AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Innovation Patent Applicant (s): CSR Building Products Limited Invention Title: Component for Rotor Ventilator The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 Component for Rotor Ventilator Technical Field A ring component for use in a rotor ventilator is disclosed, the component being 5 of unitary construction. Background Art Ventilators can be employed to evacuate air and other gases from enclosed spaces. Such enclosed spaces can include the roof space or interior of commercial and domestic buildings, shipping containers, portable buildings and sheds, automobiles etc. 10 The air and other gases evacuated can include warm or heated gases, moist gases, gases containing contaminants such as contaminated air or toxic fumes, stale gases (especially air) etc. A ventilator, known as a rotor ventilator, comprises a rotor having a plurality of vanes which are oriented in use to capture ambient wind to drive (rotate) the is ventilator rotor. In use, when the ventilator rotor is wind driven, air adjacent to the vanes is forced outwardly by the rotating vanes, and this air is in turn replaced by air from the enclosed space. This causes, in effect, a pumping-out of air from the space. Assembly of rotor ventilators is relatively cumbersome and labour intensive due to the many parts involved. The use of multiple parts can also provide regions and 20 points of weakness. It is to be understood that the reference to prior art herein does not constitute an admission that the prior art forms a part of the common general knowledge of a person of ordinary skill in the art, in Australia or any other country. 1758254_1 (GHMatters) 9/09/09 - 3 Summary According to a first aspect, there is provided a rotor ventilator ring component, the component comprising: - a central support element; s - an outer circumferential member; and - a plurality of arms extending from the central support element to the outer circumferential member; wherein the component is of unitary construction. Such a component can define one of the major parts of the rotor ventilator. 10 Being of unitary construction reduces rotor ventilator assembly time, as separate pieces are now integrally formed. The unitary construction also eliminates the need for rivet joints in the component, improving component strength and eliminating areas of weakness. In one form, the central support element lies on a central axis for the component, 15 the arms radiate out from the central axis, and the outer circumferential member is a ring that comprises a portion that tapers inwardly towards the central axis. The tapering portion may comprise part or all of the ring. For example, the ring may comprise an in-use upper portion that is generally parallel to the central axis, and an in-use lower portion that tapers inwardly towards the central axis. 20 In one form, the in-use lower portion comprises apertures therethrough for mounting wind-drivable elements thereto. Reference herein to "wind-drivable elements" does not exclude the ventilator rotor being rotated by means other than the 23186331 (GHMatters) 28/07/110 - 4 wind. For example, the ventilator rotor may be driven by thermally generated gas currents exiting the enclosed space via the ventilator, or as a result of other gas pressunsing means operating within the enclosed space (eg. conditioned or heat induced airflow). Also, "wind-drivable" means the element can be driven by the wind. s The wind-drivable element is typically a vane or a blade, which may be straight or part-spherical, but may also comprise another wind catchment device such as a cup, sail-shape etc. When a part-spherical vane is used, the tapering of the lower portion of the outer circumferential member inwardly towards the central axis allows better conformity a lower part of the vanes to the member when mounting thereto. io Additionally, the tapering of the lower portion, when the ring component is integrally moulded from plastic, simplifies mould design and assists in the removal of the ring component from the mould. Typically the rotor is oriented such that one or more of the wind-drivable elements is/are substantially exposed to the wind in use. More typically each element is 15 arranged in use to be substantially exposed to the wind. Thus, the ventilator rotor may function in a normal wind-driven manner to receive a maximum prevailing wind force. In one form, the arms radiate laterally from the central support element to an upper portion of the outer circumferential member. In this form, each arm can, in-use, extend from the central support element downwards, at a slight angle to horizontal. The 20 angle of the arms increases vertical strength to resist vertical deflection which is important under high wind loads, as the vanes exert a vertically upward force component on the ring. The angle of the arms also allows the shaft to be shortened which improves shaft strength. 23186331 (GHMatters) 28/M7/10 - 5 In one form, an in-use uppermost part of the upper portion of the outer circumferential member further comprises a lip extending laterally around the upper portion and away from the central support element. This increases the stiffness of the outer circumferential member of the ring component. s In one form, adjacent arms further comprise a web located to extend between the arms, adjacent to where the arms radiate from the central support. The webs increase the structural integrity of the ring component. Preferably, the central support element comprises an aperture therethrough. This allows the ring component to be mounted to a shaft of the rotor ventilator. The io ring component is fixed to the shaft, and the shaft rotates on spaced bearings of a frame (or stator) of the rotor ventilator. In a second aspect there is provided a rotor ventilator that comprises the ring component as defined in the first aspect. In one form the ventilator may comprise a frame for mounting to a structure. 15 The shaft can extend from and be supported by this frame. The shaft can, in addition, rotate with respect to the frame. For example, the shaft can be mounted to the frame by a bearing assembly comprising spaced upper and lower roller bearing units. In addition, an underside of the central support element can be configured to receive the upper bearing thereat (e.g. within a recess defined in the underside of the central 20 support element). A typical structure to which the rotor ventilator is mounted is a roof, wall etc of an enclosed space of a building, or portable structure such as a shed, house, automobile etc. 2318633_1 (GHMatters) 28/07/10 - 6 Brief Description of Drawings Notwithstanding any other forms that may fall within the scope of the ring component as defined in the Summary, specific embodiments of the ring component will now be described, by way of example only, with reference to the accompanying s drawings in which: Figure 1 shows a perspective view of a ring component for use in a rotor ventilator; Figure 2 shows an underside perspective view of the ring component of Figure 1; 10 Figure 3 shows a plan view of the ring component of Figure 1; Figure 4 shows an underside perspective view of the ring component when incorporated into a rotor ventilator; Figure 5 shows a perspective sectional view of rotor ventilator of Figure 4; and Figure 6 shows a detail of the mounting of the ring component to a frame of the 15 rotor ventilator. Detailed Description of Specific Embodiments Referring to the drawings, where like reference numerals are used to denote similar or like parts, Figures 1 to 3 show an embodiment of a ring component in the 20 form of component 10, and Figures 4 to 6 show the component 10 when incorporated into a rotor ventilator 100. 17582541 (GHMatters) 9/09/09 - 7 Referring to Figures 1 to 3, the component 10 is integrally moulded from a polymer material to provide a unitary construction. The component 10 has a central support element in the form of a support hub 12, an outer circumferential member in the form of ring 14 and a plurality of arms 16 (e.g. seven arms are shown in Figures 1 to 3) 5 extending from the hub 12 to the ring 14. The hub 12 is provided with an aperture 18 therethrough, so that the component 10 can be fixedly mounted to a rotor shaft 20 (as shown in Figures 4 to 6). Shaft 20 lies on a central axis A of the component 10. The ring 14 has an in-use upper ring part 22, the wall of which is generally parallel to the axis A, and an in-use lower 10 ring part 24 which tapers inwardly from the upper ring part and towards the axis A. As will be described later, the tapering of the lower part 24 of the ring 14 allows for better mounting and conformity of the vanes 32 to the member 14 and, additionally, assists in the removal of the ring component 10 from its mould (not shown). The lower part 24 also comprises a series of rivet holes 26 moulded therein, each for riveting a respective 15 lower end of a vane to the ring 14. The arms 16 are shown radiating laterally from the hub 12 to the upper part 22 of the ring 14, angled slightly downwards. A remote end of each arm is connected at a lug formation 27 that is moulded into the ring 14. The formation increases the rigidity and integrity of the ring at the region where the arm connects thereto. Webs 28 are also 20 integrally moulded to extend between adjacent arms at the point from which they radiate from the hub 12, to increase the structural integrity of the component. A circumferential lip 30, extends perpendicularly out from the uppermost part of the upper part 22 and extending away from the hub 12. This increases both the rigidity/stiffness and strength of the ring. 1758254_1 (GHMatters) 9/09/09 - 8 Referring now to Figures 4 and 5, the component 10, is shown incorporated into a rotor ventilator 100. The rotor ventilator has a plurality of wind-drivable elements in the form of part-spherical vanes 32. The vanes 32 are attached at their in-use lower portion to the tapered lower part 24 of the ring component, via rivets 34. The tapering 5 of the lower part 24 allows for better mounting and conformity of vanes 32 to the lower part 24, as the lower part 24 is shaped in a similar manner to the in-use lower portion of vanes 32, providing a complimentary fit. The in-use upper portion of the vanes 32 are attached to a rotor top plate 36, via rivets 35, with top plate 36 enclosing the rotor upper end from the elements such as debris, rain and hail, etc. 10 An underside of the top plate 36 has a shaft moulding 39 riveted to the underside via rivets 37. The shaft moulding 39 receives an upper end of the shaft 20 therein to better secure the rotor to the shaft 20. Referring now to Figure 6, a frame 38 of the rotor ventilator comprises a bearing hub 40 and arms 42 for mounting to an appropriate fitting located at a structure. The 15 frame 38 is shown in Figure 4 with three arms 42. The frame comprises part of a "stator" of the rotor ventilator. Typically, the rotor ventilator 100 is mounted to a structure such as a roof, wall etc of an enclosed space of a building, or portable structure such as a shed, house, or automobile (not shown). The aperture 18 of hub 12 is provided therein with a ledge 44 on which a 20 corresponding step-portion 46 of shaft 20 rests. A lower end of the shaft 20 is secured to the bearing hub 40 via a nut 45. When vanes 32 are exposed to the wind, shaft 20, component 10, vanes 32 and top plate 36 all rotate as a single rotor unit. In this regard, hub 12 also has a recess 48 1758254_1 (GHMatters) 9/09/09 on its in-use underside for receiving an upper bearing unit 50 of bearing hub 40. The hub 40 also houses a lower bearing unit 52 which, together with the upper bearing unit 50, form a bearing of the rotor ventilator. The bearing allows the frame 38 to be mounted to a structure, acting as the stator, whilst the shaft 20 rotates within and is 5 supported by the bearing, to act as a support for the rotor of the rotor ventilator. In contrast to powered fans, which are always enclosed in some form of cowling, the rotor ventilator 100 exposes the vanes/blades 32 to any ambient wind conditions and can make use of such conditions to achieve a ventilation effect. As best shown in Figures 4 and 5, the vanes 32 are oriented so as to be substantially exposed to 10 the wind in use (i.e. they are arranged to receive a maximum component of prevailing wind when the wind (airflow) generally laterally impinges on the rotor ventilator). In this regard, the vanes 32 are not shrouded by a cowling or the like and can function in a normal wind-driven manner. The vanes/blades 32 may be impelled by other than ambient wind. For 15 example, the ventilator rotor may be driven by thermally generated gas currents exiting an enclosed space in relation to which the rotor ventilator is located, or by other gas pressuring means (e.g. conditioned or heated airflow) operating within the enclosed space. In this regard, the ventilator can function as a controlled/controllable gas escape valve. 20 Whilst specific embodiments of the ring component for use in a rotor ventilator have been described, it should be appreciated that the component may be embodied in other forms. For example, the ring component may be used with fixed (non-rotating) shaft designs where the ring component can act as a bearing carrier itself or be attached 1758254_1 (GHMatters) 9/09/09 - 10 directly or indirectly to a bearing carrier. Also, the entire ring structure may taper towards the axis. In the description and claims, when the terms "upper" and "lower" are used with respect to the rotor ventilator they refer to a typical in-use orientation of the rotor 5 ventilator, but if the ventilator was used in a sideways, angled or upside down configuration, their orientations may be changed or reversed. Hence, "upper" and "lower" are to be interpreted broadly in this context, and as relative terms. In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word 10 "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments. 1758254_1 (GHMatters) 9/09/09