EP1679163A1 - Device for removing break-off pieces from a sheet of material and abutment device associated with such a device - Google Patents

Abstract

The device has a square shape stop (6) presented in a form of patched piece made up of rigid metal. The stop has a branch (7) installed in thickness of a matrix (4). The stop has a free branch (8) partially supported at surface of the matrix before projecting inside an opening (5) of the matrix to arrange a support zone forming the stop for break-off pieces (2) to be separated, where the branch (8) has an end in V shape. An independent claim is also included for an assembly comprising a stationary stop and a matrix to equip a break-off pieces elimination device.

Description

The present invention relates to a device for eliminating pre-cut pieces, in particular scrap, a sheet of material having cuts or the like as well as an abutment and a stop / matrix assembly for such a device.

It relates more particularly to a device for removing pre-cut pieces of a sheet of material in which said sheet is placed on a separation surface of a die so that the pre-cut piece covers a breakthrough of the die and is pushed towards the down through this breakthrough under the pressure of at least one ejection or punching member.

Such devices are known and are described in particular in DE-A-4.124.098. In the case of these devices, the breakthrough is generally of smaller size than the precut pieces so that, during a thrust exerted by the punching member on the pre-cut piece, the pre-cut piece deforms inside said breakthrough to be ejected out of said breakthrough. The problem with such a device is that it generates a number of scrap jams inside the breakthrough. These jams force a stop of the ejection station to clear said breakthrough.

As a result, more advanced devices have appeared on the market. In these more advanced devices, the punching member cooperates with an abutment member disposed below the pre-cut piece and projecting at least partially in the piercing.

There are two types of abutment members corresponding to two major families of devices.

The first family concerns devices equipped with deformable stops. Thus, the abutment member which, in a rest position, is substantially recessed or flush with the separating surface is capable of being deformed away from the separation surface during a pressure exerted by the punching member on the pre-cut piece to occupy a position inclined relative to the separation surface.

An example of such a device is described in particular in patents EP-A-446,702 or EP-A-0,886,565.

In EP-A-446,702, the waste is removed by sliding of the elastic stop member. It sometimes happens that the pre-cut piece remains attached to the punching member. In the case of this device, there is then no longer any possibility of detaching the waste from the punching member. In addition, it is noted that such a device requires fixing each stop member by means of a suitable fastener, such as a screw. This results in a long and tedious editing. Finally, such a device has a large footprint below the matrix while in all ejection stations, in general, there is very little space between the lower surface of the matrix and the rest of the station. Moreover, the disassembly of such an abutment member is relatively difficult because of its inaccessibility.

In the case of the patent EP-A-0.886.565, the realization of the stop in the form of an elastically deformable part can cause, in some cases, premature wear of said stop.

The production of a stop in the form of an elastically deformable part is also described in the international application WO 99/51405 where the stop is in the form of a solid piece with an elastically deformable protruding portion.

Consequently, the devices with deformable stop have problems in terms of the longevity of said stops, which should be increased significant the service life.

The second family of devices concerns devices equipped with stationary stop. In this case, these stops are generally provided by a portion of the matrix, serving to define the breakthrough of said matrix, which projects into said matrix. These stops are made of the same material as the matrix, namely wood. As a result, the thickness of the abutment is relatively large. In addition, it is necessary to provide, to the right of the stop, a chamfer as shown in the right part of Figure 1 which corresponds to the state of the art. The thickness of the abutment, which is chosen to avoid again premature wear of the abutment, causes an increase in the ejection time and again a risk of jamming of the scrap inside said piercing. In addition, this solution in which abutment and die are made in one piece requires the change of the entire die when the stop is damaged.

Another solution obtained from a rigid stop made in the form of a screw is described in the application EP-0.641.632. Again, the provision of the protruding abutment of a face, called peripheral, serving to delimit the breakthrough can cause an increase in the ejection time and a risk of jamming.

An object of the present invention is therefore to provide a device for eliminating pre-cut pieces of the aforementioned type, the longevity of the stops is significantly increased.

Another object of the present invention is to provide a device of the aforementioned type, the design of the stops can be adjusted at will ejection time without increasing the risk of jamming scrap.

For this purpose, the subject of the invention is a device for eliminating pre-cut pieces, in particular scraps, from a sheet of material comprising sections or the like, this device comprising an ejection member of the type punch arranged to cooperate with a matrix equipped with at least one breakthrough covered by the pre-cut piece of the sheet of material, this breakthrough being provided with at least one stationary stop to momentarily hold the precut piece to promote its separation from said sheet under the pressure of the ejection member during a relative displacement between ejection member and die, characterized in that the or at least one of the abutments is in the form of an insert made of rigid material , preferably of metal, and affects the general shape of a bracket whose branch is implanted in the thickness of the matrix and whose other arm, said free, partially bears against the surface of said matrix before protruding inside the breakthrough of the die to provide a support zone forming a stop of the pre-cut piece to be separated.

The realization of the stop in the form of a metal insert makes it possible to significantly reduce the wear observed at the stop members of the state of the art. The realization of this abutment member in the form of a bracket which makes it possible to present small thicknesses at the branches and profiling at will of the ends of the latter makes it possible to act on the ejection times and to reduce the risks of jamming scrap inside the breakthrough.

The invention also relates to a stationary stop of the type intended in particular to equip a breakthrough of a matrix of a device for eliminating pre-cut pieces of the aforementioned type, said stop being used to momentarily retain the pre-cut piece to promote its separation from a sheet of material having sections or the like, characterized in that said stop is made in the form of a rigid piece, preferably of metal, and has the general shape of a square whose branch is implantable in the thickness of the matrix and the other branch is able to partially support the surface of said matrix before protruding inside the breakthrough of the matrix to provide a support zone forming a stop of the pre-cut piece to be separated.

The subject of the invention is also an assembly of the type comprising at least one stationary abutment and a matrix capable of equipping a device for eliminating pre-cut pieces of a sheet of material of the aforementioned type, the matrix having at least one breakthrough covered by the pre-cut piece of the sheet of material, said stop equipping the breakthrough for temporarily holding the pre-cut piece to promote its separation from the sheet of material, characterized in that said stop is made in the form of a rigid piece, preferably in metal, and affects the general shape of a square whose one branch is implanted in the thickness of the matrix and whose other branch is partially supported on the surface of said matrix before projecting inside the breakthrough of the die to provide a support zone forming a stop of the pre-cut piece to be separated.

• la figure 1 représente une vue en coupe schématique partielle d'un dispositif conforme à l'invention en ce qui concerne sa partie de gauche et conforme à l'état de la technique en ce qui concerne sa partie de droite ;
• les figures 2 à 4 représentent, sous forme de vues en coupe schématiques, les opérations successives de séparation pour éliminer un morceau prédécoupé d'une feuille de matière ;
• la figure 5 représente une vue schématique en perspective d'un organe de butée conforme à l'invention ;
• la figure 6 représente une vue de dessus d'une matrice équipée d'une pluralité d'organes de butée conformes à l'invention et ;
• la figure 7 représente une vue de dessus d'un organe de butée conforme à l'invention.

The invention will be better understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which:

• Figure 1 shows a partial schematic sectional view of a device according to the invention with respect to its left side and in accordance with the state of the art with regard to its right side;
• Figures 2 to 4 show, in the form of schematic sectional views, the successive operations of separation to remove a pre-cut piece of a sheet of material;
• Figure 5 shows a schematic perspective view of a stop member according to the invention;
• FIG. 6 represents a view from above of a matrix equipped with a plurality of abutment members in accordance with the invention and
• FIG. 7 represents a view from above of an abutment member according to the invention.

The device, object of the invention, allows to eliminate precut pieces 2, including scrap, a sheet 1 of material having cuts or the like. These pre-cut pieces can still be called falling. Generally, the sheet 1 of material is for example constituted by a pre-cut cardboard blank, each precut corresponding to a piece 2 to be subsequently eliminated. This sheet 1 of material, after undergoing a number of operations, is brought and placed on the separation surface of a die 4 so that the pre-cut piece 2 covers a breakthrough 5 of the die. This breakthrough generally has a homothetic profile to the profile of the precut made in the sheet of material.

A punching member 3 is moved downwardly through this piercing 5 so as to exert pressure on the pre-cut piece 2 to allow its separation from the sheet of material 1.

This punching member 3 can affect a large number of shapes. In the examples shown, this punch 3 for ejection of the device has a needle-punched end 3A on the pre-cut piece 2 to be separated, preferably made in the form of a ring, so that the needling tips penetrate partially into the material of said piece 2 to prevent slippage of the piece 2 relative to said needled end of the punch 3. This punch 3 also has a tubular body with a shoulder 3B marking the end of travel of said body during its insertion into its carrier plane. This results in a simplification of the assembly of the punching member 3 in its carrier plane. This punching member 3 cooperates with at least one abutment member 6 disposed below the pre-cut piece 2 and projecting at least partially in the bore 5 as shown in FIGS. 1 to 4. This abutment member 6 is intended to retain momentarily the pre-cut piece 2 for the purpose of promoting its separation from the sheet 1 under the pressure of the punching member 3 during a relative displacement between the punching member 3 and the die 4.

The device, object of the invention, may comprise, for each breakthrough 5, one or more stops. These stops may be of identical or different design.

In characteristic manner to the invention, at least one, preferably each abutment 6 is in the form of an insert of rigid material, usually metal. This abutment 6 affects the general shape of a bracket as illustrated in FIGS. 5 and 7. This abutment 6 thus has a branch 7 of implantation in the thickness of the matrix 4 and a branch 8, said to be free, partially taking support on the surface, that is to say on the upper face facing the punching member 3 of said die 4 before projecting inside the breakthrough 5 of the die 4 to provide a zone of support forming stop of the piece 2 pre-cut to separate. The upper surface or face of the matrix constitutes a bearing surface of the sheet 1 of material before biasing by a punch and is generally called the separation surface of the matrix. The fact, for the abutment 6, to be supported by one of its branches on the surface or upper face of the matrix, which is generally in the form of a plate, excludes any use of an elastically deformable part to as a stop as is the case in the state of the art where the elastically deformable leg of the abutment extends in line with a vacuum constituted by a recess of the matrix opening into the breakthrough to allow a such deformation.

Preferably, the end of the free branch 8, projecting from said penetration 5, of at least one abutment 6, is profiled to provide at least one bearing surface which decreases from the connection zone of the branches 7, 8 of the stop in the direction of the breakthrough 5 matrix 4 as shown in Figure 7. This reduction of the bearing surface reduces the risk of premature wear of the abutment member. In addition, the conformation of the end of the free branch 8 of the abutment 6 may make it possible to promote shear scrap or pre-cut piece 2. Thus, when the end of one of the branches, in particular the end of the branch 8 free of at least one stop 6, is shaped notch as illustrated in Figure 7, there is a shearing phenomenon of the pre-cut piece 2 which facilitates the separation of the pre-cut piece 2 of the sheet 1 material. Other embodiments of the free ends of the branches 7, 8 of the abutment or stops can be envisaged. Thus, the free end of one of the branches 7, 8 of at least one stop 6 can be V-shaped.

The branch 7 of implantation of a stop 6 in the die 4 may have, for its part, a tip-shaped end to facilitate its insertion into the thickness of the die 4. When the free end of the branch 7 of implantation of the abutment 6 is shaped tip and the opposite end V-shaped, the abutment 6 can then be made in the form of a reversible part allowing to use indifferently each of the branches 7, 8 of said abutment 6 as a branch 7 of implantation in the thickness of the matrix 4. This configuration makes it possible, as illustrated in FIG. 6, to be able to position the stop members in the corners or angles of the breakthrough or along the edges. rectilinear of the breakthrough. The corners or angles of the breakthrough are reserved for the stops with free branch 8 in the shape of a point, whereas the rectilinear edges are reserved for the abutments with end of the branch 8 in the form of V.

The positioning of each stop member inside the die 4 is extremely easy. Generally, a pre-drilling in the matrix is performed by laser. The branch 7 of implantation of the abutment member 6 in the matrix is then forced into the hole made. The matrix 4 may furthermore have, at the right of each abutment implantation point 6, a weakening of material, in particular by etching, in order to facilitate the penetration of the limb 8 of the abutment until it can be flush with the surface of the matrix. 4. Often, this etching will prove unnecessary, the press fitting to obtain a deformation to the right of the free branch 8 of the abutment intended to bear on said matrix. Sometimes, no deformation of the matrix will be performed, pads 9 being, if necessary, used to cause an elevation of the sheet 1 of material as shown in Figure 2. These pads 9 are then plugged into the surface of the matrix and protrude above it.

The advantage of the embodiment of the abutment member 6 in the form of a bracket-shaped metal insert is to be able to deform such a piece at will without causing premature wear of the latter. Thus, the free branch 8 of the abutment 6 can be inclined towards the breakthrough 5 to prevent braking in advance of the sheet 1 of material having cuts or the like. The deformation of the free branch 8 of the abutment 6 further allows to vary at will the bearing surface of the piece 2 pre-cut on said stop. This setting again affects the ejection speed and limits the risk of jamming. In addition, since the abutment member 6 is made of metal, the free branch 8 of the abutment 6 projecting inside the penetration 5 may have a thickness of less than 1.5 mm, preferably of around 1 mm. . This small thickness, as opposed to the state of the art, where the stationary stops made in the matrix had a large thickness and had to be completed with a chamfer, again reduces the risk of jamming and reduces the time ejection. Indeed, the lower the thickness, the shorter the ejection time. Today, however, this ejection time has a considerable influence on the efficiency of the operation of eliminating falls from the sheet of material.

To facilitate their storage before implantation in the matrix, the stationary stops 6 can be arranged side by side and connected to each other by breaking primers which are torn before implantation of each stop 6 in the matrix 4 to obtain a separation of the stops. 6. Thus, the succession of stops 6 is presented before implantation in the matrix 4 in the form of a flexible bead.

Claims (12)

Device for removing precut pieces (2), in particular rejects, from a sheet (1) of material comprising cuts or the like, this device comprising a punch-type ejection member (3), arranged to cooperate with a die (4) equipped with at least one breakthrough (5) covered by the pre-cut piece (2) of the sheet (1) of material, this piercing (5) being provided with at least one stop (6) stationary to hold momentarily the pre-cut piece (2) for the purpose of promoting its separation from said sheet (1) under the pressure of the ejection member (3) during a relative displacement between the ejection member (3) and the die (4) ,
characterized in that the or at least one of the abutments (6) is in the form of an insert made of rigid material, preferably of metal, and has the general shape of a square whose branch (7) is implanted in the thickness of the matrix (4) and whose other arm (8), said free, partially bears against the surface of said matrix (4) before protruding inside the breakthrough (5) the die (4) to provide a support zone forming a stop of the pre-cut piece (2) to be separated. Device according to claim 1,
characterized in that the end of the free branch (8), projecting into said bore (5) of at least one abutment (6), is profiled to provide at least one bearing surface which decreases from the connecting the branches (7, 8) of the abutment in the direction of the breakthrough (5) of the matrix (4). Device according to claim 1,
characterized in that the end of one of the legs (7, 8) of at least one stop (6) is V-shaped. Device according to claim 1,
characterized in that the end of one of the legs (7, 8) of at least one stop (6) is notched. Device according to claim 1,
characterized in that at least one abutment (6) is provided with a limb (7) for implanting the abutment (6) in the matrix (4) with a tip-shaped end to facilitate its insertion into the abutment (6). thickness of the matrix (4). Device according to claim 1,
characterized in that at least one abutment (6) is formed in the form of a reversible part making it possible to use each of the limbs (7, 8) of said abutment (6) interchangeably as a branch (7) for implantation. in the thickness of the matrix (4). Device according to claim 1,
characterized in that at least one abutment (6) has a free limb (8) inclined in the direction of the bore (5) to prevent retarding the advancement of the sheet (1) of material having cuts or the like. Device according to claim 1,
characterized in that at least one abutment (6) has a branch (8) free projecting inside the piercing (5) less than 1.5 mm thick, preferably close to 1 mm. Device according to claim 1,
characterized in that the ejection member (3) of the device has an end (3A) needle-punched bearing on the piece (2) pre-cut to separate preferably made in the form of a ring, so that the tips needling penetrate partially into the material of said piece (2) to prevent slippage of the piece (2) relative to said needled end of the punch (3). Device according to claim 1,
characterized in that the ejection member (3) has a tubular body with a shoulder (3B) marking the end of travel of said body during its insertion into its carrier plane. Stopper (6) stationary of the type intended in particular to equip a pierce (5) of a die (4) of a device for removing precut pieces (2) according to one of claims 1 to 10, said stop (6). ) for momentarily holding the pre-cut piece (2) in order to promote its separation from a sheet (1) of material having cuts or the like,
characterized in that said abutment (6) is in the form of a rigid piece, preferably of metal, and has the general shape of a square whose branch (7) is implantable in the thickness of the matrix (4). ) and whose other leg (8) is able to partially bear against the surface of said die (4) before protruding inside the bore (5) of the die (4) to provide a zone of support forming a stop of the piece (2) pre-cut to separate. Assembly of the type comprising at least one stationary stop (6) and a matrix (4) adapted to equip a device, for eliminating pre-cut pieces (2) of a sheet of material, according to one of claims 1 to 10, the matrix having at least one breakthrough covered by the pre-cut piece of the sheet of material, said abutment (6) equipping the breakthrough for momentarily holding the pre-cut piece (2) to favor its separation from the sheet (1) of material,
characterized in that said abutment (6) is in the form of a rigid piece, preferably of metal, and affects the general shape of a square whose branch (7) is implanted in the thickness of the matrix (4 ) and whose other leg (8) partially bears against the surface of said die (4) before protruding inside the bore (5) of the die (4) to provide a bearing area forming stop of the piece (2) pre-cut to separate.

Images