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Field of the invention

The present- invention relates to devices for evacuation of smoke and heat from closed environments in the event of fire.

More in particular, the subject of the invention is an evacuator that can be applied at a substantially horizontal opening provided in the roof of the premises and comprises oscillating-shutter means mobile between a normally closed position, in which the opening is obstructed in a fluid-tight way, and an open position to enable evacuation of fumes and heat out of the opening. Actuator means are provided for governing displacement of the shutter means from the closed position to the open position in a governed or automatic way, in the event of emergency.

Prior art

Smoke and heat evacuators of the type defined above are known, for example, from the documents Nos. WO-97/33062, EP-A-20258 9, and FR-2778854. All these devices envisage opening of the shutter means, usually constituted by a single leaf, as a result of a rotation outwards, i.e., upwards, typically obtained with the use of a linear actuator, in particular a hydraulic jack.

Conventional solutions of the above sort present a dual drawback.

In the first place, in the condition where the shutter is open, the passage for evacuation of fumes and heat is partially obstructed, and hence limited, by the presence of the actuator. In the second place, the oscillation outwards of the shutter, upon command for opening thereof, can be hindered by the possible presence of snow on the roof where the opening for the evacuator is provided, which can limit, if not even preclude, opening thereof.

EP-1529911 and US-3874130 provide opening displacement of the oscillating-shutter means as a result of a rotation thereof downwards. The actuator means performing opening are however relatively complicated and unreliable, namely in case of exposition to high temperatures.

Summary of the invention

The object of the present invention is to overcome the aforesaid drawbacks, and said object is achieved thanks to the fact that a smoke and heat evacuator according to the preamble of Claim 1 is mainly characterized in that the actuator means include shape- memory means.

Advantageously, the aforesaid actuator means comprise a device for releasable retention of the shutter means in the aforesaid closed position, and a device for release of the retention device, comprising a wire made of a shape-memory metal alloy, to enable rotation downwards by gravity of the shutter means.

According to a preferred embodiment of the invention the shutter means include a pair of opposed oscillating shutters, a first one of which bears, at one end, the aforesaid retention device with the corresponding release device, and a second one rests with its end on said end of the first shutter.

Thanks to this arrangement, opening of the smoke and heat evacuator according to the invention can be obtained in the event of emergency in a prompt and immediate way, without any adverse effect due to possible loads of snow weighing on the shutters and moreover making available the widest possible section of passage towards the external environment in so far as, unlike the evacuators according to the known art referred to above, the internal actuator that in conventional evacuators governs oscillation upwards of the shutter means is eliminated.

Brief description of the drawings

The invention will now be described in detail with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

- Figure 1 is a schematic perspective view of a smoke and heat evacuator according to the invention, represented in the closed condition;

- Figure 2 is a schematic vertical cross-sectional view of the evacuator of Figure 1;

- Figure 3 is a perspective view similar to that of Figure 1 illustrating the evacuator according to the invention in the open condition;

- Figure 4 is a vertical cross-sectional view at a larger scale of the evacuator of Figure 3;

- Figure 5 illustrates in greater detail a part of Figure 2;

- Figure 6 is a further enlarged and simplified view of a detail of Figure 5;

- Figure 7 is a simplified cross-sectional view according to the line VII-VII of Figure 5;

- Figure 8 is a perspective view of Figure 7;

- Figure 9 is a view similar to that of Figure 8, in which some components are omitted for convenience of illustration;

- Figure 10 is a perspective view at a larger scale of a detail of Figure 9;

- Figure 11 shows at a larger scale a detail of Figure 7 in a first condition;

- Figure 12 is a view similar to that of Figure 11 illustrating a second operating condition;

- Figure 13 is a cross-sectional view at a larger scale according to the line XIII-XIII of Figure 2; - Figure 14 is a view similar to that of Figure 2 representing a configuration of partial opening of the evacuator according to the invention to provide periodic ventilation of the internal environment; and - Figures 15 and 16 show two details of Figure 2 at a larger scale.

Detailed description of the invention

With initial reference to Figures 1, 2 and 3, 4 a smoke and heat evacuator according to the invention basically includes an annular support 1, typically quadrangular in shape, applied directly on a base 2 at an opening 3 formed, substantially in a horizontal position, in the roof of a closed environment, such as an industrial shed, a warehouse, office premises, and the like.

Set at the top of the support 1 is a normally closed shutter, designated as a whole by 4, which can be opened completely to enable evacuation of smoke and heat from the premises, and even only partially to enable periodic ventilation of the premises.

According to the peculiar characteristic of the invention, complete opening of the shutter 4, with the modalities that will be clarified in what follows, is obtained by means of an oscillation downwards thereof, i.e., towards the inside of the opening 3, instead of upwards, i.e., towards the outside of said opening 3.

More in particular, the shutter 4, which in the closed condition can present a slight inclination with respect to the base 2 and is hence slightly oblique with respect to the horizontal in the way more clearly visible in Figure 2, is formed by a pair of leaves 5, 6 that can be sent down by gravity, starting from the closed position of Figures 1 and 2, to a substantially vertical position, in which they are set immediately adjacent to two respective opposite walls la, lb of the support 1.

With reference now in greater detail to Figures 5, 6 and 15, 16, the leaf 5 is articulated at one of its ends 7 to an oscillation pin 8 carried by the top of the wall la, whereas its opposite end, designated by 9, is provided with a device for retention in a closed position, which is releasable according to what will be clarified in what follows in order to free said end 9 and to enable rotation of the leaf 5 downwards, as has been said by gravity.

The other leaf 6 is also articulated at one end 10 to the top of the wall lb, however, indirectly via an oscillation pin 11 carried by the top of the stem 12 of a linear actuator 13, typically constituted by an electric jack, the function of which will be clarified in what follows.

The opposite end of the leaf 6, designated by 14, rests on the end 9 of the leaf 5, in the way represented in greater detail in Figure 6. As may be seen in Figure 6, set between the ends 9 and 14 is a gasket 15, inserted within a seat 16 of the end 14. In addition, said ends 9 and 14 have respective shaped and mutually compenetrated edges 17, 18, which perform a dual function: defining a labyrinth designed to prevent any infiltration of water towards the inside, and transmitting the thrust downwards from the leaf 5 to the leaf 6 upon opening of the shutter 4.

The device for retention of the leaf 5 in the closed position is shown in greater detail in Figures 7 to 9 and is designated as a whole by 19: it comprises a substantially channel-shaped sectional element 28, fixed along the bottom face of the end 9 of the leaf 5 in the way represented in Figure 6, and a blocking mechanism (omitted in Figure 6 for simplicity of illustration) designated as a whole by 20 in Figure 9. Said blocking mechanism 20 is made up of a pair of carriages 21, one of which is represented at a larger scale in Figure 10, set in a condition opposed to the ends of the guide sectional element 28. Each carriage 21 comprises a respective supporting body 22, rotatably mounted within which are two wheeled moving elements 23 and which forms at its outer end a raised appendage 24 in turn bearing two rotating side wheels 25.

The two carriages 21 are pushed, by the action of respective springs 26, so as to come to rest against contrast elements 27 fixed within the guide sectional element 28, in a position projecting outwards in the way represented in Figure 11. In said position, the appendage 24 of each carriage 21 is inserted underneath a respective canopy-like element 29 provided at the top of a respective side lc of the support 1 set in a direction transverse to the sides la, lb. Each canopylike element 29 is formed with an inclined chute 30 designed to co-operate with the rollers 25 of the appendage 24 of the carriage 21, in the way that will be clarified in what follows.

A gasket 33 (Figures 11 and 12) extends between a bottom appendage 34 projecting underneath each side of each leaf 5, 6 and the corresponding side lc of the support 1 for ensuring fluid-tight sealing along said areas in the condition where the shutter 4 is closed.

The two carriages 21 are interconnected via a wire made of a shape-memory metal alloy (SMA) 31, which extends along the guide sectional element 28. The SMA wire 31 is connected to an electrical-supply cable 32, in turn connected to the grid via a remote switch. When the SMA wire 31 is electrically supplied and heated by the Joule effect, it undergoes a linear contraction (for example, in the region of 5%) as a result of which the two carriages 21 move towards one another, against the action of the respective springs 26. In this way, the rollers 25 carried by the appendage 24 move underneath the corresponding canopy-like element-like elements 29, first intercepting the chutes 30, in the way represented in Figure 12, and then releasing the guide sectional element 28 and hence the leaf 5 from the walls lc. The interaction between the rollers 25 and the canopy-like element-like elements 29 provides a thrust downwards of the end 9 of the leaf 5, which enables, in the case of sticking, separation of the gaskets 33 from the sides lc of the support 1 so as to release the leaf 5 in a safe way.

In this way, the leaf 5 is able to turn by gravity downwards around the pin 8, first drawing along the end 14 of the leaf 6, thanks to the interaction between the terminal edges 17 and 18, and then releasing the corresponding oscillation downwards of said leaf 6, thus enabling complete opening of the shutter 4 in the position represented in Figures 3 and 4. As may be seen in said figures, the leaves 5, 6 are set vertically immediately adjacent to the walls la, lb of the support 1, and the passage of fluid from the opening 3 towards the outside is thus completely unobstructed.

As anticipated previously, the end 10 of the leaf 6 of the shutter 4 is articulated to the side lb of the support 1 in an indirect way, i.e., via the pin 11 carried by the top of the stem 12, which is normally set in the contracted configuration represented in Figures 2, 4, and 13. Extension of the actuator 13, in the way represented in Figure 14, causes oscillation of the entire shutter 4 about the articulation pin 8 so as to raise the end 10 of the leaf 6 above the side lb of the support 1 for providing, selectively, a partial opening of the shutter 4 for periodic aeration of the internal environment through the opening 3. The arrangement of the linear actuator 13 is in any case such that, in the condition of complete opening of the shutter 4, it does not obstruct in any way communication of the opening 3 with the external environment in so far as, as may be seen in Figure 4, it is in said condition confined in the space comprised between the leaf 6 and the wall lb.

Of course, the details of construction and the embodiments may vary widely with respect to what is described and illustrated herein, without thereby departing from the scope of the present invention as defined in the ensuing claims.