GB2429620A

GB2429620A - A rotary ground aerator with air injector

Info

Publication number: GB2429620A
Application number: GB0517755A
Authority: GB
Inventors: Jonathan William Hargreaves; Brian Hartley
Original assignee: SISIS EQUIPMENT; Sisis Equipment Macclesfield Ltd
Current assignee: SISIS EQUIPMENT; Sisis Equipment Macclesfield Ltd
Priority date: 2005-09-01
Filing date: 2005-09-01
Publication date: 2007-03-07
Also published as: GB0517755D0

Abstract

A rotary ground aerator comprising a chassis carrying a hollow shaft 19 on which is mounted, at axially spaced positions, a plurality of rotatable plates 15 each having a plurality of tines extending outwardly from its edge. A compressor/pump supplies air via a rotary valve to the interior of shaft 19 , and for each tine 10 a flow control valve 7 receives air from the rotary shaft and is operated by an actuator 21 bearing against an abutment 8 on the chassis thus to deliver a pulse of air through a duct 9 to an internal passage 10a in an associated one of the tines 10 thus to inject a pulse of air through an aperture 11 into the ground at the point of lowermost penetration of the tine 10 . The air may be supplemented with or replaced by a liquid substance.

Description

A ROTARY GROUND AERATOR

This invention concerns apparatus for injecting air or other substances into the ground and may consist of a machine which preferably, although not specifically, is adapted to be towed, for example by a tractor, and having one or more tines adapted repeatedly to penetrate the ground as the machine is drawn or propelled over the ground surface.

Aeration, for example, is carried out to relieve compaction of the ground, allow water penetration and, in the case of a turfed area, to allow air to reach the grass roots to improve root health and depth.

A typical rotary ground aerator comprises a chassis with a plurality of rotatable plates mounted at axially spaced positions on a rotary shaft extending transversely across the chassis, each plate carrying one or more generally radially extending tines which engage the ground surface as the chassis is moved such that the tines sequentially and progressively penetrate the ground to a depth of some 400mm. In some cases, the shaft may be driven in rotation but in most cases it is rotated by progressive and sequential ground engagement of the tines.

An object of the present invention is to enhance the action of penetration of such an aerator by injecting a substance into the ground where it is penetrated by the or each tine.

According to the present invention there is provided a rotary ground aerator comprising a chassis, one or more rotatable plates mounted, spaced apart, along a hollow driven shaft attached to said chassis for rotation thereon, the or each plate having at least one tine extending outwardly from an edge region of the plate for penetration of the ground upon rotation of the plate and being of hollow form defining an internal passage with an outlet aperture therein, the chassis supporting a supply of a fluid substance, a duct carrying the fluid substance from the supply to the interior of the hollow shaft via a first rotary valve, at least one further duct rotatable with the or each plate to carry the fluid substance from the interior of the hollow shaft to the or each hollow tine via a second rotary valve, a flow control valve in said further duct rotatable with the or each plate, an actuator on said flow control valve, and an abutment connected to the chassis to engage said actuator at a rotational position of the or each plate thus to cause said fluid substance to be released by said flow control valve into the associated hollow tine at a predetermined point in the penetration cycle of said tine.

A plurality of said hollow tines may be mounted on the or each plate at angularly spaced positions thereon, each having a respective further duct connected to said second rotary valve, and a respective flow control valve and actuator.

The fluid substance supply may be a compressor/pump to deliver air to the hollow shaft.

A plurality of said plates may be mounted on said chassis for rotation of the hollow driven shaft and axially spaced along said shaft, each having a plurality of said hollow tines extending outwardly thereof in a generally radial direction.

Each said tine may extend from its associated plate at an angle displaced from a radius thereof, towards a tangent thereto.

The or each tine may be pivotally mounted on its associated plate thus, in use, to penetrate and leave the ground at a near-vertical attitude.

The flow control valve in said further duct may be a poppet valve having said actuator resiliently mounted thereon.

The abutment may be adjustably mounted on the chassis thus to determine the rotary position of the or each plate at which the flow control valve is actuated by the actuator.

The outlet aperture may be located in a distal end region of the or each tine.

The or each tine may be substantially flat in cross-section and of tapering form towards said distal end region.

The or each tine may be of circular cross-section.

The chassis may be adapted for attachment to a towing vehicle and may be raised or lowered with respect to the ground.

The or each plate may be driven in rotation by passage of the chassis along the ground and penetration of the ground by the or each tine.

The or each plate may be driven in rotation by drive means mounted on or connected to the chassis.

The compressor/pump may be driven by drive means mounted on or connected to the chassis.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. I is a side view of a rotary ground aerator made in accordance with the invention; and Fig. 2 is a view similar to Fig. 1 but illustrating a part of the mechanism of the aerator for delivering a fluid substance to a ground-penetrating tine mounted on the aerator.

Referring now to the drawings, the rotary ground aerator comprises a chassis 13 which is adapted to be connected to and towed by a towing vehicle (not shown). The chassis 13 is pivotally connected by linkages 16 and 17 so that it may be raised or lowered on the towing vehicle with respect to the ground surface 18.

A hollow driven shaft 19 (see Fig. 2) is mounted on support bearings 14 on the chassis 13 and is thus freely rotatable thereon. Mounted at axially spaced positions on the shaft 19 are a plurality of circular plates 15 each having attached thereto a plurality of tines 10 which extend generally radially outwards from their respective plate 15 thus to penetrate the ground, as can be seen in the drawings, as the chassis 13 is drawn in the direction of arrow 20. This has the effect of rotating the plates 18 and the shaft 13.

It will be seen that the tines 10 extend from the plates 15 in a direction which is angularly displaced from a radial direction towards a tangent thereto. This aids penetration of the tine tips in hard ground.

As can be seen from Fig. 2, each tine 10 is of hollow form defining an internal passage lOa with an outlet aperture 11 in a distal end region of the tine.

A compressor or pump 2 with an air inlet I is driven, preferably by drive means mounted on the towing vehicle, or alternatively electrically driven from a motor mounted on the chassis 13, in order to produce a supply of compressed air to be fed into a feed pipe 3 having a control tap 4 therein. The feed pipe 3 delivers the air via a rotary valve 5 into the interior of the hollow shaft 19. The air delivery into the shaft may be continuous or intermittent as required.

Mounted on each plate 15 and associated, each with one of the tines 10, are a plurality of flow control valves 7. These are poppet valves and rotate with the associated plate 15 while connected via a supply duct 9 to a second rotary valve 6 thus to receive the air supply from the hollow shaft 19.

For simplicity there is shown only a single valve 7 connected via a single duct 9 to the internal passage lOa of one of the tines 10, but each tine has its associated supply duct 9 and control valve 7.

Mounted resiliently on each flow control valve 7 is a spring loaded actuator 21 which, at a certain rotational position of the plate 15 engages a fixed abutment 8 attached to the chassis 13, thus to open the control valve 7 to allow a pulse of air from the hollow shaft 19 to enter, via the duct 9, the internal passage I Oa of one of the tines 10, the air issuing from the aperture 11 into the ground substantially at its lowermost point in its penetration cycle.

Thus, each hollow tine is supplied with a pulse of compressed air at its maximum point of penetration by the action of the associated actuator 21 engaging the abutment 8 during rotation of the plates 15.

The abutment 8 is adjustably mounted on the chassis thus to determine the exact position at which each tine is supplied with its pulse of compressed air.

It is not intended to limit the invention to the above example only. For example, the tines may be of circular cross-section and they may be pivotally mounted on their respective plate 15 thus to penetrate the ground at a near-vertical attitude. In this example, each tine would have a permitted pivotal angle to both sides of a radius to the associated plate 15.

A reservoir containing a liquid substance may replace or be provided in addition to the pump/compressor 2 thus to supply, for example, a liquid fertiliser to each hollow tine for injection into the ground.

Claims

1. A rotary ground aerator comprising a chassis, one or more rotatable plates mounted, spaced apart, along a hollow driven shaft attached to said chassis for rotation thereon, the or each plate having at least one tine extending outwardly from an edge region of the plate for penetration of the ground upon rotation of the plate and being of hollow form defining an internal passage with an outlet aperture therein, the chassis supporting a supply of a fluid substance, a duct carrying the fluid substance from the supply to the interior of the hollow shaft via a first rotary valve, at least one further duct rotatable with the or each plate to carry the fluid substance from the interior of the hollow shaft to the or each hollow tine via a secondary rotary valve, a flow control valve in said further duct rotatable with the or each plate, an actuator on said flow control valve, and an abutment connected to the chassis to engage said actuator at a rotational position of the or each plate thus to cause said fluid substance to be released by said flow control valve into the associated hollow tine at a predetermined point in the penetration cycle of said tine.

2. A rotary ground aerator according to claim 1 wherein a plurality if said hollow tines are mounted on the or each said plate at angularly spaced positions thereon, each having a respective further duct connected to said second rotary valve, and a respective flow control valve and actuator.

3. A rotary ground aerator according to claim 1 or claim 2 wherein the fluid substance supply is a compressor/pump to deliver air to the hollow shaft.

4. A rotary ground aerator according to any preceding claim including, on said chassis, and mounted for rotation on the hollow driven shaft, a plurality of said plates axially spaced along said shaft, each having a plurality of said hollow tines extending outwardly thereof in a generally radial direction.

5. A rotary ground aerator according to claim 4 wherein each said tine extends from its associated plate at an angle displaced from a radius thereof, towards a tangent thereto.

6. A rotary ground aerator according to any preceding claim wherein the or each tine is pivotally mounted on its associated plate thus, in use, to penetrate and leave the ground at a near-vertical attitude.

7. A rotary ground aerator according to any preceding claim wherein the flow control valve in said further duct is a poppet valve having said actuator resiliently mounted thereon.

8. A rotary ground aerator according to any preceding claim wherein the abutment is adjustably mounted on the chassis thus to determine the rotary position of the or each plate at which the flow control valve is actuated by the actuator.

9. A rotary ground aerator according to any preceding claim, wherein the outlet aperture is located in a distal end region of the or each tine.

10. A rotary ground aerator according to any preceding claim wherein the or each tine is substantially flat in cross-section and of tapering width towards said distal end region.

11. A rotary ground aerator according to any preceding claim wherein the or each tine is of circular cross-section.

12. A rotary ground aerator according to any preceding claim wherein the chassis is adapted for attachment to a towing vehicle and may be raised or lowered with respect to the ground.

13. A rotary ground aerator according to any preceding claim wherein the or each plate is driven in rotation by passage of the chassis along the ground and penetration of the ground by the or each tine.

14. A rotary ground aerator according to any one of claims 1 to 12 wherein the or each plate is driven in rotation by drive means mounted on or connected to the chassis.

15. A rotary ground aerator according to claim 3 wherein the compressor/pump is driven by drive means mounted on or connected to the chassis.