GB2213692A - A turf aerator - Google Patents

Abstract

A turf aerator comprising a wheeled and manoeuverable frame carrying at least one transverse row of reciprocating tine holders (10) pivotally mounted on one or more transverse supporting rods on axis (11) and one or more tines (16) fixed to and extending downwardly from the bottom of the tine holder (10). A spring-loaded turf retaining plate (18) having apertures (19) to receive the tines (16) is attached to a rod (21) slidably mounted in vertically spaced bearing members (22), and compression spring (23) urges the plate (18) downwardly into contact with the turf surface to retain same during penetration and withdrawal of the tines (16). <IMAGE>

Description

A TURF AERATOR THIS INVENTION concerns turf aerators of the type comprising a wheeled and manoeuverable frame, usually motor driven, and carrying at least one transverse row of reciprocating tine holders each with one or more tines projecting downwardly therefrom. When the device is manoeuvred along the ground, the tines are repeatedly caused to penetrate the turf to aerate the soil.

To ensure efficient aeration without damaging the turf surface, it is important to retain the latter during penetration of the tines and particularly during their withdrawal. For this purpose it is known to provide a toothed retaining guard which extends transversely across the device and which moves forwards between the tines during the period of penetration and withdrawal.

A disadvantage of a fixed turf retaining device of this kind is that under very wet conditions it can have the effect of smearing the surface of the turf thus causing the latter considerable damage.

An object of the present invention is to provide a turf aerator having means for retaining the turf wherein the aforementioned disadvantage is avoided.

A turf aerator comprising a wheeled and manoeuverable frame carrying at least one transverse row of reciprocating tine holders pivotally mounted on one or more transverse supporting rods, each holder having one or more tines removably attached to its lower end and projecting downwardly therefrom to penetrate the ground, characterised by a plurality of spring loaded turf retaining plates each -slidably attached beneath one of said tine holders with the associated tine or tines projecting through an aperture or apertures in the plate thus to bear against and retain the surface of the turf during penetration and withdrawal of said tines.

Preferably, said retaining plates are mounted on rods slidably engaged within bearing members on the tine holders, there being a compression spring and stop member between two such bearing members to urge said retaining plate downwardly towards the free end of said tines.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a vertical elevation of a tine holder attachable to a turf aerating machine, and incorporating a device in accordance with the invention; and Fig. 2 is an underside view thereof.

A turf aerating machine to which the invention is applied consists of a wheeled framework (not shown), usually engine driven and either manoeuvred by hand or from a tractor, and is used for aerating areas of turf by penetration with a series of tines. The tines are mounted on a transverse rod or shaft which descends as the frame is moved forwardly to cause the tines to penetrate the turf and thereafter rises to withdraw the tines which are then presented once again for penetration. By repeated operation in this way the turf is aerated as the device proceeds over it.

Sometimes the tines are hollow and of circular cross-section having side openings for the discharge of soil cores which are later collected by sweeping, whilst in other cases the tines are solid and may be other than circular in cross-section presenting to the turf, for example, a knife edge instead of a pointed end.

Since, under certain ground conditions the surface of the turf may be excessively disturbed by the repeated penetration and withdrawal of the tines, it is preferable to place around the tines a retaining plate which presses down on to the surface holding the turf in place during penetration and withdrawal of the tines.

Referring now to the drawings, there is shown one of a transverse row of tine holders 10 bored at 11 to be pivotally mounted on a transversely directed but vertically oscillating rod (not shown) mounted on the machine. A spigot 12 at the upper end of the tine holder 10 provides a point of attachment for a spring 13 tending to cause the holder 10 to pivot about the axis of bore 11 in a clockwise direction as viewed in Fig. 1. This ensures that tine holders are always presented in a forwardly inclined position in readiness for penetration.

Removably attached to the base of each tine holder 10 is a mounting block 14 having tine retaining bolts 15 for a pair of spaced tines 16 or a single centrally located tine (not shown) may be fitted directly into tine holder 10 to extend downwardly therefrom.

In the example illustrated, the tines 16 are of the hollow type having side openings 17 for the discharge of soil cores, as is conventional. In practice, the openings 17 will face to the rear of the device, that is to the right hand side of Fig. 1, so that the soil cores are easily discharged for collection as the device proceeds over the ground. However, for the purpose of illustration, the openings 17 are shown facing transversely of the machine. In some cases, this may be acceptable.

Now in accordance with the invention, there is provided a turf retaining plate 18 having apertures 19 through which the tines 17 project. A leading edge region 20 of the plate 18 is inclined upwardly to prevent the free edge of the plate from snagging the turf surface.

The plate 18 is mounted on a rod 21 which is slidable vertically within spaced bearing members 22 welded to the rear side of each tine holder 10. A compression spring 23 bears against the upper of the two bearing members 22 and against a boss 24 fixed to rod 21. With this arrangement the rod 21 and plate 18 are normally urged into the lowermost operating position as illustrated in Fig. 1. A small clamping screw 25 enables the position of boss 24, and thus the height of plate 18 to be adjusted.

In operation, as the tine holders 10 are lowered, the plate 18 comes to rest on the surface of the turf and retains it firmly during penetration and subsequent withdrawal of the tines 17, the rod 21 and plate 18 retracting as necessary to maintain a substantially constant pressure on the surface of the ground.

Since each tine holder has its own independently mounted plate 18, any undulation in the ground surface across the width of the machine is accommodated by permitting some of the plates 18 to rise further with respect to their associated tine holders, than others in the row.

Since there is little or no sliding movement of the plates 18 with respect to the ground surface, smearing of the latter is prevented.

It is not intended to limit the invention the above example only, many variations, such as might readily occur to a person skilled in this art, being possible without departing from the scope of the invention. For example, whilst hollow tines for soil removal have been illustrated, these may be replaced by solid tines of circular or other cross-section. A single tine or a plurality of tines may be provided on each tine holder, and furthermore rod 21 may be fixedly attached to tine holder 10 or to retaining block 14, whilst plate 18 may be vertically slidable with respect to its associated rod. As a further alternative, the plate may be slidably mounted directly in block 14.

Claims (10)

1. A turf aerator comprising a wheeled and manoeuverable frame carrying at least one transverse row of reciprocating tine holders pivotally mounted on one or more transverse supporting rods each holder having one or more tines removably attached to its lower end and projecting downwardly therefrom to penetrate the ground, characterised by a plurality of spring-loaded turf retaining plates each slidably attached to and located beneath one of said tine holders with the associated tine or tines projecting through an aperture or apertures in the plate such that the plate is caused to bear against and retain the surface of the turf during penetration and withdrawal of said tines.

2. A turf aerator according to Claim 1, wherein each said retaining plate is mounted on a rod slidably engaged within bearing members on the associated tine holder, there being a compression spring and stop member between two such bearing members to urge the retaining plate downwardly towards the free end of the tines.

3. A turf aerator according to Claim 2, wherein said stop member is adjustably located on said rod to enable the normal position of the retaining plate relative to its associated tine or tines to be determined.

4. A turf aerator according to any one of Claims 1 to 3, wherein a leading edge region of each turf retaining plate is inclined upwardly to prevent the free edge of the plate from snagging the turf surface.

5. A turf aerator according to any preceding claim, wherein each turf retaining plate is attached to the rear of its associated tine holder and projects forwardly beneath the latter in the direction of travel of the aerator.

6. A turf aerator according to any preceding claim, wherein each said turf retaining plate includes three apertures each adapted to receive a tine attached to and extending downwardly from a lower end of an associated tine holder.

7. A turf aerator according to any preceding claim, wherein said tines are hollow for soil removal.

8. A turf aerator according to any one of Claims 1 to 6, wherein said tines are of solid cross section.

9. A turf aerator according to Claim 1, wherein each said turf retaining plate is slidably mounted on a tine holding block attached to a lower end of the associated tine holder.

10. A turf aerator having a plurality of spring-loaded turf retaining plates substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.