Diamond Wire Saw Dry-Cutting Method
20240051183 ยท 2024-02-15
Inventors
Cpc classification
B28D1/088
PERFORMING OPERATIONS; TRANSPORTING
B08B5/02
PERFORMING OPERATIONS; TRANSPORTING
B23D57/0053
PERFORMING OPERATIONS; TRANSPORTING
B28D1/08
PERFORMING OPERATIONS; TRANSPORTING
B28D7/02
PERFORMING OPERATIONS; TRANSPORTING
B23D57/0061
PERFORMING OPERATIONS; TRANSPORTING
International classification
B28D7/02
PERFORMING OPERATIONS; TRANSPORTING
B28D1/08
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A dust collection system comprises: a cover configured to hermetically seal nuclear power plant structure, which is a target to be cut, the cover being provided at an outer circumferential surface thereof with a plurality of cutting groove members adjusted for a height of the cutting wire, the cover being made of a transparent material; an air compressor configured to supply compressed air; an air hose configured to convey the compressed air; a passage member provided in each of the plurality of cutting groove members, the passage member being configured to receive the compressed air such that the compressed air is sprayed to the cutting wire through the cover made of the transparent material; a packing member configured to wrap at least a part of an inner circumferential surface of each of the plurality of cutting groove members.
Claims
1. A dust collection system for collecting foreign matter generated during cutting of a nuclear power plant structure and foreign matter attached to a cutting wire in a dry state, the dust collection system comprising: a cover configured to hermetically seal the nuclear power plant structure, which is a target to be cut, the cover being provided at an outer circumferential surface thereof with a plurality of cut recess members adjusted for a height of the cutting wire, the cover being made of a transparent material; an air compressor configured to supply compressed air; an air hose configured to convey the compressed air; a passage member provided in each of the plurality of cut recess members, the passage member being configured to receive the compressed air such that the compressed air is sprayed to the cutting wire through the cover made of the transparent material; a packing member configured to wrap at least a part of an inner circumferential surface of each of the plurality of cut recess members while wrapping at least a part of an outer circumferential surface of the passage member such that frictional force is formed between the passage member and the packing member; and a discharge portion provided in a vicinity of an end of the nuclear power plant structure that surrounds the nuclear power plant structure in a rotating direction of the cutting wire, the discharge portion being configured to discharge the foreign matter.
2. The dust collection system according to claim 1, wherein the passage member is configured such that a length of the passage member is adjustable so as to extend through the cover.
3. The dust collection system according to claim 2, wherein the passage member comprises a pipe.
4. The dust collection system according to claim 1, wherein the cover made of the transparent material comprises a transparent acrylic cover.
5. The dust collection system according to claim 1, wherein the plurality of cut recess members is provided along the outer circumferential surface of the cover at predetermined intervals in a direction parallel to a ground, and a vertical height of each of the plurality of cut recess members is equal to a vertical height of the cutting wire or is different from the vertical height of the cutting wire within a predetermined range.
6. The dust collection system according to claim 1, wherein the packing member comprises a packing member made of rubber.
7. A wire saw apparatus for cutting a structure using a dry method, the wire saw apparatus comprising: a main roller; a first roller unit located at one side of the structure, the first roller being configured to allow a cutting wire introduced from the main roller to pass therethrough such that the cutting wire is directed to the structure so as to surround the structure; and a second roller unit located at the other side of the structure, the second roller being configured to allow the cutting wire moving while surrounding the structure to pass therethrough such that the cutting wire is transferred to the main roller, wherein the first roller unit comprises a first fixing roller, a first auxiliary roller configured such that at least a part of the first auxiliary roller is in contact with an outer circumferential surface of the first fixing roller, a first guide roller configured to guide the cutting wire introduced from the main roller to the first fixing roller, and a second auxiliary roller configured such that at least a part of the second auxiliary roller is in contact with an outer circumferential surface of the first guide roller, and the second roller unit comprises a second fixing roller configured to allow the cutting wire moving while surrounding the structure to pass therethrough, a third auxiliary roller configured such that at least a part of the third auxiliary roller is in contact with an outer circumferential surface of the second fixing roller, a second guide roller configured to guide the cutting wire introduced from the second fixing roller to the main roller, and a fourth auxiliary roller configured such that at least a part of the fourth auxiliary roller is in contact with an outer circumferential surface of the second guide roller.
8. The wire saw apparatus according to claim 7, wherein the first roller unit comprises: a first support portion configured to support the first fixing roller and the first auxiliary roller; a first fixing portion coupled to the support portion, the first fixing portion being configured to fix the first roller unit to the structure; a first non-rotary frame located between the first fixing roller and the first guide roller, the first non-rotary frame having a hole, through which the cutting wire passes, formed therethrough, the first non-rotary frame being formed in a cylindrical shape, the first non-rotary frame being non-rotatable; and a first rotary frame inserted into the non-rotary frame, the first rotary frame being formed in a cylindrical shape, the first rotary frame being rotatable.
9. The wire saw apparatus according to claim 7, wherein the second roller unit comprises: a second support portion configured to support the second fixing roller and the third auxiliary roller; a second fixing portion coupled to the support portion, the second fixing portion being configured to fix the second roller unit to the structure; a second non-rotary frame located between the second fixing roller and the second guide roller, the second non-rotary frame having a hole, through which the cutting wire passes, formed therethrough, the second non-rotary frame being formed in a cylindrical shape, the second non-rotary frame being non-rotatable; and a second rotary frame inserted into the non-rotary frame, the second rotary frame being formed in a cylindrical shape, the second rotary frame being rotatable.
10. The wire saw apparatus according to claim 8, wherein the first rotary frame is configured to adjust an angle between the first fixing roller and the first guide roller.
11. The wire saw apparatus according to claim 9, wherein the second rotary frame is configured to adjust an angle between the second fixing roller and the second guide roller.
12. The wire saw apparatus according to claim 7, further comprising: a cover connected to a ground at one side of the structure, the cover being configured to hermetically seal the first roller unit, the cover being made of a transparent material; and a cover connected to the ground at the other side of the structure, the cover being configured to hermetically seal the second roller unit, the cover being made of a transparent material.
13. The wire saw apparatus according to claim 7, wherein the first roller unit and the second roller unit are configured to allow the cutting wire to pass therethrough while cutting the structure in a direction parallel to the ground.
14. The wire saw apparatus according to claim 7, wherein the structure comprises a nuclear power plant structure.
15. A wire saw apparatus for cutting a structure using a dry method, the wire saw apparatus comprising: a main roller; a first roller unit located at one side of the structure, the first roller being configured to allow a cutting wire introduced from the main roller to pass therethrough such that the cutting wire is directed to the structure so as to surround the structure; and a second roller unit located at the one side of the structure together with the first roller unit so as to be installed at a different height from the first roller unit, the second roller being configured to allow the cutting wire moving while surrounding the structure to pass therethrough such that the cutting wire is transferred to the main roller, wherein the first roller unit comprises a first fixing roller, a first auxiliary roller configured such that at least a part of the first auxiliary roller is in contact with an outer circumferential surface of the first fixing roller, a first guide roller configured to guide the cutting wire introduced from the main roller to the first fixing roller, and a second auxiliary roller configured such that at least a part of the second auxiliary roller is in contact with an outer circumferential surface of the first guide roller, and the second roller unit comprises a second fixing roller configured to allow the cutting wire moving while surrounding the structure to pass therethrough, a third auxiliary roller configured such that at least a part of the third auxiliary roller is in contact with an outer circumferential surface of the second fixing roller, a second guide roller configured to guide the cutting wire introduced from the second fixing roller to the main roller, and a fourth auxiliary roller configured such that at least a part of the fourth auxiliary roller is in contact with an outer circumferential surface of the second guide roller.
16. The wire saw apparatus according to claim 15, wherein the first roller unit comprises: a first support portion configured to support the first fixing roller and the first auxiliary roller; a first fixing portion coupled to the support portion, the first fixing portion being configured to fix the first roller unit to the structure; a first non-rotary frame located between the first fixing roller and the first guide roller, the first non-rotary frame having a hole, through which the cutting wire passes, formed therethrough, the first non-rotary frame being formed in a cylindrical shape, the first non-rotary frame being non-rotatable; and a first rotary frame inserted into the non-rotary frame, the first rotary frame being formed in a cylindrical shape, the first rotary frame being rotatable.
17. The wire saw apparatus according to claim 15, wherein the second roller unit comprises: a second support portion configured to support the second fixing roller and the third auxiliary roller; a second fixing portion coupled to the support portion, the second fixing portion being configured to fix the second roller unit to the structure; a second non-rotary frame located between the second fixing roller and the second guide roller, the second non-rotary frame having a hole, through which the cutting wire passes, formed therethrough, the second non-rotary frame being formed in a cylindrical shape, the second non-rotary frame being non-rotatable; and a second rotary frame inserted into the non-rotary frame, the second rotary frame being formed in a cylindrical shape, the second rotary frame being rotatable.
Description
DESCRIPTION OF DRAWINGS
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
BEST MODE
[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description disclosed hereinafter together with the accompanying drawings shows exemplary embodiments of the present invention and does not reveal a unique embodiment by which the present invention can be implemented. The following detailed description includes specific details in order to provide complete understanding of the present invention. However, those skilled in the art will appreciate that the present invention can be implemented without such specific details.
[0040] The detailed description of the present invention, which will follow, illustrates a specific embodiment by which the present invention can be implemented and refers to the accompanying drawings. These embodiments are described in detail such that those skilled in the art are capable of implementing the present invention. It should be understood that various embodiments of the present invention are different from each other but are not necessarily mutually exclusive. For example, a specific shape, structure, and characteristic of an embodiment described herein may be implemented as another embodiment without departing from the sprit and scope of the present invention. In addition, it should be understood that the position or disposition of individual elements in each disclosed embodiment may be changed without departing from the sprit and scope of the present invention. Consequently, the detailed description, which will follow, is not restrictive, and the scope of the present invention is limited by the appended claims and all equivalents thereto as long as the present invention is appropriately described. In the drawings, similar reference numerals indicate the same or similar functions in several aspects.
[0041] In some cases, in order to avoid the concept of the present invention being ambiguous, a well-known structure and apparatus may be omitted, or each structure and apparatus will be shown in the form of a block diagram including core functions thereof. In addition, the same elements are denoted by the same reference numerals throughout this specification.
[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings such that a person having ordinary skill in the art to which the present invention pertains can easily implement the present invention.
[0043] The present invention proposes a dust collection system for efficiently collecting foreign matter, dust, etc. generated when any of various structures, such as a dangerous structure, e.g. a nuclear power plant, a structure having great size, a structure having great length, and a concrete structure, is cut using a wire saw machine.
[0044]
[0045] Referring to
[0046]
[0047] In the present invention, a wire configured to cut the structure 200 is called a cutting wire 300. The cutting wire 300 may be a wire saw. As an example, the cutting wire 300 may be a diamond wire saw.
[0048] As shown in
[0049] In the wire saw machine, the cutting wire 300 may be introduced into the structure 200 through the first roller unit 410, and the cutting wire 300 may be sent to a main roller of the wire saw through the second roller unit 420. In
[0050] The cover 110 hermetically seals the structure 200, which is a target to be cut, and a plurality of cut recess members 115 may be provided at an outer circumferential surface of the cover 110 or an outer surface of the cover 110. The cover 110 may be configured to hermetically seal the remaining part of the structure 200 excluding the plurality of cut recess members 115. In
[0051] Furthermore, as shown in the right side of
[0052]
[0053] The reason that the plurality of cut recess members 115 is provided at the outer surface of the cover 110 is that it is necessary to inject compressed air through the cut recess members 115. The passage member 120 is provided in each of the plurality of cut recess members 115 in a direction toward the cutting wire 300 such that compressed air provided by the compressor 140 is sprayed to the cutting wire 300 through the cover 110. A pipe may be used as an example of the passage member 120. The passage member 120 may be implemented in any of various shapes, such as a circular shape.
[0054] The air compressor 140 provides compressed air into the plurality of cut recess members 115. The position at which the air compressor 140 is provided is not particularly restricted. As shown in
[0055] When the structure 200 is initially cut, the cutting wire 300 surrounds the structure 200 along a line indicated by I in
[0056] As the structure 200 is cut, as described above, the distance (straight distance) between the cut recess member 115 and the cutting wire 300 increases particularly from opposite corners of the structure 200. If the length of the passage member 120 is fixed even though the distance between the cut recess member 115 and the cutting wire 300 increases, foreign matter attached to the cutting wire 300 may not be easily removed when compressed air is sprayed to the cutting wire 300 through the passage member 120. To this end, the passage member 120 is configured such that the length of the passage member 120 can extend in a direction toward the cutting wire 300 through the cover 110 (or the thickness of the cover 110) and such that the length of the passage member can be adjusted. The passage member 120 located in the vicinity of each of the opposite corners of the structure 200 is configured to further extend in the direction toward the cutting wire 300 as the structure 200 is cut.
[0057]
[0058] Referring to
[0059] The packing member 150 is configured to wrap at least a part of an inner circumferential surface of the passage member 120 such that frictional force is formed between the packing member and the passage member 120, whereby it is possible to fix the passage member 120 even when compressed air is injected into the passage member 120. When the cutting wire 300 cuts the structure 200 while being rotated, pressure or vibration may be applied to the cut recess member 115. In this case, when the packing member 150 is made of rubber, the packing member may absorb external force, such as pressure or vibration, applied to the cut recess member 115, whereby it is possible to more robustly support the passage member 120.
[0060] The air compressor 140 supplies compressed air to the passage member 120 through the air hose 145. A valve 160 may be provided in the passage member 120 to adjust the amount of compressed air introduced through the air hose 145 or to allow or block the supply of compressed air based on opening and closing thereof.
[0061] Referring to
[0062] As shown in
[0063] In
[0064] When the air compressor 140 injects compressed air into the cut recess member 115, the compressed air must move along the passage member 120 and must be sprayed to the cutting wire 300 such that foreign matter (dust) attached to the outer circumferential surface of the cutting wire 300 and foreign matter, dust, etc. generated during cutting of the structure 200 can be immediately removed. Consequently, the vertical height of the cut recess member 115 and the vertical height of the cutting wire 300 must be equal to each other or must be different from each other within a predetermined range. If not, it is difficult to completely remove foreign matter attached to the outer circumferential surface of the cutting wire 300.
[0065] In addition, since the cutting wire 300 cuts the structure 200 while being rotated, high heat is generated from the cutting wire 300. When the air compressor 140 sprays compressed air through the passage member 120, it is also possible to remove heat of the cutting wire 300 generated during cutting, whereby it is possible to rapidly restore cutting force of the cutting wire 300, and therefore it is possible to improve cutting efficiency. In addition, since heat is removed during cutting, it is also possible to increase the lifespan of the cutting wire 300, and therefore it is possible to reduce expense of work.
[0066] As shown in
[0067] In order to efficiently collect such foreign matter, it is necessary for the discharge portion 130 to be located in the vicinity of the end of the structure 200 that surrounds the structure 200 in the rotating direction of the cutting wire 300. Since the cover 110 configured to hermetically seal the second roller unit 420 is connected to the ground and thus performs the function of preventing foreign matter from being dispersed to the outside, the cover serves as a dust collector. Foreign matter may be introduced into the cover 110 configured to surround the second roller unit 420 by compressed air and rotation of the cutting wire 300, and the foreign matter may be discharged through the discharge portion 130. More specifically, in
[0068] Since compressed air is sprayed to the cutting wire 300 rotating in the counterclockwise direction through the passage member 120 of each of the plurality of cut recess members 115, foreign matter is also moved in the counterclockwise direction by air pressure, falls downwards, and finally reaches the vicinity of the second roller unit 420. In the dust collection system according to the present invention, it is possible to automatically gather dust and foreign matter to the discharge portion 130 and to easily discharge the dust and the foreign matter. Consequently, it is possible to greatly reduce cost of manufacturing a dust collection facility and to reduce expenses of installation, operation, and disassembly of the dust collection facility.
[0069]
[0070] As shown in
[0071] As shown in
[0072] As shown in
[0073] The pipe bolt member 151 is formed in a bolt-shaped external shape. A space, into which the rubber packing 155 is inserted, may be formed in a central part of the pipe bolt member, and opposite ends of the pipe bolt member in a longitudinal direction may be open. A screw thread for fastening with the nut member 153 may be formed at an outer circumferential surface of the pipe bolt member 151.
[0074] A screw thread may be formed at an inner circumferential surface of the nut member 153 such that the nut member can be fastened to the pipe bolt member 151. The pipe bolt member 151 may be inserted through a through-hole of the transparent plate 117, and the nut member 153 is fastened to the pipe bolt member inside the transparent plate 117, whereby the pipe bolt member may be fixed. A rubber washer may be interposed between an inner surface of the transparent plate 117 and the nut member 153, whereby it is possible to hermetically isolate the inside of the cut recess member 115 from the outside.
[0075] The lid member 154 may be provided in the center thereof with a through-hole, through which the passage member 120 extends, and a screw thread may be formed at an outer circumferential surface of the lid member. The screw thread may be fastened to a recess formed in a head of the pipe bolt member 151, whereby the lid member may be fixed to the pipe bolt member. To this end, a screw thread may also be formed at an inner circumferential surface of the recess in the head of the pipe bolt member 151. A plastic lid member 154 may be separately formed, or the lid member 154 may be integrally formed with the rubber packing 155.
[0076] In the coupling structure of the packing member 150, the packing member 150 is securely mounted to the transparent plate 117. Even though the passage member 120 forcibly fitted in the rubber hole 156 slides, therefore, the packing member 150 may be securely fixed while the sealing performance thereof is maintained.
[0077]
[0078] Referring to
[0079]
[0080] As shown in
[0081] In the wire saw machine (e.g. a diamond wire saw (DWS)), the cutting wire 300 may be introduced into the structure 200 through the first roller unit 410, and the cutting wire 300 may be sent to a main roller of the wire saw through the second roller unit 420, in the same manner as in horizontal cutting of
[0082] The cover 110 hermetically seals the structure 200, which is a target to be cut, and a plurality of cut recess members 115 may be provided at an outer circumferential surface of the cover 110 or an outer surface of the cover 110. The cover 110 may be configured to hermetically seal the remaining part of the structure 200 excluding the plurality of cut recess members 115. In
[0083] The reason that the plurality of cut recess members 115 is provided at the outer surface of the cover 110 is that it is necessary to inject compressed air through the cut recess members 115. The air compressor 140 provides compressed air into the plurality of cut recess members 115. The air compressor 140 may be provided for each of the cut recess members 115.
[0084] The passage member 120 is provided in each of the plurality of cut recess members 115 in a direction toward the cutting wire 300 such that compressed air provided by the compressor 140 is sprayed to the cutting wire 300 through the cover 110. A metal pipe may be used as an example of the passage member 120. The passage member 120 may be implemented in any of various shapes, such as a circular shape.
[0085] When the structure 200 is initially cut, the cutting wire 300 surrounds the structure 200 along a line indicated by I in
[0086] As the structure 200 is cut, as described above, the distance (straight distance) between the cut recess member 115 and the cutting wire 300 increases, particularly from opposite corners of the structure 200. If the length of the passage member 120 is fixed even though the distance between the cut recess member 115 and the cutting wire 300 increases, foreign matter attached to the cutting wire 300 may not be easily removed when compressed air is sprayed to the cutting wire 300 through the passage member 120. To this end, the passage member 120 is configured such that the length of the passage member 120 can extend in a direction toward the cutting wire 300 via the cover 110 (or the thickness of the cover 110) and such that the length of the passage member can be adjusted. The passage member 120 located in the vicinity of each of the opposite corners of the structure 200 is configured to further extend in the direction toward the cutting wire 300 as the structure 200 is cut.
[0087] The rubber packing member 150 is configured to wrap at least a part of an inner circumferential surface (an inner surface) of each of the plurality of cut recess members 115. The packing member 150 is configured to wrap at least a part of an inner circumferential surface of the passage member 120 such that frictional force is applied between the packing member and the passage member 120, whereby it is possible to fix the passage member 120 even when compressed air is injected into the passage member 120. When the cutting wire 300 cuts the structure 200 while being rotated, pressure or vibration may be applied to the cut recess member 115. In this case, when the packing member 150 is made of rubber, the packing member may absorb external force, pressure or vibration, applied to the cut recess member 115, whereby it is possible to more robustly support the passage member 120.
[0088] As shown in
[0089] When the air compressor 140 injects compressed air into the cut recess member 115, the compressed air may move along the passage member 120 and may be sprayed to the cutting wire 300, whereby foreign matter may be completely removed.
[0090] In addition, since the cutting wire 300 cuts the structure 200 while being rotated, high heat is generated from the cutting wire 300. When the air compressor 140 sprays compressed air through the passage member 120, it is also possible to remove heat of the cutting wire 300 generated during cutting, whereby it is possible to rapidly restore cutting force of the cutting wire 300, and therefore it is possible to improve cutting efficiency. In addition, since heat is removed during cutting, it is also possible to increase the lifespan of the cutting wire 300, and therefore it is possible to reduce expense of work.
[0091] As shown in
[0092] In order to efficiently collect such foreign matter, it is necessary for the discharge portion 130 to be located in the vicinity of the end of the structure 200 that surrounds the structure 200 in the rotating direction of the cutting wire 300. Since the cover 110 configured to hermetically seal the second roller unit 420 is connected to the ground and thus performs the function of preventing foreign matter from being dispersed to the outside, the cover serves as a dust collector. Foreign matter may be introduced into the cover 110 configured to surround the second roller unit 420 by compressed air and rotation of the cutting wire 300, and the foreign matter may be discharged through the discharge portion 130. More specifically, as
[0093] Since compressed air is sprayed to the cutting wire 300 even in vertical cutting shown in
[0094]
[0095] The first roller unit 410 and the second roller unit 420 are identical in construction to each other except for position. Hereinafter, therefore, the construction of the second roller unit 420 will be described. The second roller unit 420 may include a fixing roller 421, a guide roller 422, a first auxiliary roller 423, a second auxiliary roller 424, a support portion 425, a fixing portion 426, a non-rotary frame 427, and a rotary frame 428.
[0096] The fixing roller 421, which is a roller fixed to the support portion 425 so as to be supported thereby, assists in stably moving the cutting wire 300 such that the cutting wire surrounds the structure 200. The guide roller 422 guides the cutting wire 300 introduced from the main roller of the wire saw toward the fixing roller 421, thereby assisting in the fixing roller 421 moving the cutting wire 300.
[0097] The first auxiliary roller 423, which is a roller configured to assist in the fixing roller 421, is configured such that at least a part of the first auxiliary roller is connected to an outer circumferential surface of the fixing roller 421 in order to prevent separation of the cutting wire 300 moving along the outer circumferential surface of the fixing roller 421 from the fixing roller. In the same manner, the second auxiliary roller 424 is also configured such that at least a part of the second auxiliary roller is connected to an outer circumferential surface of the guide roller 422 in order to prevent separation of the cutting wire 300 moving along the outer circumferential surface of the guide roller 422 from the guide roller.
[0098] The support portion 425 is a member configured to support the fixing roller 421 and the first auxiliary roller 423. The fixing portion 426, which is coupled to the support portion 425, is a member configured to be fixed to a wall, etc. of the structure 200. As shown in
[0099] The non-rotary frame 427 is a cylindrical frame having a hole, through which the cutting wire 300 passes, formed therethrough, and is not rotatable. The rotary frame 428 is a cylindrical rotatable frame inserted into the non-rotary frame 427. The angle between the guide roller 422 and the fixing roller 421 may be changed using the rotary frame 428, as needed.
[0100] As described above, each of the first auxiliary roller 423 and the second auxiliary roller 424 prevents the cutting wire 300 from being separated from the outer circumferential surface of a corresponding one of the fixing roller 421 and the guide roller 422 during cutting. Since force is applied to the cutting wire 300 during cutting, the cutting wire 300 is too frequently separated from the outer circumferential surfaces of the first auxiliary roller 423 and the second auxiliary roller 424. In general, cutting wire 300 may be easily separated during cutting using the wire saw machine if there are no the first auxiliary roller 423 and the second auxiliary roller 424.
[0101] The separated cutting wire 300 must be disposed on the outer circumferential surface of each of the fixing roller 421 and the guide roller 422 again; however, this remarkably reduces cutting efficiency. Since, when the cutting wire 300 is separated while cutting work is performed, the cutting work must be stopped, the cover must be removed, and setting must be performed again, increase in time and expense and decrease in productivity are incurred. In particular, when the cutting wire 300 is separated from the outer circumferential surfaces of the rollers 421 and 422 at the height of a tall structure higher than the ground, much time and effort are required to restore the cutting wire.
[0102] In the roller system proposed by the present invention, however, the second roller unit 420 is provided with the first auxiliary roller 423 and the second auxiliary roller 424, whereby it is possible to prevent separation of the cutting wire 300, and therefore it is possible to considerably improve cutting efficiency.
[0103] The embodiments described above are predetermined combinations of elements and features of the present invention. Each element or feature must be considered to be optional unless explicitly mentioned otherwise. Each element or feature may be implemented in a state of not being combined with another element or feature. In addition, some elements and/or features may be combined to constitute an embodiment of the present invention. The sequence of operations described in the embodiments of the present invention may be changed. Some elements or features in a certain embodiment may be included in another embodiment, or may be replaced with corresponding elements or features in another embodiment. It is obvious that claims having no explicit citation relationship may be combined to constitute an embodiment or may be included as a new claim by amendment after application.
[0104] Those skilled in the art will appreciate that the present invention may be embodied in other specific forms than those set forth herein without departing from essential characteristics of the present invention. The above description is therefore to be construed in all aspects as illustrative and not restrictive. The scope of the invention should be determined by reasonable interpretation of the appended claims and all changes coming within the equivalency range of the invention are intended to be within the scope of the invention.
DESCRIPTION OF REFERENCE NUMERALS
[0105] Cover (110) [0106] Cut recess member (115) [0107] Transparent plate (117) [0108] Passage member (120) [0109] Discharge portion (130) [0110] Air compressor (140) [0111] Air hose (145) [0112] Rubber packing member (150) [0113] Pipe bolt member (151) [0114] Nut member (153) [0115] Lid member (154) [0116] Rubber packing (155) [0117] Rubber hole (156) [0118] Packing member (158) for dust collection and cover recess protection [0119] Valve (160) [0120] Structure (200) [0121] Cutting wire (300) [0122] Main roller (405) [0123] First roller unit (410) [0124] Second roller unit (420) [0125] Fixing roller (421) [0126] Guide roller (422) [0127] First auxiliary roller (423) [0128] Second auxiliary roller (424) [0129] Support portion (425) [0130] Fixing portion (426) [0131] Non-rotary frame (427) [0132] Rotary frame (428)