Burglar-proof armoured roller shutter

This patent application refers to a burglar-proof armoured roller shutter.

Armoured roller shutters are currently known and used, both with adjustable and fixed slates. As it is known, roller shutters are composed of a frame made of extruded metal sections, with two opposite uprights provided with a large groove on their internal side designed to house fixing and handling means of the pins with horizontal axis located at the two ends of the slates.

Within this traditional structure, the armoured roller shutters that are currently available on the market are characterised by the fact that each slate is longitudinally crossed by a sturdy rod iron, whose lateral ends are designed to engage within suitable holes on the uprights used to fix and handle the corresponding slate.

The presence of a rod iron inside each slate strengthens the structure of the slate, thus making it stronger against the action of burglars who may attempt to cut or break it violently.

However, it must be said that, in spite of internal reinforcement, armoured slates are not able to resist the action of a lever bar fixed to the centre line of the slate and used as lever to exercise energetic traction. As a matter of fact, traction inevitably bends the slate, thus moving the centre point (or in any case the point where the lever bar is fixed) away from the hypothetical horizontal axis passing through the holes on the uprights of the roller shutter designed to receive the ends of the internal rod iron.

Consequently, the ends of the rod iron (together with the lateral pins of the corresponding slate) are extracted from the holes on the uprights of the frame and the entire slate is removed from the roller shutter.

The present invention intends to renovate the aforementioned traditional technology, with the specific purpose of making roller shutter slates

perfectly resistant to burglary actions (i.e. say total extraction) with a lever bar.

More precisely, by means of the present invention, the ends of the rod irons incorporated in the roller shutter slates cannot be extracted from their corresponding holes on the uprights of the frame, regardless of the energetic traction exercised on the slate with a lever bar or any other burglar tool.

The purposes of the present invention have been achieved modifying the typical structure of a traditional roller shutter with armoured slates.

First of all, the ends of each rod iron incorporated in the slates largely protrude downstream the holes on the front wall of the two extruded sections that represent the frame uprights.

Once inserted, each end of the rod iron is positioned in the tubular cavity normally provided on the extruded section on the back of the front wall with holes. Furthermore, according to the present invention, the ends of all rod irons used as reinforcement are respectively provided with diameter holes, and each extruded section used as frame upright is provided with a basically

C-shaped longitudinal groove on the back of the front wall, exactly behind the series of holes on the front wall used to receive the ends of the stiffening rod irons.

In particular, once the slates have been installed, the diameter holes on the ends of the stiffening rod irons are exactly positioned inside the longitudinal groove on the back of the front wall of the extruded section used as upright. Then a suitable pin is exactly engaged in each longitudinal groove, passing through the holes located at the ends of the iron rods inserted in the groove.

In view of the above, it is evident that each groove acts as a sliding guide for the corresponding pin. In any case, the presence of the pin that is inserted and connects all ends of the stiffening iron rods on the back of the front wall of the window frame makes it impossible to disengage the ends from the holes on the

window uprights, in spite of strong traction exercised on the slates with a lever bar.

For major clarity the description of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, whereby:

- Fig. 1 is a partial axonometric view of the roller shutter of the invention;

- Fig. 2 is a partial axonometric view of a roller shutter provided with adjustable slates;

- Fig. 3 is a cross-sectional view with a transversal plane of the metal section used as upright in the roller shutter of the invention.

With reference to the aforementioned figures, the roller shutter of the invention is composed of a metal frame, with two opposite uprights (1) made of extruded sections, provided with a vertical series of regularly spaced holes

(2) on the internal longitudinal wall (1a), designed to be exactly crossed by the ends (3a) of the rod irons (3) inserted as reinforcement in the slates (4) of the roller shutter (1 ).

In particular, after passing through the holes (2), the ends (3a) of the rod irons (3) end on the back of the wall (1a) of the upright (1) in the traditional tubular cavity (C) on the internal side of the extruded section (1). The aforementioned figures show that, in the present invention, the back of the internal wall (1a) of each upright (1) is provided with a longitudinal groove (5) in matching position with the vertical series of holes (2) with a central notch (5a) with basically C-shaped cross-section.

Each end of the stiffening rod irons (3) is crossed by a diametrical hole (3b), which is basically a sort of eyelet.

Evidently, the specific configuration and dimensions of each rod iron

(3) exactly match the configuration and dimensions of the upright (1).

Following the insertion of the end of the rod iron (3) in the hole (2) of the upright (1 ), the eyelet (3b) of the rod iron (3) is exactly positioned inside the longitudinal groove (5a) on the back of the wall (1 a) of the upright (1 ).

Then a suitable pin (6) is inserted in the groove (5a) on the back of the wall (1a) of the upright (1), in such a way that the pin (6) can be inserted in

the eyelets (3a) on the ends of the stiffening rod irons (3) protruding through corresponding holes (2) on the back of the wall (1a) of the upright (1).

From this perspective, it is evident that each pin (6) is designed to "connect" the lateral ends of a series of stiffening rod irons (3) on the corresponding side of the window frame, thus opposing traction exercised on the slates (4) that could determine the disengagement of each end (3a) of the rod iron (3) from the corresponding hole (2) on the upright (1), thus removing the slate (4) from the frame.