SEWING MACHINE WITH A SENSOR FOR MEASURING THE THICKNESS OF THE FABRIC

The ultrasound sensor comprises transmitter and receiver (34a, 34b). They are located ahead of the stitch-forming location, in the direction (31) of material advance. They are mounted on the sewing machine (1) head (3), with clearance (a) above the sewing support plate (23). Transmitter and receiver occupy a single housing. The controller (38) memory (44) stores the clearance (a). The controller has a second memory (45) for the thickness (d1) of the material to be sewn (24). A third memory stores combined thickness (d2) of first and second (25) pieces of sewing material. A fourth memory (47) stores a maximum thickness value (D), as a threshold. Should this be exceeded by the total thickness of material(s), a switch is triggered.