JP4673466B2 - Grand piano hammer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hammer device for a grand piano that strikes a string when a key is pressed.
[0002]
[Prior art]
Conventionally, a hammer device of this type is known as shown in FIG. In this grand piano (not shown), a large number of hammer devices 30 (only one is shown) correspond to a keyboard (not shown) and are arranged side by side in close proximity to each other. Each hammer device 30 includes a hammer shank frenzy 31 (hereinafter simply referred to as “frenzy 31”), a hammer shank 32, a hammer head 33, and the like. The flange 31 is made of synthetic resin and is fixed to a hammer shank rail (not shown) via a flange screw 34.
[0003]
Moreover, the hammer shank 32 is a long and slender rod-shaped thing, and is produced by cutting a wooden raw material. There are a plurality of types of hammer shanks 32 according to the sound range (only one type is shown), and the plurality of types of hammer shanks 32 are formed so as to have different shapes and dimensions. Two arms 32a and 32a are formed at the front end portion of the hammer shank 32, and these arms 32a and 32a extend in the front-rear direction in parallel with each other. Each of these arms 32a and 32a is formed with holes penetrating in the left-right direction so as to face each other. In addition, an engagement portion 31 a that protrudes rearward is formed at the rear end portion of the flange 31. The engaging portion 31a has holes (not shown) corresponding to the holes of the arms 32a and 32a, and the pin 35 is engaged with the engaging portion 31a engaged between the arms 32a and 32a. It passes through the holes of the arms 32a and 32a and the engaging portion 31a. Thereby, the hammer shank 32 is attached to the flange 31 via the pin 35 so as to be rotatable around the horizontal axis.
[0004]
Furthermore, both side surfaces of the engaging portion 31a of the flange 31 are formed in parallel to each other. Further, the inner surfaces of the arms 32a and 32a of the hammer shank 32 are parallel to each other and face both side surfaces of the engaging portion 31a, and between the inner surfaces of these arms 32a and 32a and both side surfaces of the engaging portion 31a. A slight gap is formed in the. With this configuration, the hammer shank 32 is guided by the arms 32a and 32a and the engaging portion 31a when rotating. Thereby, at the time of stringing operation, the hammer shank 32 and the hammer head 33 rotate smoothly without interfering with other adjacent objects.
[0005]
Further, a shank roller core 36 is attached to the front end portion of the hammer shank 32 so as to protrude downward. A cylindrical shank roller 37 is attached to the shank roller core 36, and the shank roller 37 is in contact with an action jack (or a repetition lever) from above (both not shown). The hammer head 33 described above is attached to the rear end portion of the hammer shank 32.
[0006]
In the hammer device 30 configured as described above, when the key of the grand piano is pressed, the shank roller 37 is pushed up by the jack, whereby the hammer shank 32 rotates upward, and the hammer head 33 moves the string (not shown). I hit the string.
[0007]
[Problems to be solved by the invention]
According to the conventional hammer device 30, the hammer shank 32 having a complicated shape having the arms 32a, 32a and the like must be manufactured by cutting a wooden raw material, and the shape and size are different from each other. Since it is necessary to produce a plurality of types, there is a problem that processing is troublesome and the manufacturing cost is high. In addition, in order to secure the bending rigidity of the hammer shank 32, it is necessary to carefully process the wood raw material so that the grain is not cut over the entire length, and the raw material must be selected with a straight grain and no defects. In addition, since the hammer shank 32 is formed by cutting a thick raw material, the yield is poor and the manufacturing cost increases. Furthermore, since the shank roller core 36 must be prepared separately from the hammer shank 32 and attached to it, the number of parts and man-hours increase accordingly, and the manufacturing cost further increases. Further, the wooden hammer shank 32 is more likely to be deformed by the influence of dry and wet than the synthetic resin frang 31, so that, for example, the frenzy 31 is rattled during use for a long time, and the string is struck. During operation, troubles such as the hammer head 33 coming into contact with another adjacent hammer device 30 may occur.
[0008]
Moreover, since the frenzy 31 and the hammer shank 32 are made of different materials such as synthetic resin and wood, the degree of expansion with respect to humidity is different. Specifically, the synthetic resin frenzy 31 hardly expands as the humidity changes, whereas the wooden hammer shank 32 expands more than the frenzy 31. As described above, since the gap between the arms 32a, 32a and the engaging portion 31a of the flange 31 is narrow, when the humidity rises, the hammer shank 32 expands more, which is caught by the flange 31 and smoothly. An operation failure that does not rotate (hereinafter referred to as “stick”) may occur.
[0009]
The present invention has been made to solve the above-described problems, and can reduce manufacturing costs, improve durability, and reliably perform a string-striking operation without causing a stick. It aims at providing the hammer apparatus of a grand piano.
[0010]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 is a hammer device of a grand piano that strikes a string when a key is pressed, and a hammer shank flange having a pair of guide surfaces parallel to each other, and a hammer shank flange parallel to each other. A shank holder that is rotatably attached to the hammer shank flange and is guided by the pair of guide surfaces, with the pair of planes facing the pair of guide surfaces, and the shank holder, Is configured as a separate body, one end of which is fixed to the shank holder and an elongated hammer shank, and the other end of the hammer shank is fixed. and a hammer head, the hammer shank flange and the shank holder is constituted by a molded product of synthetic resin, sheet The Nkuhoruda shank roller core for mounting the shank roller is characterized in that it is integrally formed.
[0011]
According to the hammer device of the grand piano, when a key pressing operation is performed, the shank holder and the hammer shank are guided in a state where the pair of plane portions of the shank holder are respectively guided by the pair of guide surface portions of the opposing hammer shank flange. And the hammer head rotates integrally, and the hammer head strikes the string. In this case, since the shank holder and the hammer shank corresponding to the conventional hammer shank are configured separately from each other, unlike the conventional case of producing a plurality of types of hammer shanks, all the shank holders of the grand piano are 1 It becomes possible to make it common to various types. For the same reason, the hammer shank may be fixed to the shank holder, so that it can be made into a simple and easy-to-manufacture shape such as a round bar. In addition, the length of the hammer shank is shorter than the conventional length by the amount of the shank holder. It becomes easy and the cutting amount when cutting the raw material can be greatly reduced. As a result, the material yield can be improved. As described above, according to the present invention, the productivity of the shank holder and the hammer shank can be improved as compared with the conventional case, and the manufacturing cost can be reduced.
[0012]
In addition, since the shank holder is composed of a synthetic resin molded product, the shank holder can be easily manufactured by cutting a wooden raw material compared to the conventional case of producing a hammer shank with a complicated shape. And it can be mass-produced at low cost. Also, by configuring the shank holder with a synthetic resin that is less likely to deteriorate due to the effect of moisture than wood, even when the shank holder is used for a long time, unlike the conventional case, it causes problems such as rattling on the hammer shank flange. It is difficult to improve durability. Furthermore, both the synthetic resin hammer shank frenzy and the shank holder have a smaller degree of expansion with respect to humidity than wooden ones, so unlike conventional hammer devices that combine wooden parts and synthetic resin parts, During the stringing operation, the shank holder rotates smoothly and reliably without causing a stick. As a result, the string-striking operation can be performed reliably. Further, unlike the conventional case, a shank roller core separate from the shank holder is not required, so that the number of parts can be reduced and the man-hours can be reduced correspondingly. As a result, the manufacturing cost can be further reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a hammer device for a grand piano according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a hammer device of this embodiment. In this grand piano (not shown), a large number of hammer devices 1 (only one is shown) correspond to a keyboard (not shown) and are juxtaposed in a state close to each other. Each hammer device 1 includes a hammer shank frenzy 2 (hereinafter simply referred to as “frenzy 2”), a shank holder 3, a hammer shank 4, a hammer head 5, and the like.
[0019]
The frenzy 2 is formed integrally with a synthetic resin (for example, polyacetal resin or ABS resin) that is hard to be deteriorated due to the influence of dryness and moisture and hard to wear compared to wood, and has an elongated shape with a rectangular cross section. . A hole 2 a penetrating in the vertical direction is formed at the center of the frenzy 2. A frenzy screw (not shown) passed through the hole 2a is screwed into a screw hole (not shown) of a hammer shank rail and tightened so that the frenzy 2 extends horizontally in the front-rear direction. It is fixed to the hammer shank rail. Further, an engaging portion 2b is formed at the rear end portion of the flange 2, and this engaging portion 2b is continuous with the center portion of the flange 2 and extends rearward with a predetermined width narrower than the center portion. Yes.
[0020]
The engaging portion 2b is formed with a screw hole (not shown) penetrating in the vertical direction, and the drop screw 6 is screwed into the screw hole. The length of the drop screw 6 is longer than the height of the engaging portion 2b, and the upper and lower ends protrude from the engaging portion 2b. The backstop position is adjusted by turning the drop screw 6 and adjusting the amount of protrusion of the drop screw 6 from the lower surface of the engaging portion 2b.
[0021]
Further, the shank holder 3 is integrally formed of a synthetic resin having the same quality as that of the flange 2, and has a rectangular parallelepiped shape with a rectangular cross section. The shank holder 3 basically has the same width and height as the central part of the frenzy 2. As shown in FIG. 2, the front half of the shank holder 3 is a pair of arms 3 a and 3 a, and these arms 3 a and 3 a extend in the front-rear direction in parallel with each other.
[0022]
These arms 3a, 3a are formed with holes 3b, 3b penetrating in the left-right direction so as to face each other. On the other hand, holes (not shown) corresponding to the holes 3b and 3b are formed in the engaging portion 2b of the frenzy 2, and the engaging portion 2b is engaged between the arms 3a and 3a. The pin 7 is passed through the holes 3b and 3b and the hole of the engaging portion 2b. As a result, the shank holder 3 is attached to the flange 2 via the pin 7 so as to be rotatable about the horizontal axis.
[0023]
Further, the inner surfaces 3c, 3c (plane) of the arms 3a, 3a and both side surfaces (guide surfaces) of the engaging portion 2b face each other in parallel, and a slight gap is defined between them. Yes. Thereby, when the shank holder 3 is rotated, the inner surfaces 3c and 3c of the arms 3a and 3a are guided by both side surfaces of the engaging portion 2b. Further, there is a sufficient space between the inner wall 3d connecting the inner surfaces 3c and 3c and the rear end of the engaging portion 2b, and the inner wall 3d is engaged when the shank holder 3 is rotated. It does not hit the part 2b.
[0024]
Furthermore, a shank roller core 3e is integrally formed below the central portion of the shank holder 3. The shank roller core 3e is formed over the entire left and right direction of the lower surface of the central portion of the shank holder 3, and protrudes downward. A cylindrical shank roller 8 is attached to the shank roller core 3e so as to cover it from the front and rear. The shank roller 8 is made of felt and is in contact with an action jack (or a repetition lever) from above (both not shown).
[0025]
A mounting hole 3 f is formed on the back surface of the shank holder 3. The mounting hole 3f is circular in cross section, has a predetermined depth and a predetermined diameter, and extends in the front-rear direction.
[0026]
On the other hand, the hammer shank 4 is a round bar having a constant diameter made of wood, and has a diameter slightly smaller than the mounting hole 3f and a predetermined length. The hammer shank 4 is fixed to the shank holder 3 by being bonded in a state where the front end portion is inserted into the mounting hole 3f. Moreover, the hammer shank 4 shown in FIG. 1 is for high-pitched strings, and although not shown, a plurality of types of hammer shanks for low-pitched strings are provided. These types of hammer shanks differ only in diameter compared to those for high-pitched sounds, specifically, the diameters of the front and rear ends are the same, and the diameters of the other parts are larger. Yes.
[0027]
The hammer head 5 described above is composed of a hammer wood 5a, an under felt 5b, a hammer felt 5c, and the like. The hammer wood 5a is made of wood and has a round hole (not shown) at the bottom. The hammer head 5 is fixed to the hammer shank 4 at a right angle by inserting and adhering the rear end portion of the hammer shank 4 into the round hole.
[0028]
The under felt 5b and the hammer felt 5c are both made of felt, and are bonded to the hammer wood 5a so as to cover the upper half of the hammer wood 5a in order from the front and rear.
[0029]
In the hammer device 1 configured as described above, when the key of the grand piano is pressed, the shank roller 8 is pushed up by the jack, so that the shank holder 3, the hammer shank 4, and the hammer head 5 are integrally rotated upward. To do.
[0030]
At this time, by rotating the shank holder 3 with the inner surfaces 3c, 3c of the arms 3a, 3a being guided by the both side surfaces of the engaging portion 2b, the hammer head 5 ensures that the string (not shown) I hit the string.
[0031]
As described above, according to the hammer device 1 of the present embodiment, the shank holder 3 is composed of an integrally molded product of synthetic resin, and can be manufactured by resin molding using a mold or the like. . As a result, the shank holder 3 can be mass-produced easily and inexpensively by cutting a wooden raw material as compared with the conventional case of producing a hammer shank having a complicated shape. Further, since the shank holder 3 is separate from the hammer shank 4, unlike the conventional case where a plurality of types of hammer shanks are required, all the shank holders 3 of the grand piano are made common to one type. be able to. For the same reason, the hammer shank 4 can have a simple shape (round bar) as in the present embodiment. Further, since the length of the hammer shank 4 is shorter than that of the conventional one by the amount of the shank holder 3, it is easier to select the raw material without cutting the grain than before, and when the raw material is cut. The amount of cutting can be greatly reduced. As a result, the material yield can be improved. Furthermore, since the shank roller core 3e is formed integrally with the shank holder 3, and a separate shank roller core is not required, the number of parts can be reduced as compared with the conventional one, and the man-hours can be reduced accordingly. Can do. As described above, according to the hammer device 1 of the present embodiment, the productivity of the shank holder 3 and the hammer shank 4 corresponding to the conventional hammer shank can be improved, and the manufacturing cost can be greatly reduced as compared with the prior art. it can.
[0032]
In addition, since the shank holder 3 is made of a synthetic resin that is less likely to deteriorate due to the influence of dryness and moisture than wood, even when the shank holder 3 is used for a long period of time, problems such as rattling against the frenzy 2 are less likely to occur. , Durability can be improved. Furthermore, since the synthetic resin frenzy 4 and the shank holder 3 both have a degree of expansion with respect to humidity smaller than that of wood, it differs from a conventional hammer device in which a wooden hammer shank and synthetic resin frenzy are combined. During the stringing operation, the shank holder 3 rotates smoothly and reliably without causing a stick. As a result, the string-striking operation can be performed reliably.
[0033]
Note that both the frenzy 2 and the shank holder 3 may be made of wood instead of synthetic resin. If it does in this way, the degree of expansion with respect to both humidity can be made the same, and, thereby, smooth rotation of the shank holder 3 at the time of a string-striking operation | movement can be ensured similarly to the above.
[0034]
In addition, the frenzy 2 and the shank holder 3 are made of a material such as metal that is less likely to deteriorate due to the effects of dryness and moisture compared to wood, and that has a low degree of expansion with respect to humidity, and that can be produced as a molded product. Also good. In addition, the frenzy 2 and the shank holder 3 may be made of different synthetic resins, and in this case, the materials of both may be selected so that the degree of expansion with respect to hardness and humidity is substantially the same. .
[0035]
【The invention's effect】
As described above, according to the hammer device of the grand piano of the present invention, the manufacturing cost can be reduced, the durability can be improved, and the stringing operation can be reliably performed without causing a stick. it can.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a hammer device of a grand piano according to an embodiment of the present invention.
2A is a perspective view of a shank holder of a hammer device, FIG. 2B is a side view of the shank holder, and FIG. 2C is a plan view.
FIG. 3 is a perspective view showing a conventional grand piano hammer device.
[Explanation of symbols]
1 Hammer Device 2 Hammer Shank Frenzy 3 Shank Holder 3c Inner Surface (Plane)
3e Shank roller core 4 Hammer shank 8 Shank roller

Claims (1)

A grand piano hammer device that strikes a string when a key is pressed,
Hammer shank flange having a pair of guide surfaces parallel to each other;
A shank holder having a pair of planes parallel to each other and rotatably attached to the hammer shank flange with the pair of planes facing the pair of guide surfaces, respectively, and guided by the pair of guide surfaces When,
An elongated hammer shank configured separately from the shank holder and having one end fixed to the shank holder;
A hammer head fixed to the other end portion of the hammer shank, and hitting the string by the rotation of the shank holder and the hammer shank accompanying key depression;
Equipped with a,
The hammer shank frenzy and the shank holder are composed of synthetic resin moldings,
A hammer device for a grand piano, wherein a shank roller core for attaching a shank roller is integrally formed on the shank holder .

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