EP0041033A2 - Apparatus for applying a viscous liquid and in particular an adhesive mixture to a support, and a device provided with such an apparatus - Google Patents

Abstract

1. A device for applying a viscous liquid product, and more especially an adhesive mixture, to a face (F) of a moving support (L), which device comprises an applicator shoe (19) having, at one end, a nose (21) pierced with at least one orifice (22) for distributing the application product, which is normally placed in the immediate vicinity of said face (F) of the moving support and which communicates with an application product supply duct (14) equipped with a closure valve (15), characterized in that said applicator shoe (19) is mounted for pivoting about a fixed axis (20) substantially perpendicular to the direction of movement of the support (L) and comprises means (24, 25; 34, 35, 37) for positioning the nose of the shoe adapted for maintaining this latter in a variable work position, these positioning means comprising at least one resilient member (25; 37) which urges the shoe in its pivoting direction towards the support (L).

Description

The present invention relates to a device for applying a viscous liquid product, and in particular a sticky mixture, to a substantially flat face of a support moving in front of it, as well as an installation for gluing pieces of wood equipped with such a device.

In the field of the wood industry, and more precisely in the context of the paneling technique or the manufacture of glulam beams, gluing operations are often carried out on pieces of wood. To this end, various application devices are currently available, such as metering rollers which apply a film of glue to the pieces of wood or spray bars which deposit threads of glue on moving parts under they.

These devices have the drawback of being rigid in use and of a very limited field of application. In particular, they do not allow the pieces of wood to be glued in any position and are not suitable for all the widths and thicknesses of these pieces. It also does not have an adjustable automatic supply of sizing material which makes them unprofitable and leads, in the case of a continuous sizing of pieces of wood, to losses of sizing product. These drawbacks are also found in all types of application of a viscous liquid product on a support.

The present invention proposes to remedy these drawbacks and to do this it relates to an application device of the type specified above which is characterized in that it comprises an applicator shoe mounted pivotally. about a fixed axis parallel to said face and perpendicular to the direction of movement of the support while being inclined in the direction of movement of the latter, this shoe having at its free end a nose parallel to its pivot axis and pierced d '' at least one orifice connected, via a conduit fitted with a valve, to means for supplying the product to be applied, a control member, actuated automatically when one or other of the ends of the support reaches a predetermined position relative to the nose of the shoe, being provided to make the supply means and the valve active or inactive.

While being of a relatively simple structure, this application device can be adapted to all the thicknesses of the support to be coated with the product because its shoe is pivoting. Its feeding is also automatically triggered by the control unit and can be triggered at any time.

Preferably, the nose of the shoe has a width corresponding substantially to that of said face and is pierced with several orifices arranged in an alignment perpendicular to the direction of movement of the support, to allow the deposition of parallel product threads.

According to a first embodiment, the shoe comprises a tail which extends behind the pivot axis and radially with respect thereto, this tail being biased by a spring in the direction of pivoting of the shoe towards the plane movement of the support, to bring its nose in the path of the latter, so that as soon as the support comes into contact with the nose, the shoe automatically passes, against the action of the spring, from a position lowered from rest to a raised working position in which his nose is kept pressed against the support.

In combination, the control member is constituted by a reverse microswitch disposed in the path of movement of the tail so as to pass from its open position to its closed position when the shoe is raised to its working position. The supply of hoof product is thus triggered by the hoof itself when its nose is raised by the moving support.

According to a second embodiment, the shoe is mounted oscillating around a pivot perpendicular to the pivot axis and carried by a sleeve surrounding the latter, guide means integral with the shoe being provided to keep the latter centered on the face to be coated with product. These guide means comprise a pad capable of being applied to a edge of the support and a leaf spring intended to come to bear elastically on the other edge of the support.

Advantageously, the shoe comprises an arm connected at one end to the sleeve and receiving at its other end a screw which rests freely on a fixed support plate, a spring being provided to urge the arm towards this support plate. By acting on this screw, the arm can be moved relative to the support plate and thus adjust the height of the nose of the shoe relative to the face to be coated.

In combination with one or other of the embodiments of the shoe, the control member can be constituted by a microswitch placed on the path of the support to be actuated by one or the other of the ends of this during its movement or by a photoelectric cell whose light ray cuts the path of the support.

Preferably, the microswitch is slidably mounted on a graduated rule parallel to the direction of movement of the support. We can thus adjust the position of the micro-switch upstream of the hoof nose as a function of the speed of advancement of the support, to compensate for the response time of the hoof feed system and allow precise application of the product from from the front end of the support.

For the same purpose, the photoelectric cell is associated with an adjustable timer relay.

One can also provide, always in the same perspective, to equip the shoe with a buffer tank in which slides a piston which divides the buffer tank into two chambers, one of which is connected to the feed pipe of the shoe and communicates with the orifices via an electromagnetic valve sensitive to the control member and the other is permanently supplied with compressed air, the return stroke of the piston being limited by an adjustable stop constituted by a pulse contact mounted on the electrical circuit for controlling the feed means of the shoe and the valve. This creates a reserve of product which will be applied by the piston to the support during the response time of the supply system.

In a preferred embodiment, the nose of the hoof is constituted by a hollow ramp removably mounted on the free end of the hoof. It is therefore possible to mount on the shoe ramps of any length adapted to the widths of the supports to be coated with product, and in particular very long ramps for gluing the plywood panels. Thanks to this arrangement, it is also possible to adjust the orientation of the orifices of the nose of the shoe as desired.

• - la figure 1 est une vue schématique d'une installation pour . l'encollage de lattes de bois équipée d'un premier mode de réalisation du dispositif d'application selon la présente invention ;
• - la figure 2 est une vue de côté selon la flèche A de la figure 1, du sabot du dispositif d'application ;
• - la figure 3 montre une variante de montage de ce sabot ;
• - la figure 4 est une vue de côté, partiellement en coupe et à plus grande échelle d'un deuxième mode de réalisation du dispositif d'application selon l'invention ;
• - la figure 5 est une vue de dessus du dispositif d'application de la figure 4.;
• - la figure 6 représente en coupe une variante de montage de la rampe perforée du dispositif des figures 4 et 5 ;
• - la figure 7 est une vue de dessus d'une variante de réalisation de l'organe de commande équipant le dispositif des figures 4 et 5 ; et
• - la figure 8 est une vue de côté du nez du sabot équipé d'un réservoir-tampon.

Several embodiments of the invention will be described below by way of non-limiting examples with reference to the accompanying drawings in which:

• - Figure 1 is a schematic view of an installation for. the gluing of wooden slats equipped with a first embodiment of the application device according to the present invention;
• - Figure 2 is a side view along arrow A of Figure 1, of the shoe of the application device;
• - Figure 3 shows an alternative mounting of this shoe;
• - Figure 4 is a side view, partially in section and on a larger scale of a second embodiment of the application device according to the invention;
• - Figure 5 is a top view of the application device of Figure 4 .;
• - Figure 6 shows in section an alternative mounting of the perforated ramp of the device of Figures 4 and 5;
• - Figure 7 is a top view of an alternative embodiment of the control member fitted to the device of Figures 4 and 5; and
• - Figure 8 is a side view of the nose of the shoe equipped with a buffer tank.

We will first of all describe, with reference to FIG. 1, an installation for gluing wooden slats, in which the application device according to the invention finds a particularly advantageous use.

This installation is specially designed to ensure the continuous production of a sticky mixture from a resin and a hardener, and its application on wooden slats. To this end, it comprises two reservoirs 1 and 2 respectively containing resin and hardener, and each associated with a pump 3 or 4. The pumps 3 and 4 transfer, through conduits 5 and 6, two separate streams of resin and hardener in a two-piston volumetric doser 7. A filter 8 is also provided on the resin duct 5. The doser 7, which distributes the volume of the two products in a fixed ratio, feeds a mixing head 9 in which the two products are admitted separately through valves 10 and 11. The sticky mixture formed at the outlet of the head 9 is deposited in nets, by means of an application device 12, on displaced wooden slats L in succession in front of the latter by rollers 13. A flexible duct 14 on which a valve 15 is mounted connects the outlet of the mixing head 9 to the application device 12. A water supply 16 associated with a valve 17 makes it possible to clean the mixing head 9 during the per iodine not using it. The reference 18 designates a pneumatic cabinet which supplies compressed air to the pumps 3 and 4, the metering device 7 and the valves 10, 11, 15 and 17.

The application device 12, which is more precisely the subject of the present invention, is shown in a first embodiment in FIG. 1. As can be seen, this device comprises an applicator shoe 19 mounted pivotally around a fixed axis 20 parallel to the face F to be bonded to the slat L and perpendicular to the direction of movement of the latter. The axis 20 is carried by the frame, not shown, of the installation. The shoe 19 is further inclined in the direction of movement B of the slat L and has at its free end a nose 21 shaped as a bevel and parallel to the axis 20. As can be seen better in FIG. 2, the nose 21 has a width which corresponds substantially to that of the slat L and is pierced with orifices 22 which communicate, through internal channels 23 in the shoe, with the supply duct 14, these orifices being arranged in an alignment perpendicular to the direction of displacement of the batten L, to deposit thereon sticky mixture threads parallel to the edges of the batten.

Returning to FIG. 1, it can be seen that the shoe 19 has a tail 24 which extends behind the axis 20 and radially with respect thereto. The tail 24 is biased by a spring 25 in a direction which makes the shoe 19 pivot towards the plane of movement of the slat L so that its nose 21 is placed in the path of the latter. In this way, as soon as the slat L comes into contact with the nose 21 during its movement in the direction of the arrow B, the shoe 19 automatically passes, against the action of the spring 25, from a position lowered at rest (not shown) to a raised working position in which the nose 21 is kept applied against the slat L. The rest position of the shoe can be adjusted by a screw 26 constituting a stop for the tail 24.

The shoe 19 is supplied with a sticky mixture via a valve 15. This valve 15 as well as the valves 10 and 11 and the pumps 3 and 4 are made active inactive by a control member 27 disposed in the electrical circuit. control panel 18, and constituted here by a microswitch 27, arranged in the path of the tail 24 of the shoe to be moved by the latter during the pivoting of the shoe. Thus, when the shoe is in its lowered rest position, the micro-switch is raised by the tail 24 and cuts the power to the shoe. On the other hand, as soon as the shoe is raised by the batten, it is lowered, as shown in FIG. 1 and triggers the supply of sticky mixture of the shoe 19. Once the batten has completely passed the nose of the shoe, the latter it returns to its rest position, which stops its supply of sticky mixture.

It will be noted here that the shoe 19 can be mounted around a horizontal axis (see FIG. 2) for the gluing of slats moving flat, with a view in particular to the manufacture of glued laminated beams. However, the shoe 19 can be pivotally mounted about a vertical axis (see Figure 3), in order to equip paneling and lathing machines in which the slats are glued by being erected on one of their edges.

Figures 4 and 5 show a second embodiment of the application device according to the invention, in which the shoe 19 is mounted oscillating around a pivot 28 perpendicular to the axis 20 and-carried by a sleeve 29 surrounding with a slight game the latter. Furthermore, the shoe 19 carries on one side, a shoe 30 disposed along the path of the slat L, so as to come to apply, during the displacement of the latter, on one of its edges. A leaf spring 31, integral with the shoe, faces the shoe 30 and extends slightly in the path of the batten L so as to bear elastically on the other song of the latter. Thus, the moving batten is clamped between the shoe 30 and the leaf spring 31 so that the shoe 19 is kept perfectly centered on the axis of its face to be bonded even in the event of a lack of straightness of the edges.

It should be added that the leaf spring 31 is mounted, by means of a screw-nut assembly 32, on a slide 33 secured to the shoe 19, which extends perpendicular to the direction of movement of the slat. It is thus possible to adjust the position of the blade 31 as a function of the width of the strip to be glued.

While the first embodiment of the device according to the invention operates by contacting the nose 21 of the shoe 19 on the face F to be bonded, its second embodiment shown in FIGS. 4 and 5 is more specifically designed for application by severity of sticky mix threads.

To this end, the shoe 19 includes an arm 34 which maintains the nose 21 at an adjustable height of the slat L. The arm 34 is connected at one end to the sleeve 29 and receives at its other end a screw 35 which rests on a fixed support plate 36 forming part of the frame of the installation. A spring 37 working in compression biases the arm 34 towards this support plate 36. It will easily be understood that by acting on the screw 35, it is possible to raise or lower the nose of the shoe to adjust its height relative to the strip to be glued.

FIG. 4 also shows a preferred embodiment of the nose 21 in the case of the shoe of FIGS. 4 and -5. This nose is constituted by a hollow cylindrical ramp 38, removably mounted, by screws 38a, inside a yoke 39 secured to the free end of the shoe 19. The orifices 22 are produced, in this case, through the wall of the ramp, and the supply duct 14 communicates with the interior of the latter. It will be understood that one can, by this means, easily adapt to the shoe ramps of all lengths corresponding to the width of the support to be glued, wooden slat, plywood panel or others.

Another advantage of this embodiment of the nose lies in the fact that the orientation of the orifices 22 can be modified as desired. They can thus be directed perpendicular to the support L, as shown in FIG. 4, or obliquely in the direction of movement of the support, as shown in FIG. 6.

In combination with the shoe which has just been described, it is possible to use as a control member, a microswitch 40 placed along the path of the slat L so as to be actuated by it during its passage. The microswitch 40 is positioned upstream from the nose 19 of the shoe 21 and at a distance such that the time taken by the front end E of the batten to travel this distance is equal to the response time of the supply system, c 'that is to say, the time taken by the sticky mixture, to reach the orifices 22 from the instant of actuation of the micro-switch.

Similarly, as soon as the microswitch is released by the slat, the deposition of the sticky mixture stops exactly at the rear end of the slat without going beyond.

This arrangement is essential for precisely gluing wooden slats driven at high speed over their entire length. It goes without saying that the position of the micro-switch 40 must be modified as a function of the advancement speed of the batten and, for this reason, the micro-switch 40 is slidably mounted on a graduated rule 41 parallel to the direction of displacement of the slats.

As shown in FIG. 7, a photoelectric cell 42 whose light ray intersects the path of the slat L can play the same role as the micro-switch. However, the cell 42 is arranged in a fixed place and the change in the speed of advancement of the slats is compensated by the action of an adjustable timer relay 43 mounted in series with the cell 42 in the electrical control circuit of the cabinet 18.

The microswitch 40 or the photoelectric cell 42 can obviously equip the shoe of FIGS. 1 and 2 in place of the microswitch 27.

FIG. 8 represents another means of compensating for the response time of the supply system, adaptable to the shoe of FIGS. 1 and 2.

These means comprise a buffer tank 44 in which a piston 45 is slidably mounted which divides the buffer tank into two chambers 46 and 47. The chamber 46 is connected to the supply duct 14 of the shoe 19, and communicates with the orifices 22 of the latter by means of a solenoid valve 48 controlled by the microswitch 27. The other chamber 47 is permanently supplied with compressed air through a conduit 49. An adjustable stop 50 is further provided for limiting the return stroke of the piston 45 and fixing the volume of the chamber 46. This stop is in fact constituted by a pulse contact mounted on the electrical control circuit of the cabinet 18.

• Avant le passage de la première latte sous le sabot, le micro-contacteur 27 est ouvert en maintenant fermée l'électrovanne 48. On déclenche alors manuellement l'alimentation du sabot ce qui a pour effet de remplir la chambre 46 du réservoir d'une quantité R de mélange collant déterminée par la position du contact 50,réglée en fonction de la vitesse d'avancement et de la largeur des lattes. A l'instant où le piston 45,déplacé par le mélange collant,touche le contact 50, l'alimentation du sabot est stoppée.Ensuite dès que l'extrémité frontale de la première latte vient au contact du nez 21, l'électrovanne s'ouvre et, pendant le temps de réponse du système d'alimentation, le piston 45 pousse la quantité R de mélange collant à travers les orifices 22 en attendant l'arrivée normale du mélange collant par le conduit 14.

The compensation of the response time of the supply system using this buffer tank is carried out as follows:

• Before the passage of the first batten under the shoe, the microswitch 27 is opened while keeping the solenoid valve 48 closed. The feeding of the shoe is then manually triggered, which has the effect of filling the chamber 46 of the tank with a quantity R of sticky mixture determined by the position of the contact 50, adjusted as a function of the speed of advance and the width of the slats. At the moment when the piston 45, moved by the sticky mixture, touches the contact 50, the feed to the shoe is stopped. Then as soon as the front end of the first batten comes into contact with the nose 21, the solenoid valve s opens and, during the response time of the supply system, the piston 45 pushes the quantity R of sticky mixture through the orifices 22 while awaiting the normal arrival of the sticky mixture through the conduit 14.

At the moment when the slat escapes the nose 21 of the shoe 19, the microswitch opens and the solenoid valve 48 closes. During the response time of the supply system, the chamber 46 of the buffer tank then fills with the quantity R of sticky mixture for the next supply cycle.

It goes without saying that this buffer tank can equip a shoe of the second embodiment associated with a micro-switch or a photoelectric cell placed fixed at the nose of the shoe.

It is easy to understand that the application device according to the invention allows precision gluing, automatic and continuously, of pieces of wood moving in succession in front of it, without loss of sticky mixture. It can be adapted to all the widths and thicknesses of the pieces of wood and allows gluing in all positions, and in particular horizontal and vertical, of these.

The device according to the invention can of course be used for the application of any viscous liquid product on any type of rigid support.

Claims (18)

1. Device for applying a viscous liquid product, and in particular a sticky mixture, on a substantially flat face of a support moving in front of it, characterized in that it comprises an applicator shoe (19) pivotally mounted about a fixed axis (20) parallel to said face (F) and perpendicular to the direction of movement of the support (L) while being inclined in the direction of movement (B) of the latter, this shoe having at its free end a nose (21) parallel to its pivot axis (20) and pierced with at least one orifice (22) connected via a conduit (14) equipped with a valve (15) , to means for supplying the product to be applied (3,4, 10, 11), a control member (27; 40; 42), actuated automatically when one or other of the ends of the support reaches a position predetermined with respect to the nose of the hoof, being provided to make the supply means and the valve active or inactive. 2. Device according to claim 1, characterized in that the nose (21 ¹ ) of the shoe (19) has a width corresponding substantially to that of said face (F) and is pierced with several orifices (22) arranged in a perpendicular alignment to the direction of movement of the support (L). 3. Device according to claim 1 or 2, characterized in that the shoe (19) comprises a tail (24) which extends behind the pivot axis (20) of the shoe and radially with respect thereto , this tail (24) being biased by a spring (25) in the direction of pivoting of the shoe towards the plane of movement of the support, to bring its nose (21) in the path of the latter, so that as soon as the support comes into contact with the nose, the shoe automatically switches, against the action of the spring, from a lowered position of rest to a raised working position in which its nose is kept pressed against the support by the spring ( 25). 4. Device according to claim 3, characterized in that the movement of the tail (24) of the shoe (19) in said pivoting direction is limited by an adjustment screw (26) forming a stop. 5. Device according to claim 3 or 4, characterized in that the control member is constituted by a reverse microswitch (27) disposed in the path of displacement of the tail (24) so as to pass from its open position to its closed position when the shoe (19) is raised to its working position. 6. Device according to claim 1 or 2, characterized in that the shoe (19) is mounted oscillating around a pivot (28) perpendicular to the pivot axis (20) and carried by a sleeve (29) surrounding this last, solid guide means (30, 31) of the shoe (19) being provided to keep the latter centered on the axis of the face (F) to be coated with product. 7. Device according to claim 6, characterized in that the guide means comprise a shoe (30) adapted to be applied on a edge of the support and a leaf spring (31) intended to come to bear elastically on the other support song. 8. Device according to claim 7, characterized in that the leaf spring (31) is mounted, by means of a screw-nut assembly (32), on a slide (33) perpendicular to the direction of movement of the support. 9. Device according to any one of claims 6 to 8, characterized in that the shoe comprises an arm (34) connected by one end to the sleeve (29) and receiving at its other end a screw (35) which is supported freely on a fixed support plate (36), a spring (37) being provided to urge the arm (34) towards this support plate (36). 10. Device according to any one of claims 1 to 4 and 6 to 9, characterized in that the control member is constituted by a micro-switch (40 ') placed on the path of the support (L) to be actuated by one or the other of the ends thereof when moving the support. 11. Device according to claim 10, characterized in that the micro-switch (40) is slidably mounted on a graduated rule (41) parallel to the direction of movement of the support (L). 12. Device according to any one of claims 1 to 4 and 6 to 9, characterized in that the control member consists of a photoelectric cell (42) whose light ray intersects the path of the support (L) . 13. Device according to claim 12, characterized in that the cell photoelectric (42) is fixed mounted and is associated with an adjustable timer relay (43). 14. Device according to any one of claims 1 to 10 and 12, characterized in that the shoe is equipped with a buffer tank (44) in which slides a piston (45) which divides the buffer tank into two chambers one of which (46) is connected to the feed duct (14) of the shoe (19) and communicates with the orifices (22) by means of a solenoid valve (48) sensitive to the control member, and the other (47) is permanently supplied with compressed air, the return stroke of the piston (45) being limited by an adjustable stop (50) constituted by a pulse contact mounted on the electrical circuit for controlling the supply means (3 , 4, 10, 11) and the valve (15). 15. Device according to any one of claims 1 to 14, characterized in that the nose of the shoe is constituted by a hollow ramp (38) removably mounted on the free end of the shoe (19) and pierced with the orifices (22) . 16. Device according to claim 15, characterized in that the ramp (38) is mounted in such a way that its orifices (22) are directed perpendicular to the face (F) of the support (L). 17. Device according to claim 15, characterized in that the ramp (38) is mounted in such a way that its orifices (22) are directed obliquely in the direction of movement of the support (L). 18. Installation for gluing flat supports such as slats or wooden panels, comprising two reservoirs (1, 2) respectively containing a resin and a hardener, a two-piston volumetric dispenser (7) connected to the reservoirs by pump intermediate (3, 4), a mixing head (9) supplied by the metering device, through valves (10, 11), to produce a sticky mixture and a sizing member (12) for depositing this mixture on the support (L), characterized in that the sizing member is constituted by the application device according to any one of claims 1 to 17, the control member of the latter acting on the valves (10, 11 and 15) and on the pumps (3 and 4).

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