GB2293303A - Stump cutter - Google Patents

Abstract

A stump cutter comprises a chassis, an arm 21 having one end mounted on the chassis and the other end to the one end provided with a cutting wheel 23 characterised in that the chassis is in two parts; a first part 12 provided with ground engaging wheels or tracks adapted to displace the stump cutter at least in a first longitudinal direction with the stump cutter on horizontal ground; and a second part 15 on which the one end of the arm is mounted; the second part being adopted for pivotal movement about a vertical axis relative to the first direction on horizontal ground. The stump cutter can be provided with a prime mover adapted to power the cutting wheel either directly or by way of a power transmission means. The prime mover further serves to provide propulsive power to the ground engaging tracks. An anchoring means can be provided operable to engage the ground independently of the ground engaging tracks. <IMAGE>

Description

STUMP CUTLER This invention relates to a stump cutter. The term 'stump cutter' is used to describe a machine providing for the removal of the stumps of trees or other substantial ground growth of limited height.

Known types of stump cutter comprise a chassis with ground engaging wheels in the middle enabling the chassis to be moved in a longitudinal direction, an adjustable arm with a cutter wheel extends from one end of the chassis in the logitudinal direction and a counterweight is provided at the other end of the chassis. The chassis includes an engine providing a source of power for a hydraulic or belt drive system for the cutter wheel. This known type of machine is not usually self propelled and needs to be placed in position by means of a tractor or wheel drive vehicle. Once located with the cutter adjacent the stump an operator needs to stand by the machine and operate the controls.The arm mounting of the cutter wheel enables the cutter to be located alongside the stump and thereafter the wheel powered and driven across the stump or down into it so as to grind the stump into fragments. To this extent the arm is provided with a limited degree of angular movement on the chassis about the longitudinal axis.

Stump grinders are used in a wide variety of locations but where there are a number of stumps to be dealt with a considerable degree of skill frequently needs to be exercised to get the stump cutter into a location adjacent a stump. Current designs are not readily used on steep slopes or under very adverse ground conditions such as arise from prolonged rain or disturbance during initial construction operations.

The operator conventionally has to stand adjacent the stump cutter while operating it and has to maintain close observation of the cutter while in operation.

As a consequence operation of the machine can be stressful involving the exposure of the operator to adverse weather, noise, flying cut material, and location in the vicinity of a cutting wheel capable of inflicting serious, if not fatal, injury. In addition large scale stump clearance operations are generally carried out under time pressure in preparation for a subsequent operation such as building or road making to this end stump cutting operations have to be carried out quickly to meet a deadline. An ability to carry out a stump clearing operation promptly means that other methods must be used which themselves may adversely affect the ground in the vicinity of the stumps and involve a need for subsequent infilling or reclamation operations.

Further difficulties arise when the stump cutting operation has to be carried out on ground which has already been broken up by earlier operations. In such cases the onset of wet weather can render stump cutting impossible. Cutting can only be started when ground in the vicinity of a stump to be cut is stable enough to support the stump cutter in a position where the cutting wheel can be brought to bear on the stump. The situation is further complicated when the cutting operation has to be carried out on sloping ground. In such a situation the stable location of the stump cutter can be difficult, if not impossible, to achieve. Again adverse ground or weather conditions can delay matters.

According to the present invention there is provided a stump cutter comprising a chassis, an arm having one end mounted on the chassis and the other end to the one end provided with a cutting wheel characterised in that the chassis is in two parts; a first part provided with ground engaging wheels or tracks adapted for displacement at least in a first direction with the stump cutter on horizontal ground; and a second part on which the one end of the arm is mounted the second part being adopted for rotation about a vertical axis relative to the first direction on horizontal ground.

According to a first preferred version of the present invention the stump cutter is provided with a prime mover adapted to power the cutting wheel either directly or by way of a power transmission means. Typically the prime mover further serves to provide propulsive power to the ground engaging wheels or tracks.

According to a second preferred version of the present invention there is provided an anchoring means whereby once the stump cutter has been positioned in a working location the anchoring means is operable to engage the ground independently of the ground engaging wheels or tracks.

According to a third preferred version of the present invention or the first preferred version thereof there is provided a scraper blade or other attachment mounted on the stump cutter whereby material generated by the cutter can be displaced on movement of the ground engaging wheels or tracks. Typically such as blade or other attachment can be used as an anchor for the stump cutter when in use on a slope or as a means for raising one end of the machine to level the chassis.

According to a fourth preferred version of the present invention or any preceding preferred version thereof the chassis is equipped with a seated operating location for an operator of the vehicle provided with operating controls for the cutting wheel and controls for operating the ground engaging wheels or tracks.

An exemplary embodiment of the invention will now be describe with reference to the accompanying drawings, of a stump cutter according to the present invention, of which: Figure 1 is a side view; Figure 2 is a view from above; and Figure 3 is a view from beneath.

The figures variously show a stump cutter 10 with a chassis 11 made up of a lower section 12 on which are mounted tracks 13, 14 and an upper section 15 on which are mounted cutting and control units.

Lower section 12 has a longitudinal axis L and in addition to supporting the tracks 13, 14 carries a prime mover in the form of a diesel engine 16 coupled to a hydrostatic drive unit 17 providing power for driving the track 13, 14 and for other functions. Ring 18 serves to receive upper section 15 so that the upper section 15 can be driven by hydraulic motor 19 to rotate 360 about vertical axis V. Further means are provided to lock the upper section 15 in a selected angular alignment relative to lower section 12.

Upper section 15 supports inboard end 20 of arm 21 so as to enable the arm 21 to be pivoted vertically over vertical arc Av (Figure 1) and horizontally over lateral arc Ah (Figure 2) by hydraulic power. Outboard end 22 of arm 21 is equipped with a conventional cutting wheel 23 powered by a hydrostatic motor.

A control position 24 is provided on the upper section 15 and comprises a cab 25 in which is provided a seat 26 and a control panel 27 whereby operations involving cutting by, and movement of, the stump cutter are carried out.

A scraper blade 28 is pivotably mounted on forward end 29 of the lower section 13 and is operable by hydraulic means to be raised or lowered over the arc B. The blade has several functions. It can be used as a conventional scraper blade to enable fragmented material generated by the operating cutter wheel 23 to be displaced (typically into a hole generated in the course of cutting a stump to a position beneath ground level). It can be used as an anchoring means for the cutter 10 when in an otherwise unstable location. It can be used to raise one end of the machine relative to a slope to provide for level operation. Where no scraper blade is available or in addition to a blade a separate anchoring means can be provided such as one or more hydraulically displaceable anchor spades.

By utilising a self propelled tracked chassis the present invention provides a number of substantial benefits over existing stump cutting machinery. It provides for a relatively compact machine to be readily manoeuvred by its operator to a convenient working locations even among a number of closely set stumps.

Because the upper section 15 of the chassis can be rotated 360 relative to the lower part 12 the cutting head is readily presented to a stump for cutting regardless of the alignment of the chassis to the stump. This dispenses with the need for the vehicle to be aligned in a particular manner to a stump and provides for safe operation since the vehicle can be located on the most stable position (if necessary using the scraper blade for anchorage and/or levelling of the cutter in the vicinity of the stump prior to a cutting operation.

The tracked configuration and the ability to anchor the stump cutter forming the present invention enables stump cuffing operations to be carried out on ground rendered unusable by a wheeled vehicle such as can arise from weather conditions or from earlier operations carried out on the ground.

The combined use of a tracked vehicle and an anchorage means is particularly appropriate for use on sloping working areas. Such areas can be unusable by a wheeled vehicle even when the ground is otherwise in reasonable condition.

The provision on the vehicle of a seat and operating cab for an operator provides a number of substantial benefits by making operation of the cutter less hazardous, encouraging concentration on the part of the operator and sheltering him from adverse weather and noise levels.

Claims (7)

1A stump cutter comprising a chassis, an arm having one end mounted on the chassis and the other end to the one end provided with a cutting wheel characterised in that the chassis is in two parts; a first part provided with ground engaging wheels or tracks adapted to displace the stump cutter at least in a first longitudinal direction with the stump cutter on horizontal ground; and a second part on which the one end of the arm is mounted; the second part being adopted for rotation about a vertical axis relative to the first direction on horizontal ground.

2 A stump cutter as claimed in Claim 1 provided with a prime mover adapted to power the cutting wheel either directly or by way of a power transmission means.

3 A stump cutter as claimed in Claim 2 wherein the prime mover further serves to provide propulsive power to the ground engaging wheels or tracks.

4 A stump cutter as claimed in any preceding claim provided with an anchoring and /or levelling means whereby once the stump cutter has been positioned in a working location the anchoring means is operable to engage the ground independently of the ground engaging wheels or tracks to anchor the cutter against movement and/or to provide for the levelling of the stump cutter.

5 A stump cutter as claimed in any preceding claim provided with a scraper blade mounted on the stump cutter to enable material generated by the cutter to be displaced on movement of the ground engaging wheels or tracks.

6 A stump cutter as claimed in any preceding claim wherein the chassis is equipped with an operating location for an operator of the vehicle provided with controls for operating the cutting wheel and controls for operating the ground engaging wheels or tracks.

7 A stump cutter as hereinbefore described with reference to the accompanying drawings.