CZ304839B6 - Device to regulate tension in the piano soundboard - Google Patents

Abstract

The device to regulate tension in the piano soundboard through the mediation of screw acting on the piano shell consists of a pin (1) that is slidably mounted within a vertical bore (2) of the shell (3). A screw (4), having its nut (5) anchored in the bore (2), serves as a support for the pin (1) at the lower end of the bore (2). At the bore (2) upper end, the pin bears on upper side of a horizontal continuous groove (6) performed at the upper edge of the shell (3).

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a device for regulating the voltage in a piano resonant plate, in particular in its discant region, by means of a screw acting on the piano.

BACKGROUND OF THE INVENTION

The function of the piano soundboard is to receive string tones through the bridge, to amplify them and give them the appropriate color. The soundboard is a very complex and demanding part of the piano. It is made of spruce or sparse fir wood. It is located in the case of a piano underneath the cabinet under the strings and cast iron frame. On the underside is provided with ribs to maintain its arch. On the upper surface of the soundboard there are grasshoppers - bass and discant, over which the strings are stretched. All around the perimeter, the soundboard is glued to the upper surface of the lip. The pressure of the strings on the bridge brings considerable tension to the vault of the soundboard. With conventional pianos, the distribution of tension across the area of the soundboard is given once and for all as the piano is made in production. However, it turns out that this voltage can be improved if this voltage can be corrected subsequently.

GB 267 204 discloses a device for improving the tone of a upright piano formed by a screw passing through the upright upright frame and by means of a spring and a rocker arm with a hook to draw the resonant plate to the upright frame and thereby vary the tension therein.

U.S. Pat. No. 4,640,174 discloses a device for calibrating a piano resonant plate in its discant region. It consists of a horizontal rod strut supported at one end by a bolt embedded in a nut recessed in the wedge between the lip and the strut of the piano carcass. At the other end, the bar rests on the front crossbeam of the carcass. By varying the pressure between the lip and the front crossbeam of the carcass by means of the bolt and the rod, the voltage in the resonant plate changes simultaneously. As the upright rod acts on the massive parts of the piano skeleton, the device must exert enormous force in order for its effect to be reflected in the resonant plate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple yet efficient device for regulating the voltage in the piano soundboard.

SUMMARY OF THE INVENTION

The object is solved by a device for regulating the voltage in the piano soundboard by means of a screw acting on the piano, which consists of a pin, which is slidably mounted in a vertical bore in the lip, at the bottom end is supported by a screw whose nut is anchored in the bore, and at its upper end rests on the upper side of the horizontal through groove made at the upper edge of the lip.

If the upper edge of the lip in the groove section is weakened by the inner lateral recess, the necessary pin pressing force is reduced.

Overview of the drawings

The voltage regulating device in the resonant board of the piano will be further elucidated by means of the drawing in which, in FIG. 1, the side of the piano in which the device is installed is axonometrically projected, in FIG.

Fig. 3 is a cross-sectional vertical cross-sectional view of the piano at the location of the device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the voltage control device in the piano soundboard, pin 1 is slidably mounted in vertical bore 2 of the lip 3. The pin 1 is supported at the lower end by a bolt 4 whose nut 5 is anchored in bore 2. At the upper edge of the lip 3 is horizontal a through groove 6 into which the bore 2 opens. A pin I projects from the bore 2 into the groove 6, which bears with its upper end against the upper side of the groove 6. A resonant plate 7 with a discontinuous bridge 8 is glued 3 is weakened by the inner side recess 9 in the region of the groove 6.

The screw 4 can be used to regulate the pin pressure on the top side of the groove 6, thereby deforming the upper surface of the groove 3 in the groove section 6 and hence the stress in the resonant plate 7 in its discant region.

The tuned and intonated instrument is located in the tuning cab, where the intoner plays the last few discant tones in rapid succession. The other person rotates the screw 4, thus bringing the upper end of the pin even to the upper side of the groove 6. At the time of contact, the sound perception changes. Subsequently, by further turning the screw 4, the pressure on the pin 1 is increased and thus the tension in the structure is changed until the intoner evaluates the piano sound as the best. From a certain pressure, the soundness no longer increases, but rather decreases. The screw 4 is then left in the optimum position.

Claims (2)

PATENT CLAIMS A device for regulating the tension in the piano soundboard by means of a screw acting on the piano, characterized in that it consists of a pin (1) which is slidably mounted in a vertical bore (2) in the lip (3), supported at the lower end a bolt (4) whose nut (5) is anchored in the bore (2) and rests at the upper end on the upper side of the horizontal through groove (6) made at the upper edge of the lip (3). Device according to claim 1, characterized in that the upper edge of the lip (3) is weakened in the groove section (6) by an inner side recess (9).