NZ565725A

NZ565725A - Stump grinder

Info

Publication number: NZ565725A
Application number: NZ565725A
Authority: NZ
Inventors: Bevan Phillup Olden
Original assignee: Bevan Phillup Olden
Priority date: 2005-05-11
Filing date: 2006-05-05
Publication date: 2009-10-30
Also published as: WO2006119547A1

Abstract

Disclosed is a stump grinding apparatus which includes a head with two ends, the head is adapted to be supported from a vehicle such that the longitudinal axis between the ends is generally parallel to the direction of travel of the vehicle. The head is further adapted to allow the head to be raised off the ground or lowered onto the ground. The head includes a set of cutters (15, 17, 19), each cutter having at least one cutting element which rotates about a central axis of the respective cutter to define a circular cutting path. A first cutter (15) is supported such that its central axis is transverse to the longitudinal axis of the head and a pair of second cutters (17, 19) extend perpendicularly to the first cutter. The cutting paths of the second cutters are proximate each other. A cutting zone is defined between the cutting paths of the second cutters and ahead of the cutting paths of the first cutter. Also disclosed is a vehicle having a stump grinding apparatus.

Description

565725 Stump Grinder Field of the Invention This invention relates to a means for grinding stumps.

Background Art Current procedures involved in grinding stumps comprises utilisation of a machine having a grinding disc where the outer edge of the grinding disc supports a set of cutters. In grinding the stump the edge of the grinding disc of the cutters is brought into engagement with the stump and the cutter is caused to reciprocate transversely across the stump to cause it to be ground to the desired depth within 10 the soil. This arrangement is quite satisfactory for grinding single stumps, however, in removing stumps from a plantation subsequent to harvesting of the plantation it is not an efficient procedure. The current practices in clearing stumps from a plantation site involve utilisation of machinery which serves to rip the stumps from the ground. Whilst this arrangement can be quite effective in 15 removing the stumps it leaves the site in an unsatisfactory form for future working without further treatment. This is because ground is pitted as a result of the removal of the stumps and as a result the ground requires treatment in order to render the ground suitable for agriculture and in order to prevent erosion and the collection of water.

It is an object of this invention to provide a stump grinder which addresses the aforementioned problems, or at least provide the public with an useful alternative.

Disclosure of the Invention Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to 25 imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. 565725 Accordirig to one aspect the invention resides in a stump grinding apparatus comprising a head adapted to be supported from a vehicle wherein the head has one end and another end, the head further adapted to be supported from the vehicle such that the longitudinal axis of the head between the ends is generally 5 parallel to the direction of travel of the vehicle with the one end rear-most relative to the direction of travel, the head adapted to be supported from the vehicle to enable the head to be moved into and out of engagement with the ground, the head supporting a set of cutters, wherein each cutter comprises at least one cutting element which is caused to rotate about a central axis of the respective 10 cutter to define a circular cutting path, a first cutter supported towards the one end such that its central axis is transverse to the longitudinal axis of the head, a pair of second cutters supported between the first cutter and the other end, the central axes of the second cutters being transverse to the central axis of the first cutter and to either side of the longitudinal axis of the head, the cutting paths of the 15 second cutters being proximate each other and the zone defined between the cutting paths of the second cutters being located ahead of the cutting path, of the first cutter.

According to a preferred feature of the invention the head is adapted to be pivotally mounted to the vehicle for movement about a pivot axis which is 20 substantially transverse to the head to cause the angle defined between the central axes of the second cutters and the ground to be varied.

According to a preferred feature of the invention the mounting of the head to the vehicle enables both the bodily displacement of the head relative to the ground and the angular displacement of the head relative to the ground.

According to a preferred feature of the invention the cutting path of the first cutter has a transverse extent relative to the longitudinal axis.

According to a preferred feature of the invention the cutting path of the second cutters have a longitudinal extent relative to the longitudinal axis. 565725 According to a preferred feature of the invention the cutting paths of the first and second cutters are substantially cylindrical.

According to a preferred feature of the invention the central axes of the second cutters are substantially parallel.

According to a preferred feature of the invention the spacing between the central axes of the second cutters can be varied.

According to a preferred feature of the invention the angle defined between the central axes of the second cutters can be varied.

According to a preferred feature of the invention the head is adapted to be mounted centrally on the vehicle to extend substantially centrally from the front of the vehicle. According to an alternative preferred feature of the invention the head is adapted to be mounted centrally on the vehicle to extend substantially centrally from the rear of the vehicle.

According to a preferred feature of the invention the cutters are overlaid by a protective shroud.

According to a preferred feature of the invention the apparatus comprises an attachment which can be installed onto the vehicle. According to an alternative preferred feature of the invention the apparatus comprises a part of the vehicle.

According to another aspect the invention resides in a vehicle having a stump grinding apparatus of the form as described above.

Brief Description of the Drawings The invention will be more fully understood in the light of the following description of several specific embodiments. The description is made accompanying drawings of which: 565725 Figure 1 is a schematic isometric view of the first embodiment in association with a tractor vehicle; Figure 2 is a schematic plan view of the cutting head according to the first embodiment; and Figure 3 is a set of illustrations which illustrate the action of the cutting head upon a stump; Figure 4 is a schematic isometric view of the second embodiment in association with a tractor vehicle; and Figure 5 is an illustrative elevation of the third embodiment of the invention in 10 association with tractor vehicle.

Detailed Description of Specific Embodiments The first embodiment as shown at Figures 1, 2 and 3 relates to a stump grinding head 11 which can be utilised to grind the stumps which are left behind subsequent to the harvesting of a tree plantation. The embodiment comprises a mounting which is adapted to support one end of the head 11 from the free ends of a pair of lifting arms 13 provided at the front end of a tractor vehicle 10 such that the head extends forwardly from the mounting in the direction of travel of the vehicle 10. The mounting enables pivotal movement of the head about a pivot axis which is transverse to the direction of travel of the vehicle.

In operation the vehicle 10 is caused to move along a row of stumps under the control of an operator with the row of stumps located centrally such that the wheels will pass to each side of the row of stumps. .bfy ijjfi, Iw & The head 11 comprises an elongate member which is supported from the mounting and includes a set of cutters 15, 17, and 19 which comprise a first cutter 5 which is mounted at the rear end of the head and takes the form of a cylindrical >dy supporting a set of first cutting elements where the body is rotatable about 565725 its central axis which is substantially transverse to the head 11 and is substantially parallel to the pivot axis. A pair of second cutters 17 and 19 are located forwardly of the first cutter. The second cutters each comprise cylindrical bodies having an outer face which supports a set of second cutting elements. In addition the 5 second cutters are supported from the head in spaced parallel relationship to each side of the central axis of the head such that their central axes are parallel to the central axis of the head and their cutting paths are closely spaced from each other. In addition the portions of the second cutting paths which are closely adjacent are located ahead of the cutting path of the first cutter. The spacing of 10 between the second cutters can be varied as desired. The cutters 15, 17, and 19 are each driven by a suitable drive means.

In use the head 11 is supported from a vehicle 10 which is driven such that when approaching a stump the forward end of the head comprises the leading portion of the apparatus. The head is then pivoted on the vehicle such that the first cutter is 15 located at a lowermost position where its lower surface defines the level to which the stumps are to be ground. When in that position the pair of second cutters 17 and 19 are inclined upwardly from that lowermost position. As the head is carried by the vehicle such that a stump enters into the space between the second cutters 17 and 19, each of the second cutters cut away a lateral portion of the stump to 20 the respective side of the stump such that on completion of the cutting action by the second cutters the upper surface of the stump has a pointed profile as illustrated at Figure 3B. With further movement of the cutting head relative to the stump the first cutter 15 is then brought into engagement with the remaining portion of the stump and subsequent to the action of the first cutter 15 the upper 25 portion of the stump is removed down to the desired level as defined by the lowermost extent of the cutting path of the first cutter as shown at Figure 3C.

It is envisaged that the apparatus according to the first embodiment will be able to be carried over a row of stumps and sequentially grind each of the stumps down a desired level. As a result of the circumstance that each of the cutters oves a portion of the stump only each cutter is able to more rapidly grind away tump in and as a result the grinding of each stump is effected jointly by each :er and consequently the grinding of the stump can be effected efficiently and 565725 rapidly, In addition, on completion of the grinding action all of the material which has been removed from the stump will remain resident in the vicinity of the stump and will ultimately breakdown to form a mulch. If desired the stumps can be ground to a level corresponding to ground level or a level above or below ground 5 level.

A second embodiment of the invention as shown at Figure 4 comprises a head of the same form as the first embodiment which is adapted to be supported from the rear of a vehicle though suitable support 13 which will permit the head can pivot from the vehicle about a transverse axis..

A third embodiment of the invention is illustrated at Figure 5 and is a variation of the first embodiment in that the embodiment is adapted to be supported from the from of the vehicle 10 though an articulated linkage 21 and a transverse pivot 13. The pivot is lowermost and the articulated linkage 21 incorporates an extendable fluid powered cylinder 23 which can be used to vary the inclination of the head 15 relative to the ground. In addition the head is associated with a protective shroud 25 which overlies the cutters and whereby the lower portion of the cutters extend beyond the lower edges of the shroud 25.

According to a fourth embodiment of the invention which is applicable to each of the first, second and third embodiments the head, is associated with an earth-20 working tool which will follow the cutting head and which will work the soil to leave it in a form which is desired for the purpose for which the ground is to be used subsequent to the grinding of the stumps. If the ground is to be utilised for the purposes of planting another plantation a mounding tool can be provided to provide a longitudinal mound into which seedlings can be deposited. Alternatively 25 a smoothing blade or tool can be utilised for levelling the ground subsequent to the action of the cutting head. &■ * \ 0 SEP ,Q.

According to a preferred feature of the invention the overall longitudinal extent of e cutting paths of the second and first cutters generally corresponds to the spacing between the stumps of a plantation in order that the cutters are in nstant engagement with a stump during their movement along a row of stumps. 565725 According to another embodiment the spacing between the outer ends of the second cutters can be varied.

It should be appreciated that the scope of the present invention need not be limited to the particular embodiments described in the above specification.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

The Claims Defining the Invention are as Follows:

1. A stump grinding apparatus comprising a head adapted to be supported from a vehicle, wherein the head has one end and another end, the head further adapted to be supported from the vehicle such that the longitudinal axis of the head between the ends is generally parallel to the direction of travel of the vehicle with the one end rear-most relative to the direction of travel, the head adapted to be supported from the vehicle to enable the head to be moved into and out of engagement with the ground, the head supporting a set of cutters, wherein each cutter comprises at least one cutting element which is caused to rotate about a central axis of the respective cutter to define a circular cutting path, a first cutter supported towards the one end such that its central axis is transverse to the longitudinal axis of the head, a pair of second cutters supported between the first cutter and the other end, the central axes of the second cutters being transverse to the central axis of the first cutter and to either side of the longitudinal axis of the head, the cutting paths of the second cutters being proximate each other and the zone defined between the cutting paths of the second cutters being located ahead of the cutting path of the first cutter.

2. A stump grinding apparatus as claimed at claim 1 wherein the head is adapted to be pivotally mounted to the vehicle for movement about a pivot axis which is substantially transverse to the head to cause the angle defined between the central axes of the second cutters and the ground to be varied.

3. A stump grinding apparatus as claimed at claim 1 or 2 wherein the mounting of the head to the vehicle enables both the bodily displacement of the head relative to the ground and the angular displacement of the head relative to the ground.

4. A stump grinding apparatus as claimed at claim 1 or 2 or 3 wherein the cutting ath of the first cutter has a transverse extent relative to the longitudinal axis. 565725 -9-

5. A stump grinding apparatus as claimed at any one of the preceding claims wherein the cutting path of the second cutters have a longitudinal extent relative to the longitudinal axis.

6. A stump grinding apparatus as claimed at any one of the preceding claims 5 wherein the cutting paths of the first and second cutters are substantially cylindrical.

7. A stump grinding apparatus as claimed at any one of the preceding claims wherein the central axes of the second cutters are substantially parallel.

8. A stump grinding apparatus as claimed at any one of the preceding claims wherein the spacing between the central axes of the second cutters can be varied.

9. A stump grinding apparatus as claimed at any one of 1 to 8 claims wherein the angle defined between the central axes of the second cutters can be varied.

10. A stump grinding apparatus as claimed at any one of the preceding claims wherein the head is adapted to be mounted centrally on the vehicle to extend substantially centrally from the front of the vehicle.

11. A stump grinding apparatus as claimed at any one of claims 1 to 9 wherein the head is adapted to be mounted centrally on the vehicle to extend substantially centrally from the rear of the vehicle.

12. A stump grinding apparatus as claimed at any one of the preceding claims wherein the cutters are overlaid by a protective shroud.

13. A stump grinding apparatus as claimed at any one of the preceding claims wherein the apparatus comprises an attachment which can be installed onto *v\;\the vehicle.;23®;A stump grinding apparatus as claimed at any one of claims 1 to 9 wherein the apparatus comprises a part of the vehicle.;565725;-10-;15. A stump grinding apparatus substantially as herein described with reference to the accompanying drawings.;16. A vehicle having a stump grinding apparatus of the form as claimed at any one of claims 1 to 8 and 12.;5;rgv*t«ty ^ 'if 1 0 SEP 2300