JP2007248692A - Butt of upright piano - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the butt of an upright piano capable of surely preventing a center pin from leaving due to the radial load or the moment of movement and enabling the center pin to be replaced easily. <P>SOLUTION: The butt 4 has a linear pin-holding groove 8, extending in the right and left directions, formed in the back of a butt body 5 where a hammer 31 is integrally provided, a portion 7a below the pin holding groove 8 on the back is offset forward relative to an upper portion 7b, and a fitting screw 9 is screwed in the portion 7b above the pin-holding groove 8 on the back to fit a butt plate 6 to the butt body 5. Furthermore, the butt 5 has at least a portion of the center pin 11b accommodated in the pin holding groove 8 and is turnably supported on a butt flange 11 via the center pin 11b, in a state where the center pin 11b is held between the butt body 5 and butt plate 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is supported by a butt frangible through a center pin provided so as to extend horizontally in the left-right direction on the butt frenzy, and is struck by turning a hammer as the key is depressed. Related to upright piano bats.

  As a conventional upright piano bat, for example, one disclosed in Patent Document 1 is known. This bat has a general configuration and is provided for each key. A hammer, a catcher or the like is attached to the bat (hereinafter, the bat, the hammer and the catcher are collectively referred to as “hammer assembly”). Called). The bat is supported at the lower end of the bat by the center pin of the butt flange. The bat frenzy has bat support portions that protrude upward from both left and right ends, and is detachably attached to the center rail. The center pin is attached to these left and right bat support portions so as to be horizontally rotatable.

  A bat having a bat body and a bat plate attached to the bat body is known. In this type of bat, the lower portion of the back surface of the bat main body is formed in a flat shape, and a pin holding groove having a V-shaped cross section extending in the left-right direction is formed on the back surface. The butt plate is attached to the bat body by screwing a mounting screw inserted into a hole formed at the upper end of the butt plate into the back surface of the bat body. In this state, the center pin is mostly pin-held. It is accommodated in the groove and is sandwiched between the bat main body and the bat plate, and the bat plate faces the back surface of the bat main body with a slight gap therebetween. With the above configuration, the hammer assembly including the bat is rotatably supported by the butt flange via the center pin.

  In the hammer assembly having the above configuration, when the key is depressed, the action jack causes the lower surface of the bat body to be pushed up, so that the hammer pivots backward on the center pin. A piano sound is generated by striking a string. After the string is hit, the hammer assembly is returned to its original position by the repulsive force of the string.

  In the case of the bat body configured as described above, when an external force is applied to the hammer assembly, such as when it is pushed up by the jack, or when the hammer strikes the string, the center of the bat body is centered on the bat body. A radial load acts on the pin in the radial direction. Due to this radial load, the bat body tends to move in the vertical direction relative to the center pin. That is, when viewed from the center pin side, the center pin tends to come out of the pin holding groove.

  In an upright piano, the strings extend diagonally to the left and right with respect to the vertical direction, so there is a reaction force that moves the hammer in the left-right direction in the reaction force that acts on the hammer from the string when the string is struck. As a result, there may be a moment (hereinafter referred to as “blur moment”) that causes the hammer to sway in the left-right direction around the center pin. As a result, the bat body is inclined obliquely with respect to the center pin when viewed in the left-right direction. Try to move outwards. As a result, in this case, in particular, the center pin is easily pulled out from the pin holding groove. As described above, since the center pin may be detached from the pin holding groove due to a radial load or a shaking moment, in order to prevent this, it is preferable to form the pin holding groove deeper.

  Further, in the upright piano having the bat as described above, when exchanging the center pin, this exchange is performed as follows. That is, first, after removing the butt flange from the center rail, the mounting screw is loosened, the center pin is extracted from the pin holding groove, and further removed from the bat through the gap between the butt plate and the bat body. Next, after exchanging the center pin, the center pin is engaged with the pin holding groove through the gap, and is attached to the bat by tightening the attachment screw.

  As described above, the attachment / detachment for exchanging the center pin is performed through the gap between the butt plate and the bat body. For this reason, as described above, when the pin holding groove is formed deep in order to prevent the center pin from being detached due to a radial load or a shaking moment, it becomes difficult to replace the center pin. Specifically, when the pin holding groove is formed deeper, the gap between the center pin and the butt body is extremely narrow, so the center pin is passed when replacing the center pin. In order to ensure a sufficient clearance, the mounting screw must be turned many times. This also applies to the subsequent tightening of the mounting screw. As a result, these operations are complicated and it is difficult to replace the center pin.

  The present invention has been made in order to solve the above-described problems, and can reliably prevent the center pin from being detached due to a radial load or a shaking moment, and can easily replace the center pin. The object is to provide a piano bat.

Japanese Patent Laid-Open No. 6-27934

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that it is rotatably supported by the butt flange via a center pin provided so as to extend horizontally in the left-right direction on the bat flange. Accordingly, the bat of the upright piano that performs stringing by rotating the hammer, the hammer is provided integrally, has a linear pin holding groove extending in the left-right direction on the back surface, and the back pin The part below the holding groove is screwed into the part above the pin holding groove on the back of the bat body, the butt plate, and the butt body that is offset to the front side with respect to the part above the pin holding groove. And a mounting screw for attaching the butt plate to the back of the bat body. The bat accommodates at least a part of the center pin in the pin holding groove, and While holding the center pin during the preparative plates, characterized in that it is rotatably supported by the bat flange via the center pin.

  In this upright piano bat, the bat main body has a pin holding groove extending linearly in the left-right direction on the back surface, and by screwing a mounting screw into a portion above the pin holding groove on the back surface of the bat main body. The bat plate is attached to the bat body. The center pin is provided in the butt flange so as to extend horizontally in the left-right direction. At least a part of the center pin is accommodated in the pin holding groove and is sandwiched between the bat body and the butt plate. With the above configuration, the bat body is rotatably supported by the butt flange via the center pin. When the key is pressed, the bat rotates around the center pin, and accordingly, the hammer is rotated and a string is struck to generate a piano sound.

  Further, according to the bat of the present invention, a portion of the back surface of the bat main body that is lower than the pin holding groove (hereinafter referred to as “lower back surface”) with respect to an upper portion (hereinafter referred to as “upper back surface”). Offset to the front. For this reason, for example, when exchanging the center pin, the exchanging work can be easily performed. That is, when exchanging the center pin, first, loosen the mounting screw to widen the gap between the lower back surface and the butt plate (hereinafter referred to as “plate gap”), and remove the center pin from the pin holding groove, Further, it is removed from the bat through the plate gap. Next, after exchanging the center pin, the center pin is engaged with the pin holding groove through the plate gap, and is attached to the bat by tightening the attachment screw.

  As described above, according to the present invention, since the lower back surface is offset to the front side with respect to the upper back surface, a relatively large plate gap can be secured. Therefore, it is possible to secure a sufficient plate gap to allow the center pin to pass through by slightly loosening the mounting screw. In addition, since the lower back surface is offset to the front side, the depth of the pin holding groove on the lower back surface is shallower than that on the upper back surface side, so when extracting the center pin from the pin holding groove, Does not get caught in the pin holding groove. Therefore, the center pin can be easily removed from the bat via the plate gap. Furthermore, when attaching the replaced center pin to the bat, it is only necessary to tighten the attachment screw slightly loosened as described above, so that the center pin can be attached easily. As described above, the center pin can be easily replaced.

  Moreover, since only the lower back surface is offset to the front side, a larger pin holding groove depth can be secured on the upper back surface side. Therefore, even if the left and right ends of the center pin try to move outward in the upside down direction with respect to the pin holding groove due to the above-mentioned shaking moment, the upper part of the center pin is accommodated in the deeper part of the pin holding groove. Thus, one of the left and right end portions of the center pin does not slip out of the pin holding groove, thereby preventing the center pin from being detached. The same applies to the case where the bat body moves downward relative to the center pin due to the radial load. As described above, it is possible to reliably prevent the center pin from being detached due to the radial load or the shaking moment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the action 1 to which the bat 4 of the upright piano according to the present embodiment is applied together with the keyboard 21 and the hammer 31 in the key released state. In the following description, the front side as viewed from the performer side is described as “front”, and the back side is described as “rear”. Moreover, hatching is abbreviate | omitted for convenience in all drawings including the same figure.

  The keyboard 21 is composed of a number of keys 22 (only one is shown) arranged in the left-right direction (the depth direction in FIG. 1). Each key 22 is rotatably supported by a balance pin 23 a erected on the collar 23.

  A hammer 31 is provided for each key 22 (only one is shown), and each hammer 31 has a hammer shank 32 and a hammer head 33. The hammer shank 32 is formed in an elongated bar shape having a circular cross section, is erected on the upper surface of a bat 4 described later of the action 1, and extends in the vertical direction. The hammer head 33 is provided at the upper end of the hammer shank 32, and faces the string S vertically stretched rearward in the key release state.

  The action 1 is attached to brackets (not shown) provided on the left and right ends of the flange 23 above the rear end of the keyboard 21, and is disposed between the left and right brackets. The action 1 has a whippen 2, a jack 3 and a bat 4 provided for each key 22 (only one is shown). Between the left and right brackets, a center rail 41, a hammer rail 42, and the like are passed. The whippen flange 10 and the butt flange 11 are screwed to the center rail 41 for each key 22 (both are 1). Only one is shown). The whippen 2 is rotatably supported by the whippen flange 10 at the rear end.

  The wippen 2 is formed in a predetermined shape by, for example, synthetic resin or wood, and has a heel portion 2a protruding downward from the front portion thereof, and the upper surface of the corresponding key 22 through the heel portion 2a. It is placed on a capstan button 22a provided at the rear end. A back check 12 is attached to the front end portion of the upper surface of the wippen 2. Further, a spoon 13 for driving a damper 45 to be described later is erected on a portion of the upper surface of the whippen 2 behind the whippen frenzy 10.

  The jack 3 is made of, for example, a synthetic resin and is integrally formed by injection molding. The jack 3 has a base portion 3a extending in the front-rear direction and a protruding portion 3b extending upward from the rear end portion of the base portion 3a. It is supported freely. A jack spring 14 is provided between the base 3a of the jack 3 and the whippen 2 for returning and turning the jack 3 when the key is released. Further, a regulating button 15 is provided for each key 22 above the base 3a (only one is shown). The regulating button 15 is fixed to the center rail 41 via the regulating bracket 16 and the regulating rail 17.

  The butt flange 11 described above is made of, for example, a synthetic resin, and as shown in FIG. 2, hammer support portions 11a and 11a protrude upward from left and right ends (only one is shown). A center pin 11b having a circular cross section for supporting the bat 4 is rotatably attached to the hammer support portions 11a and 11a and extends horizontally in the left-right direction. The diameter of the center pin 11b is, for example, about 1.3 mm.

  The bat 4 includes a bat main body 5 formed in a predetermined shape with a synthetic resin, and a metal bat plate 6 attached to the back surface of the bat main body 5. The lower end portion of the bat main body 5 is a pin attachment portion 7 having a smaller width in the left-right direction than other portions. A pin holding groove 8 for attaching the bat 4 to the center pin 11 b described above is formed on the back surface of the pin mounting portion 7, and this pin holding groove 8 extends over the entire left and right direction of the back surface of the pin mounting portion 7. It extends horizontally in a straight line. Further, as shown in FIG. 3, the pin holding groove 8 is formed in a V-shaped cross section by a pair of upper and lower inclined surfaces 8 a and 8 b, and both inclined surfaces 8 a and 8 b are the same as each other with respect to the back surface of the pin mounting portion 7. It is inclined at a predetermined angle, and the upper inclined surface 8a is longer than the lower inclined surface 8b.

  Of the back surface of the pin mounting portion 7, a portion below the pin holding groove 8 (hereinafter referred to as “lower back surface”) 7 a is on the front side with respect to an upper portion (hereinafter referred to as “upper back surface”) 7 b. The offset is α, and the offset amount α (see FIG. 3) is set to about 0.2 mm, for example. Thereby, the depth DU on the upper back surface 7b side of the pin holding groove 8 is larger than the depth DL on the lower back surface 7a side.

  The butt plate 6 is made of, for example, a rectangular steel plate, and a hole 6a is formed at an upper end portion thereof. The butt plate 6 is attached to the pin attachment portion 7 by screwing the attachment screw 9 into the above-described upper back surface 7b through the hole 6a, and covers the back surface thereof.

  Further, most of the center pin 11 b is accommodated in the pin holding groove 8 and is sandwiched between the pin mounting portion 7 and the butt plate 6. With the above configuration, the bat 4 is integrally attached to the center pin 11b and is rotatably supported by the butt flange 11 via the center pin 11b.

  Further, the rear portion of the center pin 11b slightly protrudes from the upper back surface 7b, and accordingly, a gap CU equal to the protruding length is formed between the butt plate 6 and the upper back surface 7b. Further, a gap (hereinafter referred to as “plate gap”) CL is also formed between the lower back surface 7a and the butt plate 6, and as described above, the lower back surface 7a is offset to the front side. The plate gap CL is larger than the upper gap CU.

  A catcher 18 is attached to the front surface of the bat main body 5, and the catcher 18 is located behind the back check 12 described above in the key-released state, and faces the same. Hereinafter, the bat 4, the hammer 31, and the catcher 18 are collectively referred to as “hammer assembly A”. Further, a butt spring 19 is provided between the upper end of the back surface of the bat 4 and the butt flange 11, whereby the hammer assembly A including the bat 4 is urged clockwise in FIG. 1. Yes.

  In the key release state, the hammer assembly A configured as described above is stationary with the protruding portion 3b of the jack 3 engaged from below with the protruding upper portion 5a formed by the front end portion of the lower surface of the bat body 5. Yes.

  Further, behind the action 1, a damper 45 is provided for each key 22 (only one is shown). The damper 45 includes a damper lever 45b rotatably attached to the center rail 41 via a damper flange 45a, a damper head 45d attached via a damper wire 45c on the upper side of the damper lever 45b, and a damper head 45d. The damper lever spring 45e is urged toward the string S side. The damper 45 performs a sound stopping operation when the damper head 45d presses the string S by the urging force of the damper lever spring 45e when the key is released.

  Next, a series of operations from the start of key pressing to the end of key release, such as action 1 described above, will be described. When the performer depresses the key 22 in the released state, the key 22 rotates around the balance pin 23a in the clockwise direction in FIG. 1, and the whippen 2 placed at the rear end thereof is the key 22 It is turned upward (counterclockwise) by being pushed up by. As the whippen 2 rotates, the jack 3 moves upward together with the whippen 2 and pushes up the bat 4 through the projecting upper part 3b. Thereby, the hammer assembly A including the bat 4 rotates counterclockwise around the center pin 11 b toward the rear string S while resisting the biasing force of the bat spring 19.

  When the whippen 2 rotates to a predetermined angle after the key pressing is started, the spoon 13 provided at the rear end of the whippen 2 comes into contact with and presses the lower end of the damper lever 45b, so that the damper lever 45b is The damper lever spring 45e is rotated clockwise against the urging force of the damper lever spring 45e. As a result, the damper head 45d is separated from the string S, and the string S can vibrate.

  When the whippen 2 further rotates to a predetermined angle, the base 3 a of the jack 3 comes into contact with the regulating button 15. As a result, the jack 3 is restricted from moving upward, so that the jack 3 rotates clockwise against the urging force of the jack spring 14 with respect to the whippen 2, and the protruding portion 3 b moves forward from the bat 4. Detach (let off) and detach from bat 4. The hammer assembly A is rotated by inertia even after the jack 3 is detached, and the hammer head 33 hits the string S to generate a piano sound. Thereafter, the hammer assembly A starts to return and rotate by the repulsive force of the string S and the urging force of the bat spring 19. Then, when the key depression is completed and the key 22 is released, the key 22 and the action 1 and the like are rotated back in the opposite direction to the time when the key is depressed to return to the key release state shown in FIG. By doing so, a series of operations from the start of key depression to the end of key release is completed.

  When an external force is applied to the hammer assembly A, such as when the hammer assembly A is rotated by the key depression as described above, particularly when the hammer assembly A is pushed up by the jack 3 or when the hammer 31 strikes the string S. A radial load acts on the center pin 11b from the bat body 5. Thereby, the bat main body 5 tends to move in the vertical direction with respect to the center pin 11b.

  According to the present embodiment, as described above, the depth DU of the pin holding groove 8 on the upper back surface 7b side is increased by offsetting only the lower back surface 7a to the front side. Thereby, since the upper part of the center pin 11b is accommodated in a deeper part of the pin holding groove 8, even if the bat body 5 moves downward with respect to the center pin 11b due to the radial load described above, the center pin 11b Does not escape from the pin holding groove 8.

  This is the same when the above-described shake moment is applied to the hammer assembly A. That is, even if the left and right end portions of the center pin 11 b try to move outward in the upside down direction with respect to the pin holding groove 8 due to the shaking moment, the upper portion of the center pin 11 b becomes a deeper portion of the pin holding groove 8. By being accommodated, one of the left and right end portions of the center pin 11 b does not come out of the pin holding groove 8. As described above, it is possible to reliably prevent the center pin 11b from being detached due to a radial load or a shaking moment.

  In the action 1 described above, the center pin 11b is exchanged as follows. That is, first, after removing the butt flange 11 from the center rail 41, the mounting screw 9 of the butt plate 6 is loosened to widen the plate gap CL, and the center pin 11b is extracted from the pin holding groove 8, and further, the plate gap CL Remove from the bat 4 via. Next, after exchanging the center pin 11b, the center pin 11b is engaged with the pin holding groove 8 via the plate gap CL, and the attachment screw 9 is tightened to attach the center pin 11b to the bat 4.

  According to the present embodiment, as described above, the lower back surface 7a is offset to the front side, and thereby the plate gap CL becomes larger. Therefore, it is possible to secure a plate gap CL sufficient to pass the center pin 11b by slightly loosening the mounting screw 9. Further, since the lower back surface 7a is offset to the front side, the depth DL of the pin holding groove 8 on the lower back surface 7a side is shallower than the upper back surface 7b side, and the lower side constituting the pin holding groove 8 Since the inclined surface 8b linearly extends obliquely downward, the center pin 11b is not caught by the pin holding groove 8 when the center pin 11b is extracted from the pin holding groove 8. Therefore, the center pin 11b can be easily removed from the bat 4 via the plate gap CL. Furthermore, when attaching the replaced center pin 11b, it is only necessary to tighten the attachment screw 9 slightly loosened as described above, so that the center pin 11b can be attached easily. As described above, the replacement work of the center pin 11b can be easily performed.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the embodiment, the cross-sectional shape of the pin holding groove 8 is V-shaped, but is not limited thereto, and other appropriate shapes may be employed, for example, a semicircular shape. Even in this case, since the depth of the pin holding groove on the lower back surface 7a side is shallow because the lower back surface 7a is offset to the front side, the center pin 11b is easily extracted without being caught by the pin holding groove. be able to.

  In the embodiment, the bat 4 is integrally attached to the center pin 11b that is rotatably attached to the butt flange 11. However, the center pin 11b is integrally attached to the butt flange 11, and the center pin 11b is attached to such a center pin 11b. The bat 4 may be pivotably attached. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

It is a sectional side view which shows the action of the upright piano to which the bat by this embodiment is applied in a key release state with a keyboard and a hammer. It is the elements on larger scale which show the bat etc. of FIG. It is the elements on larger scale which show the center pin etc. of FIG.

Explanation of symbols

4 Butt 5 Butt body 6 Butt plate 7a Lower back side (the part below the pin holding groove on the back side of the bat body)
7b Upper back surface (portion above the pin holding groove on the back surface of the bat body)
8 Pin retaining groove 9 Mounting screw 11 Butt flange 11b Center pin 22 Key 31 Hammer S String

Claims (1)

The center of the bat frangible extends horizontally in the left-right direction, and is supported by the bat frangible so that it can be rotated by rotating the hammer as the key is depressed. An upright piano bat,
The hammer is provided integrally, and has a linear pin holding groove extending in the left-right direction on the back surface, and a portion below the pin holding groove on the back surface is a portion above the pin holding groove. Bat body offset to the front side,
A bat plate,
A mounting screw that attaches the butt plate to the back surface of the bat body by being screwed into a portion above the pin holding groove on the back surface of the bat body;
The bat accommodates at least a part of the center pin in the pin holding groove and is rotated to the butt flange via the center pin in a state where the center pin is sandwiched between the bat body and the butt plate. Upright piano bat, which is supported freely.

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