GB2058535A - Mowers - Google Patents

Abstract

A rotary mower has a deck 10 suspended from front and rear axle assemblies in the shape of an inverted U having a base 26 and downwardly extending limbs 28. The base 26 extends transversely above the deck 10 and the limbs 28 are guided in vertical upwardly facing channels 31, 44 either cast directly in the deck 10 or separately fastened to the sides of the deck. Wheels are rotatably mounted on stubs 30, 46 which extend outwardly from the vertical limbs 28, 42 of the axle assemblies. The axle assemblies and wheels can be adjusted vertically, sliding in the channels 31, 44 by means of screw adjusters 32, 50. In one embodiment, a propelling handle 56 is fastened to the rear axle assembly so as to be independent of adjustment of the height of the deck 10. <IMAGE>

Description

SPECIFICATION Mowers This invention relates to mowers, and in particular to wheel suspensions for mowers.

According to one aspect of the present invention there is provided a mower having a generally horizontal deck, a rotary cutter located on the underside of the deck and mounted for rotation about a vertical axis to sweep in a horizontal plane below the deck, wheels mounted on the deck and disposed outwardly of the periphery of the sweep of the cutter, the wheels having adjustable mountings for substantially vertical, linear adjustment of the wheels with respect to the deck to permit adjustment of the height of cut ofthe cutter above the ground.

Preferably, at least one axle assembly is provided extending transversely of the deck, a pair of the wheels being mounted on said axle assembly to either side of the deck, the adjustable mounting for said pair of wheels comprising means to guide said axle assembly and thereby said pair of wheels for substantially vertical, linear movement relative to the deck and means to adjust the vertical position of said axle assembly relative to the deck.

According to a further aspect of the present invention there is provided a mower having a deck, mowing means mounted on the deck, at least one axle assembly extending transversely of the deck, a pair of wheels mounted on said axle assembly to either side of the deck, means to guide said axle assembly and thereby said pair of wheels for substantially vertical, linear movement relative to the deck, and means to adjust the vertical position of said axle assembly relative to the deck and thereby to adjust the height of the mowing means above the surface to be mown.

Preferably, said axle assembly has a pair of substantially vertical limbs disposed to opposite sides of the deck, each wheel of said pair of wheels being mounted on a respective one of said pair of limbs, said guide means comprising means for guiding each limb of said axle assembly for substantially vertical, linear movement relative to the deck.

Preferably, the guide means of said axle assembly comprise a pair of substantially vertical outwardly facing channels disposed on transversely opposite sides of the deck, the limbs of said axle assembly being slidable in the channels.

The deck may be shaped to form the channels.

Alternatively, the channels may be formed as channel members fastened to the outside of the deck.

Said axle assembly may comprise an inverted U-shaped member, the limbs of the U-shaped member forming the limbs of said axle assembly. In one arrangement the U-shaped member may be formed from two L-shaped members fixed to a central block.

Preferably the adjusting means comprises a substantially vertical screw extending between the deck and the centre of the U-shaped member and means to rotate the screw manually to adjust the vertical position of said axle assembly relative to the deck.

In the case where the U-shaped member is formed from two L-shaped members fixed to a central block, the screw preferably extends through a hole in the central block.

The wheels of said axle assembly may be mounted on stubs extending in opposite directions from the limbs of the said axle assembly.

In the case where the mower has a rotary cutter, two axle assemblies may be provided and disposed fore and aft of the cutter with a substantially constant wheelbase.

The widths of the deck fore and aft of the location of the cutter are preferably narrower than the width of the deck adjacent the location of the cutter, in which case the wheels may lie within the width of the deck adjacent the location of the cutter, the effective width of the cutter being substantially as great as the maximum width of the mower.

Normally, the mower has a handle for propelling or directing the mower manually, in which case the handle may be mounted on the axle assembly, or the rearmost axle assembly.

Embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings in which: Figure lisa side elevation of an embodiment of a mower according to the invention; Figure 2 is a front elevation of the mower illustrated in Figure 1; Figure 3 is a plan view of the mower illustrated in Figure 1; Figure 4 is a front view of a rear axle assembly of a modified combination; and Figure 5 is a side elevation of the mower of Figure 4.

Referring to the drawings, the mower has a cast alloy deck 10, suspended on front wheels 12 and rear wheels 14. A power unit such as a petrol engine 16 is mounted on the deck 10 and drives a single or multiple blade cutter (not shown), disposed to the underside of the deck 10, about a vertical axis to perform the mowing operation.

The deck 10 has a skirt 18 to prevent mown grass or the like escaping from the front and sides of the mower. The deck 10 and portions of the skirt 18 to the sides of mower are formed with arcuate bulges 20 to permit rotation of the cutter, and the effective width of the cutter is substantially as great as the maximum width ofthe mower.

Mown grass or the like is forced from the rear of the deck 10 past a safety flap (not shown) to a grass box 22, at the rearofthe deck 10. A handle 24 (partially cut away in the drawings) is provided with which to propel the mower manually.

The front wheels 12 are mounted on an axle assembly comprising an inverted U-shaped member of steel, having a base 26 and limbs 28, and stubs 30, extending outwards from the limbs 28, on which the front wheels 12 are rotatably mounted. The base 26 extends transversely above the front of the deck 10 and the limbs 28 are guided in substantially vertical, outwardly facing channels 31 cast into the sides of the deck. Each channel 31 may be formed as a vertical hole through the deck 10 adjacent the side of the deck to receive the respective limb 28 and a vertical slot extending from the hole sideways to the side of the deck 10 to permit vertical movement of the stubs 30.

The limbs 28 and/or the channels 31 may be coated or otherwise treated to reduce friction therebetween. For example, the limbs 28 may be coated with nylon which also has the advantage of preventing electrolytic action between the steel limbs 28 and the alloy deck 10.

The U-shaped member may be formed from two L-shaped members welded to a central block 38 (as illustrated in the drawings) or alternatively a single piece U-shaped member may be used.

An adjuster is provided to hold and to adjust the position of the front axle assembly relative to the deck 10. The adjuster comprises a vertical screw 32 having a knob 34 fixed at the upper end thereof. The screw 32 passes through a hole formed in the central block 38, or, if a single piece U-shaped member is used, through a hole formed in the centre ofthe base 26 of the U-shaped member, and threadingly engages a threaded boss 36 fixed to the deck 10.

By rotating the knob 34 in one direction, the threaded boss 36 is drawn towards the base 26 of the U-shaped member, and thus the height of the front of deck 10 above the ground is increased. Rotation of the knob 34 in the opposite direction lowers the front of the deck 10.

The rear wheels 14 are mounted on a similar axle assembly to the front axle assembly. Thus the height of cut is set separately front and rear. Indicators 40 may be provided to indicate the adjustment of the axle assemblies.

In a known type of mower suspension, each axle or each wheel is rotatable about a transverse axis to the front or rear of the wheel axis in order to adjust the height of cut and adjustment, means are provided between the wheels and the skirt. With such an arrangement, adjustment of the height of cut leads to a variation in the wheelbase of the machine. In the embodiment of the invention described above there is no variation in the wheelbase and therefore only a small clearance is necessary between the wheels 12, 14 and the bulges 20 to the sides of the mower leading to a more compact mower. Further in the embodiment described above the wheels 12, 14 are disposed closely adjacent the skirt 18, also leading to a more compact mower.

Also, in known mowers the rear axle assembly may obstruct the grass exit to the grass box, whereas in the embodiment described above the rear axle assembly extends transversely above the grass exit.

Figures 4 and 5 of the drawings illustrate a modified embodiment of the present invention. In the example described with reference to Figures 1 to 3, the axle assemblies are U-shaped members formed of bent tubing to provide the base portion 26 and limbs 28. In the modified arrangement illustrated in Figures 4 and 5, front and rear axle assemblies 40 and 41 respectively are formed ofthree separate members, two upright rectangular section bars 42 forming the limbs of the axle assembly and a square section tube member 43 interconnecting the bar 42 and forming the base of the axle assembly. The base member 43 is welded at each end to the upright bars 42.

The bars 42 are guided in channel members 44 which are themselves fastened to the side walls of the deck 10 of the machine. The channel members 44 are sized to allow the bars 42 to slide in them and each member 44 has a vertical slot 45 in its outer face from end to end of the memberto permit stubs 46 mounted on the bars 42 to slide up and down projecting from the channel members 44 through the slots 45. The channel members 44 are secured to vertical side portions 47 of the deck 10 by means of studs 48 projecting through holes in the side portions 47 and nuts 49 screwed on to the studs 48.

This arrangement with separate channel members 44 fastened to the deck 10 enables the deck 10 to be made more strongly, or alternatively, to have the same strength but using less weight of material.

As before, the height of the deck is adjusted by a screw adjuster 50 rotating in a block 51 provided mid-way along the base member 43 of the axle assembly. The screw 50 is threadingly engaged in a boss 52 fixed to the deck 10. Conveniently, the threaded portion of the adjuster 50 is protected by means of a flexible bellows cover 53.

Figure 4 shows the rear axle assembly of the mower. However, the parts of the axle assembly described hitherto are equally applicable to the front axle assembly. Referring to Figure 4, a handle 54 by which the mower can be propelled manually is fastened directly to the rear axle assembly itself by means of a bracket 55 which is fastened by means of bolts 56 to the upper ends of the bars 42 of the axle assembly. A handle extension 58 is adjustably fastened to a mid point of the bracket 55 by means of an adjustable clamp 57 whereby the angle ofthe extension 56 can be adjusted to suit the person propelling the mower.

With this arrangement, the setting of the handle adjustment does not vary with adjustment ofthe height of the deck 10 of the mower by means of the screw adjusters 50, because the handle is mounted directly on the rear axle assembly and does not therefore move with adjustment of the deck.

Claims (16)

1. A mower having a generally horizontal deck, a rotary cutter located on the underside of the deck and mounted for rotation about a vertical axis to sweep in a horizontal plane below the deck, wheels mounted on the deck and disposed outwardly ofthe periphery of the sweep of the cutter, the wheels having adjustable mountings for substantially vertical, linear adjustment of the wheels with respect to the deck to permit adjustment of the height of cut of the cutter above the ground.

2. A mower as claimed in Claim 1, wherein at least one axle assembly is provided extending trans verselyofthe deck, a pair of the wheels being mounted on said axle assemblyto either side of the deck, the adjustable mounting for said pair of wheels comprising means to guide said axle assembly and thereby said pair of wheels for substantially vertical, linear movement relative to the deck and means to adjust the vertical position of said axle assembly relative to the deck.

3. A mower having a deck, rowing means mounted on the deck, at least one axle assembly extending transversely of the deck, a pair of wheels mounted on said axle assembly to either side ofthe deck, means to guide said axle assembly and thereby said pair of wheels for substantially vertical, linear movement relative to the deck, and means to adjust the vertical position of said axle assembly relative to the deck and thereby to adjust the height of the mowing means above the surface to be mown.

4. A mower as claimed in Claim 2 or Claim 3, wherein said axle assembly has a pair of substantially vertical limbs disposed to opposite sides of the deck, each wheel of said pair of wheels being mounted on a respective one of said pair of limbs, said guide means comprising means for guiding each limb of said axle assembly for substantially vertical, linear movement relative to the deck.

5. A mower as claimed in Claim 4, wherein the guide means for said axle assembly comprise a pair of substantially vertical outwardly facing channels disposed on transversely opposite sides of the deck, the limbs of said axle assembly being slidable in the channels.

6. A mower as claimed in Claim 5, wherein the deck is shaped to form the channels.

7. A mower as claimed in claim 5 wherein said channels are formed as channel members fastened to the outside of the deck.

8. A mower as claimed in any one of Claims 4to 7, wherein said axle assembly comprises an inverted U-shaped member, the limbs of the U-shaped member forming the limbs of said axle assembly.

9. A mower as claimed in Claim 8, wherein the U-shaped member is formed from two L-shaped members fixed to a central block.

10. A mower as claimed in Claim 8 or Claim 9, wherein the adjusting means comprises a substantially vertical screw extending between the deck and the centre of the U-shaped member and means to rotate the screw manually to adjust the vertical position of said axle assembly relative to the deck.

11. A mower as claimed in Claim 10 as dependent on Claim 8, wherein the screw extends through a hole in the central block.

12. A mower as claimed in any one of Claims 4 to 11, wherein the wheels of said axle assembly are mounted on stubs extending in opposite directions from the limbs of said axle assembly.

13. A mower as claimed in Claim 2 or any one of claims 4 to 12 as dependent on Claim 2, wherein two axle assemblies are provided and disposed fore and aft of the cutter with a substantially constant wheelbase.

14. A mower as claimed in Claim 13, wherein the widths of the deck fore and aft of the location of the cutter are narrower than the width of the deck adjacent the location of the cutter, the wheels lying within the width of the deck adjacent the location of the cutter, and the effective width of the cutter being substantially as great as the maximum width of the mower.

15. A mower as claimed in any of claims 2 to 14 and including a handle for propelling or directing the mower manually, the handle being mounted on the axle assembly, or the rearmost axle assembly.

16. A mower substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.