EP3470580A1

EP3470580A1 - Improved shovel

Info

Publication number: EP3470580A1
Application number: EP17195946.3A
Authority: EP
Inventors: René Houmann; Henrik kildegaard
Original assignee: NCC Danmark AS
Current assignee: Ncc Road Services AS
Priority date: 2017-10-11
Filing date: 2017-10-11
Publication date: 2019-04-17

Abstract

A shovel (1) adapted for being connected to a vehicle and for being moved in a movement direction (M) along a road verge, said shovel (1) comprising a shovel bucket (10) with a leading edge (11); and a cutting axle (20) rotatably connected to the shovel bucket (10) and arranged in front of the leading edge (11) with respect to the movement direction (M), said cutting axle (20) being adapted for cutting an upper layer of soil of the road verge.

Description

The present invention relates to a shovel for being connected to a vehicle and for being moved in a movement direction along a road verge to grade the road shoulder. The invention further relates to the use of such a shovel and a vehicle comprising such a shovel.

Background of the invention

Road maintenance often involve road shoulder grading in order to keep the road shoulder plane and clear of foliage. Road shoulder grading is usually performed by large vehicles provided with either grading blades or shovels which are dragged or pushed along the road side, whereby the upper layer of earth and foliage is removed leaving a plane surface next to the road.
In areas where roadsides may be covered in dense foliage or where the roots of the foliage run deep into the earth, such grading methods may be difficult as the grading blade or shovel may rip up part or all of the peat layer when dragging the shovel through the upper layer, whereby the graded road shoulder may have an uneven surface or may be graded to deep compared to the road.
It is therefore an object of the invention to provide an improved shovel, which is capable of being used to grade road shoulders in areas with dense vegetation, while still achieving a plane road shoulder.

Summary of the invention

In a first aspect of the invention this object and more are solved by a shovel adapted for being connected to a vehicle and for being moved in a movement direction along a road verge, said shovel comprising a shovel bucket with a leading edge, and a cutting axle rotatably connected to the shovel bucket and arranged in front of the leading edge with respect to the movement direction, said cutting axle being adapted for cutting an upper layer of soil of the road verge.
By providing the shovel with a cutting axle adapted to rotate during operation, the upper soil layer is loosened and foliage and similar may be separated from the lower soil layers before being shoveled onto the shovel bucket by the leading edge. This results in a more even road shoulder surface, as the peat layer is less likely to be shoveled onto the shovel bucket during the grading of the road shoulder.
The shovel bucket is adapted for receiving the material loosened from the road verge so that it may be removed. By collecting the material removed from the road verge in the shovel bucket rather than pushing it aside as done with a grader blade, an accumulation of soil and foliage next to the road shoulder is avoided. This may be advantageous when the road shoulder lies between the road and a ditch or between the road and another trafficked area, e.g. another road, a bicycle lane or a pedestrian lane, where it would undesirable to put the soil and vegetation material removed from the road shoulder.
In an embodiment, the cutting axle is a cylindrical axle with protrusions adapted for cutting and extending outwards from the surface of the cutting axle, preferably extending at an angle with respect to the normal vector of the surface of the cutting axle towards the rotation direction of the cutting axle during operation. The protrusions may be formed integrally with cutting axle or attached by attachment elements or welding.
During operation, the cutting axle may in principle rotate any direction in order to cut the soil ahead of the leading edge. However, the cutting axle should preferably rotate opposite the movement direction during operation, i.e. rotate such that the lower side of the cutting axle moves with the movement direction and the upper side moves against the movement direction, such that the material cut from the road verge by the cutting axle is thrown over the cutting axle and onto the shovel bucket by the rotation of the cutting axle, whereby the shovel becomes easier to move as the leading edge will have to shovel less material onto the shovel bucket.
In an embodiment of the invention, the cutting axle is adapted to rotate at 50 to 3000 revolutions per minute (RPM) during operation. The cutting axle should be driven at a sufficiently high rotation speed to make the cutting axle cut the upper soil layer and not drag through it. On the other hand, driving the cutting axle at too high a rotation speed may make the shovel difficult to control when moving it along the road verge. Furthermore, driving the cutting axle at 50 to 3000 RPM may require a less complex transmission in embodiments, wherein the cutting axle is driven by an external drive source.
In some embodiments, the cutting axle may be angled with respect to the leading edge and/or the leading edge may be wedge shaped. However, in a presently preferred embodiment of the invention, the leading edge is straight and the cutting axle is substantially parallel with the leading edge. Because the shovel of the invention is adapted to collect the material removed from the road verge, the shovel works better with a straight leading edge and a parallel cutting axle adapted for being perpendicular on the movement direction during operation, such that the soil and foliage is moved onto the shovel bucket rather than being pushed aside during operation.
In an embodiment of the invention, the spacing between the cutting axle and the leading edge may be 10 to 400mm. By arranging the rotatable axle such that the spacing between the cutting axle and the leading edge is more than 10mm, it may be avoided that material cut by the cutting axle is stuck between the cutting axle and the leading edge, which may obstruct rotation of the cutting axle. On the other hand, the axle should not be spaced too far from the leading edge, as the material cut by the cutting axle should preferably be thrown over the cutting axle and onto the shovel bucket by the rotation of the cutting axle rather than into the spacing between the leading edge and the cutting axle.
In one embodiment, the shovel is adapted for being permanently mounted/attached to a vehicle. However, in a presently preferred embodiment, the shovel is adapted for being detachably mounted on a vehicle, e.g. a tractor, an excavator, or a similar utility vehicle. By providing a detachable shovel, the shovel may be moved between work places without moving the work vehicles, whereby the shovel becomes more versatile. It should be noted that the term dragged, when used herein, does not imply that the vehicle is required to pull the shovel, the vehicle may also push the shovel to the same effect as pulling it.
In an embodiment of the invention, the shovel further comprises a motor adapted to drive the cutting axle, i.e. cause it to rotate during operation. Such embodiments are less restrictive with regards to which vehicles they may be mounted on, as the shovel may drive the cutting axle autonomously of the vehicle. Furthermore, by providing the shovel with its own motor, the rotation speed of the cutting axle may be independent of the engine of the vehicle, unlike embodiments where the engine of the vehicle is used as the external drive source.
In other embodiments, the cutting axle is adapted for being connected to an external drive source, preferably provided by the vehicle. Not only are such embodiments simpler and less expensive to manufacture compared to embodiments of the shovel comprising motors, such embodiments may also be connected to more powerful motors than it would be possible to mount on the shovel itself, thus providing cutting axle capable of performing more efficiently during operation. Furthermore, shovels not comprising motors will be lighter and may therefore be moved easier.
In some such embodiments, the shovel further comprises a transmission coupled to the cutting axle and adapted for being connected to the external drive source. The transmission may comprise a belt or chain transmission, a crank shaft, or similar to connect the external drive source to the cutting axle. The transmission may also provide speed and torque conversion between the external drive source and the cutting axle by means of a gear box or similar, whereby the cutting axle may be coupled to a vehicle engine running at more revolutions per minute than the cutting axle is adapted to and gain a larger or smaller amount of torque.
In a presently preferred embodiment, the transmission comprises a gear box. Such embodiments may provide better transmission of rotational power from the external drive source to the cutting axle, thus providing a more stable and efficient shovel during operation, than belt transmissions or similar.
In most embodiments of the invention, the cutting axle is connected to the shovel bucket by bearings at the ends of the cutting axle such that the cutting axle may rotate with as little friction as possible.
In an embodiment of the invention, the cutting axle may be pivotable between and operable position, in which the cutting axle is arranged substantially flush with the leading edge, and a passive position, in which the shovel may be operated without the cutting axle engaging the soil ahead, i.e. in the movement direction, of the leading edge. By enabling the cutting axle to be moved upwards with respect to the leading edge such that the cutting axle will not engage the soil ahead of the shovel, the shovel may be used, even when external drive sources are unavailable or when separating the upper soil layer is unnecessary, e.g. in areas with scarce vegetation.
In an embodiment of the invention, the shovel further comprises one or more axle bearings attached to the shovel bucket and connected to the cutting axle at points along the length of the cutting axle between the ends of the cutting axle to support the cutting axle. Such axle bearings may help stabilize the cutting axle during rotation and may allow the shovel to be made wider, i.e. the leading edge and the cutting axle to be longer, by allowing some of the forces exerted on the cutting axle during operation to be transferred to the shovel bucket.
In an embodiment of the invention, a first axle bearing is connected to the cutting axle at a position located in the length interval from 0,1 and 0,4 of the length of the cutting axle, and a second axle bearing is connected to the cutting axle at a position located in the length interval from 0,6 and 0,9 of the length of the cutting axle. It should be noted that the full length interval, i.e. from 0 to 1 of the length of the cutting axle, would be the total length of the cutting axle between the ends of the cutting axle.
By providing at least two axle bearings supporting the cutting axle along the length, the cutting axle may be more stable during operation and be able to withstand larger forces without bending. Furthermore, if the road shoulder is equipped with manhole covers and drainage covers, such covers will usually be positioned in the middle of the road shoulder, i.e. the middle of the width of the road shoulder. An advantage of omitting axle bearings supporting the cutting axle at positions in the length interval around the center of the length of the cutting axle, e.g. in the length interval from 0,4 to 0,6, is that the cutting axle, and thereby also the shovel, may be lowered closer to any covers without risking that an axle bearing will contact the cover.
In an embodiment of the invention, the shovel further comprises a rolling coulter rotatably attached to the shovel bucket and arranged on the side of the shovel bucket that is furthest away from the road during operation. By providing a rolling coulter on the shovel, the graded road shoulder may achieve a better finish on the side of the road shoulder facing away from the road, e.g. towards the ditch of the road side.
It should be noted, that the side of the shovel on which the rolling coulter is arranged depends on the movement direction of the shovel. In general, it is preferred to adapt the shovel to move in the direction of traffic, as governed by local law, for safety reasons. The rolling coulter may therefore be arranged on the right side of the shovel if the shovel is to be used in a country with right side driving and on the left side of the shovel if the shovel is to be used in a country with left side driving.
In embodiments of the invention comprising a rolling coulter, the shovel may comprise a connection portion adapted for releasably connecting the rolling coulter on both sides of the shovel. This may allow the shovel to be used anywhere, regardless of the local direction of traffic.
In a second aspect of the invention, the objects of the invention and more are solved through use of a shovel according to the first aspect of the invention to grade road shoulders.
In a third aspect of the invention, the objects of the invention and more are solved by a vehicle comprising a shovel according to the first aspect of the invention. While the shovel of the first aspect of the invention is in most embodiments adapted to be detachably mounted on a vehicle, it is also contemplated that a vehicle designed for grading road shoulders could comprise a shovel of the first aspect of the invention permanently mounted on the vehicle.

Brief description of the drawings

The invention will be described in more detail below by means of nonlimiting examples of embodiments and with reference to the schematic drawings, in which:

Fig. 1 shows a back view of the shovel of the invention used to grade a road shoulder;
Fig. 2 shows a front view of the shovel of the invention used to grade a road shoulder;
Fig. 3 shows a perspective sketch of the shovel of the invention from a front view;
Fig. 4 shows a schematic diagram of a transmission for an embodiment of the invention; and
Fig. 5 shows a front view of part of the shovel of the invention mounted on a vehicle.

Detailed description of the invention

In the following, embodiments of the invention will be described in further detail. Each specific variation of the features can be applied to other embodiments of the invention unless specifically stated otherwise.
Turning first to Figs. 1 and 2 in which an embodiment of the shovel 1 of the invention is shown from a back and a front view, respectively. The shovel 1 is adapted to be mounted on a vehicle (as shown), whereby the vehicle may move the shovel 1 in a movement direction (M) along the road verge to grade the road shoulder. The shovel 1 comprises a shovel bucket 10 with a leading edge 11 on the front of the shovel bucket 10 and a cutting axle 20 which is rotatably mounted in front of the leading edge 11 with respect to the movement direction. The cutting axle 20 is adapted to cut an upper layer of soil and vegetation from underlying soil layers, such that the roots of the vegetation will not pull the underlying soil layers up with the upper soil layer, when the upper soil layer is shoveled onto the shovel bucket 10.
The shovel bucket 10 is formed by a bottom, two side walls and a back wall, such that soil and vegetation material shoveled onto the shovel bucket 10 during operation is collected in the shovel bucket 10 for later disposal. The leading edge 11 is formed on the front of the bottom of the shovel bucket 10 and is preferably tapered in shape, such that the leading edge 11 will more efficiently guide material onto the shovel bucket 10 during operation.
The shovel bucket 10 also comprises an attachment portion 12 adapted to enable the shovel 1 to be mounted onto a vehicle. The shovel 1 may be mounted on the front of a vehicle, but in the presently preferred embodiments, the shovel is adapted to be mounted on the side of a vehicle or on a pivotable arm, whereby the vehicle may drive on the road side while grading the road verge.
In the shown embodiment, the shovel bucket 10 is provided with a straight leading edge 11 which during operation is substantially perpendicular with the movement direction. The length of the leading edge 11, i.e. the width of the shovel bucket 11, should be approximately equal to the width of a standard traffic lane such that the graded road shoulder may serve as an emergency lane. The shovel 1 may however also be made wider or narrower depending on the intended use of the road shoulder.
The cutting axle 20 comprises a cylindrical axle which is connected to the shovel bucket 10 at the ends of the cylindrical axle by bearings such that the cutting axle 20 may be driven into rotation during operation. The cutting axle 20 comprises a number of protrusions 22 welded onto the cylindrical axle. The protrusions 22 extend outwards from the cylindrical axle, preferably at an angle between 5 and 65 degrees with respect to the normal vector of the cylindrical axle towards the rotation direction, such that the cutting axle 20 can cut an upper layer of soil and vegetation, when the cutting axle 20 is rotated and the shovel 1 is moved in the movement direction along the road verge.
In the shown embodiment, the cutting axle 20 is substantially the same length as the leading edge 11 and extends parallel with the leading edge 11 between the two side walls of the shovel bucket 10. The cutting axle 20 is mounted substantially flush with the leading edge 11 such that it during operation, when the shovel 1 is moved in the movement direction, cuts the upper layer of soil and vegetation from the underlying, whereby the leading edge 11 may easily scrape the loosened material onto the shovel bucket 10.
In most embodiments, the cutting axle 20 is arranged such that the central axis of the cutting axle 20 is aligned with the leading edge 11. In embodiments where the shovel 1 is intended to remove a thicker layer of soil, the cutting axle 20 may be shifted downwards such that the central axis of the cutting axle 20 is lower than the leading edge 11. Likewise, if the shovel 1 is intended to remove a thinner layer of soil, the cutting axle 20 may be shifted upwards such that the central axis of the cutting axle 20 is above the leading edge 11.
In the shown embodiment, the cutting axle 20 is mounted such that there is a 40mm spacing between the leading edge 11 and the cutting axle 20. This spacing is short enough so that the material cut by the cutting axle 20 is thrown over the cutting axle 20 and onto the shovel bucket 10 by the rotation of the cutting axle 20 rather than into the spacing between the leading edge 11 and the cutting axle 20, whereby the shovel 1 may be moved more easily as the leading edge 11 will have to scrape less material onto the shovel bucket 10. The spacing between the leading edge 11 and the cutting axle 20 is also large enough, that it may be avoided that rocks or other material is stuck between the leading edge 11 and the cutting axle 20, whereby rotation of the cutting axle 20 could be obstructed. It should be noted that the spacing between the leading edge 11 and the cutting axle 20 can vary from embodiment to embodiment depending on the diameter of the cutting axle 20 and the number of revolutions per minute (RPM) the cutting axle 20 is designed to be rotated at during operation.
To drive the cutting axle 20 into rotation, the shown embodiment of the shovel 1 further comprises a transmission 30 connected to the cutting axle 20 and adapted to be connected to an external drive source. In the shown Figs. the transmission 30 is connected to the vehicle, whereby the cutting axle 20 is provided with rotational power from the engine of the vehicle.
The shovel 1 further comprises a rolling coulter 13 rotatably connected to the shovel bucket 10 and mounted on one of the side walls adjacent to the cutting axle 20, such that the rolling coulter 13 may make a substantially vertical cut to separate material which is about to be shoveled onto the shovel bucket 10 from the adjacent soil and vegetation, whereby a better more well defined boundary between the road shoulder and the adjacent area, e.g. a ditch, is achieved. The rolling coulter 13 need not be driven into rotation by a motor like the cutting axle 20 as the movement of the shovel 1 is sufficient to produce the vertical cut into the soil. However, the rolling coulter 13 may in some embodiments also be connected to the drive source of the cutting axle 20.
Fig. 3 shows a sketch of an embodiment of the shovel 1 of the invention from a perspective front view. The shovel 1 of the invention is adapted for being moved, i.e. dragged or pushed, in a movement direction (M) along a road verge substantially parallel to the road as indicated by the directional arrow. The shown embodiment of the shovel 1 is symmetric so that it may be used in either side of the road, regardless of the direction of traffic. The transmission 30 may be attached on either the right or the left side of the shovel 1 depending on the vehicle the shovel 1 is to be mounted on and the direction of traffic. In some embodiments of the invention the shovel 1 may be asymmetric around its center axis.
Fig. 4 shows a schematic diagram of the transmission 30. The shown transmission comprises a gearbox adapted to connect the cutting axle 20 to an external drive source, e.g. an engine of the vehicle which the shovel 1 is mounted on. The shown transmission 30 comprises four gears, an input gear 33, i.e. the gear adapted to be connected to the external drive source, and output gear 31, i.e. the gear 31 connected to the cutting axle 20, and two intermediary gears 32.
The gears of the shown embodiments are made from iron, copper, alloys thereof, or metals/alloys with comparable or grater durability, such that the gearbox is capable of handling the torque and the rotational speeds needed to drive the cutting axle 20.
The ratio of the gear teeth and the number of gears may vary from embodiment to embodiment but in general, the ratio of the teeth and diameter of the gears may be configured to provide a suitable rotation speed and torque conversion between the external drive source and the cutting axle 20, and the number of gears may be configured to provide the correct rotation direction of the cutting axle 20.
Fig. 5 shows a part of an embodiment of the shovel 1 from a front view mounted on an arm 40 of a vehicle. Grey lines have been added to the figure to highlight the depth of the shovel bucket 10. To drive the cutting axle 20 the vehicle is connected to the transmission 30 via a flexible drive shaft cable 41 which allows a rotational force to be transferred from the vehicle 40 to the cutting axle 20. In other embodiments, the shovel 1 can comprise an electric motor to drive the cutting axle 20, such that the vehicle may transfer power via a power cable rather than a flexible drive shaft cable 41 in order to drive the cutting axle 20.
The shovel 1 of the shown embodiment comprises an axle bearing 21, e.g. a ball bearing, which is attached to the shovel bucket 10 and is connected to the cutting axle. The axle bearing 21 allows part of the forces applied on the cutting axle 20 to be transferred to the shovel bucket 10 through the axle bearing 21, thereby allowing the cutting axle 20 to be manufactured in a less rigid a more cost efficient material.
In the shown embodiment, the axle bearing 21 is connected to the cutting axle at the midpoint of the length of the cutting axle 20, i.e. at 0,5 times the length of the cutting axle 20. However, other embodiments may comprise one or more axle bearings 21 connected to the cutting axle 20 in the length interval from 0,1 and 0,4 of the length of the cutting axle 20, and in the length interval from 0,6 and 0,9 of the length of the cutting axle 20. This may be advantageous as some regional areas has a tradition of placing manholes and drains in the middle of the road shoulder. Placing the axle bearing(s) 21 away from the midpoint of the length of the cutting axle 20 may allow the shovel 1 to be brought closer to the cover of such manholes or drains, thereby allowing a more even grading of the road shoulder.
In the shown embodiment, the protrusions 22 which enables to cut an upper layer of soil and vegetation from the soil below is arranged such that they are separated radially around the cutting axle 20. The cutting axle 20 could in principle function with a single protrusion 22 protruding from the cylindrical surface of the cutting axle 20 and extending along the length of cutting axle 20. However, by providing the cutting axle 20 with several protrusions 22 separated radially, the cutting axle 20 may be driven at fewer RPM and with less torque.

Claims

A shovel (1) adapted for being connected to a vehicle and for being moved in a movement direction (M) along a road verge, said shovel (1) comprising a shovel bucket (10) with a leading edge (11);
characterized in that the shovel (1) further comprises a cutting axle (20) rotatably connected to the shovel bucket (10) and arranged in front of the leading edge (11) with respect to the movement direction (M), said cutting axle (20) being adapted for cutting an upper layer of soil of the road verge.
The shovel (1)of claim 1, wherein the leading edge (11) is straight and the cutting axle (20) is substantially parallel with the leading edge (11).
The shovel (1) of claim 1 or 2, wherein the cutting axle (20) is arranged 10 to 400mm in front of the leading edge (11).
The shovel (1) of any of the previous claims, wherein the cutting axle (20) is adapted for being connected to an external drive source, preferably provided by the vehicle.
The shovel (1) of claim 4, wherein the shovel (1) further comprises a transmission (30) coupled to the cutting axle (20) and adapted for connecting the cutting axle (20) to the external drive source.
The shovel (1) of claim 5, wherein the transmission (30) comprises a gearbox.
The shovel (1) of any of the previous claims, wherein the shovel (1) further comprises one or more axle bearings (21) attached to the shovel bucket (10) and connected to the cutting axle (20) at points along the length of the cutting axle (20) between the ends of the cutting axle (20) to support the cutting axle (20).
The shovel (1) of claim 7, wherein a first axle bearing is connected to the cutting axle (20) at a position located in the length interval from 0,1 and 0,4 of the length of the cutting axle (20), and a second axle bearing is connected to the cutting axle (20) at a position located in the length interval from 0,6 and 0,9 of the length of the cutting axle (20).
The shovel (1) of any of the previous claims, wherein the cutting axle (20) is adapted to rotate at 50 to 4000 rpm during operation.
Use of the shovel (1) of any of the previous claims to grade a road shoulder.
A vehicle comprising a shovel (1) of any of claims 1 to 9.