GB2278483A - A-Piano - Google Patents

Abstract

An "A-piano" comprises an electronic 16 key per octave keyboard 20 with a compass of seven octaves mounted on an adjustable height stand and may have 16 foot-pedals. The keyboard comprises 8 white and 8 black keys per octave each "A" key being identified by a black line and the extra white note being called "H". The extra black keys am called E#, B# and H#. The H# keys being identified by a white line. The size of the keys is such that the octave remains an average span. The keyboard is electronically connected by cable to two electronically driven hammer-banks 19 which are mounted on a 2.5 metre square diagonally strung metal frame 22 with a diaphragmatic soundboard 18 affixed thereto. The first octave (bass) is single string, and two, three and four strings may be used for tenor, treble and top treble octave respectively. The frame is diagonally reinforced by metal ribbing. The strings are tuned to the harmonic series and the sustaining pedal, sostenuto pedal, and soft pedals are operated by organ-type stops mounted on the keyboard console. <IMAGE>

Description

A-PIANO This invention relates to a sixteen keynote piano type keyboard. The keyboard is connected to a harmonically tuned soundboard by a cable.

As the soundboard is tuned to the key of A, the invention is called the A-piano in order to distinguish it from other keyboard instruments.

The conventional piano, which has basically remained unchanged in design for over 150 years, has seven white keys and five black keys, making a total of twelve keys per octave tuned to the equal temperament system. The only keynotes which are harmonic are the octaves. The standard grand piano has 88 keys spanning seven and one third octaves. The sound is activated by any key moving a felt hammer at speed and striking the string(s), a mechanism described as the pianoforte action. The strings are fixed to a substantial cast iron frame which is able to withstand the great tension of the tuned strings. A soundboard is also fixed to the frame and the keyboard is situate at one end at right angles to the strings.

The grand piano action is able to be removed from the carcase by sliding out. The instrument is enclosed in a highly finished wooden enclosure and is too well known to require any further description.

The equal temperament system was first calculated by Scheibler in 1834 to four decimal places and is a geometrical system. It is not uncommon for performers and sometimes the string section in orchestras to finish a performance out of tune with the piano.

The main reason for the invention is that it follows on from a discovery. The present 12 note equal temperament system was found to be incompatible with harmonics. Note being synonymous with key. Ebenezer Prout in his second edition on Harmony - Its Theory and Practice - printed 100 years ago stated that he had abandoned the Harmonic series as set out by him in his first edition. A piano tuner has to flatten the "fifths" and sharpen the "thirds", otherwise the piano is not in tune. It should be noted that musicians define an "octave" as seven white notes and include the next above as the "eighth" to make up the "octave". A musician's decimal system would have nine divisions between units and not ten.

The discovery is based on the binary system of harmonic intervals commencing at 2 which is the base of the series 2,4,8,16,32..., and is a geometric or logarithmic progression to base 2.

It follows that any binary system of musical intervals or notes should follow the above binary progression and have a 2 note keyboard, or a 4, 8, 16, etc., note keyboard but never a 12 note keyboard. A glance at a standard piano keyboard indicates that there are two black notes missing as there are seven white notes but only five black notes. Adding El and BI to the five black notes gives the sum of seven black notes and seven white notes of a fourteen note scale yet unknown.

Adding two extra notes, one black, the other white and calling them H and HI respectively, completes a binary harmonic scale of 16 notes. This forms the base of the discovery.

It also follows that the present design is deficient in that the piano keyboard has only 12 notes to an octave and is tuned to an incompatible geometric frequency.

The so-called "Grand" piano has the soundboard horizontal and depends on the raised lid to reflect the sound out towards the audience. Performers using an upright piano in public usually remove the front covers in order to increase the intensity of the sound. The utter impracticability of positioning a grand piano on its side requires the keyboard action to be positioned similar to an upright piano.

Accordingly the whole system now universally spread all over the globe requires a totally new approach having regard to modern engineering and electronics.

It is not suggested that an electronic piano be the solution as to date no international pianist has ever played a recital on an electronic piano.

The wire strung piano soundboard produces a timbre and quality of sound that even the best electronic device is not able to replicate.

According to the present invention the design consists of a piano type keyboard of eight white keys and eight black keys to an octave. The keyboard spans seven octaves making a total of one hundred and twelve keys.

Each key is tuned to the harmonic series of intervals which is an arithmetical series. As there is one extra white key to the octave, each white note is slightly reduced in width - about 0.25 cm - to accommodate the average span of the hand. In order that the performer can recognize octaves, each (a) key has a black stripe delineated on its white surface. The extra key called h has a white stripe on the black sharp key.

The keyboard is mounted on a suitable stand and has three pedals; one called the "soft" pedal, the other called the "sustaining" pedal, while the third is the "sostenuto" pedal similar to concert grand pianos.

Although the A-piano keyboard appears similar to a mechanical piano keyboard, the A-piano is an electronic keyboard using basic electronics and is connected by a cable using the standard ASCII American Standard Code for Information Exchange to the soundboard.

The soundboard consists of a square metal frame approximately 2.5 metres square on which the wire strings are in tension between pins. The base of the pins are in contact with the wooden diaphragmatic soundboard. The strings are mounted diagonally with the longest or base string stretched across the centre of the soundboard.

The soundboard is mounted vertically on a suitable stand with the metal frame and hammer-batteries facing the listener.

The 56 white or natural note key strings are strung diagonally between pins along the horizontal side of the frame to pins along the vertical side of the frame. The tension of the string is adjusted by means of a high tensile UNF bolt with lock-nut adjustable by means of a double spanner similar to a tappet spanner.

The 56 black or sharp key strings are fixed along the vertical side of the soundboard. Near the pins at the top of the soundboard is mounted a battery of 56 felt piano hammers. Using basic electronic circuits, when an electric impulse is received via the cable from the keyboard, the piano hammer, which is locked at rest under tension of a strong spring, is released. The impetus of the spring induces linear motion to the hammer which strikes the string(s) and at the same time, the felt damper is released from the string. As soon as the hammer has contacted the string, the electric circuit induces a relay solenoid to return the hammer to its original position. A similar battery of hammers is mounted at right angles to its twin which actuates the sharp strings along the vertical side of the sound board.

The diaphragmatic soundboard is tapered from the centre diagonal to each apex in order to give more timbre to the instrument.

For a concert performance, the pianist can position the keyboard at what he/she considers the best position and position the soundboard elsewhere as both are connected by a cable. For an orchestral performance, the soundboard can be placed behind the players and the soloist at the keyboard at whatever place desired by the conductor. The keyboard can be extended to have sixteen bass pedals similar to an organ.

The A-piano can be extended to the Fifth harmonic series of two keyboards with two soundboards, the second soundboard also having 112 strings, giving 32 keys to an octave, each key alternating between the two soundboards, the two keyboards covering the seven octaves. Trasuntino's celebrated arcicembalo now in the Civic Museo of Bologna has 32 keys per octave.

For the perfectionist, the A-piano can be extended to the Sixth harmonic series of four keyboards and four soundboards making a 64 key octave.

Each key having a frequency difference close to Scheibler' 1834 tonometer of 4 Hz per interval.

Finally, the Seventh harmonic series requires eight keyboards and eight soundboards for a 128 key octave giving a glissando effect as the performer moves up and down the scale.

A specified embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 outlines the standard piano format together with the key signature as set out in manuscript.

Figure 2 illustrates the A-piano keyboard together with the key signature as outlined in manuscript form.

Figure 3 shown in plan, the metal frame strung diagonally.

Figure 4 illustrates the keyboard battery of 56 felt hammers (Only one shown).

Figure 5 illustrates the schematic of the hammer thrust mechanism.

Figure 6 is a flow chart from the keyboard to the soundboard.

Referring to the drawing the standard A-piano comprises of a 16 key to an octave keyboard 13 as shown in Figure 2. The full keyboard (not shown) is of seven octaves making a total of 112 black and white keys.

Each key is tuned to the Fourth harmonic series of intervals. As there is one extra white or natural key to an octave, each white key is reduced from the standard width by approximately 0.25 cm in order to accommodate the average span per octave. The extra white or natural key is called h. The three other extra keys are sharps; viz bi, el, and hi which are inserted between the natural notes b and c, e and f, and h and a. Although there are 16 keynotes to an octave, eight are natural notes, and eight are sharp notes or keys, contrasting to 12 keynotes in the equal temperament series of five black notes or sharps and seven white or natural notes. The key signature 14 and manuscript 15 are also shown in Figure 2.

In order that the performer can recognize octaves, each A key has a black stripe 16 delineated on its white surface.

The extra key called h has a white stripe 17 across the black hi key.

The standard keyboard is mounted on a suitable stand (not shown) which has a variable height control to suit the performer. The keyboard is fitted with three pedals (not shown); one is the sustaining pedal which when activated, sends an electronic signal to the harmonically tuned soundboard 18 so that the felt dampers are lifted off the strings. The second pedal or "soft" pedal, when activated by the performer, sends an electronic signal to the hammer battery 19 which is positioned by servo-motors at a distance from the strings. If the performer induces a "full" soft pedal, the servo-motors move the hammer bed almost to the strings so that when a note is activated, the force of the hammer-throw is minimal and a "soft" note is sounded.Conversely, if the soft pedal is not activated and the performer gives a sharp thrust to the key, the full distance of the hammer-throw activated by a strong spring gives the loudest possible note. The speed of the descending key also activates the distance the hammer bed is from the keyboard.

The third pedal is called the "sostenuto" pedal and when activated keeps the felt damper away from the string for such period as the performer required, the note produced sounding until it dies away. The principle was perfected by Steinway in 1874.

In the deluxe model (not shown), the A-piano keyboard is fitted with 16 foot-pedals, similar to an organ, which active the notes of the lower octave. The soft pedal, the sustaining pedal, and the sostenuto pedal are activated by organ type stops on the keyboard console.

Any standard piano can be modified by tuning the keyboard to the harmonic series although this is unsatisfactory. An octave of 16 notes would span from A to cf.

By removing the keyboard and adapting it to a 16 key octave and retaining the strung frame tuned to the harmonic series would increase the octave span by one note. A pianist would call this span a "ninth." An 88 note piano of seven and one third octaves in the equal temperament system would be reduced to five and one half octaves.

Although the A-piano keyboard appears similar to a mechanical piano keyboard, the A-piano is an electronic keyboard 20 using basic electronics and is connected by a cable to the hammer battery 19 using the standard ASCII American Standard Code for Information Exchange as shown in Figure 6.

The soundboard 18 consists of a square metal frame 22 approximately 2.5 metres square on which the wire strings are in tension between pins 23. The base of the pins called sounders 24 are in contact with the wooden diaphragmatic soundboard 18. The strings 27 are mounted diagonally with the longest or bass string stretched across the centre of the soundboard. The bass string is called the generator A which has a frequency of 110 Hz. Concert pitch is a' at 440 Hz and a, the octave in between has a frequency of 220 Hz.

Although the keyboard goes to three octaves below A, the distance between the centre diagonal pins is equal to the wavelength of A, which is 3.09091 metres. The product of the frequency 110 Hz and above wavelength is approximately 340 metres per second which is the velocity v of the transmission of sound at 15 degrees Celsius.

The soundboard 18 is mounted vertically on a suitable stand with the metal frame 22 and hammer-batteries 19 facing the listener.

The 56 white or natural note key strings are strung diagonally between pins along the horizontal side of the frame to pins along the vertical side of the frame. The tension of the string is adjusted by means of a high tensile UNF bolt with lock-nut adjustable by means of a double spanner similar to a tappet spanner (not shown).The 56 black or sharp key strings are fixed along the vertical side of the soundboard. Near the pins at the top of the soundboard is mounted a battery of 56 felt piano hammers. Using basic electronic circuits, when an electric impulse is received via the cable from the keyboard, the piano hammer 25, which is locked at rest under tension of a strong spring, is released. The impetus of the spring induces linear motion to the hammer which strikes the string(s) and at the same time, the felt damper is released from the string.As soon as the hammer has contacted the string, the electric circuit induces a relay solenoid 26 to return the hammer to its original position.

A similar battery of hammers is mounted at right angles to its twin which actuates the sharp strings along the vertical side of the sound board. The diaphragmatic soundboard is tapered from the centre diagonal to each apex in order to give more timbre to the instrument.

The keyboard can be extended to have sixteen bass pedals similar to an organ. The A-piano can be extended to the Fifth harmonic series of two keyboards with two soundboards, the second soundboard also having 112 strings, giving 32 keys to an octave, each key alternating between the two soundboards, the two keyboards covering the seven octaves. For the perfectionist, the A-piano can be extended to the Sixth harmonic series of four keyboards and four soundboards making a 64 key octave. Each key having a frequency difference close to Scheibler' 1834 tonometer of 4 Hz per interval. Finally, the Seventh harmonic series requires eight keyboards and eight soundboards for a 128 key octave giving a glissando effect as the performer moves up and down the scale.

Claims (8)

1 A-piano comprising an electronic 16 key per octave keyboard with a compass of seven octaves mounted on an adjustable height stand with 16 footpedals. The keyboard is electronically connected by cable to two electronically driven hammer-banks which are mounted on a 2.5 metre square diagonally strung metal frame with a diaphragmatic soundboard affixed thereto. The first octave (bass) is single string, double strings for the tenor, three strings for the treble and four strings for the top treble octave. As the frame is required to support a stress of some 18 tons or 16,400 kg it is diagonally reinforced by metal ribbing. The strings are tuned to the harmonic series and the sustaining pedal, sostenuto pedal, and soft pedals are operated by organ-type stops mounted on the keyboard console.

2 A-piano with 16 keynotes per octave keyboard can be adapted to any standard piano simply by retuning the stings to the harmonic series and noting each key accordingly.

3 A-piano with a 16 keynote per octave keyboard can be adapted to any standard piano by removing the original keyboard, retuning the strings to the harmonic series and replacing the keyboard with a modified 16 note keyboard reducing the compass of a 88 note piano to 5.5 octaves.

4 A-piano as claimed in Claim 1 wherein the 16 foot-pedals are replaced with three conventional pedals; a sustaining pedal, sostenuto pedal, and the soft pedal.

5 A-piano as claimed in Claim 1 extended to the Fifth harmonic series of two keyboards and two soundboards, the second soundboard also having 112 note strings making 32 keynotes to an octave, each keynote alternating between the two soundboards.

6 A-piano as claimed in Claim 1 extended to the Sixth harmonic series of four keyboards and four soundboard making 64 keynotes to an octave, each keynote alternating between the four soundboards.

7 A-piano as claimed in Claim 1 extended to the Seventh harmonic series of eight keyboards and eight soundboards making 128 keynotes to an octave, each keynote alternating between the eight soundboards.

8 A-piano substantially as described herein with reference to Figures 1-6 of the accompanying drawing.