ES2367094T3 - DEVICE DISTRIBUTION DEVICE. - Google Patents

Abstract

A glue distributing apparatus comprises roller means (2) for applying a glue to an element to be glued (50), tank means (3) containing said glue and provided with an opening (3a) for conveying said glue to said roller means (2), and adjusting means (4), interposed between said roller means (2) and said opening (3a) for adjusting a quantity of glue transferred to/from said roller means (2), said adjusting means (4) comprising doctor blade means (5, 6) provided with respective cavity means (5a, 6a).

Description

[0001] The present invention relates to a glue distribution apparatus, in particular, an apparatus for distributing glue in a woodworking machine, such as a edge coating machine or a edge and edge coating machine. square

[0002] These machines, which normally perform the operations of coating panels, tables, flat elements of wood or similar material, include glue distribution devices or units that deposit or distribute a layer of adhesive glue on bands, tapes or cords that will be applied to the edges of the panels, or directly to the edges of said panels.

[0003] The adhesive used is generally a heat fusion glue that has to be properly heated before being "hot" applied to the surfaces to be joined. The glue is applied by means of a rotating glue application roller, which has a striated or rough outer surface, which retains and transmits the glue, supplied by a reservoir or container. The latter is made of a non-stick material and is provided with heating elements, such as electrical resistors, to heat the glue evenly and keep it fluid.

[0004] In some glue application units, the glue container is placed under a work area, and suitable supply means, for example, a spindle conveyor, transfers the glue from said lower tank to the application roller. of glue.

[0005] However, such devices have the disadvantage of heating the working area in excess, since the tank with the heating resistors is placed in a position in which the heat produced cannot dissipate, so it diffuses to the adjacent areas and especially upwards, in the glue application roller.

[0006] In order to overcome this serious inconvenience, which may cause a malfunction or even breakage of mechanical elements of the apparatus, glue distribution apparatus are known which are provided with glue deposits located next to the application roller. of glue and extending upwards. In this way the heat generated by the resistances of the tank can be dissipated to the external environment and does not affect, unless it is slightly, the work area and, in particular, the roller and the corresponding moving elements.

[0007] The reservoir has a bottom or chamber provided with an opening, through which the glue flows by force of gravity towards the glue application roller. The latter partially closes said opening and, by turning, transfers and distributes the glue on the surfaces of the elements to be joined.

[0008] Within the lower chamber there is generally provided, interposed between the roller and the opening, a glue adjustment means comprising fixed scrapers for adjusting the amount of glue that is distributed on the grooved surface of the glue application roller .

[0009] In particular, these devices may contain a first scraper, called a dosing scraper, to deposit or spread a uniform layer of glue, of a fixed thickness on the glue application roller, and a second scraper, called a return scraper or recovery, which recovers excess glue from the roller that has not been transferred to the surface to be glued. The return scraper also keeps foreign bodies out of the chamber.

[0010] The scrapers are arranged parallel to each other at a predetermined distance, in front of the opening of the lower chamber of the reservoir, such that they form a cavity in which the glue that is collected from the roller accumulates.

[0011] Each scraper comprises a flat elongated element, provided with an edge that rests on the glue application roller along a generatrix thereof, functioning substantially as a "spatula" to distribute a uniform layer of glue over said roller.

[0012] Alternatively, each scraper can consist of a cylindrical pivot, arranged parallel to the glue application roller and with a longitudinal plane that constitutes a flat surface that transmits and distributes the glue on the roller.

[0013] A glue distribution apparatus according to the preamble of claim 1 is known, for example, from DE 3447592 A.

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[0014] EP0945235 describes a edge covering device for panels comprising means for applying a band in the edge, the means consisting of a shaft driven by a motor, which defines a main vertical axis, which has a roller mounted and driven which makes contact with the panel edge. The contact roller rotates freely around a vertical axis of the main shaft. On the opposite sides of the contact roller there are means for supplying glue and at least one main pressure roller of the edge band, these means being in turn connected to the shaft that forms the main shaft such that they can oscillate around of the tree according to the profile of the panel.

[0015] The scrapers, due to their shape and arrangement, form in the lower chamber of the tank a cavity within which the rotation of the glue application roller causes the formation of turbulence and swirls in the liquid glue it contains.

[0016] This turbulent flow causes uneven distribution of the glue in the roller since this glue is distributed unevenly along the height of the roller.

[0017] In fact, it has been observed that an amount of glue is deposited on an upper part of the roller which is smaller than that deposited on the lower part. This causes an application of irregular glue since a layer of glue with an uneven thickness is applied to the surfaces to be glued.

[0018] Turbulent flow and vortices in the liquid glue intensify as the speed of rotation of the glue application roller increases, for example, if it is necessary to spread the glue on the rapidly moving parts, so In general, edge and square coating machines that machine straight panels in line, with high speeds of rectilinear movement. This drawback of known glue distribution devices usually forces the production speed of the machines to be reduced.

[0019] An object of the invention is to improve known glue distribution apparatus, in particular for woodworking machines for machining elements of wood or similar materials. Another objective is to obtain a glue distribution apparatus that allows a uniform and homogeneous distribution of glue in a glue application roller along its entire length.

[0020] In the invention, a glue distribution apparatus is provided as defined in claim 1.

[0021] Due to this aspect of the invention, it is possible to obtain a glue distribution apparatus for uniformly and homogeneously distributing the glue in the roller medium throughout its length. The presence of cavities made in the scraper means substantially reduces, during the operation of the apparatus, the formation of turbulence and swirls in the liquid glue near the roller means. In this way, the glue can regularly reach all the points of the roller medium, along its entire length. The apparatus also allows to precisely and effectively adjust a distribution of glue on the surface to be glued, especially the thickness of the glue layer to be applied.

[0022] The invention will be more understandable and can be practiced more easily by reference to the accompanying drawings, in which some embodiments of the invention are shown by way of non-limiting example, and in which:

Figure 1 is a schematic partial section, taken along a longitudinal plane, of the glue distribution apparatus of the invention;

Figures 2 and 3 are schematic partial sections, taken along a plane II-II of Figure 1, showing the scraper means in the respective different working positions;

Figure 4 is a schematic partial section taken along a longitudinal plane of a version of the apparatus of the invention;

Figures 5 and 6 are schematic partial sections, taken along a plane V-V of Figure 4, showing the scraper means in the respective different working positions and a closing means in an open position;

Figure 7 is a section like that of Figure 6, in which the closing means is in a closed position.

[0023] Referring to Figures 1 to 3, a glue distribution apparatus is shown schematically comprising a roller means 2, a reservoir means 3 and an adjustment means 4.

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[0024] The roller means 2 comprises a rotating roller, of known type, with a rough or grooved outer surface 2a for removing, transferring and applying a predetermined glue layer on an element 50 to be glued.

[0025] Roller 2 rotates by drive means, of known type and not shown in the figures, and can rotate both clockwise and counterclockwise, depending on the elements 50 to be glued. For example, roller 2 rotates clockwise to glue strips or tapes in the process called "soft forming", while rotating counterclockwise to glue edges of panels or tables for edging, in the process called straight "straight." The reservoir means 3, which contains the glue and is placed next to the roller means 2, extends upwards and is provided with an opening 3a for transferring said glue to the roller means 2. The reservoir means 3 is provided with a plurality of electric heater elements 23 that allow to heat and melt the glue evenly and keep it fluid.

[0026] The opening 3a of the reservoir means 3 has a height that is almost the same as that of a part of the roller 2 configured to receive the glue.

[0027] The adjustment means 4 is interposed between the roller means 2 and the opening 3a to regulate an amount of glue transferred to the roller 2 for later application on an element 50 to be glued. The adjustment means 4 is further configured to recover from the roller 2 the excess glue that has not been distributed in the element 50.

[0028] The adjustment means 4 comprises scraper means 5, 6, provided with respective cavity means 5a, 6a. The scraper means comprise a first scraper 5 and a second scraper 6.

[0029] Each scraper 5, 6 is an element with a longitudinally elongated shape, for example, an axis with an approximately cylindrical section, in which a respective cavity 5a, 6a is made, consisting of an open hollow space that extends longitudinally for approximately the entire length of the element. The cavity 5a, 6a is, for example, a straight groove with a U-shaped cross section having a concave bottom wall.

[0030] The two scrapers 5, 6 are arranged parallel to each other and separated from each other such that the respective cavities 5a, 6a are almost in front of each other to form a volume or space 7 that is shaped to contain the glue.

[0031] It has been found that said cavities 5a, 6a significantly reduce and limit the formation of turbulence and swirls in the liquid glue during the rotation of the roller 2. This allows an almost uniform and homogeneous distribution of the glue throughout the entire length of the roller. 2, regardless of the speed of rotation of the roller 2.

[0032] Each scraper 5, 6 comprises a support part 5b, 6b, configured to contact the roller 2, and a sealing part 5c, 6c suitable for resting on a respective seat 3b, 3c of the reservoir means 3.

[0033] With reference to Figures 2 and 3, the support part 5b, 6b, for example, is an edge formed on the outer surface of the scraper, while the sealing part 5c, 6c is a part of said surface exterior that has a concave shape, complementary to a seat shape 3b, 3c, for example, a cylindrical surface part.

[0034] Each scraper 5, 6 is rotatably mounted around a respective axis of rotation 5d, 6d, in order to be able to move between a first working position A and a respective second working position B. The axes of rotation 5d, 6d are parallel to each other and are also parallel to an axis 8 of rotation of the roller 2.

[0035] In the first working position A, the support part 5b, 6b of the scraper 5, 6 rests substantially on the outer surface 2a of the roller 2 to adjust the pitch of the glue that will be deposited on the roller and evenly distributed said glue on said outer surface 2a.

[0036] In the second working position B, the support part 5b, 6b of the scraper 5, 6 is separated from a respective outer surface 2a of the roller 2 to allow the excess glue to be recovered in the roller 2 and, at the same time, avoid the entry of possible foreign bodies in volume 7.

[0037] A drive means, of the type known and not shown in the figures, is provided for rotating the scrapers 5, 6 between the two working positions.

[0038] The scrapers 5, 6 can be mounted so that they rotate independently, actuated separately by respective drive means.

[0039] Alternatively, the scrapers 5, 6 can be mounted associated with each other and connected by suitable interconnecting means, such that they rotate together. Said interconnection means may be of the mechanical type, for example, pulley or gear mechanisms, or of the electronic type, for example, electronic control means of the drive means.

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[0040] When the scrapers 5,6 are interconnected, one turn of one scraper corresponds to the same turn of the other scraper. More specifically, and with reference to Figures 2 and 3, when for example the first scraper 5 is in the respective first working position A, the second scraper 6 is in the respective second working position B. In this case, the apparatus 1 is in a first operating configuration P in which the roller 2 rotates counterclockwise, for example, to apply the glue on the edge of a panel 50.

[0041] The rotation of the first scraper 5 in the respective second working position B coincides with the rotation of the second scraper 6 in the respective first working position A. In this case, the apparatus 1 is in a second operating configuration Q in which the roller 2 rotates clockwise, for example, to apply glue to a strip or tape 50.

[0042] The scraper 5, 6 can also be made as a single body. In this case, the respective axes 5d, 6d of rotation are coincident.

[0043] Figures 4 to 7 show a version of the apparatus 1 comprising a closing means 10, which is mobile and is interposed between the roller 2 and the opening 3a of the reservoir means 3 to close and / or open said opening 3a .

[0044] In particular, the closure means 10 can be inserted between the adjustment means 4 and said opening 3a.

[0045] The closing means 10 can move between a closed position C, in which said opening 3a closes to prevent the glue from passing from the reservoir means 3 to the roller 2 (Figure 7), and a completely open position D, in which opens said opening 3a and allows the glue to pass through it (Figures 5, 6).

[0046] In an intermediate position, which is not illustrated in the Figures, the closure means 10 can adjust a flow of glue towards the roller 2, partially closing the opening 3a.

[0047] The closure means 10 comprises an elongate, substantially cylindrical element, rotatably mounted on a rotation axis 11.

[0048] The closing means 10 also has a passage 12 comprising a longitudinal through opening that allows the glue to transit and having a length that is almost equal to the height of the opening 3a.

[0049] The closure means 10 is in a respective suitable seat 3d made in the reservoir means 3, within which it can rotate.

[0050] In this version of the apparatus 1, the adjustment means 4 comprises a pair of scrapers 15, 16 made of a single body and rotate about respective rotation axes 15d, 16d, which in this case coincide.

[0051] More precisely, the adjustment means 4 comprises an elongated tubular element 19 which is substantially cylindrical with an open section, provided with two opposite and opposite parts 15, 16 that act as scrapers.

[0052] Each scraper 15, 16 has a respective bearing part 15b, 16b, configured to rest on the outer surface 2a of the roller 2, and a respective sealing part 15c, 16c, configured to rest on said respective middle seat 3d Deposit 3.

[0053] As shown in Figures 5 and 6, it is sufficient to rotate the tubular body 19 of the adjustment means 4 to place the two scrapers 15, 16, at the same time and precisely in the respective working positions. In particular, when the apparatus 1 is in a first operating configuration P, the first scraper 15 is in a respective first working position, that is, substantially resting on the roller 2 to adjust the glue passage in the roller, and the second scraper 16 is in a second respective working position, that is, separated from the roller 2 to allow the recovery of excess glue. On the other hand, when the apparatus 1 is in a second operating configuration Q, the first scraper 15 is in a second respective working position and the second scraper 16 is in a respective first working position.

[0054] The tubular body 19 of the adjustment means 4 has a cylindrical inner cavity 17 into which the closing means 10 is coaxially inserted.

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[0055] In addition, a through slot 18 is provided, made in a wall of said tubular element 19 and facing said support edges 15b, 16b. The glue coming from the reservoir means 3 can pass through the groove 18 to reach the roller means 2.

[0056] This version of the distribution apparatus 1 thus comprises an adjustment means 4 and a closing means 10 in a very compact structure.

[0057] The adjustment means 4 comprising two scrapers 15, 16, which are integral and movable at the same time, allows to adjust and control the glue distribution on the surfaces to be glued in a simple, fast and efficient way, regardless of the direction of rotation of the roller 2.

[0058] At the same time, the closing means 10 can close the opening 3a tightly, thus preventing the

10 glue reaches the roller 2 and escapes through the passages and openings of the outer surface 2a of said roller during the idle phases of the apparatus.

[0059] The closure means 10 comprises a pair of recesses 13, 14, made in an internal wall of step 12 throughout the entire length of the latter.

[0060] The recesses 13, 14 are substantially equal and are arranged symmetrically with respect to a plane

Longitudinal symmetry S of the closing means 4. In particular, said recesses 13, 14, which have a practically U-shaped section, are arranged to form a respective cavity 20 that converges in the roller means 2.

[0061] By means of the recesses 13, 14, it is possible to considerably reduce the formation of turbulence or swirls in the liquid glue during the rotation of the roller 2, in order to obtain a practically uniform and homogeneous distribution of glue over the entire length of roller 2, regardless of the speed of rotation thereof. In

In another version of the apparatus 1, not shown in the Figures, the respective cavities may be provided on the walls of the tubular body 19 of the adjustment means 4 on the scrapers 15, 16.

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Claims (13)

1. Glue distribution apparatus comprising a roller means (2) for the application of glue to an element to be glued (50), a storage means (3) containing said glue and provided with an opening (3a) for transferring said glue to said roller means (2), and an adjustment means (4) interposed between said roller means (2) and said opening (3a) for adjusting the amount of glue transferred to / from said roller means (2), wherein said adjustment means (4) comprises scraper means (5, 6) provided with means of respective cavity (5a, 6a), said scraper means (5, 6) comprising two scrapers, characterized in that each scraper is provided with a respective cavity (5a, 6a), in which each cavity (5a, 6a) has a section substantially U-shaped

2.

 Apparatus according to claim 1, wherein said scraper means (5, 6) is movable mounted so that it can be moved between a respective first working position (A), to regulate the passage of the glue to be distributed on said means of roller (2), and a respective second working position (B), to recover excess glue from said roller means (2).

3.

 Apparatus according to claim 2, wherein said scraper means (5, 6) is rotatably mounted around an axis of rotation (5d, 6d).

Four.

 Apparatus according to claim 3, comprising drive means for moving said scraper means (5, 6).

5.

 Apparatus according to any of the preceding claims, wherein said scrapers (5, 6) are made in a single body.

6.

 Apparatus according to any of the preceding claims, comprising means for interconnecting said scraper means (5, 6).

7.

 Apparatus according to any of the preceding claims, wherein said scrapers (5, 6) are mounted in such a way that when a scraper (5, 6) is in the first working position (A) the other scraper (6, 5) It is in the second working position (B) and vice versa.

8.

 Apparatus according to any of the preceding claims, wherein each scraper (5, 6) comprises an elongate element, in particular, a shaped shaft.

9.

 Apparatus according to any of the preceding claims, wherein each scraper (5, 6) comprises a support part (5b, 6b) suitable for resting on the roller means (2).

10.

 Apparatus according to any of the preceding claims, wherein each scraper (5, 6) comprises an outer part (5c, 6c) suitable for resting on a respective seat (3b, 3c) of the reservoir means (3).

eleven.

 Apparatus according to any of the preceding claims, wherein each cavity (5a, 6a) extends longitudinally over almost the entire length of the respective scraper (5, 6).

12.

 Apparatus according to any of the preceding claims, wherein said scrapers (5, 6) are substantially parallel.

13.

 Apparatus according to claim 12, wherein said scrapers (5, 6) are substantially parallel to said roller means (2).