摘要:
An apparatus and method for implementing bobbin winding in place in a looptaker of a sewing machine. When a presser foot lift lever is manipulated to elevate a presser foot, and the sewing machine motor is activated, a series of two or three endwise reciprocations of the sewing machine is effected to bring an upper thread to the lower thread carrying bobbin, after which further endwise reciprocation of the sewing needle is held in abeyance while actuation of the sewing machine motor is continued, to provide the least disturbance of upper thread passage to the lower thread bobbin. No other bobbin winding signaling steps are required.
摘要:
An electronically controlled multiple pattern sewing machine is provided with an arrangement which senses when the buttonhole paddle and buttonhole presser foot are not properly positioned at the time a buttonhole pattern is selected to be sewn. Under these circumstances, an alarm is activated and stitches are not formed even though the operator may attempt to sew.
摘要:
A holder containing the light detector of the low bobbin thread detection system of a sewing machine and including a light admitting aperture through which light may pass to a photodetector is provided with a plastic tubular collar which extends over the aperture and serves both as a shield to keep lint out of the aperture and as a lens to focus light on a light sensitive surface in the photodetector.
摘要:
An SCR motor speed control system having a capacitor for triggering the SCR into conduction is provided with circuitry for limiting the top speed of the motor by sensing the time of a predetermined proportion of a motor revolution to determine the motor speed. When the time is below a predetermined time interval, indicative of motor speed above a desired top speed limit, a path is closed to bypass the charging path of the capacitor.
摘要:
A method of forming a buttonhole including two spaced apart rows of zig zag stitches so that each row is formed in a like manner with the final overlaying stitches accomplished in the forward direction and which may be initiated by a barring stitch adjacent the edge of the garment followed by a straight stitch down the cutting space to the opposite end of the garment.