DE1220706B - Bridge for piano, grand piano or the like. - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

Number:
File number:
Registration date:
Display day:

GlOc

German class: 51 b - 8

1220706
U10115IX a / 51b
September 9, 1963
July 7, 1966

The invention relates to a bridge for the strings on pianos, grand pianos or the like To increase the sonority of such musical instruments.

On pianos or grand pianos of the usual construction, each string is over a bridge between two mounting brackets. or support points spanned in such a way that the string also in the rest position opposite the straight connecting line the points mentioned outwards or upwards, d. H. in the direction away from the soundboard. The string is in yours on the support surface of the web portion resting alternately partially on the support surface provided bridge pins looped and thereby firmly and immovably connected to the bridge.

When creating notes on a piano or grand piano, a string is usually passed through a Hammer or the like struck and set in vibration. “The strings are through the bottom bridge coupled to the soundboard, and this carries out forced vibrations, which it in the form of Emits sound waves into the air «(H. Junghanns, Der Piano- und Flügelbauer, Leipzig, 1932, p. 109). This explanation of sound generation, which is known per se, must, however, be supplemented by the following new consideration will:

The vibrating string excites the soundboard in two ways in particular: the vibrating string exercises on the one hand as a result of their changes in movement or vibration excursions directly Pulses on the bridge or soundboard are essentially vertical to the soundboard run and the expression of force is very strong. These impulses are for the excitement of the soundboard characteristic and authoritative for pianos, grand pianos or the like. On the other hand, the in the vibrating string occurring tension changes at the first bridge pin secondary vibrations, which spread with the immediate impulses on the soundboard and this about excite in phase.

With the string or bridge arrangement that has been common since then on pianos, grand pianos or the like. The stretched in the manner described forms around the bridge pins Partly looped and already at rest from the bridge to the outside of the string almost seems to be insurmountable resistance to a further outward swing of that excited by the string itself Bridge or soundboard. The bridge and soundboard can therefore essentially only oscillate inwards perform, while the outward oscillation through the insurmountable resistance bridge for piano, grand piano or the like.

Applicant:

Eugen Unkel,

Stuttgart-Bad Cannstatt, Namurstr. 5;

Herbert Unkel,

Fellbach (Württ.), Membergstr. 5

Named as inventor:

Eugen Unkel, Stuttgart-Bad Cannstatt;

Herbert Unkel, Fellbach (Württ.)

the string is suppressed. Draw this waveform of the bridge or soundboard into a conventional path-time oscillation diagram, one obtains an oscillation curve that is approximately one Sinusoid is approximated, the positive half-waves of which are suppressed. Apparently, then, with the usual Arrangement above all for pianos, grand pianos or the like. Characteristic and decisive excitation effect the immediate string impulses on the soundboard or bridge from the string itself in one direction suppressed or prevented. The string itself vibrates at its free, the fundamental vibration executing part inwards and outwards, but also its outward oscillation as a result of it Outward pressure inhibited.

The fact that with pianos, grand pianos or the like. Due to the usual string guidance over the bridge the String stimulates the vibration of the bridge or soundboard on the one hand, but on the other hand at the same time, in particular in one direction, suppressed, is a major disadvantage of the construction and has been customary since then represents a design flaw that has caused the duration and richness of sound in these instruments to be considerable is decreased.

In this context it should be mentioned that in the case of the comparable stringing of a violin, the Strings are also stretched over a bridge and experience the described compression, however are not attached to the web surface, but lie there unsecured, the escapement described or damping effect does not have a significant effect, since the soundboard of a violin mainly due to the described secondary oscillations or voltage changes in the vibrating string is excited, while the immediate, preferably vertical to the soundboard directed string impulses are insignificant,

609 588/12

because the violin string is not struck, but rather bowed. So it is with the violin too no emphasis was placed on the transmission of the string impulses to the soundboard, which is also reflected in it shows that the violin strings are not attached to the bridge, which also has the restraint effect the string is reduced on the bridge and soundboard.

The invention in particular avoids the described disadvantage of the conventional string arrangement on pianos, grand pianos or the like. Above all, the intention is to create an effectively sensible, low-vibration system To achieve string and bridge arrangement to achieve fullness or tone duration of the mentioned Increase instruments.

Accordingly, the invention consists essentially in that when using a pressure bar on the the side of the bridge opposite the sounding string section is the one that resonates with the bridge and thereby an abutment for generating the string compressive force to eliminate the insurmountable Resistance forming pressure bar is arranged such that the string section between the sounding String section opposite fixed support and the pressure bar with which the two fixed Supports linearly connecting ideal string coincides and is held by the pressure bar, so that said string section around the point of support on the fixed support in both directions can swing.

The fact that, according to the invention, a pressure bar is attached to the bridge, which pushes the pressure section of the string opposite the sounding string section in the rest position towards the soundboard, causing part of the string tension, but following any vibrations of the bridge, i.e. a movable abutment, so to speak can develop when the bridge swings outwards. Excitation of the soundboard of the pressure section - relax to some extent between the bridge and the support. The kink pattern of the pressure section approaches a straight course and gives way to the outward movement of the bridge, so that ^: the vibration of the soundboard can take place unchecked in two - especially vertical - vibration directions because a length or tension compensation takes place between the sounding string section and the pressure section.

By eliminating the previously insurmountable string resistance against swinging outwards The arousal effect of the soundboard is mainly described as strong and immediate String impulse increased. The waveform of the soundboard approaches one in two Oscillation directions equally strong sine oscillation, d. H. a harmonious one Vibration, especially when the kink course of the pressure section is set so that the pressure section runs partly on the straight line connecting the outer string attachment points. This exact setting of the kink course or that exerted on the string by the pressure bar Pressure is provided in such a way that the pressure bar is advantageously connected to the web in an adjustable manner.

i5 den is.

The generation and type of overtones when a tone is sounded is determined by the invention Bar formation practically unchanged. The overtones arise from the fact that the piano string with Vibrates wavelengths of a fraction of the string length. Since the pressure bar according to the invention presses against the string outside the tone-generating string section, therefore no change can be made of the overtones. The nodal points and antinodes of the soundboard vibration also become not influenced by the measures according to the invention, so that also in this respect no change occurs.

Overall, the intensity is advantageous the soundboard vibrations increased considerably, so that opposite pianos or hills demonstrate a considerable increase in tone duration and fullness of sound with conventional string guidance leaves.

As has also been confirmed by experiments, as a result of the increase in the ability to vibrate, the Systems, especially the higher treble tones, are much fuller. The lower notes also sound longer Time, so that when playing a larger pitch

40 stands.

The following table, determined on the basis of tests, shows how the corresponding tones on a conventional piano, the tone duration in seconds for all Α tones a piano according to the invention enlarged, the times with equally strong attacks of the corresponding Keys on the instruments from the time they were struck until the Tones were measured:

Tone A ₂ extended from 17 to 26 seconds

18 to 28 seconds

19 to 27 seconds 16 to 20 seconds 12 to 15 seconds

7 to 12 seconds 3 to 5 seconds tone a ₄ extended from 0 to 3 seconds

Tone A.
Tone A
Sound a
Sound a.
Sound a
Sound a

extended by:
extended from '.
extended by:
extended by:
. ₂ extended by
extended from

(53% increase)
(55% increase)
(Growth 41%)
(25% increase)
(25% increase)
(72% increase)
(65% increase)
(Growth more than 100%)

Further details of the invention can be found in the following explanation with reference to the drawing remove. In detail shows

Fig. 1 shows a cross section through an inventive trained bridge with string guide,

2 shows the vibration conditions in a known web design,

2a shows a vibration diagram for this,
F i g. 3 the vibration conditions in a bridge design according to the invention,
F i g. 3 a shows a vibration diagram for this.

Like F i g. 1 shows, the bridge α is firmly connected to the soundboard b , via which the string s from the string support A to the string support B in such a way

it is stressed that the support surface O _{1 of} the web a is higher than the connecting line G between the supports A and B , the support surface U ₁ preferably being slightly inclined towards the support .4. On the support surface Ct ₁ , the bridge pins c and d are also attached, through which the string s is arranged in a known manner.

According to the invention , a pressure bar e is also attached to the web a by means of screws /, the screw allowing a height adjustment of the pressure bar with respect to the web α. Below the pressure bar e is the web α with z. B. provided by ribs interrupted recesses g . Through the pressure bar e , the string s between the string support A and the support surface O _{1 of} the bridge aa is pressed slightly downwards, so that the string sections s _ä and S ₃ arise, which are inclined to each other at a shallow stamping angle. In connection with the sounding string section S ₁ , the entire string takes on a slightly S-shaped kinked course.

The pressure bar e is preferably set in such a way that the string section S ₃ coincides with the ideal string indicated by the connecting line G. Beyond the support A and B , the string continues to its attachment points (pegs) on the instrument.

As in Fig. 1 is shown, arise in points C and D acting on the web α perpendicular forces P ₁ , P ₂ and P ₃ , of which the forces P ₂ and P ₃ by the kinked, tensioned string s and the force P ₁ by the elastic deflection of the soundboard ρ can be generated. The abutment for generating the pressure force is thus moved from the string support A to the pressure rail e , with the advantage that the abutment is no longer rigid and forms a resistance that cannot be overcome by the side. The additionally generated force P ₃ supports the tension force P _{1 of} the soundboard b and makes it more reactive.

This ensures that the string rest position shown in Fig. 1 is at the same time the central position of the string and the insurmountable resistance that the tensioned side made against the upward swing of the web α out of the central position is practically eliminated.

The soundboard can therefore swing both downwards and upwards from the rest position together with the bridge. By setting the pressure bar e accordingly, it can be achieved that the vibration amplitudes of the strings are the same from the middle tier.

In FIGS. 2 and 2a the vibration conditions of a previously common arrangement are on the one hand and in FIG. 3 and 3a, on the other hand, those of an arrangement according to the invention are explained in more detail: In the case of the known arrangement according to FIG. 2 a string s off when the string is struck, the bridge α can swing downwards practically unhindered together with the soundboard b , the string being slightly relaxed and supporting the downward swinging of the bridge or soundboard. In the final state, the string s with the sections S ₁ , S ₄ and s ₅ assumes a position s' with the positions S ₁ ', s / and s ₅ ' , with the string section s ₄ resting on the bridge α revolving around the oscillation amplitude r moves parallel to the position S ₄ ', while the sounding string section S ₁ receives an additional oscillation amplitude corresponding to the sound oscillation.

F i g. 2 a shows in connection with this the oscillation of the sounding string section S ₁ as a function of time, where R represents the oscillation of the bridge α with the soundboard b and also S ₁ 'is the superimposed natural oscillation of the string section S ₁ that determines the tone, see above that there is a total oscillation R + S ₁ . Swings

ίο the string upwards, the bridge α is prevented by the tensioned string from participating in an oscillation beyond the middle position. As a result, the string section S ₁ will swing upwards by itself, as in FIG. 2 is _{indicated by S 1} ". An investigation has also shown that the oscillation is discontinuous approximately when passing through the central position, so that, in relation to the time axis ζ, an upward movement _{following the oscillation S 1 'discontinuously}

vibration-S arises ₁ ". This oscillation does have substantially the same amplitude A ₁ as the oscillation S ₁ ', but the additional amplitude due to the absence of the additional vibration R during the upward swing of the string is less than the total amplitude A during the downward swing of the string.

This disadvantage is effectively remedied by a design of the web and the special type of support of the string on the pressure bar e , since when swinging upwards under the play of forces P ₁ , P ₂ there is no longer any insurmountable resistance that opposes the upwards swinging. As a result of the upward swinging of the pressure bar e , the string section s ₃ can move into the position S ₃ ″, the angle between

the string sections S ₃ and S ₂ enlarged and approached a straight angle of 180 °. The part of the string formed by the string sections S ₁ and S ₂ can therefore stretch and relax _{up to position S 3} ", s ₂ " and thereby enable the bridge α and the soundboard b to oscillate upwards. With S ₃ ', S ₂ ' and S ₁ ', for example, the lowest vibration positions are again designated, with S ₃ ", s ₂ " and S ₁ "the uppermost vibration positions of the individual string sections. The vibration amplitude r"

of the web α when swinging upwards is essentially the same as that of the amplitude / when swinging downwards, so that overall, as in FIG. 3 a is shown as a function of time ζ , the total oscillation amplitudes of the sounding string section SjL in the upward and downward direction are practically the same, ie K '+ S ₁ ' is practically equal to R "+ Sf .

Claims (5)

Patent claims: 1. Bridge for the strings on pianos, grand pianos or the like, which is combined with a pressure bar (e) on the side of the bridge (α) opposite _{the sounding string section (S 1), characterized by a with the bridge (α)} Pressure bar (e) that resonates and thereby forms an abutment for generating the string pressure force to eliminate the insurmountable resistance, which is arranged in such a way that the string section (s ₃ ) between the fixed support (A) opposite the sounding string section (S ₁ ) and the pressure bar ( e) with the the two fixed supports (A, B) straight connecting ideal string (G) coincides and is held by the pressure bar (e) so that said string section (s _s ) can swing around the point of support on the fixed support (A) in both directions . 2. Bridge according to claim 1, characterized in that the pressure bar (e) - is connected directly to the bridge (λ) ίο - preferably by means of screws (/) arranged approximately perpendicular to the strings. 3. web according to claim 1 and 2, characterized in that the pressure bar (e) is adjustably connected to the web (a) . 4. A web according to claim 1 to 3, characterized in that the pressure bar (e) is attached to a lateral extension or a lateral widening of the web (d) carrying the web pins (c, d) . 5. web according to claim 1 to 4, characterized in that the web (ä) is provided below the pressure bar (e) with recesses (g) . 1 sheet of drawings 609 588/12 6.66 © Bundesdruckerei Berlin