includes a controller 31 which generates a weft selection signal to control operation of the nip rollers 2a and 2b in accordance with preset pattern and a solenoid driver 32 which drives the solenoid for operation when a weft selection signal sa of for example level 34 h 34 is issued by the controller 31 the solenoid driver 32 urges the solenoid 8 to push up the lever 4a so that the selection rod 4 should move upwards then the nip roller 2b is brought into surface contact with the feed roller 3b so that weft insertion should be carried out by the main nozzle 7b when a weft selection signal sa of for example level 34 l 34 is issued by the controller 31 the solenoid driver 32 urges the solenoid 8 to pull down the lever 4a so that the selection rod 4 should move downwards the nip roller 2b is brought out of the surface contact with the feed roller 3b and conversely the nip roller 2a is brought into surface contact with the feed roller 3a so that weft insertion should now be taken over by the main nozzle 7a though not shown in the illustration the clampers 6a 6b and the main nozzles 7a and 7b are also selectively driven for operation by typical circuit control and operating means in response to the above described weft selection signal sa the weft exchange mechanism to be employed is not limited to the illustrated example the detection interceptor circuit 40 includes a preset counter 41 of for example a down type a one shot multivibrator 43 and an interlock setter 45 when the weft selection signal sa is put in the one shot multivibrator 43 detects rise and fall.