US1032608A - Piano. - Google Patents

Description

O. JOHNSON.

PIANO.

urmornon FILED MAR. 6, 1909.

1,032,608. Patented July 16, 1912.

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AAAAAAAAAAAAAAAAA H 60., WASHINGTON. n. c.

G. JOHNSON.

PIANO.

nrmoynon FILED ma. 6, 1909.

1,032,608. v Patented July 16, 1912..

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COLUMBIA PLANOORAPH 20., WASHINGTON, D. c.

CARL JOHNSON, OF ST. PAUL, MINNESOTA.

PIANO.

Specification of Letters Patent.

Application filed March 6, 1909.

Patented July 16,1912.

Serial No. 481,795.

To all whom it may concern:

Be it known that I, CARL JOHNSON, a cit1- zen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Pianos, of which the following is a specification.

My invention relates to improvements in pianos and more particularly to the sounding board thereof.

The object of my invention is to produce in a piano a better quality of tone and provide means for tuning up the sounding board of a piano when it has lost some of its resonant qualities.

Further objects are to reduce the weight of the piano, permit the piano to be easily knocked down for shipment or other purposes and produce a piano which is strong, durable, simple and inexpensive.

In a general way, my invention comprises a string plate made out of a single piece of metal in which the sounding board and pin block are detachably fastened under stress. Heretofore the parts of the sounding board have been fastened to the case by means which has not permitted the parts to be easily detached and further the string frame has been weak in construction where any attempt has been made to hold the pin block and sounding board by a single piece of metal. With my invention the string plate may be made of any desired strength and is adapted to hold the pin block and sounding board without working loose and changing the tone quality of the piano.

In the accompanying drawings, forming part of this specification Figure 1 is a plan view of a horizontal grand piano, with'the cover removed to display my invention; Fig. 2 is a detail section of Fig. 1 on the line XX, and Fig. 3 is a view looking up at the sounding board.

In the drawings A represents a piano case or frame which may be made shallow as compared with those in use prior to my invention.

B represents a pair of sounding boards made with two separate parts 2 and 3 which are held in a rim or flange 4c of a string plate C and may be arched to improve tone qualities as desired. The rim or flange is integral with the string plate and is continuous around the periphery of the sounding boards, being formed at substantially right angles with the plane of the plate.

The inner face 13 of the rim at against which the edges of the sounding boards impinge, is beveled outwardly. In assembling the parts the sounding boards 2 and 3 are sprung into the rim a under pressure and are spaced apart and from the string plate 5 by spacing blocks 9 which may be varied in thickness. A flanged plate 1.2 lies below the lower block 9 and is bolted to the string plate C by bolts 11 which pass through the flange plate, the blocks 9, the boards 2 and 3, and the string plate C, and by means of which the sounding boards 2 and3 are forced into the rim 4. In this way the sounding boards are held in position under a compressive stress in the plane of the board. Tie bars l0 lie beneath the sounding board B and have hook ends 14- passing through the edge of the rim 4 and engaging the same to stiffen it. The tie bars are attached to the string plate by the bolts 11. Restbars 15 are attached to the case of the piano by bolts 17 and carry the rim a of the string plate, thus assisting in supporting the sounding board. The string plate itself is attached to the case of the piano by screws 16. Thest-ring plate is formed with an extension 6 which is adapt ed to hold a pin block 7, the latter being secured to said extension by bolts 8. Flanges 2O integral with the string plate extend beneath the extension 6 and serve to stiffen the attachment of the pin block. The piano strings, not shown, are fastened to the pin block and string plate in the ordinary manner. This construction permits the easy removal of the string plate from the piano case, while the sounding boards can be taken from the string plate without unstringing the instrument, by removing the tie bars 10, and the bolts 11 from the flange rim 12 and lifting the boards from. the socket formed by the rim 4.

It is obvious to those skilled in the art to which this invention relates that the parts thereof may be variously changed and modified without departing from the spirit thereof, and I do not confine myself to the exact construction described within the scope of the following claims.

In accordance with the patent statutes I have described the principles of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof but I desire to have it understood that the construction shown is only illustrative and that the invention can be carried out by other means and applied to uses other than those above set forth within the scope of the following claims.

Having described my invention, what I claim as new and desire to protect by Letters Patent is 1. In a piano, a string plate formed in one piece having a flange entirely about the outer edge of the back thereof and disposed at substantially right angles thereto and forming an inclosing wall, the inner surface of said flange flaring outwardly, a sounding board disposed substantially parallel with said string plate and confined by said flange with the outer edge of the sounding board between the sounding board and the string plate, and means for forcing sounding board engaging the flaring surface of said flange, a stop within said flange 'between the sounding board and the string plate, and means for forcing said sounding board inwardly along the flaring surface of said flange against said stop; whereby a certain compressive stress in the board may be secured.

2. In a piano, a singlepiece string plate formed with a continuous reinforcing flange at substantially right angles to the back thereof, the inner surface of said flange flaring outwardly, a sounding board confined by said flange and means for securing said board with its outer edge forced inwardly along the flaring surface of said flange, whereby a circulnferentially continuous wedging effect is produced, for-the purposes specified.

In testimony whereof, I have signed my name to this specification, in the presence of two sitibscribing witnesses.

CARL JOHNSON.

\Vitnesses J. T. AVERY, F. G. BRADB'URY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.

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