AU2007200827A1 - Grading machine - Google Patents

Description

GRADING MACHINE TECHNICAL FIELD: This invention relates to grading machines for levelling and smoothing roads, fields and the 00 like.

1 BACKGROUND ART: 10 Grading machines comprising an elongate chassis with pairs of front and rear wheels, an engine, a cab and an elongate scraper blade mounted substantially medially between the front and rear wheels are well known. The blade is mounted to be able to rotate about a vertical axis between positions inclined to either side of the direction of travel (yaw) and (b) a horizontal axis in the direction of travel (bank/roll). In use, yaw determines the side on which scraped material will be discharged and bank determines whether the resulting surface will be horizontal or sloped to provide a desired road camber.

Grading machines are relatively expensive, so their hourly operating costs are considerable. This determines the manner in which they are used, ranging from single pass use for minor and farm roads, to multiple pass use for high traffic roads. The latter may also be combined with wetting the soil using a separate water tanker/bowser.

Regardless of the manner of use, experience shows that most sand roads are not graded often and well enough.

Thus the invention seeks to provide a grading machine that is significantly less expensive than known graders and optimally can be used with fewer passes and provide a reasonably high quality of graded surface at a substantially reduced cost.

DISCLOSURE OF THE INVENTION: One aspect of the invention provides a grading machine comprising: an elongate chassis; pairs of front and rear wheels for supporting the chassis; an elongate scraper blade; mounting means for mounting the scraper blade to rotate about vertical and horizontal axes; -2actuating means for rotating the scraper blade about vertical (yaw) and horizontal (roll) axes; and towing means for coupling the machine to a suitable tractor to draw the machine in use.

Preferably the grading machine has a roller extending substantially the width of the scraper r blade, the roller being positioned adjacent the pair of rear wheels. At least one of the roller 00 and the rear wheels is movable vertically with respect the chassis, so that the wheels may Obe used for traveling or grading if desired, while the roller can be used during grading when required. Conveniently the rear wheels are movable.

N The mounting means comprises an articulation (joints) permitting vertical and horizontal rotation of the scraper blade and rams for controlling the rotation. Some of the rams may be connected to the chassis.

Preferably a tank is mounted on the chassis. The tank may be filled with water for wetting a surface being graded and/or for adding mass to the machine to ensure the scraper can be pushed or vertically loaded to a desired depth for grading.

Preferably a cab is mounted at the rear of the chassis and is provided with means for controlling the yaw and roll of the scraper blade.

Preferably a ripper tool, such as a row of ripper teeth, is provided adjacent the front wheels, the ripper tool being mounted on the chassis for movement between a retracted position and a position in which the teeth penetrate the ground in use.

Another aspect of the invention provides a grading machine comprising: an elongate chassis; pairs of front and rear wheels for supporting the chassis; an elongate scraper blade; articulation means to permit the scraper blade to rotate about vertical (roll) and horizontal (yaw) axes; and rams for controlling rotation of the scraper blade.

Another aspect of the invention provides a grading construction comprising a motorised 35 tractor and an unmotorised grading machine as described above.

-3- Further features, variants and/or advantages of the invention will emerge from the following non-limiting description of an example of the invention made with reference to the accompanying schematic drawings and from the claims, which are to be regarded as an integral part of this description.

BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1 shows a side view of a tractor and grading machine of the invention; 00 Figure 2shows a plan view of the tractor and machine of Figure 1; SFigure 3shows a side view of part of the machine of Figure 1 on an enlarged scale; and Figure 4shows a plan view of the detail of Figure 3.

N DESCRIPTION OF ILLUSTRATED EMBODIMENTS: In the drawings the same or similar parts have the same reference numbers, certain parts having sub-numbers to identify them as part of a component. The drawings are 15 deliberately simple for clarity of illustration and description of the main components of the machine. A workable construction is shown, but persons skilled in the art will easily be able to provide alternative and/or more detailed constructions and engineering drawings therefor for building a machine in practice.

The drawings show a four-wheel-drive tractor 10, of any suitable type and make, drawing a grading machine 12.

The machine 12 comprises a chassis composed of two spaced apart beams 14 and legs 16 depending from the beams, a pair of front wheels 18 mounted on a common axle 20, a pair of rear wheels 22 each of which is supported on a trailing arm or link 24 and a stub axle 26, an elongate roller 28, a cab 30, an elongate scraper blade 32, and mounting means 34 for adjustably supporting the scraper blade on the chassis. The rear wheels are shown in their inoperative position in Figure 1. Hydraulically extendable legs 28.1 mount the roller to the chassis. A triangular draw bar 50 projects to the front of the machine to attach to the three-point hitch of the tractor A ripper tool 36 comprising a plurality of ripper teeth 36.1 is pivotally mounted on the draw bar and actuated by rams 36.2 (hydraulic piston and cylinder assemblies) to move relatively to the draw bar. The rams move the ripper teeth between an operative position in which they penetrate the ground and an inoperative position clear of the ground.

The mounting means 34 comprises spaced side plates 38 pivotally mounted at 38.1 on the front of the chassis, a draw bar 42 spaced longitudinally from the side plates, and upper and lower hinges 40 having vertical hinge pins 40.1 pivotally connecting the draw bar to the IN side plates. Rams 46 are provided between the chassis and side pla !es to control movement of the scraper blade and mounting means 34 vertically.

SThe scraper blade 32 is supported by two trailing arms 44 and a cross-beam 44.1 on the 00 draw bar. The scraper blade is slidably guided to move sideways along the cross-beam, a Oside shifting ram 44.2 being provided to control the position of the blade. The arms are connected to a mounting block 43 that has a robust axle or stud 43.1 projecting forwardly Ointo a mating bore in the draw beam 42; this enables the arms and scraper blade to rotate with respect to the mounting means. Vertically disposed rams 43.2 on opposed sides of the draw bar 42 control rotational movement of the arms about the axis of the axle 43.1 and hence the scraper blade in bank or roll movement.

Rams 48 are provided between the side plates 38 and draw bar 42, to control movement of the scraper blade in yaw, ie. to discharge material to one side of the machine or the other.

A tank 52 is mounted on the chassis beams 14. Water can be discharged from the tank via an outlet manifold or spray 54 position behind the ripper tool and in front of he scraper blade.

In practice the grading machine is used as follows. The machine 12 is coupled to the three-point hitch of tractor 10 and hydraulic fluid cables are connected between the machine and tractor. The rear wheels 22 are lowered by ram 56, so that the grading machine is supported on the front and rear wheels. The scraper blade is lifted to its maximum height by rams 48 at which stage it is mechanically secured to the chassis by lock pins, not shown, which pass through registering holes in flanges 58 on the scraper arm and flanges 60 on the beams 14. The machine can be now be driven safely to a work site.

At the work site, the rear wheels are raised so that the chassis rests on the front wheels and roller. An operator in the rear cab adjusts the ripper tool, if required, attitude of the scraper blade and attitude of the roller to provide a desired finish to a road being graded.

The roller attitude in roll/bank may be coupled to that of the scraper blade, so that it automatically follows the setting of the blade, or may be independent so that the attitude of the roller can counterbalance crabbing forces generated on the scraper blade. In use, the tractor is driven by a driver and the grading machine is controlled independently by an operator in the rear cab makes who adjustments as required, such as ripping, watering, crolling, etc.

A major benefit of the grading machine described above is that it is of relatively low cost in that it does not include the engine, gearbox, double rear wheels, tandem drive chain and sprockets, suspension, and ring gear of known graders. It is used with any suitable tractor, Swhich is easily available, much less costly to purchase, repair and restore than a grader, 00 and can be used for other purposes when not required for grading. Also the machine carries its own water supply, which adds to its static mass and obviates the use of a separate water tanker vehicle and driver. Also a horse and load-bed trailer is not required Sfor moving he machine as would be the case for most known graders moving over relatively long distances.

As will be appreciated the machine can be used simultaneously to rip, wet, grade and roll; 15 wetting is directly into the furrows; the graded surface is compacted making it smoother and longer lasting; requires fewer passes than known grading machines and systems to achieve a desired effect; requires less manpower to operate and can be used everyday if required; the roller also inhibits crabbing; and the combination separates the driving and operating functions, so that maximum effectiveness can be achieved.

The invention is not limited to the precise details described above and shown in the drawings. Modifications may be made and other embodiments developed without departing from the scope of the invention as defined in the claims. For example the 25 articulation may also be applied to a motorised grader instead of the conventional ring gear construction, to provide the same functionality whilst enabling repairs to the articulation to be effected using simple engineering tools that may be available in remote locations.

In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" and variations thereof, such as "comprises" and "comprising", are used in an inclusive sence, ie. to specify the presence of the stated elements, without precluding the presence of or addition of further elements that may be optional or may appear in various or further embodiments of the invention.

-6- It is to be understood that if any prior art publication is referred to herein, such reference

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does not constitute an admission that the publication forms a part of the common general Sknowledge in the art, in Australia or any other country.

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Claims (14)

1. A grading machine comprising: T an elongate chassis; pairs of front and rear wheels for supporting the chassis; 5 an elongate scraper blade; mounting means for mounting the scraper blade to rotate about vertical (yaw) and 00 horizontal (roll) axes; 0 actuating means for rotating the scraper blade about the vertical and horizontal axes; and towing means for coupling the machine to a suitable tractor to draw the machine in use.

2. The grading machine of claim 1, further comprising a roller extending substantially the width of the scraper blade, the roller being positioned adjacent the pair of rear wheels.

3. The grading machine of claim 2, wherein at least one of the roller and the rear wheels is movable vertically with respect the chassis, so that the wheels may be used for traveling or grading if desired, while the roller can be used during grading when required.

4. The grading machine of claim 3, wherein the rear wheels are movable.

The grading machine of any one of claims 1 to 4, wherein a tank is mounted on the chassis.

6. The grading machine of any one of claims 1 to 5, wherein a cab is mounted at the rear of the chassis and is provided with means for controlling the yaw and roll of the scraper blade.

7. The grading machine of any one of claims 1 to 6, wherein a ripper tool, such as a row of ripper teeth, is provided adjacent the front wheels, the ripper tool being mounted on the chassis for movement between a retracted position and a position in which the teeth penetrate the ground in use.

8. The grading machine of any one of claims 1 to 7, wherein the scraper blade is movable laterally with respect to the mounting means, means being provided for moving the blade lateral when required. O

9. The grading machine of any one of claims 1 to 8, wherein the mounting means Scomprises an articulation (joints) permitting vertical and horizontal rotation of the scraper blade and rams for controlling the rotation, some of the rams being connected to the chassis.

C-I 5 The grading machine of claim 9, wherein some of the rams are connected to the chassis. 00

11. A grading machine comprising: an elongate chassis; 10 0 pairs of front and rear wheels for supporting the chassis; an elongate scraper blade; articulation means to permit the scraper blade to rotate about vertical (roll) and horizontal (yaw) axes with respect to the chassis; and 15 rams for controlling rotation of the scraper blade.

12. The grading machine of claim 11, wherein some of the rams are connected to the chassis.

13. A grading construction comprising a motorised tractor and an unmotorised grading machine as claimed in any one of claims 1 to 10 or claims 11 or 12.

14. A grading machine substantially as herein described with reference to and as illustrated in the drawings.