US1432338A

US1432338A - Fiano

Info

Publication number: US1432338A
Application number: US454695A
Authority: US
Inventors: Frank H Johnston
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-03-23
Filing date: 1921-03-23
Publication date: 1922-10-17
Anticipated expiration: 1939-10-17

Description

F.'H. JOHNSTON.

PIANO. APPLICATION HLED MAR. 23, l92l- 1,432,338, I Patented Oct. 17, 1922.

2 SHEETSSHEET l.

k N N F. H. JOHNSTON.

. PIANO.

APPLICATION FILED IALZS. I921. 1,432,338.-

Patented ()Ct. 17, 1922',

ZSHEETS-SHEET 2.

Patented Oct. 17, 1922.

PATENT OFFICE.

FRANK H. JOHNSTON, OF BUFFALO, NEW YORK.

PIANO.

Application filed March 28, 1921.

To all whom it may concern:

Be it known that I, FRANK H. JOHNSTON, a citizen of Canada, residing in Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Pianos, of which the following is a specification.

This invention relates to an improvement in pianos and has the object to provide means whereby the pitch is maintained and the resonance of the same is improved and any tendency which would have the effect of dead ening the tone can be corrected so that the same is brilliant and up to standard pitch.

In the accompanying drawings: Figure 1 is a face vieW of the piano of an upright piano embodying my invention. Figure 2 is a vertical cross section of the same taken on the correspondingly numbered line in Fig. 1. Figure 3 is a rear view of the iano with a part of the same broken away. igure 4 is a fragmentary vertical section taken on line 4-4, Fig. 3.

Similar characters of reference refer to like parts throughout the several views.

Although this invention is applicable to various types of pianos including those commonly known as square and upright, the same is shown in the drawings embodied-in the string mounting of an upright piano.

In its general organization this piano comprises a sounding board 10 which is usually constructed of wood, a back frame 11 of wood having its marginal part provided on its front side with cleats 12 which engage the marginal part of the sounding board while its intermediate part is constructed. in the form of upright posts or bars 13 which are spaced apart from the rear side of the sounding board. A metal body or string plate 14c of skeleton form is mounted on the front side of the sounding board. and bridges 15 of wood are mounted on the front side of the sounding board between the front or upright and the lower or rear end of the same. Hitch pins 16 are mounted on the body plate in 1 rear of or below the bridges, a tuning pin plate or wrest plank 17 of Wood is mounted on the front part of the back frame and extends forwardly past the front end of the body plate and tuning pins 18 are mounted Serial No. 454,695.

on the tuning plate. The strings 19 extend over the upper sides of the bridges and in engagement therewith and are connected at their rear ends with the hitch pins while their front ends are connected with the tuning pins. The several groups of strings representing the treble and bass portions of the piano may be variously arranged as is customary in modern piano construction and the strings may be retained in their proper position on the bridges by means of the usual bridge pins 21 and pass over bearing beads or scale ribs 22 arranged on the tuning pin plate adjacent to the tuning pins as is commonly done.

In some pianos of this character, as heretofore constructed, the sounding board is stiffened or braced on its rear side by means of a plurality of wooden ribs which are secured thereto by means of glue or otherwise. In time, however, these ribs either become loose or weaken and therefore lose their resilience so that the sounding board sags and its resonance becomes impaired. Consequently the tone of the piano becomes dead or dull, thus reducing thevalue of the instrument by reason of the fact that the music produced on the same is not of the highest quality and therefore does not furnish the maximum enjoyment. This rib construction on the rear side of the sounding board has been found very expensive on account of the skill required in applying the same properly and the difficulty in adjusting the same so as to produce the desired tonal effect of the piano.

It has also been found in pianos, as heretofore constructed. that the tension of the strings is liable to depress the bridges to such an extent that the required pressure of the strings against the bridges is reduced to such an extent as to impair the speaking or singing qualities and pure tones of the strings.

My improvements in pianos whereby these difficulties are eliminated, the cost reduced, the resonance of the sounding board maintained and the strings tightened so as to obtain the desired full and brilliant pitch are preferably constructed as follows:

23 represents a plurality of bearing bars,

2?. 1 ,esasss one of which is arranged over each group of strings between the rear side of the companion bridge and the respective hitch pins associated with these strings. Each of these bearing bars is preferably constructed of iron and has its underside 24, which engages with the front side of the strings, made of downwardly converging form in cross section so as to produce a comparatively small bearing surface whereby this bar engages with the strings. Each of these bearing bars is adjustably connected with the adjacent part of the metal body or string plate so that this bar may be drawn backwardly toward the face of the sounding board, this being preferably accomplished by means of a plurality of screws 25 which connect this bar with the adjacent part of the body or string plate. By tightening these screws the bearing bar may be depressed or moved toward the front face of the soundiiig board to such an extent as will cause that part of the strings associated therewith to fully engage the respective bridge and press against the same sufficiently firm so that the full and true singing. or speaking effect of the strings is obtained. If, therefore, in course of time the strings of the piano become dead or the speaking tones become uncertain, this can be corrected so as to restore the former bril liance and true tone of the same by simply tightening the screws 25 whereby the bearing bar depresses the strings in rear of the bridge and again establishes a firm contact and the requisite pressure of the strings against the bridge to accomplish this purpose.

In order to properly support the sounding board on its back side when the same is originally manufactured and also to enable this board to be again restored to its normal forward position in case the same has begun to sag backwardly and becomes dead or less resonant, a plurality of pressure devices are provided which are interposed between the back of the sounding board and the back frame and which are so constructed that they produce a forward pressure against the back side of the sounding board in line with the bridges. In the preferred form of these pressure devices the same are constructed in the form of levers 26 each of which is preferably constructed of wood and pivotally mounted on the back frame by providing the intermediate part of each lever with a rounded fulcrum 27 on its rear side which engages with the adjacent flat face 28 of a part of the back frame, as best shown in Figs. 9 and at. Une end of each of'these pressure members is arranged to bear against the rear side of the sounding board in line with a bridge on the front side of this board, the pressure of this lever being preferably transmitted to the sounding board by means of a pad or cushion 29 of felt, leather or similar material. The pressure of this lever against the rear side of the soundmg board for the purpose of removing any sag in the same, may be adjusted by various means. As shown in the drawings, this is accomplished by means of a screw 80 passing through the back frame and bearing with its head against the rear side thereof, while its threaded front end engages with athreaded opening in that arm of the pressure lever opposite to the one which engages with the sounding board through the medium of the pad or cushion. By tightening the screws 30 the pressure of this lever against the sounding board may be so regulated as to produce the proper support for the same and cause the bridge to be maintained at the proper height and the sounding board to possess the requisite resonance for producing agreeable music.

These improvements are capable of being installed in pianos when originally manufactured as well as in pianos already in use, thereby permitting of providing a piano originally constructed in accordance with thisinvention with means which enable the full resonance of the same to be restored if at any time the same becomes deadened, also enables pianos already in use and lowered in quality by reason of impaired pitch or resonance, to be again restored to their original resonance and tonal qualities and render the music produced on the same to be more enjoyable.

I claim as my invention:

1. A piano comprising a sounding board, a string plate arranged over said board, a bridge on the sounding board between the front and rear ends thereof, hitch pins arranged on the string plate in rear of the bridge, tuning pins arranged in front of the bridge, strings extending over said bridge and connected at their rear ends with said hitch pins and at their front ends with said tuning pins, a bearing bar engaging said strings between the hitch pins and the bridge, and means for adjustably connecting said bearing bar with said string plate.

2. A piano comprising a sounding board, a string plate arranged over said board, a bridge on the sounding board-between the front and rear ends thereof, hitch pins arranged on the string plate in rear of the bridge, tuning pins arranged in front of the bridge, strings extending over said bridge and connected at their rear ends with said hitch pins and at their front ends with said tuning pins, a bearing bar engaging said strings between the hitch pins and the bridge, and screws connecting said bearing bar with said string plate.

3. A piano comprising a sounding board, a frame which supports the sounding board, a bridge engaging with the front of the sounding board, strings extending over said bridge, and an adjustable pressure lever engaging directly against the back of the sounding board in line with the bridge.

4. A piano comprising a sounding board, a frame which supports the sounding board and which is provided with posts in rear of the same, a bridge engaging with the front of the sounding board, strings extending over said bridge, a pressure lever pivotally mounted on sald post and engaging one end 10 directly with the back of the sounding board in line with the bridge, and an adjusting screw connecting the opposite end of said lever with said post.

FRANK H. J OHNSTGN.