Drum head fastening device and drum

Abstract

To provide a drum head fastening device capable of easily mounting a drum head on the shell of a drum.SOLUTION: A drum head fastening device 5 comprises a plurality of lugs 50 each having a lug body 52 fixed to a shell 2 of a drum and a lug nut 53 fitted to the lug body 52; and a plurality of lug bolts threadedly engaging with the respective lug nuts 53. At least one of the lug nuts 53 is a fixed lug nut 53A fixed immovably to the lug body 52. At least another one of the nuts 53 is a movable lug nut fitted movably to the lug body 52.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a drumhead fastening device and a drum. [Background technology]

[0002] Patent Document 1 discloses a drumhead fastening device for attaching a drumhead to the open end of a cylindrical shell. The drumhead fastening device has multiple lugs arranged around the periphery of the shell and multiple lug bolts threaded into the lug nuts of each lug. The multiple lug bolts are engaged with a hoop attached to the open end of the shell and then threaded into the lugs, so that the drumhead is pressed against the open end of the shell by the hoop, attaching the drumhead to the shell. In the drumhead fastening device of Patent Document 1, each of the lugs has a lug body that is fixed to the shell and a lug nut to which a lug bolt is screwed. In Patent Document 1, the lug nuts are attached to all of the lugs so that they can move relative to the lug body. This prevents damage to the drum caused by dimensional errors in various parts of the drum when attaching the drumhead. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4642874 Summary of the Invention [Problem to be solved by the invention]

[0004] Some drums require the lug bolts to be removed from the lugs when the drumhead is removed from the shell. Furthermore, all lug bolts must be attached to the lugs during drum manufacturing. Therefore, if the lug nuts for all lugs are movable relative to the lug bodies, it becomes difficult to attach the lug bolts to the lug nuts for all lugs when replacing or manufacturing the drum. This makes drumhead installation cumbersome.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has as its object to provide a drumhead fastening device that allows drumheads to be easily attached, and a drum equipped with the same. [Means for solving the problem]

[0006] A first aspect of the present invention is a drumhead fastening device for attaching a drumhead to the open end of a cylindrical shell, comprising a plurality of lugs, each having a lug body fixed to the shell and a lug nut attached to the lug body, and a plurality of lug bolts threaded onto the lug nuts, wherein at least one of the plurality of lug nuts is a fixed lug nut that is immovably fixed relative to the lug body, and at least another of the plurality of lug nuts is a movable lug nut that is movably attached relative to the lug body.

[0007] A second aspect of the present invention is a drum comprising the drumhead fastening device, a cylindrical shell to which a plurality of the lugs are attached, and a hoop attached to the open end of the shell, in which the drumhead is attached to the shell by engaging a plurality of the lug bolts with the hoop and screwing them into the respective lug nuts. [Effects of the Invention]

[0008] According to the present invention, the drumhead can be easily attached to the drum. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view showing the appearance of the drum according to the embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the drum of FIG. 1. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing the lug including the fixed lug nut and its vicinity in the drum of FIGS. 1 and 2. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. [Figure 5] FIG. 3 is an enlarged perspective view showing the lug including the fixed lug nut and its vicinity in the drum of FIGS. 1 and 2. [Figure 6] FIG. 3 is an enlarged cross-sectional view showing a lug including a movable lug nut and its vicinity in the drum of FIGS. 1 and 2. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6. [Figure 8] FIG. 10 is a plan view showing a drum according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, one embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, a drum 1 of this embodiment includes a shell 2, a drumhead 3, a hoop 4, and a drumhead fastening device 5.

[0011] The shell 2 is formed in a cylindrical shape. A plurality of lugs 50 of the drumhead fastening device 5, which will be described later, are attached to the shell 2. The shell 2 of this embodiment has an internal space 21 and one open end 22 that opens the internal space 21 to the outside. The open end 22 of the shell 2 is formed in a circular shape. The shell 2 also has a ring-shaped peripheral wall portion 23 that forms the open end 22. The shell 2 of this embodiment is formed from a non-conductive material such as plastic. However, the shell 2 may also be formed from a conductive material such as metal.

[0012] In the following description, the direction in which the axis O of the peripheral wall portion 23 of the shell 2 extends is referred to as the axial direction. The radial direction of the axis O is referred to as the radial direction, and the direction circumferentially around the axis O is referred to as the circumferential direction. One side in the axial direction where the open end 22 of the shell 2 opens is referred to as the upper side or upward direction, and the other side in the axial direction is referred to as the lower side or downward direction.

[0013] The drumhead 3 is formed in a circular shape corresponding to the shape of the open end 22 of the shell 2 in a plan view, and is attached to the open end 22 of the shell 2 so as to cover the open end 22 of the shell 2. The hoop 4 is formed in an annular shape corresponding to the open end 22 of the shell 2, and is fitted onto the open end 22 of the shell 2. The hoop 4 presses the drumhead 3 against the open end 22 of the shell 2 using a drumhead fastening device 5, which will be described later.

[0014] The hoop 4 of this embodiment is made of a conductive material such as metal. Although not shown, the hoop 4 of this embodiment has multiple insertion holes that penetrate in the axial direction and through which lug bolts 51 of the drumhead fastening device 5, which will be described later, are inserted. The multiple insertion holes are arranged at equal intervals around the circumference of the hoop 4. In the drum 1 illustrated in FIGS. 1 and 2, the number of insertion holes in the hoop 4 corresponds to the number of lug bolts 51, which will be described later. Although not shown, each insertion hole in the hoop 4 is formed as an elongated hole extending in the circumferential direction.

[0015] The drumhead fastening device 5 is a device for attaching the drumhead 3 to the open end 22 of the shell 2. The drumhead fastening device 5 includes multiple lugs 50 and multiple lug bolts 51. The multiple lugs 50 are arranged at equal intervals around the circumference of the shell 2. The number of lugs 50 and the number of lug bolts 51 correspond to each other. While the number of lugs 50 and lug bolts 51 in Figures 1 and 2 is six, this is not limiting.

[0016] As shown in FIGS. 3 to 7, each lug 50 includes a lug body 52 and a lug nut 53. The lug body 52 is fixed to the above-described shell 2. In this embodiment, the lug body 52 is formed integrally with the shell 2. Therefore, the lug body 52 is formed from the same non-conductive material as the shell 2. In this embodiment, each lug body 52 has a spherical inner surface 521. In this embodiment, the spherical inner surface 521 faces downward in the axial direction. Each lug body 52 is formed with a nut insertion hole 522 through which a lug nut 53 is inserted in the axial direction. The lower end of the nut insertion hole 522 opens to the spherical inner surface 521 described above.

[0017] The lug nut 53 is attached to the lug body 52. ​​The lug nut 53 is made of a conductive material such as metal, and has a female thread 531 into which the lug bolt 51 is screwed. In this embodiment, the lug nut 53 has a spherical outer surface 532 that is in surface contact with the spherical inner surface 521. The spherical outer surface 532 is located at the lower end of the lug nut 53 and faces upward in the axial direction when the lug nut 53 is attached to the lug body 52. ​​Therefore, when the lug nut 53 passes upward through the nut insertion hole 522 of the lug body 52, the lower end of the lug nut 53 is engaged with the spherical inner surface 521 of the lug body 52. A retaining ring 54 is attached to the upper end of the lug nut 53 inserted into the nut insertion hole 522 of the lug body 52. ​​The retaining ring 54 prevents the lug nut 53 from coming off the lug body 52.

[0018] 1 and 2 are screwed onto the lug nuts 53 of the lugs 50. The lug bolts 51 are made of a conductive material such as metal. In the drum 1, a plurality of lug bolts 51 are engaged with the hoop 4 and screwed onto the respective lug nuts 53. As a result, the drumhead 3 is pressed against the open end 22 of the shell 2 by the hoop 4, and the drumhead 3 is attached to the shell 2. In the drum 1 of this embodiment, the heads of the lug bolts 51 are engaged with the hoop 4 by inserting the main body of each lug bolt 51 into the insertion holes of the hoop 4. Note that the hoop 4 does not necessarily have to have insertion holes. In this case, it is sufficient that each lug bolt 51 has a hook provided on the head of the lug bolt 51 that engages with the hoop 4.

[0019] In the drumhead fastening device 5, the multiple lug nuts 53 include fixed lug nuts 53A shown in Figures 3 and 4 and movable lug nuts 53B shown in Figures 6 and 7. The fixed lug nuts 53A are fixed so as not to move relative to the lug body 52. ​​The movable lug nuts 53B are attached so as to be movable relative to the lug body 52. ​​The number of fixed lug nuts 53A and movable lug nuts 53B may each be at least one. In the following description, the lug 50 including the fixed lug nut 53A will be referred to as the fixed lug 50A, and the lug 50 including the movable lug nut 53B will be referred to as the movable lug 50B.

[0020] As shown in Figures 3 and 4, the spherical outer surface 532 of the fixed lug nut 53A is in surface contact with the spherical inner surface 521 of the lug body 52 and slides against the spherical inner surface 521, thereby allowing it to move radially and circumferentially relative to the lug body 52. However, the lug body 52 of the fixed lug 50A to which the fixed lug nut 53A is attached has a fixing portion 55 that prevents the fixed lug nut 53A from moving in the radial and circumferential directions.

[0021] The fixing portion 55 includes a circumferential fixing portion 551 and a radial fixing portion 552 . The circumferential fixing portions 551 are arranged on both sides of the fixed lug nut 53A inserted through the nut insertion hole 522. The spacing between the circumferential fixing portions 551 in the circumferential direction is approximately equal to the dimension of the fixed lug nut 53A in the circumferential direction, thereby preventing the fixed lug nut 53A from moving in the circumferential direction.

[0022] The radial fixing portions 552 are disposed on both radial sides of the fixed lug nut 53A inserted through the nut insertion hole 522. The radial spacing between the radial fixing portions 552 is approximately equal to the radial dimension of the fixed lug nut 53A, thereby preventing radial movement of the fixed lug nut 53A. In this embodiment, the circumferential fixing portion 551 and the radial fixing portion 552 are wall portions that extend upward from the portion of the lug body 52 where the spherical inner surface 521 is formed.

[0023] As shown in Figures 6 and 7, the spherical outer surface 532 of the movable lug nut 53B is in surface contact with the spherical inner surface 521 of the lug body 52 and slides against the spherical inner surface 521, thereby allowing it to move radially and circumferentially relative to the lug body 52. However, the lug body 52 of the movable lug 50B to which the movable lug nut 53B is attached has a circumferential restriction portion 561 that restricts circumferential movement of the movable lug nut 53B. The lug body 52 of the movable lug 50B also has a radial restriction portion 562 that restricts radial movement of the movable lug nut 53B.

[0024] The circumferential restriction portions 561 are arranged adjacent to both sides of the movable lug nut 53B inserted through the nut insertion hole 522 in the circumferential direction. The spacing between the main portions of the circumferential restriction portions 561 in the circumferential direction is greater than the circumferential dimension of the movable lug nut 53B. However, the circumferential restriction portions 561 have restriction protrusions 563 that protrude from the main portions of the circumferential restriction portions 561 and make the spacing between the circumferential restriction portions 561 approximately equal to the circumferential dimension of the movable lug nut 53B. This prevents the movable lug nut 53B from moving in the circumferential direction.

[0025] The radial restriction portions 562 are disposed adjacent to both sides of the movable lug nut 53B inserted through the nut insertion hole 522 in the radial direction. The radial spacing between the radial restriction portions 562 is greater than the radial dimension of the movable lug nut 53B. This allows the movable lug nut 53B to move radially between the radial restriction portions 562. Note that the lug body 52 of the movable lug 50B does not necessarily have to include the radial restriction portions 562, for example.

[0026] 2, the drumhead fastening device 5 of this embodiment has six lugs 50, one fixed lug 50A including a fixed lug nut 53A, and five movable lugs 50B including a movable lug nut 53B.

[0027] As shown in Figure 5, in the drum 1 of this embodiment, an electric circuit 61 is disposed inside the shell 2 (internal space 21). The electric circuit 61 may be, for example, an impact sensor unit that detects an impact on the drum 1 and outputs an electric signal. A ground wire 62 extends from the electric circuit 61. The ground wire 62 is connected to the fixed lug nut 53A described above. In the illustrated example, the ground wire 62 is passed through the through hole 25 formed in the peripheral wall portion 23, and extends from the electrical circuit 61 located inside the shell 2 to the fixed lug nut 53A located outside the shell 2. In Figures 3 and 5, the ground wire 62 is attached to the upper end of the fixed lug nut 53A.

[0028] Because the fixed lug nut 53A, lug bolt 51, and hoop 4 are made of a conductive material such as metal, the ground wire 62 is electrically connected via the fixed lug nut 53A to the lug bolt 51 that is threaded onto the lug nut 53 and to the hoop 4 to which the lug bolt 51 engages. This reduces or prevents malfunctions in the electrical circuit 61 caused by static electricity. Therefore, even if the shell 2 and lug body 52 are made of a non-conductive material such as plastic or wood, malfunctions in the electrical circuit 61 caused by static electricity can be reduced or prevented when a statically charged player of the drum 1 touches conductive members such as the lug nut 53, lug bolt 51, or hoop 4.

[0029] As described above, in the drumhead fastening device 5 and the drum 1 including the same of this embodiment, at least one of the multiple lug nuts 53 is a fixed lug nut 53A that is immovably fixed to the lug body 52. ​​At least another of the multiple lug nuts 53 is a movable lug nut 53B that is movably attached to the lug body 52. ​​In other words, some of the multiple lug nuts 53 are fixed lug nuts 53A, and the remaining lug nuts 53 that are not fixed lug nuts 53A are movable lug nuts 53B.

[0030] Therefore, in the drumhead fastening device 5 and the drum 1 including it, the lug bolts 51 can be attached more easily to the fixed lug nuts 53A than to the movable lug nuts 53B. This makes it easier to attach the drumhead 3 than if all the lug nuts 53 were movable lug nuts 53B. Furthermore, since some of the lug nuts 53 are movable lug nuts 53B, damage to the drum 1 caused by dimensional errors in various parts of the drum 1, such as the hoop 4, when the drumhead 3 is attached can be avoided.

[0031] Furthermore, in the drumhead fastening device 5 of this embodiment, the movable lug nut 53B has a spherical outer surface 532 that makes surface contact with the spherical inner surface 521 of the lug body 52. ​​The spherical outer surface 532 of the movable lug nut 53B slides against the spherical inner surface 521 of the lug body 52, allowing the movable lug nut 53B to move radially and circumferentially relative to the lug body 52. ​​However, the movable lug nut 53B is able to move actively in the radial direction of the shell 2, while its movement in the circumferential direction of the shell 2 is restricted by a circumferential direction restricting portion 561. By restricting the movement direction of the movable lug nut 53B in this manner, the lug bolt 51 can be attached to the movable lug nut 53B more easily than if the movement direction of the movable lug nut 53B was not restricted.

[0032] Because movable lug nut 53B is movable radially relative to lug body 52, the relative position of lug bolt 51 screwed onto movable lug nut 53B and the insertion hole of hoop 4 through which lug bolt 51 is inserted can be adjusted radially. Also, in this embodiment, the insertion hole of hoop 4 is an elongated hole extending circumferentially, so the relative position of lug bolt 51 screwed onto movable lug nut 53B and the insertion hole of hoop 4 through which lug bolt 51 is inserted can be adjusted circumferentially.

[0033] Furthermore, in the drumhead fastening device 5 of this embodiment, the fixed lug nut 53A, which does not move relative to the lug body 52, and the movable lug nut 53B, which moves relative to the lug body 52, are determined by the configuration of the lug body 52 (circumferential fixing portion 551, radial fixing portion 552) that constitutes the fixed lug 50A and the configuration of the lug body 52 (circumferential restricting portion 561, radial restricting portion 562) that constitutes the movable lug 50B. Therefore, the fixed lug nut 53A and the movable lug nut 53B can be configured using lug nuts 53 of the same shape.

[0034] Furthermore, in the drumhead fastening device 5 of this embodiment, the ground wire 62 extending from the electrical circuit 61 located inside the shell 2 is connected to the fixed lug nut 53A. This improves the reliability of the electrical connection between the ground wire 62 and the lug nut 53 compared to when the ground wire 62 is connected to the movable lug nut 53B. Specifically, the fixed lug nut 53A is immovable relative to the lug body 52 (and the shell 2). This prevents the relative positions of the electrical circuit 61 located inside the shell 2 and the fixed lug nut 53A from changing. This reduces or prevents the ground wire 62 from breaking or coming loose from the fixed lug nut 53A or the electrical circuit 61, even when the electrical circuit 61 is connected to the fixed lug nut 53A by the ground wire 62. This improves the reliability of the electrical connection between the ground wire 62 and the lug nut 53. Furthermore, if the earth wire 62 is connected to the movable lug nut 53B, there is a high possibility that the movable lug nut 53B will move relative to the lug body 52, causing the earth wire 62 to break or become detached from the movable lug nut 53B or the electrical circuit 61.

[0035] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0036] In the present invention, for example, as in the drum 1D and drumhead fastening device 5D shown in Figure 8, the number of fixing lugs 50A including fixing lug nuts 53A may be two or more. In this case, the two fixing lugs 50A should be positioned diagonally on the shell 2 when viewed in the axial direction of the shell 2. In order to position the two fixing lugs 50A diagonally on the shell 2, the number (total number) of lugs 50 should be at least four or an even number. 8, when two fixing lugs 50A are positioned at diagonal corners of the shell 2, the drumhead 3 can be uniformly tensioned (stretched) at the open end 22 of the shell 2. This point will be described below.

[0037] The lug bolts 51 can be attached more easily to the fixed lug nuts 53A, which do not move relative to the lug bodies 52, than to the movable lug nuts 53B, which move relative to the lug bodies 52. Therefore, when attaching the drumhead 3 to the open end 22 of the shell 2, the lug bolts 51 can be attached to the fixed lug nuts 53A before the movable lug nuts 53B, allowing for efficient installation. Furthermore, since the two fixed lugs 50A, including the fixed lug nuts 53A, are positioned diagonally on the shell 2, the two lug bolts 51 are first attached to the two fixed lug nuts 53A located diagonally on the shell 2. This allows for stable and reliable installation of the drumhead 3. Furthermore, the drumhead 3 can be uniformly tensioned (stretched) at the open end 22 of the shell 2. In addition, if two lugs 50, including a fixed lug nut 53A, are adjacent to each other around the circumference of the shell 2, and two lug bolts 51 are first attached to the two fixed lug nuts 53A when attaching the drumhead 3, it may be difficult to subsequently attach the other lug bolts 51 to the movable lug nut 53B, or the tension (stretch) of the drumhead 3 may become uneven.

[0038] In the present invention, movable lug nuts 53B may be prevented from moving radially but allowed to move circumferentially. In this case, the insertion holes in hoop 4 through which lug bolts 51 pass may be elongated holes extending radially. Additionally, the movable lug nut 53B may be movable within a predetermined range in both the circumferential direction and the radial direction, for example.

[0039] The present invention is not limited to a drum having a shell 2 with only one open end 22, but may also be applied to a drum having a cylindrical shell with two open ends, for example. [Explanation of symbols]

[0040] 1,1D...drum, 2...shell, 3...drumhead, 4...hoop, 5,5D...drumhead fastening device, 22...open end, 50...lug, 51...lug bolt, 52...lug body, 53...lug nut, 53A...fixed lug nut, 53B...movable lug nut, 61...electrical circuit, 62...ground wire, 521...spherical inner surface, 532...spherical outer surface, 561...circumferential direction restricting portion

Claims

1. A drumhead fastening device for attaching a drumhead to an open end of a cylindrical shell, comprising: a plurality of lugs, each having a lug body secured to the shell and a lug nut attached to the lug body; a plurality of lug bolts respectively threadedly attached to the plurality of lug nuts; At least one of the plurality of lug nuts is a fixed lug nut that is immovably fixed to the lug body, A drumhead fastening device in which at least another one of the plurality of lug nuts is a movable lug nut that is movably attached to the lug body.

2. the number of lugs is an even number greater than or equal to four; There are two lugs including the locking lug nuts; 2. The drumhead fastening device of claim 1, wherein the two lugs including the locking lug nuts are positioned diagonally on the shell when viewed in the axial direction of the shell.

3. The lug body has a spherical inner surface, The movable lug nut has a spherical outer surface that is in surface contact with the spherical inner surface, and the spherical outer surface slides against the spherical inner surface, allowing the movable lug nut to move radially and circumferentially relative to the lug body.

2. The drumhead fastening device according to claim 1, wherein the lug body has circumferential direction restricting portions arranged adjacent to both sides of the movable lug nut in the circumferential direction, restricting movement of the movable lug nut in the circumferential direction.

4. 2. The drumhead fastening device of claim 1, wherein a ground wire extending from an electrical circuit disposed inside the shell is connected to the fixed lug nut.

5. The drumhead fastening device according to any one of claims 1 to 4, a cylindrical shell to which a plurality of said lugs are attached; a hoop fitted to the open end of the shell, A drum in which a drumhead is attached to the shell by engaging a plurality of the lug bolts with the hoop and screwing them into the respective lug nuts.

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