AN IMPROVED FIRE COLLAR

Abstract

This invention relates to a fire collar (10) that includes a housing (11) having a bore that includes a first opening (13) and a second opening (18), said second opening being spaced from said first opening by at least one side wall (12), and wherein the fire collar further includes mounting means (14) for mounting said housing to a supporting structure, said mounting means being located adjacent said first opening. The fire collar also includes a layer of intumescent material (46) contained within the bore, adjacent the first opening, and supported in said bore adjacent the side wall. The fire collar also includes one or more torsion springs (48) which are operatively connected to the housing and wherein each spring includes a first leg (50) and a second leg (51). The second leg (51) is capable of movement between a first or non-operating position proximal to the layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially

Claims

1. A fire collar including: a housing having a bore that includes a first opening and a second opening, said second opening being spaced from said first opening by at least one side wall; mounting means for mounting said housing to a supporting structure, said mounting means being located adjacent said first opening; a layer of intumescent material contained within said bore, adjacent said first opening, and supported in said bore adjacent said side wall; one or more recesses in said side wall, and one or more torsion springs located in a respective one of said recesses, said one or more torsion springs being operatively connected to said housing, and said one or more torsion springs including a first leg and a second leg that are separated by and connected to an intermediate body portion consisting of a plurality of coils, said first and second legs extending tangentially away from said body, and wherein said second leg is capable of movement between a first or non-operating position proximal to said layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially obstructs said bore, said second leg being adapted to engage said intumescent material over a substantially broad area.

2. A fire collar including: a housing having a bore that includes a first opening and a second opening, said second opening being spaced from said first opening by at least one side wall; mounting means for mounting said housing to a supporting structure, said mounting means being located adjacent said first opening, and a layer of intumescent material contained within said bore, adjacent said first opening, and supported in said bore by retaining means, said intumescent material having an inner face that faces the interior of said bore and an outer face that faces said side wall, said layer of intumescent material being spaced from said side wall by spacing means such that there is provided a gap between said intumescent material and said side wall, whereby in use hot gases created by a fire may enter said bore via said first opening and may circulate within said gap.

3. A fire collar as claimed in claim 2, wherein said fire collar further includes actuating means operatively connected to and located within said housing, said actuating means being capable of movement from a non-operating mode proximal to said intumescent material to an operating mode in which said actuating means shall move at least a portion of said intumescent material generally towards a longitudinal axis of said bore.

4. A fire collar as claimed in claim 3, wherein there is provided one or more recesses in said side wall and wherein said actuation means includes one or more torsion springs that are each located in a respective one of said recesses and which are operatively connected to said housing, said one or more torsion springs including a first leg and a second leg that are separated by and connected to an intermediate body portion consisting of a plurality of coils, said first and second legs extending tangentially away from said body, and wherein said second leg is capable of movement between a first or non-operating position proximal to said layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially obstructs said bore, said second leg including one or more bends.

5. A fire collar as claimed in claim 3, wherein there is provided one or more recesses in said side wall and wherein said actuation means includes one or more torsion springs located in a respective one of said recesses, said one or more torsion springs being operatively connected to said housing, said one or more torsion springs including a first leg and a second leg that are separated by and connected to an intermediate body portion consisting of a plurality of coils, said first and second legs extending tangentially away from said body, and wherein said second leg is capable of movement between a first or non-operating position proximal to said layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially obstructs said bore, said second leg being adapted to engage said intumescent material over a substantially broad area.

6. A fire collar as claimed in claim 4, wherein said actuation means includes a contactor which is adapted to move in a plane extending longitudinally through said bore and wherein said contactor shall engage said outer face of said intumescent material either directly or indirectly.

7. A fire collar as claimed in claim 6, wherein said contactor is elongate and, in use, shall make contact with said intumescent material over a substantially longitudinal distance and thereby force a substantial portion of said intumescent material into an obstructing position within said bore.

8. A fire collar as claimed in claim 6, wherein said contactor is broad and, in use, shall make contact with said intumescent material over a broad area and thereby force a substantial portion of said intumescent material into an obstructing position within said bore.

9. A fire collar as claimed in claim 6, wherein said second leg, in use, is required to move from a non-operational position to an operational position and wherein said second leg is retained in its non-operational position by a fusible link connecting it to said first leg.

10. A fire collar including: a housing having a bore that includes a first opening and a second opening, said second opening being spaced from said first opening by at least one side wall; mounting means for mounting said housing to a supporting structure, said mounting means being located adjacent said first opening; a layer of intumescent material contained within said bore, adjacent said first opening, and supported in said bore by retaining means, said intumescent material having an inner face that faces the interior of said bore and an outer face that faces said side wall, said layer of intumescent material being spaced from said side wall by spacing means such that there is provided a gap between said intumescent material and said side wall, whereby in use hot gases created by a fire may enter said bore via said first opening and may circulate within said gap.

11. A fire collar according to claim 10, wherein said fire collar further includes at least one actuator operatively connected to and located within said housing, said actuator being operatively connected to said housing and capable of movement from a non-operating mode proximal to said intumescent material to an operating mode in which said actuator shall move at least a portion of said intumescent material generally towards a longitudinal axis of said bore.

12. A fire collar according to claim 11, wherein there is provided one or more recesses in said side wall and wherein one said actuators is located within each of said recesses.

13. A fire collar according to claim 12, wherein said actuator is a torsion spring that includes a first leg and a second leg that are separated by and connected to an intermediate body portion consisting of a plurality of coils, said first and second legs extending tangentially away from said body portion, and wherein said second leg is capable of movement between a first or non-operating position proximal to said layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially obstructs said bore, said second leg having at least one bend partway between its ends so that said second leg shall engage said intumescent material over a substantially broad area.

14. A fire collar according to claim 13, wherein said body portion includes a longitudinal axis and wherein an intermediate portion of said second leg is substantially parallel to said longitudinal axis.

15. A fire collar including: a housing having a bore that includes a first opening and a second opening, said second opening being spaced from said first opening by at least one side wall; mounting means for mounting said housing to a supporting structure, said mounting means being located adjacent said first opening; a layer of intumescent material contained within said bore, adjacent said first opening, and supported in said bore adjacent said side wall; one or more recesses in said side wall, and one or more torsion springs each located in a respective one of said recesses, said one or more torsion springs being operatively connected to said housing, said one or more torsion springs each including a first leg and a second leg that are separated by and connected to an intermediate body portion consisting of a plurality of coils, said first and second legs extending tangentially away from said body portion, and wherein said second leg is capable of movement between a first or non-operating position proximal to said layer of intumescent material and a second or operational position whereby said layer of intumescent material that is in contact with said second leg, either directly or indirectly, at least partially obstructs said bore, said second leg having at least one bend partway between its ends so that said second leg shall engage said intumescent material over a substantially broad area.

16. A fire collar according to claim 15, wherein said body portion includes a longitudinal axis and wherein an intermediate portion of said second leg is substantially parallel to said longitudinal axis.

Description

[0053] In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings wherein:

[0054] FIG. 1 is a pictorial view of a fire collar constructed in accordance with the present invention;

[0055] FIG. 2 is a plan view of the fire collar illustrated in FIG. 1;

[0056] FIG. 3 is a partial cross-sectional side view of the fire collar illustrated in FIG. 1;

[0057] FIG. 4 is cross-sectional side view of the fire collar illustrated in FIG. 1 along line Q-Q;

[0058] FIG. 5 is a cross-sectional view of a portion of the fire collar illustrated in FIG. 1;

[0059] FIG. 6 is a pictorial view of a torsion spring constructed in accordance with the present invention and as illustrated in FIG. 5;

[0060] FIG. 7 is a pictorial view of a portion of an alternative fire collar constructed in accordance with the present invention, and

[0061] FIG. 8 is a pictorial view of a torsion spring constructed in accordance with the present invention and as illustrated in FIG. 7.

[0062] The fire collar 10, illustrated in FIGS. 1 to 6, includes a housing 11 constructed of a plastics material and has a generally cylindrical side wall 12 which defines a bottom opening 13 and terminates in an outwardly extending bottom flange 14 at one end contiguous with the side wall 12 and an inwardly extending top flange 16 at its upper end also contiguous with the side wall 12 which terminates in a cylindrical guide ring 17 defining a top opening 18 that is adapted to receive therethrough a typical 100 mm PVC sewer pipe or ventilation duct (not shown). Suitably, the top and bottom openings are coaxial with the cylindrical side wall 12 along axis 19 and in combination with said side wall define a passage 20 extending therebetween.

[0063] The bottom flange 14 is adapted to rest against a sheet of concrete formwork and be secured thereto so that a concrete wall or floor can be poured around the housing. A plurality of screw holes 21 are provided around the flange 14 for securing the housing 11 to the formwork. Advantageously, the holes 21 are provided in frangible portions 22 of the flange 14 which break off upon removal of the formwork and remain therewith.

[0064] Four equi-angularly spaced, elongate, generally rectangular shaped, openings 23 are provided in the side wall 12 and wherein two spaced apart radial walls 24 and 25 extend outwardly therefrom and, in combination with an intermediate, substantially planar, outer wall 26, that is substantially parallel to side wall 12, define four recesses 27.

[0065] Each recess 27 houses therein a torsion spring 28 having a body 29 consisting of a plurality of helical coils and two opposing legs 30 and 31, each having a connecting portion 32 and 33 respectively, that extends tangentially away from the body in generally the same direction.

[0066] The first leg 30 includes a first bend 34, located at an end of the connecting portion 32 and generally adjacent a first end 35 of the body 29, and a second bend 36, the bends being connected by an intermediate portion 37 that extends generally away from the first end 35. Further, the obtuse angles of both bends are substantially the same such that a distal end portion 38 of the first leg, which is connected to the intermediate portion 37 at the second bend 36, is generally parallel to, and contained in the same plane as, the connecting portion 32.

[0067] The second leg 31 includes a first bend 39, located at an end of the connecting portion 33 and generally adjacent a second bend 40 of the body 29, and a second bend 41, the bends 39 and 41 being connected by an intermediate portion 42, and wherein the bend 41 is spaced from the bend 39 in a direction that is generally parallel to a longitudinal axis of the body 29 a distance generally equal to the length of the body.

[0068] The second leg 31 further includes a distal end portion or return 43 that is connected to the bend 41 and which extends away from the bend 41 in a direction that is generally parallel to the longitudinal axis of the body 29, and wherein the distal end portion 43 terminates generally in line with the connecting portion 33. Further, the connecting portion 33, intermediate portion 42 and the distal end portion 43 are all contained in a plane that is generally tangential to the body 29.

[0069] The two legs 30 and 31, which have a tendency to splay apart, are retained in parallel planes by a fusible link 44 that is connected to the two distal end portions 38 and 43.

[0070] Each torsion spring 28 is retained in a respective recess 27 by a pin 45 that extends through aligned apertures in the radial walls 24 and 25, such that the intermediate portion of the pin 45 extends through the coils of the body and whereby the coils rest on the intermediate portion, as shown in FIG. 4, and the first leg presses against an inner face of the outer wall 26.

[0071] A layer of intumescent material of known type, typically neoprene based or high density polypropylene, formed into a cylinder 46 and enclosed by a layer of stainless steel gauze, is fitted within the housing 11 adjacent the inner face of the cylindrical wall 12. In this particular embodiment, the intumescent material and the surrounding gauze is retained in place by engagement of a lower edge portion of the intumescent material with an end portion of each of the links 44, while an upper edge portion of the intumescent material abuts an underside of the top flange 16.

[0072] In the event of a fire in close proximity to the fire collar, the ambient air increases in temperature and causes the fusible link 44 to soften and break under the spring force of the torsion spring 28 (or alternatively it melts) whereupon the spring is released and the first leg 30 bears against the outer wall 26 and the second leg 31 bears against the gauze and through the gauze the intumescent material 46, thereby forcing the gauze and the intumescent material encased thereby inwards towards the axis 19 so that it obstructs the passage 20.

[0073] It will be appreciated that the PVC duct or pipe passing through the passage will have softened coincidentally and may have even burned to an extent allowing the legs 31 in combination to crush it inwards while forcing the intumescent material into the passage or at least into engagement with the crushed pipe. It will also be appreciated that as the intumescent material increases in temperature, it will expend and fully close passage 20 thereby preventing the egress of smoke and poisonous gases from the site of the fire.

[0074] Advantageously, the stainless steel gauze also assists the operation of the fire collar in directing expansion of the intumescent material inwards rather than outwards which in turn assists in forcing the collapse of the conduit or pipe therein.

[0075] It is believed that by increasing the width of the section of intumescent material that the leg 31 bears against by altering the configuration of the leg, which in the prior art was substantially straight, it is possible to obtain the same effect using a torsion spring wherein the distance separating the distal end portion from the body is shorter. Consequently the height of the fire collar, namely the distance between the top and bottom openings, is less than the prior art fire collars and whereby fire collars constructed in accordance with the present invention may be cast in the construction of walls and floors having a thickness of say .... mm to 150 mm.

[0076] FIGS. 7 and 8 show another torsion spring 48 that may be used in place of the torsion spring 28. The torsion spring 48 includes a body 49 consisting of a plurality of helical coils and two opposing legs 50 and 51, each having a connecting portion 52 and 53 respectively, that extends tangentially away from the body in generally the same direction.

[0077] The first leg 50 includes a first bend 54, located at an end of the connecting portion 52 and generally adjacent a first end 49a of the body 49, and a second bend 56, the bends being connected by an intermediate portion 57 that extends generally away from the first end 49a. Further, the obtuse angles of both bends are substantially the same such that a distal end portion 58 of the first leg, which is connected to the intermediate portion 57 at the second bend 56, is generally parallel to, and contained in the same plane as, the connecting portion 52.

[0078] The second leg 51 includes a first bend 59, located at an end of a substantially straight intermediate portion 60 that is aligned with and connected to the connecting portion 53 and a first return 61 that is connected to the bend 59 and which extends away from the bend 59 in a direction that is generally parallel to the longitudinal axis of the body 49, and a second return 62 that extends away from the first return in a general direction of the body 49, whereby the connecting portion 53, the intermediate portion 60, the first return 61 and the second return 62 are all contained in a plane that is generally tangential to the body 49. Further, the second return 62 is generally aligned with the connecting portion 52.

[0079] The foregoing description has been given by way of illustrative example of the invention and many modifications and variations which will be apparent to persons skilled in the art may be made without departing from the spirit and scope of the invention as defined by the appended claims.