Патент USA US2112734код для вставки
March 29, 1938. v 2,112,734 J, H. ,CLARK ET AL ' TUNING DIAL FOR RADIO RECEIVING SETS Filed Sept. 27, 41937 2 Sheets-Sheet l March 29, 1938. J. H. CLARK E'T AL 2,112,734 TUNING DIAL FOR RADIO RECEIVING SETS Filed Sept. 27, 1937 2 Sheets-Sheet 2 Patented Mar. 29, 1938 * 2,112,734 UNITED STATES PATENT OFFICE 2,112,734 ' TUNING DIAL FOR RAD-I0 RECEIVING SETS Jesse H. Clark, Chicago, and John Kelly Johnson, Evanston, Ill., assignors to Wells-Gardner & Company, Chicago, 111., a corporation of Illi ~ nois Application September 27, 1937, Serial No. 165,866 5 Claims. (Cl. 116—124.4) This invention is concerned with a tuning dial of the screen type onto which may be projected the image of a selected scale. Such a dial is peculiarly suited for radio receiving sets. The 5 means for operating the present dial is intercon trol shaft d having an operating knob D, the position of the indicator being shifted with each nected also withan associated tuning condenser end is operable by a cord or ?exible Wire l3 from a volume control shaft g having a‘ suitable op erating knob G. Connected with this latter shaft is the usual on-and-off switch (not shown). Mounted with the aid of resilient cushions upon the chassis base is a supporting frame H With so as to assure coordinated action therebetween. For its principal objects our invention is di rected to certain features of improvement by 10 which a simple and inexpensive mechanism is utilized for projecting images a relatively short distance within a space which is shielded only partially from external light, natural or other wise; by which an optical system is mounted to 15 swing about an axis which is substantially co incident with the focal point thereof so that the light rays may pass through a selected scale or special area of the slide; and by which a rugged construction is produced capable of operating de 20 pendably with little or no attention over a long period of time. A mechanism which embodies such features of improvement is illustrated in the accompanying drawings in the manner following: Figure 1 is a plan View of a radio receiving chassis on which is mounted a projection type of tuning dial made according to this invention. Fig. 2 is a vertical section through the chassis, taken on line 2—-2 of Fig. 1, showing the projec tion apparatus in side elevation; 30 Fig. 3 is a vertical section, taken on line 3-—3 of Fig. 1; Fig. 4 is a detail in section, taken on line 4 of Fig. 2; and Fig. 5 is a fragmentary view in elevation of the screen and its supporting plate. The parts which are special to this invention may be mounted upon a chassis base A. As shown, they are assembled into a separate unit capable of being installed or removed independ 40 ently of the remaining apparatus with which it is used. In this connection use is made of a vertical plate B in which is ?xedly mounted a screen 0 (desirably of ground glass) on which is projected an image in the manner to be pres 45 ently described. The screen, as shown, is pro vided with an opaque border 1 de?ning near each end a translucent elongated window 8. Slidably mounted upon the rear side of the plate at each of its ends are elongated indicators 50 v9 each having a marked portion l0 which is visi ble through the proximate screen window. A coil spring ll connects the plate and indicator in a manner to raise the latter to an upper position. Connected with one indicator is a ?exible cord 55 or wire I2 extending downwardly to a tone con actuation of the shaft to afford a visual engage ment of the tone control adjustment at all times. i The indicating mechanism at the opposite plate oppositely extending feet IS. The forward feet terminate in depending lugs l6 through which ex tend suitable fastenings which connect the screen plate immovably to the base’. Joined to the sup porting frame and extending rearwardly there from is a condenser frame I to the rear end of which is af?xed a vertical post J with a bracket ll connecting its lower end to the chassis base. Supported upon the post is one end of a plat form K which extends forwardly to be further supported by the frame H, and thence to the screen plate where it is formed with a depending ?ange I8 for convenient connection therewith as with screws 19. The structure just described, viz. the screen plate and frame elements rearwardly thereof is a rigid unit which is ?xedly secured to the chassis base. ' Extending rearwardly from the post J at spaced points near its top are two cars 20 and 2| form ing bearings for a spindle 22 whereon is secured 30 a pulley 23 which is con?ned against axial move ‘ment between the ears. Extending upwardly from the pulley on which it rests is a bushing 24 which is disposed axially Within a circular disk 25 forming the base of a cylindrical slide L. This disk is provided with upstanding marginal walls 26 de?ning an annular seat wherein is ?tted the lower edge of a ?lm 21 bent into circular form with its ends united. If desired, the top ?lm 40 edge may be turned down upon itself as at 28 to provide a reinforcement. Rotary movements to the cylindrical slide are imparted by an endless belt transmission 30 which extends around the horizontal pulley 23 and 45 thence forwardly over vertical pulleys 3|, and downwardly around one groove of a duplex pulley 32 which is mounted on the forward end of a con denser shaft 33 which extends horizontally through‘the frame J where it is journaled for ro 50 tation in upstanding plate bearings 34 and 35. Carried in the frame J are condenser plates, some ?xed and others movable into and out of the spaces therebetween, the latter being mount ed upon the shaft 33 so as to operate therewith. 55 2,112,734 As by a belt 36 which runs around the duplex pulley 32 and the control shaft f which is equipped with an operating knob F (see Fig. 1), adjusting movements may be imparted to the movable con denser plates concurrently with rotary movements on the part of the cylindrical slide. The platform which extends between the slide and screen supports a pair of upstanding spaced plates 40 and 4| between" which is pivotally 10 mounted a bracket M having forwardly and rear wardly depending arms 42 and 43, respectively. Between the supporting plates and the screen is pivotal connection at 73 with a link 14 which joins at 15 with a crank arm 16 carried fast by the con trol shaft e having an operating knob E. As by a tail piece 11 which carries a friction button 18 adapted to engage within a selected socket 19 in a ?xed plate 80, a detent is provided by which the shaft e with connected linkage, including the bracket M, is releasably secured in any of its ad justed positions of which three are indicated in the drawings. 10 By rotating the knob E a force is transmitted to the bell crank mechanism whereby the bracket M an open-ended light box N of ?ber or the like, secured to the platform as by a screw 44. To the bracket rear arm 43 is attached a vertically is rocked about the vfocal point as a center of movement, being either raised or lowered with a adapted to support an illuminant 46 Which, as shown, is an electric light bulb which depends from an associated socket 41 whichis ?tted ad scales may be marked upon the slide, each pref erably extending circumferentially thereof so as 15. adjustable tube 45, open at top and bottom, 20 justably into the upper end of the tube. The illuminated ?lament of the light bulb lies oppo site a horizontal tube 48 through which light rays pass for projection through a condenser lens 49 which is ?tted into the rear end of the tube 48, 25 this lens forming part of a lens system which comprises also a compound projector lens of which one, the lens 50, is placed adjustably at the forward end of this tube. Adjacent the exterior of the cylindrical slide, and upstanding from the platform to which it is secured, is an apertured consequent change in the position of the entire 15 opticalv system relative to , the slide. Various to present different object areas from any selected one of which an image may be projected onto the 20 screen, each such image being'differently colored by reason of the light rays being transmitted ~through a separate color panel of the screen. We claim: 7 , e I , 1. In a radio receiving set, a light projection 25 dial comprising, in combination, a ?xed image screen, a slide movable through a. single path, a plurality of lenses together with an illuminant forming an optical system, and a mounting for the optical system adapted for pivotal movement 30 plate 5| having a three-color screen 52 over its about an axis which substantially intersects the opening. The transparencies :r, y and 2 which form this screen are disposed horizontally edge to edge in such position that the light rays pro jected from the illuminant will pass through but one of them, depending upon the vertical adjust 'ment of the pivoted bracket M. A second lens focal point of the light rays passing through the optical system.’ 2. In. a radio receiving set, a light projection dial comprising, in combination, a ?xed image 35 screen, a slide movable through a single path, and an optical system comprising a plurality of lenses 55 of the compound projector, arranged forwardly and an illuminant, a common mounting for the of the color screen is carried by a sleeve 56 ad 40 justably ?tted into a. tube'51 ‘which is formed in connection with the forwardly depending arm 42 of the bracket. By the means described, an op lens system shiftable from one position. to another, and means guiding the mounting in its shifting 40 movements in a manner whereby the focal point lenses, through the slide, color screen, and light of the optical system will remain in a substantially ?xed position with respect to the screen.’ 3. In a radio receiving set, a light projection dial comprising, in combination, a ?xed image box, and onto the screen where is projected an image that'is readily visible from the opposite or exterior side thereof. prising lenses and an illuminant, anda pivotal mounting for the optical system located at a The'pivoted mounting of the bracket M will now be explained. It is important that the light the optical system through a swinging movement 50 rays shall remain focused upon the screen in each having a center substantially coincident with the tical system is provided for transmitting light rays from the illuminant through the several of the adjusted positions of the bracket, conse quently the center of pivotal movement should be approximately at the screen itself. In order to overcome certain mechanical di?iculties of such an arrangement, we provide in the bracket sup porting plates 40 and 4| upper and lower opposed slots 60 and 6|, respectively, all of arcuate form with a common center which is coincident with a horizontal line extending through the focal point at the screen. Slidingly ?tted within each pair of slots is a pin 62 carried in a bearing 63 which extends transversely of the bracket. Adjusting movements of the bracket about the focal point as 65 a center are effected with the aid of a bell-crank mechanism (see Fig. 4) comprising a weight arm 65 underlying a rib 66 on the depending bracket arm 42 with a spring connection 6‘! to maintain the former in. engagement with the latter, the 70 weight arm being extended from an offset bar 68 having at opposite ends ears 69 formed to receive a common pin ll] whichv is supported between lugs ‘H which upstand from the platform K, a, power arm 12 being depended from the forward ear for screen, a movable-slide, an optical system com point remote from the screen adapted to guide screen; , r 4. In a radio receiving set, a light projection dial comprising, inv combination, a ?xed image screen, an optical system comprising spaced lenses 55 and an illuminant, a light box positioned inter mediately of the screen and optical system, and a pivotal mounting for the optical system located adjacent the light box end which is remote from the screen adapted to con?ne movements of the 60 optical system through a path whose center is substantially coincident with the screen. ~ ' 5. In a radio receiving set, a light projection dial comprising, in combination, a ?xed image screen, an optical system comprising spaced lenses 65 and an illuminant, a circular rotatable slide en closing the illuminant and one lens, and a pivotal mounting for the optical system permitting swing ing movements thereof in a plane which is sub stantially coincident withthe slide axis about an 70 axis which is substantially coincident with the 4 screen. - ' JESSE H. CLARK. 'JOHN KELLY JOHNSON. '