AUSTRALIA Patents Act 1990-2001 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title "EXHAUST FAN" Name of Applicant CFM FANS PTY.LTD. The following statement is a full description of this invention including the best method of performance known to us: JohLavesPatntAttn.......................................t John L Davies, Patent Attorney For And Behalf of Applicant -1 This invention relates generally to kitchen rooftop exhaust fans and relates in particular to a system of a rooftop vertical-discharge exhaust fan unit mounted within or above multiple collectors for condensed exhaust fumes and rain water, all the components of the system can be opened for access and/or dismantled and separated for cleaning and maintenance. It is an object of the invention to provide a rooftop vertical-discharge, exhaust fan unit with multiple components for collecting condensed exhaust gas and rain water and which can be opened or separated on site for access for cleaning and maintenance purposes. According to the invention there is provided roof-top vertical discharge apparatus for exhausting cooking fumes and for collecting condensed fumes and rainwater the apparatus comprising an exhaust fan and motor unit mountable over an exhaust duct and a plurality of collector components which are openable and closable, detachable and re attachable for on-site access for cleaning and maintenance and which comprise a bowl-shaped housing for the motor/fan unit mountable over and removable from the unit and which forms a primary collector component, an open-bottom base adapted to be placed upon a roof top over an exhaust duct and having a raised floor with upstanding peripheral walls forming a tray with a central opening for passage therethrough of exhaust gas from the duct, the tray being a secondary collector for condensed, exhaust fumes and rainwater, there being a lid for the tray being pivotally mounted upon the base, the lid having a central opening adapted to align 2 0 the opening of the tray and being formed with downwardly dependent peripheral walls adapted to fit inside the peripheral walls of the tray when the lid is closed upon the tray, both a wall of the tray and a wall of the lid opposite a pivot-side wall having a waste liquid flow path gap or gaps therein, the housing being detachable from and attachable to the lid, the motor and fan unit being fixedly mounted upon the top surface of the lid and being pivotally 2 5 openable and closable with the lid. The apparatus according to the invention includes a tertiary collector for condensed exhaust fumes and rainwater and which is in the form of a detachable grease trap with an open top and a removable lid with a slot and wherein the tray of the lid of the base is provided with a water-flow spout which overhangs and empties into the box through the slot C 0 when the lid is closed. More particularly, in the apparatus according to the invention the housing is removably fastened to the lid and the lid is hingedly fastened by one end to the base and is, when closed upon the base, independently fastenable to the base with respect -2 to the housing and is releasable and openable at the opposite end to the hinged end and is openable, closable and fastenable with respect to the base independent of the motor fan unit and its housing Still more particularly, in the apparatus according to the invention the tray is permanently attached to the base, the lid is permanently and pivotally-mounted upon the base and the motor/fan unit remains attached to the lid of the base when the lid is swung up to access to the tray for cleaning. The invention includes a method of mounting the upper (or housing) straps to the housing comprises is to first pass the upper (and free) end of each strap though the uppermost of a pair of parallel slots formed in a lower portion of the housing wall and then looping the free end around a bar formed by a residual section of wall material between the slots and then joining the free end of the strap to the upper part of the strap and the portions together by suitable means such as a rivet. In a similar manner each of the two side walls of the tray are provided with fastening means in the form of dependent apertured straps 15 fastened to a respective buckle of an associated strap component upstanding from and mounted upon a side wall of the base to enable fastening of the lid to the tray and hence to the base. A non-limiting example of a preferred embodiment and practical arrangement of the invention will now be described with reference to the accompanying drawings in which: ZO Figure 1 is a partial view in perspective of the assembled and closed-up apparatus of the invention. Figure 2 is a perspective view of the apparatus of Figure 1 with housing for fan and motor unit removed. Figure 3 is a perspective view of the housing removed from the apparatus of Figure 1 Figure 4 is a perspective view of a grease trap and tertiary collector separated from apparatus of Figures 1 and 2. Figure 5 is a perspective view of the apparatus of Figures 1 to 4 with lid of grease trap and collector partly removed. Figure 6 is a perspective view of the apparatus of Figure 2 with hinged lid lifted up to .enable cleaning of the secondary collector tray. Figure 7 is a perspective view of the apparatus of Figures 1, 2 and 4 to 6 with -3 grease trap collector detached. Figure 8 is a perspective view of the grease trap of Figures 1, 2 and 4 to 6 with lid removed. Referring to the drawings and first of all generally to Figure 1, there is shown in assembled and closed-up mode, a roof-top vertical-discharge, exhaust fan and motor unit within a removable housing which is also a condensed exhaust fume and rainwater primary collector the motor/fan unit is fixedly mounted upon a hinged lid. A secondary collector is formed by a tray fixed to a base; the lid is openable and closable with respect to the base; the lid and tray both have openings placeable in alignment over an exhaust duct 10 opening. The assembly has three collectors of condensed hot exhaust fumes and also rainwater. The first collector 10 is an upper member of the assembly and is a primary collector in the form of an open-bottomed bowl forming a housing for a motor/fan unit 11 and has a hat 11a. The diameter of the open bottom of the primary collector is sufficient to enable it to clear the motor and fan unit as well as the hat. A secondary collector is (5 formed as a tray 12a fixed upon a base 12 and a lid 13 has one end hingedly mounted upon one end of the base 12 ( and also the tray 12a) by hinges 112 112a and is closable upon . and openable away from the tray and the base. The lid 13 supports the removable housing and motor and fan unit 11 which is mounted upon the lid 13 which also supports the housing ( and water primary collector) 10. The base 12 is preferably in the form of an '2 inverted, open-bottom rectangular box with a raised floor surrounded by four walls each being an upstanding extension of the base walls 14, 15, 16, 17 to form with the floor the tray 12a. The tray 12a has a central circular opening 18 provided with a peripheral collar 19 and the tray and thus the base are adapted to be installed over and upon a hot exhaust gas flue and upon a rooftop of a commercial kitchen. A corresponding opening 20 is formed *2.5- in the lid 13 which, with the motor/fan unit 11 is able to be swung up manually into an open position to gain access to the tray 12a and then swung down to a closed-up position upon the base 12. The lid 13 also has four walls which, when the lid is closed upon the tray 12a of the base 12 , fall inside the four walls of the tray 12a and leave a water-flow gap, The housing or primary collector component 10 is detachably fastened to the hinged lid by plurality of fastening means such as sets of co-operating straps and buckles, there being four strap and buckle sets co-operating between the lower rim of the housing and the upper surface of the lid- there being four downwardly-dependent upper straps without buckles but -4 which are each formed with spaced perforations for a buckle pin and four upstanding lower straps attached to and upstanding from the lid one (or upper) end of each lower or lid strap terminates in a buckle attached thereto while the other or lower end of each lower ( or lid) strap of each set is looped around a metal strip of residual housing wall material formed between two parallel lateral slots in the wall and the free end of the looped strap material is joined to form a loop and sewn or riveted together. One or upper set of straps are housing to-lid straps and comprise four downwardly-dependent, equispaced, apertured straps three of these straps are shown in Figure 4 permanently mounted on the housing and detached from the lid 13 and are respectively labelled 21, 22 and 23. Each housing to 10 lid strap is adapted to be releasably fastened to one of a set of four lid-to-housing fastening straps 21a, 22a, 23a (which are lower straps with respect to the housing-to-lid straps) by a respective buckle fixed to an upper free end of each lid-to-housing strap 21a, 22a, 23a. In Figure 1, three of four lid-to-housing straps 21a, 22a, 23a are visible as already fastened by a respective buckle to a respective housing-to-lid strap 21 or 22 or 23. The bottom end of /S each lid-to-housing strap is permanently fixed to the lid by being looped around lid material formed between parallel slots formed on the top of the lid 13 and joining the looped strap material by sewing, riveting or the like. Only two sets of fastening straps each comprising upper and lower straps are needed to fasten the lid to the base and these straps are all mounted on lid and base respectively at a location remote from the hinge axis. Thus the lid 20 is releasably fastenable to the base (and tray) by two pairs of upper or "lid-to-base straps 24, 25 respectively with one or upper end mounted to the lid by first looping one end through a pair of parallel lateral slots pre-formed or pre-cut into the metal material of the top of lid 13; the upper free end of each lid-to-base strap 24, 25 is then sewn or riveted back onto the strap to permanently mount the strap onto the lid 13. Each lid-mounted, lid-to-base strap is >' perforated and has a tapered free end and is dependent from or can extend beyond the bottom of the lid to enable it to be passed through a buckle mounted on and projecting from one of a pair of a pair of lower or base-to-lid fastening straps 26, 27 which are mounted to side walls 14, 15 of the base by means of passing the lower free end of the strap through a pair of parallel, lateral slots pre-formed in the base wall then sewing or riveting together the 3 0 free end of the strap back onto the strap. Next, the outer end of each lower or "base" strap has a buckle mounted thereon for fastening and securing the apertured lid-to-base strap thereto and thus for securing the lid when the lid is closed upon the base after closing the lid -5 upon the base. The end wall of the lid opposite to the hinged end is formed with a plurality of water-flow gaps such as the one labelled 17a, these gaps form water-flow slots which enable collected water to flow from the collector tray 12a out into and through a spout 28 and thence into the tertiary collector which is a grease trap 29 in the form of a rectangular .C container separable from the main body of the base 12 its tray 12a and thus from the lid 13, motor/fan unit 11 and housing 10. The grease trap 29 is provided with a lid 30 which has s slot 30a to accommodate the spout 28 which is designed to project from the tray 12a of the base 12 and to overhang a side wall of the grease trap container. The grease trap container body 29a which is also provided with siphon leg 31. A collected-water drain pipe 32 projects to outside of the grease trap container from one end wall. Electrical power is delivered to the motor/fan unit 11 via cable and junction box assembly 33. As shown in Figures 2 and 6 of the drawings, an additional feature is a cylindrical safety guard 211 of stainless steel mesh which surrounds the motor/fan unit 11 and which is fixed behind support rods 211a. Although straps and buckles have been described by way of example as a means of releasably fastening housing, lid and base components together it will understood by those skilled In this particular art that alternative fastening means can used. For example any dual component metal clips or catches can be used - for example automobile bonnet catches or tool box catches.