US3391754A - Waterproof radio receiver with hermetically sealed housing construction for a loudspeaker - Google Patents

Description

July 9. 1968 J. J. MONTANARO WATERPROOF RADIO RECEIVER WITH RERMETIOALLY SEALED HOUSING CONSTRUCTION FOR A LOUOSPEAKER Filed April 2, 1965 par 2 JOSEPA/ L. MOA/Tombe@ f/wE/vroe.

E4 eyW/ffy, LE/fad United States Patent O WATERPROOF RADIO RECEIVER WITH HER- METICALLY SEALED HOUSING CONSTRUC- TION FOR A LOUDSPEAKER Joseph J. Montanaro, 2550 Murrell Road', Santa Barbara, Calif. 93105 Filed Apr. 2, 1965, Ser. No. 445,115 4 Claims. (Cl. 181-31) ABSTRACT OF THE DISCLOSURE Waterproof speaker construction including a housing of water impermeable material having an open front, a front cover also of water impermeable material hermetically attachable to the housing an-d having a speaker opening formed therein and a rearwardly facing groove surrounding the opening, a flexible im-permeable membrane extending across the opening having bonded thereto a resilient ring received in the groove, and a speaker within the housing and mountable on the cover, with its acoustic output end adjacent the speaker opening, the speaker including a peripheral mounting flange overlying the portion of the membrane bonded to the resilient ring, the mounting flange being attachable to the cover outwardly of the cover groove by fastening members, whereby movement of the flange into its final mounted relation on the cover serves to abuttingly compress the ring into the groove and thereby to insure that assembly of the speaker fiange to the cover does not impose tension on the membrane, and the slackness or tension of the membrane will be as predetermined by the dimensions of the vring and groove, it being desirable that the membrane be under little if any tension.

The present invention relates generally to the construe tion of a battery-powered radio receiver, and more `particularly discloses such a construction hermetically sealing the interior of the cabinet housing the receiver; in its preferred form the internal volume of the cabinet so sealed affords sufficient buoyancy so that the entire receiver will float in water.

In accordance with the preferred form of the invention hereinafter described and illustrated in detail, there is provided a housing or cabinet made of suitable lightweight material such as a plastic and having generally rectangular open front. A facade or front cover is provided for closing the open front of the cabinet, the facade being joined to the cabinet along a waterproof line of juncture by the provision of a generally peripheral gasket therearound. Control knob shafts extend through the facade to the interior of the cabinet in order to operate the adjustable elements of the receiver, and passage of such shafts through the facade is made waterproof by suitavble means such as O-rings.

It is particularly important that the speaker opening be properly waterproofed in such a way as to minimize adverse effects on the acoustic output of the speaker.

In accordance with the present invention, this is accomplished by providing a thin flexible imperforate membrane of material such as sheeting of rubber or equivalent material such as neoprene, the membrane extending across the speaker opening and being hermetically sealed to the periphery of such opening. The membrane is maintained under little, if any, tension. It is found by this construction that the sound waves generated by the diaphragm of the speaker are transmitted through the membrane to the listener with virtually no deterioration in quality. When the membrane is mounted in accordance with the invention, there is in fact an effective filtering by the membrane of most of the high frequency hissing noises characteristic of battery-powered transistor radio receivers. Attenuation of the lower audio frequencies oc- 3,391,754 Patented July 9, 1968 ICC curs to only a limited degree, with the result that the total acoustic output reaching the listener is well balanced and pleasing.

Accordingly, it is a peripheral object of this invention to provide and disclose novel improvements in the waterproofing construction of a radio receiver. Other objects and purposes are to provide, in such a construction, flexible membrane means, impervious to water, hermetically mounted across the output end of the loud speaker of the receiver; to provide, in such construction, a radio receiver sufficiently buoyant and water-impermeable to permit the receiver to float in water; and for other and allied objects and purposes as will be clear `from the following description of a preferred embodiment of the invention, taken in connection with the accompanying drawing in which:

FIG. 1 is a front elevational view of a radio receiver embodying the present invention, with a portion of the front cover or facade broken away.

FIG. 2 is a vertical sectional view taken along the broken line II-II of FIG. 1.

FIG. 3 is a fragmentary view looking outwardly from within the cabinet showing the upper right portion as so viewed, taken along the arrows III-III of FIG. 2.

FIG. 4 is a sectional view taken along the arrows IV- IV of FIG. 3.

FIG. 5 is a fragmentary sectional view taken along the broken line V-V of FIG. l.

Referring now in detail to the drawing, there is seen in FIGS. 1 and 2 a radio receiver housing or cabinet indicated generally at 10, having a rear wall 12 and generally forwardly extending top and bottom walls 14 and 16 and side walls 15 and 17. A suitable carrying handle is indicated generally at 18, including a pair of downwardly extending legs 19 and 20 attached to the upper wall 14 of the cabinet by suitable hermetically tight means. Thus in the present embodiment of the invention, leg 19 is provided with a downwardly extending threaded stud 21 projecting through openings in a sealing gasket 22 and in the cabinet upper wall 14 and structural rib 23, the stud being retained in assembled relation as shown by a nut 24 threaded on the lower end of the stud. The other handle leg is, of course, similarly attached to the cabinet.

The otherwise open front of the cabinet is closed by a front cover member or facade indicated generally at of approximately rectangular shape. Cabinet 10` and facade 30 are retained in hermetically tight assembled relation as seen in FIG. 2 by suitable means, preferably including an elongated threaded screw near each of the four corners of the cabinet extending forwardly from the cabinet rear wall 12 into threaded engagement with the facade. For example, as seen in the lower portion of FIG. 2, an elongated screw indicated generally at 34 extends forwardly from the rear wall 12 of the cabinet, being housed in a tubular boss 36 carried by the cabinet, and the forward end portion of the screw 34 is threadedly received at 38 in an internally threaded boss 40 carried by and preferably formed integrally with the facade. The head 42 of screw 34 is received in a recess 44 formed in the Arear wall 12, and a sealing Washer 46 beneath the head 42 insures a hermetically tight connection.

Hermetic sealing between the facade and cabinet is further assured by the provision of a peripheral gasket carried by the facade and extending continuously immediately inwardly of the outer rectangular walls of the facade. Thus, with further reference to FIG. 2, a portion of the continuous sealing gasket is indicated generally at 50 housed in a rearwardly open groove 52 formed in the facade; and in the lower portion of FIG. 2, sealing gasket 50 is housed in a similar groove 54 in the facade. The front edges of the forwardly projecting walls of the cabinet are maintained in sealing contact with the gasket Y' 50 by the retaining screws 34, the gasket being made of suitable resilient material such as rubber or equivalent.

Hermetic sealing means are provided in connection with the control shafts of the present radio, there being three of such shafts provided with external knobs in the present embodiment of the invention. Thus, as seen in FIG. l, there may be a tuning knob indicated generally at 60, an off-on and volume control knob indicated generally at 62, and a tone control knob indicated generally at 64. The hermetic sealing means in connection with each of these may be the same, and such means on the tone control knob and its associated shaft are seen in detail in FIG. 5. Thus, knob =64 is fixed by suitable means to the outer end of a shaft indicated generally at `66 having mounted thereon a sealing O-ring 68 received in a groove 70 formed in the shaft. The outer periphery of the O-ring 68 forms sealing contact with the inner cylindrical surface of bore 72 formed in a boss indicated generally at 74, carried by and extending rearwardly from the facade Hermetic sealing of the speaker opening in the facade will be understood by reference to FIG. 2 and to the fragmentary views FIGS. 3 and 4 based thereon. A conventional speaker indicated generally at S includes a generally annular metallic mounting flange indicated generally at 82, provided with a number, preferably four, angularly spaced attachment ears, two of which are seen at 84 and 86, extending generally radially outwardly from the major body portion of the flange 82. A mounting screw 88 (see FIG. 4) extends through an opening formed in each of the ears, and is threadedly connected to a rearwardly extending internally threaded boss 90 carried by the facade, and preferably formed integrally therewith. Flange 82 also carries, immediately inwardly of its outer periphery, the outer marginal portion of the conventional cone diaphragm 92 of the speaker 80, as well as an annular spacing member or washer 94, the spacing member and marginal portion of the diaphragm 92 vbeing held in assembled relation as seen in FIG. 4 by suitable means, preferably adhesive, between the several parts.

A membrane assembly indicated generally at 100 (see FIG. 2) includes a membrane proper 102 made of thin sheet rubber or equivalent material such as neoprene, the membrane having its outer annular marginal portion bonded between a pair of annular rings 104 and 106, made of rubber or similar resilient material, resistant to deterioration or other adverse effects of exposure to water. The outer of the two rings, 104, is received in a rearwardly open annular groove 110 formed in the facade 30, thereby positioning the membrane 102 completely across the forwardly directed face of speaker 80. When the parts are assembled, as seen in FIGS. 2, 3 and 4, the fibre spacing ring 94 carried by the speaker ange 82 is forced into tight engagement with annular member 106 of the membrane assembly, so that annular member 104 of the assembly is similarly under compression within groove 110, thus providing a hermetically sealed connection around the speaker opening of the facade.

Membrane 102 is desirably maintained under little, if any, tension in its mounting as above discussed. By this arrangement, the acoustic output of the cone diaphragm 92 of speaker 80 is transmitted outwardly through the membrane without serious attenuation of sound energy. Such attenuation as does exist is primarily in the higher audible frequencies, thereby minimizing transmission of the hissing noise frequently observed in portable, battery-powered radio receivers. Very satisfactory results have been achieved through the use of a membrane 102 made of sheet neoprene having a thickness of approximately 1%4" or less.

It is to be especially noted that the present construction enables the use of a conventional speaker. Some prior attempts have been made to Waterproof speakers by impregnating the diaphragm in a water-resistant material such as resin, but this tendsmto seriously denigrate Vthe acoustic `bass properties of the diaphragm because of the stiffening resulting from the impregnation treatment.

The preferred construction of a receiver in accordance with the .present invention may incorporate a cabinet and facade having overall dimensions of `the order of 9 inches in width, 7 inches in height and 4 inches in depth. With circuit components now generally available, and even including the necessary. batteries, a receiverof the indicated dimensions isbuoyant in water. Thus the cabinet may be made of a lightweight plastic material and the facade and handle of a lightweight metal suc-h as zinc.

Facade 30 may be provided with an ornamental grille extending across the speaker opening outwardly of the membrane to protecty the latter againstpossible damage and rupture as by contact with items floating in a swimming pool .or other Water Vwhere the receiver is used. Thus a grille indicated generally at and including a number of thin spaced parallel bars 122 may be carried by the facade 30 across the speaker opening 124 thereof and preferably formed integrally with the facade. The grille is spaced forwardly of the membrane 102, well out of. possible contact with the membrane.

-Modifications and changes from the illustrative embodiment of the invention hereinbefore illustrated and described are within the contemplation of the invention, and are intended to be embraced within the scope of the appended claims.

I claim:

1. A hermetically sealed housing construction for a loudspeaker comprising:

a housing of water impermeable material having an open front;

a cover member hermetically closing said open front, the cover member having formed therein a speaker opening and a rearwardly directed groove surrounding the opening;

a exible impermeable membrane extending across the opening having bonded thereto a resilient ring received in the groove;

a speaker mounted on the cover member and extending rearwardly in the housing, and having an acoustic output end adjacent the speaker opening, the speaker including flange means overlying the portion of the membrane bonded to the ring;

and attachment means for mounting the flange means to the cover outwardly of the groove and compressing the ring in the groove.

2. The invention as defined in claim 1 wherein the annular portion of the membrane immediately inwardly of the groove is spaced yfrom the cover.

3. In a waterproof speaker construction including an open front housing, a cover -for closing the front and having formed therein a speaker opening and a rearwardly directed groove surrounding the opening, a speaker in the housing having lan acoustic output portion adjacent said opening and mounting flange means attachable to the cover outwardly of the groove, the provision of:

a flexible impermeable membrane having bonded thereto a resilient ring received in the groove and maintained under compression therein when the flange is mounted to the cover.

4. The invention as defined in claim 3 wherein the ring is bonded to the front surface of the membrane.

References Cited UNITED STATES `PATENTS 2,175,025 10/1939 Hooven 32.5-352 XR 2,755,343 7/1956 Levy 179-1155 l3,162,813 12/1964 Piccinini 325--360 XR

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