PIANO SOUNDING BOARD ASSEMBLY
United States Patent 3674908
There is described a piano sounding board assembly whereby the vibration from the bass bridge may be effectively transmitted and distributed to the open area of the sounding board and the tonal qualities in the bass range may be improved to a considerable extent, the sounding board assembly incorporating a connecting plate member adapted for directly interconnecting the bass and treble bridges on one side of the sounding board.
US Patent References:
Piano bridge
Bronson - May 1940 - 2200913


Application Number:
05/137465
Publication Date:
07/04/1972
Filing Date:
04/26/1971
View Patent Images:
Assignee:
Nippon Gakki Seizo Kabushiki Kaisha (Hamamatsu-shi, JA)
Primary Class:
International Classes:
G10C3/06; G10C3/00; G10C3/04
Field of Search:
84/192,209,212
Primary Examiner:
Wilkinson, Richard B.
Assistant Examiner:
Franklin, Lawrence R.
Claims:
What is claimed is

1. A piano sounding board assembly, comprising a sounding board, an elongated treble bridge member secured to one face of said sounding board and extending substantially diagonally of said sounding board, a bass bridge member disposed in spaced relationship with said treble bridge member, a connecting plate member directly connecting said bass and treble bridge members, supporting means secured to the face of said sounding board and supporting said connecting plate member.

2. A piano sounding board assembly as defined in claim 1, wherein said connecting plate member is spaced apart from said sounding board by said supporting means, and said bass bridge member is secured on top of said connecting plate member spacedly from said sounding board.

3. A piano sounding board assembly as defined in claim 1, wherein said bass bridge member is secured on said connecting plate member and extended over substantially the entire length of said connecting plate member.

4. A piano sounding board assembly as defined in claim 1, wherein said supporting means is disposed intermediate between said bass and treble bridge members.

5. A piano sounding board assembly as defined in claim 2, wherein said supporting means is disposed intermediate between said treble and bass bridge members.

6. A piano sounding board assembly as defined in claim 1, wherein said supporting means is a rod-like member extending along said bridge members.

7. A piano sounding board assembly as defined in claim 1, wherein said connecting plate member presents a substantially rectangular shape and has its one longitudinal edge securely anchored in said treble bridge member, and said bass bridge member is securely supported over the entire length thereof on the other longitudinal edge of said connecting plate member.

8. A piano sounding board assembly as defined in claim 7, wherein said connecting plate member has a substantial area acting as an auxiliary sounding board.

Description:
This invention relates to an improvement in a piano sounding board assembly and more particularly to an interconnecting assembly of bridges and a sounding board, it being the purpose of the invention to develop tonal quality in the bass range together with overall tonal amplification in a sounding board.

Usually, a sounding board for pianos is provided on one face thereof with a lengthy treble bridge and a relatively short bass bridge. It has been the conventional practice to glue the bass bridge to the sounding board separately from the treble bridge in such a manner that the bass bridge also glued to the sounding board is disposed by the side of the treble bridge along the length thereof and in spaced relationship therewith. Such sounding board construction results in undue increase in rigidity in those portions of the sounding board to which the bass and treble bridges are glued and has a drawback that the treble bridge tends to block even distribution or transmission to the sounding board of the vibration from the bass bridge. It will thus be understood that with the sounding board construction mentioned above a difficulty is encountered in obtaining bass tones which are satisfactory in volume and in lower harmonics or overtones.

More recent prior art proposes to connect one of the ends of the treble and bass bridges with the use of a rod member secured to the back side of the sounding board, thereby to permit the vibration from the bass bridge to be distributed to the open area of the sounding board through the connecting rod member and the treble bridge. This sounding board construction might succeed in overcoming the above noted difficulty to some extent; however, it is not satisfactory in that the vibration from the bass bridge cannot be effectively propelled through the treble bridge which is connected to the bass bridge simply at one end thereof and, to a further disadvantage, connected indirectly by means of a connecting rod member which is mounted on the back side of the sounding board.

It is therefore the primary object of the invention to provide a sounding board assembly which will result in improved tonal qualities in the bass range, and wherein bass tones rich in lower harmonics or overtones are obtained through direct and ample connection between the treble and bass bridges so as to permit of the bass tones being effectively transmitted to the sounding board through the treble bridge. In order to achieve this end, the connection between the treble and bass bridges is made to propel the vibration from the bass bridge out into the open area of the sounding board through the treble bridge. This, of course, effects an improvement in the bass tones of the sounding board, and therefore of the piano and results in efficient bass tone distribution.

According to the invention, there is provided a piano sounding board assembly comprising a sounding board, an elongated treble bridge member glued to one face of the sounding board and extending substantially diagonally of the sounding board, a bass bridge member disposed in spaced relationship with said treble bridge member, a connecting plate member directly interconnecting the treble and bass bridges, and a supporting member secured to the face of the sounding board and supporting the connecting plate member.

The principal feature of the invention resides in the provision of the connecting plate member establishing an ample connection between the bass and treble bridges. The plate member has a substantial area and therefore serves to efficiently transmit the vibration from the bass bridge to the sounding board and at the same time act as an auxiliary sounding board which plays a role to improve tone qualities in the bass range through increase in lower harmonics or overtones.

The above and other objects and features of the invention will be apparent from the following description and appended claims, taken in conjunction with the accompanying drawings which show by way of example a preferred embodiment of the invention.

In the accompanying drawings:

FIG. 1 is a diagrammatic plan view of a piano sounding board assembly embodying the instant invention; and

FIG. 2 is a fragmentary cross-sectional view on an enlarged scale and taken along the section line II -- II of FIG. 1 (ribs omitted).

Referring to the drawing, the sounding board assembly of the invention is designated by the reference numeral 1 and shown as being employed in a grand concert piano. Indicated at 2 are a series of sounding board reinforcing rib members which are secured to the back side or face of the sounding board and are arranged in side by side relationship with each other. A long treble bridge, on which treble and intermediate piano strings are stretched, is glued to the top face of the sounding board 1. The treble bridge 3 is disposed substantially diagonally of the sounding board 1 and has end portions secured to one longitudinal edge of a connecting plate member 5. This connecting plate member 5 has a generally rectangular shape and extends in parallelly spaced relationship with the top face of the sounding board 1. On the other longitudinal edge of the connecting plate member 5, there is supported a relatively short bass bridge 4 on which bass piano strings are stretched. The bass bridge 4 is in overlapping relationship with the connecting plate member 5 over the entire length thereof. The bass bridge 4 is thus spaced apart from the sounding board 1. In the embodiment shown in the drawing, the connecting plate member 5 is securely anchored in the treble bridge 3 in such a manner that the longitudinal edge of the connecting member 5 is fitted into an elongated groove formed in the side wall of the bridge 3 facing the bass bridge member 4. The connecting plate member 5 is glued to and supported on an elongated rod member 6 which is secured by gluing to the top face of the sounding board 1 and extended intermediate between the two longitudinal edges of the connecting plate member 5. In other words, the supporting rod member 6 is disposed in a position between the bass and treble bridges.

It will be appreciated from the foregoing that, according to the invention, the bass bridge 4 is connected over the entire length thereof to the longer treble bridge 3 by means of the connecting plate member 5 so that the vibration from the bass bridge 4 may be effectively transmitted and distributed to the sounding board through the connecting plate member 5 and treble bridge 3. Thus, by the structure of the present invention, vibrational area of the bass tones may be increased and it will be made possible to obtain improved tonal qualities in the bass range and rich in lower harmonics or overtones. As mentioned hereinabove, the connecting plate member has a substantial area which serves to act as an auxiliary sounding board and, therefore, contributes to enhancing the tonal qualities in the bass range as well as amplifying overall tones of the piano.

It will also be appreciated that the sounding board assembly of this invention may be likewise applied to an upright piano, and that the specific structural details herein shown and described are by way of illustration only, and that various changes and modifications in structure are possible and form a part of this invention insofar as they fall within the spirit and scope of the appended claims.




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