Abstract: A loom is slowly operated in reverse rotation to move the loom to a position where a cutter is able to easily cut an improper weft when there occurs an error in the picking motion. Then, the loom is operated in normal rotation to move it to a position where the improper weft remaining in the shedding motion can be easily removed. A pick finding device is then operated to temporarily separate a main shaft and the shedding motion, and a harness frame is reversely rotated for 360.degree.. A new weft is then inserted after the improper weft is removed from the shedding motion. In the course of the operation, a cloth fell is held at a fixed position to protect the cloth fell from being beaten by a reed. The take-up motion is then operated in normal rotation, and at the same time the let-off motion is rotated in the reverse direction at a fixed rotational ratio to provide a warp with proper tension.

Abstract: In a weft detecting device, optical fiber bundles, lenses, a light emitting module, a light receiving module, and an amplifier are integrated in a thin detecting sensor body having substantially the same shape of that of reed dent so that the device can be fitted in the narrow space between the reed dents of an air jet loom.