US2508918A - Pocket radio - Google Patents

Description

ay 23, 1950 F. T. HlNES, JR 2,508,918

POCKET RADIO Filed Nov. 1, 1946 2 Shets-Sheet l y 950 F. T. HlNES, JR 2,508,918

POCKET RADIO Filed Nov. 1, 1946 2 Sheets-Sheet 2 Fig.5

Patented May 23, 1 950 Frank T. Hines, Jr., Westwood Village, Calif. Application November 1, 1946, Serial No. 707,108

This invention relates to a small pocket radio and receiving apparatus.

The general object of the present invention is' mounting and are held'in position in the apparatus solely by the leads to the tubes. The elements of the receiving apparatus, including the antenna, are all made into a novel assemblywhich' is particularly characterized by the use of aplastic base, on one side of'which base a coil serving both for the purpose of an antenna and as a grid inductance is cemented in position, and on the opposite'side thereof is mounted, by a supplementary sub-base, various components of the parts, thereby holding the parts rigidly togather in operative relationship but occupying a minimum space.

Another feature of the present invention resides in the utility of novel principles of construction in the formation of a simplified and re-' duced size of variable condenser suitable for controlling the frequency of the receiving apparatus or selecting the station to be received by the apparatus.

Various further features and novelties, objects and advantages of the invention will be apparent from the following description of a preferred form or example of an apparatus embodying the invention. For that purpose I have hereafter described, with reference to the accompanying drawings, a preferred form of the invention, in which Figure 1 is a side view. Y

Figure 2 is a similar view, mainly in vertical section.

. Figure 3 is a section substantially on the line 3-3 of Fig. 2.

Figure 4 is a section substantially on the lin 4-4 of Fig. 2.

Figure 5 is a perspective layout of part of the components.

Figure 6 is an electrical diagram.

Referring, first, to Fig. 6 of the drawings, I have shown the invention as applied to a con- 2 Claims. (Cl. 250-44) It is to be understood that-many principles of' the invention are adaptable to circuits of modi-- fied forms of that shown in Fig. 6. 1 Referring to Fig. 6, I, 2, and 3 indicate thermonic'valves or tubes preferably of the hearing" aid type, such, for example, as the Raytheon C. K. SOS-AX or the Raytheon C. K. 507-AX, preferably the tube I being a 507-AX and the tubes 2 and 3 being 506-AX, or, for lower Fil current, C. K. 503-AX. These tubes are, as illustrated in Fig. 5, small tubes having glass envelopes, the envelopes being compressed at one end, as indi-' cated at 6, and the five lead wires from the tubes extending from the envelope at 6a, as indicated in Fig. 5. These tubes are of sufficiently light: weight as to be capable of being firmly suspended in position merely by the strength of the wires forming the leads to the tubes, and thus adapt themselves, as hereafter described, very well to a novel type of assembly used in this presentinvention.

As a common antenna and grid inductance, there is provided the winding 1 associated with which winding is the feed-back winding 8. These windings are formed into the spider web winding pictorially indicated at 9 in Fig. 5. The main inductance and antenna winding are wound on" a plastic plate In which is out along a plurality of spacedapart radial lines H to permit thev windings to be interwoven through the resilient fingers of plastic material which are attached to the center l2 of the mounting plate. As an illustration, a suitable inductance 1 is formed through the use of about 105 turns of a fine wire;

such as "No. 36 D. S. C. The inductance 1 may be formed in a thin spider web with none of the. windings overlapping and with the longer diam eter of the inductancernot exceeding 3% inches. Roughwound on the same plate In is the feedback winding 8, which, for example, may be about 4 turns of the same fine wire.

Preferably the antenna is made as illustrated slightly oblong and the longer ends of both the plastic plate In and the windings thereon are curved to conform with the curvature of the case hereafter described. By curving the ends of the antenna winding as illustrated, the directional characteristics are lessened. Without curving the ends of the coil as illustrated, the apparatus would tend to possess considerable directional characteristics, which are generally undesirable in a receiving apparatus of this type.

it indicates the tuning condenser for th inductance 1 which is shown in perspective in Fig.

ventional regenerative type of receiving circuit, 5. This condenser is formed bya rather thick block of plastic I5 into which is threaded a wood screw having a, handle member 16. On one face of the block is provided a thin metal plate 1'! which is preferably cemented to the block as, for example, by the use of a clear cement. An adjacent plate of thin metal I8 is attached to the rear of the block, as indicated at l9, and bent around over the plate ll, the two plates, however, being separated from each other byinsulating material, such: as a thin mica-plate it;

The plate [8 is of somewhat resilient metal" so that it tends to spring away from the plate, ,7

l1, thereby reducing the resulting capacity between these plates.

attached to handle i6. Electrical terminals 23'" and 24 are provided respectively-"connected to? the plates l1 and IS.

A trimmer condenser may be providedby" cementing a small plate.= Ha on the block i5 at the rear and cutting: the platen I8; as: indicated; at 1 [8a, to form; a section: movable 1 relative --to: the plate Ila by anvadiustmentz-screw19m:

I have found thatby the constructiorrdescribed 12am :ablei-to' provide a: very simple; compact; OOH-- denser-V having; however; sufiicient; variable ca-z pacity' to cover the; entire network broadcast rangaof stations wherrusedi inzcombinaitionwith: coils as indicated :at 1.51 Moreoven the; condenser permits; :smoothroperation zandi'thislentire: range of stations is covered withone, or .lessth'an one; revolution ofthe screw: 16;:

The condenser.- --thus. described? has. .a further advantage in. that. it" may; be built into --the .assembly as; hereby describedimerelyrby cementing thecflat. block [5 to the base .32.;

In: the electric: diagram ,of Figs..- 6 theree are. shown coupling. resistors -215 1and=condensers 26 of the usualtype 21: is thegridi resistor,r2-8: the variablescreen resistor remployed was a volume control; and 30 is the output transformer-con nectedrto-a hearing:aid:-type ofrphone 3.1. In order thatxithese various components: may-be made into- :a pocket size radior in "a: simple?- and economicala manner; there. is-- provided at main base: plate 32: which: :is. preferably iormedizof. a plastic material; one: whichr is v easilyw cut:-- or punctured. by "a heated instrument; Atsoneend ofi-thebase plate theree isi'providedan end plate which :may be also formedv of plastic material and; which may-be united; thereto by a 'cementing ;operation. The 'enduplateis: provided with three apertures; the center. -aperture:oiawhich wouldvpass zthe handle :=i5---of theayariable con denser, previously described. The: condenser restson the upper; face-of. thezplatei-32; as shown in Fig. 3, and I is cementedthereto; The variable condensen, has a knob .34: on: themember -I 5, which; knob moves relative to: a--scale-onasdial plate as indicated in; Figure- 5.

The variable; resistongzih; which as previously described: in conneotioniwith Eig.. 6,-; controls the screens grid:- potentiali; is mounte'd 011713118 end platz33i, andprovide'd with avtight'ening nut 35:?andv-control knob on? and"-o switch-indicatesat 3! in-Figr 6 is also mounted on thesend' plate as: indicated. est-.391,

The three electronic tubes I 2 and 3, as illustrated in Fig; -5; are assembi'ed 'inparallelrelation -on-the base-of a trough-shapedsubpanel member 40 with'theccoupling resistors--25 and condensers 28 on the opposite side in the'trough provided thereby.-- The subpanel 40 is then positioned with the'couplihgresistors in place-and with the tubesz in placeion themain panel 32.

, wetting the plastic plates l0 and 32 with methyl methacrylate and pressing them together, the

The movement of plate-iiitowards plate I! is effected by the wood screw I5 coilis-firmly cemented in fixed position to the subpanel. By this manner of assembly a definite spacing is-given between these coils and the. other: elements of the apparatus so that any capacity connections and couplings between the center coil and the remainder of the elements of the apparatus remain fixed in operation.

There? is: alslr provided-r then U-shaped" plastic member 4| which is set atJ-theendof the-sub base and used: to house the :transformer 30. Therwalls of; the member alsd'serve as'aparti tiouz-for dividing: tha -space 'iomthe base 32 *into' separate compartments: for receiving the-:Al battery, asvindicated: at, and the"B" battery. as indicated at 44.

There is provided-a casingflfa, openat. its two ends," one-end being united tothe: end plate 33 which encloses: the -sub-base fl and the: parts mounted andrsupported thereby. Thereis alsor providedzan outer-casing which consists: of themetal: member '4 l3v which closes; the: end: and provides :a-: common connection for-the I batteries, 42- and; 44;. The upper portion: ofthe outer case,- indicated: at ilgshould be of some' nonmetallic substance, WhiUh; WO111d not-winterferewith-the reception of thew-radio signals .bythe coil H;

The. pocketi radio constructed as described is a completely self-containedminiature apparatus. is: readil'ymade ziiliSlZESliffiCiEIlfi; to fit in a pocket or in ladies small handbags-and is complete; incl udingan antenna and't-batteries: No external i connecti'onseither-or antenna or batteries. of any kind'are required; and th'e --apparatus may be constructed with the use of minimum parts and minimum Weight andminimum'costs:

While the particular-form.-of" the apparatus herein' described'is' well adapted-to carryout the objects and advantages oi the present-invention; various modifications and changes may be-m'ade'. and-this inventionisof the scope set forth in the appended claims.

I claim:

1. A radio receiving apparatus which includes a plurality of resistivelycoupled 'mul'ti-electrode tubesand'a generally-flat wound inductance a plastic mounting plate against one side of which said flat inductance is positioned and cemented, and on the other side of which said tuberesistances are assembled, there being provided a supplemental trough-like mounting member with the trough of said member raced down against said main mounting plate and enclosing a plurality of resistively coupled multi-electrode tubes and a generally flat wound input inductonce, a plastic mounting plate against one side of which said flat inductance is positioned and cemented, and on the other side of which said 5 tube resistances are assembled, there being provided a supplemental trough-like mounting member with the trough of said member faced down against said main mounting plate and enclosing the resistances coupling said tubes, the tubes being mounted on the opposite side of said supplemental face member, the tubes laying in flat parallel relation against the supplemental member and being held in position solely by the wiring extending between the tubes.

FRANK T. HINES, JR;

REFERENCES CITED UNIFIED; STATES PATENTS Number Name v 1 Date 1,682,778 Edelman Sept-i3, 1928 2,119,107 Ketcham May" 1938 2,282,759 Garett May 12, 1942 2,398,406 Brown et a1. Apni 16, 1946 2,409,481 Fordham et al. Oct; 15, 1946 2,431,198 Posen Nov. 18, 1947

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