US1239113A - Piano. - Google Patents

Description

UNITED STATES PATENT OFFIGE.

ANTON KRIEGHOFF, OF BOSTON, MASSACHUSETTS, ASSIGNOR T0 ANTON KRIEGHOFF COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PIANO.

Specification of Letters Patent.

Patented Sept. 4, 191 '7,

Application filed. September 7, 1915. Serial No. 49,145

To all whom it may concern Be it known that I, ANTON Kinnenorr, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Pianos, of which the following descriptlon, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to a piano sounding board. The novel construction herein shown is a modification of the improvement in piano string plates and sounding boards and associated parts for which a Datent has heretofore been applied for by the inventor hereof in application filed May 13, 1915, Serial No. 27,927. i

In the present construction there is simllarly employed a sounding-board of the common type but without having the customary bridges positioned thereupon. Herein, the string plate of a piano or similar instrument is provided with a relatively flexible section which serves primarlly as an auxiliary sounding board and in addition bears the hitch pins for the treble strings and a bridge for the bass strings. The hitch pins for the bass strlngs are on the rigid metal string plate. This flexible resonant section may be suitably braced and secured to the usual string plate and, in this embodiment, is integral at one end thereof with the string plate, while the opposite end of the section is relatively free. Other objects of the invention will more fully appear from the following description and the accompanying drawings and will be pointed out in the annexed claims.

Figure 1 is a plan view of the novel piano string plate and sounding-board;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a section on the l1ne 3-3 of Fig. 1;

Fig. 4 is a sectional detail of one of the transmitters.

The drawings herein disclose the invention as embodied in a piano of an uprlght type but, obviously, the invention may equally be embodied with slight changes 1n pianos and similar instruments of different types.

The cast metal string plate 1 has secured thereto the piano sounding board 2. The string plate is generally of the type at present in use and is suitably braced to withstand the stresses entailed by the tensioned strings. This string plate has a section 3, thinner than most portions of the plate 1. The section 8, replacing the usual rigid plate portion bearing the hitch pins, is relatively flexible, and, while it may be made of any suitable resonant material, it, as shown in this selected embodiment, is integrally cast with the string plate 1 at one end. The section 3, which follows the general direction of the usual line of hitch pins, is preferably braced at the opposite end portion to the string plate. And, eX- cept as noted, this section does not come into contact with the string plate. The vertic'al string plate bars i have offset portions 5 which pass behind the section out of 0011- tact therewith. The section 3, here shown, is made wider than the section in the struc ture shown in the former application above referred to, in order to attain greater strength at the free end. The middle portion of the section is cut away, leaving the opening 6, which functions to lessen the stiffness of this section 3 at this. point, and to permit greater flexibility and afiord increased responsiveness of the section to vibratory activity imparted thereto by the pulsations which may be set up in a string.

The lower end of the section 3 is braced against the upward pull exerted thereupon by the treble strings, the lower ends of which are secured to the section. The section at the lower end bears thereupon the lugs 7 which are preferably cast integrally with the section. While two such lugs are shown in the accompanying drawing it is obvious that one or more may be used and that they may be positioned with relation to the section 3 and the string plate 1 as appears desirable and consistent with structural efliciency and section flexibility. In the brace and lug construction in this embodiment, the lower ends 8 of the braces 9 are slightly tapered and balled or rounded so that they may have a pivotal yieldable or rocking fit in the sockets 10 formed in the string plate lugs 7. The upper ends of the braces 9 are preferably recessed or cupped. These cups 11 of the braces 9 receive therein the rounded ends of set screws 12-. These set screws are received in threaded engagement in apertures 13 in a lug 14, preferably integral with the transverse stays 15 of the frame 1. Each set screw 12 through its engagement with the cupped end of a brace 9 affords a means for retaining the plate section 3 in proper spaced relation to the string plate against the pull exerted on the section by the treble strings. These plate braces 9 are mounted by means of this lug construction so that the braces cannot contact with the adjacent strings even at the moment of their vibrations of greatest amplitude. This braced construction thus gives rise to a. structure which provides a section with a relatively floating or free end. Such a section has increased flexibility and increased responsiveness to sound vibrations as compared with applicants earlier flexible section wherein the flexible section was preferably integral with the string plate at each end. The tapered and cupped construction of the braces and lugs affords a strengthening medium which effectively achieves its function yet does not greatly hinder or deaden the vibratory motion induced in the plate section by the strings as the braces are afforded a yieldable, non-rigid mounting.

The hitch pins 16 for the treble strings 17 are secured adjacent the upper edge of the flexible section. A rib 18 cast integrally with the section extends practically its length. This rib provides a bridge for the strings leading from the hitch pins 16 to the usual upper bearing 19 under the pressure bar 20 to the wrest pins 21. These wrest pins 21, following the usual practice, are passed through the string plate 1 and are embedded in the wrest plank. The hitch pins 22 for the bass strings 23 are on the plate while a bearing or bridge is preferably provided for such strings on the section. As shown in Fig. 1, this bridge consists of a rib 24 which extends a short distance along the lower edge of the section. Bearing pins 25 are secured therein and provide a bearing on the section 3 for the bass strings leading from their hitch pins over the section to their respective wrest pins 21. The portions of the treble strings which may be put in vibration by the usual hammers are those comprehended between the rib 18 of the flexible section and the bearing 19 of the string plate, while similar portions of the bass strings are between the rib 21 of the section 3 and the bearing 26 of the string plate.

The rib 18 may thus receive and directly impart to the flexible section 3 the vibrations set up in the treble strings, while the rib 24 may similarly function for the vibrations of the bass strings. The section, which as conditions demand may be made more or less flexible and elastic, readily receives and takes up the string vibrations.

The transmitters 27 are provided for the purpose of transmitting to the sounding board the vibratory energy imparted to the flexible section. These transmitters each consist of a post 28, preferably of metal, which is passed through the section and is received in threaded engagement with the wooden sounding board. In this embodiment, a block of wood 29 is aflixed to the rear face of the sounding board opposite each post and receives in threaded engagement the post end. The other end of the post, extending through the section, has threaded thereon two nuts 30 which are adapted to be turned tightly against the front and rear faces respectively of the flexible section. The sounding board freed from the usual bridges or braces readily responds to the vibrations imparted thereto by the transmitters and may resonantly and freely vibrate substantially throughout its area.

This invention thus provides a sounding board whose resonance is greatly augmented though the elimination of the customary bridges from the sounding board and hence added responsiveness to sound vibrations communicated thereto is entailed. Labor and material costs are reduced by this novel construction which is at once durable and of greater simplicity than the present structures. And, while the embodiment of the invention is disclosed herein as applied to a piano structure, it will readily be understood that the principles may be embodied in other forms of stringed instruments whether the' string actuating means be mechanical, electrical or manual.

It is to be understood that the construction disclosed herein is illustrative but not restrictive and that the same may be modified within the meaning and scope of the claims which follow.

Having thus described my invention what I claim as new, and desire to secure by Letters Patent, is:

1. In a musical instrument, a string plate, a sounding-board secured thereto, a relatively flexible section fixedly connected at one end only to said string plate, strings to produce sound vibrations upon actuation, means for causing the strin vibrations to be communicated to said section, and means for communicating to the sounding board the vibrations communicated to said section.

2. In a musical instrument, a string plate, a soundin -board secured thereto, a relatively flexible section integral at one end only with said string plate, strings to produce sound vibrations upon actuation, bridges for the strings on said section, and means for connecting said section to the sounding board whereby the vibrations set up in the section are communicated to the sounding-board.

3. In a musical instrument, a string plate, a sounding-board secured thereto, a relatively flexible section fixedly connected at one end only to said string plate, means for bracing the opposite end of the flexible section, strings to produce sound-vibrations upon actuation, bridges for the strings upon said section and means for connecting the section to the sounding-board whereby sound vibrations are communicated from the flexible section to the sounding board.

4. In a musical instrument, a string plate, a sounding-board secured thereto, a substantially diagonally disposed section having one end only integral with the string plate, strings to produce sound vibrations, hitch pins on said section for the treble strings, hitch pins on the string plate for the bass strings, a bridge on the section for the bass strings, and means for com- Inunicating the vibrations of the section to the sounding board.

5. In a musical instrument, a string plate, a sounding-board secured thereto, a relatively flexible section integrally connected at one end only to the string plate, yieldably mounted means for bracing the opposite end of said section, strings to produce sound vibrations upon actuation, means for causing the string vibrations to be communicated to said flexible section and sound posts connecting said section and the sounding-board whereby sound vibrations are communicated from the flexible section to the soundingboard.

6. In a musical instrument, a string plate, a sounding-board secured thereto, a relatively flexible section integrally connected at one end only to the string plate, yieldably mounted divergent members for bracing the opposite end of the flexible section to the string plate, strings to produce sound vibrations upon actuation, means for causing the string vibrations to be communicated to the flexible section and a plurality of members connecting said section to the sounding board whereby sound vibrations are communicated from the flexible section to the sounding-board.

7. In a musical instrument, a string plate, a sounding-board secured thereto, a relatively flexible section integral at one end only with the string plate and having its other portions free therefrom, adjustable means for bracing the opposite end of said flexible section, said bracing means having substantially ball and socket mountings, means whereby the string vibrations are communicated to the flexible section and means for communicating the section vibrations to the sounding board.

8. In a musical instrument, a string plate, a sounding-board securedthereto, strings,

an elongated, relatively flexible section integral at one end only with the string plate, said section being longitudinally apertured to increase its flexibility, means for communicating string vibrations to the section, and means for communicating to the soundingboard the vibrations communicated to the section.

In testimony whereof, I have signed my name to this specification.

ANTON KRIEGHOFF.

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

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