Marmon Company

Hammond Incorporated

Other

Ray B Schrecongost

Brian M Bagus

Edward J Perutis

A luggage cart adapted to remain attached to the luggage during stowage includes a wheeled support structure and a pair of bracket members set apart by the length of a piece of luggage. The bracket members are conformed to the shape of the cross-sectional contour of the rim of the piece of luggage to be transported and are clamped in position between two halves of the luggage to connect the luggage to the cart.

Luggage cart

A divider keyer circuit arrangement for a synthesis organ utilizing four integrated circuit chips to generate the notes for a 61 key manual with 9 harmonic drawbacks or tabs. On-chip cross wiring and the use of clock lines for synchronization pulses and other design techniques enable the use of four identical integrated circuit chips in standard 40 pin packages to be used to generate the full complement of notes for a 61 note keyboard.

Divider keyer circuit for synthesis organ

A DC offset correction circuit for use in an electronic organ for eliminating audible noise or thump produced by an instantaneous DC level shift in the standard organ keyer circuit at both key depression and release. A standard keyer circuit is responsive to the depression of a key on the manual by the organist and provides a square or stairstep waveform output at a frequency representative of the note key depressed. Each keyer output waveform includes a positive or negative polarity instantaneous DC level shift at both key depression and release which when coupled through a capacitive output circuit, such as a filter, provides an undesirable audible thump. The DC offset correction circuit comprises a monitoring circuit which is responsive to both key depression and release and a detector circuit responsive to the monitoring circuit to provide a DC level signal output of opposite polarity to the instantaneous DC level shift in the keyer circuit. The correction circuit further comprises a resistive combining circuit which receives the output signals from all the keyer circuits and the output signals from the monitoring circuit to provide a corrected output signal waveform without an instantaneous DC level shift. Standard organ output circuits receive the corrected output signal and provide corresponding audio output without the undesirable audible thump.

DC offset correction circuit for an electronic musical instrument

A touch responsive unit for a keyboard electronic musical instrument. A high frequency signal source is connected to one plate of a normally open circuited variable capacitor. The other plate of the variable capacitor being mechanically connected to a force transferring mechanism and electrically connected to a circuit means for generating a control voltage envelope. The depressive force applied to the key through the transfer mechanism causes the capacitor plates to overlap. The degree of area overlap is proportional to the depressive force and determines the capacitance value. As the plate area overlap increases, the capacitance value increases and the peak amplitude of the high frequency source passed by the capacitor increases. The control voltage envelope of the circuit means is applied to a standard keyer circuit to amplitude modulate a tone signal source corresponding to the selected key. The slope or decay rate of the control voltage envelope is regulated by the circuit means.

Touch responsive keying unit for electronic musical instruments

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.

Modulated keyer supply sampling circuit

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.

Electronic musical instrument keyboard

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.

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Park Ridge, IL, United States of America

Ray B Schrecongost