Abstract: A break in twice as many yarns is made detectable merely by slightly modifying the tension switch assembly of a knitting machine. A yarn conductor 20 is rotatably attached to the forward end of an arm 16 of the assembly and provided with a pair of yarn supports 26, 27 on opposite sides of a rotational pin 19. Upon a break occurring in the yarn 2 retained on one of the yarns supports 26, 27, torques exerted by the yarns 2, 2 on the respective supports 26, 27 are brought out of balance to rotate the yarn conductor 20 and release the remaining other yarn 2 from the support 27.