Abstract: An envelope blank is conveyed through a folding mechanism that folds one or more flaps of the blank. In folding a side flap the leading edge of the blank adjacent to the score line follows in a helical path a convex face of a plowshare. The plowshare face applies at the leading edge of the blank adjacent to the score line a force which bends the side flap through an angle of 180° to a position where the flap is folded to overlap the blank. The folding of the flap is initiated by the convex face of the plowshare so that the flap folding forces are applied to the score line where the flap has the least resistance to bending. The folding forces are removed from the flap free edge which is supported to follow the movement of the flap leading edge.

Abstract: A series of overlapping envelope blanks are fed into contact with a pull-out roll which engages and accelerates the first blank to separate it from the remaining blanks. From the pull-out roll, the separated blank is fed onto the surface of a rotary aligning wheel. A plurality of aligning pins extend from the surface of the wheel and are positioned in spaced relation around the wheel. The separated blank is fed into contact with the aligning pins forcing the blank with its trailing edge engaged with the pull-out segment to maintain the separated blank aligned on the surface of the wheel. Vacuum ports are positioned on the surface of the wheel adjacent to the aligning pins. The negative pressure from the vacuum ports secures the sheet to the surface of the wheel as the sheet is aligned into a preselected position on the wheel by contact with the pins.

Abstract: A leading edge of a leading blank in a series of overlapping envelope blanks is fed at a preselected speed into contact with a rotatably mounted backing roller. The backing roller is mounted in a frame and is selectively adjustable between a first position and a second position. A rotatably mounted segment roller is positioned opposite the backing roller. A pull-out segment is a secured to a radial portion of the backing roller. A plurality of longitudinal slots are provided in the surface of the pull-out segment and are selectively connected to a source of negative pressure. The segment roller is driven at a preselected speed greater than the speed of the series of overlapping blank. In a first mode of operation, the backing roller is adjusted to a first position in the frame so that upon rotation, the pull-out segment frictionally engages the leading edge of the leading blank, separating it from the series of overlapping blanks.

Abstract: A continuous web of sheet material is fed through the lip of a first pair of driven pull rolls around a series of idler rollers and through the nip of a second pair of driven pull rolls. The pairs of pull rolls are selectively rotated to exert a desired tension on the web in a tension zone formed between the pairs of rolls. One pair of pull rolls operates as feed rolls to advance a preselected length of the web to a rotating cutter mechanism so that envelope blanks of a selected length are cut from the web for each revolution of the cutter mechanism. The feed rolls are operated by a servo-controlled motor responsive to an operator initiated signal to adjust the feed length without interrupting the feed of the web to the cutter mechanism. The second pair of pull rolls operates as tension rolls and is servo-motor controlled to maintain a preselected tension on the web fed to the cutter mechanism.

Abstract: An envelope blank is conveyed by a transport system in an envelope making machine to a folding mechanism that folds one or more flaps of the blank. In folding a side flap, the leading edge of the blank adjacent to the score line is conveyed along a convex face of a plowshare. The plowshare face applies at the leading edge of the blank adjacent to the score line a force which bends the side flap through an angle of 180.degree. to a position where the flap is folded to overlap the blank. A crease is formed on the score line to permanently set the flap on the blank. The folding of the flap is initiated by the convex face of the plowshare. Extending from the upper edge of the plowshare face is a grid-like network of flexible rods mounted to follow the helical path of the plowshare face. The free edge portion of the flap is supported by the grid to follow the flap leading edge being folded by the plowshare.

Abstract: A stack of sheets or blanks for feeding one by one from the bottom of the stack by a feeding mechanism is supported for high speed feeding to subsequent stations. A feed cylinder rotatably supported beneath the leading edge of the stack includes a suction device. An intermediate portion of the blank leading edge is drawn by the suction device downwardly toward an opening in the periphery of the feed cylinder. Continued rotation of the feed cylinder further bends the blank. For blanks of large size and having a leading edge with an irregular contour the blank leading edge intermediate portion extends forwardly from edge lateral portions. Positioned in spaced relation along the interior of the feed cylinder are a plurality of air manifolds having outlets directed at selected angles upon the lateral portions of the blank leading edge. The manifolds are connected to a source of pressurized air which is directed in a sweeping motion upon the blank leading edge lateral portions upon rotation of the feed cylinder.

Abstract: A continuous web of sheet material is fed through the nip of a first pair of driven pull rolls around a series of idler rollers and through the nip of a second pair of driven pull rolls. The pairs of pull rolls are selectively rotated to exert a desired tension on the web in a tension zone formed between the pairs of rolls. One pair of pull rolls operates as feed rolls to advance a preselected length of the web to a rotating cutter mechanism so that envelope blanks of a selected length are cut from the web for each revolution of the cutter mechanism. The feed rolls are operated by a servo-controlled motor responsive to an operator initiated signal to adjust the feed length without interrupting the feed of the web to the cutter mechanism. The second pair of pull rolls operates as tension rolls and is servo-motor controlled to maintain a preselected tension on the web fed to the cutter mechanism.

Abstract: A pair of pull rolls unwind web material from a roll and advance the web at a preselected linear feed rate to a web cutting mechanism. The pull rolls are rotated at a preselected speed to generate the desired linear speed rate for cutting the web at selected intervals to produce blanks of a preselected length. The feed rolls are driven by a servo-motor which is operated by a controller that is microprocessor controlled. The controller is electrically connected to an encoder that is drivingly connected to a rotating knife cylinder of the web cutting mechanism. A selected length of blank to be cut from the web is inputted by the operator through a keypad to transmit a corresponding signal to the controller. In addition, the controller receives a signal from the servo-motor that drives the pull rolls, which signal is representative of the rate of rotation of the pull rolls.