Abstract: In a chopper keyer electronic organ system, a sampling network samples the drawbar inputs to the chopper keyers in order to provide a separate channel of percussion. The drawbar lines for one or more of the footages are sampled and the sample signal is amplified and shaped to provide touch envelope percussion in addition to the sounding of the chopper keyer outputs. Alternatively, the chopper keyer outputs may be disabled and separate voicing such as for piano, harpsichord or steady tones provided via the drawbar sampling circuitry.

Abstract: In a keyboard electronic musical instrument such as an electronic organ, an electro-mechanical memory device for holding in the down or actuated position one or more simultaneously depressed accompaniment chord and bass playing keys after the finger pressure from the instrument player is removed. The signal representing the note or chord associated with the depressed key or keys is sustained as long as the keys remain latched down. A plurality of keys of the lower or accompaniment manual are adapted to be retained in the depressed position and operate as part of the electro-mechanical memory device. When a key or group of keys are latched down, the depression by the instrument player of another key releases the previously retained keys but the newly depressed key is latched down. The electro-mechanical memory also operates in conjunction with the touch mode of the automatic rhythm unit to provide a rhythm signal when the accompaniment keys are retained in the depressed position.

Abstract: A machine to insert and stake rivets in a flexible sheet is disclosed. The machine includes a riveting punch and an associated anvil and, in cooperation therewith a clamping device having parts which float relative to the riveting punch and the anvil so that during insertion and staking of the rivet, the sheet, and more particularly the opening in the sheet for receiving the rivet can be adequately supported at a variety of distances relative to the midpoint between the riveting punch and anvil. The clamping device includes a frame carried by the punch and a sleeve carried by the anvil which cooperate to clamp the flexible sheet; and the frame and sleeve are resiliently associated with the punch and the anvil such that portions of the riveting motion of the press will cause clamping prior to riveting.

Abstract: The present invention is directed to a digital touch responsive tempo generating device for use in an electronic musical instrument, preferably an electronic organ. The instrument player selects a desired tempo to control a standard rhythm unit or other circuit either before or during playing by repetitively actuating a touch plate at a rate corresponding to the desired tempo. A digital value related to the time interval between predetermined repetitive touches by the instrument player is stored in a digital circuit having a memory under control of a clock circuit. A tempo generator circuit coupled to the digital circuit produces tempo output pulses spaced apart as a function of the time interval between the repetitive touches.

Abstract: A musical instrument keyboard consisting of a spring metal plate stamped into the shape of a comb with the back of the comb clamped in position and the teeth thereof mounting the keys, characterized by low cost, and including provision for comparable pressure of operation as between the long lever (white) keys and the short lever (black) keys, and requiring no soft side guides or the hardware to mount them.

Abstract: A voltage controlled filter with a plurality of cascaded phase shift circuit stages in a negative feedback path of an amplifier. Each phase shift circuit stage is a RC phase shift network which includes a series capacitor and a field effect transistor (FET) with its source-drain circuit connected as a shunt to ground. The magnitude of the effective source-drain resistance of the FET in each stage is controlled by a DC control voltage which is applied in common to the gate of each FET.

Abstract: A monophonic electronic music synthesizer in which keying signals are collected on common note busses and common octave busses. Tone signals from a top octave tone generator are gated by separate note gates controlled by keying signals on common note busses to select the note tone signal regardless of octave. A chain of frequency dividers fed by the note tone signal produce octavely related tone signals which are gated by separate octave gates controlled by keying signals on common octave busses. A preferred embodiment especially useful in an integrated organ-synthesizer system employs a low octave lockout circuit to select an active highest octave of actuated keyswitches and a preference gating arrangement for tone signals to produce high note select gating of monophonic tone signals. A D.C. keyed volts per octave circuit is also disclosed.

Abstract: A one key chording system for an electronic keyboard instrument of the type in which a single contact keyboard for DC keying of tone signals is employed. A primary keying signal from the single contact keyboard operates one of a plurality of chord gates to produce a chord keying signal which is translated by one of a set of chord logic units into secondary keying signals. The primary and secondary keying signals operate keyers for tone signals corresponding to a musical chord. An inhibit circuit prevents chord gates from responding to secondary keying signals. A mode control circuit switches the single key chording system off to return the instrument to normal operation with multiple key chording.

Abstract: Delayed vibrato and burble circuit in which a single gate between a free running modulating signal oscillator and a master voltage controlled oscillator selectively controls both functions in response to control signals from a keyboard which are processed by parallel time constant circuits.

Abstract: A plural mode envelope generator in which a basic time constant circuit is coupled by selector switches to a plurality of envelope generating means which function under the control of one or both of a keydown detector and a legato pulse generator. Fast attack-short substain and slow attack-long sustain envelope circuits involve standard techniques. A dual mode percussion circuit provides post key release sustain in one mode when the keydown detector is decoupled from the circuit and post key release tone snubbing when the keydown detector is coupled to the circuit. A sostenuto circuit with flip-flop latch includes a reset gate to hold the flip-flop in reset until sostenuto keying is desired whereupon a unidirectional circuit couples the initial keydown signal to the latch to place the flip-flop in a set state but prevents the disappearance of that signal from resetting the latch.

Abstract: An automatic rhythm programmer for an electrical musical instrument which provides electrical pulses for actuating musical voice generators according to predetermined rhythmic patterns, having provision for introducing any one of several predetermined variations into any basic rhythmic pattern and for automatically changing from one variation to another at a preselected rate. The programmer comprises a master oscillator, a first counter and an electronic commutator which periodically pulse in sequence a series of address lines in an integrated circuit read-only memory, which also contains a separate series of tracks for each basic rhythmic pattern, each track being in circuit with certain of the address lines and energized at predetermined times therefrom, each track also being connected to certain of the voice generators and operable to provide actuating pulses thereto.