GB2035424A

GB2035424A - Machine for milling or peeling road surfaces

Info

Publication number: GB2035424A
Application number: GB7940589A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-11-27
Filing date: 1979-11-23
Publication date: 1980-06-18
Also published as: DE2851191A1

Abstract

In a machine for milling or peeling road surfaces comprising a motor driven chassis moving on wheels 2, 3 and/or tracks 4 and having a rotary milling or a fixed peeling cutter, such as drum 14, the road surface alongside the cutter is engaged by a pressure device, such as a spring-loaded skid 20 optionally associated with a vertical edging blade 28, to prevent damage to the road surface adjacent the surface being worked. The skid 20 may be replaced by a roller, a series of small rollers, an endless track or a rotary spider of spring-loaded pressure plates. The may also include a heating system and a conveyer system for the milled off or peeled off material. <IMAGE>

Description

SPECIFICATION Machine for milling or peeling road surfaces The invention relates to a machine for milling or peeling road surfaces comprising a motor driven chassis moving on wheels and/or on tracks on which at least one milling or peeling apparatus is provided, which in some cases may also include a heating system and a conveyor system for the milled-off or peeled-off material.

For peeling or milling road surfaces damaged by atmospheric influences or by heavy vehicle traffic, machines are frequently employed, which include one or a plurality of milling or peeling devices arranged one after the other in travelling direction, by which the worn road surface is removed in a certain predetermined width in one or several working operations. Particularly when removing the uppermost layer of the road surface, to a certain extent also when removing the lower road surface layer, the road surface adjacent and alongside the width of the track is affected at its edges insofar as its structure is loosened and lifted and pieces of material are torn from the layer. This leads after the subsequent application of the new road surface to unevennesses and joints in the road surface which necessitate the additional use of a heavy motor driven roller.This renders the mending of the road surface substantially more expensive leaving aside that the employment of the street roller necessitates a total blocking of the road during the rolling operation which would otherwise not be necessary.

Attempts have been made to eliminate this adverse effect by reducing the advancing speed, increasing the speed of the cutting roller in cutting devices, and special positions of the cutter knives in peeling devices. Although the above described effects were reduced, they could not totally be eliminated. At the same time however, the measures required for reducing the adverse effects lead to a decrease of the efficiency of the machine and hence to an increase of the mending costs per road length unit.

These disadvantages will be overcome by the present invention. It is therefore the aim of the invention to so improve the machine of the kind described in the beginning that the adverse effects as described, such as the loosening of the substructure, lifting of the road surface, and removal of larger pieces of material from the road surface areas adjacent and alongside the width of the road being treated, as well as the after effects are eliminated while the mending costs per road length unit are not increased.

In accordance with the present invention, this aim is solved in that at least the milling or peeling apparatus which treats the uppermost layer of the road surface is provided, within the range of the operative portion, at least on its front side averted from the road shoulders, with a pressure device having a pressure area associated with the road surface not to be treated.

By this feature of the invention, damage of the road surface adjacent alongside the width of the track being treated is safely avoided and the new road surface may be applied without any disturbing unevenness or joint between the new and the old road surface. Employment of a road roller is not required. Neither is the efficiency of the machine impaired in any way by this feature of the invention.

A particular advantage of the invention is seen in that, as will be shown in the following, the pressure device, which necessitates little costs, is applied.

In accordance with an advantageous embodiment of the invention, each of the milling or peeling apparatusses is provided, within the range of the operative portion of their front sides averted from the road shoulders, with a pressure device. This makes sure that the milling or peeling apparatusses, respectively, milling or peeling off the lower layers of the road surface do not have any adverse effects upon the adjacent road surface.

It has furtheron proved to be suitable to provide within the range of the operative portion of each front side of the milling or peeling device a pressure device. Although such a pressure device is generally required only on the front side of a milling or peeling apparatus which is averted from the road shoulder, the provision of a pressure device each on both front sides of each milling or peeling apparatus has the advantage of a more extensive use of the machine.

Changing costs are moreover saved, which would occur if there was only one pressure device per milling or peeling apparatus, when the machine is employed for removing the road surface of the right track of the road in one case and for removing the road surface of the left track of a road in another and a certain milling direction is prescribed.

In accordance with a further embodiment of the invention, a skid plate is provided as the pressure device. A further possibility may be seen in providing as such pressure device at least one wheel. Such a pressure device as compared to the first mentioned device has the advantage that the pressure device is subjected to a substantially less wearthan is the case with a skid plate. in the latter pressure device, the braking force exerted by it upon the chassis is moreover much less so that a pressure device including a rotating pressure face will be preferred.

A certain disadvantage in the employment of the pressure device in the form of at least one wheel is seen in that the pressure area as compared to the pressure area of a skid plate is substantially less, and the wheel-like pressure devices does therefore not reach the favorable effects upon the road surface as obtained by the skid plate. This disadvantage may however be eliminated in that in accordance with an advantageous embodiment of the present invention a plurality of wheels of small diameter arranged one after the other is provided in travelling direction. A further advantageous possibility is seen in the provision of a single wheel, which has a diameter in the order of magnitude of the diameter of a chassis wheel. Also when using a wheel of a relatively great diameter, a pressure area sufficient for many applications may be obtained.Finally, there is a possibility to provide as the pressure device a wheel, which consists of a plurality of radial spring-suspended plates. Such a wheel however is relatively expensive and requires maintenance which exceeds the normal measure so that it will be employed only in special cases.

If the pressure area obtained with one or a plurality of wheels is not sufficient for a particular, especially brittle road surface mixture and if a skid plate is not to be employed, a track moving around two guide wheels arranged at a distance relative to each other may also be provided as the pressure device.

Particularly in case of very soft road surfaces it may happen that in spite of the employment of a pressure device, no clear edge along the treated road track is obtained because of the softness of the surface coating. This disadvantage may be overcome in accordance with a further feature of the invention in that the pressure device is provided, on the side facing the milling or peeling apparatus, with a cutting device penetrating into the road surface. In the course of this pressing process, a cutter element, for instance a knife, penetrates into the road surface so that a clear separation of the track to be treated from the untreated road surface is obtained. The depth of penetration of the cutter element need not be great in general, a depth of from 5 to 10 millimeters will generally be sufficient.

In accordance with a further embodiment of the invention, the cutting device is provided as a cutting edge integral with the pressure device. In another embodiment, the cutting device has the shape of a cutting disc, which is attached to the pressure device. This latter embodiment has the advantage as compared to the other device that it shows much less wear and a cleaner cutting edge may be obtained.

For an adaptation to different milling or peeling depths and for an adjustment of the desired pressing force, the pressure device is secured, in accordance with an advantageous embodiment of the invention, vertically adjustable on the chassis.

In accordance with another embodiment, the pressure device may also be provided vertically adjustable to the milling or peeling apparatus. The former embodiment as compared to the other embodiment has the advantage that the vibrations and shocks generated by the milling or peeling apparatus are better kept away from the chassis by the pressure device vertically adjustably secured to the milling apparatus than is the case with a pressure device secured to the chassis. If the machine is provided with a pressure device each on both front sides of each milling or peeling apparatus, vertically adjustable to the mounting support of the milling roller, the commonly employed support wheels, which are provided in the prior art machines for the improvement of the milling or peeling process and for an exact maintenance of the milling or peeling depth, may be dispensed with.This is a further particular advantage of the present invention.

Especially when employing a skid plate, it may be of advantage to provide at least one pressure spring between the pressure device and its support. By so doing, a better adaptation of the pressure device to existing road unevennesses is obtained than would be possible with a rigidly mounted pressure device.

The exemplified embodiments shown in the accompanying drawings serve to further explain the invention. In the drawings Figure lisa side view of a machine for milling road surfaces including a skid plate as a pressure device.

Figure 2 is a top view of part of the milling apparatus according to Figure 1 including the skid plate.

Figure 3 is a front view of the milling apparatus according to Figure 1 including the skid plate.

Figure 4 is a side view of the pressure device including a wheel consisting of a plurality of individual plates.

Figure 5 is a side view of a pressure device including five wheels arranged one after the other in travelling direction.

The chassis 1 of the milling machine is provided in its front portion with a steerable and driven rubber tired front wheel pair 2 and in its rear portion with a rubber tired rear wheel pair3 and a track pair 4.

Buring the course of the milling operation the machine rests on the front wheel pair 2 and the track pair 4 while in the course of pure moving operation, that is when the machine is to be moved from one place of operation to another, the rear wheel pair 3 is tilted downward so that the machine rests upon the fron wheel pair 2 and the rear wheel pair 3. For extending the rear wheel pair 3, a hydraulic motor 5 has been provided, the movable element 6 of which is connected to the wheel bearings via a double lever 7.By employing a rubber tired wheel pair 3 and a track pair 4 it is reached that in the course of the milling operation, that is when the machine rests on the track pair 4, the road surface may be removed with a high advancement speed and a great milling depth, and the machine, in view of the fact that it rests on the rubber tired rear wheels 3 during moving operation, may be moved from one place of operation to the other without employing special transport vehicles.

In the rear portion of chassis 1,there is provided the drive motor 8 and a cockpit 9 including a driver's seat 10, a steering wheel 11, and operating control levers 12.

In the direction of travel, at a short distance from track pair 4, a milling apparatus 13 is provided on chassis 1. This apparatus comprises a milling roller 14 rotatably supported between two bearing frames 15 of a support 16. The milling roller 14 is driven by a hydraulic motor 17 provided on one of the two bearing frames 15. The support 16 is secured to the movable portion 18 of a hydraulic motor 19 by which the milling apparatus may be vertically adjusted.

As can be taken from Figures 1, 2, and 3, a skid plate 20 is secured to bearing frame 15 of support 16.

Fixation of skid plate 20 is obtained by means of a supporting arm 21 secured by means of two screws to bearing frame 15 and terminating at the other end thereof between two bearing eyes 22 and 23 through which bolt 24 is provided. Skid plate 20 is thus rotatable around the axis of this bolt 24. About in the middle of the skid plate, there is provided between the latter and a base plate 25 a pressure spring 26, by which the skid plate is pressed with a higher force against road surface 27.

Integral with the edge of skid plate 20 adjacent milling roller 14, cutting edge 28 is provided, as can be taken from Figure 3, which extends, as may be seen from Figure 1, over the total length of skid plate 20.

In case of vertical adjustment of milling roller 14, the pressure of the skid plate upon the road surface becomes greater, because of the shown connection of skid plate 20 with support 16, with increasing milling depth while it decreases with decreasing milling depth. Normally, this is a desired effect considering that with increasing milling depth the danger of damaging the road surface adjacent the track of the road being treated increases, and therefore a particularly high pressure upon the road surface is necessary in order to avoid such damage.

On the other hand, the danger of a damage of the track of the road not being treated is not so great in case of smaller milling depth so that a smaller pressing force of the skid plate upon the road surface is sufficient.

The pressure device shown in Figure 4 is provided as a wheel 29 which is supported in a bearing 30 which, on its part, is secured to the movable portion 31 of a hydraulic motor 32. Hydraulic motor 32 is secured by means of an angle bracket 33 to chassis 1. By operating hydraulic motor 32, wheel 29 may be vertically adjusted.

The wheel 29 comprises a hub 34 having eight radially extending hollow cylinders 35 into each of which the pivot 36 of a rectangularly shaped peripheral plate 37 engages. Between peripheral plates 37 and the front side of the hollow cylinder 35, one pressure spring 38 each is provided. The width of the peripheral plate 37 corresponds to about the width of skid plate 20.

The pressure device depicted in Figure 5 comprises five wheels 39,40,41,42, and 43 arranged one after the other in travelling direction and supported in a bracket 44. The width of the wheels corresponds again to about the width of skid plate 20, which means that the wheels have a roller-like character.

The bracket 44 is secured via a spring system 45 including two pressure springs 46 and 47 to the movable portion 48 of a hydraulic motor 49, which on its part is secured to an angle bracket 50 screwed by means of two screws to chassis 1. By this spring system 45, the wheel carrying portion of the press ure device adapts advantageously to unevennesses in the untreated road surface.

Claims

1. A machine for milling or peeling road surfaces comprising a motor driven chassis moving on wheels and/or on tracks, at least one milling or peeling apparatus, which in some cases also in cludes a heating system and a conveyor system provided on said chassis for wherein at least the milling or peeling apparatus, which treats the upper most layer of the road surface is provided, within the range of the operative portion, at least on its front side averted from the road shoulders, with a pressure device having a pressure area associated with the road surface not to be treated.

2. Machine according to claim 1, wherein each of said milling or peeling apparatusses is provided, within the range of the operative portion of their front sides averted from the road shoulders, with a pressure device.

3. Machine according to claim 1 or 2, wherein within the range of the operative portion of each front side of a milling or peeling apparatus a pressure device is provided.

4. Machine according to one of claims 1 through 3, wherein a skid plate is provided as said pressure device.

5. Machine according to one of claims 1 through 3, wherein at least one wheel is provided as said pressure device.

6. Machine according to claim 5, wherein in the travelling direction a plurality of wheels of small diameter arranged one after the other is provided.

7. Machine according to claim 5, wherein a single wheel is provided, which has a diameter in the order of magnitude of the diameter of a chassis wheel.

8. Machine according to one of claims Sthrough 7, wherein each wheel consists of a plurality of radial spring-mounted plates.

9. Machine according to one of claims 1 through 3, wherein a track moving around two guide wheels arranged at a distance relative to each other is provided as said pressure device.

10. Machine according to one of claims 1 through 9, wherein said pressure device is provided, on the side facing said milling or peeling apparatus, with a cutting device penetrating into the road surface.

11. Machine according to claim 10, wherein said cutting device is provided as a cutting edge integral with said pressure device.

12. Machine according to claim 10, wherein said cutting device has the shape of a cutting disc which is attached to said pressure device.

13. Machine according to one of claims 1 through 12, wherein said pressure device is vertically adjustable on said chassis.

14. Machine according to one of claims 1 through 12, wherein said pressure device is provided vertically adjustable on said milling or peeling apparatus.

15. Machine according to one of claims 13 or 14, wherein a hydraulic servo motor is provided to vertically adjust said pressure device.

16. Machine according to one of claims 1 through 15, wherein at least one pressure spring is provided between said pressure device and its support.

17. Machine substancially as described with reference to and as illustrated in the accompanying drawings.