US 3336028 A
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Description (OCR text may contain errors)
Aug. 15, 1967 SCHONMEIER 3,336,028
APPARATUS FOR CONVEYING AND DEPOSITING SHEETS MOVING FROM CROSS HINES CUTTERS OR OTHER PAPER HANDLING MAC Filed July 12, 1965 United States Patent 3,336,028 APPARATUS FOR CONVEYING AND DEPOSITENG SHEETS MOVING FROM CRGSS CUTTERS OR OTHER PAPER HANDLING MACHINES Herbert Schonmeier, Dusseldorf-Benrath, Germany, assignor to Jagenberg-Werlte AG, Dusseldorf, Germany Filed July 12, 1965, Ser. No. 471,218 Claims priority, application Germany, July 30, 1964, J 26,303 7 Claims. (Cl. 27174) ABSTRACT OF THE DISCLUSURE An apparatus for conveying and depositing sheets of paper cut from a moving web in an overlapped relationship including a plurality of conveyor belts arranged in series and movable at stepwise reduced speeds. One of the conveyor belts is provided with an endless perforated surface and such belt passes over a roll having a perforated periphery. The roll is connected to a suction source and is adapted to apply suction to the rear end of a moving sheet. A control means is located within the roll in a limited circumferential zone for a timed suction effect.
A transfer table is positioned in advance of the roll and means are provided for directing compressed air from the forward end of the table in the direction of a sheet and for applying suction to a sheet at the rearward end of the table, respectively.
The present invention relates to an apparatus for conveying and depositing sheets moving from cross cutters or other paper handling machines and more particularly to an apparatus wherein, for the purpose of reducing the speed of movement and for simultaneously effecting an overlapping of the sheets, a plurality of conveyor belts arranged in series one behind another and operated at stepwise reduced speed is provided.
In German patent application No. I. 15,630, it is proposed to provide in the zone of a conveyor belt a suction braking means for initiating an overlapping of successive sheets or increasing an overlapping already initiated. The braking action is effected on that end of the sheet located rearwardly in the direction of movement and displaces such end out of the zone of travel of the forward end of the succeeding sheet. The effective upper side of the suction braking means is located somewhat lower than the preceding conveyor belt. In this arrangement, the confinement, so to speak, of the braking action to the rear end of the sheet is of special significance as there is caused a stretching of the sheet thereby avoiding wrinkling of the sheet.
At high operating speeds and particularly when processing thin papers it is essential if trouble is to be avoided to take steps for assuring that the suction braking is effected in a timed fashion dependent on the sheet sequence and upon the rearward ends of the sheets. In the German application mentioned, due to the required size of the suction braking means or box, a timed execution of a suction action occurring in a rapid sequence would meet diificulties. In a situation where the suction openings are closed and opened by mechanical means, the difficulties would be caused by the high timing sequence which necessitates a rapid back and forth movement of a covering component. Moreover, in the case of a control activated between the suction braking means and a suction producing device, other problems arise as the large volume of the suction braking means and conduits does not ensure the required rapid build up and drop of a vacuum.
To eliminate these difl'iculties, the present invention emice ploys, in lieu of stationary suction braking means or suction box, a rotatable roll or drum having perforations in its wall about which is guided a conveyor belt having perforations therein and within the roll is located control means operably coupled with vacuum producing means which control means in timed sequence and within a limited circumferential zone allows the suction to become effective.
More specifically, a rotatable conduit is arranged within the perforated roll and is provided with one or more slots disposed transversely to the direction of movement. A stationary conduit is located within the rotatable conduit and is formed with a slot positioned in the effective zone of the vacuum and the rotational speed of the rotatable conduit is so adjusted that the suction effect is only applied to the rearward end of a sheet.
In order to bridge the gap between the belt conveyor passing about the perforated roll and the preceding or belt conveyor immediately in advance thereof, a transfer table is located ahead of the perforated roll with respect to the direction of movement of the sheets and is so constructed that in its forward and rearward areas, pressure and vacuum, respectively, become operative with the vacuum be ing produced by the perforated roll. Furthermore, the upper side or surface of the transfer table is located slight ly beneath the uppermost point of the perforated roll and to improve the suction action on the upper flight of the belt conveyor moving about the perforated roll, the perforations of the conveyor are in the nature of elongated slots extending in the direction of travel of the belt and by virtue thereof the covering zone between the perforations of the roll and the slots of the conveyor belt is substantially augmented.
Further important objects and advantages of the invention will become more fully apparent to persons skilled in the art from the following detailed specification and drawings, in which drawings:
FIG. 1 is a diagrammatic view illustrating the conveying and depositing apparatus coupled in series with a cross cutter assembly,
FIG. 2 is a view in vertical cross section and on an enlarged scale of the suction braking means of the invention defined by a suction roll or drum, and
FIG. 3 is a fragmentary top plan view of the perforated conveyor belt passing about the suction roll.
Referring to FIG. 1, it will be noted that a paper web 1 emanating from a source of supply (not disclosed) is grasped and moved by feed rollers 2 towards a cross cutting assembly 3 constituted by upper and lower rotatable knives. Sheets 4 which are severed from the web by the cutting assembly 3 are moved over an immediate support 5 to the entrance area of upper and lower endless conveyor belts 6 and 7 which move at the same speed and receive the sheets between the lower flight of the conveyor 6 and the upper flight of the conveyor 7. It can be seen that the lower belt 7 is of lesser length than the belt 6 and a further conveyor belt 8 is located beyond the lower belt 7 with its upper flight 8a being disposed slightly below upper flight 7a of the belt 7. The conveyor belt 8 which moves at a lesser speed than the conveyor belts 6 and 7 is formed with a plurality of perforations 9 and, as best illustrated in FIG. 3, the perforations are in the form of elongated slots which extend in the direction of movement of the belt 8.
The belt 8 is trained about forward and rearward rolls or drums 10 and 19a, respectively. The forward roll 10 is provided with apertures 11 in the wall thereof (FIG. 2) for constituting a suction roll and is adapted to be connected to a vacuum producing means (not shown). A rotatable conduit 12 is mounted within the roll 10 and, as illustrated, the wall of the conduit 12 is formed with two substantially diametrically opposed slots 13 with the slots 13 extending in the direction of the rotational axis of the roll. A fixed or stationary conduit 14 is located within the rotatable conduit 12 and is provided with a slot 15 which extends in the direction of the rotational axis of the roll 10.
As perhaps best disclosed in FIG. 2, a transfer. table 16 is mounted in the hiatus between the exit end of the lower conveyor belt 7 and the entrance end of the conveyor belt 8. The upper side or surface of the table 16 is positioned slightly below the uppermost point of the roll or drum 11 and the end of the table facing the conveyor 7 is formed with one or more blast nozzles 17. The area or end of the table 16 adjacent the conveyor belt 8 is provided with a plurality of bores 18 which extend angularly in a direction toward the movement of the sheets.
While the operation of the present apparatus is believed readily apparent from the foregoing, it may be summarized as follows:
The vacuum constantly prevailing within the stationary conduit 14 becomes effective in a limited circumferential zone of the conveyor belt 8 when the slot 15 of the conduit 14 registers with one of the slots 13 of the rotatable conduit 12 with such zone extending from the rear of the transfer table 16 to the end of the embracernent of the roll 10 by the conveyor belt 8.
The rotational speed of the conduit 13 is so selected that the vacuum becomes operative in a timed sequence and only when the rearward end of a sheet 4 is located in the Zone of the transfer table 16 and the roll 10. As previously pointed out, since the speed of the belt 8 is less than that of the conveyor belt 7, the sheet 4-, due to the suction braking action imposed on the rearward end of the sheet, is caused to move with the lower speed of the belt 8. By reason of the foregoing, the following sheet which is moved forward by the higher speed of the belt 7 displaces itself over the preceding sheet in the direction of travel and, dependent upon the dilference in speeds respecting the conveyor belts 7 and 8, a greater or lesser overlapping of the sheets is accomplished.
In view of the fact that the uppermost point of the roll 10, the lower flight of the conveyor belt 8 and the upper surface of the table 16 are positioned beneath the conveying plane of the next succeeding sheet, the forward end of the succeeding sheet is prevented from contacting the rearward end of the preceding sheet. Moreover, in the forward zone of the transfer table 16 there is rendered effective a compressed fluid stream which is directed in a substantially upward direction for striking the lower face of the advancing sheet. The aforementioned fluid stream maintains the forward end of the sheet in the higher conveying plane until a substantial overlapping is achieved. With further advancing movement of the conveyor belt 8, the sheets thus overlapped are deposited via injection means into a stack holder 19.
The invention is not to be confined to any strict conformity to the showings in the drawings but changes or modifications may be made therein so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.
What is claimed is:
1. In an apparatus for conveying and depositing sheets of paper severed from a moving web in an overlapped relationship, a plurality of conveyor belts arranged in series and movable at stepwise reduced speeds, one of the conveyor belts being provided with an endless perforated surface, a roll having a perforated periphery about which said one conveyor belt moves, means for connecting said roll to a suction source for applying suction to the rear end of a moving sheet and control means located within said roll in a limited circumferential zone for a timed suction effect.
2. The apparatus as claimed in claim 1 wherein the control means includes a conduit rotatably mounted within the roll, said conduit having at least one slot disposed transversely to the direction of movement of said one conveyor belt, and a stationary conduit located within the rotatably mounted conduit provided with a slot disposed in the effective zone of the suction.
3. The apparatus as claimed in claim 2 in which the speed of the rotatably mounted conduit is so selected that a suction is applied only to the rear end of a sheet.
4. The apparatus as claimed in claim 1 including a transfer table having forward and rearward ends positioned in advance of the roll, means for directing compressed air from the forward end of the table in the direction of a sheet and means for applying suction to a sheet at the rearward end of the table.
5. The apparatus as claimed in claim 4, in which the means for applying suction at the rearward end of the table is effected by the roll.
6. The apparatus as claimed in claim 5 in which said transfer table is provided with an upper surface located slightly lower than the uppermost point of the roll.
7. The apparatus as claimed in claim 1 in which the perforations in said one conveyor belt are defined by elongated slots extending in the direction of movement of said one conveyor belt.
References Cited UNITED STATES PATENTS 2,065,178 12/1936 Federwitz et al. 271-74 X 3,178,174 4/1965 Schneider 27174 X M. HENSON WOOD, JR., Primary Examiner.
ALLEN N. KNOWLES, Examiner.