AU2016102016A4 - Exhaust Fan Assembly - Google Patents

Abstract

Abstract A fan assembly for extraction of fumes from a food cooking area within a building. 5 The fan assembly comprises a housing adapted to be permanently affixed into an exterior wall of a building, the housing defining an aperture through the wall. The fan assembly also includes an electric fan module mounted within the housing on a pair of substantially horizontal rails. The fan assembly can be moved along the rails in a first direction to exit the housing to within the building, and can be moved along the 10 rails in the opposite direction to exit the housing to outside the building. co

Description

2016102016 21 Nov 2016 1

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT “Exhaust Fan Assembly”

The following statement is a full description of this invention, including the best method of performing it known to me: 2 2016102016 21 Nov 2016

EXHAUST FAN ASSEMBLY

Background and Summary of the Invention 5

This invention concerns exhaust fan assemblies of the type used at the exhaust end of a duct so as to be mounted on an external wall of a building distant from a cooking area from which it is desired to remove smoke and fumes. 10 In order to reduce the noise perceived when using an air exhaust hood above a cooking area, it is known to locate the fan assembly distant from the hood. For exhaust systems of this type in multi-storey buildings, the fan is often located in an aperture in an external wall of the building and the hood and fan are commonly connected by flexible ducting concealed within a ceiling space. 15 A difficulty with such systems is that, when maintenance of the fan is required, it is usually removable from the wall from only one of the inside or the outside of the wall. The inside access is usually within a cramped ceiling space while access from the outside may be difficult because of the height of the building. The weight of a fan 20 and motor assembly makes handling it, and correctly repositioning it, difficult.

There is a need for an efficient fan assembly for this purpose where the electric motor and fan impeller are easily accessible, and removable from within its housing, from both ends, ie from inside and from outside the building. There is also a need for the 25 components to be easily replaceable into exactly the correct position from either end. In this way the internal components may be removed and replaced by whichever means the worker considers best suits the conditions and their available equipment.

An aim of the present invention is to provide a solution to the above problem. 30

Accordingly, in one aspect the invention provides a fan assembly for extraction of fumes from a food cooking area within a building, said fan assembly comprising: 3 2016102016 21 Nov 2016 - a housing adapted to be permanently affixed into an exterior wall of a building, said housing defining an aperture through said wall, - an electric fan module mounted within said housing on a pair of substantially horizontal rails, such that said fan assembly can be moved along said rails in a 5 first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building.

Preferably said rails are substantially horizontal. Preferably said rails run transversely 10 to the wall. Preferably said fan module is slid along said rails.

In another aspect the invention provides a method of mounting an electric fan module in a housing, said housing being permanently affixed into an exterior wall of a building and connected to a ducting for extraction of fumes from a food cooking area 15 within said building, and said housing defining an aperture through said wall, and said aperture including a pair of rails, said method comprising mounting said fan module on said rails such that said fan module can be moved along said rails in a first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building. 20

Preferably said rails are substantially horizontal. Preferably said rails run transversely to the wall. Preferably said fan module is slid along said rails.

In a further aspect the invention provides apparatus for the extraction of fumes from a 25 food cooking area within a building, said apparatus comprising: - a fume collection means located adjacent said food cooking area, - a duct extending from said fume collection means to a fan assembly mounted within an aperture in an exterior wall of said building, wherein said fan assembly comprises: 30 - a housing adapted to be permanently affixed into said exterior wall, - an electric fan module mounted on a pair of rails, each said rail running transverse to the wall such that said fan assembly can be moved along said 4 rails in a first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building.

Preferably said fume collection means is a hood mounted above said food cooking area.

Preferably said rails are substantially horizontal. Preferably said movement along said rails is a sliding movement.

Preferably said fan module is inserted into a first open end of said housing and slid along said rails until stopped by a stop means which indicates the correct location for operation of the fan module.

Preferably said stop means is integral with said rails. Preferably said stop means is integral with each rail.

Preferably said fan module may alternatively be inserted from the second end.

Brief Description of the Drawings

In order that the invention may be more fully understood there will now be described, by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where:

Figure 1 is a cutaway axonometric view of a fan assembly according to a first embodiment of the present invention;

Figure 2 is a part-section view through a fan assembly as shown in Figure 1 when mounted in a wall;

Figure 3 is an isometric view of a fan module which forms portion of the fan assembly in Figure 1;

Figure 4 is a side view of the fan module shown in Figure 3; 5 2016102016 21 Nov 2016

Figure 5 is a cut-away view of a housing which forms portion of the fan assembly in Figure 1;

Figure 6 shows a part-section through parts of the fan assembly in Figure 1; Figure 7 is a view of a base portion of the housing shown in Figure 6; 5 Figure 8 shows another view of the fan module in Figure 3 but this time with an added optional cover on the motor;

Figure 9 is a partly-exploded view of the fan module and motor cover shown in Figure 8;

Figure 10 is a diagram showing the way the fan assembly is mounted in the wall 10 according to Figure 2;

Figure 11 is a diagram showing an alternative way a fan assembly according to a further embodiment of the invention may be mounted in a wall; and Figure 12 shows a part-section through parts of a separated fan assembly according to a second embodiment of the present invention, being mostly the 15 same as the assembly in Figure 6 but without a backdraft shutter system.

Description of Examples of the Invention and the Preferred Embodiment

The fan assembly 10 shown in Figures 1 and 2 comprises a housing 12 which is 20 permanently affixed to an exterior wall 14 of a building. The housing 12 provides an aperture 16 through the wall. An electric fan module 18 is mounted within the housing 12. The fan module 18 includes an electric motor 20 direct coupled to a centrifugal fan impeller 22. 25 The housing 12 comprises a pair of side walls 36 and 37, a top wall 38, a bottom wall 39 and a rear wall 40. The side walls and top wall are each formed as separate sheet metal panels. The side walls, bottom wall and top wall are then fastened together by screws, rivets or welding. The bottom wall 39 is formed as a sheet metal base portion 42 which is fastened to the side walls 36 and 37. The rear wall 40 is screwed to the 30 side walls and the base portion to allow its simple removal for maintenance purposes. The front of the housing is covered by a removable grille 50 only a quarter of which is shown in Figure 5. 6 2016102016 21 Nov 2016 A main chassis plate 24 extends substantially across the full width and height of the housing 12 about midway along the housing. The fan impeller 22 and motor 20 are attached to the main chassis plate 24 by a U-shaped bracket 26 which is formed from a single piece of metal. The bracket 26 comprises a central cross member portion 28, 5 which extends across the housing, and a pair of side arm portions 30 which connect respective ends of the cross member 28 to respective sides of the main chassis plate 24. Only one of the two matching side arms 30 can be seen in the Figures.

The casing of the motor 20 is screwed to the cross member 28 such that the impeller 10 22 is free to rotate with the motor’s shaft while the motor’s casing is held stationary.

Also screwed to the cross member 28, and on the opposite side to the impeller 22, is a housing 21 which houses electrical components 23 including a capacitor, terminal block and various connections and protects those components from any water spray which may enter through the grille 50. 15

The side arm portions 30 of the bracket 26 have a generally planar form aligned vertically but include an outwardly extending flange 29 on their upper edge which rests upon a pair of side rails 32 and 33 which are fastened rigidly to respective side walls 36 and 37 of the housing. The side rails 32 and 33 extend horizontally along 20 substantially the full length of the housing.

The fan assembly is adapted to draw air from a flexible duct 49 (shown in Figure 9) which extends into the building. It is particularly adapted for drawing fumes through the duct from a hood or canopy which extends over a cooking area. The fan assembly 25 therefore draws the air through the duct by providing a partial vacuum within the duct. In this respect it operates differently to a conventional exhaust hood where the fan is located within the hood and the air is expelled with higher than atmospheric pressure within the duct. 30 The inlet of the fan impeller connects with a cylindrical adaptor 44 and a backdraft shutter system 46, which are retained by, and fastened either side of, the cross member 28. A bellmouth adaptor 48 is engaged with the backdraft shutter system 46 2016102016 21 Nov 2016 7 within the housing while, outside the housing, it receives the end of the flexible duct 49 which runs to an exhaust hood (not shown) mounted above the cooking area. The rear wall 40 may be unscrewed and removed as a rear assembly 52 which includes the rear wall 40 and the bellmouth adapter 48. 5 A first tapered mouth 45 on the internal end of the bellmouth adapter 48 provides for easy engagement and positioning of the bellmouth adapter 48 with the backdraft shutter system 46. A second tapered mouth 47, this time on the external end of the bellmouth adapter 48, provides for easy engagement and positioning of the flexible 10 duct 49 with the bellmouth adapter 48. A foam gasket 51 at the connection of the bellmouth adapter 48 with the backdraft shutter system 46 assists sealing of the airway passage connections and reduces noise transmission.

The fan module is removable from the housing in either direction, namely either to 15 within the building or to outside the building. This is provided by the grille 50 and rear wall 40 each being readily removable and the fan module resting on the side rails 32 and 33, which are fastened to the side walls of the housing, and slidably moveable thereon. A motor assembly 54 comprising the motor 20, impeller 22, cross member 28, and backdraft shutter system 46 is removable as a complete assembly. 20 A protruding stop 56 is located on each side rail 32 and 33 at the position where each stop is contacted by the front ends 34 of the respective side arms 30 when the motor assembly/fan module is pushed inwards from the rear to slide along the rails 32 and 33. This provides for accurate positioning of the fan module within the housing. 25 A short electric power lead 58 with a plug 59 is attached to the motor 20. An electric power supply outlet socket 60 is fitted to a bracket attached to the inside of the housing 12. When the housing 12 is affixed to the wall 14, the outlet 60 is permanently wired to the electrical control system in the canopy over the cooking 30 area. When the fan module 18 is removed from, or replaced within, the housing 12, the plug 59 may be readily disengaged or engaged with the outlet socket 60. 2016102016 21 Nov 2016 8

The base portion 42 shown in Figure 7 has no outstanding edge flange along its outside edge 68. This allows for any water that has entered the housing through the grille 50 to drain to outside the building. The rear comers 67 on the inside edge 69 of the base 42 are sealed with sealant to prevent any water draining to inside the 5 building.

To remove the fan module 18 from the rear of the housing 12 the securing screws 62 holding the rear wall and bellmouth adapter 48 need to be removed and the assembly moved away from the housing. The power cord is then disconnected and the module 10 withdrawn through the rear of the housing.

To remove the fan module 18 from the front (outlet grille side) of the housing 12 the grille securing screws (not shown) need to be removed allowing the release and removal of the grille 50. The power lead 58 is then disconnected from the outlet 60 15 and, by lifting the module 18 upwards clear of the rail mounted location stops 56 it can be moved forward and away from the housing.

If the fan module is pushed into the housing from the front of the housing (ie from outside the building) then the side arms 30 would be slid over the stops 56 and then 20 pulled back to contact the stops again.

The alternative fan module shown in Figures 8 and 9 includes an additional cover 72 which serves to protect the motor 20 and its electrical connections from any spray which might enter through the grille 50. 25

The housing 12 may be retained in a building wall 14 by an external wall flange 65 as indicated by Figure 10. Alternatively the housing 12 may be retained in the wall 14 by an internal wall flange 66 as indicated by Figure 11. Alternatively both internal and external flanges may be used. The flanges 65 and 66 may be an integral part of 30 the housing 12 or separate components. 2016102016 21 Nov 2016 9

The embodiment illustrated in Figure 12 comprises the fan module 18 and the rear assembly 52 as described above but with the backdraft shutter system removed and the inner half of the bellmouth adaptor also removed. A foam gasket 51 is mounted between the remaining bellmouth portion 72 and the fan module 18 to provide a seal 5 for the airway passage 74 through the fan assembly. When such a fan assembly is used, a backdraft shutter system would typically be installed further upstream in the ducting system.

Whilst the above description includes the preferred embodiments of the invention, it 10 is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention. 15 For example in some embodiments the fan module may not include the backdraft shutter system as part of that assembly. The backdraft shutter system may be located elsewhere in the ducting system or may be deleted entirely.

It will be also understood that where the word “comprise”, and variations such as 20 “comprises” and “comprising”, are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

The reference to any prior art in this specification is not, and should not be taken as, 25 an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia.

Claims (24)

1. The claims defining the invention are as follows:

   1. A fan assembly for extraction of fumes from a food cooking area within a building, said fan assembly comprising: - a housing adapted to be permanently affixed into an exterior wall of a building, said housing defining an aperture through said wall, - an electric fan module mounted within said housing on a pair of substantially horizontal rails, such that said fan assembly can be moved along said rails in a first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building.
2. 2. A fan assembly according to claim 1, wherein said rails are substantially horizontal.
3. 3. A fan assembly according to claim 1 or 2 wherein said rails run transversely to the wall.
4. 4. A fan assembly according to any one of claims 1 to 3 wherein said fan module is slid along said rails.
5. 5. A fan assembly according to any one of claims 1 to 4 wherein said fan module is inserted into a first open end of said housing and slid along said rails until stopped by a stop means which indicates the correct location for operation of the fan module.
6. 6. A fan assembly per claim 5 wherein said stop means is integral with said rails.
7. 7. A fan assembly per claim 6 wherein said stop means is integral with each rail.
8. 8. A fan assembly per any one of claims 5 to 7 wherein said fan module may alternatively be inserted from the second end.
9. 9. A method of mounting an electric fan module in a housing, said housing being permanently affixed into an exterior wall of a building and connected to a ducting for extraction of fumes from a food cooking area within said building, and said housing defining an aperture through said wall, and said aperture including a pair of rails, said method comprising mounting said fan module on said rails such that said fan module can be moved along said rails in a first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building.
10. 10. A method per claim 9 wherein said rails are substantially horizontal.
11. 11. A method per claim 9 or 10 wherein said rails run transversely to the wall.
12. 12. A method according to any one of claims 9 to 11 wherein said fan module is slid along said rails.
13. 13. A method according to any one of claims 9 to 12 wherein said fan module is inserted into a first open end of said housing and slid along said rails until stopped by a stop means which indicates the correct location for operation of the fan module.
14. 14. A method according to claim 13 wherein said stop means is integral with said rails.
15. 15. A method according to claim 14 wherein said stop means is integral with each rail.
16. 16. A method according to any one of claims 13 to 15 wherein said fan module may alternatively be inserted from the second end.
17. 17. Apparatus for the extraction of fumes from a food cooking area within a building, said apparatus comprising: - a fume collection means located adjacent said food cooking area, - a duct extending from said fume collection means to a fan assembly mounted within an aperture in an exterior wall of said building, wherein said fan assembly comprises: - a housing adapted to be permanently affixed into said exterior wall, - an electric fan module mounted on a pair of rails, each said rail running transverse to the wall such that said fan assembly can be moved along said rails in a first direction to exit said housing to within the building, and can be moved along said rails in the opposite direction to exit said housing to outside the building.
18. 18. Apparatus according to claim 17 wherein said fume collection means is a hood mounted above said food cooking area.
19. 19. Apparatus according to claim 17 or 18 wherein said rails are substantially horizontal.
20. 20. Apparatus according to any one of claims 17 to 19 wherein said movement along said rails is a sliding movement.
21. 21. Apparatus according to any one of claims 17 to 20 wherein said fan module is inserted into a first open end of said housing and slid along said rails until stopped by a stop means which indicates the correct location for operation of the fan module.
22. 22. Apparatus per claim 21 wherein said stop means is integral with said rails.
23. 23. Apparatus according to claim 22 wherein said stop means is integral with each rail.
24. 24. Apparatus according to any one of claims 21 to 23 wherein said fan module may alternatively be inserted from the second end.