GARDENBLOWERAPPARATUS This invention relates to blower apparatus. This invention has particular but not exclusive application to blower apparatus for the removal of grass clippings, leaves and debris from pathways and the like and for illustrative purposes reference will be made to such application. However, it is to be understood that this invention could be used in other applications where a forced air flow is required such as for removing cobwebs, drying off surfaces or such like.

Known leaf blowers typically comprise an engine or motor close coupled to an impeller enclosed in a casing and connected to a tube which may be manipulated to direct air to a desired location. While such blowers are effective in operation as a substitute to raking, they are purpose built and thus unsuitable for other tasks. Thus, in spite of their convenience, their ownership is limited by their relative expense. Other mechanised gardening implements are common because of their versatility and/or the difficulty of manually performing the tasks for which they are adapted. Such gardening implements include motor driven edge trimmers and brush cutters, hereinafter collectively referred to as edge trimmers.

The present invention aims to alleviate the aforementioned disadvantage and to provide blower apparatus which will be reliable and efficient in use.

With the foregoing in view this invention in one aspect resides broadly in blower apparatus including an impeller assembly and securing means for operatively securing said impeller assembly to a rotary driven member of a motorised implement. The implement may be an angle grinder, a saw or a drill for example, but preferably the blower apparatus is adapted for connection to a motorised edge trimmer.

In one form of the invention the impeller assembly includes a hub which is adapted for quick releasable

securement to the whipping line drum assembly of an edge trimmer. In another form the impeller assembly is adapted for direct connection to the drive shaft after removing the whipping line drum assembly therefrom. It is also preferred that the apparatus include flow confining means for concentrating the air flow from the impeller assembly for flow in a single direction. The confining means may be associated only with the outlet from the impeller assembly but preferably it is adapted to enshroud the impeller assembly and provide a shield preventing accidental access to the impeller assembly. Furthermore it is preferred that the confining means be adapted for quick release attachment to the support means which supports the rotary driven member of the motorised implement.

The impeller assembly and the confining means may be separately and releasably detachable to the motorised implement or they may be formed as a unit whereby operative attachment of the confining means to the motorised implement engages the impeller assembly with the rotary driven member for operative attachment thereto and or partial support thereby. However if desired, the impeller assembly may be fully supported by the confining means and engage the rotary driven member by clutch means such as a dog clutch or a friction clutch or the like.

The impeller assembly may be formed as a centrifugal blower or as an axial flow blower. In a preferred form the impeller assembly is in the form of a relatively small diameter multi-blade fan. In such form of the invention it is preferred that the air inlet be formed in the associated confining means in the top thereof. Alternatively the air inlet may be formed in the underside of the confining means. In a preferred embodiment the confining means is in the form of a split housing which may be opened to pass about an operatively mounted impeller assembly and clipped back

together about the motorised implement. The confining means may include a separate stay or locking means for operatively maintaining its alignment with the mounted impeller assembly.

In a preferred embodiment of the invention adapted for connection to a motorised manual edge trimmer or brush cutter device the impeller is a multi-blade device having a diameter in the order of 150 mm to 250 mm and a pitch compatible with the output power of the petrol or electric motor powering the device whereby the motor is able to operate at its normal high speed mode.

In such embodiment it is also preferred that the confining means be a housing enclosing the impeller and having a generally flat base panel disposed substantially at right angles to the drive axis of the motor drive shaft and a converging output nozzle extending substantially tangentially to the impeller and formed to provide a substantially uni¬ directional air flow outlet which preferably has a direction which is biassed downwardly from the plane of the base panel.

Furthermore in such embodiment it is preferred that the inlet to the housing be formed in a portion of the housing which is opposite the output nozzle and preferably in a top or side wall of the housing. Suitably, there is sufficient clearance between the base wall and the impeller to permit efficient transition of air to the outlet nozzle. In order that this invention may be readily understood and put into practical affect, reference will now be made to the accompanying drawings which illustrate one or more typical embodiments of the invention and wherein:-

Figure 1 is a diagrammatic plan view of an impeller assembly according to one form of the invention;

Figure 2 is a diagrammatic side elevation of the impeller assembly of Figure 1;

Figure 3 is a diagrammatic side elevation of the impeller assembly and an associated confining housing; Figure 4 is a diagrammatic plan view of the apparatus

shown in Figure 3;

Figure 5 is a diagrammatic plan view of the apparatus shown in Figure 4 illustrating the confining housing in an undipped attitude; Figure 6 is a perspective view of an alternative form of the confining housing, and

Figure 7 is a perspective view of the alternative form of confining housing shown in Figure 6, but in an undipped and open attitude and with an alternative form of impeller shown therein.

An impeller assembly 10 illustrated in Figures 1 to 5 includes a cylindrical hub 11 adapted to circumscribe the whipping line drum assembly 12 of an engine driven edge trimmer (part of which is shown in Figure 3). The drum assembly 12 is secured to the drive shaft 13 which protrudes from the lower stem mounting of the edge trimmer and the hub 11 is secured for rotation with the whipping line drum assembly 12 by four circumferentially spaced set bolts 14 which may be tightened to engage with the wall of the hub 11, and preferably the rearwardly facing conical portion thereof to draw the hub into firm engagement with the cylindrical wall 16 of the whipping line drum assembly 12 for rotation therewith.

The impeller assembly 10 includes four circumferentially spaced fan blades 17 which extend radially outward from the hub 11 and operate to create a downward and/or radially directed draft of air, the force of which may be varied by varying the speed of rotation of the driven member.

A shroud 19 illustrated in Figures 3, 4 and 5 may be secured to the drive shaft housing 21 by a clamp 22 which extends thereabout. The shroud 19 is substantially volute in form and has a flat base wall 20 for resting on the ground or for movement adjacent the ground and a curved upper wall 23 which covers the upper face of the whipping line drum assembly 12 and which is clamped to the drive shaft 21 by a

clamp 22, thereby clamping the housing to the edge trimmer stem 30.

A side wall 24 extends circumferentially about the impeller 10 and curves to a neck portion 25 which has an end opening 26 through which air may exit from the housing. The housing is a split housing which pivots about a pin joint 27 extending from the upper wall 23 to the base wall 20 at the outlet 26 wherein two halves of the housing 28 and 29 may be spread apart so as to be placed about the impeller 10 and the whipping line drum assembly 12 and be clamped to the drive shaft housing 21. Each housing portion also includes a stabilising lug 31 which, when the housing portions are closed, clips about the stem 30 and stabilise the shroud 19. The air inlet apertures are suitably formed in the upper wall 19 adjacent the hub 12.

In an alternative form of the invention shown in Figures 6 and 7, like parts or portions are given the same reference numerals, and perform substantially the same function as in the description set forth in respect of Figures 1 to 5. However, the two halves 28 and 29 are non-symmetrical, with one half including a discharge nozzle 35, and the other half being hinged thereto by a hinge 36. Two pairs of fastening tabs 38 are provided with snap shut, twist open connectors to close the shroud 19 to the attitude shown in Figure 6, however, it will be appreciated that any type of connector, such as bolt and captive nut, clip or clamp, may be utilised for this purpose.

One of the two halves 28 and 29 also includes overlap portions so that when the shroud 19 is in its closed attitude, the shroud 19 is stiffened by engagement of the overlap portions with the other of the two halves 28 or 29.

The impeller assembly shown in Figure 7 includes the four fixing screws 14 which are engageable with the whipping line drum assembly (not shown in Figures 6 or 7) in the same manner as described above in respect of Figures 1 to 5.

The shroud 19 also includes four air intake apertures 40 in the upper wall 23 of the half 29 of the shroud 19 which does not include the discharge nozzle 35. Extending from the upper wall 23 is a stabilising clamp plate 41 to which is attachable a stabilising clamp 42, which perform the function of the stabilising lug 31 and clamp 22 described with reference to Figures 1 to 5. The upper wall 23 in the alternative form shown in Figures 6 and 7 is curved in cross section, and includes a conical portion as a curved transition between a lower annular portion which incorporates the air intake apertures 40 and an upper annular portion constituting a neck portion.

Additionally, the clamp plate 41 extends from the upper wall 23 adjacent the split between the two halves 28 and 29. The arrangement of the clamp plate is such that it does not mate with the opposed edge of the other half of the shroud 19 whereby a further air intake is provided as shown at 45 in Figure 6.

In use the exposed whipping line, in the whipping line drum assembly 12 is rewound and the hub 11 is secured to the whipping line drum assembly 12 by the set bolts 14. It will be appreciated that the whipping line drum assemblies 12 for most edge trimmers include a base flange which affords a safe attachment of the drum assembly 12, with the set bolts 14 being tightened to make a grip on the whipping line drum assembly of sufficient firmness to accommodate the torque required for rotation of the drum assembly in use.

A draft from the blower may be readily directed by manual control of the rotational position of the edge trimmer head. However if a more directed draft of air is required the shroud 19 can be fitted to the edge trimmer. This is achieved by opening the two halves 28 and 29 of the housing a distance sufficient to permit the housing to be fitted over the fan blades 17. Once enclosed, the housing is closed and locked into the closed position by clipping the connectors on

the fastening tabs 38. This will provide a directional air blast for accurate control of refuse being swept.

It will of course be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as claimed in the following claims.