JPH0116139Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention eliminates the frame, reduces weight,
This article relates to a piano that aims to reduce the number of parts used, reduce the number of processing steps, and improve assembly accuracy.

As shown in Fig. 1, a conventional upright piano forms a support assembly R consisting of a support a, a beam b, a box c, and a base d. A pin plate f is fixed to the front surface of the column a on both sides, and a box c and a base d at the lower part of this column assembly R, and a piece h on the front surface of the column a on both sides, and a piece h around the back surface. A soundboard g having a rotor and a sounding rod n is fixed, and a frame i is mounted on the soundboard g and the pin plate f.
is fixed, and the string l is passed through the frame i and stretched over the bridge h between the tuning pin j set on the pin plate f and the hitch pin k set on the lower part of the frame i. In addition, in Figure 1, m
indicates a string pillow.

The strut assembly R is made of wood such as hemlock, matoa, lauan, etc. As is well known, these woods are greatly affected by temperature and humidity, causing warping, twisting, or cracking. Actions that affect the attached main plate (side plate) or the shelf attached to this main plate and are therefore placed on the shelf via the bracket, especially the striking point of the hammer during this action. Furthermore, if it affects the part where the string l is stretched, it will cause the pitch of the tuned string l to be out of tune.

The frame i is usually made of cast iron, but this has a number of disadvantages. In other words, the cast iron frame f is manufactured from a sand mold, making it difficult to work with.Due to its large shape, it is difficult to mechanize and requires a lot of manpower to mass produce.Also, since it is manufactured from a sand mold, its structure (shape ) is limited. Furthermore, there is instability in dimensional accuracy, non-uniformity in material and strength, large residual stress, and low Young's modulus, so in order to obtain the required strength, the cross-sectional area must be increased, and the overall weight It becomes quite heavy.

This idea was made in view of the above-mentioned points, and is one in which the conventional support column assembly R and frame i are integrated.

An embodiment of this invention will be described below with reference to FIGS. 2 to 5.

Figure 2 is a front view of the piano according to this invention, Figure 3
The figure is its rear view, and Figure 4 is A-A in Figure 2.
The sectional view, FIG. 5, is a BB sectional view in FIG. 2. In addition, these drawings show the keyboard, action,
Exterior members etc. were omitted.

As shown in the figure, a pin plate attachment member 1 made of steel with a cross-sectional shape is horizontally installed in the upper part, and a base member 2 made of steel with a similar cross-sectional shape is horizontally installed in the lower part. As shown in the figure, this base member 2 is parallel to the pin plate attachment member 1 on the bass side, but the pin plate attachment member 1 is parallel to the pin plate attachment member 1 from the middle to the treble area.
It is tilted so that it approaches. A plurality of strut members 3 connecting the pin plate attachment member 1 and the base member 2 are vertically installed by welding. These strut members 3 are rectangular pipes with a mouth-shaped cross section, and in particular, the depth of the strut members 3a, 3a on both sides is approximately twice as large as that of the other strut members 3b, 3b. The pin plate attachment member 1
A pin plate 4 is attached to the upper front part of the pin plate 4 with wood screws 15 and adhesive. Further, a hit pin installation member 5 having a cross-sectional opening shape is welded to the front lower part of the base member 2, and a driving member 6 attached around the back surface of the soundboard 7 is welded to the front lower part of the pin plate attachment member 1 and the base. The soundboard 7 is attached to the front upper part of the member 2 and the both side members 13 attached to the both side support members 3a, 3a with wood screws 16 and adhesive. pin plate 4
Tuning pins 9 are installed on the top at approximately equal pitches, and string pillows 10 are attached. Further, hit pins 11 are installed in the hit pin installation member 5 at approximately equal pitches. One end of the string 12 is locked to the hitch pin 11, the string 12 is stretched by passing over the bridge 8 and the string pillow 10, and wrapping the other end around the tuning pin 9. In addition, in FIGS. 3 and 4, 14 indicates a sound bar attached to the back surface of the soundboard 7, and in FIGS. 2 and 3, S indicates the inclined base member 2, support member 3a, and floor surface. This shows a triangular space formed by S, and since it is unfavorable in terms of appearance, it is better to cover this space S with plywood or the like.

In the above-described embodiment, the tuning pin installation member 1 and the base member 2 are made of shaped steel, but if they are made of mouth shaped steel like the support member 3 and the hitching pin installation member 5, the strength will be further increased. These members 1, 2, 3, and 5 may have a cross-sectional shape or an H-shaped cross section, and are made of iron or a light alloy.

The position of the string 12 on the lower end line of the pin plate 4 attached to the pin plate attachment member 1 or the position of the string 12 on the opening between the pin plate 4 and the striking member 6 is defined as the hammer string striking point. In this way, it is possible to easily visually determine whether the hammer is hitting the string 12 at the proper position, increasing the accuracy of hammer assembly, and reducing the complexity of the assembly work.

In FIG. 5, in order to reduce the stiffness of the soundboard 7 on the treble side (right side in the figure), the striking member 6 and both side members 13 in this portion may be omitted.

In FIG. 2, the string pillows 10 are each formed in a straight line. In this way, in the case of one key and two strings (when two strings 12 are provided for one hammer), the lengths of the two strings 12 change and the difference in stress and tension of the strings 12 causes overtones. The way the sound comes out is different, resulting in a rich tone. Furthermore, by making the string pillow 10 straight, manufacturing can be simplified. Note that this string pillow 10 is attached to the pin plate 4,
You can attach it with an epoxy adhesive, or you can simply attach it to the string 12 without using an adhesive.
It may also be in a state where it is pressed by the pressure under the string due to the tensioning of the string.

In order to straighten the keyboard and improve the accuracy of assembling the hammers, strings, etc., the cross-sectional area of the support member 3b is made smaller than that of the support members 3a on both sides, and the bone part is designed to maintain strength like a conventional piano frame. By not positioning the strings 12 on the string side with respect to the soundboard, the strings 12 are distributed at equal intervals over the entire bass, middle, and treble ranges as shown in FIG. 2 during stringing.

FIG. 6 shows an example in which arm members 17 having an L-shaped cross section for mounting and fixing a shelf board and an action bracket are attached to the front surfaces of the support members 3a on both sides. Note that this arm member 17 is shown by a dashed line in FIG. This arm member 17 is attached to a support member 3a provided with a pop nut, for example, with a bolt.

As explained above, whereas in the past the order was strut assembly → soundboard → frame → stringing, this invention eliminates the need for a frame, and the frame (pin plate attachment member 1, base member 2) , support member 3
)→soundboard→stringing, the manufacturing process is greatly simplified and it is possible to provide a piano with stable quality. In addition, the overall weight is extremely light compared to conventional products, and the number of parts used is also significantly reduced. Furthermore, there are no obstructive bones on the upper surfaces of pin boards, soundboards, etc., and the pitches of tuning pins, hitch pins, and bridge pins are not separated by these bones as in the past, and the pitches of tuning pins and Since the hitch pins can be planted at approximately the same pitch, the strings can also be planted at approximately the same pitch, and the keyboard can therefore be made into a straight keyboard, which has the advantage that the hammers used to strike the strings can also be machined straight. are doing. Furthermore, since the dimensional standards are set on the frame described above, the arm members are attached to this, and the shelf board and the action are attached to the arm members, assembly accuracy is improved.
Adjustment work has also been significantly reduced.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional upright piano, Figure 2 is a front view of a piano according to an embodiment of this invention, Figure 3 is a rear view, and Figure 4 is a second
5 is a sectional view taken along line AA in the figure, FIG. 5 is a sectional view taken along line BB in FIG. 2, and FIG. 6 is a partial perspective view of a piano according to an embodiment of the invention. In the figure, 1... pin plate attachment member, 2... base member, 3, 3a, 3b... support member, 4... pin plate, 5... hitch pin installation member, 6... driving member, 7... ...Soundboard, 8...Piece, 9...Tuning pin, 10...String pillow, 11...Hitting pin, 1
2...Strings, 13...Both side members.

Claims (1)

[Scope of utility model registration request] A pin plate attachment member 1 made of metal with a cross-sectional mouth shape or shape is installed horizontally on the upper part, and a base member 2 made of metal with a cross-sectional mouth shape or shape is horizontally installed on the lower part to connect the two members 1 and 2. A plurality of support members 3 made of metal with a cross-sectional opening shape or shape are installed vertically,
A pin plate 4 is attached to the front surface of the pin plate attachment member 1, and a hit pin installation member 5 made of metal with a cross-sectional opening shape or the like is attached to the front surface of the base member 2.
A driving member 6 is attached to each of the pin plate attachment member 1, the base member 2, and both side members 13, 13 of the support member 3. A soundboard 7 having bridges 8 on its surface is installed, tuning pins 9 are installed on the pin plate 4, and string pillows 10 are installed, and hitch pins 11 are installed on the hitch pin installation member 5. and the hitipin 1
1, the strings 12 are fixed to the strings 1, and the strings 12 are passed over the bridges 8 and then over the string pillows 10, and then wound around the tuning pins 9 and stretched.