JPS5939749Y2 - Hammershank rail on a grand piano - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hammer shank rail for a grand piano that requires less man-hours, is easy to manufacture, and can be produced at a low price.

In general, the hammer shank rail a of a grand piano is made of a light alloy and is long and narrow (approximately 1400 mm), as shown in Figure 1 A.
), and has a single-shape side surface, with the same number of hammer flanges (not shown) as the hammer flange attached to the upper surface of the horizontal piece a1, and the lower half (left half) made of wood. A regulating rail b having a trapezoidal side surface is fixed with screws through a plurality of screw insertion holes h1.

And the regulator rule b is the same figure.

As shown in Figure C, the upper surface has a plurality of small holes h2 for receiving the screws, and the lower surface has a small hole h3 for press-fitting the adjusting rod C1 of the regulating button C.

By the way, the small holes h2 for the multiple screw receivers of the regulating rail b and the numerous small holes h3 for press-fitting the adjusting rod c1 must be drilled one by one with a drill, which is time-consuming and requires a hammer junk rail. When installing the regulating rail b, it is necessary to align the hole with the screw insertion hole h1 of the horizontal piece a1, which makes the installation troublesome.Furthermore, since the regulating rail b is made of wood, it tends to warp, impairing the proper let-off of the jack. There is a fear.

Therefore, this invention was made to improve the above-mentioned drawbacks, and provides a hammer shank rail that is easy to install, does not cause warping, and is easy to manufacture.

Referring to the drawings, the embodiment will be described. In Fig. 2, reference numeral 1 denotes an elongated hammer shank rail made of light alloy, and a hollow horizontal piece 1a having a trapezoidal shape with downward facing sides.
and an upright piece 1b for fixing to the vessel body, and a slit 2 of a required width is bored along the longitudinal direction in the center of the lower wall 1c of the horizontal piece 1a, and the opposite end surface of the slit 2 is Similarly, protruding strips 3 are provided along the longitudinal direction.

Reference numeral 4 is a regulating rail made of synthetic resin made by molding, which has an upward shape on the side and is about a quarter or one third of the length of the hammer shank rail 1, and the width of the upper and lower pieces is is approximately equal to the width of the slit 2 of the hammer shank rail 1, and the height and width of the grooves 4b on both sides are approximately equal to the thickness and width of the protruding strip 3 on the opposite surface of the slit 2. In the central portion thereof, a large number of holes 5 for inserting adjustment rods G1 of the regulating button C are provided in a penetrating state along the longitudinal direction at intervals t equal to the pitch of the balance plate.

Therefore, this regulating rail 4 is coated with adhesive on the surfaces of the grooves 4a on both sides and the end surfaces of the upper and lower pieces.
The projecting strips 3 are fitted into the grooves 4a on both sides, and are sequentially inserted into the slits 2 from both sides of the hammer shank rail 1 and bonded as shown in FIGS. The adjusting rod C1 of the regulating button C is inserted into the hole 5 in the state shown in the figure.

In addition, when installing the regulating rail 4, the width of the upper and lower pieces can be adjusted by slit 2 without using adhesive.
The width of the groove 4a may be made slightly larger than the width of the protruding strip 3, and the dimension of the groove 4a may be made slightly smaller than that of the protruding strip 3, and the groove 4a may be press-fitted into the slit 2.

Further, the regulating rail 4 may not be divided into pieces, but may be a single piece having the same length as the hammer shank rail 1, and the slit 2 of the hammer shank rail 1 and the cross-sectional shape of the regulating rail 4 may also be as shown in the figure. However, any shape that has a mutually fitting relationship and is difficult to fall off may be used.

As described above, in this invention, a slit having a required width and an appropriate cross-sectional shape is formed in the central part of the lower wall of the horizontal piece of the hammer shank rail, which consists of a hollow trapezoidal horizontal piece and an upright piece. A regulating rail made of synthetic resin and having a cross-sectional shape matching the cross-sectional shape of the slit and having a large number of pores passing through it along the longitudinal direction was fitted into this slit. Compared to conventional wooden rating rails, the jack can be let off smoothly without warping, and since there is no need to align the holes when installing both rails, it is easy to install both rails. Moreover, since the pores for attaching the regulating button can be formed during molding of the regulating rail, the number of man-hours for drilling the holes can be omitted and production can be made at low cost.

[Brief explanation of the drawing]

FIG. 1A is a perspective view of a part of a conventional hammer shank rail. Figure 1 is a partial perspective view of a conventional regulating rail seen from above. FIG. 1C is a partial perspective view seen from below. FIG. 2 is an exploded perspective view of a part of the embodiment of this invention. Figure 3 is a side view. Figure 4 is a front view. In the diagram, 1...Hammer shank rail, 1a.
...Horizontal piece, 1b... Standing piece, 2...
...Slit, 3...Protruding strip, 4...
Regulating rail, 4a... Groove, 4
b...Rib, 5...Pore.

Claims (1)

[Scope of utility model registration request] It consists of a hollow trapezoidal horizontal piece 1a and an upright piece 1b made of light alloy, and a slit 2 having a required width and an appropriate cross-sectional shape is formed in the center of the lower wall 1c of the horizontal piece 1a in the longitudinal direction. The slit 2 is fitted with a regulating rail 4 made of synthetic resin and having a cross-sectional shape matching that of the slit 2, and having a number of pores 5 extending through the longitudinal direction in the center thereof. A hammer shank rail on a grand piano.