AU718751B3

AU718751B3 - Soil sampling device

Info

Publication number: AU718751B3
Application number: AU35836/99A
Authority: AU
Inventors: David Ronald York
Original assignee: WESTDEEN HOLDINGS Pty Ltd
Current assignee: WESTDEEN HOLDINGS Pty Ltd
Priority date: 1999-06-24
Filing date: 1999-06-24
Publication date: 2000-04-20
Anticipated expiration: 2005-06-24

Description

SOIL SAMPLING DEVICE The invention is a hand-held soil sampling device used primarily to investigate the nutrient and pH status of agricultural soils. The invention is designed to extract discrete samples of soil from the ground, to three or more predetermined depths, without removing the device from the ground.

In order to determine the suitability of a particular plot of land for various agricultural, viticultural, horticultural or silvicultural purposes, it is necessary to extract soil samples for analysis. Results from this analysis are used to determine management practices such as the application of nutrients or lime to overcome deficiencies or to correct soil pH.

Soil sampling for agricultural purposes is usually done with the aid of a slightly tapered hand-held tubular device (commonly referred to as a "pogo stick") which is pushed into the ground using a foot lever. The accuracy of this device can vary depending on soil type. In light sandy soils there is a tendency for a portion of the sample to fall from the pogo stick as it is removed from the ground. In dry hard soils it is often difficult to penetrate to a predetermined nominal depth (typically 10 cm).

Because of these problems, it is common for insufficient numbers of samples to be taken, or individual cores may vary in depth, making accurate analysis of the soil sample difficult.

The deleterious effects of soil acidity on plant production are dependant on changes in soil pH through the soil profile at depths covering the major root zone. Collection of soil samples through the soil profile (typically 0-10cm, 10-20 cm and 20-30 cm) to analyse pH and mobile nutrient status is necessary. The conventional pogo stick does not allow quick, easy and accurate sampling of soils other than the surface topsoil (0 1 0cm), The present invention provides a hand-held soil sampling device that can quickly provide accurate and consistent discrete soil samples to three or more predetermined depths, without removing the device from the ground.

The invention comprises: An elongate hollow member with a solid shaft protruding through the centre of said member, parallel with its length.

Said solid shaft has a cutting bit designed to penetrate the ground fabricated on one end.

Preferably, said cutting bit is fabricated with tungsten carbide cutting faces.

Said elongate hollow member has a centralising bearing in one end near said cutting tip, to maintain said solid shaft in a central position along its length within said member.

The end of said member opposite said end near said cutting bit is fitted internally with two wear resistant bushes.

The end of said member opposite said end near said cutting bit is fitted with an adaptor sleeve for connection with a pneumatic drill, whereby on operation of said pneumatic drill, said shaft can rotate about an axis parallel to the direction of its length.

Said adaptor sleeve is fitted with pneumatic finger lever valves for the control of remote pneumatic devices Page 1 of 8 EDITORIAL NOTE FOR APPLICATION 35836/99 THE SPECIFICATION IS NUMBERED AS FOLLOWS 1 OF8 2 OF 3 OF CLAIMS (NO PAGE NUMBER) THERE IS NO ABSTRACT DRAWINGS PAGE 7 OF 8 AND 8 OF 8 Said elongate hollow member has an outlet opening branching from said hollow member, distant from said end near said cutting bit.

Said outlet opening features a venturi vacuum constructed within said outlet.

A sleeve fitted over said outlet opening forms a chamber, and is provided with an inlet for allowing compressed air to flow into said chamber.

Said chamber is configured so as to direct compressed air to flow through said venturi vacuum, creating a vacuum within said elongate hollow member causing soil to be lifted from the cutting tip to said outlet opening.

The compressed air, upon exiting the venturi, becomes a propulsion force, carrying with it soil extracted from the ground as a sample to a soil collection means.

Said elongate hollow member has an opening opposite said branched outlet opening, which is slidably covered by a curved shield. Exposure of said opening by sliding said curved shield causes a loss of vacuum within said hollow member, while still allowing the propulsion force to continue carrying the soil already extracted.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a cross sectional view of the soil sampling device, also showing the cutting tip description.

As shown in the accompanying drawings, Figure 1, a soil sampling device (1) for extracting discrete soil samples from the ground to three or more predetermined depths, comprises an elongate hollow member with a solid shaft protruding from its centre, and an outlet opening branching from the hollow member distant from the cutting end. The solid shaft is fitted with a fabricated cutting end (4) consisting of tungsten carbide cutting faces The hollow member is fitted with a centralising bearing near the cutting end and two polyurethane centralising bushes above the outlet opening A sleeve (10) is fitted over a length of the outlet opening and is configured so as to direct compressed air to flow from outside the sleeve (11) through communicating holes (16) toward end through a vacuum venturi When compressed air is caused to flow through the venturi it creates a low pressure area or vacuum at area lifting soil from the cutting end (12) and carrying the soil through the outlet opening thereby extracting a sample of soil. An opening (12) in the side of the hollow member is covered by a curved shield and is configured such that exposure of the opening (12) causes a reduction of vacuum within the hollow member and prevents further soil being lifted. A pneumatic drill (not shown) is connected to the solid shaft at the end opposite the cutting end and fixed to the elongate hollow member by an adaptor (not shown).

The operation of the soil sampling device will now be described.

The device is placed on the ground in a perpendicular position. A supply of compressed air (not shown) is connected to the pneumatic drill (not shown), the finger toggle switches (not shown), and the venturi vacuum device The pneumatic drill is operated so that the solid shaft rotates, causing the cutting bits to drill into the ground, allowing the hollow tube to penetrate the soil to a predetermined depth, controlled visually by the operator. A guide for depth determination is inscribed on the outside of the device. At the same time, compressed air entering through inlet flowing through chamber holes venturi (9) Sand exiting through outlet causes a vacuum to be created inside the hollow tube Page 2 The vacuum lifts the soil disturbed by the action of the cutting bit as it rotates, and carties the soil from the cutting end (12) through the venturi Upon exiting the venturi the compressed air then becomes a propulsion force at causing the soil to be blown through a connecting hose (not shown) towards a soil collection device (not shown). When the required depth of sampling has been reached, operation of the pneumatic drill is ceased by the operator, allowing the device to clear soil from within the hollow tube The operator has the option, once the desired depth has been reached, of moving a sliding cover (13) to expose a hole (12) in the side of the device This has the effect of reducing the vacuum within the hollow tube so that excess sample is not collected, while still allowing the venturi to deliver the soil already collected to the collection device (not shown).

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Claims

1. A soil sampling device for extracting a soil sample from the ground including: an elongate hollow member having an end adapted to penetrate the ground in use, an outlet opening remote from said end, a venturi vacuum device adjacent said outlet opening, and a sleeve accommodated on said device so as to provide a passageway adapted to direct compressed air, in use, to flow through the venturi vacuum device to cause a partial vacuum to be created within the hollow member and thereby effect soil sample extraction.

2. A soil sampling device according to claim 1, wherein said hollow member is provided with an aperture and the device further includes a sliding cover movable between a first position and a second position, whereby, in use, when the cover moves from the first position to the second position the aperture is progressively increasingly opened, thereby causing a progressive reduction in the volume of soil extracted. 1

3. A soil sampling device according to claimi or claim 2, further including cutting means disposed at said end, the cutting means being mounted on an elongate shaft extending through said member and the elongate shaft being rotatably mounted relative to said member. DATED THIS 22ND DAY OF FEBRUARY 2000. WESTDEEN HOLDINGS PTY LTD By their Patent Attorneys LORD COMPANY PERTH, WESTERN AUSTRALIA.