Abstract: A generator for spherical ultrasonic waves can replace a point source transducer and has a large-area transducer whose output ultrasonic waves are condensed in a funnel and fed to a monomodal waveguide, e.g. a tube at the output end of which phase-correct perfectly spherical waves are emitted.

Abstract: A folded acoustical horn is disclosed, having an acoustical transmission path that is generally arcuate about an axis, including a pair of arcuate mouths that are longitudinally spaced apart a selected distance and directed radially outwardly. A horn tuner is operable to selectively adjust the acoustical path to match selected sound frequencies.

Abstract: A fluidic sound amplification system couples successive laminar proportional amplifiers through acoustic radiation between output and input horns to avoid the propagation of null offset signals. A second approach to obviating DC null bias in a fluidic sound amplification system comprises splitting the input signal, effecting a selected time delay on a portion of the signal such that the bandpass frequencies and dead zones or cancellation frequencies respectively of the amplified signals are 180.degree. out of phase and combine to produce a near uniform frequency response. A third approach is to use multiple parallel elements in each stage of amplification in such a manner that mechanical errors cancel each other out.

Abstract: The present invention relates to an apparatus which is easily convertible from a container such as a drinking cup, into a megaphone and thereafter back to a container. Ideally, the apparatus will include a team logo or other such representation of support thus making it especially suitable for use at sporting events and the like.

Abstract: The present invention involves a moving-coil electrodynamic electroacoustical transducer, comprising a disk made of a hard, nonmagnetic material (12), which is superimposed on the diaphragm (11) and has openings for the output of sound, a power-factor-improvement device/super charger (13) made of a nonmagnetic material which is placed in the concavity of the diaphragm (11) and which has annular, concentric ducts (13') having a conical shape, and a cover (14) made of a nonmagnetic material serving as the lid in both configurations of the transducer, the said cover being applied to the body facing the concavity of the said diaphragm in a direct-radiation transducer, while it is applied to the body facing the convexity of the said magnetic disk (12) in an indirect-radiation transducer.

Abstract: The present invention relates to an acoustical transducer enclosure which is particularly adapted for directing sound waves and is housed in a multisided enclosure. The enclosure has a cylindrical hollow tube, held in position by a pair of forward baffles, with a speaker housed within. Forward wave guides line the interior area of the enclosure. A wave form vent is located on a horizontal plane with the speaker at one end of the cylindrical hollow tube. A rear back pressure booster baffle is located at the end of the cylindrical hollow tube with a wave splitter which is located proximate the rear back pressure booster.

Abstract: A speaker and horn array having improved audio characteristics is formed in a baffle case. A plurality of small speakers are mounted in the baffle case in a vertical array in close proximity with one another. Each of the speakers has an acoustic baffle over the back of the speaker with an opening located in the baffle. An array of small horns are located in association with the speakers in the baffle case. As with the speakers the horns are also in a vertical array. Each of the horns includes an individual throat, however, all of the horns are joined into a common vertically oriented mouth. The throat of each horn is connected to the opening in the baffle of one of the speakers. This backloads the individual speakers with the common mouth of each of the horns resulting in common backloading of each of the speakers.

Abstract: An acoustic detection device having a parabolic dish antenna for gathering ound waves and providing a first stage of amplification, an exponential horn located at the focus of the parabolic dish antenna for further acoustic amplification, a fluidic gainblock for a final stage of amplification, and acoustic earphones for listening. Either a hand operated latex bulb or a mechanical pump is used to pressurize a plastic fluid storage container that is used to supply fluid to the fluidic gainblock. Within the fluidic gainblock are four or more staged laminar proportional amplifiers having a bandwidth of 0 to 4,000 Hz.

Abstract: Disclosed is an acoustic horn to aid in bulk powdered material handling particularly from trucks and railroad cars. Such acoustic horn is comprised of an external cone having a driver affix thereto. There is also an inverted internal cone contained within the external cone. There is a cylindrical throat communicating with the acoustic wave driver which extends into the internal cone, the combination of the throat extending into the internal cone contained within the external cone creates a folded horn arrangement wherein a horn of relative shortened length can achieve the desired low fundamental frequencies needed for bulk powdered material handling.Extending radially from the mouth of the external cone is a flange. Means are provided to detachably affix said flange from the flange on existing manways present on trucks and railroad cars.

Abstract: In a sound emitter including an emitting piston powered by a three phase asynchronous electric motor, the torque curve of the motor may be adjusted to suit any temperature, causing variations in the emitted resonance frequency by using a motor having its maximum torque at less than half the maximum speed. This may be done by using an alloy of silicon and aluminum in the rotor winding.

Abstract: An ultrasonic rangefinder capable of detecting a distance between a vehicle and an object with high accuracy is shown. The measurements for microphones for transmitting and receiving ultrasonic waves are chosen so that detour waves are restricted.

Abstract: A horn loudspeaker with a convex diaphragm in which the throat of the horn is formed by an assembly including the diaphragm, a cover plate for the diaphragm, a tapered plug, and a base, the plug and cover forming linear channels of equal length confronting different portions of the convex dome of the diaphragm.

Abstract: An ultrasonic wave transmitter and receiver adapted to be mounted on the rear portion of a vehicle to detect the distance between the rear end of the vehicle and any obstruction located at the rear side of the vehicle. The ultrasonic wave transmitter and receiver includes an ultrasonic transducer attached to a lower part of the vehicle at a portion spaced from the rear end of the vehicle in the forward direction of the vehicle by a predetermined distance, a horn opening rearwardly from the vehicle and a wave guide tube through which the horn and the ultrasonic transducer are coupled to each other. The distance between the ultrasonic transducer and the rear end of the vehicle is selected to correspond to a time length which is long enough to sufficiently attenuate the residual oscillation of the ultrasonic transducer.

Abstract: An ultrasonic transducer which is suited to be placed in the place exposed to water, comprises an ultrasonic vibrator which transmits and receives ultrasonic wave, a horn which imparts directivity to the ultrasonic wave and a bent wave guide which connects the ultrasonic vibrator and the horn, and a reflecting plate which is provided in the bent portion of the wave guide for guiding the ultrasonic wave into the horn or the ultrasonic vibrator. According to the ultrasonic transducer of the present invention, the ultrasonic vibrator can be positioned above the horn when the horn is horizontally disposed. Therefore, the ultrasonic vibrator is not splashed with water entering from the horn.

Abstract: A horn speaker wherein a pole piece of a yoke is arranged inside an annular permanent magnet and a moving coil which vibrates a diaphragm, is arranged in an air gap between the pole piece and the annular permanent magnet. A plurality of linear grooves are formed in the front surface of the pole piece in order to suppress the generation of the heat of the pole piece and the moving coil.

Abstract: A portable apparatus (100) for mechanically amplifying voice and percussive sound includes a flared horn (10) with a horn mouth (26) and voice opening (28) for projecting sound in a desired directional sound radiation pattern. Within an opening formed in the body of the horn, a vibratile membrane (20) is secured by a retaining ring (22). The vibratile membrane (20) is tensioned to produce a drum sound when excited by percussion. Two handles (12) are mounted to the outer surface of the horn to enable lefthanded and righthanded persons to conveniently hold the horn. The horn is of frusto-conical shape and appropriate dimensioning of the horn flare in relation to the width of the horn mouth defines a structure operable to permit the sound waves to cling to the horn inner surface and project outwardly therefrom.