GB2160401A - Ground care implements and appliance - Google Patents

Abstract

An aerator 50 for turf treatment that can be coupled to the rear of a tractor 12 by a conventional three point linkage 14 comprises a frame that carries an open bottomed cage 17 and a hollow and rotatable drum 18. The drum 18 has on its outer surface a series of lugs arranged in a helical pattern around the drum. Blades 26 are attached to the lugs. The drum 18 is fillable with ballast to increase the downwards pressure exerted on the blades so as to increase ground penetration. In addition a movable weight 56 is provided. <IMAGE>

Description

SPECIFICATION Ground care implements and appliances This invention concerns ground care implements and appliances and is particularly concerned with aerators that are suitable for turf treatment.

Aeration of the soil of grassed areas, such as of sports fields and golf courses, is important for grass growth and drainage. For large areas mechanical aeration is used, wherein a rotatable blade or tine carrier is pulled by a tractor across the grassed area with either its own weight or weight transferred from the tractor aiding penetration of the soil by the blades or tines. It is known for the blades or tines to be arranged about the periphery of discs arranged side by side on a spindle orforthe blades or tines to be arranged on transverse bars arranged circumferentially with the blades in line. The blades or tines are often in the form of spikes that may be hollow.

The known aerators are not entirely satisfactory since ripping of turf can occur, which of course, is undesirable in the case of for example, golf courses.

Ripping occurs often when blades or tines have been bent due to uneven weight distribution on the aerator and also if the aerator is rotated too quickly.

The object of this invention is to provide an aerator that eliminates or mitigates against the above-mentioned disadvantages.

According to this invention there is provided an aerator comprising a rotatable hollow drum having blades or tines attached to the outer surface thereof, say on lugs.

The drum is preferably adapted to rotate when being pulled by a tractor or the like.

The blades are preferably arranged about the drum such that a pleasing pattern of aeration holes is formed as the aerator passes over the ground. A helical or spiral arrangement of blades about the drum is preferred.

The position of the blades or tines relative to the drum may be adjustable so that different depths of 'ground penetration by the blades or tines is possible. In other words the angle of the blades or tines relative to a radius of the drum that intersects the attachment point of the blade or tine may be altered. To achieve this the blades or tines may be attachable to the attachment lugs in different positions. For example, the lugs may have a series of bolt holes and selection thereof for passage of bolts therethrough and through holes of the blades or tines determines the position of the blades or tines. Two positions for the blades or tines are preferred, such as to provide penetration depths of six or eight inches.

The blades or tines may be of any suitable shape but preference is given to a blade that is widest at its attachment end and narrows at about its mid-length to a constant width portion before finishing in a point.

The drum is hollow so that its weight can be adjusted by filling with ballast, such as water. The amount of ballast can be chosen according to the desired ground penetration. This ballasting can also give a more even weight distribution over the length of the drum and so give even depth of ground penetration.

Alternatively the aerator of the invention may be used in conjunction with a weight transfer system such as of the type described in our patent application No.8412076, wherein the aerator has means for controlled weight transfer for pressure downwards on the drum as desired.

This invention will now be further described, by way of example only, with reference to the accompanying drawings, wherein: Figure lisa side view of a first embodiment of the invention; Figure 2 is a side view of a second embodiment of the invention; Figure 3 is a perspective view of the second embodiment of the invention; Figure 4 is a front view of part of an aerator drum of both embodiments; and Figure 5 is a side view of an aerator blade of both embodiments.

Referring to Figures 1 and 4 of the drawings, an aerator 10 is shown coupled to the rear of a tractor 12 via a conventional three point linkage 14.

The aerator 10 comprises a frame 16 that carries an open bottomed cage 17 and a rotatable drum 18 by means of axle boxes 20 on the frame 16 and axle 22 of the drum 18.

The drum 18 has on its outer surface a series of lugs 24 arranged in a helical or spiral pattern around the drum. Blades 26 are attached to the lugs 22 by nuts and bolts through corresponding holes of the lugs and the blades.

The lugs 22 have two sets of holes (not shown) so that each blade 26 can be attached in two different positions A and B relative to a radius of the drum intersecting the lug. These two positions will give rise to two different depths of ground penetration by the blades 26.

The drum 18 is hollow and so may be ballasted by filling with, for example, water. The amount of ballast used will depend on the necessary downward pressure to be exerted to achieve a desired depth of ground penetration by the blades.

Furthermore, the drum is to be rotated only by the action of being pulled by a tractor so that some downward pressure is desirable to achieve rotation of the drum at an even speed.

The blades themselves are shown in Figure 5.

They are widest at the attachment end i.e. in the region 28 of holes 30 for attachment bolts and narrow to approximately the mid-point of the blade where there is a constant width region 32 before pointed end 34. This blade formation is believed to be particularly advantageous in providing easy initial ground penetration and then a much wider cut in the ground for good aeration.

Turning to Figures 2,3 and 4 an aerator 50 is shown combined with a weight transfer system. The aerator is generally the same as in Figure 1 and like reference numerals have been used. The main difference is that the aerator frame 16 has pivotably mounted on lugs 52 thereof arms 54 that carry between them at their other ends a weight 56. The arms 54 are pivoted by means of double acting hydraulic rams 58 having their cylinder 59 coupled to the frame 16 and piston 60 coupled to the arms 54. Hydaulic fluid supply for the rams 58 is via a pump on the tractor 12.

Rests 62 are provided at the rear of the frame 16 for the arms 54 for when the weight is at its rearmost position i.e. with the rams 58 fully extended.

The position of the weight 56 is chosen according to the desired amount of downward pressure on the aerator drum. As shown in Figure 2 the weight 56 is rearward of the aerator and so exerts greatest downward pressure. For transportation to and from an area to be worked, the weight 56 will be positioned forward of the aerator drum as shown in Figure 3 so that it is clear of the ground.

In all embodiments, the aerator drum can have a large diameter so that its peripheral velocity is low.

This may avoid the problem of turf ripping.

Claims (9)

1. An aerator comprising a hollow, fillable and rotatable drum having blades or tines attached to the outer surface thereof.

2. An aerator as claimed in claim 1 wherein the drum is adapted to rotate when the aerator is being pulled.

3. An aerator as claimed in claim 1 or 2, wherein the blades or tines are attached to lugs of the drum.

4. An aerator as claimed in claim 1,2 or 3, wherein the blades or tines are in a helical or spiral arrangement about the drum.

5. An aerator as claimed in any one of claims 1 to 4, wherein the position of each blade or tine is adjustable relative to the drum.

6. An aerator as claimed in claim 5, wherein the blades or tines are attachable to the attachment lugs in at least two different positions.

7. An aerator as claimed in any one of claims 1 to 6 wherein the blades or tines are widest at their attachment end, narrow at about their mid-length to a constant width portion before finishing in a point.

8. An aerator as claimed in any one of claims 1 to 7 having means for controlled weight transfer for pressure downwards on the drum.

9. An aerator substantially as hereinbefore described with reference to and as illustrated in Figure 1 with Figures 4 and 5 or Figures 2 and 3 with Figures 4 and 5 of the accompanying drawings.