Abstract: An improved wheelchair which can pass through a narrow aisle, for example in an airplane. The wheelchair has an axle with a pair of main wheels, removably mounted to the wheelchair frame so as to be removable without lifting the frame, as well as auxiliary wheels narrow enough to pass through such an aisle. The main wheels are sufficiently spaced for stable travelling.

Abstract: In an electronic musical instrument of a digital processing type, an operation of a key causes the generation of a digital value corresponding to the operated key and a tone having a frequency determined by that digital value is produced. The instrument comprises a key assigner which assigns the operated keys from among a large number of keys to a small number of channels, which small number is a number of maximum available tones to be produced simultaneously. The instrument further comprises a modifying value generator for generating modifying values for the respective channels, the value being a first value upon key operation and subsequently varying to a second value to provide an attack pitch fluctuation effect. The key assigner and the modifying value generator are of a time division multiplexing type with the channels being defined by the corresponding time slots.

Abstract: A cover member for a safety air-cushion device is made up of a bag-shaped outer laminate of high density polyurethane foam, and a bag-shaped inner laminate of low density polyurethane foam which is integral with the outer laminate, the inner laminate being made by pouring the fluidized foamable material into a mold after solidification of the other fluidized foamable material having been poured into the mold for the formation of the outer laminate.

Abstract: In an electronic musical instrument of a numerical value processing type, an operation of a key causes the generation of a numerical value corresponding to the operated key and a tone having a frequency determined by the numerical value is produced. A vibrato effect is obtained by periodic modification of the value. The instrument comprises a circuit which generates a periodic signal having a portion in which the amplitude of the periodic signal increases at a predetermined rate, and a succeeding portion having a constant amplitude, and a circuit for varying the rate. The rate varying circuit sets the rate to be either a low rate that can be discriminated by human ears or a high rate that can not be discriminated by human ears.

Abstract: In an electronic musical instrument comprising a keyboard including a plurality of keys, a frequency information memory device for storing frequency informations corresponding to respective keys, a plurality of musical tone forming means including a waveshape memory device for forming musical tones in response to the output of the frequency information memory device, and a shift circuit interposed between the frequency information memory device and the musical tone forming means for effecting a footage change of an octave unit, there is provided a preset circuit for applying a plurality of preset footage signals to the shift circuit and for applying another preset signals which are necessary to form musical tones to the musical tone forming means.

Abstract: An envelope generator for use in an electronic instrument generates an envelope waveshape control voltage having separate attack, first decay and second decay sections. The control voltage representing each waveshape section is derived from a separate voltage divider network. The divider networks are connected in series, with separate voltages supplied to the ends and junctions thereof. These supplied voltages correspond to the initial, attack, sustain and final voltage levels of the generated control voltage. The output nodes of the separate divider networks are accessed at different clock rates.A scanning circuit sequentially enables consecutive pairs of gates associated with each divided voltage output node. These gates alternately are connected to separate first and second output lines which provide divided voltages from adjacent gate pairs to opposite ends of an interpolation circuit. This circuit interpolates the provided voltages to derive the envelope waveshape control voltage.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth key code in a digital representation. This key code is used for reading out frequency information from a frequency information memory. The frequency information is accumulated to make an address signal for reading out the waveform memory.When a key is depressed, a counter starts counting and opens a gate for a predetermined period of time. The gate passes a code representative of an interval of a grace note with respect to the note of the depressed key (i.e. principal note) to an addition and subtraction circuit for addition or subtraction between the key code and the code representative of the interval for the grace note. Accordingly, the key code is modified and the desired grace tone is produced.

Abstract: An electronic musical instrument capable of producing an attack repeat effect. The attack repeat effect is a musical effect produced by repeated occurrences of attack and decay during a single continued sounding of a musical tone, giving to an audience an impression as if the tone started and stopped repeatedly. According to the invention, a complete envelope shape starting by an attack portion and ending by a decay portion is stored in a memory. When a key on the keyboard is depressed, the stored envelope shape is read from the memory and, upon completion of reading of one cycle of the envelope shape, reading of the envelope shape is resumed from the beginning. A time division multiplexed reading out of the envelope shape is conducted with respect to a plurality of channels. The read out envelope shape is used for controlling the amplitude of the musical tone signal. If the key is released, reading of the envelope shape is no longer repeated for a next and subsequent cycles.

Abstract: A cover member for a safety air-cushion device is made up of a bag-shaped outer laminate of high density polyurethane foam, and a bag-shaped inner laminate of low density polyurethane foam which is integral with the outer laminate, the inner laminate being made by pouring the fluidized material into a mold after solidification of the other fluidized material having been poured into the mold for the formation of the outer laminate.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth key code in a digital representation. This key code is used for reading out frequency information from a frequency information memory. The frequency informaton is accumulated to make an address signal for reading out the waveform memory. The read out waveform is reproduced as a musical tone through a tone-color and volume control circuit. This tone-color and volume control circuit is controlled keyboard by keyboard.The key code produced upon depression of the key contains a signal representing the kind of the keyboard to which the depressed key belongs. This signal is applied to a conversion circuit and converted to a signal representative of a different kind of keyboard.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth frequency information in a digital representation. The frequency information is accumulated to make an address signal for reading out the waveform memory. When a depressed key is moved laterally, a touch detection circuit produces an analog detection signal representing the amount of displacement of the key. In the meanwhile, a clock pulse is counted by an up-down counter and the counting output is converted by a D-A converter to an analog signal to obtain a triangular wave function signal. When the analog detection signal coincides, in amplitude, with the triangular wave function signal, the digital signal from the up-down counter is sampled and held by a sample and hold circuit. Thus a digital signal representing the key displacement is obtained.

Abstract: An electronic musical instrument includes a pitch determining voltage signal generating circuit adapted to produce one of 12 pitch determining voltage signals having different magnitudes corresponding to 12 notes in one octave in response to any of keys belonging to different octave ranges in a keyboard and having the same note name. A pitch determining voltage signal common to the different octave ranges is converted by a voltage converting circuit and taken out as a voltage signal having a magnitude corresponding to the note of a key being depressed on the keyboard. The voltage converting circuit includes a voltage dividing network having a plurality of output points and gate circuits connected to the output points, respectively. Each gate circuit is enabled in response to the depression of a key belonging to a corresponding octave range.

Abstract: An electronic musical instrument is of a type wherein an envelope to be imparted to a musical tone is stored in a memory as its sampled values and sequentially read out to constitute an envelope shape. A key depression causes the read-out of the memory.The instrument is improved to provide a rich sound effect of legato performance by successively and smoothly shifting the tone of the former key to that of the latter key while maintaining a predetermined constant tone volume. This legato effect can be carried out by successively maintaining the sustain level of the musical tone envelope from the tone of the former key shifted to the latter key. The musical tone envelope is read from the envelope memory by an address which is shifted by a clock pulse.

Abstract: In this electronic musical instrument, two separate tone generators of different type each produce a tone corresponding to an actuated key switch. Advantageously, one of the tone generators is of the Fourier synthesis type. In the other tone generator, a source waveshape having abundant harmonic components is processed by a tone color and volume control system which modifies the frequency spectrum and amplitude of the source waveshape in a time variant manner. The two generated tones are combined to produce the desired musical note.Actuation of each key switch produces, in an assigned time slot, frequency information corresponding to the selected note, and designating the phase angle between successive sample points to be read from a waveshape memory. In the Fourier synthesis type generator, plural waveshape memories store harmonically related sinusoids, all of which are accessed simultaneously and weighted by harmonic coefficients to produce the first tone.

Abstract: An electronic musical instrument wherein, by merely depressing one key, the tone pitch corresponding to that key varies periodically with cyclic repetition at a specific rate. The pitch variation is made on the octave basis by periodically shifting digits of binary signals of plural bits which designate readout addresses of a musical tone waveform. Various patterns of the pitch variation can be obtained by suitably setting a pattern of shifting of the digits of the binary signals.

Abstract: An electronic musical instrument of a type wherein a plurality of systems are provided each system comprising memories storing respective harmonic component waveshapes which are read at the same reading rate and the read out harmonic waveshapes are suitably mixed to obtain a desired musical tone. Each system also comprises a circuit for controlling the envelope of the waveshapes read from the memories. In the first system, the envelope control is made in such a manner that the envelope will rise upon depression of a key, thereafter maintain a constant level as long as the key is kept depressed and decay upon release of the depressed key. In the second system, the envelope is controlled so that the envelope will rise in a short time and immediately decay thereafter. The respective harmonic waveshapes thus controlled in envelope in the respective systems are then suitably selected and mixed together.

Abstract: A semipermeable composite membrane which shows only a small reduction of water permeability even when it is subjected to one time hot water treatment or drying treatment is provided according to the method of the present invention. Said semipermeable composite membrane consists of a porous substance and a reinforcing material embedded therein. Said porous substance has a porous region of network structure at least in one part thereof and numbers of voids in said porous region. Said reinforcing material is a fabric in case of flat type membrane or a braid having a central hollow portion in case of hollow fiber type membrane which is embedded in the wall of the membrane. Said method comprises impregnating said reinforcing material with a polymer solution and treating the impregnated reinforcing material with a coagulating liquid.