WO2007053888A1

WO2007053888A1 - An apparatus and method to replace string lines especially in roadworks

Info

Publication number: WO2007053888A1
Application number: PCT/AU2006/001664
Authority: WO
Inventors: Kevin James Moller; William Richard Theodore
Original assignee: Kevin James Moller; William Richard Theodore
Priority date: 2005-11-10
Filing date: 2006-11-07
Publication date: 2007-05-18
Also published as: AU2005232270B1

Abstract

A laser assembly can be used to replace a string line on roadworks. A system to determine the level of a road using a laser assembly is also described.

Description

AN APPARATUS AND METHOD TO REPLACE STRING LINES ESPECIALLY IN ROADWORKS

Field of the Invention.

This invention is directed to a laser system that can replace string lines especially on roadworks, embankments and the like, by using a laser beam to replace the string line.

Background Art.

In roadworks, it is extremely important to have levels accurately determined. For instance, a road needs to have a taper running from the middle of the road to each side such that water can run off the road and into road gutters.

Conventionally, surveyors will survey the road, and hammer pegs at particular positions to show where road excavation etc needs to take place. A string line is tensioned between a particular peg on one side of the road and another peg on the other side of the road. A road grader or other road equipment can then grade the road to the required level. Of course, the string line needs to be removed every time the road grader passes past the string line and replaced thereafter. Also, roads are graded in successive layers with the layers being compacted. The string lines therefore need to be continually adjusted.

Once the road has been initially levelled, a taper needs to be cut in each side to allow water to run off the road. Using a string line for such a taper is difficult.

Embankments also need to be levelled. To do so, a surveyor will peg the top of the embankment with two spaced apart pegs (typically about 40 cm apart) and will then nail an angled crosspiece between the pegs with the angle showing the taper of the embankment. An excavator can then cut the embankment to the desired angle.

Sometimes, it is necessary to run a string line from the top of one of the pegs to the bottom of the embankment to see if the taper is correct. There are many disadvantages with the use of string lines. One disadvantage is that the string line need to be dropped and raised as a road grader etc passes along the road. Another disadvantage is that the string line will sag especially if it is strung over a relatively long distance (for instance 10-20 m or more). The string line presents a continual tripping hazard. The string line cannot be used at night-time or under low light conditions. In most cases, the string line requires two people, one on each side of the road. Another disadvantage is the repetition required in adjusting the string line. For instance, as the road is formed, the height of the string line may need to be adjusted many times. The string line can be quite easily damaged or cut. Strong winds can also cause vibrations in the string line.

It is known to use a dumpy level to assist in levelling. These devices have a telescope attached to a tripod. While the device is quite accurate, the main disadvantage is that a person always needs to look through the telescope to determine if a level is being achieved.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Object of the Invention.

It is an object of the invention to use a laser levelling system for use in roadworks and particularly to replace the string line system and which may overcome at least some of the above-mentioned disadvantages or provide a useful or commercial choice.

In one form, the invention resides in a system for use in roadworks, the system comprising a laser positioned on one side of the roadworks and adapted to emit a laser beam across the roadworks, and a target board or similar device that typically has calibrations and which can be placed on the roadworks, the position of the laser beam striking the target board providing information about the road level.

Thus, instead of a string line, a laser can be positioned to shine a laser beam across the area where levelling is required. A person can then walk across the area with a target board, and the position where the laser beam strikes the target board will tell the person if the level is too high, too low, or correct.

The target board will typically comprise a board member containing calibration lines, or other types of calibration means, and a pole or post or stake or similar member to which the board member is attached and which can be placed on the road. Alternatively, the target board may comprise a sensor which, emits an audio signal or a visual signal when struck by the laser beam.

In another form, the invention resides a levelling system for use in roadworks, the system comprising placing a peg on each side of the road, placing a control level or control levels on the pegs, providing a laser which emits a laser beam from a desired control level on one of the pegs to a desired control level on the other of the pegs, and a target board or similar device that typically has calibrations and which can be placed on the roadworks, the position of the laser beam striking the target board providing information about the road level.

In this particular form of the invention, a surveyor will typically peg each side of the road with pegs. Then, the surveyor will set control levels on the pegs, and these control levels can be markings on the pegs. A laser beam can then be positioned to go from the control level on the peg on one side of the road to hit the peg on the other side of the road and on the particularly desired control level. The laser beam will therefore provide a level. The target board can then be used to see if the road is at the desired level. Typically, these control levels are positioned higher than the desired level of the road such that the laser beam will be some distance above the desired level of the road (typically 10-100 cm) to make it easier for the person holding the target board.

In another form, the invention resides in an adjustable laser assembly for use with roadworks, the laser assembly comprising a stake member which can be pushed into the ground, an arm member that is adjustably mounted to the stake member, an angle adjustment member that is supported by the arm member and which can be adjusted to various angles, a laser which is supported by the angle adjustment member such that adjustment of the member adjusts the angle of the laser beam emitting from the laser.

This assembly can be used with the system described above. The assembly is relatively simple and robust in design and can be easily adjusted for height, beam angle and the like.

In another form, the invention comprises a method for determining levels in roadworks, comprising the steps of placement of a survey peg in an area where a level needs to be determined, marking the peg to show the correct level, placement of a laser emitter relative to the survey peg such that the laser emitter directs a laser beam across the area and at an angle which is consistent with the marking on the survey peg, and using a portable target which is positioned on the area, the position of the laser beam striking the target providing information about the level.

Suitably the area comprises a road surface or an embankment.

Suitably, a survey peg is placed on opposed sides of the area to be levelled.

Suitably, the target comprises a post, and a target board attached to the post, the board having calibration lines, the position of the laser beam on the board providing information about the level.

Suitably, the laser emitter is attached to a substantially upright support, an arm member that is adjustably mounted to the support, an angle adjustment member that is supported by the arm member and which can be adjusted to various angles, the laser emitter being supported by the angle adjustment member such that adjustment of the member adjusts the angle of the laser beam .

Suitably, there is provided a method for determining levels in roadworks, comprising the steps of placement of a plurality of survey pegs in an area where a level needs to be determined, marking the pegs to show the correct level or levels, placement of a plurality of laser emitters relative to at least some of the said survey pegs such that the laser emitters direct a laser beams across the area and at an angle which is consistent with the marking on the survey pegs, and using a portable target which is positioned at various positions in the area, the position of the laser beam(s) striking the target providing information about the level at various positions.

In another form the invention comprises a laser levelling apparatus for determining levels in roadworks, the apparatus comprising a laser emitter, a support assembly on which the emitter is supported, the support assembly comprising vertical adjustment means and horizontal adjustment means to enable the direction of the laser beam of the emitter to be adjusted, and attachment means on the support assembly to enable the emitter to be supported by a post via the attachment means.

The stake member can be made of any suitable material such as metal, plastic, fibreglass, wood, composite materials and the like. The stake member may be hollow or solid, may be cylindrical, as a rectangular cross-section, an oval cross-section, may be plate like and the like. The stake member will typically have a length of between 0.5-2 m. It is considered that this length will be suitable for most roadwork and embankment uses. The stake member may contain a pointed end to assist in pushing the stake member into the ground. Alternatively, some form of pointed end can be attached to the otherwise plain end of the stake member. The stake member may contain graduations, indicia and the like if required.

An arm member can be adjustably mounted to the stake member. The arm member may be fixed to or relative to a collar that can slide along the stake member. The collar may contain a camping of fixing screw that can lock the collar to the stake member at a particular position. If desired, a plurality of collars can be provided. Some of these collars or similar members can be used as a depth indicator of the stake member in the ground. The arm member may have a length of between 50-200 mm and should be long enough and strong enough to support the laser. The arm member may comprise a rod, a plate, a tube and the like.

An angle adjustment member can be supported by the arm member. The angle adjustment member may comprise an elongate member and may particularly comprise a U-shaped channel that can be made of any suitable material such as metal (steel or aluminium), plastic, composite materials and the like. The channel may comprise a pair of sidewalls connected by a bottom wall. The bottom wall may be attached to or relative to the arm member. The angle adjustment member may comprise a second member which may also comprise a U-shaped channel that can be made of materials similar to that described above. The second member will typically be attached to an elongate pin that spans the first U-shaped channel and which can rotate/tilt/rock relative to the first U-shaped channel such that when the second U-shaped channel is attached to the pin, rotation of the pin will rotate/tilt/rock the second U-shaped channel. If desired, adjustment means can be provided to adjust the angle (the rotation) of the pin. The adjustment means may comprise a threaded bolt and the like.

The laser may be attached to or relative to the second U-shaped channel. Typically, the laser will be positioned within a housing, and the housing can be attached to the second U-shaped channel.

If desired, a protective cover/weather shield can be positioned to protect the laser.

In a power source may be provided to power the laser. The power source may comprise a portable power source such as a battery.

Brief Description of the Drawings.

Embodiments of the invention will be described with reference to the following drawings in which:.

Figure 1. Illustrates an adjustable laser assembly. Figure 2. Illustrates a close-up of the upper part of the adjustable laser assembly of figure 1.

Figure 3. Illustrates the adjustable laser assembly from the side.

Figure 4. Illustrates use of the adjustable laser assembly. Figure 5. Illustrates a side elevation of a mounting post with a laser housing.

Figure 6. Illustrates a front elevation of figure 5.

Figure 7. Illustrates a side elevation of the same type of laser as illustrated in figure 5, but with a different type of mounting post.

Figure 8. Illustrates a front elevation of figure 7. Figure 9. Illustrates a front elevation of a laser housing attached to a bracket of a particular design to enable the laser housing to be attached to a star picket.

Figure 10. Illustrates the side elevation of figure 9.

Figure 11. Illustrates a laser emitter attached to a post and an adjacent surveyor's peg- Figure 12. Illustrates the front elevation of figure 11.

Figure 13. Illustrates a section view of the laser emitter and the support assembly on which the laser emitter is mounted.

Figure 14. Illustrates the front elevation view of figure 13 and also shows the section line A-A. Figure 15. Illustrates a bottom view of figure 14.

Figure 16. Illustrates a side elevation of the "target board" which is also known as a "three way staff.

Figure 17. Illustrates a front elevation of figure 16.

Figure 18. Illustrates a plan section view along section line B-B of figure 16. Figure 19. Illustrates a plan view of the level bubble which is on top of the staff of figure 16 and figure 17.

Figure 20. Illustrates another view of the bracket of figure 9.

Best Mode.

Referring to the figures and initially to figures 1-3, there is illustrated an adjustable laser assembly. The assembly comprises a stake member or support post 10 which can be made of aluminium tube closed at the bottom end and also pointed at the bottom end to enable the stake to be more easily inserted into the ground. The support post will typically have a length of between 40-120 cm, and a diameter of between 10- 100 mm.

Attached to the post 10 is an adjustable and removable clamp 11 which in the particular embodiment comprises a collar which can slide along post 10 and which contains a threaded bolt that can be tightened to clamp the collar on the post. The collar can be entirely removed from the post if desired. Collar 11 functions to provide extra support to the laser device which is also attached to post 10 (see below) and can also function as a depth marker giving a consistent insertion point into the ground.

Also attached to post 10 is another adjustable clamp 12 which can be similar to collar

11 in that it also can slide along post 10 and can be clamped into position by a threaded bolt.

Attached to clamp 12 is an arm member 13 which is best illustrated in figure 2. The arm member 13 comprises a small extension rod or tube that can be attached to clamp

12 and the arm member will typically have a length of between 50-200 mm. As clamp 12 can swivel around post 10, the arm member can also swivel about the post by being attached to clamp 12.

An angle adjustment member is supported by arm member 13. In the particular embodiment, the angle adjustment member comprises a U-shaped channel 14 (see figure 2) typically formed from aluminium. The U-shaped channel will have a length of between 50-250 mm. The U-shaped channel contains a bottom wall, and opposed sidewalls.

An elongate pin 15 is journalled between the sidewalls of the U-shaped channel and therefore can rotate relative to the channel about a substantially horizontal axis.

A second U-shaped channel 16 is welded or otherwise fixed to the main body of elongate pin 15 such that rotation of the pin causes rocking of the U-shaped channel 16. An adjustment knob 17 is provided that extends through an opening in the bottom wall of U-shaped channel 14 and engages with the second U-shaped channel 16. Thus, rotation of adjustment knob 17 will ultimately cause the second U-shaped channel 16 to tilt upwardly or downwardly.

A laser beam housing 18 is attached to the second U-shaped channel 16. The housing is made from machined aluminium hollow cylinder which can be completely removed for easy access to the laser emitter (bulb) and power lead. The hollow cylinder contains an end cap which can be removed to access the laser emitter etc. Housing 18 can be screwed or otherwise attached to U-shaped channel 16. Ih the particular embodiment, an adjustable bolt 20 is used to clamp housing 18 into position on channel 16.

Inside housing 11 is a laser emitter which may be of conventional manufacture. The emitter passes a laser beam through a small opening in the front of housing 18.

A weather shield/cover 21 is positioned on top of housing 18.

Power leads (not illustrated) pass from inside housing 11 to a power source which may be a battery, generator, mains power etc.

Referring to figure 4, in use, the adjustable laser assembly 23 is placed adjacent a surveyors peg 24. Another peg 25 is positioned by the surveyor on the other side of road 26. The surveyor would have marked each peg with control levels in the usual form. The laser assembly 23 is adjusted such that the laser beam 27 passes across the road and from one control level (on peg 24) to the other control level (on peg 25). Thus, the laser beam correctly marks the level of the road.

A target board 28 can then be "walked" along the road by a person. The target board will typically comprise a flat target formed with graduations which will identify if the road level is correct. If not, additional road base can be placed on the road (or removed) until the level is correct. When the correct road level has been achieved, the next step is to create a taper on each side of the road. The present invention allows this to be done quite conveniently by adjusting the laser assembly 23 to shine the laser beam 29 downwardly to mark a taper 30. To create a taper on the other side of the road (31) the laser assembly 23 is now placed adjacent peg 25 and shone downwardly.

Referring now to figures 5 - 20, there is illustrated various modifications to the system.

Referring initially to figure 5 and figure 6, there is shown a side elevation and a front elevation of a laser emitter 40 positioned within a housing 41, the housing being positioned on top of a support assembly 42 which is quite sophisticated in design and which will be described in greater detail with reference to figures 13 - 15.

The support assembly 42 can be attached to a mounting post 43, and mounting post 43 can be hammered or pushed into the ground 44, with the support assembly 42 being adjustably positioned somewhere along mounting post 43.

A battery 45 provides power to the laser emitter 40 via a power lead 46.

Post 43 can be telescopic and adjustable in length in a manner described previously with reference to figures 1 - 2. The support assembly 42 is mounted onto post 43 using an attachment means 47 which, in the particular embodiment, comprises a collar 48 which can slide along the mounting post 43 and then be releasably locked in a desired position.

Referring to figure 7 and figure 8 there is illustrated a side elevation and a front elevation of a laser assembly which is substantially the same as that described with reference to figure 5 and figure 6 except that the laser assembly is mounted onto a different type of mounting post. The mounting post 49 is attached to a relatively large and stable base member 50 which means that the laser assembly + the mounting post 49 + the base member 50 can be easily lifted and transported to a desired position and it is not necessary to hammer the post into the ground. This version of the invention is suitable for use on the hard ground (for instance pavement) where it is undesirable to hammer the mounting post into the ground.

Referring to figure 9 and figure 10 there is illustrated a front elevation and a side elevation of the laser assembly 51 which may be similar to that described previously but which is attached to a particular type of bracket 52 to enable the laser assembly to be fixed to a star picket 53. Bracket 52 is also illustrated in figure 20. A star picket is a steel member usually having a length of between 0 .5 -3 m and comprising three steel flanges which are equally spaced apart such that the angle between an adjacent pair of flanges is 120°. These pickets are extremely common at least in Australia and are widely used as temporary post members.

Referring to figure 11 and figure 12, there is illustrated a side elevation view and a front elevation view laser assembly attached to a mounting post 43. Also illustrated is a surveyor's peg 55. The surveyor's peg 55 contains a marking or something similar 56 which sets the angle. In this particular embodiment, a sight 57 is mounted onto peg 55 and enable the laser beam 58 to pass through sight 57 only if the laser beam is at the correct angle. This is a convenient manner to ensure that the laser beam is correctly positioned.

Referring to figure 13, figure 14, and figure 15, there is illustrated greater detail of the laser emitter and the support assembly 42. The laser emitter is positioned within and protected by a housing 41 which can act as a weatherproof shield. Housing 41 extends almost about laser emitter 40 as is illustrated in figure 14. The laser emitter 40 itself comprises a laser "bulb" within a substantially tubular cover. Emitter 14 is clamped in position by a bolt 60. The support assembly 42 is rather sophisticated in design and provides easy adjustment of the position of the laser emitter and therefore the direction of the laser beam. Support assembly 42 comprises a top plate 61. Below plate 61 is a laser tilt pivot 62. A second plate 63 is positioned below plate 61 and the two plates are separated by a spring 64. A fine tilt adjustment screw 65 can be rotated to tilt top plate 51 and therefore adjust the direction of the laser beam. Similarly, a horizontal pivot 66 is provided to provide pivoting movement and the pivot is locked by a lock nut 67.

The support assembly 42 is mounted to an attachment means 47 (see figure 14) which enables the entire arrangement to be mounted to a post or something similar.

Figures 16 - 19 illustrate the target board, which in the embodiment, is a quite sophisticated design and is also known as a "three-way staff. The staff comprises a post 69 which can be held by a person and "walked" across the area to be levelled. Attached to the lower end of the post 69 is a calibration arrangement 70 which comprises a flat board 71 containing adjustable level indicators to indicate whether the ground should be raised or lowered at the position where the bottom of the post is placed on the ground. The particular three-way staff contains three such boards 71 which means that the calibration arrangement 70 is triangular in shape which is best illustrated in figure 18. As the post 69 needs to be kept vertical, a level bubble 72 is provided on the top of the post 69 and a plan view of the level bubble 72 is illustrated in figure 19.

There may be circumstances where the laser power may need to be reduced, and a visual indication on the target board may be difficult. In these circumstances, the board may contain a sonic receiver which may be battery powered. When the low power laser strikes the receiver, a sound may be emitted.

As technology advances, there may be circumstances where the laser might be replaced by some other type of emitter.

The system according to the present invention provides many advantages. Firstly, there is a significant time-saving by speeding up and improving work production. Less staff are required. There is a significant safety improvement especially around working machines. There is less disruption on job site. The system can be used at night time. The system can be used on slopes and will prevent undercutting of the batter slope.

Throughout the specification and the claims (if present), unless the context requires otherwise, the term "comprise", or variations such as "comprises" or "comprising", will be understood to apply the inclusion of the stated integer or group of integers but not the exclusion of any other integer or group of integers.

Throughout the specification and claims (if present), unless the context requires otherwise, the term "substantially" or "about" will be understood to not be limited to the value for the range qualified by the terms.

It should be appreciated that various other changes and modifications can be made to any embodiment described without departing from the spirit and scope of the invention.

Claims

Claims.

1. A method for determining levels in roadworks, comprising the steps of placement of a survey peg in an area where a level needs to be determined, marking the peg to show the correct level, placement of a laser emitter relative to the survey peg such that the laser emitter directs a laser beam across the area and at an angle which is consistent with the marking on the survey peg, and using a portable target which is positioned on the area, the position of the laser beam striking the target providing information about the level.

2. The method of claim 1, wherein the area comprises a road surface or an embankment.

3. The method of claim 1, wherein a survey peg is placed on opposed sides of the area to be levelled.

4. The method of claim 1, wherein the target comprises a post, and a target board attached to the post, the board having calibration lines, the position of the laser beam on the board providing information about the level.

5. The method of claims 1 wherein the laser emitter is attached to a substantially upright support, an arm member that is adjustably mounted to the support, an angle adjustment member that is supported by the arm member and which can be adjusted to various angles, the laser emitter being supported by the angle adjustment member such that adjustment of the member adjusts the angle of the laser beam .

6. A method for determining levels in roadworks, comprising the steps of placement of a plurality of survey pegs in an area where a level needs to be determined, marking the pegs to show the correct level or levels, placement of a plurality of laser emitters relative to at least some of the said survey pegs such that the laser emitters direct a laser beams across the area and at an angle which is consistent with the marking on the survey pegs, and using a portable target which is positioned at various positions in the area, the position of the laser beam(s) striking the target providing information about the level at various positions.

7. A laser levelling apparatus for determining levels in roadworks, the apparatus comprising a laser emitter, a support assembly on which the emitter is supported, the support assembly comprising vertical adjustment means and horizontal adjustment means to enable the direction of the laser beam of the emitter to be adjusted, and attachment means on the support assembly to enable the emitter to be supported by a post via the attachment means.