DE2357840A1 - METHOD AND DEVICE FOR CUTTING SHEET MATERIAL - Google Patents

Description

DB. BERG DI PL.- IN G. ST \ PF

DIPL.-ING. SCHWABS DR. DR, SANCHAIR 2357840

PATCH; Ai-; VY. \ LT £
8 MÖNCHEN 60 · MAU ERICiRCH ERSTR. 45

24 506 '

Lawyer File 2k 506 November 20, 1973

ILPQRD LIMITED, Ilford, .Essex, England

Method and apparatus for cutting sheet material

The invention relates to a method for cutting a movably guided web of material into individual sheets, which are then subject to further processing as well as a device for carrying out the method.

In known methods of this type, the material web is usually cut across. Is then at the so educated

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trailing edge of the severed sheet, another Processing required, the sheet must be advanced so that the trailing edge of the same from the to Cut off device used removed.

The invention provides a method in which a cut sheet is not used for further processing the cutting station needs to be moved.

In a method of cutting individual sheets of a movably guided, flexible material web with subsequent processing of the trailing edge of the cut Single sheet is provided according to the invention that the front edge of the movable material web to a ffestspanneinrichtung brought up and firmly ge tensioned that the Good web to form a single sheet of the flexible Gutbahnmaterial is cut across that the cut sheet in its central area a predetermined Curvature granted and the trailing edge of the same thereby parallel to the position in which it was cut off was held, so that it moves over a predetermined distance towards the leading edge moved, and that then the processing of the trailing edge of the cut sheet is carried out.

In order to give the cut sheet in its central area the predetermined curvature, this area can using compressed or suction air or by means of a mechanical device in one on one side of the

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The existing cavity can be deformed into it.

To achieve the curvature, the central region of the cut sheet is preferably attached to one with a recess provided, so concave die nestled. For this purpose, a convex stamp is preferably used, which has the same curvature as the recess in the die and thereby the central region of the sheet into the recess deformed into the die. The deformation can be caused by emerging from the punch in the direction of the die Compressed air or by negative pressure generated on the die.

The punch may be provided with a planar clamping rail, which clamps the cut sheet on a flat portion of the die to the trailing edge to hold flat and parallel to the position in which it was cut _s, after the punch the central region of the sheet has deformed into the recess of the die. In another embodiment, a separate clamping rail for plaguing the cut sheet is provided on a flat part of the die.

In the preferred embodiment, the die and the punch are covered with a protective material, for example nylon loop velvet. This reduces the risk of pressure points on the sheet.

One application for the method according to the invention is that Cutting of light-sensitive foil sheets with rounded

deten corners from a web of light-sensitive material. Examples of such film sheets are X-ray films, which preferably rounded corners received in order to prevent the envelopes receiving them from being pierced.

Accordingly, in another embodiment, the invention provides a method of trimming photosensitive ! "turn the page with rounded corners from a good web photosensitive material, it is provided that the front edge of the material web to a clamping device is brought up and tightened so that the corners at the front edge of the material web are removed, that the material web is cut across the central area of the cut sheet to form a single sheet given a predetermined curvature and its expiring Edge is kept parallel to the position in which it was cut so that it is aligned with the front Approximates the edge of the sheet by a predetermined amount, and that the corners at the trailing edge of the sheet are then removed.

The four corners of the pilm leaf are preferably removed by punching.

Particularly in this embodiment of the invention, the cut sheet is preferably given the predetermined curvature granted in that its central region is deformed into a concave die by means of a convex punch

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Preferably, the punch and the die each have a clamping rail for clamping the film sheet therebetween flat and parallel to the position in which the trailing edge was cut.

In this embodiment of the invention, the die are as well the stamp is preferably covered with a protective material, for example Ifylon loop velvet. One such Material does not curl and therefore can prevent pressure marks from forming on the photosensitive material.

For cutting individual leaves from a web made of light-sensitive material and rounded corners the cutting of the leaves and the rounding of the corners could also be carried out in one operation, whereby then, however, the web as well as a coating present on it could be seriously damaged. It is on the other hand, it is possible to round off the corners of sheets by making a strip running across the material path punch away to remove the corner on the trailing edge of a sheet. However, this is quite a waste, because the carrier material and the coating on it are quite expensive. When using the In contrast, according to the method according to the invention, the only waste arises from the trimming of the corners alone.

In a further embodiment, the invention provides a device for cutting off individual sheets of a flexible material path and for rounding off the corners of the sheets, with a die over which a material path is removed

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can be guided, with devices arranged on the die for clamping the front edge of the material web, with a Device for the cross-cutting of the material web, with a formed between the clamping device and the cutting device above or below the feed path of the material web Recess, with one of the recess arranged opposite with respect to the material web, on the recess aligned and one of these complementary shape having stamp, with devices for lowering the stamp into the recess and thus to deform the intermediate web of material to a predetermined curvature, with a clamping device for flat clamping of the cut part of the material web parallel to the previous one Cutting position, and with punching devices for rounding off the four corners of the cut sheet. Preferably are the recess of the die and the punch with a protective material, such as Fylon loop velvet, based. The apparatus preferably further includes a pair of powered transport rollers between which the Gutbahn is guided and which are used to To transport material web through the device and to exert a tensile stress on it.

An exemplary embodiment of the invention is described below with reference to the drawing. It shows:

1 shows a schematic oblique view of a device

for performing the method according to the invention and 2 shows a schematic representation of the individual steps of the method according to the invention.

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In Fig. 1 you can see a table or a die 1 with a clamping rail 2 arranged thereon for clamping the front edge of a material web V guided through the device. Both sides of the clamping rail 2 are Punch knives 3 »4- arranged. At the opposite end the die is a drop knife 5 for cutting off the web ¥ provided. Inward of the drop knife 5 are two punching knives 6 and 7 for rounding off the corners of the trailing edge Edge of a cut sheet arranged. The punching knives 3 »4-, 6, 7 sit on one of the clarity sake not shown support frame above the die. A die 3A, 4A, 6A is located below the punching knife or 7A, in which the respective punching knife lowers. Electromagnets 3B, 4-B, 6B and 7-B arranged above the same are used to actuate the punching knives. In the In the middle, the die 1 has a rounded recess 9 » which is followed by a level table 10. A stamp 11, the underside of which corresponds to the shape of the recess 9 Is convexly rounded, is arranged above the recess and aligned with this. The inner surface of the recess 9 »the underside of the stamp 11, the underside the clamping rail 2, the table 10 and the underside of a further clamping rails 12, all of which come into contact with the material web W, "are covered with a protective covering made of MyIon loop velvet Mistake. The further clamping rail 12 is above the flat table 10 of the die 1 on the (not shown) support frame. A pair of transport rollers 13 is mounted on a flat part of the die.

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When the device is in use, a material web W is passed under the drop knife 5, over the recess 9 the gap between the transport rollers 13 and passed under the clamping rail 2 and pushed forward so far, that the front edge on the back of the clamping rail comes to a standstill. The material web is then applied by means of the clamping rail 2 clamped in place and the punch knives 3 and 4- are actuated to make the corners on the front edge of the flexible Round off the straight track. Then the drop knife 5 is operated to cut the web of material across, so that you have a single Sheet receives. The punch 11 is then lowered in order to deform the cut sheet into the recess 9. This gives the sheet a predetermined curvature while its trailing edge is parallel to the position in which it was cut remains and is then clamped between the table 10 and the clamping rail 12. By the formation of the curvature in the cut sheet its trailing edge moves towards the leading edge by a certain amount. The punching knife can then use it 6 and 7 are actuated to round off the corners at the trailing edge of the sheet as well. In the end Then the punch 11 is raised again, the clamping devices are released and the transport rollers 13 are set in motion to discharge the finished sheet from the device.

Fig. 1 shows a separately arranged above the table 10 clamping rail 12. in another embodiment of the. invention

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a clamping rail protruding above the table can also be used be formed in one piece with the punch 11.

In Fig. 2, the four essential steps of the method are shown.

The first illustration (a) shows the clamping of the front edge of the movably guided material web V. The second illustration (b) shows the cutting of a single sheet from the material web.

The third illustration (c) shows the deformation of the central area of the cut sheet into a predetermined one Curvature. The trailing edge of the sheet moves towards the leading edge by a predetermined amount L, whereby it is parallel to the position in which it was initially has been cut, remains.

The fourth illustration (d) shows the machining of the leading edge of the sheet. If necessary, a processing the front edge of the sheet can be done at the same time.

Machining the leading edge of the sheet can also be done too take place at any other point in time after the step shown in the first illustration (a), for example between the in steps shown in Figures (a) and (b).

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Claims (1)

Claims ; 1.1 Procedure for cutting individual sheets from a +. * / movably guided, flexible material web with subsequent processing of the trailing edge of the cut. Single sheet, marked by the fact that the front edge of the movable material web to a clamping device is brought up and tightened that the material web to form a single sheet from the flexible GutbaiLnmaterial is cut across that the cut Sheet given a predetermined curvature in its central area and the trailing edge of the same while being held parallel to the position in which it was cut, so that it extends over a predetermined range Line moved towards the leading edge, and that then the processing of the trailing edge of the cut sheet is carried out. 2. The method according to claim 1, characterized in that the central region of the cut off Sheet of flexible Gutbahnmaterial the predetermined Curvature is given with the use of compressed air or suction air or by being given by means of a mechanical Device is deformed into an existing cavity on one side of the sheet. 3. The method according to claim 1 or 2, characterized g e k e η η draws that the central region of the sheet to achieve the predetermined curvature in a recess of a Die is deformed into it. 4 0 9822/0366 Λ. Method according to claim 3i, characterized in that the sheet is deformed into the middle part of the die by means of a convex punch which has a curvature complementary to the lOrm of the recess in the die. 5. The method according to claim 4, characterized in that an e "plane on the convex punch Clamping rail is provided, which serves to hold the cut off After deforming the sheet, clamp it into the recess of the die by means of the punch and its free end flat and parallel to the position in which it was cut, on a flat part of the To hold the die in place. 6. The method according to claim 4, characterized in that the cut sheet according to its Deformation by means of the punch into the recess of the die by means of a separate clamping rail clamped and with the free end level and parallel to the position in which it was cut on one flat part of the die is held. 7. The method according to at least one of claims M- to 6, characterized in that the convex punch and the recess of the die are coated with a protective material. 80 The method according to claim 7 »characterized in - g e k e η η draws, that the protective material is NyIon loop velvet. 409822/0366. 235784Q 9. A method for cutting photosensitive film sheets with rounded corners from a web of material light-sensitive material, characterized in that the front edge of the material web to a clamping device is brought up and clamped that the corners are removed at the front edge of the material web that the material web cut across to form a single sheet is that the central area of the cut sheet is given a predetermined curvature and its trailing Edge is kept parallel to the position in which it was cut so that it is aligned with the front Edge of the sheet by a predetermined amount approaches, and that then the corners on the trailing edge of the Sheet must be removed. 10. The method according to claim 9 _5, characterized in that the four corners of the film sheet are removed by punching. 11. The method according to claim 9 or 10, characterized in that the predetermined curvature in the central area of the cut sheet is achieved in that this is achieved by means of a convexly rounded one The stamp is deformed into a recess of a die having the same rounding. 12. The method according to claim 11, characterized in that the stamp and the recess the die are coated with a protective material. 409822/0366 ¹³ 23578AÖ 13. The method according to claim 12, characterized in that the protective material is SyIon loop velvet is. 14. Device for cutting off individual sheets from a flexible material web and for rounding the corners of the sheets, characterized by a die (1) over which a material path is fü hr bar, by means arranged on the die (2) for clamping the front ones Edge of the good web (¥), by a device (5) for transversely cutting the good web, through a recess (9) formed between the clamping device and the cutting device above or below the feed path of the good web »through one of the recess in relation to the good web oppositely arranged, aligned with the recess and having a complementary shape having this stamp (11), by means for lowering the stamp into the recess and thus for deforming the intermediate material web to a predetermined curvature, by a clamping device (12) for flat clamping of the cut part of the web parallel to the previous cutting position, and by punching means (3, 4-, 6, 7) for rounding the four corners of the cut sheet. 15 · Device according to claim 14, characterized in that the recess (9) of the die (1) as well as the stamp (11) are coated with a protective material. 409822/0366 _ 14 - 16. The apparatus of claim 14 or 15 »further characterized by a driven pair of transport rollers (13) 17- method of cutting individual sheets of a movable, guided, flexible material web with subsequent processing of the trailing edge of the individual cut sheets according to claim 1, essentially as described above. 18. Method for cutting photosensitive film sheets with rounded corners from a web of material of a light-sensitive material according to claim 9 »im essentially as described above. 19- device for cutting individual sheets of a flexible material web and for rounding off the corners of the sheets, essentially as above with reference to the drawing described. 409822/0366 Blank page