US238733A - Piano-forte - Google Patents

Description

(No Model.)

W. P. ULMAN.

Piano Forte. No. 238,733. Patented March 8,1881.

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N. PETERS, PHOTUUTHOGRAPHER, WASHNGTON. D c.

UNITED STATES PATENT OFFICE.

WVILLIAM F. ULMAN, OF BOSTON, MASSACHUSETTS.

PIANO-FORTE.

SPECIFICATION forming part of Letters Patent No. 238,733, dated March 8, 1881.

Application filed April 23, 1880.

To all whom it may concern Be it known that I, WILLIAM F. ULMAN, a citizen ofthe United States, residing at Boston, in the county of Sufi'olk and State of Massachusetts, have invented certain new and use ful Improvements in Piano-Fortes, of which the followingis a specification.

Myimprovements relate chiefly to the stringing of the piano, and have for their objects to increase the power and improve the quality of the instrument, and to cause it to retain its tone better than heretofore.

In the accompanying drawings, Figure 1 is a plan of a square piano embodying my improvements, the lid or cover having been re moved. Fig. 2 is a vertical longitudinal section of the same, taken in the plane of the line 00 00. Fig. 3 is a like section taken in the plane of the line y y. Fig. 4 is a similar section, on a larger scale, taken in the plane of the line z z,- and Fig. 5 is a fragmentary plan View, enlarged, of the wrest-plate and tuningpins.

Let A indicate the outer case of the instrument; A, the key-board recess; B, the stringframe, which is preferably of metal; 0, the soundin g-board; D, the sounding-board bridge, and E the overhanging or shelf bridge.

F is the wrest-plate, through which the tuning-pins pass, and G and H are the hitch-pin plates, these plates being all parts of the frame B. The plate G bears the hitch-pins, to which the strings that bear upon the bridge D are attached, and the plate H bears those to which the overstrung strings which bear upon the shelf-bridge E are attached.

I is the wrest-plank beneath the plate F.

With the exception of the two bridges, the parts thus far referred to are all of the usual construction.

As heretofore constructed, the plate G has been the only distinct portion of the stringframe that has not been re-enforced and sup ported by contact with a firm wooden framing beneath. As its central portion is entirely unsupported, its connection with the remainder of the frame being only at its ends, and as it is subjected to a powerful strain from the pull of the strings, and is in direct connection with them, it is found to vibrate sympathetically with some of the strings, thus emitting (lis- (No model.)

cordant sounds, and by its vibration to impair the tone of the strings that are connected to it. In order to overcome these defects I lag the plate G with a firm plank, J, of wood or other similar substance, which I fasten firmly to the plate, so as to deaden or destroy its discordant vibrations, thus rendering the tone from the strings more pure and clear.

The sounding-board bridge I), instead of being a narrow solid strip, as heretofore, is swelled or widened in its central portion, and made hollow, so as to form an air-space, d, which extends downward to the soundingboard G. The air in this space is thrown into active vibration by its confinement between the vibrating walls of the chamber and by its contact with the soumling-board, whereby a louder tone is produced. The strings which cross the air-space are in contact with both sides or walls of the bridge, so that their vibrations are communicated to the soundingboard at two points. The portion of the string extending across the bridge is not muffled.

I am aware that a piano has been made with two sounding-board bridges, so that the vibrations of the strings are communicated to the board at two points but 1 am not aware that a single bridge has been swelled centrally or made double between its ends, or that an airspace has been formed in or between a bridge or bridges.

The air-space (Z does not extend to the treble end of the bridge, the latter being there made narrow and solid, as usual. Instead, however, of passing the strings between pins or through agraftes on the bridge, I provide a strip, 6, which is let into the bridge edgewise, and suitably secured therein, and pass the strings through a series of holes made through its projecting portion. As shown in Fig. 4, the top of the bridge is beveled "from each side toward the strip 0, and the string-holes in the strip are below the level of the sides of the bridge, so that the strings are drawn down by the strip close onto the surface of the bridge, bringing them into firm and intimate contact with it. They have an upward bearing upon the holes in the strip, and a downward bearing upon the sides of the bridge.

I am aware that an agrat'te has been fitted witha block of wood upon one side, so as to raise the string and cause it to bear upon the upper side of the hole in the agraffe. My construction is an improvement upon this, inasmuch as the strings are brought directly into contact with the wooden bridge, instead of a metallic fitting being interposed; and as the strip 6 is continuous, being used for the entire series of strings, its fastening is light, and it adds but little to the weight of the bridge. Furthermore, I give the string a downward bearing upon each side of its upward bearing, instead of on but one side, thus balancing the tension and bringing the string into more intimate contact with the bridge.

Instead of passing all the strings over the bridge D, as heretofore, I pass part of them through it, as shown at a in Figs. 1 and 3. The bridge is perforated to admit the strings, and they are arranged to bear upwardly upon the holes, thus neutralizing to some extent the downward bearing of the strings which pass over the bridge, and thereby reducing the strain upon the sounding-board and leaving it more free to vibrate.

I am aware that strings have been passed through perforations in a bridge; but they have had no bearing therein, being passed through free of the sides of the perforations and extending to the top of a second and lower bridge, so that they have had no connection whatever with the bridge through which they passed.

In Figs. 1 and 2, b b are the overstrung bassstrings, passing over clear of the bridge D and bearing upon the overhanging or shelf bridge E. This bridge has been made heretofore of an upright strip, f, and a horizontal shelf, g, projecting therefrom, the strings bearing upon the outer edge of the latter and extending thence to the hitch-pins on the plate H. The object of thus arranging the string-bearing and the sounding-board bearing in different vertical planes is to give the vibrating portions of the strings as great length as possible, that they may give forth a low note, and at the same time to make connection with the sounding-board as far from its confined edge as possible, that the vibrations communicated to it may be transmitted over its entire surface. Such a bridge tends to tilt in use, and the pressure of the strings is transmitted diagonally to the board. To overcome these defects, as well as to assist in crowning the sounding-board toward its center, is the object of my improvement, which consists in extending the shelf 9 upon the opposite side of the strip f, as at h in the drawings, thus forming the bridge of T shape in cross-section, and connecting the portion h to the soundingboard by a tie-piece or upward-bearing connection, t'. The strip f presses down upon the sounding-board, while the tie-piece i pulls upward thereon. The shelf-board of the bridge I acts as a lever whose fulcrum is the strip f,

the downward pressure of the strings on one side being neutralized by the downward pull of the tie-piece 2' on the other.

In Fig. 5 is best shown my improved tuningpin connection. The holes j j in the wrestplate F, through which the tuning-pins or wrest-pins c 0 pass down into the wrest-plank I, are formed with two substantially straight and angular or diverging sides, it, against which the tuning-pins fit closely, so that the pull of the strings draws them tightly in between the two sides and wedges them fast. By this means the pins are retained securely in the position given them by the tuner, so that they cannot turn back and loosen the tension on the strings, whereby the tone given to the strings is preserved much more perfectly than by the ordinary construction. In fact, with my construction, the only deteriora tion of tone is that due to the actual stretching of the strings.

I claim as my invention- 1. In a piano, the hitch-pin plate Gr, joined to the remainder of the string-frame B at its ends only, and having a plank, J, of wood or similar material fixed firmly to it, whereby it is stiffened and its vibrations are deadened, substantially as set forth.

2. In a piano, the bridge D, fixed to the sounding-board O, and provided with an airspace, d, formed within it and extending down to the surface of the sounding-board, substantially as and for the purposes set forth.

3. In a piano, the bridge D, formed solid at its ends, swelled throughout its central portion, and there formed with an air-space, d, which extends from the top of the bridge down to the sounding-board B, substantially as set forth.

4. In a piano, the combination, with the strings and sound-bridge, the surface of the latter being beveled down from its sides to ward its center, of a narrow strip, 0, let edgewise into the bridge, extending longitudinally thereof, and its upper edge projecting therefrom and provided with a series of perforations, which are arranged on a lower level than the top of the bridge, wherebythe strings passing through said perforations are drawn down firmly against the top of the bridge, substantially as set forth.

5. A piano having the strings arranged in relation to the bridge in the manner describedthat is, with a portion of them having their bearings on the bridge in the usual manner, and a portion having their bearings in perforations in the body of the same, substantially as set forth.

6. 1n apiano, anumber of strings arranged to pass over the top of the bridge, with a downward bearing upon the same, and a further number arranged to pass through perforations therein, with an upward bearing thereagainst, substantially as set forth.

7. The overhanging shelf-bridge E, consisting of a downward-bearing strip, f, and shelf 0 g h, mounted thereon and extending both sides thereof, arranged as described, to receive on the side 9 the downward pressure of the strings, and on the side It the downward pull of a tie piece, a, which has an upward bearing or pull on the sounding-board, substantially as set forth.

8. The wrest-plate F, provided with wedge- 5 shaped or angular holes j j for the tuning-pins c 0, substantially as and for the purposes set forth.

9. The wrest-plate F, provided with tuningpin holes j 7', each of which is formed with 10 two substantially straight sides, 70 is, at an acute angle to each other, and arranged relatively to the strings in the manner described, whereby their pull tends to wedge the tuningpius tightly between the said sides, substantially as set forth.

In testimony whereofI have signed my name to this specification in presence of two subscribing witnesses.

WILLIAM F. ULMAN.

In presence of- WM. H. MILLER, N. E. BEMroK.

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