fully described hereinafter secured to the support member 22 a threaded stem 62 extends upwardly from said support up to a level above the lever 40 a flat leaf spring 60 is secured by one end to the upper end of the stem 62 by means of two bolts 61 the said spring 60 extends substantially parallel to the lever 40 and is provided at its free end with a head piece 63 abuting against the upper surface of lever 40 to the free end of the lever 40 a downwardly projecting head member 64 is secured beneath the head member 64 a box 65 is secured to the extension 222 of the support 22 the said box 65 fig7 and 8 is provided with two opposed openings 66 coaxial one with the other and with the weft inserting needles 3 the said openings 66 opens into a chamber 67 formed in the box 65 and communicating with the exterior inside of said chamber a sliding block 68 is freely disposed extending with its upper end outwardly of box 65 into contact with the head 64 of lever 40 the said block 68 is provided at its lower side with two opposed slanting sides 168 confronting the openings 66 and cooperating with the needle points 103 for the purposes which will be described later on both sides of the support 22 there are provided two upright weft holding wings or arms 51 extending parallel to the warp threads in a forward direction toward the path of the weft inserting needles 3.