EP0198778B1 - Machine for the application of a treatment product to a wood, metal or plastic beam - Google Patents

Abstract

An apparutus for coating a liquid on an elongated profile having a longitudinally extending front surface and a longitudinally extending back surface has a housing forming a generally closed treatment chamber and having an inlet opening and an outlet opening spaced downstream along a treatment path extending through the chamber from the inlet opening. Both openings are of a size and shape slightly larger than the section of the molding. A mist of the coating liquid is supplied to the chamber. An upwardly open channel guide extending in the chamber between the openings is formed with an upwardly open groove open longitudinally at each of the openings. This guide is generally complementary to the back surface of the molding. The molding is displaced through the chamber from the inlet to the outlet opening with its back surface in engagement with the channel guide over the groove so that the molding generally upwardly closes the groove to form same into a passage having ends open longitudinally substantially only at the inlet and outlet openings. The chamber is evacuated so as to draw outside air thereinto through the openings and into the ends of the passage.

Description

The subject of the invention is a machine intended for the treatment, and more particularly for the decoration of any profile made of wood, metal, plastic material, etc .; and this is how it aims, for example, at decorating moldings used for the manufacture of picture frames or the like or for decorating furniture of all kinds, the term "decoration" being taken in its most meaningful sense. general to include in particular the painting and varnishing of these moldings.

To clarify the description below, it will mainly be a question of decorating wooden moldings, without however resulting in a limitation of the scope of the invention to this single application.

Considering therefore, by way of example, the decoration of wooden moldings, it is known to carry out this decoration continuously, by means of a machine in which the molding, animated by a movement of continuous movement by an endless belt , passes through a chamber in which the product to be applied (for example paint or varnish) prevails in the state of mist. To obtain this mist atmosphere, the product to be applied is introduced under pressure and in the liquid state into the aforementioned chamber, after having passed through a grid placed in its lower part, and the chamber traversed by the molding is in depression because it is connected to a vacuum pump.

On two of its opposite walls, the product application chamber has two openings which face each other and allow the free passage of the molding. By moving continuously in this chamber in which the product to be applied prevails in the state of mist, the molding receives the product to be applied, which product is deposited on the molding; and it is important to observe that this deposit is made on all sides and therefore on the entire surface of the molding, which results in a relatively large consumption of product, when in reality, certain faces of the molding do not not worth treating. This is so for the faces of the molding which will be invisible when this molding is used. These are in particular the rear face of the molding and possibly grooves which can be arranged in the molding to be used for its fixing or to receive additional elements, which is the case for example when the molding is intended for manufacturing. picture frames.

The subject of the invention is a machine which is of the general type mentioned above, but which, thanks to a particular arrangement, allows a saving of treatment product, because thanks to this arrangement, the product is only applied to the subsequently visible faces of the molding.

For this purpose, the box delimiting the treatment chamber comprises a guide which extends between the inlet and outlet orifices of the molding in and out of the box, is traversed longitudinally both by the molding and by a current of air from the outside through the orifices and created by the depression prevailing in the box, and successively comprises an upstream zone annularly closed around the molding and in which the mist of treatment product does not prevail, and a downstream zone which only obscures the areas of the molding that should not be subjected to this fog.

In any case, the invention will be clearly understood with the aid of the description which follows, with reference to the appended diagrammatic drawing representing, by way of nonlimiting example, an embodiment of this machine.

• Figure 1 is a general view;
• Figures 2 and 3 are, on a larger scale, views respectively in cross section and in longitudinal section of the box or chamber for applying the treatment product;
• Figure 4 is a perspective view of the molding guide;
• Figure 5 and 6 are, on a larger scale, cross sections along V-V and VI-VI of Figure 4.

In FIG. 1, (1) designates the product application box, and (2) designates a reservoir located below this box. In this tank is contained the treatment liquid (3); and a pump (4) is provided to send this liquid through a pipe (5) in the lower part of the box. A vacuum pump (6), driven by a motor (7), is provided to create a vacuum in the tank (2) above the treatment liquid (3). Above this pump (6), the machine frame carries an endless belt (8) which is driven in a continuous movement movement and is intended to convey and pass the molding (9) through the treatment box (1) of which two opposite lateral faces are equipped with two doors (10) which are located opposite and have orifices (12) profiled to allow the free passage of the molding respectively at its entry into the box (1) and at its exit from this box.

The vacuum produced by the vacuum pump prevails not only in the tank (2), but also in the box or chamber (1) for applying the product, because a connection is made between this tank and this box by means of two chimneys side (13) which opens into the upper part of the box.

As for the liquid treatment product, it is admitted to the lower part of the box (1 as has been indicated above. This admission is carried out through the pipe (5) which opens into a rigid tube (14) placed longitudinally and having openings (15) through which the treatment product is caused to move upwards, due to the vacuum prevailing in the box (1); and.so that the liquid thus brought into the box becomes a mist , a grid (16) is placed horizontally in the lower part of the box, above the supply tube (14), but below the area to be crossed by the molding (9).

In this zone, the box (1) is provided with a guide, generally designated by (17). This guide is constituted on the one hand, by a base plate (18) which allows its fixing on supports (19) provided in the box (1), and on the other hand, by a profile (21) having two zones (20a, 20b) whose arrangement is different. In the first zone (20a), which is the upstream one, this profile has two lateral wings (21a) connected by a profiled upper wing (21b); and in its downstream area (20b), the profile (21) only includes the two lateral wings (21c).

The guide (17) further comprises, internally, an element (22) whose profile is a function of that of the lower or rear face of the molding (9). It is in fact, for this molding, its face or its areas of faces which will not have to be covered with the treatment product.

In the case shown, by way of example, in the drawing, it is a molding intended for the manufacture of picture frames; and the inner element (22) of the guide (17) then has a U shape whose two legs are of unequal height and which, by its legs, delimits a channel (23) communicating with the outside, outside the box (1).

It is important to observe that there is a play in the molding (9) inside the guide (17) and that this guide (17) communicates with the outside through the orifices (12) provided in the doors ( 10) to allow the passage of the molding.

Thanks to this communication of the guide (17) with the outside, and thanks to the play of the molding (9) in the guide (17), the vacuum prevailing in the box (1) causes a call for air through the orifices (12) of the doors (10), and a current of air is thus established in the guide (17), under all the regions of the underside of the molding (9). As a result, the treatment liquid cannot be deposited in these zones and ultimately only deposits on the part of the molding which appears in the downstream zone (20b) of the guide (17), namely above the two lateral wings (21 a) and downstream with respect to the upper wing (21 b) of the guide (17). In other words, the treatment product is applied to the molding only in a reduced area of the guide (17). This is its second zone (20b), that is to say that located downstream of its upper wing (21b); and it is in this downstream area that only the areas of the molding which will be visible during the use of this molding are finally covered with the treatment product.

This arrangement allows a considerable saving in treatment product.

This is an essential advantage that can be taken advantage of regardless of the shape of the molding. It suffices for this that the guide (17) is easily removable and that this guide has a shape depending on that of the molding. By simply changing the guide, it becomes possible to process moldings of very different shapes.

Claims (4)

1. A machine for the application of a liquid treatment product to a moulding of the type in which the moulding, transported by an endless belt, passes through a container to the lower part of which the treatment liquid is admitted and in which a reduced pressure exists that causes the liquid to pass through a grill contained in the container and to transform itself into a mist in which the moulding is moved, characterised in that the container (1) comprises, above the grid (16), a guide (17) that extends between the orifices (12) by which the moulding (9) enters into and departs from the container (1 is ion- gitudinally traversed both by the moulding (9) and by a current of air flowing from the space outside trough the orifices (12) and induced by the reduced pressure existing inside the container, and comprises in succession a forward region (20a) that is annularly closed around the moulding and inside which the treatment product mist does not exist, and a rear region (20b) that shields only those portions of the profile moulding that should not be subjected to this mist.

2. A machine according to Claim 2, characterised in that its guide (17) is formed by a baseplate (18) fitted inside the container and by a profile fitted to this plate which in the forward region (20a) of the guide is formed as an inverted «U», and in the rear region (20b) of the guide only possesses two wings (21 c) that extend the two side-limbs of this «U».

3. A machine according to Claims 1 and 2, characterised in that its guide (17) comprises an internal element (22) acting as a sliding path for the moulding (9) and in which a groove (23) is machined that opens out outside the container (1) and contributes to the creation of a current of air beneath the moulding.

4. A machine according to any of Claims 1 to 3, characterised in that the internal unit (22) of the guide (17) has a transverse cross-section that is complementary to that of the moulding (9).

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