Abstract:
A horn speaker system includes a dome-shaped diaphragm, a coil bobbin, a phase equalizer, and a magnetic circuit. The coil bobbin is integral with the dome-shaped diaphragm, and a voice coil is wound on the coil bobbin near a free end thereof. The magnetic circuit coacts with the voice coil for producing forces to actuate the dome-shaped diaphragm. The magnetic circuit includes a cylindrical magnet, a first annular yoke attracted to one end of the cylindrical magnet and having a central opening, a plate cooperating with the first yoke in defining a gap in which the coil bobbin is inserted, and a second yoke attracted to an opposite end of the magnet. The magnet, the first yoke, the first plate, and the second yoke jointly make up a closed magnetic circuit. The phase equalizer serves to keep sounds outputted from the dome-shaped diaphragm in phase. The phase equalizer is mounted on the first yoke and has a plurality of slits defined therein. The magnet, the first yoke, the phase equalizer, and the dome-shaped diaphragm are stacked coaxially with each other.
Abstract:
Acoustic speaker cones have a plurality of thin, pie-shaped segments radiating outwardly from their center with each of the segments having an arcuated cross-section. The cones are made of polycarbonate plastic and take the form of being convex towards the center for high frequency cones or of being concave towards its center for larger broad range cones. The present invention is also directed to a system containing both the aforesaid high frequency cone, and an outer broad range cone with similar radial characteristics The segments of the outer cone preferably terminate at a flexible, high sound absorption ring. The center cone fits within a central orifice at the center of the outer cone. The polycarbonate cones have a specific gravity of about 1.10 and about 1.40, having an electrical dissipation factor of about 0.05 to about 0.30 at 60 Hertz, having an electrical dissipation factor of about 1.00 to about 1.25 at 10.sup.6 Hertz, and having a thermal condutivity of at least 1.2 BTU/hr/ft.sup.2 /.degree.F./in.
Abstract:
A film molding method and apparatus capable of shortening a mold cycle time and obtaining a molded product of an excellent quality. A method of hot-press molding a polyparaphenyleneterephthalamide (PPTA) film into a predetermined shape includes a first step of evaporating water from a PPTA film containing water at least 50% or more as a swelling agent, and obtaining an amorphous film having a density less than a predetermined density and a modulus in tension of about 70%; and a second process of hot-press molding the film for a predetermined time period by metal molds heated up to at least 330.degree. C. to crystallize the film to have a predetermined density specific to a PPTA film and produce an intrinsic physical value, and obtaining a molded product of the film. A film molding apparatus for performing the film molding method includes holes or slits opening at the surface of each of the metal molds, and an air suction unit and an air exhaust unit provided for each of the metal molds.
Abstract:
This invention provides an acoustic vibrational material containing various fibers as the reinforcement material and having the epoxy resin as the matrix resin, wherein the epoxy resin is modified by a polybutadiene base elastomer containing not less than 90 mole percent of 1,2-linked units. The epoxy resin modified with the above polybutadiene elastomer exhibits a maximum value of loss coefficient at the temperature region near the room temperature. This region is much higher than that of the conventional epoxy resin modified with polybutadiene elastomer mainly including 1,4-linked unit. Decrease in elastic modulus of the epoxy resin with increase of temperature is lesser in the epoxy resin of the present invention, whereas larger in the conventional one. Thus compatibility between large internal loss and high elastic modulus is achieved.
Abstract:
A diaphragm for use with an electro-acoustic transducer includes a diaphragm portion, an edge portion and a supporting portion. The diaphragm portion is molded by a synthetic resin material, such as polypropylene or the like. The edge portion is molded integrally with the supporting portion by a thermoplastic synthetic resin material and provided at the outer peripheral side of the diaphragm portion. The edge portion is molded integrally with the diaphragm portion by dichromatic molding.
Abstract:
A miniaturized electrodynamic sound generator comprises a diaphragm, a permanent magnet with pole pieces, a magnet yoke, and a coil. The yoke is designed such that is constitutes a housing or a cabinet of the sound generator. The permanent magnet and the pole pieces are provided in a recess in the cabinet or the yoke and surrounded by the coil, which is connected to the diaphragm at a peripheral area thereof. The diaphragm is provided above the magnet system of the recess and fastened to the outside of the cabinet. The dynamic response of the sound generator is determined by the magnetic, electrical, mechanical, and acoustic parameters which are used in the design of the sound generator. By varying some of these parameters, the frequency and amplitude of a resonance may be chosen such that the sound generator may reconstruct the natural acoustic transfer function in the range of 2-4 kHz in the human meatus. This makes the sound generator particularly suitable for use in hearing aids.
Abstract:
A loudspeaker component is bonded to a diaphragm formed of an olefinic resin, by applying an adhesion primer to bonding positions of the component and/or the diaphragm, applying an adhesive to the bonding positions after the primer has cured, and superposing the component and diaphragm. An air curing unsaturated polyester resin is used as the adhesion primer.
Abstract:
An improved audio transducer includes a diaphragm having a pair of cylindrically-shaped webs that provide greater bandwidth, reduced distortion and greater horizontal dispersion of sound. The audio output of the transducer is further improved by forming the diaphragm of a polyvinyl fluoride film. Other improvements include the use of damping pads to damp internal sound waves and damping strips on the diaphragm to minimize distortion at the resonant frequency of the transducer. In one alternative embodiment a laminated diaphragm is used to damp resonance in the high-frequency end of the transducer operating range.
Abstract:
An electroacoustic diaphragm is provided, which diaphragm comprising a pyrolytic graphite film obtained from a polymer selected from polyoxadiazole, an aromatic polyimide obtained by polycondensation of pyromellitic acid and an aromatic diamine, polybenzthiazole, polybenzbisthiazole, polybenzoxazole, polybenzbisoxazole, poly(pyromellitimide), poly(m-phenyleneisophthalamide), poly(m-phenylenebenzoimidazole), poly(m-phenylenebenzobisimidazole), polythiazole and poly(m-phenylenevinylene. The graphite film has a discontinuous layer of a polymeric material formed on and in the film whereby not only good electroacoustic characteristics, but also good mechanical strength and good adhesion of an adhesive applied thereof are obtained. A method for fabricating such diaphragm is also described.
Abstract:
A waterproof ground audio speaker apparatus has a speaker housing having a cylindrical sidewall, one open end and a closed end. A hollow cylindrical inner housing has a pair of open ends and is attached to the speaker housing with its walls in a spaced relationship to the walls of the speaker housing to form a passageway between the walls of the inner housing and the walls of the speaker housing. A loud speaker is mounted in the hollow inner housing facing one open end thereof for directing acoustical energy out the open end of the speaker housing and directing the backwave of the speaker through the hollow inner housing and through the passageway between the inner housing and the speaker housing to the open end of the speaker housing. A rigid domed supporting cover extends over the opening of the speaker housing and a filter membrane cover covers the open end of the speaker housing to protect the inside of the speaker enclosure. Annular flanges on either end of the speaker housing helps support the speaker housing in the earth and a special filter membrane made of laminated polyester and a polytetrafluoroethylene (TEFLON) sheet which allows the acoustical energy to pass therethrough while blocking the ingress of fluids and other materials into the speaker housing.