Joint for right-angle connection of two wooden boards.

The present patent application for industrial invention relates to a joint for right-angle connection of two wooden boards, preferably used to form a window frame.

The peculiarities and advantages of the invention will become more evident after a short description of the prior art.

As it is known, wood workers often need to fix wooden boards or sections in right-angle configuration, typically when making window frames, and also when building furniture components, such as doors, panels and the like.

Traditional fitting systems, such as mortise and tenon joints or dovetail joints, are generally used in these situations.

However, the parts to be connected in right-angle configuration undergo very sophisticated and expensive operations. Moreover, the mounting of these parts requires a highly skilled operator,

In view of the above, the purpose of the present invention is to devise a right-angle connection method for wooden boards or sections that is especially simple and inexpensive.

An additional purpose of the present invention is to make said right- angle connection possible also for unskilled workers without the use of sophisticated tools.

In other words, the present invention allows do-it-yourself users to assemble the various parts of a wooden frame or any other frame structure purchased as an assembly kit.

The inventive idea of the present invention is to obtain a metal joint made of two metal bars that are mutually joined with fast-coupling and "drowned" in the thickness of the two boards to be connected in right-angle configuration.

In particular, the first board is provided in the front with a metal bar on the transversal edge, facing the second board.

The second board is provided with a metal bar mounted in lateral position on the longitudinal edge, facing the first board near the end to be connected in right-angle configuration with the first board.

The first of said bars is frontally provided with two hooks adapted to be exactly coupled, after a suitable sliding movement, with two hooks provided on the second bar and basically acting as housing and retention seats.

After coupling the two bars, their mutual position must be stabilized in order to prevent them from uncoupling and disconnecting the wooden boards joined with them.

Such stabilization can be obtained by means of a stop pin that prevents any additional mutual sliding movement between the two bars as illustrated in detail in the description below.

In order to understand the practicality of the new technology, it must be noted that the two metal bars that cooperate on the boards to be connected can be very easily mounted by the user as long as the boards are provided with suitable grooves to house the bars.

The operator simply needs to screw the metal bars into the grooves provided on the wooden boards to be connected in right-angle configuration.

For explanatory reasons, the description of the invention continues with reference to attached drawings, which only have an illustrative, not limiting value, wherein:

- Figure 1 is an axonometric view of the two metal bars of the joint of the invention before being mounted on the boards; - Figure 2 is an axonometric view of the same two bars after being mounted on the boards and mutually coupled.

Referring to said figures, the joint of the invention (G) is formed of two flat metal bars (1 , 2) with narrow elongated shape, which are adapted to be mutually coupled.

The first bar (1 ) is frontally provided with a pair of identical hooks (10, 1 1 ) directed along the longitudinal axis (x-x) of the bar (1 ) and contained in the width of the same.

In particular, each of said hooks (10, 1 1 ) is formed of a basically parallelepiped projection directly projecting from the front side of said first bar (1 ) and provided on the most external section with a point disposed in such manner to define a compartment (12) in combination with the front side of the first bar (1 ).

Moreover, the points of the two hooks (10, 1 1 ) are faced towards the same direction, it being provided that the distance between the first hook (10) and the second hook (1 1 ) is higher than the length (z) of each hook.

The first bar (1 ) is provided with a through hole (1 a) adapted to be crossed by a screw (V1 ) used to fix it against the wooden board (T1 ).

According to the preferred embodiment shown in the attached figures, two identical parallel arms (13) diverge perpendicularly from the two longitudinal ends of said first bar (1 ), facing the opposite side with respect to the hooks (10, 1 1 ).

Each arm (13) is provided with at least one through hole (13a) adapted to receive a fixing screw (V1 ').

Also the second bar (2) is frontally provided with a pair of identical hooks (20, 21 ) having a basically identical shape and size as the hooks (10, 1 1 ) provided in said first bar (1 ).

In view of the above, each of the hooks (20, 21 ) of the second bar (2) is formed of a basically parallelepiped projection provided in the most external section with a point disposed in such manner to define a compartment (22) in combination with the front side of the second bar (2).

Also the two hooks (20, 21 ) of the second bar (2) are provided with points facing the same direction and directed along the longitudinal axis (y-y) of the second bar (2), as well as contained in the width of the same; likewise, the distance between the first hook (20) and the second hook (21) is higher than the total length (z) of each hook.

Also the second bar (2) is provided with through holes (2a) adapted to be crossed by screws (V2) used to fix it against the wooden board (T2).

It must be noted that the second bar (2) is provided, at the height of one of its ends and in correspondence of the front side, with a parallelepiped block (23) disposed in such manner that its longitudinal axis (k-k) is parallel to the longitudinal axis (y-y) of the second bar (2); it being also provided that said block (23) is centrally crossed by an axial cylindrical hole (23a) with threaded walls.

The distance between said parallelepiped block (23) and the first hook (20) of the second bar (2) is higher than the total length (z) of each of said two hooks (20, 21 ).

The second bar (2) is frontally provided with a first housing, comprised between the block (23) and the first hook (20), which is adapted to receive the first hook (10) of the first bar (10) when the two bars (1 , 2) are brought in contact one against the other. Moreover, the second bar (2) is provided with a second housing comprised between the first hook (20) and the second hook (21 ), which is adapted to receive the second hook (1 1 ) of the first bar (1 ) when the two bars (1 , 2) are in interfaced position.

Given the basically identical shape of the two bars (1 , 2), it is easy to understand that their mutual interference causes an additional condition, wherein the first hook (20) of the second bar (2) is engaged into the housing provided between the first hook (10) and the second hook (1 1 ) on the front of the first bar (1 ), whereas the second hook (21 ) of the second bar (2) is engaged against the front side of the first bar (1 ) in more external position with respect to the second hook (1 1 ) of the same.

Reference is made to Fig. 2 for a better understanding of the cooperation mode of the two bars (1 , 2). As shown, the bars (1 , 2) are designed to be substantially mounted in the center of the thickness of the wooden boards (T1 , T2) to be mounted in right-angle configuration.

For this reason, a surface portion of the two wooden boards (T1 , T2) has been removed in both figures, being this the only condition to make the two bars (1 , 2) visible.

Referring to the same figures, it must be noted that the first bar (1 ) must be positioned in such manner that its back side is engaged against one of the transversal edges (BT) of the first wooden board (T1 ), basically having the same length.

When in such a position, the first bar (1 ) must be firmly fixed with the screws (V1) that are engaged in the wood of the first board (T1 ) after crossing the through holes (1 a).

According to the embodiment shown in the attached figures, the first bar (1 ) is provided at its ends with the opposite arms (13) that project from the opposite side with respect to the hooks (10, 1 1 ).

In order to house the two parallel arms (13) the first wooden board (T1 ) is provided with two identical grooves (S1 ) obtained on the longitudinal edges.

After being inserted into the grooves (S1 ) of the first board (T1 ), the arms (13) are firmly fixed with the screws (V1 ') that are engaged in the wood of the first board (T1 ) after crossing the through holes (13a).

In order to mount the second bar (2) a groove (S2) is obtained on one of the longitudinal edges (BL) of the second board (T2) at the height of its end. The second bar (2) is firmly engaged inside said groove (S2) with the fixing screws (V2) that are engaged in the wood of the second board (T2) after crossing the through holes (2a) of the second bar (2).

In particular, such a groove (S2) has a suitable depth to completely house the second bar (2) together with the hooks (20, 21 ) and the block (23), as well as to exactly contain the first bar (1 ) in its mouth, when it is interfaced with the second bar (2). In particular, such a housing capability of the groove (S2) is shown in Fig. 2.

Moreover, while mounting the two bars (1 , 2) in the wooden boards (T1 , T2), the hooks (10, 1 1 ; 20, 21 ) must be positioned in such manner to face opposite directions. The right-angle connection of the two boards (T1 , T2) provided with the bars (1 , 2) is illustrated below.

The hooks (10, 1 1 ) of the first bar (1 ), which is fixed to the transversal edge (BT) of the first board (T1 ), are inserted inside the groove (S2) obtained on the longitudinal edge (BL) on the second board (T2), thus providing exact interface with the second bar (2) that is already fixed in position.

During such an operation, the two hooks (10, 1 1 ) of the first bar (1 ) are inserted in the insertion points provided on the front of the second bar (2).

The first hook (10) of the first bar (1 ) is inserted between the block (23) and the first hook (20) of the second bar (2). Likewise, the second hook (1 1 ) of the first bar (1 ) is inserted between the first hook (20) and the second hook (21 ) of the second bar (2).

When the two bars (1 , 2) are in interfaced position, the first hook (20) and the second hook (21 ) of the second bar (2) reach the insertion points provided on the front of the first bar (1 ).

In particular, the first hook (20) of the second bar (2) is inserted between the first hook (10) and the second hook (1 1 ) of the first bar (1 ), whereas the second hook (21 ) of the second bar (2) is positioned on the front of the first bar (1 ) in more external position with respect to the second hook (1 1 ) of the latter.

Now, the board (T1 ), and the first bar (1 ) joined to it, slides transversally in such manner that the points of the two hooks (10, 1 1 ) of the first bar (1 ) are exactly inserted into the compartments (22) provided on the back of the points of the hooks (20, 21 ) of the second bar (2).

Further to such an operation, the points of the hooks (20, 21 ) provided on the second bar (2) are exactly engaged inside the compartments (12) provided on the back of the points of the hooks (10, 1 1 ) of the first bar (1 ) as shown in Fig. 2.

At least theoretically, such a mutual coupling between the hooks (10, 1 1 ; 20, 21 ) of the two bars (1 , 2) can be impaired by the occasional inverse sliding movement of the first bar (1) with respect to the second bar (2), possibly caused by the stress transmitted by the board (T1 ) .

In order to prevent such a possibility, a stop pin (24) is provided and adapted to engage in said axial hole (23a) of the block (23) provided on the second bar (2).

As shown in Fig. 2, said pin (24) is provided with stem (24a) having a higher length than the insertion hole (23a), in such manner that, after coming out from the opposite part of said block (23), said point is brought in contact against the first hook (10) of the first bar (1) that lies in the proximity of the block (23).

The contrast produced by said pin (24) in favor of said first hook (10) of the first bar (1 ) prevents the latter from occasionally sliding "backwards" with respect to the second bar (2), thus generating the uncoupling of the cooperating hooks (10, 1 1 ; 20, 21 ).