GB2150620A

GB2150620A - Road surface cutting machine

Info

Publication number: GB2150620A
Application number: GB8428954A
Authority: GB
Inventors: Alan Richard Morris; Ronald Peter Parker
Original assignee: Bowmer & Kirkland Product Sale
Current assignee: Bowmer & Kirkland Product Sale
Priority date: 1983-11-19
Filing date: 1984-11-16
Publication date: 1985-07-03
Also published as: GB8428954D0

Abstract

A road surface cutting machine comprises a wheeled frame (10), a cutter disc (19) mounted on the frame for rotation about a horizontal axis and drive means (17) connected to the cutter disc to effect rotation. The disc is provided with a plurality of apertures or notches (25) opening at its periphery and preferably comprises a series of arcuate segments disposed eccentrically to the axis of rotation. Preferably the disc is arranged to be driven such that its forward edge moves downwardly into the road surface and acts to propel the machine over the ground. At least one wheel of the frame may be mounted in alternative positions inboard and outboard of the cutter disc. <IMAGE>

Description

SPECIFICATION Road surface cutter This invention relates to machines for cutting asphalt, concrete or other materials such as are used for the surfacing of roads, car parks, aircraft runways or the like. For purposes of simplicity such machines will be referred to hereinafter as "road surface cutting machines".

Road surface cutting machines have previously been proposed incorporating rotating discs for cutting through the road surface.

Such machines are used to cut lines of demarcation around areas of road surface which require to be broken up and removed for repair and resurfacing purposes or to enable access to be gained to damaged water or gas pipes or other utilities buried beneath the road surface. Cutting through the surface at the edges of the areas to be removed prevents damage to the adjacent surface when the surface to be removed is broken up and facilitates resurfacing. Previously proposed road surface cutting machines however suffer from various disadvantages and it is an object of the present invention to provide an improved machine suitable for such purposes.

According to one aspect of the invention there is provided a road surface cutting machine comprising a wheeled frame, a cutter disc mounted on the frame for rotation about a horizontal axis and drive means operatively connected to the cutter disc to effect rotation thereof, the cutter disc being provided with a plurality of peripheral apertures or notches opening at and spaced around the periphery thereof Preferably the cutter disc is arranged to be driven in a direction such that its forward edge moves downwardly into the road surface. The periphery of the disc preferably comprises a series of arcuate segments disposed eccentrically relative to the axis of rotation and connected by radial or inclined edge portions. The drive means is preferably a fluid motor.

Preferably also at least one wheel on which said frame is supported is mountable thereon in alternative positions which are respectively inboard and outboard of the cutter disc.

Thus the invention also provides a road surface cutting machine comprising a wheeled frame, a cutter disc mounted on the frame for rotation about a horizontal axis and drive means operatively connected to the cutter disc to effect rotation thereof at least one wheel of the machine being mountable thereon in alternative positions which are respectively inboard and outboard of the cutter disc.

Preferably the or each said wheel is rotatably mounted on an extended axle together with a removable spacer sleeve which serves when fitted to displace said wheel from said inboard to said outboard position. Alternatively said wheel may be slidably mounted on said axle and lockable in its inboard and outboard positions.

Normally the wheel or wheels at one side of said frame only are arranged to be mounted in both inboard and outboard positions. In a preferred arrangement said frame is mounted on a single axis having wheels rotatably mounted at opposite ends thereof, said cutter disc being mounted towards one side of said frame and the wheel at that side of the axle being mountable in said inboard and outboard positions.

Means is preferably provided for adjusting the depth of cut of the cutter disc. For this purpose a guard may be provided around the disc having a movable forward section which may be selectively clamped in different positions on the guard and incorporates a groundengaging member adapted for engagement with the surface to be cut. The ground-engaging member may comprise a skid or preferably a wheel.

Preferably the frame incorporates an upwardly and rearwardly directed portion forming a handle by means of which the machine may be propelled and steered. The handle may advantageously be of hollow tubular construction and preferably houses supply lines for fluid motor drive means. Preferably the handle contains a grip portion extending to one side of the machine and incorporating a control valve operable on the supply lines to energise the motor.

The machine preferably incorporates means for preventing spread of dust generated during the cutting operation. For this purpose a spray device is preferably mounted adjacent the cutter blade and supplied with water from a reservoir mounted on the machine frame.

The cutter disc is preferably mounted directly on the shaft of the fluid motor and rotated at a speed between 3500 and 6000 rpm. The motor may comprise an air motor or a hydraulic motor.

When an air motor is employed air exhausted from the motor has been found to form ice particles under some circumstances due to the sudden temperature change to which it is subjected. It is therefore preferred to incorporate guard means serving to prevent these particles from contacting the operator when the machine is in use. Advantageously said water reservoir may be shaped to form a screen between the operator and the area in which the ice particles are generated.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of one form of road surface cutting machine according to the invention; Figure IA is a side view of a cutter blade or disc; Figure 2 is a plan view of the machine shown in Fig. 1; Figure 3 is a rear view of the machine; Figure 4 is a side elevation of an alternative form of road surface cutting machine according to the invention; Figure 5 is a plan view of the machine shown in Fig. 4; and Figure 6 is a rear view of the machine.

Referring to Figs. 1 to 3, the machine comprises a wheeled frame indicated generally at 10 and comprising an axle 11 having wheels 1 2 rotatably mounted at its opposite ends, an upstanding frame member 1 3 of generally inverted U-shaped form, and an upwardly and rearwardly inclined tubular member 1 4 defining a handle and terminating in a cross-piece 1 5. The handle 14 extends downwardly beyond the frame 1 3 and terminates in a mounting flange 1 6 secured to an air motor 1 7. A base or platform 1 8 extends forwardly from the axle 11 and is secured to the underside of the motor 1 7. A cutter blade or disc 1 9 is mounted on the output shaft 20 of the motor 1 7 and is enclosed in an arcuate guard member 21 mounted on the platform 1 8. One form of cutter blade or disc is shown in Fig. 1 and an alternative form in Fig. 1A.

The periphery of the disc 1 9 is provided with a series of notches 25 and comprises three arcuate portions or segments 26 eccentric to the motor shaft 20 and connected by generally radially extending portions or steps 26A. The motor is arranged to rotate the disc 1 9 in the direction of the arrow R in Fig. 1 such that the forward end of the blade 1 9 moves downwardly into contact with the surface of the ground which is indicated at 27.

The motor rotates at a speed of between 3500 and 6000 rpm and generally in the region of 4500 rpm when cutting and operates at an air supply pressure of 80-100 psi.

It has been found that by virtue of the use of this blade configuration and the speed of rotation of the air motor, the blade tends to dig itself into the ground and also draw the machine forwards so that the machine becomes largely self-propelled. In order to limit the depth of penetration of the blade a visor 28 is pivotally mounted on the guard 21 for angular movement about a pivot pin 29 enabling the visor to be raised and lowered relative to the disc 19. A skid or shoe 30 is provided at the forward end of the visor 28 for sliding contact with the ground to maintain a constant depth of cut as the machine moves forward. A clamping screw 31 extends through a slot 32 in the visor into engagement with an anchorage on the guard 21 enabling the visor to be clamped in different angular positions relative to the guard to vary the depth of cut.

The handle 14 and cross piece 1 5 are of hollow tubular construction and accommodate an air supply line (not shown) extending between the motor 1 7 and a remote source of air under pressure. A control lever 35 is mounted on the cross-piece 1 5 and is operable to control supply of air to the motor 1 7 to drive the cutter disc 1 9. By virtue of the fact that the cross-piece 1 5 extends past and to one side of the operator the air supply line is held clear of and passes around the operator as the machine moves forward. The control lever 35 is arranged to cut off the air supply to the motor 1 7 when the lever is in its released position thereby acting as a "dead man's handle".

The guard 21 extends around and encloses the upper part of the blade 1 9 and is provided with downwardly directed rear and side projections 21A and 21B serving to prevent particles of material dislodged from the road surface being thrown back towards the operator and sideways into the path of the adjacent road wheel 1 2. In order to prevent spread of dust generated during the cutting operation a water tank 40 is mounted on the platform 1 8 and connected by a line 41 incorporating a control valve 42 to an outlet 43 adjacent the blade 1 9. When the valve 42 is opened water flows through the pipe to the outlet 43 under gravity and this has been found to cause dust created by the cutting operation to settle'on the ground. thereby preventing the generation of dust clouds which might interfere with the operator's view or cause discomfort or annoyance.

Due to the high velocity with which air is exhausted from the motor 1 7 to the surrounding atmosphere, particles of moisture in the air can freeze and be thrown rearwards towards the operator. In order to protect the operator from frozen particles of this kind the water tank 40 is shaped to largely fill the area between the limbs of the frame 1 3 and beneath the handle 1 4 thereby forming a guard to protect the operator.

Thus in operation the supply line emerging from the cross-piece 1 5 is connected to a suitable remote supply of compressed air, the clamp 31 is released and the visor 28 adjusted to a position corresponding to the desired cutting depth, whereupon the clamp 31 is tightened and the control valve 35 actuated to supply compressed air through the handle 14 to the motor 17. The blade 19 rotates in a clockwise direction as viewed in Fig. 1. The blade cuts into the second surface to a depth limited by engagement of the shoe 30 with the ground and draws the machine forward as it cuts a slot in the road surface. As the machine moves forward water from the tank 40 is delivered through the valve 42 and line 41 into the guard 21 to prevent spread of dust and material dislodged by the cutting action is contained by the guard 21 and drops to the ground behind the cutter disc. The operator steers the machine along the desired line of cut by means of the handle 14.

Referring now to Figs. 4 to 6 of the drawings, the machine is generally similar to that of Figs. 1 to 3 and a wheeled frame indicated generally at 110 and comprising an axle 111 having wheels 112A, 11 2B rotatably mounted at its opposite ends, an upstanding frame member 11 3 of generally inverted Ushaped form, and an upwardly and rearwardly inclined tubular member 114 defining a handle and terminating in a cross-piece 11 5.

The handle 114 extends downwardly beyond the frame 11 3 and terminates at a connector member 11 6 secured to a hydraulic motor 11 7. A base or platform 118 extends forwardly from the axle 111 and is secured to the underside of the motor 11 7. A cutter disc 11 9 is mounted on the output shaft 1 20 of the motor 11 7 and is enclosed in an arcuate guard member 1 21 mounted on the platform 118.

The wheel 11 2A is rotatably mounted in a fixed location at one end of the axle 111, but the wheel 11 2B is adjustable between alternative positions axially of the axle. For this purpose a removable sleeve 111 A is fitted to the axle between the wheels and acts as a spacer which, when fitted, locates the wheel 11 2B at the adjacent end of the axle in a similar manner to the wheel 11 2A. In this position the wheel 11 2B is positioned laterally outboard of the cutter disc 11 9. By detaching the wheel 11 2B and removing the sleeve 111A, the wheel may be re-fitted in the position previously occupied by the sleeve in which it is disposed laterally inboard of the cutter disc.A portion of the platform 11 8 is cut away at 11 8A to accommodate the wheel in this position. The wheel is retained on the axle 111 in both locations by split pins inserted through appropriately located diametral holes in the axle.

In the outboard position of the wheel 11 2B the stability of the machine is increased and this position will normally be used to cut existing generally flat road surfaces. In the inboard position of the wheel 11 2B the cutter disc is located laterally outwards of the wheel and can be used to trim the edge of a section of newly laid road surface which is at a different level from the surface on which the machine is supported.

The periphery of the disc 11 9 is provided with a series of notches 1 25 and comprises three arcuate portions 1 26 eccentric to the motor shaft 1 20. The motor is arranged to rotate the disc 11 9 in the direction of the arrow R in Fig. 4 such that the forward edge of the blade 11 9 moves downwardly into contact with the surface of the ground which is indicated at 127. The motor rotates at a speed of between 3000 and 6000 rpm and generally in the region of 4500 rpm when cutting and operates at a hydraulic pressure of 1500-2500 psi.It has been found that by virtue of the use of this blade configuration and the speed of rotation of the hydraulic motor, the blade tends to dig itself into the ground and also draw the machine forwards so that the machine becomes largely selfpropelled.

In order to limit the depth of penetration of the blade a visor 1 28 is pivotally mounted on the guard 121 for angular movement about a pivot pin 1 29 enabling the visor to be raised and lowered relative to the disc 11 9. A wheel 1 30 is provided at the forward end of the visor 1 28 for rolling contact with the ground to maintain a constant depth of cut as the machine moves forward. A clamping screw 131 extends through a slot 132 in the visor into engagement with an anchorage on the guard 121 enabling the visor to be clamped in different angular positions relative to the guard to vary the depth of cut.

A supply line 1 33 for hydraulic fluid under pressure extends through the cross-piece 11 5 and down the outside of the handle to the inlet side of the motor 1 17. A return line 134 extends from the outlet side of the motor through the handle 114 which is of hollow tubular construction to the low pressure side of the hydraulic fluid source. A control lever 1 35 is mounted on the cross-piece 11 5 and is operable to control supply of fluid to the motor 11 7 to drive the cutter disc 11 9. By virtue of the fact that the cross-piece 11 5 extends past and to one side of the operator the supply and return lines are held clear of and pass around the operator as the machine moves forward.The control lever 1 35 is arranged to cut off the supply of hydraulic fluid to the motor 11 7 when the lever is in its released position thereby acting as a "dead man's handle".

The guard 121 extends around and encloses the upper part of the blade 11 9 and is provided with downwardly directed rear and side projections 1 21 A and 1 21 B serving to prevent particles of material dislodged from the road surface being thrown back towards the operator and sideways into the path of the adjacent road wheel 11 2. In order to prevent spread of dust generated during the cutting operation a water tank 140 is mounted on the platform 118 and connected by a line 141 incorporating a control valve 1 42 to an outlet 1 43 adjacent the blade 11 9. When the valve 142 is opened water flows through the pipe to the outlet 1 43 under gravity and this has been found to cause dust created by the cutting operation to settle on the ground, thereby preventing the generation of dust clouds which might interfere with the operator's view or cause discomfort or annoyance.

In operation the wheel 11 2B is fitted in the inboard or outboard position to suit the cutting operation to be carried out and the supply and return lines are connected to a suitable remote supply of hydraulic fluid under pressure. The clamp 131 is released and the visor 1 28 adjusted to a position corresponding to the desired cutting depth whereupon the clamp 1 31 is tightened and the control valve 1 35 actuated to supply hydraulic fluid to the motor 11 7. The blade 119 rotates in a clockwise direction as viewed in Fig. 4. The blade cuts into the ground surface to a depth limited by engagement of the wheel 1 30 with the ground and draws the machine forward as it cuts a slot in the road surface.As the machine moves forward water from the tank 140 is delivered through the valve 142 and line 141 into the guard 121 to prevent spread of dust and material dislodged by the cutting action is contained by the guard 1 21 and drops to the ground behind the cutter disc.

The operator steers the machine along the desired line of cut by means of the handle 114.

Machines constructed in the manner described have been found to produce a clean cut matching the standard of previously proposed disc cutters but with a greatly increased blade life. This is believed to be due to the construction of the blade itself, to the speed of rotation, and to the fact that the blade is directly coupled to the motor shaft. Further advantages arise from the ability to control and maintain the depth of cut and to prevent formation of dust clouds, and by virtue of the laterally adjustable ground wheel, where provided, the machine may be easily and quickly adapted to different cutting operations and ground level conditions. Moreover by running the air or hydraulic lines along and within the handle of the machine they are protected from damage and maintained clear of contact with the operator.

Various modifications may be made without departing from the invention. For example the peripheral formations on the cutter disc may be varied and alternative means of adjusting the depth of cut may be provided. The water supply system could also be omitted in some circumstances and the disc could be coupled to the motor shaft through belt or chain drives if desired. The cutter disc may also be arranged to rotate in the opposite direction, in which event the machine is best used by drawing it behind the operator, for which purpose a modified handle construction may be provided. It is preferred however that the cutter blade should rotate so that its forward edge moves downwardly as this produces a self-propulsion effect and reduces or eliminates the need for the operator to apply force to move the machine forward.

The laterally adjustable ground wheel may be provided on the pneumatically operated version of the machine. In the case of the hydraulically operated version both the supply and return lines may be housed within a handle of increased diameter or within parallel tubular members secured together to form a handle structure. Means may be provided to alter the flow of hydraulic fluid to suit different supply pressures and control means for this purpose may be mounted adjacent the motor and coupled to a control lever on the handle by means of a cable or mechanical linkage. The hydraulically driven version of the machine is particularly suited to the use of larger cutting blades producing a deeper cut.

It should also be appreciated that the laterally adjustable wheel arrangement could be provided on a machine having a different form of cutter blade and/or driven by means other than a fluid motor, for example by an internal combustion engine. Moreover the spacer or collar may be omitted and the wheel arranged to be locked against movement along the axle in either direction in both of its alternative positions.

Claims

1. A road surface cutting machine comprising a wheeled frame, a cutter disc mounted on the frame for rotation about a horizontal axis and drive means operatively connected to the cutter disc to effect rotation thereof, the cutter disc being provided with a plurality of peripheral apertures or notches opening at and spaced around the periphery thereof.

2. A machine according to claim 1 the periphery of said disc comprises a series of arcuate segments disposed eccentrically relative to the axis of rotation and connected by radial or inclined edge portions.

3. A machine according to claim 1 wherein the cutter disc is arranged to be driven in a direction such that its forward edge moves downwardly into the road surface.

4. A machine according to any of claims 1 to 3 wherein at least one wheel on which said frame is supported is mountable thereon in alternative positions which are respectively inboard and outboard of the cutter disc.

5. A road surface cutting machine comprising a wheeled frame, a cutter disc mounted on the frame for rotation about a horizontal axis and drive means operatively connected to the cutter disc to effect rotation thereof, at least one wheel of the machine being mountable thereon in alternative positions which are respectively inboard and outboard of the cutter disc.

6. A machine according to claim 4 or 5 wherein the or each said wheel is rotatably mounted on an extended axle together with a removable spacer sleeve which serves when fitted to displace said wheel from said inboard to said outboard position.

7. A machine according to claim 4, 5 or 6 wherein the wheel or wheels at one side of said frame only are arranged to be mounted in both inboard and outboard positions.

8. A machine according to claim 7 wherein said frame is mounted on a single axis having wheels rotatably mounted at opposite ends thereof, said cutter disc being mounted towards one side of said frame and the wheel at that side of the axle being mountable in said inboard and outboard positions.

9. A machine according to any preceding claim wherein said drive means comprises a fluid motor.

10. A machine according to any preceding claim wherein means is provided for adjusting the depth of cut of the cutter disc.

11. A machine according to claim 10 wherein said means for adjusting the depth of cut comprises a guard disposed around the cutter disc and having a movable forward section which may be selectively clamped in different positions on the guard and incorporates a ground-engaging member adapted for engagement with the surface to be cut.

1 2. A machine according to claim 11 wherein said ground-engaging member comprises a wheel.

1 3. A machine according to any preceding claim wherein said frame incorporates an upwardly and rearwardly directed portion forming a handle by means of which the machine may be propelled and steered.

1 4. A machine according to claims 9 and 1 3 wherein said handle is of hollow tubular construction and houses a supply line for the fluid motor.

15. A machine according to claim 14 wherein said handle contains a grip portion extending to one side of the machine and incorporating a control valve operable on said supply line to energise the motor.

1 6. A machine according to any preceding claim incorporating means for preventing spread of dust generated during the cutting operation.

17. A machine according to claim 16 wherein said means for preventing spread of dust comprises a spray device mounted adjacent the cutter blade and supplied with water from a reservoir mounted on the machine frame.

1 8. A machine according to any preceding claim wherein said drive means is an air motor and guard means is provided to prevent frozen ice particles in the exhaust air from contacting an operator.

1 9. A machine according to claims 1 7 and 1 8 wherein said water reservoir is shaped to form a screen between the operator and the area in which the ice particles are generated.

20. A machine according to any preceding claim wherein said cutter disc is mounted directly on the shaft of said drive means, the drive means comprising a fluid motor adapted to rotate at a speed between 3500 and 6000 revs/min.

21. A machine according to claim 20 wherein said motor is a hydraulic motor designed to operate at a hydraulic pressure of 1500-2500 psi.

22. A machine according to claim 21 wherein said motor is a pneumatic motor designed to operate at an air supply pressure of 80-100 psi.

23. A road surface cutting machine substantially as hereinbefore described with reference to Figs. 1 to 3 of the accompanying drawings.

24. A road surface cutting machine substantially as hereinbefore described with reference to Figs. 4 to 6 of the accompanying drawings.

25. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.