AU2003101021A4

AU2003101021A4 - Air extraction device

Info

Publication number: AU2003101021A4
Application number: AU2003101021A
Authority: AU
Inventors: Larry John Richards
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-12-18
Filing date: 2003-12-12
Publication date: 2004-03-11
Anticipated expiration: 2011-12-12

Description

P/00/009A Section 29

AUSTRALIA

Patents Act 1990 INNOVATION PATENT SPECIFICATION Invention Title: AIR EXTRACTION DEVICE Applicant: LARRY JOHN RICHARDS The invention is described in the following statement: AIR EXTRACTION DEVICE The present invention relates to an air extraction device incorporating an electric fan unit for the purposes of ventilation.

Fan units are typically employed in bathrooms, kitchens and work places to extract air, steam, vapour and/or other fumes and gases from the room or work space. In some cases, the electric fan unit is mounted in the room itself from which the air and/or vapour is to be extracted. In other cases, the fan may be remotely located, for example on an external wall of a building, and be in communication with the room or space to be ventilated via a duct.

The present invention is particularly applicable to this latter scenario, where the fan unit is to be located externally such that it may be exposed to the weather, and in particular to wind and rain. Electrical equipment to be installed in such adverse environmental conditions must typically satisfy minimum design and safety standards, and in Australia the standards specify a range of water intrusion tests under the "IP Code". For example, one such test involves spraying the device with about 10 litres of water per minute from a distance of about 300mm and for a period of five minutes.

It is an object of the invention to provide a new and improved air extraction device that satisfies the above water intrusion requirements. It would be particularly desirable to provide such a new and improved air extraction device, which satisfies the above water intrusion requirements when mounted in a range of different orientations. Accordingly, water splashed at the device from almost any direction should desirably have no harmful effects.

Broadly, the present invention provides an air extraction device including an electric fan unit mounted within a housing. The electric fan unit includes a fan rotor and an electric motor that drives the rotor about a central axis. The housing includes a cover portion and a base portion, with the housing defining an axial air intake for the fan unit at one side of the rotor, and a peripherally located exhaust outlet. The base portion of the housing includes a central air intake opening at the intake side of the rotor, with that intake opening designed for connection to ducting leading to the room or space from which the air, vapour and/or fumes is to be extracted. The cover portion of the housing extends across a side of the fan unit opposite the axial air intake, and the cover W:WaryO\DaAn\Pmvisionals Extractioninriovationpatent.doc portion includes a skirt or shroud that extends around the periphery of the fan rotor to at least partially define one or more exhaust outlet opening(s).

Importantly, the base portion and cover portion of the housing cooperate to together direct water away from, and/or prevent ingress of water to the electrical components of the fan unit, when the fan unit is mounted within the housing.

In a preferred form of the invention, the cover portion is formed as a shell and the shell defines a cavity for receiving and mounting the fan unit. The shell preferably includes a central mounting portion to which the fan unit, and more particularly the electric motor of the fan unit, is adapted to be rigidly secured.

The shell is preferably dome-shaped, and the skirt portion of the shell may form a flow guide for directing the extracted air-flow to the peripheral exhaust outlet.

A free edge region of the skirt portion may at least partially define the peripheral exhaust outlet for the fan unit.

The fan unit itself is typically in the nature of a centrifugal fan. The fan rotor is preferably of the backward curved impeller-type having an axial air intake and a radial air discharge, and the electric motor is located centrally of the generally annular rotor.

In a preferred form of the invention, the housing includes a recess for retaining one or more electrical components of the fan unit, such as a capacitor and associated electrical wiring. For example, such a recess may be provided adjacent the central mounting portion of the shell-like cover portion, and the recess may open to an outer side of the shell. The housing therefore preferably includes an outer panel for covering the recess and preventing ingress of water to the electrical components located therein.

In a preferred form of the invention, the outside of the shell-like cover portion has at least one outwardly projecting flange member, which extends around the recess for the electrical components, and the inside of the cover panel has at least one complementary inwardly projecting flange member.

These flange members are preferably circular, and are adapted to interact and/or inter-engage with one another to together define a tortuous path that inhibits or prevents ingress of water to the component recess. Preferably also, at least one of these flange members seats against a resilient seal element to prevent ingress of water. In a particularly preferred form of the invention, each W:%MaryOOa v inProvisional s E x traci ioninnoval io npatenl.doc of the shell and the outer panel has two such circular flange members, concentrically arranged.

In a preferred form of the invention, the housing cover portion includes drainage channels to facilitate escape of any water that may accumulate on the outside of the extraction unit housing. For example, drainage channels may be provided in the flange member(s) of the cover portion to enable escape of water there-through.

In a preferred form of the invention, the housing cover portion includes drainage holes to facilitate escape of any water that may accumulate on the inside of the extraction device housing. The drainage holes typically extend through the cover portion shell, and each of the holes is preferably surrounded by a raised rim on the outside of the housing to substantially prevent any water that may be running off the outside of the housing from flowing inside, particularly when the device is installed in an upright orientation. When the air extraction device is in an inverted orientation, however, any water that does finds its way into the housing, eg via the exhaust outlet opening, is able to readily escape via the drainage holes through the cover portion.

In a preferred form of the invention, the base portion is designed to be rigidly secured to the cover portion to thereby substantially enclose the fan unit within the housing. Preferably, the base portion is adapted to be removably secured to the cover portion by means of any appropriate fastening arrangement, such as screws, snap-lock catches, or the like. The base portion is also adapted to cooperate or combines with the free edge region of the cover portion skirt to define the one or more exhaust outlet opening(s). Desirably, the base portion may further include a rim member adjacent the fan unit, which may act as a flow guide for directing air discharged from the fan rotor to the exhaust outlet, and also form a guard inhibiting ingress of water to the fan unit from the exhaust outlet opening(s).

In a preferred from of the invention, the base portion comprises.two parts, namely an inner part adapted to be secured to the cover portion adjacent the fan unit, and an outer mounting part adapted to secure the air extraction device to a roof or wall, or under an eave. or soffit at an exterior of a building.

The inner and outer parts of the base portion preferably include complementary coupling members adapted to rigidly, but releasably, engage with one another.

W:VAary0 DavinTmvisionalsXExtractioninnovationpatenl.doc Each coupling member is preferably in the form of a circular collar surrounding the air intake opening of the base portion.

The outer mounting part preferably includes a flange plate, which extends radially outward to approximately the same diameter. as the skirt of the cover portion and which, together with the free edge region of the skirt, defines the circumferential exhaust outlet opening(s). The flange plate preferably facilitates mounting of the air extraction device at an external wall or surface of a building, and also includes an adaptor for engagement with a section of ducting communicating with the room or space from which the air, vapour and/or fumes are to be extracted.

In a preferred form of the invention, the housing of the air extraction device of this invention is fabricated from plastic material, such as a polycarbonate (eg ASA. polycarbonate) or polypropylene. In particular, the cover portion, the inner part of the base portion and the outer mounting part of the base portion are preferably fabricated as separately moulded elements.

The various preferred embodiments of the present invention provide an air extraction device that enables the electric fan and its associated electrical components to be substantially protected from wind and/or rain in an outdoor environment regardless of the orientation in which the device is mounted. This provides the device with tremendous flexibility in its application, as it will be suitable for installation projecting from a roof in an upright orientation, or projecting from an eave in an inverted orientation, or even for installation projecting laterally from a wall.

Importantly, also, in the air extraction device of the invention the power supply to the fan unit is preferably adapted to extend through the ducting and air-intake, at least in the vicinity of the fan unit. Accordingly, separate sealing for a power cable extending to the fan unit in an air extraction device of the invention may not necessary. The power cable can extend internally of the ducting, at least for that portion of the ducting that is external to the building, and the cable need only emerge from the ducting for connection to the actual power supply once inside the building. In this way, the only weather-proof sealing required for the unit is around the area where the ducting emerges from the building.

W:xMaryO\Davin PmvisionalS Extractioninnovationpatenl.(Ioc For assistance in arriving at a better understanding of the present invention, an example of an air extraction device according.to the invention is hereafter described with reference to the accompanying drawings. The preceding description of the air extraction device may also be read with reference to those drawings. However, as the drawings illustrate an example only, their particularity is not to be understood as superseding the generality of the preceding description.

In the drawings: Fig. 1 is a sectioned side view showing an air extraction device according to a particularly preferred form of the invention in an upright orientation.

Fig. 2 is a partially sectioned perspective view of the air extraction device in Fig. 1 without the base portion of the housing.

Fig. 3 is another partially sectioned perspective view of the air extraction device in Fig. 1 without the base portion of the housing.

Fig. 4 is a partially sectioned perspective view of the housing cover portion.

Fig. 5 is an exploded, partially sectioned side view of the air extraction device in Fig. 1, without the cover panel.

Figs. 6 and 7 are exploded, partially sectioned perspective views of the air extraction device shown in Fig. Fig. 8 is a schematic illustration of the air extraction .device mounted for use in an upright orientation.

Fig. 9 shows the air extraction device installed, in an outdoor environment in three different orientations.

Fig. 10 is an exploded side view of an air extraction device according to another particularly preferred form of the invention.

Figs. 11 and 12 are exploded perspective views of the air extraction device shown in Fig. Referring firstly to Fig. 1 of the drawings, an air extraction device (1) according to the invention is shown in cross section. The air extraction device comprisesan electric fan unit (10) mounted within a moulded plastic housing The fan unit (10) includes a fan rotor (11) and an electric motor (12) that drives the rotor about a central axis (13).

W:WaryOXDavinPmvisionalsExlraLtioninnovationp2tent.60C As can also be clearly seen in Fig. 2 and Fig. 3 of the drawings, the electric motor (12) is located centrally of the generally annular rotor and the fan .rotor is of the centrifugal impeller-type having backward-curved blades such that the fan unit has an axial air intake and a radial air discharge.

Accordingly, the housing (20) defines an axial air intake (21) for the fan unit at one side of the rotor and a peripherally located exhaust outlet More specifically, the housing (20) includes a cover portion (100) and a base portion (200). The cover portion (100) and the base portion (200) combine to define the peripherally located exhaust outlet and the base portion defines a central opening (202) for the axial air intake (21) at the intake side of the fan rotor (11).

The cover portion (100) is formed as a dome-shaped shell (101), which defines a cavity (110) for receiving and mounting the fan unit therein. The shelllike cover portion (100) extends across a side of the fan unit opposite the axial air intake side and includes a skirt or shroud (102) that extends around the periphery of the fan rotor (11) terminating at a free edge region (103). The skirt (102) of the dome-shaped shell (101) therefore acts as a flow guide for directing radial air flow discharged from the fan rotor (11) to the peripheral exhaust outlet (22) located adjacent the free edge region (103) of the skirt.

The cover portion shell (101) includes a central mounting plate (104) to an inner side of which the electric motor (11) of the fan unit is rigidly secured by any suitable means, such as screws, through fastener holes (105). At an outer side of the shell adjacent the central mounting plate (104), the cover portion (100) has a recess (120) for retaining electrical components of the fan unit, such as a capacitor (15) and the associated electrical wiring as is best seen in Fig. 4. This recess (120) for retaining electrical components is defined by the mounting plate (104) and an upstanding circular flange member (106) projecting outwardly from the top of the cover portion shell (101).

The housing (20) furthermore includes an outer panel (300) adapted to cover and substantially seal the component recess (120) against ingress of water. The outer panel (300) has a substantially flat and plate-like element (301) that spans and covers the recess (120) and three circular flange members (302, 303, 304) located at the periphery of the plate element, which project towards the cover portion shell (101). These flange members (302, 303, 304) are designed to interact or interleave with complementary flange members (106, W: Mary0 Da inkPm isionalskExImLtioninm ationpalent.Wc 107) projecting outwardly from the cover portion shell to define a tortuous path against ingress of water to the component recess (120). Furthermore, a resilient seal element (305) is provided in a channel (108) adjacent the flange member (106) at the outer side of the shell (101) for engagement with the edge of the radially innermost flange member (302) of the outer panel (300) to form a water-tight seal around the recess (120). The outer panel (300) is typically rigidly secured to the cover portion (100) by fasteners, such as screws or the like, which extend through holes (306) into fastener-receiving bosses (109).

Referring to Figs. 1 to 4, the cover portion shell also includes a flange member (111) which projects in the axial direction inwardly into the fan unit cavity (110). This flange member (111) is again circular and is designed to extend to a position closely adjacent an edge of the annular fan rotor (11) to also act as a shield or guard preventing water ingress to electrical components of the fan unit in the event that water enters the cavity (110) via the exhaust outlet It will be appreciated that this is particularly important when the air extraction device is mounted in.an inverted orientation, where the likelihood of water flowing into the cavity (110) through the exhaust outlet is significantly increased. Against this eventuality, the cover portion shell (101) includes drainage holes (112), which permit any such water that flows into the cavity (110) when the extraction device is installed in an inverted or lateral orientation to simply drain out of the cavity there-through. Each of the drainage holes (112) has an outer rim (113) which stands proud of the outside of the shell (101) so that any water running off the outside of the shell when the device is installed in an upright or lateral orientation is substantially prevented from flowing into the holes (112). Additional drainageholes (114) are also provided through.the shell (101) under the panel (300). These holes (114) each have a particularly high rim (115), which prevents any water that happens to find its way under the panel (300) from entering the fan unit cavity (110) when the device is in an upright orientation.

Referring now to Figs. 5, 6, and 7 of the drawings, it can be seen that the base portion (200) has a two-part construction, comprising an inner part (240) and an outer mounting part (280). The inner part (240) has an annular component (241) with a plurality of projecting arms or struts (242). These arms or struts (242) are designed to extend to the inside of the free edge region (103) W:kMaryOkDavin ProvisionaislE tactioninnovationpatent.doc of the cover portion skirt (102). Each of the arms or struts (242) is provided with a fastener-receiving boss (243) at its free end which is designed for alignment with complementary fastener-receiving holes (116) in the cover portion skirt (102). This inner part (240) of the base portion (200) is therefore designed to be rigidly secured to the cover portion (100) by screw-type fasteners to thereby enclose the fan unit (10) in the housing cavity (110).

The generally annular component (241) of the inner part (240) is configured to substantially complement and receive the geometry of the fan rotor (11) at the air-intake side of the rotor. The central opening in this annular component (241) naturally forms part of the base port air intake opening (202).

This annular component also includes a curved rim member (244) adjacent the fan unit which not only combines with the skirt or shroud (102) of the cover portion shell to form a flow guide for directing air discharged from the fan rotor to the exhaust outlet, but also acts as a guard or shield against water that may enter the housing via the exhaust outlet (22) from reaching the fan unit The outer, mounting part (280) of the base portion (200) is provided with three snap-lock catches (281) provided on a circular collar (282) surrounding the air intake opening (202). As is most clear from Fig. 6 and 7, these catches (281) are designed for releasable locking engagement with complimentary clasps (245) provided on the inner part (240) of the base portion. The outer part (280) furthermore includes a circular flange plate (283) which extends radially outward to approximately the same diameter as the dome-shaped cover portion (100). This flange plate (283) combines with the free edge region (103) of the cover portion shell to define the circumferential exhaust outlet (22) from the housing The outer mounting part (280) of the base portion furthermore includes a tubular adaptor (284) for connection with the ducting that communicates with the room or space from which the air, vapour and/or fumes are to be extracted. The ducting may advantageously be formed from 100 mm diameter PVC pipe which is standard in many plumbing applications. The.end of the ducting pipe may be simply inserted and sealed/bonded within the tubular adaptor (284).

As shown in Fig. 1, the flange plate (283) may be used for mounting the air extraction device directly to a wall, eave or roofing panel using screws through the flange plate (283) itself. Alternatively, as shown in Fig. 8 of the W; MaryO\Davin Pmvis'lonals\Extractioriinnovationpateni.doc drawings, the air extraction device may be mounted on the ducting pipe work such that the device is spaced further from the exterior surface of the building.

The arrows in Fig. 8 indicate the direction of air flow through the ducting to the air intake (21) and out through the exhaust outlet (22) of the housing Fig. 9 of the drawings illustrates the air extraction device of the invention installed in three different orientations; namely, in an upright orientation projecting from the top of a roof, in an inverted orientation beneath an eave, and in lateral orientation at the side wall of a building.

Importantly, the design and configuration of the new air extraction device of the invention enables it to be installed in any one of the orientations shown in Fig. 9 and still satisfy the Australian standards specified for water intrusion by the tests under the "IP Code". That is, the same air extraction device is suitable for use in all orientations.

With reference to Figs. 10 to 12 of the drawings, another slightly modified version of the air extraction device of the invention is illustrated. In this particular example the rim (244) of the inner part (240) of the base portion is not as pronounced or curved as in the previous example. The device also includes a separate lower mounting plate (104') for the fan unit This lower mounting plate (104') is adapted to be securely fastened within the cover shroud (102). The basic features of this air extraction device remain otherwise substantially unchanged compared with the example of Figs 1-8, and it can be installed in the same orientations as shown in Fig. 9.

Another important advantage of the present invention is the fact that the power supply to the fan unit (10) can extend through the ducting and air-intake Accordingly, it is not necessary to provide separate sealing for a power cable extending to an air extraction device of the invention. The power cable can extend internally of the ducting for that portion of the ducting that is external to the building, and need only emerge from the ducting for connection to the actual power supply once inside the building. Thus, the only weather-proof sealing required for the unit is around the area where the ducting emerges from the building.

W: Mary0 Dayin provisionals\Extractioninnvationpolem.doc Finally, it will be appreciated that various alterations and/or additions in the construction and arrangement of the various parts of the extraction device described with reference to the drawings may be made without departing from the spirit or scope of the present invention.

W:\Maryo DavinPro i-sionals\Extractannnvainptetno

Claims

1. An air extraction device including: an electric fan unit mounted within a housing; the electric fan unit including a fan rotor and an electric motor that drives the rotor about a central axis; the housing including a cover portion and a base portion, with the housing defining an axial air intake for the fan unit at one side of the rotor, and .a peripherally located exhaust outlet; the base portion of the housing including a central air intake opening at the intake side of the rotor, with the central air intake opening designed for connection to ducting leading to the room or space from which the air, vapour and/or fumes is to be extracted; the cover portion of the housing extending across a side of the fan unit opposite the axial air intake, and the cover portion including a skirt or shroud that extends around the periphery of the fan rotor to at least partially define at least one exhaust outlet opening; and wherein the base portion and cover portion of the housing cooperate to together direct water away from, and/or prevent ingress of water to electrical components of the fan unit, when the fan unit is mounted within the housing.

2. An air extraction device according to claim 1, wherein the cover portion is formed as a shell and the shell defines a cavity for receiving and mounting the fan unit.

3. An air extraction device according to claim 1 or 2, wherein the housing includes a recess for retaining one or more electrical components of the fan unit, such as a capacitor and associated electrical wiring.

4. An air extraction device according to claim 3, wherein the outside of the cover portion has at least one outwardly projecting flange member, which extends around the recess for the electrical components, and the inside of the cover panel has at least one complementary inwardly projecting flange member. W: kMaryo Davin\provisiamisExtractioni n mvation patem.doc An air extraction device according to any one of the preceding claims, including a power supply for the fan unit, which is adapted to extend through ducting and the air-intake, at least in the vicinity of the fan unit. Dated: 11 December 2003 PHILLIPS ORMONDE FITZPATRICK Attorneys for: LARRY JOHN RICHARDS W:VaryO\aain'PPmvsiona\Extrctionlnamnatn~o