EP1480800B1 - Method for production of sheets made from binder, production line for said sheets and device for generation of an impression - Google Patents

Description

The present invention relates to a method for manufacturing hydraulic binder-based plates, in particular plasterboard with thinned edges, a production line for such plates, and an apparatus, in particular for producing an impression in a preform with a hydraulic binder base, known from US-A-2,246,987 .

In a production line of plates based on hydraulic binder, the plates are generally obtained by cutting a preform based on hydraulic binder at specific lengths.

In general, a cutting system consisting of a wheel placed on the top of the preform and driven in rotation by the movement of the latter is used. The wheel is graduated and coupled to a counter which actuates the cutting device once the desired length for the plate is reached.

The wheel and the meter are usually located at the downstream end of the production line, at a short distance from the cutting device, in order to avoid the phenomena of elongation or shrinkage of the preform.

The invention aims to propose an alternative to this wheel / counter system.

More specifically, the invention relates to an apparatus, a use a method and a production line according to claims 1, 7, 8 and 12.

Such a method has the particular advantage of allowing the determination of the length of the plate at the time of forming the preform.

In addition, it makes it possible to trigger other operations, such as the introduction of a slat under the preform, the making of an impression in the preform or a marking of the plate centered in length.

Such a method also has the advantage of being able to be used in the production of thin-edged hydraulic binder-based boards.

Concerning this subject, US Pat. No. 4,781,558 describes an apparatus intended for the manufacture of gypsum boards having depressions. It therefore proposes to make, on a preform intended to be cut to give plasterboard, recesses by means of a drum 34 having bumps 36 (see in particular FIG. figure 1 of this patent). The depth of the hollows is therefore determined by the size of the bumps. Thus, to change the depth and / or the shape of these recesses, it would be necessary to replace the drum 34 with another drum having bumps of different size and / or shape (s).

In US Pat. No. 2,991,824, indentations 51A, 51B are made in a preform intended to be cut to give plasterboard, by means of figure 1 and column 3, lines 29 to 43 of this patent) of a strip 20 rotating around two rollers 21 and having a protuberance 25. The preform is then cut in the middle of the impressions so as to produce plates with thinned edges.

In this case too, to change the dimensions and / or the shape of the impressions, it would be necessary to replace the band 20 by another band having protuberances of different size and / or shape (s).

The invention therefore also aims to solve the problem of making impressions in a preform while offering the ability to easily and quickly change the size and / or shape of these prints.

Thus, the invention makes it possible to produce, in a satisfactory manner, plates based on hydraulic binder with thinned edges.

• la figure 1 représente schématiquement et en perspective, la partie amont d'une ligne de production de plaques à base de liant hydraulique ;
• 1a figure 2 représente schématiquement et en perspective, la partie aval d'une ligne de production de plaques à base de liant hydraulique ;
• la figure 3 représente schématiquement et en perspective, un appareil pour la réalisation d'empreintes dans la préforme à base de liant hydraulique ;
• la figure 4 représente schématiquement et en coupe l'assemblage d'un fil sur un maillon de chaîne ;
• la figure 5 représente schématiquement un axe pince-fil ;
• la figure 6 représente schématiquement et en vue de dessus une pièce-support montée sur un maillon de chaîne ;
• la figure 7 représente schématiquement la pièce-support de la figure 6 en vue de face ;
• la figure 8 représente une plaque que l'on peut obtenir avec le procédé selon l'invention ;
• la figure 9 représente une autre plaque que l'on peut obtenir avec le procédé selon l'invention ;
• la figure 10 illustre une étape intermédiaire optionnelle d'un procédé de fabrication de plaques à base de liant hydraulique ;
• la figure 11 représente schématiquement et en perspective, un dispositif pour l'introduction de lattes sous une préforme à base de liant hydraulique ;
• la figure 12 représente schématiquement et en vue de dessus, le dispositif de la figure 11 ;
• la figure 13 représente schématiquement et en vue de côté, le dispositif de la figure 11 ;
• la figure 14 représente schématiquement et en vue de côté une variante du dispositif de la figure 11 ;
• la figure 15 représente schématiquement et en coupe, un détail du dispositif de la figure 11 illustrant l'introduction d'une latte sous une préforme à base de liant hydraulique ;
• la figure 16 représente schématiquement une partie d'une ligne de production de plaques à base de liant hydraulique comportant une variante l'appareil pour la réalisation des empreintes; et
• les figures 17 et 18 représentent schématiquement un poussoir et son réceptacle, éléments de l'appareil pour la réalisation des empreintes de la figure 16.

The invention will now be described in detail in the following description, which is given with reference to the figures, in which:

• the figure 1 represents diagrammatically and in perspective, the upstream part of a production line of plates based on hydraulic binder;
• 1a figure 2 schematically represents in perspective the downstream part of a hydraulic binder-based plate production line;
• the figure 3 shows diagrammatically and in perspective, an apparatus for producing impressions in the preform based on hydraulic binder;
• the figure 4 schematically shows in section the assembly of a wire on a chain link;
• the figure 5 schematically represents a pin-wire axis;
• the figure 6 schematically and in plan view a support piece mounted on a chain link;
• the figure 7 schematically represents the support piece of the figure 6 in front view;
• the figure 8 represents a plate that can be obtained with the process according to the invention;
• the figure 9 represents another plate that can be obtained with the method according to the invention;
• the figure 10 illustrates an optional intermediate step of a process for manufacturing hydraulic binder-based plates;
• the figure 11 shows schematically and in perspective, a device for the introduction of laths under a preform based on hydraulic binder;
• the figure 12 schematically and in plan view, the device of the figure 11 ;
• the figure 13 represents schematically and in side view, the device of the figure 11 ;
• the figure 14 schematically and in side view a variant of the device of the figure 11 ;
• the figure 15 represents schematically and in section, a detail of the device of the figure 11 illustrating the introduction of a batten under a preform based on hydraulic binder;
• the figure 16 schematically represents a part of a production line of plates based on hydraulic binder including a variant the apparatus for producing impressions; and
• the Figures 17 and 18 schematically represent a pusher and its receptacle, elements of the apparatus for producing impressions of the figure 16 .

DETAILED DESCRIPTION OF THE INVENTION PROCESS ACCORDING TO THE INVENTION

Referring to the figure 1 , we see an upstream part of a production line of plates based on hydraulic binder.

In the upstream zone of the line, a binder material 1 is poured onto a binder material 1 and, generally, it is covered by means of a second facing material 3. The passage of the assembly under the binder plate 1 forming 4 gives a preform 5, which moves, supported by a conveyor belt 7, to the downstream zone of the line, where it is cut transversely by a cutting device 9, generally consisting of a roller provided with a knife ( figure 2 ), to give plates.

The terms "upstream" and "downstream" refer to the direction of travel of the preform 5.

By "upstream zone" is thus meant in the present description, that part of the production line located near the forming plate 4.

"Downstream zone" means that part of the production line situated near the cutting device 9.

The hydraulic binder composition preferably comprises plaster.

The facing materials 1 and 3 may consist of sheets of paper or cardboard, glass mats or any material known to those skilled in the art as being used as facing material.

Marking means 300 are provided, generally upstream of the forming plate 4, to produce at least one mark, preferably on the facing material 3 of the preform 5.

The mark is therefore generally made upstream of the forming plate 4, that is to say before the preform 5 is formed.

The mark may be produced by depositing a material such as an ink on the surface of the facing material, to make a stain, a line, or any sign. The deposited material may or may not be visible to the null eye. The dimensions of the mark can be very variable.

The mark may also be constituted by a relief or a hollow formed on the surface of the facing material.

The marking means 300 may thus consist of an ink-stamp part which is regularly moved back and forth in the direction of the facing material 3 illustrated by the double arrow B. When the piece forming a buffer between in contact with the facing material 3, it leaves a mark 301 on the face this material.

Alternatively, it is also possible to use other marking means 300 such as an encoder wheel coupled to an ink jet device for triggering a net anchor (indexing of the jet speed, depending on the speed of scrolling carton) at the desired periodicity, controlled by the skilled person or the operator.

On the figure 2 detection means 302 disposed above the preform 5 can also be seen at a suitable place so that when a mark 301 passes beneath them, they can detect it.

These detection means 302 are of course chosen according to the type of the mark to be detected. They can be constituted by a photoelectric sensor.

Thus, whenever the presence of a mark 301 on the preform 5 is detected by the detection means 302, a detection signal is sent to actuating means (not shown), which then send a signal of actuation to the cutting device 9, so that the latter cuts the preform 5 to give a plate.

According to an advantageous embodiment also visible on the figure 1 additional detection means 303 are provided downstream of the marking means 300, preferably in the upstream zone, generally upstream of the forming plate 4.

These additional detection means 303 are generally of the same type as the detection means 302, since they must be able to detect the mark 301.

Additional actuation means are then also provided for, after receiving a detection signal from these additional detection means 303, sending an actuation signal to an apparatus for making an impression or reservation in the preform 5.

This additional detection of the mark 301 for producing an impression therefore takes place before the detection of the mark 301 of step 2) of the process that triggers the cutting of the preform 5.

For the imprint, however, an apparatus is used which will now be described in detail.

Realization of fingerprints

The preferred apparatus for producing impressions is schematically represented on the figure 3 .

It comprises a frame 101 which is H-shaped, but which the person skilled in the art could easily give many other forms.

On this frame 101 are supported, to a first. end 104, first two pulleys 102 and 103 and, at a second end 107, two second pulleys 105 and 106.

The first pulleys 102,103 are in a first plane, the second pulleys 105,106 in a second plane and the first plane is parallel to the second plane.

The pulley 102 and the pulley 105 are located opposite each other and identical.

The pulley 103 and the pulley 106 are also located opposite each other and identical.

The pulleys 102, 103, 105 and 106 can turn on themselves.

A first transmission belt 108 surrounds the first pulleys 102,103 and a second transmission belt 109 surrounds the second pulleys 105,106.

The transmission belts 108 and 109 are identical. They are connected to one another by at least one thread 111.

This wire 111 is removably attached to the first and second belts 108, 109 and extends between these belts 108, 109 so that its longitudinal axis is parallel to the axis of rotation of the pulleys.

Thus, when one of the pulleys, for example the pulley 102 rotates, it drives the transmission belt 108 which itself drives the other pulley located in the same plane as it (the pulley 103) and the wire 111. The latter then moves according to the trajectory defined, on the one hand, by the loop constituted by the belt 108 and, on the other hand, as it is connected to the second belt 109, also by the loop formed by the latter .

The symmetry of the apparatus according to the invention therefore allows the axis of the wire 111 to move in an ellipse, its axis remaining constantly parallel to that of the pulleys.

It can be provided that two pulleys located opposite each other are fixed on the same shaft.

The apparatus may also comprise means for driving in rotation at least one of the pulleys. These means may possibly lead to two pulleys by means of the shaft on which they are mounted.

The wire 111 generally has a cylindrical shape, but it can take a large number of forms including parallelepipedal, prismatic, etc.

It can be fixed for example by screwing on the transmission belts so that it can be unscrewed and easily replaced by another means of elongated shape.

According to a preferred embodiment of the invention, a plurality of wires 111 are arranged parallel to one another along the transmission belts 108 and 109 (see FIG. Figure 3 ).

The pulleys are preferably gear wheels and the chain transmission belts can cooperate with these toothed wheels.

The fixing of the wires can then be carried out as illustrated by the figure 4 .

On this figure 4 it is possible to see a thread 111 held at a chain link 112 by means of a support member 113 and a thread clamp axis 114.

The latter replaces, in the chain link 112, one of the roller carrier axes conventionally used.

• une extrémité filetée 115,
• une partie généralement cylindrique et lisse 116, apte à s'introduire dans le rouleau du maillon de chaîne 112 en vue de remplacer l'axe porte-rouleau utilisé classiquement,
• une partie lisse également généralement cylindrique et lisse 117, de diamètre généralement supérieur à celui de la partie 116 et apte à s'introduire dans le perçage 118 de la pièce support 113 (voir figures 6 et 7),
• une tête 119, et
• un alésage central 120 usiné généralement à partir de la tête 119, pouvant s'étendre jusqu'à la partie 116 et destiné à recevoir le fil 111.

The pin-thread axis 114 is shown in detail on the figure 5 . He understands, in order:

• a threaded end 115,
• a generally cylindrical and smooth part 116, able to be introduced into the roll of the chain link 112 in order to replace the roller holder axis conventionally used,
• a smooth part, also generally cylindrical and smooth 117, of diameter generally greater than that of the part 116 and able to be introduced into the bore 118 of the support part 113 (see Figures 6 and 7 )
• a head 119, and
• a central bore 120 machined generally from the head 119, which can extend to the portion 116 and intended to receive the wire 111.

The support piece 113 is visible on the Figures 4,6 and 7 .

It comprises the bore 118 adapted to cooperate with the corresponding portion 117 of the pin-thread pin 114 and a bore 121 opening into the bore 118. This bore 121 is threaded so that it can be screwed in a pressure screw 122 for compressing the wire 111 present inside the bore 118 to hold it firmly (see figure 4 ).

Thus, to fix a wire 111 on the chain link 112, the assembly of the figure 4 . To do this, simply insert the part 117 of the pin-thread pin 114 into the support piece 113, to remove the normal roller bearing pin from the link 112, to introduce into the axis of the roller the part 116 of the thread-gripping pin 114, to tighten the assembly while aiming at a nut 123 on the end 115 of the thread-gripper shaft 114, to introduce the thread 111 into the central bore 120 of the axis thread clamp 114 and hold it firmly by screwing the set screw 122 into the threaded bore 121 until it effectively compresses the wire 111.

Of course, the pin-wire axis 114 is mounted so that its head 119 is on the inside of the chain, that is to say facing the other chain.

The support member 113 preferably comprises two pairs (bore 118, threaded bore 121), the spacing between the axes of the bores 118 corresponding to the normal spacing between the axes of the rollers of a chain link 112, so that that two son 111 can be maintained on the same link 112, as can be deduced from Figures 6 and 7 .

Thus, having several identical support pieces 113 on adjacent links, it is possible to align several wires 111 in parallel so as to constitute a means of elongated shape.

In order that the apparatus which has just been described can be optimally used on a production line of plates based on hydraulic binder, the distance between the transmission belts of this apparatus is at least equal to the width of the preform. 5. Thus, these belts and the pulleys are located on each longitudinal side of the preform.

In addition, the apparatus is suitably arranged so that, when its transmission belts rotate, its or thread (s) 111 (s) creates an imprint in the preform 5.

The apparatus may be above the preform 5, in which case it creates the impression 12 or under the preform 5, in which case it creates the imprint 12bis visible on the figure 10 .

For practical reasons, it is preferred that the apparatus according to the invention is located above the preform 5.

The operation of the motor is adjusted so that the belts move at the same speed as the preform.

Of course, one could provide two (or more) devices according to the invention, one being located above and one below the preform, so as to create respectively, an imprint 12 on the top of the preform 5 and a footprint 12bis on the underside of the preform 5 (see Figure 10 ), the underside of the preform 5 being the side of this preform 5 which rests on the conveyor belt 7.

The impression position 12 is not directly related to that of a mark 301, so that an imprint 12 may or may not be performed on a mark 301.

Likewise, the position of the impression 12bis is not directly linked to that of a mark 301, so that an impression 12bis may or may not be made under a mark 301.

The position of the mark 301 and that of the imprint are advantageously chosen so that the preform 5 is cut at an imprint 12.

Plates 9a having transverse thinned edges 10 visible on the surface are thus obtained. figure 8 .

If we are dealing with an impression 12a made on the underside of the preform, the cutting device can be set to cut the preform opposite the location where this impression 12a was made (ie say on the other side of the preform).

The preform is preferably cut about in the middle of the imprint 12 or 12bis.

Introduction of slats under the preform

According to another embodiment, the additional actuation means are able, after receiving a detection signal from the additional detection means 303, to send an actuation signal to a slat insertion device under the preform 5.

1. 1) on coule sur un matériau de parement 1 supporté par un tapis transporteur 7, une composition de liant hydraulique 2 de façon à obtenir une préforme 5, puis on introduit sous la préforme 5, une latte 6 dont la longueur est au moins environ égale à la largeur de la préforme 5;
2. 2) on laisse la prise hydraulique de la composition de liant hydraulique 2 s'effectuer 2 et on retire ladite latte 6 ;
3. 3) on coupe la préforme 5 au niveau de l'amincissement 8 créé par la latte 6.

Thus, the method according to the invention complements a method of manufacturing plasterboard with thinned edges comprising the following steps (see figure 1 ):

1. 1) pouring on a facing material 1 supported by a conveyor belt 7, a hydraulic binder composition 2 so as to obtain a preform 5, then is introduced under the preform 5, a batten 6 whose length is at least about equal to the width of the preform 5;
2. 2) the hydraulic setting of the hydraulic binder composition 2 is allowed to proceed 2 and said batten 6 is removed;
3. 3) the preform 5 is cut at the level of the thinning 8 created by the lath 6.

The additional detection means 303 and the electronic means thus make it possible to introduce the slat 6 under the preform 5, after the detection of the mark 301, by sending an actuation signal to a lath introducing device 6 under the preform 5.

This additional detection of the mark 301 for the introduction of the slats 6 thus takes place before the detection of the mark 301 of step 2) of the process that triggers the cutting of the preform.

The position of the mark 301 is not directly related to the introduction of the slat 6, so that a slat 6 may or may not be introduced just under a mark 301.

This introduction of the slats 6 under the preform to manufacture plates with thinned-edge hydraulic binder will now be described in detail with reference to figures 1 , 2 and 8 to 15 .

First of all, it is specified that "transverse edges" means in this presentation the edges perpendicular to the direction of movement of the conveyor belt in a production line of hydraulic binder based plates. Such transverse edges are also called "plate ends".

Referring to the figure 1 it can be seen that after the exit of the preform 5 from under the forming plate 4 or from under the equivalent device used in the production line (for example, a forming roll called in English "Master roll"), a slat 6 is inserted between the preform 5 and the beginning of the conveyor belt 7. The distance between the forming plate 4 and the beginning of the conveyor belt 7 is such that the preform 5 has not yet had the time to harden substantially and still has great plasticity. The introduction is made from such that the longitudinal axis of the slat 6 is substantially perpendicular to the direction of movement of the conveyor belt 7.

The slat 6 is then driven by the conveyor belt 7, just like the preform 5. The hydraulic setting and hardening of the plaster composition 2 is then performed throughout the movement of the preform 5, designated by the arrows A.

Preferably, the withdrawal of the slat 6 takes place before the cut of the preform 5.

Thus, after a certain time, which corresponds to a distance traveled by the preform 5 on the conveyor belt 7, which the skilled person knows to determine according to the speed of movement of the conveyor belt 7 and the setting time of the composition of plaster 2, the hardness of the preform 5 is sufficient so that the slat 6 can be removed without deforming the preform 5 and without the plaster composition 2 filling the space or thinning 8 ( figure 2 ) left by the withdrawal of the lath 6.

The removal of the slat 6 can be carried out in any appropriate manner. For example, when the length of the slat 6 is greater than the width of the preform 5, the slat 6 protrudes with respect to the preform 5, and can then be removed quickly in a direction substantially perpendicular to the direction of travel of the conveyor belt 7 and moving away from it. This retraction action is illustrated by arrow B on the figure 1 .

The withdrawal of the slat 6 can also occur by the fall of the slat 6 in the space between two rollers constituting the conveyor belt system, which, in general, is not continuous throughout the production line, but is formed by several carpets driven by rollers between which there are free spaces.

After removing the slat 6, the preform 5 continues to move, still driven by the conveyor belt 7 and the hardening of the plaster composition 2 continues.

According to the invention and as can be seen on the figure 2 the mark 301 is then detected, in the downstream zone of the production line, by the additional detection means 302 which then trigger the operation of the cutting device 9.

The position of the mark 301 and that of the thinning 8 are advantageously chosen so that the preform 5 is cut at the level of the thinning 8, preferably about the middle of this thinning.

Plates 9a having transverse thinned edges 10 visible on the surface are thus obtained. figure 8 , whose lengths are defined by the distance traveled by the conveyor belt between two cutting operations, that is to say, generally by the distance traveled by the conveyor belt between two consecutive thinning 8. This plate 9bis thus has two thinned transverse edges 10.

The size of each thinning 8 depends on the dimensions of the batten 6. The latter is generally a parallelepiped whose thickness is generally between 0.5 and 4 mm, preferably between 1.5 and 4 mm. Its width is generally between 5 and 20 cm and its length is at least approximately equal to the width of the preform 5 (possibly less the width of the longitudinal strips "tape" present if necessary), but generally higher in order to be able to seize it to remove it from below the preform 5. In addition, it is desirable that the slat 6 is longer than the width of the preform 5, so as to project relative thereto, which can facilitate its withdrawal.

The constituent material of the slats 6 does not matter, as long as it allows these slats to withstand the weight of the preform thickness 5 which is above each slat 6. This can therefore be a plastic material, wood , metal, etc. having good wear resistance and stability over time.

Preferably, the method which has just been described comes in addition to a known method for manufacturing plaster having two longitudinal edges thinned. The latter generally provides for the introduction of a strip, generally made of plastic material, generally called "tape", on each longitudinal side of the conveyor belt 7. Such a method is described for example in the European patent application no. 482,810 .

This therefore makes it possible to obtain a plate based on hydraulic binder 11 as illustrated on FIG. figure 9 , having, in addition to its two thinned transverse edges 10, two longitudinal edges 25 thinned, ie a total of four thinned edges.

The length of the plasterboard manufactured depends of course on the speed of movement of the conveyor belt and the frequency of cutting operations.

The frequency of the cutting operations is generally directly related to the frequency of introduction of the slats, since it is generally sought to obtain slabs having two transverse edges thinned, and the slats introduction frequency is a function of the detection of the marks. 301 and therefore the frequency of marking operations.

This way of manufacturing plates with thin edges is very flexible, because, to change the length of the plates manufactured, it is generally sufficient simply to change the frequency of the marking operations, the latter determining the frequency of introduction of the slats and the frequency cutting operations.

Combination of impression making and the introduction of slats

According to a particularly advantageous embodiment of the invention, the method according to the invention comprises both the production of a print 12 or 12bis in the preform 5 and the introduction of a batten 6 under the preform 5.

The additional actuation means are therefore capable, after detection of a mark 301 by the additional detection means 303, to send an actuation signal to the means for producing the imprint 12 or 12bis and a signal of actuation the lath introduction device 6, to introduce a slat 6 under the preform, to let the grip hydraulic take place and remove the batten 6, as explained previously.

Generally, the steps of introducing a slat 6 under the preform 5, and then hydraulically setting the hydraulic binder composition and removing the slat 6 take place after the step of producing the impression in the preform 5 .

The impression is preferably made either opposite the place where it is intended to introduce the slat 6 (impression 12), or where it is intended to introduce this slat 6 (imprint 12 bis ).

This makes it possible to compensate for the localized excess thicknesses that may possibly form in the preform 5, due to a displacement of material, when the slat 6 has a large dimension.

It is also possible, in order to mitigate, where appropriate, the local extra thicknesses, to provide for the presence of a straightener 4bis of conventional type (visible on the figure 1 ), downstream of the place where the batten 6 is inserted.

PRODUCTION LINE OF PLATES BASED ON HYDRAULIC BINDER

The hydraulic binder-based plate production line according to the invention is preferably a thin-edged hydraulic binder plate production line.

Such a line may comprise a device for introducing laths and / or means for producing impressions.

A tapered hydraulic binder plate production line provided with means or a device for introducing slats 23 under the preform 5 will first be described in detail with reference to figures 1 , 2 and 8 to 15 .

Device for introducing laths under the preform

Referring to the figure 11 the upstream zone of a hydraulic binder-based plate production line comprises a device for the introduction of laths under the preform.

This device comprises a slatted magazine 20 formed of a rectangular horizontal surface 21 from the corners of which rise vertically and parallel, four angular pieces 22, shaped angle and turned towards each other, so as to frame a pile of slats 23.

The dimensions of this slat magazine 20 are such that it can store a large number of slats 23 (see also Figures 12 and 13 ).

The horizontal surface 21 of the lath magazine 20 is supported by feet 24.

At the level of the first slat 23, that is to say that located at the bottom of the stack, are arranged parallel two cylinders 26, which are oriented so as to extract the first slat 23 from the stack by pushing it and sliding it towards an inclined plane 27 consisting of an inclined surface 28 downwards and a rim 29 at its lower part to retain the slat which has just been extracted and guide it later.

At the transverse side 30 of the inclined plane 27, that is to say the opposite side to the conveyor belt 7, a jack 31 is arranged parallel to the longitudinal axis of the inclined plane 27, so that the actuation of this jack 31 can give an impetus to the slat which has just been extracted from the slatted magazine 20. The slat thus propelled can then move by sliding parallel to the longitudinal axis of the inclined plane 27, the flange 29 the guide , towards a second inclined plane 32 which extends the first inclined plane 27, the transverse side opposite the side 30. This second inclined plane 32 is also constituted by an inclined surface 33 provided with a flange 34 at its lower part. It further comprises a stop 35 at its end opposite to the jack 3i, this stop being generally constituted by a pneumatic damper and being intended to put an end to the movement of the batten propelled by the jack 31.

The flange 34 is provided with openings 36 in front of which are arranged two jacks 37 oriented so as to propel the lath positioned on the second inclined plane 32 towards the top of the inclined surface 33.

The first inclined plane 27 and the second inclined plane 32 are supported by feet, respectively, 38 and 39.

According to a variant visible on the figure 14 , a flat surface 40 is provided parallel to the surface 23, between the latter and the first inclined plane 27 for horizontally supporting a slat extracted from the slatted magazine 20 before its descent on the inclined surface 28 of the first inclined plane 27.

So, as we can see on the figure 15 , the height of the feet 24, 35 and 36 is chosen such that a slat positioned on the second inclined plane 32 is at a height less than that of the preform 5.

• l'axe longitudinal du rebord 34 du deuxième plan incliné 32 est perpendiculaire à l'axe longitudinal du tapis transporteur ;
• les moyens 32,33,34,35 pour supporter la latte déplacée se situent en face du début du tapis transporteur 7 ; et
• la surface inclinée 33 du deuxième plan incliné 32 est adjacente au tapis transporteur 7.

In general :

• the longitudinal axis of the flange 34 of the second inclined plane 32 is perpendicular to the longitudinal axis of the conveyor belt;
• the means 32,33,34,35 for supporting the displaced lath are opposite the beginning of the conveyor belt 7; and
• the inclined surface 33 of the second inclined plane 32 is adjacent to the conveyor belt 7.

The length of the second inclined plane 32 is at least equal to that of the slat 23, that is to say at least equal to, and preferably greater than, the width of the preform 5.

In this way, as can be understood by referring to the figure 10 when the cylinders 37 are actuated, the batten lying on the second inclined plane 32 is pushed upwards from the inclined surface 33, that is to say towards the conveyor belt 7 and the preform 5, and it is located stuck between them and driven by them.

The difference between the length of the slat and the width of the preform 5 makes it possible to grasp the slat and remove it once the plaster composition has hardened.

The production line according to the invention generally comprises electronic means which control its operation and allow, where appropriate, to enslave between them the implementations of different operations.

These electronic means can provide that after the introduction of a slat under the preform by the actuation of the cylinders 27, the actuator 31 is actuated to introduce a new slat on the second inclined plane 32, then the cylinders 26 are actuated to introduce another batten on the first inclined plane 27, and so on.

As explained above, the electronic means are able to send an actuation signal to the lath introduction device 23, after receiving a detection signal from the additional detection means 303.

Thus, the frequency of the introduction of the slats under the preform is determined by the frequency of making marks 301 on the facing material 3 of the preform 5.

variant of the device for the production of impressions

A thin-tapered hydraulic binder plate production line equipped with a fingerprinting apparatus as generally described above will now be described.

The figure 16 represents the upstream zone of such a line comprising a variant of the apparatus for producing impressions, which is seen in profile in this figure.

According to this variant, the apparatus comprises four first gearwheels 201,202,203,204 supported by a frame 205 and surrounded by a chain 206 constituted by links, some of which, the links 207, each support 2 wires, as indicated in connection with the figure 2 .

This apparatus is symmetrical with respect to a vertical plane aligned with the direction of movement of the preform 5. Thus, the wires held by the links 207 extend transversely with respect to the preform 5 to a second chain, identical to the chain 206, and which surrounds second gearwheels identical to the first gearwheels 201,202,203,204.

The apparatus is provided with an electric motor 209 driving in rotation by means of a belt 211 the shaft 210 on which the wheel 203 and its symmetrical wheel are mounted. The rotation of these wheels causes that of the chain 206 in the direction indicated by the arrow D.

This preform 5 is obtained in known manner by introducing the hydraulic binder paste according to the arrow E between the first facing material 2 and the second facing material 3 and passing the assembly between the upper platen 214 and lower 215 forming of the device.

The distance between the gears 201,202,203,204 and their symmetrical wheels is at least equal to that of the preform 5 so that these gears do not touch this preform 5.

The apparatus is set at a suitable height so that, during operation of the production line, the movement of the chain 206 resulting in that of the son connected to the links 207, these son pass into the forming plate, that is to say between the trays 214 and 215 and project downwards with respect to the upper plate 214. The space occupied by these wires between the upper plate 114 and the second facing material 3 is then reflected at this point by a thinning of the thickness of the preform 5.

It goes without saying that the operation of the motor is adjusted so that the chain 206 moves at the same speed as the preform 5. The son then accompany the preform 5 a few centimeters and, when it separates from it to go up by turning around the wheel 204, they leave an impression in the upper part of the preform 5.

As explained above, the electronic means of the production line are able to send an actuation signal to this apparatus, so that it carries out each imprint after receiving a detection signal from the additional detection means 303. .

Combined use of a device for producing impressions and a device for introducing laths

According to a particularly advantageous embodiment of the invention, the means for producing impressions cooperate with the slats introduction device under the preform 5 (consisting of the means 20 to 22 and 24 to 39 described above in FIG. relationship with Figures 11 to 15 ).

The additional actuation means are therefore capable, after detection of a mark 301 by the additional detection means 303, to send an actuation signal to the means for producing the imprint 12 or 12bis and a signal of FIG. actuation at the slat introduction device 6.

The apparatus which has just been described is used with reference to the figure 3 .

This variant is then advantageously disposed upstream of the slats introduction device.

The electronic means then preferably calculate the precise moment at which they must send the actuation signals to the fingerprinting apparatus and to the batten introduction device, so as to synchronize their operations, so that the batten is introduced. in a recess 12a on the underside of the preform 5, or, if the recess 12 is on the upper face of the preform 5, substantially opposite this recess 12.

According to a preferred embodiment of the cooperation between the device for producing impressions and the device slats introduction under the preform, the introduction of slats 23 under the preform 5 is operated in part by the apparatus for the realization of fingerprints.

As a variant, this mechanical link between the fingerprinting apparatus and the slat introduction device can be replaced by a combined apparatus combining both fingerprinting means and batten introduction means.

This makes it possible to obtain an easy and perfect synchronization of said apparatus and device, resulting in the introduction of the slats at the best time, or in other words, in the best place with respect to the preform 5.

In order to obtain such a synchronization, the cylinders 37 ( figure 15 ) are replaced by pushers 217 which can take place in the openings 36 of the rim 34 ( figure 11 ).

The chain 206 is then provided with a thrust pin 216 which is fixed on the outer side of the chain 206, that is to say the one opposite to that where the son are located. This thrust pin 216 has the function of hitting and moving the pusher 217 during the rotation of the chain 206. It can be fixed on a link of the chain 206 for example instead of a bearing axis of the roller of this link .

On the figure 16 , one can see the inclined surface 33 of the slats introduction device ( figure 15 ), as well as its flange 34 and a slat 23 resting on the inclined surface 33.

The shape of a pusher 217 is more visible on the Figures 17 and 18 . This pusher comprises a ruler-shaped elongated portion 218 provided at one end with a right-angled triangle-shaped portion 219 traversed by an axis 220 protruding from both sides of the portion 219. The vertex of the right-angled triangle is cut to give a face 221 parallel to the axis of the rule-shaped portion 218.

Returning to figure 16 it can be seen that the pusher 217 can occupy two positions. In its initial position (shown in dotted lines), it rests on the plate 215 and is turned towards the ground, so that its axis 220 is arranged transversely with respect to the preform 5 and its face 221 is located at the lower part of the inclined surface 33, in the opening 36 of the flange 34.

When the pusher 217 is hit by the pushing finger 216, it moves up the inclined surface 33. In doing so, it pushes the batten 23 which then comes to be inserted between the preform 5 and the conveyor belt 7.

The pushing finger 216 on the chain 206 is at a distance, relative to the threads held by the links 207, such that the slat 23 is introduced substantially opposite the location of the preform 5 where said threads come from form the imprint. This has the consequence that the movement of material caused by the introduction of the slat 23 is at least partially compensated by the imprint. It follows that the preform does not have a bump at the opposite point to where the slat 23 was introduced. This means that after removal of this slat 23, the thinning obtained on the underside of the preform 5 does not match any bump on the top of the preform 5.

The pusher 217 moved by the pushing finger 216 arrives in a second position ending in a receptacle, visible on the Figures 17 and 18 , and which is formed by two arcuate pieces 222 fixed by their upper ends on either side of the outer end 225 of the rod 223 of a jack 224. Each side of the axis 220 of the pusher 217 is received in an arcuate piece 222 and the portions 219 and 218 of the pusher 217 can be inserted into the space formed between the arcuate pieces 222, under the rod 223 of the jack 224.

On the Figures 17 and 18 , the rod 223 of the jack 224 is output, to receive the pusher 217.

However, as is visible on the figure 16 , by retracting the rod 223 of the jack 224 into the body of the latter, the pusher 217 is brought back above its initial position, then again emerging the rod 223 of the jack 224, the pusher 217 separates from the arcuate pieces 222 and falls back on the plateau 215. He then finds himself in his initial position with its face 221 inside the opening 36.

It goes without saying that the dimensions of the pusher 217 are chosen so that it remains above the inclined surface 33.

The cylinder 224 can be fixed to the frame 205 of the device, its location and its dimensions being determined according to the pusher 217 with which it must cooperate. The actuator 224 therefore has the function of returning the pusher 217 to its initial position. Its rod 223 is normally in the extended position, waiting to receive the pusher 217.

Of course, the entire apparatus is designed symmetrically, each of the chains being provided with a thrust finger 216 each cooperating with a jack 224, and in a synchronized manner.

The electronic and pneumatic (or possibly hydraulic) means of the production line control the operation of the apparatus for producing the impressions and the device for introducing the slats under the preform (constituted by the means 20 to 22 and 24 to 39 described above), so that once the pusher 117 returned to its initial position and the rod 223 of the cylinder 224 again output, a new slat 23 can be slid on the inclined plane 33.

It can be provided that the actuation of the jack 224 is determined by the detection for example, by means of a photoelectric sensor, the passage of a pin or finger fixed at a suitable place on the chain 206, for example the same the pushing finger 216, this pin acting as a flag, that is to say when it is detected by the photoelectric sensor disposed at a suitable place on the production line or the apparatus, the electronic means control the return of the rod 223 of the cylinder 224 in the body of the cylinder, this return causing, as explained above, the return of the pusher 217 to its initial position. Limit sensors of the cylinder 224, can then, once the rod 223 retracted, cause a new actuation of the cylinder 224 to out its rod 223, which drops the pusher 217 in its initial position.

The frame 205 of the apparatus can, as is apparent from the figure 16 to be integral with the trays 214 and 215. It follows that the device can be used in place of a flat forming or a master roll that is used conventionally.

Claims (17)

1. Apparatus for making an impression (12 or 12bis) in a preform (5) based on hydraulic binder, this apparatus comprising at least:

   - a frame (101); and characterized in that it comprises:

   - two first pulleys (102, 103) supported at a first end (104) of the frame (101) and two second pulleys (105, 106) at a second end (107) of the frame (101); the first pulleys (102, 103) and second pulleys (105, 106) being in parallel planes, the pulleys (102, 103) and (105, 106) facing each other being identical;

   - two transmission belts (108, 109) wrapped respectively around the first pulleys (102, 103) and the second pulleys (105, 106);

   - at least one wire (111) fixed removably to the belts (108, 109) and extending between these belts (108, 109) so that its longitudinal axis is parallel to the axis of rotation of the pulleys (102, 103, 105, 106).
2. Apparatus according to Claim 1, characterized in that it comprises a plurality of wires (111) arranged parallel to each other, along the transmission belts (108, 109) and fixed removably.
3. Apparatus according to Claim 1 or 2, characterized in that the pulleys (102, 103, 105, 106) are sprockets and the transmission belts are chains.
4. Apparatus according to Claim 3, characterized in that the wires (111) are held on the chains by means of support pieces (113) and wire gripper pins (114).
5. Apparatus according to one of Claims 1 to 4, further comprising means for driving the rotation of at least one of the pulleys (102, 103, 105, 106).
6. Apparatus according to one of Claims 1 to 5, further comprising an upper forming plate (214) and a lower forming plate (215) between which plates the wires (111) can pass.
7. Use of an apparatus according to one of Claims 1 to 6 in a production line for producing sheets based on hydraulic binder, particularly on plaster.
8. Method of manufacturing a sheet based on hydraulic binder from a preform (5) intended to be cut, this method comprising a step during which an apparatus according to one of Claims 1 to 6 is used to make an impression (12 or 12bis) in the preform (5), the apparatus being arranged in an appropriate way so that when its transmission belts are turning, its wire or wires (111) create the impression (12 or 12bis) in the preform (5).
9. Method according to Claim 8, characterized in that the preform is cut at the impression (12) or opposite the place where the impression (12bis) has been made.
10. Method according to Claim 9, comprising the following steps:

    1) a hydraulic binder composition (2) is poured onto a facing material (1) supported by a conveyor belt (7) so as to obtain a preform (5), then a lath (6, 23) the length of which is at least approximately equal to the width of the preform (5) is introduced under the preform (5);

    2) the hydraulic binder composition (2) is left to set and said lath (6, 23) is removed;

    3) the preform (5) is cut at the feathering (8) created by the lath (6, 23);

    and in which, before introducing the lath (6, 23), an apparatus according to one of Claims 1 to 6 is used to make an impression (12) in the preform (5) opposite the place where it is intended that the lath (6, 23) be introduced, or to make an impression (12bis) at the place where it is intended that this lath (6, 23) be introduced.
11. Method according to one of Claims 8 to 10, characterized in that the hydraulic binder contains plaster.
12. Production line for producing sheets based on hydraulic binder from a preform (5) comprising a facing material (1) covered with a hydraulic binder composition (2) and supported by a conveyor belt (7), characterized in that it comprises an apparatus according to one of Claims 1 to 6, the distance between the transmission belts (108, 109, 206) of this apparatus being at least equal to the width of the preform (5) and this apparatus being arranged in an appropriate way so that when its transmission belts (108, 109, 206) are turning, its wire or wires (111) creates or create an impression (12 or 12bis) in the preform (5).
13. Production line according to Claim 12, characterized in that it further comprises, near the conveyor belt (7), means (20-22, 24-39) for introducing a lath (6, 23) the length of which is at least approximately equal to the width of the preform (5) between the preform (5) and the conveyor belt (7) at the impression (12bis) or opposite the place on the preform (5) where the impression (12) has been made.
14. Production line according to Claim 12 or 13, characterized in that its transmission belts (206) each comprise a pushing finger (216) and pushers (217) resting on a plate (215) are provided, these pushers being able to be pushed by the pushing fingers (216) toward the preform (5) and in their movement to drive a lath (23), so that the latter is introduced under the preform (5), and means for returning the pusher (217) to its initial position.
15. Production line for producing sheets based on hydraulic binder according to one of Claims 12 to 14, characterized in that it further comprises means for covering the hydraulic binder composition (2) with a second facing material (3).
16. Production line for producing sheets based on hydraulic binder according to one of Claims 12 to 15 and comprising the apparatus according to Claim 6, this apparatus being situated above the preform (5) and replacing a forming plate or a forming roller, the wires (111) then passing between said upper plate (214) and lower plate (215).
17. Production line according to one of Claims 12 to 16, characterized in that the hydraulic binder contains plaster.

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