Surface acoustic transducer

Abstract

The present invention provides for a surface acoustic transducer optimally structured to produce sound within an aircraft cabin by vibrating the interior cabin walls. Specifically, the surface acoustic transducer comprises a primary assembly comprising a voice coil assembly having a voice coil former and wire, and a transducer housing for retaining said primary assembly and a magnet therein such in movable relations. The present surface acoustic transducer may further include a spider structured to provide an improved excursion. An external housing may additionally be provided comprising a rigid retaining wall for protecting the surface acoustic transducer from potential externally applied forces and a malleable excursion cover allowing for an excursion of the primary assembly thereof.

Claims

1. A surface acoustic transducer assembly comprising: a magnet providing a magnetic field; a primary assembly comprising at least a voice coil assembly; a transducer housing cooperatively structured for retaining said primary assembly and magnet therein, such that said primary assembly is permitted to move outwardly from said magnet along a linear path of excursion, when the primary assembly enters an excited state; an external housing comprising at least a retaining wall and an excursion cover cooperatively structured to retain said transducer housing and primary assembly therein, said retaining wall formed of a rigid composition and protectively enclosing said transducer therein and said excursion cover malleably attached to a proximal end of said retaining wall via a plurality of contact portions, facilitating the excursion of said primary assembly outwards from said external housing.

2. The surface acoustic transducer assembly of claim 1 wherein said primary assembly further comprises a coupler ring attached to a proximal end of said primary assembly.

3. The surface acoustic transducer assembly of claim 1 further comprising a top shunt plate disposed in juxtaposing relations between said magnet and said primary assembly.

4. The surface acoustic transducer assembly of claim 1 wherein said voice coil assembly further comprises a voice coil former and a voice coil wire wound in surrounding relation to said voice coiler former.

5. The surface acoustic transducer assembly of claim 4 wherein an exterior edge of said top shunt plate is disposed in substantially overlying relations relative to said voice coil wire, when the surface acoustic transducer is in a rest state.

6. The surface acoustic transducer assembly of claim 4 wherein an exterior edge of said magnet is disposed in partially overlying relations relative to said voice coil wire, when the surface acoustic transducer is in a rest state.

7. The surface acoustic transducer assembly of claim 1 further comprising a spider for damping the movement of said primary assembly, said spider disposed in juxtaposing surrounding relations relative to said primary assembly.

8. The surface acoustic transducer assembly of claim 1 wherein said transducer housing further comprises a flange disposed in surrounding relations to said primary assembly, said flange comprising a terminal attachment structured to receive power from a power source and relay the power to said voice coil assembly.

9. The surface acoustic transducer assembly of claim 1 wherein said transducer housing comprises a yoke coupled in surrounding relations relative to a distal portion of said primary assembly.

10. The surface acoustic transducer assembly of claim 1 wherein said voice coil comprises a wattage of between 20 W to 30 W.

11. The surface acoustic transducer assembly of claim 1 wherein said transducer housing comprises a diameter of between 25 mm to 30 mm.

12. The surface acoustic transducer assembly of claim 1 wherein said excursion cover is attached to a proximal end of said retaining wall via three contact portions.

13. The surface acoustic transducer assembly of claim 1 wherein said excursion cover comprises a spiral structure.

14. A surface acoustic transducer assembly comprising: a magnet and a primary assembly; a transducer housing cooperatively structured for retaining said primary assembly and magnet therein, such that said primary assembly is permitted to move outwardly from said magnet along a linear path of excursion, when the primary assembly enters an excited state; an external housing comprising a retaining wall and an excursion cover cooperatively structured to retain said transducer housing and primary assembly therein; said retaining wall formed of a rigid composition and protectively enclosing said transducer housing therein; and, said excursion cover malleably attached to a proximal end of said retaining wall via a plurality of contact portions, to allow for the excursion of said primary assembly outwards from said external housing.

15. The surface acoustic transducer assembly of claim 14 further comprising a top shunt plate coupled to a proximal surface of said magnet, wherein an exterior edge of said top shunt plate is disposed in overlying relations relative to a voice coil assembly of said primary assembly, when then surface acoustic transducer is in a rest state.

16. The surface acoustic transducer assembly of claim 15 wherein an exterior edge of said magnet is disposed in partially overlying relations relative to a voice coil wire of said voice coil assembly, when then surface acoustic transducer is in a rest state.

17. A surface acoustic transducer comprising: a magnet and a primary assembly; a transducer housing for retaining said magnet and said primary assembly therein, said primary assembly disposed in movable relation to said magnet, outwardly from said magnet along a linear path of excursion, when the primary assembly enters an excited state; said primary assembly having a cylindrical profile protruding partially outward from said transducer housing, and comprising a voice coil assembly having a voice coil former and a voice coil wire wound in surrounding relations to said voice coil former; said magnet providing a magnetic field and coupled to a distal end interior to said transducer housing; a spider for damping the movement of said primary assembly, said spider disposed in juxtaposing surrounding relations relative to said primary assembly and being secured by said transducer housing; and, an external housing disposed in protective, surrounding relation to said transducer housing and primary assembly, said external housing comprising at least a retaining wall formed of a rigid composition and an excursion cover malleably attached to a proximal end of said retaining wall via a plurality of contact portions, to allow for the excursion of said primary assembly outwards from said external housing.

18. The surface acoustic transducer of claim 17 further comprising a top shunt plate coupled to a proximal surface of said magnet, wherein an exterior edge of said top shunt plate is disposed in overlying relation to said voice coil wire when the surface acoustic transducer is in a rest state.

19. The surface acoustic transducer of claim 18 wherein an exterior edge of said magnet is disposed in partially overlying relation to said voice coil wire when then surface acoustic transducer is in a rest state.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

(2) FIG. 1 is a perspective external view of a surface acoustic transducer in one embodiment of the present invention.

(3) FIG. 2 is a bottom profile external view of the surface acoustic transducer of FIG. 1.

(4) FIG. 3A is a side profile external view of the surface acoustic transducer of FIG. 1

(5) FIG. 3B is a side profile partially cut away view of the surface acoustic transducer of FIG. 1.

(6) FIG. 4A is another side profile cut away view of the surface acoustic transducer of FIG. 1.

(7) FIG. 4B is an expanded view of a cross section of the surface acoustic transducer shown in FIG. 4A.

(8) FIG. 5 is a profile view of a coupler ring forming part of the surface acoustic transducer of the present invention.

(9) FIG. 6 is a profile view of the coupler ring of FIG. 5 in connection with a voice coil assembly forming part of the surface acoustic transducer of the present invention.

(10) FIG. 7 is a profile view of a magnet forming part of the surface acoustic transducer of the present invention.

(11) FIG. 8 is a profile view of a flange forming part of the surface acoustic transducer of the present invention.

(12) FIG. 9 is a profile view of a spider forming part of the surface acoustic transducer of the present invention.

(13) FIG. 10 is a profile view of a top shunt plate forming part of the surface acoustic transducer of the present invention.

(14) FIG. 11 is a profile view of a yoke forming part of the surface acoustic transducer of the present invention.

(15) FIG. 12 is a profile view of a surface acoustic transducer mounted within an external housing.

(16) FIG. 13A is a profile view of the external housing of FIG. 12.

(17) FIG. 13B is a top down view of the external housing of FIG. 12.

(18) FIG. 13C is a side view of the external housing of FIG. 12.

(19) FIG. 14 is a schematic view of an active noise cancellation system utilizing one or more of the surface acoustic transducers of FIG. 1 mounted along a periphery of an aircraft window panel via the external housing of FIG. 12.

(20) FIG. 15 is a schematic view of another active noise cancellation system utilizing one or more of the surface acoustic transducers of FIG. 1 mounted along a periphery of an aircraft window area via the external housing of FIG. 12.

(21) Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE EMBODIMENT

(22) As illustrated by the accompanying drawings, the present invention is directed to a surface acoustic transducer. In a preferred embodiment, the surface acoustic transducer of the present invention is optimally structured, as described below, for producing high quality sound within an aircraft cabin by vibrating its interior cabin walls, bulkheads, and/or windows. Of course, the present surface acoustic transducer may also be utilized to vibrate other surfaces. Specifically, the surface acoustic transducer of the present invention includes a transducer housing structured to at least partially enclose a primary assembly having a voice coil assembly and a magnet. In an embodiment, the transducer housing may further be mounted within an external housing or mounting bracket having a rigid retaining wall and an excursion cover. This excursion cover may be formed of a malleable helix structure such as to protect the surface acoustic transducer from external disturbance, yet at the same time allow for an excursion of the transducer via the excursion cover. This prevents or minimizes the distortion of sound when, for example, a person leans against a cabin wall that a surface acoustic transducer is attached to, or other surfaces or materials that are in close or contacting proximity to the surface acoustic transducer, all without sacrificing the sound range and quality of the transducer.

(23) As schematically represented, FIGS. 1 and 2 illustrate a surface acoustic transducer 100 of the present invention. FIG. 1 provides a perspective view of the present transducer 100, and FIG. 2 provides a bottom profile view of the present transducer 100. As shown initially, the transducer 100 may exteriorly comprise a transducer housing 120 and a primary assembly 110 retained therein.

(24) The primary assembly 110 may form a substantially cylindrical shape and may comprise and/or be formed at least partially from a voice coil assembly 117, with at least a portion of its proximal end protruding outwardly from the transducer housing 120. The transducer housing 120 may comprise a flange 103 forming a proximal portion of the transducer housing 120, and a yoke 104 forming a distal portion of the transducer housing 120. Further, the distal end of the primary assembly 110 may terminate within the yoke 104.

(25) The flange 103 may be coupled to a proximal end of said transducer housing 120, forming a portion thereof. Said flange 103 being disposed in surrounding relations to the primary assembly 110. The flange 103 may comprise a terminal attachment 105 coupled to an end or edge of the flange as shown in the accompanying Figures. The terminal attachment 105 being structured with at least a positive terminal and negative terminal portion for receiving power from a power source, and further relay the power to a voice coil assembly 117. In at least one embodiment of the present invention, the transducer housing 120, or more particularly the diameter of the flange 103 comprises a diameter of between 25 mm to 30 mm.

(26) The yoke 104 may be coupled to a distal end of said transducer housing 120, forming another portion thereof. The yoke 104 may be coupled in at least partially surrounding relation to a distal portion of the primary assembly 110.

(27) Drawing attention to FIGS. 3A and 3B, respective side profile and partial cutaway side profile views of the surface acoustic transducer 100 are shown. As in FIG. 3A, the primary assembly 110 may further comprise a coupler ring 101 attached to a proximal end thereof. The primary assembly 110 may comprise a voice coil assembly 117 disposed between the coupler ring 101 and the yoke 104.

(28) Drawing attention to FIG. 3B, a partial cutaway view of the surface acoustic transducer 100 further illustrates a spider 102 at least partially coupled to the flange 103, and structured to dampen the movement of the primary assembly 110 comprising the voice coil assembly 117. As such, the spider 102 may be coupled in surrounding relations to the primary assembly 110, or more specifically, a portion of the voice coil assembly 117. A magnet 111 providing a magnetic field may be coupled to a distal end of the transducer housing 120 and disposed in proximity to a distal end of the primary assembly 110 and/or voice coil assembly 117, and the voice coil wires 116 thereof, such as when the voice coil assembly 117 is in a resting state. A top shunt plate 112 may form circumferentially along a distal portion of the voice coil assembly 117, and disposed in juxtaposing relations to the magnet 111.

(29) Drawing attention to FIG. 4A illustrating a cutaway view of the surface acoustic transducer 100, and more particularly FIG. 4B illustrating an exploded view of the cross section C, the voice coil assembly 117 comprises a voice coil former 115 and voice coil wire 116. The voice coil former 115 may comprise a cylindrical shape and may form a part or a portion of the voice coil assembly 117. The voice coil wire 116 may be wound in surrounding relations to at least a portion of the voice coil former 115, as illustrated in FIG. 4B, such that the voice coil wire 116 may be at least partially immersed within the magnetic field provided by the magnet 111.

(30) In at least one embodiment of the present invention, a top shunt plate 112 may be disposed in substantially overlying relations relative to the voice coil wire 116, while only a portion of the magnet 111 is disposed in overlying relations relative to the voice coil wire 116, when the voice coil assembly 117 is at a rest state. Further, the magnet 111 of the present invention is preferably mounted at a distance of approximately 0.33 mm away (or providing a gap of 0.33 mm) from the voice coil assembly 117, to ensure that the magnet 111 and voice coil assembly 117 do not collide. In other embodiments, the gap will be preferably between various ranges of 0.25 to 0.4 mm. When the voice coil assembly 117 is in an excited state, such as when electrically excited by an input electrical signal via the terminal attachment 105 from an external power source, the voice coil assembly 117 may move in accordance with the received signal. The spider 102 coupled to the flange 103 is in juxtaposing surrounding relations with the voice coil assembly 117, such as to abut the voice coil former 115 in order to at least partially impede and/or dampen its movement. In a preferred embodiment, the spider 102 is formed of a flexible material such as to allow for a large excursion range or movement of the voice coil assembly 117.

(31) Drawing attention back to FIG. 4A, and in at least one embodiment of the present invention, the transducer housing 120 is structured to house the primary assembly 110 including the voice coil assembly 117, and the magnet 111, such that the voice coil assembly 117 is disposed in movable relations relative to the magnet 111. In other words, the voice coil assembly 117 is movably attached to the transducer housing 120 comprising the flange 103 and the yoke 104, such that it may move axially outwards from the transducer housing 120 along a path of excursion during various excited state(s), and return to rest in a position as illustrated in FIGS. 4A and 4B.

(32) Moving further to FIGS. 12-13, other embodiments of the present invention further comprises an external housing 200 utilized for mounting the surface acoustic transducer 100 described above onto a surface or material, such as an interior cabin, bulkhead, and/or window panel of an aircraft. As indicated in FIG. 12, the external housing 200 may at least partially enclose the surface acoustic transducer 100, in order to retain the transducer 100 therein and attach the same to a surface via at least one mounting bracket, such as mounting bracket(s) 203 and/or 203. When mounted or installed therein, the transducer 100 maintains a center alignment with the external housing 200, and a center line screw 206 may be utilized to stabilize and affix the transducer 100 within the external housing 200, such that the screw may cooperatively enter a center aperture 205 of an excursion cover 201 forming on a proximal portion of the external housing 200, and reach distally down towards the yoke 104 attached to or forming the distal portion of the transducer housing 120, and therefore serving as a structural securing mechanism.

(33) Drawing attention to additional details in FIGS. 13A-13C, the external housing 200 generally comprises a retaining wall 202, at least one mounting bracket 203 and/or 203, and an excursion cover 201. The retaining wall 202 is preferably formed of a cylindrical shape and rigid composition such as to protect the interior thereof from external forces, such as when a person leans against a surface or interior cabin of an aircraft that the surface transducer 100 and external housing 200 are attached to. As such, the retaining wall 202 may further be attached to, or formed with, at least one mounting bracket 203 and/or 203, comprising at least one aperture on each bracket so as to secure the external housing 200 to a substantially flat surface by conventional means, such as nails or screws, or adhesive. In one embodiment, the mounting brackets or alternatively, their respective apertures, may be optional as the external housing may be secured to a surface via adhesives. In another embodiment, the mounting brackets or alternatively, their respective apertures may allow mechanical reinforcement of bonding from adhesive as adhesive flows into the aperture and onto the opposing surface creating a mushroom shape when dry resulting in additional mechanical fastening strength.

(34) The excursion cover 201 is formed on or attached to the retaining wall 202 via a plurality of contact portions 207. In the embodiment illustrated in FIG. 13B, the excursion cover 201 comprises a spiral or helix structure having three contact portions 207, such as to provide a degree of protection to the transducer 100 housed therein, yet at the same time allow for the excursion of the transducer 100, and more specifically its primary assembly and/or voice coil assembly outwardly. In other words, the structural configuration, composition, contact portions, and/or combinations therefore, support the malleability of the excursion cover 201, which may also move outwardly in response to the transducer 100 entering excited state(s), and therefore help support a richer and more vibrant sound rather than dampening it. Of course, in other embodiments, it should be understood that two or more contact portions 207, in addition to various compositional and physical characteristics of the excursion cover 201, may be used, depending on the degree of malleability or rigidness required.

(35) In one embodiment, the external housing 200 may be formed from injection molding as an injection molding resin including but not limited to polypropylene, polyethylene, ABS, polycarbonate, glass reinforced molding resin, injection molding resin with flame retardant. In other embodiments, the external housing 200 may be formed from steel stamping, and/or other appropriate materials known to those skilled in the art.

(36) Drawing attention to back to FIGS. 5-11, each element of the transducer 100 of the present invention is further shown separately in perspective views.

(37) FIG. 5 illustrates a coupler ring 101 of the present invention. The material composition of the coupler ring 101 may comprise polycarbonate, plastic, and/or other appropriate materials or combinations thereof. The coupler ring 101 may be intended to be disposed against an external surface, such as an aircraft's interior cabin, in order to transfer the vibrations from the primary assembly for the production of sound.

(38) FIG. 6 illustrates a voice coil assembly 117 comprising a voice coil former 115 attached to the coupler ring 101. The voice coil former 115 is preferably formed of aluminum, but may also utilize other appropriate materials. The voice coil former 115 may comprise a thickness of approximately 0.05 mm in a preferred embodiment of the present invention. A voice coil wire 116 may be wound in surrounding relation to the voice coil former 115. In a preferred embodiment, the voice coil former 115 and wire 116 may comprise a diameter of 20-28 mm. In another embodiment, a single layer winding of the voice coil wire may result in a diameter of 26.5 mm. In another embodiment, a two-layer winding may result in a diameter of 26.8 mm. The voice coil wire 116 is preferably formed of copper but may also utilize other appropriate materials. In at least one embodiment of the present invention, the surface acoustic transducer 100 comprises a voice coil having a wattage of between 20 W to 30 W. In a preferred embodiment, the voice coil will have a wattage of 25 W.

(39) FIG. 7 illustrates a magnet 111 of the present invention for providing a magnetic field to the voice coil assembly 117 and voice coil wire 116 thereof. The magnet 111 may comprise a neodymium iron boron (NdFeB) N42H magnet in at least one embodiment. Of course, other grades of NdFeB ranging from N24 to N52 may be used in other various embodiments of the present invention. Various other materials may include Alnico (AlNiCo), Samarium Cobalt (SmCo), as well as other known and appropriate rare-earth magnet or permanent magnets may be utilized. In a preferred embodiment, the magnet comprises a substantially cylindrical and/or disc shape or profile.

(40) FIG. 8 illustrates a flange 103 of the present invention, and structured to retain a terminal attachment 105 for receiving electrical input from an external source. The material composition of the flange 103 may comprise a polycarbonate or plastic compound and/or mixture.

(41) FIG. 9 illustrates a spider 102 of the present invention, and structured and cooperatively disposed to dampen or at least partially impede the movement of the voice coil assembly 117. The material composition of the spider 102 may comprise a resin dipped cloth or fabric. However, other flexible materials and/or coatings known to those skilled in the art may also be used in order to accomplish a desired mechanical compliance (or the inverse of stiffness). The preferred mechanical compliance of the spider 102 is 0.23 millimeters per Newton (mm/n), offering a greater excursion range (less damping) than other transducers known in the art. A range of between 0.2 mm/N to 0.3 mm/N may also be used in various other embodiments.

(42) FIG. 10 illustrates a top shunt plate 112 of the present invention, preferably coupled to the magnet 111 of the present invention. The material composition of the top shunt plate 112 may comprise a mild steel or low carbon steel such as EN1A, but may also comprise other appropriate metals known to those skilled in the art.

(43) FIG. 11 illustrates a yoke 104 of the present invention, forming a distal end of the transducer housing 120. As shown, the yoke may comprise a plurality of taps for the insertion of screws such as M4 screws or other screws for affixing and stabilizing the transducer housing 120. The yoke 104 may similarly comprise a mild steel or low carbon steel such as EN1A, but may also comprise other appropriate metals known to those skilled in the art.

(44) Further embodiments of the present invention are directed to systems and methods for using the surface acoustic transducer of the present invention, or like transducers, in order to produce quality sound and/or for noise cancelling applications.

(45) In at least one system embodiment of the present invention, a plurality of surface acoustic transducers, such as the transducer 100 described above, may be attached a panel or surface such as a window, a wall, or an interior cabin of a vehicle. Specifically, one embodiment may be directed to an aircraft window panel having a plurality of surface acoustic transducers disposed thereon and hidden beneath the bulkhead or cabin wall within an aircraft.

(46) At least one embodiment of the panel may be directed to noise cancelling operations for reducing the net vibration of the window and/or various panels or surfaces in proximity thereof. As such, a plurality of surface transducers may be mounted to a surface of a window and/or window panel underneath a bulkhead or other non-visible area internal to an aircraft cabin, as external noise generally resonates loudest at the windows. Ideally, the transducers are mounted along a perimeter of the window, so as to avoid obstruction of the view, such as general illustrated in FIGS. 14 and 15 as systems 300 and 400 respectively. These Figures and systems are example embodiments of various configurations of transducer 100 placement via external housing 200, and are by no means limiting. In other words, any number of transducers 100 may be mounted via housing 200 on one or more external and/or internal structural window panels, dust covers, chromatic and/or electrochromatic panels, glass, or other transparent materials, as well as nontransparent bulkhead connections, that may act as points of entry of external sound such as engine noise into an interior cabin of an aircraft or other vehicle.

(47) The panel may further comprise various components configured for active noise control (ANC) or noise cancellation, such as to cause the plurality of transducers to emit an anti-noise signal in order to counter the noise source, and installed or disposed within an interior or non-visible portion of an aircraft cabin in proximity to the window panels whether by wired or wireless communication to each of the transducers 100. For example, the panel may comprise a power source, a receiver module, a processing unit, and at least one transducer. The receiver module may be mounted within an interior or exterior of the panel, or may be mounted remotely and be communicably connected to the panel and the processing unit. The receiver module may comprise a microphone, and is configured to receive sound signals or noise signals to relay to the processing unit. The processing unit is configured to receive the noise signals and produce an anti-noise signal, which may comprise a sound signal with the same amplitude but with an inverted phase relative to the noise signal (or antiphase). This anti-noise signal is then transmitted to the at least one transducer to be reproduced at the panel, therefore canceling any noises received by the receiver module, such as external engine noise.

(48) Other embodiments of the present invention may be directed to methods for sound processing as directed to a surface acoustic transducer, such as transducer 100 described above. As discussed, one known limitation in the art is the inadequacy of bass frequencies of surface transducers, primarily due to their mechanical limitations, i.e. the lack of adequate mechanical excursion. To overcome this limitation, and in order to provide a richer bass sound, a method of the present invention contemplates first selecting the various points at which to limit the peak decibels of a sound signal. Next, the sound is processed at these points, such that the amplitude of the sound signal is reduced and its frequency proportionately enhanced. This, and other sound processing methodology may be accomplished pursuant to the Applicant's digital signal processing methods as recited in U.S. Pat. No. 8,160,274, which is hereby incorporated by reference in its entirety.

(49) It should be understood that the above steps may be conducted exclusively or nonexclusively and in any order. Further, the physical devices recited in the methods may comprise any apparatus and/or systems described within this document or known to those skilled in the art.

(50) Since many modifications, variations and changes in detail can be made to the described preferred embodiment of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents.

(51) Now that the invention has been described,