US2121767A - Tuning and indicating apparatus for radio receivers - Google Patents

Description

June 21, v I J. TUNING. AND mm'cmine APPARATUS FOR RADIO'VRECEIVERS Filed June 29, 1936 s Sheets-Sheet June 21, 1938. L. J. WRONKE 2,121,767

TUNING AND INDICATING APPARATUS FOR RADIO RECEIVERS Filed June 29, 1936 3 Sheets-Sheet 2 O If x June 21, 1938. J, WR N 2,121,767

TUNING AND INDICATING APPARATUS FOR RADIO RECEIVERS Filed June 29, 1936 3 Sheets-Sheet 5 [May aw? Patented June 21, 1938 TUNING AND mwime APPARATUS Eon more nEcEIvEns Louis J. Wronke,Ohicago,1ll.. assignmto Bel.-

mont Radio Corporation, Chicago, 111., a

i poration of Illinois Application June 29, 1936. Serial Na. 87,892

Claims.

This invention relates to dial ap ratus especially suitable for radio receiving sets, together with a mounting for such apparatus.

It is an object of the present invention to pro-' vide a more economical and satisfactory support and housing for the dial anddial apparatus than has heretofore been known] This'is accomplished by using a single piece of metal drawn to shape as a complete support and housing. The drawn member also serves as a reflector and mounting for the dial lights to illuminate the dial.

Another object of the .inventionis to provides.

simplified form of indicator for indicating, some fact other than that indicated by the main dial, such as the wave band on which the set is operated. This is accomplished by providing a perforated disc rotated by the band'control switch to illuminate different slots in the dial.

A further objectof the invention is to provide a3 dial having independent calibrations for short wave reception and broadcast reception, together with means for indicatingwhich of said bands the set is adjusted to receive, the calibrations" and the .wave band indicator being so correlated as to,

facilitate choosing the proper scale of calibra- 3 tions in reading the dial. Thus, in the ilIustrated form the slot indicator fo'r'e'ach frequency bandis alined with the calibrations for that band.

Another object of the invention is to provide with little additional cost a micrometer indicator for indicating the position of thecondensers more accurately than is possible with the-main hand on the ordinary dial. According to the present invention such a micrometer indicator is mounted on the pinion driving the gear segment connected to the main needle. An additional object of the invention is to provide a simplified combination of condenser frame and control mechanism mounting with a corresponding reduction in cost of production.

Another object of the invention is to decrease the current consumption of radio receiving sets; first, by providing a housing for the dial appad ratus of such nature that it is a good reflector so that adequate dial illumination may be obtained by a single lamp even though the dial is relatively large; and second, by providing means for automatically turning the dial light oil, except during tuning. This last named feature is ac-,

complished by normally open contacts closed by the tuning knob of the receiver so that'the dial may be illuminated .very easily, whenever desired. The saving of current drain due; to the dial light is, of course, especially valuable when 7 section, of a modification of,

in automobile receiving sets, when excessive cur- H rent consumption may cause great inconvenience.

Additional objects and advantages of my invention will be apparent from the following description, taken with the drawings, in which:

Fig. 1 is a front view of the dial assembly. N Fig. 2 is a side view ofthe same. showing its connection to the condenser frame. 1 1 Fig. 3 is a bottom view of the same with a portion broken away. a

Fig. 4 is a sectional view of the same, taken substantially along the line 4-4 of Fig. 2."

Fig.5 is afragmentary sectional view, showing the mouhting of the micrometer'indicator' and driving pinion.

Fig. 6 is'a front view of the mounting bracket 7 for the mechanism illustrated in Fig. 5.

Figs. 10 and 11 are fragmentary sectional views taken substantially along the line Ill-i 0 of Fig. 7, showing two forms of dial light switches.

Fig. 12 is a fragmentary side view, partly in Fig. 5. (p g a. Although thisinvention may take numerous forms; only a few have been chosen for the pur- In all of these forms the pose of illustration.

apparatusare supported dial and part of the by a drawn metal support housing ll, which in cludes a cupped portion i2 secured to the tu n. ing condenser frame of the receiving-set. .In the form shown in Fig. 1 it-ls secured to the end plate i3 of the condenser frame. Covering the front side of the cupped portion i2 is a dial 16, preferably of translucent nature and inscribed with suitable wave length or frequency mark:

the structure of ing which aresuitably illuminated- In'Fig. 4 I

the dial is illuminated from the back by two lamps l5. reflecting their light of! of the sides and rear.

of the housing. As a matterof fact the, house by the condenser shaft" 1 8,.

I 0 ing II is such a good reflector that a single lamp trated in Fig. 12. This includes the pulley 23.

mounted on a bearing shaft 200, carrying a spur gear 2M. A brass bearing plate 202 is secured .to

the end plate It of the gang condenser, and has a tapered hole 203 centrally thereof tosupport the tapered end of the shaft 202. A substan-" tlally U-shaped bracket 288 with both legs secured to the bearing plate and end plate supports the entire assembly.

The dial I6 is printed in reverse with an opaque ink with the indicia left clear so that the indicia are illuminated on a dark background. For simplicity of illustration, the black and white parts of the dial have been reversed within the line 28 in the drawings, so it should be understood that the entire face of the dial withinthatline is black except for the figures and lines which have been shown'black, which on the actual dial are left white. The part of the dial outside of the line 23 will of course be hidden by an escutcheon plate or other shield. Within the escutcheon the indicia will be illuminated from behind by the lamps l6.

A second control knob may be mounted on a shaft 3|, which may operate a switch 30 .for shifting the receiving apparatus from one frequency band, as the broadcast frequency band, to another frequency band such as the short wave band. A wave band indicator disc'33 is rotatably mounted on the housing l2 by a rivet 35 holding the disc in engagement with a tension washer (not shown), and said disc is connected to the shaft 2| to be rotated by it. This connection is accomplished by means of a crank 39 disc so that the crank-link mechanism is inv effect a bell-crank connection between the switch shaft and disc to place the openings 34 in the latter in the proper position for wave band indication as the wave switch is rotated. The plureality of slots 34 are covered by a translucent strip 34 and sopositioned that for each wave band to which the receiving apparatusmay be adjusted light shining through the slots 34 shines through one of the various slots 38 in the dial l6. It will beobserved that each of the wave band indicating slots 38 is alined withone of the three calibration lines. This makes it very easy for the user to know which of the three calibration lines he should read, since he reads the one alined with the illuminated slot 38. The knowledge of which calibration line to read is made still more clear by the arrangement of colors on the back of the dial. Thus, a strip 4| of one color such as green is applied behind the inner short wave line of calibration 39 and a' strip 42 of another color such as red is applied behind the middle calibration line 39. A green strip or a strip of a third color may be applied behind the outer or broadcast calibration line, or, as illustrated, it may be left white. The colored strips 4| and 42 may be bands of translucent The link paint or a separately formed strip of translucent material. They may be applied by a printing process, or they may be sprayed or brushed on through stencils. The inner zone of color 43 is merely decorative. Since the dial is illuminated from behind by lamps ii, the color on the back will be imparted to the lines 'as seen from the front, and the light is prevented from shining through the dial except along the desired lines and to show the desired indicia by the opaque ink printed on the face of the dial as previously mentioned. I

Although a single strip 34' has bee illustrated as covering all three slots 34, it she d be obviousthat they may each be covered with a translucent strip corresponding in color to the color of the particular calibration strip 39 which it designates. Even without this, however, the fact that the three calibration lines are differently colored makes them very easily followed, and the user very soon becomes so accustomed to the dial that without any conscious effort he reads the right line of calibration as indicated by the particular slot 38 which is illuminated.

The general construction of the apparatus will be sufllciently clear in view of the foregoing rather general description, but a few of the details may also be described in case they may not be self-evident from the drawings. It should be recognized, however, that each of the novel fea tures can be used with variations as to the other features. For example, various types of drive mechanism may be used in place of that shown.

As has been stated, the support housing I I is a single piece of metal drawn to the desired shape. If it is to be attached to plate 13 it is provided with three attachment bosses 5| pressed out from the bottom of the cupped portion l2. In Fig. 2 all three of these bosses are shown, while in Fig. 3

. it may be understood that on the right side is seen the boss shown at the middle of Fig. 2, while on the left side are both the bosses shown at the top and bottom in Fig. 2. These two bosses are in alinement so that only one shows. Screws 52 fitting in said bosses to rigidly fasten the housing ii to the condenser frame l3 are shown in dotted lines in Fig. 1, to more clearly indicate the position of the three bosses, which positions are chosen so that these elements may be secured firmly together without any danger of applying distortional strain to the condenser frame. The

- plate i3 be omitted, and a support housing II I be provided which is capable of serving the functions of the plate I3-as well as its other functions, as shown in Fig. 9. This is of course a more economical construction.

Support housing I I maybe punched to provide any required openings, including the'opening 56 in the bottom of the cupped portion l2, the opening 51 in the back of the cupped portion l2, the openings for the control shafts 21, 3|, the openings for the lamps l5, as well as the numerous small openings that are necessary for the attachment of parts. The belt 24 will extend downwardly through the opening 58, and the gear mechanism may be supported on the condenser frame and extend through theopening 91, al-

though, if preferred, the gear mechanism could be supported by the support housing, II. Although the gearing has been shown positioned within the housing in Fig. 3, it may be positioned behind the end plate I3, or behind the housing H or the housing II I as'seen in Fig. 9.

If back-lash or play is present between the variable condenser and gear-mechanismdriving the dial, which gear mechanism is actuated by a control knob, it is impossible to get accurate readingson the dial, and'it also affects the accuracy of thetuning control of the receiver. The constructionof the split gearsegment' I9 is such as to eliminatethis back-lash or play between it and the pinion 2|. The gear includes two segments side byside, one of which is keyed to the shaft I8 and the other of which is urged by a spring 6| toward. a different angular position, with the result that theteeth of pinion 2I are squeezed between the respective teeth and the two segments comprising the split segment I9;

Although this feature alone eliminates all backlash between the indicating needle, the micrometer indicator, and the condenser, it is also desirablethat back-lash be eliminated between these members and the manually turned shaft 21. This is accomplished by providing a spring belt tightener including pulley 62 carried by an arm t8 forming an extension of a coil spring 8| carried by a suitable peg 88, whim may be secured to the support, housing II in any suitable manner, as by a crimped split washer on the back of the housing. The tension on the arm 83 should be enough so that'there will be no appreciable backlash in the belt 24, as the shaft 21 is turned in opposite directions. One advantage of the belt tightener is that it permits positioning the shaft 21 at one side as seen in Fig. 7, when desired, while holding the belt away from the other working parts.

As seen in Fig. 5, the shaft 20 carrying pinion 2I, pulley 23, and micrometer indicator 22 is preferably journaled in a bracket, which may desirably be a U-shaped bracket so as to support the rotating structure on opposite sides of the pinion H. The bracket 68 may be secured by suitable screws Hi to the condenser frame I3 with intervening spacer posts 89 to hold it at the proper position. Of course, when the pinion 2 I is ,on one s de ofthe housing I l I (or plate I 3 J and the pulley 28 on the other, the specialbracket 68 may not be necessary, especially if a bushing 15 is secured to the housingIII for journaling the shaft which the pinion 2 I; is carried.

through a suitable hole in the dial I 6. To prevent leakage of light between the disc 22 and the dial I6, the-disc may be provided withan outwardlyextending flange 83 which'overlaps the sides of the hole formed inthe dial. I

The lamps I may conveniently be mounted insockets II, which are supported by the housing support II by means of being inserted through rubber grommets I2. Thisavoids any electrical connection between the dial light and the condenser frame. provided, as in Figs. 7 and 8, the lamps will be positioned with their-filaments in alinement with the glass I I6 as there shown. It has been found, in the commercial embodimentiof the invention, that the edge illumination from the top willcarry When edge illumination is to be:

the dial is such that additional illumination is desired, a lamp I22 may be mounted at the top and in the center as shown in Fig. 8. I

It has long been recognized that dial lamps consume an undesirable amount .of current, especially'in an automobile when there may be trouble in keeping the battery sufliciently charged. It has been the custom in the past to have the dial lamps lit whenever the set is oper ating. However, the only time when the lamps are needed is when the set is being tuned, and, therefore, the present invention. contemplates a convenient means for having the lights lit whenever illumination oi! the dial is desired for tuning and having them turned off at all other times. As seen in Figs. land 7, a pair of contacts 88 are positioned near the tuning shaft 21. The arrangement of these contacts 88 and the associated parts is seen best in'Figs. and 11, in which two modifications of the associated parts are shown.

In Fig. 10 it is seen that the shaft 21 is carried by'abushing81 secured to the housing I I in any suitable manner, as by being peened over in the hole therethrough; as shown. This shaft 21 may be slidably Journalled in the bushing 81 or not, as preferred. In Fig. 10 the control knob "is provided with a tubular sleeve 88- iitting over the .shaft 21 and slidable thereon, with sliding movement being limited by a pin 88. The sleeve 88- bears against an insulating button 82 slideable' contacts 86 and completes .the circuit to the diallamp or lamps IS.

A similar, but somewhat simplified, arrangement is shown in Fig. 11, in which the structureis substantially the. same except that the sleeve 89 is omitted. In this instance the entire shaft 2! slides in the bushing 81in response to pres-,

sure on the knob 88 with the same result of pressing the contact washer 88 against the contactsBB. Theshaft 21 and the contact washer 98 are both pressed outwardly by the spring washcrill. d

When this contact arrangement is used, it is especially desirable that the depending portion of the housing II be'adequately rigid. For this purpose it may bestifiened by ribs 88. preferably depressed -in opposite directions to obtain the greatest stiffening effect. The entire front flange of the support housing member is stiffened by a peripheral flange 8|.

Some reference has already been made to the edge illumination features shown in Figs. 7 and 8. The principle of edge illumination is already.

well known and need not be fully described.

' Preferably a may b'e stated that light from'the lamps I I6 passes into the edge of the glass dial II6, which bears suitable indicia. Except where it strikes theseindicia, the light within the glass is not noticeable. A black backing plate may be provided if desired, as if some translucent indicators such as the micrometer indicator Here [to be used positioned adjacent holes in the backing plate ,III. r i

The housing II lends itself admirably to the use ofdial illumination, since the lamps may be mounted near the edge thereof, as shown in Fig. 8, and since the glass dial H8 may very easily 7 over the entire dial, but if the size or nature of be upp rted in the h g y, providing stamped out lugs 8 on which the glass may rest and by providing opening H9 in which clips I 20 may be inserted, as seen best in Fig. 8.

The reference character IZI designates an es-- cutcheon plate for the dial and cabinet, Fig. 8,

illustrating how the dial and dial lamp are posi- V tioned with respect to said plate.

From the foregoing it is seen that a dial-tuning assembly mechanism and mounting combination is provided which at the same time is both econot only the main indicator needle but also a micrometer indicator. Furthermore, this construction provides for a main tuning indicator, and vernier indication with two separate pointers, on separated shafts, and in its simplicity is even less expensive than the single concentric shaft construction heretofore employed in the art. The present mechanism makes for more accurate tuning than the prior structure. though the main indicator needle moves along three lines of calibrations, the correct one to be read is made obvious by an illuminated slot alined therewith. The various lines of calibrations are further distinguished by distinctive coloring. A simple disc with a plurality of slots in it is the means for selectively illuminating one of the slots.

Although the preferred form of my invention has been herein shown and described, it is to be understood that the invention is not limited thereby, but is to be limited only by the'prior art. The following claims are intended to point out some of the features now recognized as new, rather than to limit the invention to these features, except as may be required by the prior art.

I claim:

1.. The combination of a radio tuning condenser having a condenser frame, a condenser shaft rotatable with respect'thereto for adjusting the condenser, a housing support member drawn from a single piece of sheet metal and including a rearwardly cupped housing portion secured to said condenser frame, and an extension to one side of said cupped housing portion a dial secured to said cupped housing portion, an

indicator movable with respect to said dial, and

mechanism for moving said indicator supported entirely by the support structure including said housing support member and extension and said condenser frame, said mechanism including a ear segment mounted on said condenser shaft on which said indicator is also mounted, and a pinion engaging said gear segment and carried by a shaft spaced radially from said condenser shaft and independent thereof, and a micrometer indicator.visible from in front of the dial operating over a micrometer scale and carried by said pinion shaft.

. 2. A dial apparatus for a radio receiving set adjustable to receive signals on a plurality-of bands of wave lengths with the same main dial settings, including a dial and an indicator mov-' ceiving ,set, said dial also having a plurality of windows therein so positioned that one of said dial windows is alined withone of said disc windows for each adjustment of the set.

3. A dial apparatus for a radio receiving set adjustable to receive on a plurality of bands of wave lengths with the samemain dial settings, including a dial and an indicator movable with respect .thereto, said dial having a plurality of lines of calibrations along which said indicator moves simultaneously, and means for indicating which of said lines of calibrations should be read for the particular adjustment of the set, including a disc having a plurality of windows therein, means for moving said disc in accordance with the adjustment of said receiving set, said dial also having a plurality of windows therein so positioned that .one of said dial windows is alined with one of said disc windows for each adjustment of the set, each of-said dial windows being in alinement with the line of calibrations corresponding thereto.

4. A dial apparatus for a radio receiving set adjustable to receive on a plurality of bands of wave lengths with the same main dial settings, including a dial and an indicator movable with respect thereto, said dial having a plurality of lines of calibrations alongwhich said indicator moves simultaneously, and means for indicating which of said lines of calibrations should be read for the particular adjustment of theset, including means for providing a visible indication substantially'in alinement with both ends of the line to be read and. intermediate said ends, and means for imparting distinctive indicating colors to-said lines of calibrations.

5. The combination of a radio tuning mechanism including a dial, a drawn metal support housing for said dial, and a control knob mounted thereon for both rotative and axial movement and biased toward one axial position, a dial light for illuminating said dial, and a switch for said light closed by axial movement of said knob away from its biased position; said switch including a pair of contacts insulated from and supported by said support housing, and a bridging contact operated by said knob but: insulated from said housing.

6. Apparatus for controlling the tuning of a radio receiver and indicating the tuned position thereof, including a dial having a plurality of tuning scales thereon, with each of said scales corresponding to a single wave band for radio reception and following a. path closed over the greater part of the length thereof and interrupted at one point therein byaviewing spacaan indicator movable oversaid dial, tuning means for operating said indicator, and a single member operating behind said dial and providing an indication visible through said-viewing space to indicate which of said scales is being utilized in the tuning of said radio receiver.

7. Apparatus for controlling the tuning of a radio receiver and indicating the tuned position thereof, including a dial having a plurality of tuning scales thereon, with each of said scales corresponding to a single wave band for radio reception and followingapath closed over the greater part of the length thereof and interrupted at one point by'a viewing space, an indicator movable over said dial, tuning means for operating member movable to bring said aperture into alinement witha viewing space in the dial whereby the color or said material is visible through a viewing space in said dial to indicate the particular scale being utilized in the tuning of said radio receiver.

'8. A multi-band radio receiver having a wave band change-switch, a dial having a plurality of tuning scales thereon, lighting means to the rear of the dial, a sight opening in the path of each tuning scale, an indicator member movable in back of said sight openings having a plurality of translucent portions therein corresponding in number to the number of tuning scales, and means operable by said band change switch to move said indicator member to position a translucent portion behind a corresponding sight opening to permit light to shine through said portion and said opening to indicate the wave band being utilized. 7

9. A compact tuning and indicating apparatus for a multi-wave band radio receiver including a tuning condenser, a dial plate with a plurality of tuning scales thereon, indicating mans ineluding an indicator movable over said scales, a wave-band indicator movable to the rear of said dial plate and rotatable control shaits having connecting means to both said indicators and condenser, anda one-piece frame for supporting said condenser, dial plate and indicating means with connected control shafts, said frame comprising a cupped housing with 1 the condenser supported directly on the rear thereoi,-withsaid wave-band indicator movable therein behind the dial plate thereon, and an integral depending flange from said cupped portion for supporting said control shafts.

i0. Indicating apparatus for a multi-wave band radio receiver includinga dial member having a plurality of tuning scales thereon. a plurality of viewing spaces on said member corresponding in number to the number of tuning scales, a disc rotatable behind said dial member having means to provide scale indication selectively visible at a viewing space, a control shait spaced from said disc and eccentric connecting means between said shaft and disc comprising a pair of pivoted arms with one arm rigidly secured to said shaft and the other arm pivoted to said disc at a point adjacent the outside edge thereof.

IDUIS J. WRONRE.

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