Abstract: A piano keyboard apparatus has an action assembly that includes a four bar linkage having four pivotably connected bars including a whippen pivotably connected to a repetition lever. An articulated jack has a lower link pivotably connected to an upper link and the lower link is pivotably connected to the whippen.

Abstract: A combination acoustic mode and electronic mode grand piano is provided including a hammer shank stop rail that intercepts the hammer shank when operating in its electronic mode, so that the hammer cannot complete its normal travel to strike its corresponding string(s) when its key is actuated. The positioning of the hammer shank stop rail is actuated by a user-operated control that, when placed into the "acoustic" mode, raises the hammer shank stop rail to a non-engaged position that does not interfere with the normal movements of the hammer shank. When in the "electronic" mode, the control lowers the hammer shank stop rail into an engaged position where it intercepts the hammer shanks of the piano, thereby preventing each hammer head from striking its respective string(s).

Abstract: An electronic keyboard key apparatus includes a longitudinally extending key pivotally mounted on a supporting base and a simulated hammer assembly including a simulated hammer mounted on a hammer shank that is independently pivotally mounted with respect to the key on the base. A jack means is mounted on the key for striking and pivoting the hammer assembly when the key is struck and a preferably flexible bridle for controlling the hammer assembly connects the hammer assembly to the key. A spring is connected between a back end of the key and the base for quickly returning the key to its at rest position. The bridle may be a flexible strap. The simulated hammer may be a metallic cylinder disposed about a first distal end of the hammer shank. A butt is attached to a second distal end of the shank and the butt has a butt end that is bifurcated to form two hinge lugs that are hinged to a single hinge lug of a lug mount fixedly connected to the base.

Abstract: A combination acoustic mode and electronic mode grand piano is provided including a hammer shank stop rail that intercepts the hammer shank when operating in its electronic mode, so that the hammer cannot complete its normal travel to strike its corresponding string(s) when its key is actuated. The positioning of the hammer shank stop rail is actuated by a user-operated control that, when placed into the "acoustic" mode, raises the hammer shank stop rail to a non-engaged position that does not interfere with the normal movements of the hammer shank. When in the "electronic" mode, the control lowers the hammer shank stop rail into an engaged position where it intercepts the hammer shanks of the piano, thereby preventing each hammer head from striking its respective string(s).

Abstract: An electronic keyboard musical instrument is provided having optical emitters and detectors both positioned beneath each of the instrument's keys, whereby optical energy is emitted upon the bottom reflective surface of the key and the reflected light is detected. The distance between the optoelectronic sensor and the bottom of the key is detected by the light detector which produces an analog output signal and, by measuring the time between a first and second threshold crossing, the key's velocity can be determined. The two thresholds are preferably chosen to measure a rising voltage as the key is depressed, and the threshold values are preferably chosen at 50% of key travel and 75% of key travel. By use of these thresholds, a relatively clean and useful waveform is available at both threshold crossings, particularly since the mechanical movement of the key has nearly reached its terminal velocity.

Abstract: An improved combination acoustic-mode and electronic-mode piano is provided which includes a hammer shank stop rail that intercepts the hammer shank, when in the electronic mode, so that the hammer cannot complete its normal travel and cannot strike its corresponding string(s) when its piano key is actuated. The hammer shank stop rail is actuated by an intermediate crank that, in turn, is actuated by a pedal dowel attached to one of the pedals of the piano. When operated in the acoustic mode, the stop rail occupies a position that will not interfere with the hammer shank's movements, and when in the electronic mode, the stop rail intercepts the hammer shank so that its associated hammer will not be able to travel all the way into contact with their associated string. A second embodiment operates the stop rail by use of a cable and cam mechanism. A third embodiment uses a hand-actuator to operate the stop rail via a dowel and intermediate crank.

Abstract: An electronic digital timing control apparatus for controlling different durations for two sequential events in alternation, especially in environmental systems. The timing control apparatus is programmable and contains a single oscillator and a binary counter which counts a predetermined fixed number of output cycles from the oscillator. At one end of the first count, tuning components for the oscillator are switched in order to change the oscillator frequency and thereby the duration for the next count for the next corresponding event.

Abstract: An augmented bass hammer striking distance is provided in both upright and grand pianos. At least those strings in the bass section having an optimum striking distance (d) to speaking length (L) ratio (d/L) of a value greater than 1/7 have their hammers located at a striking distance (d) along their lengths as determined by their optimum d/L value. The hammers of all of the bass section strings can be so located. Alternatively, the hammers of those bass section strings having an optimum value of d/L of 1/7 or less can be conventionally located at the same striking distance (d) determined from a preselected d/L value falling within the range of 1/7 to 1/9, or can be incrementally varied. When the lowest few strings of the bass section appear to have subjectively less apparent fullness of tone, the striking distance of the lowest few strings can be shortened string-by-string toward the low end of the bass section by amounts which will modify their subjective d/L - dependent pitch in 100-cent increments.

Abstract: A microprocessor-based processing system for monitoring the tempo rate and rhythm in an electronic musical instrument having an automatic rhythm accompaniment unit. In a first mode of operation, the monitor displays the tempo of the rhythm accompaniment unit in numeric characters representing the number of beats per minute. In a second mode of operation, the monitor displays a numerical 1 representing the down beat in a first display device, a numerical 2 representing the second beat in adjoining display device, and successively incremented numerical integers associated with successive beats in successive numerical display devices until all numerical integers associated with beats have been displayed, thereby producing a timing display having a motion effect for synchronizing the music being played with the rhythm accompaniment tempo.

Abstract: A small mass having a weight within the range of from about 50 grams to about 200 grams is utilized in an upright or grand piano to minimize or eliminate a difference in tonal amplitude and/or decay rate between at least two notes produced by playing at least two adjacent piano keys. The difference in tonal amplitude and/or decay rate may occur in a small group or region of notes produced by adjacent keys, or at those notes of adjacent keys located at certain natural scale "breaks". The mass is affixed to that soundboard bridge on which the note demonstrating the greatest amplitude and/or decay rate terminates vibrationally and is located adjacent the at least one string of that note.

Abstract: The present invention is an electronic piano that includes various "easy play" features that enable a person with little musical training to play the piano producing music similar to that of a skilled musician. The "easy play" feature automatically creates musical and rhythmic piano accompaniment patterns in response to playing either one key (One Finger Chord mode) or a chord (Funchords mode) with the left hand. The player plays the melody of the desired tune with the right hand. Instead of having to move the fingers of the left hand to play complex piano accompaniment patterns, as with a conventional piano, the player only needs to play a note or chord, and move the finger or fingers of the left hand to a different playing key or keys to change chords and patterns. In the standard piano mode, this instrument resembles an acoustic piano in function. The invention also includes a set of pushbutton switches which control the "easy play" features of the instrument.

Abstract: In an electronic musical instrument, an apparatus and method are described for automatically generating arpeggios from selected chords while requiring only a minimum amount of performance sophistication and dexterity. In the preferred embodiment, a plurality of voice priority switches are included, each of which corresponds to a voice-related rhythmic pattern or an arpeggio variation of tones played. The desired variation of the voice-related rhythmic pattern of tones is implemented as selected notes are played. The played notes and corresponding notes in higher octaves are stored in a random access memory and subsequently accessed by a microprocessor which searches up or down in frequency to find the available notes in the random access memory. Subsequently, the microprocessor converts chosen notes to audible tones.

Abstract: A tone generator system for an electronic organ, which incorporates N programmable generators (where N is less than 12, and typically 7) which forms a system having the ability to sound notes of N different nomenclature tones at one time. A microprocessor controls the assignment of particular notes to each of the programmable generators, in accordance with the played keys of the keyboard(s) (and the tab switches, in the event that a partial footage is selected). Each of the programmable generators is connected to a chain of dividers and gates which are also under the control of the microprocessor. The information ascertained by the microprocessor from the keyboard(s) (and the tab switches) is used to control the selection of gates which control the passage of tone signals from appropriate dividers in the chains of dividers to an audio output system. More than one note of a particular nomenclature can be simultaneouly gated from the divider chain of a particular programmable generator.

Abstract: The present invention provides a system for communicating data among microprocessors which are utilized to control an electronic musical instrument. A master microprocessor transmits a synchronizing signal comprising two, spaced pulses to the other microprocessors causing the other microprocessors to interrupt their operations and become synchronized with the synchronizing signal. Thereafter, according to a prearranged sequence, one microprocessor commences transmitting data while simultaneously the other microprocessors commence inputting data.

Abstract: A two-phase, period-proportional voltage-controlled oscillator circuit is provided for clocking an analog delay line which can be used, for example, in an electronic musical instrument. The voltage-controlled oscillator circuit provides two clock output signals of opposite phase and having a period directly proportional to the control voltage, i.e., the frequency of the two clock signals is inversely proportional to the control voltage. Since the delay provided by the analog delay line is directly proportional to the period of the clock signals, the delay is directly proportional to the control voltage thereby eliminating a source of distortion in a delay modulation system.

Abstract: The present invention relates to a process and apparatus for use in musical instruments. In particular, the invention is useful for identifying a chord played on a keyboard of a musical instrument, such as the accompaniment manual of an electronic organ, and for identifying the root and the type of chord being played. Pursuant to the invention, a microprocessor used in conjunction with the instrument selectively causes the associated circuitry of the pedal and/or accompaniment keyboard of the musical instrument to play automatically in an appropriate octave either the identified root or a sequence of notes which is compatible with the identified root and chord. A pedal override feature is also provided which overrides the chord identification invention when the musician plays one or more pedal notes.

Abstract: A multiple octave generator system for providing tones in an electronic organ permits the production of both ensemble and celeste effects by providing the appropriate amounts of detuning among cascaded ranks of divide-by-two locked octave type tone generators. The generator system programs from the ranks adjacent octaves of generator into groups having slightly overall stretched tuning which, when combined with an unstretched rank, closely resemble pipe organ celeste tuning. This permits the celeste beat rate of the lower octaves to be increased to a more desirable rate without causing the beat rate of the upper octaves to become too fast.

Abstract: A parallel motion linkage is taught for the sliding keyboard cover of a piano to assure that the sliding keyboard cover, when shifted between its open (key exposing) position and its closed (key covering) position will remain perpendicular to the direction of its motion and will not skew or jam between the sides of the piano case. The structure comprises a pair of bell cranks rotatively mounted to the underside of the sliding keyboard cover near the ends thereof. The bell cranks each have a first short arm, which arms are joined together by a tie rod pivotally connected thereto. The bell cranks each have a long arm to which one end of a connecting rod is pivotally mounted. The free end of each connecting rod is detachably and adjustably affixed to a bracket mounted on its respective side of the piano case.