To prevent the end part of a weft from becoming longer and to prevent weft waste from arising in a large quantity by being provided with a clamp-opening device coupled with a driving motor through a lever mechanism and by electrically controlling the operation of the clamp-opening device for every weft.

An apparatus where the opening movement of a clamp-opening device 6 coupled with a driving motor 11 through a lever mechanism consisting of a driving lever 9 and a connecting rod 8 acting on the free end of the lever 9 is operated by the driving motor 11 comprising a program-controllable step motor or servomotor and a clamp lever 3 rotatably fastened to the body of a receiving gripper 2 through an shaft 5 is made to open and shut on the side of a shed outlet in a gripper loom is turnably and/or detachably fastened to the body of the loom with a supporting angle bar. The driving motor 11 is electrically driven for every weft to control the operating time of the clamp- opening device 6.