Abstract: A fetal heart monitoring system preferably comprising a backing plate having a generally concave front surface and a generally convex back surface, and at least one sensor element attached to the concave front surface for acquiring acoustic fetal heart signals produced by a fetus within a body. The sensor element has a shape that conforms to the generally concave back surface of the backing plate. In one embodiment, the at least one sensor element comprises an inner sensor, and a plurality of outer sensors surrounding the inner sensor. The fetal heart monitoring system can further comprise a web belt, and a web belt guide movably attached to the web belt. The web belt guide being is to the convex back surface of the backing plate.

Abstract: A surface acoustic wave device includes a piezoelectric substrate and at least one interdigital electrode disposed on the piezoelectric substrate. The interdigital electrode is made of ?-tantalum.

Abstract: A loudspeaker diaphragm affixed with a coil includes an edge portion located outside of a portion affixed with the coil and a center portion located inside of the portion affixed with the coil. The center portion is provided thereon with ribs. With these ribs, the height of the center portion can be limited to the height of the ribs. Therefore, it is possible to save a space of a loudspeaker where the loudspeaker diaphragm is placed, thereby slimming down the loudspeaker. Furthermore, with these ribs, the rigidity of the center portion can be improved without using a conventional solution of forming, for example, a dome shape on the center portion.

Abstract: A speaker's surround to be attached to an edge of a diaphragm in a speaker system is provided, which is capable of keeping its predetermined shape while repeating elastic deformation for accommodating large amplitude vibration of the diaphragm. Further, the surround is highly durable to withstand the repeated large amplitude vibration, and which can achieve high sound pressure levels. The surround for a speaker system includes a surround piece made of a rubber mold and a base member embedded in the surround piece. The base member is obtained by soaking a cloth material made of cotton or aramid fiber with a thermosetting resin such as phenol resin, and press-formed with heat into a predetermined shape. The surround thus has enhanced its shape maintaining capability.

Abstract: An annular surround for a loudspeaker cone wherein a radial cross-section of the surround varies around the circumferential extent of the surround, so as to accommodate peripheral expansion or contraction of the surround by bending. Thus a trough shaped cross-section of the surround may vary sinusoidally with angle around the polar axis of the surround between a semicircular and semielliptical cross-section. The trough section may bland to an adjacent portion of the surround by a fillet which also varies sinusoidally in cross-section in phase with the variation of the trough.

Abstract: A tweeter with a light, thin sandwich plate which can be excited into multiple reflected bending waves, and a driver which makes a vibrating contact and excites the sandwich plate, where the driver is designed for higher sound frequencies and the sandwich plate for propagating bending waves with low damping. The sandwich plate is freely carried with low damping by holding elements, where the latter are designed to be low damping at higher sound frequencies.

Abstract: A method and apparatus for mounting an acoustic emitter or detector of other sensor apparatus with respect to mounting structure therefor and so as to be isolated at least partially with respect thereto from the transmission of acoustic and/or electrical energy. The mounting provides a non-elastomeric snap-together bushing formed of a plastics material which accurately positionally locates the sensor or emitter with respect to its mounting while providing an unexpectedly high degree of isolation with respect to transmission of acoustic and other energy forms through the mounting.

Abstract: A symmetrically loaded, shallow suspension speaker with stiff diaphragm having a minimum dimension that is greater than the diameter of the magnet that drives the diaphragm thus allowing the suspension of the diaphragm to extend nearly to the bottom of the speaker basket on the maximum inward excursion of the voice coil and diaphragm such that the suspension operational depth is not the limiting factor of the overall height of the speaker. The elements of the suspension system are designed to maximize the spacing between the inner and outer portions of the suspension, thus minimizing the possibility of wobble in the speaker. The speaker design maximizes air movement in a given mounting depth with a configuration that optimizes the operation of the moving parts that complements the fixed mechanical structural configuration of the non-moving parts in either an overhung or underhung configuration. The design also accommodates user replacement of the voice coil or cone.

Abstract: The invention is a suspension element having an outer edge and an inner edge. The suspension element, such as a spider or surround, varies in shape along at least a portion of the suspension element to help relieve both the radial and tangential stress placed on the suspension element when it is stretched. The shape employed in the suspension element allows the suspension element to stretch more easily, creating a higher performance speaker of the same size by increasing the diaphragm excursion and voice coil movement.

Abstract: A speaker edge is molded of a rubber material with 0.1 wt % to 10 wt % short fibers added to the rubber material which ranges from 1.0 mm to 10 mm in length and are resistant to softening by heat, in which the short fibers are oriented to the radial direction of the edge.

Abstract: In an electroacoustic transducer (21) with a stationary transducer part (23) and with a membrane configuration (17) comprising a membrane (15) and a handling ring (1) for the membrane (15) connected with the membrane (15), the membrane configuration (17) is connected with the stationary transducer part (23) via the handling ring (1), and the handling ring (1) and membrane (15) are connected together via an interlocking connection.

Abstract: A damper for a speaker includes an auxiliary damper 12 impregnated with a thermosetting resin, a laminate film 121 laminated on the auxiliary damper 12, and a primary damper formed on the auxiliary damper 12 or the laminate film 121. Alternatively, the damper may include the auxiliary damper 12 impregnated with the thermosetting resin (phenol) and coated with a coating agent, and the primary damper formed on the auxiliary damper and the coating agent 122. Thus, the dual damper which has enhanced reliability in resisting a high power and can be produced at a low cost without variation in the production can be obtained.

Abstract: This invention presents a novel means to passively achieve a compact moving-coil actuator with a very low natural frequency. The diaphragm and voice coil are mounted in a sealed enclosure from which the air is partially or completely evacuated. This reduces the air spring effect. The diaphragm is supported by a non-linear, buckling, or collapsible support apparatus. By taking advantage of the non-linear stiffness properties of such structures, the stiffness of the actuator can be designed to be small at the operating point, which when combined with the moving mass, yields a low natural frequency.

Abstract: A system for tensioning a membrane within a frame for a loudspeaker or a microphone is characterized by a frame containing an opening, a membrane connected to an exterior surface of the frame and spanning the frame opening, and a tensioning device connected with the frame for deflecting a portion of the membrane within the frame opening. The tensioning device is compliant thereby allowing the membrane to exhibit a high degree of flexure both within and beyond a plane containing the membrane.

Abstract: A cone suspension is for mounting a speaker cone to a housing. The cone suspension has an inner periphery supporting the speaker cone, an outer periphery mounted to the housing, and a resilient central portion extending between the inner periphery and the outer periphery. In cross section, the resilient central portion is separated from a base plane extending between the inner periphery and the outer periphery, and has a central apex spaced from the inner periphery and the outer periphery and spaced from the base plane by a selected height. The inner periphery and the outer periphery are separated by a selected width. The selected height is substantially greater than ½ of the selected width.

Abstract: An audio speaker for incorporation into garments, upholstery, etc., has a diaphragm (10) and connecting wires (18) or switch (48), and a concave cover (20 or 44) made of a heat-molded textile having a ceramic textile covering. The speaker is attached by stitching (16) to an aperture (12) in a piece of conventional textile (14), for easy incorporation into a garment. The speaker may be sewn into the hood of a sports garment, or may be attached by the switch to a conducting area within a concave area of a garment such as a dress.

Abstract: A loudspeaker includes: a frame; a vibrating section including a diaphragm having an internal periphery and an external periphery, a voice coil attached to the internal periphery of the diaphragm, a spider which connects the voice coil to the frame, and a dust cap attached to the internal periphery of the diaphragm; and a surround which connects the external periphery of the diaphragm to the frame, wherein the ratio between the weight of the vibrating section and the weight of the surround is 0.9:1 to 1.5:1.

Abstract: A speaker diaphragm edge obtained by hot-forming into a desired edge shape, a resin-treated base material, which was prepared by using a silkscreen printing technique to apply a shaping agent layer only to the necessary portion of a base material.

Abstract: The speaker has a diaphragm main body 30 supported resiliently on a frame 23 via an edge portion 31 around its outer circumference, and the groove ribs 35 integrally formed in the edge portion 31, wherein a regulation member 37 for partially improving a flexural strength of the edge portion 31 is provided on a part of the front or back face of the edge portion 31.

Abstract: A symmetrically loaded, shallow suspension speaker with stiff diaphragm having a minimum dimension that is greater than the diameter of the magnet that drives the diaphragm thus allowing the suspension of the diaphragm to extend nearly to the bottom of the speaker basket on the maximum inward excursion of the voice coil and diaphragm such that the suspension operational depth is not the limiting factor of the overall height of the speaker. The elements of the suspension system are designed to maximize the spacing between the inner and outer portions of the suspension, thus minimizing the possibility of wobble in the speaker. The speaker design maximizes air movement in a given mounting depth with a configuration that optimizes the operation of the moving parts that complements the fixed mechanical structural configuration of the non-moving parts in either an overhung or underhung configuration. The design also accommodates user replacement of the voice coil or cone.

Abstract: In a speaker including a voice coil which is wound on a voice coil bobbin and is inserted into a magnetic circuit gap of a magnetic circuit, and a cone which is coupled to the voice coil bobbin for vibration, the cone (16) is constructed of two divided cones: a drive cone (16A) linked to the voice coil bobbin (14) and a cone paper (16B) linked through an edge (17) to a frame (F).

Abstract: A connection of the sound bowl and connecting portion of a loudspeaker is disclosed. The connection area is adhered with the elastic materials similar to the materials of sound bowl and connecting portion in order to beautify the appearance of loudspeaker and enhance the adhesion. Thereby the tolerance of the loudspeaker is enhanced. Thus, the loudspeaker is tolerable to vibration and produces sound with precise tunes, and stabilizes the quality of sound.

Abstract: A damper 3A is provided with an inner peripheral waveform portion 11 and an outer peripheral waveform portion 12. A flat portion 10 is provided between the inner peripheral waveform portion 11 and the outer peripheral waveform portion 12. When the damper is used for a loudspeaker, the flat portion 10 does not elastically deform in a radial direction R, so that linearity of the damper 3A in a vibrating direction Z is ensured by elastic deformation of the waveform portions. In addition, a rolling phenomenon of a voice coil bobbin and a diaphragm can be suppressed.

Abstract: The present invention relates to a protector for a loudspeaker cone. The loudspeaker protector (25) comprises: a sheet of flexible material (26), the sheet being bounded by an edge (28); one or more mounting points (36) on the sheet (26), each mounting point (36) being adapted to receive a fixing member (38) through the sheet (26) and being positioned in a peripheral region (56) of the sheet (26); and one or more lines of weakness (50) in the sheet, the sheet (26) being thereby adapted to tear or break preferentially along the lines of weakness (50); in which the lines of weakness (50) separate the peripheral region (56) at each mounting point (36) from a central area (52) of the sheet (26), so that the central area (52) of the sheet may be torn from the peripheral regions (56) after the mounting points (36) have been held down by said fixing members (38).

Abstract: A speaker's surround to be attached to an edge of a diaphragm in a speaker system is provided, which is capable of keeping its predetermined shape while repeating elastic deformation for accommodating large amplitude vibration of the diaphragm. Further, the surround is highly durable to withstand the repeated large amplitude vibration, and which can achieve high sound pressure levels. The surround for a speaker system includes a surround piece made of a rubber mold and a base member embedded in the surround piece. The base member is obtained by soaking a cloth material made of cotton or aramid fiber with a thermosetting resin such as phenol resin, and press-formed with heat into a predetermined shape. The surround thus has enhanced its shape maintaining capability.

Abstract: A passive radiator and method is disclosed which improves frequency response linearity and greatly reduces the possibility that wobble of a passive radiator which will occur without the displacement limitations of a spider containing speaker structure. Two substantially flat surfaced speaker diaphragms are tied together and supported by two sets of surrounds oriented in opposite directions to reduce the non-linearity in the surround spring rate and improve low frequency sound generation. A vent (pressure relief) system is provided to improve the frequency response and range of motion of the passive speaker system. A progressive surround roll arrangement provides for improved sound quality by utilizing localized position based extension while maintaining the range of maximum travel during resonance.

Abstract: The invention described herein is a low-mass, light-weight sound generator with particularly good performance at mid and low audio frequencies. It is expected to find principal use in applications where mass is of crucial importance. It is capable of delivering the high acoustic levels, as required for sound generation or active sound control. The present invention uses a generally planar acoustic membrane as a diaphragm, the diaphragm being in tension and attached at its outer edge to a support frame which provides a soft boundary condition to the acoustic diaphram. In a preferred embodiment, the support structure is an inflatable toroidal tube of rubber or rubber-like material. A polymer membrane is attached to the support structure by heat sealing the membrane in place. A voltage is applied to a piezoelectric bender-type actuator, which imparts axial displacement to a region of the diaphragm, causing resonance of the diaphragm in the desired frequency range.

Abstract: A yoke structure of a speaker diaphragm comprises a casing having a front side being installed with an enlarged opening and rear side thereof being installed with a magnetic element; a coil being placed in the magnetic element; a damper being engaged with the coil; and a diaphragm being placed at the enlarged opening of the casing and being sticky to the coil, and a diaphragm being placed at the enlarged opening of the casing and being sticky to the coil. In the present invention, a yoke portion with two layer curved portions is placed between the casing and the diaphragm; the yoke portion is made of elastic material and has front and a rear layer, and each layer is formed with bent arcs. As a result, the diaphragm can be assembled conveniently at one time and is adhered well. Moreover, the center thereof can be positioned preferably. Thus, the output of the speaker will avoid interference from the vibration of the diaphragm.

Abstract: This invention provides a transducer having at least two surrounds supporting a cylinder. With at least two surrounds, the transducer may handle more power. This increased power may be used to drive the voice coil that is wrapped around the cylinder enabling a greater excursion range of the diaphragm. With a greater excursion range, the transducer may operate at low frequency as well as mid to high frequencies. The two surrounds may also be coupled to the cylinder increasing stability of the cylinder. With the two suspensions stabilizing the cylinder, the side-to-side movement of the cylinder may be reduced minimizing the chance of the voice coil short-circuiting with the other electrical and/or mechanical circuits in the transducer. In addition, the cylinder made a substantially rigid material may better support the two flexible surrounds so that the two surrounds do not induce wobbling in the diaphragm.

Abstract: A loudspeaker is provided including a frame formed with an upper end having a seat which receives the outer edge of a surround. The surround is retained within the seat by the combination of an o-ring in contact with the surround, and a C-shaped clamp having an upper arm which engages the o-ring and a lower arm releasably mounted to the upper end of the frame.

Abstract: A speaker damper comprises a damper casing and a metallic whisker, wherein the damper casing is substantially a woven pad formed as a circular wafer with corrugated sections, while the metallic whisker is substantially a conductive wire intermittently penetrated and buried in the damper casing. A fastening string is provided to tie the metallic whisker intermittently and hold it steadily to the damper casing without incurring the so-called repetitious jump-rope phenomenon during vibration of the later.

Abstract: A damper 3A is provided with an inner peripheral waveform portion 11 and an outer peripheral waveform portion 12. A flat portion 10 is provided between the inner peripheral waveform portion 11 and the outer peripheral waveform portion 12. When the damper is used for a loudspeaker, the flat portion 10 does not elastically deform in a radial direction R, so that linearity of the damper 3A in a vibrating direction Z is ensured by elastic deformation of the waveform portions. In addition, a rolling phenomenon of a voice coil bobbin and a diaphragm can be suppressed.

Abstract: A cone suspension is for mounting a speaker cone to a housing. The cone suspension has an inner periphery supporting the speaker cone, an outer periphery mounted to the housing, and a resilient central portion extending between the inner periphery and the outer periphery. In cross section, the resilient central portion is separated from a base plane extending between the inner periphery and the outer periphery, and has a central apex spaced from the inner periphery and the outer periphery and spaced from the base plane by a selected height. The inner periphery and the outer periphery are separated by a selected width. The selected height is substantially greater than ½ of the selected width.

Abstract: It is an object of the present invention to provide a speaker edge which is high in strength, less in scattering of f0, high in waterproofness, small in amplitude at the time of resonance, easy to mold, and easy to be integrated with a cone body. That is, the present invention provides a speaker edge constituted by a molding which is molded in a manner so that a speaker edge raw material composition containing isocyanate and polyol is injected into a cavity of a mold by an agitating/mixing apparatus and subjected to reaction, foaming and curing in the cavity.

Abstract: A mid-frequency loudspeaker drive unit includes a substantially conical diaphragm having a forward periphery and a surround connected to and extending from the forward periphery of the diaphragm to form a substantially smooth transition from the diaphragm to the surround, the diaphragm and the surround presenting a substantially smoothly continuous outwardly facing surface. The drive unit can be part of a compound loudspeaker drive unit including a high-frequency drive unit coaxially disposed within the diaphragm and a chassis encompassing the mid-frequency drive unit with the surround being secured to the chassis to form the smooth transition from the diaphragm to the surround.

Abstract: A loudspeaker is provided including a frame formed with an upper end having a seat which receives the outer edge of a surround. The surround is retained within the seat by the combination of an o-ring in contact with the surround, and a C-shaped clamp having an upper arm which engages the o-ring and a lower arm releasably mounted to the upper end of the frame.

Abstract: A high stability loudspeaker has a yoke with a plurality of vents installed therein. The yoke is combined to a bottom of a frame of the loudspeaker. A magnet is placed in the yoke. A washer is arranged above the magnet. A periphery of the magnet is surrounded by a voice coil. A coil winding surrounds the voice coil. A combining portion is formed at a periphery of the yoke. The combining portion serves to be combined with a surround connected to a bottom of end of the voice coil. The voice coils is vertically installed in a gap between the portions of the yoke. The top of the voice coil is connected to another surround. Thereby, vibration of the voice coil is confined at the two ends. As a result, the gap between portions of the yoke structure into which the voice coil extends between portions of the yoke is reduced and therefore, the sensitivity of the loudspeaker is increased and the distortion is decreased.

Abstract: A frame (14) supporting a diaphragm (12) by its outer periphery is constructed by a connecting ring (30) and a base (28) which comprises a bottomed cylinder portion (28A) and a mounting portion (28B) which extends radially outward from the bottomed cylinder portion (28A) which is a part of the magnetic circuit unit (18). The connection is achieved by the caulking of the ring (30) and the mounting portion (28B) with the diaphragm (12) clamped therebetween.

Abstract: The invention is a suspension element having an outer edge and an inner edge. The suspension element, such as a spider or surround, varies in shape along at least a portion of the suspension element to help relieve both the radial and tangential stress placed on the suspension element when it is stretched. The shape employed in the suspension element allows the suspension element to stretch more easily, creating a higher performance speaker of the same size by increasing the diaphragm excursion and voice coil movement.

Abstract: A speaker edge is molded of a rubber material with 0.1 wt % to 10 wt % short fibers added to the rubber material which ranges from 1.0 mm to 10 mm in length and are resistant to softening by heat, in which the short fibers are oriented to the radial direction of the edge.

Abstract: Several different acoustic radiator designs improve performance over the prior art while providing a larger baffle (cone), a lesser volume of air displaced than by the smaller prior art speaker design, while maintaining the same enclosure mouth diameter and allowing the use of a shallower enclosure.

Abstract: A butterfly damper comprises an inner circumferential frame, an outer circumferential frame and at least one arm member. The outer circumferential frame has opposite end surfaces and an inner peripheral surface. The inner peripheral surface is connected to the opposite end surfaces to form opposite connecting edge portions. The arm member has one end connected to the outer circumferential frame and the other end connected to the inner circumferential frame. The one end of the arm member is connected to a portion of the inner peripheral surface of the outer circumferential frame, which portion exclude the opposite connecting edge portions.

Abstract: A butterfly damper comprises an inner circumferential frame, an outer circumferential frame and at least one arm member. The arm member has one end connected to the outer circumferential frame and the other end connected to the inner circumferential frame. The arm member has a racetrack-shaped cross section.

Abstract: An annular surround for a loudspeaker cone wherein a radial cross-section of the surround varies around the circumferential extent of the surround, so as to accommodate peripheral expansion or contraction of the surround by bending. Thus a trough shaped cross-section of the surround may vary sinusoidally with angle around the polar axis of the surround between a semicircular and semielliptical cross-section. The trough section may bland to an adjacent portion of the surround by a fillet which also varies sinusoidally in cross-section in phase with the variation of the trough.

Abstract: A passive radiator and method is disclosed which improves frequency response linearity and greatly reduces the possibility that wobble of a passive radiator which will occur without the displacement limitations of a spider containing speaker structure. Two substantially fiat surfaced speaker diaphragms are tied together and supported by two sets of surrounds oriented in opposite directions to reduce the non-linearity in the surround spring rate Hand improve low frequency sound generation. A vent (pressure relief system is provided to improve the frequency response and range of motion of the passive speaker system. A progressive surround roll arrangement provides for improved sound quality by utilizing localized position based extension while maintaining the range of maximum travel during resonance.

Abstract: A passive radiator comprising a frame (1) and a radiator body (3) which is connected to the frame and which is movable relative to the frame along a translation axis (T). The radiator is suitable for the displacement of comparatively large air volumes. The radiator body comprises a central mass element (3a) and at least one mass element (3b, 3c, 3d) which is concentrically arranged with respect to the central mass element. The radiator further comprises connection units (5a, 5b, 5c, 5d) for the movable interconnection of each pair of adjoining mass elements and for the movable fastening of one of the mass elements to the frame.

Abstract: A receiver suspension for isolating a hearing device receiver within a hearing device comprises a housing that defines a chamber. The housing is adapted to be inserted into a hearing device shell. The receiver suspension also comprises a cover that is adapted to engage with a proximal end of the housing. An isolation membrane at least partially surrounds the hearing device receiver such that, upon inserting the hearing device receiver into the housing, the isolation membrane suspends the receiver within the housing chamber, thus preventing the receiver from contacting the inside surface of the housing. Preferably, the isolation membrane is formed from a stretched polymer material such as polyurethane or silicone and forms a series of pleats when engaged with the receiver. Alternately, the receiver suspension includes an isolation spring having two grasping members interconnected with a flexure member.

Abstract: A transducer includes a supporting frame, a motor assembly providing a magnetic field across an air gap, a coil former supporting a voice coil in the magnetic field, a diaphragm attached to the coil former and coupled by a surround at its outer perimeter to the frame, and a spider having an inner perimeter coupled to the coil former and an outer perimeter coupled to at least one of the frame and motor assembly. The spider includes a plurality of rolls. The roll next adjacent the inner perimeter may have a first height. The roll next adjacent the outer perimeter may have a second height less than the first height. The surround may include a plurality of rolls. The roll next adjacent the diaphragm may have a third height, and the roll next adjacent the frame a fourth height less than the third height.

Abstract: A kind of vibrating diaphragm of false speaker structure which includes a center piece with integrated formation directly on a larger outer diameter surface layer body, a connected suspended edge provided at the side way of the surface layer body in circle, and the hardness of the center piece is greater than the surface layer body and a gap reserved at the separation of the formation of the surface layer body and the suspended edge; with this provision, it provides aesthetic and consistence in appearance to the vibrating diaphragm formation, and save the adhesion of the suspended edge and the center piece which reduce the process and lower cost and make the center piece embedded with the product firmly without loosen, meeting various test condition and prolong the service life of the structure in practice.

Abstract: An outer marginal edge of a loudspeaker cone is connected to an annular suspension member of laminated structure which supports the loudspeaker cone on a support frame. The annular suspension member includes a layer of cloth and a first layer of flexible plastic foam integrally bonded to the cloth. The first layer of foam has an inner surface in contact with the outer marginal edge, and the cloth covers an outer surface of the first layer of foam opposite to the inner surface. A second layer of foam which is thinner than the first layer of foam is disposed between and bonded integrally to the cloth and the first layer of foam. The suspension member is strong and durable and still exhibits good formability and flexibility.