US2761344A - Combined musical instrument - Google Patents

Description

vSe t. 4, 1956 J. A. KQEHL 2,761,344

COMBINED MUSICAL INSTRUMENT Filed April 15, 1953 5 Sheets-Sheet 1 Sept. 4, 1956 J. A. KOEHL 2,761,344

COMBINED MUSICAL INSTRUMENT Filed April 15, 1955 5 Sheets-Sheet 2 Ell Sept. 4, 1956 J. A. KOEHL COMBINED MUSICAL INSTRUMENT 5 Sheets-Sheet 3 Filed April 15, 1953 SepI. 4, 1956 J. A. KOEHL COMBINED MUSICAL INSTRUMENT 5 Sheets-Sheet 4 Filed April 15, 1953 Sept. 4, 1956 Filed April 15, 1953 J. A. KOEH 5 Sheets-Sheet 5 UPPER KEYBOflRdWF/ZHES LOWER lrs )EOHRDJWITGHES -J '?7 I A/ OUHLITV l P awn [Ty CONTROL corvrnoz.

F J, IIMPLIFIER ZZ'ZZ Z E E1 [3 g L TONE Gf/VffiflTOfifi /I v z? Paw/u CLRVIER V United States Patent COMBINED MUSICAL IN STRUlVIENT James A. Koehl, Evanston, 11]., assignor to Central Commercial Industries, Inc., Cook County, 111., a corporation of Illinois Application April 15, 1953, Serial No. 348,915

3 Claims. (Cl. 84171) This invention relates to musical instruments and more particularly to an instrument for the playing of both percussive and sustained tones and whereby either of these types of tones can be produced separately or together for versatile musical eifects.

An essential object of the invention is the provision of an organization of elements providing a composite instrument in which use is made of a piano having a conventional action operated from the instruments keyboard for the playing of piano music in the customary manner and means including a removable section of the case of the piano for supporting a keyboard in playing relation to the keyboard of the piano so that and by coaction of both keyboards with an electrical tone generating and translating system the combined or composite instrument can be played in a manner typical of a dual manual type, reed or electric organ.

A further object of the invention is the provision of a combined piano and electric organ in which an extra keyboard is embodied in the case of the piano to provide a dual keyboard in playing relation to the keyboard of the piano without necessitating any change in the elevation of the latter from the floor.

A still further object of the invention is the provision of an organization of elements including a removable section of the case of a piano, which section supports a keyboard and a system of tone controls, in a manner enabling said section and all of its supported elements to be readily applied to and removed from the case of the piano as a unitary structure and whereby both of the aforementioned keyboards will be related to each ,other for playing thereof the same as is customary with a conventional two-manual organ.

Another object is the provision of means for use with a piano for the production of electrically generated sustained tones of any selected timbre and whereby the key ing switches employed in the organization are separable from a tone signal transmitting mechanism in a manner enabling convenient removal of said detachable section of the case and subsequent connection of the keying switches in said network when reattaching said section to the case.

A still further object is the provision of a dual set of electric keying switches which are formed, constructed and adapted for convenient installation in the case of a piano and so that accessibility is had thereto for the purpose of adjustment, cleaning and repair of the switches.

Another object of the invention is the provision of a unique combination of elements, which, when installed in a piano will give to the instrument a pleasing effect and function in the system in a manner making for ease and convenience in playing.

Other objects and advantages of the invention will be pointed to in the following description and disclosed in the accompanying drawings, in which:

Figure 1 is a perspective view of the combined instrument;

Figure 2 is a vertical transverse section through a por- Patented Sept. 4, 1956 'tion of the instrument taken in the boards;

Figure 3 is a perspective view of the front section of the case of the piano with its supported keyboards and quality control;

Figure 4 is a detailed section in plan view showing the manner of maintaining a fixed relation of the keyboard to the conventional keyboard of a piano;

Figure 5 is a sectional detail perspective view of one of the key assemblies;

Figure 6 is a schematic view of an electrical network show-ing the invention connected therein;

Figure 7 is a view similar to Figure 2 showing a slight- 1y modified form of the invention; and

Figure 8 is a schematic view of the two keyboards to make clear the relationship to each other of the white and black keys of like note letter and pitch.

At Figure 1 is shown the complete instrument and in Figure 2 of the accompanying drawings are upper and lower keyboards to be described hereinafter in detail. Underneath all keys of the upper keyboard and underneath at least certain keys of the lower keyboard are similar electric switches 20, such that the individual switches are selectively actuable according as pressure is plane of both key- 1 applied to and removed from said keys.

At Figure 6 is a schematic illustration of an electrical network including a system of electrical tone generators A, a pedal clavier B, an audio amplifier C having a loudspeaker D in its output circuit, a volume control device E, quality controls F and G, a set of electric switches H for the upper keyboard and a similar set of electric switches I for the conventional keyboard of the piano.

From the generators A are cables I and K detachably coup-led at J and K to the switches of the respective sets of switches H and I. Each of these cables will consist of as many leads as there are switches in any set of said switches. Generators A will comprise a number of individual audio frequency generating devices suflicient to supply all switches of a keyboard with signal voltages in the pitch relation to notes associated with the keys thereof.

At L and M are cables connecting the switches of the respective sets of switches to the respective quality controls F and G, the cable M including a separable coupling N for disconnecting said cable from quality control F. From the quality controls P and G are output conductors O and P connected :to the input circuit of amplifier C by separable couplings Q and R.

'The pedal clavier B connects to the amplifier C via lead S and to the generators A via lead T.

It is intended that output tone signals from said generators A shall be available as desired when playing one or both keyboards of the herein disclosed instrument. It sufficies to say that signal voltage will be transmitted to a respective quality control F or G and then to amplifier C for activation of loudspeaker D. The purpose of couplings K, J, N, Q, and R is to enable disconnecting the switches H and the quality of controls F and G from other parts of the electrical network, as parts of a removable section of a piano as will be more fully pointed to in the following description.

At Figure l the case U of the piano U has upper and lower keyboards disposed in superposed parallel relation to each other, the upper keyboard carried by a removable front section W of said case.

The approximate dimensional size of the case U is as follows:

Elevation of .the lower surface of the bed plank V above the floor, 24"; Elevation of the upper surfaces of the white keys of the upper keyboard above the playing surfaces of the white keys of the lower keyboard, 2 /2;

Length of the elfective playing surfaces of the white keys of the upper keyboard 5 /2, the same as the effective playing surfaces of the white keys of the piano keyboard;

Distance from front of back check of action to the inner face of the vertical portion W of the removable front section W of case, between one and two inches.

The action and other instrumentalities of the piano may be of any well-known construction. When the front section of the case is removed, free access is had to the tuning pins of the piano.

In carrying the invention into practice, use is made of any well-known tone signal generators such as those shown in the Larsen Patent No. 2,403,090. The invention is primarily designed, adapted and intended for use in a system in which the tone signal generators are mounted on the inner face of the kneeboard Z of the piano, upon which the loudspeaker is also mounted so as to project sound in a forward direction. Such an arrangement is disclosed in the Patent No. 2,649,007 to Walter J. Anderson. The main feature, however, is the embodiment in a piano of a second keyboard above the conventional keyboard, the latter and the former having respective key switch assemblies associated therewith for the transmission of signal voltages to an electroacoustical translating system when playing said keyboards.

Figure 1 of the accompanying drawings discloses the general features of the invention and embodiment thereof in the case of a piano whose bed plank and keyboard are at the accepted or customary elevations abov the floor. At Figure 2 the bed plank V of the case of the piano is provided at its front end with the customary key slip 10. The conventional keys 11 of the keyboard of the piano are carried by a mounting 12 which includes a fulcrum or balance rail 13 for the keys and front guide pins 14. The keys 11 extend under a removable stop strip 15 and their upward pivotal movement is stopped and cushioned by felt 16 on the lower surface of the strip. At the back of the strip is a longitudinal shell 17 positioned at an elevation to dispose a key mounting 18 in a position to support the playing-keys 19 of the upper manual 20 at an elevation to bring the keyboard of the piano and said keyboard 20 within the span of the hand. In practice, the vertical distance separating the back ends of the effective playing surfaces of the white keys of the piano keyboard and the front ends of the effective playing surfaces of the white keys of the keyboard 20 is about 2 /2". The keys 19 of the keyboard 20 project underneath the felt faced lower edge of the vertical portion W of the section W of the case of the piano. Said vertical portion W is secured to a horizontal section 21 which, with the longitudinal strip 22 provides a music rest and from the back edge of the horizontal portion 21 is an upwardly and rearwardly flared portion 23. The flared section 23 of the removable section W of the case of the piano extends to the top of the case as shown at Figure 1. It is also co-extensive with the effective length of the piano inside the ends of the case. The mounting 18 is provided with devices 24 and 24' which coact with devices 25' and 26' on the white and black keys of keyboard 20 to limit upward pivotal motion of said keys. The back edge of said mounting has detachably secured thereto a longitudinal strip 25 having a longitudinal row of equi-distantly related flat leaf springs 26, the upper ends of which are secured at 27 to the respective keys so that the springs function to resiliently support the keys, and hinge-like enable the keys to be depressed when playing pressure is applied thereto.

The keyboard support 18 has a length substantially coextensive with that of the removable front section W of the case of the piano as clearly shown at Figure 3. At the respective ends of the keyboard 20 are stop controls 31 and 32, each provided with a number of pivoted switch controlling tablets 33. Laterally of these controls are wood blocks 34 which are in stepped relation to the cheeks 35 at the respective ends of the keyboard of the piano.

The controls 31 and 32 may be hollow box-like structures of plastic or any other suitable well-known material. At the respective ends of the flared portion 23 of the removable section W of the case U are strips of wood 35 and at the base of the section are angle brackets 35' which extend under and are secured to the bottom surface of the keyboard support 18. To these brackets and also secured to the inner face of the vertical portion of the section W are depending supporting legs 36, preferably of metal, eaoh provided at its lower end with a horizontal flat foot 37 the under surface of which is preferably felted as at 38.

The construction disclosed in Figures 2 and 3 is such that the section W of the case of the piano may be removed by pulling same upward when the cover of the piano is opened. The legs 36 are narrow and such that their foot portions 37 rest upon the upper surface of the bed plank V just outside the extreme end keys of the keyboard of the piano. When the section W is thus disposed the upper edge of the flared portion 23 comes immediately in line with the under surface of the cover of the piano. The end strips 35 extend into the case immediately adjacent to the inner faces of the ends thereof and forwardly of the plate of the piano as shown at Figure 4. Wedges 39 are then inserted between the front of the plate and said strips 35 so as to force the forward edge of the keyboard support 18 against the stop 17. This provides a rugged construction that prevents any of the parts of the device from rattling when the piano is played.

The quality controls 31 and 32 may comprise any well-known system of Wave filters and coacting electric switches, the latter actuable by said tablets 33. The system disclosed in said Larsen patent is satisfactory for the general purpose of the invention but shall not be construed as limiting the invention to use of such device.

Upon referring to Figures 2 and 5 of the drawings, it is noted that underneath the respective keyboards are sets of electric switches 20' such that for each separable key there is an electric switch actuable thereby to closecircuited conditioning when the key is depressed and to a circuit breaking condition when the key is at the uppermost limit of its pivotal motion. I have previously pointed to the method of connecting the separate sets of switches in an electrical tone generating and translating network and it need only be mentioned that the switches are such that they can be easily mounted under the respective keyboards for coaction with the keys thereof.

Should it be desired to remove the front section W of the case of the piano, it is only necessary to disconnect the key switch assembly of keyboard 20 from the network as provided for by means of the couplings N, K, Q and R and then remove the wedges 39 and lift the front section from the case.

All circuit connections to the quality controls may be made from in back of the removable section W of the case when the cover of th case is opened. When strip 25 with its springs 26 is removed the keys 19 may be lifted from the mounting 18, thus to expose the switch assembly underneath the keys.

In the form of the invention shown at Figure 7 a horizontal key mounting 40 is carried by the vertical portion 41 of the removable section W of the case of the piano, the arrangement being the same as described in the aforementioned first embodiment of the invention. The forward portion of said mounting rests upon a stop strip 42 which limits the upward movement of the keys 43 of the keyboard of the piano, and said strip may be detachably attached to the case of the piano in any well-known manner. The support 40 is provided with a key slip 44 having a stop flange 45 which coacts with a lug 46 on the bottom side of each key of a keyboard 47. Guide pins 48 project upwardly from the support 40 and are coactive with the keys of said keyboard to guide them in their movement. The keys in this embodiment of my invention are of shorter length than the keys in the first referred to embodiment and as illustrated they are organ-type keys in which the front ends of the white keys project into the vertical plane of the keyboard of the piano. The overhang is about 1 /2" of the total length of the white keys of the piano keyboard and the distance between the upper playing surfaces of the keys of this keyboard and the upper surfaces of the white keys of the piano keyboard is about 2 /2 measured from a line close to the back ends of the effective playing surfaces of the white keys of said piano keyboard. Attached to the back edge of the support 40 is a strip 50 having a longitudinal row of equi-distantly spaced-apart fiat leaf springs 51, the upper ends of which are secured at 52 to the back ends of the keys. Each key is also provided with a switch actuator 53 which extends upwardly and is so related to switch contactor 54 that when a key is depressed the actuator will move the contactor 54 into circuit making connection with switch contactor 55. Contactor 54 is adapted to be connected to a source of signal voltage and contactor 55 may be connected to a signal output bus-bar, not shown. As first above stated, the keys in this type of keyboard are shorter than the keys of the conventional piano keyboard but by projecting the back ends of the keys a slight distance through the vertical portion 41 of the removable section W of the case, and mounting same, as shown, the effective playing surfaces of the white keys may be about 4".

Also in the embodiment shown at Figure 7, I preferably mount under each of the keys, a block of very yieldable sponge or foam rubber 55'. For each of these blocks is a vertically adjustable presser 56 having a screw 57 which is exposed from the underside of the mounting 40 so that the upper end of the screw will move pressing element 58 against the underside of a respective block 55, thereby displacing the rubber sufficiently to control the amount of pressure applied to a key to depress same. It is understood that the back ends of the keys pass through a longitudinal slot 59 in the vertical portion 41 of the removable section W of the case, and, as shown, the upper wall of this slot is faced with felt 59'. As in the first embodiment of my invention, this modified form may be applied to the case of the piano and removed therefrom with the keyboard as a unitary structure.

It is understood that the upper keyboard of the invention will generally consist of about 60 keys and that they will be aligned with keys of like note letter and pitch of the piano keyboard. It is also understood that the tone generators will consist of a number of individual generators, generally not less than sixty and that they will produce output tone signals for a scale tuned in equal temperament. Each individual generator may concurrently serve both keyboards of the instrument and also the keys of the pedal clavier, the latter connected in the circuit as set forth in the description of Figure 6 of the accompanying drawings.

The switches underneath the playing-keys 11 of the keyboard of the piano and switches 20' underneath the keys of keyboard 20 consist of similar assemblies of switches, the switches for the keys of said keyboard 20 being contained in the space between the underside of the keys and the upper surface of the mounting 18. The switches 20 for the keys of the piano keyboard are similarly supported by the aforementioned mounting 12, all as shown at Figure 2.

While any well known type of electric switch may be combined with said keyboards, I have shown a switch which is satisfactory for the purpose of my invention. Each separate assembly of switches will consist of a flat longitudinal strip 643 of hard insulating material provided with a bus-bar 61 with which the resilient longitudinally spaced apart contactors 61a are engageable when their associated playing-keys are depressed. These contactors extend underneath a strip of hard insulating material 62 secured at 63 to strip 60 and having terminals 64 exposed, as shown, from one edge of said strip 60 for attachment thereto of a tone signal conducting lead 65. Attached to said strip 62 are resilient actuators 66, such that there is one such actuator for each of the contactors 61a. Each actuator has an upwardly curved portion 67 hearing with only light pressure against the underside of a respective playing-key, and, as shown, said portion 67 has a free end 63 which is spaced apart from the free end 69 of coacting contactor 61a when the key is at the uppermost limit of its pivotal motion and is adapted to engage said contactor and advance same into circuit completing engagement with said bus-bar 61 when the key is depressed. The lead wires 65 of these contactors are formed into cables such as those schematically shown at K and I at Figure 6. Thus, it can be assumed that leads L and M at Figure 6 are bus-bars for conducting tone signal voltages to the respective quality controls P and G.

The tone generators A, amplifier C and loudspeaker D are preferably but not necessarily mounted inside the case U and upon the kneeboard Z. I prefer this arrangement in that all parts of the invention are self-contained in a common case, thus to provide a two-manual electric organ combined with a conventional vertical piano, all within a space no larger than that required to accommedate a vertical piano of average size, and whereby the instrument can be readily moved from place to place with ease and convenience.

In each of the herein disclosed embodiments of my invention, use is made of a conventional piano to provide a combined instrument characterized by an upper short keyboard mounted on a detachable section of the case of the piano and the customary keyboard of the piano, such that when said detachable section is applied to the case, both keyboards will be in stepped relation to each other. It follows that if the upper keyboard has, say, 60 playingkeys, a like number of playing-keys of an 88 note piano keyboard constitutes therewith a system of keys enabling the instrument to be played in a manner typical of a twomanual organ. I accordingly stress the unique and novel arrangement of the herein disclosed parts.

At Figure 8 of the drawings there is schematically shown a piano keyboard having 88 notes and a short keyboard having 60 playing-keys, the latter providing a tonal range of five octaves. The figure illustrates clearly that the bottom key of the short key bearing the note letter (C: 65.41 C. P. S.) is in line with key O of the same vibration frequency of the piano keyboard. Similarly, the last key in the upper register of the short keyboard, namely B=l975.53 C. P. S. is aligned with key B of the same tone frequency.

What I claim as my invention is:

1. A musical instrument comprising a case having therein tuned vibratile elements for producing audible sounds in the pitch relation to the vibration frequencies of notes of the chromatic scale; a keyboard extending forwardly from the case; an action actuable by the keys of said keyboard and coactive with said vibratile elements for placing same in audible vibration; said case having a substantially vertically disposed front member provided with a forwardly extending keyboard mounting having thereon a keyboard, the dimensional size and the shape of said member being such that when the member is applied to the case the second named keyboard is disposed above and in stepped relation to the first named keyboard; means rigidly securing said member to and for enabling removal thereof from the case; generators respectively producing output tone signals in the aforementioned pitch relation; sets of electric switches for and actuable by the playing-keys of the respective keyboards; an electroacoustical translating system; and an electrical network in which the switches of said sets of switches, the said generators and the translating system are connected for activation of said system according as one or both of said keyboards are played, the set of electric switches common to the second named keyboard being separable from said network enabling removal as desired of the aforementioned member from the case together with the second named keyboard and the set of switches common thereto as a unitary structure.

2. An organization of elements adapted for use in combination with a vertical piano of the class embodying a case having a bed plank, a keyboard mounted on said bed plank, a hammer action actuable from said keyboard, and tuned strings coactive with said action and adapted to be selectively vibrated to produce audible percussive sounds when playing said keyboard; said mechanism comprising a member adapted to be removably fitted to said case between the top thereof and said keyboard and serving when removed to expose the interior of the case above said keyboard and when applied to the case to close the front thereof above said keyboard; a keyboard carried by said member and disposed in stepped playing relation to the keyboard of the piano; and means for producing sustained organ-like tones when playing one or both of said keyboards, said means comprising a system of tone generators respectively producing waveforms of audio signals at the tone frequencies of notes of the scale associated with different keys of said keyboards, means for translating said signals into audible sounds, sets of electric switches coactive with the keys of the respective keyboards and said sustained tone-producing means for rendering said generators effective for activation of the translating means, one of said sets of switches being supported by said removable member and having separable connection with said sustained tone-producing means enabling removal of the second named keyboard from and application of same to the case as a unitary part of said member.

3. An organization according to claim 1 wherein the removable member is provided with legs freely resting on said bed plank and wherein means coactive with the case and said member are provided for securing the member against vibration.

References Cited in the file of this patent UNITED STATES PATENTS 64,371 Rox Apr. 30, 1867 308,415 Kuster NOV. 25, 1884 1,092,291 Robinson Apr. 7, 1914 1,169,654 Knabe Ian. 25, 1916 1,196,401 Severy et a1 Aug. 29, 1916 1,561,100 Mills Nov. 10, 1925 1,622,364 Barbieri Mar. 29, 1927 1,623,211 Starkie Apr. 5, 1927 2,250,065 Koehl July 22, 1941 2,471,534 Muth et al. May 31, 1949 2,555,040 Jordan May 29, 1951 FOREIGN PATENTS 17,128 Great Britain of 1914

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