FR2625136A1 - Method and installation for manufacturing composite plates - Google Patents

Abstract

The installation comprises means 5, 6, 8, 13 for step-by-step unwinding from a reel 4 of a thin strip 2 between the plates of a press 1, tooling-setting means 30 for sequentially introducing a thick plate 3 between the plates of the press 1, a press 1 bearing a die and a punch surrounded by a holding-down clamp in order to form a composite plate C formed by the joining of a thick plate 3 with a thin plate cut out from the thin strip 2, and separation means 12, 31, 32 arranged downstream of the press 1 for separating each composite plate C from the thin band to which it is attached. Application to the manufacture of registration plates for vehicles.

Description

 The present invention relates to a method and an installation for manufacturing composite plates consisting of a relatively thick base plate and a substantially thinner second plate which are superimposed and secured to each other at their periphery.

 Such plates are particularly, though not exclusively, intended to serve as license plates for vehicles. For this purpose, there are subsequently formed identification signs, such as letters or numbers which stand out in relief and with a color contrast. French Patent No. 1,307,854 describes a method for forming such signs on a surface. composite plate consisting of two aluminum plates of different thicknesses and colors, which method comprises subjecting the composite plate to a cold forming operation having the effect of pushing portions of the thick plate back through the thin plate and to break and detach the corresponding portions of the thin plate, so that the pushed portions of the thick plate appear in relief through the thin plate with a color contrast.

 It is obviously essential to achieve a good bonding of the two plates, since the composite plate is constituted by their assembly and it loses all used if the thin and thick plates come to separate.

 It is already known, by the French certificate of addition No. 94,687, French Patent No. 72 44628 and its addition No. 73 02224, to join together the thick base plate and the thin plate & their periphery by a mechanical forming & cold operation having the effect of forming a peripheral portion in relief on the thick plate, to fit the thin plate inside this peripheral portion and to break the corresponding peripheral portion of the thin plate.

 If the method described in French Patent 72 44628 and its addition gives full satisfaction from the point of view. the quality of the bonding between the plates and sleep of the final product obtained, it does not present less limitations related to its implementation process.

 Indeed, the composite plates, which dr # ivcnt.

between produced at high rate for reasons of cost, are currently manufactured in presses fed and controlled manually. The press operator has at his fingertips a repository of thin, thick, pre-cut plates, usually assembled in pairs, and must perform the following sequence of operations
- manually take a pair of thin and thick plates from the reserve;
- insert the two plates between the plates of the press ensuring that they are perfectly superimposed and suitably placed with respect to the matrix and / or the punch
order the tightening of the press by medium-s which generally require the use of both hands to prevent the risks of accident;
- remove the composite plate obtained from the press;
separating from the composite plate the peripheral waste of the thin plate which has been broken during the forming operation but which is likely to remain attached to the composite plate; and
- discard the waste and place the composite plate in a suitable place for subsequent storage, before starting a new cycle of operation.

 This manual manufacturing process requires a repetitive and tedious work, is a source of accidents, has a productivity linked to the rates that are able to ensure the operators, and requires a large workforce since it is necessary to add to the operators of staff presses to prepare the pairs of thin and thick plates, feed the reserve available to each operator and evacuate and store the composite plates coming out of the presses.

 In addition, the feeding of the press or presses requires the constitution of stocks of thin plates and thick plates in the various formats and colors that will be required later for the manufacture of composite plates. From these stocks are then formed the reserves of thin and thick plates of desired characteristics assembled in pairs. The constitution of these stocks, their storage and handling are of course expensive.

 The invention aims to provide a method and an installation for manufacturing composite plates as described above which overcomes the aforementioned drawbacks through extensive automation of the manufacturing process.

 For this purpose, the invention firstly relates to a method of manufacturing composite plates consisting of a thin plate and a thick plate superimposed and secured to one another at their periphery by a mechanical operation forming having the effect of forming a peripheral portion in relief on the thick plate, embofter the thin plate inside said peripheral portion and break the corresponding peripheral portion of the thin plate, characterized in that it consists not to unwind and not sections of a continuous thin strip between the plates of a press provided with a die, a punch and a blank-holder surrounding the punch, to introduce into the press an individual thick plate & each advancement of one step of the thin strip, to clamp the trays of said press to secure each thick plate with a thin plate cut in a thin strip section by the effect of said ope mechanical assembly, to clamp together, during said mechanical operation, the corresponding peripheral portions of the thick plate and the thin strip section between the die and the blank holder in a manner to ensure the attachment of the plate composite composite thus formed & BR <the peripheral portion of the thin strip section, & conveying said composite plate out of the press by advancing the thin strip and separating the composite plate from the thin strip out of the press.

 Thanks to this process, the manufacturing process does not require any manual intervention and the peripheral waste which, on leaving the press, is in the form of a continuous perforated strip whose cutouts correspond to the thin plates which were found each recessed in a thick plate, is used both to ensure the advancement step by step of the thin strip through the press and the evacuation out of it of the composite sheets obtained which remain attached to the perforated strip or waste.

The invention also relates to an installation for implementing the method defined above by means of a press comprising two plates carrying, one the matrix, the other the punch and the clamp, characterized in that it further comprises
- Yirxge means a coil of thin tape to scroll step said thin strip between the plates of said press;
tooling means for introducing, at each step advance of the thin strip, a thick plate between the plates of the press, and
separation means arranged downstream of the press for separating each composite plate from the thin strip to which it is attached.

 According to one characteristic, the separation means comprise at least one directional roller for modifying the direction of travel of the thin strip downstream of the press and at least one separating member cooperating with the directional roller to give each composite plate a different trajectory from said modified direction of scrolling of the thin strip.

 According to another feature, said separator member comprises at least one separator roller parallel to and adjacent to the directional roller, and preferably a second separator roller spaced from and parallel to the first roller.

 According to another characteristic, the installation comprises a coil unwinding unit disposed upstream of the press, a device for feeding the thin strip placed downstream of the press and separation means, and shearing means of said thin strip disposed downstream of the feeder. Preferably, means for tensioning the thin strip are arranged upstream of the press.

 According to a preferred embodiment of the installation, the latter comprises a second reeling unit of a thick strip reel, second shearing means of the thick strip to form the thick plates and conveying means of the thick plates. said tooling means. Thus, the composite plates can be manufactured directly and automatically from thin and thick web rolls.

 If necessary, a unit of paint thick plates. may be interposed between the second shearing means and the conveying means.

 Preferably, the installation co-carries second conveying means for discharging the composite plates detached from the thin strip by said separation means.

 According to another characteristic, said press comprises a horizontal fixed upper plate carrying the punch and the blank holder and a movable horizontal lower plate carrying the die on which said thick plates are put in place, one under the corresponding section of thin strip. by said tooling means.

 According to yet another characteristic, the press comprises a movable horizontal top plate carrying the die and a fixed horizontal lower plate carrying the punch and the blank holder and said tooling means are arranged to introduce each individual thick plate onto the thin strip. stretched between the said trays.

 According to yet another characteristic, the blank clamp is elastically biased towards an abutment position by hydraulic cylinders fed by a first hydraulic circuit comprising means for adjusting the clamping force of said peripheral portions of the thin strip and the thick plate between the blank holder and the die.

 According to yet another characteristic, the spring comprises an ejector resiliently biased in a permanent manner towards an abutment position by hydraulic cylinders fed by a second hydraulic circuit and the first hydraulic circuit comprises a distributor whose actuation is controlled by said press. when opened to push the blank holder to the stop position and eject the composite plate of the punch after the ejection of said composite plate out of the die by said ejector.

Other characteristics and advantages of the invention will emerge from the following description of an embodiment given solely for purposes of illustration and illustrated by the appended drawings in which:
Figure 1 is a schematic plan view of an installation according to a first embodiment of the invention.

 FIG. 2 is a more detailed view in side elevation and in partial section of a press traversed by a thin strip and of an evacuation conveyor for the composite plates manufactured, which is equipped with the installation of Figure 1.

 FIG. 3 is a plan view of the thin strip at the exit of the press of FIG. 2.

 Figure 4 is a longitudinal sectional view of the strip of Figure 3, which shows composite plates hung on the thin perforated strip.

 Fig. 5 is a sectional view of the press tool of Fig. 2, shown in a position corresponding to a first step of the manufacturing process.

 Figure 6 is a view similar to that of Figure 5 showing the tooling in a position corresponding to the second step of the manufacturing process.

 Figure 7 is a view similar to that of Figure 5 showing the press tooling in a position corresponding to a third step of the manufacturing process.

 Figure 8 is a view showing in section an alternative embodiment of the press tooling of Figure 2 and the diagram of the hydraulic circuit associated with this tool.

 Figures 9 & 12 are sectional views of the tool of Figure 8 shown at positions corresponding to different steps of the manufacturing process.

 Figure 13 is a view similar to that of Figure 2 illustrating a second embodiment of the installation according to the invention.

 Figure 14 is a sectional view of the press tooling along the line 14-14 of Figure 13.

 Referring to FIG. 1, the installation shown comprises a press 1 to which are fed, on the one hand, a relatively thin continuous metal strip 2, on the other hand relatively thick metal plates 3. The thin strip 2 is unwound starting from a spool 4 mounted on a web roll derailleur 5 and downstream traversing a motorized rectifier 6 which straighten the web 2 and unwinding it from the spool 4. Between the straightener 6 and a support 7 (FIG. 2) the band 2 forms a loop whose amplitude is controlled by a detector 8.

 As also shown in Figure 2, the continuous thin strip 2 passes horizontally between the upper plates 9 and lower 10 also horizontal of the press 1, without contact with the latter in the spaced apart position of the trays shown in the figure. The strand of the band 2 which passes through the press 1 is guided, on the one hand at the end of the loop by a crazy roll it provided at the upper part of the support 7, and on the other hand downstream of the press 1 by a directional roller 12 around which the band undergoes a change of direction at right angles. The vertical strand of the thin strip is pulled upwards by an electronic roller feeding device 13 which drives the portion of the thin strip 2 situated downstream of the loop formed between the support 7 and the straightener 6. In addition, roller guide and tensioning means 14 of the web 2 are provided immediately upstream of the entrance of the web into the press to ensure proper guiding and tensioning of the web 2 web running through the press. 1. The guide and voltage means 14 is associated with a non-contact detector 15 for the presence of the band which may be of any suitable type, for example optical.

 After passing through the press 1, the thin strip is perforated by cuts made during mechanical assembly operations with thick plates 3 as will be explained in the following and constitutes a continuous waste designated by reference 2a. On leaving the electronic feeding device 13, the continuous waste 2a is guided at 16 to a shear 17 and is cut into sections which are received in a receptacle 18. From the receptacle 18, the waste sections of the perforated band are evacuated by appropriate manual or automatic means (not shown) to a nibbling and / or compaction device for subsequent transport for possible recycling. A detector 20 similar to the detector 15 is arranged between the directional roller 12 and the electronic roller feeding device 13 to detect any breakage of the perforated strip or waste 2a which could interrupt the manufacturing process.

 The thick plates 3 are obtained by cutting a thick band 21 by a shear 22. Like the band 2, the band 21 is unwound from a reel 23 mounted on a tape drive 24. The unwinding of the reel 23 and straightening of the band 21 is provided by a motorized rectifier 25 downstream of which is formed a loop whose amplitude is controlled by a loop detector 26.

 The unit 24, 25, 26 and 22 for feeding and shearing the thick band 21, as well as the unit 5, 6 and 8 for feeding the thin band 2, constitute conventional assemblies well known to those skilled in the art. technical and it is not necessary to describe in more detail in the present application. Such sets are in particular marketed by the French company NORMATIC, 76360 TARENTIN.

 The thick plates 3 cut by the shears 22 are transported by a belt conveyor 27 to a tooling unit 28 associated with the press 1. This tooling unit comprises inter alia a stop 29 for stopping the plates 3. as well as a tooling cylinder 30 intended to ensure at the desired time the introduction of each plate 3 between the plates 9 and 10 of the press 1.

 If necessary, an automated screen printing unit (not shown) may be arranged between the shear 22 and the conveyor 27. In this case, the plates 3 conveyed by the conveyor 27 are painted, usually on one of their two. while leaving a thin, unpainted strip next to the zone where, under the effect of the forming operation carried out in the press 1, the thick plate 3 will be deformed to form a trapping inner rim the thin plate as will be explained in more detail later.

Finally, downstream of the press 1 are provided two separating rollers 31, 32 parallel to each other and to the directional roll 12 and one of which is adjacent to the latter, the rollers 12, 31 and 32 being substantially tangent to the defined plane. by the strand of the band 2 extending horizontally through the press 1. Thus; at the exit of the press 1, the relatively flexible open-web strip 2a undergoes a right-angle change of direction about the directional roller 12, while each composite plate
C relatively rigid which is then attached to the same band 2a is forced by the separator rollers 31 and 32 to continue a horizontal trajectory :: this results in a pulling force which contributes to gradually separate the one from the other plate Composite C and the perforated strip 2a as the progress of the latter. Once completely separated from the web 2a, the composite plates C fall on a belt conveyor 33 by means of which they are discharged to a storage area (not shown).

 Referring to Figures 2 and 5 to ~ 7, the press 1 comprises a fixed upper plate 9 and a movable lower plate 10 actuated by a hydraulic jack 34 and guided in a frame 35 resting on the ground. The plate 10 carries a matrix 36 formed of a body 36a pierced with an opening 36b in which a puller 36c biased toward one of its extreme positions can slide by springs 37 which bear on the soleplate or plate 10.

 The upper plate 9 carries a punch 38 having an end surface 38a located vis-à-vis the or vertex 36b of the matrix and whose dimensions coincide approximately exactly with those of this opening.

A blank holder 39 disposed laterally around the punch 38 is slidably mounted relative to the punch 38 between two end positions respectively shown in Figures 5 and 7 on the one hand, 6 on the other hand. This blank holder 39 is biased towards one of its extreme positions by springs 40 which bear on the plate or sole 9 and whose stiffness is adjustable by appropriate conventional means.

 Note that the various tools carried by the trays 9 and 10 are identical to those of French Patent 72 44628 which gives a more detailed description to which we can refer. The tooling of the press 1 may further comprise a crimping tool as described in French patent 72 44628. The only difference with this French patent lies in the fact that in the where the movable die is placed under the fixed punch whereas this patent provides a reverse provision.

 To fix ideas, it will be assumed in the following that the thin strip 2 can be painted on its outer face.

the color of the thick plates 3 and the thickness of the latter is, for example, of the order of 1.4 mm, and that of the plate 2 of the order of 0.3 mm, the strip 2 being preferably made of an aluminum alloy harder than that of which the plates 3 are formed.

In operation, the unwinding units 5, 6 and 8 of the strip feeding belt 2 and 24, 25 and 26 of the strip 21 operate autonomously and asynchronously with respect to the remainder of the installation because the unwinding of each reel is controlled depending on the length or amplitude of the loop formed downstream of the rectifier and horned by the detectors 8 and 26. The shear 22 and the motorization of the conveyor 27 are slaved to the plate tooling unit 3, while the motorization of the electronic feeding device 13 and the actuation of the tooling unit 28 of the plates 3 are slaved to the opening movements of the press 1.The operation of the shears 17 is slaved to the device electronic feeding 13 so as to cut a section of the perforated strip 2a after each advancement of a step thereof. The electronic feeding device rolls 13 is a known material for electronically advance advance of a band of such materials are marketed by the French companies ERMELEC 78790
SEPTEUIL, DIMECO 11630 BESANCON, and NORMATIC.

 It follows from the foregoing that the installation described only requires the synchronization of a very small number of members, which synchronization can be provided in a manner known per se by a programmable controller (not shown). This programmable controller will set the manufacturing rate, that is to say the frequency of the opening and closing cycles of the press 1, which will result directly or indirectly the synchronization of the other organs of the installation. The closure of the press will be authorized by the programmable logic controller only if it has not received from the detector 15 an informa tic, ri meaning the absence of band 2 between the press platens and complementary means (no shown) such as photocells may further be provided inside the press to detect the presence of a thick plate 3 and prohibit the closure thereof in case such a plate is lacking.

 In normal operation, the tools of the press 1 are in the open position shown in FIG. 5 after a plate 3 has been inserted by the jack 30 under the strip 2 and the latter has been advanced by one step. .

 The press is then closed and, at the end of the closing stroke, the tools are in the position shown in FIG. 6: it can be seen that the thin strip 2 has been broken due to the approach of the matrix 36a and the pCJinçori. and that under the effect of this mechanical operation a peripheral portion 3a has been formed in relief with respect to the bottom 3b of the plate 3 and that the part 2b which has been loosened in the strip 2 is applied against the forci 3b and The plates 3 and 2b thus juxtaposed and joined together constitute the composite plate C in which identification signs may subsequently be formed by a similar operation.

 During this clamping movement of the press, the bringing together of the die 36 of the punch 38 has the effect of pushing the blank holder 39 slidably mounted relative to the punch 38. This results in a certain tightening of the peripheral portion 3a of the plate 3 and the corresponding peripheral portion 2aa of the thin strip 2a between the body 36a of the die and the blank holder 39. However, this clamping can be adjusted independently of the relative position of the punch 38 and the die 36. end of court se, relative position represented by the dimension d in FIG. 6. According to the invention, this tightening of the peripheral portions 3a and 2aa of the plate 3 and of the band 2a between the matrix body 36a and the blank holder 39 is used to ensure the desired attachment of the composite plate C to the thin perforated strip 2a after the plates of the press have opened. This snagging phenomenon sometimes occurs in manual control presses when the tools are not properly adjusted, and it is then felt as a disadvantage because it complicates the task of the operator responsible for separating the waste from the machine. the composite plate. On the contrary, it is used in accordance with the inversion to ensure the conveying of the composite plates manufactured out of the press. This tightening, the value of which depends on a large number of parameters, can be very easily adjusted empirically by means of a few tests by a skilled person at the time the tools are set for a given manufacture.

 When the press opens, the ejector 36c and the blank holder 39 are elastically urged by their respective springs 37 and 40 and ensure that the composite plate C does not remain attached to the tools. The thin strip 2, 2a then resumes its horizontal position shown in FIG. 7 under the effect of the tension exerted by the guiding and tensioning means 14, and the composite plate C remains attached under the thin strip for the reasons indicated. previously.

 In this same figure, it has been assumed that a new blank plate 33 is introduced into the die 36 as soon as the press is opened, before the composite plate C which comes from to be manufactured has been evacuated. Alternatively, the evacuation of the composite plate C by entraining the band 2a and the introduction of a new thick plate 3 can be provided simultaneously, or the composite plate C can be transported out of the press before the setting in tooling of a new thick plate 3.

 FIG. 3 is a view from above of the appearance of the thin perforated strip 2a at the exit of the press, the contour 2c corresponding to the edge of the cuts of the thin plate 2b in the initial thin strip 2. This same 2a, under which are hung composite plates C, has been shown in section in Figure 4.

 At the end of the opening of the press 1, the electronic feeding device & rollers 13 causes a length of the thin perforated strip 2a to bring a new virgin section of the thin strip 2 between the plates of the press 1. The This then presents the configuration shown in FIG. 5 and a new cycle for manufacturing a composite plate can be started.

 During the formation of the strip 2a, the composite plate C is detached from it by means of the red direct line. 12 and the separator rollers 31, 32 which give the strip 2a and the composite plate C directicrls divergent and perpendicular to each other. The composite plate C is progressively torn off the web 2a while continuing to advance as long as it remains partially attached to it until it falls on the carpet of the exit conveyor 33.

 Moreover, after each retraction of the tooling ram 30, the conveyor 27 is started to bring a new plate 3 in position against the stopper 29 and the shear 22 cuts a length of the band 21 to form a new plate 3 which is received on the conveyor 27.

 Similarly, the free end of the band 2a is cut by the shears 17 as it is stepped stepwise by the electronic feeder 13 and the waste collected at 18 is then processed as indicated above.

 Referring now Figure 8 shows an alternative embodiment of the press tooling in which the springs 37 and 40 have been replaced by hydraulic cylinders. In this figure, as in Figures 9 to 12, the same references as those used in Figures 17 have been retained to designate the same orgarze.

 In the third embodiment described above, the clamping force exerted between the peripheral portion 2aa of the thin strip and the corresponding peripheral portion 3aa of the thick plate 3 is determined by the stiffness of the springs 40: this stiffness is adjustable by any means suitable, for example by means of shims (not shown) which are screwed into the upper plate 1 and allow to change the preload of the springs 40. Alternatively, it can be expected to use several sets of springs of different stiffness and to make tests to determine which set of springs provides a suitable clamping to provide the desired attachment of the composite plate to the added thin strip 2a.

Whatever the means used, obtaining the desired clamping force between the peripheral portions 2aa and 3a generally involves a great deal of rigor. In addition, this clamping force is likely to vary during the operation of the press and thus affect the manufacturing process.

 In the variant of Figure 8, the springs 40 are replaced by hydraulic cylinders 50 distributed in appropriate numbers around the punch 38. Each cylinder 50 comprises a piston 51 integral with the blank holder 39 and sliding in a cylinder 52 constituted by a bore Bore in the body of the punch 38. The pressurized liquid is distributed to the various cylinders 50 through a main line 53 from which extend secondary pipes 53 '. The pipes 53 and 53 'are also constituted by bores pierced in the body of the punch 38.

 The hydraulic circuit feeding the cylinders 50 comprises a cover 54 from which the liquid is pumped by a pump 55 driven by a motor 56. The discharge side of the pump 55 is connected to an inlet of a distributor & four tracks 57 through a pipe 58. Between the pipe 58 and the tank 54 is disposed an adjustable pressure limiter 59, while a pressure gauge 60 makes it possible to measure the pressure prevailing in the pipe 58. An outlet of the four-way distributor 57 is connected to the main channel 53 by a pipe 61.A third channel of the hydraulic distributor 57 is connected to the tank 54 by a pipe 62, while the fourth channel of the distributor 57 is connected to the tank by a con duct 63 in which is inserted an adjustable valve In addition, a pressure gauge 65 is connected to the pipe 63 to measure the pressure prevailing therein.

 The distributor 57 comprises a slide 57a moved against a spring 57b by a cam 57c whose rotary or reciprocating movements are synchronized with the closing and opening movements of the press.

In one of its two extreme positions in which it is urged by the spring 57b and which is shown in Figure 8, the slide 57a communicates, on the one hand the pipe 58 with the pipe 61, on the other hand the pipe 63 with the pipe 62. When it is moved in its second position by the cam 57c, the slide 57a puts in cc, mrsurlic <#tiorl, on the one hand the pipe 58 with the corsduite 62, and other the duct 61 with the duct 63.

 In the matrix 36, the springs 37 urging the ejector 36c towards one of its extreme positions are replaced by hydraulic cylinders 66 whose pistons 67 are integral with the ejector 36c. These pistons 67 slide in cylinders 68 constituted by bores pierced in the body 36a of the matrix 36. These cylinders 68 are supplied with pressurized liquid through a pipe 69 pierced in the body 36a of the matrix and, if the number of cylinders requires it, by secondary lines (not shown) which put in communication some of the jacks 66 with the main line 69.

The latter is aliniented by a second hydraulic circuit comprising a task 70 in which the liquid is pumped by a pump 71 driven by a motor 72. The discharge side of the pump 71 is connected to the pipe 69 by a pipe 73. A valve or similar member 74 for adjusting the maximum pressure in the cylinders 66 is mounted in shunt between the pipe 73 and the tank 70. This second hydraulic circuit is completed by a manometer 75 75 for measuring the pressure in the pipe 73.

 In the open position of the press shown in FIG. 8 and corresponding to that of FIG. 5, a predetermined hydraulic pressure is applied to the cylinders 50 and 66 by the pumps 55 and 71 respectively and the '. associated pressure limiters. The blank holder 39 and the ejector 36 are then in one of their extreme positions limited by stops (not shown) as is also the case in the spring embodiment of FIGS. position, the blank holder 39 is substantially flush with the surface of the punch opposite the die and likewise the ejector 36c is substantially flush with the face of the die body 36a facing the punch 38.

 When the press closes, the die 36 rises towards the punch 38 until the plate 3 is in contact with the thin strip 2. This position has been shown in FIG. 9. During this closing stroke of the press, the drawer 57a of the distributor is moved by the cam 57c in its second position in which the pipe 61 communicates with the pipe 63. The cylinders 66 are then subjected to a pressure fixed by the valve 64. Therefore, the pump 55 flows directly on the tank 54 through the conduits 58 and 62 which are interconnected.

 The press continues its closing stroke to the extreme position shown in FIG. 10 which corresponds to that of FIG. 6. During this second phase of the closing stroke, the peripheral portions 2aa and 3a of the thin strip 2 and the plate 3 are clamped between the die body 36a and the blank holder 39, the latter pushes back and pushes the pistons 51, and the liquid coitriu in the pipes 53 and 53 'is partially pushed back to the sheet 54 by the intermediate, ducts 61 and 63. Thus, the valve 64 can accurately and easily adjust the clamping effect applied between the peripheral portions 2aa and 3a of the thin strip 2 and the plate 3.

 Similarly, during this closing phase of the press which provides the forming of the composite plate, the ejector 36c is pushed until it abuts against the bottom of the cavity 36b formed in the matrix, as shown in FIG. 10, which corresponds to the position of the tools of FIG. 6. The pistons 67 of the cylinders 66 generate during this closure a delivery pressure whose value is limited by the adjustable limiting valve 74.

 When the press starts its opening stroke, the pressure in the pipes 53 and 53 'is low while the pressure in the pipe 69 remains high. Consequently, the ejector 36c is pushed back by the jacks 66 and ejects the composite plate c from the body 36a of the die as the latter moves away from the punch 38. The plate C remains, on the other hand, fastened to the punch 38 because the pressure prevailing in the pipes 53, 53 'is insufficient to push the blank holder 39.

This is the situation prevailing to the vicinity of the complete opening of the press, as shown in Figure 11.

 When the press continues its opening movement, the cam 57c releases the drawer 57a which returns to the initial position shown in Figure 8. The conds 58 and 61 are again put in communication and the pressure generated on the discharge side of the The pump 55 is applied to the cylinders 50 which cause the sliding of the scribe to reach its end stop position and the critical ejection of the composite plate C of the punch 38 as shown. 12. The blank holder 39 acts as both an ejector and a clamping member for the corresponding peripheral portions of the thin strip 2 and the plate 3.

It follows from the foregoing that the hy hydraulic control of the blank holder 39 and the ejector 36c allows, on the one hand to ensure proper clamping of the thin strip and the thick plate for the attachment of the composite plate to the thin strip at the end of the forming operation, on the other hand to perform a two-stage ejection of the composite plate assembly and strip 2a of the tooling 36, 38.Thus, the thin strip of low mechanical strength is subject to very limited tensile forces because the displacement it undergoes per- vertlcularly to its plane are very small and independent of the amplitude of the race from the die to the punch
FIG. 13 shows a second embodiment of the installation according to the invention which differs from that of FIG. 2 in that the mobile matrix 36 is placed above the fixed punch 38. In this variant, the The thick plate 3 is introduced into the tool by the jack 30, no longer under, but on the thin strip 2.

 The punch 38 is preferably provided with means for positioning the plate 3 such as longitudinal edges 38a which project upwardly as shown in FIG. 14 and which make it possible to ensure the correct positioning of the plate 3 when this it is pushed onto the thin plate 2 by the tooling cylinder 30.

 The forming process of the composite plates is also identical to that described above, except that at the end of the process the composite plate C is placed on the thin perforated strip 2a, that is to say in the This variant of the manufacturing process makes it possible to substantially lessen the problems of attachment of the composite plate to the perforated thin plate 2a since the composite plate obtained rests by gravity on the latter.

 At the outlet of the press, the thin perforated strip 2a is deflected downwards on the directional roller 12 and is separated by the roller 31 of the composite plate C which falls on the conveyor 33. For the rest, the installation is identical to that described with regard to the first embodiment of FIGS. 1 and 2.

 Of course, the hydraulic variant of the tooling of FIGS. 8 to 12 can be applied to the second embodiment of the installation of FIGS. 13 and 14.

 It goes without saying that the embodiments described are only examples and the oral could modify them, especially by substituting technical equivalents, without departing from the scope of the invention.

Claims (14)

 1. A method of manufacturing composite plates consisting of a thin plate and a thick puddle superimposed and secured to each other to their periphery by a mechanical forming operation having the effect of forming urine peripheral portion embossed on the thick plate, to fit the thin plate inside said peripheral portion and to break the corresponding peripheral portion of the thin plate, characterized in that it consists of stepwise unwinding of the sections of a continuous thin strip between the plates of a press (1) provided with a die (36), a punch (38) and a blank holder (39) surrounding the punch, to be introduced into the press a individual thick plate (3) at each advancement of one step of the thin strip (2), to clamp the plates (9, 10) of said press to secure each thick plate (3) with a thin plate cut in a section of the thin band (2) by the effect of said operand In the course of said mechanical operation, the metric portions of the thick plate and the section of thin strip between the matrix and the blank are clamped together in such a way as to ensure that the composite plate (C) thus for mec at the peripheral portion of the thin strip section, to convey said composite plate out of the press by advancing the thin strip and to separate out of the press the composite plate of the thin strip.  2. Installation for carrying out the method defined above by means of a press comprising two plates carrying, one the matrix, the other the punch and the blank holder, characterized in that it comprises in outraged  means (5, 6, 8, 13) for feeding a reel (4) of thin strip (2) for stepwise scrolling of said thin strip between the plates (9, 10) of said press;  tooling means (30) for introducing, at each step advance of the thin strip (2), a thick plate (3) between the plates of the press, and  - Separating means (12, 31, 32) disposed downstream of the press (1) for separating each composite plate (C) from the thin strip (2a) to which it is attached.  3. Installation according to claim 2, characterized in that the separating means comprise at least one directional roller (12) for modifying the deflection direction of the thin strip downstream of the press (i) and aii molys an organ. separator (31) cooperating with the E? directional roller) for imparting to each composite plate (C) a path different from said modified direction of travel of the thin strip.  4. Installation according to claim 3, characterized in that said separator member comprises at least one separator roller (31) parallel to and adjacent to the directional roller (12).  5. Installation according to claim 4, characterized in that it comprises a second separator roller (32) spaced from the first separator roller (31) and parallel to ee i r-  6. Installation according to any one of the claims. 2 to 5, characterized in that it comprises a coil unwinding unit (5, 6, 8) disposed upstream of the press (1), a device (13) for feeding the thin strip arranged downstream. the press and separation means (12, 31, 32), and means (17) for shearing said thin strip (2a) arranged downstream of the feeder (13).  7. Installation according to claim 6, characterized in that it comprises means # (l9) nibbling portions of the thin strip cut by the shearing means (17).  8. Installation according to any one of claims 1 to 7, characterized in that it comprises means (14) for energizing the thin strip disposed upstream of the press (1).  9 Apparatus according to any one of claims 2 to 8, characterized in that it comprises a second unit (24, 25, 26) of unwinding a coil (21) of thick band, second means (22) of shearing said thick band to form said thick plates (3) and means (27) for conveying the thick plates to said tooling means (30).  10. Installation according to any one of claims 2 to 9, characterized in that it comprises second means (33) for conveying the evacuation of the composite plates (C) detached from said thin strip (2a) .par said separation means (12, 31, 32).  11. Installation according to any one of claims 2 to 10, characterized in that said press (1) comprises a horizontal fixed top plate (9) carrying the punch 38 and the blank holder (39) and a movable horizontal lower plate (# 0) carrying the matrix (36) on which said thick plates (3) are placed, one by one, under the corresponding section of thin strip (2), by said tooling means (30).  12. Installation according to any one of claims 2 to 10, characterized in that said press (1) comprises a movable horizontal top plate - (10 ') carrying the matrix (36) and a fixed horizontal lower plate (9') carrying the punch (38) and the blank holder (39) and in that said tooling means (30) are arranged to introduce each individual thick plate (3) onto the thin strip (2) stretched between said plates.  13. Installation according to any one of claims 2 to 12, characterized in that the blank holder (39) is elastically biased to an abutment position by hydraulic cylinders (50) supplied by a first hydraulic circuit comprising means ( 59, 64) for adjusting the clamping force of said peripheral portions of the thin strip and the thick plate between the blank holder (39) and the die (36).  14. Installation according to claim 13, charac terized in that the matrix (36) comprises an ejector (36c) elastically biased permanently to an abutment position by hydraulic cylinders (66) fed by a second hydraulic circuit and in that the first hydraulic circuit comprises a distributor (57) whose actuation is controlled by said press when it is opened in order to push the blank holder <39) towards the stop position and to eject the composite plate (C) from the punch (38). ) after ejecting said composite plate (C) out of the die (36) by said ejector (36c).