. The machine is normally driven at high speed by the motor 24 controlled by a treadle 40. If the treadle pressure is removed a clutch 30 engages the low speed drive to move the needle to a standstill in the down position which position is detected and the low speed motor drive disengaged by a commutator. Pressure on the treadle 40 again starts the machine at high speed or pressure on the pedal 46 starts the machine at low speed. To operate yarn catching and severing devices a pedal 48 is pressed in the needle down position. At this needle down position the yarn catching finger operates last only after a time delay, determined by electrical circuitry, ensures the machine has stopped. The machine is then moved by the low speed drive to a needle up position when the yarn severer operates and also a needle thread wiper 71, 72. The machine is mounted on a stand and the electrical control circuits are formed as printed circuits which may be plugged in by a multisocket connection so that if the type of machine on the stand is changed then the control circuits may be replaced by ones necessary for the new type of machine.</p> |
