THAT IS TO BE MOUNTED ON ORBITAL SANDERS, AND DUAL- PURPOSE ORBITAL SANDER EQUIPPED WITH SAID PLATE

DESCRIPTION

The present invention regards a new-conception sanding plate that is to be mounted on an orbital sander, characterized in that it is equipped, on its bottom or operating face, with a detent or contrast element having a C-shaped curved end that is able to receive the rounded edge of a single slat, preventing it from being faceted during the sanding operations.

By adopting this stratagem, it is possible to use also an ordinary orbital sander for sanding not only plane surfaces but also the slats of wooden Persian blinds or the like provided that it has a disk in which it is possible to make the four holes for anchoring the plate in place.

The traditional system for sanding slats of wooden

Persian blinds envisages use of a sander with extended plane plate that enables sanding only of the upper and lower plane parts of the slats of Persian blinds. This sanding process produces, even before a finishing process of sanding by hand is carried out, faceting of the two rounded parts of the slats themselves. This entails the need to round off again said faceted surfaces, with a supplementary sanding process to complete sanding only of the upper part; also sanding of the lower part of the same slat poses the same problems. Finally, it is necessary to sand the internal lateral part of the upright that supports the slats between one slat and the next, which is so narrow as not to enable use of a tool, and hence this process must be carried out manually.

The task of the present invention is to overcome the above drawbacks by resorting to the stratagem of providing the bottom or operating face of an extended plane plate for orbital sanders with a C-shaped contrast element, which, by coming to bear upon the rounded part of the slat, prevents faceting thereof.

In a first embodiment, the plate in question constitutes an accessory that can be fixed by screwing in four points on the sanding plate or disk of a sander of an orbital type already in use, when it is necessary to carry out sanding of the slats of wooden Persian blinds, provided, however, that the sander has a disk in which it is possible to make the four anchoring holes. According to a characteristic of the invention, this plate is longer than the disk of the sander and comes to project from the latter for a stretch that extends outwards beyond the C-shaped contrast element for protecting the edges of the slats for a length such as to enable any slat to be sanded of a length of up to 10 cm or more. In said portion of plate, an array of through holes is made that enables discharge of the sawdust accumulated during processing and that extends from the C-shaped contrast element outwards so as to bring the rounded edge of the slat to bear upon the contrast element itself when the projecting portion of plate has substantially reached the entire surface of the slat.

In a second embodiment, the plate forming the subject of the present invention constitutes an integral part of the disk normally present on a plane sander, rendering the sander itself capable of sanding plane surfaces with the stretch of plate set beneath the fixed base, whereas it is possible to intervene operatively on the slat only with its jutting stretch provided with the array of holes.

As regards the abrasive sheets that are used by the machine in sanding operations, in order to facilitate replacement thereof, either for reasons of wear or in order to select a more effective grain size, there is envisaged the use of a Velcro kit that is adhesive on the side of the stainless-steel plate and grips on the other side and is provided with an array of holes corresponding to the one present on the plate to enable convenient fixing of various types of hook- and-loop replaceable abrasive sheets which are also appropriately provided with a similar array of holes.

Advantageously a sander of this dual-purpose type is provided with two ergonomic grips that extend in diametrally opposite directions with respect to the central body where the motor is contained. These ergonomic grips, in the form of bars, do not only have the purpose of facilitating gripping of the machine, but also have functional purposes. In fact, the grip applied on the front side is located lower down than the other and is slightly inclined upwards, and this enables a transverse movement to be made without the sander turning over and a higher pressure to be exerted on the wood, thus rendering sanding more efficient and reducing the processing time.

Further characteristics and advantages of the invention will emerge clearly from the ensuing description with reference to the attached plates of drawings, which illustrate, purely by way of non- limiting example, some preferred embodiments thereof.

In the plates of drawings:

Figure 1 shows in top plan view the sanding plate with the contrast element according to the invention;

Figure 2 is a side view of the same plate with the contrast element of Figure 1;

Figure 3 is a perspective view from beneath of the plate with the contrast element, turned through 90° with respect to the representation of Figure 1;

Figure 4 is a side elevation of a dual-purpose sander according to the present invention;

Figure 5 shows the same sander viewed from the front ;

Figure 6 shows the same sander in top plan view; Figure 7 shows the sander of Figure 6 in perspective view from above; and

Figure 8 shows the same sander in perspective view from beneath.

With reference to the figures, a sander of an orbital type, designated as a whole by the reference number 8, is equipped with a motor contained within a casing of a fixed base 12 and with an underlying mobile disk 14, on which the abrasive paper (not illustrated) is mounted.

The motor, which acts at a rate of approximately 3000 r.p.m., causes the disk to perform orbital movements with respect to the fixed plate in so far as said disk is guided by an oval-shaped groove. For sanding the slats of a wooden Persian blind, the present invention envisages the use of a plate 16, preferably made of stainless steel, bearing on its lower face, which is the operative one, a C-shaped transverse contrast element 24 that is able to receive the rounded edge of a single slat of the Persian blind. This plate 16 is fixed by screwing on the operating face of the disk 14. For this purpose, provided on the plate 16 are four 5-mm holes 18 for four steel bolts 5x20mm countersunk head indicated with reference 20, which, once they have been passed through corresponding holes made in the disk 14, are fixed with nut and lock nut .

According to a characteristic of the invention, the plate 16 has a length greater than that of the disk 14 so that, once it has been fixed, it will project from the latter for a stretch that extends outwards for a length of up to 10 cm , and beyond the C-shaped contrast element 24 that is to come into contact with the edges of the slats. In this portion of plate, an array of through holes 26 is made that enables discharge of the sawdust that accumulates during processing .

Advantageously, the distance of the contrast element from the free end of the plate is such as to bring the rounded edge of the slat to bear upon the contrast element itself when the plate has substantially engaged the entire surface of the slat.

In a preferred embodiment, the sanding plate is press-bent at the end that projects from the disk of the sander by bending the free end thereof outwards to form a C-shaped contrast element that is to receive the rounded edge of a slat.

As may be seen from Figures 5, 6, and 7, provided also in the C-shaped contrast element 24 are holes for discharging the sawdust produced.

To facilitate the sanding process, the sander forming the subject of the invention is provided with two ergonomic grips 28, 30, which extend in diametrally opposite directions with respect to the central body 10 where the motor is contained. These ergonomic grips, in the form of bars, not only have the purpose of facilitating gripping of the machine but also have functional purposes. In fact, the grip 28 applied on the front side is located lower down than the other 30 and is slightly inclined upwards, and this enables a transverse movement to be made without the sander turning over and a higher pressure to be exerted on the wood, thus rendering sanding more efficient and reducing the processing time.

With a sander equipped with the plate 16, by moving the sander all along the slat, it is possible to sand simultaneously the entire upper plane part of the slat, partially the lower part thereof, and the entire upper and lower curved part. By positioning the (abrasive) glass paper so as to wrap round the plate also laterally, it is possible to sand also the lateral surface of the internal upright that supports the slats between one slat and the next, possibly carrying out a movement in the direction of the depth, once again guided laterally by the contrast element.

Finally, to complete the operation of sanding of the underside of the slat, it is sufficient to turn the Persian blind over and proceed as for the upper side of the slat itself.