warp threads 7b the area ab is an area of length a and width b and designates that zone of the lowlevel warp threads 7b over which the two gripper heads 3a 3d slide or fly during each weft yarn insertion at the latest towards the middle of the weave the two gripper heads 3a and 3d lie on the low level warp threads 7b and slide into one another whereupon the yarn 11 is taken over by the taker gripper head 3d and thereupon the two gripper heads 3a and 3d are pulled out of the shed by the insertion rapier tapes 9 sliding mainly on the warp threads 7b no guide elements are provided inside the shed for the gripper heads 3a and 3d so that the direction of insertion of the gripper heads 3a and 3d is determined mainly by the insertion rapier tapes 9 which are stiff in the direction of the cloth beat up the position of the area ab on the lower warp threads 7b is therefore determined mainly through the arrangement of the rapier tape drums 8 and insertion rapier tapes 9 and at least in the direction of the cloth beat up always remains approximately at the same place whereas the low level warp threads 7b move during the weaving process in the direction of beat up the width b of the region within which the gripper heads 3a and 3d slide or fly over the warp threads may also be greater than the effective width of a gripper head 3 since the insertion rapier tapes 9 are affected by play in the direction of beat up this play of the.