US1482670A - Grand piano - Google Patents

Description

Feb. 5 1924.

J. H. WILLIAMS GRAND PIANO Patented Feb. 5, 1924.

UNITED STATES JAMES H. WILLIAMS, 0F BALTIMORE, MARYLAND.

GRAND PIAliTO.

Application filed July 6,

T 0 all whom it may concern:

Be it lniown that I, James H. IVILLIAMS, a citizen of the United States, residing at Baltimore, in the county of Baltimore, State of Maryland, have invented certain new and useful Improvements inGrand Pianos; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of the invention is to provide, more especially in connection with pianos of the horizontal or rand type, including concert, parlor and b a construction of sound board supporting frame whereby it may be possible to secure an increased volume and duration of tone and an appreciable sustaining of the overtones and harmonics, with a view to prolonging the vibrations incident to such overtones and harmonics, throughout a period approximating that which is ordinarily secured in reference to the fundamental tones, so as to preserve the richness and quality of the tones and avoid the resolution, as in the ordinary practice, to the fundamental or basic tone, with a loss of the characteristic overtones; and with this general object in view, the invention consists in a construe tion, combination and relation of parts of which a preferred embodiment is illustrated in the accompanying drawings, wherein:

Figure 1 is a plan view of a piano frame of the grand type, having a construction embodying the invention.

Figure 2 is a longitudinal sectional view of the same on the plane indicated by the line 2-2 of Figure 1.

Figure 3 is a transverse section on the plane indicated by the line 3-3 of Figure 1.

In the construction illustrated, the sound board supporting frame consists of the marginal members 10 and 11 of which the former represents the usual transverse bar or member and the latter the partly curved member, conforming to the outer casing or housing 12, with which marginal frame is associated a plurality of bracing members 13 of which any desired number may be employed to suit the size and required peculiarities of the instrument and which, though variously arranged in practice, in. the matter of detail, are usually disposed in a substantially radiating relation particu' larly in the matter of the main group which aby grand and the like,

1921. Serial N0. 482,720.

springs in substantially intersecting relation from the transverse bar or member 10 at or about one-third of the, length of said bar from the bass end of the instrument.

The sound board, which is indicated at 14, is adapted to rest upon the marginal frame members to which, as in the ordinary practice, it may be glued or otherwise adhesively fastened and in the upper or outer surface of this marginal frame or the members thereof are formed channels 15 which are covered by the marginal portions of the sound board and of which the sound board may, as illustrated, form the upper walls, as in dicated in Figures 2 and 3. The portions of the channels in the transverse bar or member and the partly curved member which have been referred to herein as the marginal members, are stopped or are provided with no terminal outlets permitting of the liberation or release of longitudinal vibrations of the columns of air confined therein, but preferably, as also indicated in the drawings, the extremities of these channels at the intersections of the members are arranged in communication'so that, as illustrated, there is a continuous channel formed 7 under the marginal edge of the sound board throughout its extent, including the portion resting upon the transverse bar or member 10 and that resting upon the partly curved member 11.

In addition, the bracing members 13 are provided in the surfaces facing the plane of the sound board or, in other words, the upper surfaces thereof with channels 16 corresponding with the channels in the mar ginal members of the frame and also terminally stopped, so far as communication with the atmosphere is concerned, but preferably in communication with the channels formed in the intersecting; portions of the marginal members so as to permit of communication of vibrations from the columns of air in the filler or bracing members to the columns of air in the marginal members.

The sound board, by reason of the channels in the marginal members are, in a sense, supported on air cushions and, in order that there may be an unrestricted vibration of the sound board, it is preferable to space the edges thereof slightly from the adjacent surfaces of the casing or housing to the end that the vibrations of the sound board may be communicated to the supporting frame having the channelled construction described, without binding or limitation and may be free to communicate vibrations to the columns of air in the channels of the marginal frame members.

The channels of the bracing members are provided with relatively thin covering walls 17 which are in spaced relation with the surface of the sound board extending thereover, and in practice these walls may be provided with spaced perforations 18, constituting vents or outlets, while the channels in the marginal members are preferably provided with lateral outlets 19. These vents, both in the marginal and in the filler members, are deemed desirable, though not absolutely indispensable, but as should be noted are disposed in lateral relation with the channels rather than in terminal or longitudinal relation therewith, so that there is a terminal limitation or restrictionof the columns of air in the several members, both bracing and marginal, with the result of prolonging a longitudinal vibration responsive to the vibrations of the sound board, which obviously receives its vibratory impulses from the strings of the instrument. Owing to the fact that these confined columns of air in the channels are more responsive to the overtones and harmonics than are the sound board or the frame members which support the sound board, it is submitted that they serve individually and collectively to sustain the filler or body tones to an extent at least approximately commensurate with those of the fundamental or basic tones and thereby maintain the richness of a sound, as compared with those instruments in which the sound board is relied upon as the .sole

means of prolonging the tones and which is moredirectly adapted to sustain those of a deeper pitch than the more mobile columns of air defined by the channels.

lVhat is claimed is:

1. A piano of the horizontal type having a marginal soundboard supporting frame comprising a transverse front member and a continuous partly curved member, each of said members having an uninterrupted channel formed therein with its terminals in communication with those of the channel in the other member.

2. A piano of the horizontal type having a sound board and a marginal soundboard supporting frame comprising a transverse front member and a continuous partly curved member, each of said members having an uninterrupted channel formed therein with its terminals in communication with those of the channel in the other member, the upper opening of the channel in each member being closed by the sound board.

A piano of the horizontal type having a marginal soundboard supporting frame comprising a transverse front member and a continuous partly curved member, each of said members having an uninterrupted channel formed therein with its terminals in communication with those of the channel in the other member and also having bracing members, connecting the transverse and partly curved members and provided with channelsin open communication with the said connected channels therein.

In testimony whereof, I affix my signature.

JAMES H. WILLIAMS.

Images