The present invention relates to a joint adapted to connect two or more section beams, that is beams in the form of section bars. Such a joint is particularly useful for assembling carrying structures of the type designed, for example, to build greenhouses, protecting roofs and so on, obtained by means of section beams that may be of the channel, Tee and, particularl ,I-type.

It is known that when carrying structures are accomplished by means of section beams, the individual beams are usually connected to each other by means of metal plates fastened to the latter by bolting, riveting or welding.

This connecting method which is almost universally utilized in the sector, involves a series of drawbacks of different types.

One of these is due to the fact that, owing to the great number of bolts or rivets used and/or on account of the time required for carrying out welding, the mutual connection of the beams always appears long and difficult This situation assumes a particularly negative character when such operations have to be carried out for example at some height from the ground or in hardly accessible locations, which often happens when the beams have to be connected on already partially assembled structures.

A further drawback related to the above mentioned plates resides in that each of them is specifically adapted to

- 2 - connect to one another a predetermined number of beams according to a determined angular disposition. As a result, it is necessary to dispose of many types of differently-shaped plates in order to be in a position to connect the beams each time in the most appropriate manner. But, on the one hand, this fact involves high costs for producing said plates while, on the other hand it gives rise to serious problems as to the storage of the same. In addition, it must be ^" noted that the connection of two or more beams according to a determin¬ ed angular disposition can take place only if the beams are cut according to a determined angle depending upon the angular disposition that it is desired to obtain. This fact too adversely affects the practical use of said plates.

Further drawbacks reside in the mechanical characteristics of the plates. In fact they have an elastic behavior, due to the fact that small slidings between the various parts jointed together always occur. Furthermore and above all, referring particularly to the case in which the connection between the plates and the beams takes place by riveting or bolting, it may happen that the rivets or bolts utiliz¬ ed are submitted to important shearing stresses caused by the tendency of the connected parts to slide. This often results in the deformation of the rivets and bolts which tend to take a longitudinal S-shaped development. This is an important drawback especially when, referring particularly to the use of bolts, the above structures need -to be periodically disassembled and assembled again. In fact in this case it becomes very hard to remove the deformed bolts from their housings.

- 3 - For the purpose of solving the above mentioned draw¬ backs at least partially, joints consisting, for example, of two or more tubular members suitably dimensioned and oriented with respect to each other have been provided, each of them being designed to receive a beam in engagement, which could be fastened thereto in the manner described above with reference to the metal plates.

With the use of said joints it was no longer necessary to cut the beam ends at an angle and the connection of the same became quicker, but all the other drawbacks proper to the metal plates remained unchanged.

The object of the present invention is therefore to solve the above mentioned prior art drawbacks and to provide a joint adapted to be universally used for the quick connection of a suitable number of section beams according to any angular disposition, which joint must also have a reduced cost.

The foregoing and still further objects that will become more apparent in the following description are substantial _^ ly achieved by a joint for connecting two or more section beams, of the type comprising perforated plates engageable in a removable manner to the ends of said beams and to one another, characterized in that it comprises at least two connecting members, each of them consisting of a connecting plate having flat and parallel faces and exhibiting a rounded profile in the form of an arc of a circle and a through hole obtained concentrically there¬ to and at right angles to said faces, as well as provided with at least a shoulder in the region of one of its

- 4 - flat faces and at a distance from the centre of said through hole equal to the radius of said arc of a circle; and of an attachment flange, having a substantially rectangular profile, extending in a parallel and suitably offset plane with respect to the extension plane of said connecting plate, and rigidly connected to the latter in the region of their sides in common,said connecting members being engageable to each other in a rigid and removable manner, upon disposing the respective- connecting plates side by side, by means of a threaded element engaged in the respective through holes, each of said connecting members being also rigidly engageable with a respective section beam through said attachment flange.

Further features and advantages will become more apparent from the detailed description of a preferred embodiment of a joint for connecting two or more section beams, according to the present invention, given hereinafter by way of non-limiting example with reference to the accompanying drawings, in which:

- Figs. 1 and 2 show a front and side view respectively of a connecting member being part of the joint in question;

- Figs. 3 and 4 show a front and side view of the connect¬ ing member seen in Figs. 1 and 2 but rotated through 180°; - Fig. 5 is a perspective view of the connecting member seen in Fig. 1 ;

- Fig. 6 shows the joint in question mounted on section beams of the I-type;

- Fig. 7 is a sectional view taken along the line VII- VII in Fig. 6;

- Fig. 8 is a sectional view taken along the line VIII- VIII in Fig. 6;

- 5 -

- Fig. 9 is a sectional view taken along the line IX-IX in Fig. 6;

- Fig. 10 shows a further possibility of application of the joint according to the invention.

Referring particularly to figures 1 to 9, a joint designed to connect two or more section beams according to the present invention is generally identified by the reference numeral 1. As it is possible to see, it is made up of a number of connecting members 2, suitably disposed symmetri£ ally to the main extension axis of two section beams 3 and 4 that have to be mutually engaged.

Referring particularly to Figs. 1 to 5, each connecting member 2 is comprised of a connecting plate 5 and of an attachment flange 6 rigidly connected to each other in the region of their sides in common 7. In the embodiment shown, the connecting plate 5 and the attachment flange 6 are of one piece construction and are obtained by molding.

The connecting plate 5 exhibits two flat and parallel main faces, as well as a profile in the form of an arc of a circle 8 turned towards the opposite part with respect to the common side 7. In greater detail, the connecting plate can be considered as a quadrangular plate one side of which corresponds to the total height of the section beam 3 or 4 while, obtained tangentially to the other three sides is the above mentioned profile in the form of an arc of a circle 8.

In addition, a through hole 9 of an appropriate diameter has been machined concentrically to said profile and at

right angles to the main faces of the connecting plate 5.

The attachment flange 6 is in turn composed of a plate¬ like member of rectangular flat form, one long side of which, equal to the height of the section member core, corresponds to the common side 7.

Due to the dimensional differences between the connecting plates 5 and the attachment flange 6 άn the region of their common side 7, the connecting plate 5 is provided with two abutments 10 adapted to act on the ends of the section beam 3 or 4 for the purposes to be described below.

As shown in Figs. 1 and 3, the attachment flange 6 has a rounded section in the region of its edges 6a extending at right angles to the common side 7 in order to allow said flange to be readily connected to the section beam 3 or 4. In addition, the attachment flange 6 extends in a plane parallel to and slightly offset with respect to the plane of extension of the connecting plate 5.

According to a preferred embodiment, it is provided that such offsetting as well as the thickness of the attach¬ ment flange 6 are adapted to cause, in the region of the common side 7, the projecting of the connecting plate 5 relative to the attachment flange 6 on one side and the projecting of the attachment flange relative to the connect¬ ing plate on the other side. In greater detail it is possible to see that the projecting of the connecting plate 5 relative to the attachment flange 6 is such as to create a shoulder 12 on the latter, the thickness of which is equal to half the thickness of the

- 7 - section beam core. Likewise, the projecting of the attach¬ ment flange 6 relative to the connecting plate 5 forms a shoulder 13 on the latter, the thickness of which is equal to the connecting plate 5 itself less half the thickness of the section beam core.

By virtue of these features, the joint 1 may advantageous¬ ly consist of four connecting members 2 which, as previous¬ ly mentioned, are symmetrically mounted, two by two, at the ends of the respective section beams 3 or 4 that have to be mutually connected, as shown in Fig. 7.

In said figure it is possible to see that the end portion of the core of each section beam 3 or 4 is surrounded by the attachment flange 6 of the corresponding connecting members 2, engaged thereto through threaded connecting elements 14 engaging into the corresponding holes 11 as well as further holes 15 previously machined in the core of the section beams 3 or 4. Once mounted on the respective section beams 3 or 4, the connecting members 2 extend the respective connecting plates 5 parallelly and outwardly to the beam 3 or 4.

In greater detail, the connecting members 2 mounted on the section beam 3 are disposed so that they mutually mate in the region of the respective connecting plates 5. The connecting members related to the section beam 4, i"n turn, are substantially rotated through 180° with respect to the connecting members 2 related to the section beam 3, and therefore they have their respective connecting plates 5 symmetrically spaced apart from each other.

- 8 - The mutual connection of the section beams 3 and 4 is obtained by the engagement of the connecting plates corresponding to the beam 3 in the space comprised bet¬ ween the connecting plates corresponding to the beam 4 and by the engagement of a threaded element 16 into the through hole 9.

Advantageously, the beams 3 or 4 can be connected accord¬ ing to any angular disposition that can be easily adjusted before tightening the threaded element 16.

A further example of application of the joint according to the invention is shown in Fig. 10.

in this case the joint is adapted to connect to one another three section beams,identified respectively at 17, 18 and 19, according to any angular disposition.

For the purpose, the joint 1 comprises six connecting members 2, four of them mounted on the respective beams 17 and 18 in the same manner as described with reference to the connection of the two section beams 3 and 4. The remaining connecting members 2 are connected to the beam 19 in the same manner as specified with reference to the assembling of the connecting members 2 with the beam 4 seen in Fig. 7, upon interposing, for each of them, a shim 20 which, advantageously, can have a structure similar to that of the attachment flange 6. The shims 20 are interposed for the purpose of suitably spacing apart the connecting members 2 from each other, in order to enable the introduction of the connecting members 2 related to the beams 17 and 18 into the space existing therebetween.

- 9 - In this case too, like in the preceding embodiment, the connection of the beams 17, 18 and 19 is obtained by means of a threaded connecting element 16 engaged into the through holes 9.

After the above description it can be readily understood that, by the simple addition of connecting members 2 as well as of the necessary shims 20, it is possible to achieve joints 1 adapted to connect an appropriate number of section beams.

The operation of the present invention does not need further explanations. It will be however recognized that, as shown in Fig. 6, the subject joint is structured in such a way that it discharges the stresses to which it is submitted directly onto the corresponding beams, without stressing the threaded connecting elements 14 and 16, except for the case in which the beams are submitted to a tensile stress,which seldom happens in carrying structures of the above type.

This operative feature is ^' determined both by the presence, on the connecting members 2, of the shoulders 13 which oppose _^ themselves to the action of the connecting plates 5 acting on the same in the region of the respective profiles in the form of an arc of a circle 8, and to the action of the shoulders 12 and of the abutments 10 acting directly on the end portion of the corresponding beam in the region of the core and of the wings of the same respectively, and by the contact between the edges 6a of the attachment flanges 6 and the wings of the beam, which defines the rigid engagement between the same, discharging the bending

- 10 - stresses onto the wings of the beam.

It should also be noted that, advantageously, the rounded shape of the edges 6a remarkably facilitates the introduction of the attachment flange 6 into the wings of the corresponding section beam.

The present invention achieves the intended purposes. In fact the subject joint allows the mutual connection, according to any angular disposition, of a suitable number of beams, cutting said beams at a right angle, shortening them a fixed amount with respect to the desired length, and machining two holes in each of them for the engagement of the threaded elements 14.

Furthermore, it will be recognized that such a result is obtained with a joint of very simple structure and low cost as it is composed of a number of like parts.

In addition, the absence of stresses on the threaded connecting elements utilized allows that a reduced number of said elements may be used, which substantially increases the practical use of the joint in question. The facility in using said joint is further enhanced by the possibility of separately assembling the different parts of the joint with the respective beams and afterwards connecting the beams rigidly to one another by means of the only threaded element 16: it is clear that in this way it is much easier to assemble and disassemble the beams even in a position raised from the ground or of difficult accessibility.

It is understood that many modifications and variations

- 11 - may be made to the present invention without departing from the spirit and scope of the inventive idea characterizing it. For example, the joint in question can be obtained using a single connecting member 2 on each beam, especially if the latter need not support heavy loads.