US3665796A

US3665796A - Apparatus for cutting a web of material

Info

Publication number: US3665796A
Application number: US83005A
Authority: US
Inventors: Horst Witte
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-09-10
Filing date: 1970-10-22
Publication date: 1972-05-30
Anticipated expiration: 1989-05-30
Also published as: JPS5011635B1; FR2102976A5; DE2044820C3; DE2044820A1; BE757875A; CA942181A; ES384835A1; NL7015142A; GB1322529A; SE353157B; ZA707204B; AT311787B; DE2044820B2

Abstract

This invention relates to an improvement in an apparatus for cutting a web of material, the apparatus including supply means for the web of material, a first feeding means for feeding the web to a cutting means, a cutting means, and a second feeding means behind the cutting means, and the improvement comprising movable guide means for the web positioned between the cutting means and the second feeding means, said first feeding means being stationary and said second feeding means being in operation during a cutting operation.

Description

United States Patent Witte [54] APPARATUS FOR CUTTING A WEB OF MATERIAL [72] Inventor: Horst Wltte, Wiesbaden-Biebrich, Germany [22] Filed: Oct. 22, 1970 21 App]. No.: 83,005

[30] Foreign Application Priority Data Sept. 10, 1970 Germany ..P 20 44 820.8

[52] US. Cl ..83/l56, 83/175, 83/424 [51] Int. Cl ..B26d 7/14 [58] Field ofSearch ..83/l10, 156,175,424

[56] References Cited UNITED STATES PATENTS 3,468,202 9/1969 Hollis ..83/l75 [451 May 30, 1972 3,542,267 11/1970 Ida ..83/l75X 3,587,376 6/1971 Hirano ..83/175X Primary Examiner-Andrew R. J uhasz Assistant Examiner-David R. Melton Attorney-James E. Bryan 57 ABSTRACT This invention relates to an improvement in an apparatus for cutting a web of material, the apparatus including supply means for the web of material, a first feeding means for feeding the web to a cutting means, a cutting means, and a second feeding means behind the cutting means, and the improvement comprising movable guide means for the web positioned between the cutting means and the second feeding means, said first feeding means being stationary and said second feeding means being in operation during a cutting operation.

4 Claims, 4 Drawing Figures Patented May 30, 1972 3,665,796

2 Sheets-Sheet 1 mv ENTOR HORST WITTE ATTOR N EY Patented May 30 1972 2 Sheets-Sheet 2 mvmwon HORST WIT TE ATTORNEY material, at least one feeding device for the web of material ahead of the cutting station, a cutting station, and a feeding device behind the cutting station.

The apparatus according to the invention may be used either as an independent apparatus or as a component of a copying apparatus. Irrespective of which particular copying process is employed, it is of advantage to use the copying material in a copying apparatus in the form of an endless web stored upon a magazine roll, from which a length determined by the size of the original to be copied is withdrawn and severed. Therefore, the apparatus according to the invention may be used in thermographic and electrophotographic apparatuses, and also in photoprinting machines. Copying machines in which several rolls of copying material are stored are of particular advantage, because, in this case, copying material may be selectively withdrawn from one of the rolls, depending upon the width of the original, and then severed. The apparatus according to the invention is particularly suitable for use in such machines.

Normally, the web of material should be fixed and tensioned during the cutting operation, in order to achieve a clean cut. From published German Pat. application No. 1,461,239 (DOS), for example, a device for cutting a web of material is known in which the web of material is held under tension between a clamp and a tightening-up roller at the time of cutting. v

In the case of automatic copying machines, such as photoprinting machines, this would mean that the feeding devices ahead of and behind the cutting station are stopped for the cutting operation. However, since it is of advantage to feed the copying material and the original at the same constant speed, so that they reach the exposure station simultaneously, in an overlying position, and pass it at the steady speed required for correct exposure, it would be more advantageous for the feeding device behind the cutting station to operate at a constant speed even during the cutting operation. On the other hand, it is normally necessary to switch off the feeding device ahead of the cutting station when a sufficient length of copying material, corresponding to the scanned length of the original, has been 'withdrawn from the magazine roll, to enable the cutting operation to be performed accurately and with as little trouble as possible. This means that during the cutting operation, the web of copying material would be between a stationary and an operating feeding device. As a consequence, higher tensions would be created in the web which would cause it to break.

Several attempts have been made to solve this problem. German utility Pat. No. 1,977,676, for example, describes a cutting device in which the feed speed behind the cutting station is lower than the feed speed ahead of the cutting station. ln this manner, a loop is formed in the web of material behind the cutting device when the web is withdrawn from the magazine roll. This loop enables the web of material to be severed between a stationary and an operating feeding device without creating tensions in it. However, this device is unsuitable for very long originals, because the loop would have to be correspondingly large and could be passed on only with difficulty. Therefore, an additional scanning device must be provided for this case, which responds to a particular size of the loop and initiates a re-adjustment of the feed speeds or temporarily disconnects the feeding device ahead of the cutting station. This device has the advantage that, due to the formation of a loop, no tensions occur in the web of material which may cause it to break, but, on the other hand, the feeding device must be temporarily arrested when long originals are to be copied. Moreover, the web of material is not so tight as is desirable for a clean and smooth cut.

The present invention provides a cutting apparatus which avoids the above-described drawbacks. The apparatus should be such that it cuts a tightened web of material, the front portion of which is continuously conveyed, whereas the trailing portion thereofis maintained stationary before and during the cutting operation, without breaking the web of material.

As a further embodiment of the invention, the cutting apparatus should be suitable for use in copying machines in which a web of material is selectively withdrawn from one of several magazine rolls.

The present invention deals with an apparatus for cutting a web of material which comprises at least one magazine roll for the web of material, at least one feeding device for the web of material ahead of the cutting station, a cutting station, and a feeding device behind the cutting station. In the apparatus, a movable guide means for the web of material ispositioned between the cutting station and the feeding device behind the cutting station and, during the cutting operation, the feeding device ahead of the cutting station is stationary, whereas the feeding device behind the cutting station is in operation;

The apparatus according to the invention is particularly suitable for cutting a web of paper. The web-like material is reeled upon a magazine roll from which it is withdrawn when desired and fed to the cutting device by means of a feeding device.

Several magazine rolls may be provided on which webs of material of different properties, for example, of different widths, may be stored. The material is selectively withdrawn from one of these rolls and conveyed to the cutting station by means of the feeding device connected with it.

After passing the cutting station, the web of material is conducted, by means of guide means, to a feeding device which transports it even during the cutting operation. The severed sheets may be subjected to a further treatment, for example, when the apparatus is a component of a copying machine.

The feeding devices may consist, in known manner, of endless conveyor belts, of pairs of rollers, or the like. The movable guide means behind the cutting station has the function of yielding when the web of material presses upon it and thus opening a shorter path for the web of material between the cutting station and the feeding device behind the cutting station. The guide means causes the web of material to be tightened during the cutting operation. On the other hand, it prevents the web of material from being tightened by a. jerk and break, when the feeding device ahead of the cutting station is stopped shortly before the cut, whereas the feeding device behind the cutting station continues its operation.

If the apparatus according to the'invention forms part of a photoprinting machine, for example, in which a web of material is selectively drawn from one of several magazine rolls,

of the web of material is slightly pulled back from the cutting 7 station after the cutting operation, because trouble may occur if the leading edge of this web of material is still at the cutting stationwhen another web of material is brought up. This is avoided by providing the guide means for the individual webs of material ahead of the cutting station with return springs. The portion of the web which, immediately before cutting, is situated between the stationary feeding device ahead of the cutting station and the operating feeding device behind the cutting station pushes the movable guide means up. By the weight of the movable guide means, the web of material is tightened and deforms the return springs. After the cutting operation, the web of material is without tension, the movable guide means is lowered, the return springs are lifted, and thereby pull the leading edge of the web of'material slightly back from the cutting station.

The cutting station preferably comprises a stationary lower blade and a movable upper blade clamped in a support. The cutting edge of the upper blade is roof-shaped when seen in the direction of feed of the material. Thus, it cuts the material from the outside to the inside.

In order to achieve a clean cut, the upper blade and the lower blade must be pressed upon each other within the cutting zone. Normally, the upper blade is several mm thick and is pressed against the lower blade by means of springs, for example. This arrangement is expensive, because it requires 'an accurate mounting and because damaged upper blades can be replaced only with difficulty. Consequently, a very thin upper blade of an elastic material in web form is used according to the invention. Preferably, it consists of a spring steel band of less than l mm thickness. Because of its easier production, the upper blade may comprise two individual halfblades the cutting edges of which are likewise arranged in a roof-like position to each other when seen in the direction of transport of the material.

The upper blade or blades are provided with a break over their entire length and thus are pressed over their entire length against the lower blade under tension. Whereas above the break the upper blade or upper blades form an angle of 90 or less with the lower blade, the angle below the break is slightly larger than 90. By this arrangement, a uniform pressure of the blades upon each other is achieved during the entire cutting operation.

In the'following, the invention will be described in detail with reference to one embodiment thereof in which the apparatus forms part of a photoprinting machine, taken in connection with the accompanying drawings,

In the drawings; I

FIG. 1 is a vertical section through the apparatus according to the invention, seen in the direction of the feed of the material,

FIG. 2 is a perspective view of the movable guide means,

FIG. 3 is a front elevation of the cutting station, without drive and lateral guide means, and

' FIG. 4 is an enlarged view of a cross-section along line A-B through the cutting station of FIG. 3.

The photoprinting paper is stored on two magazine rolls .1 and 2, the axle ends 3 of which are held in the mountings 4. The

paper webs

5 and 6 are withdrawn from the magazine rolls 1 and 2 by means of two pairs of draw-off rollers 7 and 8 and conveyed by means of two pairs of

feed rollers

9 and 10 through the guide plates 11 and 12 to the cutting station 13. Behind the cutting station 13, the web of paper selected, viz. either 5 or 6, is transported past a guide bar 14 and the movable guide means 15 to the pair of rollers 16. This pair of rollers 16 transports the web 5 or the web 6 between the guide plates 17 to the pair of inlet rollers 18 of the exposure station (not shown), the leading edge of the paper web 5 or the web 6 and the leading edge of the original 19 arriving in an overlying position at the inlet rollers 18.

Displaceable rollers

20 and 21, respectively, are positioned between the pair of draw-off rollers 7 and the pair of feed rollers 9, in one case, and the pair of draw-off rollers 8 and the pair of feed rollers 10, in the other case. The

displaceable rollers

20 and 21 can be shifted in their guides 22 and 23, respectively, to assume positions 20' and 21', respectively, so that a sufficient quantity of paper freed from the weight of the rollers is always available at the

feed rollers

9 or 10. The guide plates 11 and 12 are provided with return springs 24 and 25, which cause the leading edge of the

paper web

5 or 6 to be pulled back after the cutting operation.

The cutting station 13 consists of a stationary support for the lower blade 26, which carries the lower blade 27, and a movable support for the upper blade 28, which carries the upper blade 29.

The support 28 for the upper blade 29 is provided with guide bars 30 which are guided in guide rolls 31. The guide rolls 31 are attached to the side walls (not shown) of the housing. The guide bars 30 and the support 28 for the upper blade 29 connected with them are driven by an eccentric shaft 32. FIG. 3 shows the blades 27 and 29in the opened position. The upper blade 29 contains a break along the line 33. The upper blade 29 consists of two

blades

29 a and 29 b the cutting edges of which form a roof-like arrangement when seen in the direction of feed of the paper. Even in the open position of the cutting station 13, the two outer ends of the

blades

29a and 29b of the upper blade are pressed against the lower blade 27 with tension. In FIG. 4, the shape of the upper blade portion 29a is distinctly visible.

The movable guide means 15 consists of a curved guide plate 34 to which the

rods

35, 36a and 36b with the guide rolls 37 are attached. The web of paper is' conveyed along the curved guide plate 34. The guide plate 34 is movably mounted by the guide rollers 37 which slide in the guide rails 38, 39a and 38b. The rods 36a and 36b and the guide rails 39a and 39b connectedwith them are in a mirror-image relation to each other (see FIG. 2). The rod 35 and the. guide rail 38 are swiveied through with respect to the rods 36a and 36b and the guide rails 39a and 39b connected therewith (see FIG. 2).- By this arrangement, a lateral capsizing of the movable guide means 15 is avoided. The guide rails 38, 39a, and 39b are fastened to a fixedly mounted angle iron 40.

Beneath the hinged guide plate 41, a collecting trough 42 for waste paper is provided which is accessible from both ends of the apparatus.

An original 19 is fed into the apparatus from a location on the feed table 43 which is determined by its width, and is conveyed to the exposure station by means of the pairs of

feed rollers

44, 45, and 18. On its path, the original is conducted past scanners 46. Depending on which of the scanners 46 is contacted by the original 19, one of the two magazine rolls 1 or 2 is selected. The operation will be described in the following with reference to a case in which the magazine roll 1 is selected.

When the leading edge of the original 19 actuates the scanners 46, the pair offeed rollers 9 begins to rotate and feeds the web of paper 5 at a speed which corresponds to the feed speed of the original 19 through the opened cutting station 13 and between the movable guide means 15 and the guide plate 41 to the pair of rollers 16. This latter pair of rollers seize the leading edge of the paper web 5 and convey it further. At the pair of inlet rollers 18 of the exposure station, the paper web 5 meets with the original 19 in such a manner that the leading edges of both materials take an overlying position. From here, the materials are conveyed together to the exposure station.

Due to the rotation of the pair of feed rollers 9, the displaceableroller 20 is lifted in its guide rails until it maximally assumes position 20'. Thereby, it pushes the switch 47 into position 47', which causes the pair of draw-off rollers 7 to begin rotation. This pair of draw-off rollers 7 withdraw the web of paper 5 from the magazine roll 1 at a speed which exceeds that of the pair of feed rollers 9. Therefore, the displaceable roller 20 is lowered again and disconnects the pair of feed rollers 7. This procedure may be repeated several times, depending upon the length of the original used. A friction brake (not shown) positioned between the axle end 3 and the roll core 48, and the weight of the displaceable roller 20 prevent the formation of a loop in the paper web 5 when the pair of draw-off rollers 7 has been switched off.

When the trailing edge of the original 19 passes the scanners 46, the pair of feed rollers 9 are switched off. A brake (not shown) provided within the pair o f feed rollers 9 prevents the rollers from rolling on for an appreciable time after being switched off. After an adjustable delay which depends upon the copying speed the paper is cut. During this delay, the pair of rollers 16 lying behind the cutting station 13 continue their conveying operation. Thereby, the web of paper 5 is tightened and is pressed upon the movable guide means 15, thus causing it to be displaced within its

guide rails

38, 39a, and 39b in the direction of thearrow shown in FIG. 1. By the tightening of the paper web 5, the return springs 24 are deformed. By the guide bar 14, the web of paper 5 is maintained in a horizontal position in the neighborhood of the blades and near the lower blade 27. After the delay, the cutting operation is performed by a single revolution of the eccentric shaft 32. The guide bars 30 and the support 28 for the upper blade 29 firmly attached to them execute a lowering and lifting movement.

After the cutting operation, the movable guide means 15 returns to its original position. The return springs 24 are lifted and thus pull the leading edge of the paper web 5 slightly back from the cutting station 13. The cutting station 13 is thus made free, so that, in the following operation, paper web 6 may be conveyed to it without causing trouble.

It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. In an apparatus for cutting a web of material including supply means for at least one web of material, at least one first feeding means for feeding the web to a cutting means, a cutting means, and a second feeding means behind the cutting means, the improvement which comprises movable guide means for the web positioned between the cutting means and the second feeding means, said first feeding means being stationary and said second feeding means being in operation during a cutting operation.

2. An apparatus according to claim 1 including guide plate means ahead of the cutting means and being provided with return spring means, whereby the leading edge of the web of material can be retracted from the cutting means after the cutting operation.

3. An apparatus according to claim 1 in which the cutting means comprises a stationary lower blade, a movable upper blade having a roof-shaped cutting edge, and a support for the upper blade.

4. An apparatus according to claim 3 in which the upper blade is made in two parts from a resilient material and presses against the lower blade over its entire length by virtue of a break or corrugation in the upper blade.