GB2226839A - Road-laying machine - Google Patents

Abstract

A road-laying machine comprises a sledge frame having one or more runners for engaging the ground surface, a hopper supported by said frame and tapering downwardly towards an elongated aperture at a height above that of the ground-engaging runner surface, means for adjusting the vertical distance between the elongated aperture and the ground- engaging surface, and a towing connection to enable the sledge frame to be moved over the ground in a direction transverse to the length of the elongated aperture. <IMAGE>

Description

Road-laying Machine The present invention is a machine which has been devised to enable a road to be laid, especially in settings where oonventional road-laying equipment and operative teams would be unduly or prohibitively expensive.

Conventional practice in the laying of roads usually entails several successive operations and several items of heavy equipment, supported by the necessary manpower. Although high quality roads can be produced in this way, there are many situations where the demands on the road cannot justify the considerable equipment and labour oosts entailed. Fbr example, if a road is required to afford temporary access to a new site during the initial construction phase, conventional laying of an asphalt road is unduly expensive and it may be decided simply to drive over the existing land surface, zilch is an unsatisfactory way of solttdng the problem, Similarly, in the case of farm roads or forest access roads, where use of the road is relatively limited and/or the oost must be borne wholly by the landowner, conventional road-laying methods are prohibitively expensive.

Nonetheless, sane form of road surface is highly desirable, if it can be provided at an acceptable met.

To meet this med for a road surface at reasonable cost, a cammon practice is to abtain quantities of gravel or similar stone and to diztp it in loads along the intended ray. The loads must then be distributed as miformly as is practicable and then levelled, using a simple loader or similar equipment.

A reasonably uniform road surface can only be attained by the expenditure of considerable time and care, which of course adds to the cost of the exercise.

It is therefore an object of the present invention to provide a machine which enables a road of acceptable quality to be laid in a single operation and with minimal use of labour.

The road-laying machine according to the present invention comprises a sledge frame having one or more runners for engaging the ground surface, a hopper supported by said frame and tapering downwardly towards an elongated aperture at a height above that of the ground-engaging runner surface,' means for adjusting the vertical distance between said elongated aperture and said ground-engaging surface, and a towing connection to enable the sledge frame to be moved over the ground in a direction transrse to the length of said elongated aperture.

In use, the zipper is filled with a material selected for the road surface and the height of the elongated aperture above the ground is set to correspond with the desired depth of the surface layer. The sledge is then towed over the ground and the road is thus laid in a single operation, if desired by ane operator. Optionally, the road thus figured may be aonsolidated by zit rolling.

The sledge frame preferably takes the form of an open structure, preferably of steel section, of solid construction to withstand the intended heavy duty which it mst perform and designed essentially as a support for the ground-engaging inner or runners and for the hopper and any associated components. The structure preferably cerises two such runners, spaced apart in parallel relationship along the opposite sides of the france, with the hopper extending between them.

The hopper is formed to taper domwardly towards the elongated aperture and conveniently is constructed fran a pair of end-plates and downwardly-verging front and back plates.

Preferably the front plate and end plates are set at a fixed height above the ground-engaging surface and the vertical position of the aperture is set by adjustment of the hopper back-plate towards or away fran that surface. st conveniently, the front plate of the hopper is inclined at an acute angle to the vertical and the back plate is in a generally vertical orientation.

It is particularly preferred that the front plate of the hopper be in at least two sections, such that remval of an upper section reduces the capacity of the hopper but improves access to the hopper to load it with material. In this way, the sledge may be towed in use by a tipper lorry and the hopper may then be continuously replenished from the tipper as the road is laid.

The hover capacity may be further modified by the fitting of removable baffles at the sides swithin the interior of the bor, sueh that the effective width of the hopper and the length of the elongated aperture are reduced then a narrower road is to be laid.Alternatively, but less satisfactorily, the length of the acre may be modified by means of plates fitted to the exterior of the wiper. Thus, by means of appropriate baffles, a road-laying machine suitable for laying a road surface of the order of 3 metres.wide may be modified to lay a surface of about 2.5 or,2 metres wide.

A towing connection is provided to enable the sledge to be moved to lay the desired surface. At its most convenient, the towing connection may comprise two chains (or a continuous chain) extending from the front of the respective sides of the sledge to a towing hook or eye, by means of which the sledge may be connected to a tractor, a loader or a lorry or other vehicle.

In a particularly preferred form of the invention, a vertically-adjustable blade is provided, extending across the sledge generally parallel to, and rearwardly of, the elongated aperture. Pbr example, such a blade may extend close to the rearward edge of the sledge, spaced fran the hopper back-plate by a distance which may, for example, be of the order of one metre. The blade operates to move the uniformity of the upper surface of the road material when the latter has been laid and may be adjusted, in cooperation with the hopper back-plate, to adapt to different desired depths of road surface.

Preferably the blade is Spring-loaded in a downward direction.

Tb enable the road-laying mashine according to the present invention to be moved fran one site of use to another, roadwheels are preferably provided. Since the averall width of the machine will usually be greater than that of a normal narrow road, the wheels are preferably designed to allow the machine to be towed sidays relative to its direction of use, so that the machine may legally and safely be taken on to pUblic roadways.

The wheels may be mounted for retraction fran their position of use into a stowed position but it is particularly preferred to provide demountable wheels. Such demountable wheels may be provided with stowage locations upon the machine for when the latter is in use laying a road.. At least when the reels are of the demuntable type, jacks may be provided to enable the machine to be lifted away fran the grood for fitting and demounting of the wheels.Such jacks may be hydraulically operated or may be positioned near to, but spaced fran > the centre of gravity of the machine, to. enable the machine to be tipped about the jacks for the wheels to be fitted or rerrved. Towing of the machine along a roadway, and the raising and lowering or tipping of the machine, may be assisted by the provision of a suitable drawbar.

The machine may be used for laying one or more of a wide range of materials, including gravel, hoggin and crushed brick.

A particularly suitable and preferred material is that knows as "road planings", which are the scrapings removed fran a tarmac road when it is being prepared for recoating. By the use of this latter material in particular, a very acceptable road may be laid by a single operator using the machine according to the present invention.

The machine may be used for laying a base and/or a surface layer. As a1re indicated, the road, once laid, may advantageously be rolled to consolidate the surface.

The invention will now be dee=ibed with referEnce to .the accompanying drawings, which illustrate one preferred embodiment of the road-laying machine according to the present invention and wherein:- Fig. I is an elevation fran one side of the machine; Fig. 2 is a cross-sertisnal view corresponding to Fig. 1; and Fig. 3 is a perspective view of the machine, prepared for towing on a public roadway.

The illustrated machine is constructed as an open framework of box-section steel members 10 and channel section steel mixers 11 to form a sledge supported on a pair of parallel runners 12. The sledge carries a hopper 13 comprising side panels 14 and 15, a front panel 16 and rear panel 17; panel 16 is inclined to the vertical and panel 17 is essentially vertical so that these two panels converge downwardly to define at their lower ends an aperture 18 running across the full width of the machine.

The hopper front-panel 16 is formed in two sections 16a and 16b. The uE per section 16a is shown in position but may be removed so as to lower the front upper edge of the hopper and make the interior of the hopper more readily accessible from that dixon. The rear panel 17 is vertically adjustable by means of locking bolts 19 hid are slidable in vertical slots 20, so that the tower edge of the panel may be set at a predetermined height above the groF. That bright is an important determinant of the thickness of the road material laid by the machine.If desired, additional plates (not shown) may be fitted at the ends of the lower edge of the rear panel 17 in order to yield a layer of reduced thickness adjacent to the edges of the resulting road, to form a canter to assist drain-off of surface water.

Towards the rear of the machine a levelling blade 21 in the form of a transverse inverted channel section is pivoted at 22 upon arms 23 to enable its height above ground level to be adjusted by screws 24. The blade 21 is pressured downwardly be helical compression springs 25. A towing chain 26 links the forward end of the machine to a towing hook 27.

In use, the hopper is filled to a desired level with road surfacing material 28, for example road planings, and the sledge is towed along behind a suitable vehicle (not shown) in the direction of the arrow 29 of Figs. 1 and 2. Fbr example, the sledge may be towed behind a tipping lorry, the upper front hopper panel 16a being roved to allow fresh material to be tipped directly into the hopper fran the lorry as the chine proceeds. As one alternative, the sledge may be loaded by means of a front loader vehicle, which may then, by driving in reverse, tow the sledge and lay the road surface.

As As the machine proceeds, the road material 28 is fed continuously on to the ground via the aperture 18, the thickness of the layer being detwdfled initially by the vertical position of the hopper back-panel 17 and then levelled off by the levelling, blade 21. The road surface thus produced may subsequently be consolidated by rolling.

When the machine is to be transported to a new site, roadwheels 29 are fitted by means of sockets in the ends of two of the box-section members 10. Jacks 30 (of which one is shown in Fig. 3) are provided to cooperate with a drawbar (not shown) to allow one side of the machine to be raised from the ground to enable the wheels 29 to be fitted. When the machine reaches the new irking site, the wheels 29 and the drawbar are red and stoeed in suitable stowage positions on the sledge frame (Figs. 1 and 2), so that they remain readily available but do not impede normal use of the machine during road-laying.

Claims (14)

1. A road-laying machine capprising a sledge frame having one or nore runners for engaging the ground surface, a hopper supported by said frame and tapering damwardly towards an elongated aperture at a height above that of the groundengaging runner surface, Means for adjusting the vertical distance between said elongated aperture and said groundengaging surface, and a towing connection to enable the sledge frame to be moved over the ground in a direction transverse to the length of said elongated aperture.

2. A road-laying machine as claimed in claim 1, wherein the sledge frame is an open structure of steel section and having two said runners, spaced apart in parallel.

3. A road-laying machine as claimed in either of the preceding claims, wherein the hopper comprises a pair of end-plates and domwardly converging front and back plates and wherein the position of the back-plate is adjustable.

4. A road-laying machine as claimed in claim 3, herein the front plate of the hopper is inclined at an acute angle to the vertical and the back plate is in a generally vertical orientation.

5. A road-laying machine as claimed in either of claims 3 and 4, wherein the front plate of the hopper is in at least two sections, such that an upper section is removable.

6. A road-laying machine as claimed in any of the preceding claims, provided with rsvable baffles or plates to enable the length of the elongated aperture to be reduced.

7. A road-laying machine as claimed in any of the preceding claims, wherein the towing connection comprises two chains or a continuous chain, extending fram the front of the sledge sides to a towing hook or eye.

8. A road-laying machine as claimed in any of the preceding claims, further comprising a vertically-adjustable blade extending across the sledge generally parallel to, and rearward of, the elongated aperture.

9. A road-laying machine as claimed in claim 8, wherein said blade is spring-loaded in a downward direction.

10. A road-laying machine as claimed in any of the preceding claims, having delrDuntable roadkeels.

11. A road-laying machine as claimed in claim 10, provided with stowage locations for the roadReels upon the machine.

12. A road-laying machine as claimed in claim 10 or 11, having jacks to assist fitting and remounting of the roadwheels.

13. A road-laying machine as claimed in any of the preceding claims, having a drawbar to enable the machine to be towed along a roadway.

14. A road-laying machine substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.