GB2486430A

GB2486430A - Apparatus for laying and grading the sub-formation of a path

Info

Publication number: GB2486430A
Application number: GB201021150A
Authority: GB
Inventors: Patrick James King
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-13
Filing date: 2010-12-13
Publication date: 2012-06-20
Anticipated expiration: 2030-12-13
Also published as: GB2486430B; GB201021150D0

Abstract

The apparatus, primarily for use on footpaths and the like that are bordered by parallel kerbs, comprises a frame 12-15 supportable on the kerbs such that it can move along the path and one or more transverse blades 31-34 mounted to the frame such that they extend across the path between the kerbs with the lower edges of the blade(s) extending at a depth below the top of the kerbs. The depth of the blade(s) may be adjustable with a blade preferably extended perpendicular to the kerbs in use. Wheels 22 may be provided to roll along the upper surface of each kerb. At least one spreader blade may be provided that extends at an angle to the kerbs, preferably with a number of spreader blades extending alternately from opposing sides of the frame. Also claimed is a method of laying and grading a sub-formation of a pathway.

Description

PATH LEVELLING APPARATUS

The present invention relates to apparatus for levelling foundations of pathways and the like. More particularly, but not exclusively, it relates to apparatus for grading the sub-formation of footpaths.

To produce a desirably smooth and even surface on a road, path or the like, it is necessary that the surface is laid on a firm and generally even foundation layer. In * Os British terminology, this is widely referred to as the "sub-formation", the "formation" * s*,** * being the underlying natural terrain. A consistently-laid sub-formation also provides *: . better support for the surface layer of the path, etc, potentially lengthening its service * S.....

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* The sub-formation for footpaths typically comprises a coarse gravel, deposited in a single layer. The use of multiple layers of aggregate with graduated particle sizes, often employed for roads, is usually unnecessary for footpaths designed for normal pedestrian traffic.

A variety of equipment has been devised for laying the sub-formation of roads. A road surfacing machine is generally a massive, slow-moving, self-propelled vehicle with complex hydraulically or electrically-driven arrangements to lay down gravel or aggregate evenly across an entire lane of a road being built or repaired, followed by laying down surfacing material at the rear of the machine. White it has been suggested that smaller versions of these machines might be used for the construction of footpaths, this approach is generally considered to be much too expensive, as regards both capital costs and running costs.

Instead, the customary approach to footpath construction is to dump piles of gravel or the like at intervals along the route of the path (previously cut into the natural formation) and for a team of workers provided with shovels to distribute the gravel or other aggregate within this cut. The correct level of the gravel is estimated by eye, and periodically checked using strings and plumblines. This is not a wholly reliable * . method, and progress may be greatly slowed by frequent level checks. This is likely to * S*s** * S escalate overall costs significantly. S. * * S * * S. S*** * e

If the sub-formation is not evenly deposited and spread, the surface laid on top of it is

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* liable to be uneven, particularly if the footpath is to be flagged or finished with block paving. Footpaths beside roads are commonly specified to be finished with a particular thickness of "black" (also known as asphalt, bitumen aggregate, tarmacadam, asphalt concrete or blacktop, depending on the location), the upper surface of which should extend substantially level with the kerbs lining each edge of the footpath. If the sub-formation is not correctly laid, it can be difficult to meet the specifications for thickness and for surface finish, and the "black" may subside, crumble or crack if not of the right thickness or poorly supported by the sub-formation.

It would hence be beneficial if apparatus andlor a method of construction could be devised to obviate some or all of the above drawbacks of existing approaches to laying the sub-formation of paths and the like, while improving the accuracy of grading andlor the speed of laying the sub-formation.

According to a first aspect of the present invention, there is provided apparatus for use in laying and grading a sub-formation of a pathway, said pathway being defined between first and second generally parallel kerb means, wherein said apparatus comprises frame means supportable by said first and second kerb means and adapted to be propelled along said kerb means longitudinally of said pathway, and transverse blade means so mounted to said frame means as to extend substantially between the * *** * * first and second kerb means, with a lower in use, edge of the transverse blade means * * * extending at a set depth below an upper surface of the kerb means. ** ss * *

Preferably, the apparatus comprises adjustment means to set said depth of the lower *.es edge of the transverse blade means to a desired value.

Advantageously, said transverse blade means extends generally perpendicularly to each kerb means.

Preferably, the apparatus is provided with wheel means adapted to roll along an upper surface of each said kerb means.

Advantageously, the apparatus is provided with a plurality of said wheel means.

The frame means preferably extends, in use, both transversely across the pathway and longitudinally thereof In a preferred embodiment, the apparatus further comprises at least one spreader blade means extending at an oblique angle to the kerb means.

Advantageously, the or each said spreader blade means is so mounted to the frame means as to extend from adjacent one of the kerb means partway towards the other of the kerb means, so as to leave a gap between its respective end and said other kerb means. * ee * S * SS

* The apparatus may comprise a plurality of said spreader blade means.

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Said plurality of spreader blade means may then be disposed along the frame means, so as to extend alternately from adjacent each opposing kerb means in turn. S...

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SSS 5.5 * S Said plurality of spreader blade means may thus together form a herringbone pattern.

A lower, in use, edge of the or each spreader blade means may extend at a set depth below an upper surface of the kerb means.

Optionally, said lower edge of the or each spreader blade means may be at substantially the same depth as the lower edge of the transverse blade means, or slightly higher.

Preferably, the apparatus comprises towing means by which it may be drawn along the pathway.

Said towing means may comprise towing eye means, connectable to a towing vehicle travelling along the pathway.

The apparatus may comprise frame means having a front end, a rear end and two side elements, wherein the towing means is mounted to said front end of the frame means, the transverse blade means is located adjacent the rear end of the frame means, and the or each spreader blade means extends from a respective side element of the frame * * **** * means at a point intermediate between said ends thereof * ****. * *

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* The, or a foremost of the, spreader bar means may extend from a side element of the *51e* * S frame means at a point adjacent the front end thereof

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The apparatus may be provided with one or more guide plate means, disposed to extend in use generally parallelly adjacent an inner or an outer face of a respective kerbstone means, so as to maintain the apparatus atop and aligned with the kerb means.

According to a second aspect of the present invention, there is provided a method of laying and grading a sub-formation of a pathway, comprising the steps of forming a cut along a route for the pathway, installing a substantially continuous line of kerb means along each lateral edge of said cut, providing apparatus as described in the first aspect above, so disposing said apparatus that it is supported between the lines of kerb means, depositing a supply of particulate foundation material within the cut, and moving the apparatus along the cut such that the transverse blade means of the apparatus contacts the foundation material and pushes forwards any foundation material located above a level defined by a lower edge of the transverse blade means.

Preferably, apparatus comprising at least one oblique spreader blade means is provided, and the foundation material is so deposited that it is first contacted by the spreader blade means.

* The spreader blade means thus spreads the foundation material evenly from side to * ***.* * * side of the pathway cut, before the transverse blade means levels the foundation material off at a desired depth.

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An embodiment of the present invention will now be more particularly described by * *. *..

way of example and with reference to the accompanying drawings, in which: Figure 1A shows, in schematic cross-section, a preparatory stage in the laying of a footpath; Figure 113 shows, in schematic cross-section, an intermediate stage in the laying of a footpath; Figure 1C shows, in schematic cross-section, a final stage in the laying of a footpath; Figure 2 is a perspective view from in front, above and to a right side of a path grading apparatus embodying the present invention; Figure 3 is a perspective view from in front and above of the path grading apparatus shown in Figure 2; and Figure 4 is a schematic frontal elevation of the path grading apparatus shown in Figure 2, in use to grade a sub-formation of a path.

Referring now to the Figures, and to Figures IA to 1C in particular, stages of the construction of a footpath 1 are shown. In this case, the footpath 1 is being constructed along a margin of a road 3. (The construction of garden paths 1 and the like would proceed along very much the same lines). S... * *

A route for the pathway I is first formed by digging through the underlying terrain 2 (the "formation") to form a shallow trench or cut. (Figure 1A). This may be done * manually, but is usually carried out with a small tracked vehicle equipped with a digging scoop or bucket on an articulated arm (a so-called "mini-digger"). A S...

* ..: continuous line of kerbstones 4, 5 is then installed along each side wall of the cut for the pathway 1. Where a footpath I is laid adjacent a road 3, relatively substantial kerbstones 4 are used, often with a profiled face aligned towards the road 3. Where the footpath is adjacent natural terrain 2, relatively narrow kerbstones 5 may be used instead. (A garden pathway 1 would therefore usually have a line of narrower kerbstones 5 along each edge).

The cut of the pathway 1 is then partially filled with coarse particulate material, such as various sizes of aggregate, particularly gravel, or in some cases rubble or road surface planings from a tom-up or repaired road or path. Typically, a mini-digger would be driven along the cut of the pathway 1, scooping batches of gravel or the like from a stock carried by a further vehicle, conveniently one passing along the adjacent road 3. This gravel, etc, would be piled at intervals along the cut 1, and would then be spread out across the cut 1 by a team of workers with shovels. This creates a foundation, or "sub-formation" 6 for the pathway 1 (Figure IB).

A surface layer 8 of the pathway 1 is then laid down on top of the sub-formation 6 (Figure IC). The surface layer 8 may comprise a wide range of materials; in this example, the footpath 1 is finished with a layer of asphalt (also variously known as bitumen, bitumen aggregate, tarmacadam, asphalt concrete, blacktop or simply "black"). Other widely-used materials for this surface layer 8 are concrete or stone PeS.

flags, block paving or poured concrete. In each case, it is highly desirable that a top surface of the surface layer 8 is substantially flat and level with a top surface of the * * respective kerbstones 4, 5 to either side of the pathway 1. *00

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* For a pathway I surfaced with "black", it is standard practice to specify the thickness of "black" to be laid down, in order for the pathway 1 to stand up to expected levels of use and climatic conditions for its planned service of life. It is therefore desirable that the material of the sub-formation 6 is spread evenly across the pathway 1 from kerbstone 4 to kerbstone 5 and has a substantially level upper surface at a set depth 7 below an line extending between respective upper surfaces of each line of kerbstones 4, 5 (Figure 1B).

When the sub-formation 6 is spread by shovel, it is difficult to guarantee evenness.

The standard method for checking that the depth 7 of its upper surface is correct involves stretching strings between the kerbstones 4, 5 and dropping plumb lines from the string to the upper surface. This is an inexact and time-consuming procedure.

As a result, laying pathways 1 properly is a relatively slow procedure. A good rate for a skilled team is to lay 100 metres of footpath 1 in a ten-hour shift.

Figures 2 and 3 show path grading apparatus 11 embodying the present invention.

The path grading apparatus 11 comprises a generally rectangular frame made up of four frame members 12, 13, 14, 15, each comprising an elongate steel section. A first 12 and a third 14 frame member extend in parallel, spaced apart by a second 13 and a fourth 15 frame members, each extending between the first 12 and third 14 frame Sn. * S

* members and at right angles thereto. The second 13 and fourth 15 frame members are * **** * S *: substantially the same length, but the first frame member 12 is significantly longer * than the third 14. Thus, the second frame member 13 links a respective distal end of ** S... * .

each of the first 12 and third 14 frame members while the fourth frame member 15 S...

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links a proximal end of the third frame member 14 to a point part-way along the first frame member 12. A proximal portion 16 of the first frame member 12 thus extends outwardly beyond the rectangle defined by the first to fourth frame members 12, 13, 14, 15. A fifth, central frame member 17 extends parallelly to the first 12 and third 14 frame members between a midpoint of the second frame member 13 and a midpoint of the fourth frame member 15. (Narrower embodiments of the apparatus are envisaged with shorter second 13 and fourth 15 frame members and without the fifth frame member 17 along the centreline). A towing eye 18 is mounted at a midpoint of the fourth frame member 15, marking a front of the apparatus 11.

The path grading apparatus 11 is provided with four vertically-extending screw jacks 20, each operated with a handle 21 at its upper end and having a nylon wheel 22 mounted at its lower end. The screw jacks 20 are mounted respectively at a proximal and a distal end of the first frame member 12 and at a proximal and a distal end of the third frame member 14. The screw jacks 20 mounted to the first frame member 12 are each mounted thereto by a laterally-adjustable connector 23. Each wheel 22 is aligned to allow the path grading apparatus 11 to be rolled in a direction parallel to the first 12, third 14 and fifth 16 frame members. The laterally-adjustable connectors 23 allow the track width between the wheels 22 on the first frame member 12 and the wheels 22 on the third frame member 14 to be adjusted as necessary (see below for details). S's * .

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Three angled grader bars 31, 32, 33 are mounted fixedly to the frame of the path * grading apparatus 11, within the rectangle defined by the first to fourth frame * . members 12 to 15. Each grader bar 31, 32, 33 comprises a blade aligned in a vertical 0*** S...

plane and extending from one of the first 12 and third 14 frame members partway towards the other 14, 12 thereof A first grader bar 31 and a third grader bar 33 each extend from the first frame member 12 most of the way across towards the third frame member 14, while a second grader bar 32, intermediate between the first 31 and the third 33, extends from the third frame member 14 most of the way across towards the first frame member 12. The blade of each grader bar 31, 32, 33 extends at an angle to the respective frame member 12, 14, slanted backwards towards its tip. The grader bars 31, 32, 33 thus form a herringbone pattern. The grader bars 31, 32, 33 extend generally in a horizontal plane, below the plane defined by the frame members 12, 13, 14, 15. Each grader bar 31, 32, 33 is welded to a respective first to third vertical side plate 35, 36, 37 extending parallel to and downwardly from an inner face of the respective frame member 12, 14.

A rear grader bar 34 is mounted beneath and parallel to the second frame member 13.

The rear grader bar 34 thus extends symmetrically across a distal end of the frame of the path grading apparatus 11, and is mounted to the third frame member 14 by means of a respective fourth vertical side plate 38, extending parallel to and downwardly from the third frame member 14. Unlike the first to third grader bars 31, 32, 33, the rear grader bar 34 comprises a blade that extends in a plane sloping forwardly towards its lower edge. *.. S * * *S*s

For strength, a connecting bar 39 (concealed in these views) extends between the first S..... * S

grader bar 31 adjacent its tip and the second grader bar 32, and a further connecting * . bar 39 extends between the second grader bar 32 adjacent its tip and the third grader bar 33. Each grader bar 31, 32, 33 may be also spot welded to an underside of the S...

fifth frame member 17 for additional strength. Removable guide plates 41 may be mounted to an outside face of the first frame member 12, extending parallel to the first frame member 12 and downwardly therefrom. Two lifting eyes 40 are provided on an upper surface of each of the first 12 and third 14 frame members.

The use of the path grading apparatus 11 is conveniently describable with reference to Figure 4. As in Figures IA to 113, a cut has been made through the "formation" 2 to define the course of a footpath, here adjacent a roadway 3. Continuous lines of kerbstones 4, 5 are emplaced to run along each side of the cut.

The path grading apparatus 11 is then lifted into position with the two pairs of wheels 22 resting on top of respective lines of kerbstones 4, 5. The laterally-adjustable connectors 23 may be adjusted to ensure that each wheel 22 is aligned suitably with the kerbstones 4, 5 (see horizontal arrows) while the screw jacks 20 are adjusted to position a lower edge of each grader bar 31, 32, 33, 34 at a desired depth beneath a plane joining an upper surface of each kerbstone 4, 5 (NB: in the particular embodiment illustrated, the grader bars 31, 32, 33, 34 are so mounted that a lower edge of each extends in the same plane; alternatively, a lower edge of the second grader bar 32 may be slightly deeper than a lower edge of the first grader bar 31, a lower edge of the third 33 may be slightly deeper than a lower edge of the second 32, and a lower edge of the rear grader bar 34 may be slightly deeper than that of the third * * * 33; or the first to third grader bars 31, 32, 33 may have their lower edges at the same * ** *e* * * level, with the rear grader bar 34 having its lower edge at a slightly deeper level).

*IS..s * * A depth of the lower edge of the rear grader bar 34 is selected to correspond to a *e*.

* ** desired thickness of "black" to be used to finish the pathway.

The path grading apparatus 11 is shackled by its towing eye 18 to a towing vehicle, usually a mini-digger travelling along the cut for the pathway. The apparatus 11 may thus be pulled along the course of the pathway, rolling along the upper surfaces of the kerbstones 4, 5. The vertical side plates 35, 36, 37, 38 will contact an inner face of a respective kerbstone 4,5 if the apparatus goes off course. Where a line of kerbstones 4 is adjacent a roadway 3 or other lower terrain, the guide plates 41 may also be fitted, to contact an outer face of the kerbstones 4, so as to ensure that the wheels 22 and the apparatus 11 as a whole remain aligned with the lines of kerbstones 4, 5 defining the pathway.

To lay and grade the sub-formation 6 of the pathway, gravel or the like is piled in the cut in front of the first grader bar 31. Most conveniently, a load of gravel, etc is transported along the roadway next to the mini-digger and the apparatus 11 towed thereby, and the mini-digger scoops piles of gravel from this load and dumps these piles immediately in front of the first grader bar 31.

Thus, the first grader bar 31 will be drawn into contact with these piles of gravel, etc. Gravel below the lower edge of the grader bar 31 is left substantially undisturbed, but as the apparatus 11 proceeds, the remainder will be pushed sideways along the backwardly-slanted grader bar 31 towards its tip. The gravel escaping the tip of the 0� first grader bar 31 will next contact the second grader bar 32 near its root, close to where it meets its respective side plate 35. The passage of the second grader bar 32 forwards will then push the remainder of the gravel sideways towards the respective * **.

tip of the bar 32. Once the remainder of the gravel escapes around the tip of the second grader bar 32, it will be collected and pushed back sideways again by the third grader bar 33.

Thus the gravel will be combed from side to side of the cut and back again, allowing it to fill any gaps left in the gravel beneath the level of the grader bars 31, 32, 33. The rear grader bar 34 carries out a final levelling step, ensuring that none of the gravel in the sub-formation 6 extends above the selected level within the cut, once the apparatus 11 has passed.

The pathway can thus be finished with "black" simply by topping up the cut, level with the upper surfaces of the kerbstones 4, 5. One may be confident that the depth 7 left for the "black" is consistent all along the pathway, with few or no localised hillocks or dips in the sub-formation 6 to spoil the appearance and durability of the "black" laid thereon.

It has been found that using the path grading apparatus, the sub-formation of a conventional path may be laid with the required accuracy at a speed equivalent to 1000 metres in a seven hour shift, compared with a speed of 100 metres in ten hours for the conventional method employing manual spreading and frequent checks of the correct level of the sub-formation 6. * *** * S S. .*

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Claims

CLAIMS1. Apparatus for use in laying and grading a sub-formation of a pathway, said pathway being defined between first and second generally parallel kerb means, wherein said apparatus comprises frame means supportable on said first and second kerb means and adapted to be propelled along said kerb means longitudinally of said pathway, and transverse blade means so mounted to said frame means as to extend in use substantially between the first and second kerb means, with a lower, in use, edge of the transverse blade means extending at a set depth below an upper surface of the kerb means.
2. Apparatus as claimed in claim 1, comprising adjustment means operable to set said depth of the lower edge of the transverse blade means to a desired value.S0SSSS* * *S* I**S* * 5
3. Apparatus as claimed in either claim I or claim 2, wherein said transverse blade means extends in use generally perpendicularly to each kerb means. ** .s * S*
4. Apparatus as claimed in arty one of the preceding claims, provided with wheel * means adapted to roll along an upper surface of each said kerb means.
5. Apparatus as claimed in any one of the preceding claims, wherein the frame means extends, in use, both transversely across the pathway and longitudinally thereof.
6. Apparatus as claimed in any one of the preceding claims, further comprising at least one spreader blade means extending in use at an oblique angle to the kerb means.
7. Apparatus as claimed in claim 6, wherein the or each said spreader blade means is so mounted to the frame means as to extend in use from adjacent one of said kerb means partway towards the other of said kerb means, leaving a gap between a respective end of the spreader blade means and said other kerb means.
8. Apparatus as claimed in either claim 6 or claim 7, comprising a plurality of said spreader blade means.S..... * .* *0s*.* *
9. Apparatus as claimed in claim 8, wherein said plurality of spreader blade * . means are so disposed along the frame means as to extend in use alternately 5* ..** * from adjacent each opposing kerb means in mm. ****I ***.I.....*
10. Apparatus as claimed in any one of claims 6 to 9, wherein a lower, in use, edge of the or each spreader blade means extends at a set depth below an upper surface of the kerb means.
11. Apparatus as claimed in claim 10, wherein the lower edge of the or each spreader blade means extends at substantially the same depth as or slightly higher than the lower edge of the transverse blade means.
12. Apparatus as claimed in any one of the preceding claims, comprising towing means by which the apparatus may be drawn along the pathway.
13. Apparatus as claimed in any one of the preceding claims, provided with one or more guide plate means, disposed to extend in use along an inner or an outer face of a respective kerb means, so as to maintain the apparatus atop and aligned with the kerb means.
14. Apparatus for use in laying and grading a sub-formation of a pathway substantially as described bercin with reference to the Figures of the accompanying drawings.* * *S* *
15. A method of laying and grading a sub-formation of a pathway, comprising the * : steps of forming a cut along a route for the pathway, installing a substantially continuous line of kerb means along each lateral edge of said cut, providing apparatus as claimed in any one of the preceding claims, so disposing said * *: apparatus that it is supported between the lines of kerb means, depositing a supply of particulate foundation material within the cut, and moving the apparatus along the cut such that the transverse blade means of the apparatus contacts the foundation material and pushes forwards any foundation material located above a level defined by a lower edge of the transverse blade means.
16. A method as claimed in claim 15, wherein said apparatus provided comprises at least one oblique spreader blade means, and the foundation material is so deposited that it is contacted by said oblique spreader blade means, prior to contacting the transverse blade means.
17. A method of laying and grading a subformation of a pathway, substantially as described herein and with reference to the Figures of the accompanying drawings. a**q* 0 * a a S..... * * * . * S S * .* a*Saa*S * aS *5*SSS..... * S