WO2007069017A2

WO2007069017A2 - Plant uprooting implement

Info

Publication number: WO2007069017A2
Application number: PCT/IB2006/003530
Authority: WO
Inventors: Charles Richard Venables
Original assignee: Charles Richard Venables
Priority date: 2005-12-13
Filing date: 2006-12-08
Publication date: 2007-06-21
Also published as: WO2007069017A3; ZA200805082B; WO2007069021A1; ZA200806794B

Abstract

A plant uprooting implement (1) is provided comprising a first stem engaging formation (10, 19), an operating lever (2, 15), and a ground engaging fulcrum (3) about which the first stem engaging formation can be operatively raised by manipulating the operating lever. The fulcrum is in the form of a rocker configured to rotate in unison with the operating lever such that, in use, the distance between a lowermost ground engaging part of the rocker and a plant stem (13, 18) increases as the first stem engaging formation rises. A second stem engaging formation (12) is carried on a pivotally mounted arm (11) with the pivotal mounting being spaced operatively upwards of the ground engaging part of the rocker such that engagement of the second stem engaging formation with a stem on a side thereof opposite the first stem engaging formation, in use, urges the second stem engaging formation towards the first stem engaging formation to operatively clamp the stem therebetween.

Description

PLANT UPROOTING IMPLEMENT

FIELD OF THE INVENTION

This invention relates to a plant uprooting implement that is particularly suitable for use in uprooting young as well as moderately well-developed trees or other plants such as may constitute alien vegetation but that may also be used for uprooting any other unwanted plants that have a root structure conducive to removal by such a technique.

The invention relates to both manually operable implements and implements that may be operated by a vehicle to which they are attached, typically, a tractor.

BACKGROUND TO THE INVENTION

A number of different uprooting implements have been proposed and used in the past, most of these being manually operable. Typically, such as in the case of my earlier US patent 4,462,918; US patent 4,856,759; US patent

5,743, 340; and international patent publication number WO 00/21352, a manually operable lever is provided with a pair of jaws at one end that are arranged to grip the stem of a tree or other plant at generally diametrically opposite positions with progressively increasing force as the lever is rotated about a fulcrum offset from the jaws. In the case of the last of these applications, the entire force transmitted from the lever to the fulcrum is transmitted through the stem gripped by the jaws in order to rotate the fulcrum. In each instance, as the jaws are lifted about the fulcrum, the plant is uprooted. Using such a device can result in the stem being crushed by somewhat excessive force being required to operate the implement to initiate uprooting. US patent 6,213,527, on the other hand, employs a Vee-shaped claw as a primary stem engaging element with the fulcrum being defined by an opposite edge of an elongate head attached at right angles to a lever. A secondary gripping extension is apparently found to be necessary for holding the plant stem in the claw. Engaging such an implement with the stem of a plant in the manner suggested in the patent could be difficult and tedious and would only be appropriate to rather thin flexible stems and not a somewhat more developed plant such as a young tree.

My own later international patent publication number WO 2004/082364 also proposes a Vee shaped stem engaging formation with a rocker shaped fulcrum such that the fulcrum moves away from the stem of the plant progressively from a position in which a large mechanical advantage and small movement is achieved to one in which diminished mechanical advantage and larger movement is achieved. However, the engagement of the stem of the plant is not always satisfactory with the arrangement described in my earlier patent application.

OBJECT OF THE INVENTION

It is an object of this invention to provide a plant uprooting implement that utilises the concept of my said later patent application whilst providing for enhanced engagement of the stem of a plant to be uprooted.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided a plant uprooting implement comprising a first stem engaging formation, an operating lever, and a ground engaging fulcrum about which the first stem engaging formation can be operatively raised by manipulating the operating lever and wherein the first stem engaging formation, operating lever and ground engaging fulcrum are all rotatable in unison, and wherein the fulcrum is in the form of a rocker configured to rotate in unison with the operating lever such that, in use, the distance between a lowermost ground engaging part of the rocker and a plant stem increases as the first stem engaging formation rises; and a second stem engaging formation movable towards and away from the first stem engaging formation to operatively clamp the stem between the first and second stem engaging formations; the implement being characterised in that the second stem engaging formation is carried on a pivotally mounted arm with the pivotal mounting being spaced operatively upwards of the ground engaging part of the rocker such that engagement of the second stem engaging formation with a stem on a side thereof opposite the first stem engaging formation, in use, urges the second stem engaging formation towards the first stem engaging formation to operatively clamp the stem therebetween.

Further features of the invention provide for the first plant engaging formation to have a series of gripping formations such as ridges formed thereon; for the second plant engaging formation to be configured to contact the stem of a plant at a position above that at which the first plant engaging formation operatively engages a stem; for the second plant engaging formation to be of a shallow Vee shape with the bottom of the Vee operatively remote from the first plant engaging formation to provide convergent stem engaging edges adapted to engage the stem of a plant effectively; for the stem engaging edges of the second plant engaging formation to decrease in thickness towards the edges so as to promote operative biting thereof into the stem of a plant; for the rocker to be made of a suitable metal plate optionally bent to an arcuate configuration or composed of a series of flat plate sections following the general shape of an arc, in each case, with an operatively generally horizontal axis; and for the arcuate shape of the rocker to follow generally the shape of a geometric involute in side elevation starting from approximately the region of the first plant engaging formation. In the context of this invention the plant uprooting implement may be manually operable in which case the operating lever is configured as a handle at its operatively upper end and optionally has, at its upper end, a curved shape with the curve being located on the operatively trailing side of the operating lever to facilitate manipulation thereof when the operating lever has been moved to a near horizontal position in close proximity to the ground.

In accordance with a second aspect of the invention there is provided a plant uprooting implement suitable for operation by a vehicle such as a tractor wherein the free end of the operating lever is pivotally attached to one end of an elongate link having a remote controlled end configured for attachment to a vehicle.

Further features of this aspect of the invention provide for the controlled end of the elongate link to be configured for attachment to a three point hitch of a tractor; for the operating lever to be spring biased relative to the elongate link to return the operating lever to a starting position relative to the elongate link; and for the operating lever to be inclined to the horizontal in said starting position whilst preferably being generally upright.

In the case of either aspect of the invention, the pivotally mounted arm may also be pivotally movable about an axis at right angles to that allowing movement of the second plant engaging formation towards and away from the first plant engaging formation so that the second plant engaging formation can be swung laterally out of the way as the first plant engaging formation is moved towards a stem of a plant. The arm can thereafter be swung back into its operative position in which it is on the opposite side of a stem relative to the first plant engaging formation. In order that the above and other features of the invention may be more fully understood different embodiments thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a perspective view of the plant engaging head of a first embodiment of the invention, being a manually operable embodiment;

Figure 2 is a front elevation thereof showing the second plant engaging formation raised relative to the first plant engaging formation;

Figure 3 is a side elevation of the plant engaging head of the embodiment illustrated in Figures 1 and 2;

Figure 4 is a side elevation of the lower part of the implement showing the implement in a starting position preparatory to uprooting a tree or shrub;

Figure 5 is a side elevation similar to Figure 4 showing the implement fully engaged with stem of the tree or shrub;

Figure 6 is a side elevation similar to Figure 5 showing the tree being uprooted and showing the full length of the manually operable operating lever;

Figure 7 is a side elevation of a second embodiment of the invention that is adapted for fitment to, and operation by, a tractor, with the implement being engaged with a tree trunk ready for uprooting thereof;

Figure 8 is a view similar to Figure 7 showing the tree the process of being uprooted;

Figure 9 is a view similar to Figure 8 showing the tree fully uprooted;

Figure 10 is an oblique projection of an alternative arm arrangement for supporting the second plant engaging formation in particular, but not exclusively, for application to a tractor operated embodiment of the invention;

Figure 11 is a schematic plan view illustrating the operation of the variation illustrated in Figure 10;

Figure 12 is similar to Figure 11 but illustrates a further variation in which two arms and second plant engaging formations are provided;

Figure 13 is a side elevation of one form of arm and second plant engaging formation;

Figure 14 is a side elevation of an alternative form of second plant engaging formation;

Figure 15 is a plan view of one form of arm and second plant engaging formation; and

Figure 16 is a plan view of a further alternative form of arm and second plant engaging formation. DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

In the embodiment of the invention illustrated in Figures 1 to 6 of the drawings, a plant uprooting implement, generally indicated by numeral (1), comprises a manually operable operating lever (2) to the operatively lower end of which is fixed an arcuate fulcrum rocker (3) that is conveniently made from two spaced metal plates (4) having a peripheral edge conforming substantially to that of a geometric involute.

The end of the lever is attached generally tangentially to the end (5) of the involute having the larger radius of curvature and an inclined reinforcing brace (6) connects an inner region of the involute to the handle at a position intermediate its ends (indicated by numeral (8)) so that a very strong composite lever is formed in the plane of the fulcrum rocker. A bearing plate (9) that follows the involute shaped edges of the metal plates (4) is secured thereto as a soil engaging surface.

The said other end (7) of the rocker has formed thereon a first plant engaging formation (10) that may simply assume the form of a flat surface with multiple parallel ridges, as illustrated particularly in Figures 1 and 3.

Pivotally attached to the rocker at a position radially inwards of the bearing plate is a freely rotatable, laterally offset arm (11) that has at its free end a transverse second plant engaging formation (12) that is shown particularly in Figures 1 and 2. The position of the pivot and the length the arm are selected such that the second plant engaging formation may be swung towards and away from the first plant engaging formation. The arrangement is such that a stem or trunk (13) positioned between plant engaging formations, and with the operating lever extending generally vertically, the second plant engaging formation is generally located above the first plant engaging formation in the vertical direction. This is shown clearly in Figures 4 and 5. In use, the handle can be manipulated so that the stem (13) of a sapling or other plant can be used to lift the arm (11) with the second plant engaging formation contacting the stem. The implement can then be moved sideways so that the first plant engaging formation is located on the opposite side of the stem and below it. With the bearing plate contacting the soil, and the operating lever extending generally vertically, the lever can be rotated about the rocker bearing surface progressively from the position illustrated in Figure 4 to that in illustrated in Figure 5 and finally to that illustrated in Figure 6, thereby uprooting the sapling as shown.

It will be understood that with the arrangement described above, the involute shaped bearing surface contacts the soil initially in a region corresponding with a smaller radius of curvature located closer to the stem to provide a very much enhanced mechanical advantage to initiate uprooting. This is enhanced considerably by the fact that the second plant engaging formation is positioned above the first plant engaging formation which provides an added twisting force to the stem as it is urged upwards. The result is a very much facilitated uprooting action. As the plant's roots are loosened utilizing this enhanced mechanical advantage so the fulcrum point moves towards the end of the bearing surface remote from the stem which increases the extent of the vertical lift and twist being applied to the stem in order to pull the roots reasonably clear of the soil.

Turning now to the embodiment of the invention illustrated in Figures 7 to 9 the drawings, substantially the same arrangement as is described above can be made on a larger and more robust scale for operation by a tractor (14).

The main difference in this case is that the upper end of the operating lever

(15) is pivotally attached to an elongate link (16) that connects it to the three point hitch (17) of the tractor. In use, the removal of a tree (18) takes place in an analogous manner to that described above with the elongate link and operating lever opening out during the procedure to a generally horizontal, extended condition as shown in Figure 9. In order to facilitate the location of the second plant engaging formation (19) (see Figures 10 and 11) it is carried at the end of a pivotally mounted arm (20) that itself is permitted, by means of a second pivot (21) having its axis at right angles to the first pivot (22), to swing upwards and downwards. The second pivot enables the arm (20) to be swung laterally outwards so that the tractor can be reversed into position with the first plant engaging formation against the trunk of the tree after which the arm is swung back to a position in which the second plant engaging formation is located behind trunk. An eye (23) may be provided on the free end of the arm so that a flexible cable or the like can be attached thereto in order to facilitate remote operation of the arm in the manner indicated above.

It will be understood that the second plant engaging can be configured in any suitable manner to enhance engagement thereof with the stem and, as a general rule, it is considered to be sufficient to provide a reasonably thin contact edge (24), as shown in Figure 13, that can bite into the stem, at least to some extent, to provide purchase on stem. Alternatively, an arcuate jaw (25) having a series of stem engaging ridges may be fixed to the arm, as shown in Figure 14. Also, the operative edge of the second plant engaging formation could be serrated, as indicated by numeral (26) in Figure 15 and it could either be of concave arcuate shape, as indicated by numeral (27) in Figure 15, or of shallow Vee-shape, as indicated by numeral (28) in Figure 16. Any other suitable grip enhancing configuration may also be employed.

Numerous variations may be made to the embodiments of the invention described above without departing from the scope hereof. Simply by way of example, in the instance of the laterally pivotable arm described with reference to Figures 10 and 11, a second oppositely movable pivot able arm (29) may be provided, as shown in Figure 12. Numerous other variations are possible within the scope of the invention.

Claims

CLAIMS:

1. A plant uprooting implement (1) comprising a first stem engaging formation (10, 19), an operating lever (2, 15), and a ground engaging fulcrum (3) about which the first stem engaging formation can be operatively raised by manipulating the operating lever and wherein the first stem engaging formation, operating lever and ground engaging fulcrum are all rotatable in unison, and wherein the fulcrum is in the form of a rocker configured to rotate in unison with the operating lever such that, in use, the distance between a lowermost ground engaging part of the rocker and a plant stem (13, 18) increases as the first stem engaging formation rises; and a second stem engaging formation (12) movable towards and away from the first stem engaging formation to operatively clamp the stem between the first and second stem engaging formations; the implement being characterised in that the second stem engaging formation is carried on a pivotally mounted arm (11) with the pivotal mounting being spaced operatively upwards of the ground engaging part of the rocker such that engagement of the second stem engaging formation with a stem on a side thereof opposite the first stem engaging formation, in use, urges the second stem engaging formation towards the first stem engaging formation to operatively clamp the stem therebetween.

2. A plant uprooting implement as claimed in claim 1 in which the first plant engaging formation has a series of gripping formations formed thereon.

3. A plant uprooting implement as claimed in either one of claims 1 or 2 in which the second plant engaging formation is configured to contact the stem of a plant at a position above that at which the first plant engaging formation operatively engages a stem.

4. A plant uprooting implement as claimed in any one of the preceding claims in which the operative edge of the second plant engaging formation has a shaped selected from an arcuate shape (27) and a shallow Vee shape (28) with the bottom of the Vee operatively remote from the first plant engaging formation to provide convergent stem engaging edges adapted to engage the stem of a plant effectively.

5. A plant uprooting implement as claimed in any one of the preceding claims in which the stem engaging operative edge of the second plant engaging formation decreases in thickness towards the edge so as to promote operative biting thereof into the stem of a plant.

6. A plant uprooting implement as claimed in any one of the preceding claims in which the rocker is made of a suitable metal plate (9) bent to an arcuate configuration with an operatively generally horizontal axis with the arcuate shape of the rocker following generally the shape of a geometric involute in side elevation starting from approximately the region of the first plant engaging formation.

7. A plant uprooting implement as claimed in any one of the preceding claims in which the plant uprooting implement Is manually operable with the operating lever being configured as a handle at its operatively upper end.

8. A plant uprooting implement as claimed in claim 7 in which the handle has, at its upper end, a curved shape with the curve being located on the operatively trailing side of the operating lever.

9. A plant uprooting implement as claimed in any one of claims 1 to 6 in which the implement is suitable for operation by a vehicle wherein the free end of the operating lever (15) is pivotally attached to one end of an elongate link (16) having a remote controlled end configured for attachment to a vehicle.

10. A plant uprooting implement as claimed in claim 9 in which the controlled end of the elongate link is configured for attachment to a three point hitch of a tractor.

11. A plant uprooting implement as claimed in either one of claims 9 or 10 in which the operating lever is spring biased relative to the elongate link to return the operating lever to a starting position relative to the elongate link.

12. A plant uprooting implement as claimed in any one of the preceding claims in which the pivotally mounted arm (20) is also pivotally movable about an axis at right angles to that allowing movement of the second plant engaging formation towards and away from the first plant engaging formation so that the second plant engaging formation can be swung laterally out of the way as the first plant engaging formation is moved towards a stem of a plant.