End pin stopper

Abstract

This endpin stopper significantly reduces unwanted vibrations (vibrations in the low-amplitude range) generated by stringed instruments, allowing the pure sound of the stringed instrument to be delivered clearly to the audience. It also provides an endpin stopper with adjustable vibration damping capabilities depending on the situation. [Solution] An endpin stopper comprising a support frame with a stopper hole on its surface side for the tip of the endpin to abut against, and a vibration damping plate made of Fe-Al alloy, wherein the vibration damping plate is fitted from the back side of the support frame, and the support frame and vibration damping plate are detachably fixed together by a magnet.

Description

Technical Field

[0001] The present invention relates to a stopper for fixing the position of a fulcrum of an endpin provided on a stringed instrument such as a cello or a double bass. Background Art

[0002] At the bottom of large low-pitched stringed instruments such as cellos, double basses, and bass clarinets, there is a rod-shaped metal part that stands on the floor to support the instrument, and this metal part is called an endpin. The tip of the endpin abuts against the floor surface, which can support the weight of the instrument body and fix its position, and also has the role of transmitting vibration to the floor to amplify the sound.

[0003] Here, the tip of the endpin is acute, and if used as it is, it will damage the floor surface. Therefore, many performers place a member called an endpin stopper on the floor, and perform while taking care to prevent the tip of the endpin from directly touching the floor surface. In addition, since endpin stoppers affect the operability of the instrument and the sound perceived by the audience, endpin stoppers of various shapes and materials have been proposed.

[0004] For example, in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-110315), with the problem of "providing an endpin stopper for a stringed instrument that enables stable performance without slipping of the endpin stopper even when the floor material is a fiber floor covering such as a carpet or a rug whose base has fibers exposed", there is disclosed "an endpin stopper for a stringed instrument placed on a floor surface, wherein the endpin stopper comprises a main body having an endpin receiving portion for supporting the endpin and a contact portion with the floor surface, the main body for supporting the endpin is formed of urethane elastomer, and the contact portion with the floor surface is formed of urethane gel".

[0005] In the endpin stopper described in Patent Document 1, it is stated that "if the contact surface of the endpin stopper is made of urethane gel, which is an extremely soft material that even fibers can penetrate, it will not slip even on carpets," and "even if the flooring is a fibrous floor covering such as a carpet or rug with fibers protruding from the base, the endpin stopper will not slip, allowing for stable playing."

[0006] Furthermore, Patent Document 2 (Japanese Patent Publication No. 2021-67854) discloses an endpin stopper for supporting the endpin of a cello or double bass that "contributes to improving the playing effect of low-pitched string instruments and achieves durability and long-term performance maintenance," and describes an endpin stopper "formed by cutting only a disc made by cutting a brass rod to a predetermined thickness, wherein one of the cut surfaces of the disc has a concave spherical endpin receiving portion for contacting the tip of the endpin, a concave tapered inclined surface that slopes gently toward the endpin receiving portion, and a plurality of guide grooves that extend radially toward the inclined surface with the endpin receiving portion as the center."

[0007] The endpin stopper described in Patent Document 2 states that "an endpin stopper formed by cutting a brass rod to a predetermined thickness and then applying only machining to the disc is more durable than an endpin stopper composed of multiple parts, and can maintain its initial performance over a long period of time," and that "it can improve the acoustic effect in the frequency range that is particularly important for bass string instruments." [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2023-110315 [Patent Document 2] Japanese Patent Publication No. 2021-67854 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Since an endpin stopper is inserted between the stringed instrument and the floor, it affects the sound (vibration) emitted from the instrument. In other words, the sound perceived by the audience changes significantly depending on the endpin stopper. However, the endpin stopper described in Patent Document 1 above does not take this aspect into consideration at all.

[0010] Furthermore, while the endpin stopper described in Patent Document 2 is said to "improve acoustic effects in frequency bands that are particularly important in low-pitched string instruments," the material used is brass, and therefore it cannot cut out extraneous vibrations (vibrations in the small amplitude range) to achieve the effect of clarifying subtle sounds.

[0011] In addition, the endpin stopper described in Patent Document 2 is made entirely of brass, and it is not possible to adjust the characteristics of the endpin stopper in relation to the sound perceived by the audience, depending on the type of stringed instrument, the condition of the floor, the conditions of the performance hall, etc.

[0012] In view of the problems of the prior art described above, the object of the present invention is to provide an endpin stopper that can significantly cut out extraneous vibrations (vibrations in the low amplitude range) generated from stringed instruments, thereby delivering the pure sound of the stringed instrument clearly to the audience. Furthermore, the present invention also aims to provide an endpin stopper whose vibration damping performance can be adjusted according to the situation. [Means for solving the problem]

[0013] In order to achieve the above objective, the inventors diligently researched the structure, configuration, and materials of the endpin stopper. As a result, they found that a structure having a main body and a vibration damping plate, and making the vibration damping plate containing an Fe-Al alloy detachable from the main body using a magnet, is extremely effective, leading to the present invention.

[0014] In other words, the present invention is An outer frame of the support device is provided with a stopper hole into which the tip of the end pin can be abutted, It has a vibration damping plate made of Fe-Al alloy, The vibration damping plate is fitted onto the back side of the outer frame of the support, and the outer frame of the support and the vibration damping plate are detachably fixed together by magnets. We provide an endpin stopper characterized by the following.

[0015] Fe-Al alloys are often noted for their excellent vibration damping properties, but they are also ferromagnetic. This invention makes maximum use of the characteristics of Fe-Al alloys as ferromagnetic materials with vibration damping properties, and one of its features is that the vibration damping plate can be easily and simply attached to and detached from the support frame using magnets. By making the vibration damping plate detachable from the support frame, it is easy to replace it with a vibration damping plate of a different shape or thickness, and it becomes possible to select an appropriate vibration damping plate according to the type of string instrument used, the conditions of the performance hall, etc.

[0016] If the outer frame of the support is made of a magnetic material, the damping plate can be directly fixed to the outer frame of the support by a magnet. If the outer frame of the support is not made of a magnetic material, for example, a magnetic material such as an iron-based material can be bonded or attached to the inside of the outer frame of the support, and the damping plate can then be fixed to the outer frame of the support by a magnet. Here, magnets may also be bonded or attached to the damping plate made of Fe-Al alloy.

[0017] Furthermore, because Fe-Al alloy exhibits high vibration damping properties for vibrations in the small amplitude range, resonance (noise) caused by vibrations transmitted from the endpin of a stringed instrument to the floor is efficiently cut off, allowing both the performer and the audience to clearly perceive the pure sound of the instrument. As a result, the performer can play as intended, and the audience can hear even the subtlest nuances of the sound.

[0018] Furthermore, the endpin stopper of the present invention not only cuts out resonance and clarifies the sound of stringed instruments, but can also be used as a booster by having a configuration that allows the sound to resonate after the effect of the vibration damping plate has been achieved. In this case, for example, a suitable metal material can be provided around or below the vibration damping plate.

[0019] Furthermore, it is preferable that the endpin stopper of the present invention has a vibration damping plate thickness of 1 to 6 mm. While Fe-Al alloys generally have poor formability, a vibration damping plate thickness of 1 mm or more allows for easy and inexpensive manufacturing. In addition, a vibration damping plate thickness of 1 mm or more ensures sufficient vibration damping for all stringed instruments. On the other hand, while Fe-Al alloys are more expensive than carbon steel, a vibration damping plate thickness of 6 mm or less reduces the amount of material used, making the vibration damping plate inexpensive.

[0020] Furthermore, it is preferable that the endpin stopper of the present invention uses a neodymium magnet. A neodymium magnet is a rare-earth magnet whose main components are neodymium, iron, and boron. In addition to being a powerful permanent magnet, neodymium magnets are inexpensive and can be mass-produced, allowing the vibration damping plate to be sufficiently firmly fixed to the outer frame of the support and enabling the endpin stopper to be made at a low price.

[0021] Furthermore, it is preferable that the end pin stopper of the present invention has a magnet inserted into a through hole in the vibration damping plate, and that the vibration damping plate and the magnet are of the same thickness. The shape, size, and installation position of the magnet are not particularly limited as long as they do not impair the effects of the present invention, but by inserting a magnet of the same thickness as the vibration damping plate into the through hole in the vibration damping plate, the surface of the vibration damping plate and the surface of the magnet can be made to the same height, and the vibration damping plate and the outer frame of the support can be easily fixed without impairing the vibration damping performance of the vibration damping plate.

[0022] Further, in the endpin stopper of the present invention, it is preferable that the support outer frame is made of any one of thermoplastic resin, brass and aluminum. By forming the support outer frame from a thermoplastic resin or aluminum, the shape of the abutment hole or the like provided in the support outer frame can be formed simply and easily, and mass production of the support outer frame can be achieved. In addition, since thermoplastic resin and aluminum are lightweight, the weight of the endpin stopper can be reduced. The endpin stopper is carried by the performer, and weight reduction is one of the required characteristics thereof. On the other hand, forming the support outer frame from brass can impart a high-grade feel to the endpin stopper. In addition, brass is easier to cut than other metal materials, and an increase in processing costs can be suppressed.

[0023] Further, in the endpin stopper of the present invention, it is preferable that the damping plate contains 6.0 to 10.0% by mass of Al, with the balance being Fe and unavoidable impurities, and has an average crystal grain size of 20 to 40 µm. By forming the damping plate from an Fe-Al alloy containing 6.0 to 10.0% by mass of Al, sufficient damping performance can be imparted to the damping plate. In addition, although Fe-Al alloys have poor plastic workability, by refining the crystal grains to set the average crystal grain size to 20 to 40 µm, a plate material having a thickness of 1 to 6 mm can be efficiently obtained by rolling.

[0024] Furthermore, in the endpin stopper of the present invention, it is preferable that the damping plate has a loss factor (η) of 0.05 or more for sound with an amplitude of 5 to 15 µm. Since the loss factor (η) is 0.05 or more for sound with an amplitude of 5 to 15 µm, resonance (noise) caused by vibration transmitted from the endpin of a string instrument to the floor is extremely efficiently cut off, enabling both the performer and the audience to clearly perceive the pure sound of the instrument. As a result, the performer can perform as they intend, and the audience can hear even fine sounds.

Effect of the Invention

[0025] According to the present invention, it is possible to provide an endpin stopper that can significantly cut out unwanted vibrations (vibrations in the low amplitude range) generated from stringed instruments, thereby delivering the pure sound of the stringed instrument clearly to the audience. Furthermore, the present invention can also provide an endpin stopper that can adjust the vibration damping performance according to the situation. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram relating to one embodiment of the end pin stopper of the present invention. [Figure 2] This is a schematic diagram relating to one embodiment of the end pin stopper of the present invention. [Figure 3] This is a schematic diagram relating to one embodiment of the end pin stopper of the present invention. [Figure 4] This is a schematic cross-sectional view showing an example of a booster incorporating the endpin stopper of the present invention. [Figure 5] This is a photograph of the surface view of an end pin stopper obtained as an embodiment of the present invention. [Figure 6] This is a photograph of the back side of an endpin stopper obtained as an embodiment of the present invention. [Figure 7] This is a photograph of the exterior view with the vibration damping plate removed from the outer frame of the support structure. [Figure 8] This is a photograph of the exterior of a vibration damping plate with an anti-slip surface on the back. [Figure 9] This is a photograph of the external appearance of a booster equipped with the endpin stopper of the present invention. [Figure 10] This is a photograph showing the booster with the endpin stopper removed. [Figure 11] This is the result of the structural observation of the vibration damping plate. [Figure 12] This is an example of a damping curve obtained from an accelerometer attached to a vibration damping plate. [Figure 13] This is an example of a damping curve obtained from an accelerometer attached to an SPCC plate. [Modes for carrying out the invention]

[0027] The following describes in detail some typical embodiments of the endpin stopper of the present invention with reference to the drawings, but the present invention is not limited to these embodiments.

[0028] 1. Main components of the endpin stopper Figure 1 shows a schematic cross-sectional view, a schematic view from the back, and a schematic view from the front of one embodiment of the endpin stopper of the present invention. The endpin stopper 2 has a support frame 4 and a vibration damping plate 6, and the vibration damping plate 6 is fitted to the back side of the support frame 4. A stopper hole 8 into which the tip of the endpin is inserted is provided approximately in the center of the support frame 4, and an annular projection 10 is provided around the stopper hole 8.

[0029] The abutment hole 8 of the support frame 4 is a through hole, and by inserting the endpin into the abutment hole 8, the stringed instrument can be held stably during performance. Furthermore, the tip of the endpin abuts against the vibration damping plate 6, and since the vibration damping plate 6 is located between the endpin and the floor, resonance (noise) caused by vibrations transmitted from the endpin to the floor is efficiently cut off, allowing the performer and audience to clearly perceive the pure sound of the instrument. The diameter of the abutment hole 8 and the height and width of the annular protrusion should be designed so that the endpin can be inserted and held.

[0030] Furthermore, the vibration damping plate 6 is detachably fixed to the support frame 4 by magnets 12. In this embodiment, magnets 12 are attached to the support frame 4, and the vibration damping plate 6 and the support frame 4 are integrally fixed by the magnets 12. The shape, size, type and placement of the magnets 12 are not particularly limited as long as they do not impair the effects of the present invention, and can be adjusted as appropriate so that the support frame 4 and the vibration damping plate 6 are sufficiently fixed. However, it is preferable to use neodymium magnets, which have strong magnetic force and are inexpensive, and to place the smallest possible magnets 12 at the ends of the support frame 4 and the vibration damping plate 6.

[0031] The material of the support frame 4 is not particularly limited as long as it does not impair the effects of the present invention, and various metal materials and resin materials can be used. As for the metal material, non-ferrous metals are preferred, and aluminum (including aluminum alloys) and brass are more preferred. As for the resin material, thermoplastic resins are preferred.

[0032] The vibration damping plate 6 is made of Fe-Al alloy, and it is preferable that the entire vibration damping plate 6 is made of Fe-Al alloy, but a part of the vibration damping plate 6 may be made of a material other than Fe-Al alloy. The Fe-Al alloy preferably contains 6.0 to 10.0 mass% Al, with the remainder being Fe and unavoidable impurities. By making the vibration damping plate an Fe-Al alloy containing 6.0 to 10.0 mass% Al, sufficient vibration damping properties can be imparted to the vibration damping plate. In addition, it is preferable that the average grain size of the Fe-Al alloy is 20 to 40 μm. Although Fe-Al alloy has poor plastic workability, by refining the grains to an average grain size of 20 to 40 μm, a plate material with a thickness of 1 to 6 mm can be efficiently obtained by rolling.

[0033] The thickness of the vibration damping plate 6 is preferably 1 to 6 mm. While Fe-Al alloys generally have poor formability, a thickness of 1 mm or more allows for easy and inexpensive manufacturing of the vibration damping plate 6. Furthermore, a thickness of 1 mm or more ensures sufficient vibration damping for all stringed instruments. On the other hand, while Fe-Al alloys are more expensive than carbon steel, a thickness of 6 mm or less reduces the amount of material used, making the vibration damping plate 6 more affordable.

[0034] The vibration damping plate 6 preferably has a loss coefficient (η) of 0.05 or higher for sounds with an amplitude of 5 to 15 μm. A loss coefficient (η) of 0.05 or higher for sounds with an amplitude of 5 to 15 μm effectively cuts out resonance (noise) caused by vibrations transmitted from the endpin of a stringed instrument to the floor, allowing both the performer and the audience to clearly perceive the pure sound of the instrument. As a result, the performer can play as intended, and the audience can hear even the subtlest nuances of the sound.

[0035] It is preferable to provide an anti-slip surface on the bottom surface of the vibration damping plate 6. Since the bottom surface of the vibration damping plate 6 comes into contact with the floor surface, providing an anti-slip surface will enable stable performance. The type and placement of the anti-slip surface are not particularly limited as long as they do not impair the effects of the present invention, but for example, a thin resin material can be attached in a grid pattern to the entire bottom surface of the vibration damping plate 6.

[0036] The size of the endpin hole 8 depends on the type of stringed instrument and the player's preference, but it is preferable that the diameter be 1 to 3 cm. A diameter of 1 cm or more for the endpin hole 8 allows for easy insertion of the endpin, while a diameter of 3 cm or less helps to prevent the endpin's position from changing significantly during performance.

[0037] Furthermore, the height of the inner wall of the annular projection 10 provided around the abutment hole 8 depends on the type of stringed instrument and the player's preference, but is preferably 0.5 to 2 cm. Setting the height of the inner wall to 0.5 cm or more prevents the endpin from coming out of the abutment hole 8 during playing. Setting the height of the inner wall to 2 cm or less increases the degree of freedom in the angle of the endpin relative to the surface of the vibration damping plate 6 during playing.

[0038] Furthermore, the shape and size of the support frame 4 and the vibration damping plate 6 are not particularly limited as long as they do not impair the effects of the present invention, but from the viewpoint of portability, it is preferable to make them as small (light) as possible. On the other hand, since vibration damping performance can be expected to improve with increasing mass of the vibration damping plate 6, it is preferable to provide the vibration damping plate 6 over as wide an area as possible on the bottom surface of the support frame 4.

[0039] Regarding another embodiment of the end pin stopper of the present invention, Figure 2 shows a schematic cross-sectional view, a schematic view from the back, and a schematic view from the front when the magnet 12 is provided only on the vibration damping plate 6. When the support frame 4 is made of a ferromagnetic material, the support frame 4 and the vibration damping plate 6 can be fixed together in this embodiment.

[0040] Regarding another embodiment of the end pin stopper of the present invention, Figure 3 shows a schematic cross-sectional view, a schematic view from the back, and a schematic view from the front when magnets are provided on both the support frame 4 and the vibration damping plate 6. In Figure 3, magnets 12 are provided on the support frame 4 and magnets 14 are provided on the vibration damping plate 6. In this embodiment and the embodiment shown in Figure 2, the support frame 4 and the vibration damping plate 6 can be fixed together regardless of the material of the support frame 4, and in particular, the embodiment shown in Figure 3 allows for a more secure fixation of the support frame 4 and the vibration damping plate 6 together.

[0041] 2. Use as a booster The endpin stopper 2 can also be used in a booster. Figure 4 shows a schematic cross-sectional view of an example of a booster incorporating the endpin stopper 2.

[0042] A recess is formed on the surface of the metal plate 20, and the end pin stopper 2 (the bottom surface of the support frame 4 and the vibration damping plate 6) is fitted into this recess. In addition, the metal plate 20 is equipped with three or more height adjustment bolts 22, which allow the horizontal and height of the metal plate 20 from the floor to be adjusted.

[0043] The endpin stopper 2 (vibration damping plate 6) very efficiently cuts out resonance (noise) caused by vibrations transmitted from the endpin of a stringed instrument to the floor, allowing only the pure sound of the instrument to be amplified.

[0044] Although typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design modifications are possible, all of which fall within the technical scope of the present invention. [Examples]

[0045] An endpin stopper was manufactured in the manner shown in Figure 3. The outer frame of the support was made of ABS resin, and the vibration damping plate was made of an Fe-Al alloy containing 8.0% by mass of Al, with the remainder being Fe and unavoidable impurities. Photographs of the appearance of the obtained endpin stopper from the front and back sides are shown in Figures 5 and 6, respectively.

[0046] It can be seen that a stopper hole is provided in the center of the support frame into which the tip of the end pin is inserted, and an annular projection is provided around the stopper hole. In addition, a vibration damping plate is fitted from the back side of the support frame, and disc-shaped neodymium magnets are provided at the four corners of the vibration damping plate.

[0047] Figure 7 shows an external view of the support frame with the damping plate removed. The back side of the support frame is shown. Disc-shaped neodymium magnets are also provided at the four corners of the support frame, and by contacting the neodymium magnets on the damping plate, the support frame and the damping plate can be firmly fixed together.

[0048] Figure 8 shows a photograph of the vibration damping plate with an anti-slip surface on the back. PVC (polyvinyl chloride) resin is attached to the back of the vibration damping plate in a grid pattern, which effectively suppresses the slippage of the endpin stopper during performance.

[0049] A booster with a built-in endpin stopper was manufactured in the manner shown in Figure 4. Figures 9 and 10 show the external appearance of the booster and the booster with the endpin stopper removed, respectively. A recess is formed on the surface of a brass metal plate, into which the endpin stopper (support frame and bottom surface of vibration damping plate) can be fitted. In addition, the metal plate is equipped with three height adjustment bolts, which allow the horizontal position and height from the floor surface of the metal plate to be adjusted.

[0050] The cross-section of the damping plate used in the endpin stopper shown in Figure 3 was mirror-polished and etched, and then the microstructure was observed using an optical microscope. The obtained microstructure observation results are shown in Figure 11. As shown in Figure 11, the damping plate made of Fe-Al alloy has a fine structure, and it can be seen that the average grain size is 20 to 40 μm.

[0051] Regarding the damping plate used in the endpin stopper shown in Figure 3, the loss coefficient (η) for a sound with an amplitude of 10 μm was measured using the damping method of a cantilever beam, and it was found to be 0.062. An example of a damping curve obtained from an accelerometer attached to the damping plate is shown in Figure 12. For comparison, an example of a damping curve similarly obtained for a general-purpose cold-rolled steel sheet (SPCC) is shown in Figure 13. Here, the full scale of the time axis in Figure 12 is 1 / 4 of that in Figure 13. It can be confirmed that the vibration of the Fe-Al alloy damping plate is attenuated in a much shorter time compared to the cold-rolled steel sheet. From these results, it can be seen that the damping plate used in the endpin stopper of the present invention has extremely good damping properties.

Claims

1. An outer frame of the support device is provided with a stopper hole into which the tip of the end pin can be abutted, It has a vibration damping plate made of Fe-Al alloy, The vibration damping plate is fitted onto the back side of the outer frame of the support, and the outer frame of the support and the vibration damping plate are detachably fixed together by magnets. An endpin stopper featuring the following characteristics.

2. The thickness of the vibration damping plate is 1 to 6 mm. The end pin stopper according to claim 1, characterized by the following:

3. The aforementioned magnet is a neodymium magnet. An end pin stopper according to claim 1 or 2, characterized by the above.

4. The magnet is inserted into the through hole of the vibration damping plate. The vibration damping plate and the magnet are of the same thickness. An end pin stopper according to claim 1 or 2, characterized by the above.

5. The outer frame of the support is made of one of thermoplastic resin, brass, and aluminum. An end pin stopper according to claim 1 or 2, characterized by the above.

6. The vibration damping plate contains 6.0 to 10.0 mass% Al, with the remainder being Fe and unavoidable impurities, and has an average crystal grain size of 20 to 40 μm. An end pin stopper according to claim 1 or 2, characterized by the above.

7. The loss coefficient (η) of the aforementioned damping plate for sounds with an amplitude of 5 to 15 μm is 0.05 or greater. An end pin stopper according to claim 1 or 2, characterized by the above.

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