Abstract: A sewing unit comprises a sewing machine having a guide device for a binding. A controlled positionable guide member of the guide device makes it possible to sew a binding on an endless edge of a workpiece portion by means of a plurality of separately sewing seams.

Abstract: For the production of circular seams with overlapped ends on a workpiece, a sewing machine driven in a controlled manner and provided with a marker for applying a mark, and a sensor for detecting the mark after marking the workpiece with a mark. The workpiece is sewn until the mark is effectively detected by the sensor which is disposed in a predetermined relationship to the marker, and thus initiates a control operation which initiates the end of the sewing operation in dependence upon a particular number of oversewn stitches. The mark may be applied and detected on the work material in one operating cycle. Thus, for example, circular workpiece openings may be sewn in such a way that the seam end is matched to the start of the seam in spite of different diameters of the work piece opening.

Abstract: A drive device for a reciprocating part having a part which is connected to a stepping motor whose direction of rotation can be changed. The stepping motor is reciprocatingly actuated in a single step length between no more than two step positions, such that it is possible to move the reciprocating part backwards and forwards in a predetermined manner in a simple and reliable way.

Abstract: A device for the automatic formation and sewing of a hem at a continuous edge of an opening of variable width in a workpiece, a hem-forming device on a sewing machine which is controlled by a logic device. An actual force acting upon a guide body is compared with at least one desired force preselectably stored in the logic device. In the event of a difference between these forces, an adjusting device actuates the guide body, serving as a cloth tensioner, until an actual force corresponding to the desired force is established on the guide body.

Abstract: A sewing machine for the controlled sewing on of a tape from a tape supply onto a tubular edge region of an elastic workpiece thus forming a band, which is provided with an additional feed dog in front of the usual feed dog in the region of the needle plate. The additional feed dog is driven by a stepping motor transversely with respect to the workpiece feed direction and is used to guide and align the workpiece. Sensors control the alignment movement of the workpiece.

Abstract: A trimming device for trimming a top cover thread from a workpiece on a multiple needle sewing machine having a thread catching device which is movable between a counter-plate and a knife. In operation the top cover thread is picked up by the thread catching device between a workpiece and a top cover thread guide. A top cover thread trap serves as a counter-plate for the thread catching device. The knife is attached to the counter plate with a gap therebetween, with the thread catching device being swingable within said gap.

Abstract: A thread break detector for a thread in a sewing machine comprising, a sensor device having a signal path cross section for scanning, a first thread guide disposed on one side of the sensor device, and a second thread guide disposed on the other side of the sensor device and being movable in synchronism with the stitch formation of the sewing machine, such that the second thread guide deflects the thread in the region of the sensor device a greater amount than the cross section of the sensor device signal path.

Abstract: An automatic sewing apparatus capable of blind stitching an S-shaped hem in the marginal edge of a tubular workpiece. The sewing apparatus is provided with a tensioning device including a pair of roller supports which arrange an open end of the workpiece in a closed loop formation. The roller support, arranged on the downstream side of the sewing machine, is provided with a guiding portion adapted to receive and controllably guide the sewn and hemmed edge of the tubular workpiece.

Abstract: This invention relates to a feed mechanism for a blindstitch sewing machine including a stitch shortening and tacking mechanism. Elliptical feeding movement is imparted to the feed dog by a fulcrumed lever driven off an eccentric on the main shaft of the machine. An operator controlled eccentric actuator is operatively connected to mechanism which changes the fulcrumed position of the feed lever to vary the elliptical path of the feed dog whereby effecting the advancement of the workpiece during the sewing operation without effecting needle reciprocation. An auxiliary thread tensioning assembly is provided to control the amount of thread utilized during the stitch tacking operation.