JPH0224151Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a piano whose purpose is to reduce weight, reduce the number of parts used, reduce processing steps, and improve assembly accuracy.

As shown in Fig. 1, a conventional upright piano forms a strut assembly R consisting of a strut a, a girder 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 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 is attached to the front surface of the column A tuning pin in which a soundboard g having a rotating e and a sounding rod n is fixed, a frame i is fixed on the soundboard g and the pin plate f, and a string l is implanted in the pin plate f through the frame i. A piece h is placed between j and a hitch pin k planted in the lower part of frame i.
It is stretched through the top. In addition, the first
In the figure, m indicates a string pillow.

The pillar assembly R is made of wood such as hemlock, matoa, lauan, etc. As is well known, these woods are greatly affected by humidity and temperature, 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, and its large shape makes it difficult to mechanize.
Mass production requires a lot of manpower, and the structure (shape) is limited because it is manufactured from a sand mold. 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 created in view of the above-mentioned drawbacks.
This is a structure in which a conventional support column assembly R and a 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 this 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 parts, etc. are omitted.

As shown in Fig. 7A, the base 1 is made of a steel plate in the shape of a horizontally long rectangle, cut from the lower center to the middle of one side. The section up to the center is bent parallel to the upper end, and the section from the center to the other end is bent upward at an angle to form a U-shaped cross section. It is formed integrally by pressing by punching out the center part except for the space where a post member 3, which will be described later, is installed vertically between the upper surface and the bent piece of the inclined surface, and folding the upper and lower parts inward. Incidentally, the periphery of the punched out central portion may be integrally drawn inward with a press, as shown in FIG. 7B. A hit pin installation member 2 made of steel and having a □-shaped cross section is horizontally installed by welding on the lower front surface of the base 1 which is formed into a U-shaped cross section, and is further connected to both ends between the bent pieces having a U-shaped cross section. Between these columns, a plurality of support columns 3 made of steel with a □-shaped cross section are vertically installed by welding.
The depth dimension is approximately twice that of the other support members 3b, 3b.

A pin plate 4 is attached to the upper front surface of the base 1 with adhesive, and an L-shaped washer 5 is installed horizontally on the upper end of the pin plate 4, and is connected to the pin plate 4 by bolts and nuts 6. 1 is fixed.

Further, if the center portion of the pin plate 4 and the base portion 1 are fastened with wood screws, further reinforcement can be achieved. In addition to this attachment method, the rotating member 9 may be passed from above the soundboard 7 and connected to the base 1 using tapping screws.

A tuning pin 10 is installed on the pin plate 4, and a string pillow 11 is attached. Further, a hit pin 12 is installed in the hit pin installation member 2. Then, the string 13 has one end locked to the hitch pin 12,
The other end is wrapped around the tuning pin 10 and stretched over the bridge 8 and the string pillow 11.

In addition, 14 in FIGS. 3 and 4 indicates a sound rod attached to the back surface of the soundboard 7, and in FIGS. 2 and 3, S indicates the inclined base 1, the hit pin installation member 12, and the support member 4a. It shows a triangular space formed by the space S and the floor surface, and it is better to cover this space S as it is not desirable in terms of appearance.

In the above-described embodiment, the support member 3 and the hitch pin installation member 2 are made of □-shaped steel, but they may also be U-shaped or H-shaped in cross section, and the material may be iron or a light alloy.

In addition, since the tension of the strings 13 reaches more than 10 tons in total, in order to prevent the pin plate 4 from rotating or slipping due to the tension of the strings 13, a pin plate reinforcing member 15 is installed as shown in FIGS. 7A and 7B. may be provided on the base 1 by welding or the like.

Also, the position of the string 13 on the lower end line of the pin plate 4 attached to the base 1, the position of the string 13 between the pin plate 4 and the striking part 9, or the string on the upper end line of the soundboard 7. Position 13 is the hammer string striking point. In this way, it can be easily visually determined whether the hammer is hitting the string 13 at the proper position, the accuracy of assembling the hammer increases, and the assembling work becomes less complicated.

In FIG. 5, in order to reduce the stiffness of the soundboard 7 on the treble side (right side in the figure), the rotating member 9 in this portion may be omitted.

In FIG. 2A, the string pillows 11 are each formed in a straight line. In this way, in the case of one key and two strings (one hammer has two strings of 13
), two strings 1 stretched on the bridge 8 and the string pillow 11 that are inclined to each other as shown in FIG.
The length of the string 13 is l ₁ >l ₂ , and as the length changes, the output of overtones varies due to the stress and tension of the string 13, resulting in a rich tone.

Furthermore, by making the string pillow 11 straight, manufacturing can be simplified. Note that this string pillow 11 is attached to the pin plate 4, but it may be attached using an epoxy adhesive, or it may be attached simply by attaching the string pillow 11 to the pin plate 4 without using an adhesive. It may be in a state where it is suppressed by the pressure under the string due to tensioning, or it may be fastened with wood screws.

In order to straighten the keyboard and improve the accuracy of assembling hammers, strings, etc., the cross-sectional area of the strut member 3b is reduced by the strut members 3a on both sides, and the bone part to maintain strength is reduced like a conventional piano frame. By not positioning the strings 13 on the string side with respect to the soundboard, the strings 13 are distributed at equal intervals over the entire bass, middle, and treble ranges during stringing, as shown in FIG.

FIG. 6 shows an example in which arm members 16 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 16 is shown by a dashed line in FIG. This arm member 16 is attached to the support member 3a provided with a pop nut, for example, by bolts or welding. Further, in order to improve the perpendicularity accuracy between the arm member 16 and the support member 3a, as shown in FIG. 8, a shelf support member 18 may be provided separately, and the arm member may be made into two parts, so that it can be rotated and the perpendicularity can be adjusted. .

As explained above, the hitch pin implantation member and the support member are fixed to the base with the base as a base,
Since a frame body is formed and a pin board and a sound board are attached to the base, the overall assembly accuracy is good and the complexity of assembly is very low.

Furthermore, whereas in the past the order was strut assembly -> soundboard -> frame -> string stringing, in this invention, the order of stringing was strut assembly (base 1, hit pin mounting member 2,
The assembly order is as follows: (including the strut member 3) -> soundboard -> string stringing, and the manufacturing process is greatly simplified, making it possible to provide a piano with low quality. In addition, the overall weight is extremely light compared to the conventional one, and the number of parts used is extremely small.Furthermore, the dimensions are set in the frame described above, the arm members are attached to this, and the shelves are attached to the arm members. By attaching the plate and the action, assembly accuracy was improved and adjustment work was significantly reduced.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional upright piano, Figure 2A is a front view of a piano according to an embodiment of this invention, Figure 2B is an enlarged view of section C in Figure 2A, and Figure 3 is an enlarged view of section C in Figure 2A. Similarly, FIG. 4 is a sectional view taken along the line AA in FIG. 2, FIG. 5 is a sectional view taken along BB in FIG. 2, and FIG. 6 is a partial perspective view of a piano according to an embodiment of the invention. Figures 7A and 7B are sectional views of main parts in Figure 2 showing other embodiments of this invention;
FIG. 8 is a perspective view of the arm member portion. 1... base, 2... hittipin implantation member, 3,
3a, 3b... Support member, 4... Pin plate, 5...
Washer, 6...Bolt/Nut, 7...Soundboard, 8...
... Piece, 9 ... Driving member, 10 ... Tuning pin, 11 ... String pillow, 12 ... Hitchi pin, 1
3... String, 14... Sound bar, 15... Pin plate reinforcing member, 16... Arm member, 17... Wood screw, 18...
Shelf support member.

Claims (1)

[Scope of utility model registration request] The front surface of the lower part of the base 1 is made of metal and has a substantially U-shaped cross section, with the upper and lower ends and the inclined part bent in the same direction, respectively, from the lower central part of the horizontally long rectangle to the middle part of one side surface. There is a hit pin installation member 2 made of metal with a cross-section of an opening or a U-shape.
is installed horizontally, and a plurality of support members 3 made of metal are installed vertically on the side and back surfaces of the base 1, each having an opening-shaped or U-shaped cross section, and a pin plate 4 is attached to the upper front surface of the base 1. A turning member 9 having a soundboard 7 and a bridge 8 is attached to the front surface of the base 1, and a tuning pin 10 is attached to the pin plate 4.
At the same time, a string pillow 11 is attached, a hitch pin 12 is installed in the hitch pin installation member 2, a string 13 is locked to the hitch pin 12, and the string 13 is passed over the bridge 8. The piano is formed by passing over the string pillow 11 and wrapping it around the tuning pin 10.