Fire-resistant accessory for installation in a flush-mounting box and fire-resistant assembly comprising a flush-mounting box and such a fire-resistant accessory

Abstract

The invention relates to a firestop accessory (10) for a recessed box (200) comprising an elongated element (100) provided with an intumescent material (110), the elongated element being adapted to be threaded through a passage opening (240) of electrical conduit of the recessed box and comprising retention means (120) capable of cooperating with an internal part of the recessed box to fix the elongated element to the recessed box in such a way that the elongated element extends predominantly outside of it.

Description

Title of the invention: Fire-resistant accessory to be installed in a flush-mounting box and fire-resistant assembly comprising a flush-mounting box and such a fire-resistant accessory

[0001] The present invention relates, in general, to the field of recessed boxes for drywall partitions for receiving electrical equipment.

[0002] The invention relates more particularly to a firestop accessory to be installed in a recessed box.

[0003] It also relates to a fire-resistant assembly comprising a flush-mounting box and this fire-resistant accessory.

[0004] Current standards require restoring the original fire-resistant performance of a drywall partition which has been pierced with the hole necessary for the installation of a recessed box, i.e. preventing fire from passing through the drywall for a predefined period (for example 30 or 60 minutes).

[0005] To comply with these standards, it is known to place an intumescent material, which may be in the form of a patch, inside the recessed box. When the intumescent material is exposed to heat, it swells and then blocks the duct inlet openings of the box, thus expelling air and preventing the passage of flames and gases through them.

[0006] A box for embedding such as the one mentioned above is already known from document EPI221749, in which the intumescent material is in the form of a layer placed against the bottom wall of the box.

[0007] The disadvantage of this solution is that the intumescent material occupies part of the internal volume of the recessed box which is useful for receiving bases for electrical equipment mechanisms and their wiring.

[0008] In order to remedy this drawback of the prior art, the present invention proposes to move the intumescent material outside the internal volume of the recessed box in order to increase the volume available for mounting the electrical elements of electrical equipment.

[0009] More particularly, according to the invention, a fire-resistant accessory is proposed for a recessed box comprising an elongated element provided with an intumescent material, the elongated element being adapted to be threaded through an electrical conduit passage opening of the recessed box and comprising retention means capable of cooperating with an internal part of the recessed box to fix the elongated element to the recessed box in such a way that the elongated element extends predominantly outside of it.

[0010] Thanks to the fire-resistant accessory according to the invention, the intumescent material is located outside the interior volume of the recessed box. Indeed, the elongated element is inserted into the recessed box in such a way that it protrudes primarily outside of it, thus artificially increasing the internal volume of the recessed box. The intumescent material therefore generates little or no obstruction within the recessed box.

[0011] In addition, this fire-resistant accessory makes it possible to make a conventional recessed box fire-resistant, by mounting it in one of its openings not used for the passage of an electrical conduit.

[0012] Other characteristics of the fire-resistant accessory according to the invention are as follows: - the elongated element includes a hollow casing carrying the retention means and housing the intumescent material, the casing having at least one exit opening for the passage of the intumescent material towards the recessed box when the intumescent material is exposed to heat; - the retention means extend outward from the case on the side of each exit opening; - the case is in the form of a sheath with a single exit opening; - the restraint means include a stop collar bordering said exit opening; - the intumescent material is in the form of a sheet or a rolled strip housed in the case; - the intumescent material is molded into the casing; - the intumescent material occupies only part of the internal volume of the case to leave storage space; - the elongated element is at least partially made of the intumescent material; - it is provided that the elongated element is fixed to the recessed box in such a way that more than 90% of the volume of the intumescent material is positioned outside the recessed box; - the elongated element extends straight or in a curve; and - the elongated element includes a longitudinal portion having a tubular shape of revolution.

[0013] The invention also proposes a fire-resistant assembly for the installation of electrical equipment comprising: - a recessed box comprising a wall delimiting an internal volume of the recessed box, the wall having at least one opening for the passage of an electrical conduit, and - a fireproof accessory as mentioned above, accommodated in the passage opening.

[0014] The following description with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0015] On the attached drawings:

[0016] [Fig-1] is a schematic exploded perspective view of a firestop assembly according to the invention.

[0017] [Fig.2] is a schematic assembly perspective view of the firestop accessory of the firebreak assembly of [Fig.1].

[0018] [Fig.3] is a schematic rear-assembled perspective view of the assembly firebreak of the [Fig.l].

[0019] [Fig.4] is a schematic front view of the firestop assembly of [Fig.3].

[0020] [Fig.5] is a schematic cross-sectional view along plane AA of [Fig.4].

[0021] Figure 1 shows a fire-resistant assembly 1 for installing electrical equipment according to the invention. This fire-resistant assembly 1 is designed to be embedded in a cavity made in a wall (not shown) such that a portion of this fire-resistant assembly 1 is accessible from the front of this wall for installing electrical equipment to perform a given electrical function.

[0022] This wall (not shown) is here a drywall partition.

[0023] It should be noted in this regard that, as is known, such a drywall partition, also called a hollow wall, is generally composed of a metal frame (made up of vertical studs and / or horizontal rails) and plasterboard panels attached to at least one of the two faces of the metal frame. The cavity made in this drywall partition to accommodate the firestop assembly 1 is then simply formed by a circular opening made with a hole saw in one of the plasterboard panels.

[0024] In the description, the terms "front" and "rear" shall be used with respect to the angle of view of the installer of the firestop assembly 1 in the plasterboard panel. Thus, the terms front and rear shall respectively designate the outward and inward faces of the drywall partition. The terms "inside" or "internal" shall designate the position facing the center of the firestop assembly 1, and the terms "outside" or "external" the opposite position.

[0025] Furthermore, the electrical equipment (not shown) to be included in the fire-resistant assembly 1 essentially comprises, in a conventional manner, an equipment support and an equipment mechanism mounted in the equipment support. The equipment mechanism includes a base attached to the equipment support and housing the electrical components adapted to be connected to the electrical network, as well as a cover plate giving access to the electrical elements to ensure the electrical function of the electrical equipment (for example a switch function, two-way switch, electrical dimmer, network socket, smoke detector, etc.).

[0026] As shown in [Fig.1], the firestop assembly 1 includes a firestop accessory 10 and a flush-mounting box 200.

[0027] The 200 flush-mounting box is a standard design, used for the protection, fixing, and wiring of electrical equipment. The internal volume 201 of the 200 flush-mounting box accommodates the base of the electrical equipment mechanism and allows for its wiring. The fire-resistant accessory 10 restores the fire resistance of the drywall partition, thus providing passive fire protection.

[0028] Essentially, the mounting box 200 comprises a body 210 which here has a general cylindrical shape around a central axis A3 (see figures 4 and 5), but which could of course have a different shape, in particular parallelepiped.

[0029] As shown in Figures 1, 3, 4 and 5, the body 210 of the flush-mounting box 200 comprises a generally tubular side wall 211 of revolution and a bottom wall 212 which closes the flush-mounting box 200 at the rear. The flush-mounting box 200 is open at the front by a front opening 201A opposite the bottom wall 212. The body 210 thus delimits, between the side wall 211, the bottom wall 212 and the front opening 201A, the internal volume 201 (see [Fig. 4]) of the flush-mounting box 200 which allows, in particular, the accommodating of the base of the electrical equipment as well as the electrical wires from the network, necessary for its wiring.

[0030] For fixing it in the circular opening made in the plasterboard panel of the drywall partition, the body 210 of the recessed box 200 has an external flange 213 that runs along the outside edge of the front opening 201A and is adapted to bear against the front face of the plasterboard panel, all around the circular opening. This external flange 213 allows the body 210 of the recessed box 200 to be locked rearward in the drywall partition.

[0031] As shown more particularly in Figures 1, 3 and 4, to lock the body 210 forward in the drywall, the recessed box 200 is equipped with two screws 221 and claws 220 which are positioned diametrically opposite on the external face 21 IA of the side wall 211. Each screw 221, to the free end of which a claw 220 is screwed, passes through features provided in the side wall 211, namely a channel 222 opening at the front of the recessed box 200 and holding the head of said screw 221 so that said screw is only free to rotate about its axis (and therefore blocked in translation), a recess 223 in the external face 21 IA of the side wall 211, and an opening 224 opposite the opening. of the chimney in the recess 223. A ramp 223A is provided at the bottom of each recess 223, part of which is inclined. Once in place, each claw 220 is partially housed in a recess 223, resting against the ramp 223A. Each claw 220 is prevented from rotating within the recess 223, while each screw 221, free to rotate about the axis of its threaded body, is fixed in translation. The assembly is conventionally made so that the rotation of each screw 221 in the chimney 222 causes a translational movement of the corresponding claw 220 along the threaded body of the screw 221. During its movement, each claw 220 slides on the ramp 223A provided at the bottom of the recess 223 to come out of the recess 223, protruding from the external face 211A of the side wall 211 of the recess box 200, and come to press against or hook onto the back face of the plasterboard of the drywall partition.

[0032] As shown more particularly in [Fig.4], for fixing the electrical equipment support to the flush-mounting box 200, the side wall 211 of the body 210 of the flush-mounting box 200 has on its inner face 21 IB two diametrically opposed screw holes 230, into which are screwed two screws 231 intended to be engaged through holes, for example in the form of a keyhole, provided in the equipment support.

[0033] The screw holes 230 and the arrangements for the claw screws 221 are placed at the four cardinal points of the circle followed here by the edge of the front opening 201A of the flush-mounting box 200.

[0034] The flush-mounting box 200 also includes a plurality of cable routing conduit inlets. Such a conduit (not shown) houses the cables and / or electrical wires from the local electrical network. As shown in the figures, the flush-mounting box 200 has four cable routing conduit inlets. Each inlet is a passage opening 240 extending partly along the side wall 211 of the body 210 of the flush-mounting box 200 and partly along the bottom wall 212 of the body 210 of the flush-mounting box 200. The outline of each passage opening 240 is generally oblong.

[0035] Each passage opening 240 is closed by a tearable or perforable cover 241. This cover 241 is here made of a flexible membrane (of the type marketed by the applicants under the reference "Batibox™").

[0036] The body 210 is made of rigid plastic material (typically polypropylene). The flexible membranes are made of a more flexible thermoplastic material (typically SEBS, an acronym for Styrene Ethylene Butylene Styrene) overmolded onto the rigid material.

[0037] Remarkably, as clearly shown in [Fig. 2], the firestop accessory 10 comprises an elongated element 100 provided with an intumescent material 110. As such is shown in figures 3 to 5, advantageously, the elongated element 100 is adapted to be threaded through one of the passage openings 240 of the recessed box 200 and includes retaining means 120 suitable to cooperate with an internal part of the recessed box 200 to fix the elongated element 100 to the recessed box 200 in such a way that the elongated element 100 extends predominantly outside of it.

[0038] As shown in [Fig.1], the elongated element 100 comprises a hollow sheath 130 in the form of a sleeve and housing the intumescent material 110. This hollow shape defines a housing 101 for the intumescent material 110. By sheath shape, it is understood that the sheath 130 has a longitudinal portion 131 with a closed end 132 and an opposite open end 133, the open end 133 here having a single exit opening 133A (see [Fig.2]).

[0039] The longitudinal portion 131 is here elongated along a longitudinal axis Al (visible in Figures 1, 4 and 5) and therefore has a straight shape. More specifically, it has a tubular shape of revolution centered on the longitudinal axis Al. Alternatively, the longitudinal portion could be elongated in a curved manner.

[0040] The longitudinal portion 131 of the case 130 is here very slightly tapered in that the cross sections, defined as sections made in planes orthogonal to the longitudinal axis Al, are decreasing from the open end 133 of the case 130 to the closed end 132 of the case 130. As shown in Figures 1 to 5, the cross sections of said longitudinal portion 131 are continuously and regularly decreasing from the open end 133 to the closed end 132 of the case 130. Alternatively, the longitudinal portion could be cylindrical, for example of revolution.

[0041] The exit opening 133A of the open end 133 of the casing 130 is here generally circular and centered on the longitudinal axis AL. The exit opening 133A has dimensions substantially equal to those of the inside of the longitudinal portion 131, that is to say here to an internal diameter of the longitudinal portion 131, at the level of the open end 133. The exit opening 133A is here formed in continuity with the receiving housing 101 of the casing 130. As shown in [Fig. 2], the dimensions of the exit opening 133A are thus adapted to place the intumescent material 110 in the casing 130.

[0042] The longitudinal portion 131 of the sleeve 130 is adapted to be threaded through one of the passage openings 240 provided in the mounting box 200 in the sense that, on the one hand, its cross-sections have a size less than or equal to that of the passage opening 240, and, on the other hand, the sleeve 130 has a length such that the longitudinal portion 131 can be engaged in the passage opening 240 from the inside of the mounting box 200.

[0043] Here, as clearly shown in [Fig.5], the longitudinal portion 131 of the case 130 has, at the open end 133 of the case 130, a section of identical size, apart from the mounting clearance, to that of the part of the passage opening 240 made in the side wall 211 of the body 210 of the flush-mounting box 200. The firestop accessory 10 is therefore adapted to be placed in this part of the passage opening 240 to close it.

[0044] As shown in [Fig. 1], the closed end 132 of the casing 130 has a beveled wall 132A which extends more specifically along a frustoconical surface around the longitudinal axis A1. The beveled wall 132A connects the longitudinal portion 131 of the casing 130 to a circular face 132B of the closed end 132. The surface area of ​​the circular face 132B of the closed end 132 is smaller than the surface area of ​​the outlet opening 133A. The casing 130 thus has, at its closed end 132, a tapered shape which facilitates its insertion into the passage opening 240 of the recessed box 200.

[0045] The case 130 carries the retaining means 120 on the side of the open end 133, more specifically around the exit opening 133A. The retaining means 120 thus project from the longitudinal portion 131 of the case 130. Here, the retaining means 120 extend generally radially with respect to the longitudinal axis AL

[0046] . In this case, as shown in Figures 1 and 2, the retaining means 120 include a stop in the form of a stop collar 121. The stop collar 121 is adapted to bear against the body 210 of the recessed box 200 around the edge of the passage opening 240. As shown in [Fig. 5], the stop collar 121 is thus larger than the passage opening 240. Here, the stop collar 121 borders the exit opening 133A of the open end 133 of the case. 130, which means that it surrounds the open end 133.Alternatively, the collar could be positioned further back from the outlet opening.

[0047] The retaining collar 121 here has a flared shape, visible in particular in [Fig.2]. Thus, as shown in [Fig.5], the retaining collar 121 does not extend in a plane but is slightly curved so as to follow the shape of the inner face 21 IB of the side wall 211 of the body 210 of the mounting box 200.

[0048] The case 130 and the retention means 120 are made by molding in one piece from insulating material, here from ABS (acrylonitrile butadiene styrene).

[0049] As shown in [Fig. 1], the intumescent material 110 is in the form of a rolled sheet or strip housed in the casing 130. This sheet or strip is rolled around a winding axis A2 which extends parallel to the longitudinal axis AL. The intumescent material 110 thus has the shape of a cylinder of revolution whose bases 111, that is, its end faces, are in overall shape of disc, have a diameter less than or equal to that of the internal cross-section of the longitudinal portion 131 of the case 130. The intumescent material 110 can typically be rolled tightly and held as such for insertion into the case 130. Once in place, it can then unroll slightly to conform to the internal surface of the case 130.

[0050] Alternatively, the intumescent material could be in any other form suitable for the case, for example, as a rod or as a foam injected into the case. The intumescent material could also be injected or poured into the case in liquid form and then solidify within it. In other words, the intumescent material could thus be molded into the case. The intumescent material would then be a single piece and would at least partially conform to the internal surface of the case 130.

[0051] The intumescent material used may be a composite material comprising a polymer matrix, incorporating: - an acid (boric acid, phosphoric acid, sulfuric acid) or a source of organic acid (urea phosphates, melamine phosphates) or inorganic acid (ammonium borates, ammonium phosphate, diammonium phosphate, ammonium polyphosphate, ammonium sulfate); - a carbon source compound, usually a dehydrating polyalcohol such as pentaerythritol, a simple sugar (arabinose, maltose) or a polysaccharide (cellulose, starch); and - a blowing agent generating non-combustible gases under the effect of heat such as melamine (NH3, H2O, CO2), guanidine (NH3, H2O, CO2) or urea (NH3, H2O, CO2).

[0052] Such a material may incorporate graphite as a mineral filler and chopped or unbonded fibers.

[0053] As shown in [Fig.5], the intumescent material 110 here occupies almost the entire internal volume of the case 130. In particular, it occupies the entire longitudinal part 131, stopping at the closed end 132 at the level of the beveled wall 132A, and protruding slightly into the exit opening 133A of the open end 133.

[0054] However, it can of course be provided that the intumescent material 110 occupies only part of the internal volume of the case 130, thus creating storage space within it. This storage space can, for example, extend along the longitudinal axis A1 and be obtained by unwinding the intumescent material 110 after its insertion into the case 130. The intumescent material 110 can also be shorter, along the longitudinal axis A1, than the longitudinal portion 131, which also generates storage space. In this case, it is preferably pushed to the bottom of the case 130 against the closed end 132. In all cases, this storage space can be used to perform electrical functions, such as placing a terminal electrical connection, a wire clamp, or various types of sensors, for example, temperature, sound, smoke, etc...

[0055] The firestop accessory 10 mounted in the flush-mounting box 200 is shown in figures 3 to 5.

[0056] As shown in [Fig. 4], the elongated element 100 then extends substantially radially with respect to the cylindrical body 210 of the mounting box 200. Here, this means that the longitudinal axis Al, along which the longitudinal portion 131 of the sleeve 130 extends, is perpendicular to the central axis A3 of the body 210 of the mounting box 200. Thus, as can be seen in Figures 3 and 5, the longitudinal portion 131 of the sleeve 130 extends here substantially parallel to the bottom wall 212 of the body 210 of the mounting box 200.

[0057] The stop collar 121 is in contact with the side wall 211 of the body 210 of the flush-mounting box 200, and more specifically with the inner face 21 IB of this side wall 211. It is also in contact with the bottom wall 212 of the body 210 of the flush-mounting box 200 and a part of the cover 241 which closes the part of the passage opening 240 extending on the bottom wall 212 of the body 210 of the flush-mounting box 200.

[0058] As clearly shown in [Fig. 5], the firestop accessory 10 is mounted in the flush-mounting box 200 such that the sleeve 130 extends well beyond the flush-mounting box 200. Indeed, only the open end 133 of the sleeve 130 extends into the passage opening 240, while the longitudinal portion 131 projects outward from the side wall 211 of the body 210 of the flush-mounting box 200 and away from it. Thus, more than 90%, and preferably more than 95%, of the volume of the intumescent material 110 is positioned outside the flush-mounting box 200, that is, outside its internal volume 201.

[0059] The exit opening 133A of the housing 130 opens into the internal volume 201 of the flush-mounting box 200. Here, the exit opening 133A of the housing 130 opens entirely into the internal volume 201 of the flush-mounting box 200.

[0060] In the event of a fire, when the intumescent material 110 is exposed to heat and expands, it flows into the recessed box 200 and fills it, thereby sealing the passage openings 240 and / or the front opening 201A of the frame box 200, and thus preventing the passage of flames and gases through the circular opening in the plasterboard panel. The outlet opening 133A of the sleeve 130 is therefore designed to allow the intumescent material 110 to pass into the recessed box 200 when it is exposed to heat. As mentioned previously, the outlet opening 133A also allows the intumescent material 110 to pass through in its initial state (not expanded by heat) in order to position it within the sleeve 130.

[0061] The installation of the firebreak assembly 1 is carried out in the following manner.

[0062] The installer begins by opening at least two passage openings 240 in the body 210 of the recessed box 200, by releasing two covers 241.

[0063] The installer then pulls a cable routing conduit through the other passage opening 240, so as to pull the electrical wires from the local electrical network into the recessed box 200. These electrical wires will be used to connect the electrical elements of the electrical equipment.

[0064] He then engages and fixes the recessed box 200 in the circular opening made in the plasterboard using the claw screw system 220, 221.

[0065] The firestop accessory 10 is finally engaged from inside the flush-mounting box 200 through one of the passage openings 240. For this, the closed end 132 of the sleeve 130 is engaged first, then the longitudinal part 131 is engaged up to the stop collar 121. The longitudinal part 131 is typically engaged obliquely at first before being straightened in a second step to extend radially, as shown in figures 3 to 5.

[0066] Thus the firestop assembly 1 is ready to be used to install the electrical equipment.

[0067] The present invention is in no way limited to the embodiment described and represented, but a person skilled in the art will be able to make any variation in accordance with the attached claims.

[0068] One could, in particular, replace the case collar with simple protruding lugs on the longitudinal portion of the case. These lugs would then preferably be located at the edge of the open end of the case. Alternatively, they could also be located some distance from this edge, preferably less than one centimeter from it.

[0069] As a further alternative, it could be envisaged that the case is formed of two distinct parts, one of which could for example constitute the longitudinal portion of the case and the other of which could for example constitute the stop collar to be snapped onto said longitudinal portion.

[0070] The case could have non-circular cross-sections, for example rectangular, square, triangular, hexagonal, etc...

[0071] The casing could also be partially or entirely made of the intumescent material. The elongated element could even be made in one piece of intumescent material. It could then be in the form of a rod with retention means provided at one end of the rod.

[0072] The exit opening of the case could have dimensions smaller than the cross-sections of the longitudinal portion, particularly at the end open. This would, for example, allow the intumescent material to be retained in the sheath after its insertion.

[0073] The open end of the casing could also have several outlet openings, for example, a plurality of small orifices (significantly smaller than the cross-sections of the longitudinal portion). These orifices could be arranged around the circumference of the longitudinal portion or on an end surface transverse to the longitudinal portion (facing the circular face of the closed end). Preferably, all the outlet openings lead into the casing to channel the intumescent material during its expansion.

Claims

Demands

1. A fire-resistant accessory (10) for a flush-mounting box (200) comprising an elongated element (100) provided with an intumescent material (110), the elongated element (100) being adapted to be inserted through an electrical conduit passage opening (240) in the flush-mounting box (200) and having retaining means (120) capable of cooperating with an internal portion of the flush-mounting box (200) to fix the elongated element (100) to the flush-mounting box (200) such that the elongated element (100) extends predominantly outside the box, characterized in that the elongated element (100) comprises a hollow sleeve (130) carrying the retaining means (120) and housing the intumescent material (110), the sleeve (130) having at least one opening output (133A) for the passage of the intumescent material (110) to the flush-mounting box (200) when the intumescent material (110) is exposed to heat.

2. Firestop accessory (10) according to claim 1, wherein the retaining means (120) extend in projection from the case (130) on the side of each exit opening (133A).

3. Firestop accessory (10) according to any one of claims 1 or 2, wherein the case (130) is in the form of a sheath having a single exit opening (133A).

4. Firestop accessory (10) according to claim 3, wherein the retaining means (120) comprise a stop collar (121) bordering said exit opening (133A).

5. Firestop accessory (10) according to any one of claims 1 to 4, wherein the intumescent material (110) is in the form of a sheet or rolled strip housed in the case (130).

6. Firestop accessory (10) according to any one of claims 1 to 4, wherein the intumescent material (110) is molded into the casing (130).

7. Firestop accessory (10) according to any one of claims 1 to 6, wherein the intumescent material (110) occupies only a part of the internal volume of the case (130) to provide storage space.

8. Firestop accessory (10) according to any one of the preceding claims, wherein the case (130) is made of intumescent material (110).

9. Firestop accessory (10) according to any one of the preceding claims, wherein the elongated element (100) is provided to be attached to the recessed box (200) in such a way that more than 90% of the volume of the intumescent material (110) is positioned outside the recessed box (200).

10. Firestop accessory (10) according to any one of the preceding claims, wherein the elongated element (100) extends straight or curved.

11. Firestop accessory (10) according to any one of the preceding claims, wherein the elongated element (100) comprises a longitudinal portion (131) having a tubular shape of revolution.

12. Firestop assembly (10) for the installation of electrical equipment comprising: - a flush-mounting box (200) comprising a wall (211,212) delimiting an internal volume (201) of the flush-mounting box (200), the wall (211,212) having at least one passage opening (240) for electrical ducting, and - a firestop accessory (10) according to any one of claims 1 to 11 accommodated in the passage opening (240).

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