Background Art Walls, floors and. ceilings of a building usually a multi-storey building commonly have pipes, ducts and conduits formed of a plastics material which penetrate the wall, floor or ceiling for carrying services for example water, sewerage or electrical services. In the event of fire however, the penetrating pipes, ducts or conduits allow flames and/or smoke and gases to spread rapidly through the wall, floor or ceiling. To overcome this problem, a number of devices are currently known for use in conjunction with plastic services pipe or ducts for closing off the pipes or ducts in the event of fire.

Some of the devices which are used incorporate a heat reactive expandable material or intumescent which is in the form of a flexible wrap and which is located on the inside of a steel or plastic sleeve or housing which is placed about the pipe or duct. When exposed to heat, the heat expandable material will rapidly expand inwardly to squeeze and collapse the pipe which has softened to due heat exposure. These devices can either be surface mounted or fully or semi-cast into masonry floors, walls or ceilings or can be mounted on one or both sides of the floor, wall or ceiling depending upon the direction of risk.

The devices which are available however have some deficiencies. Sometimes, the pipe is not fully sealed by the heat expandable material and thus they are not fully effective as fire barriers. Retention devices are essential to retain the intumescent material in their housing however, often the retention devices are not effective with that result that the intumescent material as it expands can fall out of the housing or sleeve and slab. The intumescent material in plastic housings is usually retained in the housing by means of a metal retaining ring. When the intumescent material expands under the influence of heat, it tends to push the ring out of the housing and thus the intumescent material also falls out. Further, some of the devices are made up of a number of components which can be of more than one part, the intumescent material, and a spacer or retention device within the housing. As a result, such devices can be relative complex or time consuming to assemble and are thus costly. A further disadvantage

associated with fire barrier devices having'metal housings is that the metal rapidly conducts heat through a slab and thus some of the devices of this type do not satisfy fire rating requirement. To reduce this effect, the housings have to be as low as possible in the slab to reduce the conduction of heat however this sometimes is not possible in the case of larger penetration pipes where the metal housings are relatively large.

Summary of the Invention The present invention aims to provide an improved fire barrier device for providing a barrier to the passage of smoke or gases and/or flames along pipes, ducts or conduits passing through walls, floor or ceilings of a building which is of a simple construction, which is effective in use and which is relatively inexpensive. The present invention in a further aspect aims to provide a method of manufacturing a fire barrier device of the above type. The present invention further aims to provide a method of installing a fire barrier device of the above type in a slab or ceiling.

The present invention thus provides in a first aspect a fire barrier device for use with pipes, ducts or conduits passing though a wall, floor or ceiling of a building, said device comprising a substantially annular main body portion adapted to be located about said pipe, duct or conduit and characterised in that said body is moulded from a material containing a heat reactive expandable material.

The present invention in a further aspect provides a method of manufacturing a fire barrier device for use with pipes, ducts or conduits passing through a wall, floor or ceiling of a building and having a substantially annular main body portion adapted to be located about said pipe, duct or conduit, said method including the step of injection moulding said fire barrier device from a material containing a heat reactive expandable material.

Preferably, the material for forming the fire barrier device and for injection moulding includes the heat reactive expandable (or intumescent) material and a carrier or plasticiser. Typically, the intumescent material comprises graphite in particulate form. The carrier or plasticiser may comprise HDPE (high density polyethylene) or other similar material. The material may additionally include a fire retardant to prevent or minimize flaming or burning of the material. A typical flame or fire retardant may comprise sodium silicate. The material may additionally include a smoke suppressant to prevent excess generation of smoke when the fire barrier device is subject to heat or flames.

The fire barrier device may be mounted to a wall, floor or ceiling of a building around a pipe, duct or conduit penetrating the wall, floor or ceiling or installed within a wall, floor or ceiling such as a slab wall, floor or ceiling either by being cast in situ within a slab or located in a recess in the slab around the pipe, duct or conduit.

The present invention in thus a further aspect provides a fire barrier device for use with pipes, ducts or conduits passing through a wall, floor or ceiling slab formed of a settable material, said device comprises a moulded main body formed of a material containing a heat reactive expandable material, said main body being adapted to receive a pipe, duct or conduit therethrough, said main body being shaped so as to be retained within said slab by the material of said slab. Preferably, the main body has an axial bore therethrough to receive the pipe, duct or conduit.

Typically, the barrier device is installed within and adjacent one side of the slab. Preferably, the main body has a maximum transverse dimensions located in use at a position spaced from one side of the slab to resist detachment of said main body from said one side of the slab. Such a configuration will ensure that the main body will be retained within the slab by the material thereof.

Preferably, the main body is of substantially annular form to extend in use generally radially of the pipe, conduit or duct such as to be retained within the slab by the material thereof when installed within the slab during the construction thereof.

Typically at least portion of the outer surface of the main body is curved. Typically the main body is of substantially spherical or part spherical configuration with the maximum diameter region thereof being arranged in use within the slab and the minimum diameter region being located in use adjacent the one side of the slab. The spherical or part-spherical external surface or surfaces which is centred on the axial bore cooperate/s with the slab material to concentrate the expansion forces of the heat expandable material to more effective close off the pipe, duct or conduit.

Alternatively, the main body may be of frustonconical form centred'on the axis of the bore. The external surface of the body however may be of any other divergent form in cross section. For example, the body may have a stepped outer wall defining a shoulder which cooperates with the material of the slab to retain the device within the slab.

The main body may additionally or alternatively include integrally formed retaining means adapted for cooperation and bonding with the material of the slab. The

retaining means may comprise an external groove in the body in which the"wet" material of the slab locates during slab construction. The groove suitably is a substantially annular groove extending peripherally about the main body. The main body may include one or more peripherally extending grooves. Alternatively, or additionally, the main body may include one or more radially extending projections which are adapted to cooperate with the slab material to assist in retaining the main body within the slab. The projections may be of substantially annular form to extend substantially peripherally of the body.

In one form, the device includes mounting means integrally formed with the main body for mounting the device to formwork defining one side of the slab during the construction thereof. The mounting means may include a radially extending annular flange or radially extending lugs by which the device may be secured to the formwork.

The flange or lugs may include openings or slots to receive or locate fasteners such as nails, cleats or screws to secure the device to the formwork or alternatively, nails, or cleats may be driven through the flange or lugs into the formwork. In another form, means may be provided for cooperation with the flange for holding or clamping the flange to the formwork. Such means may be in the form of an annular clamping ring which is engageable with the flange. Any suitably fasteners may be used for fastening the clamping ring to the formwork. Typically the fasteners may be cleats or other nails or screws.

The axial bore through the main body may include a first portion at one end of the main body and a second portion larger than the first portion at or adjacent the opposite end of the main body. Suitably, the first portion is remote from the mounting means and has an internal diameter substantially the same as the duct or pipe so as to grip and support the latter during installation thereof in the wall or floor slab.

The second enlarged portion of the axial bore may extend from the first portion, being stepped outwardly therefrom. The second enlarged portion may extend to adjacent the mounting means to open in use to the one side of the wall or slab after formation thereof.

The mounting means may include between the main body and annular flange or lugs, a wall which is coaxial with the main body and formed integrally therewith with the main body extending radially outwardly of the wall. The sleeve-like member or

wall may join the annular flange or lugs or may include an outwardly stepped or inclined portion to join the annular flange or lugs. The wall defines at least adjacent the flange a third bore portion which extends from and is coaxial with the second portion or the bore through the main body. Both the second and third bore portions are suitably of greater diameter than a pipe, duct or conduit with which the device is to be used so as to define an annular space between the main body portion and sleeve like member which opens to one side of the slab in the direction of the fire risk such that heat from a fire can rapidly reach the main body to cause rapid expansion thereof. The annular space in addition, allows connection of the pipe, duct or conduit with a further pipe, duct or conduit or fitting.

Preferably, the main body joins at its end opposite the mounting means, a collar which is coaxial with the axial bore. The collar may be formed integrally with the main body. The collar has an internal diameter substantially the same as the pipe, duct or conduit with which the device is to be used so as to firmly engage and support the pipe, duct or conduit during installation in a slab. In addition, the collar provides a seal with the pipe, duct or conduit to prevent escape of smoke and/or gases in the event of a fire.

This ensures that smoke is contained in the pipe, duct or conduit and is directed out of the building through the pipe, duct or conduit rather than being trapped in the building.

The collar may define at least a part of the first portion of the axial bore extending through the main body.

In another form, mounting means which may be separate from the main body. may be provided for mounting the main body to the slab formwork. Suitably the mounting means is of generally annular form and defines an annular flange by which the device may be secured to the formwork. The flange may include spaced openings to receive fasteners such as nails, cleats or screws to secure the device to the formwork or alternatively nails or cleats may be driven through the flange into the formwork. The mounting means may be in the form of an annular spacer which includes an annular side wall extending axially from the annular flange. The annular spacer may also include a further radially inwardly directed wall upon which the moulded main body is seated and is secured. The moulded main body may be secured to the spacer by adhesives or alternatively by a mechanical connecting arrangement. For example, the main body may be formed with members such as lugs which cooperate with slots or apertures in the inwardly directed wall of the spacer such that relative rotation between the spacer

and main body will secure them together. Alternatively, the spacer may include members which project into the material of the main body.

Retaining means may also be provided on the spacer to assist in retaining the device in the slab. The means on the spacer may comprise an annular bead or enlargement or alternatively an annular groove in the spacer. The bead, enlargement or groove may be formed in the annular side wall of the spacer.

In yet an alternative arrangement, the mounting means may comprise a hollow body formed of a heat softenable material and the main body of intumescent material which is mounted to surround the hollow body. The hollow body may have a side wall surrounding an opening through which a duct or pipe may pass, and the main body is in the form of a collar of a heat reactive expandable material surrounding the side wall and extending outwardly therefrom so as to retain said device in the slab when said material thereof sets or cures.

The collar of heat expandable or intumescent material may be formed integrally with the hollow body which itself is thus formed of the heat expandable material or alternatively, the annular collar is separate of the hollow body and may be located thereover coaxially. The annular collar may supported or seat on a shoulder formed in an external wall of the hollow body. The annular collar may be of any cross sectional form but typically may have a curved outer configuration. The annular collar suitably extends radially outwardly of the body so as to be retained in the material of the slab.

The wall of the hollow body may have means at one end for securing the body to formwork defining a boundary of said slab during the formation thereof. The means at one end may comprise and annular flange.

The hollow body may be in the configuration of a sleeve. Suitably, the outer wall of the sleeve is stepped to define a shoulder upon which the collar may seat. The portion of the sleeve wall adjacent the shoulder and within the collar is preferably relatively thin so as to soften rapidly when subject to heat and not prevent expansion of the collar. Preferably also the outer diameter of the sleeve wall portion is substantially the same as the internal diameter of the collar such that the later may be firmly engaged with the sleeve wall portion. The upper portion of the sleeve suitably has an internal diameter such as to enable the sleeve to firmly grip the outer wall of the duct or pipe to support the duct or pipe in an upstanding attitude.

In a further embodiment, a sleeve may be associated with the device to act as a

stack through the slab for accepting the pipe, duct or conduit therethrough, the sleeve being of such a length as to project beyond the slab when formed. The sleeve may be secured to any part of the device such as to the collar of the device where provided for example by adhesives or mechanical fasteners. In a further embodiment, the sleeve may be formed integrally with the device and extend coaxially therefrom relative to the axial bore through the body.

The device may also include on its underside, a radially extending recess for accommodating radially extending lugs of a joining sleeve or fitting. The recess may be defined by an integrally formed radially extending tunnel shaped member extending from the main body. The joining sleeve or fitting may be of the type which incorporates a heating coil to effect joining by heat fusion to a pipe, duct or conduit which terminates in connecting terminal or lugs extending radially therefrom for connection to a current source.

The present invention in yet a further aspect provides a method of installing a fire barrier device of the above type in a wall, floor or ceiling slab formed of a settable material, said method including the steps of inserting a pipe, duct or conduit into the bore of said main body, securing said device to formwork defining one side of said wall, floor or ceiling slab, and applying the settable material of said slab to said formwork and around said fire barrier device such that said settable material encases said device and leaves said pipe, duct or conduit projecting beyond said slab. The method may also include the step of removing the formwork when said settable material is set or cured, said device being retained in said slab by cooperation between the material of said slab and said device.

Typically the formwork is formed of timber and is removed after formation of the slab. In however an alternative arrangement, the formwork may be metal decking sheets such as that known as Bondeck and remain in situ after curing of the slab material. The fire barrier devices in such situations are secured to the metal sheets by metal fasteners such as screws or rivets and a circular opening is formed in the metal decking in alignment with the fire barrier device to enable the service line or pipe to be passed therethrough. The opening may be formed before or after affixing of the fire barrier device. To support the service lines or pipes during casting of the slab, radially extending stop means may be associated with the fire barrier device to span the device adjacent the mounting flange, the stop means being abutted by the end of the pipe.

Brief Description of the Drawings In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein: Fig. 1 illustrates the fire barrier device according to an embodiment of the invention in side view; Fig. 2 illustrates in perspective view, the fire barrier device of Fig. 1; Fig. 3 illustrates in sectional view, the manner in which the fire barrier device or Figs. 1 and 2 is installed within a slab; Fig. 4 illustrates in sectional view, the installed fire barrier device within a slab; Figs. 5 and 6 illustrate in side and perspective views a further form of fire barrier device according to the invention similar to the embodiment of Figs.

1 and 2; Fig. 7 is a perspective view of a further form of fire barrier device according to the present invention; Fig. 8 is a side elevational view of the device of Fig. 7; Fig. 9 is a cross sectional view of the device of Fig. 7 installed within a slab.

Fig. 10 illustrates in plan view, a fire barrier device according to a further embodiment of the invention; Fig. 11 is a sectional view of the fire barrier device of along line A-A of Fig. 10 with associated clamping ring; Fig. 12 illustrates the manner in which the fire barrier device of Fig.

10 is installed within a slab; Fig. 13 illustrates in sectional view, the installed fire barrier device of Fig. 10 within the slab; Fig. 14 is a plan view of a fire barrier device according to a further embodiment of the invention; Fig. 15 is a sectional view along line B-B of Fig. 14; Fig. 16 illustrates in sectional view, the manner in which the device of Figs. 14 and 15 is installed within a slab; Fig. 17 illustrates in sectional view the fire barrier device of Figs. 14

and 15 installed in a ceiling; Fig. 18 illustrates in sectional view a further form of fire barrier device according to the invention; Fig. 19 illustrates in perspective view, a fire barrier device according to a further embodiment of the invention; Fig. 20 illustrates the fire barrier device of Fig. 19 in side view; Fig. 21 illustrates in sectional view the manner in which the fire barrier device of Figs. 19 and 20 is installed within a slab; Fig. 22 illustrates in sectional view, the installed fire barrier device of Figs. 19 and 20 within the slab; Fig. 23 illustrates in perspective view, a fire barrier device according to a further embodiment of the invention ; Fig. 24 illustrates the fire barrier device of Fig. 23 in side view; Fig. 25 illustrates in sectional view the manner in which the fire barrier device of Figs. 23 and 24 is installed within a slab; and Fig. 26 illustrates in sectional view, the installed fire barrier device within the slab.

Detailed Description of the Preferred Embodiment Referring to the drawings and firstly to Figs. 1 and 2, there is illustrated a fire barrier device 10 according to a first embodiment of the present invention including a main body 11 integrally formed with a mounting portion 12 which is adapted to mount the body 11 in a desired position within a slab of settable material such as concrete as described further below. The device 10 comprising the main body 11 and mounting portion 12 are formed integrally in a conventional injection moulding process. The material for moulding includes a heat reactive expandable material or intumescent material which has suitable properties such as to expand when subject to heat as encountered in a fire. Typically the intumescent material comprises graphite. The moulding material also includes a plasticiser or carrier for example HDPE to enable moulding, a smoke suppressant and a fire suppressant for example sodium silicate. The main body 11 is circular in cross-section and has an external part spherical wall 13 centred on the central axis of the body 11 in which is formed an annular groove 14.

Wall 13 has a maximum diameter adjacent the mounting portion 12 and the body 11 is stepped inwardly adjacent portion 12 to present an annular wall portion or shoulder 13'

which faces the mounting portion 12.

The main body 11 joins at its upper end an integrally formed collar 15 which defines a bore 16 with an internal diameter substantially the same as the external diameter of pipe, duct or conduit to be received in the device 10. The bore 16 is stepped outwardly in the main body 11 to form a second enlarged bore 17 which extends through the main body 11.

The mounting section 12 includes a sleeve-like member or wall 18 extending from and formed integrally with the main body 11, the bore 17 extending through the member 18. The member 18 is stepped outwardly through an annular radially extending wall 19 and a second cylindrical wall 20, the latter terminating in a radially extending flange 21. The annular flange 21 includes circumferentially spaced slots 22 for locating fasteners. Alternatively, the slots 22 may be replaced by preformed apertures in the flange 21.

The device 10 may be used in a number of different situations to close off pipes, ducts or conduits passing through walls, floor or ceilings. Most commonly, however the device 10 may be installed within a concrete or concrete composite slab wall, floor or ceiling during its construction in the manner shown in Figs. 3 and 4. A pipe 23 is initially passed through the collar 15 such that it is frictionally gripped by the internal wall thereof and thereafter the device 10 may be secured to formwork 24 which defines one face of a concrete slab to be formed. This is achieved by means of the flange 21 of the device 10 which is seated on the formwork 24 with cleats 25 or other fasteners located by the slots 22 drive into the formwork 24 to clamp the flange 21 and thus the device 10 to the formwork 24. Of course, devices 10 may be initially secured to the formwork 24 at the desired positions where the service pipes 23 are to penetrate the slab and thereafter the pipes 23 inserted into the devices 10 to be supported in an upstanding attitude in the manner shown, the lengths of the pipes 23 being such that they will extend beyond the side of the wall, floor or ceiling slab to be formed opposite the formwork 24.

The concrete or concrete composite material 26 may then be poured or deposited onto the formwork 24 and around the devices 10 secured to the formwork 24 and pipe 23 until the required thickness of the wall, floor or ceiling slab 27 is achieved. As shown, the pipe 23 extends above or beyond the slab 27 to enable connection to further pipes to form the service line through the slab 27. After the concrete or concrete

composite material has cured or set, the formwork 24 is removed as shown in Fig. 4 which leaves the device 10 embedded in the concrete slab 27. The device is retained in the slab 27 due to the radially enlarged form of the main body 11 of the device which is embedded within the slab 27. Retention is further enhanced by the interlocking achieved through the material 26 of the slab filling the annular groove 14 and further because of the slab material filling the undercut annular space 28 between the shoulder 13'and the annular wall 19. The device 10 is thus anchored within the formed slab wall, floor or ceiling.

The bore 17 in the main body 11 defines with the pipe 23, an annular space 29 which opens through the mounting section 12 to the underside of the slab and which ensures that in the event of fire on the underside of the slab 27, the generated heat will be directed towards the inside of the main body 11 so that the intumescent material thereof is rapidly subject to heat which will cause it to expand and close over the softened pipe 23 as illustrated in dotted outline in Fig. 4. The curved nature of the external wall of the body 11 ensures that there is a concentrated expansion of the intumescent material as indicated by the arrows in Fig. 4 reacting against the surrounding slab material 26 which directs the expansion forces generally radially as illustrated to rapidly close over the softened pipe 23 as indicated in dotted outline. The space 29 also facilitates the connection between the pipe 23 and a further pipe or other fitting such as an elbow 30 (shown in dotted outline) having a mating female socket for joining to the end of the pipe 23 within the space 29 by suitable adhesives usually contact adhesives.

The annular finger of concrete or other settable material in the space 28 defined by the outwardly extending wall 19 serves to govern the exposure of part of the bodyl l to heat to control the rate of expansion of the body 11 and so that the device 10 has sufficient fire rating and will continue to be effective over a considerable period of time.

Whilst the body 11 is preferably of part-spherical external configuration as illustrated, it may be of alternat configurations for example of toroidal shape or simple ring-like shape and include alternative retention means for retaining the device 10 in the slab 27. For example, the body portion 11 may have outward projections which may be of annular form to cooperate with the slab material 26. The cylindrical wall or member 18 in some embodiments may simply extend downwardly to join the annular flange 21 and thus in this case, the walls 19 and 20 may be eliminated. In yet an alternative

configuration, the annular flange 21 and wall 20 may be eliminated and the wall 19 radially extended to service as a mounting flange for the device.

In yet a simplified form, the mounting portion 12 of the device may be eliminated such that the main body 11 may seat on the formwork so that the bore 17 opens to the underside of the slab 27. In another form, the mounting section 12 may be eliminated and the body 11 be of simple annular form with the bore 17 reduced to the internal diameter of the collar 16 to engage firmly a pipe, duct or conduit with which the device is to be used. The main body 11 may the be located within the slab 27 at any desired position prior to forming the slab 27 such that it is retained within the slab 27 about a pipe passing through the slab 27. Alternatively, the device 10 may be engaged about a pipe externally of a slab.

Figs. 5 and 6 illustrate an alternative form of fire barrier device 31 according to the invention which is similar to the embodiment of Figs. 1 and 2 and which is used in the same manner as that described with reference to Figs. 3 and 4. In Figs. 5 and 6, like parts to those of Figs. 1 and 2 have been given like numerals.In this case the collar 15 is of extended length to provide additional support to a pipe or duct 23 passing therethrough, the collar 12 also extending into the main body 11. Further the wall 20 in this case is inclined outwardly.

The devices 10 and 31 may also be used with a sleeve-like member 32 (shown in Fig. 3 in dotted outline) which forms a stack extending beyond the top side of the slab 27 with the pipe 23 passing coaxially therethrough. The sleeve-like member 32 may be fixed to the collar 12 by mechanical or adhesive means or alternative may be formed integrally with the device 10 or 31.

Referring now to Figs. 7 to 9, there is illustrated a further embodiment of fire barrier device 33 according to the present invention in which like components to those of the embodiment of Figs. 1 to 6 have been given like numerals. The device 33 as in the first embodiment includes a collar 15 for closely receiving a pipe, duct or conduit, a substantially annular main body 11 and a mounting portion 12 comprising an annular wall or member 18 which is outwardly angled to join an annular mounting flange 21.

In this embodiment, a radially extending tunnel shaped member 34 is formed integrally with the device 33 and intercepts the wall 18 to define on the underside of the device 32, a radially extending recess 35 extending from the space 29 for a purpose which will hereinafter become apparent. The tunnel shaped member 34 is closed at its outer end

36.

The device 33 may be installed and used in the same manner as the collar 10 as described with reference to Figs. 3 and 4. The device 33 however is particularly suited for use with HDPE or similar pipes which are joined by heatable joining sleeves 37 (see Fig. 9). Sleeves 37 of this type are used for joining by heat fusion, pipes formed of HDPE or other heat formable or joinable material which cannot be glued with conventional adhesives. The joining sleeves 37 are provided with heating elements which extend circumferentially of the sleeve and which terminate in a pair of radially extending terminals 38 to which a current can be applied through wires 39 connected to the terminals 38 via suitable plugs to effect heating of the sleeve 37. A first HDPE pipe 40 is inserted into the device 33 to be gripped by the collar 15 and supported in an upstanding attitude prior to pouring the settable material on to the formwork 24 (shown in dotted outline) to form the slab 27. The sleeve 37 may then be engaged with the lower end of the pipe 40 in the space 29 with the radially extending recess 35 accommodating the radially extending terminal or terminals 38 of the sleeve 37 providing sufficient room for receipt of the connecting plugs of the wires 39. A further HDPE pipe 41 (or other fitting) may be inserted into the lower end of the sleeve 37 and current applied through the wires 39 to effect connection and sealing by fusion heating between the sleeve 37 and pipes 40 and 41 to form the service line through the slab 27.

After connection, the wires 39 of course are disconnected from the terminals 38.

Whilst the devices 10,31 and 33 are preferably installed within a slab, they may be secured to one or both sides of a slab and around a service line or pipe extending through the slab or in a ceiling space. In the latter installation for example, the devices 10 (or 31 or 33) may be secured to a plasterboard ceiling panel with an enlarged opening formed in the panel in alignment with the device 10 (or 31 or 33) such that a pipe 23 supported by the device 10 (or 31 or 33) may be secured to a further pipe or fitting through a female socket on the end of the further pipe or fitting which locates within the enlarged opening and space 29 in the device 10 (or 31 or 33). The device 10 (or 31 or 33) will function in the same manner as that described above to shut over the service pipe in the event of fire.

Referring now to Figs. 10 and 11, there is illustrated a fire barrier device 42 according to a further embodiment of the present invention, the device 42 comprising or consisting of a heat reactive intumescent material and being moulded in one piece

in any suitable moulding apparatus. The device 42 is of a generally hat shaped configuration in side view and includes a main body 43 which is circular in cross- section and which has a generally spherical outer configuration defined by an external curved wall 44 such that the diameter of the body 43 in the middle thereof is greater than the diameter at each end for a purpose which will become apparent. A central bore 45 extends through the body 43 and is of a stepped configuration to define at one end a first bore portion 46 which is of a diameter substantially the same as the diameter of a pipe or duct to be passed through the body 43 and a second bore portion 47 at the other end of the body 43 which is of an enlarged diameter relative to the bore portion 46. Extending peripherally about the end of the body 43 adjacent the bore portion 47 is a peripheral flange or rim 48 which extends generally radially of the body 43. The outer edge of the flange or rim 48 is provided with an annular recess 49 formed in the surface of the flange or rim 48 adjacent the body 43.

Adapted for cooperation with the flange or rim 48 is an annular stepped securing ring 50 which includes an inwardly projecting rim portion 51 complementary to and adapted to be received in the recess 49. The securing ring 50 may be formed of plastics or metal and may be provide with a series of preformed apertures 52 for accepting cleats or other or other fasteners 53. Alternatively, the material of the ring 50 may be such that it may be easily penetrated by cleats 53 or other fasteners driven therethrough.

As above, the device 42 may be used in a number of different situations to close off pipes or ducts passing through walls, floors, or ceilings. Most commonly however, the device 42 is installed within a concrete or concrete composite slab wall, floor or ceiling during its construction in the manner shown in Figs. 12 and 13. A pipe or duct 54 is initially passed through the bore 45 such that it is frictionally gripped by walls of the first portion 46 of the bore 45 and thereafter the device 42 may be secured to formwork 55 which defines one face of a concrete slab to be formed. This is achieved by means of the securing ring 50 which is engaged with the flange 48 in the above described manner and cleats 53 or other fasteners are driven through the ring 50 into the formwork 55 to clamp the flange 48 and thus the device 42 to the formwork 55. Of course, devices 42 may be initially secured to the formwork 55 at the desired positions where the service pipes or ducts are to penetrate the slab and thereafter the pipes or ducts 54 are inserted into the devices 42 to be

upstanding therefrom in the manner shown, the lengths of the pipes or ducts 54 being such that they will extend beyond the side of the wall, floor or ceiling slab to be formed opposite the formwork 55.

The concrete or concrete composite material 56 may then be poured or deposited onto the formwork 55 and around the devices 42 secured to the formwork 55 and pipe or duct 54 until the required thickness of the wall, floor or ceiling is achieved. As shown, the pipe or duct 54 extends above or beyond the slab to enable connection with joining pipes or ducts. After the concrete or concrete composite material has cured or set, the formwork 55 is removed as shown in Fig. 13 which leaves the device 42 embedded in the concrete slab. The device 42 is retained in the concrete slab due to the interlocking achieved through the material of the slab filling the undercut portion 57 of the device 42 defined between the curved wall 44 of the device 42 and the flange 48 and further because the largest diameter portion of the device 42 is located within the slab at a position spaced from the adjacent side of the slab defined by the formwork 55. The device 42 is thus locked within the formed slab wall, floor or ceiling.

The enlarged diameter portion 47 of the bore 45 defines with the pipe or duct 54, an annular space 58 which ensures that in the event of fire, the generated heat will be directed towards the enlarged portion of the body 42 so that the intumescent material is rapidly subject to heat which will cause it to expand and close over the softened pipe 55. The curved nature of the wall 44 of the body 43 ensures that there is a concentrated expansion of the heat expandable material as indicated by the arrows in Fig. 13 against the wall 44 which directs the forces generally radially as illustrated to rapidly close over the softened pipe 54 as indicated in dotted outline. Further the space 58 facilitates the connection between the pipe or duct 54 and a further pipe or duct 59 (showing in dotted outline) having a mating female socket for joining to the end of the pipe or duct 54 within the space 58.

Figs. 14 and 15 illustrate a further embodiment of fire barrier device 60 according to the invention in which similar components to the embodiment of Figs. 12 and 13 have been given like numerals. In this case however, the body 61 is of a generally half-spherical configuration having a curved external wall 62 which is at a minimum diameter adjacent the securing flange 48 and at a maximum at its opposite end 63.

This device 60 is used in a similar manner to that described above with the flange 48 being secured to formwork 55 as shown in Fig. 16 and a pipe or duct 54 being received within the body 62, passing through the bore 45 to be supported in an upstanding attitude by the bore portion 46. To form the slab, concrete or other settable material 56 is applied to the formwork 55, the latter normally being removed after curing or setting of the material 56. The device 60 thus remains in situ within the slab being held therein due to the diverging nature of the side wall 62 which places the maximum diameter end 63 of the body 61 within the slab and the minimum diameter portion 64 adjacent one side of the slab.

Again in this embodiment in the event of fire, the heat applied to the intumescent material of the body 60 will cause that material to expand with the expansion forces being concentrated by the curved surface of the concrete at the interface with the side wall 62 of the body 61 in a generally radial direction as indicated by the arrows in Fig. 16 to rapidly close over the softening pipe 54.

Whilst the devices described with reference to Figs. 1 to 16 are preferably installed within a slab, they may be secured to one or both sides of a slab and around a service line or pipe extending through the slab or in a ceiling space as illustrated in Fig. 17. In the latter installation, the device 60 (or 10,31,33 or 42) is secured to plasterboard ceiling panels 65 by the appropriate fastening arrangement as described above with an enlarged opening 66 being formed in the panels 65 in alignment with the bore portions 46 and 47 in the body 61 such that a pipe 54 supported by the body 61 may be secured to a further pipe 68 (shown in dotted outline) through a female socket 69 on the end of the further pipe 68 which locates within the opening 66 and bore portion 47. The device 60 (or 10,31,33 or 42) will function in the same manner as that described above with the heat expandable or intumescent material of the body expanding when subject to heat to close over the pipe 54.

Referring now to Fig. 18, there is illustrates a further embodiment of fire barrier device 70 according to the invention and wherein like components to the components of the embodiments of Figs. 10 to 16 have been given like numerals. In this case, the body 71 of the device 70 comprises an enlarged collar 72 having an internal bore 73 for neatly receiving the pipe 54 and an inner annular leg 74 which extends from the collar 72 at a position radially inwardly from the outer circumference thereof to define a shoulder 75 which cooperates with the concrete or

other settable material 56 of the slab to be formed to retain the device 70 in the slab.

The leg 74 terminates in an annular flange 76 which may be secured to the formwork 55 by cleats through the flange 76 or by a separate clamping ring 50 as in the embodiments of Figs. 10 to 17. The pipe 54 is gripped by the walls of the bore 73 which support the pipe 54 in an upstanding attitude whilst the concrete 56 is applied to the formwork 55. The leg 74 forms with the pipe 54 a space 77 which allows rapid passage of heat of the fire to the collar 72 of the device 70 to cause rapid expansion thereof as shown in dotted outline to close over the pipe 54. The space 77 also allows for connection of the pipe 54 with a further pipe in a similar manner to that shown in Fig. 13 after the formwork 55 has been removed. The device 70 as well as being used within a slab may also be used in a ceiling space as in the arrangement of Fig. 17.

The devices 42,60 and 70 by being moulded in one piece do not have an external housing and thus there is no rapid transfer of heat as in the prior art devices where the housing is metal. Further the material of the devices is self-supporting within or out of a slab and no retention device is required to maintain the devices within the slab. When installed within a slab, the material from which the bodies of the devices are formed may form a mechanical and/or chemical bond with the material of the slab to further assist in retention of the bodies within the slab. The devices additionally are highly resistant-to weather conditions, moisture or other adverse environments. Whilst the devices 42 or 60 in a preferred form have an outer curved wall which provides an enlarged body of intumescent material for closing a pipe or duct, the curved wall may be of other configurations which flares or is stepped outwardly between the minimum and maximum portions of the device as in Fig. 9 or which have an enlarged portion located in use within the slab. Further whilst the devices 42,60 and 70 are preferably of circular cross section, they may be of square cross sectional form or of any other cross section. Whilst the device 42 and 60 are shown to be secured to formwork by a clamping ring 50, they may be secured thereto by cleats or other fasteners driven directly through the flange 48 or preformed apertures or slots therein.

Referring now to Figs. 19 to 21, there is illustrated a fire barrier device 78 according to a further embodiment of the present invention, the device 78 comprising an annular spacer 79 preferably formed of metal having an annular side wall 80, an

annular flange 81 at one end of the wall 80 and a disc-like end wall 82 (see Fig. 21) at the opposite end of the side wall 80 and extending inwardly towards the central axis of the spacer 79. Seated upon the end wall 82 is an annular body 83 moulded from a material comprising or consisting of a heat reactive intumescent material as described above. The body 83 is circular in cross-section and has an upper collar 84 and a curved external wall 85 curving inwardly from the outer periphery of the spacer 79 to the collar 84. so as to be externally of part-spherical form. The body portion 85 has an internal bore portion 86 of an internal diameter greater than the internal diameter of the collar 84 and has in its external surface 85 an annular radially inwardly extending groove 87. The body 83 is attached to the spacer 79 by any suitable means such as by suitable adhesives or by a mechanical connection. The mechanical connection may include lugs on the body 83 which locate in slots or apertures in the disc-like wall 82. The body portion 85 may be locked to the spacer 79 by rotating one relative to the other. Typically the body 85 may include downwardly extending headed lugs which may locate in keyhole shaped apertures in the wall 82 such that when rotated relative to each other, the body 85 becomes mechanically connected to the spacer 79. The collar 84 has an internal bore which is of a diameter substantially the same as the diameter of a pipe or duct to be passed through the device 78.

The device 78 may be used in a number of different situations to close off pipes or ducts passing through walls, floors, or ceilings. Most commonly however, the device 78 is installed within a concrete or concrete composite slab wall, floor or ceiling during its construction in the manner shown in Figs. 21 and 22. A pipe or duct 90 is initially passed through the sleeve 84 such that it is frictionally gripped by the internal wall thereof and thereafter the device 78 may be secured to formwork 91 which defines one face of a concrete slab to be formed. This is achieved by means of the flange 81 of the spacer 79 with cleats 92 or other fasteners are driven through the flange 81 into the formwork 91 to clamp the flange 81 and thus the device 78 to the formwork 91. Of course, devices 78 may be initially secured to the formwork 91 at the desired positions where the service pipes or ducts 90 are to penetrate the slab and thereafter the pipes or ducts 90 are inserted into the devices 78 to be upstanding therefrom in the manner shown, the lengths of the pipes or ducts 90 being such that they will extend beyond the side of the wall, floor or ceiling slab to be formed opposite the formwork 91.

The concrete or concrete composite material 93 may then be poured or deposited

onto the formwork 91 and around the devices 78 secured to the formwork 91 and pipe or duct 90 until the required thickness of the wall, floor or ceiling is achieved to form the slab 94. As shown, the pipe or duct 90 extends above or beyond the slab 94 to enable connection with joining pipes or ducts. After the concrete or concrete composite material 93 has cured or set, the formwork 91 is removed as shown in Fig. 22 which leaves the device 78 embedded in the concrete slab 94. The device 78 is retained in the concrete slab due to the interlocking achieved through the material 93 of the slab 94 filling the annular groove 87. The slab material 93 will also exert a grip on the side wall 80 of the spacer 79. The device 78 is thus locked within the formed slab wall, floor or ceiling.

The bore 86 in the body 83 defines with the pipe or duct 90, an annular space 95 which ensures that in the event of fire, the generated heat will be directed towards the inside of the body 83 so that the intumescent material thereof is rapidly subject to heat which will cause it to expand and close over the softened pipe 90 as illustrates in dotted outline in Fig. 22. The curved nature of the external wall of the body 83 ensures that there is a concentrated expansion of the intumescent material as indicated by the arrows in Fig. 22 reacting against the surrounding slab material 93 which directs the forces generally radially as illustrates to rapidly close over the softened pipe 90 as indicated in dotted outline. Further the space 95 facilitates the connection between the pipe or duct 90 and a further pipe or duct 96 (shown in dotted outline) having a mating female socket for joining to the end of the pipe or duct 90 within the space 95 by suitable adhesives usually contact adhesives.

Whilst the body 83 is preferably of the part-spherical configuration as shown, it may be of alternate configurations and include alternative retention means for retaining the device 78 in the slab. For example, the body 83 may have outwardly extending projections which may be of annular form to cooperate with the slab material 93. The annular spacer 79 may also include on its external wall 80, outward projections which may also be in the form of an annular outwardly extending protrusion. In yet a further arrangement, the body 83 may be flared or extend radially outwardly of the spacer 79 as shown in dotted outline at 97 to have a larger diameter than the spacer 79 such as to cooperate with the slab material to retain the device 78 in the slab 94.

Whilst the spacer 79 is shown to have an external wall 80, the wall 80 may be reduced in size so that the spacer is of generally disc-like form and accordingly

positions the body 83 in use adjacent to one side of the slab 94. Alternatively, the wall 80 may be extended in width to position the body 83 further within the slab 94.

Figs. 23 to 26 illustrate a further embodiment of fire barrier device 98 according to the invention which in this case includes a sleeve-like body 99 which has a wall 100 having a number of outward steps and which terminates in an annular flange 101, the body 99 suitably being formed of a plastics material. Supported on one stepped portion or shoulder 102 of the wall 99 is a ring 103 of heat expandable material, the ring 103 having a curved outer wall and being self-supporting and being suitably moulded from a material comprising or containing intumescent material as described above to be of a relatively rigid construction. The wall portion 104 of the body 99 inwardly of the ring 103 is relatively thin for a purpose which will hereinafter become apparent. The wall 100 of the body 99 at its upper end 105 has an internal diameter which is substantially the same as a duct or pipe to be received in the body 99 whilst the internal diameter of the wall portion 104 is greater than the diameter of the pipe or duct again for a purpose which will hereinafter become apparent.

The device 98 is used in a similar manner to that described above with the flange 101 being secured by cleats or nails 106 to formwork 107 as shown in Fig. 25 and a pipe or duct 108 inserted into the body 98 to be gripped by the upper end 105 of the body 99 to be supported in an upstanding attitude. To form the slab, concrete or other settable material 109 is applied to the formwork 107 to form the slab 110, the formwork 107 being removed after curing or setting of the material 109. The device 98 remains in situ within the slab 109 as shown in Fig. 26 being held therein due to the configuration of the ring 103 of intumescent material which a diameter greater than the lower adjacent portion of the wall 100 to define a region 111 which fills with the settable material. The pipe 108 may be connected to a further pipe 112 having a female socket in the space between the wall 104 and pipe 107.

Again in this embodiment in the event of fire, the heat applied to the ring 103 of intumescent material from the underside of the slab 110 will cause the ring 103 to expand with the expansion forces being concentrated radially through interaction with the surrounding slab material 109. This is further concentrated by the convex outer surface of the ring 103 as indicated by the arrows in Fig. 26 to rapidly close over the softening pipe 108 (and 112).

In the embodiment shown in Figs. 23 to 26, the ring 103 of intumescent material

is a separate component such that the sleeve-like body 99 may be used for other purposes but may be converted for use in the applications described above. In other embodiments however, the body 99 and ring 103 may be formed integrally such as by moulding from a material including or consisting of intumescent material as referred to previously.

If desired, the sleeve-like body 99 may have at its upper end 105 an internal annular recess for engagement by a puddle flange of conventional form which locates about a penetrating pipe 107.

As with the previous embodiments, the devices 78 and 98 are preferably installed within a slab, however they may be secured to one or both sides of a slab and around a service line or pipe extending through the slab or in a ceiling space. In the latter installation, the device 78 or 98 may be secured to a plasterboard ceiling panel with an enlarged opening being formed in the panel in alignment with the device 78 or 98 such that a pipe 90 or 108 supported by the device 78 or 98 may be secured to a further pipe through a female socket on the end of the further pipe which locates within the enlarged opening and enlarged axial bore in the device 78 or 98. The device 78 or 98 will function in the same manner as that described above to shut over the lines of pipes in the event of fire.

Unlike the prior art devices, the intumescent material of the devices of the invention is self-supporting within or out of a slab. When installed within a slab, the intumescent material from which the heat expandable bodies of the devices are formed may form a mechanical and/or chemical bond with the material of the slab to further assist in retention of the bodies within the slab. The devices additionally are highly resistant to weather conditions, moisture or other adverse environments. Further whilst the devices are preferably of circular cross section, they may be of square cross sectional form or of any other cross section. Of course, the devices and the bores therein may be varied in size to suit the application and the size of pipe, duct or conduit with which the devices are to be used.

Whilst the devices commonly may be used in connection with formwork which is removed after moulding of a slab, they may be used in connection with formwork which remains in situ after slab moulding for example metal decking which defines formwork for forming of the slab. In this case, the metal decking may need to be cut out at the required locations where pipes are required to penetrate the slab, the devices

of the invention being mounted in alignment with the cut out portions so that the pipes or ducts passing through the devices can pass through the cut out portions of the decking. When used with this type of formwork, the devices are usually secured in position by suitable metal fasteners. Further to prevent the pipes upstanding from the devices falling through the cut out portions of the decking during moulding of the slab, the devices may be provided with stop members. A typical configuration of stop member 113 is shown in Fig. 4, the stop member 113 simply comprising a strap extending diagonally of the device and being secured at opposite ends to the device and being removable therefrom after slab moulding.

Whilst the above has been given by way of illustrative embodiment of the invention, all such variations and modifications thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein defined in the appended claims.