US3037577A

US3037577A - Acoustical enclosures

Info

Publication number: US3037577A
Application number: US810483A
Authority: US
Inventors: Herbert H Steglich
Original assignee: Zenith Radio Corp
Current assignee: Zenith Electronics LLC
Priority date: 1959-05-01
Filing date: 1959-05-01
Publication date: 1962-06-05
Anticipated expiration: 1979-06-05

Description

June 5, 1962 H. H. STEGLICH ACOUSTICAL ENCLOSURES Filed May 1, 1959 .Z-Fal 5 4 2 2L7 H "a Z M r h w W :1 a H/ W 7 1 I B i i n 2 m J .2 a. I T fi l i H4 u [El 2 27 l m. m 5\ I m m i i w W m w M Q M c. 0 6 Wu 2 M 2 E'QS INVENTOI? Herberi H ,S'Zeg Zz'ch V ATTORNEY United States Patent 9 3,037,577 ACOUSTICAL ENCLOSURES Herbert H. Steglich, Wilmette, Ill., assignor to Zenith Radio Corporation, a corporation of Delaware Filed May 1, 1959, Ser. No. 810,483 4 Claims. (Cl. 18131) This invention is directed in general to acoustical enclosures, and more particularly to radio cabinets and the like.

In the design of radio cabinetry, the use of grille-cloth material or a louvred panel construction for the decorative front piece overlying the loudspeaker is conveniently resorted to in order to conceal the speaker and its mounting panel. If the grille-cloth consists of a Weave of substantially rigid material, acoustical "loss is not severe; however such material does not withstand abuse and can be permanently damaged even by digital pressure.

A louvred construction, on the other hand, while effectively concealing the loudspeaker, attenuates the higher audio frequencies by preventing direct acoustical radiation from the speaker. Radio receivers, such as FM sets, capable of high fidelity reproduction therefore usually employ a grille-cloth cabinet construction to permit straight-through acoustical radiation. This in turn has resulted in rather stereotyped cabinet designs.

Moreover, radio cabinets are frequently provided with decorative trim conforming to the size and shape of the loudspeaker, and such trim cannot be mounted conveniently unless maintained in alignment with the speaker itself. This practice obviously subverts cabinet and escutcheon design to the orientation of the mechanical constituents of the receiver.

It is therefore an object of the invention to provide a cabinet construction which effectively conceals underlying structure, such as a loudspeaker or the like, without the use of grille-cloth.

It is a further object of the invention to provide a cabinet construction which achieves this objective without limiting or attenuating the high audio frequency performance of the unit.

Still another object of the invention is to provide such a cabinet construction which provides for great latitude of design in permitting the use of decorative trim as desired without regard to the mechanical construction of the enclosed audio reproducer.

In accordance with the invention, an acoustical enclosure comprises a cabinet having side panels and a darkcolored front panel which is provided with a principal aperture for accommodating a sound-directing member such as the diaphragm of a conventional loudspeaker. An escutcheon of substantial thickness overlies the front panel and is provided with a plurality of straight-through openings having a width which is less than the thickness of the escutcheon. A sound reproducer is disposed within the enclosure and comprises a dark-colored sounddirecting member in register with the principal aperture in the front panel. Mounting means, coupled between the escutcheon and the cabinet are provided for attaching the escutcheon to the cabinet in spaced juxtaposition with the front panel to provide a clearance between the escutcheon and the front panel to prevent chattering of the escutcheon against the cabinet and to render the front panel and the sound-directing member substantially invisible through the openings in the escutcheon.

The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood however, by reference to the following description taken in conjunction with the accompanying drawings, in the several fig- 3,037,577 Patented June 5, 1962 ice ures of which like reference numerals identify like elements, and in which:

FIGURE 1 is an elevational view, partly in section, of a radio receiver embodying the subject invention;

FIGURE 2 is a cross-sectional view taken along line 22 in FIGURE -1;

FIGURE 3 is a fragmentary cross-sectional view taken along line 3-3 in FIGURE 2; and

FIGURE 4 is a fragmentary view, similar to that of FIGURE 3, illustrating an alternate construction of the subject invention.

The radio receiver shown in FIGURES 1 and 2 comprises an acoustical enclosure, specifically a radio cabinet 10, having a plurality of side panels 11 and a recessed dark-colored front panel 12 which is provided with principal and

auxiliary apertures

13 and 14 respectively. A radio chassis 15 is mounted within the cabinet and includes a pair of

loudspeakers

16, 17 having respective dark-

colored diaphragms

18, 19 in register with

apertures

13, 14, respectively. The radio receiver is further provided with a tuning selector 20 and a pair of

audio controls

21, 22.

An escutcheon 23 of substantial thickness overlies recessed panel 12 and is provided with a plurality of in dividually narrow and preferably uniformly distributed unobstructed straight-through openings 24'. The maximum thickness of the escutcheon is determined by the frequency range of the associated receiver, that is, the thickness must not exceed a small fraction (less than onefourth) of a wavelength at the highest audio frequency to be reproduced. This requirement is necessary to avoid a hollowed sound, sometimes designated tube effect. On the other hand, the escutcheon thickness is preferably greater than the width of the individual openings 24 to provide for most effective concealment of the underlying structure. While the openings 24 as shown are uniformly distributed throughout the escutcheon, actually it is only necessary to have that portion of the escutcheon overlying the

loudspeakers

16, 17 apertured, and non-uniformity of the aperture pattern is not detrimental so long as the other criteria set forth herein are observed. In order to minimize attenuation of the higher audio frequencies, the total aperture area presented to the loudspeakers constitutes at least 30% of that portion of the escutcheon directly in front of the loudspeaker diaphragtns; more briefly stated, the transmission factor of the escutcheon is at least 30% to maintain optimum loudspeaker fidelity.

A plurality of spaced support studs 25, which are preferably integrally formed with escutcheon 23, and a like number of conventional fasteners such as screws 26, comprise mounting means for securing escutcheon 23 to recessed panel 12 in spaced juxtaposition therewith and with the front edges of side panels 11, as best shown in FIGURE 3. Support studs 25 are spaced inwardly of the periphery of the escutcheon for concealment and to facilitate mounting the escutcheon directly upon the recessed panel 12. This construction provides a clearance between the escutcheon and the cabinet to prevent undesirable chattering of the escutcheon against the cabinet side panels 11 in response to vibration of front panel 12 sympathetically with the loudspeakers. To illustrate the design flexibility resulting from the use of the present invention, escutcheon 23 is provided with a depressed central portion 27 framed with decorative trim to create the illusion of a loudspeaker in a position unrelated to that of the

actual loudspeaker system

16, 17 on recessed panel 12.

In operation, even the high audio frequency components are passed with negligible attenuation because of the straight-through openings incorporated in escutcheon 23. However, "both recessed panel 12 and the

loudspeaker diaphragms

18, 19 are effectively concealed under any but the closest and most scrutinizing inspection. This is attributable in part to the spacing of escutcheon 23 from front panel 12 and the use of narrow openings in an escutcheon of substantial thickness which provides for parallax concealment of the front panel and, in part, to the shadows cast upon the recessed front panel by the forwardly projecting portions of side panels 11 in response to peripheral illumination components. The frontal 1ighting which does gain access through the narrow openings is rendered relatively ineffective through the use of a front panel 12 which is dark-colored to minimize the contrast with the speaker diaphragms and to provide for substantial light absorption FIGURE 4 discloses an alternative cabinet construction in which the front panel 12 is mounted flush with the front edges of side panels 11. The escutcheon member 23 differs from that of the principal embodiment in that an inwardly extending peripheral flange 30, preferably of integral construction, replaces mounting studs 25, being provided with threaded holes for receiving screws 26 by which the escutcheon 23 is secured to front panel 12. A vibration inhibiting gasket 31 of resilient material such as rubber is interposed between flange 30 and the cabinet. This alternative construction eliminates the necessity of a recessed front panel since flange 30 and gasket 31 shield the front panel 12' from peripheral illumination while the spaced narrow openings in the thick escutcheon obscure the front panel and the speaker diaphragms as in the principal embodiment.

The invention thus provides a new and improved cabinet arrangement of a simple and economical construction which provides greatly increased design flexibility through concealment of underlying structural components without the use of grille-cloth, and without imposing any acoustical limitations on the audio fidelity achieved with the contained radio or other unit.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broader aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

I claim:

1. An acoustical enclosure comprising: a cabinet having side panels and a dark-colored front panel provided with a principal aperture for accommodating a sounddirecting member; an escutcheon of substantial thickness overlying said front panel and provided with a plurality of unobstructed straightathrough openings having a width which is less than said thickness of said escutcheon; a sound-reproducing device disposed within said enclosure and comprising a dark-colored sound-directin g member in register with said principal aperture in said front panel; and mounting means coupled between said escutcheon and said cabinet comprising a plurality of spaced support studs for attaching said escutcheon to said cabinet in spaced juxtaposition with the front edges of said side panels and said front panel for preventing chattering of said escutcheon against said cabinet and for effectively concealing said front panel and said sound-directing member despite the provision of said straight-through openings in said escutcheon.

2. An acoustical enclosure comprising: a cabinet having side panels and a recessed dark-colored front panel provided with a principal aperture for accommodating a loudspeaker; an escutcheon of substantial thickness overlying said front panel and provided with a plurality of unobstructed straight-through openings having a width which is less than said thickness of said escutcheon; a loudspeaker mounted within said enclosure and comprising a dark-colored diaphragm in register with said principal aperture in said recessed front panel; and means including a plurality of spaced support studs integral with said escutcheon of a length greater than the amount by which said panel is recessed and spaced inwardly from the periphery of said escutcheon for attachment to said front panel to maintain said escutcheon in spaced juxtaposition with the front edges of said side panels and said front panel for preventing chattering of said escutcheon against said cabinet and for effectively concealing said recessed front panel and said diaphragm despite the provision of said straight-through openings in said escutcheon.

3. An acoustic enclosure comprising: a cabinet having side panels and a dark-colored front panel provided with a principal aperture for accommodating a loudspeaker; a loudspeaker mounted within said cabinet and comprising a dark-colored diaphragm in register with said principal aperture in said front panel; an escutcheon of substantial thickness overlying said front panel and having a recessed portion, said recessed portion provided with a plurality of unobstructed straight-through openings having a width which is less than said thickness of said escutcheon and displaced relative to said loudspeaker aperture; and mounting means coupled between said escutcheon and said cabinet for attaching said escutcheon to said cabinet in spaced juxtaposition with the front edges of said side panels and said front panel to provide a clearance between said escutcheon and said front panel thereby effectively concealing said front panel and said diaphragm despite the provision of said straight-through openings in said escutcheon.

4. An acoustical enclosure comprising: a cabinet having side panels and a dark-colored front panel provided with a principal aperture for accommodating a sound-directing member; an escutcheon of substantial thickness overlying said front panel and provided with a plurality of unobstructed straight-through openings having a width which is less than said thickness of said escutcheon; a soundreproducing device disposed within said enclosure and comprising a dark-colored sound-directing member in register with said principal aperture in said front panel; and mounting means coupled between said escutcheon and said cabinet for attaching said escutcheon to said cabinet in spaced juxtaposition with the front edges of said side panels and said front panel for preventing chattering of said escutcheon against said cabinet and for effectively concealing said front panel and said sound directing member despite the provision of said straight-through openings in said escutcheon.

References Cited in the file of this patent UNITED STATES PATENTS 2,113,623 MacNabb Apr. 12, 1938 2,247,171 Harman June 24, 1941 2,282,384 Schenck May 12, 1942 2,552,309 Carlson et al. May 8, 1951 2,829,728 Brown Apr. 8, 1958 2,853,145 Martin Sept. 23, 1958