AU715635B2 - Push mower - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

*o*o Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: Details of Associated Provisional Application(s) ROLAND LEONARD ZACHER Roland Leonard Zacher

INTELLPRO

Patent Trade Mark Attorneys Level D, 308 Edward Street BRISBANE, QLD, 4000 (GPO Box 1339, BRISBANE, 4001) "Push Mower" No(s): Australian Patent Application filed 14 June 1996.

No. P00479 The following statement is a full description of this invention, including the best method of performing it known to me: THIS INVENTION relates to a push mower and in particular but not limited to a push mower employing a front wheel assembly for improved manoeuvrabi I ity.

At present push mowers employ fixed axle front and rear wheels. This means steering is by a skid action where the front or rear wheels must be pushed sideways or raised slightly and skid pivoted to turn the mower. This adds to the work involved in mowing and promotes fatigue. In addition turning can be particularly difficult when working in thick grass or in wet conditions.

It is an object of the present invention to alleviate at least to some degree the abovementioned problem of the prior art.

In one aspect therefore the present invention resides in a push mower comprising a mower body having a motor and blade assembly, front and rear wheel assemblies supporting the body and a rearwardly projecting handle for, in use, an operator to push the mower, the front wheel assembly comprising a pair So-. 15 of spaced wheels, each wheel being rotatable about horizontal axes and :mounted for independent pivotable movement about respective spaced vertical axes in order to improve manoeuvrability. Preferably locking means are employed so that at least one of the wheels can be selectively locked against pivotal movement about the vertical axes.

oooo• In one embodiment the front wheel assembly is a retrofit assembly so that the front wheel assembly can replace existing wheel assemblies on existing push mowers. To this end the front wheel assembly preferably comprises spaced S"mounting means securable to the body of the mower at spaced apart locations, respective arms means projecting forwardly of each mounting means, each arm means being pivotally coupled at one end thereof to the mounting means and at its other end to one of the front wheels. Preferably the arm means are configured so that the front wheels are positioned forwardly of the previously existing wheels, each arm comprising a parallelogram linkage pivotable about horizontal pivots and there being provided lever means to raise and lower the linkages in order to raise and lower the front wheels while maintaining the 6/ vertical pivot axes substantially vertical.

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In this form, the front wheel assembly is preferably a single unit adapted to bridge across the mower body and being rigidly secured on opposite sides thereof.

In this form, the mounting means can be of any form but is preferably a bracket means mountable to or adjacent existing wheel mountings on the mower so that there is no need to further modify the mower. The mounting bracket is preferably a rigid generally U-shaped member extending across the mower body with respective mounting bracket arms at each end of a cross part providing a rigid frame member for the wheel assembly.

In one preferred form the mounting means comprises a universal coupling assembly so that the front wheel assembly can be fitted to most mowers once the existing wheels have been removed. Typically, spaced ~adjustable body connectors are employed so that the wheel assembly can be mounted to a body of a mower at a plurality of locations. Preferably the connections are hooks that hook under the body and spacers that engage the top of the body.

~In another embodiment the front wheel assembly is not a retrofit but the mower is purpose built with the body having mountings for the wheel assembly and the shroud being configured to accommodate movement of the front wheels within side recesses.

In another embodiment means are provided to elevate the blade assembly by moving the front and rear wheel assemblies in concert, the said means preferably comprising a manually operable lever and a connecting rod extending between the front and rear wheel assemblies, the respective wheel assemblies having crank means operative in concert to raise and lower the blade assembly relative to the wheel assemblies.

Preferably the mower body includes cut-outs or side recesses for the respective wheels of the front wheel assembly to provide a fairly compact shroud wheel arrangement so that the front wheels do not project too far in front of the shroud.

In order that the present invention can be more readily understood and be put into practical effect reference will now be made to the accompanying drawings and wherein:- Figure 1 is a perspective view illustrating a push mower according to the present invention.

Figure 2 is an exploded view illustrating a preferred front wheel assembly of a push mower according to the present invention; and Figure 3 is a section illustrating how the wheels of the front wheel assembly are raised and lowered.

Figure 4 is a view similar to Figure 2 but illustrating an alternative embodiment.

Figure 5 is a perspective view at an alternative embodiment of the present invention.

Figure 6 is a part cut-away perspective view from one side of the embodiment of Figure Figure 7 is a perspective view illustrating the left front side wheel.

Figure 8 is a section through 8-8 of Figure 7.

Figure 9 is a section through 9-9 of Figure 7; and Figure 10 is an opposite side view of the left front wheel.

Referring to the drawings and initially to Figure 1 there is illustrated a push mower 10 comprising a mower body having a motor 11 and a blade assembly 12 beneath a shroud 13, a front wheel assembly 14 rear wheel assembly 15 and a rearwardly projecting handle 16, the front wheel assembly comprising a pair of spaced wheels 17 and 18, each wheel 17 and 18 being rotatable about respective horizontal axes and being mounted for pivotable movement about respective spaced vertical axes in order to improve manoeuvrability. In the illustrated embodiment the wheel assembly 14 has been fitted to the mower body as a retrofit and this will be described in more detail in Figure 2.

Referring now to Figure 2 there is illustrated the wheel assembly 14 in greater detail. The wheel assemblies 14, 15 as illustrated are positioned relative to wheel mountings 19 and 20 (not shown) which were used to retain axles for the previous wheels shown in phantom at 21 and 22. Once the preexisting wheels 21 and 22 are removed the wheel assembly 14 can be easily put in place.

As can be seen the wheel assembly 14 includes a main frame comprising a cross member 23 welded or otherwise secured to spaced apart brackets 24 and 25. The brackets 24 and 25 have holes 26 and 27 respectively that can be aligned with the axel hole 28 and hole 29 (not visible) on the other side and held in place by bolts. The brackets include respective notches 30 and 31 used to key the bracket into position so that a rigid connection is obtained between the brackets 24 and 25 and the body of i. the mower 13. The frame 23 supports arms in the form of parallel linkages 32 and 33 where the lower linkage arms 34 and 35 are rigidly coupled to a crank S"bar 36 which in turn is rigidly coupled to a crank arm 37. The other end of the linkages 32 and 33 support shafts 38 and 39 journalled in bearings 40 and 41 respectively which shafts 38 and 39 are held vertical. The shafts 38 and 39 i o carry stub ends on which the wheels 17 and 18 rotate about horizontal axes.

It will be appreciated that the wheels 17 and 18 are free to pivot about the shafts 38 and 39 and this assists in and improves manoeuvrability of the mower. Crank arm 37 is pivotally coupled to a threaded shaft 42 which has a hand crank 43 pivotally coupled on the end thereof so that upon operation of the hand crank 43 the lower linkage arms 34 and 35 raise and lower the wheels 17 and 18 according to the direction of rotation of the hand crank 43.

This is illustrated in Figure 3 showing different positions of the linkages in solid outline and in phantom. It will be appreciated that by using the hand crank 43 the blade assembly of the mower illustrated in Figure 1 can be raised or lowered as desired.

Referring to Figure 4 there is illustrated an alternative embodiment where the wheel assembly 50 is the same as the wheel assembly of the previous figures except it employs a universal type mounting means 51. The mounting means 51 includes a pair of hook assemblies 52 and 53 where hooks 56, 57, 58 and 59 hook under the rim 60 of the shroud 61 as shown at 62, 63, 64 and 65 respectively. The hooks 56 and 59 can be adjusted in length and sideways in slots to tighten the mountings against spacers 66 and 67. The hooks and spacers can be changed for different shrouds thereby giving the "universal" variability. Of course universal does not mean all but a proportion of commonly used mowers can be fitted.

Referring now to Figures 5 and 6 there is illustrated an alternative embodiment of the present invention where the front wheel assembly is not made as a retrofit for the mower but made and constructed as an integral unit with the mower specially designed to cater for the front wheel assembly. As can be seen in Figures 5 and 6 there is illustrated a mower 70 having a mower body including a motor 71 and a blade assembly located beneath a shroud 72, the shroud 72 having respective cut out regions 73 and 74 on either side of a projecting nose portion 75. Each of the cut out portions 73 and 74 are formed in order to enable rotation of the respective wheels 76 and 77 in close *proximity to the shroud and in the cut-out regions 73 and Each of the wheels 76 and 77 are mounted so as to rotate in similar fashion as described in relation to the previous embodiments. Where :appropriate like numerals have been used to illustrate like features.

The main difference between the embodiment of the previous cases in relation to Figures 5 to 10 is that the front and rear wheels are raised and lowered in concert thereby maintaining the blade assembly substantially :-*parallel to the ground surface.

Front and rear crank assemblies 78 and 79 are employed as can clearly be seen in Figures 6, 9 and The front crank assemblies include a pair of respective mounting brackets 80 and 81 a crank 82 and a linkage 83 all operated via a connecting rod 84 coupled to the rear crank assembly 79. The connecting rod is adjustable in length to enable fitting and adjustment. The crank assembly configuration and ratios are selected to give the desired adjustment for proper vertical movement of the blade assembly. The rear crank assembly 79 is operated by a lever and crank adjuster 85 best seen in the cutaway section of Figure 6, the lever 86 being biased into detent means in the form of a curved slotted plate 87 by a biasing leaf type spring 88.

The action of the connecting rod 84 is transferred to the other front wheel assembly by a rod 89 which is displaced forwardly to allow sufficient space for the motor body.

Whilst the above has been given by way of illustrative example of the present invention, many variations and modifications such as described above will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as herein set forth. A typical modification is illustrated in Figure 5 where bolts 68 and 69 are employed to lock the wheels 70 and 71 in a desired position. For example the wheels can be locked straight as shown when operating on steep inclines.

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Claims (17)

1. A push mower comprising a mower body having a motor and blade assembly, front and rear wheel assemblies supporting the body and a rearwardly projecting handle for, in use, an operator to push the mower, the front wheel assembly comprising a pair of spaced wheels, each wheel being movable about horizontal axes and mounted for independent pivotal movement about respective spaced vertical axes in order to improve manoeuvrability.

2. The mower according to claim 1 wherein the mower further having locking means for selectively locking at least one of the front wheels against the pivotal movement about respective vertical axes.

3. The mower according the claim 1 or claim 2 wherein the front wheel assembly is a retrofit assembly adapted for replacing an existing front wheel assembly on the mower.

4. The mower according to claim 1 or claim 2 wherein the mower is 15 purpose built, the body being configured to accommodate movement of the spaced front wheels.

The mower according to any one of claims 1 to 4 wherein means are :provided for elevating the blade assembly and moving the front and rear wheel assemblies in concert. 20

6. The mower according to claim 3 wherein the front wheel assembly further comprising spaced mounting means securable to the body at spaced apart locations, respective arm means projecting forwardly of each mounting means, each arm means being pivotally coupled at one end thereof to the mounting means and at its other end to one of the front wheels.

7. The mower according to claim 6 wherein the arm means are configured so that the front wheels are positioned forwardly of position of the previously existing wheels.

8. The mower according to claim 6 or claim 7 wherein each arm comprising a parallelogram linkage pivotable about horizontal pivots and lever means "V V. provided to raise and lower the linkages in order to raise and lower the front wheels while maintaining the vertical axes substantially vertical.

9. The mower according to any one or claim 6 to 8 wherein the wheel assembly is a single unit adapted to bridge across the body and being rigidly secured on opposite sides thereof.

The mower according to any one of claims 6 to 9 wherein the mounting means is in the form of a bracket means mountable to or adjacent to wheel mountings on the body for previously existing wheels.

11. The mower according to claim 10 wherein the bracket means comprising a rigid generally U-shaped frame member extending across the mower body, the U-shaped member having a cross part and respective mounting bracket arms at each end of the cross part for mounting to the body.

12. The mower according to any one of claims 6 to 9 wherein the mounting means comprising a universal coupling assembly which is configurable for fitting 15 the front wheel assembly to mowers of different body configurations once the °existing wheels have been removed.

13. The mower according to claim 12 wherein the universal coupling *assembly having spaced adjustable body connectors for connecting the front wheel assembly to the body at a plurality of locations. S 20

14. The mower according to claim 13 wherein the body connectors include ot hooks for hooking under the body and spacers for engaging top of the body.

The mower according to any one of claims 12 to 14 wherein the mower body includes cut-outs or side recesses for the respective wheels of the front wheel assembly.

16. The mower according to claim 5 wherein the elevating means comprising a manually operable lever and a connecting rod extending between the front and rear wheel assemblies, the respective wheel assemblies having crank means operative in concert to raise and lower the blade assembly relative to the wheel assemblies.

17. A push mower substantially as described with reference to Figures i to 3, or Figure 4 or Figures 5 to DATED this 29th day of November 1999 ROLAND LEONARD ZACHER By his Patent Attorneys INIELLPRO