Abstract: An envelope machine which makes two envelopes at once. One web is used up to a relatively advanced point in the envelope forming process to simultaneously form two envelopes. At a terminal portion of the envelope processing, the web is cut lengthwise to form two envelopes. The device also includes improved structure for maintaining uniform the tension on the web. This need for uniform tension is made more prevalent by the thickness of the web which must be used to form two envelopes in parallel. The structure of the present invention which maintains uniform the thickness of the web is formed herein by a dancer roll which moves in a longitudinal fashion in cooperation with movement of other associated rolls. Whenever the dancer roll reaches one of its stopping points, it sets off a limit switch which operates a piston to change the type of moving being applied to the dancer rolls.

Abstract: An envelope machine which makes two envelopes at once. One web is used up to a relatively advanced point in the envelope forming process to simultaneously form two envelopes. At a terminal portion of the envelope processing, the web is cut lengthwise to form two envelopes. The device also includes improved structure for maintaining uniform the tension on the web. This need for uniform tension is made more prevalent by the thickness of the web which must be used to form two envelopes in parallel. The structure of the present invention which maintains uniform the thickness of the web is formed herein by a dancer roll which moves in a longitudinal fashion in cooperation with movement of other associated rolls. Whenever the dancer roll reaches one of its stopping points, it sets off a limit switch which operates a piston to change the type of moving being applied to the dancer roles.