Apparatus for welding a strip of tape to film

An apparatus for welding a strip of tape to film comprising:

• means for feeding the film at a constant speed;
• first rollers disposed in spaced relationship and through which the film fed from said film feeding means passes;
• second rollers disposed above the first rollers at narrower spaces than the space between the first rollers and through which the film which is to pass through said first rollers and the film which has been passed through said first roller pass, said second rollers comprising four equally spaced rollers;
• four guide rollers disposed at a right and left of said second rollers;
• a roller differential mechanism for moving said second rollers in a first direction relative to said first and guide rollers at one quarter of said constant speed to temporarily reduce a speed of part of the film being fed continuously to zero and for moving said second rollers in a second direction opposite to said first direction relatively to said first and guide rollers at a high speed to temporarily increase a speed of part of the film being fed continuously to a speed higher than said constant speed;
• tape feeding means for feeding the tape to the part of the film which the speed is temporarily reduced to zero by said roller differential mechanism;
• means for cutting the tape being fed into a strip;
• and
• means for welding the tape cut into the strip to the part of the film of which the speed is temporarily reduced to zero.