US1988564A - Instrument producing music - Google Patents

Description

JanfY 23.,"1935, H, w. NERNST 1,988,564

I NSTRUMENT PRODUC I NG MUS I C Filed Nov. 24, 1931 2 Sheets-Sheet l Fig 1.

wfg/rn Jn. 22, 1935. H w NERNST 1,988,564

. INSTRUMENT PRODUCING MUSIC Filed Nov. 24, 1931 2 Sheets-Sheet 2 If [y Patented Jin. n, lacs 1,988,564

UNITED STATES PATENT rE/ICE 1,988,564 INSTRUMENT PRODUCINGMUSIC Hermann Walther Nernst, Berlin, Germany Application November 24, 1931, Serial No. 577,082 In Germany November 30, 1930 11 Claims. (Cl. 84-173) This invention relates toan apparatus adapted is achieved either by additionally. positively to produce music by means of strings which may damping the oscillations of the strings or by using be mechanically oscillated by means of a device special micro-hammers, preferably damped at constructed like a piano. These` mechanical osthat end of their movemet exciting the strings.

cillations of the strings directly influence elec- However, both means can be used at the same 6 trical relays whereby the mechanical oscillations time. are converted in electrical oscillating currents. Further particulars of the invention may be These currents arel then suitably amplified and explained with reference to the embodiments of inuence acoustic reproducers which transform the invention shown in the drawings, Fig. 1 of the electrical oscillations into audible sound oswhich shows a vertical cross-section of a piano l0 y cillations. Such an apparatus is described in my and, more schematically, the electric connections, copending parent application, Serial Number Fig. 2 showing a detail of the damping means and 516,480. This application forms a continuation micro-hammer, Fig. 3 showing another performin part of the co-pending application, Ser. No. ance of the micro-hammer, while Fig. 4 shows a 516,480. general electrical connection and arrangement l5 It is the object of my invention to improve a usable for practically operating the instrument form of such apparatus adapted to produce music. according to the invention.

Upon comparing such an apparatus with the Referring to Fig. 1 it is to be understood that usual pianos I discovered that in such pianos the this figure merely corresponds to my mentioned oscillations of the strings are damped by the older copending application. It isassumed that 20 resonant body. In an apparatus according to the piano possesses the usual structure, having said copending application, however, no such a keyboard suitably connected with hammers. resonant board is present and therefore no such Accordingly the keylevers 21 are pivotally supdamping takes place. On the other hand with ported at 22 on the bracket 20. A link 23 is 25 such new apparatus the mass of the strings can pivotally connected to the rear end of the key- 25 be substantially reduced and as a consequence lever 21 and is held inupright position by another the strings can oscillate through a much longer link 24 which is pivotally connected with a time interval than the prior art strings of larger bracket 25. The upper end of the' link 23 is mass, especially when said last-mentioned strings pivotally connected with another lever 26 which an are damped by the resonant body. Sometimes, is pivotally connected in well-known manner with 30 however, it happens that the strings of the said a support 28. The lever 26 bears the hammer new apparatus oscillate longer than is desirable 27. The foot 30 is pivotally connected to the and suitable for a piano. If such longer oscilla- 'support 28 and provided with a back-stop 29 tions' are allowed to occur, then the instrument opposing the hammer 27. There is rigidly conoperates like a harmonium (parlor organ) or nected with the foot 30 a stem 31 oi' the hammer 36 organ. Although in the last-mentioned case 10. A lug 32 on the foot 30 bears a spring or organ-like music is produced by strings actuated other resilient member 33 and a damping means in an easy manner similar to that of a normal 34 positioned approximately at the end of the piano without using pipes, nevertheless it is demember 33. The hammer l0 lies with its stem n sirable to alter the operation of the instrument 31, in normal position, on the abutment 35. This so that it works in a manner identical with` a arrangement approximates the well-known keynormal piano. board-hammer operating mechanism of a piano.

There are further described in my copending It is therefore to be played upon in the same application the micro-hammers for exciting the manner as on the usual piano. One may use oscillations of the strings. Such hammers are also the damping means 34 for producing the 45 capable Of exciting such oscillations with the same finesses as in normal pianos. smallest possibly energy. In addition, this sub- For adjusting the timber of the instrument in stantially prevents an undesired oscillation of the the desired way, so that at will it approximates strings during a longer time than that usual either anormal piano, an organ, or aparlor organ with normal pianos. (harmonium), a special damping means is pro- 50 A further object of the invention is to prevent vided, as shown at the top of Fig. 2, and comundesired duration of the oscillations of the prising a member 42 having an edge of felt, textile strings for the purpose of adapting the new incork or the like, preferably adjustable in a supstrumenttotheusual pianos. porting bracket 43. By choosing the material According to the invention the desired result comprising the edge which either touches or is 55 .tions of the player.

in the neighborhood of the strings 36, andl by adjusting the pressure between the edge and the string, extremely ne adjustment can be made of the period of oscillation of the string 36. It is possible to coordinate a single damping means to all the strings of the instrument, or to use several damping means, one for each group of such strings. There can be also coordinated to each string a special damping means adjustable independently from others.

Means can be provided to lift the damping means simultaneously, or if desired, only several at a time, a handle or pedal being provided for this purpose, connected with the support 43 in suitable manner, it being necessary to this end, that the bracket 43 be slidably or shiftably supported on the frame of the instrument.

For exciting the mechanical-oscillations of the strings 36 micro-hammers 11 are provided. These miem-hammers are slidably supported in a bracket 44 which, in turn, is fastened to the frame (not shown) ofv the instrument. This micro-hammer 11 is contacted by the` hammer 10, upon actuation of the keyboard, and is driven with according energy against the coordinated string 36. But the movement of the hammer 10 is stopped by the abutment 12 before the microhammer 11 touches the string 36. Therefore the micro-hammer 11 continues its own movement towards a string 36 Vonly by influence of therelatively very small kinetic energy passed to'its small mass by the hammer. Apparently the micro-hammer 11 is freely movable in this case in an approximately straight course. Therefore the strings can be excited to mechanical oscillations in a very fine manner following the inten- A 'I'he striking face of the micro-hammer 11 is to be formed in this case by an elastic material so that it is driven back after the stroke by reflection into its initial position. Otherwise a course inclined to the horizontal is necessary. Another kind of performance is shown in Fig. 2.

According to the principal invention no resonant body is provided. The strings 36 are fastened and stretched on brackets 19 which are `in turn fastened on the rigid frame or support 41 whichv may be held in any suitable way in the preferably sound-tight casing 38 of the piano. 39 is a lining e. g. of felt. '37 are tuning pins for adjusting the tension of the strings.

Telephone magnets 14 are rigidly connected to the frame 41 which is sufllciently rigid in itself and therefore is not capable of oscillating. Thereby any relative voscillations of the telephone magnets 14 to the strings are prevented. Thereby any troubling oscillations or noises are prevented,

which would otherwise be originated by the sup-l port 41 if the latter were capable of mechanical oscillations within an audible range.

The strings 36, if excited by the micro-hamme oscillate accordingly and excite electrical currents in the telephone magnets 14 which are connected by the leads to a thermionic amplifier within the casing 15. The amplified currents then excite one or more loud speakers 16 or other acoustic reproducers.

Fig. 2 shows in detail a damping arrangement and a freely movable micro-hammer according to the invention, but applied to a so-called "grand pian In such a grand piano the strings are usually arranged in a horizontal, or approximately horizontal plane. Accordingly, in Fig. 2 the strings 36 are supposed to be stretched approximately horizontally. The damping means 42 are applied from. above the plane of the strings. There is arranged a horizontal shaft '45 above the strings, and pivotally connected to said shaftare levers 43 each of which is coordinated to a single string 36 and is provided with a threaded opening in which a screw 46 with handle 47 is to be threaded in. On the lower end of the screw -46 an edge 48 is secured formed of suitable material, as e. g.i'e1t. By choosing the weight of the lever 43 and the screw 46 it is possible to' adjust very exactly the intensity of the damping of the oscillations of the string 36 by the feltedge 48 lying upon such string.

The shaft 45 is provided with a key 49. In the end of the lever 43 is provided a recess 50. Therefore, upon rotating the shaft 45 by means of a handle 51 connected in any suitableway, then the key 49, cooperating with the 'recess 50 lifts the lever 43. In such manner both an adjustable and movable damping is provided. If damping is used, the timber of the instrument is similar to that of a usual piano. Upon lifting the damping means, then the timber is more similar to that of an harmonium or organ.

Instead of using gravity action for pressing the damping edge 48 on the string 36 there may be used any other power as e. g. a coiled or flat spring. 'Ihe lever 43 in Fig. 1 may be elastic so that any desired tension can be applied to the damping edge 42. However the natural frequency of such elastic lever must not lie within a disturbv ing range. By regulating the tension in the lever, or in similar manner, such disturbing oscillations can be easily avoided.

It is furtherpossible to adjust the damping by choosing to the. desired value and/or changing the distance between the end of the string and the place on whi'ch the damping edge touches the strings.

Fig. 2 fin'ther shows the micro-hammer as used in Fig. .1, but on an enlarged scale. Between the bracket 44 and the micro-hammer 11 a sleeve 52 can be provided, reducing the friction between the stem of the micro-hammer and the'opening in the bracket 44. 0n the top of the micro-hammer a-suitable pad 53 e. g. of felt can be provided. 'Ihe stem of the micro-hammer is preferably tapered towards its lower end, so that it is easily moved upwardly by the stroke of the hammer 10. Apparently the .distance between the lower surface of the bracket 44 and the tip54 of the microhammer is smaller-than the distance between the string 36 and the upper surface of the pad'53. Therefore the micro-hammer 1l moves freely, by kinetic energy only, a certain part of its way towards the string 36 and excite the string 36 very quickly and will rebound almost instantaneously. This back-movement is assisted by the gravity action of the micro-hammer.

Fig. 3 shows another detail of the invention.

It is possible thereby to execute a quick and sharp stroke on the string 36 without using a complicated mechanism between the key-lever 21 and the hammer 10. The note 21 is there provided on its rear end with a stop 55. A piston 56 of large diameter is arranged within acasing 57 above the stop 55. A hollow cylinder 58 is connected to the upper end of the casing 57. A piston 59 of smaller diameter is slidably arranged within the cylinder 58 and is provided with an upper striking face e. g. of lfelt 60. An outlet 61 is provided on the cylinder 58.

Upon shifting the key lever 21, by actuating the key the piston 56 is driven upwardly and compresses the airin the casing 57. Accordingly the piston 59 in the cylinder 58 is moved upwardly very rapidly by the alr thus compressed, because of the fact that the diameter of piston 56 is much larger than that of piston 59. As soon as the piston 59 with its surface 60 comes close to the string 36, but has not yet touched it, the lowerend of the piston 59 opens the outlet 61. Consequently, the compressed air escapes through the outlet 61 and the piston 59 continues its movement toward the string 36 only by kinetic energy. The air escaping through outlet 81 momentarily produces a vacuum below the piston 59. In every case the piston 59 causes a rapid and sharp stroke on the string 36 and rebounds at once to its lower position, under the inuence of both gravity action and suction produced by the piston 56 returning to its initial position upon release of the key lever 21. In every case the outlet 61 prevents the piston 59 and its striking surface 60 from being pressed for a longer time interval against the strings 36 by the air compressed in the casing 57 and cylinder 58 by the piston 56. 'I'hereby the movement of the piston (micro-hammer) 59 is free, and is independent of the position of the piston 56 and the key vlever 21. The compressed air forms an intermediate cushion of a compressed elastic fluid accelerating the piston 59 with a desired force and speed. 'Ihis force is further dependent upon the proportions of the diameters of the pistons 56 and 59, and also upon the mass of the piston 59.

The edge 48 can be made of felt, textile, cork or the like, or can be covered by such materials.

If the lever 43 in Fig. 2 is made entirely or partly elastic, as e. g. using a flat spring, then it is possible to shift the shaft 45 to increase or decrease the degree of damping produced by the edge 48. Instead of such spring any power accumulator can be used.

Fig. 4 shows an electrical connection suitable for operating an instrument according to the invention. It is assumed that the strings are connected in groups and e. g. only four telephone magnets are coordinated to these groups. In the casing 14 the amplifiers and the regulating means for them are provided. In the casing 62 a powerampliner is arranged and connected wth the loud speaker 16. In the casing 62 a radio set is provided with handles 64 for well-known purposes and with a radio wave-length or frequency-scale 65. The radio set preferably comprises only a few tubes (high frequency amplifier,

detector) and -can be connected over the switch 66 to a power-amplifier of audio-frequency 62. There exists further the possibility of connecting with the tubes inside the casing 63 in a` wellknown way over the switch 67 the pickup 6B of a gramophone and to insert in the connection thereof means 69 for regulating the power of the sound.

The switches 66, 67 can bev actuated by the same or separate handles. Obviously it is possible hereby to use the same loud speaker and power-amplifier for the piano or grand piano or the radio set or the gramophone. It is also possible to receive radio music and to accompany it at the same time on the piano, reproducing in the loud speaker both the radio and the piano.

It is further possible to have reproduced in the .the mechanical oscillations of said strings while oscillating, said damping means being incapable of audible resonant oscillations with said strings.

2. In a stringed musical instniment provided with a resonant body and electrical means to be influenced by the oscillations `of said strings without mechanical intermediary, and being adapted to influence acoustic reproducers by way of ampliiiers, the arrangement of means for permanently damping the mechanical oscillations of said strings while oscillating, said damping means being different from the resonant body and incapable of audible resonant oscillations with said strings.

3. In a stringed musical instrument, as claimed in claim 1, the damping means being common to all the strings.

A 4. In a stringed musical instrument, as claimed in claim l, the arrangement of separate permanently damping means for each of the strings.

5. In a stringed musical instrument. as claimed in claim 1, the arrangement ot separate permanently damping means for each of a plurality of groups of said strings.

6. In a stringed musical instrument, as claimed in claim 1, the arrangement of adjustable permanently damping means.

7. In a stringed musical instrument, as claimed in claim 1, variable weights for adjusting the permanently damping means.

8. In a stringed musical instrument, as claimed in claim 1, the arrangement oi' permanently damping means being movable longitudinally of said strings for adjusting the damping action.

v 9. In a stringed musical instrument, as claimed in claim 1, the arrangement of means for switching in and out of operation the permanently damping means.

10. In a stringed musical instrument, as claimed in claim 1, the arrangement of a power accumulator for adjusting the permanently damping means.

1l. In a stringed musical instrument, as claimed in claim 1, the arrangement of a spring for adiusting the permanently damping means.

HERMANN WALTHER NERNST.

Images