GB2144961A

GB2144961A - Aerator of power drive type

Info

Publication number: GB2144961A
Application number: GB08322249A
Authority: GB
Inventors: Masutoshi Kotani
Original assignee: Iwatani Corp; Iwatani Sangyo KK
Current assignee: Iwatani Corp
Priority date: 1983-08-12
Filing date: 1983-08-18
Publication date: 1985-03-20
Also published as: FR2550416A1; AT383457B; GB8322249D0; FR2550416B1; ES8406142A1; DE3329136A1; ES525050A0; ATA291183A; GB2144961B; NL8302856A

Abstract

A power driven soil aerator comprises a spike pipe 5, a reservoir 2 of compressed air to be supplied through the spike into the soil, a compressed air path 15 formed in the spike pipe, a shut-off valve 16 intercepting the compressed air path to control the air supply into soil therethrough and a power driving device 3 for driving the spike pipe into soil; the power driving device is comprised of air actuator such as an air hammer, air motor or the like. <IMAGE>

Description

SPECIFICATION Aerator of power drive type The present invention relates to an aerator for cultivation .

It is known to provide a spike pipe to be stabbed into soil, a tank for reserving compressed air to be supplied into soil, a compressed air path formed in the spike pipe and a shut-off valve intercepting the compressed air path to control the air supply into soil therethrough. Such an arrangement is described in West German Patent No.

27 16 456 in the name of the present inventor.

However, in this prior art the spike pipe is to be hand-driven by the use of the weight of the compressed air tank. Hence it is difficult to drive the spike deep enough into soil when the surface of the ground is hard.

It is a primary object of the present invention to overcome the above shortcoming.

For accomplishment of this object the driving device of the aerator of the invention consists essentially of air actuator comprising air hammer, air motor or the like.

A second object of the present invention is to make the prior art counterpart smaller and compacter in general structure.

For accomplishment of this second object a driving air path for supplying compressed air to the driving device is, according to the present invention, branched from an air inducing path to the above-mentioned tank.

In a preferred embodiment of the present invention the above-mentioned tank is to be provided with a pressure gauge for measuring its internal pressure, and this pressure gauge is preferably attached to the side wall of the tank. Thus, the risk of damage of the pressure gauge due to reaction of the air hammer is precluded and, moreover, the overail height of the aerator can be reduced.

The air tank is also provided with a safety valve, which may preferably be mounted low on the side wall of the air tank lest the compressed air possibly gushing out thereof should be directed at the operator's face, this being also advisable for keeping the aerator's overall height small.

This invention will be more clarified and understood deeper in the following detailed description of a preferred embodiment thereof referring to the accompanying drawings.

In the accompanying drawings: Figure 1 is a front view of an embodiment of the present invention, Figure 2 is a plan view thereof, Figure 3 is a vertical sectional view taken along line lil-lil of Fig. 2.

The illustrated aerator of power drive type comprises a compressed air tank 2 with a lateral pair of handles 1 attached thereto, a power driving device 3 comprising an air hammer thereunder adapted to be vertically displaceable by means of a guide sleeve 4 and a spike pipe 5 fixedly connected to the bottom of the power driving device 3.

The power driving device 3 consists essen tially of an air hammer using compressed air drawn from a compressed air source (not shown) via a connector 6 under the inner end of the right handle 1, but it may as well be an 'air motor.

There is provided a drive control lever 7.

,The drive control valve 8 shown in Fig. 3 is opened when this lever 7 is pushed down and compressed air is supplied through the driving air path to the power driving device 3.

from the power driving device 3 is discharged to atmosphere through an exhaust air cham ber 11 formed in a casing 1 0.

An inlet path 1 2 as a communicating means between the connector 6 and the com pressed air tank 2 is on-off controlled by an inlet valve (not shown). This inlet valve is of the same construction as the drive control valve 8 and is located in front thereof.

Numeral 1 3 designates an inlet valve lever.

A shut-off valve 16 provided in an com pressed air path 1 5 connecting the bottom of the compressed air tank 2 with a nozzle hole 1 4 near the lower-end of the spike pipe 5 is manually operable, and is arranged on one side of the power driving device with its casing being integral with the casing 1 0 of the power driving device 3. Low in a valve chamber 1 7 there is set an valve seat 1 8 made of a corrosion- and wear-resistant metal.

A ball valve 19 comes into contact with this valve seat 1 8 from the upstream side and it is then biased in the closed position by the closing spring 20 loaded in the upper part 1 7a of the valve chamber 17. The upper end of a valve stem 21a of a valve operating system 21 runs vertically through the center of the ball valve 1 9, that is, screwed into the ball valve 19, and the ball valve 1 9 and the valve stem 21a is connected by a pin 21b.

The valve stem 21 a runs through the casing to be freely slidable therethrough, extending downward therefrom, and is pin-connected toward one end of a intermediate lever 21c The intermediate lever 21c is pinned at one end to the casing, to the other end thereof is connected one end of the release wire 21e via connecting piece 21d, and the other end of the release wire 21 e is connected to a supply control lever 21f. The supply control lever 21f is pivoted freely swingable on the topside of the handle 1.When the supply control lever 21f is pressed down manually, the intermedi ate lever 21 c is swung upward via the release wire 21 e with the fulcrum pin 21 h as the centre and the ball valve 1 9 is pushed up by the valve stem 21a against the closing spring 20 into the open position. Compressed air is led out of the compressed air tank 2 through a conduit pipe 1 5a leading downward from the bottom of the tank 2 into the casing to be slidable therein and past the valve chamber 1 7 into an annular chamber 1 sub surrounding a shaft sleeve 3a and thence through holes in the wall of the shaft sleeve 3a into the compressed air path in the spike pipe 5.In order to minimize the air passage resistance in the shut-off valve 1 6 to prevent undue drop of compessed air pressure in the compressed air path 15, the valve chamber 1 7 and the compressed air path 1 5 upstreams and downstreams thereof are dimensioned sufficiently big. At the same time the configuration of the valve 1 9 is made spherical with its surface convex on both upstream and downstream sides for minimized air passage resistance.

As the material of ball valve 1 9 is used polyacetal resin (trade name Juracon) of outstanding wear- and corrosion resistance, but it may be made of any other synthetic resin or a metallic material such as stainless steel.

When this aerator is used for aerating the soil at the root of a fruit tree, street tree or the like, first the drive control lever 7 is operated to supply compressed air through the compressed air supply path 9 to the cushion chamber 9a and the power driving device 3, impact is applied to the tip of the spike pipe 5 through the valve 3b of the air hammer, and as the compressed air pressure in the cushion chamber 9a is applied to the top face of the piston rod 22 and piston 22a so that the piston rod 22 is pressed down in the guide sleeve 4, the impact from the air hammer being absorbed, and the spike pipe 5 is stabbed into the soil as the aerator as a whole is worked downward.Thus, when the aerator has been worked down to where a cover plate 23 has come into contact with the ground surface, an inlet valve opening lever 1 3 is operated to accumulate compressed air in the compressed air tank 2, and then operate the supply control lever 21 f, the shut-off valve 1 6 is rapidly opened, and the compressed air in the compressed air tank 2 is caused to be let through the compressed air path 1 5 and the nozzle holes 14 into the soil around the spile pipe 5 for cultivation of soil through smashing thereof by its jetting force.

When the supply control lever 21f is released, the closing spring 20 urges the ball valve 1 9 to close it and the supply control lever 21f is restored to the original position by means of the release wire 21 e.

Numeral 24 designates a safety valve and 25 a pressure gauge.

The safety valve 24 is provided to the bottom wall of air tank 2 lest the compressed air possibly gushing out therefrom should be derected to the operator's face. And this is more advantageous in making aerator small than that the safety valve is provided at the top of the air tank 2.

The pressure gauge 25 is provided to the side wall of the air tank 2, to avoid damage to the gauge from the reaction of the air hammer. The connecting tube of the pressure gauge 25 serves to absorb the oscillation transmitting from the air hammer through the air tank 2.

Claims

1. An aerator of power drive type, having a vertical spike pipe to be stabbed into soil, a power drive device for driving said spike pipe into soil, a compressed air tank connected to said spike pipe, an air supply path formed in said spike pipe and communicated to said tank, and a shut-off valve intercepting said air supply path to control the air supply into soil therethrough, said power driving device being provided to said spike pipe at the upper part thereof, and consisted of air actuator accompanying a drive air path branched out from the air induction path of said tank to said power driving device.

2. An aerator of power drive type as recited in claim 1, wherein said tank is provided with a pressure gauge at the lateral side thereof.

3. An aerator of power drive tyye as recited in claim 1 or claim 2, wherein said tank is provided with a safety valve at the bottom thereof.

4. A soil aerator comprising a hollow spike arranged to be percussively driven at its upper end by means of a pneumatic hammer disposed in a support common to the spike and hammer, and means for supplying compressed air to the spike to provide aeration jets from the lower end thereof.