Patent GB-905251-A (GB)
Title: Improvements in or relating to apparatus for the production of envelopes or the like
IPC: B31B150/00
Filed: 1960-03-30
Abstract: 905,251. Feeding sheets. WINKLER, R., and DUNNEBIER, K. March 30, 1960 [Dec. 5, 1959], No. 11152/60. Class 100 (1). [Also in Group XVII] In machines for making envelopes, prior to the application of adhesive, the envelope blanks are stepped-out in overlapping relationship by means of a staggering wheel and staggering rollers, and by further pairs of rollers arranged intermediate the wheel and staggering rollers and rotating at a peripheral speed which lies between that of the wheel and staggering rollers. As shown in Fig. 1, an. envelope blank 7 is supplied from the machine to a suction staggering wheel 1 on each half revolution of the wheel, and is gripped and fed between pairs of opposed rollers 9, 15 at the moment when one of the sets of recesses 9<SP>1</SP>, 9<SP>11</SP> in the rollers 9 is opposite the rollers 15. The rollers 9, 15 are driven at the same angular speed as the wheel 1, and have a peripheral speed of about onefifth of that of the wheel, so that when the blank is gripped by the rollers its speed is reduced. The blank is fed by further pairs of rollers 27, 29 and 35, 37, which rotate at the same speed as the rollers 9, 15, to staggering rollers 47, 49 which are rotated at a peripheral speed which is adjustable and is considerably lower than that of the previous rollers. The second blank 7 fed by the wheel 1 arrives between the rollers 9, 15 when the second set of recesses in the rollers 9 is opposite the rollers 15, and is therefore fed under the first blank to overlap it; an air-blast assists this overlapping. The rollers 35, 37 are adjustable transversely of their axes so that they release the rear edge of each blank at the moment when the staggering rollers 47, 49 grip the leading edge thereof. The overlapping blanks are conveyed between belts 58, 59 to a gumming apparatus. All the rollers, with the exception of the rollers 15, are mounted for transverse adjustment on supporting shafts, but the rollers 15 are mounted on opposite sides of the wheel 1 in formed levers 17 which are transversely adjustable on pins 18, and are urged upwardly by springs 21. In the modification shown in Fig. 3, two partially-recessed rollers 79 are keyed to a shaft 78 mounted in levers 86 connected by a cross-bar 88, the levers being mounted for rotation about the shaft 74 of a suction staggering wheel 71. Each lever 86 has a gear segment 86<SP>1</SP> engaged by a handoperated gear-wheel 90, whereby the position of the rollers 79 can be adjusted around the wheel 71. The rollers 79 co-operate with rollers 100 in resiliently-urged forked levers 97 carried by levers 95 secured to the cross-bar 88. The rollers 79, 100 rotate once during a half rotation of the wheel 71. Two staggering rollers 103, driven at a much lower angular speed than the rollers 79 through a variable-speed gear, co-operate with spring-urged rollers 105. In operation, a blank 7 is taken by the suction wheel 71 on each half rotation thereof and fed between the rollers 79, 100 which, when projections on the rollers 79 grip the blank, slows it down. The second blank 7 is similarly fed between the rollers 79, 100 to overlap the first. The staggering rollers 103, 105 grip the leading edge of each blank when it is released by the rollers 79, 100, and convey the overlapping blanks between belts 116, 117. In another modification (Fig. 5, not shown), there are two suction staggering wheels arranged in sequence, the first gripping a blank on each half revolution to convey it to a pair of rollers which grip it at its leading edge at a greatly reduced speed. This results in a preliminary staggering of the blanks. The blanks are then conveyed by a suction disc and fixed arcuate guides to the second staggering wheel which feeds them between a second pair of staggering rollers, where the desired width of overlap is imparted to the blanks.