Pipe holding device

A pipe holding device includes a fixed clamp member, a movable clamp member, an upper ring and a lower ring. The fixed clamp member and the movable clamp member each have inner peripheral surfaces as metal surfaces coming into contact with the outer peripheral surface of the small diameter pipe. Furthermore, inner peripheral surfaces of cylindrical bodies correspond to a first resin surface and a second resin surface coming into contact with the outer peripheral surface of the small diameter pipe, respectively. The inner peripheral surface of the cylindrical body, the inner peripheral surfaces of the fixed clamp member and the movable clamp member, and the inner peripheral surface of the cylindrical body are adjacent to one another in an axial direction of a large diameter pipe.

BACKGROUND OF THE INVENTION

The present invention relates to a pipe holding device that fixes or slidably holds pipes having different diameters.

For example, Japanese Laid-Open Patent Publication No. 2007-79437, Japanese Laid-Open Patent Publication No. 2001-159407, and German Patent Application Publication No. 10,257,515 disclose a pipe holding device of this type. The pipe holding device disclosed in Japanese Laid-Open Patent Publication No. 2007-79437 holds an upper pipe on a lower pipe extending upward from a bass drum. The pipe holding device is provided with a clamp member made of metal, a bolt inserted into a hole of the clamp member, and a T-shaped nut screwed to the bolt. With this configuration, since the clamp member holds the upper pipe by tightening the T-shaped nut, the upper pipe is fixed to the lower pipe. Since holding of the upper pipe by the clamp member is released when loosening the T-shaped nut, the upper pipe can slide with respect to the lower pipe.

The pipe holding device disclosed in Japanese Laid-Open Patent Publication No. 2001-159407 is provided with a holding tool, a bushing made of resin housed in the holding tool, a bolt inserted through both holes of the holding tool and the bushing, and a T-shaped nut screwed to the bolt. With this configuration, when turning the T-shaped nut, since a washer presses end portions of the bushing and the bushing fastens a small diameter pipe, the small diameter pipe is fixed to a large diameter pipe. Since pressing of the bushing by the washer is released when loosening the T-shaped nut, the small diameter pipe can slide with respect to the large diameter pipe.

The pipe holding device disclosed in German Patent Application Publication No. 10,257,515 is provided with a clamp, a bushing made of resin and located inside the clamp, a bolt inserted through a hole of the clamp, and a T-shaped nut screwed to the bolt. With this configuration, when turning the T-shaped nut, since the clamp fastens the bushing from the outside and the bushing fastens a small diameter pipe, the small diameter pipe is fixed to a large diameter pipe. Since fastening of the bushing by the clamp is released when loosening the T-shaped nut, the small diameter pipe can slide with respect to the large diameter pipe.

As described above, the pipe holding device disclosed in Japanese Laid-Open Patent Publication No. 2007-79437 is configured to directly hold the upper pipe by the metal clamp. For this reason, it is possible to sufficiently ensure a fixing force for fixing the upper pipe to the lower pipe, by the rigid, metal clamp. However, since the metal clamp comes into direct contact with the upper pipe, an outer peripheral surface of the upper pipe may be damaged, or when allowing the upper pipe to slide, a harsh metallic sound may be produced. Meanwhile, the pipe holding devices disclosed in Japanese Laid-Open Patent Publication No. 2001-159407 and German Patent Application Publication No. 10,257,515 are configured to directly hold the small diameter pipe by the bushing made of resin. In this case, since the resin has self-lubricating properties, it is possible to allow the small diameter pipe to smoothly slide with respect to the large diameter pipe. However, since the rigidity of the resin bushing is smaller than that of the metal clamp, it is not possible to sufficiently ensure a fixing force for fixing the upper pipe to the lower pipe.

SUMMARY OF THE INVENTION

An object of the invention is to provide a pipe holding device that is able to sufficiently ensure a fixing force for fixing the small diameter pipe to the large diameter pipe, and improves operability when allowing the small diameter pipe to slide with respect to the large diameter pipe.

In order to solve the above-described problems, according to a first aspect of the invention, there is provided a pipe holding device that fixes or slidably holds pipes having different diameters. The pipe holding device is provided with a metallic member configured to hold a small diameter pipe on a large diameter pipe, and a resin member provided on the metallic member to hold the small diameter pipe together with the metallic member, the metallic member has a metal surface that contacts an outer peripheral surface of the small diameter pipe, the resin member has a resin surface that contacts the outer peripheral surface of the small diameter pipe, and the resin surface and the metal surface are adjacent to each other in an axial direction of the large diameter pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment in which a pipe holding device10according to the invention is embodied will be described with reference toFIGS. 1 to 9.

As shown inFIG. 1, the pipe holding device10is attached to a column1of a stand for a musical instrument provided with a height adjustment function. The column1is made up of two pipes having different outer diameters. An upper pipe2as a small diameter pipe is inserted into a lower pipe3of a large diameter pipe. The pipe holding device10is fixed to an upper end of the lower pipe3. The upper pipe2is fixed or slidably held with respect to the lower pipe3via the pipe holding device10.

As shown inFIG. 2, the pipe holding device10is provided with a fixed clamp member12and a movable clamp member13as metallic members, a fastening member made up of a bolt16and a nut17, and an upper ring14and a lower ring15, which are resin members. The pipe holding device10is formed by assembling the fixed clamp member12, the movable clamp member13, the upper ring14, and the lower ring15, using the bolt16and the nut17. Furthermore, the upper ring14is a first resin member, and the lower ring15is a second resin member.

As shown inFIGS. 2 and 3, the fixed clamp member12is provided with a cylindrical base portion20to which an outer peripheral surface of the lower ring15is fitted, a annular portion21to which an outer peripheral surface of the upper ring14is fitted, and a holding portion23provided between the base portion20and the annular portion21. The fixed clamp member12holds the small diameter pipe2together with the movable clamp member13. The base portion20is coaxial with the annular portion21.

The base portion20has a lower fitting hole20ato which the outer peripheral surface of the lower ring15is fitted, and a fixing hole20bto which a leading end of the large diameter pipe3is fixed. In the fixing hole20b, a guide member18is located between the large diameter pipe3and the small diameter pipe2. The guide member18has a cylindrical portion18a, and an enlarged diameter portion18bon the upper end of the cylindrical portion18a. The enlarged diameter portion18bis engaged with an opening end of the large diameter pipe3.

The lower fitting hole20ais coaxial with the fixing hole20band is in communication with the fixing hole20b. Furthermore, a diameter of the lower fitting hole20ais smaller than a diameter of the fixing hole20b. For this reason, a step20cis formed at a boundary portion between the lower fitting hole20aand the fixing hole20b. A groove24is provided between the base portion20and the holding portion23. The groove24is provided on a side opposite to the movable clamp member13. The groove24extends along the inner peripheral surface of the lower fitting hole20a.

As shown inFIGS. 4 to 6, the holding portion23has a shape that is substantially symmetrical to the movable clamp member13with respect to an axis C1of the fixed clamp member12. A proximal end of the movable clamp member13is pivotally connected to one side portion of the holding portion23via a connecting pin25. In the other side portion of the holding portion23, an insertion hole23ainto which the bolt16is inserted is formed. Furthermore, at a leading end of the movable clamp member13, an insertion hole13ainto which the bolt16is inserted is also formed. By fastening the nut17to the bolt16inserted through the both insertion holes23aand13a, the leading end of the movable clamp member13is fixed to the holding portion23. Thus, since the fixed clamp member12and the movable clamp member13grip the small diameter pipe2therebetween, the small diameter pipe2is held so as not to move with respect to the large diameter pipe3. That is, the small diameter pipe2is fixed to the large diameter pipe3via the pipe holding device10.

The holding portion23has an inner peripheral surface23d, which is a metal surface, coming into contact with an outer peripheral surface of the small diameter pipe2. The movable clamp member13also has an inner peripheral surface13d, which is a metal surface, coming into contact with the outer peripheral surface of the small diameter pipe2. Both inner peripheral surfaces23dand13dare arcuate surfaces centered on the axis C1of the fixed clamp member12. Both inner peripheral surfaces23dand13dform a holding hole23bfor holding the small diameter pipe2. The holding hole23bextends along the axis C1of the fixed clamp member12.

As shown inFIGS. 2 and 3, the annular portion21has an upper fitting hole21ato which the outer peripheral surface of the upper ring14is fitted, and an insertion hole21binto which the connecting pin25is inserted. A groove27is provided between the annular portion21and the holding portion23. The groove27is provided on a side opposite to the movable clamp member13. The groove27extends along an inner peripheral surface of the upper fitting hole21a.

The upper ring14is provided with a cylindrical body14afitted into the upper fitting hole21a. At a proximal end of the cylindrical body14a, a protruding portion14band a flange14care formed. The protruding portion14band the flange14cprotrude outward from the outer peripheral surface of the cylindrical body14a, respectively. The flange14cis provided on a side opposite to the protruding portion14bwith respect to the center of the cylindrical body14a. The upper ring14is mounted into the upper fitting hole21aof the annular portion21in a state in which a leading end of the cylindrical body14afaces upward. In this state, the protruding portion14bis engaged with the groove27of the fixed clamp member12, and the flange14cis located between the lower end surface of the annular portion21and the upper end surface of the movable clamp member13.

The lower ring15is provided with a cylindrical body15afitted to the lower fitting hole20a. At the proximal end of the cylindrical body15a, a protruding portion15band a flange15care formed. The protruding portion15band the flange15cprotrude outward from the outer peripheral surface of the cylindrical body15a, respectively. The flange15cis provided on a side opposite to the protruding portion15bwith respect to the center of the cylindrical body15a. The lower ring15is mounted to the lower fitting hole20aof the base portion20in a state in which the leading end of the cylindrical body15afaces downward. In this state, the protruding portion15bis engaged with the groove24of the fixed clamp member12, and the flange15cis located between the lower end surface of the movable clamp member13and the upper end surface of the base portion20. The lower ring15has a shape that is substantially symmetrical to the upper ring14.

The upper ring14, the lower ring15, and the guide member18are formed of the resin material of the same kind. As the resin material, materials having high strength and wear resistance and having excellent moldability and self-lubricating properties are used, and specifically, nylon, polyacetal, or the like is used. The thickness of the cylindrical body14ais set to be greater than the thickness of the cylindrical body15a. Furthermore, the thickness of the cylindrical portion18ais set to be greater than the thickness of the cylindrical body15aand smaller than the thickness of the cylindrical body14a.

As shown inFIGS. 4, 7 and 8, the upper ring14has a holding hole14ethat holds the small diameter pipe2on the inside of the cylindrical body14a. The inner peripheral surface14dof the cylindrical body14ais a first resin surface that comes into contact with the outer peripheral surface of the small diameter pipe2. The lower ring15also has a holding hole15ethat holds the small diameter pipe2on the inside of the cylindrical body15a. The inner peripheral surface15dof the cylindrical body15ais a second resin surface that comes into contact with the outer peripheral surface of the small diameter pipe2.

Next, the operation of the above-described pipe holding device10will be described.

First, a state in which the small diameter pipe2is fixed to the large diameter pipe3by the pipe holding device10will be described.

As shown inFIG. 3, the upper ring14is located so that both inner peripheral surfaces23dand13dof the clamp members12and13are between the inner peripheral surface14dof the cylindrical body14aand the leading end of the large diameter pipe3. The lower ring15is located so that the inner peripheral surface15dof the cylindrical body15ais between the inner peripheral surfaces23dand13dof the clamp members12and13and the leading end of the large diameter pipe3. The guide member18is located so that the inner peripheral surface15dof the cylindrical body15ais between the inner peripheral surface18dof the cylindrical portion18aand the inner peripheral surfaces23dand13dof the clamp members12and13.

The inner diameter of the cylindrical body14ais set to be the same as the diameter of the holding hole23b, which is defined by the inner peripheral surfaces23dand13d, the inner diameter of the cylindrical body15a, and the inner diameter of the cylindrical portion18a. Furthermore, the cylindrical body14ais coaxial with the holding hole23b, the cylindrical body15a, and the cylindrical portion18a. For this reason, the inner peripheral surface14dof the cylindrical body14a, the inner peripheral surfaces23dand13dof the clamp members12and13, the inner peripheral surface15dof the cylindrical body15a, and the inner peripheral surface18dof the cylindrical portion18aare adjacent to one another in the axial direction of the large diameter pipe3, in the following order: the inner peripheral surface14d, the inner peripheral surfaces23dand13d, the inner peripheral surface15d, and the inner peripheral surface18d. Furthermore, the inner peripheral surface14dof the cylindrical body14a, the inner peripheral surfaces23dand13dof the clamp members12and13, the inner peripheral surface15dof the cylindrical body15a, and the inner peripheral surface18dof the cylindrical portion18aare located on the same cylindrical surface.

In this state, the outer peripheral surface of the small diameter pipe2is held by the fixed clamp member12and the movable clamp member13and by the upper ring14and the lower ring15. The inner peripheral surface14dof the cylindrical body14aand the inner peripheral surface15dof the cylindrical body15aare resin surfaces, and the inner peripheral surfaces23dand13dof the clamp members12and13are metal surfaces. Metal is harder than resin, and has higher rigidity. In this case, the small diameter pipe2is directly held by the inner peripheral surfaces23dand13dof the clamp members12and13, which have higher rigidity. For this reason, the fixing force for fixing the small diameter pipe2to the large diameter pipe3is sufficiently ensured by the pipe holding device10. Further, since the inner peripheral surface14dof the cylindrical body14a, the inner peripheral surfaces23dand13dof the clamp members12and13, and the inner peripheral surface15dof the cylindrical body15aare located on the same cylindrical surface, substantially uniform holding force is applied to the outer peripheral surface of the small diameter pipe2held by the pipe holding device10.

Next, a state in which fixing of the small diameter pipe2due to the pipe holding device10is released will be described.

As shown inFIG. 9, by releasing the holding of the small diameter pipe2by the fixed clamp member12and the movable clamp member13, the small diameter pipe2is held by the inner peripheral surfaces14dand15dof the cylindrical bodies14aand15aand the inner peripheral surface18dof the cylindrical portion18a. Resin is softer than metal and has self-lubricating properties. In this case, the small diameter pipe2can slide on the inner peripheral surfaces14dand15dof the cylindrical bodies14aand15aand the inner peripheral surface18dof the cylindrical portion18a, which have self-lubricating properties.

In this case, the protruding portion14bis engaged with the groove27of the fixed clamp member12, and the flange14cis in contact with the lower end surface of the annular portion21. Further, the protruding portion15bis engaged with the groove24of the fixed clamp member12, and the flange15cis in contact with the upper end surface of the base portion20. For this reason, even when the small diameter pipe2is caused to slide up and down with respect to the large diameter pipe3(caused to telescope), the upper ring14is held to prevent its escape from the annular portion21, by the protruding portion14band the flange14c. Furthermore, the lower ring15is also held to prevent its escape from the base portion20, by the protruding portion15band the flange15c.

Therefore, according to this exemplary embodiment, it is possible to obtain the following effects.

(1) The pipe holding device10is provided with the fixed clamp member12and the movable clamp member13, and the upper ring14and the lower ring15. The fixed clamp member12and the movable clamp member13each have inner peripheral surfaces23dand13das metal surfaces that come into contact with the outer peripheral surface of the small diameter pipe2. Further, the inner peripheral surfaces14dand15dof the cylindrical bodies14aand15acorrespond to a first resin surface and a second resin surface coming into contact with the outer peripheral surface of the small diameter pipe2, respectively. The inner peripheral surface14dof the cylindrical body14a, the inner peripheral surfaces23dand13dof the clamp members12and13, and the inner peripheral surface15dof the cylindrical body15aare adjacent to one another in the axial direction of the large diameter pipe3.

With this configuration, when fixing the small diameter pipe2to the large diameter pipe3, it is possible to hold the outer peripheral surface of the small diameter pipe2by the clamp members12and13and the rings14and15. In this case, since the small diameter pipe2is directly held by the metal surface having the rigidity, it is possible to sufficiently ensure a fixing force for fixing the small diameter pipe2to the large diameter pipe3. When releasing the fixation of the small diameter pipe2to the large diameter pipe3, since the holding of the small diameter pipe2by the clamp members12and13is released, it is possible to hold the small diameter pipe2only by the resin surface of the rings14and15. In this case, it is possible to allow the small diameter pipe2to smoothly slide along the resin surface, which has self-lubricating properties. Thus, the operability when allowing the small diameter pipe2to slide with respect to the large diameter pipe3is improved. Furthermore, since the clamp members12and13do not directly come into contact with the small diameter pipe2, the outer peripheral surface of the small diameter pipe2is not damaged, and a the harsh metallic sound is not generated when sliding the small diameter pipe2.

(2) The upper ring14is located so that inner peripheral surfaces23dand13dof the clamp members12and13are between the inner peripheral surface14dof the cylindrical body14aand the leading end of the large diameter pipe3. Furthermore, the lower ring15is located so that the inner peripheral surface15dof the cylindrical body15ais between the inner peripheral surfaces23dand13dof the clamp members12and13and the leading end of the large diameter pipe3. With this configuration, it is possible to allow the inner peripheral surfaces14dand15dof the rings14and15, which are resin surfaces, to adjoin both sides (opposite sides) of the inner peripheral surfaces23dand13dof the clamp members12and13, which are metal surfaces. Thus, the posture of the small diameter pipe2fixed to the large diameter pipe3is further stabilized. Furthermore, since it is possible to suppress the fluctuation of the small diameter pipe2with respect to the large diameter pipe3, the operability when allowing the small diameter pipe2to slide with respect to the large diameter pipe3is further improved.

(3) The inner peripheral surface14dof the cylindrical body14a, the inner peripheral surfaces23dand13dof the clamp members12and13, the inner peripheral surface15dof the cylindrical body15a, and the inner peripheral surface18dof the cylindrical portion18aare located on the same cylindrical surface. With this configuration, it is possible to improve the holding force of the small diameter pipe2due to the clamp members12and13and the rings14and15. Therefore, it is possible to further increase the fixing force for fixing the small diameter pipe2to the large diameter pipe3.

(4) The fixed clamp member12is provided with the cylindrical base portion20to which the outer peripheral surface of the lower ring15is fitted, and the annular portion21to which the outer peripheral surface of the upper ring14is fitted. With this configuration, by fitting the lower ring15and the upper ring14to each of the base portion20and the annular portion21, when releasing the fixing of the small diameter pipe2with respect to the large diameter pipe3, it is possible to maintain a constant internal diameter of both rings14and15. In this case, since the constant contact pressure of both rings14and15with respect to the outer peripheral surface of the small diameter pipe2is kept, it is possible to allow the small diameter pipe2to smoothly slide along the inner peripheral surfaces14dand15dof both rings14and15. Thus, the operability when allowing the small diameter pipe2to slide with respect to large diameter pipe3is further improved.

(5) Since the leading end of the movable clamp member13is fixed to the holding portion23by fastening the nut17to the bolt16inserted into both insertion holes23aand13a, the fixed clamp member12and the movable clamp member13grip the small diameter pipe2. With this configuration, the fastening force of the fastening member is applied to the entire outer peripheral surface of the small diameter pipe2. Thus, the holding force of the small diameter pipe2due to the clamp members12and13and the rings14and15is further improved, and it is possible to further increase the fixing force for fixing the small diameter pipe2to the large diameter pipe3.

(6) The upper ring14is provided with the cylindrical body14afitted to the upper fitting hole21a. The protruding portion14bis formed at the proximal end of the cylindrical body14a. The protruding portion14bis engaged with the groove27of the fixed clamp member12. With this configuration, it is difficult for the upper ring14to fall out of the fixed clamp member12. Similarly, it is difficult for the lower ring15to fall out of the fixed clamp member12, by engaging the protruding portion15bwith the groove24of the fixed clamp member12.

(7) In the state of releasing the holding of the small diameter pipe2due to the fixed clamp member12and the movable clamp member13, the protruding portion14bis engaged with the groove27of the fixed clamp member12, and the flange14cis in contact with the lower end surface of the annular portion21. In addition, the protruding portion15bis engaged with the groove24of the fixed clamp member12, and the flange15cis in contact with the upper end surface of the base portion20. With this configuration, it is more difficult for each of the upper ring14and the lower ring15to fall out of the fixed clamp member12.

(8) The flanges14cand15care formed at the proximal ends of the cylindrical bodies14aand15a, respectively. In the state of fixing the small diameter pipe2to the large diameter pipe3by the pipe holding device10, the flange14cis located between the lower end surface of the annular portion21and the upper end surface of the movable clamp member13. Furthermore, the flange15cis located between the lower end surface of the movable clamp member13and the upper end surface of the base portion20. With this configuration, it is possible to reliably hold both rings14and15within the clamp members12and13.

(9) The guide member18is located between the large diameter pipe3and the small diameter pipe2. With this configuration, the posture of the small diameter pipe2fixed to the large diameter pipe3is further stabilized. Further, since the fluctuation of the small diameter pipe2with respect to the large diameter pipe3is also suppressed, the operability when allowing the small diameter pipe2to slide with respect to large diameter pipe3is further improved.

In addition, this exemplary embodiment may be modified as follows.

In this exemplary embodiment, as illustrated inFIG. 10, the lower ring15may be excluded from the pipe holding device10. Even in this configuration, as compared to the case of providing the ring as the resin member between the metal surfaces of the clamp members12and13and the leading end of the large diameter pipe3, the posture of the small diameter pipe2fixed to the large diameter pipe3is further stabilized.

In this exemplary embodiment, as shown inFIG. 11, a screw hole30amay be formed in the cylindrical metallic member30fixed to the large diameter pipe3, thereby fastening the bolt31screwed into the screw hole30a. In this case, the small diameter pipe2is pressed against the inner wall surface30bof the metallic member30and fixed by the leading end of the bolt31.

In this exemplary embodiment, the upper ring14and the lower ring15were used as the resin member, but a resin member40constituted by integrating the upper ring, the lower ring, and the guide member of the first embodiment may be used. For example, as illustrated inFIGS. 12 and 13, the resin member40has an upper annular portion41fitted to the annular portion21of the fixed clamp member12, and a lower annular portion42fitted to the base portion20of the fixed clamp member12. The resin member40is formed as a cylindrical body having an axis. The upper annular portion41has an opening41aat the position where the movable clamp member13is located. The upper annular portion41has a protruding portion41bthat protrudes in a direction perpendicular to the axis of the resin member40from the outer peripheral surface of the lower annular portion42. In the annular portion21of the fixed clamp member12, a recess portion21cas an engaging groove engaged with the protruding portion41bis formed.

The lower annular portion42has a flange portion42aand a cylindrical guide portion42b. The flange portion42ais located on a side opposite to the protruding portion41bof the upper annular portion41with respect to the axis of the resin member40. The flange portion42ais located between the lower end surface of the movable clamp member13and the upper end surface of the base portion20. The guide portion42bis located between the inner peripheral surface of the large diameter pipe3and the outer peripheral surface of the small diameter pipe2. The resin member40is located to allow the resin surface40dto adjoin both sides of the inner peripheral surface13dof the movable clamp member13, which is a the metal surface.

With this configuration, since the movable clamp member13and the resin member40grip the small diameter pipe2therebetween by fastening the nut17, the small diameter pipe2is held so as not to move with respect to the large diameter pipe3. Furthermore, according to the pipe holding device50, the resin member40has the cylindrical guide portion42blocated between the inner peripheral surface of the large diameter pipe3and the outer peripheral surface of the small diameter pipe2. For this reason, the posture of the small diameter pipe2fixed to the large diameter pipe3is further stabilized. Further, since the fluctuation of the small diameter pipe2with respect to the large diameter pipe3is also suppressed, the operability when allowing the small diameter pipe2to slide with respect to the large diameter pipe3is further improved.

In this exemplary embodiment, the flanges14cand15cmay be excluded from the upper ring14and the lower ring15, respectively.

In this exemplary embodiment, the guide member18located between the large diameter pipe3and the small diameter pipe2may be excluded.

In this exemplary embodiment, as the upper ring14and the lower ring15, a ring in which a surface of substrate is coated with fluorine resin may be used.

In this exemplary embodiment, the pipe holding device10may also be applied to a microphone stand having a height adjustment function or a horizontal bar having a length adjustment function, in addition to the stands for musical instrument.