Pfaff Industriemaschinen Gmbh

Mathias Ulmen

Heinrich Bungert

Herbert Wenz

Dieter Balzer

Process for carrying out a sewing operation with a sewing machine with

In a sewing machine with a feed device which comprises a feed wheel arranged next to a stitch formation point, driven synchronously with stitch formation tools, and mounted in a support provided at the housing of the sewing machine, in order to obtain an extremely exact drive in both directions, the feed wheel is placed in driving connection with a step motor. In a manner known in itself, the step motor receives stepping pulses which can be generated by a pulse generator operating synchronously with a main shaft of the machine and via a counting device that determines the feed amount. This feed amount is presettable by selectable digital data contained in a memory. In an arrangement wherein the feed wheel is connected to its drive via a deflection gearing and a transmission shaft mounted in the support, the deflection gearing consists of a ring gear attached to the feed wheel and of a pinion firmly connected to the transmission shaft. An especially compact solution results by attachment of the step motor on the support and by rigid coupling of its output shaft to the transmission shaft.

Sewing machine with step motor operated feed device

A sewing machine assembly comprises a work holding device which is mounted in a fixed location on a support such that a sewing machine carriage frame is movable toward and away from the workpiece holding device. The sewing machine carriage frame carries a support for the sewing machine which is movable transversely relative to the workpiece holding device by cog belts which are driven by a rotatable motor so that the sewing machine support moves backwardly and forwardly. The sewing machine is also mounted on a resilient support of a plate and an eccentric motion is imparted to the sewing machine by a driving motor and an oscillatory motion is imparted to the sewing machine in addition to its relative movement in respect to the holding device.

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Kindsbach, Germany

Mathias Ulmen