| 摘要 |
The sewing machine (20) has, as a downwards sewing machine, a sewing arm (23). For the sewing of lap seams, a guide tongue (32) is arranged on the top side of the sewing arm in the region of the needle plate (26). Of the two length portions (34; 35) of the guide tongue (32), the first length portion (34) is of fin-like design and is oriented parallel to the path of movement of the sewing material, specifically in the region of the cloth-web edges to be sewn together. In the second length portion (35) adjoining this, the back line is curved arcuately downwards continuously at least from its middle as far as the end. The entire length portion (35), in horizontal projection, is curved, in the running direction of the sewing material, to the right in a continuous arcuate path out of the mid-plane of the first portion (34) up to a particular angle. The side face of the second length portion (35) located on the inside in relation to this curvature is inclined outwards from the lower edge towards the upper edge and, at the same time, is convexly curved continuously. Expediently, there is arranged next to the end of the guide tongue (32) a guide tab (33) which projects from the side into the region of the mid-plane of the guide tongue (32) and which has an underside which is convexly curved in two directions and which, in horizontal projection, has an edge extending arcuately. <IMAGE>
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