Sewing machine

摘要

A first sewing machine comprises: (a) a needle bar (8) with a needle (11a, 11b); (b) a main shaft (6) connected to the bar; (c) a loop catcher (15, 16) which works in coordination with the needle to catch a thread loop led through the needle; (d) a shaft (17) connected with the catcher; (e) a motor (7, 21) to drive at least the needle bar or the catcher by turning main or catcher shafts; (f) a first sensor (38, 47) to detect a first reference position for either shaft and send a first signal to indicate that the position has been reached and; (g) a second sensor to indicate the motor has reached a second reference position. An indicating device, on the basis of the first signal, shows when the shaft has reached its reference position and, on the basis of the second signal, that the motor has reached the second reference position. Also claimed is a second machine similar to the last where the sensor is an angular position sensor, i.e. it has a plate (47) fixed to the appropriate shaft and a signal transmitter (38) which indicates when the first reference position has been reached. The signal has one characteristic to show that the shaft lies within a first 180 deg sector and another to show that it is in a non-overlapping second 180 deg sector.