摘要:
A sewing machine includes a needle bar that is equipped with a sewing needle at a lower end of the needle bar, a presser bar that is equipped with a presser foot at a lower end of the presser bar, which holds down a work cloth, a sewing machine motor which is a driving source that drives the needle bar in an up and down direction, and a switching device that switches between a normal mode in which the needle bar is driven in the up and down direction to form stitches and a practice mode in which the sewing machine is operated in a condition where at least the needle bar is not driven.
摘要:
There are provided an upper shaft clutch mechanism 140, a bobbin 22 including a slit 39, a horizontal holder 4 including an inner holder 18 and a blade tip 42, a bobbin driving member 11, bobbin driving member moving means 94 for moving the bobbin driving member 11 to freely advance or retreat between two positions having a separating position and a connecting position, a thread holding and catching member 48 including an upper thread holding portion 59, an upper thread engaging portion 60 and a thread position regulating portion 58 which are always set in a retreat position and are set in an entry position during a thread winding operation, thread holding and catching member moving means 53 for moving the thread holding and catching member 48 to freely advance or retreat between two positions having a retreat position and an entry position, and a thread winding operation control portion 193 for controlling the operation of each portion during the thread winding operation.
摘要:
A sewing machine-driving apparatus forms an accurate and stable seam at a first stitch in a conventional double chain stitch or covering chain stitch sewing machine. Its motor is controlled so as to drive the sewing machine in a direction reverse to that of the usual sewing operation for a limited time period between the completion of a thread cutting operation and a point of time when the sewing machine needles reach their needle-down position. Thus, the stitching needles reach their lowest points without scooping a looper thread at the first stitch; assuring the formation of a stable and accurate seam in the second stitch.
摘要:
By means of this method and apparatus for sewing a seam, it is possible to end a seam exactly at a predetermined location. When the predetermined location is reached, the forward movement of the sewing material is interrupted, and only the stitch that had been begun at the time of the interruption is completed. In this way, on the one hand, visually attractive seams can be produced and, on the other hand, it is possible to sew a small part onto a main part with a seam which does not extend past the small part.
摘要:
In a drive for a sewing machine, especially an industrial sewing machine, with a needle that can be reciprocated between an upper and lower end position by a sewing machine main shaft, in which the drive is in direct driving connection with the main shaft and can be controlled at variable speed through a control system, provision is made for improving the dynamic performance of the combination of drive and sewing machine by equipping it with at least one input switch connected electrically to the control system for the input of command pulses for the step-wise actuation of the drive such that with each command pulse a certain, defined amount of movement of the drive and hence of the main shaft is triggered.
摘要:
A stopping device for an eyelet button holing machine provides a stopper arm which plunges into a recess portion of a stopper cam positioned coaxial to the main shaft. To absorb the stopping impulse, extra wheel cams are provided coaxial to the main shaft which induce the stopper arm to be inclined such that its position causes a clutch pulley to contact with a low speed pulley and then the stopper arm plunges into the recess portion of the stopper cam. Thus, the machine is stopped in two steps and the stopping impulse force is effectively alleviated.
摘要:
A sewing machine driving system comprises: a reluctance motor operatively coupled to a sewing machine main shaft and having a stator and a rotor; a drive circuit for driving the reluctance motor; an angular position detector for detecting the angular position of the rotor with respect to the stator; a needle position detector for detecting the position of a sewing needle connected to the main shaft; a first control unit responsive to a drive command and a signal from the angular position detector for driving the reluctance motor at variable speeds; and a second control unit responsive to a stop command and signals from the angular position detector and the needle position detector for braking the reluctance motor to stop the sewing needle in a prescribed needle position.
摘要:
A driving control device for an electronic sewing machine has a computer and an automatic needle stop system. The needle stopping arrangement is responsive to operation of the foot control regulator, and is arranged to stop the needle in its upper position in response to a first raising of the regulator, and is responsive to a second raising of the regulator within a half cycle of the machine operation for stopping the needle at its lowermost position.
摘要:
Stitches have once been formed in a sewing machine in four steps to produce a buttonhole, the number of the stitches to be used in each of the steps are stored in a memory, and the stitches in each step are formed with the number of stored stitches for following buttonhole such that all sizes of the buttonholes are made of the same size. The sewing machine is provided with a central circuit which includes a pattern selecting device which selects a cam from a plurality of pattern cams in correspondence to stitching of the designated step in producing the buttonholes. An electronic control device provided in the sewing machine stores the number of stitches formed in accordance with each of the steps with the memory designation, and a stitching mode check device designates a subsequent step in each of the steps. An indicating device provided in the central circuit indicates this designation, and the buttonhole is repeatedly formed. A machine motor control circuit stops a machine motor at completion of the number of stitches stored in each step and the machine motor again starts with selection of new patterns of the stitches.
摘要:
A needle positioner for a stitching machine for positioning of such needle selectively in an up or down position. The positioner is pneumatically powered and adapted to be installed on existing machines. The needle positioner functions to selectively position the needle in an up position or a down position. The stitching mechanism includes an air motor for reciprocating the drive shaft of the stitching mechanism. Two pneumatic cylinders are disposed proximate the drive shaft so that when the piston rods of the cylinders are extended, they contact the drive shaft and interrupt rotation of the drive shaft stopping the needle in an up position or a down position. The needle positioner also includes valves in the pneumatic circuit between a source of pressurized fluid and the pneumatic cylinders for directing the flow of air to a desired one of the two cylinders. The valves are operated by a pedal device which allows an operator of the stitching machine to activate the valves and select to stop the needle in its up or down position.