To provide a device for automatically extending pieces of covering cloth and the like each having an opening on one side and throwing them into the following process for eliminating the need for preparation of the pieces of covering cloth and the like.

The device has at least one pair of extending clamps 21 and 22 which can move along a horizontal rail 20. The pieces 11 of covering cloth are oriented sideways with their openings 19 placed longitudinally or are oriented lengthways with their openings 19 placed downward. Their ends in the direction of the rail 20 are detachably held by the extending clamps 21 and 22. The pieces 11 of covering cloth can be extended in the direction of the rail 20 by moving the extending clamps 21 and 22 along the rail 20. Sandwiching the pieces 11 of covering cloth, a pressing member 36 is provided at the front of the pieces 11 of covering cloth and, on the other hand, a movable plate 37 which can move back and forth is provided behind the pieces 11 of covering cloth. The upper parts of the pieces 11 of covering cloth are pressed against the pressing member 36 by advancing the movable plate 37. While the pieces 11 of covering cloth are fixed, their openings 19 are shaken for correcting misalignment, creases or the like. The corrected pieces 11 of covering cloth are guided to the conveyer from their upper edges by moving the movable plate 37 backward.