A sound suppressing nacelle arrangement is provided for an airplane gas turbine engine wherein the nacelle is mounted over the wing of the airplane and an aft exhaust duct is made translatable therewith for telescoping engagement within the nacelle in order to expose a portion of the overlying wing surface which functions as a sound reflection shield at those altitudes where the noise levels of the engine and exhausting jet stream are not substantially attenuated before reaching ground.

Method and apparatus for tuning an electronic keyboard instrument in pure scale are disclosed herein. The apparatus comprises frequency modifier means such as potentiometers which are electrically associable with the normal tone generators of the instrument, said frequency modifier means being adjustable so as to influence a tone produced by said generator to have a particular frequency or pitch, and switching means for grouping said frequency modifier means for playing in a particular key. The ...

The operating elements of a portable, top-loading inclination balance are mostly mounted in a housing from which a pan carrier and the weighing pan project. The weight of an object on the pan is projected on a screen visible from outside the housing. A cover pivoted to the housing may be swung wide for access to the weighing pan, swung closer to the housing into an intermediate position for protecting the pan against the influence of air movement, or swung into a closed position in which it enve...

A muffler which can be attached to the exhaust of an engine to muffle the sound while permitting the escape of exhaust gases, including a cylindrical shell coupled to the exhaust of the engine and having numerous holes arranged in several rings. A flexible band covers each ring of holes in a sealing fit thereover, to prevent the escape of gases except when the localized pressure on the inner side of the hole is sufficient to deflect a band portion away from the hole to permit the escape of gas t...

A method and apparatus for electrically producing musical sounds wherein a cavity resonator is formed by a hollow body defining a cavity having a constant configuration with a small opening communicating with the oral cavity of the mouth of a player and a change in the size of the oral cavity changes the resonant frequency and thereby the fundamental frequency of the sound produced. A vibrating cone in a closed chamber produces sound waves in the cavity resonator. An electric amplifier is driven...

An electronic circuit for correction of the time display on an electronic timepiece, this circuit including a selector switch having a rest position for which the timepiece advances normally, and operating positions for minute setting, hour setting and day setting. Delay means are connected between said selector switch and the setting means of one or more display means for minutes, hours or days in order that such setting means only start to operate when the selector switch has been shifted to t...

A normally-deflated, readily-flexible, inflatable pad which underlies a bed patient can be inflated to raise that bed patient and to gently but firmly hold that bed patient in raised position. When that inflatable pad is inflated, it defines a recess at the lower surface of the center thereof into which the supporting surface of a portable support can be moved; and that inflatable pad and that portable support can thereafter hold the bed patient at a desired level relative to the bed on which th...

In an electronic musical instrument, actuation of each key switch produces a key data signal indicative of the identification name of the key switch. A key address code corresponding to this key data signal is stored in a key address code memory. Frequency data corresponding to the fundamental frequencies of musical tones for the respective key switches are stored beforehand in a frequency information memory. The key address code read from the key address code memory is used to read frequency in...

There is disclosed an assembly for assuring zero return of a gradation disc comprising a drive transmission assembly including worm and worm gear means for a counter gradation disc in which the gradation disc driving gear is provided with a cutaway portion such that the gradation disc idles after being driven to a predetermined gradation, with the driving gear being returned to zero return by a moveable stop member spring biased to restore a predetermined position against the rotating potential ...

A sampling modulation system for an electronic musical instrument has an audio frequency signal source, a sampling circuit, a memory circuit for memorizing the sampled signals, an output circuit for reading out the signals from the memory circuit, a control circuit which generates a sampling pulse train and a reading pulse train, and a modulating signal source. At least either the sampling pulse train or the reading pulse train has the frequency modulated by the modulating signal generated from ...