FIRE SEALING OF LEADS-THROUGH FOR CONDUITS

Abstract: A prefabricated fire-sealing lead-through body (1) for one or more conduits (32) through a wall, for example. The body comprises a casing (2) with elastic fire retardant foamed material (4) disposed therein, said material being kept in the casing compressed transverse to the longitudinal axis of the casing, sealingly surrounding the conduit or conduits. From its one free end the casing is only partially filled with foamed material, the length of said material being adjusted to correspond to safety requirements made for the fire seal in question. The unfilled part of the casing has a length which adapts the whole length of the body to the wall thickness in question.

Description: FIRE SEALING OF LEADS-THROUGH FOR CONDUITS TECHNICAL FIELD The present invention relates to fire sealing a lead-through for a conduit through a building member such as a cast concrete wall, roof or floor, or cast section thereof. The building iTifcir.ber can also consist of a relatively thin wall, for example, in a fireproof material such as steel, e.g. a vessel bulkhead. By the term "conduit" is intended, for example, electric cable, piping, ventilation, ducting or the like, and the term is atso intended to include a group of such elements. The Lead-through, i.e. the hole in a wall or floor enabling the passage of electric cables, piping, ventilation, ducting or other installation components from cne room to another always constitute a large risk in connection with fire. These leads-through constitute obvious propagation paths for both smoke and flames. It is therefore often of decisive importance for fire safety that such a lead-through is sealed in a mode effectively preventing the propagation of both smoke and fire. The lead-through is usually provided by leaving a recess in a wall or the like on casting concrete or laying the courses of a wall. Alternatively a passage can be cut in the ready-cast or laid wall. At a later building stage conduits are then taken through these leads-through, which are subsequently sealed against fire, i.e. the free space between the conduits and the wall of the lead-through is filled out with a fire resistant filling material. BACKGROUND ART It is known to mount a frame in a lead-through, said frame being filled with a plurality of paralletepipedic blocks. At least some of these blocks are parted and have r.utually opposing semici rcular recesses for a cable. The cylindrical space between these block halves is filled with a cylindrical sealing body which can -thus be removed to make room for a cable. By tightening, or clamping, the damping frame affords the desired tight engagement between the blocks and the cables. The drawback of such a clamping frame is however that the blocks supplied only afford sealing for certain cable dimensions and a certain number of cables. In turn, this has resulted in that during the supplementary laying of cable through such a clamping frame, a whole block is cuite simply remcv d sc that the seal between the cable and the-.adjacer DISCLOSURE OF INVENTION The present invention relates to a special means for fire sealing a lead-through for a conduit through a buildning member such as a cast wall, roof or floor or cast section thereof e.g. lightweight concrete blocks or wall modules or structural flooring from precast concrete or lightweight concrete units, whereby the above-ment oned disadvantages are considerably reduced or eliminated by the nvention^' and furthermore particular advantages are gained with regard to simplicity and economy in production, economic stockkeeping and simple and reliable application. The invention furthermore enables a reliable fire seal during buildning also. The means in accordance with the invention includes a prefabricated body with a tubular casing and an elastomeric fire retardant foamed material adapted in the casing, this material being compressed by the casing transverse the longitudinal axis of said casing, whereby the conduit is sealingly clamped in the foamed material by compression of- the latter. What is characterizing for the invention is that the casing is filled with foamed material from the one end uo tp a distance from the opposite end of the casing,. the length of the foamed material being adapted to comply with safety requirements placed on the fire seal in question and said unfilled length being intended for adjustment of the whole length of the body to the thickness of the building elements being used. Apart from the above-mentioned disadvantages in previously known devices for fire-sealing a lead-through having been substantially reduced or elimi¬ nated there is also won by means of the invention the advantage that bodies can be utilized, which can be prefabricated in a factory under conditions which can be easily and well controlled with respect to foam conditions, and that the bodies can be adapted for " filling with the length of foam material which is at a minimum, inter alia in respect of the fire classification in question, and at a maximum with respect to electrical safety stipulations for avoiding risky heating from the cable or cables. There is hereby obtained an advantageous limitation of the amount of foamed material. The desired adaption of the body length to the thickness of the building element in question can be easily obtained, if the length does not agree, by cutting the casing at the portion of the body not filled with foam material. This can be economically advantageous, since the casing can be made from a mate¬ rial which is cheap in comparison with the foamed material, preferable a thermoplastic material such as polythylene. No foamed material is lost by this process. The casing ends can furthermore be utilized after fitting the body for easy insertion of some suitable detail, e.g. a decoration flange suitable from the point of view of appearance. During casting a building element, wall or the like between two shuttering walls it is essential that the bodies are placed firmly between the form walls when the heavy mass of concrete is poured in. In one embodiment of the invention the foamed mate- rial projects outside said one end of the casing for this reason. There is thus obtained in a simple way a retention of the body at this end against the engaging shuttering wall by friction between the wall and the projecting foamed material. In accordance with the invention this retention can be further ensured by arranging a fastening means engaging with the foamed material between the shuttering wall and the foamed material at the free end of the casing. Positive fastening of the body against the other shuttering wall can be obtained in a plurality of modes. For example, a fastening element adapted to the shape of the casing can be attached to the shuttering wall and the casing end inserted to a clamped position on the fastening element. In a preferred embodiment of the invention, in which the body has a circular cross-sectional shape, the casing is provided with at least external threading, preferably internal threading as well, in this case the fastening element preferably comprises a fastening frame with internal threading adapted to the external threading on the casing. The body can then be simply screwed into the fastening frame, whereby screwing on to different lengths in the fastening frame enables an adjustment to correct length in relation to the wall thickness. There is also obtained by means of the external threading on the casing the advantage that the body is cast in situ with retention due to its shape and good sealing around it, and by means of the internal threading there is obtained the advantage of retention due to its shape of the expanded foamed material in the threads during production of the body, and a good seal between the casing and the foamed material. Preferred embodiments of the invention w ll now be described in more detail with reference to the appended drawing. OMPI BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a section along the line I-I in Figure 2 of an embodiment of a fire sealing body. Figure 2 is an endview of the body seen from the left in Figure 1. Figure 3 illustrates in side view and in an exploded sketch the-fitting of a fire sealing body between two shuttering walls. Figure 4 is a section corresponding to the one in Figure 1 and showing the body in a fitted position between two shuttering walls and after the shutterin has been filled with concrete. Figure 5 is a plan view to a larger scale of a fastening element suitably formed for the fire sealing body according to Figures 1 a>--d 2, for fixinq the body during casting, e.g. casting as illustrated in Figure 4. Figure 6 is a section along the line VI-VI in Figure 5. Figure 7 is a section along the line VII-VII in Figure 5. Figures 8-11 are sections corresponding to Figure 4, but after taking away the shuttering.; and in different work operations illustrates putting a cable through the body with the aid of a tool specially constructed for this purpose. Figure 12 is a perspective view and to a larger scale of the head of a handle incorporated in the tool. Figures 13 and 14 are perspective views of two different examples of fixing a fire sealing body in a previously made hole in a cast wall or building element, for example. Figure 15 is a perspective view of the attachment of a fire sealing body in a thin wall of fireproof material such as steel. OMPI BEST .WDE FOR CARRYING OUT THE INVENTION Figures 1 and 2 illustrate the principle construciton of a fire sealing body, generally denoted by the numeral 1. This consists of a casing 2, axially formed with a thread 3. In the illustrated embodiment the casing 2 is formed so that there is an external as well as an internal thread. The casing may consist of a thermoplastic such as polyethylene. The interior of the casing from one end along a portion 3 thereof is filled with an elastic fire retardant foamed material 4, which is foamed in situ in the casing so that the cured foam is kept compressed by the casing. The foamed material suitably comprises a silicon foam which is commercially available under the designation "Dow Corning 3-6548 RTV", this scum suitably being produced in situ in the casing 2. Since the material expands as it is produced, when it assumes a consistency like that of foam rubber, the interior threads of the casing are also filled, which, apart from the casing holding the foamed material co-pressed transverse the axial direction of the casing, contributes to the retention of the foamed material and furthermore gives a decidedly better seal than if the inside of the casing were smooth. Although not shown, one or more reinforcing nets can be set into the foamed material, partly to prevent the material from being broken off during subsequent cable laying (see Figures 8-11), and partly for enabling a sealing arrangement of a plurality of cables through the fire sealing body without breaking up the material and forming cracks in it. The length 3a, filled with foamed material, is adapted to the stipulations applicable for the fire seal in question, which have the form of a fire classification signifying a given minimum length, and electrical safety stipulations signifying given maximum length. The fire sealing body 1 is produced with an unfilled portion 5 suitably having a length enabling the use of the fire sealing body for different current wall thicknesses. The portion 5 can be easily cut, suitably with a saw, to the correct- length, e.g. as illustrated in Figure 1, along the chain- dotted line 6. Figures 3 and 4 illustrate how a fire sealing body is cast in between two shuttering walls 7 and 8, the body having the principle embodiment illustrated in Figures 1 and 2. Figure 3 illustrates how a fastening frame generally denoted by the numeral 10 is attached by means of nails 9 to one shuttering wall 7, said frame having an embodiment such as is more closely described below with reference to Figures 5-7, i.e. it has, inter alia, an internal thread adapted to the thread 3 of the casing 2. After cutting the body 1 to at least the approximate length, the body is fixed relative the shuttering wall 7 by being screwed into the attachment frame 10. By screwing-in to different depths, there is offered a possibility of adjustment with relation to wall thickness. The shuttering wall 8 is subsequently erected and the shuttering pulled together, whereby the fire sealing body is clamped firmly between the shuttering walls. Adjustment within a given tolerance for the length of the body is also obtained by the elasticity the body has longitudinally, due to. its threaded form. As will be seen from Figure 3 (and also Figure 1) the foamed material thrusts out a small distance (some millimeters) outside the casing 2. This projecting portion is denoted by the numeral 11. There is thus obtained by friction between the foamed material and the shuttering wall a retention of this end of the fire sealing body against the shuttering wall. Further surety for retaining this end can be obtained by nailing a suitably relatively flat means (not shown) against the shuttering wall 8 this means being provided with inwardly thrusting means, e.g. in the form of concentric rings, which come into engagement with the foamed material after erecting the shuttering wall. In this case, as an alternative, the projecting foamed material 11 could be avoided. By using a fastening frame, there is no longer the requirement for cutting off the body perfectly with relation to the. ZZ.'.?ι flatness of the cut as well as perpendicularity to the longitudinal axis of the body. Figure 4 illustrates the fire sealing body 1 with the fastening frame 10 after filling concrete 12 between the shuttering walls 7 and 8. By the external threads also being filled with concrete, a retention of the fire sealing body by means of its shape is obtained in the concrete. The body forms a gas-, fire-, water- and sound-proof lead-through during the whole of the building time, both before and after cable laying through it. An advantageous embodiment of the fastening frame 10 illustrated in Figure 3 will now be described with reference. to Figures 5-7. This frame comprises an annulary shaped wall 13, along the inside of which a thread is formed. The latter comprises, in the illustrated embodiment, two straight and practically semi-circular ridges 14 and 15, the free ends of which do not meet, seen in plan view. On the outside of the wall 13 there are arranged four diametrically opposing nail holes 16 for nailing the frame to the shuttering wall (wall 7 in Figures 3 and 4). The nail holes 16 flare out in a direction towards the edge side of the frame wall 13 which is to engage against the shuttering wall. When the wall 8 is taken down, the nails accompany it, but the frame remains -in the concrete. On the opposite endge side of the frame wall 13, four diametrically opposing corner portions 17 and 18 project out at right angles to the wall. The corner portions 17 are hereby formed with outwardly open slots 19 and the corner portions 18 are provided with buttons 20 which can be snapped into the slots 19 in an adjacent frame to form a desired number of frames 10 snapped together in a row. To ensure a positive such snapping together of adjacent frames, each frame is provided with- locking means comprising a dovetail tongue 21, projecting from the surface of the fastening frame wall and situated between the buttons 20 and a complementally shaped, diametrically opposite slot 22. Figures £-11 illustrate different work operations in pulling a conduit through a fire sealing body after the shuttering has been taken down. The body illustrated in exemplification corresponds to the body according to Figure 4 and is illustrated cast into the concrete wall 23. To obtain a sealed r 5 -- s 9 e 0 "f the conduit a special lead-through tool is used. It ccmprises three parts, a conical tip 24, g, sleeve 25 and a handle 26 with a OMPI head 27, whfch coact in a mode apparent from the following description. As shown in Figure 8, it is suitable to push the tip 24 by itself into the foamed material 4, or if several conduits are to be pulled through, a tip is inserted for each conduit, the placing of the different conduits can 5 thereby be planned with the aid of the tips. The forward end 28 of the sleeve is inserted in the tip and with the aid of the handle. Tip and sleeve are pressed through the foamed material, and when the tip has ' passed there¬ through it falls away of its own accord. For this penetration, the handle can press against the back end 29 of the sleeve with the handle in a 10 position s shown in Figure 8, there being in the head 27 of the handle an annularlyfor ed bottomning groove (see Figure 12) in which the sleeve end is inserted during penetration. As an alternative, by special forming of the head 27 (shown in more detail in Figure 12) with recesses 30 for hooking onto two of four heels ' or abutments 31, evenly distributed around the circu - '-* ference of the sleeve 25 in the vicinity of the back end of the sleeve, through penetration of the tip 24 and sleeve 25 can take place, after such a hooking-on, and in an attitude which -is angular relative to the sl.eeve for the handle 26, which can be valuable for more inaccessible places. 20 Figure 9 illustrates a position of the sleeve 25 after it has been pressed through the fire sealing body, and a conduit 32 has been pulled through the sleeve. Since the hole provided through the body is lines by the sleeve and thereby protected by it, the conduit can be pulled through the body without damaging the latter. As is shown, the sleeve is slit up at the ends 28, 29 to form tunnel-shaped openings, thus preventing the conduit from being jammed. as it is being pulled. Figure 10 illustrates the withdrawal of the sleeve 25 from the foamed material after pulling the conduit is completed. Especially for this with¬ drawal, the sleeve is provided with said abutments 31 and the head portion 30 27 of the handle with said recesses 30. By r.εar.s of the four abutments 31, arranged around the circumfereπce of the sleeve, there is permitted an all- round engagement between two abutments and the recesses, for good accessi¬ bility. Turning the sleeve to the most comfortable position is thus also permitted. Furtherrcre, the recesses 30 ere flared outwards so that the 35 abutments 31 are also guided into the bottoms of the recesses for ar. angle within a relatively large angular range between the central axis of the handle and that of the sleeve, whereby there is also allowed a similarly large a n gular range between the handle and sleeve during withdrawal. After . withdrawal, the sleeve must be removed from the conduit. For easily providing 5 this, the sleeve is formed with perforation or other weakened stretch (not shown) extending between two opposing bottoms of the slit-up ends 28, 29. After cutting up this perforation, the sleeve can be opened out and removed from the cable. The head 27 of the handle is specially adapted for use during this cutting. On the back of the head 27, relative to the recesses 30, the 10 head is provided with slitting-up portions (see Figure 12) each comprising a " cutting edge 33, situated inside an outwardly rounded-off slide knob 34. A positive engagement of the slitting-up portion of the head 27 is obtained ' in the slits at the sleeve ends 28, 29, between which the perforation extends, the slitting-up portion also being formed so that the handle can be kept 15 within a large angular range relative the sleeve, e.g. 15-55°, for comfortable accessibility. The accessibility furthermore increases by the head 27 being formed with two slitting-up portions, one behind each recess 30, which thus also increases the life of the handle. The rounded-off slide knob 34 is adapted for preventing the c.utting edge 33 damaging the conduit 32 during 20 slitting-up. Figure 11 illustrates the conduit 32 inserted in the lead-through after sleeve ' 25 is removed. Since no foamed material has been taken away, and the material has only been compressed, the foamed material 4 springs back elastically and a sealing closure of foamed material is obtained round the conduit. 25 As given above, the head 27 of the handle is more clearly shown in Figure 12, which illustrates the forming of recess 30, cutting edge 33 and slide knob 34.' The annular groove is further shown in the Figure, the end 29 of the sleeve 25 being inserted in said groove during pressing the tip 24 and sleeve 25 through the fcar.ed material 4 of the body 1. This groove is denoted by the numeral 30 35 in the Figure. A groove 36 is also shown, defined by the side of the slide kncb 3^ facing towards the recess 30 and a bottom wall, the lower edge shewn in the Figure forming the cutting edge 33. One of the slit-up edges is successively guided by this groove 36 during slitting-up of the sleeve 25. With re erence to Figures 1-12 there has been described above a fire sealing ** ____— — — — - 'BU tATT" OMPI 10 body partially filled with foamed material and having a circular cross section and threaded casing. Many of the advantages set forth in this description as well as in the introduction under the title "DISCLOSURE OF THE INVENTION" can be obtained with a fire sealing body having a cross- sectional shape other than that which is circular, e.g. quadratic, rectangular or oval, whereby the casing for such a body can indeed have external threads or other corrugations or other projecting portions or be smooth and instead of being threaded ήnto the fastening frame it can be attached in some ' other way, e.g. by snapping onto a suitably formed fastening frame. Another alternative is to use a fire sealing body completely filled with foamed material, with a circular cross section arid threaded casing. Such a body has all the above-mentioned advantages, apart from those obtained by having the casing of the body only partially filled with foamed material. Other examples of fire sealing bodies, wholly or partially filled with foamed material, are shown in Figures 13-15, in Figures 13 and 14 there being shown bodies for attaching to a previously made hole in a wall or building element, and in Figure 15 there is shown a fire proof sealing body in a hole in a comparatively thin wall of material, e.g. a vessel bulkhead. In Figure 13 there is shown a part of a wall or a building element 37 with a hole 38. An exterior sleeve 39 of foamed material is moulded on a slit pipe 40, and further to the illustrated internal thread 41, this pipe can have an exterior thread, and suitably taper towards the edges of the slits. The pipe • 40 with sleeve 39 are inserted in the hole 38. A casing for a lead-through body 43, wholly or partially filled with foamed material 4, provided with an exterior thread 42 and preferably also an internal thread, is threaded into the pipe 40. On threading in, the slit tube 40 is forced against the outer sleeve 39 by expansion, the latter in turn pressing against the walls of the hole 38. In Figure 14 there is illustrated a wall or a building element 44 shown in a section through a hole provided with thread 45. The thread 45 can be formed in a cast-in sleeve, or formed in the material itself with certain wall materials. A lead-through body comprises two halves 46 and 47, semi-circular in cross section, with a mantle having an exterior thread 48 and to advan¬ tage an internal thread also, as illustrated and with grooves 11 circular in cross section. The halves 46 and 47, for example those illustra¬ ted, are filled for their entire length with foamed material 4, are pressed onto a conduit 50 and squeezed against each other, whereafter the assembled halves are threaded into the hole provided with thread 45. This embodiment of a fire sealing body is intended for a single conduit, specially of heavy dimensions, and is particularly utilizable for conduits which cannot be pulled through the foamed material of a fire sealing body because the conduit is provided with some projecting connection, for example. Alternatively, it is possible to cast in the fire sealing body in a conventional way, thereafter to screw it out to put it round the conduit and then screw it back into the threaded hole. This has the advantage that a sealed lead-through can be obtained during building as well. Another alternative is to have a slit-up lead-through body instead of two separate halves 46, 47. Finally, in Figure 15 there is illustrated a lead-through body 51 with a casing provided with an exterior thread 52.and preferably an inner thread also, the casing enclosing a foamed material 4 in a customary manner. The lead-through body is threaded through fastening pieces 54 provided with internal threads 53, said fastening pieces being previously fastened on either side of a wall 55 with the collars or flanges 56 of the fastening pieces sealingly surrounding a hole 55 made through the wall. If only one conduit is to be arranged through the lead-through body in the embodiments according to Figures 13 and 15, the body can be divided into halves or slit-up similar to what has been shown and described with reference to the embodiment according to Figure 14. Oi ri

Claims: WHAT WE CLAIM IS:- 1 A device for fire-sealing a lead-through for at least one conduit to a building element, comprising a prefabricated body with a tubular casing and elastic fire retardant foam material disposed in the casing, said mate¬ rial being compressed by the casing transverse the longitudinal axle of the casing, whereby the conduit is sealingly clamped in the foamed material by compression of the latter, characterized in that the casing (2) is filled with foamed material (4) from one end up to a distance from the opposite end of the casing, the length (3a) of the foamed material being adapted to comply with safety requirements placed on the fire seal in question, and said distance (5) without foamed material having a length for adjusting the whole length of the body (1) to the thickness of the building element in question. 2 A device as claimed in claim 1, characterized in that the foamed material ( 4) projects a small distance (11) outside said one end for engagement with friction against a shuttering wall (8) during casting the building element (23). 3 A device as claimed in claims 1 or 2, characterized in that the foamed material (4 ) at said one end is in engagement with a means retaining this end, and attached to the shuttering wall (8) arranged for casting of the buildning element (23). 4 A device as claimed in any of the preceding claims, characterized in that the said opposite end of the casing ( 2 ) is fastened to a fastening element (10) attached to a contiguous shuttering wall (7) during casting of the building element (23). 5 A device as claimed in any of the preceding claims, wherein the body (1) has a circular cross-sectional shape, characterized in that the casing (2) of the body cs formed with an external thread (3). 6 A device as claed in claims 4 or 5, characterized in that the fastening element comprises a fastening frame (13 ) with an internal thread (14, 15) adapted to the external thread (3) of the casing ( 2 ) . _ -gU EATT O PI 13 7 A device as claimed in any of the preceding claim.s, wherein the body ( 1 ) has a circular cross-sectional shape, characterized in that the casing ( 2 ) of the body is formed with an internal thread (3).

Inventors: LEGERIUS B
Applicants: ERICSSON TELEFON AB L M, LEGERIUS B
Application year: 1981
Main classification: H02G3
IPC codes: F16L5, H02G3