AU2007100010A4 - Improvements in weed extractors - Google Patents

Description

AUSTRALIA

Patents Action 1990 COMPLETE SPECIFICATION INNOVATION PATENT IMPROVEMENTS IN WEED EXTRACTORS The following statement is a full description of this invention, including the best method of performing it known to me:- IMPROVEMENTS IN WEED EXTRACTORS The present invention relates to improvements in hand operated Weed Extractors or Mechanical Weed Killers.

The invention is designed to conveniently remove unwanted broadleaf weeds and/or nuisance grasses with minimal disturbance to the preferred species of a lawn for example.

In particular, the invention is especially good at removing a broadleaf weed known in Australia as "Flatweed" which is relatively difficult to kill with conventional tools. As this particular weed's habit is to hug the surface of the ground, it is easy to simply rip off the leaves during attempted hand pulling, which often leaves the growing point intact, 1 thus allowing the weed to re-grow quickly. Alternatively a conventional hand hoe tends to cut off lawn or turf in a relatively large area adjacent to the nuisance weed or grass, to the detriment of the lawn or turf.

A variety of nuisance weeds that grow in fine lawns or turf can be 1O conveniently and effectively killed using this invention with minimal overall disturbance. The method involves severing the offending weed or grass in two, just below the growing point, thus effectively killing the weed or grass, but without actually removing the root system. The advantage is that the surrounding lawn or turf is disturbed minimally and the root system of the weed or grass becomes humus.

One preferred embodiment of the device as a hand operated rotary weeder implement is described with reference to the series of Figures numbered 1 through 4.

FIGURE 1 shows a stick human figure operating the weeder implement. The preferred design utilizes a substantially vertical bar or shaft with a substantially horizontal T bar handle or similar, attached to the top of the shaft for ease of use, so that the handle S can be twisted with one or two hands depending upon the hardness of the soil being penetrated, the nature of the weed and other factors. The base of the weeder comprises a spike or prong that can be plunged into the ground close to the offending weed or grass At or near the base of the shaft a sharpened cutting blade is set at preferred 140 and precise angles in 3 mutually perpendicular planes, to minimize the amount of effort required and to maximize the accuracy of the root cutting process. The position of the cutting blade tends to control the depth to which the implement is plunged into the soil. Due to the angles of the cutting blade a simple hand driven rotation of less A than of a rotation of the implement following judicious placement of the prong or spike allows the root system of the offending weed (4) to be cut easily and quickly. The actual height of the handle above ground level can be varied to suit the height of the operator's convenience. The prong or spike may be replaced with a more blunt arrangement to maximize safety aspects.

FIGURE 2 is an elevation view showing the sharpened blade set at "angle A" declining lengthwise from the horizontal.

SFIGURE 3 is an elevation view of the cutting blade at right angles to Figure 2, showing the sharpened blade set at "angle B" which is a lateral twist.

FIGURE 4 is a bottom view of the implement shows the sharpened O blade set at "angle c" relative to the handle Although the preferred embodiment utilizes a single cutting blade with blade set at precise preferred angles in 3 mutually perpendicular dimensions relative to the shaft the invention is not limited to this Sembodiment.