US 2630526 A
Description (OCR text may contain errors)
March 3, 1953 v. I. ZELOV 2,630,526
HOUSING FOR RADIO RECEIVERS Filed Nov. 4, 1948 2 SHEETS-SHEET 1 HTZ'ORNEY March 3,1953 v. I. ZELOV nousmc FOR RADIO RECEIVERS 2 SHEETS-SHEET 2 Filed NOV. 4, 1948 INVENTOR HTTOENEY Patented Mar. 3, 1953 UNITED STATES PATENT OFFICE 3 Claims.
This invention relates to radio apparatus and the like, more particularly to home receiving sets, and has for an object to provide improved apparatus of this character.
Another object of the invention is to provide a radio apparatus having a plastic casing which is circular in cross section, whereby the tools for forming the latter may be turned on a lathe with consequent minimum tooling costs.
Yet another object of the invention is to provide a radio apparatus in which the chassis is retained in position solely by clamping between the front of the casing and a removable rear panel.
A further object of the invention is to provide, in a radio, means for cross ventilation for improved cooling of the interior thereof.
Another object of the invention is to provide a radio apparatus having unitary front and side walls and a separable rear panel, together with resilient leg members which clamp the rear panel to the unitary front and side wall structure.
Yet another object of the invention is to provide a radio apparatus having a plastic casing of circular cross section and a flat horizontal chassis, with the heat-emanating elements so arranged on the chassis that the hottest elements are located adjacent the transverse center of the casing, whereby they are spaced the maximum distance from the plastic casing.
A further object of the invention is to provide a radio apparatus whose casing is closed at all sides, but wherein the front and rear walls are provided with openings for cross circulation of cooling air therethrough.
An additional object of the invention is to pro vide a radio apparatus whose speaker is positioned rearwardly of the tubes.
A further object of the invention is to provide a radio apparatus whose speaker is positioned rearwardly of the tubes with the speaker diaphragm adjacent the latter so that it is heated by the tubes during normal use.
Thermoplastic materials are easier to form and possess many advantages over thermosetting materials, but heretofore it has been considered impractical to use the former for radio apparatus casings due to the fact that it tends to deform at temperature of from 150 degrees F. to 200 degrees F., which temperatures may be reached or exceeded in conventional radio apparatus. Thermo-setting materials, on the other hand, can withstand temperatures as high as 400 degrees F.
Accordingly, it is another object of the invention to provide a radio apparatus in which the maximum temperatures are sufficiently low to permit use of a casing of thermo-plastic material.
These and other objects are effected by the invention as will be apparent from the following description and claims, taken in connection with the accompanying drawings forming a part of this application, in which:
Fig. 1 is a front perspective view of a radio apparatus constructed with the present invention;
Fig. 2 is a rear perspective view of the radio apparatus shown in Fig. 1;
Fig. 3 is an exploded rear perspective view of the radio apparatus shown in Figs. 1 and 2;
Fig. 4 is an enlarged fragmentary sectional view, taken along the line IVIV of Fig. 3, looking in the direction indicated by the arrows;
Fig. 5 is a perspective view of one of the leg members;
Fig. 6 is a sectional view, taken along the line VIVI of Fig. 1, looking in the direction indicated by the arrows.
Fig. '7 is a sectional view, taken along the line VII-VII of Fig. 6, looking in the direction indicated by the arrows;
Fig. 8 is a fragmentary front elevational View of a modification of the invention; and,
Fig. 9 is a sectional view, taken along the line IX-IX of Fig. 8, looking in the direction indicated by the arrows.
Referring now to the drawings more in detail, the reference character I0 indicates, in its entirety, a radio receiving set or the like, including a casing I I which is circular in cross section and comprised by a cylindrical portion I2 having an integral front wall l3 and a separable rear wall in the form of an independent panel I4. As result of the casing II being completely circular in cross section, the dies, punches and other tools required for its manufacture can be produced by relatively simple turning operations on a lathe, as distinguished from the expensive and com" plicated machine operations involved in producing tools for manufacture of conventionally shaped home receiving sets, which are generally rectangular.
Preferably, the front wall I3 includes a centrally-located boss it havin an enlarged opening I"! therethrough (Fig. 6), in which is positioned the journal portion I8 of a tuning dial I9. The dial I9 is fixedly secured to the forward end of a shaft 20 carried by the usual tuning condenser 2|. a
Directly below the tuning dial I9 is an off-on 3 and. volume control dial 22 rotatably mounted in the inwardly-directed boss 23 (Fig. 6).
Disposed in the lower portion of the casing is a flat horizontal chassis 25 on which are mounted many of the conventional elements of a radio receiving set including a power output tube as and a rectifier tube 21, both of which will be referred to later. The chassis has a pair of forwardly-extending lugs 28 at its front edge, received in openings29 formed in bosses 3d integral with th innersurface of the front wall it (Figs. 6 and '7). A pair of similar lugs 3i extend rearwardly from the rear edge of the chassis 2e and are received in mating recesses. 32 formed in the rear panel I 4 (Figs. 3 and '7). From consideration of Fig. 7 it will be apparent that no other supporting or securing means for the chassis 25 is necessary, and that the chassis may be conveniently removed simply by taking off the rear panel 14 and moving the chassis rearwardly from the casing.
Heretofore it hasbeen considered impractical to construct the casings for radio receiving sets of thermo-plasticmaterials, as such materials are subject to deformation at temperatures of the order of 150 to 200 degrees R, which temperatures may frequently be exceededduring normal operation of such apparatus. Consequently, where plastic materials have been desired, those of a thermo-setting nature have been relied upon as they are satisfactory up to temperatures as high as 400 degrees F. However, the thermosetting materials are: subject to wastage due to cracking or other, forms of damage occurring durin manufacture.-
The present invention renders possible the use of the more satisfactorythermal-plastic materials, by incorporating novel means for cooling the casing. To this end the hottest elements in the apparatus, such as the power output tube 26 and the rectifier tube 21, areso positioned with respect to the circular configuration of the casing as to place them the maximum distance from the latter. As best shown in Figs. 3 and 7, these tubes are located adjacent the axial center line of the casing-where the maximum height of the casing occurs, with consequent maximum spacing of these tubes fromthe thermo-plastic wall structure.
To promote removal of heat from the interior of the casing, provision is made for cross venti lationof the latter. To thisend the front wall 13 is provided with a plurality of openings shaped and located to beornamental as well as functional. Likewisetherear, panel it is formed at its edges with spaced lugsSB, providin therebetween openings 31. for: circulation of air through the interior of the casing; to, promote removal of heat therefrom.
The openings 35 in the; front wall it not only cooperatewith the-openings 3'! in the rear panel to provide for cross, ventilation, but also serve as emission. openings for sounds from the speaker it, which is positioned at the rear of the casing, in anovel manner.
As shown in Figs. 2 and 6, the rear panel it includes a, central portion 4| of generally frustoconical shape Withits base integral with a radially-extendingfiange portion l2, carrying the previously-mentioned lugs 36.. These lugs 36 have forwardlyextending projections d3 so spaced with respect to the axis of the frusto-conical portion that they are closely received within the rear end of the. cylindrical casin ortion i2,
4 while the outer tips of the lugs 35 abut the rear edge of portion 52 to position the rear panel with respect to the casing structure.
A single screw M (Figs. 2 and 5) extends through a special lug G5 at th top of the flange portion 42 of the rear panel and into a boss 26 formed at the rear top of the casing cylindrical portion it.
A pair of U'shaped legs so of resilient material have their forward. terminal portions iii engaged in openings in the casing front wall it and their rearward terminal portions 52 received between spaced pairs of lugs 53 on the rear panel flange 42 (Figs. 1 and 2). Thus, the legs 5% perform the double function of supportin the set itand of clamping the rear panel is to the remaining casing structure, the only other holding means being the single screw td.
In the construction illustrated in Figs. 8 and 9, the only change from the structure previously described liesin the substitution of leg members 5500 formed integral with the main casing structure H, for, the resilient legs iii]. In place of the clamping action of the legs 50, there are substituted a pair of screws Ma extending through lugs the on the rear panel into bosses 16a secured to the legs 46a.
The frusto-conical portion ll of the rear panel provides a housing for the speaker 50, which may be of conventional construction, The flange portion '52 of the rear panel it has a plurality of lugs or projections of therrno-plastic material integral with the forward face thereof and projecting forwardly therefrom and so located as to be received in the usual openings 5% in the flange 5i of the speaker t0. lhese loss or projections 55 are headed over by the application thereto of heat and pressure to secure the speaker to the rear panel (Fig. i).
The above-described arrangement of the speaker as the rearmost element of the receiving set it effects at least two novel results. In the first place, vibrations set up by the speaker promote movement of air within the casing from the back to the front thereof, cooling air entering through the openings 37 in the rear panel i i and exiting through the openings 35 in the front wall l3 and carrying with it heat from the tubes and other heat-producing elements of the apparatus.
Secondly, with the diaphragm 6d of the speak or located adjacent the heated interior of the set, the diaphragm is maintained in a dry conditionat all times during use, thereby effecting maximum quality of reproduction, as distinguished from speakers located in such positions that their diaphragms are subject to the changing atmospheric conditionsoutside of the sets.
While the invention has been illustrated in but two forms, it will be apparent to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof.
What is claimed is:
1. In a radio receiving set, a cylindrical casing constituting side walls, a transverse end wall integral with the casing at one end of the latter and constituting the front, a horizontal chassis positioned within said cylindrical casing a material distance below the axial centerline of the latter for supporting heat-emanating elements in spaced relation to saidv casing, a pair of for wardly-projecting lugs integral with said chassis at the front thereof, a pair of rearwardlyprojecting bosses integral with the inner face of the transverse end wall andhaving recesses in the rear ends thereof receiving the pair of forwardly-projecting lugs on the chassis to support the latter at the front, a pair of rearwardlyprojecting lugs integral with said chassis at the rear thereof, and a panel member closing said cylindrical casing at the rear, said panel member having a pair of openings therein into which said pair of rearwardly-projecting lugs extend, whereby said chassis is supported by said front wall and said panel member.
2. Structure as specified in claim 1, wherein the panel member includes a frusto-conical central portion extending rearwardly of the cylindrical casing and providing a housing for a speaker located rearwardly of the heat-emanating elements supported by the horizontal chassis.
3. Structure as specified in claim 2, wherein the front wall has openings therethrough and the panel member has openings therethrough radial- 1y outward of the frusto-conical speaker housing, whereby circulation of cooling air through the casing may occur.
VICTOR I. ZELOV.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS