Inner and outer tube integrated structure, method for securing and retaining inner and outer tubes, and tube-shaped sleeve for inner and outer tube integrated structure

Abstract

The present invention is capable of adequately securing and retaining inner and outer tubes (X1, X2) in a simple manner by tightening a fastening screw (48), and comprises: an outer tube (X2) in which a first through-hole (16) and a second through-hole (18) provided with a female thread section (22) are provided to an outer peripheral surface; an L-shaped pressing body (38) comprises a load-bearing member (30) having an oversized hole, and a pressing member (36) that extends from one end of the load-bearing member (30) and is provided with a pressing surface (34); and a fastening screw (48) in which a male screw section (40), a head section provided at one end of the male screw section (40), and a contact surface (46) on the male screw section (40)-side of the head section are formed. The first through-hole (16) is provided such that when the fastening screw (48) is screwed in and the pressing surface (34) presses against the outer peripheral surface (58) of the inner tube (X1), the other end of the load-bearing member (30) is inclined on the inner and outer tube (X1, X2)-side, producing a wedging effect on a corner portion that includes an edge portion (55) of the pressing surface. When the pressing surface (34) is inserted into the first through-hole (16), the circumferential expansion of the outer tube (X2) and the longitudinal expansion of the outer tube (X2) each establish a shape within a prescribed range.

Description

Integrated inner and outer pipe structure, method for fixing and holding the inner and outer pipes, and tubular sleeve for integrated inner and outer pipe structure.

[0001] The present invention relates to an integrated inner and outer pipe structure, a method for fixing and holding the inner and outer pipes, and a tubular sleeve for an integrated inner and outer pipe structure. More specifically, the present invention relates to an integrated inner and outer pipe structure, a method for fixing and holding the inner and outer pipes, and a tubular sleeve for an integrated inner and outer pipe structure, which enable sufficient fixing and holding of the inner and outer pipes with the required fixing and holding force depending on the application, by tightening the fastening screw portion by hand.

[0002] Conventionally, height-adjustable stands using interlocking inner and outer tubes have been used in a wide range of applications, including music stands, medical stands, and holders. Such stands can be broadly classified into two types: one in which a fastening screw is threaded into a screw hole on the outer circumference of the outer tube in a direction intersecting the longitudinal direction of the tubes, and the tip of the screw is pressed against the outer circumference of the inner tube to secure it; and another in which a male thread is provided on the end circumference of the outer tube, and a tubular sleeve with a female thread that screws into the male thread is provided on the inner circumference, and the interlocking part is tightened by screwing into the tubular sleeve. However, in both cases, the fixing of the inner and outer tubes is insufficient, and the applicant of this application has proposed a length adjustment jig for stands that improves upon this problem, as shown in Patent Document 1.

[0003] The length adjustment jig of the present invention is an interposed length adjustment jig between an inner tube and an outer tube that fit together. The outer surface of the outer tube is provided with a pair of through slits spaced apart from each other, and a female screw portion is provided between the pair of through slits. The jig has a pressing portion positioned on the outer surface of the outer tube, passing through the pair of through slits and contacting the outer surface of the inner tube, and a tightening screw portion that can press and fix the pressing portion toward the outer surface of the inner tube. The tightening screw portion has a male screw portion that can be screwed into the female screw portion. After adjusting the fitting position of the inner tube with respect to the outer tube, the male screw portion is screwed into the female screw portion by the tightening screw portion, while the pressing portion passes through the pair of through slits and is pressed and fixed toward the outer surface of the inner tube. Alternatively, a tubular sleeve may be used, which has a female screw portion and a through hole within a predetermined range from the female screw portion on its outer surface and is attached and fixed to the outer surface of one end of the outer tube, and the tubular sleeve may be used to fix and hold the fitting portion of the inner and outer tubes.

[0004] According to the length adjustment jig having the above configuration, a female screw portion provided on the outer surface of the outer tube, at least one through hole within a predetermined range from the female screw portion, and at least one pressing portion that penetrates the through hole from the outer peripheral surface of the outer tube and contacts the outer peripheral surface of the inner tube, and a tightening screw portion capable of pressing and fixing the pressing portion toward the outer peripheral surface of the inner tube, when adjusting the length of the fitting portion of the inner and outer tubes that fit together, the tip surface of the pressing portion is shaped along the outer peripheral surface of the inner tube so as to be capable of surface contact with the outer peripheral surface of the inner tube. After adjusting the fitting position of the inner tube with respect to the outer tube, by rotating the tightening screw portion, while screwing the male screw portion into the female screw portion provided on the outer peripheral surface of the outer tube, by screwing in the tightening screw portion, the pressing portion within a predetermined range from the female screw portion is caused to penetrate the through hole, and the tip surface can be pressed and fixed in a manner of surface contact with the outer peripheral surface of the inner tube. With a simple structure, without requiring excessive tightening force, the overall length of the inner tube and the outer tube can be adjusted to be fixedly held by a simple operation.

[0005] However, the pressing portion is positioned on the outer surface of the outer tube, passing through a pair of through-slits to contact the outer surface of the inner tube. More specifically, the male threaded portion of the tightening screw portion comprises a hole that penetrates in the thickness direction and two pressing legs that extend in opposite directions from the hole portion, forming a pressing body with a roughly U-shaped cross-section. As a result, the following technical problems exist. Firstly, with such a U-shaped pressing body, when tightening by hand using the fastening screw portion, the fixing of the inner and outer tubes becomes insufficient, and in the case of a stand application, music stands, microphones, speakers, etc., supported by a stand with inner and outer tubes extending in the vertical direction may slide down over time. More specifically, the pair of pressing surfaces have two through holes in the outer circumference of the outer tube accordingly, but because they press simultaneously and horizontally against the outer circumference of the inner tube, no wedge effect occurs due to the pressing surfaces, and the pressing force from the pressing surfaces is not increased by the lever principle due to the tightening force toward the outer circumference of the inner tube by the tightening force of the U-shaped plate. It is possible to some extent to increase the tightening force of the fastening screw by increasing the diameter of the head of the fastening screw and making the pitch of the male screw finer, but the use of non-standard fastening screws increases costs, and the tightening itself may loosen over time due to the increased tightening force.

[0006] Secondly, in the case of a conventional type where the inner and outer tubes are fitted together by screwing, it is advantageous to utilize the male threaded portion provided on the outer surface of the outer tube. When a tubular sleeve is provided to fit into the male threaded portion, it is preferable to use resin from the viewpoint of low cost and weight reduction. However, from the viewpoint of ensuring the strength of the tubular sleeve, it is preferable to have a small area and number of through holes provided in the thickness direction from the outer surface of the tubular sleeve. On the other hand, if both the inner and outer tubes are made of resin, if the wedge effect from the pressing surface is too strong, scratches or dents may occur on the outer surfaces of the inner and outer tubes.

[0007] Thirdly, the vertical fixing force at the mating portion between the inner and outer tubes depends on the manner of contact between the inner and outer tubes. The roundness and / or surface smoothness due to the processing of the inner and outer tubes have a significant influence on the vertical fixing force at the mating portion between the inner and outer tubes. In particular, there is variation in the roundness and / or surface smoothness due to the processing of metal inner and outer tubes compared to the molding of resin inner and outer tubes, and the fixing of the inner and outer tubes in the longitudinal direction by screwing in the fastening threads tends to be insufficient.

[0008] In this regard, Patent Document 2 discloses an inner and outer tube fastening device for nested tubes, which is a jig for fitting and fastening an inner tube B and an outer tube A in a nested relationship, and comprises a pressing lever 61, a U-shaped pressing tool 4, and a tubular sleeve 1, and is configured such that when the pressing lever 61 is rotated, a pair of legs of the U-shaped pressing tool 4 pass through a pair of through holes provided on the outer circumferential surface of the outer tube A and are pressed against the outer circumferential surface of the inner tube B. More specifically, a curved receiving plate 2 is provided inside the tubular sleeve 1, and accordingly, an opening complementary in shape to the curved receiving plate 2 is provided on the diametrically opposite side of the pair of through holes on the outer circumferential surface of the outer tube A, and is inserted into the curved receiving plate 2 and pressed against the outer circumferential surface of the inner tube B via the curved receiving plate 2 on the diametrically opposite side of the pair of through holes on the outer circumferential surface of the outer tube A. Furthermore, Patent Document 3 discloses a height adjustment device for an extendable sub-pipe, which is a jig for fitting and tightening an inner pipe 2 and an outer pipe 1 in a nested relationship. It comprises a fastening screw portion 11, a U-shaped pressing tool 9, and a tubular sleeve 4. The male screw portion of the fastening screw portion 11 is inserted through the oversized hole of the U-shaped pressing tool 9 and screwed into the female screw portion provided in the tubular sleeve 4. This configuration allows a pair of legs of the U-shaped pressing tool 9 to pass through a pair of through holes 8 provided on the outer surface of the outer pipe 1 and be pressed against the outer surface of the inner pipe 2.

[0009] Furthermore, Patent Document 4 discloses a fastening device for the inner and outer tubes of a telescopic pipe, relating to Figures 1 to 3, which comprises an outer tube A, an inner tube B, a ring 1 with a male threaded portion 3, a U-shaped member 4 with a clearance hole, a nut 5 that can be screwed onto the male threaded portion 3, and an arc-shaped member 2 that can be positioned inside the opening of the outer tube A. When the nut 5 is tightened, the U-shaped member 4 is pushed in the direction of the outer tube A, and its leg ends 4, 4 are pressed against the outer surface of the outer tube A, creating a tensioning force between the U-shaped member 4 and the screw 3, causing the screw 3, ring 1, and arc-shaped member 2 to be pulled together in the direction of the U-shaped member 4. It is stated that, as a result, the surface of the arc-shaped member 2 contacts the outer surface of the inner tube B, and the inner tube B is pressed and clamped by the arc-shaped member 2 and the inner wall surface of the outer tube opposite to the member 2, thereby being tightly fastened together with the outer tube A. The U-shaped member 4 is used to fasten the inner and outer tubes of the telescopic tube, but it is not disclosed, or even suggested, that the U-shaped member 4 is pressed and fixed to the outer surface of the inner tube in a manner that makes surface contact with the outer surface of the inner tube, while the outer surface of the inner tube on the opposite side of the surface contact portion with the inner tube is directly pressed and fixed to the inner surface of the outer tube. Furthermore, Patent Document 5 discloses a retractable rod structure in which an inner pipe 2 and an outer pipe 3 are fitted together via a sleeve 41 so as to be length adjustable, an annular shoulder is formed on the inner circumferential surface of the sleeve 41, the annular shoulder is placed on the annular end face EN of the outer pipe 3, and two positioning bolts 4112 and fixing bolts 4122 are screwed into through holes in the sleeve 41, so that one positioning bolt 4112 fixes the inner pipe 2, while the fixing bolt 4122 fixes the outer pipe 3. However, in Patent Document 5, an elastic engagement plate 42 is fitted into a groove provided on the inner circumferential surface of the sleeve 41, and the positioning bolt 4112 fixes the inner pipe 2 via the elastic engagement plate 42, not directly fixing the inner pipe 2, and the positioning bolt and fixing bolt are provided separately.Furthermore, while Patent Document 5 discloses an annular shoulder on the inside of a sleeve 41 corresponding to a tubular sleeve, it only discloses that the annular end face EN of the outer pipe is brought into contact with the annular shoulder of the sleeve 41 in order to position the sleeve 41 relative to the outer pipe 3. On the other hand, it discloses that the sleeve is fixed to the inner pipe 2 with a separate bolt 4122 before the positioning bolt 4112 is fastened. It does not disclose, or even suggest, that the sleeve is rotated axially to a desired position in the circumferential direction, that is, that the annular shoulder of the sleeve 41 is placed on the annular end face EN of the outer pipe and the tubular sleeve is rotated around the axial direction to a desired position in the circumferential direction. Furthermore, the fixation of the tubes in the elongation direction at the fitting portion of the inner and outer tubes depends on the frictional force based on the coefficient of friction between the outer surface of the inner tube and the inner surface of the outer tube. In particular, in the case of metal inner and outer tubes, even if the inner and outer tubes are made of the same material, the frictional force fluctuates depending on machining errors such as roundness and surface smoothness treatment, which can lead to unstable fixation and holding of the tubes in the elongation direction depending on the inner and outer tubes. In this sense, there is a need for stable fixation and holding of the inner and outer tubes in the elongation direction that is not affected by machining errors of the inner and outer tubes. Patent No. 7369944, Utility Model Publication No. 54-69633, Utility Model Publication No. 58-89605, Utility Model Publication No. 51-71610, U.S. Patent Application Publication 2012-0001416.

[0010] In view of the above technical problems, the object of the present invention is to provide an integrated inner and outer pipe structure, a method for fixing and holding the inner and outer pipes, and a tubular sleeve for an integrated inner and outer pipe structure, which enable sufficient fixing and holding of the inner and outer pipes with the required fixing and holding force depending on the application, by tightening the fastening screw part by hand.

[0011] To achieve the objectives of the present invention, the integrated inner and outer pipe structure of the present invention is an integrated inner and outer pipe structure in which inner and outer pipes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer pipe, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and when the pressing member penetrates the first through hole, the pressing surface presses against the outer surface of the inner tube as the load-receiving surface receives a pressing load through the pressing surface by screwing in the fastening threaded portion, The first through-hole is provided on the outer surface of the outer tube so as to straddle the longitudinal direction of the outer tube passing through the center of the female thread portion of the outer tube on the outer surface of the outer tube, so that a clearance is formed between the pressing surface of the pressing member and the inner circumferential surface of the first through-hole, causing the other end of the load-receiving member to be inclined toward the outer circumferential surface of the inner and outer tubes, and a wedge effect is generated at the corner including the edge of the pressing surface that is inclined toward the outer circumferential surface of the inner and outer tubes, and the pressing surface is set to a shape such that when inserted into the first through-hole, the circumferential and longitudinal spreads of the outer tube are each within a predetermined range.

[0012] To achieve the objectives of the present invention, the integrated inner and outer pipe structure of the present invention is an integrated inner and outer pipe structure in which inner and outer pipes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer pipe, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and as the pressing member passes through the first through hole while the load-receiving surface receives a pressing load through the pressing surface when the fastening threaded portion is screwed in, the pressing surface presses against the outer circumferential surface of the inner tube, and a clearance is formed between the one flat portion of the pressing member on the load-receiving member side and the inner circumferential surface of the first through hole, causing the other end of the load-receiving member to be inclined toward the outer circumferential surface of the inner and outer tubes, and the other flat portion to contact the inner circumferential edge of the first through hole, thereby increasing the pressing force against the outer circumferential surface of the inner tube at the edge of the one flat portion of the pressing surface by the principle of leverage, and the width between the two ends of the pressing surface and / or the position of the clearance hole in the load-receiving member are set accordingly.

[0013] To achieve the objectives of the present invention, the integrated inner and outer pipe structure of the present invention is an integrated inner and outer pipe structure in which inner and outer pipes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer pipe, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and when the pressing member penetrates the first through hole, the pressing surface presses against the outer surface of the inner tube as the load-receiving surface receives a pressing load through the pressing surface by screwing in the fastening threaded portion, The configuration is such that, by forming a clearance between the one flat portion of the pressing member on the load-receiving member side and the inner circumferential surface of the first through-hole, the other end of the load-receiving member is inclined toward the outer circumferential surface of the inner and outer tubes, and the other flat portion contacts the inner circumferential edge of the first through-hole. This creates a wedge effect at the corner of the pressing surface including the edge that is inclined toward the outer circumferential surface of the inner and outer tubes, and increases the pressing force against the outer circumferential surface of the inner tube at the edge of the one flat portion of the pressing surface due to the lever principle. Thus, in order to ensure the fixed holding of the inner and outer tubes under a given weight of the object to be supported, the width between the edges of both ends of the pressing surface and / or the position of the over-hole on the load-receiving member are set while the wedge effect is exerted by the magnitude of the inclination angle of the L-shaped pressing body according to the clearance between the outer circumferential surface of the inner tube and the inner circumferential surface of the outer tube.

[0014] In the integrated inner and outer tube structure having the above configuration, when the inner and outer tubes are fitted together to form an integrated structure, the degree of fixing and holding at the fitting portion becomes an issue depending on the application, such as a music stand, microphone stand or other music stand, or an IV stand, monitor stand or other medical stand. However, a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer tube, and a female thread portion is provided on the inner circumferential surface of the second through hole. Using the L-shaped cross-sectional pressing body and fastening screw portion, the load-receiving member of the pressing body is inserted into the first through hole from the pressing surface at the tip, and the load-receiving surface receives the pressing load as the fastening screw portion is screwed in, and as the pressing surface presses against the outer circumferential surface of the inner tube, a clearance is formed between one flat portion of the pressing body on the first through hole side and the first through hole, so that the other end of the load-receiving member is inside The first through-hole is provided on the outer surface of the outer tube, straddling the longitudinal direction of the outer tube passing through the center of the female thread portion of the outer tube, so as to be inclined toward the outer circumferential surface of the outer tube, creating a wedge effect on the clearance side of the pressing surface, and increasing the pressing force by the fastening screw portion by the lever principle with the part opposite to the clearance side of the pressing surface as the fulcrum, the load-receiving surface as the point of effort, and the part on the clearance side of the pressing surface as the point of application. The thickness of the load-receiving member and / or the size of the first through-hole are set accordingly, and the pressing surface is shaped so that when inserted into the first through-hole, the circumferential and longitudinal spreads of the outer tube are within predetermined ranges. Thus, depending on the application, the inner and outer tubes can be easily and sufficiently fixed and held with the required fixing force by tightening the fastening screw portion 48 by hand.

[0015] Furthermore, a tubular sleeve is provided at the end of the outer tube on the side where it fits with the inner tube, which can be fitted onto the outer surface of the outer tube and through which the inner tube can pass. The first and second through holes are provided in the thickness direction from the outer surface of the tubular sleeve. Moreover, the pressing body is used to penetrate the first through hole, and the pressing surface is brought into surface contact with the outer surface of the outer tube or the tubular sleeve. The outer surface of the inner tube opposite to the surface contact portion of the pressing surface with the inner tube is pressed and fixed against the inner surface of the outer tube or the tubular sleeve. Furthermore, the pressing surface is made hard enough not to deform when pressed against the outer surface of the inner tube, and the pressing surface is formed to follow the outer surface of the inner tube. In addition, the inner and outer tubes are arranged so that the inner tube is at the top and the outer tube is at the bottom, extending in the vertical direction, and the fitting portions of the inner and outer tubes are both made of a circular cross-section.

[0016] Furthermore, the inner tube and the outer tube are both cylindrical in shape, and the outer surface of the inner tube is pressed against and fixed to the inner surface of the outer tube by pressing the outer surface of the inner tube on the opposite side of the pressing and fixing portion against the inner surface of the outer tube in a vertical line contact manner, thereby fixing and holding the outer tube to the inner tube by support at two points. Furthermore, the load-receiving surface is preferably formed as an annular projection around the clearance hole. Moreover, the load-receiving surface is preferably formed as a projection on the end side of the load-receiving member. In addition, the load-receiving member and the pressing member are preferably provided so as to be perpendicular to each other. Furthermore, the oversized hole is provided on the other end side of the load-receiving member, and the tubular sleeve is provided with a through hole having a female thread on its inner circumferential surface, such that a male thread can be screwed into the through hole via the oversized hole, and the length of the male thread is set so that the tip of the male thread does not come into contact with the outer circumferential surface of the inner tube when screwing. Furthermore, the overall planar shape of the pressing surface is preferably an inverted U shape that opens toward the second through hole and is passable through the first through hole, and is provided around the second through hole. Furthermore, the overall planar shape of the pressing surface is preferably an inverted V shape that opens toward the second through hole and is passable through the first through hole, and is provided around the second through hole. In addition, the overall planar shape of the pressing surface is preferably an L shape that is passable through the first through hole, and is provided around the second through hole.

[0017] Furthermore, the overall planar shape of the pressing surface is preferably elongated horizontally, passing through the center of the second through-hole and allowing it to penetrate the first through-hole. Moreover, the pressing member is preferably having a constant cross-section in the longitudinal direction, with its tip surface forming the pressing surface. Furthermore, the inverted U-shaped and inverted V-shaped pressing surfaces are preferably arranged symmetrically with respect to the longitudinal direction of the inner and outer pipes passing through the center of the female screw. In addition, the inverted U-shaped pressing surface is preferably arranged concentrically with respect to the second through-hole.

[0018] Furthermore, the first through-hole and the second through-hole are preferably provided parallel to each other and at a predetermined angle with respect to the extension direction of the inner and outer tubes or the tubular sleeve. Moreover, while the first through-hole is provided at a predetermined angle with respect to the extension direction of the inner and outer tubes or the tubular sleeve, the second through-hole is preferably set perpendicular to the outer circumferential surface of the outer tube or the tubular sleeve. Furthermore, the fastening screw portion has a shank portion and a male screw portion extending downward from the lower surface of the shank portion, and an annular surface is formed on the lower surface surrounding the male screw portion, and by screwing the male screw portion into the female screw portion through the clearance hole, the lower surface of the shank portion and the load-receiving surface of the pressing body come into contact, thereby pressing and fixing the fastening screw portion and the pressing body together to the inner tube and screwing and fixing them to the outer tube. In addition, the tightening screw portion preferably has a head portion at the end of the shank portion opposite to the male screw portion end, which can be gripped and rotated with fingers.

[0019] Furthermore, it is preferable that the fastening of the fastening screw portion prevents rotation of the inner and outer tubes of the tubular sleeve about the longitudinal direction of the inner and outer tubes, while fixing and holding the inner and outer tubes in a predetermined fitting position. Moreover, it is preferable that the longitudinal length of the tubular sleeve and / or the length of the load-receiving member be set such that the tip of the male screw portion of the fastening screw portion directly presses against the outer circumferential surface of the outer tube. Furthermore, it is preferable that the maximum inclination angle in which the other end of the load-receiving member of the pressing body approaches the outer tube or the outer circumferential surface of the tubular sleeve when the fastening screw portion is fastened is set by the thickness of the tubular sleeve and / or the clearance between the outer circumferential surface of the inner tube and the inner circumferential surface of the outer tube and / or the clearance between the pressing surface and the first through hole. In addition, it is preferable that a male screw is provided on the side circumferential surface of one end of the outer tube, and a female screw that can be screwed into the male screw is provided on the inner circumferential surface of the tubular sleeve.

[0020] Furthermore, the load-receiving member and the pressing member are provided at an obtuse angle, and the clearance hole is preferably provided closer to the other end of the load-receiving member. Moreover, an annular shoulder is formed on the inner circumferential surface of the tubular sleeve, the width of the annular shoulder is large enough to rest on the annular end face EN of the outer tube, and the tubular sleeve is preferably rotatable around its longitudinal direction. Furthermore, it is preferable that the stand is for music use and supports a music stand, musical instrument, speaker, or amplifier with the end of the inner tube or outer tube opposite to the fitting portion of the inner and outer tubes. In addition, it is preferable that the stand is for medical use and supports an IV drip, monitor, or lighting with the end of the outer tube or inner tube opposite to the fitting portion of the inner and outer tubes, making it movable. Furthermore, it is preferable to set the diameter of the head and the diameter and / or pitch of the male thread portion so that the inner and outer tubes are sufficiently fixed and held in place by tightening the fastening screw portion by hand. In addition, it is preferable to increase the tightening force by the lever principle using the fastening screw portion by setting the ratio of the clearance between the other flat portion of the pressing member and the center of the clearance hole and the distance between the other flat portion of the pressing member and the center of the second through hole.

[0021] To solve the above problems, the present invention provides an integrated inner and outer tube structure in which inner and outer tubes, both extending in the vertical direction, are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer tube, the second through hole has a female thread on its inner circumferential surface, a load receiving member having opposing flat surfaces, one of the flat surfaces having a load receiving surface, and a clearance hole penetrating through the thickness direction between the opposing flat surfaces, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat surfaces, and having a pressing surface at its tip, and having an L-shaped cross-sectional shape, the pressing member having a length at least longer than the depth of the first through hole, and the clearance hole being provided in the load receiving member at a position where the male thread can be screwed into the female thread when the pressing member is inserted into the first through hole, and further having a pressing lever having an annular circumferential surface that rotates about an axis parallel to the load receiving surface while in contact with the load receiving surface, The annular circumferential surface is curved in such a way that the radius from the axis changes from a first radius to a second radius as it expands, and the pressing body is movable in the thickness direction of the first through-hole within the first through-hole by the rotation of the pressing lever, and by rotating the pressing lever about an axis provided at a predetermined height from the outer circumferential surface of the outer tube, the pressing body begins to press toward the outer circumferential surface of the inner tube at a rotation position corresponding to an intermediate radius between the first and second radii, and ends pressing toward the outer circumferential surface of the inner tube at a rotation position corresponding to the second radius, bringing the pressing surface into surface contact with the outer circumferential surface of the inner tube, and pressing and fixing the outer circumferential surface of the inner tube on the opposite side of the surface contact portion of the pressing surface with the inner tube against the inner circumferential surface of the outer tube.As the pressing lever rotates, the load-receiving surface receives a pressing load via the pressing surface, and the pressing member penetrates the first through-hole, pressing the pressing surface against the outer circumferential surface of the inner tube. This creates a clearance between the one flat portion of the pressing member on the first through-hole side and the inner circumferential surface of the first through-hole, causing the other end of the load-receiving member to tilt toward the outer circumferential surface of the inner and outer tubes, resulting in a wedge effect at the corner of the pressing surface including the edge of the one flat portion. The first through-hole is provided on the outer circumferential surface of the outer tube, straddling the longitudinal direction of the outer tube passing through the center of the female thread portion of the outer tube. The pressing surface is configured such that, when inserted into the first through-hole, the circumferential and longitudinal expansion of the outer tube are both within predetermined ranges.

[0022] To solve the above problems, the present invention provides a method for fixing and holding inner and outer tubes, comprising: a step of preparing a load-receiving member having a load-receiving surface and a clearance hole, a pressing member extending from one end of the load-receiving member toward the opposite side of the load-receiving surface and having a pressing surface at its tip, a pressing body having an L-shaped cross-section, a tubular sleeve having a first through hole and a second through hole on its outer circumference, the second through hole having a female thread on its inner circumference, and a fastening screw portion having a male thread that can be screwed into the female thread and having a pressing surface that can contact the load-receiving surface; a step of fitting the tubular sleeve having a circular cross-section on its inner circumference onto the upper end of the outer tube; a step of fitting the inner tube into the tubular sleeve or the outer tube; and a step of rotating the tubular sleeve around the longitudinal direction of the outer tube to a desired rotational position. The configuration includes the steps of: tightening the fastening screw portion to press the inner tube toward the outer surface of the inner tube from the outside of the tubular sleeve in the thickness direction of the tubular sleeve, thereby fixing the tubular sleeve to a desired rotational position around the longitudinal direction of the outer tube, while pressing the outer surface of the inner tube opposite to the tubular sleeve or the inner surface of the outer tube, thereby fixing and holding the inner and outer tubes together in the longitudinal direction; and the fixing and holding step further includes the step of creating a clearance between the one flat portion of the pressing member on the second through-hole side and the second through-hole, causing the other end of the load-receiving member to be inclined toward the outer surface of the inner and outer tubes, creating a wedge effect in the clearance side portion of the pressing surface, and increasing the pressing force by the fastening screw portion by the lever principle.

[0023] Furthermore, it is preferable to further include the step of fixing the tubular sleeve at a desired rotational position around the longitudinal direction of the outer tube by pressing the outer circumferential surface of the outer tube from the outside of the tubular sleeve toward the outer circumferential surface in the thickness direction of the tubular sleeve, while pressing the outer circumferential surface on the opposite side of the outer tube toward the inner circumferential surface of the tubular sleeve to fix and hold the inner and outer tubes together in the longitudinal direction. Moreover, the inner circumferential surface of the tubular sleeve is provided with a reduced diameter portion set to be larger than the diameter of the inner tube and an expanded diameter portion set to be larger than the diameter of the outer tube, and an annular shoulder portion is formed at the connection between the reduced diameter portion and the expanded diameter portion, and it is preferable to place the annular shoulder portion on the annular upper end surface of the outer tube and rotate the tubular sleeve at a desired rotational position around the longitudinal direction of the outer tube.

[0024] To solve the above problems, the integrated inner and outer pipe structure of the present invention is an integrated inner and outer pipe structure in which the inner and outer pipes are fitted together, wherein a through hole is provided on the outer circumferential surface near one end of the fitting portion side of the outer pipe, with a female thread portion formed on the inner circumferential surface, and the pressing body has a shape that can be inserted into the through hole, with a load-receiving surface on one end face and a pressing surface against the outer circumferential surface of the inner pipe formed on the other end face, and the pressing body has a male thread portion that can be screwed into the female thread portion, and a head portion provided at one end of the male thread portion, with a fastening screw portion having a push-in surface that can contact the load-receiving surface formed on the male thread portion side of the head portion, the pressing body has a length shorter than the depth of the through hole, and when the fastening screw portion is screwed in, the tip surface of the male thread portion rotates around the longitudinal direction of the male thread portion, without co-rotation, and the load-receiving surface receives a pressing load, and the pressing body presses against the outer circumferential surface of the inner pipe in a tight-fitting manner through the through hole.

[0025] In an integrated inner and outer tube structure having the above configuration, when the inner and outer tubes are fitted together to form an integrated structure, the degree of fixed retention at the fitting portion becomes an issue depending on the application, such as a music stand, microphone stand or other music stand, or an IV stand, monitor stand or other medical stand. A through hole is provided on the outer circumference near one end of the outer tube on the fitting portion side, with a female thread formed on the inner circumference. A pressing body has a shape that can be inserted into the through hole, with a load-receiving surface on one end face and a pressing surface against the outer circumference of the inner tube on the other end face, and a pressing body having a length shorter than the depth of the through hole can be screwed into the female thread. The fastening screw portion has a male threaded portion and a head portion provided at one end of the male threaded portion, with a pressing surface formed on the male threaded portion side of the head portion that can contact the load-receiving surface. By screwing in the fastening screw portion, the tip surface of the male threaded portion rotates around the longitudinal direction of the male threaded portion, without co-rotation, and the load-receiving surface receives the pressing load. The pressing body presses against the outer surface of the inner tube in close contact with it through the through hole. Depending on the application, the inner and outer tubes can be fixed and held with the required fixing force by tightening the fastening screw portion manually, making it possible to easily and sufficiently fix and hold the inner and outer tubes.

[0026] Furthermore, the flexible pressing body, which can be inserted into the second through-hole, preferably has hardness such that the pressing surface can be deformed into a shape that conforms to the outer surface of the inner tube by screwing in the fastening screw portion.

[0027] To solve the above problems, the present invention provides a tubular sleeve for an integrated inner and outer structure, which is a tubular sleeve that can be fitted onto the outer surface of the outer tube and through which the inner tube can pass, at the end of the outer tube on the fitting portion side with the inner tube, and has a first through hole and a second through hole on the outer surface near one end, the second through hole has a female thread on its inner surface, and further comprises a load-receiving member having opposing flat surfaces, one of which has a load-receiving surface, and a clearance hole that penetrates in the thickness direction between the opposing flat surfaces, and a pressing member having a pressing surface at its tip that extends from one end of the load-receiving member toward the opposite side of the load-receiving surface, has opposing flat surfaces, penetrates the first through hole and can be pressed against the outer surface of the inner tube, and has an L-shaped cross-sectional pressing body, and has a male thread that can be screwed into the female thread, and a head provided at one end of the male thread, the head having a pressing surface that can contact the load-receiving surface.

[0028] Furthermore, it is preferable that a male thread is provided on the outer circumferential surface of one end of the outer tube, and a female thread that can be screwed onto the male thread is provided on the inner circumferential surface of the tubular sleeve.

[0029] A first embodiment of the integrated inner and outer tube structure 10 of the present invention will be described in detail below, using a music stand as an example, with reference to the drawings. As shown in Figures 1 to 8, the integrated inner and outer tube structure 10 fixes and holds an inner tube X1 and an outer tube X2 that fit together in the longitudinal direction of the tubes, and is generally composed of an inner tube X1 and an outer tube X2, a tubular sleeve 54 attached and fixed to the outer circumferential surface of one end of the outer tube X2, a pressing body 38 having a pressing surface 34 that can be pressed against the outer circumferential surface 58 of the inner tube X1 from the outer circumferential surface 56 side of the tubular sleeve 54, and a fastening screw portion 48 that can press and fix the pressing body 38 toward the outer circumferential surface 58 of the inner tube X1. The length, thickness, and cross-sectional shape of the inner tube X1 and outer tube X2 are selected according to the application, and as will be described later, the fitting length of the inner tube X1 and outer tube X2 is adjusted so that the overall length of the inner tube X1 and outer tube X2 is adjusted.

[0030] For example, the inner tube X1 and the outer tube X2 are both hollow cylindrical in shape, and the outer tube X2 is fitted onto the inner tube X1 by inserting the inner circumferential surface 60 of the outer tube X2 into the outer circumferential surface 58 of the inner tube X1 through the opening at one end. From the viewpoint of fitting the outer tube X2 onto the inner tube X1, the outer tube X2 needs to be hollow, but it does not necessarily need to have a circular cross-section. On the other hand, the inner tube X1 does not need to be hollow and may be solid, for example, from the viewpoint of ensuring strength. When fitting the outer tube X2 and the inner tube X1, a small clearance C1 may be provided between the inner circumferential surface 60 of the outer tube X2 and the outer circumferential surface 58 of the inner tube X1, as long as the outer tube X2 is fixed and held longitudinally relative to the inner tube X1 via the pressing body 38 by the fastening screw portion 48, as will be explained later. The small clearance C1 is, for example, 0.05 mm to 0.1 mm.

[0031] As shown in Figures 2 to 4, a first through-hole 16 is provided on the outer circumferential surface 56 of the tubular sleeve 54, and a female threaded portion 22 is provided adjacent to the first through-hole 16. The distance between the two can be selected according to the application of the integrated inner and outer pipe structure 10, as will be explained later. More specifically, the tubular sleeve 54 is a hollow cylindrical shape that can be fitted onto one end of the outer pipe X2 from one end, and the inner pipe X1 is inserted into the other end with a predetermined clearance from the inner circumferential surface 57 of the tubular sleeve 54. The tubular sleeve 54 is preferably made of metal, is hollow cylindrical, and the diameter of the inner circumferential surface is set to be at least larger than the inner diameters of the inner pipe X1 and the outer pipe X2, but the outer shape is not necessarily cylindrical, and may be, for example, cocoon-shaped with a diameter that widens in the center. The thickness th and longitudinal length L3 of the tubular sleeve 54 can be set appropriately, as long as it is possible to fix and hold the inner tube X1 and outer tube X2, which fit together, in the longitudinal direction of the tube, for example, a few millimeters or a few centimeters.

[0032] The tubular sleeve 54 is composed of a first fitting portion 53 that extends from one end toward the outer tube X2 and whose inner circumferential surface 57 is fitted onto the outer tube X2 with a first predetermined clearance facing the outer circumferential surface 50 of the outer tube X2, and a second fitting portion 55 that extends from one end toward the inner tube X1 and whose inner circumferential surface is fitted onto the inner tube X1 with a second predetermined clearance facing the outer circumferential surface of the inner tube X1. The first through hole 16 is provided in the first fitting portion 53, and the diameter of the second fitting portion 55 is set to be smaller than the diameter of the first fitting portion 53. The second fitting portion 55 constitutes a reduced diameter portion, and the first fitting portion 53 constitutes an enlarged diameter portion. An annular shoulder portion 94 is formed at the connection between the first fitting portion 53 and the second fitting portion 55, and the annular shoulder portion 94 can be placed on the annular end face EN of the outer tube X2. The clearance between the inner circumferential surface 57 of the tubular sleeve 54 and the outer circumferential surface 58 of the inner tube X1, the clearance between the inner circumferential surface 57 of the tubular sleeve 54 and the outer circumferential surface 50 of the outer tube X2, and the clearance C1 between the inner tube X1 and the outer tube X2 can be determined, for example, from a viewpoint appropriate for use as a music stand, and are all, for example, 0.5 mm to 1 mm. Alternatively, by adjusting the width of the annular shoulder portion 94 and adjusting the vertical positional relationship between the inner tube X1 and the outer tube X2, the clearance C1 between the inner tube X1 and the outer tube X2 can be eliminated, and by tightening the fastening screw portion 48, the outer circumferential surface 58 of the inner tube X1 may be pressed and fixed against the inner circumferential surface 60 of the outer tube X2 together with the inner circumferential surface 57 of the tubular sleeve 54. As a variation, a male thread may be provided on the circumferential surface of one end of the outer tube X2, and a female thread that can be screwed into the male thread may be provided on the inner circumferential surface of the tubular sleeve 54, and the upper end level of the tubular sleeve 54 can be adjusted according to the amount the tubular sleeve 54 is screwed into the outer tube X2.

[0033] The first through-hole 16 is provided so as to extend radially through the inner and outer tubes X1 and X2. More specifically, the first through-hole 16 is an elongated opening, and the width of the opening only needs to be such that the pressing member 36 of the pressing body 38 can pass through in the thickness direction. As will be explained later, the pressing body 38 is fastened and fixed to the outer tube X2 via the fastening screw portion 48, so the pressing body 38 does not need to pass through the first through-hole 16 provided on the outer circumferential surface 50 of the outer tube X2 in an interlocking manner, and a clearance is allowed between the periphery of the first through-hole 16 and the outer circumferential edge of the pressing body 38.

[0034] As shown in Figure 5, the pressing body 38 is positioned on the outer circumferential surface 56 of the tubular sleeve 54, passes through the first through hole 16, and contacts the outer circumferential surface 58 of the inner pipe X1. More specifically, the pressing body 38 has an L-shaped side cross-section along the center line, and comprises a load-receiving member 30 having opposing flat surfaces 43, a load-receiving surface 26 on one of the flat surfaces 43A, and a clearance hole 28 that penetrates the thickness direction between the opposing flat surfaces 43, and a pressing member 36 extending from one end 32 of the load-receiving member 30 toward the opposite side of the load-receiving surface 26, having opposing flat surfaces 41, and having a pressing surface 34 at its tip, and the load-receiving member 30 and the pressing member 36 are provided to be perpendicular to each other. The pressing member 36 has a length at least longer than the depth of the first through hole 16, and the oversized hole 28 is provided in the load-receiving member 30 at a position that allows the male threaded portion 40 to be screwed into the female threaded portion 22 when the pressing member 36 is inserted into the first through hole 16. An oversized hole 68 is provided on the other end 33 side of the load-receiving member 30, and the tubular sleeve 54 is provided with a through hole 66 having a female threaded portion on its inner circumferential surface, so that the male threaded portion 70 can be screwed into the through hole 66 via the oversized hole 68. The length of the male threaded portion 70 is set so that the tip of the male threaded portion 70 does not come into contact with the outer circumferential surface 58 of the inner pipe X1 when screwing it in. This makes it possible to prevent the pressing body 38 from falling off when the fastening screw portion 48 is completely detached from the female screw portion 22, and the tightening force of the male screw portion 70 can be set from this perspective, and the diameter of the male screw portion 70 may be smaller than the diameter of the male screw portion 40. As a modified example, as shown in Figure 35, the clearance hole 28 through which the male screw portion 40 of the fastening screw portion 48 can pass does not have to be composed of a closed inner circumferential surface that penetrates in the thickness direction of the load-receiving member 30, as shown in Figure 5, but may be an open clearance hole 28 as long as it is a passage zone for the male screw portion 40 of the fastening screw portion 48, rather than being composed of a closed inner circumferential surface as shown in Figure 35.

[0035] The pressing surface 34 has sufficient hardness to not deform when pressed against the outer surface 58 of the inner tube X1, and is curved to conform to the outer surface 58 of the inner tube X1 so that it can make surface contact with the outer surface 58 of the inner tube X1. For example, if the outer surface 58 of the inner tube X1 is the outer surface of a cylinder, the cross-section of the pressing surface 34 will be an arc shape with a diameter equal to that. In this case, unlike the fastening screw portion 48, the pressing body 38 itself does not need to be rotated toward the outer surface 58 of the inner tube X1, so the pressing surface 34 can be pressed against the outer surface 58 of the inner tube X1 with its arc-shaped cross-section facing the outer surface 58 of the inner tube X1. The load-receiving surface 26 is formed as an annular projection circumferential surface around the clearance hole 28. The width of the annular projection circumferential surface is set such that when the fastening screw portion 48 is screwed in, the pressing surface 46 comes into contact with the load-receiving surface 26, the pressing load is transmitted to the pressing body 38 via the load-receiving surface 26, and the pressing surface 34 can be pressed against the outer circumferential surface 58 of the inner pipe X1. As an alternative, the load-receiving surface 26 may be formed as a projection surface on the end side of the load-receiving member 30.

[0036] As the fastening screw portion 48 is screwed in, the load-receiving surface 26 receives a pressing load, and the pressing member 36 passes through the first through hole 16, causing the pressing surface 34 to press against the outer surface 58 of the inner pipe X1, the side of the pressing member 36 to the first through hole 16 The first through-hole 16 is provided on the outer surface 50 of the outer tube X2 so as to straddle the longitudinal direction of the outer tube X2 passing through the center of the female thread portion 22 of the outer tube X2, thereby setting the thickness t2 of the load-receiving member 30 and / or the size of the first through-hole 16, and setting the shape of the pressing surface 34 such that when inserted into the first through-hole 16, the circumferential and longitudinal spreads of the outer tube X2 are within predetermined ranges. Each of the inner tube X1 and outer tube X2 is cylindrical. The pressing and fixing of the inner tube X1 and outer tube X2 via the tubular sleeve 54 is achieved by pressing the outer circumferential surface 58 of the inner tube X1 on the opposite side of the pressing and fixing portion by the pressing surface 34 against the inner circumferential surface 57 of the second outer part 57 of the tubular sleeve 54 in a vertical line contact manner, thereby fixing and holding the outer tube X2 to the inner tube X1 with support at two points. As a modified example, if there is no risk of damaging or denting the outer circumferential surface 50 due to the material and surface treatment of the outer tube X2, the longitudinal length L3 of the tubular sleeve 54 or the length L2 of the load-receiving member 30 may be set so that the tip of the male threaded portion 40 of the fastening screw portion 48 directly presses against the outer circumferential surface 50 of the outer tube X2.

[0037] The overall planar shape of the pressing surface 34 (hereafter, meaning the projected shape onto a plane) is an inverted U-shape that opens toward the second through-hole 18 and is passable through the first through-hole 16, and is arranged concentrically around the second through-hole 18. The width WD of the strip is constant and set to ensure a desired clearance between it and the first through-hole 16, and the arc length of the strip can be determined from the viewpoint of the wedge effect or lever principle described later, and is at most semicircular. As a modification, the overall planar shape of the pressing surface 34 may be an inverted V-shape that opens toward the second through-hole 18 and is passable through the first through-hole 16, and may be provided around the second through-hole 18. The inverted U-shaped and inverted V-shaped pressing surfaces 34 are each arranged symmetrically with respect to the longitudinal direction of the inner and outer tubes X1 and X2 passing through the center of the female screw portion 22. Regarding the overall planar shape of the pressing surface 34 of the L-shaped pressing body 38, it is preferable that the pressing surface 34 of the L-shaped pressing body 38 be a reverse U-shaped band composed of a pair of parallel linear parts and a curved part connecting one end of each of the linear parts. However, each of the pair of linear parts does not have to be straight, and as long as it is possible to fix and hold the inner and outer tubes X1 and X2 in the vertical direction, for example, it may be composed entirely of curved shapes as part of an ellipse as a whole. In order to fix and hold the inner and outer tubes X1 and X2 in the vertical direction and to prevent relative rotation of the inner and outer tubes X1 and X2 about the longitudinal direction of the tubes, it is preferable that the overall planar shape of the pressing surface 34 of the L-shaped pressing body 38 be a quarter-circumference band concentric with the female screw part, with one end on the longitudinal direction of the tube and the other end on the circumferential direction of the tube. Alternatively, it may be an L-shaped band composed of a vertical linear part extending in the longitudinal direction of the tube around the female screw part and a horizontal linear part extending in the circumferential direction of the tube from one end of the vertical linear part. The overall length, width, and distance from the female thread portion of the strip can all be selected as appropriate. As a further modification, the overall planar shape of the pressing surface 34 may be L-shaped, allowing it to penetrate the first through hole 16, and may be provided around the second through hole 18.In this case, by arranging the L-shape so that one end extends in the longitudinal direction of the inner and outer tubes X1 and X2 next to the female screw portion 22, and the other end extends in the circumferential direction of the inner and outer tubes X1 and X2 below the female screw portion 22, similar to the inverted U-shape and inverted V-shape, the other end of the L-shape functions to fix and hold the inner and outer tubes X1 and X2 in the vertical direction, while the other end of the L-shape functions to suppress relative rotation of the inner and outer tubes X1 and X2 around the longitudinal direction of the tubes, making it possible to effectively use it for applications such as a spearhead. As a further modification, the overall planar shape of the pressing surface 34 may be a transversely elongated shape that passes through the center of the second through hole 18 and is passable through the first through hole 16, traversing the longitudinal direction of the tube. The pressing member 36 has a rectangular cross-section, and a pressing surface 34 is formed on its end face. However, as a modification, as long as the desired clearance can be secured, only the end of the pressing member 36 that forms the pressing surface 34 may be formed in a tapered and wide shape toward the pressing surface 34, provided that it can pass through the first through hole 16.

[0038] As shown in Figure 6, the fastening screw portion 48 is configured to press and fix the pressing body 38 toward the outer circumferential surface 58 of the inner tube X1. The fastening screw portion 48 has a shank portion 82 and a male thread portion 40 extending downward from the lower surface of the shank portion 82. The male thread portion 40 can be screwed into the female thread portion 22, and a pressing surface 46 surrounding the male thread portion 40 is formed on the lower surface. After adjusting the fitting position of the inner tube X1 with respect to the outer tube X2, the fastening screw portion 48 is used to screw the male thread portion 40 into the female thread portion 22, while the pressing body 38 is passed through the first through hole 16 and pressed and fixed toward the outer circumferential surface 58 of the inner tube X1. The tightening torque by the fastening screw portion 48 is preferably adjusted by the diameter D of the head portion 44 and / or the pitch of the male thread portion 40 (female thread portion 22). The fastening screw portion 48 has a head portion 44 at the end of the shank portion 82 opposite to the end on the male thread portion 40 side, which can be gripped and rotated with fingers. The diameter D of the head portion 44 is preferably enlarged to allow the head portion 44 to be rotated with little force by gripping it with fingers, and from the viewpoint of preventing slippage, multiple shallow grooves spaced apart in the circumferential direction may be provided. The distance between the first through hole 16 and the female thread portion 22 is set so that the pressing member 36 of the pressing body 38 can be inserted into the first through hole 16, and the male thread portion 40 of the fastening screw portion 48 can pass through the clearance hole 28 of the pressing member 36. Regarding the fixing and holding of the inner and outer pipes X1 and X2 by the fastening screw portion 48, it is preferable to set the diameter D of the head portion 44 and / or the pitch of the male thread portion 40 so that the inner and outer pipes X1 and X2 are sufficiently fixed and held by tightening the fastening screw portion 48 by hand.

[0039] Regarding the use of the integrated inner and outer pipe structure 10, the first through hole 16 is provided so as to extend in the circumferential direction of the inner and outer pipes X1 and X2, the inner and outer pipes X1 and X2 are oriented vertically, and a heavy object is supported at a predetermined height by either the inner or outer pipe X1 or X2. In particular, when using the integrated inner and outer pipe structure 10 to fix and hold a heavy object at a predetermined height by adjusting the fitting length of the inner and outer pipes X1 and X2 that extend in the vertical direction, from the viewpoint of supporting the weight of the heavy object by the frictional force between the pressing surface 34 of the pressing body 38 and the outer circumferential surface 58 of the inner pipe X1, it is preferable that the resistance force of the pressing surface 34 of the pressing body 38 against the outer circumferential surface 58 of the inner pipe X1, i.e., the tightening force by the fastening screw portion 48, is large. For this reason, strength to withstand a large tightening force is required, so it is preferable that the pressing body 38, the fastening screw portion 48, and the inner and outer pipes X1 and X2 constituting the integrated inner and outer pipe structure 10 are made of metal.

[0040] As a variation, the integrated inner and outer tube structure 10 may be made of resin from the viewpoint of lightness, and in particular, even if the openings for the first through hole 16 and the female threaded portion 22 are provided, it is preferable to ensure sufficient thickness from the viewpoint of ensuring strength around them.

[0041] The following describes a method for fixing and holding existing inner and outer tubes X1 and X2 that fit together, and further describes the method for fixing and holding the inner and outer tubes X1 and X2: A pressing body 38 having an L-shaped cross-section, comprising a load-receiving member 30 having a load-receiving surface 26 and a clearance hole 28, and a pressing member 36 extending from one end 32 of the load-receiving member 30 toward the opposite side of the load-receiving surface 26 and having a pressing surface 34 at its tip, and a tubular sleeve 54 having a first through hole 16 and a second through hole 18 on its outer circumference, the second through hole 18 having a female threaded portion 22 on its inner circumference, and a fastening screw portion 48 having a male threaded portion 40 that can be screwed into the female threaded portion 22 and having a pressing surface 46 that can contact the load-receiving surface 26; a step of preparing the above, a step of fitting the tubular sleeve 54 with a circular cross-section on its inner circumference onto the upper end of the outer tube X2, and a step of fitting the inner tube X1 into the tubular sleeve 54 or the outer tube X2. The process includes the steps of: rotating the tubular sleeve 54 around the longitudinal direction of the outer tube X2 to a desired rotational position; and tightening the fastening screw portion 48 to press the tubular sleeve 54 from the outside toward the outer circumferential surface 58 of the inner tube X1 in the thickness direction of the tubular sleeve 54, thereby fixing the tubular sleeve 54 at the desired rotational position around the longitudinal direction of the outer tube X2, while pressing the outer circumferential surface 58 on the opposite side of the inner tube X1 toward the tubular sleeve 54 or the inner circumferential surface 60 of the outer tube X2, thereby fixing and holding the inner and outer tubes X1 and X2 toward each other in the longitudinal direction, wherein the fixing and holding step is performed on the side of the second through hole 18 of the pressing member 36 The device includes a step in which, by forming a clearance between one flat portion 41A and the second through hole 18, the other end of the load-receiving member 30 is inclined toward the outer circumferential surface of the inner and outer tubes X1 and X2, causing a wedge effect against the outer circumferential surface 58 of the inner tube X1 at the corner of the pressing surface 34 including the edge closer to the load-receiving member 30, and increasing the pressing force by the fastening screw portion 48 by the principle of leverage.

[0042] Furthermore, it is preferable to have a step of fixing the tubular sleeve 54 to a desired rotational position around the longitudinal direction of the outer tube X2 by pressing the tubular sleeve 54 from the outside toward the outer circumferential surface 50 of the outer tube X2 in the thickness direction of the tubular sleeve 54, while pressing the outer circumferential surface on the opposite side of the outer tube X2 against the inner circumferential surface 57 of the tubular sleeve 54 to fix and hold the inner and outer tubes X1 and X2 together in the longitudinal direction. In addition, the inner circumferential surface 57 of the tubular sleeve 54 is provided with a reduced diameter portion set to be larger than the diameter of the inner tube X1 and an expanded diameter portion set to be larger than the diameter of the outer tube X2, and an annular shoulder portion 94 is formed at the connection portion between the reduced diameter portion and the expanded diameter portion, and the annular shoulder portion 94 is placed on the annular end face EN of the outer tube X2, thereby rotating the tubular sleeve 54 to a desired rotational position around the longitudinal direction of the outer tube X2.

[0043] The following describes the application of the integrated inner and outer tube structure 10 to an existing music stand, using a music stand as an example. As shown in Figure 1, in an existing music stand, the inner and outer tubes X1 and X2 are fitted together, with the music stand connected to the upper end of the inner tube X1, while the tripod LG is connected to the lower end of the outer tube X2 to hold the music stand upright. The fitting between the lower end of the inner tube X1 and the upper end of the outer tube X2 is, for example, screwed in so as to be height adjustable, with the screw passing horizontally through the through hole in the outer tube X2, and the tip of the screw contacting the outer surface of the inner tube X1 to hold it in place.

[0044] First, loosen the screws, remove the screws, and then adjust the fitting position between the lower end of the inner tube X1 and the upper end of the outer tube X2 according to the desired height of the music stand F. At that position, while supporting the inner tube X1 with one hand, fit the tubular sleeve 54 of the inner and outer tube integrated structure 10 from one opening onto the upper end of the outer tube X2 with the other hand, and place the annular shoulder 94 of the tubular sleeve 54 on the annular end face EN of the outer tube X2. The tubular sleeve 54 covers around the upper end of the outer tube X2, and a predetermined clearance is ensured between the inner peripheral surface 57 of the tubular sleeve 54, the outer peripheral surface 50 of the outer tube X2, and the outer peripheral surface 58 of the inner tube X1. The tubular sleeve 54 is supported at the upper end of the outer tube X2 and is free to rotate about the longitudinal direction of the inner and outer tubes X1 and X2. Next, rotate the tubular sleeve 54 with the other hand about the longitudinal direction of the inner and outer tubes X1 and X2, and position it at a desired rotational position, for example, a position where the fastening operation of the fastening screw portion 48 can be performed with the right hand in the case of a right-handed person.

[0045] Next, while supporting the inner tube X1 with one hand, fasten the fastening screw portion 48 with the other hand to lock the rotation of the tubular sleeve 54 about the longitudinal direction of the inner and outer tubes X1 and X2, fix and hold the inner and outer tubes X1 and X2 together, and set the music stand F at the desired height. More specifically, the fastening screw portion 48 penetrates the blind hole 28, screws the male screw portion 40 into the female screw portion 22, presses the pressing body 38 to penetrate the first through hole 32 of the first outer fitting portion 53, and while making the pressing surface 34 in surface contact with the outer peripheral surface 58 of the inner tube X1, the outer peripheral surface 58 of the inner tube X1 on the opposite side of the surface contact portion of the pressing surface 34 with respect to the inner tube X1 can be pressed and fixed against the inner peripheral surface 60 of the outer tube X2 at the fitting portion of the inner and outer tubes X1 and X2. Until the fastening screw portion 48 is screwed in, the tubular sleeve 54 mounted on the outer peripheral surface of one end portion of the outer tube X2 is free to rotate about the longitudinal direction of the inner and outer tubes X1 and X2. By screwing in with the fastening screw portion 48, such rotation of the tubular sleeve 54 is fixed, and the inner and outer tubes X1 and X2 can be fixedly held with respect to the longitudinal direction of the inner and outer tubes X1 and X2. When applying such an inner and outer tube integrated structure 10 to a music stand, it is possible to improve the usability with a simple structure during the adjustment of the stand height.

[0046] The operation of the L-shaped pressing body 38 will be explained with reference to Figure 7. The load-receiving member 30 and the pressing member 36 of the L-shaped pressing body 38 are perpendicular to each other, and the first through hole 16 and the second through hole 18, which is the female thread portion 22, provided in the tubular sleeve 54 are perpendicular to the longitudinal direction of the tubular sleeve 54 and provided in the thickness direction of the tubular sleeve 54. With the pressing surface 34 of the pressing member 36 of the L-shaped pressing body 38 inserted into the first through hole 16, the male thread portion 40 of the fastening screw portion 48 is passed through the clearance hole 28 of the load-receiving member 30 of the L-shaped pressing body 38 and screwed into the second through hole 18 of the tubular sleeve 54. In this state, the load-receiving member 30 is parallel to the outer surface 56 of the tubular sleeve 54, that is, the pressing member 36 is perpendicular to the outer surface 56 of the tubular sleeve 54.

[0047] By screwing in the fastening screw portion 48, the pressing surface 46 of the head portion 44 comes into contact with the load-receiving surface 26 of the load-receiving member 30 of the L-shaped pressing body 38, causing the load-receiving member 30 of the L-shaped pressing body 38 to approach the outer surface 56 of the tubular sleeve 54, and the pressing surface 34 of the L-shaped pressing body 38 to approach the outer circumferential surface 58 of the inner pipe X1 through the first through hole 16. By further screwing in the fastening screw portion 48, the pressing surface 34 of the L-shaped pressing body 38 is formed in a shape that follows the outer circumferential surface 58 of the inner pipe X1, that is, an arc-shaped curved surface of a predetermined diameter, so that the entire surface presses against the outer circumferential surface 58 of the inner pipe X1 in a surface contact manner. By further screwing in the fastening screw portion 48, the L-shaped pressing body 38 becomes supported at one point at its end by the pressing surface 34 of the pressing member 36. As a result, the load-receiving member 30 of the L-shaped pressing body 38 begins to tilt so that the end 32 on the pressing member 36 side and the opposite end 33 approach the outer surface 56 of the tubular sleeve 54. Consequently, the contact between the pressing surface 34 of the pressing member 36 and the outer surface 58 of the inner tube X1 changes from surface contact to line contact.

[0048] More specifically, the contact area of ​​the pressing surface 34 of the pressing member 36 decreases toward the circumferentially extending edge 55 of the tubular sleeve 54 on the load-receiving member 30 side, and the edge 55 of the pressing surface 34, that is, the intersection corner between the pressing surface 34 and one of the flat portions 41A, bites into the outer circumferential surface 58 of the inner pipe X1, thereby increasing the pressing pressure against the outer circumferential surface 58 of the inner pipe X1, along with a so-called wedge effect. As a result, compared to the case where the entire pressing surface 34 of the L-shaped pressing body 38 presses the outer surface 58 of the inner tube X1 in a surface contact manner, when, for example, a heavy object such as a music stand or speaker is supported at the upper end of the inner tube X1, the weight makes it impossible to maintain the fixation between the inner and outer tubes X1 and X2, and as time passes, the inner tube X1 supporting the heavy object tries to slide downward relative to the outer tube X2, the wedge effect described above is exerted even more strongly, making it possible to strengthen the downward fixation and retention of the inner tube X1 relative to the outer tube X2 of the inner and outer tubes X1 and X2 that extend in the vertical direction. From this, regarding the positional relationship of the pressing surface 34 of the L-shaped pressing body 38 with respect to the female thread portion 22, when the distance between the pressing surface 34 of the L-shaped pressing body 38 and the female thread portion 22 is the same, it is more advantageous for the pressing surface 34 of the L-shaped pressing body 38 to be positioned below the female thread portion 22, that is, for the first through-hole 16 to be positioned below the female thread portion 22, than for it to be positioned above, in order to prevent the inner pipe X1 from slipping down relative to the outer pipe X2 due to the increased wedge effect. The maximum inclination angle ΘMAX of the L-shaped pressing body 38 is determined by the position of the overhang hole 28 on the load-receiving member 30, the distance between the outer surface 58 of the inner pipe X1 and the outer surface 56 of the tubular sleeve 54 (clearance C1 between the inner and outer pipes X1 and X2 + thickness th of the tubular sleeve 54), and / or the clearance C between the L-shaped pressing body 38 and the first through hole 16. The thickness th of the tubular sleeve 54 and / or the clearance C between the L-shaped pressing body 38 and the first through hole 16 should be determined according to the desired degree of reinforcement in fixing and holding the inner and outer pipes X1 and X2 in the vertical direction.For example, when the tubular sleeve 54 is made of resin, from the viewpoint of ensuring strength, the thickness th of the tubular sleeve 54 is large, the opening area of the first through hole 16 is made small, and the clearance C is made narrow. On the other hand, accordingly, the position of the blank hole 28 on the load receiving member 30 is adjusted closer to the end portion 33 on the side opposite to the end portion 32 of the pressing member 36. When the tubular sleeve 54 is made of metal, the thickness th of the tubular sleeve 54 may be small and the opening area of the first through hole 16 may be made large.

[0049] In this case, using the edge 55 of one of the flat portions 41A on the side of the first through-hole 16 of the pressing member 36 of the pressing surface 34 as the point of application, the edge of the other flat portion 41B of the pressing surface 34 facing the one flat portion 41A as the fulcrum, and the center of the oversized hole 28 of the load-receiving member 30 as the point of force application, the tightening force of the fastening screw portion 48 increases according to the principle of leverage, in proportion to the ratio of the distance D2 between the fulcrum and the point of force application to the distance D1 between the fulcrum and the point of application. By making the distance D1 smaller and the distance D2 larger, in other words, by making the longitudinal width of the inner and outer tubes X1 and X2 of the pressing surface 34 smaller and positioning the oversized hole 28 of the load-receiving member 30 closer to the other end 33, it becomes possible to more firmly fix and hold the inner and outer tubes X1 and X2 while maintaining a constant tightening force due to the fastening screw portion 48. In this regard, in relation to the wedge effect described above, while the size of the first through-hole 16 remains constant, the smaller the longitudinal width of the inner and outer tubes X1 and X2 of the pressing surface 34, the larger the clearance C formed between one of the flat portions 41A on the first through-hole 16 side of the pressing member 36 and the inner circumferential surface of the first through-hole 16. This makes it possible to increase the maximum inclination angle ΘMAX of the L-shaped pressing body 38, and to adjust the increase in tightening force due to the tightening of the fastening screw portion 48 by the lever principle and the wedge effect. The increase in tightening force due to the lever principle by the fastening screw portion 48 may also be achieved by setting the ratio of the distance between the first through-hole 16 and the clearance hole and the distance between the first through-hole 16 and the second through-hole 18. As described above, the expansion of the pressing surface 34 in the longitudinal direction of the inner and outer tubes X1 and X2 is related to the increase in tightening force due to the tightening of the fastening screw portion 48 by the wedge effect and the lever principle. On the other hand, the expansion of the pressing surface 34 in the direction perpendicular to the longitudinal direction of the inner and outer tubes X1 and X2, i.e., in the circumferential direction of the inner and outer tubes X1 and X2, is preferably set considering that the pressing force component on the outer circumferential surface 58 of the inner tube X1 due to the tightening force by the fastening screw portion 48 gradually decreases as the pressing surface 34 expands 90 degrees to the left and right in the circumferential direction from the center of the female screw hole 22. The pressing surface 34 preferably expands in the circumferential direction so as to straddle the longitudinal direction of the inner and outer tubes X1 and X2 passing through the center of the female screw hole 22.

[0050] As described above, when the fastening screw portion 48 is screwed in, the load-receiving surface 26 receives a pressing load via the pressing surface 46, and the pressing member 36 penetrates the first through hole 16, the pressing surface 34 presses against the outer circumferential surface 58 of the inner pipe X1. Due to the formation of a clearance between one flat portion 41A of the pressing member 36 on the load-receiving member 30 side and the inner circumferential surface of the first through hole 16, the other end of the load-receiving member 30 inclins toward the outer circumferential surface of the inner and outer pipes, and the other flat portion 41B strikes the inner circumferential edge of the first through hole 16. This creates a wedge effect at the corner of the pressing surface 34, including the edge that inclins toward the outer circumferential surface of the inner and outer pipes, and increases the pressing force against the outer circumferential surface 58 of the inner pipe X1 at the edge of one flat portion 41A of the pressing surface 34 by the lever principle, thereby ensuring the predetermined fixed holding of the inner and outer pipes under a given weight of the supported object. Alternatively, the width between the edges of the pressing surface 34 and / or the position of the oversized hole 28 on the load-receiving member 30 may be set such that, by creating a clearance between one flat portion 41A of the pressing surface 36 on the load-receiving member 30 side and the inner surface of the first through-hole 16, the other end 33 of the load-receiving member 30 is inclined toward the outer surface of the inner and outer pipes, and the other flat portion 41B strikes the inner edge of the first through-hole 16, thereby increasing the pressing force on the outer surface 58 of the inner pipe X1 at the edge of one flat portion 41A of the pressing surface 34 by the lever principle.

[0051] The pressing surface 34 is formed as a curved surface that follows the outer circumferential surface 58 of the inner tube X1. More specifically, it is preferable that the radius of curvature be the same as that of the circular outer circumferential surface 58, but in some cases, it does not have to be set to be the same as that of the circular outer circumferential surface 58. More specifically, the pressing surface 34 is set to be slightly smaller than the radius of curvature of the circular outer circumferential surface 58, so that the entire surface of the pressing surface 34 does not come into contact with the outer circumferential surface 58 of the inner tube X1, and the circumferential edges of the inner and outer tubes X1 and X2 of the pressing surface 34 come into contact with the outer circumferential surface 58 of the inner tube X1, and there may be a gap between the pressing surface 34 and the outer circumferential surface 58 in the portion between the two edges of the pressing surface 34. This may concentrate the wedge effect on one of the longitudinal edges of the inner and outer tubes X1 and X2 of the pressing surface 34, specifically on the circumferential edges of the inner and outer tubes X1 and X2. As a modified example, as shown in Figure 34, the wedge effect can be increased by adopting two-stage curved surfaces 34A and 34B as the form of the pressing surface 34. More specifically, by providing a curved surface 34B connected to the edge of one flat portion 41A with different degrees of curvature, and a curved surface 34A connected to the edge of the other flat portion 41B, as the load-receiving member 30 of the L-shaped pressing body 38 is inclined so that the end 32 on the pressing member 36 side and the end 33 on the opposite side approach the outer surface 56 of the tubular sleeve 54, the contact surface with the outer surface 58 of the inner pipe X1 shifts from the curved surface 34A to the curved surface 34B, thereby increasing the wedge effect with respect to the outer surface 58 of the inner pipe X1.

[0052] For example, in the case of a big band where multiple instruments are played in front of an audience, the music stands placed in front of each instrument player are not foldable, lightweight music stands, but rather heavy music stands with a large diameter tube. When multiple such heavy music stands are set in a aligned, rotating position, it is easy to create a unified and visually appealing appearance. To change the height of the music stand F, one simply loosens the fastening screw 48, adjusts the fitting position of the inner tube X1 with respect to the outer tube X2, and fastens it again. In particular, when lowering the height of the music stand F, one only needs to loosen and quickly fasten the fastening screw 48 with one hand, and the inner tube X1 will fall under its own weight, so there is no need to support the inner tube X1 with the other hand.

[0053] In short, firstly, by adjusting the internal fitting length of the inner tube X1 to the outer tube X2 according to the desired height, and then placing the annular shoulder portion 94 formed at the boundary between the second outer portion 55 and the first outer portion 53 of the tubular sleeve 54 on the annular end face EN of the outer tube X2, the tubular sleeve 54 is free to rotate around the longitudinal direction of the inner and outer tubes X1 and X2. Therefore, while holding the inner tube X1 with one hand, the tubular sleeve 54 can be easily rotated to the desired rotation position with the other hand.

[0054] Secondly, by screwing the fastening screw portion 48 into the tubular sleeve 54, the pressing surface 34 of the L-shaped pressing body 38 contacts the outer circumferential surface 58 of the inner tube X1, and the outer circumferential surface 58 of the inner tube X1 on the opposite side in the diametrical direction is pressed against the inner circumferential surface of the second outer portion 55 of the tubular sleeve 54. As a result, the inner tube X1 and the outer tube X2 are fixedly held in place with respect to the tubular sleeve 54, even if there is a clearance at the fitting portion of the inner and outer tubes X1 and X2, they are fixedly held in place with respect to each other in the longitudinal direction of the tubes, and the rotation of the tubular sleeve 54 around the longitudinal direction of the inner and outer tubes X1 and X2 is fixed.

[0055] Furthermore, by setting the width of the annular shoulder portion 94 formed at the boundary between the second outer portion 55 and the first outer portion 53 of the tubular sleeve 54 to be larger, and by preparing multiple types of pressing bodies 38, it becomes possible to apply a general-purpose tubular sleeve 54 to an existing music stand having inner and outer tubes X1 and X2, and by selecting the type of L-shaped pressing body 38, it becomes possible to add only the fixing and holding jig having the tubular sleeve 54, L-shaped pressing body 38, and fastening screw portion 48, rather than replacing the entire music stand.

[0056] On the other hand, by precisely setting the width of the annular shoulder portion 94 of the tubular sleeve 54 relative to the existing inner and outer tubes X1 and X2, and creating a custom-made tubular sleeve 54 with no clearance at the fitting portion of the inner and outer tubes X1 and X2, the fastening screw portion 48 not only presses the inner and outer tubes X1 and X2 against the inner circumferential surface 57 of the tubular sleeve 54 with the L-shaped pressing body 38, but also, at the fitting portion of the inner and outer tubes X1 and X2, on the diametrically opposite side of the pressing surface 34 by the L-shaped pressing body 38, the outer circumferential surface 58 of the inner tube X1 is pressed against the inner circumferential surface 60 of the outer tube X2 in a line contact manner. As a result, the inner tube X1 and the outer tube X2 can be more firmly fixed and held together in the longitudinal direction of the tubes, which is effective, for example, for stands that support heavy objects such as music amplifiers and large musical instruments. Furthermore, by screwing in the fastening screw portion 48, the inner and outer tubes X1 and X2 are fixed and held together via the tubular sleeve 54. After fixing the rotation of the tubular sleeve 54 around the longitudinal direction of the inner and outer tubes X1 and X2, the male screw 70 is screwed into the female screw portion 66 of the tubular sleeve 54 through the clearance hole 68 of the L-shaped pressing body 38. This completely detaches the male screw portion 40 of the fastening screw portion 48 from the female screw portion 22 of the tubular sleeve 54. Even if the L-shaped pressing body 38 becomes free, the male screw 70 prevents the L-shaped pressing body 38 from falling off the tubular sleeve 54. In the case of medical stands for intravenous drips, monitors, lighting, etc., casters 96 are usually provided at the bottom of the inner and outer tubes X1 and X2, and the stands are moved to many treatment sites. During this time, the stands vibrate up and down due to unevenness in the floor surface, so there is a high need to firmly fix the fitting and fixing parts of the inner and outer tubes X1 and X2. Furthermore, there is a high need to adjust the direction of the intravenous drip, monitor, and lighting during treatment. For these reasons, the integrated inner and outer tube structure of the present invention is more useful than music stands, which are usually transported to performance venues and for which there is little need to adjust the height and direction of music stands, microphones, amplifiers, etc. during performances.

[0057] As a variation, by using a tubular sleeve 54, the inner and outer tubes X1 and X2 can be fixed and held even when the inner tube X1 is detached from the outer tube X2. More specifically, the pressing surface 34 of the pressing body 38 is pressed against the outer surface 58 of the inner tube X1, and it is not necessary to directly fix and hold the inner and outer tubes X1 and X2 through the fitting portion of the inner and outer tubes X1 and X2. It is sufficient to indirectly fix and hold the inner and outer tubes X1 and X2 via the tubular sleeve 54. Therefore, it is possible to fix and hold the inner and outer tubes X1 and X2 even when there is no fitting portion of the inner and outer tubes X1 and X2, in other words, when the overall length of the inner and outer tubes X1 and X2 is long.

[0058] With the integrated inner and outer tube structure 10 having the above configuration, when the inner and outer tubes X1 and X2 are fitted together to form an integrated structure, the degree of fixing and holding at the fitting part becomes an issue depending on the application, such as a music stand, microphone stand or other music stand, or an IV stand, monitor stand or other medical stand. However, a first through hole 16 and a second through hole 18 are provided on the outer circumferential surface near one end of the fitting part side of the tubular sleeve 54 or the outer tube X2, and a female thread portion 22 is provided on the inner circumferential surface of the second through hole 18. Using the L-shaped pressing body 38 and the fastening screw portion 48, the load receiving member 30 of the pressing body 38 is inserted from the pressing surface 34 at the tip into the first through hole 16, and the load receiving surface 26 receives the pressing load as the fastening screw portion 48 is screwed in, and when the pressing surface 34 presses against the outer circumferential surface 58 of the inner tube X1, the side of the pressing member 36 to the first through hole 16 The clearance formed between one flat portion 41A and the first through hole 16 causes the other end 33 of the load-receiving member 30 to tilt toward the outer circumferential surface of the inner and outer tubes X1 and X2, creating a wedge effect on the clearance side of the pressing surface 34, and increasing the pressing force by the fastening screw portion 48 by the lever principle with the portion of the pressing surface 34 opposite the clearance side as the fulcrum, the load-receiving surface 26 as the point of force application, and the portion of the pressing surface 34 on the clearance side as the point of application. The first through hole 16 is positioned on the outer circumferential surface 50 of the outer tube X2, and the female screw portion 2 of the outer tube X2 The load-receiving member 30 is provided so as to straddle the longitudinal direction of the outer tube X2 passing through the center of 2, and the thickness of the load-receiving member 30 and / or the size of the first through hole 16 are set, and the pressing surface 34 is set to a shape such that when inserted into the first through hole 16, the circumferential and longitudinal expansion of the outer tube X2 are within a predetermined range. Therefore, depending on the application, the inner and outer tubes X1 and X2 can be easily and sufficiently fixed and held with the required fixing force by tightening the fastening screw portion 48 by hand.

[0059] Furthermore, after the entire pressing surface 34 of the L-shaped pressing body 38 presses against the outer circumferential surface 58 of the inner pipe X1 in a surface contact manner, the L-shaped pressing body 38 may begin to tilt, transitioning to line contact. In addition, as long as the aforementioned wedge effect is achieved, the tilting of the L-shaped pressing body 38 may begin before the pressing surface 34 of the L-shaped pressing body 38 contacts the outer circumferential surface 58 of the inner pipe X1, and the entire pressing surface 34 of the L-shaped pressing body 38 does not need to be in surface contact. The intersection angle between the load-receiving member 30 and the pressing member 36 of the L-shaped pressing body 38, and / or the orientation of the first through hole 16 and the second through hole 18, which is the female thread portion 22, provided in the tubular sleeve 54 (tilting relative to the thickness direction of the tubular sleeve 54) may be set appropriately as long as the so-called wedge effect is achieved by screwing in the fastening screw portion 48.

[0060] A second embodiment of the present invention will be described below. In the following description, components similar to those of the first embodiment will be given the same reference numerals and their descriptions will be omitted. Below, the characteristic parts of this embodiment will be described in detail with reference to Figures 8 and 9. The second embodiment of the present invention is a stand as an integrated inner and outer tube structure, and in order to fix and hold the inner and outer tubes in the vertical direction at the fitting portion, an L-shaped pressing body 38 and a fastening screw portion 48 are used, and the fastening screw portion 48 presses the pressing surface 34 of the L-shaped pressing body 38 against the outer surface of the inner tube, which is common to the first embodiment. However, the characteristic of the second embodiment of the present invention is that the object supported by the stand is a lightweight music stand in the first embodiment, but a heavy speaker S in this embodiment. Accordingly, while the first embodiment employs a single L-shaped pressing body 38, this embodiment employs a pair of L-shaped pressing bodies 38. More specifically, as shown in Figures 8 and 9, the pair of L-shaped pressing bodies 38 have the same structure and are arranged at intervals in the longitudinal direction of the inner and outer pipes X1 and X2, with the second through-hole 18 in between. One has a U-shaped portion extending in the longitudinal direction of the pipe at the top, with an open portion facing downwards into the through-hole, while the other has a U-shaped portion extending in the longitudinal direction of the pipe at the bottom, with an open portion facing upwards into the through-hole. The distance between the first through-hole 16 and the second through-hole 18 may differ between the upper first through-hole 16 and the lower first through-hole 16. The overall planar shape of the L-shaped pressing body 38 may be a long U-shape, a short U-shape, a long V-shape, a short V-shape, a vertically elongated shape, or a horizontally elongated shape, and the pair of L-shaped pressing bodies 38 may have different overall planar shapes. A tubular sleeve 54 may be used, as in the first embodiment, or it may not be used. As described above, in each of the pair of L-shaped pressing bodies 38, the inner and outer pipes X1 and X2 can be fixed and held together by the wedge effect and the lever principle, similar to the first embodiment, and a tightening force can be applied to each of the pair of L-shaped pressing bodies 38 by tightening with a single fastening screw portion 48.The pair of L-shaped pressing bodies 38 do not need to have the same structure. For example, one may have an overall planar shape that is a long U-shape and the other a long V-shape. Alternatively, the overall planar shape may be the same, but the length of the pressing member 36 of one may differ from the length of the pressing member 36 of the other, thereby causing the wedge effect and lever principle of the pair of L-shaped pressing bodies 38 to differ.

[0061] As a result, the male thread portion 40 of the fastening screw portion 48 passes through the clearance hole 28 of the upper L-shaped pressing body 38 and the clearance hole 28 of the lower L-shaped pressing body 38, and is tightened to the female thread portion 22 of the tubular sleeve 54. This causes the pressing surface 34 of the upper L-shaped pressing body 38 to be pressed against the outer circumferential surface 50 of the outer tube X2, and the pressing surface 34 of the lower L-shaped pressing body 38 to be pressed against the outer circumferential surface 58 of the inner tube X1. Thus, the inner and outer tubes X1 and X2 can be fixed and held together in the same manner as in the first embodiment. However, unlike the first embodiment, the two L-shaped pressing bodies 38 move and adjust independently within their corresponding through-slits, but they can be separated by attaching and detaching the fastening screw portion 48. Therefore, each L-shaped pressing body 38 is provided with a male thread 70 and a corresponding through-hole.

[0062] A third embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. Below, the characteristic parts of this embodiment will be described in detail with reference to Figures 10 to 12. In the third embodiment of the present invention, as a stand as an integrated inner and outer tube structure 10, an L-shaped pressing body 38 and a fastening screw portion 48 are used to fix and hold the inner tube X1 and outer tube X2 in the vertical direction at the fitting portion. The fastening of the fastening screw portion 48 presses the pressing surface 34 of the L-shaped pressing body 38 against the outer surface 58 of the inner tube X1, which is common to the first embodiment. However, a characteristic of the third embodiment of the present invention is that the object supported by the stand is a lightweight music stand in the first embodiment, but in this embodiment it is a microphone M, and accordingly In the first embodiment, the music stand is supported at the upper end of the inner tube X1 in the integrated inner and outer tube structure 10, and the height of the music stand is adjusted by adjusting the length of the fitting portion of the inner and outer tubes X1 and X2, and then firmly fixing and holding the inner and outer tubes X1 and X2 together using an L-shaped pressing body 38. In contrast, in this embodiment, instead of fixing and holding the inner and outer tubes X1 and X2 together, the L-shaped pressing body 38 is used to fix and hold between a tubular sleeve 54 that is diagonally fixed to the upper end of the inner tube X1 and a rod-shaped boomer B that supports the microphone M at its end. More specifically, as shown in Figures 10 to 12, in order to adjust the height or position of the microphone M, the internal fitting position of the boomer B with respect to the tubular sleeve 54 is adjusted, and then, similar to the first embodiment, the fastening screw portion 48 is fastened in such a manner that it is screwed into the second through hole 18, which is provided with the female thread portion 22 of the tubular sleeve 54, through the oversized hole 28 of the load-receiving member 30 of the L-shaped pressing body 38. This presses the pressing surface 34 of the pressing member 36 of the L-shaped pressing body 38 against the outer circumferential surface of the boomer B through the first through hole 16, thereby enabling the boomer B to be fixedly held against the tubular sleeve 54. As a modification, by using an L-shaped pressing body 38 with a particularly long load-receiving member 30 for an existing tubular sleeve 54, the load-receiving member 30 may protrude from the end of the tubular sleeve 54 without providing the first through hole 16 in the tubular sleeve 54, and the pressing surface 34 of the pressing member 36 may be directly pressed against the outer circumferential surface of the boomer B.

[0063] More specifically, L-shaped pressing bodies 38 and fastening screw portions 48 are provided near each end face of the tubular sleeve 54. The load-receiving member 30 of each L-shaped pressing body 38 protrudes from the corresponding end face of the tubular sleeve 54, and the pressing member 36 faces the outer circumferential surface 50 of the inner tube X1 or outer tube X2 on the inner tube X1 or outer tube X2 side of the corresponding end face of the tubular sleeve 54. As a result, unlike the first embodiment, it is possible to omit the first through-hole 16 through which the pressing member 36 passes in the tubular sleeve 54. The length of the load-receiving member 30 of each L-shaped pressing body 38 is set so that the corresponding pressing member 36 protrudes from the corresponding end face of the tubular sleeve 54. Furthermore, from the viewpoint of convenience when rotating the tubular sleeve 54 to a desired rotation position around the longitudinal direction of the outer tube X2, it is preferable that the pair of L-shaped pressing bodies 38 and the pair of fastening screw portions 48 be set on the same side of the tubular sleeve 54. As a variation, if the microphone M supported by the boomer B is lightweight, an L-shaped pressing body 38 and a fastening screw portion 48 may be provided near one end face of the tubular sleeve 54. Furthermore, similar to the first embodiment, an L-shaped pressing body 38 and a fastening screw portion 48 may also be used in the fitting portion of the inner and outer tubes X1 and X2.

[0064] In the case where the overall length of the inner tube X1 is short and the height of the microphone M cannot be raised to the desired level, by setting the length of the tubular sleeve 54 provided at the fitting portion of the inner and outer tubes X1 and X2 to be longer, and by providing L-shaped pressing bodies 38 and fastening screw portions 48 near each end of the tubular sleeve 54, which omits the first through hole 16, it is possible to rotate the tubular sleeve 54 to the desired rotational position around the longitudinal direction of the outer tube X2 until each fastening screw portion 48 is fastened, similar to the first embodiment, thereby fixing the rotation of the tubular sleeve 54 around the longitudinal direction of the inner and outer tubes X1 and X2, and fixing and holding the inner and outer tubes X1 and X2 together with the pair of L-shaped pressing bodies 38.

[0065] On the other hand, if the length of the tubular sleeve 54 is short, the L-shaped pressing body 38 and fastening screw portion 48 may be provided in a similar manner only at one end of the tubular sleeve 54, or the U-shaped pressing body 38 may be provided so as to straddle the tubular sleeve 54.

[0066] Furthermore, for each L-shaped pressing body 38 of the tubular sleeve 54, the fastening screw portion 48 may be set independently of each other, with one being the fastening screw portion 48 and the other being the pressing lever 100 (seventh embodiment).

[0067] A fourth embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. Below, the characteristic parts of this embodiment will be described in detail with reference to Figure 13. In the fourth embodiment of the present invention, as a stand for an integrated inner and outer pipe structure 10, an L-shaped pressing body 38 and a fastening screw portion 48 are used to fix and hold the inner pipe X1 and outer pipe X2 in the vertical direction at the fitting portion. The fastening screw portion 48 is used to press the pressing surface 34 of the L-shaped pressing body 38 against the outer circumferential surface 58 of the inner pipe X1. This is common to the first embodiment, but the characteristic of the fourth embodiment of the present invention is that the pressing body 38 is used as a filler for the second through hole 18. More specifically, as shown in Figure 13, a through hole 18 is provided on the outer circumferential surface near one end of the fitting side of the outer tube X2, with a female thread portion 22 formed on its inner circumferential surface. The pressing body 38 has a shape that allows it to be inserted into the through hole 18, with a load-receiving surface 26 on one end face and a pressing surface 34 against the outer circumferential surface 58 of the inner tube X1 on the other end face. The pressing body 38 has a length shorter than the depth of the through hole 18, and when the fastening screw portion 48 is screwed in, the tip surface of the male screw portion 40 rotates around the longitudinal direction of the male screw portion 40, without co-rotating, while the load-receiving surface 26 receives the pressing load, and the pressing body 38 presses against the outer circumferential surface 58 of the inner tube X1 in a tight-fitting manner through the through hole 18. The flexible pressing body 38 that can be inserted into the second through hole 18 has a hardness that allows the pressing surface 34 to deform into a shape that conforms to the outer circumferential surface 58 of the inner tube X1 when the fastening screw portion 48 is screwed in, and is made of, for example, tin.

[0068] In the integrated inner and outer tube structure 10 having the above configuration, when the inner and outer tubes X1 and X2 are fitted together to form an integrated structure, the degree of fixing and holding at the fitting part becomes an issue depending on the application, such as a music stand, microphone stand or other music stand, or an IV stand or monitor stand or other medical stand. However, a through hole 18 is provided on the outer circumferential surface near one end of the outer tube X2 on the fitting part side, with a female threaded portion 22 formed on the inner circumferential surface. A pressing body 38 has a shape that can be inserted into the through hole 18, with a load-receiving surface 26 on one end face and a pressing surface 34 against the outer circumferential surface 58 of the inner tube X1 on the other end face, and has a length shorter than the depth of the through hole 18. A male threaded portion 40 that can be screwed into the female threaded portion 22 is provided. The fastening screw portion 48 has a head portion 44 provided at one end 42 of the male thread portion 40, and the head portion 44 has a pressing surface 46 formed on the male thread portion 40 side that can contact the load receiving surface 26. By screwing in the fastening screw portion 48, the tip surface of the male thread portion 40 rotates around the longitudinal direction of the male thread portion 40 without co-rotating, and the load receiving surface 26 receives a pressing load. The pressing body 38 presses through the through hole, and the pressing surface 34 presses against the outer circumferential surface 58 of the inner tube X1 in close contact. Depending on the application, the inner and outer tubes X1 and X2 can be fixed and held with the required fixing force by tightening the fastening screw portion 48, and the inner and outer tubes X1 and X2 can be easily and sufficiently fixed and held by tightening the fastening screw portion 48 manually.

[0069] In conventional designs for a stand with an integrated inner and outer tube structure 10, when a screw is screwed horizontally into the female screw hole of the matching outer tube X2 and the tip of the screw is fixed to the outer surface 58 of the inner tube X1, it is difficult for the tip of the screw to make close contact with the outer surface 58 of the inner tube X1 due to the rotation of the screw. As a result, over time, for example, the music stand may slide down. However, by using the L-shaped pressing body 38 as a filler for the second through hole 18 instead of the L-shaped pressing body 38, the second through hole 18 is utilized, eliminating the need for the first through hole 16 compared to the first embodiment. This is advantageous when using a flexible and lightweight resin tubular sleeve 54.

[0070] A fifth embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. Below, the characteristic parts of this embodiment will be described in detail with reference to Figures 14 and 15. In the fifth embodiment of the present invention, as a stand for an integrated inner and outer pipe structure 10, an L-shaped pressing body 38 and a fastening screw portion 48 are used to fix and hold the inner pipe X1 and outer pipe X2 in the vertical direction at the fitting portion. The fastening of the fastening screw portion 48 presses the pressing surface 34 of the L-shaped pressing body 38 against the outer circumferential surface 58 of the inner pipe X1, which is common to the first embodiment. However, the characteristic of the fifth embodiment of the present invention lies in the form of the L-shaped pressing body 38. In the first embodiment, In the L-shaped pressing body 38, the load-receiving member 30 and the pressing member 36 are perpendicular to each other, and a clearance hole 28 through which the male threaded portion 40 of the fastening screw portion 48 passes is provided in the center of the load-receiving member 30. In this embodiment, however, the load-receiving member 30 and the pressing member 36 of the L-shaped pressing body 38 are connected at an obtuse angle, and a clearance hole through which the male threaded portion 40 of the fastening screw portion 48 passes is provided near the end of the load-receiving member 30 opposite to the end on the side of the pressing member 36. More specifically, as shown in Figures 14 and 15, the first through-hole 16 and the second through-hole 18 are parallel to each other and provided at a predetermined angle to the extension direction of the inner and outer pipes X1, X2 or the tubular sleeve 54. The inclination angle is, for example, 10° or less, which enhances the wedge effect generated by the fastening of the fastening screw portion 48. As a result, even if the tightening force by the fastening screw portion 48 is the same, the inner and outer pipes X1 and X2 can be more firmly fixed and held together.In this case, the degree of obtuseness of the intersection angle between the load-receiving member 30 and the pressing member 36 of the L-shaped pressing body 38, and the extent to which the clearance hole 28 through which the male threaded portion 40 of the fastening screw portion 48 passes is located on the opposite end of the load-receiving member 30 from the end on the side of the pressing member 36, can be determined according to the extent to which the wedge effect and / or lever principle are to be enhanced. In some cases, the load-receiving member 30 and the pressing member 36 of the L-shaped pressing body 38 may be connected only at an obtuse angle, or the clearance hole 28 through which the male threaded portion 40 of the fastening screw portion 48 passes may be located only on the end of the load-receiving member 30 opposite to the end on the side of the pressing member 36. As shown in Figure 14, the pressing surface 34 of the pressing member 36 is formed on a curved surface along the outer circumferential surface 58 of the inner pipe X1 until, similar to the first embodiment, the load-receiving member 30 of the L-shaped pressing body 38 begins to tilt in a direction in which the end 32 on the pressing member 36 side and the end 33 on the opposite side approach the outer surface 56 of the tubular sleeve 54, upon fastening of the fastening screw portion 48. In a modified example, the first through hole 16 and the second through hole 18 are provided parallel to each other and at a predetermined angle with respect to the extension direction of the inner and outer pipes X1, X2 or the tubular sleeve 54, and the load-receiving member 30 and the pressing member 36 are provided at an obtuse angle so that the load-receiving member 30 is parallel to the extension direction of the inner and outer pipes X1, X2 or the tubular sleeve 54, and the clearance hole 28 may be provided closer to the pressing member 36 on the load-receiving member 30. As a further modification, the first through-hole 16 may be provided at a predetermined angle to the extension direction of the inner and outer tubes X1, X2 or the tubular sleeve 54, while the second through-hole 18 may be set perpendicular to the outer circumferential surface 56 of the tubular sleeve 54. The overall planar shape of the pressing surface 34 can vary as in the first embodiment, including U-shaped, V-shaped, horizontally elongated, and vertically elongated shapes.

[0071] A sixth embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. The characteristic parts of this embodiment will be described in detail below with reference to Figures 16 and 17. The sixth embodiment of the present invention, as a stand as an integrated inner and outer tube structure 10, uses an L-shaped pressing body 38 and a fastening screw portion 48 to fix and hold the inner tube X1 and outer tube X2 in the vertical direction at the fitting portion, and the fastening screw portion 48 fastens the pressing surface 34 of the L-shaped pressing body 38 against the outer surface 58 of the inner tube X1, which is common to the first embodiment. However, the feature of the second embodiment of the present invention is that the object supported by the stand is a lightweight music stand in the first embodiment, but in this embodiment, it is a long and slender instrument such as a saxophone. Accordingly, in the first embodiment, the tubular sleeve 54 that fixes the inner and outer tubes X1 and X2 together is rotatable in the longitudinal direction of the tube, whereas in this embodiment, from the viewpoint of protecting the instrument from twisting, the inner and outer tubes X1 and X2 have rectangular cross-sections to prevent relative rotation around the longitudinal direction of the tube between the inner tube X1 and outer tube X2. More specifically, as shown in Figures 16 and 17, the instrument stand is configured such that the lengths of the inner and outer tubes X1 and X2 are adjusted according to the length of the instrument body and fixed in place. The top and bottom of the inner and outer tubes X1 and X2 are respectively fitted with U-shaped instrument support parts SU1 and SU2, and the instrument body is supported by being sandwiched between these U-shaped support parts SU1 and SU2. In the first embodiment, the inner and outer tubes X1 and X2 have a rectangular cross-section, while in the first embodiment, the inner and outer tubes X1 and X2 have a circular cross-section. In the first embodiment, the outer surface 58 of the inner tube X1 is pressed against the inner surface 60 of the outer tube X2 by the outer surface 58 of the inner tube X1 on the opposite side of the pressing and fixing portion by the pressing surface 34, in a manner of line contact in the vertical direction, thereby fixing and holding the outer tube X2 with respect to the inner tube X1 by support at two points. In contrast, in this embodiment, the outer surface 58 of the inner tube X1 on the opposite side of the pressing and fixing portion by the pressing surface 34 is pressed against the inner surface 60 of the outer tube X2 in a manner of surface contact.In this embodiment, unlike the first to fifth embodiments, the music stand, speaker S, microphone M, etc., are not supported in the longitudinal direction (up and down direction) of the tube. Instead, the slender instrument is supported by leaning it diagonally against the length-adjusted inner and outer tubes X1 and X2. Therefore, as in the second embodiment, there is little need to employ a pair of L-shaped pressing members 36, and a single L-shaped pressing member 36 is sufficient.

[0072] The seventh embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. The characteristic parts of this embodiment will be described in detail below with reference to Figure 18. The seventh embodiment of the present invention uses an L-shaped pressing body 38 as a stand for the integrated inner and outer pipe structure 10, to fix and hold the inner pipe X1 and outer pipe X2 in the vertical direction at the fitting portion, and the pressing surface 34 of the L-shaped pressing body 38 is pressed against the outer circumferential surface 58 of the inner pipe X1, which is common to the first embodiment. However, the characteristic of the seventh embodiment of the present invention is that, in the first embodiment, a fastening screw portion 48 is used to press the pressing surface 34 of the L-shaped pressing body 38 against the outer circumferential surface 58 of the inner pipe X1, but in this embodiment, a pressing lever is used instead of a fastening screw portion 48. More specifically, as shown in Figure 18, the device has a pressing lever 100 that has an annular circumferential surface 108 that rotates around a rotation axis 102 parallel to the load-receiving surface 26 while in contact with the load-receiving surface 26. The annular circumferential surface 108 is curved in shape, with the radius from the rotation axis 102 changing from a first radius to a second radius as it expands. By rotating the pressing lever 100, the pressing body 38 is movable in the thickness direction within the first through hole 18. By rotating the pressing lever 100 around the rotation axis 102, the pressing body 38 begins pressing toward the outer circumferential surface 58 of the inner tube X1 at a rotation position corresponding to an intermediate radius between the first and second radii, and ends pressing toward the outer circumferential surface 58 of the inner tube X1 at a rotation position corresponding to the second radius, bringing the pressing surface 34 into surface contact with the outer circumferential surface 58 of the inner tube X1, and pressing and fixing the outer circumferential surface 58 of the inner tube X1 on the opposite side of the surface contact portion of the pressing surface 34 toward the inner tube X1 to the inner circumferential surface 60 of the outer tube X2. The pressing lever 100 has a pair of rotating parts 109 and a lever part 106 connected to the pair of rotating parts 109.The rotating shaft 102 is supported by clearance holes 110 provided in each of a pair of rotating parts 109 spaced apart in the longitudinal direction of the inner and outer tubes X1 and X2. With the hole 104 in the rotating shaft 102 and the clearance hole 28 aligned, the screw 112 is inserted and screwed into the female threaded portion 16 provided on the outer surface of the tubular sleeve 54. As a result, the lever portion 106 presses the press body 38 against the outer surface 58 of the inner tube X1 through the second through hole 16, while the annular surface 108 is in contact with the load-receiving surface 26 of the L-shaped press body 38, with the rotating shaft 102 as the center. Furthermore, as the fastening screw portion 48 is screwed in, the load-receiving surface 26 receives a pressing load via the pressing surface 46, and the pressing member 36 penetrates the first through hole 16, causing the pressing surface 34 to press against the outer circumferential surface 58 of the inner pipe X1. Due to the formation of a clearance between one flat portion 41 on the first through hole 16 side of the pressing member 36 and the inner circumferential surface of the first through hole 16, the other end of the load-receiving member 30 inclins toward the inner and outer pipes X1 and X2, and the pressing surface 3 The first through-hole 16 is provided on the outer circumferential surface 50 of the outer tube X2 so as to straddle the longitudinal direction of the outer tube X2 passing through the center of the female thread portion 22 of the outer tube X2, so as to occur a wedge effect at the corner including the edge 55 of one of the flat portions 41 of 4, and the pressing surface 34 is set to a shape such that when inserted into the first through-hole 16, the circumferential and longitudinal expansion of the outer tube X2 are within predetermined ranges, as in the first embodiment.

[0073] The eighth embodiment of the present invention will be described below. In the following description, components similar to those in the first embodiment will be given the same reference numerals and their descriptions will be omitted. The characteristic parts of this embodiment will be described in detail below with reference to Figures 19 and 20. The eighth embodiment of the present invention uses an L-shaped pressing body 38 as a stand for the integrated inner and outer pipe structure 10, to fix and hold the inner pipe X1 and outer pipe X2 in the vertical direction at the fitting portion, and the pressing surface 34 of the L-shaped pressing body 38 is pressed against the outer circumferential surface 58 of the inner pipe X1, which is common to the first embodiment. However, the characteristic of the eighth embodiment of the present invention is that, in the first embodiment, a fastening screw portion 48 is used to press the pressing surface 34 of the L-shaped pressing body 38 against the outer circumferential surface 58 of the inner pipe X1, but in this embodiment, a pressing lever is used instead of a fastening screw portion 48. More specifically, as shown in Figures 19 and 20, in the first embodiment, the inner tube X1 is fixed and held in place without sliding downward by pressing the pressing surface 34 against the outer circumferential surface 58 of the inner tube X1, while the tubular sleeve 54 is placed on the annular shoulder portion 94 of the outer tube X2, and as shown in Figure 3, there is a clearance between the inner tube X1 and the outer tube X2, so the inner tube X1 can be removed upward from the outer tube X2 together with the tubular sleeve 54. In contrast, in this embodiment, the inner tube X1 is pressed against the outer circumferential surface 58 of the inner tube X1 by the pressing surface 34, and the outer circumferential surface 50 of the outer tube X2 is pressed against the outer circumferential surface 50 of the outer tube X2 by the pressing surface 35, so the inner tube X1 cannot be removed upward together with the tubular sleeve 54, and the inner and outer tubes X1 and X2 are fixed and held both downward and upward.

[0074] More specifically, as shown in Figure 19, the U-shaped pressing surface 34 of the first embodiment has a step, and a pressing surface 35, which is lower in height from the load-receiving member 30, is provided to separate the pressing surface 34. The pressing surface 34 presses against the outer circumferential surface 58 of the inner pipe X1, and the pressing surface 35 presses against the outer circumferential surface 50 of the outer pipe X2. From this viewpoint, the height of the step should be set accordingly. When the fastening screw portion 48 is screwed in, the load-receiving surface 26 receives a pressing load via the pressing surface 46, and the pressing member 36 passes through the first through hole 16, causing the pressing surface 34 to press against the outer circumferential surface 58 of the inner pipe X1. Due to the formation of a clearance between one flat portion 41 on the first through hole 16 side of the pressing member 36 and the inner circumferential surface of the first through hole 16, the other end of the load-receiving member 30 inclins towards the inner and outer pipes X1 and X2, and the pressing surface 3 The first through-hole 16 is provided on the outer circumferential surface 50 of the outer tube X2 so as to straddle the longitudinal direction of the outer tube X2 passing through the center of the female thread portion 22 of the outer tube X2, so as to occur a wedge effect at the corner including the edge 55 of one of the flat portions 41 of 4, and the pressing surface 34 is set to a shape such that when inserted into the first through-hole 16, the circumferential and longitudinal expansion of the outer tube X2 are within predetermined ranges, as in the first embodiment.

[0075] To confirm the effects of the present invention, the inventors manufactured a prototype and conducted limit load tests. More specifically, the vertical fixing and holding effect at the fitting portion of the inner and outer pipes X1 and X2 was confirmed using the configuration of the pressing body 38 as a parameter. The prototype consists of a metal inner pipe X1, a metal outer pipe X2 that fits into the inner pipe X1, a metal tubular sleeve 54 that is firmly fixed to the end of the outer pipe X2 and has a female threaded portion 22 and a first through hole 16 provided in a predetermined positional relationship with the female threaded portion 22, a metal pressing body 38 with an L-shaped side cross-section having a clearance hole 28, and a fastening screw portion 48 having a male threaded portion 40 that screws into the female threaded portion 22 of the outer pipe X2 via the clearance hole 28 of the pressing body 38. The specific test method involved applying a predetermined torque to the fastening screw portion 48 using a hammer trench, thereby pressing the pressing surface 34 of the pressing body 38 against the outer surface 58 of the inner tube X1. With the lower end of the outer tube X2 placed on a horizontal test stand, the integrated structure of the inner and outer tubes X1 and X2 via the tubular sleeve 54 was fixed upright. A compressive load was then applied from the upper end of the inner tube X1 in the vertical direction, which is the extension direction of the inner and outer tubes X1 and X2, and the critical compressive load at which the outer tube X2 began to move relative to the inner tube X1 was measured. For each of several prototypes, the change in critical compressive load was observed using a predetermined torque as a parameter.

[0076] The test conditions are shown in Figures 29 to 33, and the test results are shown in Figures 21 to 28. In all cases, as the load is applied, a slight compression inherent to the material of the prototype occurs, reaching a limit load at which the inner and outer tubes X1 and X2 can no longer be fixedly held by the prototype. Thereafter, the load decreases as it moves, and in this test, the limit load under a predetermined torque is measured. The test conditions are presented, including the overall planar shape of the projection of the pressing surface 34 onto the plane, the contact area of ​​the pressing surface 34, the positional relationship with the female thread portion, the tightening torque value, and the specifications of the L-shaped pressing body 38, the inner and outer tubes X1 and X2, and the tubular sleeve 54. In the test conditions shown in Figures 29 to 33, the test numbers (XYZ) indicate the following: X represents the overall planar shape of the pressing surface 34, which can be 0 (U-shaped side cross-section), 1 (L-shaped side cross-section with a U-shape), 2 (L-shaped side cross-section with an elongated shape), or 3 (L-shaped side cross-section with an oblique shape); Y represents the variation in the overall planar shape of the pressing surface 34, where lowercase letters a, b, c… indicate a tightening torque of 3 Nm, uppercase letters A, B, C… indicate a tightening torque of 5 Nm; and Z represents the positional relationship with respect to the female screw portion 22, which can be U (upward) or L (downward). In case 3 (with an L-shaped side cross-section and a slanted shape), the overall planar shape of the pressing surface 34 is the same as in 1cU and 1cL. In cases 3cU and 3dU (Figure 32), and 3cL and 3dL (Figure 33), in the case of lowercase d, the pressing surface 34 is set to be slightly smaller than the radius of curvature of the circular outer surface 58. As a result, the entire surface of the pressing surface 34 does not contact the outer surface 58 of the inner tube X1, and both circumferential edges of the pressing surface 34 contact the outer surface 58 of the inner tube X1. In the case of the first case, there is a gap between the outer surface 58 of the inner tube X1 in the portion between the edges of the pressing surface 34. In contrast, in the case of the second case, the pressing surface 34 is set to be slightly larger than the radius of curvature of the circular outer surface 58. As a result, the entire surface of the pressing surface 34 does not come into contact with the outer surface 58 of the inner tube X1, and only the portion between the circumferential edges of the pressing surface 34 contacts the outer surface 58 of the inner tube X1, creating a gap between the pressing surface 34 and the outer surface 58 of the inner tube X1 on both edges.

[0077] The following can be observed from the test results: 1. According to Figure 21, when the pressing body 38 with a U-shaped side cross-section is positioned above the female screw hole of the fastening screw portion with a tightening torque of 3 Nm, it was confirmed that the pressing body 38 with an L-shaped side cross-section can securely fix the inner and outer pipes X1 and X2 more firmly than the pressing body 38 (0a) with a U-shaped side cross-section. Comparing 1dU and 1cU, 1bU1 and 1aU, it was found that the longer the length of the U-shaped planar band, the greater the limit load. Comparing 1dU and 1cU, and 1bU and 1aU, it was found that the greater the distance from the female screw hole of the fastening screw portion, the greater the limit load. 2. According to Figures 22 and 23 (detailed view of displacement up to 0.08 mm in Figure 22), when the clamping body 38 with a U-shaped side cross-section is positioned below the female screw hole of the fastening screw portion with a tightening torque of 5 Nm, it was confirmed that the clamping body 38 with an L-shaped side cross-section can securely fix the inner and outer pipes X1 and X2 more firmly than the clamping body 38 with a U-shaped side cross-section. A comparison of 1DL and 1CL, and 1BL and 1AL shows that a longer length of the U-shaped strip results in a greater limit load. A comparison of 1DL and 1CL, and 1BL and 1AL shows that a greater distance from the female screw hole of the fastening screw portion results in a greater limit load. 3. According to Figure 24, when the tightening torque is 3 Nm and the L-shaped side cross-section pressing body 38 is positioned above and to the side of the female screw hole of the fastening screw portion, a comparison of 2dS, 2cS, and 2aU shows that the limit load is greater when the L-shaped side cross-section pressing body 38 is positioned to the side of the female screw hole of the fastening screw portion than when it is positioned above. A comparison of 1dU and 2aU shows that the limit load is greater when the overall planar shape is U-shaped and extends in the circumferential direction of the pipe relative to the female screw hole of the fastening screw portion than when it is elongated vertically and extends in the longitudinal direction of the pipe passing through the center of the female screw hole of the fastening screw portion. 4. According to Figure 25, when the tightening torque is 5 Nm and the L-shaped side cross-section pressing body 38 is positioned to the side of the female screw hole of the fastening screw portion, a comparison between 2FS and 2ES confirmed that a vertically elongated overall planar shape of the L-shaped side cross-section pressing surface 34 allows for stronger fixing of the inner and outer pipes X1 and X2 compared to a U-shape.Comparing 2FS and 1DL, the limit load is almost the same when the L-shaped side cross-section pressing body 38 has an overall planar shape that is elongated vertically and is positioned to the side of the female screw hole of the fastening screw portion, and when the L-shaped side cross-section pressing body 38 has an overall planar shape that is U-shaped and is positioned below the female screw hole of the fastening screw portion, and there is no difference in the firm fixing and holding of the inner and outer pipes X1 and X2. 5. According to Figure 26, when the tightening torque is 3 Nm, and the U-shaped side cross-section pressing body 38 is positioned above the female screw hole of the fastening screw portion, and the L-shaped side cross-section pressing body 38 is mounted diagonally to the tubular sleeve 54, comparing 3dU and 3cU, the limit load is greater when the pressing surface 34 is smaller. Comparing 3eU and 3bU, the limit load is greater when only the clearance hole is inclined and the female screw hole is perpendicular to the extension direction of the tubular sleeve 54 (the load receiving member is parallel to the tubular sleeve 54). 6. According to Figure 27, when the tightening torque is 3 Nm and the L-shaped side cross-section pressing body 38 is mounted diagonally to the tubular sleeve 54, a comparison of 3aL and 3bL shows that when the L-shaped side cross-section pressing body 38 is positioned below the female screw hole of the fastening screw portion, a larger inclination angle (where the female screw hole and the clearance hole are parallel) results in a larger limit load. A comparison of 3cL and 3dL shows that a smaller pressing surface 34 results in a larger limit load. A comparison of 3bL and 3hL shows that when only the clearance hole is inclined and the female screw hole is perpendicular to the extension direction of the tubular sleeve 54 (where the load-receiving member is parallel to the tubular sleeve 54), the limit load is larger. 7. According to Figure 28, when the L-shaped side cross-section pressing body 38 is mounted diagonally to the tubular sleeve 54 with tightening torques of 3, 2, and 1.6 Nm, a comparison of 3h'L, 3h''L, and 3bL with 3bU shows that the limit load is greater when the L-shaped side cross-section pressing body 38 is positioned below the female screw hole of the fastening screw portion than when it is positioned above it. In a comparison of 3h'L (2 Nm), 3h''L (1.6 Nm), and 3bL (3 Nm), the limit load is 3h''L > 3h'L > 3bL, indicating that a larger tightening torque does not necessarily correlate with a larger limit load.

[0078] In summary, firstly, it was confirmed that differences in pressing and fixing capacity arise depending on the relative positional relationship of the L-shaped side cross-section pressing body 38 with respect to the female thread portion 22 (through hole), due to differences in the wedge effect and the lever principle. Secondly, it was confirmed that differences in pressing and fixing capacity arise in the L-shaped side cross-section pressing body 38 depending on whether the female thread portion 22 (through hole) and the through hole are parallel to the thickness direction of the tubular sleeve 54 or oblique to the thickness direction of the tubular sleeve 54. Thirdly, it was confirmed that differences in pressing and fixing capacity arise in the L-shaped side cross-section pressing body 38 depending on the proportion of the female thread portion 22 (through hole) that is positioned along the longitudinal direction of the pipe passing through the center. Fourthly, it was confirmed that the existence of an optimal overall planar shape exists due to the balance relationship between the wedge effect and the lever principle in the pressing force against the outer surface 58 of the inner pipe X1, and that it is possible to reduce the occurrence of scratches and depressions on the outer surface 58 of the soft material inner pipe X1 when the wedge effect is strong. In general, compared to the press body 38 with a U-shaped side cross-section, the limit load is increased by more than twice when an L-shaped side cross-section press body 38 is used. The longitudinal fixing of the inner tube X1 and outer tube X2 depends on the frictional force between the inner and outer tubes X1 and X2. In the case of a stand made of metal inner and outer tubes X1 and X2, the degree of longitudinal fixing of the inner tube X1 and outer tube X2 varies depending on machining errors such as the roundness of the circular cross-section of the inner and outer tubes X1 and X2, and surface processing errors such as the surface smoothness. However, it was confirmed that the L-shaped side cross-section press body 38 can absorb such variations in the degree of fixing better than the press body 38 with a U-shaped side cross-section. Furthermore, it was confirmed that the limit load does not increase monotonically as the tightening force by the fastening screw portion 48 increases, but rather the limit load varies depending on the magnitude of the tightening force by the fastening screw portion 48.

[0079] Although embodiments of the present invention have been described in detail above, various modifications and changes are possible for those skilled in the art without departing from the scope of the present invention. For example, in the first to seventh embodiments, the present invention has been described as a music stand, microphone M, speaker S, and a finished music stand for musical instruments, but it is not limited to these. In an existing music stand, as long as it is necessary to firmly fix and hold the inner and outer tubes X1 and X2 in the vertical direction at the fitting portion, for example, if the fitting portion of the inner and outer tubes X1 and X2 is fixed and held by fastening a tubular sleeve 54, which has a female threaded portion 22 on its inner circumference that can be screwed onto a male threaded portion 40 on the outer circumference of the end of the outer tube X2, in the longitudinal direction of the tube, then only such a tubular sleeve 54 may be replaced with the tubular sleeve 54 of this embodiment. In this case, a female thread portion 22 may be provided on the inner circumferential surface, allowing the tubular sleeve 54 to rotate in the longitudinal direction of the pipe. Alternatively, as in the first embodiment, an annular shoulder portion 94 may be provided on the inner circumferential surface and placed on the annular end face EN of the outer pipe X2, allowing the tubular sleeve 54 to rotate in the longitudinal direction of the pipe. For example, although the first to seventh embodiments have described the design as a music stand for music, a microphone M, a speaker S, and a musical instrument, the design is not limited to these. Insofar as it is necessary to firmly fix and hold the inner and outer pipes X1 and X2 in the vertical direction at the fitting portion, a caster 96 may be provided on the end of the inner pipe X1 or outer pipe X2 opposite to the fitting portion of the inner and outer pipes X1 and X2, making it movable. The design is also applicable to medical stands such as infusion stands and monitor stands, where the outer pipe X2 or inner pipe X1 supports an IV drip, monitor, or lighting at the end of the outer pipe X2 or inner pipe X1 opposite to the fitting portion of the inner and outer pipes X1 and X2.For example, in the first embodiment, from the viewpoint of protecting the outer surface 58 of the inner tube X1, the tip of the male thread portion 40 of the fastening screw portion 48 is made to penetrate the female thread portion 22 of the outer tube X2 or tubular sleeve 54 so as not to come into contact with the outer surface 58 of the inner tube X1. However, the invention is not limited to this, and when the inner and outer tubes X1 and X2 are made of metal, in addition to the pressing surface 34 of the pressing body 38, the tip of the male thread portion 40 of the fastening screw portion 48 comes into contact with the outer surface 58 of the inner tube X1, making it possible to more firmly fix the position of the outer tube X2 relative to the inner tube X1. This is effective when the inner and outer tubes X1 and X2 are oriented vertically and either the inner or outer tube X1 or X2 supports a heavy object at a predetermined height.

[0080] For example, in the first embodiment, the fastening screw portion 48 has a male screw portion 40 and a head portion 44 that is pinched and rotated with the fingers, while the outer circumferential surface 50 of the outer tube X2 is provided with a female screw portion 22. However, the invention is not limited to this, and the male screw portion 40 may be provided on the outer circumferential surface 50 of the outer tube X2, while the fastening screw portion 48 is nut-shaped and screws onto the male screw portion 40. For example, in the first to seventh embodiments, a single pressing body 38 is made to pass through the first through hole 16, and the outer circumferential surface 58 of the inner tube X1 on the opposite side of the surface contact portion of the pressing surface 34 with the inner tube X1 is pressed and fixed against the inner circumferential surface 57 of the outer tube X2 or tubular sleeve 54. More specifically, the inner tube X1 and outer tube X2 are cylindrical, and the pressing and fixing of the outer circumferential surface 58 of the inner tube X1 with the inner circumferential surface 60 of the outer tube X2 is described as pressing and fixing the outer circumferential surface 58 of the inner tube X1 on the opposite side of the pressing and fixing portion by the pressing surface 34 against the inner circumferential surface 60 of the outer tube X2 in a manner of vertical line contact, thereby fixing and holding the outer tube X2 with respect to the inner tube X1 by support at two points. However, the invention is not limited to this, and for example, a pair of pressing bodies 38 may be provided on opposite sides of the outer tube X2 in the diametrical direction.

[0081] For example, in the fifth embodiment, when fixing and holding the inner and outer tubes X1 and X2 using the tubular sleeve 54, for the convenience of fastening the fastening screw portion 48, the tubular sleeve 54 is described as being rotated independently to a desired position, and the annular shoulder portion 94 provided on the inner circumferential surface of the tubular sleeve 54 is placed on the annular end face EN of the outer tube X2 in order to fasten the fastening screw portion 48 at that position. However, the invention is not limited to this, and if a male screw portion 40 is originally provided on the outer circumferential surface near the upper end of the outer tube X2, a female screw portion 22 that can be screwed into the male screw portion 40 may be provided on the inner circumferential surface of the tubular sleeve 54 as an alternative to the annular shoulder portion 94, and the tubular sleeve 54 may be rotated to a desired position by utilizing this screwing mechanism. For example, in the fifth embodiment, when fixing and holding the inner and outer tubes X1 and X2 using the tubular sleeve 54, for the convenience of fastening the fastening screw portion 48, the tubular sleeve 54 is rotated independently to the desired position, and in order to fasten the fastening screw portion 48 at that position, the annular shoulder portion 94 provided on the inner circumferential surface 92 of the tubular sleeve 54 is placed on the annular end face EN of the outer tube X2. However, the embodiment is not limited to this, and originally, the outer circumferential surface near the upper end of the outer tube X2 is In a conventional stand for an integrated inner and outer tube structure 10, which uses a tubular sleeve 54 having a male threaded portion 40 and a female threaded portion 22 on its inner circumference that can be screwed into the male threaded portion 40, the inner and outer tubes X1 and X2 are fixed and held in place by screwing the tubular sleeve 54 onto the outer tube X2, but the tubular sleeve 54 may be replaced with a new tubular sleeve 54 having an annular shoulder portion 94 on its inner circumference, and the tubular sleeve 54 may be rotated to the desired position by placing the annular shoulder portion 94 on the annular end face EN of the outer tube X2.

[0082] For example, in the first to fifth embodiments, the use of a single L-shaped pressing body 38 (first embodiment), the use of a pair of L-shaped pressing bodies 38 stacked on top of each other (second embodiment), the use of an angled L-shaped pressing body 38 corresponding to an angled first through hole 16 (fifth embodiment), and the use of a cylindrical pressing body 38 inserted into a female screw portion 22 (fourth embodiment) have been described. However, the invention is not limited to these, and combinations thereof, such as using a pair of L-shaped pressing bodies 38 stacked on top of each other, with an angled L-shaped pressing body 38 corresponding to an angled first through hole 16, and a cylindrical pressing body 38 inserted into a female screw portion 22, may also be used. This is useful when stably supporting heavy objects as a height-adjustable stand. For example, in the first to fifth embodiments, the L-shaped pressing body 38 was described as having an overall planar shape of the pressing surface 34 that is U-shaped, V-shaped, L-shaped, vertically elongated, or horizontally elongated, and in all cases having a constant width of the strip. However, it is not limited to this, and as long as the pressing member 36 of the L-shaped pressing body 38 penetrates the first through hole 16 and the pressing surface 34 can contact the outer circumferential surface 58 of the inner pipe X1, the width of the strip may vary regularly or irregularly. For example, in the first embodiment, the L-shaped pressing body 38 was described as having an overall planar shape of the pressing surface 34 that is U-shaped, and was arranged in a symmetrical shape with respect to the longitudinal direction of the pipe passing through the center of the female screw portion 22. However, it is not limited to this, and may be arranged in a linearly asymmetrical shape with respect to the longitudinal direction of the pipe passing through the center of the female screw portion 22, for example, one side being shorter and the other side being longer.

[0083] For example, in the first embodiment, the inner and outer tubes X1 and X2 are both circular with a constant cross-section, and the tubular sleeve 54 is placed on the annular end face EN of the outer tube X2. The tubular sleeve 54 is rotated to a desired angle position around the longitudinal direction of the tube, and the rotation of the tubular sleeve 54 is fixed by the fastening screw portion 48 via the L-shaped pressing body 38, while the inner and outer tubes X1 and X2 are fixed and held together. However, the embodiment is not limited to this, and for example, the inner tube X1 may have a constant circular cross-section, but the outer tube X In the case where the inner tube X1 is a rectangular, for example, square, shape that can be fitted inside, the tubular sleeve 54 can be held in one hand and, without placing it on the annular end face EN of the outer tube X2, the tubular sleeve 54, which is concentric with the inner tube X1, can be rotated to a desired angle around the longitudinal direction of the tube while floating on the upper, circular-section inner tube X1 side, and the rotation of the tubular sleeve 54 can be fixed in place by fastening the screw portion 48 at that height or by placing it on the annular end face EN of the outer tube X2, thereby fixing the rotation of the tubular sleeve 54 and securing the inner and outer tubes X1 and X2 to each other.

[0084] This is an overall perspective view of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is a partially exploded view of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention, passing through the center of the female thread portion and along the longitudinal line segment of the tubular sleeve. This is a perspective view of the tubular sleeve of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is a perspective view of the pressing body of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is a perspective view of the fastening thread portion of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is a conceptual diagram showing the operating principle of the integrated inner and outer pipe structure 10 according to the first embodiment of the present invention. This is an overall perspective view of the integrated inner and outer pipe structure 10 according to the second embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the second embodiment of the present invention, passing through the center of the female thread portion and along the longitudinal line segment of the tubular sleeve, and is similar to Figure 3. This is an overall perspective view of the integrated inner and outer pipe structure 10 according to the third embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the third embodiment of the present invention, passing through the center of the female thread portion and along a longitudinal line segment of the tubular sleeve, similar to Figure 3. This is a partially exploded view of the integrated inner and outer pipe structure 10 according to the third embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the fourth embodiment of the present invention, passing through the center of the female thread portion and along a longitudinal line segment of the tubular sleeve, similar to Figure 3. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the fifth embodiment of the present invention, passing through the center of the female thread portion and along a longitudinal line segment of the tubular sleeve, similar to Figure 3. This is a perspective view of the pressing body of the integrated inner and outer pipe structure 10 according to the fifth embodiment of the present invention. This is an overall perspective view of the integrated inner and outer pipe structure 10 according to the sixth embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the sixth embodiment of the present invention, passing through the center of the female thread portion and along a longitudinal line segment of the tubular sleeve, similar to Figure 3. This is a partially exploded view of the integrated inner and outer pipe structure 10 according to the seventh embodiment of the present invention. This is a perspective view of the pressing body of the integrated inner and outer pipe structure 10 according to the eighth embodiment of the present invention. This is a partial side cross-sectional view of the integrated inner and outer pipe structure 10 according to the eighth embodiment of the present invention, passing through the center of the female thread portion and along the longitudinal line segment of the tubular sleeve, and is similar to the view in Figure 3. This is a graph showing the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement.This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This graph shows the results of the limit support load measurement test, with the vertical axis representing the support load and the horizontal axis representing the displacement. This table shows the test conditions for the limit support load measurement test. This table shows the test conditions for the limit support load measurement test. This table shows the test conditions for the limit support load measurement test. This table shows the test conditions for the limit support load measurement test. This table shows the test conditions for the limit support load measurement test. This is a perspective view of the pressing body of an integrated inner and outer pipe structure according to a modified example of the first embodiment of the present invention. This is a perspective view of the pressing body of an integrated inner and outer pipe structure 10 according to a modified example of the first embodiment of the present invention.

[0085] X1 Inner tube X2 Outer tube C Clearance between pressing member and first through hole C1 Clearance between inner tube and outer tube L1 Length of pressing member L2 Length of load-bearing member L3 Longitudinal length of tubular sleeve t1 Thickness of pressing member t2 Thickness of load-bearing member th Thickness of tubular sleeve Θmax Maximum inclination angle of pressing body D Diameter of head D1 Distance between fulcrum and point of application D2 Distance between fulcrum and point of force application D3 Distance between first through hole and second through hole 10 Inner and outer tube integrated structure 12 Fitting part 14 Outer surface 16 First through hole 18 Second through hole 20 Inner surface 22 Female thread part 24 Flat part 26 Load-bearing surface 28 Oversized hole 30 Load-bearing member 32 One end of load-bearing member 33 Other end of load-bearing member 34 Pressing surface 36 Pressing member 38 Pressing body 40 Male threaded portion 41 Flat portion 42 One end of male threaded portion 44 Head portion 46 Pushing surface 48 Fastening screw portion 50 Outer surface of outer tube 52 Hollow portion 54 Tubular sleeve 55 Edge portion 56 Outer surface of tubular sleeve 57 Inner surface of tubular sleeve 58 Outer surface of inner tube 60 Inner surface of outer tube 62 Annular projection surface 64 Projection surface 66 Insertion hole 76 One end of pressing surface 82 Shank portion 84 Annular surface 86 Head portion 88 Male thread 90 Female thread 92 Inner surface of tubular sleeve 94 Annular shoulder portion 96 Caster 98 Annular surface 100 Pressing lever

Claims

1. Both are integrated inner and outer tube structures in which inner and outer tubes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer tube, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and when the pressing member penetrates the first through hole, the pressing surface presses against the outer surface of the inner tube as the load-receiving surface receives a pressing load through the pressing surface by screwing in the fastening threaded portion, An integrated inner and outer pipe structure characterized in that, by forming a clearance between the pressing surface of the pressing member and the inner circumferential surface of the first through hole, the other end of the load-receiving member is inclined toward the outer circumferential surface of the inner and outer pipes, and a wedge effect is generated at the corner including the edge of the pressing surface that is inclined toward the outer circumferential surface of the inner and outer pipes, the first through hole is provided on the outer circumferential surface of the outer pipe so as to straddle the longitudinal direction of the outer pipe passing through the center of the female thread portion of the outer pipe, and the pressing surface is set to a shape such that when inserted into the first through hole, the circumferential spread of the outer pipe and the longitudinal spread of the outer pipe are each within a predetermined range.

2. Both are integrated inner and outer tube structures in which inner and outer tubes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer tube, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and the pressing member penetrates the first through hole while the load-receiving surface receives a pressing load via the pressing surface when the fastening threaded portion is screwed in, and the pressing surface presses against the outer circumferential surface of the inner pipe, the width between the edges of the pressing surface and / or the position of the clearance hole in the load-receiving member is set such that the other end of the load-receiving member is inclined toward the outer circumferential surface of the inner and outer pipes, and the other flat portion strikes the inner edge of the first through hole, thereby increasing the pressing force against the outer circumferential surface of the inner pipe at the edge of the one flat portion of the pressing surface by the principle of leverage.

3. Both are integrated inner and outer tube structures in which inner and outer tubes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided on the outer circumferential surface near one end of the fitting portion side of the outer tube, the second through hole has a female threaded portion on its inner circumferential surface, a load receiving member having opposing flat portions, one of which has a load receiving surface, and a clearance hole penetrating in the thickness direction between the opposing flat portions, and a pressing member extending from one end of the load receiving member toward the opposite side of the load receiving surface, having opposing flat portions, and having a pressing surface at its tip, the pressing body having an L-shaped cross-section, a male threaded portion that can be screwed into the female threaded portion, and a head portion provided at one end of the male threaded portion, the head portion having a fastening screw portion on the male threaded portion side having a pressing surface that can contact the load receiving surface, The pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male threaded portion can be screwed into the female threaded portion when the pressing member is inserted into the first through hole, and when the pressing member penetrates the first through hole, the pressing surface presses against the outer surface of the inner tube as the load-receiving surface receives a pressing load through the pressing surface by screwing in the fastening threaded portion, An integrated inner and outer pipe structure characterized in that, by forming a clearance between the one flat portion of the pressing member on the load-receiving member side and the inner circumferential surface of the first through-hole, the other end of the load-receiving member is inclined toward the outer circumferential surface of the inner and outer pipes, and the other flat portion contacts the inner circumferential edge of the first through-hole, thereby creating a wedge effect at the corner of the pressing surface including the edge that is inclined toward the outer circumferential surface of the inner and outer pipes, and increasing the pressing force against the outer circumferential surface of the inner pipe at the edge of the one flat portion of the pressing surface by the lever principle, the width between the edges of both ends of the pressing surface and / or the position of the oversized hole in the load-receiving member are set while the wedge effect is exerted by the magnitude of the inclination angle of the L-shaped pressing body according to the clearance between the outer circumferential surface of the inner pipe and the inner circumferential surface of the outer pipe, in order to ensure a predetermined fixed holding of the inner and outer pipes under a given weight of the object to be supported.

4. An integrated inner and outer pipe structure according to any one of claims 1 to 3, wherein a tubular sleeve is provided at the end of the outer pipe on the fitting portion side with the inner pipe, which can be fitted onto the outer surface of the outer pipe and through which the inner pipe can pass through the inner hollow portion, and the first through hole and the second through hole are provided in the thickness direction from the outer surface of the tubular sleeve.

5. The inner and outer pipe integrated structure according to any one of claims 1 to 4, wherein the pressing body is used to penetrate the first through hole, and the pressing surface 34 is brought into surface contact with the outer surface of the outer pipe or the tubular sleeve, while the outer surface of the inner pipe opposite to the portion of the pressing surface 34 that is in surface contact with the inner pipe is pressed and fixed against the inner surface of the outer pipe or the tubular sleeve.

6. The inner and outer pipe integrated structure according to claim 5, wherein the pressing surface has a hardness such that it does not deform when pressed against the outer surface of the inner pipe, and the pressing surface is formed to conform to the outer surface of the inner pipe.

7. The inner and outer pipes are arranged so that the inner pipe extends upward and the outer pipe extends downward, and the fitting portions of the inner and outer pipes both have a circular cross-section, as described in any one of claims 1 to 4.

8. The inner tube and the outer tube are each cylindrical, and the inner tube is pressed against and fixed to the inner tube by pressing the outer tube surface on the opposite side of the pressing surface against the inner tube surface in a vertical line contact manner, thereby fixing the outer tube to the inner tube by two support points, as described in claim 7.

9. The load-bearing surface is formed as an annular projection circumferential surface around the clearance hole, the integrated inner and outer pipe structure according to any one of claims 1 to 3.

10. The integrated inner and outer pipe structure according to any one of claims 1 to 3, wherein the load-receiving surface is formed as a protruding surface on the end side of the load-receiving member.

11. The integrated inner and outer pipe structure according to any one of claims 1 to 3, wherein the load-receiving member and the pressing member are provided so as to be perpendicular to each other.

12. The integrated inner and outer pipe structure according to claim 4, wherein the clearance hole is provided on the other end side of the load-receiving member, and the tubular sleeve is provided with a through hole having a female thread on its inner circumferential surface, such that a male thread can be screwed into the through hole via the clearance hole, and the length of the male thread is set so that the tip of the male thread does not come into contact with the outer circumferential surface of the inner pipe when screwed in.

13. The overall planar shape of the pressing surface is an inverted U-shape that is penetrating the first through-hole and opening toward the second through-hole, and the integrated inner and outer pipe structure according to any one of claims 1 to 4 is provided around the second through-hole.

14. The overall planar shape of the pressing surface is an inverted V shape that is penetrating the first through hole and opening toward the second through hole, and the integrated inner and outer pipe structure according to any one of claims 1 to 4 is provided around the second through hole.

15. The overall planar shape of the pressing surface is L-shaped, allowing it to penetrate the first through-hole, and the integrated inner and outer pipe structure according to any one of claims 1 to 4 is provided around the second through-hole.

16. The integrated inner and outer pipe structure according to any one of claims 1 to 4, wherein the overall planar shape of the pressing surface is transversely elongated, passing through the center of the second through-hole and allowing it to penetrate the first through-hole.

17. The internal and external pipe integrated structure according to any one of claims 1 to 4, wherein the pressing member has a constant cross-section in the longitudinal direction and its tip surface forms the pressing surface.

18. The inverted U-shaped and inverted V-shaped pressing surfaces are each arranged symmetrically with respect to the longitudinal direction of the inner and outer tubes passing through the center of the female screw, as described in claim 13 or claim 14.

19. The inverted U-shaped pressing surface is arranged concentrically with respect to the second through hole, as described in claim 13 or claim 18.

20. The inner and outer pipe integrated structure according to claim 1 or claim 2, wherein the first through hole and the second through hole are provided parallel to each other and at a predetermined angle with respect to the extension direction of the inner and outer pipe or the tubular sleeve.

21. The integrated inner and outer pipe structure according to any one of claims 1 to 4, wherein the first through-hole is provided at a predetermined angle with respect to the extension direction of the inner and outer pipes or the tubular sleeve, while the second through-hole is set perpendicular to the outer circumferential surface of the outer pipe or the tubular sleeve.

22. The fastening screw portion comprises a shank portion and a male screw portion extending downward from the lower surface of the shank portion, the lower surface having an annular surface surrounding the male screw portion, and by screwing the male screw portion into the female screw portion through the clearance hole, the lower surface of the shank portion and the load-receiving surface of the pressing body come into contact, thereby the fastening screw portion and the pressing body are pressed and fixed together to the inner pipe and screwed into the outer pipe, as described in any one of claims 1 to 4.

23. The inner and outer pipe integrated structure according to claim 20, wherein the tightening screw portion has a head portion that can be rotated by pinching it with your fingers at the end of the shank portion opposite to the end of the male screw portion.

24. The integrated inner and outer tube structure according to claim 4, wherein the fastening of the fastening screw portion prevents rotation of the inner and outer tubes of the tubular sleeve about the longitudinal direction, while fixing and holding the inner and outer tubes in a predetermined fitting position.

25. The integrated inner and outer pipe structure according to claim 4, wherein the longitudinal length of the tubular sleeve and / or the length of the load-receiving member are set such that the tip of the male thread portion of the fastening thread portion directly presses against the outer surface of the outer pipe.

26. The inner and outer pipe integrated structure according to any one of claims 1 to 4, wherein the maximum inclination angle in which the other end of the load-receiving member of the pressing body approaches the outer surface of the outer pipe or the tubular sleeve due to the fastening of the fastening screw portion is set by the thickness of the tubular sleeve and / or the clearance between the outer surface of the inner pipe and the inner surface of the outer pipe and / or the clearance between the pressing surface and the first through hole.

27. The fixing and holding jig according to claim 4, wherein a male thread is provided on the side circumferential surface of the outer tube on one end, and a female thread that can be screwed into the male thread is provided on the inner circumferential surface of the tubular sleeve.

28. The integrated inner and outer pipe structure according to any one of claims 1 to 4, wherein the load-receiving member and the pressing member are provided to form an obtuse angle, and the clearance hole is provided near the other end of the load-receiving member.

29. The inner and outer tube integrated structure according to claim 4, wherein an annular shoulder is formed on the inner circumferential surface of the tubular sleeve, the width of the annular shoulder is such that it can be placed on the annular end face EN of the outer tube, and the tubular sleeve is rotatable about its longitudinal direction.

30. An integrated inner and outer tube structure according to any one of claims 1 to 29, which is a stand for music that supports a music stand, a musical instrument, a speaker, or an amplifier by the inner tube or the outer tube at the end opposite to the fitting portion of the inner and outer tubes.

31. An integrated inner and outer tube structure according to any one of claims 1 to 29, wherein a caster is provided on the end of the inner tube or the outer tube opposite to the fitting portion of the inner and outer tubes, making it movable, and the end of the outer tube or the inner tube opposite to the fitting portion of the inner and outer tubes supports either an intravenous drip, a monitor, or lighting.

32. The integrated inner and outer pipe structure according to claim 22, wherein the diameter of the head and the diameter and / or pitch of the male thread portion are set so that the inner and outer pipes are sufficiently fixed and held in place by tightening the fastening screw portion by hand.

33. The internal and external pipe integrated structure according to any one of claims 1 to 4, wherein the increase in the tightening force by the lever principle due to the fastening screw portion is achieved by setting the ratio of the clearance between the other flat portion of the pressing member and the center of the clearance hole and the distance between the other flat portion of the pressing member and the center of the second through hole.

34. An integrated inner and outer tube structure in which inner and outer tubes extending in the vertical direction are fitted together, wherein a first through hole and a second through hole are provided in the thickness direction on the outer circumferential surface near one end of the fitting portion side of the outer tube, the second through hole has a female thread on its inner circumferential surface, and the pressing body has an L-shaped cross-section, comprising a load-receiving member having opposing flat surfaces, one of which has a load-receiving surface, and a clearance hole that penetrates the thickness direction between the opposing flat surfaces, and a pressing member extending from one end of the load-receiving member toward the opposite side of the load-receiving surface, having opposing flat surfaces, and having a pressing surface at its tip, wherein the pressing member has a length at least longer than the depth of the first through hole, and the clearance hole is provided in the load-receiving member at a position where the male thread can be screwed into the female thread when the pressing member is inserted into the first through hole, and further comprising a pressing lever having an annular circumferential surface that rotates about an axis parallel to the load-receiving surface while in contact with the load-receiving surface, The annular circumferential surface is curved in such a way that the radius from the axis changes from a first radius to a second radius as it expands, and the pressing body is movable in the thickness direction of the first through-hole within the first through-hole by the rotation of the pressing lever, and by rotating the pressing lever about an axis provided at a predetermined height from the outer circumferential surface of the outer tube, the pressing body begins to press toward the outer circumferential surface of the inner tube at a rotation position corresponding to an intermediate radius between the first and second radii, and ends pressing toward the outer circumferential surface of the inner tube at a rotation position corresponding to the second radius, bringing the pressing surface into surface contact with the outer circumferential surface of the inner tube, and pressing and fixing the outer circumferential surface of the inner tube on the opposite side of the surface contact portion of the pressing surface with the inner tube against the inner circumferential surface of the outer tube.As the pressing lever rotates, the load-receiving surface receives a pressing load via the pressing surface, and the pressing member penetrates the first through-hole, pressing the pressing surface against the outer surface of the inner tube. This creates a clearance between the one flat portion of the pressing member on the first through-hole side and the inner surface of the first through-hole, causing the other end of the load-receiving member to tilt closer to the outer surface of the inner and outer tubes. This creates a wedge effect against the outer surface of the inner tube at the corner of the pressing surface including the edge of the one flat portion. The first through-hole is provided on the outer surface of the outer tube so as to straddle the longitudinal direction of the outer tube passing through the center of the female thread portion of the outer tube. The pressing surface is shaped such that, when inserted into the first through-hole, the circumferential and longitudinal spreads of the outer tube are within predetermined ranges.

35. A pressing body having an L-shaped cross-section, comprising a load-receiving member having a load-receiving surface and a clearance hole, and a pressing member extending from one end of the load-receiving member toward the opposite side of the load-receiving surface and having a pressing surface at its tip, and a tubular sleeve having a first through hole and a second through hole on its outer circumference, the second through hole having a female thread on its inner circumference, and a fastening screw portion having a male thread that can be screwed into the female thread and having a pressing surface that can contact the load-receiving surface; a step of preparing the above, a step of fitting the tubular sleeve having a circular cross-section on its inner circumference onto the upper end of the outer pipe, a step of fitting the inner pipe into the tubular sleeve or the outer pipe, and a step of rotating the tubular sleeve to a desired rotational position around the longitudinal direction of the outer pipe. A method for fixing and holding inner and outer pipes, comprising the steps of: tightening the fastening screw portion to press the pressing surface from the outside of the tubular sleeve toward the outer circumferential surface of the inner pipe in the thickness direction of the tubular sleeve, thereby fixing the tubular sleeve to a desired rotational position about the longitudinal direction of the outer pipe, while pressing the outer circumferential surface on the opposite side of the inner pipe toward the inner circumferential surface of the tubular sleeve or the outer pipe, thereby fixing and holding the inner and outer pipes toward each other in the longitudinal direction; and the fixing and holding step further comprising the step of creating a clearance between the one flat portion of the pressing member on the second through-hole side and the inner circumferential surface of the second through-hole, thereby inclining the other end of the load-receiving member toward the outer circumferential surface of the inner and outer pipes, and generating a wedge effect toward the outer circumferential surface of the inner pipe at the corner of the pressing surface including the edge closer to the load-receiving member.

36. The method for fixing and holding inner and outer tubes according to claim 35, further comprising the step of fixing the tubular sleeve to a desired rotational position about the longitudinal direction of the outer tube by pressing the outer tube from the outside of the tubular sleeve toward the outer surface of the outer tube in the thickness direction of the tubular sleeve, while pressing the outer surface on the opposite side of the outer tube toward the inner surface of the tubular sleeve, thereby fixing and holding the inner and outer tubes together in the longitudinal direction.

37. The method for fixing and holding inner and outer tubes according to claim 36, wherein the inner circumferential surface of the tubular sleeve is provided with a reduced diameter portion set to be larger than the diameter of the inner tube and an expanded diameter portion set to be larger than the diameter of the outer tube, an annular shoulder portion is formed at the connection portion between the reduced diameter portion and the expanded diameter portion, and the tubular sleeve is rotated at a desired rotational position around the longitudinal direction of the outer tube by placing the annular shoulder portion on the annular upper end surface of the outer tube.

38. An integrated inner and outer pipe structure in which inner and outer pipes are fitted together, wherein a through hole is provided in the thickness direction of the outer pipe on the outer circumferential surface near one end of the fitting portion side of the outer pipe, with a female thread portion formed on the inner circumferential surface; a pressing body having a shape that can be inserted into the through hole, with a load-receiving surface on one end face and a pressing surface against the outer circumferential surface of the inner pipe formed on the other end face; a fastening screw portion having a male thread portion that can be screwed into the female thread portion, and a head portion provided at one end of the male thread portion, with a push-in surface formed on the male thread portion side of the head portion that can abut the load-receiving surface; the pressing body has a length shorter than the depth of the through hole; and when the fastening screw portion is screwed in, the tip surface of the male thread portion rotates about the longitudinal direction of the male thread portion, the load-receiving surface receives a pressing load via the push-in surface, and the pressing body does not rotate together with the pressing body, and the pressing surface presses against the outer circumferential surface of the inner pipe in a tight-fitting manner through the through hole.

39. The integrated inner and outer pipe structure according to claim 38, comprising a flexible pressing body insertable into the second through hole, wherein the pressing surface has hardness such that it can be deformed into a shape that conforms to the outer surface of the inner pipe by screwing in the fastening screw portion.

40. A tubular sleeve for an integrated inner and outer structure, having an end of the outer tube on the fitting portion side with the inner tube, which can be fitted onto the outer surface of the outer tube and through which the inner tube can pass, characterized in that a first through hole and a second through hole are provided in the thickness direction on the outer surface near one end, the second through hole has a female thread on its inner surface, and further comprises a load-receiving member having opposing flat surfaces, one of which has a load-receiving surface, and a clearance hole that penetrates in the thickness direction between the opposing flat surfaces; a pressing member having an L-shaped cross-section, which extends from one end of the load-receiving member toward the opposite side of the load-receiving surface, has opposing flat surfaces, and has a pressing surface at its tip that can penetrate the first through hole and press against the outer surface of the inner tube; and a fastening screw portion having a male thread that can be screwed into the female thread, and a head portion provided at one end of the male thread, the head portion having a pressing surface formed on the male thread side that can contact the load-receiving surface.

41. The tubular sleeve for an integrated inner and outer structure according to claim 40, wherein a male thread is provided on the outer circumferential surface of one end of the outer tube, and a female thread that can be screwed onto the male thread is provided on the inner circumferential surface of the tubular sleeve.

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