JP2013241951A - Reinforcement instrument and reinforcement method of existing bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide reinforcement instrument of an existing bolt, in which the existing bolt is effectively used (reused) by substantially increasing allowable strength of the existing bolt.SOLUTION: A reinforcement instrument 1 includes: a reinforcement sleeve 6 screwed with an existing bolt 5; a member fixing nut 7 screwed with the outer peripheral face of the reinforcement sleeve 6 to pinch an overlapped portion of members, between the fixing nut and a head part 5b of the existing bolt 5; and a lock nut 8 screwed with a shaft part 5a of the existing bolt 5 to abut on the member fixing nut 7. The reinforcement instrument 1 may include: a reinforcement sleeve integrally formed with a flange which is screwed with the existing bolt to pinch an overlapped portion of the members, between the flange and the head part of the existing bolt; and a lock nut screwed with the shaft part of the existing bolt to abut on the reinforcement sleeve.

Description

  The present invention relates to a reinforcing device and a reinforcing method for reinforcing an existing bolt used in a steel tower or the like, and more particularly to a technique that can be used as it is without replacing an existing bolt by increasing the allowable strength of the existing bolt. .

  In steel towers used for electric power and communication equipment such as electric wires, televisions and radios, the load applied to the steel tower increases due to changes in the wire type and expansion of equipment, etc., and the existing steel tower members and bolts are subjected to allowable strength (stress If it exceeds), it is necessary to perform reinforcement work.

For example, as shown in FIG. 5A, when the wire type is changed from a 410 mm ² steel core aluminum wire to a 610 mm ² steel core aluminum wire, the load applied to the tower 20 increases. Become. In such a case, it is necessary to reinforce this portion because the load applied to the bolt 5 that joins the steel tower members 2 increases, and the strength may be insufficient.

  In such a case, as shown in FIG. 5B, a new bolt 5 is added to the connecting portion of the steel tower member 2 in addition to the existing bolt 5, or the existing bolt 5 is sized up. It is common to reinforce (for example, by changing the bolt size from M16 to M20).

Among these, as shown in FIG. 6, the existing bolts 5 inserted through the bolt holes 3 of the respective members and screwed into the nuts 10 are fixed to join the stacked tower members 2 to each other. If so, a series of operations as shown in FIG. 7 is performed.
First, the nut 10 screwed into the existing bolt 5 that needs to be replaced is loosened with a ratchet wrench or a monkey spanner (a), the nut 10 is removed from the bolt 5, and the existing bolt 5 is attached to the tower member 2 Remove from the bolt hole 3 (b). Then, the diameter of the bolt hole 3 is increased according to the size of the bolt 5 'that increases the size of the bolt hole 3 using a reamer, a stick file, or the like (c) (d). Thereafter, a new sized bolt 5 'is inserted into the bolt hole 3 (e), and a nut 10' corresponding to this is screwed into the bolt 5 ', temporarily tightened with a ratchet wrench or the like, and specified with a torque wrench. The nut 10 'is tightened with torque (f). If necessary, a lock nut or idling is attached to the bolt 5 'and tightened with a ratchet wrench or the like to prevent the bolt from loosening.

  However, in such a reinforcing method, a new bolt is required. In particular, when dealing with an increase in size, the existing bolt is discarded, and resources are wasted. In addition, since it is necessary to transport new bolts and removed bolts, there is a disadvantage that a great amount of labor and cost are generated.

  Therefore, conventionally, in a configuration in which a portion where the steel tower members are overlapped is fastened with a high-strength bolt, the fastening to the member to be joined is performed between the shaft portion of the high-strength bolt inserted into the bolt hole of the member to be joined and the bolt hole. A configuration is considered in which the length of the material is shorter than the attached length, and a sheath material having a strength higher than that of the high-strength bolt is interposed to increase the maximum proof stress as a joint portion to reduce the number of bolts.

JP 2007-92984 A

  However, in the above configuration in which the sheath material is interposed between the shaft portion of the high-strength bolt and the bolt hole, the sheath material is composed of a short tube, or the short tube is halved so as to be opposed from both sides. It can be arranged, or the plate can be formed into a cylindrical shape and formed with a molded body that does not join the end faces. Although the shear strength as a joint can be reinforced, the existing bolt is integrated with the sheath material. Since it is not a thing, there exists a possibility that it may generate | occur | produce a distortion separately from a sheath material and may fracture | rupture, and the allowable proof stress of bolt itself does not increase. For this reason, there is a concern that inadequate effects cannot be obtained at locations where an increase in the allowable proof stress of existing bolts is required.

  The present invention has been made in view of such circumstances, and a reinforcing device for an existing bolt capable of effectively increasing (allowing for reuse) an existing bolt by substantially increasing the allowable proof stress of the existing bolt and using the same. The main issue is to provide a reinforcement method.

  In order to achieve the above object, the existing bolt reinforcing device according to the present invention is used to reinforce the existing bolts that are inserted and fixed in the bolt holes of the respective members in order to join the overlapped members. A reinforcing sleeve for an existing bolt which is formed to be longer than the thickness of a portion where the members are overlapped with each other and overlapped with each other, and shorter than a shaft portion of the existing bolt. A member fixing nut that is screwed onto the outer peripheral surface of the reinforcing sleeve and sandwiches the overlapping portion of the members with the head of the existing bolt, and a shaft portion that protrudes from the reinforcing sleeve of the existing bolt And a lock nut that is screwed onto the member fixing nut to be brought into contact with the member fixing nut.

  Therefore, according to such a reinforcing device, since the existing bolt is integrated by screwing the reinforcing sleeve, the existing bolt has an allowable strength equivalent to that of a bolt having the same outer shape as that of the reinforcing sleeve. Thus, it is possible to substantially increase the allowable strength of the existing bolt.

  And since the existing bolt to which the reinforcing sleeve is screwed is attached to the overlapping portion of the members by tightening the member fixing nut, a strong coupling structure is obtained, and the member fixing nut is loosened by the lock nut. Therefore, a strong bonding structure can be maintained.

  Moreover, in order to achieve the said subject, in order to reinforce the existing bolt which the reinforcement tool of the existing bolt which concerns on this invention is inserted and fixed to the bolt hole of each member in order to couple | stack the overlapped members. It is a reinforcing device for existing bolts used in the above-mentioned, and is screwed into the existing bolts, formed shorter than the shaft portion of the existing bolts, and the members overlapped with the heads of the existing bolts You may make it comprise the reinforcement sleeve by which the flange which pinches | interposes a part was integrally formed, and the lock nut screwed together by the axial part protruded from the said reinforcement sleeve of the said existing bolt, and contact | abuts to the said reinforcement sleeve.

  Even in such a configuration, since the reinforcing sleeve in which the flange is integrally formed with the existing bolt is screwed and integrated, the existing bolt is allowed to have the same tolerance as the bolt having the same outer shape as the reinforcing sleeve. It becomes possible to give proof strength, and it becomes possible to increase the allowable proof strength of an existing bolt substantially. Also, by tightening the reinforcement sleeve screwed to the existing bolt, it is attached to the overlapping part of the members, so a strong coupling structure is obtained, and the lock nut prevents the reinforcement sleeve from loosening, It becomes possible to maintain a strong bonding structure.

  In particular, in the latter configuration, when the size of the reinforcing sleeve is long, a gap may be formed between the flange and the member of the reinforcing sleeve, and a strong coupling state may not be obtained even if the reinforcing sleeve is tightened. In this case, a washer may be interposed between the flange of the reinforcing sleeve and the member. As a result, the axial tightening force can be reliably transmitted between the members, and the members can be firmly coupled to each other.

  In addition, as a method for reinforcing the existing bolt using the former reinforcing instrument, a step of removing the existing bolt from the bolt hole of each member, a step of screwing the reinforcing sleeve into the removed existing bolt, and the bolt hole Expanding the diameter of the reinforcing sleeve so that the reinforcing sleeve can be inserted, inserting the existing bolt into which the reinforcing sleeve is screwed together with the reinforcing sleeve, and the reinforcing sleeve inserted into the bolt hole. A step of screwing the member fixing nut into a portion protruding from the bolt hole and sandwiching the overlapped portion of the members between the member fixing nut and the head of the existing bolt; and protruding from the reinforcing sleeve And a step of screwing the lock nut onto the shaft portion of the existing bolt and bringing it into contact with the member fixing nut.

  Further, as a method of reinforcing the existing bolt using the latter reinforcing device, the step of removing the existing bolt from the bolt hole of each member, the step of expanding the bolt hole so that the reinforcing sleeve can be inserted, and the step of removing Inserting the existing bolt into the bolt hole; and screwing the reinforcing sleeve into the existing bolt inserted into the bolt hole from the side opposite to the insertion direction of the existing bolt, and the head of the existing bolt and the A step of sandwiching the overlapped portion of the members with the flange of the reinforcing sleeve, and a step of screwing a lock nut into a shaft portion of the existing bolt protruding from the sleeve to contact the reinforcing sleeve It is good to comprise.

  At this time, in the configuration in which the washer is interposed between the flange of the reinforcing sleeve and the member, the step of inserting the removed existing bolt into the bolt hole, and the existing bolt inserted into the bolt hole inserted into the bolt hole A washer between the step of screwing the reinforcing sleeve from the opposite side of the insertion direction and sandwiching the overlapped portion of the members between the head of the existing bolt and the flange of the reinforcing sleeve. A step of interposing between the flange of the reinforcing sleeve and the member may be provided.

As described above, according to the reinforcing device and the reinforcing method for an existing bolt according to the present invention, the reinforcing sleeve is screwed and integrated with the existing bolt, so that the allowable strength of the existing bolt can be substantially increased. Thus, the existing bolts can be reinforced without being discarded, and can be effectively reused.
For this reason, since it is not necessary to replace the existing bolt with a new bolt, it is not necessary to transport a new bolt and a removed bolt, and labor and cost can be reduced.

FIG. 1 shows a first configuration example of a reinforcing device for existing bolts according to the present invention. FIG. 1 (a) is a cross-sectional view showing an attached state thereof. (B) is a figure which shows each member which comprises the reinforcement instrument attached to an existing volt | bolt, (i) is a top view and side sectional view which show a reinforcement sleeve, (ii) is a plane which shows a member fixing nut The figure and the side sectional view, (iii) are a plan view and a side sectional view showing the lock nut. FIG. 2 is a diagram for explaining a reinforcing method using the reinforcing device of FIG. FIG. 3 shows a second structural example of a reinforcing device for existing bolts according to the present invention, wherein (a) is a cross-sectional view showing the mounting state, and (b) is a structure of (a). It is sectional drawing which shows the attachment state which further attached the washer with respect to it. (C) is a figure which shows each member which comprises the reinforcing instrument attached to an existing volt | bolt, (i) is the top view and side sectional view which show a reinforcement sleeve, (ii) is the top view which shows a washer, Side sectional views (iii) are a plan view and a sectional view showing a lock nut. FIG. 4 is a diagram for explaining a reinforcing method using the reinforcing instrument of FIG. FIG. 5 is a diagram for explaining a conventional reinforcing method for a connecting portion between steel tower members accompanying a change in the wire type of the steel tower. FIG. 6 is a cross-sectional view showing an installed state of existing bolts that connect steel tower members. FIG. 7 is a diagram for explaining a conventional reinforcing method.

  Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the 1st structural example of the reinforcement tool of the existing volt | bolt which concerns on this invention is shown.
The reinforcing instrument 1 includes an existing bolt 5 that is inserted into bolt holes 3 and 3 that are provided in alignment with the tower members 2 and 2 that are overlapped, a reinforcing sleeve 6 that is screwed into the existing bolt 5, A member fixing nut 7 that is screwed to the outer peripheral surface of the reinforcing sleeve 6, and a lock nut 8 that is in axial contact with the member fixing nut 7 and screwed to the shaft portion 5 a of the existing bolt 5 are provided. It is configured.

  The existing bolt 5 is a per se known shaft portion 5a erected vertically from the head portion 5b. The shaft portion 5a is formed longer than the thickness of the two steel tower members 2 and will be described later. The reinforcing sleeve 6 is longer than the axial dimension. In addition, a thread groove (male thread) 5c is formed in the shaft portion 5a from the distal end to the vicinity of the proximal end.

  The reinforcing sleeve 6 is made of the same material as the existing bolt 5 (galvanized iron), and a screw groove (female screw) 6a that can be screwed into the screw groove 5c of the existing bolt 5 is provided on the inner peripheral surface. It is formed in a cylindrical shape that is longer than the thickness of the portion where the steel tower members are overlapped with each other and shorter than the shaft portion 5a of the existing bolt (the dimension in the axial direction is the steel tower member 2). Are formed to be equal to or longer than the dimension obtained by adding the thickness of the two sheets and the thickness of the member fixing nut 7 described later). Further, a thread groove (male thread) 6 b into which the member fixing nut 7 is screwed is formed on the outer peripheral surface of the reinforcing sleeve 6.

  In this example, the screw groove 6a formed on the inner peripheral surface is formed from the tip to the vicinity of the center, and the screw groove 6b formed on the outer peripheral surface is substantially equal to the thickness of the member fixing nut 7 from the tip. Or it is formed slightly larger than this.

  The member fixing nut 7 has a screw groove 7 a that is screwed into a screw groove 6 b formed on the outer peripheral surface of the reinforcing sleeve 6, and has a diameter larger than the diameter of the bolt hole 3.

The lock nut 8 has a screw groove 8a that is screwed into the screw groove 5c of the existing bolt 5 on the inner surface, and an annular protrusion that protrudes toward the member fixing nut on the periphery of the end surface facing the member fixing nut 7. Article 8b is formed. The annular protrusion 8 b is formed to have a diameter larger than the outer diameter of the reinforcing sleeve 6, and the axial dimension (α) is larger than the protruding amount of the reinforcing sleeve 6 protruding from the member fixing nut 7. It is formed long. Therefore, the lock nut 8 is brought into contact with the member fixing nut 7 in the axial direction so as not to contact the reinforcing sleeve 6.
The member fixing nut 7 and the lock nut 8 are also made of the same material as the existing bolt 5 (galvanized iron).

In order to obtain the reinforcing structure shown in FIG. 1 (a) using the reinforcing device 1 described above, as shown in FIG. 2, firstly, a nut 10 screwed into an existing bolt 5 that needs to be replaced. Loosen with a ratchet wrench or a monkey spanner. And the nut 10 is removed from the existing bolt 5, and the existing bolt 5 is pulled out from the bolt hole 3 of each steel tower member 2 (FIG. 2 (a)).
Depending on the place of replacement, the load applied to the existing bolt 5 is reduced with a wire tensioner (lever block (registered trademark)) or the like before the existing bolt 5 is removed.

  Thereafter, the reinforcing sleeve 6 is extrapolated to the removed existing bolt 5 from the side where the screw grooves 6a and 6b are not formed, and is screwed to be coupled (FIG. 2B).

  Then, if necessary, the diameter of the bolt hole 3 is increased with a reamer or the like so as to be larger than the outer diameter of the reinforcing sleeve 6, and the bolt 5 in which the reinforcing sleeve 6 is screwed into the bolt hole 3 together with the reinforcing sleeve 6. Insert (FIG. 2 (c)).

  Thereafter, the member fixing nut 7 is screwed into the thread groove 6b on the outer peripheral surface of the reinforcing sleeve 6 protruding from the bolt hole 3, and temporarily tightened with a ratchet wrench or the like, and the member fixing nut 7 is tightened with a specified torque by a torque wrench. Tightening and sandwiching the overlapped portion of the tower members between the member fixing nut 7 and the head 5b of the existing bolt 5 (FIG. 2 (d)).

  Thereafter, the lock nut 8 is screwed into the thread groove 5c of the existing bolt 5 projecting from the reinforcing sleeve 6, and is tightened with a ratchet wrench or the like to bring the protrusion 8b of the lock nut 8 into contact with the member fixing nut 7 (FIG. 2 ( e)).

Therefore, since the reinforcing sleeve 6 is screwed and integrated with the existing bolt 5, the existing bolt 5 has an allowable strength equivalent to that of a bolt having the same outer shape as that of the reinforcing sleeve 6. It becomes possible to substantially increase the allowable proof stress of the existing bolt. For this reason, since it can reinforce using the existing volt | bolt 5, it becomes possible to use a resource effectively and to reduce a waste material. For this reason, it is not necessary to transport the removed bolts or new bolts, and it is possible to reduce labor and transportation costs.
Furthermore, since the reinforcement sleeve 6 is retrofitted to the existing bolt 5, it can be reused to reinforce other existing bolts after removal.

  In the above configuration, in order to reinforce the existing bolt, a reinforcing sleeve, a member fixing nut, and a lock nut are added. However, the reinforcing sleeve and the member fixing nut are integrated into a reinforcing device. The number of structural members may be reduced and the number of steps of reinforcement work may be reduced.

  FIG. 3 shows an example of such a configuration. In this example, the reinforcing device 1 includes a reinforcing sleeve 11 screwed into an existing bolt and integrally formed with a flange, and a reinforcing sleeve screwed into the existing bolt 5. 11 includes a lock nut 12 that abuts in the axial direction, and a washer 13 attached as necessary.

  The reinforcing sleeve 11 includes a cylindrical portion 11b in which a screw groove 11a that can be screwed into a screw groove 5c formed in the shaft portion 5a of the existing bolt 5 is provided on the inner peripheral surface, and a proximal end side of the cylindrical portion 11b. And a flange 11c integrally extending in the radial direction from the outer peripheral surface. The flange 11c is formed in a hexagonal shape and can be attached to a ratchet wrench or a torque wrench. The cylindrical portion of the reinforcing sleeve has an axial dimension that is substantially the same as the dimension obtained by adding the thickness of the two steel tower members and the thickness of the member fixing nut, and can be screwed onto the shaft portion 5a of the existing bolt 5. The thread groove 11a is formed from the end on the side where the flange 11c is formed to the middle.

  The lock nut 12 has a thread groove 12a screwed into the thread groove 5c of the existing bolt 5, and in this example, the reinforcing sleeve 11 does not protrude in the axial direction from the flange 11c. The end surface facing the flange 11c is formed flat.

When the axial dimension of the cylindrical portion 11b of the reinforcing sleeve 11 is longer than the thickness of the two steel tower members 2, the washer 13 has a gap formed between the steel tower member 2 and the flange 11c, and the existing bolt 5 Since there is a concern about the inconvenience of rattling, it is interposed between the flange 11c of the reinforcing sleeve 11 and the steel tower member 2 in order to eliminate this gap, and the inner diameter is the cylindrical portion 11b of the reinforcing sleeve 11. A flat washer that is larger than the outer diameter and smaller than the diameter of the flange 11c and has no thread groove on the inner peripheral surface is used.
The reinforcing sleeve 11, the washer 13, and the lock nut 12 are made of the same material as the existing bolt 5 (galvanized iron). In addition, since the other configuration is the same as that of the above configuration example, the same reference numerals are given to the same portions and the description thereof is omitted.

In order to obtain the reinforcing structure shown in FIG. 3 (a) or FIG. 3 (b) using the reinforcing device 1 as described above, first, as shown in FIG. 4, it is screwed into the existing bolt 5 that needs to be replaced. Loosen the nut 10 with a ratchet wrench or a monkey spanner. And the nut 10 is removed from the existing bolt 5, and the existing bolt 5 is pulled out from the bolt hole 3 of each steel tower member 2 (FIG. 4 (a)).
Depending on the place of replacement, the load applied to the existing bolt 5 is reduced with a wire tensioner (lever block (registered trademark)) or the like before the existing bolt 5 is removed.

Thereafter, the bolt hole 3 is expanded with a reamer or the like as necessary to make it larger than the outer diameter of the reinforcing sleeve, and the removed existing bolt 5 is inserted into the bolt hole 3 (FIG. 4B). The reinforcing sleeve 11 integrally formed with the flange 11c is inserted from the side opposite to the insertion direction of the existing bolt 5 on the side where the flange 11c is not formed (FIG. 4C), and is screwed into the existing bolt 5 (FIG. 4). 4 (d)). At this time, when a gap is formed between the steel tower member 2 and the flange 11c, the washer 13 is externally attached to the existing bolt 5 before the reinforcement sleeve 11 is attached, and then the reinforcement sleeve 11 is attached to the existing bolt 5. Screwed on.
Then, it is temporarily tightened with a ratchet wrench or the like, and the flange 11c is tightened to a specified torque with a torque wrench, and the flange 11c is pressed against the steel tower member 2 or the washer 13.

  Thereafter, the lock nut 12 is screwed into the shaft portion 5a (thread groove 5c) of the existing bolt 5 protruding from the reinforcing sleeve 11, and is tightened with a ratchet wrench or the like to bring the lock nut 12 into contact with the reinforcing member 11 (flange 11c). (FIG. 4 (e)).

  Therefore, in such a configuration, the same effect as the above configuration example can be obtained, and the reinforcing sleeve 11 integrally formed with the flange 11c is used, so that the number of reinforcing steps can be reduced and the working efficiency can be improved. It becomes possible to make it.

  In addition, in the above structure, although the example which piled up the two steel tower members 2 was demonstrated, it can employ | adopt similarly with respect to the existing volt | bolt which piled up and bolted three or more steel tower members. is there. Moreover, in the above structure, although the case where the existing bolt used for the joining location of the steel tower member 2 was reinforced was demonstrated, the same structure is employ | adopted also when reinforcing the existing bolt of the other location where a bolt is utilized. May be.

DESCRIPTION OF SYMBOLS 1 Reinforcing tool 2 Steel tower member 3 Bolt hole 5 Existing bolt 5a Shaft part 5b Head part 5c Screw groove 6 Reinforcement sleeve 7 Member fixing nut 8 Lock nut 11 Reinforcement sleeve 11c Flange 12 Lock nut 13 Washer

Claims (6)

An existing bolt reinforcement device used to reinforce an existing bolt that is inserted and fixed in a bolt hole of each member in order to join the overlapped members,
Reinforcement sleeve that is screwed into the existing bolt and formed longer than the thickness of the overlapping parts, and shorter than the shaft portion of the existing bolt;
A member fixing nut that is screwed onto the outer peripheral surface of the reinforcing sleeve and sandwiches the overlapped portion of the members with the head of the existing bolt;
An existing bolt reinforcing instrument comprising: a lock nut that is screwed into a shaft portion protruding from the reinforcing sleeve of the existing bolt and is brought into contact with the member fixing nut. An existing bolt reinforcement device used to reinforce an existing bolt that is inserted and fixed in a bolt hole of each member in order to join the overlapped members,
A reinforcing sleeve that is screwed into the existing bolt, is formed shorter than the shaft portion of the existing bolt, and is integrally formed with a flange that sandwiches the overlapped portion of the members with the head of the existing bolt; ,
An existing bolt reinforcing instrument comprising: a lock nut that is screwed into a shaft portion protruding from the reinforcing sleeve of the existing bolt and is brought into contact with the reinforcing sleeve.   The reinforcing device for an existing bolt according to claim 2, wherein a washer is interposed between the flange of the reinforcing sleeve and the member. A method for reinforcing an existing bolt using the reinforcing device for an existing bolt according to claim 1,
Removing the existing bolt from the bolt hole of each member;
Screwing the reinforcing sleeve on the removed existing bolt;
Expanding the bolt hole so that the reinforcing sleeve can be inserted;
Inserting the existing bolt into which the reinforcing sleeve is screwed together with the reinforcing sleeve into the bolt hole;
The member fixing nut is screwed into a portion protruding from the bolt hole of the reinforcing sleeve inserted through the bolt hole, and the members are overlapped between the member fixing nut and the head of the existing bolt. A step of sandwiching the part;
And a step of screwing the lock nut into a shaft portion of the existing bolt projecting from the reinforcing sleeve and bringing the lock nut into contact with the member fixing nut. An existing bolt reinforcement method using the existing bolt reinforcement device according to claim 2,
Removing the existing bolt from the bolt hole of each member;
Expanding the bolt hole so that the reinforcing sleeve can be inserted;
Inserting the removed existing bolt into the bolt hole;
The reinforcing sleeve is screwed into the existing bolt inserted through the bolt hole from the side opposite to the insertion direction of the existing bolt, and the members between the head of the existing bolt and the flange of the reinforcing sleeve A step of sandwiching the overlapped portions;
And a step of screwing a lock nut into a shaft portion of the existing bolt projecting from the sleeve to contact the reinforcing sleeve.   A step of inserting the removed existing bolt into the bolt hole; and a head of the existing bolt by screwing the reinforcing sleeve into the existing bolt inserted into the bolt hole from a side opposite to the insertion direction of the existing bolt. A step of interposing a washer between the flange of the reinforcing sleeve and the member is provided between the step of sandwiching the overlapped portion of the members between the flange of the reinforcing sleeve and the member of the reinforcing sleeve. The method for reinforcing an existing bolt according to claim 5.

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