Field of the invention

The present invention relates to a set of panels and connectors for surface coating structures.

The invention refers to the large variety of panels or slats which serve to cover horizontal and vertical surfaces of floors and walls. By panels, slats, listels or the like, is meant any coating element which is greater in length than in width. For simplicity this coating element will be called in the following only panel. Panels laterally connected to each other are called adjacent, while panels that follow each other longitudinally are called consecutive.

Prior art

A panel of those currently commercially available is joined to the adjacent panels along its lateral ends. The arrangements to connect these panels are various, generally by fixed joints that keep precise lateral gaps between adjacent panels. The surface coatings often have aesthetic functions, and it would be desirable that the lateral gaps be always of the same size. Therefore, the current panels allow identical lateral gaps to be maintained thanks to the fixed joints or other types of existing lateral connections, but this does not happen for the gaps at the longitudinal ends of the panels since it seems that no connection between consecutive panels has been so far provided. This connection will be cited in the following as a head connection. Due to the absence of this connection various causes, such as thermal expansions, structural tensions and other, can lead to a variation of the dimensions of the longitudinal gaps between one end and the other of consecutive panels.

US-1,445,901 discloses a wall structure including building blocks, each provided with holes used inter alia for a link between consecutive blocks by means of U- shaped bars.

US-4,228,628 discloses a brickwork consisting of building blocks stacked to form horizontal continuous superimposed layers. The high sides of the blocks in the lower layers and the low ones of the blocks in the immediately upper layers have symmetrical mirror setting cavities for receiving spherical connectors. Further auxiliary connectors can be provided to connect to one another neighboring blocks of each layer. These auxiliary connectors are shaped as ribs received in aligned channels of the respective blocks, and as end portions which extend into blind holes of such blocks.

It should be understood that the above cited patents relate to walls and not to coating structures, and connectors or similar connecting elements are used to structurally connect together the building elements.

FR 2691491 describes a parquet element formed by a rectangular plate formed from a set of traditional juxtaposed parquet panels. Formed in the lower part of the rectangular plate, on both opposite sides, are elongated recesses terminating internally with an orthogonal hole. There is no head connection of individual panels. EP 2740858 mentions "near panels" that are connected in the bottom with various connecting elements.

DE 102008053230 describes locking elements as long as the sides of the panels. The locking elements are equipped with pins for engagement in holes formed on the sides of the panels.

EP 2878743 describes substantially panels fitted in their lower side with recesses in which pairs of protrusions formed on elongated slats are likely to fit. Each strip connects across all the overlying panels. In turn, the slats are received in a substrate made of shaped cross-section s.

The object of the present invention is to allow the gap between consecutive panels not to be affected by the lapse of time only for aesthetic purposes.

Another object is to provide panels equipped with means to maintain such a gap constant in the course of time, without requiring use of tools for installing the panels. These can, therefore, be placed only by hands on the surface to be coated. Summary of the invention

These and other objects and advantages are achieved by a set of panels and connectors for surface coating structures, each panel having a visible part and a hidden part opposite to the visible part, side portions for engagement with adjacent panels and longitudinal end portions, in which the hidden part of each panel has at least one cavity in each of its longitudinal end portions, the cavity being adapted to partially receive a connector for the head connection of consecutive panels, according to features as defined in the main claim attached to the present description and in the dependent claims.

Brief description of the drawings

Embodiments of the invention are shown in the detailed description which follows, with reference to the accompanying drawings in which:

- Figure 1 is an end view of a set of panel and connector according to an embodiment of the present invention;

- Figure 2 is a partial perspective view of the panel in Figure 1 from the hidden side opposite to the visible one;

- Figures 3 to 5 area perspective view, an end view and an enlarged side view, respectively, of the connector in Figure 1 ;

- Figure 6 is a partial exploded perspective view of a first panel with a connector and of a second panel before their mutual connection; and

- Figures 7 to 10 are end views of variants of the panel with connector identical to that in Figure 1.

Description of embodiments of the invention

Reference is made initially to Figures 1 and 2, which are an end view of a set of a panel 1 and a connector 2 according to an embodiment of the present invention and, a partial perspective view of the panel in Figure 1 from its hidden side, respectively. The panel 1, which is designed to rest on a base frame, is described in detail in pending patent application RM2014A000219 of the same Applicant; therefore it will not be here described in detail in its parts. For convenience the visible side of the panel 1 is indicated as 3, while its hidden side opposite thereto is indicated as 4. The panel 1 has side portions 5, 6 for the engagement with adjacent panels (not shown). The panel 1 differs from that described and illustrated in the above cited patent application by the fact that the hidden side 4 of the panel has a longitudinal groove 7 in a central position. Further, the panel 1 differs from that disclosed in FR 2691491 where there are transversal grooves for the engagement between adjacent panels, and not between consecutive panels. The longitudinal groove 7 has a prismatic profile with side walls 8 and 9 and a bottom 10. Formed in the bottom 10 is a blind hole, preferably cylindrical, indicated as 11. The blind hole 11 is preferably formed in a longitudinal panel end portion indicated as 40. The longitudinal groove 7 of prismatic profile has a rectangular cross-section with corners 12, 13 that are internal to the panel and rounded.

Advantageously, as will be described later, a further longitudinal slot 14 is formed in the bottom 10 of the longitudinal groove 7 of the panel 1.

As will be understood better later, the prismatic profile of the longitudinal groove 7 can be different from that shown; further, more blind holes 11 may be present, as well as more longitudinal slots 14 can be formed on the base 10.

As explained below it is convenient that longitudinal knurls 15 are formed on the side walls 8 and 9 of the longitudinal groove 7 of prismatic profile.

The connector 2 is shown in greater detail in Figures 3 to 5 which are a perspective view, an end view, and an enlarged side view of the connector in Figure 1, respectively. It can be seen that the connector 2 has a body with shape complementary to the cavity of the panel 1 obtained by combining the prismatic profile of the longitudinal groove 7, the cylindrical blind hole 11, and the further longitudinal slot 14.

Therefore, the connector 2 has a body 16 of prismatic shape with a rectangular cross-section. The body 16 has an outer face 17, opposite side faces 18, 19 and an inner face 20 opposite to the outer face 17. A pair of cylindrical pins 21, 22 protrude from the inner face 20, but they may be greater in number, and an elongated projection 23, which is interrupted in the intersection with the cylindrical pins 21, 22. The body 16 has chamfered edges 24, 25 between the opposite side faces 18, 19 and the inner face 20, respectively.

The opposite side faces 18 and 19 of body 16 of the connector 2 have knurls generically indicated as 26 for half of their length, in particular in the portion 27 of the side faces 18 and 19, while a portion 28 thereof that lacks knurls has a smooth surface. The knurls 26 have preferably a horizontal direction, i.e. longitudinal, and are projecting with respect to the smooth surface of the portion 28 of the same side faces 18 and 19. Reference is made now to Figure 6, which is a partial exploded perspective view of a first panel 1 with a connector and of a second panel 29 before their mutual connection. Shown with dashed lines are only the relative longitudinal grooves 7 as cavities of interest. For clarity, the connector 2 is represented with continuous lines also in its hidden side internal to the panel 1. The first panel 1 and the second panel 29 are cut transversely to their longitudinal direction with cross-section plans a and β·

Joined to the panel 1 is the connector 2 in its longitudinal groove 7 according to the present invention. It should be understood that in the mutual engagement of the connector 2 with the panel 1, the body 16 of the connector 2 occupies a portion of the longitudinal groove 7, its cylindrical pin 21 is inserted in the blind hole 11 formed in the bottom 10 of the longitudinal groove 7, while the elongated projection 23 of the cylindrical connector 2 is inserted in the longitudinal slot 14, also formed in the bottom 10 of the longitudinal groove 7.

The function of the connector 2 in the connection between the first panel 1 and the consecutive second panel 29 should be easily understood. When in work, the gap between the end 30 of the panel 1 and the end 31 of the panel 29 remains constant in the course of time without undergoing changes due to thermal expansions or changes in humidity, stresses and other causes that could alter the coating structure made of such panels. The mutual engagement of the elongated projection 23 with the longitudinal slot 14 is useful to maintain aligned the panels, although these are already engaged laterally with the adjacent panels.

In the installation the connector 2 is kept adhering to the panel 1 thanks to the presence of the longitudinal knurls 26 of the connector 2 and of the longitudinal knurls 15, formed on the side walls 8 and 9 of the longitudinal groove 7 of prismatic profile. These longitudinal knurls are not essential but they are effective for maintaining the panel 1 in connection with the connector 2 in the installation before the panel 1 rests on the ground. It is obvious that the longitudinal knurls 26 may be formed on the entire side faces 18 and 19 of the connector 2, but this could lead to difficulties should the coating structure formed by the set of panels and connectors of the invention be removed.

It should be apparent that the present invention is not limited only to the use of the panels described in the above cited Italian patent application. In fact, such invention can be put into practice also with panels of different cross-sections and profile. By way of example, some panels are shown in the figures 7 to 10 that are end views of variants of the panel with identical connector to that in Figure 1. These variants of panel are configured so as to rest on a flat surface without engagement with a base frame, but only through their side portions.

Shown in Figures 7 and 8 are two variants of panel, respectively, having the same side portions for a male-female engagement with adjacent panels. The panel 32 in Figure 7 has a full cross-section while the panel 33 in Figure 8 has a lightened cross- section with square prismatic cavities 34. The side female portions are generally indicated as 35.

Shown in figure 9 is a variant of the panel according to the present invention, indicated generally as 36 and provided with lateral engagement portions 37.

Shown in figure 10 is a variant of the panel indicated as 38 in whose hidden part 39 double longitudinal grooves generically indicated as 7 are formed, as in the previous figures. The variant 38 of the panel according to the present invention is useful when the panels have a considerable width.

The embodiment of the invention has been described with its variations only as an example because other modifications may be made without departing from the scope of the invention defined by the appended claims.