JPH07500536A - Method and apparatus for producing rounded corners at each corner of a stack of sheets - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for producing rounded corners at each corner of a stack of sheets; It is particularly suitable for products such as X-ray film.

The invention further relates to a device capable of carrying out the method of the invention.

Sheets such as X-ray film or card materials such as cash withdrawal cards are round It is known that the edges must have rounded corners.

According to the first known technique, such rounded corners are initially a notch in the edge of the lip with the shape of a rounded corner common to two adjacent sheets and then cutting this strip in the middle of said notch. Served. The problem with this technique is to position the cutting device correctly relative to the center of the cut. The problem lies in the difficulty of doing so. In fact, even the slightest error in the positioning of the cutting device incomplete rounded corners on one sheet and unnecessary strips on the other sheet edge. will occur.

Other known techniques include the process of locating and creating rounded corners on cut sheets need to stop. This technology is of course disadvantageous from a productivity standpoint. .

Additionally, there are other devices such as line rotators, which vary from one type to another. A major problem is that the operations required to convert the expression into an expression are complex.

Figure 1 referred to herein shows an apparatus capable of rounding the corners of a stack of sheets. Other known formats are shown.

The illustrated device mainly comprises an inclined plane l on which the sheets 2 are arranged, facing each other. Two reference surfaces 3.4 which are perpendicular to each other are provided on the inclined plane 1, and on this reference surface The sheets are then placed under the action of gravity. Advantageously, vibrations are not applied to the reference surface. This allows for better positioning of the sheet relative to the two reference surfaces 3.4. Ru. These reference surfaces are spaced apart from the bottom corner of the inclined plane 1 by 3° between said two reference surfaces. a cutting tool can be placed between the four corners, said cutting tool cutting the desired shape of the round corner In the illustrated example, the cutting device 5 is adapted to produce an arrow pointing in two directions. Equipped with a curved blade movable to reciprocate in the direction shown diagrammatically by mark 6. It is equipped. The rounded corners of each corner of the laminate can be connected by manually moving the laminate. produced continuously.

The main problem with such devices is the positioning of the sheet relative to the reference surface. . The apparatus shown in Figure 1 is such that the sheets of the laminate are initially relatively well aligned and therefore The length of each sheet that protrudes beyond the normal aligned edges of the laminate is sloped sufficiently small. The sheet can withstand the force applied in the axial direction to the surface of the plane l without deforming. It operates satisfactorily when

Such a method allows the sheets to be relatively stiff and initially aligned relatively well. It is clear that this is limited to applications where the friction between the surfaces is sufficiently small. Made of X-ray In addition to these restrictions, in the production of photographic film such as The photosensitive layer on the product has a reference surface 3. due to forces arising from abrasion, especially contact, between the sheets. The fact is that damage occurs due to wear on the edges that contact 4. Therefore One of the objects of the present invention is to ensure that each corner of the stack of sheets has a 1 of creating rounded corners without damaging the sheet when positioned. The goal is to provide a way to make it possible.

Another object of the invention is to provide an apparatus capable of carrying out the method of the invention. It is.

Yet another object of the invention is to create rounded corners at the four corners of the stack of sheets. , at least one dimension (length and/or radius) of this corner in one of the stacks. To provide a method and apparatus that allows changing from one sheet to another. That's true.

These objectives are achieved by four cutting devices arranged at the four corners of a substantially rectangular surface. and applying the stack of sheets to a cutting device to cut at least one of said substantially rectangular surfaces. A component defining two reference surfaces at right angles to each other at one corner. by a device having suitable means for correct positioning so as to be in contact with the , which creates rounded corners at the four corners of a stack of sheets of substantially the same size. achieved by law. The method includes the following steps.

(a) Inject air between the sheets in the laminate to inject air between the sheets in the laminate forming a lubricating fluid film.

(b) at least one corner of said substantially rectangular surface comprising two reference surfaces; placing at least one corner of the laminate against the two reference surfaces;

(c) Activate the four cutting devices to create the desired rounded corners in each of the four corners.

According to another embodiment of the invention, from one sheet to another in a stack of sheets, one dimension (length or width) that varies from one dimension to the other dimension within said laminate. the four corners of a stack of sheets that are substantially constant for all sheets of a method of creating pairs of rounded corners on a surface, arranged at four corners of a substantially rectangular surface. Four cutting devices are installed, and the sheet is moved relative to the cutting device. shaped at one corner of each of the ends of said substantially rectangular surface along a dimensional axis; suitable for precise positioning on two mutually perpendicular reference surfaces A method performed by an apparatus comprising means is provided. This method is the next step Contains.

(a) injecting air between the sheets in the stack to create a lubricating fluid between the sheets; form a film.

(b) the first end of the laminate abuts the two reference surfaces of the first end of the substantially rectangular surface; Place the corner of 1.

(d) a laminate abutting two reference surfaces at a second end of said substantially rectangular surface; Place the second corner of the

(e) actuating the cutting device simultaneously at each corner of the second end of the substantially rectangular surface; let

According to yet another embodiment of the method of the invention, four corners of a substantially rectangular surface four cutting devices disposed in Continuously touching two mutually perpendicular reference surfaces provided at each corner of a generally rectangular surface. The rounded corners of the sheet are The four corners of the laminate are produced in succession, and the method continues with the following steps, namely: (a) Injecting air between the sheets in the laminate to inject air between the sheets in the laminate (b) forming said stack of sheets at right angles to each other; moving in two directions and pressing a first corner of the laminate against two corresponding reference surfaces; To go.

(c) actuating a cutting device corresponding to the corner to produce the desired rounded corner;

(d) Repeat steps (b) and (C) above for the other three corners.

The above steps (a) to (d) are included.

The method of the invention makes it possible to create rounded corners of the desired shape and substantially four cutting devices arranged at four corners of a generally rectangular surface; and suitable means for correctly positioning said sheets. A device that makes it possible to create rounded corners on the four corners of the body wherein the positioning means comprises: (a) directing air over substantially the entire height of at least one edge of the laminate; means for injecting air between the sheets in the laminate; (b) two mutually perpendicular groups at at least one corner of said substantially rectangular surface; a component forming a stopper arranged to define a quasi-surface; (c) a translatably movable part of the laminate (facing both sides and substantially directly aligned therewith); two reference surfaces disposed at corners of at least one corner of said substantially rectangular surface; a component operative to position at least one corner of the laminate in contact with the It is characterized by the fact that it is equipped with

According to another embodiment of the device, the sheets in the stack have one dimension (length or width) varies from one sheet of the laminate to the other, while the other dimension varies from one sheet of the laminate to the other. substantially the same for all sheets in the body, and said stop means two bases in one corner of each end of the laminate along the varying dimensional axis of the sheet; A movable component arranged to form a quasi-surface covers at least three of the laminates. facing and substantially perpendicular to two sides and referenced to two corners of the laminate; mutually relative to two reference surfaces corresponding to the corners of a substantially rectangular surface with surfaces. It is designed to operate by continuously pressing in two directions perpendicular to .

According to yet another embodiment, said stop means are arranged on said substantially rectangular surface. The movable components are arranged to form two reference surfaces at each corner of the stack. facing and substantially perpendicular to the four sides of the body and facing each corner of the laminate. two reference tables of corresponding corners of said substantially rectangular surface in two directions perpendicular to each other; It operates by continuously pressing against the surface.

In the following detailed description, reference is made to the drawings.

FIG. 1 shows a known device for producing rounded corners at the four corners of a stack of sheets.

FIG.

FIG. 4 shows a second embodiment of the invention.

FIG. 5 shows yet another embodiment of the device of the invention.

FIG. 6 shows a modification of the embodiment of FIG.

FIG. 7 diagrammatically shows the steps of the method carried out by the apparatus of FIG.

Reference is now made to FIG. 2, which shows a first embodiment of the apparatus of the present invention. this Embodiments are particularly adapted to stacks of sheets having substantially the same dimensions (width and length). , so that four rounded corners can be created simultaneously after a single positioning operation. Make it.

This device is equipped with four cutting devices (for clarity, one of these devices is (only one shown), these cutting devices cut into four corners of a substantially rectangular surface. and the dimensions (length and width) of this rectangle are at least equal to each maximum dimension of the sheet. It's getting better. The cutting device may be - for example, of the bunch/punching type; According to the embodiment shown, the punch is controlled by a pneumatic jack. A pressing means 51 is provided to press the corresponding corner of the laminate 52 and press the sheet in the laminate. the corresponding rounded corner cut. child Such cutting devices are well known in the art and therefore no further description is required. do not need.

The apparatus of the invention also includes a support 5 adapted to receive said stack of sheets. It is equipped with 3. In a preferred embodiment, this support is provided by suitable means 54. produced by a top portion of at least one tubular chamber connected to a source of compressed air; The surface of the plane is divided into sections.

Each chamber is disposed on its top surface and distributed over substantially the entire surface of the laminate. It has multiple holes. Such an arrangement allows air to be injected through the holes. When applied, a film of fluid is formed between the laminate 52 and the support 53, thereby As described in more detail below, the sliding of the laminate relative to the reference surface was This makes positioning easier. The apparatus shown in FIG. two reference surfaces mutually perpendicular to at least one corner of the substantially rectangular surface; A component forming a stopper 55, 56, 57 arranged to define a section. According to the embodiment shown, these two reference surfaces are comprised of three stacks. It is divided into sections by pillars.

Two of these studs 55, 56 are located on said substantially rectangular surface. arranged in one corner (one stud 55 is partially located behind the pressing device 51). (hidden), one stud on each face of the laminate defining the corresponding corner. are placed facing each other. A third stud 57 also defines the corner. placed facing one of the faces of the layer and interacting with the other two studs to The two abutment surfaces are defined at right angles to each other. with the third stud The greater the distance between the first two studs, the greater the distance between these sheets and the studs. It is clear that the positioning is more accurate.

The third stud 57 is connected to the first two stands in the embodiment shown in FIG. is located near a corner that is close to a corner that has a

All of these studs and all of the devices described below constituting the positioning means. is at a distance from each of the corners at least equal to the radius of the rounded corner being created. It is clear that the cutting tool must be able to pass through. That's it. The apparatus further includes at least one substantially opposite edge of the stack of sheets. Means 55, 56, 57 are provided for directing compressed air over the entire height.

A possible structure for such means is a manifold. As an illustration, this means It is arranged facing one of the faces of the laminate and substantially in the center of said face. Other examples According to located substantially in the center of the corresponding surface. In the embodiment shown in FIG. These means for ejecting air also perform the above-mentioned stopper action and Closed at both ends and connected to a source of air (not shown), as shown in more detail in Figure 3. This is a type of nozzle 60 consisting of connected cylindrical bodies. The cylindrical body is substantially A pinch groove 6 through which a jet of air can be distributed over the entire height of the laminate. 1. Preferentially, said narrow groove 61 is located in the part facing the top part of the laminate. The area facing the bottom of the laminate is wider than the area facing the bottom of the laminate. laminate due to the difference in force applied to the top sheet compared to the bottom sheet. The thickness of the lubricating fluid film formed between each of the sheets within the total height of the laminate Make sure it is uniform throughout. Of course, the number of nozzles used will depend on their location and Obviously, it depends on the size of the sheet and the height of the stack. As shown in Figure 2 In the embodiment shown, three nozzles 55, 56, 57 are used and the compressed air is The air is preferably first dried and filtered. I already mentioned In other words, these three nozzles also define two reference surfaces as described above. It is arranged.

The apparatus of the present invention also has a structure that faces at least two sides of the laminate 52 and that substantially faces the sides of the laminate 52. At least one corner A of the laminate is arranged perpendicularly to the side surface and is aligned with the above two criteria. Translationally movable component 58.5 operative to position against a surface It has 9. In Figure 2, a pneumatic jack is placed on the two reference surfaces above. They are disposed facing each of the surfaces of the laminate opposite to the facing surfaces. Such a transfer The location and number of movable devices also depend on the size of the seat. According to the example, two During operation, jacks are provided facing each of said surfaces, the support and sides of the laminate are Nozzles 55, 56, 57 are supplied with compressed air and lubricating fluid film to lubricate the laminate. The two pneumatic jacks 58 and 59 separate each seat inside the seat. is actuated to position one of the corners A of the laminate against two perpendicular reference surfaces. and finally the cutting device is actuated at each of the four corners. Preferably four The cutting devices are activated simultaneously. Such an arrangement structure is used to form sheets that form a laminate. are particularly suitable when the four corners have substantially the same width and the same length, and the four corners have substantially the same width and the same length. Perfect positioning occurs when one of the corners touches two reference surfaces. and have substantially the same width and length as permitted by the location and size of the rounded corners. resulting in differences between the sheets in any one laminate that do not exceed the tolerances specified. .

In FIG. 4 referred to here, one dimension (length or width indicated by axis X) is varies from one sheet to another within the stack, and the dimensions of the other vary within the stack. The present invention is particularly suitable for stacks of sheets that are substantially identical for all sheets of shows another embodiment of. According to this embodiment stop means 12.13. 14.15 are provided in pairs and stacked along the axis X of the varying dimensions of said sheet. Two reference surfaces are formed at corners A and D at each end of the layer.

Shape the stop 12.13.14.15 as in the previous embodiment. The means for producing the compressed air preferably comprises a nozzle connected to a source of compressed air, In addition to the stopper action, there is also a It is designed to eject air.

In the embodiment shown in FIG. 4, the two pairs of reference surfaces are said substantially rectangular surfaces. are formed at two adjacent corners A and D of. According to another embodiment, two pairs of criteria The surfaces are two opposing corners A of the laminate.

C, each of the pairs of reference surfaces having at least three abutment points as described above. Therefore, it is formed.

The device further includes a laminate facing at least three sides of the laminate and substantially facing the sides of the laminate. are arranged at right angles and have two corners of the stack relative to each pair of corresponding reference surfaces. A movable arrangement that operates in pairs to press in succession in two directions at right angles to each other. It comprises elements 16.17.18.

When the paired reference surfaces are arranged at two opposite corners of a substantially rectangular surface, Components that move in a forward motion shall be provided facing each face of the stack of sheets. It is clear that there is no such thing. Similar to the previously described embodiment, this movable configuration Elements 16.17.18 consist of pneumatic jacks and are in contact with the seat. The end of the lug is provided with a pad 1 made of a suitable flexible material such as silicone. 9 is provided so as not to damage the edge of the sheet when the jack presses the sheet. The embodiment shown can be configured such that three of the faces of the bundle of sheets a single pneumatic jack located substantially in the center of the Especially the size of the seat It is clear that a number of jacks can be provided on each surface depending on the size. Ru.

Each step of the method carried out by the apparatus shown in FIG. Starting from the case along the axis shown diagrammatically by the mark X, the The nozzle forming the stopper 12.13° 14, 15 is also suitable when the machine is operated. If available, the chambers forming the support of the laminate are provided with a lubricating film between each of the sheets. Corner A of the laminate is provided to form a pneumatic jack 17.18. Place it against the stopper 12.14.15 by moving it towards the corresponding surface of the body. Then, the cutting devices at corners A and B are activated simultaneously, and the corner edges are moved by pneumatic jack 1. Stopper 12.13.1 by moving 6.17 towards the corresponding surface of the laminate. 4 and finally the cutting devices at corners C and D are activated simultaneously. .

Figure 5 referred to here shows both dimensions (length and width) of one sheet in the laminate. Other implementations of the invention are particularly suitable for stacks of sheets varying from one sheet to another. Indicates the mode. According to this embodiment, the stop means 46.47.48.49.7 0.71.72.73 is a substantially rectangular section defined by four cutting devices are provided in pairs at each of the four corners of the surface. This also forms a stop Preferably, at least some of the means for between the sheets in said laminate in addition to the stopper action. to allow air to be injected. According to another embodiment, the stopper is The means for forming is separate from the means capable of blowing air between the sheets. . The components movable in translation are arranged so as to face each side of the laminate. such that each corner of is successively placed against two corresponding reference surfaces. As shown in Figure 5. According to an embodiment, the two sides of the laminate have movable components (one of which is 4 5 is hidden by the cutting device shown), and the two other parts of the laminate The surface of the sheet is a single movable structure disposed substantially centrally on the corresponding surface of the stack of sheets. facing the components.

In FIG. 6 showing a modification of the embodiment of FIG. 5, structural elements movable in translation are shown. Elements 21-28 are located near the components forming the stopper (in each of the four corners of the device). They are arranged in pairs. Advantageously, fewer of the components forming the stop In addition to blowing air between the sheets, some components move in translation. This makes it possible to eliminate the need for auxiliary moving means.

During operation of this embodiment, these eight components intended for this purpose may After compressed air has been supplied to the chamber forming the support of this device, if available, the transfer The movable components 22, 23, and 25 are actuated to form two reference surfaces in the first corner. abut against the components forming the stoppers X, Y and Z which are partitioned at right angles to each other. Place the laminate. A cutting device corresponding to the first corner is actuated.

This same operation is repeated successively for the other three corners of the stack.

These different stages are illustrated more clearly in Figure 7, where the symbol 2 represents the cutting device to be operated for each step of the process.

In all the above descriptions, certain configurations, such as the laminate support and the cutting device, are mentioned. The elements are common to all embodiments and therefore for each of the above embodiments. The system is not even listed.

The sheet has at least one of its dimensions from one sheet to another in the laminate. In all of the above embodiments varying from The ends of the components are provided with suitable means to accommodate dimensional variations. Illustration For relatively small fluctuations (on the order of 2-0), the thickness is Polyurethane foam matching the dimensional variations is placed at the ends of the movable components. will be placed. For larger differences between sheets, the density and length of their bristles are The movable configuration of the nylon brush depends on the sheet thickness and dimensional differences. Can be placed at the end of the element. Assemble with a lubricating fluid film between each of the sheets. The combined effect of the above means is to compensate for dimensional variations of 20- or more. be able to do so.

Special Table Sen7-500536 (7) EP　9202429 S^　66205

Claims (20)

[Claims] 1. Allows to create rounded corners of the desired shape and virtually rectangular tables Four cutting devices (50) disposed at the four corners of the surface and a seam attached to the cutting devices. a stack of sheets (52) comprising suitable means for correctly positioning the sheet; In an apparatus for creating rounded corners at four corners, the positioning means (a) directing air over substantially the entire height of at least one edge of said laminate; means (55, 56, 57) for injecting air between the sheets in the (b) two mutually perpendicular groups at at least one corner of said substantially rectangular surface; Components (55, 56) forming a stopper arranged to define a quasi-surface , 57); and (c) facing and substantially perpendicular to at least two sides of the laminate. and defining at least one corner of the laminate as a small portion of the substantially rectangular surface. a translational movement actuated to position at least one corner tangent to two reference surfaces; Components (58, 59) that move with A device that creates rounded corners at the four corners of a laminate. 2. Said sheet has one of its dimensions (length or width) in one of the stacks. varies from one sheet to another, and the other dimension is constant for all sheets in the stack. and the stopper means (12, 13, 14, 15) are substantially the same as the stopper means (12, 13, 14, 15). In one corner of each end of the laminate along the axis of varying dimensions of the sheet (X) movable components (16, 17, 18) arranged to form a reference surface; facing and substantially perpendicular to at least three sides of the laminate; The two corners (A, D) of the laminate formed by forming the substantially rectangular surface constituting the reference surface Continuously press in mutually perpendicular directions against two reference surfaces corresponding to the corners of 2. A device according to claim 1, characterized in that it operates as follows. 3. The stopper means (46, 47, 48, 49, 70, 71, 72, 73) disposed and moved to form two reference surfaces at each corner of said substantially rectangular surface; Movable components (40-45) face and perpendicular to the four sides of the laminate. and each corner of the laminate is connected to two bases of corresponding corners of said substantially rectangular surface. It acts to press the quasi-surface continuously in two mutually perpendicular directions. An apparatus according to claim 1, characterized in that: 4. The sheet dimensions vary from one sheet to another in both length and width. 4. The device according to claim 3, characterized in that: 5. The components forming the stops are located at four corners of the substantially rectangular surface. each of the pins (46, 49; 70, 73) arranged in pairs, and The four corners of the laminate can be moved in translation by two bases corresponding to each of the four corners. It is arranged and acts so as to press continuously against the quasi-surface in two mutually perpendicular directions. comprising at least six components (40-45) of four edges of the laminate; each facing at least one component moving in translation The device according to claim 3 or 4. 6. The positioning means moves in translation and faces each of the four edges of the stack. It is characterized by comprising eight components (21 to 28) arranged in pairs. The apparatus according to claim 5. 7. a component movable in translation relative to each corner of the substantially rectangular surface; and each of said movable components is disposed proximate a locating pin. 7. A device according to claim 6, characterized in that: 8. Said means intended for injecting air between the sheets in the stack at least one nozzle (60) connected to a source, said nozzle having opposite ends. in the form of a cylindrical body which is closed and has a narrow groove (61) over substantially its entire length. Device according to one of claims 1 to 7, characterized in that: 9. The narrow groove (61) is narrower than the portion facing the top portion of the laminate. The claimant is characterized in that the part disposed facing the bottom part of the laminate is wide. The device according to item 8 of the scope of demand. 10. A means intended for injecting air between the sheets in the laminate is provided in the laminate. characterized by comprising a nozzle substantially centrally disposed on one of the edges Apparatus according to claim 8 or 9. 11. Means intended for injecting air between the sheets in the laminate are provided in said laminate. disposed substantially centrally between the two edges of the lamina and independently opposite said edges at right angles to each other; Claim 8 or 9, characterized in that it is equipped with two nozzles. Apparatus described in section. 12. A planar surface (53) supporting a stack of sheets inside the substantially rectangular surface ), said surface (53) being connected to a source of air. The top portion of the chamber defines a section, and substantially the entire surface of the laminate is formed on the surface of the plane. Claim 1, characterized in that holes are provided distributed over the surface. Apparatus according to one of paragraphs 11 to 11. 13. A means intended for injecting air between the sheets in the laminate is provided in the laminate. Each corner is equipped with eight nozzles arranged in pairs, with the first nozzle of each pair a first edge and a second nozzle faces a second edge forming a corresponding corner; The device according to any one of claims 3 to 12, characterized in that: Place. 14. characterized in that the component moving in translation consists of a pneumatic jack Apparatus according to one of claims 1 to 13. 15. Means intended for injecting air between the sheets in the stack are further provided. acts as a topper and replaces at least a portion of the component forming the stopper According to one of claims 1 to 14, which is characterized in that: The device described. 16. A means intended to inject air between the sheets in the laminate is a pressing device. can be selectively moved in translation to replace at least a portion of the 16. A device according to claim 1, characterized in that: 17. four cutting devices disposed at four corners of a substantially rectangular surface; defining two mutually perpendicular reference surfaces in at least one corner of a rectangular surface; suitable for correctly positioning said sheet relative to the cutting device in contact with the components forming the and four stacks of sheets of substantially equal size. In the method of creating rounded corners at the corners of (a) injecting air between the sheets in the laminate to moisturize between the sheets in the laminate; forming a synovial fluid film; (b) the substantially rectangular surface with the reference surface; at least one corner of the surface of the laminate in abutment against two reference surfaces of at least one corner of the surface of the shape; also placing one corner; (c) activating a cutting device to create the desired rounded corners in each of the four corners; A method of creating rounded corners at the four corners of a stack of sheets comprising and. 18. The dimensions of one vary from one sheet to another in the laminate and the dimensions of the other vary. a stack of sheets whose dimensions are substantially constant for all sheets in said stack; A method of creating pairs of rounded corners at four corners of a body, the method comprising forming substantially rectangular corners. Four cutting devices are placed at the four corners of the surface of the shape and the sheet is attached to the cutting device. and each of the edges of said substantially rectangular surface along the axis of varying dimensions of said sheet. Accurate positioning on two mutually perpendicular reference surfaces formed at one corner of each producing rounded corners, which is done by a device having suitable means for The method includes: (a) injecting air between the sheets in the laminate to separate the sheets; forming a lubricating liquid film therebetween; (b) a first end of the substantially rectangular surface; (c) placing a first corner of the laminate against two reference surfaces of the laminate; activating the cutting device simultaneously at each corner of the first end of the rectangular surface; , (d) a laminate abutting two reference surfaces at a second end of said substantially rectangular surface; (e) placing a second corner of the substantially rectangular surface at each step of the second end of the substantially rectangular surface; simultaneously operating the cutting devices at the A method of creating pairs of rounded corners at the four corners of a stack of sheets comprising. 19. four cutting devices disposed at four corners of a substantially rectangular surface and said sheet; a reciprocal section provided at each corner of said substantially rectangular surface for each of said cutting devices; means suitable for successive positioning on two reference surfaces perpendicular to A device that continuously creates rounded corners at the four corners of the stack of sheets. In the method, (a) Inject air between the sheets in the laminate to inject air between the sheets in the laminate (b) forming a lubricating fluid film on the stack of sheets at right angles to each other; in two directions and pressing the first corner of said laminate against two corresponding reference surfaces. (c) actuating a cutting device corresponding to the corner to create the desired rounded corner; the stage of starting the process; (d) repeating steps (b) and (c) for the other three corners. A method of continuously creating rounded corners at the four corners of a laminate. 20. Sheet dimensions vary from one sheet to another in the stack in terms of length and width. 20. A method according to claim 19, characterized in that both are varied.