US3139476A

US3139476A - Electrical musical string instrument

Info

Publication number: US3139476A
Authority: US
Publication date: 1964-06-30
Anticipated expiration: 1981-06-30

Description

June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 1 INVENTOR.

OCTAVIO JOSE ALVAREZ AT TORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 2 1 I I I I], I I!!! It I I///// 1 1/ 11 1111/1 1 111) zrv INVENTOR OCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 3 INVENTOR.

OCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ ELECTRICAL MUSICAL STAR ING INSTRUMENT #8 Sheets-#Sheet 4 Filed June 25, 1958 FIG. /5

.. a 9 .2 m f M w W @W W 4 m z v. I P W a g 7 u a l \M 7 a m m a L Q m 3 w m 6 m. 3 z

FIG. /6

INVENTOR.

OCTAVIO JOSE ALVAREZ fiu' fim J J/W ATTORNEY June 30, 1964 0. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 5 eels/5,64

INVENTOR.

OCTAVI O JOSE ALVAREZ BY .5 JAM? ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 6 INVENTOR. OCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 7 64 FIG. 22

INVENTOR.

OCTAVIO JOSE ALVAREZ BY m .r- 14.x

ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet 8 FIG. 23

sCllldl'ole a: FIG. 25

INVENTOR.

2 OCTAVIO JOSE ALVAREZ AM J. f/n/u/ ATTORNEY United States Patent 3,139,476 ELECTRICAL MUSICAL STRING INSTRUMENT Octavio Jose Aivarez, 6 E. 65th St, New York, N.Y. Filed June 25, 1958, Ser. No. 744,559 33 Claims. (Cl. 84-413) The present invention relates to musical instruments.

More particularly, the present invention relates to musical instruments such as pianos which are electrically operated so as to produce musical sounds which simulate and are the same as the sounds of a conventional piano.

Electrical pianos are relatively expensive and complex. Furthermore, the electrical signals which are amplified are not always pure and undistorted. For example, as a result of the damping of vibratile elements of such a musical instrument hissing sounds are created which are difficult to eliminate. Also, in the damping of the vibratile elements the latter are placed in a position other than that which they would naturally assume if unstressed, and as a result the vibratile elements require periodic adjustment in order to maintain the musical instrument properly tuned. it should be noted that the same consideration applies to the strings of a conventional piano. Also, where vibratory motion of a vibratile element is relied upon for initiating the creation of a musical sound, it is diflicult to support the vibratile element in such a way that its support is completely insulated from and does not participate in any way in the creation of the musical sound. Some supports superimpose their own vibrations on the vibrations of the vibratile elements, and furthermore many supports for the vibratile elements do not remain dimensionally stable over along period of time with the result that the changes in the shape and size of the supports for the vibratile elements also produce distortions which necessitate readjustments. Such lack of dimensional stability of the supports for the vibratile elements occurs particularly where such vibratile elements are set into vibratory motion as a result of inertia forces transmitted to the vibratile elements through their supports.

One of the objects of the present invention is to provide a musical instrument of the above type which is of a relatively simple, inexpensive construction and which at the same time is quite compact and capable of operating reliably over a long period of time with a minimum of maintenance.

A further object of the present invention is to provide a musical instrument of the above type which will require no re-tuning.

Another object of the present invention is to provide for a musical instrument of the above type a unit which includes a vibratile element of the musical instrument and which can be purchased as a unit to replace a vibratile element in the instrument.

An additional object of the present invention is to provide a structure which supports the vibratile elements of the musical instrument in such a way that the supports themselves do not in any way participate in the production of the musical sound even when the vibratile elements are vibrated as a result of transmitting inertia forces thereto through their supports.

It is also an object of the present invention to damp the vibrations of the vibratile elements without producing any hissing sounds or other undesirable sounds.

Still another object of the present invention is to provide in a musical instrument strings which are not sensitive to corrosion in certain climates.

It is furthermore an object of the present invention to provide a musical instrument which is capable of behaving in every way in the same way as a conventional musical instrument and which even eliminates some of the faults ofa conventional musical instrument.

Furthermore, the objects of the present invention include the provision of a musical instrument such as a piano which is capable of having pedals thereof operated for the purpose of sustaining a musical tone.

It is also an object of the present invention to provide a musical instrument of the above type which is capable of interrupting the musical tones and reliably preventing the continuation thereof and is also capable of repeating the same musical tone rapidly with distinct extremely short periods of silence between the repetitions of the same tone.

Among the objects of the present invention is also the provision of a musical instrument which is capable of operating reliably with all types of vibratile elements Whether the latter are extremely fine and delicate or whether they are relatively heavy and in the form of metal bands or spirals.

With the above objects in view, the present invention includes a musical instrument whereinan elongated vibratile element and a support means therefor form together at least part of a unit which can be connected to or removed from the musical instrument. This vibratile element participates in the production of the musical sound when it is set into vibratory motion, and it is charged either electrically or magnetically and cooperates with other elements such as pick-up coils or condenser plates, or the like, to electrically produce the musical tones. The vibratile element is set into vibratory motion by the transmission of inertia forces thereto, and in accordance with the present invention these vibratory motions of the vibratile elements are damped both mechanically and electrically, and means are provided for preventing this damping when desired in order to sustain a musical tone.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal axial sectional elevational view of a unit according to the present invention, this unit including the vibratile member as well as the support therefor and a mechanical damping means;

FIGURE 2 is an axial sectional elevational view of another embodiment of a unit according to the present invention which includes the vibratile element, a mechanical damping element, and the support for the vibratile element and mechanical damping elements;

FIGURE 3 illustrates the manner in which the damping elements of FIG. 2 are magnetically actuated;

FIGURE 4 shows a stage in the process of manufacture of the structure shown in FIG. 2;

FIGURE 5 illustrates another stage in the process of manufacture of the unit of FIG. 2;

FIGURE 6 is a perspective view of one of the damping elements of the present invention, this damping element having a structure different from those shown in FIGS. 2-5;

FIGURE 7 shows a unit similar to that of FIG. 2 but including damping elements as illustrated in FIG. 6;

FIGURE 8 illustrates an intermediate stage in the operation of the damping elements of FIG. 7;

FIGURE 9 shows the elements of FIG. 8 when they have progressed further and are located in their final damping position;

FIGURE 10 is a longitudinal sectional elevational view of another embodiment of a unit according to the present invention;

FIGURE 11 is a longitudinal sectional elevational view of still another embodiment of a unit according to the present invention which includes a vibratile element, damp- Patented June 30, 1964 ing means therefor, and a support for the damping means and vibratile element;

FIGURE 12 shows the structure of FIG. 11 with the vibratile element damped so that it can no longer vibrate; FIGURE 13 is a transverse sectional view illustrating details of the damping structure of FIGS. 11 and 12;

FIGURE 14 is a perspective view of one of the damping elements of FIGS. 11 and 12;

FIGURE 15 illustrates in a partly diagrammatic manner part of the entire assembly associated with a key of a piano :and including one of the units of the present invention;

FIGURE 16 shows the structure of FIG. 15 and the position it takes when the key has been moved by the operator to the operating position;

. FIGURE 17 illustrates the position which the parts of FIG. 15 takes when the operator actuates a pedal of the piano;

FIGURE 18 is a partly diagrammatic illustration of another embodiment of a piano structure according to the present invention;

FIGURE 19 is a diagrammatic illustration of' still another embodiment of a structure according to the present invention, the parts being shown in FIG. 19 in the position they take when the piano key is at rest;

FIGURE 20 shows an embodiment slightly different from that of FIG. 19, the structure being shown in FIG. 20. in theposition it takes when the piano key has been moved to its operating position;

FIGURE 21 also shows an embodiment of the invention somewhat different from that of FIG. 19, FIG. 21 showing the position the parts take when the pedal is actuated;

FIGURE 22 is a partly diagrammatic illustration of a still further embodiment of the present invention;

FIGURE 23 is a partly diagrammatic illustration of still another embodiment of a piano according to the present invention, the parts being shown in FIG. 23 in the position they take when the piano key has been moved to its operating position;

FIGURE 24 shows the embodiment of FIG. 23 with the piano key in the rest position thereof; and

FIGURE'ZS shows the structure of FIGS. 23 and 24 with the key of the piano in its rest position and after the pedal has been actuated.

Referring now to FIGURE 1 of the drawings, there is illustrated therein a unit according to the present invention, this unit including the vibratile element 31 as well as the'support therefor and a damping means 44, 45. As may be seen from FIG. 1, an elongated hollow glass tube forms a housing for the vibratile element 31 which may be in the form of an elongated wire having heads 32 and 33 located at its opposite ends. The tube 30 is closed at its leftend, as viewed in FIG. 1, and the vibratile element 31 extends through an opening at the end wall of the tube 30 with the head end 32 thereof engaging the exterior surface of this end wall to limit the movement of the vibratile element to the right, as viewed in FIG. 1. A plate'34 of an electrically non-conductive material is located next to the open end of the tube 30, as illustrated in FIG. 1, and this plate as well as the right end of the tube 30, as viewed in FIG. 1, are received ber 35 is formed with a threaded bore 37 which threadedly receives an elongated screw member 38 having at its right end, as viewed in FIG. 1, a transverse notch 39 adapted to receive the tip of a screwdriver, for example, so'that the screw member 38 may be turned to adjust its 7 position. This screw member 38- is formed with an elongated bore 40 extending parallel to its axis, and the vibratile element 31 extends through this bore 4t) and has its head end 33 engaging the right end face of the screw member 38, as viewed in FIG. 1. apparent that the vibratile element 31 is deflected at the opening 36 of the plate 34 into the bore 4t) of the screw member 38, and turning of the screw member 38 will adjust the tension of the wire 31 between the left end wall of the tube 30, as viewed in FIG. 1, and the left edge of the opening 36, as viewed in FIG. 1, which is tapered in the manner illustrated in FIG. 1, so that the vibratile element 31 will be supported for free vibratory motion at its portion which extends from the left end of the tube 3% up to the plate 34. The screw member 38 may be in the form'of a permanent magnet having the polarity illustrated in FIG. 1, so that the vibratile element 31 may be permanently charged in order to participate properly in the production of a musical sound, as will be apparent from the description below in connection with FIG. 10.

Once the tension of the vibratile element 31 has been properly set, a sealing compound 41 may be placed at the front end of the cap member 35 around the screw the tube 30, so that the interior of the tube 39 is sealed 7 off from the outer atmosphere, and before the sealing compound 41 and 42 is applied the interior of the tube 30 may be evacuated in any known way. is of particular significance where the vibratile element 31, has a relatively large mass, because in this way the air resistance to the vibratory motion of such a vibratile element is greatly reduced. Furthermore, where a vibratile element 31 is of a relatively delicate nature it is completely protected by the above-described supportingstructure therefor. It should be noted that the vibratile element 31 is shown in FIG. 1 in the form of a simple wire only by Way of example.

The above-described unit of FIG. 1 further includes;

'45 are inserted into the tube 30 with the string 31' passing through the bore 46 before the plate 34 and the other elements are joined to the assembly. The ring 43 presses with its exterior surface against the inner surface of the tube 30 so that the ring 43 remains reliably at the left.

end of the tube 30, as viewed in FIG. 1. 1

The use of an elongated tube such as the tube 30 supporting and housing the vibratile element is of particular advantage not only with respect to the. protection of the vibratile element and the possibility of locating the latter in an evacuated atmosphere, but also with respect to the dimensional stability of the support. Thus, a structure such as the elongated tube 30 with its circular well will reliablymaintain its configuration without being infiuenced in any way by interia forces which are transmitted through the tube 30 to the vibratile element 31, so that the tube 30 will never superimpose its own vibration on those of the vibratile element and will never change its shape or size so as to provide distortions which cannot be controlled.

In the embodiment of FIG. 1, as well as in the other embodiments of string-carrying units of the invention described below, it is preferred to enclose the spring in a tubular housing made of glass for several reasons. Thus, this material is not too heavy or expensive, need not be precision machined, and at the same time is strong enough to maintain the tuning stable. Also, glass is not too sensitive with respect to thermal expansion and is unlikely to become permanently distorted. Furthermore,

the current-conductivity of glass is too low to produce any.

Thus, it is Such evacuation p which would cause the string support to vibrate in interference with the string itself, and the result would be undesirable sound distortions and exaggerations.

The air-tight enclosing of the string protects it from corrosion and from dust and other particles which might greatly disturb the proper operation of the musical instrument. Also, an enclosed string can be handled without exercising great care during packing, shipping and mounting. Furthermore, by locating the mechanical damping elements within the tubular enclosure injury to the mechanical damping elements is avoided.

The above described unit of FIG. 1 is manufactured separately and is also sold separately, so that a purchaser can at any time replace a unit of his piano with a new unit as shown in FIG. 1, and the vibratile element of the unit is already tensioned so as to have the proper vibratory motion. In this way if for any reason it is desired to replace one of the vibratile elements of a piano, then with the structure of the present invention it is only necessary to purchase another unit as shown in FIG. 1.

Of course, with the embodiment of the FIG. 1, if it should become necessary to retune the vibratile element 31, it is possible to turn the screw 38 for this purpose so that purchase of another unit may not be necessary. Also, the forms which the vibratile element 31 may take are not limited to those mentioned above.

FIG. 2 of the drawing shows another embodiment of the invention which includes an elongated tubular housing member 50 having at its right end, as viewed in FIG. 2, the end wall 51 to which the right end of a vibratile element 52 is fixedly connected, in the manner shown in FIG. 2. In the interior of the tubular housing 50 is located an elongated plug 53, aid this plug as well as the tube 50 may be made of glass, for example. The left end of the vibratile element 52 is connected to the right end of the plug 53, as shown in FIG. 2, and at their left ends the tube 50 and the plug 53 are fused to each other. Between the plug 53 and the tube 50 are located a pair of elongated

springy strips

54 and 55 made of a magnetic material and carrying at their right free ends, which are in the interior of the tube 50, pads 56 and 57, respectively, which may be made of rubber, cotton, or the like. It will be noted that the

strips

54 and 55 have their left free end portions, as viewed in FIG. 2, extending to the exterior of the unit beyond the left ends of the tube 50 and the plug 53, as viewed in FIG. 2.

FIGURE 3 illustrates the manner in which the

strips

54 and 55 are operated in order to damp the vibratory motion of the vibratile element 52. As is shown in FIG. 3 a permanent magnet 58 is placed adjacent to the left free end portions of the

strips

54 and 55, as viewed in FIG. 3, and in this way the strip 54 is given a North polarity while the strip 55 is given a South polarity. As a result the ends of these strips which are in the interior of the tube 50 and which carry the pads 56 and 57, respectively, are attracted to each other and engage the vibratile element 52 at opposite faces thereof, respectively, and with equal and opposite forces, so that in this way any vibratory motion of the vibratile element 52 is damped, and at the same time because equal and opposite forces are applied toopposite face portions of the vibratory element the latter is in no way distorted by the damping means so that it will not become stretched by the damping means and will not require the retuning. Of course, as soon as the permanent magnet 58 and the left free and portions of the

strips

54 and 55 are spaced from each other so that the

strips

54 and 55 are no longer under the influence of the permanent magnet, these strips will by their own resiliency return to the position shown in FIG. 2 so as to release the vibratile element 52 for vibratory motion.

FIGS. 4 and 5 show stages in the process of manufacture of the structure of FIGS. 2 and 3. As may be seen from FIG. 4 the plug 53 is first connected with the string 52 which is guided through an opening in the end wall 51 of the tube 50, and the

strips

54 and 55 are located alongside of the plug 53 in the manner shown in FIG. 4. Then the plug 53 with the

strips

54 and 55 located against opposed surface portions thereof are slipped into the tube Stl and the entire assembly is then placed on the frame 60 which is shown in FIG. 5. Thus, before the plug 53 is inserted into the tube 59 this plug 53 is slipped through the opening of the left wall 61 of the frame 69, as viewed in FIG. 5, and the

strips

54 and 55 are also positioned so as to pass through this opening. After the plug 53 has been located approximately at its proper position within the tube 50, the string 52 is pulled tight and formed into an enlarged head end which engages the exterior surface of the wall 51, as shown in FIG. 5. This may be done in any suitable way, as by heat ing the wire 52 to sever the portion of the wire which is located beyond the end Wall 51 and so as to form the enlarged head end. Then the end wall 51 is placed in a T-slot of a member 66 which is guided for movement to the right and left by the member 67 carried by the right wall 62 of the frame 60, and this member 66 is connected with a member 65 which turnably supports the left end 64 of a threaded crank 63 which passes through a threaded opening in the right wall 62 of the frame 60. With this construction it is possible to turn the crank 63 so as to advance the tube 56 to the right, as viewed in FIG. 5, with respect to the plug 53 and thus tension the vibratile element 52 to a desired degree. The condition of the vibratile element 52 is tested by the unit 68 which includes a pick-up coil 68a, amplifier assembly 68b and loud speaker 680, and which indicates the sound which will be produced by vibration of the vibratile element 52, and the structure for picking up the vibrations and reproducing these vibrations into an audible sound is described in greater detail below. When the desired tension of the vibratile element 52 is reached, which is indicated by the production of the desired sound, then with a burner 69, for example, the left end of the tube 50 is fused with the plug 53, and the portion of the latter which extends to the left beyond the tube 50 is cut-ofi leaving the free end portions of the

strip

54 and 55 which are located to the left beyond the tube 56, and these free end portions are also cut off so as to have the length shown in FIGS. 2 and 3.

In this way the structure of the invention may be very easily made, and if desired the tube 50 may be evacuated before the tube 50 is fused with plug 53. Of course, it is to be understood that the extending of the

strips

54 and 55 to the left beyond the tube 54 as shown in FIGS. 2 and 3, is illustrated only by way of example. This feature is not at all essential, and the left ends of the

strips

54 and 55 could also be located within the tube 5% fused between the latter and the plug 53 or simply gripped in the space between the tube 50 and the plug 53, since the magnetic force will act equally well on these ends even if they are embedded in the glass or other material of the tube 50 and the plug 53.

FIGURE 6 shows in a perspective view a single damping strip 70 similar to the strips 44 and 45 of FIG. 1, this strip 76 being bent upon itself so as to have a pair of elongated substantially parallel portions one of which has the padding 71 connected to its free ends, this padding being of rubber, cotton or the like, as was mentioned above. The strip 70 is made of a springy magnetic metal, such as any ferrous material.

FIGURE 7 shows a unit similar to that of FIGS. 2 and 3 including the damping strips 70 which are mounted in the unit in the same way as the

strips

54 and 55 of FIGS. 2 and 3. Thus, FIG. 7 shows .the elongated tube 72 having its end wall '73 connected with one end of the vibratile element 74 whose opposite end is connected with the plug 75 which is fused at its left end to the left end of the tube72 with the damping strips 70 fixed between the plug 75 and the tube 72 and extending to the left beyond the plug and tube, in the particular example shown in FIG. 7.

perior to that of FIGS. 2 and 3.

FIGURES 8' and 9 show the operation of the damping strip 70. Referring'first to FIG. 8, it will be seen that when the permanent magnet 76 is located close to the exterior ends of the damping strips 7%, then these strips are respectively energized with the, different polarities as indicated in FIG. 8. Thus, the adjacent right free ends of the upper strip 70 of FIG. 8 both have a North polarity while the adjacent right free ends of the lower strip 70 both have a South polarity, in the particular example individual strips are now attracted to each other because of their opposite polarity and thus push against opposed faces of the vibratory element so as to damp the vibrations thereof without in any way stretching the vibratile element so that it will not be lengthened and will not require tuning after a periodof time, as was mentioned above.

This construction which is shown in FIGS. 7-9, is su- In the latter figures, the forces with which the damping members engage each other depends upon the strength of the magnet. However, with the arrangement of FIGS. 79 when the damping members '76 have the position shown in FIG. 7 their free ends will repel each other with a considerable force even if the magnet 76 is relatively weak because the free ends of each strip 70 are located closely adjacent to each other. Then when the padded ends are located close enough to each other to attract each other, very little of the magnetic force is delivered to the free ends of the strip 70 which remain next to the inner surface of the tube 72. Almost all of the magnetic force goes through the padded ends of the strips, because this is the line of least resistance, and it is therefore possible with the arrangement of-FIGS. 7-9 to provide the desired mechanical damping with a relatively weak magnet and in a very reliable, quick manner. The speed of the action is obtained by the initial repulsion forces in each of the damping strips, as indicated in FIG. 8.

, FIGURE 10 of the drawings illustrates an embodiment of a unit of the present invention which is particularly suited for producing the lower tones of a piano. This unit includes an envelope 77 which is similar to conventional vacuum tubes and which is evacuated in a known way, and within this tube 77 is located the vibratile element 78 which in the illustrated example is coiled, and the convolutions of the vibratile element 78 may take I any desired configuration and need not be absolutely circular. This vibratile element 78 has a considerable mass, and the evacuation of the tube 77 reduces the air V cludes the springy damping arms 83 which are also made of a magnetic material and which are provided with padding at their right ends, as viewed in FIG. 10, and

'the left ends of these arms are embedded in a member 82 which is fixed in the interior of the tube 77 and which ismade of anon-magnetic material such as a suitable plastic, for example. The member 79 extends threadedly through the plate 82 to the exterior of the tube so that this member 79 may be turned to adjust the tension of the vibratile element 78. An electrically conductive member 81 extends into the interior of the tube 77, and is coiled about both ofthe damping arms 83, and then extends back to the exterior of the tube where the member '81 terminates in a pair of contacts adapted to be engaged by another pair of contacts for completing a circuit through the member 81, and as a result of the winding of the member 81011 the arms 83 the latter are given a predetermined polarity which is opposed to the polarity. of the vibratile element '78, so that the arms 83 both move into engagement with the vibratile element 78 to damp the Vibrations thereof when the coil 80 and the element 81 are both energized. Because of the greater mass of the vibratile element 78 With respect to the arms 83, in

the embodiment of FIG. 10, the attraction force between the vibratile element 78 and the members 83 is relatively great and with this particular embodiment the illustrated arrangement operates to reliably provide desired me-- chanical damping of the Vibratile element '78. .The member 82 may be made of a resilient material, if desired.

It should be noted that the embodiment of FIG. 1 is similar in its operation to that of FIG. 10, in that the vibratile element 31 of FIG. 1 is permanently charged with a North polarity by the permanent magnet 38. Thus, a pair of permanent magnets, for example, are applied with their South poles to the mechanical damping elements 4% and 45 to give the latter identical polarity. The

ends of each of the mechanical damping elements will repel each other and the repelled ends of elements i4 and 45 are then attracted to the vibratile element 31 to press against opposed faces thereof with equal and opv posite forces so as to mechanically damp the same. Of

course, the mass of element 31 is sufiicient to prevent elemerits 44 and 45 from repelling each other when they engage the element 31. FIGS. 15 and 16 show how a pair of permanent magnets may cooperate with a unit of the type shown in FIG. 2.

, The embodiment of FIGS. 11*14 is similar to that of FIGS. 2 and 7 in that it includes an outer tube 35 and inner plug $7 located within and fused to the outer tube .85 at the left end thereof, as viewed in FIGS. 11 and 12.

Also, the vibratile element 86 is stretched between the right end of the tube $5 and the right end of the plug 87,

as indicated in FIGS. 11 and 12. However, the damping structure is different from the other embodiments. as

may be seen from FIGS. 11-14, the damping structure in.- cludes an outer substantially U-shaped strip 88 having a pair of parallel legs extending along the inner surface of the tube and having an intermediate portion located at the exterior of the tube 85 and surrounded by a coil 92; Next to the strip 88 is located another substantially U-shaped strip 89 which engages the inner surface of the strip 38 and is substantially coextensive therewith. Both 'of these strips 83 and 89 are made of a magnetic material so tlat they become energized when the coil 92 is energize A third strip so of substantially U-shaped configuration is located against the inner surface of the inner strip $9 and has free ends extendingbeyond the same in the interior of the tube 85, these free ends respectively carrying the padding 91. This strip 9t? is made of nonmagnetic spring material. The strips $S-tl areall made a the example illustrated in FIG. 12, and the lower'free ends of the strips 89 and 88 with an opposed polarity, so that the free ends of the strips 88 and 89 cooperate first to repel each other, and then the free ends of the strip 89 attract each other, and the movement of the strip 89 is transmitted to the strip 90 which is moved in this way from the rest position of FIG. 11 to the damping position of FIG. 12 where the padding 91 engages the vibratile element 86 to mechanically prevent the vibration thereof, and in this embodiment also the vibratory element 86 is engaged at opposite faces with equal and opposite forces in order to produce the damping thereof, so that there is no stretching of the vibratile element 86 as a result of the damping thereof.

This embodiment of the invention is of particular ad vantage since it keeps all of the magnetic fields of the damping structure away from the vibratile element 86 which is charged by the

conductors

95 and 96 shown fragmentarily in FIGS. 11 and 12. Thus, with this arrangement the magnetism of the damping means will not interfere with the reproduction of the sound. Furthermore, because a coil 92 is used, when this coil is not energized there is no magnetism present, as would be the case if a permanent magnet were used, so that for this reason also the structure operates very reliably to prevent the magnetic forces of the damping means from interfering with the sound producing structure.

If desired the intermediate portions of the strips 88-90 could be located flush with the left end of the tube 85 or in the interior of the plug 87.

As may be seen from FIGS. 13 and 14, the strip 89 is provided at one of its free ends with a pair of ears 97 and at its opposite free end with a pair of ears 98, and the ears 97 are respectively directed toward the ears 98 and the latter also extend toward the cars 97. As a result, when the coil 92 is energized the

ears

97 and 98 become located relatively close to each other, as indicated in FIG. 13, so that the gap therebetween is quite small and the force of attraction operates very reliably even if it is not particularly large. Furthermore, as is shown in FIG. 14, the parallel arms of the strip 89 may be provided with any cutouts 99 or the like so as to render these arms more easily bendable.

FIGS. -17 show one of the units of the present invention incorporated into a piano structure which includes further features of the present invention. Simply by way of example a unit similar to that of FIG. 2 is shown included in the assembly of FIGS. 15-17, although any other units described above may be included. Referring now to FIG. 15, which shows the parts at rest, the structure illustrated therein includes a conventional piano frame 100 and one of the piano keys 101 is shown supported for turning movement about the rod 102, this illustration being diagrammatic. When the operator actuates the key 101, the latter turns in a clockwise direction about the rod 102. The unit 103, may be the same as the unit shown in FIG. 2, is provided with a hollow plug 104. The unit 103 is attached to the key 101 at its inner end portion by

bands

105 and 106. which may be any,

suitable bands such as bands of adhesive tape, for example. When the key 101 is in its rest position it rests on a bar 121 made of rubber, for example. The key 101 additionally carries a pick-up coil 107 which is connected electrically with an amplifier 108 which is in turn connected electrically with a loud speaker 109, so that when the vibratile element vibrates in the field of the pick-up coil 107 the vibrations will be converted into a musical sound. The vibratile element 103a of the unit 103 is set into vibratory motion by engagement of the key 101, when it is turned to an operating position, with a stop means 110, which is in the form of a bar of any suitable fairly rigid material which can be sound-proofed with respect to the frame 100 in any suitable way, as by locating any desired padding or the like between the stop means 110 and the frame 100.

The frame 100 carries a springy a rm 111 which in the position shown in FIG. 15 presses the permanent magnets 112 against a layer of foam rubber or the like 113 carried by an extension 114 of the frame 100. A second springy arm 115 is carried by the arm 111, and this springy .free the latter for vibration.

arm 115 supports at its upper free end a second coil 116 which is wound oppositely to the coil 107 and which is also connected electrically with the amplifier 108, as illustrated in FIG. 15. This coil 116 cooperates with the coil 107, in a manner described below, to electrically damp the vibrations of the vibratile element.

An electromagnet 117 is supported on the bottom wall of the frame 100, and this magnet cooperates with an armature 117 carried by the arm 111 so that when the electromagnet 117 is energized it will pull the arm 111 down into engagement with the layer of foam rubber 118, or the like. Of course, the arms 111 and 115 are made of non-magnetic material.

The structure illustrated in FIG. 15 further includes a pedal 120 capable of being turned downwardly by the operators so as to close a switch 119 located in the circuit of the electromagnet 117 for energizing the latter when the pedal 120 is actuated.

It will be noted that in the position of the parts shown in FIG. 15, the permanent magnet 112 cooperate with the magnetic damping arms 10312 of the unit 103 to cause the padded ends thereof to be pressed with equal and opposite forces against opposite faces of the vibratile element so as to mechanically prevent any vibrations of the vibratile element. When the key 101 is turned from the rest position of FIG. 15 to operating position of FIG. 16, it will strike against the stop means 110, and furthermore the unit 103 will be moved away from the field of influence of the magnets 112, so that the springy damping arms move outwardly away from the vibratile element to Upon striking against the stop means inertia forces induced in the vibratile element set the latter into vibratory motion, and this vibratory motion is picked-up by the pick-up coil 107 and is converted into a musical sound by the amplifier 108 and the loud speaker 109. The vibratile element tries to continue to move after the key 101 engages the stop 110 and thus vibrates due to inertia. It will be noted from FIG. 16 that the vibratile element is located at a relatively large distance from the coil 116, so that the latter does not enter into the operation at this time. Furthermore, it will be noted from FIG. 16 that the coil 116 has moved upwardly from the position which it has in FIG. 15, the springy arm being acted upon in the position of the parts shown in FIG. 15 so as to be placed in a position lower than the position which it naturally takes, this latter position being illustrated in FIG. 16. In this way the musical sound is produced.

When the operator releases the key so that it returns from the position of FIG. 16 back to the position of FIG. 15, it will be seen that the unit 103 will engage the coil 116 just before the key 101 reaches its rest position, so that just before this rest position is reached the

coils

107 and 116 are located equidistantly from the vibratile element. Therefore, just before the key 101 reaches its rest position the

coils

107 and 116 cooperate to cancel out any signals which might be transmitted to the amplifier inasmuch as these coils are oppositely wound, and in this way the vibrations are electrically damped. Thus, the electrical damping takes place just before the mechanical damping elements have reached a position with respect to the permanent magnets 112 which will provide the full force of the mechanical damping. It has been found that the mechanical damping will produce an undesirable hissing sound, and the electrical damping just before the mechanical damping reaches its final position eliminates this hissing sound. Actually, the electrical damping by itself would be sufficient to cancel out any sounds when the key returns to its rest position, except that it is frequently desired to repeat the same tone quickly with distinct abrupt periods of silence between repeated tones, and the electrical damping by itself cannot be relied upon for this purpose. For this purpose it is essential that the actual vibratory motion of the string 1 1 be terminated, and this is brought about by the mechanical damping means.

FIG. 17 shows the position in which parts take when the pedal 120 is actuated. As is apparent from FIG. 17, the actuation of the pedal 120 will close the switch 119 so as to energize the electromagnet 117 which draws the armature 117' down to the position shown in FIG. 17, with the result that the arm 111 is placed against the layer of foam rubber or the like 118,.and both the permanent magnet 112 as well as the coil 116 are moved downwardly to a position where they no longer influence I the unit 103. Therefore, assuming that the pedal 120 has trically damped, and the, tone will be sustained, and the same is true even if the key is again actuated before releasing the pedal or if the pedal is released after the key is again actuated so that the parts have the position shown in FIG. 16. I

In the embodiment of the invention which is illustrated inFIG. 18, the piano frame 125 carries a rod 127 which pivotally supports the piano key 126. This piano key 126 carries a unit 128 which in the illustrated example is similar to the unit of the invention which is illustrated in FIG. 7.

, In the embodiment of FIG. 18, the vibratile element 128a of the unit 128 is energized through a super-sonic generator129, which is connected with the line current and which has a well known construction, so as to induce at the vibratile element a field having a super-sonic frequency which is of course inaudible. Thus, when the vibratile element is set into vibratile motion, this field vibrates with the vibratile element to cause the pick-up coil 130, which is carried by the key 126, to transmit the vibrations to the amplifier 131 to be reproduced into a musical sound at the loud speaker 132. This amplifier is connected into one unit with a detector which detects the super-sonic frequencies and filters out these frequencies so that only the audible frequencies are transmitted to the loud speaker 132. Thus, with the embodiment of 'FIG. 18, instead of a permanent magnet the super-sonic generator 129 is used to energize the vibratile element of 126 when the pedal 135 is actuated by the operator.

The bar 133, which is of an electrically non-conductive material, carries one of the contacts of a switch 138, the other contact of this switch 138 beingicarried by'the key .126 and this switch 138 being closed in the position of the parts shown in FIG. 18. In addition, the embodiment of FIG. 18 includes a stationary electromagnet 1.36

which is energized by a circuit which includes the switch 138, and this magnet 136 cooperates with the mechanical damping means 12817 of the unit 1215 to cause the mechanical damping means to' engage the vibratile element and prevent vibratory motion thereof in the position of the parts shown in FIG. 18.

The bar 133 additionally carries a coil 137 which is wound oppositely to the coil 131i and which is also connected with the detector and amplifier assembly 131, so that when the parts have the positionshown in FIG. 18

a the vibrations are both electrically and mechanically dampedf The spring 134 is of such a force that the coil 137 moves upwardly through a slight distance after the key 126 is actuated, so that the electrical damping takes place just before the key returns to its rest position, as

was described above in connection with the embodiment 7 of FIG. 15.

Of course, when the pedal 135 is actuated, the downward movement of the bar 133 opens the switch 138 so that the electromagnet 136 cannot become energized, and furthermore the coil 137 moves downwardly with the bar 133 so that it cannot oppose thecoil 130 and as a result no electrical damping can take place.' It is therefore apparent that the structure of FIG. 18 is capable of producing the sameresults as the structure of FIG. 15.

In the embodiment of the invention which is illustrated in FIG. 19, the piano frame 143 carries a rod 142 which pivotally supports the key 141, and when the latter is turned from its rest position to its operating position, the portion of the key located forwardly of the rod 142 will turn downwardly. Upon movement of the key 141 to its operating position it strikes against the stop means 143 in the form of a block of rubber or thelike, and this stop means in this embodiment carries the unit 144 which in the particular example illustrated may be the unit which is illustrated in FIG. 2, although any other one of the units of the present invention may beused. .The stop means 143 also carries the pick-up coil 145 which is connected electrically through the leads 161 with the detector and amplifier assembly 146 which is in turn connected with the loud speaker 147. A supersonic generator 148, which may be identical with the generator 129 of FIG. 18, is connected to the line and through leads 159 with a primary coil 149 of a transformer, this primary coil 149 being carried by the key 141 and being adapted to coopso as to locate the secondary coil 150 within the primary coil 149 when the key 140 is in its rest position which is illustrated in FIG. 19.

It will benoted that the support member 151, which is made of an electrically non-conductive material, has at its left end, as viewed in FIG. 19, an upwardly directed extension located beneath an arm 156 which is also of an electrically non-conductive material and which at 7 its right end is provided with a portion extending around the rod 142 so that the arm 156 can be turned around the rod 142. The key 140 carries a pin 166 just beneath the arm 156. Y

The top end of the arm 156 supports theelectromagnet 157 which cooperates with the mechanical. damping means of the unit 144 in the manner described above when the electromagnet 157 is energized, and a switch means 153 is provided for energizing the electromagnet 157 when it has the position shown in FIG. 19. The secondary coil 150 of the transformer is connected through the leads 160 with the vibratile element to energize the latter.

When the key 141 is.depressed,the primary-coil 149 moves downwardly to a position surrounding and over- 14h strikes against the stop means 143, and this vibratory motion is picked-up by thepick-up coil 145 to be transmitted to the discriminator and amplifier assembly 146 which filters out of the supersonic frequencies and causes only the audible frequencies to be heard'through the loud speaker 147. Whenkey 141 engages block 143 the latter is suddenly compressed and produces a sudden slight upward movement of unit 144 to cause the'vibratile element 13 to vibrate as a result of inertia effects. The filtering out of the supersonic frequencies with the embodiment of FIG. 19 as Well as with the embodiment of FIG. 18 prevents distortions in the sound produced by the loud speaker 147.

When the key 141 is turned to its operating position, the pin 166 turns the arm 156 so as 'to raise the electromagnet 157 away from the switch means 158 to thus cause the circuit of the electromagnet to become interrupted, and in this Way the electromagnet is de-energized so that the mechanical damping means 144b is released and the vibratile element is free to vibrate before the key strikes against the stop means 143.

In this way a musical sound is provided with the structure of FIG. 19. Upon the release of the key 141 it returns to its rest position so as to cause the electromagnet 157 to become again energized by the switch 158 which closes automatically upon the return of the key 141 to its rest position. Of course, the return of the key 141 to its rest position causes the primary coil 149 to move upwardly away from the coil 150 so as to prevent cooperation between these coils, and in this way it is impossible for any vibrations to be electrically transmitted to the loud speaker. 9

Assuming now that the pedal 154 has been actuated, then the support member 151 is in its upper operating position, and at this time even if the key 141 returns to its rest position the secondary coil 150 remains within the primary coil 149, and the extension 155 of the support member 151 prevents the arm 156 from returning to the position thereof shown in FIG. 19, so that there will be no mechanical damping of the vibratile element, and the tone will be sustained. It istherefore apparent that the structure of FIG. 19 also is capable of behaving exactly like a conventional piano.

The embodiment of FIG. 20 is very similar to that of FIG. 19 and the same elements are indicated with the same reference characters. The structure is shown in FIG. 20 in the position which it takes when the key is in its operating position engaging the stop means 143. The only difference between the structure of FIG. 20 and that of FIG. 19 is that leads 159 connect the supersonic generator 148 to the coil 150, so that in this embodiment the coil 150 is the primary coil of the transformer, and the secondary coil is carried by the key, this secondary coil being the coil 149 with the electrical circuit of FIG. 20. In this embodiment the secondary coil is connected through leads 160 with the vibratile element in order to energize the latter. It is apparent that the embodiment of FIG. 20 will operate to produce the desired results also.

The embodiment of FIG. 21 also is very similar to that of FIGS. 19 and 20, and the same elements are indicated with the same reference characters. The parts are shown in FIG. 21 in the position they'take when the pedal is actuated with the key in its rest position. The structure of FIG. 21 differs from that of FIGS. 19 and 20 in that the vibratile element itself acts as a pick-up. The leads 162 connect the supersonic generator 148 to the coil 150 which is still the primary coil, as is the case with FIG. 20, but leads 165 connect the vibratile element directly with the detector and amplifier assembly, as shown in FIG. 21. The coil 145 is connected through the leads 164 with the secondary coil 149 of the embodiment of FIG. 21, so that the field of high-frequency is transmitted from the transformer to the coil 145 so that this coil 145 sets up the field in which the vibratile element vibrates, and this vibratile element picks-up its own vibrations and transmits them to the discriminator and amplifier assembly. It is apparent that the structure of FIG. 21 also will behave in the manner of a conventional piano.

In the embodiment of the invention which is illustrated in FIG. 22, the piano frame 171) carries a rod 172 which pivotally supports the key 171, and this key 171 carries the unit 173 which in this embodiment is the unit of the invention which is illustrated in FIGS. 1l-14. When the key 171 is actuated by the operator it moves into engagement with a stop means 184 in the form of an elongated rubber bar extending along the entire length of the piano so as to cooperate with all of the keys thereof, and in this way inertia forces are induced in the vibratile element 173a of the unit 173 to set this vibratile element into vibratory motion. With the embodiment of FIG. 22 the key 171 carries a condenser plate 174, and the vibratile element itself forms the other plate of the condenser, so that the vibratile element and the plate 174 cooperate as a variable condenser. The plate 174 and the vibratile element are connected electrically with a coil 175 carried by the key 171, and this coil 175 forms the secondary coil of a transformer which includes a primary coil 176 carried by a support member 177 which includes a downwardly extending pin 178 of non-circular cross section extending through an opening in the frame 170 which is of mating cross section, so that the support member 177 can only move vertically and cannot turn. A pedal 179 cooperates with the pin 178 so that when the pedal 179 is actuated the support member 177 will be raised. Located in the path of upward movement of the support member 177 is a switch 180 which is opened by upward movement of the support member 177 as is apparent from FIG. 22. This switch 180 is located in an electrical circuit which is connected with a pair of elongated conductors carried by the piano frame and cooperating with the contacts of the coil of the mechanical damping means of the unit 173, as is apparent from FIG. 22.

A high frequency oscillator 181 is connected to the line and is also connected electrically with the primary coil 176 of the transformer, and a discriminator and amplifier assembly 182 is also connected electrically with the oscillator and with the loud speaker 183.

With the construction of FIG. 22, when the key 171 is actuated by the operator, the secondary coil 175 will move downwardly around the primary coil 176, so that the high frequency field will be established at the condenser elements, and their oscillation will be transformed by the amplifier 182 and loud speaker 183 into a musical sound, the discriminator portion of the assembly 182 discriminating out or filtering out the super-sonic frequencies which are inaudible, so as to prevent any distortions in the audible frequencies. Of course, when the key 171 returns to its rest position in FIG. 22, the transformer coils no longer cooperate with each other so that in this way the electrical circuit is opened and it is impossible for any of the vibrations of the vibratile element to be electrically transmitted, and of course when the key 171 returns to its rest position the coil of the mechanical damping means 173b engages the electrically conductive elements 185 so that this coil becomes energized and the mechanical damping also takes place.

When the pedal 179 is actuated, the primary coil 176 is moved up into the secondary coil even if the key 171 is in its rest position, and furthermore the switch 180 is opened, so that the mechanical damping means cannot become energized, and in this way a tone may be sustained, so that the structure of FIG. 22 also is capable of very closely simulating the operation of a conventional piano.

In the embodiment of the invention which is illustrated in FIGS. 23-25, the piano frame carries a rod 191 on which the key 192 is pivotally supported, and this key 192 carries a unit 173 which is identical with the unit 173 of FIG. 22 and which is shown in detail in FIGS. 11-14. The key 192 additionally carries a condenser plate 194 which cooperates with the vibratile element of the unit 173 in the same way as the condenser plate 174 of the FIG. 22, and electrically conductive bars 185 are provided to cooperate with the contacts of the coil of the mechanical damping means of the unit 173.

In the embodiment of FIGS. 23-25, a second condenser plate 195 is located at the same distance from the 15 vibratile element as the condenser plate 194 in the rest position of the parts shown in FIG. 24 and this condenser 'plate195 is identical with the condenser plate 194 and is itself supported by a springy arm 197 which is connected with the frame 190. An elongated rod 198 or the like is hooked onto the support 196 in the manner shown in FIGS. 23-25 and is connected with the pedal 199 so when the latter is actuated the rod 198 will be pulled downwardly.

Connected electrically with the high frequency oscillator, both before and after the same, as was the case with the embodiment of FIG. 22, is a discriminator and amplifier assembly 201 which is connected electrically with a loud speaker 202.

As was mentioned above, the parts are shown in the rest-position in FIG. 24. When the key is actuated the parts move to the position shown in FIG. 23, so that the key 192 comes into engagement with the stop means 193 in order to set the vibratile element into vibratory motion.

At this time the vibratile element cooperates with the condenser plate 194 to act as a variable condenser, and the supersonic frequencies are filtered out by the discrimi- 'nator and the sonic frequencies are converted into a musical sound at the loud speaker.

It will be noted that the frame 190 includes a projection 293 which cooperates with the upper conductor 185 to prevent the support 1% from moving upwardly beyond the position thereof shown in FIG. 24. Therefore, when the key is actuated, the support 1% cannot move upwardly and therefore, as is shown in FIG. 23, the vibratile element is located relatively distant from the condenser plate 195 and the circuit of the coil of themechanical damping means of the unit 173 is interrupted, so that the vibratile element is free to vibrate freely in order to produce the musical sound.

Upon return of the key from the operating position of FIG. 23 to the rest position'of FIG. 24, the condenser plate 195 will become located at the same distance from the vibratile elementas the condenser plate 194, and in 'this position of the parts the two condenser plates oppose each other so as to cancel out any signals which might be provided by vibration of the vibratile element, and in A this way electrical damping takes place with this embodiment.

Also, when the contacts of the coil of the mechanical damping means engage the conductors 185, the mechanical damping means is also actuated in order to mechanically damp thevibrations, and the electrical damping prevents the transmission of any hissing sounds, as was pointed out above.

When the pedal of the embodiment of FIGS. 23-25 is actuated, the parts take the position which is illustrated in FIG. 25. Thus, the support 196 is lowered against the 'force of the spring 197, and as a result the conductors 185 are moved away from the coil of the mechanical damping means, so that the mechanical damping can no longer take place. Also, the lower condenser plate 195 'is moved away from the vibratile element, so that there Thus, with this embodiment of the invention it is necessary to provide only a pair of arms 196 at the opposite ends of the piano, and a single elongated strip 195 can be supported at its opposite ends by these arms to cooperate with all of the keys, whilethe conductors 185 can also extend along the entire length of the piano and be supported at their ends by the arms 196 in order to cooperate with all of the coils of all of the units 173, so that when the entire piano structure is considered the embodiment of FIGS. 23-25is quite simple.

The units 260 and 201 are of a well known construction. The high frequency oscillator. 2% has its oscillator tank circuit connected with one lead to the condenser plates and with its other lead to the vibratile element.

I Also, although the unit 260 is called a high frequency oscillator, in the case of FIGS. 23-25 as well as in the case of 131 of FIG. 22, the oscillator can operate at radio frequencies as well as at frequencies higher'than radio frequencies. Y

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of pianos diifering from the types described above.

While the invention has been illustrated and described as embodied in electric pianos, it is not intended to'be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, theforegoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. For use in a musical instrument, in combination, a elongated tubular housing having a hollow interior portion; a string carried-by said housing and having a magnetic stretched portion located in said interior portion of said housing spaced from the walls thereof; and a screwmember threadedly carried by said housing and cooperating with said string for stretching said portion thereof to a predetermined degree, said screw member being also a magnet for magnetically influencing the stretched portion of said string.

2. In a musical instrument, in combination, a vibratile member adapted to be set into vibration for participating in the production of a musical sound; support means supporting said vibratile member for free vibratory motion along at least a portion of said vibratile member, said portion of said vibratile member when it is'unengaged by any other element assuming a predetermined position when said vibratile member is at rest; and'damping means cooperating with said vibratile member for damping the vibratory motion thereof without moving said portion of bratile member with equal and opposite forces for damping the vibrations of said vibratile member without plac ing said vibratile member in any position other than that which it would naturally assume when at rest and uninfiuenced by any other elements; and means cooperating with said damping members for movingthe same away from said vibratile member to free the same for vibratile motion and back into engagement with said vibratile member to damp the vibrations thereof.

4. In a musical instrument, in combination, a vibratile member having an elongated portion adapted to be.

set into vibratory motion to participate in the produc tion of musical sound; support means supporting said vibratile member for free vibratory motion at said portion thereof; a pair of damping members located subtile member having an elongated portion adapted to. be set into vibratory motion for participating in the pro duction of a musical sound; ,a pair of elongated springy arms respectively located at opposite sides of and ex-' tendingvsubstantially parallel to said vibratile member, said arms being substantially equidistant from said vibratile member and having free damping end portions respectively directed toward opposed faces of said portion of said vibratile member; the resiliency of said arms maintaining said free damping end portions thereof out of engagement with said vibratile member so that the latter is free to vibrate at said portion thereof; and magnetic means cooperating with said arms for moving said free damping end portions thereof with equal and opposite forces into engagement with said opposed faces o f'said vibratile member, respectively, to damp the vibration thereof without exerting any distorting forces on said vibratile member. t

6. In a musical instrument, in combination, an elongated vibratile member having an elongated portion adapted to be set into vibratory motion for participiating in the production of a musical sound; support means suporting said vibratile member for free vibratory motion at said portion thereof; a first pair of magnetic parallel strips located next to each other on one side of said vibratile member in spaced relation thereto and extending substantially parallel thereto, said first pair of strips including an inner strip and an outer strip with said inner strip located between said outer strip and said' vibratile member; a. second pair of elongated magnetic strips located next to each other on the opposite side of said vibratile member from said first pair of strips and being spaced from said vibratile member by substantially the same distance as said first pair of strips and also extending parallel thereto, said second pair of strips also including inner and outer strips with the inner strip located between said outer strip and said vibratile member, said support means cooperating with the outer strips of said first and second pair of strips for preventing movement of said outer strips away from said vibratile member; and magnetic ,meanscooperating with said first and second pair of strips for' inducing one polarity in said first pair of strips and an opposite polarity in said second pair of strips, whereby said first pai'r of strips will repel each other and said second pair of strips will repel each other to cause the inner strips to approach each other, and said inner strips approaching each other to an extent where they become attracted to each other due to their opposite polarity; and damping means co-t operating with said inner strips to move into engagement with saidvibratile member for damping the vibratory motion thereof when said inner strips are attracted toward each other. I

7. For use in a musical instrument, in combination, an elongated tubular housing; an elongated vibratile member having an elongated portion located in the interior of said housing spaced from the walls thereof and adapted to, be set into vibration for participating in the production of a musical sound; and magnetic damping means carried by said housing and having a portion locat'ed in the interior thereof for cooperating with said portion of said vibratile member for damping the vibration thereof.

8. In a musical instrument, in combination, an elongated tube; a vibratile member carried-by said tube and having an elongated portion located in' the interior of said tube spaced from-the walls thereof to be set into free vibratory motion for participating in the production of a musical sound; damping means located in said tube for cooperating with said portion of said vibratile morn-s ber for damping the vibratory motion thereof; and means located at the exterior of said tube and cooperating with;

said damping means for actuating the same.

9. A process for manufacturinga unit for use in a musical instrument, comprising the steps of fixing a string to one end of an elongated hollow tube; locating in said tube a plug for axial movement therein'and connectingthe string also to said plug; axially moving said plug and tube with respect to each other. until the string is tensioned to a predetermined degree; and then" fixing said plug to said tube to maintain said string stretched to said predetermined degree.

10. A process for manufacturing a unit for use in a musical instrument, comprising the steps of placing a plug in an elongated hollow tubular member for axial movement therein; connecting a string to said plug and to said tubular member so that said string will become stretched during axial movement of said-plug and tubu-v lar member one with respect to theother; locating between said plug and tubular member a damping means having a portion directedtowards part of the string bea tween said plug and tubular member for damping the string; axially moving'said plug and tubular member tubular member and string, so that said dampingmeans also forms part of said unit.

11. A unit for use in a musical instrument, comprising,

in combination, an elongated hollow tube of non-magnetic material having a closed end and an opposite open end; a plug located in said open end of said tube and closing said open end, said plug also being made of a non-mag netic material; a'string fixed to said'clos'ed end of said tube and said plug and stretched between said closed end of said tube andsaid plug, said string being adapted to vibrate to participate in the production of a musical sound; a pair of elongated strips of magnetic material respectively located at opposite sides of said string and extending sub-v stantially parallel thereto, said strips being fixed between said plug and tube and each strip being folded upon itself and having a pairof portionslocated next to each other, said strips being of a springy material and remaining by their own resiliency distant from said string next'to the 7 wall of said tube in the interior thereof, the portions of;

said strips which are nearest to said string having free ends adapted to move toward said string to damp the vibrations thereof, whereby when one polarity is'induced in one of said strips and an opposite polarity is induced in the other of said strips the portions of each strip will repel each other so that the strip portions nearest to said string will move toward each other and will then attract each other due to their opposite polarity so as to move with equal and opposte forces toward said string to damp the vibration thereof without stretching said string out of; the position which it naturally-takes due-to-thetension of the string between said closed end ofsaid tube and said 7 plugs.

12. For use in a musical instrument, in combination; an elongated vibratile member adapted to be set into 1i). netic material and respectively having free damping end portions movable toward and away from said vibratile member for engaging the latter to damp the vibratory motion'thereof; and magnetic means cooperating with said vibratile member and said springy members for inducing one polarity in said springy members and an opposite polarity in said vibratile member so that said springy members are attracted to said vibratile member at said free damping end portions of said springy members for engaging said vibratile member at opposed surfaces thereof with equal and opposite forces to damp the vibration of said vibratile member.

13. In a musical instrument, in combination, an outer magnetic substantially u-shaped strip having a pair of parallel legs and an intermediate portion between said legs at oneend of said legs, said legs having free ends distant from said intermediate portion; an inner magnetic strip of substantially U-shaped configuration located along and engaging said outer strip at said intermediate portion and legs thereof, said inner strip having free ends located next to the free ends of said outer strip and said inner strip' being made of a springy material so that said free ends of said inner strip are movable toward and away from each other; means cooperating with said outer strip for preventing said free ends thereof from moving away from each other; an electrically conductive coil surrounding the intermediate portions of said U-shaped strips for inducing at the freeend portions of said strips, when said coil is energized, a given polarity at the adjoining free end portions at one side of an axis extending between said legs-and an opposite polarity at the free end portions at the opposite side of said axis, so that the free end portions of said strips at each side of said axis will repel each other until the free end portions of said inner strip approach each other sufficiently to be attracted toward each other by their opposed polarity; an elongated vibratile member extending parallel to said axis; and damping means located on opposite sides of said vibratile member and operatively engaged by said free end portions of said inner strip to be moved thereby with equal and opposite forces into engagement with opposed parts of said vibratile member for engaging thelatt'er to damp vibrations I thereof when said coil is energized.

next to the free ends of said outer strip andssaid inner strip being made of a spring'y material so that said free 1 ends of said inner strip are movable toward and away from each other; means cooperating with said outer strip for preventing said free ends thereof from moving away' from each other; an electrically conductive coil surrounding the intermediate portions of said U-shaped strips for inducing at the free end portions of said strips,

when said coil is energized, a given polarity at the adjoining free end portions at one side ofan axis extending between said legs and an opposite, polarity at the free end portions at the opposite side of said axis, so that the free end portions of said strips ateach side of said axis will repel each other until the free endportions of said inner strip approach eachiother sufliciently to be attracted toward each other by their opposed polarity; an

elongated vibratile member. extending parallel to said axis, said free end portions of said inner strip each being provided with a pair of lateral flap portions and the lateral 'flap portions at each free end portion of said inner strip extending toward the lateral flap portions. at the other free end portion of said inner strip, so that said lateral'flap portions are located relatively near to each other when said free end portions of said inner strip attract each other; and damping means located on opposite sidesof said vibratile member and operatively engaged bysaid free end portions of said inner strip to be moved thereby withequal and opposite forces into engagement with opposed parts of said vibratile member for engaging the latter to damp vibrations thereof when said coil is enerlegs at one end of said legs, said legs having free ends distant from said intermediate portion; an inner magnetic strip of substantially U-shaped configuration located along and engaging said outer strip at said intermediate portion and legs thereof, said inner strip having free ends located next to the free ends of said outer strip and said inner strip being made of a springy material so that said free ends of said inner strip are movable toward and away from each other; means cooperating with said outer strip for preventing said free'ends thereof from moving away from each other; an electrically conductive coil surrounding the intermediate portions of said U-shaped strips for inducing at the free end portions of said strips, when said coil is energized, a given polarity at the adjoining free end portions at one side of an axis extending between said legs and an opposite polarity at the free end portions at the opposite side of said axis, so that the free end portions of said strips at each side ofsaid axis will repel each other untilthe free end portions of said inner strip approach each other sufiiciently to beattracted toward each other by their opposed polarity; an elongated vibratile member extending parallel to said axis, the legs of said inner strip being formed with cutouts so that said legs are easily bendable; and damping means located on opposite sides of said vibratile member and operatively engaged by said free end portions of said inner strip to be moved thereby with equal and opposite forces into engagement with opposed parts of said vibratile member for engaging the latter to clamp vibrations thereof when said coil is energized.

16. In a piano, in combination, a piano key turnable from a rest to an operating position; an elongated vibratile member carried by said key for turning movement therewith and adapted to have a portion thereof set into vibratory motion for participating electrically in the production of a musical sound; stop means located in the path of movement of said piano key for setting said por tion of said vibratile member into vibratory motion; a pick-up coil carried by said key adjacent said vibratile member for picking up the vibration thereof; a damping coil connected in electrical opposition with said pick-up coil and located at the same distance from said vibratile member as said pick-up coil when said key is in the region of said rest position thereof so that said coils oppose each other electrically for cancelling out the transmission of vibratory movement of said vibratile member when from a rest to an operating position; an elongated vibratile member carried by said key for turning movement therewith and adapted to have a portion thereof set into vibratory motion for participating electrically in the production of a musical sound; stop means located in the path of movement of said pianokey for setting said portion of said vibratile member into vibratory motion; a pick-up coil carried by said key adjacent said vibratile member forpicking up the vibration thereof; a damping coil connected in electrical opposition with said pick-up coil and located at the same distance from said vibratile member as said pick-up coil when said key is in the region of said rest position thereof so that said coils oppose each other electrically for cancelling out the transmission of vibratory movement of said vibratile memberwhen said key is in the region of its rest position; support means supporting'said damping coil for movement away 21 7 g from said vibratile member when said key is in said rest position thereof; electro-magnetic means cooperating with said support means for moving said damping coil away from said vibratile member when said electro-magnetic means is energized; and pedal-operated means cooperating with said electro-magnetic means for energizing the same, so that when the operator actuates said pedal-operated means the damping coil will be moved to a position Where it is incapable of opposing said pick-up coil and the sound produced by the vibratory motion of said portion of saidvibratile member will be sustained. I

- 18'. In a musical instrument, in combination, a pair. of parts cooperating electrically to participate in the production of a musical sound, said pair of parts being formed respectively by an elongated vibratile member having a portion adapted to be setinto vibratory motion and a pick-up coil located adjacent said portion of said vibratile member; means cooperating electricallywith one of said parts for generating at said one part a field having a super-sonic frequency; and means cooperating with the other said parts for amplifying signals produced by the vibrations of said portion of said vibratile member and for filtering out the super-sonic inaudible frequencies.

19. In a piano, in combination, a piano key movable from a rest position to an operating position and back to said rest position; an elongated vibratile member carried by said key for movement therewith and supported on said key for free vibratory movement at a portion of said vibratile member; means cooperating electrically with said vibratile member for generating at said vibratile member a field having a super-sonic frequency; a pick-up. coil carried by said key for movement therewith and located adjacent said vibratile member for picking up the'vibrations thereof; a second, damping coil located adjacent said vibratile member at the same distance therefrom as said pick-up coil when said key is in said rest position thereof for cancelling out vibrations of said vibratile member when said key is in the'rest position thereof, said damping coil being connected in electrical opposition with said pick-up coil; support means support ing said damping coil for movement away from said vibratile member when said key is in said rest position thereof; pedal means capable of being actuated by the operator and cooperating with said support means for moving said damping coilaway from said vibratile member; electrical means cooperating with said coils for amplifying the signals received thereby and for filtering out super-sonic frequencies; magnetic damping means cooperating with'said vibratile member for mechanically damping, the vibrations thereof; a stationary electro-magnet cooperating with said magnetic damping means for actuating the same to mechanically damp said vibratile member when said key is in said rest position thereof; and switch means located in the circuit of said electro-magnetic means and operatively connected with said support means for automatically opening the latter circuit when said pedal means is actuated to move said damping coil away from said vibratile member when said key is in said rest position thereof, so that said vibratile member will not be mechanically damped when said pedal is actuated. I

20. In a piano, in combination, a pairof parts'which cooperates electrically to participate in the production of a musical sound, said parts respectively being an elongated vibratile member and a pick-up coil; key means cooperating with said vibratile member for setting the same into vibratory motion when said key means is actuated by the operator; a pair of transformer coils one of which is carried by said key means for movement therewith and the other of which becomes located within said one coil when said key means is actuated, one of said coils being a primary coil and the other of said coils being a secondary coil; means cooperating with said primary coil for energizing the same at a super-sonic frequency;

means connecting said secondary coil electrically with one of said parts for inducing at the latter a field of said super-sonic frequency when said key means is actuated; and means cooperating with the other of said parts for amplifying signals picked up by said other part and for filtering out the super-sonic frequencies, said transformer coilsvbeing axially displaced from each other and out of overlapping relation with respect to each other when said key means is in its rest position to prevent the transmission of signals which would transform vibrations of said vibratile member into a musical sound, so that said transformer coils also cooperate to prevent the operation when said key means is in said rest position thereof.

21. In a piano, in combination, a pair of parts which cooperates electrically to participate in the production of a musical sound, said parts respectively being an elongated vibratile member and a pick-up coil; key means cooperating With said vibratile member forsetting the same into vibratory motion when said key means is actuated by the operator; a pair of transformer coils one of which is carried by said key means for movement therewith and the other of which becomes located within said one coil when said key means is actuated, one of said coils .being a primary coil and the other of said coils being a secondary coil; means cooperating with said .primary coil for energizing the same at a super-sonic frequency; means connecting said secondary coil electrically with one of said parts for inducing at the latter a field of said super-sonic frequency when said key means is actuated; means cooperating with the other of said parts for amplifying signals picked up by said other part and for filtering out the super-sonic frequencies, said transformer coils being axially displaced from each other and out of overlapping relation with respect to each other when said key means is in its rest position to prevent the transmission of signals which would transform vibrations of said vibratile member into a musical sound, so that said transformer coils also cooperate to prevent the operation when said key means is in said rest position thereof; and pedaloperated means cooperating with the transformer coil which is not carried by said key means for moving the latter coil into the transformer coil which is carried by said key means when said key means is in said rest position thereof for sustaining a tone produced by vibratory motion of said vibratile member.

22. In a piano, in combination, a key pivotally supported for turning movement from a rest to an operating position and having a forward portion which moves downwardly during movement of said key from said rest to said operating position thereof; avprimary transformer coil carried by said forward portion of said key for movement therewith; means cooperating with said coil for energizing the latter at a super-sonic frequency; a support member mounted for vertical movement; a secondary coil carried by said support member substantially coaxially with said-primary coil beneath the latter when said key is in said rest position thereof, said primary coil moving to a position surrounding and overlapping said secondary coil When said key is moved from said rest to said operating position; stop means located in the path of movement of said key during movement of the latter from said rest to said operating position for stopping the movement of said key; a vibratile element carried by said stop means to be set into vibratory motion by inertia when said stop means is engaged by "said key; means connecting said vibratile elementelectrically with said secondary coil to charge said vibratile element with said super-sonic frequency; mechanical clamping means responsive to electromagnetic forces and cooperating with said vibratile element for mechanically damping the vibratory movement thereof; an electro-magnet cooperating with said mechanical damping means for actuating the same to damp said vibratile element when said key is in said rest position thereof; motion transmitting means cooperating with said key and with said electro-magnetic means formoving the latter away from said mechanical damping means to deactivate said mechanical damping means when said key is moved from said rest to said operating position; a pick-up coil carried by said stop means adjacent to said vibratile element for picking up the vibrations thereof; electrical means cooperating with said pick-up coil for amplifying the signals received by said pick-up coil from said vibratile element and for filtering out the super-sonic frequencies; and pedal operated means cooperating with said'support member for raising'the same when said pedal operated means is actuated by the operator, so that upon operation of said pedal operated means said secondary coil moves into said primary coil even when said key is in saidrest position thereof, said support member also moving said'electro-magnetic means away from said mechanicoil of a transformer carried by said forward portion of said key for'movement therewith; a support member a mounted for vertical movement; a primary transformer coil carried by said support member substantially coaXially with said secoondary coil and located beneath the latter when said key is in said rest position thereof, said secondarycoil moving downwardly to a position surrounding and overlapping said primary coil when said key is moved to said operating position thereof. means coopcrating with said'primary coil for generating at the latter a field having a super-sonic frequency; stop means cooperating with said key for stopping the movement thereof when said key is in said operating position; an'elonga-ted vibratile element carried by said stop means to be set into vibratory motion by inertia upon engagement bysaid stop means with said key when the latter is moved to said operating position; means connecting said secondary coil with said vibratile element for'inducing in the latter a field of said super-sonic frequency; a pick-up'coil carried by said stop means adjacent to said vibratile. element for picking up the signals produced by the vibratory motion of said vibratile element; means cooperating with said pick-up coil for amplifying the audible vibrations and for filtering out the inaudible super-sonic vibrations; mechanical damping means cooperating with said vibratile element for damping the vibration thereof, said mechanical damping means being responsive to electro-magnetic forces; electro-rnagnetic means cooperating with said damping means, for actuating the same to mechanically damp the vibratory motion of said vibratile element; mo-

tion transmitting means operatively connected with said key and with said e'lectro-magnetic means moving the; I same away from said mechanical damping means to, prevent the later from damping said vibratile element when said key is moved from said rest to said operating position, said motion transmitting means being located in the 1 path of movement of said support member during upported for turning movement from a rest to an operating position, said key having a forward portion which moves 7 downwardly during movement of said key from said rest to said operating position thereof; a secondary transformercoil carried by said forward portion of said key for downward movement therewith; a support, member guided for vertical movement; a primary transformer coil carried by said support member substantially coaxially 1 With said secondary coil at a position located beneath the latter when said key isin said rest position thereof; means cooperating with said primary coil for generating at the latter a field having a super-sonic frequency; stop means located in the path of movement of said key to be en gaged and suddenly moved by the latter when said key is moved to said operating position thereof; an elongated vibratile element carried by said stop means to be set into vibratory motion by inertia upon engagement of said stop means with said key when the latter is moved to said operating position; a pick-up coilcarried by-said stop means for picking up the vibrations'of said vibratile element;,means connecting said secondary "transformer coil electrically with'said pick-up coilfor inducingthe latter a field of said super-sonicfrequency,"so, that said. field is influenced by the vibrations of said vibratile ele-'- ment; means cooperating with said vibratile elementfor amplifying the signals produced by vibration thereof and for filtering out super-sonic frequencies, so that only audible frequencies are amplified; mechanical damping means cooperating with said vibratile element for mechanically damping the vibration thereof; electromagnetic means cooperating with said mechanical damping means for actuating the latter to dampthe vibrations of said vibratile element; motion transmitting means cooperating with said key and with said electro-magnetic means for moving the same away from said mechanical damping means so that the latter does not damp the vibrations of said vibratile element when said key is moved from said rest to said operatingv position thereof; and pedal operated means cooperating with said support member for raising the latter when said pedaloperated means is actuated by'the operator, to move said primary coil into said secondary coil even when said key is at a rest position thereof, said'support member when it is raised also cooperating with said electro-ma gnetic means for mov-i ing the same away from said mechanical damping means, so that upon actuation of said pedal operated means a tone produced by vibration of said vibratile element will be sustained.

25. In a piano, in combination, a key turnably sup ported for turning movement between a rest and anop crating position; stop means cooperating with said key to be engaged by the latter when said key is moved to said operating position; an elongated vibratile element carried by 'said key to be set into vibratory motion by inertia upon engagement between sai dkep and stop means; a condenser plate carried by said key adjacent said vibratile element to cooperate with the latter as a vari 26. In a piano, in combination, a key turnably sup ported for turning movement between a rest and an operating position; stop means cooperating with said key .to be engaged by the latter when said key is moved to said operating position; an elongated vibratile element carried by said key to be set into vibratory motion'by inertia upon engagement between said key and stop means; a condenser plate carried by said key adjacent said vibratile element to cooperate with the latter as a variable condenser during the vibration of said vibratile element; and an electrical circuit cooperating with said vibratile element and said condenser plate, said circuit including a high frequency oscillator cooperating with said plate and. I

Claims

1. FOR USE IN A MUSICAL INSTRUMENT, IN COMBINATION, AN ELONGATED TUBULAR HOUSING HAVING A HOLLOW INTERIOR PORTION; A STRING CARRIED BY SAID HOUSING AND HAVING A MAGNETIC STRETCHED PORTION LOCATED IN SAID INTERIOR PORTION OF SAID HOUSING SPACED FROM THE WALLS THEREOF; AND A SCREW MEMBER THREADEDLY CARRIED BY SAID HOUSING AND COOPERAT-