Pfaff Industriemaschinen Gmbh

Karl H Walther

Kurt Vollmar

A sewing machine includes a main shaft driving a sewing needle to reciprocate it through the material to be sewn which is fed over a needle slide of a stitch plate. The main shaft also drives a trimming knife drive which drives a reciprocating knife which cooperates with a counter blade adjacent the stitch plate for trimming the material. The trimming knife drive includes an eccentric driven by the main shaft and operating a knife operating linkage connected to reciprocate the knife. An eccentric rod is driven by the eccentric and it drives a swing lever through a guide rod which is pivoted thereto. The swing lever in turn drives the knife through a linkage connected between it and the knife and selectively moves it upwardly and downwardly for stopping its motion in either an upward or downward position. A device is connected to the eccentric rod so as to pivot the swing lever into a position in which it actuates the linkage to move the knife to its cutting position independently of the position of the eccentric.

Sewing machine with a trimming device

A sewing machine has a work bearing surface in a substantially horizontal plane and a cutting device for the work including a bottom knife disposed in the horizontal plane of the work bearing surface and a top knife movable in the vertical direction. The cutting device has a toggle lever transmission drive comprising two articulatedly connected connecting rods, the joint of which is connected with a drive element. One of the two connecting rods is connected, at an outer joint thread with the top knife.

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Weilerbach, Germany

Karl H Walther