Title of Invention	"A DEVICE FOR PORVIDING CENTERLINES IN A CONTINUOUS MANNER DURING CONSTRUCTION IN UNDER GROUND MINES/TUNNELS"
Abstract	We claim: 1. A device for providing centerlines in a continuous manner during construction in underground mines/tunnels, which comprises an assembly (6) having a four-arm mounting unit with four numbers laser emitting pointers and lenses for emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°,180°and 270°, wherein the 180° arm is rotatble, the said assembly being accommodated in an antistatic housing(5,9) equipped with two perpendicular spirit levels(7,8) and power source such as dry or rechargeable cells for energizing the said laser emitting pointers, the said housing(5,9) being provided at the top surface with a ball and socket joint(2) fixed to a position adjusting C-shaped cross channel(19) for mounting onto a ceiling through a bolt(20). 2. A device as claimed in claim 1, wherein the fourth rotating arm is set at a pre-determined angle varying between 120° to 240° in the same plane or in a parallel plane. 3. A device as claimed in claim 1-2, wherein the laser emitting pointers are laser diodes provides a guide beam upto a distance of atleast 100 m. 4. A device as claimed in claim 1 -3, wherein the four-arm mounting is holding the laser units in such as way that the beams are emitted in a single or in a parallel plane. 5. A device as claimed in claim 1-4, wherein the four-arm mounting has arms in 0°, 90°, 180° and 270° directions, respectively, and in each arm provided with means such as holding plates with co-axial center holes for holding the lens and aligning the laser beam. 6. A device as claimed in claim 1-5, wherein the a roof bolt(20), pointed at one end and threaded on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed Cshaped channel and the pointed end of the bolt is grouted in the mine/tunnel roof. ^^cX"^^^^ "^^^^^^ 1V<V^^>^ Dated this 2005 (Chetan Kumar) Sc^nflst IPMD,Council of Scientific & Industrial Research -16-

Title of Invention

"A DEVICE FOR PORVIDING CENTERLINES IN A CONTINUOUS MANNER DURING CONSTRUCTION IN UNDER GROUND MINES/TUNNELS"

Abstract

We claim: 1. A device for providing centerlines in a continuous manner during construction in underground mines/tunnels, which comprises an assembly (6) having a four-arm mounting unit with four numbers laser emitting pointers and lenses for emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°,180°and 270°, wherein the 180° arm is rotatble, the said assembly being accommodated in an antistatic housing(5,9) equipped with two perpendicular spirit levels(7,8) and power source such as dry or rechargeable cells for energizing the said laser emitting pointers, the said housing(5,9) being provided at the top surface with a ball and socket joint(2) fixed to a position adjusting C-shaped cross channel(19) for mounting onto a ceiling through a bolt(20). 2. A device as claimed in claim 1, wherein the fourth rotating arm is set at a pre-determined angle varying between 120° to 240° in the same plane or in a parallel plane. 3. A device as claimed in claim 1-2, wherein the laser emitting pointers are laser diodes provides a guide beam upto a distance of atleast 100 m. 4. A device as claimed in claim 1 -3, wherein the four-arm mounting is holding the laser units in such as way that the beams are emitted in a single or in a parallel plane. 5. A device as claimed in claim 1-4, wherein the four-arm mounting has arms in 0°, 90°, 180° and 270° directions, respectively, and in each arm provided with means such as holding plates with co-axial center holes for holding the lens and aligning the laser beam. 6. A device as claimed in claim 1-5, wherein the a roof bolt(20), pointed at one end and threaded on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed Cshaped channel and the pointed end of the bolt is grouted in the mine/tunnel roof. ^^cX"^^^^ "^^^^^^ 1V<V^^>^ Dated this 2005 (Chetan Kumar) Sc^nflst IPMD,Council of Scientific & Industrial Research -16-

Full Text	The present invention relates to a device for providing centerlines in a continuous manner during construction in underground mines / tunnels. The present invention particularly relates to an instrument for providing centerlines in four directions in a mine/tunnel, in which three centerlines are in 0°, 90° and 270° fixed directions in a single plane and the other one is capable of rotating from 120° to 240° in a parallel plane. This device of the present invention is to be installed in a mine / tunnel junction at a pre-determined survey point on the roof. The device of the present invention is an instrument which is useful for providing centerlines in a continuous manner in underground mine headings or tunnel headings. This novel device has scientifically arranged laser pointers, which can guide underground miners or tunnel makers about the straightness and direction of their headings below ground. There are about 500 underground coal mines in various coalfields in India. Moreover, there are numerous tunnels being constructed either for railways or for hydroelectric dams. Everywhere surveyors are deployed to mark the directions of the mines and tunnel headings in form of centerlines. After few meters of progress again these lines have to be re-marked to guide the miners or the tunnel makers for progress in the predetermined directions. It is well known that in underground mines or tunnels centerlines are provided to guide the mine / tunnels in a predetermined direction. This has to be ensured by a group of surveyors. These centerlines have to be extended on daily basis to maintain the straightness and direction of these underground openings. This job is presently carried out by using expensive theodolites (survey instruments) and is a very time taking process. This process also requires at least three to four skilled persons shift wise. In Indian mine conditions this job is also done in a conventional crude method by extending lines by coloured (commonly called red-oxide) powder marks by means of strings. This conventional system is often very misleading as this process is not very accurate as a result the tunnels / mine roadways often gets deviated from the predetermined direction. Extensive efforts have been devoted to the development of several survey instruments to provide survey lines as well as marking of centerline in mines / tunnels. To highlight the wide mining and tunneling usage and the continual efforts, which have been made by other inventors to improve the performance of surveying by use of laser based survey instruments a few patent references are provided below for illustration. Reference may be made to US patent no. 6,688,009, titled: 'Laser survey Instrument'. The invention relates to the field of survey instruments comprising a laser projector for projecting a laser beam onto a plane by rotary irradiation, a tilting unit for tilting the laser projector in two directions running perpendicularly each other and a tilt setting unit for setting a desired tilt angle for the laser projector at least in one direction, wherein the tilt setting unit comprises a tilt sensor for detecting a horizontal position and an angle detector for detecting an angle between the tilt sensor and the laser projector. This is a survey instrument and a very complicated machine. It requires an expert to operate it and cannot monitor the tunnel heading in underground continuously during the progress. The main drawback is that it may obstruct/delay other jobs, during marking of center lines. Reference may be made to patent no. WO0047950, entitled: 'Laser Survey Device' wherein a laser survey device, which can be used inter alias in setting out roads and splits in board-and-pillar mining practice. The device has a housing, which can be mounted at a survey point in a mine working in a manner allowing the housing to be rotated about a vertical axis. In the housing are laser beam directing means in the housing for projecting from the housing first and second laser beams at predetermined angles to one another and transverse to the axis. The drawbacks of this survey device are that it requires skilled persons to fix it on the roof, costly and difficult to repair. This prior art also house several beam splitting device, which are eliminated in the present invention. Reference may be made to US patent no. 4,836,669, entitled 'Apparatus and method for projection of reference planes of light' wherein an apparatus and a method to project light in two orthogonal planes to provide reference planes of light for use in laying out a construction site or the like. The apparatus comprises a laser light source for providing a source beam of light, and a light diverting arrangement. The light diverting arrangement diverts a first portion of the source beam of light to project a first thin reference fan beam of light substantially in a first reference plane, and diverts a second portion of the source beam of light to project a second thin reference fan beam of light substantially in a second reference plane. The second reference plane is substantially perpendicular to the first reference plane. The apparatus may advantageously be used in laying out a grid. Therefore it is required to provide grid lines useful for blasting pattern and drilling direction. The drawbacks of this survey device are that it requires very skilled and experienced persons to fix it on the roof or floor as it may require a tripod. Other disadvantages are that it is costly and difficult to repair. Reference may be made to US patent no. 6,457,246, entitled 'Mounting and switching of survey apparatus' wherein a survey apparatus which can be used in the underground mining industry comprises a mounting means adapted to be mounted in a fixed surface (such as a tunnel wall) and an alignment means to releasable engagement with the mounting means, wherein the alignment means is capable of operating only when the alignment means is engaged with the mounting means. The mounting means is preferably a sleeve member insert able in a wall. The alignment means preferably has a laser module and a suitable compartment for accommodating a battery. The mounting means, which is a set aligned in the fixed surface, together with the factory-set alignment means is used for the purpose of setting out and alignments. When the cylindrical shaft is inserted into the sleeve member, a rod, permanently in contact with spring presses against the screw and makes an electrical connection. As the laser module cannot be switched on when out of the sleeve member, battery life is improved and improper use is minimized. This invention claims about the mounting of the survey device and it electrical connection. The drawbacks of this device are that it requires a transformer and other electrical devices which will be a cumbersome method to use in an Indian gassy coal mine which requires flame proof equipments. Another drawback of the mounting of this invention is much complex, costly and difficult to manufacture. Reference may be made to US patent no. 5,584,458, entitled 'Quick-action mount for self-leveling laser' wherein a quick action bar clamp has provision for mounting an alignment laser instrument on one jaw of the clamp. The mounting provision allows manual pointing of the laser to facilitate projecting a level line or plane of light with a self-leveling laser instrument. By engagement of the clamp on a fixed structure such as a column, wall stud or door frame, the operator can quickly bring the laser instrument into its self-leveling range and easily adjust the beam height. The attachment of the laser instrument to the clamp is via a threaded rod or a magnetic attachment retention. An L-shaped magnetic attachment can be used in another procedure, to connect the laser to the steel slide bar of the clamp. The main drawback of this device is that it is liable to be disturbed by the blasting vibration in underground mine/tunnels. All the above-mentioned inventions are of different underground survey instruments. The disadvantages of these inventions are in their complicated designs and difficulty in installation. Another disadvantage of these instruments are that these require very skilled manpower to erect and mark the centerlines in every shift. Yet another disadvantage of these prior art is that these are costly and requires expert hand to repair. Still another disadvantage of these instruments are that they have to be removed from the position after marking of the lines. Most of these have to be carried back to the surface as these instruments are costly. To eliminate the involvement of highly skilled surveyors in every working shift for extending powder mark center lines which usually gets omitted due to deposition of dust generated from blasting, the use of laser survey instruments has came into picture due to their accuracy and expediting of survey jobs. The main disadvantages of these instruments are their sophistication and high cost. Most of these instruments also prevent progress of other jobs to some extent during the survey work. Being costly, these instruments cannot be kept lying under mines/tunnels unattended. These instruments are heavy of about 5-6 kg each moreover there are other accessories like tripods, which require more than one person to carry a single set.. Hence, it is clear from the hitherto known prior art that there is a definite need to provide a system which can easily and reliably provide centerlines in a continuous manner in underground mines and tunnels at a comparatively lesser cost and effort and does not hamper important progressive jobs such as material transport, blasting, supporting. Moreover, a device is required which will not get disturbed by blast vibration and does not require skilled manpower to mark the lines in every shift. The main object of the present invention is to provide a device for providing centerlines in a continuous manner during construction in underground mines / tunnels, which obviates the drawbacks of the hitherto known prior art as detailed above. Another object of the present invention is to provide centerlines in four directions in a same plane so that the instrument can be kept at junction of galleries and three mine/tunnel headings can be progressed. Yet another object of the present invention is to provide three lines in form of laser beams in fixed direction to each other and the fourth one can be turned in the predetermined direction as and when required. Still another object of the present invention is to provide a simple device to cross check the alignment of mine / tunnel progress in each operating shift. Still yet another object of the present invention is to provide a centerline marking instrument which does not require to be transported in and out of mines daily after a survey measurement job. A further object of the present invention is to provide a centerline marking device which enables easy mounting over the mine / tunnel roof and does not get disturbed by blast vibrations. > A still further object of the present invention is to provide a device which is light and easily transportable at different places inside the mine and tunnel. In the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels, there is provided in combination a four-arm mounting unit with four numbers laser beam-emitting diodes and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation. This combination being housed in an anti-static housing with appropriate openings and the housing being provided with means for adjustable and movable ceiling mounting. The housing is made up of metallic anti-static material because it should not accumulate static electricity which may produce spark to ignite the methane which is generally present inside a gassy coal mine. The housing can be adjusted in various directions to suit the predetermined bearing of the mine or the tunnel. The housing is mounted on a sliding channel for fine adjustment with the previous centerline, if any, or with the previously marked survey station/point. The sliding channel on the other hand is bolted with a peg that is grouted in the mine roof. The device of the present invention is useful for marking center lines and other survey lines in a continuous manner in a number of faces of a working in underground mine or tunnels. This device can emit four lines in a same or parallel plane at a time. The device of the present invention has scientifically arranged laser pointers which can guide underground miners or tunnel makers about the straightness and direction of their headings below ground. The device is light, easily transportable, re-installable and adjustable to meet the survey line requirement in a mine or a tunnel. This device is much cheaper and lighter compared to the existing survey instruments used for marking centerlines. This will eliminate the requirement of manpower to do the line marking jobs in every shift. Accordingly the present invention provides a device for providing centerlines in a continuous manner during construction in underground mines / tunnels, which comprises an assembly having in combination a four-arm mounting unit with four numbers laser emitting pointers and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation, the said assembly being accommodated in an anti-static housing equipped with two perpendicular spirit levels and power source such as dry or rechargeable cells capable of energizing the said laser emitting pointers, the said housing being provided at the top surface with a ball and socket joint fixed to a position adjusting C-shaped cross channel capable of being mounted onto a ceiling through a bolt. In an embodiment of the present invention, the four-arm mounting unit has three fixed arms capable of holding three laser emitting pointers and lens units to point 0°, 90° and 270° in a single plane and a fourth rotating arm capable of being set at a pre-determined angle varying between 120° to 240° in the same plane or in a parallel plane. In another embodiment of the present invention, the laser emitting pointers are laser diodes capable of providing a guide beam upto a distance of atleast 100 m. In yet another embodiment of the present invention, the four-arm mounting is capable of holding the laser units in such as way that the beams are emitted in a single or in a parallel plane. In still another embodiment of the present invention, the four-arm mounting has arms in 0°, 90°, 180° and 270° directions, respectively, and in each arm there are means such as holding plates with co-axial center holes capable of holding the lens and aligning the laser beam. In still yet another embodiment of the present invention, there is provided a roof bolt, pointed at one end and threaded on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed C-shaped channel and the pointed end of the bolt is grouted in the mine/tunnel roof. The various features, embodiments and advantages of the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels will be set forth by the reference to the following description of the invention and referenced drawings. The present invention is illustrated in figure 1 to 7 of the drawings accompanying this specification. In the drawings like reference numbers/letters indicate corresponding parts in the various figures. In figure 1 and 2 of the drawings accompanying this specification, block schematic diagrams of the various parts constituting the device of the present invention, is depicted. Figure 2 is the cross sectional view of figure 1 along the plane 1-1. This device of the present invention useful for providing center lines in underground mine / tunnels, comprises of four laser beam emitting devices (6) mounted on units (5) and (9), made of brass or any anti static material. Both mountings (5) and (9) are fitted in a single hinge (16). The hinge (16) may be fitted with a hook (not shown in the figures) at the bottom to hang a plumb bob pointer, if required, for alignment of the housing with any center point of a survey station. Each of the laser emitting devices are fixed by four guides (15) on these mountings as shown in figure 2. The mounting unit (5) has a fixed three directional (arms) arrangement to house three laser units to point 0°, 90° and 270° in a single plane. The mounting unit arm (9) is a partially rotating unit which can be set at the desired pre-determined angle in the same plane or in a parallel plane that can vary from 120° to 240° marked (17) on the housing (12). This unit can be tightened by a wing nut (10) to the housing (12). There are three numbers of lens (3) attached to the housing (12). The fourth lens is attached to the movable mounting (9) it self at the extreme outer end. These lenses may have a X-mark for a better pointing of the centerlines. Each laser beam has to pass through two holes and the lens to ensure a straight line. These holes are drilled in projecting parts (4) (two in each arm) of the mountings (5) and (9). The housing unit (12) is made up of some light antistatic material has two spirit levels (7) and (8) attached at the bottom of (12) arranged perpendicularly to each other. The housing also have a battery case (11) to hold dry cells or rechargeable cells. The housing is attached to a circular plate (13) by a ball and socket arrangement (2). The housing and the plate can be adjusted at different angles by three adjusting wing screws (14). There is a hexagonal nut (1) fixed at the center of the circular plate (13). In figure 3, 4, 5, 6 and 7 of the drawings accompanying this specification, block diagrams of the various parts constituting mounting device on the roof of the mine/tunnel, is depicted. Figure 5 represents a pointed bolt (20) or a peg, which will be grouted in a hole made on the mine/tunnel roof as near as possible to the survey point or junction of two roadways or at the centerline. The bolt (20) has a threaded end that will fit in the hexagonal nut (18). Figure 4 is the cross sectional view of figure 3. The hexagonal nut (18) is fixed in the center of C - shaped channels (19) welded at right angles or manufactured is such a way that the circular head (21) of the bolt (22) just fits and slides in these channels. The bolt (22) will fit in the nut (1) to hold the housing (12) and the plate (13). There is a hole (23) on the head (21) through which a tightening screw will pass to tighten this bolt (22) with the sliding channel (19) after adjusting the housing at the center of the predetermined point. The bolt head (21) may also be manufactured in the shape of a gear. In that case the inner lining of the C-Shaped channels will have to be uniformly corrugated in one side to give a rack and pinion effect. The laser unit mountings (5) and (9) are manufactured and fitted to accommodate the laser units in such as way that the beams are emitted in a single or in a parallel plane wherein the mounting (5) has three arms to point 0°, 90° and 270° directions and in each arm there are two plates (4) with center holes where all the holes of 90° and 270° arms are in one line, which can be ensured by passing a laser beam or a thread through all the four holes of these two arms during manufacture or during any calibration process moreover the 0° and the rotary 180° arm are aligned and fitted in the same manner furthermore the lenses (3) are also fitted by aligning it with external laser beam with the two holes of each arm. In present invention a ball and socket arrangement (2) is provided to adjust the horizontal level with the help of two spirit levels (7) and (8) moreover the wing nuts (14) will help in adjusting and tightening with the circular plate (13). In the present invention there is a small length roof bolt (20) of the order of 25cm in length and 21mm in diameter, is pointed at one end and threaded on the other wherein the pointed end of the bolt (20) will be grouted in a small hole of diameter of the order of 26mm to be made on the mine/tunnel roof. The threaded portion of the bolt (20) will en suite in the hexagonal bolt (18) fitted at the center of the crossed C-shaped channels (19). In the present invention a sliding bolt (22) which has a circular head (21) such that the head exactly fits in the C-shaped channel (19) which means that the diameter of the circular head (21) will be slightly less than the width of the C-shaped channel (19) wherein the bolt (22) is slided inside. The threaded portion of the bolt (22) is fitted in the hexagonal nut (1) attached at the center of the circular plate (13), which was already attached to the housing (12) therefore this arrangement will help in adjustment of the housing (12) and the hinge (16) at the exact survey point marked earlier. In the present invention a tightening arrangement is made by using a screw in the threaded hole (23) so that the bolt (22) is fixed with the C-shaped channel at a certain adjusted point. The novelty of the device of the present invention, useful for providing continuous straight centerlines in underground mines and tunnels, resides in the capability to accommodate four laser beams in a single plane or a parallel plane. Further, it provides means to mount it on mine and tunnel roof with great ease. Still another novelty of the present invention is that the mounting device cannot be disturbed by blast vibration unless kept very near to the blasting face i.e, within 15 m due to presence of several tightening screws. Yet another novelty of this invention is that it is extremely light weight compared to the prior arts. One man can carry 4 to 5 numbers of such devices at a time to install at different place in underground workings. Still yet another novelty of the present invention is the elimination of external electrical connection, beam splitters and costly prisms to deviate the beams in different directions, which are used in the hitherto known prior art. This simple step makes the device a very low cost and effective centerline provider in four predetermined directions. The novelty of the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels, has been realized by the non-obvious inventive steps of providing in combination a four-arm mounting unit with four numbers laser emitting pointers and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation. The said assembly being accommodated in an anti-static housing equipped with two perpendicular spirit levels and power source such as dry or rechargeable cells capable of energizing the said laser emitting pointers. The said housing being provided at the top surface with a ball and socket means fitted with a bolt through a position adjusting C-shaped cross channel having wing nuts and screws for ceiling fitment, such that it does not get disturbed by blast vibrations. This device therefore helps in eliminating the requirement of skilled surveyor in every shift for marking centerlines and also to do away with transportation of the costly survey instruments in and out of the mines after every center lines marking and extending jobs. The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention. Example: 1 A prototype of the devices of the present invention was fitted in the underground tunnels of a coal mine on an experimental basis in the Jharia coalfield. The immediate fallout was that te consumption of red power for marking reduced considerably. The surveyors were not required to go underground daily for marking center lines, so that they were able to engage in other constructive planning. The underground supervisors and workers themselves could guide the progress on the direction of the laser beams. Even after a month the direction of the beams were not altered by blast vibrations. The progress of the mine galleries were made more than 120m with the help of this device. As this was done on an experimental basis cross check was done at an interval of seven days in which no deviation was found. The main advantages of the device for providing center lines, in a continuous manner during underground mine/ tunnels construction, of the present invention are: 1. Allows to provide centerlines and other four-way direction lines in underground tunnel excavations or mines easily and reliably. 2. Reduces the manpower requirement of updating the centerlines or survey lines daily. 3. Enables easy installation of the device in underground. 4. Enables easy and quick adjustment with the previously marked centerline or any survey point (for back-sight check). 5. Ensures minimum deviations in the predetermined mine /tunnel directions. 6. It does not get disturbed by blast vibrations. 7. It need not be taken out of the mine daily, as it does not interfere with other construction jobs or mine working. 8. Cheap and easy to manufacture and assemble. 9. Reduces consumption of red powder (locally called red oxide) used for marking of survey lines. 10. Very light weighted and easy transportable. One man can easily carry 4-5 of these instruments at a time. 11. Calibration can be done by the user at the site and does not required to be sent to a specialist or any laboratory. We claim: 1. A device for providing centerlines in a continuous manner during construction in underground mines/tunnels, which comprises an assembly (6) having a four-arm mounting unit with four numbers laser emitting pointers and lenses for emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°,180°and 270°, wherein the 180° arm is rotatble, the said assembly being accommodated in an antistatic housing(5,9) equipped with two perpendicular spirit levels(7,8) and power source such as dry or rechargeable cells for energizing the said laser emitting pointers, the said housing(5,9) being provided at the top surface with a ball and socket joint(2) fixed to a position adjusting C-shaped cross channel(19) for mounting onto a ceiling through a bolt(20). 2. A device as claimed in claim 1, wherein the fourth rotating arm is set at a pre-determined angle varying between 120° to 240° in the same plane or in a parallel plane. 3. A device as claimed in claim 1-2, wherein the laser emitting pointers are laser diodes provides a guide beam upto a distance of atleast 100 m. 4. A device as claimed in claim 1 -3, wherein the four-arm mounting is holding the laser units in such as way that the beams are emitted in a single or in a parallel plane. 5. A device as claimed in claim 1-4, wherein the four-arm mounting has arms in 0°, 90°, 180° and 270° directions, respectively, and in each arm provided with means such as holding plates with co-axial center holes for holding the lens and aligning the laser beam. 6. A device as claimed in claim 1-5, wherein the a roof bolt(20), pointed at one end and threaded on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed Cshaped channel and the pointed end of the bolt is grouted in the mine/tunnel roof. ^^cX"^^^^ "^^^^^^ 1V^ Dated this 2005 (Chetan Kumar) Sc^nflst IPMD,Council of Scientific & Industrial Research -16-

Full Text

The present invention relates to a device for providing centerlines in a continuous manner during construction in underground mines / tunnels. The present invention particularly relates to an instrument for providing centerlines in four directions in a mine/tunnel, in which three centerlines are in 0°, 90° and 270° fixed directions in a single plane and the other one is capable of rotating from 120° to 240° in a parallel plane. This device of the present invention is to be installed in a mine / tunnel junction at a pre-determined survey point on the roof.
The device of the present invention is an instrument which is useful for providing centerlines in a continuous manner in underground mine headings or tunnel headings. This novel device has scientifically arranged laser pointers, which can guide underground miners or tunnel makers about the straightness and direction of their headings below ground.
There are about 500 underground coal mines in various coalfields in India. Moreover, there are numerous tunnels being constructed either for railways or for hydroelectric dams. Everywhere surveyors are deployed to mark the directions of the mines and tunnel headings in form of centerlines. After few meters of progress again these lines have to be re-marked to guide the miners or the tunnel makers for progress in the predetermined directions.
It is well known that in underground mines or tunnels centerlines are provided to guide the mine / tunnels in a predetermined direction. This has to be ensured by a group of surveyors. These centerlines have to be extended on daily basis to maintain the straightness and direction of these underground openings. This job is presently carried out by using expensive theodolites (survey instruments) and is a very time taking process. This process also requires at least three to four skilled persons shift wise. In Indian mine conditions this job is also done in a conventional crude method by extending lines by coloured (commonly called red-oxide) powder marks by means of strings. This conventional system is often very
misleading as this process is not very accurate as a result the tunnels / mine roadways often gets deviated from the predetermined direction.
Extensive efforts have been devoted to the development of several survey instruments to provide survey lines as well as marking of centerline in mines / tunnels. To highlight the wide mining and tunneling usage and the continual efforts, which have been made by other inventors to improve the performance of surveying by use of laser based survey instruments a few patent references are provided below for illustration.
Reference may be made to US patent no. 6,688,009, titled: 'Laser survey Instrument'. The invention relates to the field of survey instruments comprising a laser projector for projecting a laser beam onto a plane by rotary irradiation, a tilting unit for tilting the laser projector in two directions running perpendicularly each other and a tilt setting unit for setting a desired tilt angle for the laser projector at least in one direction, wherein the tilt setting unit comprises a tilt sensor for detecting a horizontal position and an angle detector for detecting an angle between the tilt sensor and the laser projector. This is a survey instrument and a very complicated machine. It requires an expert to operate it and cannot monitor the tunnel heading in underground continuously during the progress. The main drawback is that it may obstruct/delay other jobs, during marking of center lines.
Reference may be made to patent no. WO0047950, entitled: 'Laser Survey Device' wherein a laser survey device, which can be used inter alias in setting out roads and splits in board-and-pillar mining practice. The device has a housing, which can be mounted at a survey point in a mine working in a manner allowing the housing to be rotated about a vertical axis. In the housing are laser beam directing means in the housing for projecting from the housing first and second laser beams at predetermined angles to one another and transverse to the axis. The drawbacks of this survey device are that it requires skilled persons
to fix it on the roof, costly and difficult to repair. This prior art also house several beam splitting device, which are eliminated in the present invention.
Reference may be made to US patent no. 4,836,669, entitled 'Apparatus and method for projection of reference planes of light' wherein an apparatus and a method to project light in two orthogonal planes to provide reference planes of light for use in laying out a construction site or the like. The apparatus comprises a laser light source for providing a source beam of light, and a light diverting arrangement. The light diverting arrangement diverts a first portion of the source beam of light to project a first thin reference fan beam of light substantially in a first reference plane, and diverts a second portion of the source beam of light to project a second thin reference fan beam of light substantially in a second reference plane. The second reference plane is substantially perpendicular to the first reference plane. The apparatus may advantageously be used in laying out a grid. Therefore it is required to provide grid lines useful for blasting pattern and drilling direction. The drawbacks of this survey device are that it requires very skilled and experienced persons to fix it on the roof or floor as it may require a tripod. Other disadvantages are that it is costly and difficult to repair.
Reference may be made to US patent no. 6,457,246, entitled 'Mounting and switching of survey apparatus' wherein a survey apparatus which can be used in the underground mining industry comprises a mounting means adapted to be mounted in a fixed surface (such as a tunnel wall) and an alignment means to releasable engagement with the mounting means, wherein the alignment means is capable of operating only when the alignment means is engaged with the mounting means. The mounting means is preferably a sleeve member insert able in a wall. The alignment means preferably has a laser module and a suitable compartment for accommodating a battery. The mounting means, which is a set aligned in the fixed surface, together with the factory-set alignment means is used for the purpose of setting out and alignments. When the cylindrical shaft is inserted into the sleeve member, a rod, permanently in contact with spring
presses against the screw and makes an electrical connection. As the laser module cannot be switched on when out of the sleeve member, battery life is improved and improper use is minimized. This invention claims about the mounting of the survey device and it electrical connection. The drawbacks of this device are that it requires a transformer and other electrical devices which will be a cumbersome method to use in an Indian gassy coal mine which requires flame proof equipments. Another drawback of the mounting of this invention is much complex, costly and difficult to manufacture.
Reference may be made to US patent no. 5,584,458, entitled 'Quick-action mount for self-leveling laser' wherein a quick action bar clamp has provision for mounting an alignment laser instrument on one jaw of the clamp. The mounting provision allows manual pointing of the laser to facilitate projecting a level line or plane of light with a self-leveling laser instrument. By engagement of the clamp on a fixed structure such as a column, wall stud or door frame, the operator can quickly bring the laser instrument into its self-leveling range and easily adjust the beam height. The attachment of the laser instrument to the clamp is via a threaded rod or a magnetic attachment retention. An L-shaped magnetic attachment can be used in another procedure, to connect the laser to the steel slide bar of the clamp. The main drawback of this device is that it is liable to be disturbed by the blasting vibration in underground mine/tunnels.
All the above-mentioned inventions are of different underground survey instruments. The disadvantages of these inventions are in their complicated designs and difficulty in installation.
Another disadvantage of these instruments are that these require very skilled manpower to erect and mark the centerlines in every shift.
Yet another disadvantage of these prior art is that these are costly and requires expert hand to repair.
Still another disadvantage of these instruments are that they have to be removed from the position after marking of the lines. Most of these have to be carried back to the surface as these instruments are costly.
To eliminate the involvement of highly skilled surveyors in every working shift for extending powder mark center lines which usually gets omitted due to deposition of dust generated from blasting, the use of laser survey instruments has came into picture due to their accuracy and expediting of survey jobs. The main disadvantages of these instruments are their sophistication and high cost. Most of these instruments also prevent progress of other jobs to some extent during the survey work. Being costly, these instruments cannot be kept lying under mines/tunnels unattended. These instruments are heavy of about 5-6 kg each moreover there are other accessories like tripods, which require more than one person to carry a single set..
Hence, it is clear from the hitherto known prior art that there is a definite need to provide a system which can easily and reliably provide centerlines in a continuous manner in underground mines and tunnels at a comparatively lesser cost and effort and does not hamper important progressive jobs such as material transport, blasting, supporting. Moreover, a device is required which will not get disturbed by blast vibration and does not require skilled manpower to mark the lines in every shift.
The main object of the present invention is to provide a device for providing centerlines in a continuous manner during construction in underground mines / tunnels, which obviates the drawbacks of the hitherto known prior art as detailed above.
Another object of the present invention is to provide centerlines in four directions in a same plane so that the instrument can be kept at junction of galleries and three mine/tunnel headings can be progressed.
Yet another object of the present invention is to provide three lines in form of laser beams in fixed direction to each other and the fourth one can be turned in the predetermined direction as and when required.
Still another object of the present invention is to provide a simple device to cross check the alignment of mine / tunnel progress in each operating shift.
Still yet another object of the present invention is to provide a centerline marking instrument which does not require to be transported in and out of mines daily after a survey measurement job.
A further object of the present invention is to provide a centerline marking device which enables easy mounting over the mine / tunnel roof and does not get disturbed by blast vibrations. >
A still further object of the present invention is to provide a device which is light and easily transportable at different places inside the mine and tunnel.
In the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels, there is provided in combination a four-arm mounting unit with four numbers laser beam-emitting diodes and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation. This combination being housed in an anti-static housing with appropriate openings and the housing being provided with means for adjustable and movable ceiling mounting.
The housing is made up of metallic anti-static material because it should not accumulate static electricity which may produce spark to ignite the methane which is generally present inside a gassy coal mine. The housing can be adjusted in various directions to suit the predetermined bearing of the mine or the
tunnel. The housing is mounted on a sliding channel for fine adjustment with the previous centerline, if any, or with the previously marked survey station/point. The sliding channel on the other hand is bolted with a peg that is grouted in the mine roof.
The device of the present invention is useful for marking center lines and other survey lines in a continuous manner in a number of faces of a working in underground mine or tunnels. This device can emit four lines in a same or parallel plane at a time. The device of the present invention has scientifically arranged laser pointers which can guide underground miners or tunnel makers about the straightness and direction of their headings below ground. The device is light, easily transportable, re-installable and adjustable to meet the survey line requirement in a mine or a tunnel. This device is much cheaper and lighter compared to the existing survey instruments used for marking centerlines. This will eliminate the requirement of manpower to do the line marking jobs in every shift.
Accordingly the present invention provides a device for providing centerlines in a continuous manner during construction in underground mines / tunnels, which comprises an assembly having in combination a four-arm mounting unit with four numbers laser emitting pointers and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation, the said assembly being accommodated in an anti-static housing equipped with two perpendicular spirit levels and power source such as dry or rechargeable cells capable of energizing the said laser emitting pointers, the said housing being provided at the top surface with a ball and socket joint fixed to a position adjusting C-shaped cross channel capable of being mounted onto a ceiling through a bolt.
In an embodiment of the present invention, the four-arm mounting unit has three fixed arms capable of holding three laser emitting pointers and lens units to point
0°, 90° and 270° in a single plane and a fourth rotating arm capable of being set at a pre-determined angle varying between 120° to 240° in the same plane or in a parallel plane.
In another embodiment of the present invention, the laser emitting pointers are laser diodes capable of providing a guide beam upto a distance of atleast 100 m.
In yet another embodiment of the present invention, the four-arm mounting is capable of holding the laser units in such as way that the beams are emitted in a single or in a parallel plane.
In still another embodiment of the present invention, the four-arm mounting has arms in 0°, 90°, 180° and 270° directions, respectively, and in each arm there are means such as holding plates with co-axial center holes capable of holding the lens and aligning the laser beam.
In still yet another embodiment of the present invention, there is provided a roof bolt, pointed at one end and threaded on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed C-shaped channel and the pointed end of the bolt is grouted in the mine/tunnel roof.
The various features, embodiments and advantages of the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels will be set forth by the reference to the following description of the invention and referenced drawings.
The present invention is illustrated in figure 1 to 7 of the drawings accompanying this specification. In the drawings like reference numbers/letters indicate corresponding parts in the various figures.
In figure 1 and 2 of the drawings accompanying this specification, block schematic diagrams of the various parts constituting the device of the present invention, is depicted. Figure 2 is the cross sectional view of figure 1 along the plane 1-1. This device of the present invention useful for providing center lines in underground mine / tunnels, comprises of four laser beam emitting devices (6) mounted on units (5) and (9), made of brass or any anti static material. Both mountings (5) and (9) are fitted in a single hinge (16). The hinge (16) may be fitted with a hook (not shown in the figures) at the bottom to hang a plumb bob pointer, if required, for alignment of the housing with any center point of a survey station. Each of the laser emitting devices are fixed by four guides (15) on these mountings as shown in figure 2. The mounting unit (5) has a fixed three directional (arms) arrangement to house three laser units to point 0°, 90° and 270° in a single plane. The mounting unit arm (9) is a partially rotating unit which can be set at the desired pre-determined angle in the same plane or in a parallel plane that can vary from 120° to 240° marked (17) on the housing (12). This unit can be tightened by a wing nut (10) to the housing (12). There are three numbers of lens (3) attached to the housing (12). The fourth lens is attached to the movable mounting (9) it self at the extreme outer end. These lenses may have a X-mark for a better pointing of the centerlines. Each laser beam has to pass through two holes and the lens to ensure a straight line. These holes are drilled in projecting parts (4) (two in each arm) of the mountings (5) and (9). The housing unit (12) is made up of some light antistatic material has two spirit levels (7) and (8) attached at the bottom of (12) arranged perpendicularly to each other. The housing also have a battery case (11) to hold dry cells or rechargeable cells. The housing is attached to a circular plate (13) by a ball and socket arrangement (2). The housing and the plate can be adjusted at different angles by three adjusting wing screws (14). There is a hexagonal nut (1) fixed at the center of the circular plate (13).
In figure 3, 4, 5, 6 and 7 of the drawings accompanying this specification, block diagrams of the various parts constituting mounting device on the roof of the
mine/tunnel, is depicted. Figure 5 represents a pointed bolt (20) or a peg, which will be grouted in a hole made on the mine/tunnel roof as near as possible to the survey point or junction of two roadways or at the centerline. The bolt (20) has a threaded end that will fit in the hexagonal nut (18). Figure 4 is the cross sectional view of figure 3. The hexagonal nut (18) is fixed in the center of C - shaped channels (19) welded at right angles or manufactured is such a way that the circular head (21) of the bolt (22) just fits and slides in these channels. The bolt (22) will fit in the nut (1) to hold the housing (12) and the plate (13). There is a hole (23) on the head (21) through which a tightening screw will pass to tighten this bolt (22) with the sliding channel (19) after adjusting the housing at the center of the predetermined point. The bolt head (21) may also be manufactured in the shape of a gear. In that case the inner lining of the C-Shaped channels will have to be uniformly corrugated in one side to give a rack and pinion effect.
The laser unit mountings (5) and (9) are manufactured and fitted to accommodate the laser units in such as way that the beams are emitted in a single or in a parallel plane wherein the mounting (5) has three arms to point 0°, 90° and 270° directions and in each arm there are two plates (4) with center holes where all the holes of 90° and 270° arms are in one line, which can be ensured by passing a laser beam or a thread through all the four holes of these two arms during manufacture or during any calibration process moreover the 0° and the rotary 180° arm are aligned and fitted in the same manner furthermore the lenses (3) are also fitted by aligning it with external laser beam with the two holes of each arm.
In present invention a ball and socket arrangement (2) is provided to adjust the horizontal level with the help of two spirit levels (7) and (8) moreover the wing nuts (14) will help in adjusting and tightening with the circular plate (13).
In the present invention there is a small length roof bolt (20) of the order of 25cm in length and 21mm in diameter, is pointed at one end and threaded on the other
wherein the pointed end of the bolt (20) will be grouted in a small hole of diameter of the order of 26mm to be made on the mine/tunnel roof.
The threaded portion of the bolt (20) will en suite in the hexagonal bolt (18) fitted at the center of the crossed C-shaped channels (19).
In the present invention a sliding bolt (22) which has a circular head (21) such that the head exactly fits in the C-shaped channel (19) which means that the diameter of the circular head (21) will be slightly less than the width of the C-shaped channel (19) wherein the bolt (22) is slided inside.
The threaded portion of the bolt (22) is fitted in the hexagonal nut (1) attached at the center of the circular plate (13), which was already attached to the housing (12) therefore this arrangement will help in adjustment of the housing (12) and the hinge (16) at the exact survey point marked earlier.
In the present invention a tightening arrangement is made by using a screw in the threaded hole (23) so that the bolt (22) is fixed with the C-shaped channel at a certain adjusted point.
The novelty of the device of the present invention, useful for providing continuous straight centerlines in underground mines and tunnels, resides in the capability to accommodate four laser beams in a single plane or a parallel plane. Further, it provides means to mount it on mine and tunnel roof with great ease.
Still another novelty of the present invention is that the mounting device cannot be disturbed by blast vibration unless kept very near to the blasting face i.e, within 15 m due to presence of several tightening screws.
Yet another novelty of this invention is that it is extremely light weight compared to the prior arts. One man can carry 4 to 5 numbers of such devices at a time to install at different place in underground workings.
Still yet another novelty of the present invention is the elimination of external electrical connection, beam splitters and costly prisms to deviate the beams in different directions, which are used in the hitherto known prior art. This simple step makes the device a very low cost and effective centerline provider in four predetermined directions.
The novelty of the device of the present invention for providing centerlines in a continuous manner during construction in underground mines / tunnels, has been realized by the non-obvious inventive steps of providing in combination a four-arm mounting unit with four numbers laser emitting pointers and lenses capable of emitting laser beam in a single or in a parallel plane in four predetermined directions, such as 0°, 90°, 180° and 270°, wherein the 180° arm being capable of rotation. The said assembly being accommodated in an anti-static housing equipped with two perpendicular spirit levels and power source such as dry or rechargeable cells capable of energizing the said laser emitting pointers. The said housing being provided at the top surface with a ball and socket means fitted with a bolt through a position adjusting C-shaped cross channel having wing nuts and screws for ceiling fitment, such that it does not get disturbed by blast vibrations. This device therefore helps in eliminating the requirement of skilled surveyor in every shift for marking centerlines and also to do away with transportation of the costly survey instruments in and out of the mines after every center lines marking and extending jobs.
The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention.
Example: 1
A prototype of the devices of the present invention was fitted in the underground tunnels of a coal mine on an experimental basis in the Jharia coalfield. The immediate fallout was that te consumption of red power for marking reduced considerably. The surveyors were not required to go underground daily for marking center lines, so that they were able to engage in other constructive planning. The underground supervisors and workers themselves could guide the progress on the direction of the laser beams. Even after a month the direction of the beams were not altered by blast vibrations. The progress of the mine galleries were made more than 120m with the help of this device. As this was done on an experimental basis cross check was done at an interval of seven days in which no deviation was found.
The main advantages of the device for providing center lines, in a continuous manner during underground mine/ tunnels construction, of the present invention are:
1. Allows to provide centerlines and other four-way direction lines in underground tunnel excavations or mines easily and reliably.
2. Reduces the manpower requirement of updating the centerlines or survey lines daily.
3. Enables easy installation of the device in underground.
4. Enables easy and quick adjustment with the previously marked centerline or any survey point (for back-sight check).
5. Ensures minimum deviations in the predetermined mine /tunnel directions.
6. It does not get disturbed by blast vibrations.
7. It need not be taken out of the mine daily, as it does not interfere with other construction jobs or mine working.
8. Cheap and easy to manufacture and assemble.
9. Reduces consumption of red powder (locally called red oxide) used for marking of survey lines.
10. Very light weighted and easy transportable. One man can easily carry 4-5 of these instruments at a time.
11. Calibration can be done by the user at the site and does not required to be sent to a specialist or any laboratory.

We claim:
1. A device for providing centerlines in a continuous manner during construction in underground
mines/tunnels, which comprises an assembly (6) having a four-arm mounting unit with four
numbers laser emitting pointers and lenses for emitting laser beam in a single or in a parallel
plane in four predetermined directions, such as 0°, 90°,180°and 270°, wherein the 180° arm is
rotatble, the said assembly being accommodated in an antistatic housing(5,9) equipped with two
perpendicular spirit levels(7,8) and power source such as dry or rechargeable cells for energizing
the said laser emitting pointers, the said housing(5,9) being provided at the top surface with a
ball and socket joint(2) fixed to a position adjusting C-shaped cross channel(19) for mounting
onto a ceiling through a bolt(20).
2. A device as claimed in claim 1, wherein the fourth rotating arm is set at a pre-determined
angle varying between 120° to 240° in the same plane or in a parallel plane.
3. A device as claimed in claim 1-2, wherein the laser emitting pointers are laser diodes provides
a guide beam upto a distance of atleast 100 m.
4. A device as claimed in claim 1 -3, wherein the four-arm mounting is holding the laser units in
such as way that the beams are emitted in a single or in a parallel plane.
5. A device as claimed in claim 1-4, wherein the four-arm mounting has arms in 0°, 90°, 180°
and 270° directions, respectively, and in each arm provided with means such as holding plates
with co-axial center holes for holding the lens and aligning the laser beam.
6. A device as claimed in claim 1-5, wherein the a roof bolt(20), pointed at one end and threaded
on the other, wherein the threaded portion of the said bolt is fitted at the center of the crossed Cshaped
channel and the pointed end of the bolt is grouted in the mine/tunnel roof.
^^cX"^^^^ "^^^^^^ 1V^ Dated this 2005
(Chetan Kumar) Sc^nflst
IPMD,Council of Scientific & Industrial Research
-16-

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Patent Number

269614

Indian Patent Application Number

801/DEL/2005

PG Journal Number

44/2015

Publication Date

30-Oct-2015

Grant Date

29-Oct-2015

Date of Filing

31-Mar-2005

Name of Patentee

COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH

Applicant Address

ANUSANDHAN BHAWAN, RAFI MARG, NEW DLEHI-110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	PAUL BISWAJIT	CENTRAL MINING RESEARCH INSTITUTE BARWA ROAD, DHANBAD, DHANBAD, JHARKHAND, INDIA-826001

PCT International Classification Number

G01C

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA