US2333355A - Radio tuning apparatus - Google Patents

Description

Nov. 2, 1943- H. z. BENTON ETAL RADIO TUNING APPARATUS Original Filed Dec. 4, 1939 2 Sheets-Sheet l INVENTORS: flezzlm and BY Llqyai flMolris,

Nov. 2, 1943. z, BENTON ETAL 2,333,355

RADIO TUNING APPARATUS Original Filed Dec. 4, 1939 2 Sheets-Sheet 2 LMVENTORS:

ATTORNE'I I Patented Nov. 2, 1943 RADIO TUNING APPARATUS,

Harold Z. Benton, Glencoe, and Lloyd P. Morris, Chicago, 111., assignors to Crowe Name Plate & Manufacturing 00., Chicago, 111., a corporation of Illinois Griginal application December 4, 1939, Serial No.

307,362. Divided and this application December 30, 1941, Serial No. 424,884

2 Claims.

The. invention here disclosed relates to radio tuners generally, but more particularly to cam type push button tuners adapted for use in connection with either permeability or capacity tuning, continuously variable over a wide range of frequencies and is a division of patent application Ser. No. 307,362, filed December 4, 1939, and issued April- 28, 1942, as Patent 2,281,093.

It isan object of the present invention to provide a new and improvedtuning device especially adapted for use in continuously variable permeability tuning.

It is another object to provide a structure which is simple and rigid andv free from back lash so as to accurately maintain its adjustment and alignment.

It isalsoan object to provide a construction of this character composed of but few and simple parts and capable of commercial production and useat moderate cost.

Other-and further objects will appear as the description proceeds.

Certain preferred embodiments of the invention have been shown in the accompanying drawings, in which- Fig.- 1 is an elevation of the construction partly broken away;

Fig. 2 is a plan view oftheconstruction als partly broken away;

Fig. 3 is a vertical transversesection taken on line 33 of Fig. 2; showing a push button in inoperative position;

Fig. 4 is a fragmentaryview similar to a portion of Figure 3 and showing a push button lever in operative position; and

Figure 5 is a fragmentary section showing a modified form ofdial drive connection.

The tuning apparatus frame is shown as sup ported on a chassis H, and as comprising end plates l2 and 1-3 which are secured together at their upperforward edges by a dial plate carrying member M. The chassis H has an opening HA cut therein so that the tuning assembly may be mounted thereon as a unit. The end plates I2 and 13 are also secured together and braced by a coil carrying cross frame member 15. The push button lever shaft 16 is supported in the end plates l2 and IB-and is provided with circumferential grooves to receive the push-button levers H and support them in spaced relation. These levers H are provided with notches 18 to fit in the grooves formedin the shaft l5 and their-forward ends are provided with the enlarged buttons I9 for-manualoperation. The; lower portions-of'thebuttons Hare formed with an'arcuate forward face ISA, the arc having a-center approximately at the axis of the shaft 1 6 upon which the levers l1 swing; Theselower portions of the buttons serve, with the-buttons in normal position, to fill the large openings in the panel orescutcheon which are required because of theswinging movement of the push button levers. The springs 26 hold the levers H in place on the supporting shaft it. Each lever I is provided with the cam operating lugs 2 l and 22.

The cam shaft 23 is pivotally supported in the end plates I2 and I3 and has a threaded end to receive the cup-shaped nut 24 shown in Figures 1 and 2, which nut is provided with the slot 25 so that it may be screwed on or off the end of shaft 23 or tightened or loosened upon the shaft by means of a screw driver or small coin. The shaft 23 is shown in cross-section in Figures 3 and 4 and has two opposite sides flattened to form what is commonly called a double D section. The manual operating disc 28 has a corresponding opening therein and is fitted upon the shaft so as torotate the shaft. Theshaft 23' carries a plurality of tubular spacing washers 2'1 and a number of flat spacing washers 23. The tubular washers are free to rotate on the shaft while the flat washers have double D-shaped openings fitting the shaft so that they rotate with the shaft. The shaft 23' is provided with an enlarged portion 23A adjacent the frame member or end plate l2, this portion 23A serving to receive the end thrust when the members slidable on the shaft are clampedtogether. The portion 23A may be formed integrally with the shaft 23' or fixedly secured thereto. The shaft 23 has a reduced end 23B-fitting in a bearing in the end plate l2.

The shaft 23 carries a stop member 29. between twospacing sleeves or tubular washers '27: and 21A outside of the end' plate [3, this member 29 having an opening fitting the flattened portions of the shaft so that it rotates with the shaft. Stop lugs 30 and 3! are carried by the end plate I3 to cooperate with the stop 29 to limit rotation of the shaft 23 and the members carried by theround openings fitted on the'shaft so that they may befreely turned relative to-the-- shaft whennot clamped tightly between washers 28 by tightening up the nut 24. The cams 32 are shown in face view in Figures 3 and 4 and are provided with arcuate surfaces 33 and 34 which are adapted to be engaged by the cam operating lugs 2| and 22, respectively, on the push button arm l1 for moving the cams to predetermined positions, which movement serves to rotate the shaft 23 when the cams are clamped in place.

The shaft 23 also carries a plurality of tuning arms 35 and 36 which are fitted between disc washers 28. These tuning arms are provided with openings closely approximating the shape of the shaft with its flattened sides so that they are rotated with the shaft at all times. Adjacent the tuning arms 35 and 36 are located armed washers 31 and 38 having arms 39 and 40 extending therefrom. The spring 4| connects the arm 39 on washer 31 with the tuning arm 35. The

spring 42 similarly connects the arm 40 and tuning arm 36. The washers 31 and 39 are provided with openings similar to those in arms 35 and. .36 so that they are constrained to rotate with shaft 23. The spring 4| tends to rotate the tuning arm 35 in the counterclockwise direction, as seen from the right of Figure 2, while it tends to rotate the washer 31 in the clockwise direction. This spring, therefore, serves to take up any slack or play between the tuning arm 35 and the shaft 23 and holds it at all times in a definite rotary relationship to the shaft regardless of the rotary position of the shaft. The spring 42 performs a similar function for the tuning arm 36.

The dial mechanism support 50 is a flat member extending rearwardly above the shaft 23. having its forward end secured to the dial plate l4 and its rear portion secured to a flat support member 5| extending transversely of the frame parallel to the dial front, this member being supported from the .end plates I 2 and I3. ,7 The bell crank lever 52 is pivotally supported at 53 upon the support 56.- One arm 54 of the bell crank has connected thereto the cable '55 which, as best shown in Figure 3, passes over idler pulley 56, supported from the member 56, down over a cable drive drum 51 which is carried upon shaft 23 and which rotates with that shaft. Thesecnd arm 58 of the bell crank lever 52 has the lever 59 pivotally supported thereon at 60. One end of the lever 59 carries the guide member 6| which fits in an elongated slot 62, formed in the rear portion of member 56. The opposite end of the lever 59 carries an indicating member 63 which is moved back and forth in front of the dial plate 14 upon movement of the bell crank lever 52 caused by the cable 55 when shaft 23 is rotated. The coil spring 64, one end of which engages the bell crank lever 52 and the other end of which engages the lever 59, is carried on pivot 65 and serves to maintain tension on the drive cable 55. This spring 64 also has the important function of taking up play in the pointer assembly and preventing back lash between the pivot 66 and levers 52 and 59, between the guide member 6! and slot 62, between the bell crank lever 52 and its pivot 53, as well as in the cord coupling unit at the end of arm 54 of lever 52. The parts are so proportioned that a rectilinear movement is imparted to the indicating means 63, which moves parallel to and closely adjacent the dial plate i4. This plate bears indicia, as

. shown in Figure l.

The coil supporting cross frame member l carries the U-shaped members 16, with slotted tensioning legs into which are adjustably fitted the coils 12, as shown in Figures 3 and 4. These coils may be moved in their U-shaped supports during the alignment of the receiver, and then secured in place by wax or cement or by any suitable means. As shown in Figure 4, the tuning arm 36 is connected by means of the link and spring 14 and 15 to the core 16. The spring 15 holds the thrust link 14 firmly against the eye 11 in the core 16 and the pin 18 carried by the tuning arm 36 so that there is no play or lost 'motion between the arm and core.

The modified form of construction shown in Figure 5 reduces the number of parts required to drive the dial indicator. The cable 55A is provided with a hook'55B which may be hooked around the pin 18 as shown, or which may be selectively hooked through one of the holes 36B in the coreactuating arm 36A. This construction gives an indicator travel which may be adjusted-in amount due to the several possible points of connection of the cable to the swinging arm with consequent different amountsrof travel of the cable 55A. This construction eliminates the cable drum and connections of the form of construction shown in Figuresl to 4. A further modification may comprise a second bell crank lever suitably supported by the framewith one leg operatively connectedto the arm 36 or 36A and with the other leg in operative association with the bell crank 52.

In assembling the device, the yarious tubular and fiat spacing washers, cam members, tuningarms and armed washers 31 and 38 are placed upon the; shaft 23 in proper order and relationship and the shaft is assembled in the end frame members l2 and I3. The members tothe right of the frame member l3, as shownin Figures 1 and 2,-are then assembled onthe -shaft,-whereupon tightening upthe cup-shaped nut 24 serves to retain all of the parts carried 1 by the shaft in the rotary relationship which they have at the time. As has been previously described, the tubular washers 21 are freely slidable and rotatable on the shaft 23. The fiat washers 28 and armed washers 31 and 38 and tuning, arms 35 and 36 are not freely rotatable on the shaft but are slidable thereon. The cam members-32 are rotatable upon the shaft. The push button arms l1 are assembled upon their shaft 16 by being 7 placed in the grooves formed therein, and are held in place by their respective springs 26.. The tuning arms 35 and 36 are connected to'their respective cores by the push rods and coilv springs, the cores being fitted intheir coils 12.

The bell crank 52 is assembled with its lever 59 upon the support 53, the guide member 6| passing into the large slotted end of the elongated slot 62. The cable 55 is connected to the bell crank and passed around pulley 56 and around.

all of the members loosely carried upon shaft 2 3.j The selected push button is swung downwardly to its limit of movement, as shown in Figure 4, so as to engage the corresponding cam member 32.

and their associated cores to tune the set t0 the desired station. When this position has been;

Then by means of the manual tuning disc 26, shaft 23 is rotated to swing the tuning arms reached, the push button is released and the nut 24 is screwed on tightly, which clamps the cam member 32 firmly in the desired position. It is necessary to release the push button before tightening nut 24 as turning the nut will turn the shaft and disturb the cam setting if the cam is held against turning by means of the push button lever assembly. This method of setting up may be repeated with the other cam members and may be used at any time to change the ad justment of any particular cam. Due to the plurality of interposed tubular and disc washers, there is no tendency for cams, once set, to be disturbed in their setting by the setting up of an adjacent cam. The springs connecting the tuning arms and the armed washers serve to hold the tuning arms in fixed rotary relationship to the shaft without play during any period when the shaft assembly is unclamped so that the arms will always be uniformly located when clamped in position.

The construction shown and described affords a compact and efficient radio tuner and dial combination with provision for both push button tuning and continuous manual tuning. The device may be supplied as a complete unit to be installed upon a radio chassis. The mechanism for moving the dial indicator is compact and is located at the top of the device so that it will not interfere with other parts mounted on the chassis adjacent the tuning unit. All parts and coils may be readily aligned and adjusted and the structure will retain them in adjusted position.

While We have shown preferred embodiments of our invention, these are to be understood to be illustrative only as it is capable of variation and change to meet differing conditions and requirements, and we contemplate such modifications as come within the spirit and scope of the appended claims.

What is claimed is:

1. In a device of the character disclosed, a

frame, a horizontal shaft rotatably mounted in said frame, means for effecting rotary adjustments of said shaft, a vertically disposed horizontally extending dial plate in front of said shaft, a horizontal support above said shaft in rear of said dial plate, a horizontally disposed bell crank lever pivotally mounted on a vertical axis on said horizontal support, operating connections extending upwardly from said shaft to one arm of said bell crank lever, a forwardly and rearwardly extending horizontally disposed lever pivoted intermediate its ends on a vertical axis on the other arm of said bell crank lever, the rearwardly extending portion of said lever having a slidingly guided engagement with said horizontal support and a dependent indicator on the forwardly extending end of said lever cooperatively related with said dial plate.

2. In a device of the character disclosed, a frame, a horizontal shaft rotatably mounted in said frame, means for eifecting rotary adjustments of said shaft, a vertically disposed horizontally extending dial plate in front of said shaft, a horizontal support above said shaft in rear of said dial plate, a horizontally disposed bell crank lever pivotally mounted on a vertical axis on said horizontal support, operating connections extending upwardl from said shaft to one arm of said bell crank lever, a forwardly and rearwardly extending horizontally disposed lever pivoted intermediate its ends on a vertical axis on the other arm of said bell crank lever, the rearwardly extending portion of said lever having a slidingly guided engagement with said horizontal support and a dependent indicator on the forwardly extending end of said lever cooperatively related with said dial plate and a spring for tensioning said pivoted indicator lever in one direction on the arm of the bell crank lever on which it is mounted.

HAROLD Z. BENTON. LLOYD P. MORRIS.

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