GB2054333A - Mowing machine - Google Patents

Abstract

A rotary mowing machine comprises a shroud 11 which is open at its underside and carries a cutter blade 14 rotatable about a vertical axis. A motor 16 is arranged to drive the cutter blade. The shroud is supported above the ground for movement over the ground by wheels 18 and the height of the shroud with respect to the wheels is adjustable by adjustment means 21. Guards 23 are mounted on the spindles of wheels 18 so that when the shroud is raised by the adjustment means the guards close off the gap between the bottom of the shroud and the ground. <IMAGE>

Description

SPECIFICATION Rotary mowing machines The invention relates to rotary mowing machines.

Atypical rotary mowing machine incorporates a shroud open at its underside, a cutter blade rotatable about a vertical axis in and supported from the shroud, a motorto drive the cutter blade and supports such as wheels for supporting the shroud above the ground for movement over the ground. It is normal to arrange for the edge of the shroud to be close to the ground in the interests of safety. Two dangers which can arise from two large a gap between the shroud and the ground are that the toes of an operator could pass under the shroud and be injured by the cutter blade and that stones or other debris in the path of the cutter blade could be projected out from under the shroud and cause damage or injury.Some rotary mowing machines have adjustment means for adjusting the height of the shroud and hence of the cutter blade with respect to the supports such as wheels so that the height of cut of the mower is adjusted. When setting the machine for a high cut, an excessive gap automatically appears between the edge of the shroud and the ground. A high cutting height and hence large gap is normally used in connection with rough terrain where there is a greater risk of stones and other debris above the surface and where there is a greater risk of the operator handling the machine in such a way that his foot could slip under the shroud.

An object of the invention is to provide a rotary mowing machine in which the dangers associated with a gap between the shroud and the ground are reduced.

According to the present invention there is provided a rotary mowing machine comprising a shroud open at its underside, a cutter blade rotatable about a vertical axis in and supported from the shroud, a motor arranged to drive the cutter blade, supports for supporting the shroud above the ground for movement over the ground, adjustment means for adjusting the height of the shroud with respect to the supports and a guard for the gap between the shroud and the ground carried by the supports so that the guard remains close to the ground as the shroud is raised by the.adjustment means.

Preferably the supports incorporate wheels and the guard is supported on the wheel spindles. There may be four wheels, one near each corner of the mowing machine and two guards one at each side of the machine extending between two wheels. The ends of the two guards may be joined by front and rear guards to form in effect a single peripheral guard.

The guard may be mounted for vertical movement with respect to the supports so that it can be raised by engagement with an irregularity in the ground if the machine is used on rough terrain.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which; Figure 1 is a perspective view of a rotary mowing machine according to the invention.

Figure 2 is a perspective view showing details of a guard as used in the mowing machine of Figure 1.

Figure 3 is a cross section through the attachment of the guard of a spindle, and; Figure 4 shows a modified form of guard and guard mounting.

The mowing machine of Figure 1 incorporates a shroud 11 which constitutes the main body or structure of the machine. The shroud is constituted by a generally flat top surface 12 and depending sides 13 which result in a shroud open at its lower end. The interior of the shroud carries a cutter blade 14 shown in chain dotted outline which is rotatable about a vertical spindle 15 which in turn is driven by a motor such as an internal combustion engine 16. The engine 16 is mounted on the shroud 11. When the blade 14 is rotated at high speed by the engine 16 it cuts grass or similar vegitation in its path. This grass may be conducted by conventional means such as air currents into a grass collection box 17 at the rear of the machine.Supports for holding the shroud above the ground are constituted by four wheels 18 which rotate on spindles 19 (see Figure 3) and are adjustable in height in a conventional way with respect to the shroud by adjustment means 21. A handle 22 is provided to enable an operator to push the machine over the ground while it is supported on the wheels 18.

The adjustment means 21 are arranged in relation to the shroud 11 so that the height of the lower edge of the shroud can be adjusted between a low position of about 1 cm above the ground and a high position of about 5 cm above the ground. In the low position, the small gap is acceptable from the safety point of view. However in the high position the above mentioned dangers of a foot passing under the shroud or stones being ejected from the shroud are serious problems.

In order to overcome this difficulty the mowing machine is provided with a guard assembly 22 constituted by two side guards 23 and a front guard 24.

The side guards 23 are mouldings of plastic material incorporating stiffening ribs 30 as shown in Figure 2.

Within the stiffening ribs there are provided bosses 25 which serve to mount the guards on the wheel spindles 19 with the aid of pins 26 as shown in Figure 3. The depth of the guard below the wheel spindle is such that the lower edge of the guard is at a height of about 1 to 2 cms above the ground. This gap of 1 to 2 cms is maintained regardless of the height of the shroud set by the adjustment means 21. The guard 23 prevents the foot of an operator inadvertantly being placed under the edge of the shroud in the path of the blade 14. It also tends to stop stones or other debris which may be hit by the blade from flying out and causing damage or injury.

As an alternative to having a guard around the front and the two sides of the machine, two separate guards may be provided one at each side of the The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

machine. Atypical mowing machine is longerthan it is wide so that the rotating blade does not come near to the front or rear of the shroud. For this reason it is less important to provide a guard at the front and rear. Similarly, in a machine which is not provided with a grass box such as the grass box 17, the guard may be provided across the back of the mower as well as the sides and front.

In a further alternative which is illustrated diagrammatically in Figure 4, a side guard 27 is mounted by means of vertical slots 28 in the guard which are free to slide up and down the wheel spindle (not shown) and are held on to the spindle by means of a head 29. Such a guard can be mounted very low down - perhaps less than 1 cm above the ground and then if the machine is used in rough terrain where the guard comes into contact with the ground, the guard itself is simply lifted up by the engagement with the ground, leaving the machine supported on its wheels. This arrangement allows a particularly low guard to be used. The amount of vertical movement allowed on the guard with respect to the spindles should be less than the amount of adjustment available in the adjustment means between the shroud and the wheels so that even if the guard is inadvertantly lifted up the gap under the guard is less than the maximum gap between the shroud and the ground. However in normal use, the guard 27 will drop down under its own weight and act as an effective guard very close to the ground.

Claims (5)

1. A rotary mowing machine comprising a shroud open at its underside, a cutter blade rotatable about a vertical axis in and supported from the shroud, a motor arranged to drive the cutter blade, supports for supporting the shroud above the ground for movement over the ground, adjustment means for adjusting the height of the shroud with respect to the supports and a guard for the gap between the shroud and the ground carried by the supports so that the guard remains close to the ground as the shroud is raised by the adjustment means.

2. A rotary mowing machine as claimed in Claim 1 wherein the supports incorporate wheels and the guard is supported on the wheel spindles.

3. A rotary mowing machine as claimed in Claim 2 incorporating four wheels, one near each corner and two guards one at each side of the mower and extending between two wheels.

4. A rotary mowing machine as claimed in Claim 3 wherein the ends of the two guards are joined by front and rear guards to form in effect a single peripheral guard.

5. A rotary mowing machine as claimed in any preceding claim in which the guard is mounted for vertical movement with respect to the supports so that the guard can be raised or lowered by engagement with an irregularity in the ground if the machine is used on rough terrain.