AUXILIARY DEVICE FOR A SEWING MACHINE

摘要

An auxiliary device for sewing machines comprises tappets and switches in the coupling parts of the presser foot shaft. The tappets are arranged in accordance with a determined code and they activate a combination of the switches. The switches are connected to an electronic circuit in which the coded information relative to the presser foot is compared with information characterizing the set up of the machine for a desired sewing operation. A display is activated for indicating if both sets of information coincide or do not coincide with each other so that the user knows if the correct presser foot is inserted.