d1 moreover a clamping cam 60 is mounted on the cam shaft 10 so as to rotate therewith with the peripheral edge of the clamping cam 60 a middle portion of a clamp lever 61 is contacted one end of the clamp lever 61 is pivotally supported with an axis member not shown and the other end thereof is connected with a clamp equalizer bar 62 the other end of the clamp lever 61 is adapted to be swung about the one end thereof according to the rotation of the clamping cam 60 so as to move the clamp equalizer bar 62 along to the feeding direction d1 the lift drive unit 7 has a lift member 7a which is mechanically connected with the transfer bars 5 to and has a lift drive mechanism 7b mechanically connected with the lift member 7a and the lift equalizer bar 22 the lift drive mechanism 7b is adapted to produce a lift driving power by using the movement of the lift equalizer bar 22 whereby to move the lift member 7a along to the lifting direction d2 so that the transfer bars 5 moves along to the lifting direction d2 with the lift member 7a the clamp drive unit 8 has a clamp member 8a which is mechanically connected with the transfer bars 5 and has a clamp drive mechanism 8b mechanically connected with the clamp member 8a and the clamp equalizer bar 62 the clamp drive mechanism 8b is adapted to produce a clamp driving power by using the movement of the.