WO1996016229A1

WO1996016229A1 - Cutting device

Info

Publication number: WO1996016229A1
Application number: PCT/GB1995/002771
Authority: WO
Inventors: John Edwin Oakes
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-11-24
Filing date: 1995-11-24
Publication date: 1996-05-30
Anticipated expiration: 1997-05-24
Also published as: GB9524135D0; AU4308996A; GB2295564A; GB9423761D0

Abstract

A cutting device (10) comprises a main frame (12) which supports a pair of front wheels (14) and a pair of rear wheels (16), and a sub-frame (60) which is pivotably mounted relative to the main frame about an axis coincident with that of the wheels (16). Cutting blades (34, 36) are mounted on the sub-frame and are arranged to be driven by an engine (38) such that, at their cutting positions, they are driven in the same direction as the direction of forward movement of the device in order to form a parallel sided trench.

Description

CUTTING DEVICE

This invention relates to a cutting device and particularly, although not exclusively, relates to a cutting device for forming spaced apart substantially parallel cuts in a material. In a preferred embodiment, the invention provides a method for forming a trench in a roadway.

Roadways for road vehicles or pedestrians may be made of asphalt or concrete. It is often necessary to form trenches in such roadways for receiving, for example gas pipes or cables. A known method for forming a trench utilises a cutting device. Such a device may comprise a "single" rotatably mounted circular diamond-tipped steel blade mounted in a frame and driven by an engine. Referring to Figure l of the accompanying diagrammatic drawings, the blade 2 is arranged so that, at its cutting position 4, it rotates in a direction 6 which is opposite to the direction 8 of forward movement of the saw device. Such cutting devices have a tendency to jump out of their line of cut. To obviate this problem, such devices tend to be relatively heavy so as to increase the inertia to such jumping movement.

To form a trench using a cutting device of the type described, the device is moved along the roadway and a first elongate cut is made therein to define one side of the trench. Then, the device is moved along the roadway a second time and a second elongate cut is made therein to define the other side of the trench. The road material between the elongate cuts is then removed to form the trench. One problem associated with forming a trench in this way is that the first and second elongate cuts must be made separately and this is time-consuming. Furthermore, it is difficult for an operator to ensure that the first and second elongate cuts are substantially parallel to one another and to accurately control the width between the cuts. As a result, trenches formed using the known device may not be parallel sided and, furthermore, may be made wider than necessary, since an operator will always ensure that the width of a trench is too large rather than too small. However, the wider the trench, the more material is needed to subsequently fill the trench in and, consequently, unnecessarily wide trenches will increase costs.

Known cutting devices for forming trenches include a pair of handles positioned at waist height and arranged to be grasped by an operator so that he can push the device forward. However, such devices are relatively heavy and, consequently, significant effort is required to move the device forward. Furthermore, all the effort tends to be concentrated through the operators' arms, the muscles of which tend to be relatively weak, compared to those of, for example the legs. Therefore, the arms of operators of known cutting devices may become fatigued relatively quickly.

It is an object of the present invention to address problems associated with known cutting devices.

According to the invention, there is provided a cutting device for forming spaced apart substantially parallel elongate cuts in a material, the device being arranged to move in a forward direction and comprising first and second cutting means each being arranged to form a cut in the material, wherein said cutting means are rotatably mounted and arranged to be driven such that, at their cutting positions, they move in the same direction as the direction of forward movement of the device.

Said cutting device is preferably arranged for forming cuts in a material which is generally horizontally arranged. Said device is preferably arranged for forming cuts in a roadway material, for example of asphalt or concrete.

Said first and second cutting means preferably comprise cutting blades which are preferably substantially circular. Said blades may have a diameter in the range 6" (15.2 cm) to 20" (50.8 cm), preferably in the range 8" (20.3 cm) to 18" (45.7 cm) and, more preferably, in the range 10" (25.4 cm) to 16" (40.6 cm).

The rotational axes of the blades are preferably aligned. Preferably, the blades are arranged to be driven at exactly the same speed. To this end, preferably, said blades are arranged to be driven by the same drive means. Preferably, the blades are mounted on a shaft or shafts, more preferably on the same shaft which is arranged to be driven by said drive means.

Blade spacing adjustment means is preferably provided for adjusting the lateral spacing between said blades. This allows the distance between cuts to be formed by the device to be adjusted. Said adjustment means is preferably arranged to adjust the distance in stages - that, it is preferably not continuously adjustable. Said adjustment means may comprise spacing means arranged to be positioned between the blades. Where the blades are mounted on a shaft or shafts, said spacing means may be arranged to co-operate with the shaft(s) for adjusting the spacing between the blades.

Preferably, a set of spacing means is provided for said device.

Said device is preferably arranged to roll over the surface of the material to be cut. Said device preferably is arranged to be free-standing. It preferably includes three, more preferably four wheels. The rotational axes of said cutting means are preferably in front of the rotational axes of each of said wheels.

The device preferably includes a main frame means on which said wheels are mounted. Said first and second blades are preferably movable, preferably pivotable, relative to said main frame means.

The device preferably includes a sub-frame means on which said first and second blades are mounted. Said sub- frame means is preferably movable, more preferably pivotable relative to said main frame means.

Depth means is preferably provided for adjusting the depth of cut of said blades. Said depth means is preferably arranged to move the blades thereby to adjust the depth of cut. Where the device includes a main frame and a sub-frame on which said blades are mounted, said depth means is preferably operable to move, preferably to pivot, the sub-frame relative to the main frame for adjusting the depth of cut. Locking means is preferably provided for locking the sub-frame and main frame relative to one another so as to fix a selected depth of cut. Said locking means may comprise a locking pin arranged on one of either said sub-frame or main frame which pin is co- operable with a keeper provided on the other one of either said sub-frame or main frame. Means for moving the pin relative to the keeper is preferably provided, said means suitably being operatively connected to a foot pedal or the like arranged towards the rear of the device.

Shield means is preferably provided for shielding the blades from an operator. Said shield means preferably extends from one side of the device to the opposite side. Said shield means preferably comprises a housing in which said blades are positioned. Said housing may include an inspection cover arranged to allow access to said blades and/or arranged to allow blades to be removed from the device. Said shield means is preferably fixed relative to the main frame means, when provided.

The device preferably is arranged to be pushed by an operator and, to this end, preferably includes an operator contact member. Said contact member is preferably arranged to be lent against by an operator. It is preferably generally planar. It preferably has a surface having a width of at least 10 cm and, more preferably, at least 20 cm. Said surface preferably extends transversely to the forward direction of the device. The surface area of said member is preferably greater than 100 cm² and is, more preferably, greater than 200 cm².

Said contact member is preferably inclined to the vertical. Said contact member may include spaced apart hand grip regions, suitably outside said surface of the contact member. Said contact member may be incorporated into any device which comprises a movable carriage, irrespective of whether the device includes a cutting means or not.

The invention extends to a cutting device for forming a cut in a material, the device including a cutting means arranged to form a cut in the material, the device including an operator contact member as described in any statement herein.

The invention extends to a method of forming spaced apart substantially parallel cuts in a material, for example a roadway, comprising providing a device having first and second spaced apart rotatably mounted cutting means and driving said cutting means such that, at their cutting positions, they move in the same direction as the direction of forward movement of the device.

The invention extends to a method of forming a trench, for example in a roadway, the method comprising forming spaced apart parallel cuts in a method according to the preceding statement and removing material from a region between the cuts.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

Figure 2 is a side elevation of a cutting device;

Figure 3 is a cross-section of the cutting device about line III-III of Figure 2;

Figure 4 is a cross-section of the cutting device about line IV-IV of Figure 2; Figure 5 is a schematic front elevation showing alternative positions of the cutting blades of the cutting device;

Figure 6 is a schematic side elevation showing the direction of rotation of the cutting blades and the forward direction of the cutting device; and

Figure 7 is a rear elevation of part of the device showing an operator contact area of the device.

The cutting device 10 comprises a main frame 12 which supports a pair of front wheels 14 and a pair of rear wheels 16. The main frame 12 is generally H-shaped, in that it comprises two parallel frame members 13 which are rigidly spaced apart by a transverse frame member 15. A blade height adjustment plate 17 is fixed to the member 15 and it includes a plurality of openings arranged to define an arc-shape and to receive a locking pin 19.

A cut guide pointer assembly 26 is also secured to the main frame 12. The assembly 26 includes an L-shaped square cross-section pointer element support 28 which is arranged to slidably receive a pointer element 30, along its shorter limb 29. The pointer element is arranged to be releasably secured at a selected position on the shorter limb 29.

A sub-frame 60 is mounted on the main frame 12 and is arranged to pivot about an axis 62 about which rear wheels 16 are arranged to rotate. The locking pin 19 is fixed relative to the sub-frame 60 and is arranged to be engaged and disengaged by operation of a foot pedal (not shown) , in the openings in the blade height adjustment plate 17 for adjusting the angular position of the sub-frame relative to the main frame.

Cutting blades 34, 36 are mounted on, and are translationally fixed relative to, the sub-frame. The blades 34, 36 are circular and made of diamond-edged steel. They are arranged within a downwardly open housing 32. The sub-frame also supports an engine 38 and all the associated drive means, including a vee belt 39, for coupling the engine to the blades 34, 36.

The cutting blades 34, 36 are mounted, at spaced apart positions, on a shaft 40 which is supported in bearings 42. The blades are releasably secured in position between respective inner stops 44, 46 and respective outer stops 48, 50. The outer stops 48, 50 are releasably securable on the shaft 40. This allows the distance between the blades 34, 36 to be adjusted. For example, stops 48, 50 may be secured in position in contact with the respective blades 34, 36, as shown in Figure 4. In this case, the blades are spaced apart a distance "a", as shown in Figures 4 and 5. Distance "a" is typically 10" (25.4 cm) . The distance between the blades may be adjusted by removing the stops 48, 50 and the blades 34, 36 by sliding them from the shaft 40. Then, selected spacer blocks 52, 54 (Figure 5) may be fitted on to the shaft 40 so that they abut the inner stops 44, 46 and then the blades are fitted on to the shaft 40 so as to abut the spacer blocks 52, 54. The blades are secured in position by securing the outer stops 48, 50 in position.

Referring to Figure 5, the blades 34a, 36a, shown in chain lines are spaced apart by a distance "b" by using spacer block 52 to abut stop 46 and spacer block 54 to abut stop 44. Stops 48, 50 then secure the blades in position.

The blades may in fact be spaced apart by a relatively small distance by arranging both blades on the same side of the bearings 42 and using spacer blocks to space the blades apart by distances of about 25 mm, 50 mm or 75 mm. Such narrowly spaced blades may be used to form channels for cables or the like.

Spacer blocks 52, 54 may simply comprise steel annuluses which are slidable on the shaft 40. Block 52 may have a width of 2" (5.08 cm) and block 54 may have a width of 1" (2.54 cm). Thus, distance "b" is about 13" (33.0 cm) .

A further spacer block (not shown) having a width of 3" (7.62 cm) may be provided and arranged to be mounted on the shaft. The further spacer block may be used, together with the other spacer blocks, to increase the distance between the blades to 14" (35.56 cm), 15" (38.1 cm) or 16" (40.64 cm) .

An upright strut 18 of the sub-frame carries a square cross-section collar 20 which is adapted to slidably receive an operator contact area support strut 22. Securement means (not shown) is associated with the collar 20 for securing the support strut 22 at a selected height relative to the other parts of sub-frame. A water receptacle 24 is releasably secured, by means of a strap (not shown) , to the sub-frame.

The support strut 22 includes a contact member 23 which includes respective hand grip regions 25 and an abutment surface 27 which is planar, but angled at about 45° to the horizontal. The contact member 23 comprises a steel former which is encased within heavy duty resilient sponge material. The sponge material is covered by a PVC skin. The surface 27 of the member 23 is arranged to be lent against by an operator. For example, the operator's chest or the side of an operator's arm may abut the surface in use. This allows the operator to utilise the power of his legs to move the device forward, rather than relying, to a significant degree, on his arms to provide the force to push the device forward. It is found that, in view of the resilient nature of the member 23, vibrations transmitted to the operator at his point of contact with member 23 are minimised and the contact member 23 provides a comfortable means of urging the device forward.

The depth of cut to be made using the device may be adjusted by an operator by pivoting the sub-frame relative to the main frame until the sub-frame has been pivoted to an appropriate position, and then causing the locking pin 19 on the sub-frame to enter an appropriately positioned opening in the height adjustment plate 17. The angular position of the sub-frame to the main frame is thereby fixed and the depth of cut defined. For example, the sub- frame may be arranged relative to the main frame to define a depth of cut "y" as defined in figure 2.

Indicator means is provided so as to indicate the depth of cut "y", so that an operator can easily set the desired depth of cut.

The drive means, including vee belt 39, is arranged to cause the blades to rotate in direction 49 such that at their cutting positions 50 (Figures 2 and 6) they move in the same direction as the direction 52 of forward movement of the device 2. The water receptacle 24 includes pipework arranged to direct water in use to a position on the blade which is upstream of the cutting position 50.

The device 2 may be used as follows:

Initially the device is set up by selecting the blade width and depth of cut, adjusting the pointer 30 if necessary and adjusting the position of the contact member 23 so that it may be contacted comfortably by the operator. Then, with the blades rotating in the direction described and with water being delivered from the receptacle to the blade, the device 2 is gradually urged forward by the operator, across the surface of the material to be cut, whereupon two parallel cuts of a predetermined spacing, are formed in the material. It has been found that the device 2 does not jump out of the cuts but efficiently and relatively easily forms the cuts. Furthermore, any dust produced during cutting is quickly damped down by the water delivered to the device. Additionally, less effort is required by the operator to move the device forward and effect cutting.

After the cuts have been formed, the material between the cuts may be removed to form a trench in the normal way.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) , may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CJΔIMS

1. A cutting device for forming spaced apart substantially parallel elongate cuts in a material, the device being arranged to move in a forward direction and comprising first and second cutting means each being arranged to form a cut in the material, wherein said cutting means are rotatably mounted and arranged to be driven such that, at their cutting positions, they move in the same direction as the direction of forward movement of the device.

2. A device according to Claim l, which is arranged for forming cuts in a roadway material.

3. A device according to Claim 1 or Claim 2, wherein the rotational axes of the blades are aligned.

4. A device according to any preceding claim, wherein the blades are arranged to be driven at exactly the same speed.

5. A device according to any preceding claim, wherein blade spacing adjustment means is provided for adjusting the lateral spacing between said blades.

6. A device according to Claim 5, wherein said adjustment means comprises spacing means arranged to be positioned between the blades.

7. A device according to Claim 6, wherein a set of spacing means is provided.

8. A device according to any preceding claim, which device is arranged to be free-standing.

9. A device according to any preceding claim, which includes three wheels.

10. A device according to Claim 9, wherein the rotational axes of said cutting means are preferably in front of the rotational axes of each of said wheels.

11. A device according to Claim 9 or Claim 10, which includes a main frame means on which said wheels are mounted.

12. A device according to Claim 11, wherein said first and second blades are pivotable relative to said main frame means.

13. A device according to any preceding claim, including a sub-frame means on which said first and second blades are mounted.

14. A device according to Claim 13, wherein said sub- frame means is pivotable relative to said main frame means.

15. A device according to any preceding claim, wherein depth means is provided for adjusting the depth of cut of said blades.

16. A device according to any preceding claim, wherein shield means is provided for shielding the blades from an operator.

17. A device according to any preceding claim, which includes an operator contact member by means of which the device is arranged to be pushed forward by an operator.

18. A device according to Claim 17, wherein said contact member is arranged to be leant against by an operator.

19. A device according to Claim 17 or Claim 18, wherein said contact member is generally planar.

20. A device according to Claims 17 to 19, wherein said contact member has a surface having a width of at least 10 cm.

21. A device according to any of Claims 17 to 20, wherein the surface area of said contact member is greater than 100 cm².

22. A device according to any of Claims 17 to 21, wherein said contact member is inclined to the vertical.

23. A cutting device for forming a cut in a material, the device including a cutting means arranged to form a cut in the material, the device including an operator contact member arranged to be leant against by an operator for pushing the device forward.

24. A method of forming spaced apart substantially parallel cuts in a material comprising providing a device having first and second spaced apart rotatably mounted cutting means and driving said cutting means such that, at their cutting positions, they move in the same direction as the direction of forward movement of the device.

25. A method of forming a trench, the method comprising forming spaced apart parallel cuts in a method according to Claim 24 and removing material from a region between the cuts.