AU2003268582B2 - Vent - Google Patents

Description

5.DEC.2003 15:42 WRAY AND ASSOCIATES NO- 944 P. 4/19 P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Ean Lawrence McDonald Ean Lawrence McDonald WRAY ASSOCIATES Level 4, The Quadrant 1 William Street Perth, WA 6000 Attorney code: WR Invention Title: "Vent" Details of Associated Provisional Application No(s): 2002953253 filed on December 2002 The following statement is a full description of this invention, including the best method of performing it known to me:-

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COMS ID No: SMBI-00524193 Received by IP Australia: Time 18:39 Date 2003-12-05 DEC. 2003 15:42 WRAY AND ASSOCIATES NO, 944 P. 5/19 -2- "Vent" Field of the Invention This invention relates to roof ventilators.

Background In the past ventilation of buildings by utilisation of roof ventilators has utilised ventilators of a variety of forms.

One common form of ventilator has comprised utilisation of an upstanding circular duct which is covered at its upper end by a conical cowl. The conical cowl overlies the other upper end of the pipe but is spaced from the upper end to allow for air flow between the upper end and the cowl and the outer edge of the cowl generally extends below the upper end of the duct, While such ventilators can be effective under some conditions they are not effective under all conditions. One significant difficulty with such ventilators comprises the entrapment of warm air between the upper end of the duct and the cowl which creates an air pocket at the upper end of the duct and prevents any further air flow out of the duct. In addition because of their limited size a large number of these vents have to be installed on a roof to provide for adequate ventilation.

Another form of ventilator which has been utilised in the past has utilised a rotating turbine which is driven by the wind and which is associated with an extractor rotor associated with the vent which on rotation of the turbine actively draws air from the roof space through the duct. These forms of ventilators however are dependant upon the presence of wind in order to effect the ventilation and it is often necessary to maximise ventilation under conditions where no wind is present. As a result such ventilators can have little effect under low or no wind conditions and can in fact restrict air flow because of the presence of the rotor.

COMS ID No: SMBI-00524193 Received by IP Australia: Time 18:39 Date 2003-12-05 5-DEC-2003 15:42 5. DC. 263 1:42WRAY AND ASSOCIATES O94 P.69 NO.944 P. 6/19 -3- The subject of Australian Patent specification 440510 is a ventilator which provides a circular cowl located over the upper end of the duct and which is spaced from the upper end of the duct to allow for air flow. The duct is surrounded by an annular second cowl which protects the space between the first cowl and the upper end of the duct from the entry of weather. The second cowl generally has a curved configuration and because of its profile provides a barrier for air flow across the roof space and deflects the air flow over it.

Because of the configuration of the second cowl such deflection creates a turbulent air flow over the opening formed in the central part of the second cowl.

The creation of this turbulence serves to reduce the degree of air flow from the ventilator that could be generated by such air flow. Furthermore since the ventilator comprises a circular duct, the amount of air flow that can pass through the duct is limited by the dimensions of the duct. In order to provide for adequate ventilation of the space below the roof a large number of ventilators must be applied to the root.

Another form of ventilator has comprised an elongate housing which is mounted over a slot shaped aperture provided in a roof and which overlie the aperture to provide ventilation: The ventilators are suitably configured to prevent rain and wind from entering the duct under adverse weather conditions. A difficulty with such ventilators however is they provide a barier to any air flow passing over the roof surface and create turbulence in the region of the opening of the ventilator which restricts the amount of air flow from the ventilator under Windy conditions.

The preceding discussion of the background to the Invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge anywhere in the world as at the priority date of the application.

COMS ID No: SMBI-00524193 Received by IP Australia: Time 18:39 Date 2003-12-05 -4- Disclosure of the Invention Accordingly the invention resides in a ventilator which in use is intended to be received over an aperture provided in a roof, the ventilator comprising a first cowl which is to be located to each side of the aperture and to be coextensive therewith, said first cowl having a first side wall to be located to one side of the oo00 tV aperture, a second wall to be located to the other side of the aperture and an end 00 INO wall at each end interconnecting each side wall, said first and second side wall a being convergent towards each other, the upper edges of the side walls being Ospaced from each other and in use to be located above the aperture; said ventilator further comprising a second cowl located between said side walls and beneath the upper edge of said side walls, said second cowl extending between the end walls of the first cowl and having a sufficient lateral extent to in use overlie the aperture and, the side edges of the second cowl being located in spaced relation between the aperture and below the upper edges, the side edges of the second cowl being spaced inwardly from the side walls, said second cowl comprising a plurality of elements which jointly span the lateral extent in an overlapping relationship the elements being inclined downwardly from their innermost portion to their outermost extent.

According to a preferred feature of the invention the side walls are arcuate in profile. According to an alternative feature of the invention each side wall has a profile which comprises a lower and upper planar portion whereby the upper portions are convergent and the lower portions are parallel. According to another alternative feature of the invention each side wall has a profile which comprises a lower and upper planar portion whereby the lower portions have a lesser degree of convergence than the upper portions.

According to a preferred feature of the invention wherein the ventilator incorporates a base which in use is to overlie the roof to either side of the aperture and is formed with a central opening conforming substantially to the configuration and dimensions of the aperture wherein said first cowl is fixed at its lower edge to the base. According to a preferred feature of the invention the Qedges of the opening are defined by an upstanding portion which surrounds the

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aperture.

According to a preferred feature of the invention the second cowl is supported from said base by an upstanding bracket to each side of the opening. According N 5 to a preferred feature of the invention the bracket supports the upper edge of the 00 V) adjacent side wall.

00 According to a preferred feature of the invention the ventilator is to be mounted Sover an aperture provided in the ridge of a pitched roof. According to an alternative feature of the invention the ventilator is to be mounted over an aperture located on an inclined roof.

A ventilator as claimed at any one of the preceding claims wherein a flow control means is provided in association with the ventilator.

According to a preferred feature of the invention the first and second cowl are formed by a metal section whereby the upper edge of each side wall is interconnected with the adjacent side edges of the second cowl by a web having apertures formed therein.

According to a preferred feature of the invention the second cowl comprises an upper and lower element having opposed upper and lower faces respectively said upper element having an inverted V- shaped cross-section. According to a preferred feature of the invention the lower element has an inverted V- shaped cross-section. According to a preferred feature of the invention the upper element has a greater lateral extent than the lower element and the upper element is formed with an opening intermediate of its width, said opening being located above the lower element. According to a preferred feature of the invention the opening extends for the length of the upper element. According to a preferred feature of the invention the opening comprises a set of longitudinally spaced openings.

-6- Q- According to a preferred feature of the invention the second cowl comprises an

(N

upper and lower element each having an inner edge and an outer edge wherein the portions of the elements adjacent the inner edges overlap and the elements extend in opposite directions such that their outer edges overlie the portion of the roof to the respective side of the aperture, said elements being downwardly N inclined from their inner edge to their outer edge. According to a preferred 00 Vfeature of the invention the elements are substantially planar.

00 NO According to a preferred feature of the invention the elements of the second cowl

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Oare formed at least in part from a light transmissive material.

According to a preferred feature of the invention the elements of the second cowl are formed at least in part of a fusible material.

According to a preferred feature of the invention the side walls and end walls are integral.

According to a preferred feature of the invention the lower portion of the side walls are adapted to provide drainage apertures to permit communication between the interior and exterior of the ventilator proximate the roof.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawings The description is made with reference to the accompanying drawings of which: Figure 1 is a sectional elevation of a roof ventilator according to the first embodiment of the invention; and Figure 2 is a sectional elevation of a roof ventilator according to a second embodiment of the invention.

-7- O Detailed Description of Specific Embodiments The first embodiment shown at Figure 1 is directed to a roof ventilator which is to be applied over an aperture formed along the ridge of a pitched roof. The roof 12 comprises a first and second roof panel 12a and 12b which are upwardly N 5 convergent to jointly define ridge at their upper extent. For a portion of the ridge oo 0 the upper edges of the roof panels 12a and 12b are spaced from each other to oo 00 0 define an aperture 14 therebetween. The ventilator comprises a first cowl 16 m formed by a pair of side walls 18 which are substantially parallel to the sides of Othe aperture 14 and an end wall (not shown) at each end which interconnects the side walls 18. The side walls are formed at their lower edge with a lower flange (not shown) which is fixed to the roof. The side walls 18 are substantially planar and each comprise a lower planar portion 18a and an upper planar portion 18b.

While the side walls are upwardly convergent the lower planar portion has a lesser degree of convergence than the upper planar portion. The upper edges of each of the side walls 18 are parallel and spaced from each other to be substantially equidistant to each side of the central longitudinal axis of the aperture 14.

The ventilator further comprises a second cowl 20 located between the side walls 18 and below their upper edges. The second cowl has a lateral span extending between the side walls and which is positioned to overlie the aperture 14. The width of the second cowl 20 is such that the side edges of the second cowl extend to each side of the aperture 14. The second cowl is formed of two elements 20a and 20b which are in a vertical overlapping relationship. The uppermost element 20a has an inverted V-shaped profile and is formed with a central longitudinal slot 22. The second and lowermost element 20b also has a inverted V-shaped profile corresponding to the profile of the uppermost element but does not have a central slot and is of a reduced width.

The mounting of the lower edge of each side wall 18 to the roof 12 is such that it provides one or more drains (which are shown schematically at 34) at the junction therebetween to provide for the drainage of any water that may collect in O the space between the side wall 18 and the roof. The drains are formed as a result of the disparity of the cross-sectional profile of the roof which is usually corrugated or convoluted and the profile of the lower edge of the side wall 18 The operation of the ventilator is such that because of the spaced relation N 5 between the second cowl 20 and the aperture 14 in the roof, there is a free flow 00 Vof air upwardly through the aperture 14 past the second cowl 20 and through the 00 I space defined between the upper edges 26 of the side walls 18. Since the C second cowl 20 is located such that its side edges are located above the upper Oedge of the boundary of the aperture 14 there is no impediment to the flow of air from the aperture 14 as a result of the entrapment of any hot air beneath the second cowl 20 and the aperture.

In addition the use of a pair of elements to form the second cowl enables an adequate lateral span to prevent the entry of rain through the aperture 14 even under high wind conditions while facilitating good ventilation.

The inclination of each of the side walls 18 is such that air flow induced over the ventilator as a result of wind is substantially non turbulent. The substantially inclined planar nature of the side walls 18 ensure that any wind incident on the side wall will be deflected upwardly over the space between the upper edges 26 of the side walls in a substantially non turbulent manner. The effect of such deflection results in an increase in air speed over the space formed between the upper edges 26 of the side walls 18 and a resultant decrease in pressure in that region which serves to enhance the flow of air through the aperture 14. In addition a region of low pressure will be generated on the downwind side of the ventilator, which will result in a further extraction of air from within the roof space and through the ventilator. Furthermore, the variation in inclination of the upper planar portion with respect to the lower planar portion 18a serves to improve the air flow across the base formed between the upper edges of the side walls 18 and create a greater degree of "lift" in the space between the upper edges 26 of the side walls 18 and thus aids in increasing the air flow through the aperture 14.

-9- The ventilator according to the embodiment is a static ventilator which is able to

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facilitate the free flow of air through it under both static air conditions and in the event of wind. Furthermore, in the event of the wind being incident upon the ventilator, the degree of air flow is enhanced by the configuration of the side walls 18. Furthermore, the ventilator extends over an extended elongate N aperture provided in a roof to facilitate a high degree of ventilation from an

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V airspace underneath a roof.

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IND

The second embodiment as shown at Figure 2 is of an identical form to the

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Oventilator of the first embodiment, with the exception of the configuration of the second cowl. In the case of the ventilator of the second embodiment the elements 20a and 20b of the second cowl comprise planar elements where their inner edges overlap and they are inclined downwardly towards each side of the vent.

In the case of each of the embodiments, a ventilator is provided which is easily manufactured and has little or no moving parts or mechanical controls which results in a ventilator which is not prone to wear and is thus of improved reliability. Further the ventilators of the embodiments are weatherproof and may be readily applied over a relatively large aperture provided in a roof where the venting of air from the space defined by the roof will take place under both static and non static air-conditions and whereby in the event of wind being incident upon the ventilator the flow of air from the ventilator will be enhanced as a result of the deflection of the air flow over the side walls.

In the case of each of the embodiments the base may accommodate a flow control device (not shown) to facilitate the control of air through the aperture 14.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

in 0 It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.

00 c 00

Claims (24)

1. A ventilator which in use is intended to be received over an aperture N provided in a roof, the ventilator comprising a first cowl which is to be 00 V 5 located to each side of the aperture and to be coextensive therewith, said N first cowl having a first side wall to be located to one side of the aperture, a a second wall to be located to the other side of the aperture and an end wall Sat each end interconnecting each side wall, said first and second side wall being convergent towards each other, the upper edges of the side walls being spaced from each other and in use to be located above the aperture; said ventilator further comprising a second cowl located between said side walls and beneath the upper edge of said side walls, said second cowl extending between the end walls of the first cowl and having a sufficient lateral extent to in use overlie the aperture and extending between the end walls of the first cowl, the side edges of the second cowl being to be located in spaced between the aperture and the upper edges, the sideedges of the second cowl being spaced inwardly from the side walls, said second cowl comprising a plurality of elements which jointly span the lateral extent in an overlapping relationship the elements being inclined downwardly from their innermost portion to their outermost extent.

2. A ventilator as claimed at claim 1 wherein the side walls are arcuate in profile.

3. A ventilator as claimed at claim 1 or 2 wherein each side wall has a profile which comprises a lower and upper planar portion whereby the upper portions are convergent and the lower portions are parallel.

4. A ventilator as claimed at claim 1 or 2 wherein each side wall has a profile which comprises a lower and upper planar portion whereby the lower portions have a lesser degree of convergence than the upper portions. -12- O

5. A ventilator as claimed at any one of the preceding claims wherein the ventilator incorporates a base which in use is to overlie the roof to either side of the aperture and is formed with a central opening conforming substantially to the configuration and dimensions of the aperture wherein said first cowl is fixed at its lower edge to the base. 00 V

6. A ventilator as claimed at claim 6 wherein the edges of the opening are 00 D defined by an upstanding portion which surrounds the aperture.

7. A ventilator as claimed at claim 5 or 6 wherein the second cowl is supported from said base by an upstanding bracket to each side of the opening.

8. A ventilator as claimed at claim 7 wherein the bracket supports the upper edge of the adjacent side wall.

9. A ventilator as claimed at any one of the preceding claims wherein the ventilator is to be mounted over an aperture provided in the ridge of a pitched roof.

A ventilator as claimed at any one of claims 1 to 8 wherein the ventilator is to be mounted over an aperture located on an inclined roof.

11. A ventilator as claimed at any one of the preceding claims wherein a flow control means is provided in association with the ventilator.

12. A ventilator as claimed at any one of the preceding claims wherein the first and second cowl are formed by a metal section whereby the upper edge of each side wall is interconnected with the adjacent side edges of the second cowl by a web having apertures formed therein.

13. A ventilator as claimed at any one of the preceding claims wherein the second cowl comprises an upper and lower element having opposed upper -13- Q- and lower faces respectively, said upper element having an inverted V- (N shaped cross-section.

14. A ventilator as claimed at claiml3 wherein the lower element has an inverted V- shaped cross-section. O 00 5

15. A ventilator as claimed at claim 13 or 14 wherein the upper element has a O 00 Igreater lateral extent than the lower element and the upper element is formed with an opening intermediate of its width, said opening being Slocated above the lower element.

16. A ventilator as claimed at claim 15 wherein the opening extends for the length of the upper element.

17. A ventilator as claimed at claim 15 wherein the opening comprises a set of longitudinally spaced openings.

18. A ventilator as claimed at any one of claims 1 to 12 wherein the second cowl comprises an upper and lower element each having an inner edge and an outer edge wherein the portions of the elements adjacent the inner edges overlap and the elements extend in opposite directions such that their outer edges overlie the portion of the roof to the respective side of the aperture, said elements being downwardly inclined from their inner edge to their outer edge.

19. A ventilator as claimed at claim 18 wherein the elements are substantially planar.

A ventilator as claimed at any one of the preceding claims wherein the elements of the second cowl are formed at least in part from a light transmissive material.

21. A ventilator as claimed at any one of the preceding claims wherein the elements of the second cowl are formed at least in part of a fusible material. -14-

22. A ventilator as claimed at any one of the preceding claims wherein the side CN Swalls and end walls are integral.

23. A ventilator as claimed at any one of the preceding claims wherein the lower portion of the side walls are adapted to provide drainage apertures to C 5 permit communication between the interior and exterior of the ventilator 00 I proximate the roof. 00oO NO

24. A ventilator substantially as herein described with reference to the accompanying drawings. Dated this fifth day of December 2003. Ean Lawrence McDonald Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant