Sewing machine with precisely regulated feed - has an electronically controlled feed for elasticated band

摘要

A sewing machine has a controlled band feed, pref. for an elasticated tape, which has a motor drive. There is a tension arrangement of rollers on a lever adjusted by means of a regulator circuit connected to the drive motor. This consists of an analogue measurement between the lever faces controlled by a spring. The signal is converted to digital, and fed through an analogue and gate to a discriminator and register, then to amplifier circuits to control the motor which feeds the band through rollers. The sewing machine (1) has an attachment (2) to hold the motor (3) which drives the feed rollers (6,7,8) and draws the band (12) from the roll (19). This then surrounds the controller roller (9) held on the L shaped lever (15), hinged at (14) and having a rear face (16). A flat spring (13) holds the gap to the sensor (17) at a certain distance, which is measured electrically, and supplies an analogue signal to the discriminator circuit in a module. A logic and gate connects to a register, and by means of amplifiers the rotation of the motor (3) is controlled to attain the correct tension on the band in the sewing position. ADVANTAGE - The feed is precisely regulated as required for elasticated material being fed into the sewing machine.