Extension rod

Abstract

To provide a jointed fishing rod that can prevent fall-off of a columnar member.SOLUTION: A jointed fishing rod has a connection body 10 for a jointed fishing rod in which a hollow first columnar member 21 and a hollow second columnar member 22 accommodating at least part of the first columnar member 21 are combined. The jointed fishing rod has: lid parts 212, 222 attached to the first columnar member 21 and the second columnar member 22 and including openings; a string-like member 3 arranged inside the first columnar member 21 and the second columnar member 22; a first stationary member attached to the lid part 212 of the first columnar member 21 and fixed to the string-like member 3; and a second stationary member 42 attached to the lid part 222 of the second columnar member 22 and fixed to the string-like member 3. The length of the string-like member 3 between the first stationary member and the second stationary member 42 is shorter than the length of the second columnar member 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a jointed fishing rod, and also to an auxiliary member for fixing a jointed fishing rod used in the jointed fishing rod, and a set screw member used as part of the auxiliary member. [Background technology]

[0002] Long rods that can be extended for use in high-altitude work such as photography, underwater work, and the like are known (Non-Patent Document 1). These long rods are widely used as photography equipment that transmits images and photos from a camera attached to the tip to a monitor such as a smartphone for photographing high places. These long rods can be extended to lengths that cannot be achieved with a typical tripod, such as 4 m to 15 m at their maximum. This length can be used to safely perform photography from high places such as aerial photography, as well as inspections, surveying, and underwater photography. Meanwhile, when not in use as a long rod, the tube can be retracted to a length of about several tens of centimeters to just under 2 m, making it easy to store and carry.

[0003] As for such long rods, for example, pole-shaped work aids are sometimes used when working at height, such as cameras that can be adjusted to any height while taking pictures, or construction work using various tools such as scissors for cutting branches at high altitudes. For example, Patent Document 1 discloses an aerial photography device for taking pictures from high altitudes, which is used in archaeological excavations, construction sites, design studios, etc.

[0004] Methods for adjusting the height include a telescopic rod-like auxiliary tool that has multiple cylindrical bodies of different diameters built into the same axis and that advances the tubes sequentially during use, or a joint rod-like auxiliary tool that has threads or fittings on both ends of cylindrical bodies of the same diameter and connects them by screwing the threads together or fitting them together with a fitting structure.

[0005] Patent Document 2 also discloses a cylindrical body for connecting rods, which includes a hollow first cylindrical body, a hollow second cylindrical body that is wider in diameter than the first cylindrical body and contains a part of the first cylindrical body, an adhesive portion provided between the outer periphery of the first cylindrical body and the inner periphery of the second cylindrical body, with a part of the first cylindrical body contained within the hollow portion of the second cylindrical body, an upper end joining portion at the upper end of the first cylindrical body and a lower end joining portion at the lower end, the upper end side of the first cylindrical body that protrudes and is not contained within the second cylindrical body forms an insertion portion, and the hollow portion at the lower end side of the second cylindrical body that does not contain the first cylindrical body and can fit the insertion portion forms a receiving portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-150414 [Patent Document 2] Japanese Patent Application Publication No. 2018-81148 [Non-patent literature]

[0007] [Non-Patent Document 1] Bi(R) Rod Store (URL:https: / / birodstore.com / ) Summary of the Invention [Problem to be solved by the invention]

[0008] In Patent Document 1 and other common tripods, the legs that move within the tripod are provided with a large-diameter section that catches the inside and outside of the legs to prevent them from coming off when extended for extension. However, with this type of design, the legs for length adjustment must be thin enough to move freely while still allowing the large-diameter section to move within the tube, resulting in a large difference in thickness between the outer and inner legs. This makes it difficult to increase the number of leg sections, making it impossible to shorten the length when stored while lengthening it when extended.

[0009] In order to solve this problem, Patent Document 2 and Non-Patent Document 1 use cylindrical members with approximately the same outer diameter at both ends, and between adjacent cylindrical members, an inner cylindrical member with an outer diameter approximately equal to the inner diameter of the outer cylindrical member is used. This prevents excessive changes in the diameter difference between the cylindrical members even when multiple stages are used, making it easier to maintain sufficient strength even when multiple stages of the tube are connected together.

[0010] However, if the inner diameter of the outer tube and the outer diameter of the inner tube are approximately equal, there is a possibility that the outer tube will be accidentally pulled out beyond its full length, causing the outer tube and inner tube to unintentionally separate. This situation can occur, for example, when the inner tube is pulled out too far because the stop mark for feeding is overlooked, when the inner tube falls out due to the weight of the tube when working without fastening the clamp, or when the clamp loosens and falls off during use.

[0011] In view of the above circumstances, an object of the present invention is to provide a connecting rod that can prevent the pole members from falling off, and components therefor. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above problems and have found that the following inventions meet the above objectives, thereby completing the present invention.

[0013] <1> A joint rod having a joint rod connector that combines a hollow first post member and a hollow second post member that accommodates at least a portion of the first post member, a cover member having an opening attached to the first pillar member and the second pillar member; a string-like member disposed inside the first pillar member and the second pillar member; a first fixing member attached to the lid portion of the first pillar member and fixed to the string-like member; a second fixing member attached to the lid portion of the second pillar member and fixed to the string-like member, A joint rod, wherein the length of the string-like member between the first fixing member and the second fixing member is shorter than the length of the second pillar member. <2> the opening of the lid portion has a female thread portion, and the first fixing member and the second fixing member have male thread portions that are received in the female thread portions, the first fixing member and the second fixing member each have a first fixing member that fixes the string-like member and a setscrew member that has an accommodating portion that accommodates the first fixing member, The set screw member has a first groove portion provided along the length direction and a second groove portion intersecting the length direction of the first groove portion, and the second groove portion serves as the accommodation portion that accommodates the first fixing member. <1> The extension rod described in. <3> A joint rod fixing auxiliary member having a string-like member, a first fixing member fixed to the string-like member, and a second fixing member fixed to the string-like member, and attached at a predetermined length of the string-like member between the first fixing member and the second fixing member. <4> A set screw member having a first groove portion provided along a length direction and a second groove portion intersecting the length direction of the first groove portion. [Effects of the Invention]

[0014] According to the present invention, it is possible to prevent the pole members of the extension rod from falling off. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of an example of a joint for a joint rod according to the present invention. [Figure 2] FIG. 10 is a schematic diagram showing the relationship between conventional pillar members. [Figure 3] 1 is a schematic diagram of an example of a set screw member according to the present invention; [Figure 4] 1 is a schematic diagram of an example of an auxiliary member for fixing a connecting rod according to the present invention. [Figure 5] 10A to 10C are schematic diagrams illustrating an example of an operation for attaching a fixing member to a lid portion of a pole member according to the present invention. [Figure 6] 1 is a schematic diagram of an example of a joint rod according to the present invention. FIG. [Figure 7] FIG. 10 is a schematic diagram of an example of a fixing method for a joint rod according to the present invention. [Figure 8] 1 is a schematic diagram of an example of a jointed fishing rod according to the present invention. [Figure 9] 10A to 10C are schematic diagrams illustrating an example of an operation for attaching a fixing member to a lid portion of a pole member according to the present invention. [Figure 10] 1 is a schematic diagram of an example of attachment of the end of a handle pole member of a joint rod according to the present invention. FIG. [Figure 11] 1 is an image of a manufacturing example of a first fixing member and a second fixing member according to the present invention. [Figure 12] 10 is an image showing an example of an operation for attaching a fixing member to a cover portion of a pole member according to the present invention. [Figure 13] 1 is an image of a manufacturing example of a joint for a fishing rod according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following describes in detail an embodiment of the present invention, but the following description of the constituent elements is one example (typical example) of an embodiment of the present invention, and the present invention is not limited to the following content unless the gist of the present invention is changed. Note that when the expression "to" is used in this specification, it is used as an expression that includes the numerical values ​​before and after it.

[0017] [The joint rod of the present invention] The extension rod of the present invention is an extension rod having an extension rod connector that combines a hollow first pillar member and a hollow second pillar member that accommodates at least a portion of the first pillar member, a cover member having an opening attached to the first pillar member and the second pillar member; a string-like member disposed inside the first pillar member and the second pillar member; a first fixing member attached to the lid portion of the first pillar member and fixed to the string-like member; and a second fixing member attached to the lid portion of the second pillar member and fixed to the string-like member, wherein the length of the string-like member between the first fixing member and the second fixing member is shorter than the length of the second pillar member.

[0018] [Auxiliary member for fixing a joint rod according to the present invention] The auxiliary member for fixing a connecting rod of the present invention comprises a string-like member, a first fixing member fixed to the string-like member, and a second fixing member fixed to the string-like member, and is attached at a predetermined length of the string-like member between the first fixing member and the second fixing member.

[0019] [Set screw member of the present invention] The setscrew member of the present invention has a first groove provided along the length direction and a second groove intersecting the length direction of the first groove.

[0020] In this application, the auxiliary member for fixing a joint rod of the present invention and the set screw member of the present invention can be used in the joint rod of the present invention, and the corresponding configurations in this application can be used mutually.

[0021] Fig. 1 is a schematic diagram of an example of a connecting body for extension rods according to the present invention. Fig. 1(a) is a schematic diagram showing a connecting body for extension rods 10 in a state in which a pole member is housed. Fig. 1(b) is a diagram showing a state in which a first pole member 21 is extended by being fed out from a second pole member 22. Fig. 1(c) shows a state in which the first pole member 21 is pulled out from the second pole member 22 to explain the relationship in length between the first pole member 21, the second pole member 22, etc.

[0022] FIG. 2 is a schematic diagram showing the relationship between conventional pillar members. The first pillar member 21 and the second pillar member 22 are a combination of parts related to the connecting rod 10, which is part of the connecting rod. The first pillar member 21 and the second pillar member 22 are secured with a clamp 223 to prevent them from falling off. As a guide for this securing position, a colored or other mark 211 is provided on the first pillar member 21 located on the inside, and the second pillar member 22 is secured with a clamp 223 within a range where this mark 211 is visible. The second pillar member 22 also has a mark 221 provided for when another pillar member is attached. If the first pillar member 21 continues to be fed without being secured with the mark 211 or the clamp 223, it will come off the second pillar member 22. The extension rod of the present invention is attached so that each pillar member of the extension rod connecting body 10 does not fall off by using a string-like member 3 related to the extension rod fixing auxiliary member of the present invention, a first fixing member 41, and a second fixing member 42.

[0023] [Connector for extension rod 10] The extension rod connector 10 is a combination of a first pillar member 21 and a second pillar member 22 that houses at least a part of the first pillar member 21.

[0024] [First pillar member 21, second pillar member 22] The first pillar member 21 and the second pillar member 22 are pillar members that constitute the connecting body 10 for the extension rod. The first pillar member 21 and the second pillar member 22 can be similar in basic cross-sectional shape, length, thickness, etc., except for the difference in the outer circumferential thickness, which corresponds to the diameter in the case of a cylinder. The extension rod can be a combination of multiple pillar members. Therefore, in terms of the relationship between the pillar members arranged in multiple stages, when another inner pillar member is arranged inside the first pillar member 21, that inner pillar member can be considered as the first pillar member, and when another outer pillar member is arranged outside the second pillar member 22, that outer pillar member can be considered as the second pillar member, thereby forming a repeated structure. For this reason, when describing the configuration common to the first pillar member 21 and the second pillar member 22, they may be simply referred to as pillar members.

[0025] The pillar member is hollow. Adjacent thin pillar members are housed in this hollow portion. The pillar members can be cylindrical with a circular cross section, polygonal pillar with a polygonal cross section, or a cross section that combines straight lines and curves. It is particularly preferable to use cylindrical members, as it is easy to connect multiple pillar members to form a long structure.

[0026] Such pillar members are preferably formed from a lightweight material that is resistant to bending loads. Furthermore, it is preferable that they have excellent shape stability in the usage environment. For example, such materials are preferably formed from at least one material selected from the group consisting of carbon fiber, glass fiber, and aluminum. These may also be combined, and a configuration combining different materials may be used, such as by making the first inner pillar member from glass fiber and the second outer pillar member from carbon fiber.

[0027] It is preferable to use pole members of approximately the same length. Specific lengths are, for example, approximately 30 cm to 200 cm for each pole member, and preferably approximately 50 cm to 150 cm. This length avoids the need for an excessively large number of joints to achieve lengths of 3 m or more, or 5 m or more (e.g., approximately 12 m) when the pole members for a jointed rod of the present invention are joined together to form a jointed rod, and also provides a length that is easy to transport and easy to handle. The diameter of the pole member at its outermost diameter can be, for example, approximately 10 to 100 mm, more specifically, approximately 20 to 50 mm.

[0028] [Lid parts 212, 222] The first pillar member 21 has a lid portion 212 with an opening. The second pillar member 22 has a lid portion 222 with an opening. The lid portions 212, 222 are attached to prevent the pillar member from slipping out on the opposite side of the shape designed as the direction in which the pillar member is fed out and extended, and to increase the strength of the pillar member so that it is less likely to deform when fastened with a clamp 223 or the like. For this reason, the lid portion 212 of the first pillar member 21 is provided on the second pillar member 22 side in the length direction of the first pillar member 21. The lid portion 222 of the second pillar member 22 is provided on the opposite side of the first pillar member 21 in the length direction of the second pillar member 22.

[0029] The lids 212 and 222 also have openings. These openings also function as holes for passing through and arranging the string-like member 3 or the like inside the extension rod connector 10. Furthermore, these openings can also be used as attachment positions for the first fixing member 41 and the second fixing member 42 (see FIGS. 4 and 5).

[0030] [String-like member 3] The string-like member 3 is disposed inside the first pillar member 21 and the second pillar member 22. When the first pillar member 21 is housed in the second pillar member 22, the string-like member 3 is tucked between the lid portion 212 and the lid portion 222. On the other hand, when the first pillar member 21 is fed out from the second pillar member 22 and stretched, the string-like member 3 is stretched. For this reason, the string-like member 3 is preferably one that is easy to bend, resistant to tangling, and has high strength when pulled. A high-strength thread or the like can be used as such a string-like member. For example, various types of fishing line can be used, and in particular, polyethylene fishing line can be used.

[0031] [First fixing member 41, second fixing member 42] The first fixing member 41 is attached to the lid portion 212 of the first pillar member 21 and fixed to the string-like member 3. The second fixing member 42 is attached to the lid portion 222 of the second pillar member 22 and fixed to the string-like member 3.

[0032] The first fixing member 41 and the second fixing member 42 are both fixed to the string-like member 3. As described above, the first fixing member 41 is attached to the first pillar member 21, and the second fixing member 42 is attached to the second pillar member 22. The length of the string-like member 3 in its extended state, from the position where the first fixing member 41 is fixed to the position where the second fixing member 42 is fixed (corresponding to length L1 in FIG. 1(c)), is designed to be shorter than the length of the second pillar member 22 (corresponding to length L22 in FIG. 1(c)). As a result, even if the first pillar member 21 is pulled out, the string-like member 3 is fixed to both the first pillar member 21 and the second pillar member 22 in a stretched state up to length L1, so it becomes difficult to pull out any further and stops. Therefore, even if the mark 211 of the first pillar member 21 being pulled out is overlooked and the first pillar member 21 is not fastened with the clamp 223, it is possible to avoid a situation in which the first pillar member 21 and the second pillar member 22 are unintentionally separated and dropped off.

[0033] The difference between the length of the second pillar member 22 (corresponding to length L22 in FIG. 1(c)) and the length of the string-like member 3 in its stretched state from the position where the first fixing member 41 is fixed to the position where the second fixing member 42 is fixed (corresponding to length L1 in FIG. 1(c)) can be appropriately set within a range that allows the first pillar member 21 to be appropriately pulled out and prevents it from falling off. Using length L22 and length L1, it is more preferable that "length L22 - length L1" is approximately 2 cm to 10 cm, or approximately 3 cm to 8 cm. When determining the length (L22) based on the position where the first fixing member 41 is fixed and the position where the second fixing member 42 is fixed, the respective positions can be measured based on the center of the length of the first fixing member 41 and the center of the length of the second fixing member 42.

[0034] It is preferable that the first fixing member 41 and the second fixing member 42 are detachably fixed to the first pillar member 21 and the second pillar member 22, respectively. By making them detachable, the first pillar member 21 and the second pillar member 22 can also be separated. In normal use, it is better to keep them fixed to prevent unintentional detachment and ensure safe use. On the other hand, depending on the use conditions of the extension rod, for example, when used in seawater, it may be better to perform maintenance such as cleaning and drying after use. When performing such maintenance, a structure that allows for easy separation is advantageous in that each component can be easily cleaned and replaced as needed.

[0035] The string-like member and the first and second fixing members are fixed to the post member so as to prevent the post member from separating or falling off during use, and a combination that can be arranged inside the post member can be used. For example, a combination can be used in which the opening of the lid is threaded, and the first and second fixing members can be attached by aligning them with the threads, and the string-like member can be fixed by wrapping or entangling it around part of the threads.

[0036] The first fixing member 41 and the second fixing member 42 can be a combination of first fixing members 411, 421 that fix the string-shaped member 3 and set screw members 412, 422 that have a housing portion that houses the first fixing members 411, 421. With this combination, the first fixing members 411, 421 are attached to the string-shaped member 3 in advance, making it easy to adjust the length interval (L1) of the first fixing member 41 and the second fixing member 42. Furthermore, because the set screw members 412, 422 are used when attaching the first fixing member 41 and the second fixing member 42 to the respective pillar members, they are also easy to attach to the cover portions 212, 222. Furthermore, this combination of the first fixing member and the set screw member provides excellent workability, strength, and productivity for relatively small members that are continuously arranged through the hollow portion of the pillar member while being attached to the cover portion of the pillar member.

[0037] Fig. 3 is a schematic diagram of an example of a setscrew member according to the present invention. Fig. 4 is a schematic diagram of an example of a joint rod fixing auxiliary member according to the present invention. In the embodiment shown in Figs. 1 and 4, a ring is used as the first fixing member 411, 421. This ring is attached to the string-like member 3 at a predetermined length that is shorter than the length of the pole member adjusted to the attachment position to prevent it from falling off.

[0038] [Set screw members 412, 422] The set screw members 412, 422 have first grooves 4121, 4221 provided along the length direction. These first grooves 4121, 4221 also extend along the length direction of the extension rod, and the string-like member 3 can be passed through these grooves. The set screw members 412, 422 further have second grooves 4122, 4222 that intersect the length direction of the first grooves 4121, 4221. In other words, they have grooves that run across the shaft portions of the set screw members 412, 422. These second grooves 4122, 4222 serve as accommodation portions for accommodating the first fixing members 411, 421.

[0039] FIG. 5 is a schematic diagram illustrating an example of the operation of attaching a fixing member to the lid of a pillar member according to the present invention. Here, an example is described in which a string-shaped member 3 and a first fixing member 41 are attached to a first pillar member 21. The opening of the lid portion 212 of the first pillar member 21 has a female threaded portion. The first fixing member 41 has a male threaded portion that is received in the female threaded portion. The first fixing member 41 is assembled with a first fixing member 411 and a setscrew member 412. This first fixing member 411 is attached to the string-shaped member 3 and housed in the housing of the setscrew member 412. As shown in FIG. 5( a), in this assembled state, the setscrew member 412, which has a male threaded portion, is pushed into the lid portion 212. Then, when the setscrew member 412 is sufficiently pushed in as shown in FIG. 5( b), the first fixing member 411, which was sandwiched in the housing, becomes covered by the female threaded portion of the lid portion 212. This allows the string-like member 3 to be fixed to the first pillar member 21 by the first fixing member 41. By performing the same operation on the second pillar member 22, the string-like member 3 can be fixed to the second pillar member 22 by the second fixing member 42.

[0040] [Extended rod] In this way, the extension rod of the present invention has the configuration of an extension rod connector 10, which combines at least a first pillar member 21 and a second pillar member 22, and combines a string-like member 3 and a first fixing member 41 and a second fixing member 42 to prevent the first pillar member 21 from being let out beyond the length of the second pillar member 22. The extension rod of the present invention can be made to conform in its external shape and use to that of Non-Patent Document 1 (Lumica Co., Ltd.'s "Bi (registered trademark) Rod"). Extension rods usually have multiple pillar members. A configuration equivalent to the extension rod connector 10 may be provided on all or only some of the pillar members of the extension rod.

[0041] While Figure 1 and other figures show the extension rod connector 10 connecting two pole members, the configuration using the extension rod connector 10 of the present invention is also suitable for connecting a larger number of extension rod connectors, allowing multiple extension rod connectors to be connected with a simple operation. The number of connections can be, for example, 3 or more, preferably 5 or more, and more preferably 8 or more. There is no particular upper limit to the number of connections, but for general use, the length of the pole member of each extension rod connector can be optimized to suit the application, and up to about 30 connections, for example, can be assumed.

[0042] Figure 6 is a schematic diagram of an example of a jointed fishing rod according to the present invention. Here, an example of a jointed fishing rod using 10 stages of pole members will be explained. In Figure 6, a thick pole member is placed on the right side for use by the handle, and pole members that become gradually thinner as they move to the left side are used.

[0043] Figure 7 is a schematic diagram illustrating an example of a fixing method for a connecting rod according to the present invention. To prevent each pillar member of a connecting rod like that shown in Figure 6 from falling off, a ring that serves as part of the fixing member is attached to the string-like member at an interval shorter than the length of the thicker pillar member that will become the second pillar member of the adjacent pillar members, in accordance with the length between the adjacent pillar members. As shown in the cross-sectional view at the bottom of Figure 7, this ring is fitted and fixed into the threaded portion of the cover with a set screw that can accommodate the ring, thereby attaching the string-like member to the pillar member via the fixing member. This results in a structure that prevents the pillar members from falling off throughout the entire connecting rod.

[0044] 8 to 10 are related schematic diagrams for making it easier to understand the extension rods shown in FIGS. 7 and 8. FIG. 8 is a schematic diagram for explaining an example of an extension rod according to the present invention. FIG. 9 is a schematic diagram for explaining an example of the procedure for attaching a fixing member to the cover of a pole member according to the present invention. FIG. 10 is a schematic diagram for explaining an example of attaching the end of a hand-held pole member of an extension rod according to the present invention. The tip of the extension rod can be designed to allow any object to be attached, and can be used for work, etc. For example, it can be used as a platform or holder for attaching a camera or the like, for taking photographs at high altitudes, underwater, or remote locations. This extension rod can be used handheld or fixed to a tripod or the like. In addition, the hand-held pole member or the like may be provided with a controller, a holder for attaching a smartphone, or a fixing belt.

[0045] Figure 8 shows the state in which the pole member is stored and the tip pole member is extended. In the stored state, the extension rod of the present invention can be made compact. Figure 9 shows the process of attaching the line to the ring, fitting the ring into a threaded rod-shaped fixing member, and screwing it into the cover of the pole member. Figure 10 shows the state in which it is fixed to the pole member at hand with a shorter threaded rod-shaped fixing member.

[0046] Fig. 11 is an image of a manufacturing example of the first fixing member and the second fixing member according to the present invention. Fig. 12 is an image showing an example of the operation of attaching fixing members to the cover of the pole member according to the present invention. Fig. 13 is an image of a manufacturing example of the connecting body for extension rods according to the present invention.

[0047] In this way, stopper rings are fixed at predetermined positions on nylon or polyethylene threads with a diameter of about 1 to 3 mm, and the rings and thread are sandwiched between them.Then, a screw-type jig is screwed into the lids at the bottom of each rod, facilitating binding of the rods and easy removal for disassembly.In other words, the present invention relates to a method for preventing falling off in which stopper members such as rings or discs are fixed at multiple predetermined positions and then attached in sequence to threaded rods such as so-called set screws with cross notches to bind the bottoms of the rods together. [Industrial Applicability]

[0048] The present invention can be used for extension rods that can be used for high-altitude photography, etc., and is industrially useful. [Explanation of symbols]

[0049] 10. Extension rod connector 21 First pillar member 22 Second pillar member 211, 221 landmarks 222 Lid 223 Clamp 3. String-like member 31 Mounting part 41 First fixing member 42 Second fixing member 411, 421 First fixing member 412, 422 Set screw member 4121, 4221 First groove 4122, 4222 Second groove

Claims

1. A connecting rod having a connecting body for connecting rods that combines a hollow first pillar member and a hollow second pillar member that accommodates at least a part of the first pillar member, a cover member having an opening attached to the first pillar member and the second pillar member; a string-like member disposed inside the first pillar member and the second pillar member; a first fixing member attached to the lid portion of the first pillar member and fixed to the string-like member; a second fixing member attached to the lid portion of the second pillar member and fixed to the string-like member, A joint rod, wherein the length of the string-like member between the first fixing member and the second fixing member is shorter than the length of the second pillar member.

2. the opening of the lid portion has a female thread portion, and the first fixing member and the second fixing member have male thread portions that are received in the female thread portions, the first fixing member and the second fixing member each have a first fixing member that fixes the string-like member and a setscrew member that has an accommodating portion that accommodates the first fixing member, 2. The extension rod according to claim 1, wherein the set screw member has a first groove portion provided along the length direction and a second groove portion intersecting the length direction of the first groove portion, and the second groove portion serves as the accommodation portion for accommodating the first fixing member.

Images