RU2565720C2 - Device, plant and method for wrapping of article in shell of sheet material - Google Patents

Abstract

FIELD: process engineering.SUBSTANCE: invention relates to metal forming. Shell is composed of two semi-shells made of sheet material and shaped to appropriate parts of the article outer surface. Note here that said semi-shells have flange, a female part. Said flanges are coupled by bending or squeezing to make an integral shell. This device comprises supports for article place between semi-shells arranged in opposition. Joint sealing means can bend off said flanges and, optionally, squeeze bent-off flanges in configuration whereat end of said flanges remote from the article is located at the angle to flange part nearby the article. Note here that said sealing means comprise the tool with bore and profile homologous and expanded relative to profile of perimeter set by the flange remote end. Said tool can displace perpendicular to the plane wherein the near part of flanges is located and parallel with that of near part of said flanges. Note here that used drives allow arranging of this tool surrounding remote part of the flange to bring the hole profile section in contact with homologous section of perimeter profile defined by flange remote inclined part. This done for approach to the article with the help of hole profile section in contact with flange remote part for its additional bending onto flange near part and for reiteration of said jobs on additional sections of flange remote part profile. Plant for article packing comprises above described device. Proposed process comprises support of the article arranged between two semi-shells with appropriate flanges arranged relative to each other and to flange parts remote from the article and inclined to the plane wherein flanged parts nearby the article are located. Besides, it comprises the moving tool of design and displacement identical to abode described.EFFECT: simplified design, higher efficiency.14 cl, 17 dwg

Description

The present invention relates to a packaging device and installation for wrapping an item, usually a food product, in a shell formed by a pair of half-shells made of sheet material and having a shape that matches the corresponding part of the surface of the item, and to a related packaging method.

In known processes, two preformed half shells are connected to one another around the subject and connected to each other through an operation known as sealing the joint, which involves folding and / or crimping flanges surrounding the mouth contour of each half shell.

The term “joint seal”, which is used in machining technologies to refer to the crimping operation of the edges of riveted sheets, is used in this description in the broad sense to refer to the deformation operation in which the edges of the flanges of each half shell are folded and / or crimped so that such edges of the flanges are joined together.

The packaging process and machine of the type mentioned above are described in DE 1784647U. The process described there assumes an initial step in which small aluminum sheets are drawn in respective shaped molds so as to form two half shells of the shell; then the food product is placed in one of two half-shells supported by the corresponding mold, and the second half-shell placed in the corresponding mold is superimposed on the part of the product protruding from the first half-shell, whereby the edges of the flanges of the two half-shells are arranged opposite to each other friend.

When two molds have been closed, the edges of the flanges are cut or perforated; then the edges of the flanges of the two half-shells are connected to each other by means of thermal bonding, gluing or bending; however, this last operation is not described in detail.

GB 952925 describes a process and a sealing device as part of a method that uses two half-shells of sheet aluminum shaped as a mold to form a hollow chocolate body; the joint sealing operation is carried out by arranging objects placed one after one between two half-shells of sheet aluminum in the first press, which, by means of an annular forming element, causes the initial folding of the edges of the flanges in a direction perpendicular to the common plane of the flanges.

Then the items are moved to a second press, with which an annular forming element is connected, which, in turn, causes the flanges to twist.

One objective of the present invention is to provide a device that makes it possible to perform joint sealing operations on multiple objects at the same time.

Another objective of the invention is to provide a process and installation that provides sequential packaging, either continuously or step by step, whereby making it possible to pack a plurality of objects into half-shells of sheet material with high productivity.

In view of these objectives, a joint sealing device, an installation comprising it, and a method, as defined in the claims that follow, are the subject of the invention.

Additional features and advantages of the invention will be apparent from the following detailed description, which is purely illustrative and non-limiting and which is made with reference to the accompanying drawings, in which:

- Figures 1-15 are schematic views showing successive steps of a packaging process according to a preferred embodiment;

- on figa and 7b shows two consecutive position of the operation performed in Fig.7;

- Fig. 16 is a perspective view of a tool for sealing a joint used in a method; and

- Fig.17 is a top view of the tool according to Fig.16, depicted in the working position together with the subject, relative to which the tool works for the operation of sealing the connection.

The installation in accordance with the invention performs sequential packaging of a given item, starting from the initial stage of drawing sheet material to obtain half-shells that make up the shell, and continues until the release of a fully packed item.

As will be apparent from the description that follows, some of the work steps described below with reference to the accompanying drawings are exclusively optional.

Figure 1 shows the pulling step for the formation of the first and second half-shells 2, 4 in the corresponding mold 6 and 8 with a cellular structure. Half-shells 2, 4 are obtained from a sheet of plastic deformable material. Usually this is an aluminum sheet, for example, with a thickness of 10 μm to 40 μm, which optionally can be coated on at least one surface with varnish or other hot-melt or hot-melt adhesive coating. Molds 6 and 8 have a profiled molding cavity 9, 11 (figure 2) with a form that coincides with the corresponding part of the outer surface of the object for packaging.

The packaging subject is shown in the drawings presented along with this description, and in particular in FIGS. 1-15, with a circular cross section, so that the two half shells 2, 4 are equal to each other in cross sections that are the subject of the figures.

It is obvious that this is only an illustrative alternative, taken for simplicity of illustration, since the invention should not be understood in any way limited on items for packaging with circular cross sections or with axial symmetry; on the contrary, the process is particularly preferred for shaped articles for packaging with complex and asymmetric shapes, such as the one shown in FIG. 17, for example.

Two half-shells made of sheet material into which the object is packaged can in this case have shapes that differ from each other, it being understood that, in any case, the mouth profile of the half-shells corresponds to the profile of the maximum longitudinal section of the object.

Thus, the item to be wrapped may, for example, be a body of food material, for example chocolate, optionally a hollow, such as a chocolate egg (which is a typical example of a body with axial symmetry), for example, or a body with a complex shape, such as a body representing a toy, symbol or animal.

It is also assumed that, although each mold is shown in the accompanying drawings with one place for pulling the corresponding half shell, in industrial practice, each mold can contain many places located, for example, in the form of a matrix, in order to make it possible to pull many half shells in one step.

A continuous strip of sheet material, unwound from a roll, is cut to obtain a sheet, which is located on each mold; in the case in which each mold has a plurality of sockets, after arranging the sheet so that it covers the spaces, the first cutting operation is usually performed in order to divide the sheet into small separate sheets, each of which covers the corresponding socket.

The drawing operation is performed in a manner that is essentially known, for example, by using a punch 10 (or a plurality of punch 10) with a mold that is complementary to the surface of each cavity or cavity of the mold.

The drawing operation is performed without fixing, or only with a slight fixing of the peripheral edges of each sheet to be drawn. The half-shells of sheet material 2, 4 thus obtained have a hollow surface part 2a, 4a and a peripheral surface part 2b, 4b surrounding the contour of the hollow part connector, the external profile of which corresponds to the perimeter of each sheet fed to the corresponding mold.

However, it should be clarified that the described process also applies to packaging an item that has a surface with a flat base, and in this case, one of the half-shells consists of an unstretched sheet, i.e. flat sheet; therefore, the fact that two parts of the shell are defined as half shells in this description is intended to include a shell in which one of these parts is a flat sheet.

Figures 2 and 3 show the steps (and optional), in which the elongated half-shells 2, 4 are transferred to the auxiliary supporting elements 12, 14, each of which has at least one corresponding socket 16, 18 for accommodating and / or supporting the corresponding half-shell and a part with a common flat surface 20, 22 surrounding the mouth of the corresponding socket, and adapted to support the peripheral part 2b, 4b of the corresponding half-shell.

As shown in figure 3, one of these supporting elements has an annular groove or groove 24 surrounding the profile of the mouth of the socket 16, the function of which is shown below. As indicated, the steps of FIG. 2 and FIG. 3 are optional since the drawing operation may be performed in a mold with features in accordance with the supporting member 12.

Then, the object P is located in the half-shell 2 by using means of movement essentially known, for example, as a suction cup, and the half-shell 4 is connected to the half-shell 2 in a position to overlap a part of the surface of the object P that protrudes from the socket 16; the result is a configuration in which two half-shells 2, 4 are located with their peripheral surface parts 2b, 4b that surround the contours of the mouth of the half-shells, mutually arranged opposite to each other and essentially located in the same plane, as shown in Fig.6.

To obtain this configuration, the support member 14 can be rotated 180 ° to the support member 12, as shown in FIG. 5; for this purpose, the supporting elements 12, 14 can be pivotally connected to each other in the form of a book; however, this solution is only illustrative, since it is assumed that the configuration according to Fig.6 can be obtained by other working means that move the half shells 4, relatively elongated in a separate line, on the half shells 2.

The process then includes the operation of cutting off the peripheral edges 2b, 4b of the half-shells in order to obtain, on each half-shell, a flange, indicated generally by 5, 7, which surrounds the mouth contour of the half-shells 2, 4, preferably at an equal distance.

This cutting operation shown in FIGS. 7, 7a, 7b is preferably performed by causing, at the same time as cutting, the folding of part 5a, 7a of the flanges 5, 7 remote from said object P in an angle position, preferably orthogonal to the plane, on which lie the flange parts 5b, 7b closest to item R.

This operation can be performed by means of a device, such as that shown in FIG. 7, which interacts with a support member 12 provided with an annular groove 24.

This cutting device comprises a vertically movable support element 26 with an associated annular cutting means or punching die 28 and clamping means 30, 32, preferably elastically connected to the supporting element 26, which surround the annular cutting means 28 inside and out.

The cutting device is located by means of the clamping means 30, 32 in contact with the peripheral part 4b and with the cutting means 28, which is able to penetrate into the groove 24. The cutting end 28a of the cutting means 28 is adapted to penetrate into the groove 24 with a small radial distance from the radially inner wall 24a of the groove 24 while this distance is such that it is able to accommodate the edges 7a and 5a of the flanges.

Thus, during the cutting operation, the pressing means 30 and 32 press the peripheral parts 2b and 4b of each half-shell and lowering the cutting means into the grooves 24 causes the remote flange parts 5a and 7a to be folded down simultaneously (FIGS. 7a and 7b) at the same time, as the cutting of these peripheral parts with a flange profile that corresponds to the contour of the mouth of the half shells.

The trimmed parts, indicated generally by 13, can be removed after being cut, for example, by extraction at a later stage of the process.

The process then preferably involves the operation of turning the object P through 180 ° together with the associated half-shells 2, 4, so as to position the bent edges 5a, 7a of the flanges up.

This operation can, for example, be carried out in accordance with the operating steps of FIGS. 8, 9, 10 and 11, which include turning the supporting member 14 onto the supporting member 12 to obtain the configuration of FIG. 9, in which two half-shells are clamped between the respective supporting elements 12, 14, turning 180 ° of two connected supporting elements 12, 14 (FIG. 10) and then opening the upper supporting element 14 to obtain the configuration according to FIG. 11.

In this configuration, the two half-shells 2 and 4 are not pressed against one another, so it is necessary to perform the operation of sealing the connection with bending and possibly crimping the bent edges of the flanges.

In accordance with the invention, this operation can be carried out by means of a device for sealing a joint having the distinctive features defined in the attached claims and described with reference to FIGS. 12 and 17, which is set to operate starting from an item wrapped in two half-shells in configuration according to 11.

However, it is contemplated that the configuration of FIG. 11, which makes it possible to operate with the device described below, can be obtained independently, with operating steps that do not necessarily correspond to the steps described previously.

However, such a device, which may be a section of a packaging machine that performs one or more of the operations previously described in turn, or which can be a stand-alone device, to which items with associated half shells 2, 4 can be fed, usually contains support means, such as for example, a supporting element 12 in FIG. 11, containing at least one socket 16, adapted to support an object P placed between two half-shells of sheet material, or a plurality of sockets, like waiting for the corresponding item; the support means comprise a substantially flat surface 34 that surrounds the aforementioned socket 16 and which is suitable for supporting the flanges 5, 7 of two half shells arranged to overlap one another.

The device comprises means for sealing the joints, adapted to cause bending and / or crimping of the flange parts 5a, 7a, remote from the object P, starting from the configuration of these flanges, in which their removed parts 5a and 7a are already bent to an angle, usually practically orthogonal to the surface 34 of the support element.

The aforementioned means for sealing the connection comprise a tool for sealing the connection, indicated by 36, which may be a plate-shaped body with a hole 38 (Fig. 16) (or a plurality of holes, one for each object intended for sealing) having a profile 40 perimeter, homologous and extended relative to the perimeter profile defined by the ends of the flanges 5, 7.

Thus, the tool 36 for sealing the connection is able to be in contact with the surface 34 of the supporting element 12, with the hole 38 in the position surrounding the remote flange parts 5a, 7a at a distance, that is, in the configuration shown in Fig.17, visible on which are the upper half-shell 2, the perimeter profile defined by the remote parts 5a, 7a, and the profile 40 of the hole 38, which is located at almost equal distance from the edges of the flanges.

The tool for sealing the connection is vertically movable relative to the means for supporting, between the raised position and the lowered position in which it is in contact with the surface 34. The tool 36 for sealing the connection is also movable in a horizontal plane. The drive means 42 is configured to perform vertical and horizontal movements of the tool to seal the connection.

In particular, the drive means 42 is configured to bring consecutive or non-consecutive sections of the profile 40 of the hole 38 into contact with the homologous section of the profile defined by the previously folded remote flange parts 7a, 5a. This operation can be performed in a position in which the lower end of the tool for sealing the connection is in contact with the surface 34 and is also used to obtain, where necessary, the correct location of these remote flange parts 5a, 7a in a position orthogonal to the surface 34 (Fig.12 )

Then, the tool for sealing the joint is vertically displaced by a distance d greater than the thickness of the two superimposed flange portions 5b, 7b superimposed on each other and so that the lower end of the profile 40 of the hole 38 is still able to interact following the horizontal displacement the upper end of the remote flange parts 5a, 7a (Fig.13).

Consistently, the tool 36 for sealing the connection is subjected to horizontal movement closer to the object P, so as to cause additional bending inside the remote flange parts 7a, 5a (Fig.14), superimposed on the nearest parts 5b, 7b.

Optionally and in any case, preferably, the tool 36 for sealing the connection is then subjected to vertical movement closer to the surface 34 of the supporting element 12 in order to cause crimping (Fig.15).

The above operations, that is, the operations according to FIGS. 12, 13 and 14, and, optionally, also the operations according to FIG. 16 (crimping), are performed for additional consecutive or non-consecutive sections of the flange profile. For example, when an item has a substantially quadrangular profile, the above operations are performed for each of the parties that define the profile; however, it is contemplated that performing a joint sealing operation along the entire flange profile is not an essential and mandatory aspect of the process, as in specific applications it may be desirable to maintain an unsealed portion of the flange profile, or to maintain a portion of the flange profile in which the flanges are superposed other position and not bent by themselves; this solution can, for example, be applied in the case in which the connection of one section of the flanges is made by applying a sticker. Thus, the process in accordance with the invention has the additional advantage of making it possible to perform joint sealing operations on only one part of the perimeter profile of the flanges or on specific parts, even parts that are not adjacent to each other.

In particular, in the case of the type profile shown in FIGS. 16 and 17, the joint sealing tool can perform a complete (or partial) joint sealing operation, being driven with translational movement in two directions orthogonal to each other.

In the case of an object with a body having a profile with curved sections, for example, an egg-shaped profile, the tool for sealing the connection can be made with the possibility of rotational and eccentric movement in the horizontal plane in order to bring consecutive or inconsistent sections of the profile 40 of the hole 38 into contact again with the edges of the flanges and perform the subsequent operations shown.

As indicated above, the final crimping operation is optional since, in the case of specific configurations of an object to be densified, such as, for example, in the case of an ovoid, the consolidation of the joint (if necessary) can be performed at a later stage by means of an auxiliary tool 36b (Fig. 15), vertically movable under the action of the drive means 42a, and provided with an opening, the inner profile of which essentially corresponds to the profile of the mouth of two half-shells. The aforementioned auxiliary tool 36b may be brought into vertical movement until it contacts the edges of the flanges, which are folded onto themselves, in order to crimp along the entire contour of the edges of the flanges in one crimping operation.

The described process and device for sealing the connection, thus, make it possible to pack items that have a complex or mixed profile, similar to bodies with the correct profile or with straight and curved sections.

As already indicated, it is assumed that the process and the device can be performed to work simultaneously on many objects.

As indicated, it is possible to perform the operation of sealing the joint along the entire contour of the flanges, due to the ability to move the tool 36 to seal the joint at least in only two orthogonal directions in the horizontal plane; in this case, the device for sealing the connection is particularly simple and preferred, since it makes it possible to work on objects with different shapes, simply by changing the profile 40 of the hole or holes 38.

Of course, without prejudice to the principle of the invention, the actuation patterns and details of the embodiments may be changed from what has been described and shown for non-limiting illustrative purposes only, without going beyond the scope of the claims that follows.

Claims (12)

1. A device for wrapping an object (P) in a shell formed of a pair of half-shells (2, 4) made of sheet material, with a shape that matches the corresponding parts of the outer surface of the specified subject (P), and these half-shells (2, 4) provided with a corresponding flange (5, 7) surrounding the corresponding contour of the mouth, and said flanges (5, 7) are connected to each other by bending and / or crimping in order to jointly define the specified shell, containing:
- supporting means (12), adapted to support the specified item (P), placed between the indicated half-shells (2, 4) of sheet material, with corresponding flanges (5, 7) installed with relative position to each other;
- means (36) for sealing the joints, configured to bend said flanges on themselves and, optionally, crimp said bent flanges, from a configuration in which the end part (5a, 7a) of said flanges (5, 7), remote from the specified item (P), is located at an angle relative to the flange part (5b, 7b), closest to the specified item (P),
characterized in that said means (36) for sealing the connection comprise a tool having an opening (38) having a profile (40) that is homologous and expanded with respect to the perimeter profile defined by the distal end (5a, 7a) of said flanges (5, 7 ), while the specified
the tool (36) is movable in a direction perpendicular to the plane in which the closest part (5b, 7b) of the indicated flanges (5, 7) lies, and is also movable parallel to the plane of the indicated nearest part of the flanges, and drive means (42) are provided, made with the possibility of placing the specified tool (36) for sealing the connection with the profile (40) of the specified hole (38) in a location surrounding the specified angled remote part (5a, 7a) of the specified flange (5, 7), and to bring the section about il (40) of said hole (38) in contact with a homologous portion of a perimeter profile defined by said angled remote portion of said flanges (5, 7), and to induce movement closer to said subject (P) using said portion of said profile holes (38) in contact with the specified remote part (7a) to cause it to additional bend to the specified nearest part (5b, 7b), and to repeat the above operations on additional sections of the profile of the remote part (5a, 7a) of the indicated flags ant (5, 7). 2. The device according to claim 1, characterized in that after the indicated movement with the approximation of the profile of the indicated hole (38), which causes additional bending of the indicated remote part (5a, 7a) to the specified nearest part (5b, 7b), the drive means is made with the ability to create movement of the specified tool (36), perpendicular to the plane of the specified nearest part (5b, 7b), to cause crimping of the specified remote parts (5a, 7a), bent to the specified nearest parts (5b, 7b). 3. The device according to claim 1 or 2, characterized in that said supporting means (12) have a substantially flat surface (34) surrounding said socket (16), adapted to support the nearest parts (5b, 7b) of said flanges (5) , 7), and these drive means are configured to:
- driving the specified tool (36) to seal the connection from a position remote from the specified surface (34), in a position in which the specified tool (36) is in contact with the specified surface (34) and the specified profile (40) of the hole ( 38) and surrounds the angled remote parts (5a, 7a) of these flanges (5, 7) at a distance,
- driving said tool (36) parallel to said surface (34) until a section of profile (40) of said hole (38) is brought into contact with a homologous section of an angled remote portion (7a) of said flange,
- driving said tool (36) in a direction perpendicular to said surface (34), to a distance (d) from said surface (34), so that the profile (40) of said hole (38) is able to interact with the end of the remote parts (5a, 7a) of said flanges (5, 7) and do not interact with overlapping nearest sections (5b, 7b) of said flanges (5, 7),
- driving the specified tool (36) in accordance with the movement parallel to the specified surface (34) in accordance with the movement closer to the specified object (P) to cause the bending of the specified remote part (5a, 7a) of the indicated flanges (5, 7 ) to the indicated nearest part (5b, 7b), and
optionally, driving said tool (36) in a direction perpendicular to said surface (34) to cause crimping of said remote end portion (5a, 7a) to said nearest portion (5b, 7b). 4. The device according to claim 3, characterized in that it comprises an auxiliary element (36b) for crimping said flanges (5, 7), containing a tool (36b) provided with an opening with a perimeter profile (40b) substantially coinciding with the mouth profile said half shells (2, 4), wherein said auxiliary tool (36b) is movable in a direction perpendicular to the plane of the nearest portion of said flanges (5, 7), and is movable between a position remote from said flanges (5, 7), and lowered position in contact with part (5a, 7a) of these flanges (5, 7), bent to the specified nearest part (5b, 7b) to crimp it. 5. A device according to claim 1 or 2, characterized in that said sealing tool (36) is movable parallel to the plane of said nearest part (5b, 7b) of said flanges (5, 7) in accordance with two perpendicular directions. 6. A device according to claim 1 or 2, characterized in that said tool (36) is movable parallel to the plane of said nearest parts (5b, 7b) of said flanges (5, 7) in accordance with rotational or eccentric movement. 7. Installation for packaging an object (P) in a shell formed of a pair of half-shells (2, 4) made of sheet material, containing a device according to any one of paragraphs. 1-6. 8. Installation according to claim 7, characterized in that it contains:
- the first and second means (6, 8, 10) for drawing, adapted to obtain the first (2) and second (4) half-shells of sheet material, each of which has a part (2a, 4a) of the surface with a matching shape for the corresponding part of the surface said item (P) and a part (2b, 4b) of the surface surrounding said first part (2a, 4a);
- means for connecting the specified first and second sheet with the corresponding parts (2a, 4a) of the surface of the specified object (P) with the specified peripheral parts (2b, 4b) of the surface in a mutual arrangement with overlapping; and
- means for cutting the specified first and second sheet in accordance with the profile surrounding the specified item (P), in order to form a pair of peripheral flanges (5, 7), while these cutting means (26, 28, 30, 32) are provided in order to cause, at the same time as cutting, the bending of the remote part (5a, 7a), relative to the object (P), the specified flange (5, 7) to an angle position relative to the common plane of the indicated flanges (5, 7). 9. The method of wrapping an object (P) in a shell formed of a pair of half-shells (2, 4) made of sheet material having a shape that matches the corresponding external side parts (2a, 4a) of the specified subject (P), wherein said half-shells ( 2, 4) are provided with a corresponding flange (5, 7) surrounding the corresponding mouth contour, and said flanges (5, 7) are connected to each other by means of a joint sealing operation, including bending and, optionally, crimping of said flanges (5, 7) for in order to jointly define specified a new shell, characterized in that it includes operations:
- maintaining the specified item (P), placed between a pair of half-shells (2, 4), provided with corresponding flanges (5, 7) with relative position to each other, with parts (5a, 7a) of these flanges, removed relative to the object, located in position at an angle relative to the plane in which the flanged parts (5b, 7b) lie closest to the specified object,
- providing a movable tool (36) for sealing the connection containing the hole (38) having a profile (40) that is homologous and extended relative to the perimeter profile defined by the remote end of these flanges,
- the location of the specified tool (36) with the profile of the specified hole (38) with a mutual arrangement surrounding the specified located at an angle remote part (5A, 7A) of these flanges,
- driving said tool for introducing a portion of said profile (40) of said hole into contact with a homologous portion of a perimeter profile defined by said angled remote parts (5a, 7a) of said flanges,
- causing movement closer to the specified object (P) of the specified section of the profile of the specified hole (38) in contact with the specified remote part (7a) to cause its additional bending to the specified nearest part (5b, 7b), and
- repeating the above operations for additional sections of the profile of the removed parts (5a, 7a) of the indicated flanges (5, 7). 10. The method according to p. 9, characterized in that after said movement with the approximation of the profile of said hole (38), which causes an additional bending of said remote part (5a, 7a) to the indicated nearest part (5b, 7b), it includes the creation operation moving said tool perpendicularly to the plane of said proximate portion (5b, 7b) to cause crimping of said distant portions (5a, 7a) bent to said proximate portions (5b, 7b). 11. The method according to p. 9 or 10, characterized in that it includes operations:
- providing the first and second sheet, each of which has a part (2a, 4a) of the surface, profiled so as to coincide with the corresponding outer part of the surface of the specified item (P), and the peripheral part (2b, 4b)
the surface surrounding the specified profiled part,
- connecting the specified first and second sheet with the corresponding parts of the surface of the specified object (P) with the specified peripheral parts (2b, 4b) of the surface in a mutual arrangement with overlapping,
- performing the cutting operation on the specified first and second sheet in accordance with the profile surrounding the specified item (P) to form a pair of peripheral flanges (5, 7), and
further characterized in that said cutting operation is performed in such a way as to cause, at the same time as cutting, to bend a portion (5a, 7a) of said flanges (5, 7) remote from said object (P) into an angled configuration relative to a common plane the indicated flanges (5, 7). 12. The method according to p. 9, including, after the specified cutting operation, the operation of turning the specified object (P) 180 ° with the indicated half-shells connected (2, 4).

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