This application claims the priority benefit of Japan application serial no. 2012-269452, filed on Dec. 10, 2012. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The present invention relates to a percussion attachment. In particular, the present invention relates to a percussion attachment that is adapted for suppressing damage of the hoop and preventing looseness or tightness of the tension bolt during performance, and has high versatility.
2. Description of Related Art
Percussion attachments are known to be detachably installed on percussion instruments, such as acoustic drums or electronic drums, etc. Among such percussion attachments, some may include sensors for detecting striking of the player. They may be used as electronic percussion instruments or controllers for playing or stopping songs.
For example, U.S. Pat. No. 8,178,768 discloses a percussion attachment that is tightened together with the rim (hoop) by one or two tension bolts 1 to be supported on the drum 11.
However, the aforementioned traditional percussion attachment is supported on the percussion instrument only through a part that is tightened with the rim by the tension bolts 1. For this reason, the rim receives a large stress when being struck, which easily causes damage to the rim.
Besides, in the situation that the aforementioned traditional percussion attachment is tightened together with the rim by one tension bolt 1, the tension bolt 1 may easily rotate around the axis thereof when the percussion attachment is struck. As a result, problems such as looseness or tightness of the tension bolt may occur during performance.
On the other hand, in the situation that the aforementioned traditional percussion attachment is tightened together with the rim by two tension bolts 1, the tension bolts 1 can be prevented from rotating around their axes. In that case, the percussion instruments have to satisfy certain conditions, such as a specific interval between the adjacent tension bolts 1 in the circumferential direction or a specific curvature of the rim, so that the percussion attachment can be installed thereon. Therefore, the versatility of the attachment is low.
[Patent Literature 1] U.S. Pat. No. 8,178,768 (FIG. 1 and FIG. 4, etc.)
Considering the above, the present invention provides a percussion attachment that is adapted for suppressing damage of the hoop and preventing looseness or tightness of the tension bolt during performance, and has high versatility.
The percussion attachment of the present invention has the following effects. An extended part extending from a side surface of a main body part is tightened together with a hoop by one of a plurality of tension bolts, and in such a state, a restricting part which is disposed to protrude from the side surface of the main body part touches a percussion instrument, so as to restrict a displacement of the main body part and the extended part that results from striking on a struck part. Accordingly, the stress that occurs to the hoop when the struck part is struck can be reduced. In other words, damage of the hoop can be suppressed.
Moreover, in the state that the extended part is tightened together with the hoop by one tension bolt, the tension bolt can be prevented from rotating with the extended part around an axis thereof when the struck part is struck. Thus, the versatility of the attachment is increased, and looseness or tightness of the tension bolt during performance can be prevented. In other words, a change in the tension of the head can be avoided.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. In the state that the extended part is tightened together with the hoop by one tension bolt, a portion of the tension bolt, which is between a portion locked to the extended part and a portion screwed into the lug, can be supported by a bolt supporting part that is formed under the extended part. Accordingly, the bolt supporting part can restrict the displacement of the main body part and the extended part relative to the tension bolt.
The displacement of the tension bolt is restricted by the hoop and the lug. Thus, the displacement of the main body part and the extended part relative to the tension bolt is restricted, and accordingly, the stress that occurs to the hoop when the struck part is struck can be reduced. In other words, damage of the hoop can be suppressed.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. The bolt supporting part has a substantially U shape when viewed from above, which is recessed toward the main body part. In comparison with the case where the bolt supporting part touches the tension bolt through an insertion of the tension bolt into a hole that is substantially circular when viewed from above, an installation or detachment process for installing/detaching the attachment of the present invention to/from the percussion instrument is simplified.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. In the state that the extended part is tightened together with the hoop by one tension bolt, the bolt supporting part is open inward in a radial direction of the hoop. Thus, the bolt supporting part can restrict the displacement of the main body part and the extended part relative to the tension bolt with certainty.
Here, if the struck part of the main body part is struck in the state that the extended part is tightened together with the hoop by one tension bolt, a force is generated to cause the displacement of the portion of the tension bolt, which is locked to the extended part, in a direction away from the hoop, namely, outward in the radial direction of the hoop. Meanwhile, a force is generated to cause the displacement of the bolt supporting part that touches the tension bolt under the extended part in a direction toward the hoop, namely, inward in the radial direction of the hoop.
By contrast thereto, in the state that the extended part is tightened together with the hoop by one tension bolt, the bolt supporting part can be opposed to the portion of the tension bolt that is under the extended part and faces in the direction away from the hoop, namely, outward in the radial direction of the hoop. Therefore, while the installation or detachment process for installing/detaching the percussion attachment of the present invention to/from the percussion instrument is simplified, the bolt supporting part can surely restrict the displacement of the main body part and the extended part relative to the tension bolt.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. In the state that the extended part is tightened together with a flange supporting part of the hoop by one tension bolt, the flange supporting part touches one of a plurality of flange parts at two sides in a circumferential direction of the hoop with the tension bolt therebetween. Thus, when the struck part of the main body part is struck, the flange supporting part can restrict the tension bolt from rotating with the extended part around the axis thereof. Accordingly, change of the tension of the head resulting from looseness or tightness of the tension bolt during performance can be prevented.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. The elastic part and the pressure contact part can be integrally formed using the same elastic material, so as to reduce the number of the parts.
Moreover, because a gap is formed between the pressure contact part of the flange supporting part and the main body part, the gap can be used to make the pressure contact part elastically deform easily. Therefore, even if the elastic part and the pressure contact part are made of the same elastic material, the pressure contact part can be elastically deformed more easily than the elastic part.
Accordingly, by making the elastic part less elastically deformable than the pressure contact part, elastic deformation of the elastic part resulting from the displacement of the main body part and the extended part relative to the tension bolt can be suppressed. On the other hand, by making the pressure contact part more elastically deformable than the elastic part, the pressure contact part can easily be in close contact with flange parts of various shapes. As a result, damage of the hoop can be prevented and the versatility of the attachment can be increased.
According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. In the state that the extended part is tightened together with the hoop by one tension bolt, the rigid part that has higher stiffness than the elastic part supports the tension bolt through the elastic part. Since the elastic part touches the tension bolt, damage of the male screw of the tension bolt can be avoided. Moreover, the elastic deformation of the elastic part is restricted by the rigid part, and therefore the displacement of the main body part and the extended part relative to the tension bolt can be restricted with certainty. According to other aspect of the present invention, in addition to the aforementioned effects, the percussion attachment of the present invention further has the following effects. The main body part includes a sensor that detects striking on the struck part. Thus, the percussion attachment can be used as an electronic percussion instrument or a controller for playing or stopping a song.
Below preferable exemplary embodiments of the present invention are described in detail with reference to the affixed figures. First, referring to
The drum 1 is an electronic percussion instrument adapted to be struck by the player. As shown in
The body part 2 is a member that serves as the body of the drum 1, and includes a shell 2a, a bottom part 2b, and extended parts 2c. The shell 2a has a cylindrical shape that is open at one side and the other side (the upper side and lower side of
The head 3 includes a membrane-shaped striking surface part 3a and a frame part 3b (see
Nevertheless, it should be noted that the frame part 3b is not necessarily made of the metal material, and may also be made of a resin material, etc., that has the predetermined stiffness.
The hoop 4 is an annular member, which is adapted to press the frame part 3b of the head 3, so as to apply tension to the striking surface part 3a. An inner diameter of the hoop 4 is larger than the outer diameter of the shell 2a and smaller than an outer diameter of the frame part 3b. Moreover, the hoop 4 includes flange parts 4a and through holes 4b (see
Each of the tension bolts 5 includes a male screw part 5a, a head part 5b, and an engagement part 5c. A male thread is formed on the male screw part 5a. The head part 5b is connected with the male screw part 5a at one side (the upper side of
An inner diameter of the through hole 4b of the hoop 4 is larger than an outer diameter of the male screw part 5a and smaller than an outer diameter of the engagement part 5c. Thus, by inserting the male screw part 5a into the through hole 4b from a top surface side of the flange part 5a, the engagement part 5c is locked to the top surface of the flange part 4a.
The lug 6 is a cylindrical member and has a female thread to be screwed to the male thread formed on the male screw part 5a of the tension bolt 5. The lug 6 is installed upright on the extended part 2c at a position apart from an outer circumferential surface of the shell 2a of the body part 2. An interval between two adjacent lugs 6 in the circumferential direction is set to be equal to the interval between two adjacent through holes 4b of the hoop 4 in the circumferential direction (see
The engagement part 5c of the tension bolt 5 is locked to the flange part 4a of the hoop 4. In such a state, the male screw part 5a of the tension bolt 5 is screwed to the lug 6, and thereby the frame part 3b of the head 3 (see
The attachment 100 is an electronic percussion instrument. The attachment 100 is detachably installed on the drum 1 and is adapted to be struck by the player.
The attachment 100 includes a sensor (not shown) and a jack 100a. The sensor is used to detect a vibration of the attachment 100, and the jack 100a is electrically connected with the sensor. The jack 100a and a sound source device (not shown) are electrically connected with each other via a connection cable (not shown). When the attachment 100 is struck, the vibration of the attachment 100 is detected by the sensor, and a detected signal is outputted from the jack 100a to the sound source device via the connection cable. As a result, the sound source device generates musical tones based on the detected signal.
Next, the appearance and shape of the attachment 100 are explained in detail with reference to
As shown in
The main body part 10 is a member that serves as a main body portion of the attachment 100, and includes an upper main body part 11 and a lower main body part 12. The upper main body part 11 constitutes an upper portion of the main body part 10, and the lower main body part 12 is connected to a bottom surface of the upper main body part 11 and constitutes the lower portion of the main body part 10.
The upper main body part 11 is a member adapted to be struck by the player and is made of a rubber material. The lower main body part 12 is a member made of a resin material. The jack 100a is installed at an end side (the left side of
The plate 20 is a member tightened together with the flange part 4a of the hoop 4 by the tension bolt 5 (see
The restricting part 30 is a member that restricts the displacement of the main body part 10 and the plate 20 relative to the drum 1 (see
The flange supporting part 40 is a member made of an elastic material, and includes a pair of protrusion parts 41 and a connection part 42. The protrusion parts 41 are disposed to protrude inward (the left side of
The protrusion parts 41 are members for supporting the flange part 4a of the hoop 4 (see
The bolt supporting part 50 includes a rigid part 51 and an elastic part 52. The rigid part 51 is disposed to protrude from the inner circumferential surface of the main body part 10 (the surface at the upper side of
The rigid part 51 is a member that restricts the displacement of the main body part 10 and the plate 20 relative to the tension bolt 5 (see
The arc-shaped portion of the recess part 51a is formed to be concentric with the locking hole 20a of the plate 20. In addition, an inner diameter of the arc-shaped portion is larger than the outer diameter of the male screw part 5a of the tension bolt 5 (see
The rigid part 51 is formed integrally with the plate 20 using the same metal material as the plate 20. Moreover, the upper main body part 11 and the lower main body part 12 are fixed in a state that a portion connecting the rigid part 51 and the plate 20 is received inside the main body part 10. Accordingly, in comparison with the case that the rigid part 51 and the plate 20 are formed separately, the number of the parts can be reduced. In addition, it is not required to align the positions of the recess part 51a of the rigid part 51 and the locking hole 20a of the plate 20, and therefore, the production efficiency of the attachment 100 can be improved.
The elastic part 52 is a member that touches the male screw part 5a of the tension bolt 5 (see
The elastic part 52 is formed integrally with the flange supporting part 40 using the same elastic material as the flange supporting part 40. Thus, the number of the parts can be reduced. In addition, the gap S is formed between the pressure contact part 41a of the flange supporting part 40 and the main body part 10. With the gap S, the pressure contact part 41a can be elastically deformed easily. Therefore, even though the flange supporting part 40 and the elastic part 52 are made of the same elastic material, the pressure contact part 41a can be elastically deformed more easily than the elastic part 52.
Next, with reference to
As illustrated in
As the male screw part 5a is screwed into the lug 6, the engagement part 5c of the tension bolt 5 is locked to the plate 20. Besides, the engagement part 5c presses the frame part 3b of the head 3 toward the other side (the lower side of
The rigid part 51 and the elastic part 52 of the bolt supporting part 50 of the attachment 100 are recessed outward (the right side of
Here, among hoops that are used for various percussion instruments, some may have flange parts whose top surfaces incline outward in the radial direction. In such a case, when the plate 20 is placed on the top surface of the flange part and tightened together with the flange part, the plate 20 and the main body part 10 are installed in a state that they incline outward in the radial direction of the hoop.
By contrast, in the attachment 100, the recess part 51a of the rigid part 51 and the arc-shaped portion of the elastic part 52 are formed to be concentric with the locking hole 20a of the plate 20, so as to install the plate 20 perpendicular to the axle center of the tension bolt 5, and by screwing the tension bolt 5 into the lug 6, the axle center of the tension bolt 5 can be consistent with an axle center direction of the hoop 4. Accordingly, even if the top surface of the flange part inclines outward in the radial direction, by installing the plate 20 perpendicular to the axle center of the tension bolt 5, the plate 20 and the main body part 10 can be installed horizontally in the radial direction of the hoop 4.
The pressure contact parts 41a are in pressure contact with the flange part 4a at two sides thereof along the circumferential direction of the hoop 4 with the tension bolt 5 therebetween. Therefore, when the upper main body part 11 of the main body part 10 is struck, the flange supporting part 40 of the restricting part 30 can restrict the rotation of the tension bolt 5 together with the main body part 10 and the plate 20 around the axis, so as to prevent the tension of the striking surface part 3a of the head 3 from changing due to the looseness or tightness of the tension bolt 5 during performance and further to prevent the main body part 10 from rattling due to the looseness of the tension bolt 5.
Moreover, the pressure contact parts 41a are in pressure contact with the flange part 4a under the plate 20. Therefore, the displacement of the upper main body part 11 away from the hoop 4 due to the striking on the upper main body part 11 of the main body part 10 can be restricted, and the stress applied on the flange part 4a when the upper main body part 11 is struck can be reduced. In other words, damage of the hoop 4 can be suppressed.
Here, given that the restricting part touches the shell of the body part, the dimensions of the protrusion of the restricting part from the inner circumferential surface of the main body part 10 need to be set in accordance with a distance between the tension bolt and the outer circumferential surface of the shell. However, the distance between the tension bolt and the outer circumferential surface of the shell may vary depending on the overall shape of the percussion instrument. For this reason, the versatility of the attachment is low.
Meanwhile, the distance between the flange part of the hoop and the tension bolt is shorter than the distance between the outer circumferential surface of the shell and the tension bolt. In addition, even in the case that the hoop has different curvatures or the percussion instrument has different overall shapes, the shape of the flange part is seldom different.
In comparison with the situation that the restricting part 30 touches the shell 2a, the flange supporting part 40 of this exemplary embodiment touches the flange part 4a, and thus the versatility of the attachment 100 can be increased.
In the state that the plate 20 is tightened together with the hoop 4 by the tension bolt 5, the bolt supporting part 50 formed under the plate 20 supports a portion of the male screw part 5a of the tension bolt 5, which is between a portion locked to the plate 20 and a portion screwed into the lug 6.
Here, when the upper main body part 11 of the main body part 10 is struck, a force is generated to cause displacement of the main body part 10 and the plate 20 in a direction away from the hoop 4 (outward in the radial direction of the hoop 4; the right side of
By contrast, the bolt supporting part 50 is formed to have a substantially “U” shape when viewed from above, which is recessed outward (the right side of
The displacement of the tension bolt 5 is restricted by locking the engagement part 5c onto the hoop 4 and screwing the male screw part 5a into the lug 6. Accordingly, the displacement of the main body part 10 and the plate 20 relative to the tension bolt 5 can be restricted, and the stress that occurs to the hoop 4 when the upper main body part 11 of the main body part 10 is struck can be reduced. In other words, damage of the hoop 4 can be suppressed.
Moreover, the bolt supporting part 50 of the restricting part 30 is formed in a way that the elastic part 52 touches the male screw part 5a of the tension bolt 5, and the arc-shaped portion of the elastic part 52 is formed to be concentric with the locking hole 20a of the plate 20. Further, the bolt supporting part 50 of the restricting part 30 is formed in a way that the inner diameter of the arc-shaped portion of the elastic part 52 is smaller than the outer diameter of the male screw part 5a of the tension bolt 5. Therefore, damage of the male screw part 5a can be prevented.
Besides, the entirety of the recess bottom surface of the elastic part 52, which is formed into an arc shape, can touch the male screw part 5a, so as to prevent a rotation of the tension bolt 5 around the axis thereof during performance and prevent looseness or tightness of the tension bolt 5 with more certainty. Moreover, since the elastic part 52, made of an elastic material, is used to touch the male screw part 5a, a range of the outer diameter of the tension bolt 5, in which the tension bolt 5 can be used for the present invention, is widened. That is to say, the versatility of the attachment 100 can be increased.
In addition, the rigid part 51 which has higher stiffness than the elastic part 52 supports the male screw part 5a of the tension bolt 5 through the elastic part 52. Thus, the bolt supporting part 50 can restrict the displacement of the main body part 10 and the plate 20 relative to the tension bolt 5.
That is, given that the bolt supporting part 50 is completely made of a high elastic material, when the upper main body part 11 of the main body part 10 is struck, a force is generated to cause the displacement of the main body part 10 relative to the tension bolt 5, and elastically deform the bolt supporting part 50 easily. In other words, the displacement of the main body part 10 cannot be restricted properly. On the other hand, in the case that the bolt supporting part 50 is completely made of a material of high stiffness, the displacement of the main body part 10 can be restricted, but the male thread formed on the male screw part 5a may be easily damaged, and the outer diameter of the usable tension bolt 5 becomes limited. In other words, the versatility of the attachment 100 is low.
By contrast thereto, the rigid part 51 that has higher stiffness than the elastic part 52 supports the male screw part 5a of the tension bolt 5 through the elastic part 52. Therefore, the elastic deformation of the elastic part 52 can be restricted by the rigid part 51 and damage of the male screw part 5a can also be avoided.
Moreover, in the flange supporting part 40, the gap S is formed between the pressure contact part 41a of the protrusion part 41 and the main body part 10, so that the pressure contact part 41a can be elastically deformed more easily than the elastic part 52. By making the elastic part 52 less elastically deformable than the pressure contact part 41a, elastic deformation of the elastic part 52 resulting from the displacement of the main body part 10 and the plate 20 relative to the tension bolt 5 can be suppressed. On the other hand, by making the pressure contact part 41a more elastically deformable than the elastic part 52, the pressure contact part 41a can easily be in close contact with flange parts of various shapes. As a result, damage of the tension bolt 5 and the hoop 4 is prevented and the versatility of the attachment 100 is increased.
As described above, in the state that the plate 20 is tightened together with the hoop 4 by one tension bolt 5, the restricting part 30 that protrudes from the inner circumferential surface of the main body part 10 touches the flange part 4a and the male screw part 5a. Thus, the attachment 100 can restrict the displacement of the main body part 10 and the plate 20, resulting from the striking on the upper main body part 11 of the main body part 10, with the restricting part 30. As a result, the stress that occurs to the hoop 4 when the upper main body part 11 is struck can be reduced. Namely, damage of the hoop 4 can be suppressed.
In addition, while the plate 20 is tightened together with the hoop 4 by one tension bolt 5, the tension bolt 5 can be prevented from rotating with the plate 20 around the axis thereof when the upper main body part 11 is struck. In comparison with a situation of using two tension bolts 5 to tighten the plate 20 with the hoop 4, the attachment 100 has higher versatility. Moreover, looseness or tightness of the tension bolt 5 can also be avoided to prevent the tension of the striking surface part 3a of the head 3 from changing during performance.
The above illustrates the present invention on the basis of the exemplary embodiments. However, it should be understood that the present invention is not limited to any of the exemplary embodiments, and various modifications or alterations may be made without departing from the spirit of the present invention.
In the aforementioned exemplary embodiments, the attachment 100 is installed on an electronic percussion instrument, for example. However, the present invention is not limited thereto. The attachment 100 may also be installed on an acoustic percussion instrument.
In the aforementioned exemplary embodiments, the attachment 100 is used as an electronic percussion instrument that includes a sensor for detecting striking on the upper main body part 11. However, the present invention is not limited thereto. The attachment 100 may also be used as a controller for playing or stopping a song when the sensor detects striking on the attachment 100. Moreover, the attachment 100 may be used as the so-called acoustic percussion instrument that does not have a sensor and generates an impact sound when the upper main body part is struck. In that case, the upper main body part may be made of a metal material or wood, etc., and the shape or size of the upper main body part may be varied properly to change the impact sound that is generated when the upper main body part is struck.
In the aforementioned exemplary embodiments, the main body part 10 is curved in an arc shape. However, the present invention is not limited thereto. The main body part 10 may have other shapes, e.g. a straight shape.
In the aforementioned exemplary embodiments, the restricting part 30 includes the flange supporting part 40 that touches the flange part 4a of the hoop 4 and the bolt supporting part 50 that touches the male screw part 5a of the tension bolt 5. However, the present invention is not limited thereto. The restricting part 30 may include only one of the flange supporting part 40 and the bolt supporting part 50, so as to simplify the structure of the attachment 100 and reduce the production costs. Moreover, the restricting part 30 may include a shell supporting part provided to touch the outer circumferential surface of the shell 2a of the body part 2. The shell supporting part may be made of the same rubber material as the flange supporting part 40, for example. In the state that the plate 20 is tightened together with the hoop 4 by the tension bolt 5, the shell supporting part may extend from the inner circumferential surface of the main body part 10 to touch the outer circumferential surface of the shell 2a at a position whose height allows the shell supporting part to touch the shell 2a. In that case, the length of the shell supporting part in an extending direction thereof may be adjustable according to the shape of the percussion instrument to which the attachment is installed. For example, a member may be detachably attached to the shell supporting part through a bolt, etc., and the shell supporting part may support the shell 2a through the member. In addition, the shell supporting part may be detachably attached to the inner circumferential surface of the main body part 10 through a bolt, etc., and the shell supporting part may be attached according to the shape of the percussion instrument on which the attachment is installed. The aforementioned shell supporting part may be used to replace the flange supporting part 40 or the bolt supporting part 50, or be used together with the flange supporting part 40 or the bolt supporting part 50.
In the aforementioned exemplary embodiments, the flange supporting part 40 and the elastic part 52 of the bolt supporting part 50 are integrally formed using the same elastic material. However, the present invention is not limited thereto. The flange supporting part 40 and the elastic part 52 may be formed separately. Moreover, the flange supporting part 40 and the elastic part 52 may be made of elastic materials that are different in elasticity, such that the elasticity of the flange supporting part 40 and the elastic part 52 can be set at will.
In the aforementioned exemplary embodiments, the plate 20 and the rigid part 51 of the bolt supporting part 50 are integrally formed using the same metal material. However, the present invention is not limited thereto. The plate 20 and the bolt supporting part 50 may be formed separately. Moreover, the plate 20 and the bolt supporting part 50 may be made of different materials. The rigid part 51 may be made of a material that at least has higher stiffness than the elastic part 52. The rigid part 51 may also be made of a resin material, such as ABS, etc., instead of a metal material. Moreover, in the aforementioned exemplary embodiments, the plate-shaped plate 20 extending from the inner circumferential surface of the main body part 10 is tightened together with the hoop 4 by one tension bolt 5. However, the present invention is not limited thereto. Instead, a cylindrical member may extend from the inner circumferential surface of the main body part 10 in replacement of the plate-shaped plate 20, and the cylindrical member may be tightened together with the hoop 4 by one tension bolt 5. An inner diameter of the cylindrical member is larger than the outer diameter of the male screw part 5a of the tension bolt 5 and smaller than the outer diameter of the engagement part 5c. In addition, the cylindrical member has dimensions of a predetermined height in an insertion direction (the vertical direction of
In the aforementioned exemplary embodiments, the bolt supporting part 50 includes the rigid part 51 and the elastic part 52 that has higher elasticity than the rigid part 51. However, the present invention is not limited thereto. The bolt supporting part 50 may include only one of the rigid part 51 and the elastic part 52, so as to simplify the structure of the bolt supporting part 50 and reduce the production costs. In that case, the inner diameter of the recess part 51a of the rigid part 51 may be substantially equal to the outer diameter of the male screw part 5a of the tension bolt 5, so that the displacement of the main body part 10 and the plate 20 relative to the tension bolt 5 can be restricted with certainty.
In the aforementioned exemplary embodiments, the bolt supporting part 50 has a substantially “U” shape when viewed from above. However, the present invention is not limited thereto. The bolt supporting part may also be formed to have a substantially “V” shape or “C” shape with corners similar to “[” when viewed from above. Moreover, a hole, which has a substantially circular shape when viewed from above, may be formed on the bolt supporting part to receive the male screw part 5a of the tension bolt 5, and by inserting the male screw part 5a into the hole, the bolt supporting part may touch the male screw part 5a.
If the bolt supporting part is formed in the substantially “V” shape when viewed from above, the bolt supporting part can touch the outer circumferential surface of the male screw part 5a of the tension bolt 5 at two positions. Thus, a range of the outer diameter of the male screw part 5a, in which the male screw part 5a can touch the bolt supporting part, is widened. In other words, the versatility of the attachment is increased. If the bolt supporting part is formed with the substantially circular hole thereon, and the male screw part 5a is inserted thereinto, the bolt supporting part can be opposed to the entire outer circumferential surface of the male screw part 5a, so that displacement of the main body part 10 and the plate 20 relative to the tension bolt 5 can be restricted with certainty.
In the aforementioned exemplary embodiments, the flange supporting part 40 is formed lower than the plate 20 and touches the flange part 4a of the hoop 4 under the plate 20. However, the present invention is not limited thereto. The flange supporting part 40 may also be formed higher than the plate 20 and touch the flange part 4a above the plate 20.
The aforementioned exemplary embodiments illustrate that, in the state that the plate 20 is tightened together with the hoop 4 by the tension bolt 5, the flange supporting part 40 touches the flange part 4a of the hoop 4. However, the present invention is not limited thereto. The flange supporting part may touch a portion other than the flange part 4a of the hoop 4, namely, the outer circumferential surface of the arc-shaped portion formed between adjacent flange parts 4a.
According to the aforementioned exemplary embodiments, the plate 20 is tightened together with the hoop 4 by the tension bolt 5 in the state that the plate 20 is placed on the top surface of the flange part 4a of the hoop 4. However, the present invention is not limited thereto. The plate 20 may be tightened together with the hoop 4 by the tension bolt 5 when a spacer is inserted between the flange part 4a and the plate 20, wherein the spacer may be made of a material, e.g. elastomer, which has lower stiffness than the metal material that forms the plate 20 and the hoop 4. Accordingly, damage that may easily occur due to the contact between metal materials can be prevented, and looseness of the tension bolt 5, which results from rattling of the main body part 10 relative to the flange part 4a, can be prevented as well.
Number | Date | Country | Kind |
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2012-269452 | Dec 2012 | JP | national |