GB2247484A

GB2247484A - Road cutter

Info

Publication number: GB2247484A
Application number: GB9117002A
Authority: GB
Inventors: William G Lupton
Original assignee: Econ Group Ltd
Current assignee: Econ Group Ltd
Priority date: 1990-08-07
Filing date: 1991-08-07
Publication date: 1992-03-04
Also published as: GB9017318D0; GB9117002D0

Abstract

A cutter apparatus for cutting road surfaces (slitting or planing) is adapted to be carried by manipulating arms of a vehicle. The apparatus has a support wheel by which the apparatus can be loaded onto the road by the vehicle, and then can be rocked to bring the rotating cutter gradually into engagement with the ground. When the cutter has penetrated the ground the apparatus by the manipulating means is moved linearly to form a slit or channel. A linkage between the cutter and the manipulating means facilitates the manipulating operation. <IMAGE>

Description

Improvements Relating to Road Working Apparatus This invention relates to road working apparatus, being apparatus for use in connection with the working on road surfaces, especially road surfaces which are of a hard material such as asphalt, concrete or the like, and the invention has particular application for the cutting of slits or slots in such road surfaces for roadway repairs, insertion of servicing or other operations. The apparatus is particularly useful for roadway patching wherein a section of a roadway surface is to be repaired by slitting the surface to define the area to be repaired, followed by removal of the old road surface material and subsequent filling by asphalt or the like to form a new patch of roadway surface, hence the expression patching.

Patching work in the past has generally been done by hand and hand operated tools, but such patchwork has tended to be rough edged and unsightly. Furthermore, new regulations require that the patch edges be much neater and regular in order to create the minimum disturbance to road traffic.

There is a need therefore to provide an apparatus which can form sufficiently neat and accurate slits or channels in the road surface to define the area to be patched (and also to define sufficiently neat trench edges when a trench is to be dug in the road) and the present invention seeks to provide such an apparatus.

The need to provide accurate slits or channels suggests that power operated equipment is required, but the difficulty with providing slits in a road surface using a power operated cutter especially one with cutting picks, is that because the road surfaces in which the slits or channels are to be formed invariably is of a relatively hard material, e.g. asphalt, concrete or the like, it is difficult to make the cutter accurately penetrate the road surface when a slit or channel is to be started, and also to keep the cutter in position in the road surface during or cutting in view of the very high reaction forces tending to throw the cutter away from the hard road surface material.

The present invention in one aspect seeks to overcome these disadvantages, and seeks to provide an apparatus which can be used for the effective cutting of road surfaces. The apparatus according to the invention might also be used as a road planing apparatus i.e. with a wider cutter, wherein the cutter is used to remove the road surface over a substantial width at each pass, but a main application of the present invention is in connection with a slitting operation.

In accordance with the invention, there is provided a power operated apparatus for forming slits or channels in a road surface, said apparatus comprising a rotary cutter mounted on a support frame enabling the disc to be power driven from a suitable power source, said frame also mounting a support means adapted to engage the road surface prior to the penetration of the cutter into the road surface for stabilising the apparatus, and means adapting the frame for connection to manipulating apparatus such as the loader arms of a back hoe loader vehicle, so that the apparatus can be manipulated in use to bring the support means initially into engagement with the ground, followed by the pivoting of the apparatus around said support means to bring the cutter into engagement with the ground whilst the apparatus is stably held in relation to the ground via loading from the manipulating means.

The frame preferably also has a depth control means, which may include said support means, in order to control the depth to which the cutter can penetrate the road surface. The depth control means may include a skid, roller or the like and will be adjustable. The support means may be a support roller or a pair of rollers disoposed to opposite sides of the cutter.

The frame may be in the form of a guard or shroud covering the cutter except that portion which is to penetrate the road surface to effect the cutting of same.

The cutter may be in the nature of a slitter disc and the disc and its shroud preferably are of relatively narrow width. The shroud may be provided with bearings for supporting the disc shaft, and also a mounting for supporting a drive motor which is drivingly connected to the slitter disc. The drive motor may be hydraulic in which case it can be operated from the hydraulic supply also used for the manipulating means, or the motor may be electric in nature.

The depth control means preferably is adjustable in order to adjust the extent to which the slitter disc can penetrate the road surface.

The shroud also has several mountings adapting the apparatus to be connected to the manipulating means.

There may be a control link device connected between the manipulating means and the shroud so that the shroud is pivotally mounted on the control link so that the shroud, cutter and depth control means can pivot to follow the contour of the ground. The control link device is adapted to be connected to the manipulating means and has stops to limit the extent to which the shroud can pivot relative to the control link device.

The manipulating means may comprise hydraulically operated loader or back hoe arms connected to a suitable vehicle, and the arms may be adapted to be loaded by hydraulic rams and to transfer that loading onto the depth control means of the slitting cutter apparatus to keep it firmly in engagement with the ground both when the slitting cutter disc is pivoted so as to make the initial penetration into the road surface, and also as the apparatus is moved, by means of the manipulating arms, along the direction in which the slit in the road surface is to be made.

The vehicle to which the manipulating arms are connected may be any suitable such as a back hoe digger, a skid steer vehicle or a tractor. If the vehicle is provided with support legs enabling it to be lifted clear of its propulsion means (e.g. wheels or crawler tracks) it may be so lifted whilst the setting operation is proceeding.

According to another aspect of the present invention there is provided a power operated apparatus for forming slits or channels in a road surface, said apparatus comprising a rotary cutter mounted in a support frame enabling the cutter to be power driven from a suitable power source, depth control means controlling the depth to which the cutter can penetrate the ground, and means adapting the frame for connection to manipulating apparatus such as the loader arms of a back hoe loader vehicle, said means comprising a link device to which the support frame is connected for pivotal movement limited by stop means to enable the depth control means and the cutter to pivot to follow the undulations of the road surface during cutting.

The linkage device may comprise a plate with a notch in which is located a stop carried by the support frame.

Any one or more of the features of any aspect of the invention, or any one or more of the features disclosed herein with reference to the accompanying drawings can be used in conjunction with any other aspect of the invention, even if not specifically recited for use in connection therewith.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, wherein Fig. 1 is a side view of slitting cutter apparatus according to a first embodiment of the invention; Fig. 2 is an end view of the apparatus of Fig. 1 looking in the direction of arrow 2 in Fig. 1; Fig. 3 is a plan view of the apparatus shown in Fig. 1 looking in the direction of arrow 3 in Fig. 1; Fig. 4 is a side view of the apparatus of Fig. 1 when connected to the vehicle and when in use; Fig. 5 is a side view of the apparatus of Fig. 1 when in use, but when connected to a vehicle of a different type; and Fig. 6 is a view similar to Fig. 1 but showing another embodiment of the invention.

Referring to the drawings, and firstly to Fig. 1, the slitting cutter apparatus comprises a slitting cutter disc 10 which is held in a frame in the form of a casing or shroud 12 provided with bearings to enable the disc 10 to be rotated about axis 14. To this end, the shroud 12 has suitable bearings for the shaft of the disc 10, and as shown in Figs.

1, 2 and 3, the shroud has an extension housing 16 for accommodating -a drive motor which will be connected to the disc shaft in order to drive same. The motor may be of any suitable type such as hydraulic or electric.

The shroud 12 comprises basically a pair of plates 18, 20 with the motor housing connected to the outside of plate 18, and these plates are separated by a separating strip 22 which roughly conforms to the peripheral shape of the wheel 10.

The disc 10 protrudes from the shroud as shown in Fig. 1 to enable the protruding portion to enter the road surface as will appear more clearly from Figs. 4 and 5, and the shroud 12 defines a toe end 24 and a heel end 26. At the toe end 24 there is provided a support means in the form of a ground engaging roller 28, whilst at the heel end the strip 22 is provided with a flap portion 30 swingable about axis 32.

The purpose of the flap portion is to permit the exit of spoil and debris which result from the cutting operation to be described.

The plates 18 and 20 at the top edge thereof are provided with mounting fixtures 34, 36, 38 and 40 by which the apparatus can be coupled for example to arms 42 and 44 of a suitable vehicle whereby the apparatus can be manipulated in the manner to be described. Arm 44 is an extensible and contractable hydraulic ram by which the angularity of the frame 12 relative to arm 42 can be adjusted.

The extension housing 16 carries a depth control post 46 having at the lower end thereof a skid plate 48. The post 46 is slidable in a bracket 50 carried by the extension housing 16, and can be locked in any adjusted position by means of a locking screw 52. Instead of using a skid plate 48, a ground engaging roller can be utilised if required. The roller 28 and skid 48 form depth control means.

The cutting disc 10 is fitted with tungsten carbide cutting 10A, but it could alternatively be a diamond tipped cutting saw or other suitable disc. The picks are preferred as they create a rough wall surface in the roadway wear layer (although the cut line is neat) to which the new material of the road covering will effectively anchor. A diamond saw tends to leave this wall surface too smooth. It is desirable for slit cutting that the overall cutting width W as shown in Fig. 2 should lie between 2% and 20% of the overall diameter of wheel 10, including the teeth 10A, and it is also desirable that the overall width of the frame or shroud should be no greater than 200% of the width of the cutter if possible.

Referring now to Fig. 4, the cutting apparatus of Fig. 1 is shown as being connected to a conventional industrial tractor loader 60 provided with a hydraulic digger arm arrangement 62, 64, 66 for the purposes of illustrating its utilisation.

It should be mentioned that the view of Fig. 4 is looking at the apparatus of Fig. 1 from the opposite side, and also that the arm 66 shown in Fig. 4 is also the arm 42 shown in Fig.

1. Fig. 4 shows that arm 44 in Fig. 1 is connected to a bell crank lever 68 which in turn is coupled to the arm 66 by means of the hydraulic ram 70. A further ram 72 is connected between arms 62 and 64 to enable the arm assembly to be manipulated for example as shown in chain-dotted lines in Fig. 4.

The operation of the apparatus will now be explained in conjunction with Figs. 1 and 4.

In Fig. 1, the slitting apparatus is shown as being slightly tilted relative to the ground surface 71 in which a slit is to be formed by the disc 10. The apparatus rests on the support roller 28 so that the disc 10 is clear of the ground 71 and rotates in the direction 72, being driven by the drive motor. Using the rams 70 and 72 the operator in vehicle 60, whilst facing rearwards, loads the apparatus onto wheel 28 so that the apparatus is held firmly and stably onto the ground 71. With the apparatus so loaded, the ram 70 is operated to tilt the apparatus about roller 28 in the direction of arrow 74 so that the spinning disc 10 commences engagement with the roadway surface and penetration of same until in fact the position is reached where the skid 48, having been set at the appropriate position to give the correct degree of penetration into the ground, engages the ground.For the continued formation of the slit shown at 76 in Fig. 4, the rams 70 and 72 is operated so as to jack-knife the arm assembly 62, 64, 66 and tilt the cutting head and the cutting apparatus is moved along the surface 70 making the slit 76 as it proceeds. The loading on the apparatus is maintained via the arm assembly, it will be noted furthermore from Fig. 4 that the vehicle 60 is jacked clear of its propulsion wheels 78 by legs 81. A front loader bucket 82 may also be urged into engagement with the ground 71 to keep the vehicle in a stable position. The loading on the slitting apparatus is maintained. This ensures that the depth control means is pressed firmly onto the ground 71 to keep the entire apparatus stable during cutting by the cutting disc of the road surface.When the cutter disc 10 has fully penetrated the ground as shown, the arm assembly 62, 64, 66 is jack-knifed as shown in Fig. 4 so that the cutter moves in a direction of arrow 80 in Fig. 4 forming the slit 76, the downwards pressure on the apparatus being maintained to keep the depth control means in firm contact with the ground. The upward reaction exerted by the cutting disc 10 is counteracted by the downward pressure on the roller 28 and skid 48 which form the depth control means.

Vibration is largely eliminated, and the cutting apparatus is maintained in a stable working relationship against the hard road surface.

The arrangement of Fig. 5 is an alternative construction and needs little explanation except that the cutting apparatus is connected to an alternative form of vehicle 84, in particular a pedestrian skid steer unit 90 which is provided with arms 92 mounting the cutting apparatus. Ram 93 loads arms 92 and ram 94 tilts the cutting head relative to arms 92. The skid steer vehicle 90 is arranged to travel in a forwards direction as indicated by arrow 95, and therefore the apparatus is connected to the arms 92 as shown and travels in a forwards direction. The operator, who stands in the vehicle as shown, arranges for the penetration of the cutting disc 10 into the road surface in the same fashion as described in relation to Figs. 1 and 4, and also manipulates the arms in order to maintain the pressure on the apparatus to keep it stable as it engages the road surface by rams 93 and 94.

Referring now to the embodiment of the invention shown in Fig. 6, which is a modified arrangement of Fig. 1, those parts which appear in Fig. 6 and which also appear in Fig. 1 and have been described in relation thereto carry the same reference numerals and are not described further. With the arrangement of Fig. 1, as the cutting head is moved along the ground so as to form the slit 76 as shown in Fig. 4, the driver must manipulate the rams 70 and 72 in order to keep the head in the correct disposition as cutting is taking place. This can to some extent be difficult, and the modified arrangement of Fig. 6 overcomes this difficulty. In the arrangement of Fig. 6, instead of the shroud 12 being directly connected to the rams 42 and 44, they are connected through the control link 100 which is in the form of a pair of plates pivotally mounted on the shroud at pivot axis 102.

The fittings 34, 36, 38 and 40 are provided on the control plates 100 so that the arms 42 and 44 are connected thereto.

The plates 100 have a stop notch 104 defining a pair of stop faces 106 and 108. Located between the stop faces 106 and 108 is a stop plate 110 which is connected to the shroud 12.

The stop plate 110 is much narrower than the spacing between the stop faces 106 and 108 so that the plates 100 can pivot relative to the shroud to the extent dictated by the thickness of plate 110 and the spacing of the faces 106 and 108. Therefore as the driver jack-knifes the arms between the positions shown in Fig. 4 to remove the cutting head along the ground, he will not have to adjust the ram 70 until such times as the stop plate 110 abuts the stop face 106. He is required therefore only to make periodic adjustments with the ram 70 rather than having to effect continuous control thereon.

Fig. 6 shows a further modification compared to Fig. 1 insofar as the skid and leg arrangement 46 and 48 of Fig. 1 has been omitted and is replaced by a different form of depth control means. In the arrangement of Fig. 6 a depth control frame 112 is provided, and it comprises depth control rollers 114. The frame 112 is pivotted about the axis of roller 28 which forms part of the depth control means, and the frame has an arm 116 with a series of holes 118 therein through any one of which a bolt can be passed to lock with a registered aperture in shroud 12, whereby the frame and hence the depth control means can be adjustably pivoted about the axis of the roller 28. The frame 112 as an alternative may be mounted for adjustment by means of an adjusting screw and crank arrangement.

The vehicle which is used in connection with the apparatus may be any suitable such as a back hoe or back hoe loader, or an industrial tractor or skid steer arrangement as shown in the drawings. Also a crawler excavator may be employed in conjunction with the apparatus. The apparatus can be mounted on the front or rear as required. The mounting at the front appears preferable as the driver does not have to turn round to see the operation.

Using the apparatus in conjunction with a vehicle as described enables the digger arms to be used to control accurately the cutting of the slit despite the considerable force being exerted on the arms during the cutting operation.

Also the support means enables the application of sufficient weight to enable penetration of the road surface, which otherwise would not be possible.

Although a single steadying roller 28 is shown in the drawings, there may be such steadying rollers at opposite sides of the cutter wheel 10, but it is preferable that the support wheel should be positioned so that the apparatus can be loaded onto the wheel or wheels so that the whole weight of the machine can press on the ground through such wheel or wheels but with the rotating cutter disc 10 initially clear of the surface to be cut. Also, in the Fig. 1 embodiment, it is possible to provide rear depth control wheels or a single wheel in place of the skid plate 48.

Although the invention is not limited to any particular dimensions, in a particularly suitable arrangement the cutter disc 10 may be of the order of 80mm wide and of in the order of lOOOmm diameter, with the wheel extending out of the shroud 12 to an extent in the order of 250mm or in other words 25% of the wheel diameter.

Claims

1. A power operated apparatus for forming slits or channels in a road surface, said apparatus comprising a rotary cutter mounted on a support frame enabling the disc to be power driven from a suitable power source, said frame also mounting a support means adapted to engage the road surface prior to the penetration of the cutter into the road surface for stabilising the apparatus, and means adapting the frame for connection to manipulating apparatus such as the loader arms of a back hoe loader vehicle, so that the apparatus can be manipulated in use to bring the support means initially into engagement with the ground, followed by the pivoting of the apparatus around said support means to bring the cutter into engagement with the ground whilst the apparatus is stably held in relation to the ground via loading from the manipulating means.

2. Apparatus according to Claim 1, including a depth control means including said support means.

3. Apparatus according to Claim 2, wherein the depth control means includes a skid, roller or the like.

4. Apparatus according to Claim 2 or 3, wherein the depth control means comprises a depth control frame.

5. Apparatus according to any preceding claim, wherein the support means includes a support roller or a pair of support rollers disposed to opposite sides of the cutter.

6. Apparatus according to any preceding claim, wherein the support frame comprises a guard or shroud covering the cutter except that portion which is to penetrate the road surface.

7. Apparatus according to Claim 6, wherein the cutter is in the nature of a cutter disc.

8. Apparatus according to any preceding claim, including a control link device connected between the manipulating means and the shroud so that the shroud is pivotally mounted on the control link so that the shroud, cutter and depth control means can pivot to follow the contour of the ground.

9. Apparatus according to Claim 8, wherein the control link device is adapted to be connected to the manipulating means and has stops to limit the extent to which the shroud can pivot relative to the control link device.

10. A power operated apparatus for forming slits or channels in a road surface, said apparatus comprising a rotary cutter mounted in a support frame enabling the cutter to be power driven from a suitable power source, depth control means controlling the depth to which the cutter can penetrate the ground, and means adapting the frame for connection to manipulating apparatus such as the loader arms of a back hoe loader vehicle, said means comprising a link device to which the support frame is connected for pivotal movement limited by stop means to enable the depth control means and the cutter to pivot to follow the undulations of the road surface during cutting.

11. Apparatus according to Claim 8, 9 or 10, wherein control link or linkage device comprises a plate with a notch in which is located a stop carried by the support frame.

12. A power operated apparatus substantially as hereinbefore described with reference to the accompanying drawings.

13. The combination of a vehicle having manipulating means and a power operated apparatus according to any one of the preceding claims with said apparatus connected to the manipulating means to be manipulated thereby.