WO2011061529A2

WO2011061529A2 - Hedge cutter attachment

Info

Publication number: WO2011061529A2
Application number: PCT/GB2010/051911
Authority: WO
Inventors: Vivian Blick
Original assignee: Vivian Blick
Priority date: 2009-11-17
Filing date: 2010-11-16
Publication date: 2011-05-26
Also published as: GB2475332B; GB2475332A; GB0920086D0; WO2011061529A3

Abstract

A hedge cutter attachment (10) is provided for use with a vehicle such as a garden tractor or ride-on lawn mower. The attachment (10) includes a carriage (38) adjustably mounted to a hedge cutter arm (36) and provides for a full range of movement of a hand-held hedge cutter (58), which is releasably mounted within the carriage (38).

Description

HEDGE CUTTER ATTACHMENT

The present invention relates to a hedge cutter attachment for a vehicle and particularly, but not exclusively, to a hedge cutter attachment for a garden tractor.

BACKGROUND TO THE INVENTION

Known vehicle-mounted grass and hedge trimmers typically have a flail head carried at a distal end of an articulated arm, the proximal end being attached to the vehicle such as a tractor, using a standard 3-point linkage. These trimmers are usually powered by a hydraulic motor. Hydraulic oil is typically carried in a tank or reservoir, attachable to the tractor, a pump being mounted in the tank and driven by a power take-off shaft of the tractor. Alternatively, the trimmer may utilise the hydraulic circuit of the tractor.

A problem with this type of vehicle-mounted cutter is that they are intended for use with agricultural tractors and cannot easily be mounted to smaller domestic garden vehicles such as ride-on lawn mowers. This is because the smaller vehicles do not necessarily have a three point linkage, a power take-off or the weight distribution to balance the weight of a hydraulically powered cutter. Furthermore, these devices are complicated and expensive to produce, run and maintain. They are also relatively complicated to operate.

It is an object of the invention to provide a hedge cutter attachment that is suitable for mounting on a small domestic vehicle, for example, a ride-on lawn mower or small garden tractor for use with a hand-held hedge cutter.

SUMMARY OF INVENTION According to the first aspect of the present invention there is provided a hedge cutter attachment for a vehicle comprising a support member, a ground support adjustably mounted to the support member, means for adjustably mounting a hedge cutter to the support member and connection means disposed at each end of the support member for connecting the hedge cutter attachment to attachment points at the front and rear of the vehicle.

The advantage of this simple construction is that it may be attached to a small domestic vehicle such as a ride-on lawn mowers as well as an agricultural vehicle with little or no modification.

The support member may be substantially C-shaped and may include a central member adapted to be positioned substantially parallel with the longitudinal axis of the vehicle, and front and rear end members disposed perpendicularly thereto, to one side of the central member.

By having the central member substantially parallel with the longitudinal axis of the vehicle, the weight of the attachment is substantially evenly distributed over the length of the vehicle and reduces the risk of the vehicle toppling over due to the weight of the attachment when used with a small vehicle.

Preferably, the ground support includes a radius arm having a wheel mounted thereon for contact with the ground, the radius arm being mounted to the support member about a pivot.

In this embodiment, the ground support takes the bulk of the weight of the attachment and improves the stability of a vehicle with the attachment in place. Ideally, the angular position of the radius arm relative to the support member is controlled by a linkage driven by an electric motor. The electric motor obviates the need for the vehicle driver to physically adjust the position of the hedge cutter in the attachment to alter the angle of attack. Optionally, as detailed below, the motor can be automatically controlled.

The means for adjustably mounting a hedge cutter to the support member may include a hedge cutter arm, the hedge cutter arm being mounted to the support member about a pivot and being movable between an operative position in which the hedge cutter is mounted perpendicularly relative to the support member and a stowed position in which the hedge cutter is mounted substantially parallel with the support member.

Conveniently, by having a pivotable hedge cutter arm that is movable between these two positions, when the hedge cutter is not required, the hedge cutter arm may be lowered into the stowed position, thereby making the vehicle with hedge cutter attachment more compact for ease of storage. In particular the height of the attachment is reduced for passing through a garage door. It is envisaged that the hedge cutter arm may have a carriage mounted thereon for carrying the hedge cutter. Ideally, the carriage is movable along the length of the hedge cutter arm. In use, this facilitates the cutting of a hedge at any height.

Movement of the carriage in an upward direction may be powered by a winch pulley system, and movement in a downward direction may be substantially under gravity. This overcomes the drawbacks of using hydraulically powered displacement systems as is often found in the art. Additionally, a winch pulley system is simple to maintain and/or replace. The carriage may comprise a first part mounted to the hedge cutter arm, and a second part for releasably mounting the hedge cutter, the second part being pivotally mounted to the first part about a first axis, thereby allowing the hedge cutter to be positioned substantially perpendicular to the hedge cutter arm or substantially parallel to the hedge cutter arm, or any angle therebetween.

This beneficially facilitates cutting of the two main surfaces of a traditional rectangular hedge, notably a vertical side and a horizontal top. However, other surfaces having any angle relative to the horizontal may also be cut. The carriage may also comprise a first part mounted to the hedge cutter arm, and a second part for releasably mounting the hedge cutter, the second part being pivotally mounted to the first part about a second axis, perpendicular to the first axis and a longitudinal axis of the hedge cutter arm. With the introduction of rotation about a second axis, the area of hedge surface that can be reached with the hedge cutter is extended. Relatively very low surfaces and very high surfaces of a hedge may be reached with ease.

The carriage may further comprise a deflector plate for protecting the hedge cutter. The deflector plate prevents uncut hedge from interfering with the hedge cutter during use. It also stops cut hedge from flying towards the driver of the vehicle, preventing injuries.

Ideally, a generator is mounted on the support member, for generating an AC voltage to power at least the hedge cutter. Advantageously the hedge cutter may be any commercially bought off-the-shelf hedge cutter or trimmer. This is useful because it means the attachment can be used with existing hedge cutters, making it a cheaper option that existing hedge cutter attachments which have integral cutting blades.

In one embodiment, the generator is adapted to be driven from a power take-off of the vehicle. This increases the travel range of the vehicle since the vehicle is not physically connected to a fixed power supply.

Preferably, the connection means is a coupler for receiving a tow ball. This is a very simple and quick way of connecting the hedge cutter attachment to the vehicle that the user will find easy and straightforward to use. A lock may be added to the connection means to prevent unauthorised removal of the attachment.

By incorporating an inclinometer into the hedge cutter attachment, the angular position of the support member relative to the horizontal may be measured. The inclinometer may be mounted either to the front member or to the rear member. A control unit may be provided for controlling the position of the hedge cutter relative to the vehicle. The control unit may be adapted to automatically control the angular position of the radius arm, in response to an output for the inclinometer. This in turn controls the angle of the cutting blade of the hedge cutter relative to the horizontal. Advantageously, the controls can react to uneven ground in the automatic mode.

According to a second aspect of the present invention, there is provided a hedge cutter attachment for a vehicle comprising a support structure and a cutting blade, and an inclinometer for automatically controlling the position of the cutting blade relative to the horizontal.

Feedback from the inclinometer may be used to signal corrections to the motors controlling the position of the cutting blade. DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

Figure 1 shows a perspective front view of a lawn tractor fitted with a hedge cutter attachment of the invention;

Figure 2 shows a perspective view of the attachment of the hedge cutter attachment of Figure 1 , to the rear of the lawn tractor;

Figure 3 shows a perspective side view of part of the attachment of Figure 1, and in particular shows the ground support; Figure 4 shows a perspective view of the support arm and hedge cutter arm in a vertical, operative position; Figure 5 shows a perspective view of the support arm and hedge cutter arm in a second vertical position, and in particular how the carriage is mounted to the hedge cutter arm; Figure 6 shows a perspective view of the carriage, with a hedge cutter in situ, and in particular the first and second parts of the carriage;

Figure 7 shows a perspective view of the control box of the invention; and Figure 8 shows a perspective view of the carriage and hedge cutter in use, with a blade of the hedge cutter trimming a hedge.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring firstly to Figure 1, a hedge cutter attachment is indicated generally at 10 and is shown mounted to a lawn tractor 12. The lawn tractor 12 has a centrally mounted mowing deck 14 positioned between the front and rear wheels and the attachment 10 is disposed substantially to one side of the lawn tractor 12 and does not affect the operation of the mowing deck 14.

Referring also to Figure 2, the attachment 10 includes a substantially C-shaped support member 16, having a central portion 18 and front and rear portions 20, 22, which are connected to the front and rear of the lawn tractor 12 respectively by couplers 24 connected to conventional tow balls fixed to the front and rear of the tractor. The C-shaped support member 16 lies in a substantially horizontal plane, when mounted to the tractor 12, and the front and rear portions 20, 22 are dog-legged downwards at their distal ends to the couplers 24. These doglegs, indicated at 26 and 28, enable the positions of the front and rear couplers 24 for attachment to the tractor tow balls to be positioned lower than the plane of the central portion 18 of the support member 16.

Referring now to Figure 3, the central portion 18 is supported by an adjustable ground support 30. The ground support 30 includes a radius arm 32 pivotally mounted at one end to the central portion 18 proximate the front of the central portion. A wheel 33 is mounted at the other end of the radius arm 32 and contacts the ground. The wheel 33 may be a free-wheeling pneumatic castor suitable for use on grass. The height of the central portion 18 above the ground is determined by the angular position of the radius arm 32 relative to the central portion 18 of the support member 16.

A motorised jack 34 controls the angular position. In the embodiment shown the jack is a scissor jack powered by a 12 volt electric motor.

A hedge cutter arm 36, as shown in Figure 4, is an elongate member, mounted to the support member 16 at the front end of the central portion 18. The hedge cutter arm 36 is pivotally mounted and can move from a stowed position as shown in Figure 1 , in which the hedge cutter arm lies flat on top of the central portion 18 of the support member 16, and an operative position as shown in Figure 4, in which the hedge cutter arm 36 extends perpendicularly upwards from the support member 16. A locking pin retains the hedge support member in either the stowed or operative position.

A carriage 38 is mounted to the hedge cutter arm 36, as shown most clearly in Figure 5. The carriage 38 provides a means for mounting a hand- he Id hedge cutter, as described with reference to Figure 6 below, to the attachment 10. The carriage 38 includes a first part 46 mounted on the hedge cutter arm 36 by two pairs of rollers 42 mounted between two plates 40a, 40b. The plates 40a, 40b are disposed on either side of and are spaced from the elongate member. Each roller 42 is oriented to roll along a surface of the hedge cutter arm 36 and has a peripheral flange 43, which engages an outer edge of the hedge cutter arm 36. The rollers 42 work in pairs on either side of the arm 36, ensuring that the carriage moves smoothly and without lateral movement along the arm 36. Each roller 42 rotates relative to the plates 40a, 40b on a pivot pin extending between the plates.

Referring now to Figure 6, the carriage 38 includes a second part 48, adjustably mounted to the first part 46 about two axes of movement. On the back of plate 40b, a shaft 52 is laterally oriented and rotationally mounted within a pair of roller bearings 54 fixed to plate 40b. One end of the shaft 52 terminates at a C-shaped frame 50 fixed to the shaft 52. Rotation of the shaft 52 (and therefore the frame 50) within the roller bearings 54 provides for one axis of movement. The shaft 52 is also laterally moveable within the roller bearings 54 and this enables the distance between the second part 48 of the carriage 38 and the hedge cutter arm 36 to be varied. The lateral and angular positions of the shaft 52 are lockable by a lock 56. The ability to move the second part laterally is useful when attempting to trim particularly wide hedges or reaching over another object such as a fence.

The second part 48 of the carriage 38 includes a cradle arrangement 62 rotationally mounted to the frame 50 of the first part 46. A hedge cutter 58 is releasably mounted within the cradle arrangement 62. Rotation of the cradle arrangement 62 with respect to the frame 50 about pivots 51 provides for a further axis of movement. The hedge cutter 58 is preferably electric, as shown, although it is possible for a petrol or diesel engine cutter to be provided.

The second part 48 also includes a deflector plate 60, attached to the cradle arrangement 62. The deflector plate 60 has a central panel section flanked by two smaller panels, bent inwards relative to the central panel section towards the hedge cutter arm 36. The deflector plate 60 protects the hedge cutter 58 from cut and/or uncut hedge during use.

As viewed in Figure 6, the hedge cutter 58 is mounted substantially vertically such that a blade 59 of the hedge cutter 58 is substantially parallel with the hedge cutter arm 36.

Vertical movement of the carriage 38 along the length of the hedge cutter arm 36 is provided by a winch pulley system. The winch pulley system includes a wire cable 66, a conventional winch 68 mounted on the central portion 18 of the support member 16, a pulley 70 mounted to the end of the hedge cutter arm 36 distal from the winch 68, and a clasp 72 at the free end of the cable 66 for attachment to the carriage 38. Cable 66 is wound around the winch 68, extends along the length of the hedge cutter arm 36 through the pulley 70 and back down the other side of the hedge cutter arm 36 to the carriage 38. The winch 68 is driven by a 12V electric motor, electrically connected to battery of the lawn tractor 12. The winch 68 powers the upward movement of the carriage 38. Downward movement of the carriage 38 is under its own weight. An AC generator 74 is mounted at the rear of the lawn tractor 12 to the rear portion 22 of the support member 16 and is driven by a power take-off of the lawn tractor 12. The generator 74 is able to power the hedge cutter 58 by providing a 230V alternating current along a flexible coiled electric cable 64, which passes from the rear of the lawn tractor 12 to the pivot point of the hedge cutter arm 36 and up to the carriage for connection to the hedge cutter 58, as shown in Figure 6. The power output of the generator is determined by the speed of the power take-off. An advantage of using a generator with an electric hedge cutter is that the hedge cutter can be used constantly without the need for refuelling. In another possible arrangement, the generator 74 may be a free-standing generator mounted to the rear portion 22 of the support member 16 and can be refuelled as necessary.

A control box 76 is mounted on the lawn tractor 12 preferably within easy reach of the driver. On an external surface of the control box, as shown in Figure 7, are five buttons for controlling the movement of the carriage 38 and the motorised jack 34. Up button 76a and down button 76b control the vertical movement of the carriage 38 along the hedge cutter arm 36 when the hedge cutter arm 36 is in its operative position. Left tilt button 76c and right tilt button 76d control the movement of the motorised jack 34 in a manual mode of operation. Left tilt button 76c causes the motorised jack 34 to increase the angular position of the radius arm 32 with respect to the support member 16. Right tilt button 76d causes the motorised jack 34 to decrease the angular position of the radius arm 32 with respect to the support member 16. Auto levelling button 76e controls the movement of the motorised jack 34 in an automatic mode of operation.

To achieve this automatic mode of operation, an inclinometer 78 is mounted to the front portion 20 of the support member 16, as shown in Figure 1, and is in electrical communication with the control box 76. The inclinometer 78 measures the position of the front portion 20 with respect to the horizontal. When any change in position is detected, such as when the wheel 33 of the radius arm 32 passes over undulating ground, a signal is fed back to the control box 76, which will then automatically instruct the motorised jack 34 to increase or decrease the angular position of the radius arm 32 with respect to the support member 16. This corrects the level of the support member 16 and therefore the hedge cutter arm 36 and the hedge cutter 58. It maintains the front and rear portions 20, 22, of the support member 16 in a horizontal position, and hence the hedge cutter arm 36 is maintained in a vertical position, in use. This self- levelling ability is advantageous as it prevents the hedge cutter 58 from temporarily cutting hedge at an undesirable angle when undulating ground is encountered by the lawn tractor 12.

The attachment 10 provides a full range of movement of the hedge cutter blade, as described below. In use, as shown in Figure 8, a driver 80 steers the lawn tractor 12 in a line adjacent to a hedge 82. By way of example, the carriage 38 is elevated to a raised position near or at the top of the hedge 82. The blade 59 of the hedge cutter 58 is pointed downwardly and is substantially parallel with and proximate to the surface of hedge 82 to be trimmed. As the lawn tractor 12 advances, hedge 82 contiguous the blade 59 is trimmed. It will be appreciated that the blade 59 of the hedge cutter 58 can be positioned in any rotational position within the cutting plane by rotation of the shaft 52. The lateral position of the cutting plane can be altered by sliding the shaft 52 longitudinally within the bearings 54. The cutting plane can be angled to substantially any position by rotation of the cradle arrangement 62 relative to the frame 50.

The hedge cutter attachment 10 disclosed is advantageous because it can be fitted and removed with ease from any type of domestic garden vehicle, typically a lawn tractor. The components are robust and durable. By utilisation of a readily available electric hedge cutter, there is no need to manufacture a bespoke cutting head. Furthermore, should the hedge cutter break, then it can be replaced with ease at minimal cost.

Claims

A hedge cutter attachment for a vehicle comprising a support member, a ground support adjustably mounted to the support member, means for adjustably mounting a hedge cutter to the support member and connection means disposed at each end of the support member for connecting the hedge cutter attachment to attachment points at the front and rear of the vehicle.

A hedge cutter attachment as claimed in claim 1 , in which the support member is substantially C-shaped and includes a central member adapted to be positioned substantially parallel with the longitudinal axis of the vehicle, and front and rear end members disposed perpendicularly thereto, to one side of the central member.

A hedge cutter attachment as claimed in claim 1 or 2, in which the ground support includes a radius arm having a wheel mounted thereon for contact with the ground, the radius arm being mounted to the support member about a pivot.

A hedge cutter attachment as claimed in claim 3, in which the angular position of the radius arm relative to the support member is controlled by a linkage driven by an electric motor.

A hedge cutter attachment as claimed in any preceding claim, in which the means for adjustably mounting a hedge cutter to the support member includes a hedge cutter arm, the hedge cutter arm being mounted to the support member about a pivot and being movable between an operative position in which the hedge cutter is mounted perpendicularly relative to the support member and a stowed position in which the hedge cutter is mounted substantially parallel with the support member.

A hedge cutter attachment as claimed in claim 5, in which a carriage is mounted on the hedge cutter arm for carrying the hedge cutter.

7. A hedge cutter attachment as claimed in claim 6, in which the carriage is movable along the length of the hedge cutter arm.

8. A hedge cutter attachment as claimed in claim 7, in which movement of the carriage in an upward direction is powered by a winch pulley system, and movement in a downward direction is substantially under gravity.

9. A hedge cutter attachment as claimed in any one of claims 6 to 8, in which the carriage comprises a first part mounted to the hedge cutter arm, and a second part for releasably mounting the hedge cutter, the second part being pivotally mounted to the first part about a first axis, thereby allowing the hedge cutter to be positioned substantially perpendicular to the hedge cutter arm or substantially parallel to the hedge cutter arm, or any angle therebetween.

10. A hedge cutter attachment as claimed in claim 9, in which the second part is pivotally mounted to the first part about a second axis, the second axis being perpendicular to the first axis and a longitudinal axis of the hedge cutter arm.

11. A hedge cutter attachment as claimed in any one of claims 6 to 10, in which the carriage further comprises a deflector plate for protecting the hedge cutter.

12. A hedge cutter attachment as claimed in any preceding claim, in which a generator is mounted on the support member, for generating an AC voltage to power at least the hedge cutter.

13. A hedge cutter attachment as claimed in claim 12, in which the generator is adapted to be driven from a power take-off of the vehicle.

14. A hedge cutter attachment as claimed in any preceding claim, in which the connection means is a coupler for receiving a tow ball.

15. A hedge cutter attachment as claimed in any preceding claim, in which an inclinometer is mounted to the support member, for measuring the angular position of the support member relative to the horizontal.

16. A hedge cutter attachment as claimed in claim 16, in which the inclinometer is mounted either to the front member or to the rear member.

17. A hedge cutter attachment as claimed in any preceding claim, in which a control unit is provided for controlling the position of the hedge cutter relative to the vehicle.

18. A hedge cutter attachment as claimed in claim 17, when dependent on claim 15 or 16 and 3, in which the control unit is adapted to automatically control the angular position of the radius arm, in response to an output for the inclinometer.

19. A hedge cutter attachment for a vehicle comprising a support structure and a cutting blade, and an inclinometer for automatically controlling the position of the cutting blade relative to the horizontal.

20. A hedge cutter attachment substantially as described herein with reference to and as illustrated in the accompanying diagrams.