Pfaff Haushaltmaschinen Gmbh

G.m. Pfaff Aktiengesellschaft

Helfried Hanus

Uwe Winkler

Patrice J Kemmel

Dieter Grossman

A catch thread device is provided for a sewing machine with a scanning element controlled by the upper thread in the rhythm of sewing. The scanning element triggers a signal for the operator and/or for switching off the drive of the sewing machine via an electronic control circuit in the case of a thread break. The catch thread device includes a support fastened to the housing in the sewing machine as well as a pivotable switching lever. The pivotable switching lever is pretensioned and mounted in the support and is connected to the scanning element extending into the course of the upper thread between an eye of the needle and a thread guide of a thread lever of the sewing machine. The scanning element is connected to a magnet which is arranged adjacent to a Hall IC (integrated circuit) fastened to the support wherein the Hall IC is connected via lines to the control circuit for evaluating the signals triggered by the magnet in the Hall IC during the movement of the switching element.

Catch thread device for sewing machines

Digitizing device

A pulse generator for a sewing machine drive, having a shaft revolving synchronously with the main shaft of the sewing machine. The pulse generator shaft is connected with two support elements which carry a strobe disk provided with control segments of bright and dark zones, the strobe disk extends between pairs of light emitting and light receiving components. The strobe disk includes a first partial disk non-rotationally connected with one support element and a second partial disk arranged adjacent and non-rotationally connected with the other support element, the angle regions of the mutually correlated bright and dark zones of the control segments of the two partial disks differing from each other, one support element being rotatable relative to the other support element, so as to change the bright and dark zones of the strobe disk.

Pulse generator for a sewing machine drive

A pulse generator of variable-speed drives, particularly sewing machine drives having a main rotatable shaft and a housing comprising a casing defining an inner space connected to the sewing machine housing, a generator shaft rotatable and synchronous with the main shaft and mounted for rotation in the casing, a pulse disc with light-dark zones connected to the shaft and rotatable within the inner space of the casing, a light transmitting module and a light receiving module connected to the casing, the casing including bearing surfaces on either side of the disc bearing against and bearing surfaces of the shaft for supporting the pulse disc for rotation. Bearing surfaces provide a seal against stray light and dust and the like and also accurately center and support the pulse disc.

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Karlsruhe-Durlach, Germany

Helfried Hanus