BACKGROUND OF THE INVENTION In order to perform building construction, renovation or finishing works, building firms are obliged to respect severe safety regulations, aimed at preventing accidents to the workers or to any third party.

For the same purpose, there are metallic scaffolds, which lean against the building, and which are equipped, in the working area, with suitable parapets aimed at preventing the workers from falling down, and with one or more protection devices, for example a net, a fabric or the like, which cover/s the whole extension in height of the scaffold and prevents pieces of material from falling down.

The protection net is first positioned by the workers, and then it is fastened to the uprights of the scaffold by metallic threads, which engage suitable openings made in the net and a corresponding upright of the scaffold.

Both the operations of positioning and fastening of the protection net to the uprights and the final removal of the net from the scaffold, require a lot of time and labor, which increases the cost of works to be done on the building.

, After removing, the protection net must be folded. In order to perform this operation, the worker must spread the net along the street and fold it.

A repeated use of the protection net causes wearing out and tearing of the areas, where the net is fastened, due to the fastening by metallic means; then, the protective effect of the net is lacking.

Another disadvantage of the net derives from the fact that the net must be perfectly spread along the street and folded by the worker, which is very difficult when the renovation works are done in the areas with insufficient space; actually the net winding can be approximate or, in some cases, the net is amassed casually and then folded.

SUMMARY OF THE INVENTION The object of the present invention is to propose a protection device for building scaffolds, which is easy to be used in absolute safety conditions.

Another object of the present invention is to propose a protection device for scaffolds, which allows protection of a prefixed height extension of the scaffold.

Another object of the present invention is to propose a protection device for building scaffolds obtained by simple means, which allows an easy and rapid mounting.

A further object of the present invention is to propose a device, whose conformation simplifies its dismantling from the scaffold as well as its storing in a magazine.

A still further object of the present invention is to propose a protection device for building scaffolds, which can be used also by not particularly skilled operators.

A yet further object of the present invention is to propose a protection device, which can be obtained at low cost.

The above mentioned objects are obtained, in accordance with the contents of the claims, by a protection device for scaffolds which includes: a protection strip wound on a core, to define a reel; means for rotatably fastening the core with substantially horizontal orientation, to the scaffold, so that said strip can be unwound from and wound on said reel; means for removable fastening the portion of the strip unwound from the reel, to said scaffold.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to particular, non-limiting embodiments and with reference to the accompanying drawings, in which: - Figure 1 is a schematic front view of a building scaffold; - Figure 2 is a section view taken along II-II of Figure 1; - Figure 3A is a perspective, substantially front view of the part of the scaffold shown in Figure 1, with means for fastening a protection net, obtained according to a first embodiment, being pointed out ; - Figure 3B is a lateral, in part sectional view of what is shown in Figure 3A; - Figure 4A is a front view of the scaffold shown in Figure 1, with means for fastening a protection net,

obtained according to a second embodiment, being pointed out; - Figure 4B is a top, in part sectional view of what is shown in Figure 4A.

BEST MODES OF CARRYING OUT THE INVENTION With reference to the enclosed figures, a reference letter W indicates a building scaffold.

The scaffold W is a temporary structure formed by vertical tubular elements 9, or uprights, connected one to another and to horizontal elements 7, likewise tubular, by known joints 8.

Smaller elements, not shown, are situated above the horizontal elements, in order to support a continuous wood floor, which can be walked upon.

The upper end of the scaffold W features other upper horizontal elements 6, fastened to consecutive pairs of vertical elements 9 by suitable joints 80, at a prefixed distance from the horizontal elements 7 at parallel thereto.

The protection device D is formed by a protection strip R, for example a net, fabric or the like, having eyelets O of known type situated along the longitudinal edges.

The protection net R is wound on a core 90, for example tubular, to define a reel B, a corresponding upper element 6 is freely introduced into the core, as it is shown in Figure 2, consequently, the reel B is oriented horizontally.

The protection net R, as shown in Figures 3A, 3B, is fastened to the uprights 9 by coupling fastening means 80 to the eyelets 0, one of which is seen in Figure 3A.

The fastening means 80, as shown in Figure 3B, include an elastic element, for example a thread-like one, suitably curved, so as to define a head 89 and two mirror-like and curved arms 88a, 88b, whose ends are curved outwards to define an insertion slope V, whose task will be explained later.

When in use condition, the head 89 is press fitted into a corresponding eyelet O made in the net R, while the two arms 88a, 88b tightly fasten round a corresponding upright 9.

According to a second embodiment, shown in Figure 4B, the fastening means 800 are defined by two mirror-like arms 800a, 800b, having curve portions C and straight portions T, which tighten a portion of the longitudinal edge of the net R by known fastening means 809.

While in use conditions, the curve portions C tightly fasten round a corresponding upright 9.

The protection device D for building scaffolds can be used in the following way.

After a scaffold has been mounted and before the upper element 6 has been fastened thereto, the operator introduces freely the upper element 6 into the tubular core of the reel B, which consequently, can rotate on its axis.

After this coupling, the operator acts either on the reel B or on the net R, so as to allow the protection net R to unwind up to the desired height extension, and fastens

the net R to the uprights 9 of the scaffold by positioning the fastening means 80,800.

The protection device D can use motor means, not shown, connected to the core 90, which drive the reel B into rotation, so as to automatically unwind and rewind the reel.

The positioning of the fastening means 80 includes snap fitting of the head 89 into one of the eyelets 0 and the pressing of the arms 88a, 88b to fasten around the corresponding upright 9, since the ends of the arms 88a, 88b get in contact with the upright 9 with the insertion slope V, and elastically deform by opening wide, so as to receive the upright 9 therebetween.

The positioning of the fastening means 800 includes elastic deformation of the curve portions C of the arms 800a, 800b to tighten an upright 9.

The core 90, on which the net R is wound, can include spring mechanism of known type, which allow unwinding and facilitate the automatic rewinding of the net R.

According to a variant, not shown, the tubular core is fastened independent to the scaffold W by known fastening means.

The protection device for building scaffolds is advantageous, because the use of a reel B to be fitted on the upper element 6, or to be connected to the scaffold W, allows a simple and rapid positioning, and fastening of the reel R (with respect) to the scaffold.

The fastening of the net R to the uprights of the scaffold W by the fastening means 80,800 allows to safe a lot of technical and human resources, which results in

the reduction of time necessary to install the net R and to its removal.

Actually, the positioning and fastening of the reel B and the coupling between the net and the corresponding uprights is rapid, simple and avoids net damages.

The use of the reel B supported rotatably by an upper element 6, or connected to the scaffold W, allows to rewind rapidly the net R on the reel B, when the work is over and to remove the reel easily and to store it immediately.

The protection device D allows to use the net R necessary to protect the scaffold in different height extensions; the exceeding net remains wound on the reel B.