TECHNICAL FIELD

The present invention relates to a tool which makes holes for conduits in fire-sealing leads-through located in a building member such as a concrete wall, ceiling or floor, or case section thereof. The building member can also constitute a relatively thin wall, for example, in a fireproof material such as steel, e g a vessel bulk head. By the term "conduit" is intended, for example, electric cable, piping or the like, and the term is also intended to ^' include a group of such elements.

Leads-through, i e the facilities in walls and floors enabling the pas ^¬ sage of electric cables, piping, ventilation ducting or the like from one 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 of decisive importance for fire safe¬ ty that such a lead-through is sealed in a mode effekctively preventing the propagation of both smoke and fire. The lead-through is usually pro- vided 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-ttirough is filled out with a fire-resistant filling material.

BACKGROUND ART

In a lead-through, it is known to use a fastening frame which is rigid¬ ly and sealingly mounted in the building member, this frame then being filled with a plurality of parallelepipedic blocks. At least some of these blocks are parted and have mutually opposing semicircular reces- ses, which form a cylindrical space for a conduit. This space is filled with a cylindrical sealing body which can be removed to make room for a conduit. By tightening or clamping, the fastening frame affords the desired tight engagement between the blocks and the conduits. The dis¬ advantage with the known arrangements with this kind of fastening frame is that the blocks supplied only afford sealing for certain conduit dimensions and a certain number of conduits. In turn, this has resulted

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in that during the supplementary laying of conduits through such a frame, a whole block is quite simply removed so that the seal betwee the cable and the adjacent blocks is lost. Furthermore, it has often been found that blocks have become lost during handling and have not 5 been replaced, the lead-through thus having through-openings which nullify the fire-protecting function of the device.

It is also known in the prior art to utilize rubber bushings for sea ing a conduit lead-through (cf. British Patent Specification 953,869 a tubular rubber grommet being pressed into a lead-through, subseque 0 to which a cable group is forced through the hole in the grommet. Ho ever, such a technique is not particularly suitable for fire-sealing purposes, since the conduits must usually be pulled a long way throu the grommet, as well as a new lead-through having to be arranged and new grommet provided if a further conduit is to be taken through the 5 wall.

A plastics moulding technique has therefore been adopted, the steps here being that the conduit or conduits are laid through the lead- through, which is thereafter temporarily sealed with shuttering, and fire-resistant silicon is foamed in situ in the lead-through. This 0 technique is offered by Studsviks Energiteknik AB under the name "Br tatningssystem FC 225" ("FC 225 Fire Sealing System") where a silico - foam commercially available under the name Dow Corning 3-6548 RTV is - - ^■ utilized. If it is subsequently desired to lay a further conduit, a lead-through should be made for it, e g in an existing wall, and sea 5 with the FC 225 technique. This is troublesome, especially if the wa consists of concrete, and expensive, not in the least with the thoug that in preparing the lead-through, wall claddings such as panels an wallpaper are often damaged and must be replaced.

DISCLOSURE OF THE INVENTION

The present invention relates to a tool specially formed for making 0 holes through a fire-sealing lead-through having an elastic fire-re¬ sistant foam material which is kept in a compressed condition in the lead-through. The lead-through can be prefabricated or r.ade on site.

Conduits are taken through the holes which are made, a sleeve having been inserted in the through-holes before laying out the conduits to facilitate laying out and to prevent damage to the hole walls. After the conduits have been laid and the sleeves removed where necessary, the conduits are sealingly clamped in the foamed material by the com¬ pression already in the latter. The object of the invention is to pro¬ vide a tool for making the holes simply, rapidly and reliably, and which does not destroy the material in the Lead-through when so doing, e g by crumbling off or breaking the material. There is hereby enabled holes which keep the conduits well sealed in the lead-through while at the same time allowing an advantageous utilization of its entire cross section.

The characterizing features of the invention for attaining said object will be seen from the following claims.

Preferred embodiments of the invention will now be described in the fol¬ lowing while referring to the appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

Fig 1 is a side view, partly in cross section, of one embodiment of a tool in accordance with the invention.

Fig 2 is a perspective view of some segment parts of which the hole- making part of the tool is built up.

Fig 3 illustrates to a larger scale in side view and partially in sec¬ tion the forward end of a tool for expanding holes made by a tool ac¬ cording to Fig 1.

Fig 4 is a side view of a tool for enabling differently sized holes to be made.

PREFERRED EMBODIMENTS

The tools illustrated on the drawings are shaped for making holes through

a fire-sealing lead-through including an elastic fire-sealing foamed material, said holes being intended for the passage of a conduit as defined hereinbefore. Before conduit-Laying takes place, a sleeve is suitably inserted in the hole to facilitate laying. In the Swedish Patent Application 8002047-2 there is shown an example of a Lead-thr of the kind in question, where it is suitable to use a tooL in accor ance with the present invention, there also being shown an example o a suitabLy formed sleeve.

The tool illustrated in Fig 1 comprises a driving end 1 in the form a conical tip portion for facilitating driving the tool through the elastic foamed material without breaking it apart, a hole-making par and a handle part 3. In the illustrated embodiment, the tip part 1 a the handle part 3 are provided with an internalLy threaded sleeve-sh insert 4 and 5, respectively, for threaded engagement with a rod 6 e tending through the hole-making part and threaded at its ends.

The tip part 1, the hole-making part 2 and the handle 3 are preferab made in a suitable plastics material, while the rod 6 is preferably from stainless steel.

The tip part 1 is provided with grooves 7 along at least two opposin sides for facilitating driving the tooL through and forcing aside th material.

The hole-making part 2 comprises a plurality of parts of segments 8 which are slipped onto the rod 6 and mutually interconnected. The fo of the segments 8 in the illustrated tool is best seen from Fig 2. F making holes in the foamed material, the segments are provided with group of protuberances or teeth 9 of which there are six evenly dist buted round the circumference of the segment in this example. For in terconnection, the segments 8 are forir.ed with a projection 10 at one end, and at the opposite end with a recess 11 complemental to the pr jection 10. As will be best seen from Fig 2, the projections 10 and cesses 11 are so located that in the longitudinal direction of the t the teeth 9 in one segment will register with the gaps between the t in the next segment. Furthermore, and as shown, the teeth preferably f OMPI WIPO

have an extension in the circumferential direction such that they fill out the gaps between the teeth in the next segment. This arrangement of the teeth and their form ensures in a simple way the formation of a hole with a substantially constant cross section along the hole, for a prefer- red simple reciprocatory motion of the hole-making portion through the ateriaL in the Lead-through, this arrangement of the teeth and their form facilitating the transport of cut-away material out of the hole. The teeth 9 can naturally be given some other placing and form, but then suitably at Least in a helical Line along the hole-making part 2, partly to obtain a hole in the Lead-through with at least a substantially con¬ stant cross section, by solely executing the simple reciprocatory motion through the materiaL and partly to facilitate transport of cut-away ma¬ terial. Rotational movement of the tool during driving the hole-making part through the material can naturally be carried out, and here the teeth should also lie in line one after the other, but this results in a more complicated task as well as the risk of greater tearing-away of the material with resulting holes of poorer quality, e g such as could obtain a cross-sectional shape other than that of a circle along a portion of their Length.

The illustrated, preferred subdivision of the hole-making part 2 into segments 8 is above all made for production reasons. Production of the hole-making part in one piece, especially for a helically placed teeth, would signify a more complicated forming tool than what is required for producing the segments. Furthermore, the segments afford the formation of hole-making parts having different Length, and also optional placing of the teeth along the hole-making portion. In another embodiment (not shown) the projections 10 and recesses 11 can be evenly distributed at the ends of the segments, there being thus obtained a plurality of choices for placing the teeth in relation to those on an adjacent seg- ment. There is, of course, the possibility of producing the hole-making part 2 in one piece.

If it is desired to make larger holes than can be suitably made with a tool according to Fig 1, bearing in mind the tearing of the material, a tool as illustrated in Fig 3 can be used after making the hole with a tooL according to Fig 1, the tool of Fig 3 having a larger cross-sectional

OMPI ^

area along the hole-making part 2, which is provided with a rounded instead of the pointed Lip 1, which becomes unnecessary. As an alter tive hereto a tool as illustrated in Fig 4 can be used. This tool co prises a driving end 1 and a hole-making part 2 in accordance with t shown in Fig 1, but by means of a conical portion 12 this tool now m es into a hole-making part with a Larger cross-sectional area, e g a illustrated in Fig 3. At Least one further hole-making part can subs quently be arranged via a conical part corresponding to the part 12.

The height of the teeth 9 is of .importance. If it is too great, ther is a risk of the foamed materiaL being torn off and that the tool is jammed in the materiaL. A suitable tooth height is 1-3 mm, preferabl 1.5 mm.

Some leads-through may be reinforced, i e provided with a wire mesh reinforcing net, and there may be a hard materiaL, e g so-called dam boards, arranged on the outsides of a lead-through. By the form of t conical driving tip 1 and its grooves 7, the tip can easily penetrat especially with a rotating movement, any reinforcing and Like hard m terial which may be present.

The invention is naturaLly not Limited to the embodiment examples il Lustrated on the drawings but can be varied in a plurality of modes, which inter alia will be seen from the description hereinbefore, wit the scope of the following claims.