GB2482467A

GB2482467A - Mowing apparatus with resiliently mounted secondary mower

Info

Publication number: GB2482467A
Application number: GB201007385A
Authority: GB
Inventors: Kevin John Thulborn
Original assignee: K J Thulborn Contractors & Engineers Ltd
Current assignee: K J Thulborn Contractors & Engineers Ltd
Priority date: 2010-04-30
Filing date: 2010-04-30
Publication date: 2012-02-08
Anticipated expiration: 2030-04-30
Also published as: GB2482467B; GB201007385D0

Abstract

The mowing apparatus comprises a primary mower 14 for cutting a first strip of ground in the direction of travel of the apparatus and a secondary mower 18 arranged to be selectively deployed on one side of the mower apparatus for cutting a second strip of ground parallel to the first strip, the secondary mower being resiliently mounted with respect to the primary mower and arranged to deflect inwards towards the primary mower when the secondary mower encounters an obstruction such as barrier support posts, sign posts or the like in the cutting direction. This arrangement enables roadside verges to be mowed. The secondary mower may comprise a cutter head 28 mounted on a pivot arm 32 which may include a parallelogram type linkage 36. The pivot arm may be pivotally connected to support means about a first axis.

Description

Mowing Apparatus This invention relates to mowing apparatus and in particular mowing apparatus for highway verges or similar ground having periodically spaced upstanding obstructions.

Highway verges bearing grass and/or light foliage are usually maintained using a mower centred behind or in front of a tractor travelling along the length of the verge to mow a strip of ground in the direction of travel of the mower. Road side verge mowers are generally of the rotating cylinder type with the width of cut being set up for the verge to be cut. It is desirable to mow as close as possible to roadside crash barriers or the like found on highway verges. With known mowing machines a guide plate or the like may be positioned at one or both lateral extremities of the device for guiding the mowing machine along the crash barrier by engagement with or in close proximity to 1 5 the crash barrier.

Mowing roadside verges in the above mentioned manner is usually supplemented by manual cutting of vegetation under the crash barrier structure using hand held strimming devices. This practice is effective but relatively inefficient since it usually more than doubles the manpower required to mow a particular length of verge. For example, practice in the United Kingdom usually requires two manual operatives to strim vegetation under the region of the crash barrier in order to maintain pace with the tractor. In addition, the presence of work personnel on the roadside requires additional health and safety measures to be taken into account which in the United Kingdom usually requires there to be two safety vehicles, with appropriate warning elements positioned up stream of the tractor and maintenance personnel. in the carriage way immediately adjacent to the verge being cut.

By comparison, on verges where there are no crash barriers and it may be possible to mow using a tractor only. In these situations only one such safety vehicle is required because the driver is seated in the cab of the tractor.

Various mowing machines have been proposed in the past, particularly in the field of agricultural machinery for mowing orchards, which can deal with the presence of periodically spaced upstanding obstructions such as trees, as may be found in a planted orchard. Examples of such mowing devices are described in GB 1, 180, 645, EP 0, 909, 075 and US 4, 104, 851 where an additional swing arm" side cutter is provided, in addition to the main mower for mowing the region between adjacent trees. Sensing devices, typically in the form of a flexible strip, are provided on the mowing device at a forward cutting end thereof. The flexible sensing strips protrude laterally from the side of the mowing device and are caused to deflect when engaged by an obstruction in the direction of mowing, such as a tree trunk. The sensor causes the side cutter to be retracted so that the mowing device may pass by the tree without the side cutter hitting the trunk. There are various disadvantages associated with this type of arrangement, not least the vulnerability of the sensor devices, including the flexible strips, to damage caused by constant impact with upstanding obstructions. Both the aforementioned arrangements require relatively complex control arrangements to ensure that the side cutter is retracted to a non-interfering position when an obstruction is encountered by the sensor. This can add significantly to the complexity, cost and reliability of such devices.

There is a requirement therefore for an improved mowing device for mowing highway verges having roadside crash barriers or the like, or like ground having other periodically spaced upstanding obstructions such as trees.

According to an aspect of the present invention there is provided mower apparatus for mowing highway verges having roadside crash barriers or the like, or like ground having other periodically spaced upstanding obstructions to mowing, said apparatus comprising a primary mower for cutting a first strip of ground in the direction of travel of the said apparatus and a secondary mower arranged to be selectively deployed on one side of the mower apparatus for cutting a second strip of ground parallel to the said first strip, the said secondary mower being resiliently mounted with respect to the said primary mower and arranged to deflect inwards towards the primary mower when the said secondary mower encounters an obstruction in the cutting direction.

The above aspect of the invention readily enables roadside verges to be mowed using a tractor or the like coupled to a mowing apparatus according to the above aspect of the invention. It will be understood that additional maintenance personnel with strummers for cutting the region underneath roadside crash barriers are made redundant by the mowing apparatus of the present invention, since the secondary mower is capable of performing this aspect of verge maintenance automatically in conjunction with the main or primary mowing device. Not only does this reduce the number of personnel required for mowing and strimming, it also reduces the number of vehicles, and personnel, required for protecting the maintenance personnel on the roadside. The resilient mounting of the secondary mower relative to the primary mower readily enables the secondary mower to deflect out of the way of any upstanding obstructions such as barrier support posts, sign posts or the like when the mower is moved along the verge in the mowing direction.

In preferred embodiments the secondary mower is deflected inwards so that it overlaps the strip mowed, or to be mowed, by the primary mower. In this respect the above aspect of the present invention contemplates embodiments where the secondary mower is positioned fore or aft of the primary mower.

In preferred embodiments the mower apparatus further comprises biasing means for biasing the secondary mower away from the primary mower when the secondary mower is deployed for cutting. Thus, in the secondary mower is biased outwards when deployed so that it projects laterally outwards of the primary mower.

Preferably the biasing means comprises spring means arranged to bias the secondary mower outwards from the line of cut of the primary mower and thereby deflect inwards against the restoring force of the spring means when the secondary mower encounters an obstruction in the mowing direction. The spring means may be of any suitable type.

In addition, stop means may be provided to determine the final biased outward position of the secondary mower when deployed. In this way the spring means may be arranged to operate under tension or compression for biasing the secondary mower to its outward deployed position.

Preferably the secondary mower is capable of deflecting inwards when an obstruction is encountered and may deflect inwards to an extent that it does not project laterally beyond the cutting edge of the primary mower, that is to say the secondary mower may be deflected inwards so that its line of cut substantially overlies that of the primary mower.

In preferred embodiments the secondary mower is moveable between a raised and stowed position for storage and a lowered deployed position for cutting. In this way the secondary mower can be readily stowed in a region that does not interfere, hinder or adversely effect the operation of the primary mower, either in use, transportation or storage.

In preferred embodiments the secondary mower comprises a cutter head mounted on a pivot arm. Preferably the cutter head includes a rotary cutting blade or blade mounted on the underside of a shield. In preferred embodiments the shield is provided by a generally circular disc, preferably having rounded edges so as to readily deflect inwards when if encounters an obstruction, by contact, in the cutting direction. The circular and rounded nature of the cutter head readily enables the cutter head to ride around the obstruction and return to its undeflected position when the obstruction has been passed.

In preferred embodiments the cutter head of the secondary mower is provided at or towards a distal end of the pivot arm.

Preferably the pivot arm comprises a plurality of articulated sections, the pivot arm may include a parallelogram type linkage for pivotal movement of the cutter head with respect to the proximal end of the pivot arm. This arrangement, and in particular the parallelogram, provides for limited upwards movement of the cutter head when the mowing apparatus is moving across slightly undulating ground. Movement of the cutter head in an up and down manner with respect to the ground is limited by appropriate stops provided on the pivot arm, preferably on the parallelogram linkage. Preferably a first stop determines the height of the cutter head above the ground being mowed when the secondary mower is in its deployed position. with another stop determining the extent of vertical travel of the deployed cutter head and pivot arm to accommodate undulating ground.

In preferred embodiments the pivot arm is pivotally mounted about a first axis about which the pivot arm and cutter head are arranged to deflect inwards toward the primary mower, when the cutter head and/or arm encounters an obstruction in the cutting direction.

Preferably when the cutter head and pivot arm are deployed for mowing, the first axis defines a vertical axis of rotation about which the pivot arm, and hence cutter head, rotate when deflected inwards or when returning to them outward biased position.

Preferably the pivot arm is pivotally connected to support means about the first axis and the support means is pivotally mounted with respect to the primary mower about a second axis, substantially orthogonal to the first axis. Thus, embodiments are contemplated where the first axis is provided for deflection of the cutter head and pivot arm and a second axis for rotation of the pivot arm and cutter head between their stowed and deployed positions.

In preferred embodiments the support means is hinged to the primary mower about the second axis. This arrangement provides a compact and simple arrangement in which one of the hinge plates of the hinge is fixed to the support means and the other is fixed relative to the support structure/chassis of the primary mowing device.

The mower apparatus may further comprise actuator means for moving the support means about the second axis to deploy or retract the primary mower as hereinbef ore described. Thus the above aspect of the present invention contemplates embodiments where the secondary mowing device may be deployed and retracted by means of a single actuator, for example a linear actuator. In preferred embodiments the linear actuator is a hydraulic actuator controlled by the mower apparatus and/or vehicle it is coupled to.

In preferred embodiments where the cutter of the secondary mower is powered by hydraulic pressure, a safety valve may be provided to remove power from the secondary mower cutter when it is raised from its deployed cutting position. Thus embodiments are contemplated where power to the secondary mower is removed as soon as it is raised.

An embodiment of the invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a view of from the front of a mower apparatus according to an embodiment of the invention, shown coupled to Ihe front of an agricultural tractor; Figure 2 is a perspective front side view of the mowing apparatus of Figure 1 showing a secondary side arm cutter of the mowing apparatus in a raised position; Figure 3 is a close-up perspective view of the side arm cutter of Figure 2 also in the raised position; Figure 4 is a side perspective view from the rear of the raised side arm cutter shown in Figures 2 and 3; Figure 5 is a perspective view from above of the raised side arm cutter; Figure 6 is a perspective view from the rear of the raised side arm cutter; Figure 7 is a perspective view from the rear of the side arm cutter in its lowered deployed position; Figure 8 is similar to Figure 7 but is a close-up view of the side arm cutter; and Figure 9 is a perspective view from above of the side arm cutter in its lowered deployed position.

Referring to Figure 1, there is shown mowing apparatus 10 according to an embodiment of the present invention. The illustrated mowing apparatus is particularly suited for mowing highway verges having road side crash barriers or the like, or other ground having other such periodically spaced upstanding obstructions such gs trees or the like. The mowing apparatus 10 is a modified arrangement of a conventional roadside verge mower arranged to be propelled by a maintenance vehicle such as an agricultural tractor 12, with the mower coupled to the front end thereof, preferably rigidly coupled, and driven by power take off from the tractor 12 as is well known in the art.

The mowing apparatus 10 comprises a primary mower 14, which is of a conventional arrangement, for cutting a first strip of ground in the direction of travel of the coupled unit. The primary mower 14 is of a conventional rotating cylinder type mower having a width of cut determined by the length of the rotating cylinder or cylinders. As can be seen in the view of Figure 1 the mowing apparatus is supported at its forward end by a wheeled support 16 and at its other end by the coupling (not shown) with the vehicle 12. A secondary mower, generally indicated 18, is mounted on the chassis or main structure of the primary mower 14 on one side thereof. In the illustrated embodiment.

shown in Figures 1 to 9, the secondary mower device 18 is mounted on the left hand side of the primary mower 14, when looking in the forward direction of travel as determined by the tractor 12.

An upstanding guide plate 20 is fixed to the side of the primary mower 14 for guiding the mower apparatus 10 against a roadside crash barrier that may be present on the verge to be mowed. The secondary mower 18 does not extend laterally beyond the guide plate 20 when in the raised position shown in Figures 1 to 6.

As can best be seen in Figures 3 to 6, the secondary mower, or side cutter 18 comprises a rotary cutter blade 22 mounted on a shaft 24 which is powered by a hydraulic motor 26 positioned on the other side of the cutter head 28 to the cutter blade 22. The cutter head 28 includes a circular disc 30 which shields the cutter blade 22 when the side cutter is deployed in its lowered position, as shown in Figures 7 to 9. The cutter head 28 is connected to a side pivot arm 32 which comprises a plurality of articulated sections including a distal end section 34, a mid section 36 and a proximal end section 40. As can best be seen in Figure 5, the distal end section 34 is fixed to the disc 30 of the cutter head 28. The mid section 36 comprises a pair of spaced apart parallel links which are pivotally connected at respective ends to the distal end section 34 and proximal end section 40 of the pivot arm 32 to provide a parallelogram type linkage in the pivot arm 32. One of the link elements 42 includes an angled plate 44 which provides abutment stops 46 and 48 at opposite ends thereof for limiting the angular movement of the parallelogram type linkage by abutment with respective parts of the distal end section 34 or proximal end section 40. This arrangement provides the pivot arm 32 with a limited degree of vertical movement when the secondary mowing device is deployed to its lowered position. This enables the secondary mowing device to move vertically to take account of uneven ground when deployed for cutting. The pivot arm 32 is pivotally connected to a support member 46 by means of a pivot pin 48 which defines the pivot axis of the pivot arm 32.

As can best be seen in the drawings of Figures 3, 4 and 8 the support member 46 is fixed to a hinge plate 50 which is hinged to the chassis 52 of the primary mower device by hinge 54 the axis of which is orthogonal, or substantially orthogonal, to the pivot axis defined by pivot pin 48.

Referring now to Figures 7, 8 and 9 which show the secondary mowing device in its lowered deployed position. The pivot arm and cutter head are lowered and raised by extension and retraction of a single linear actuator ram 52, which is secured at one end to the chassis of the primary mower and at its output end to the support member 46 for rotating the hinge plate 50 about the hinge axis 54, through an angle of approximately degrees so that the hinge plates 50, 52 are brought together to lower the associated components of the secondary mower to the deployed operational position shown in Figures 7, 8 and 9. In this position the rotary cutter head 28 extends beyond the line of the guide plate 20 at the lateral extremity of the primary mower so that the secondary mower provides a line of cut beyond that of the primary mower on one side of the mowing apparatus. In the illustrated embodiment the secondary mower extends the cutting width of the mowing apparatus by approximately 30 to 60 cm beyond that of the primary mower.

As can best be seen in the view of Figure 8 and 9, the pivot arm 32 is resiliently mounted in that it can be deflected inwards in the direction 54 about pivot axis 48 if the cutter head 28 encounters an obstruction when the mower apparatus is being moved in the cutting direction. Inwards movement of the pivot arm and cutter head is resisted by biasing means in the form of a coil spring 56 which is secured at one end to the hinge plate 50 and at the other to the pivot pin arrangement 48 such that the return force of the coil spring biases the pivot arm and cutter head of the secondary mower to the lateral outward position shown in Figures 7 to 9 when the cutter head is deployed for use. Rotation of the cutter head and pivot arm about the pivot pin 48 is limited by an abutment stop 60 which limits the lateral position of the cutter head when deployed for use, that is to say abutment stop 60 prevents further rotation of the cutter head about the pivot axis in a clockwise direction when viewed from above as in Figure 9.

The ability of the cutter head to be deflected inwards in a counter clockwise direction about the pivot axis, when viewed from above as in Figure 9, enables the secondary mower to be used in mowing operations where there is a requirement to cut the ground between obstructions, such as underneath roadside verge crash barriers. It will be understood that when the mower apparatus is travelling in a forward direction the secondary mower side cutter may be deployed for mowing the ground underneath a roadside crash barrier. The guide 20 positions the mowing apparatus against or closely adjacent to the barrier with the secondary mower being deployed to cut the ground underneath the crash barrier. The cutter head 28 will be deflected inwards when an obstacle is encountered such as an upright support of the crash barrier. The rounded edge of the shield 30 ensures that contact with the crash barrier upright supports is readily accommodated and results in the inward deflection of the cutter head so that cutting the ground immediately surrounding the upright support is also accomplished.

Although the embodiments of Figures 1 to 9 shows the secondary mower arranged on one side of the mower apparatus this invention also contemplates embodiments where a secondary mower is provided on the other, or both sides, or arrangements where the mower apparatus can be readily reconfigured to move the secondary mower from one side to the other.

Claims

CLAIMS1. Mower apparatus for mowing highway verges having roadside crash barriers or the like, or like ground having other periodically spaced upstanding obstructions to mowing, said apparatus comprising a primary mower for cutting a first strip of ground in the direction of travel of the said apparatus and a secondary mower arranged to be selectively deployed on one side of the mower apparatus for cutting a second strip of ground parallel to the said first strip, the said secondary mower being resiliently mounted with respect to the said primary mower and arranged to deflect inwards towards the primary mower when the said secondary mower encounters an obstruction in the cutting direction.
2. Mower apparatus as claimed in Claim 1 further comprising biasing means for biasing said secondary mower away from said primary mower when the secondary mower is deployed for cutting.
3. Mower apparatus as claimed in Claim 2 wherein said biasing means comprises spring means arranged to bias the said secondary mower outwards from the line of cut of the said primary mower and deflect inwards when said secondary mower encounters an obstruction in the mowing direction.
4. Mower apparatus as claimed in any of Claims 1 to 3 wherein said secondary mower is capable of deflecting inwards when an obstruction is encountered to an extent that it does not project laterally beyond the cutting edge region of the said primary mower.
5. Mower apparatus as claimed in any preceding claim wherein the said secondary mower is movable between a raised position for storage and a lowered deployed position for cutting.
6. Mower apparatus as claimed in any preceding claim wherein said secondary mower comprises a cutter head mounted on a pivot arm.
7. Mower apparatus as claimed in Claim 6 wherein said cutter head is provided at or towards a distal end of the said pivot arm.
8. Mower apparatus as claimed in Claim 6 or Claim 7 wherein said pivot arm comprises a plurality of articulated sections.
9. Mower apparatus as claimed in any of Claims 6 to 8 wherein the said pivot arm includes a parallelogram type linkage for pivotal movement of the cutter head with respect to the proximal end of the said pivot arm.
10. Mower apparatus as claimed in Claim 9 wherein the said linkage includes stop means for limiting the extent of pivotal movement of the said cutter head with respect to the said proximal end.
11. Mower apparatus as claimed in any of Claims 6 to 10 wherein said pivot arm is pivotally mounted about a first axis about which the said pivot arm and cutler head are arranged to deflect inwards towards the primary mower when the cutter head or secondary arm encounter an obstruction in the cutting direction.
12. Mower apparatus as claimed in Claim 11 wherein said pivot arm is pivotally connected to support means about said first axis and said support means is pivotally mounted with respect to said primary mower about a second axis orthogonal to the said first axis.
13. Mower apparatus as claimed in Claim 12 wherein said support means is hinged to the said primary mower about said second axis.
14. Mower apparatus as claimed in Claim 12 or Claim 13 further comprising actuator means for moving the said support means about the said second axis, thereby to deploy or retract the said primary mower.
15. Mower apparatus substantially as hereinbefore described and shown in the accompanying drawings.