US2411619A

US2411619A - Control apparatus

Info

Publication number: US2411619A
Application number: US514463A
Authority: US
Inventors: Harold F Elliott
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-12-16
Filing date: 1943-12-16
Publication date: 1946-11-26
Anticipated expiration: 1963-11-26

Description

Nov. 26, 1946. H. F. ELLIOTT CONTROL APPARATUS Filed Dec. 16, 1945 I 4 Sheets-Sheet 1 INVENTOR. Hamid 171 7 16017? Nov. 26, 1946. H. F. ELLIOTT 2,411,619

CONTROL APPARATUS a? 215 Q 41a 420.

745% 28b fall I, v $4 Z9 Z915 5 44b INVENTOR. I

Nov. 26, 1946. H. F. ELLIOTT CONTROL APPARATUS Filed Dec.

16, 1945 4 Sheets-Sheet 3 1 'INVENTOR.

flaroldfi'llwii,

Nov. 26, 1946. H, F, ELLIOTT I 2,411,619

C ON TROL APPARATUS Filed Dec. 16, 1943 4 Sheets-Sheet 4 T0 CATHODE HEA TEES INVENTOR.

.sv Mpgm v 0g acting lost-motion and also "for -p have been movedinto Patented Nov. 26,1946

UNITED STATE I ooN'raoL APFARATUS v Harold fF'. Elliott, Belmont, Mass.

Application The present invention relates to improvements .in controlmechanisms and more particularly to improved control apparatus for automatically andao'curately tuning a radio receiving system to any desired one of a plurality of signal channel-: I Itis an object of the present invention to provideautomatic' tuning apparatus for a radio receiven'which' is extremelyaccurate and positive inits operation to move the frequency changing means to any setting corresponding to a desired station, compact in arrangement, and is of simple and inexpensive construction.

Itii another object 'of the invention to'provide control'apparatusof the character described, wherein a control xunit of improved rugged construction is provided for 'moving' the settable element of the frequency changing means into each pr'e'de'termined:sett'in'gv and for locking the element' in the established setting, while at the same time permitting the settable elementito be'moved in" .either direction away :from the established setting when. actuated through a second control unit corresponding to adiiierent predetermined setting... v r

According to each'control unit is provided with two positively mechanisms of small size and an improved ruggeds'tructure for establishing the driving and locking connections required to acitua'te the settable" element to'the desired settin precision accuracy,

and then stop the same "with "erm itting a wide range of adjust- =ment "of the settable element when actuated 'throughothers of the control uniti i It'is another objector-the invention to provide a lost-motion device wherein an improved 'speed. reducing mechanism em loying a dinerential gear assembly having an exceedingly high drive ratio, is employed totactuate. one of the relatively movable'lost motion parts. of the device, thereby to enhance the accuracy withwhich 'anothe'r of'the. parts is -.actuated after. the parts predetermined relative positions."

In accordancewith still. another object of the invention, an improved cam and cam follower "assembly occupying a minimum'ot'spaceis utilized to providethe 'required' lost motion in each 'device. p

It is a still furtherpbject of 'the invention to provide; an improved mechanism for operating }a' controlled element with precision accuracy When an associated actuating" element is operated to a predetermine Sett afurther object of the invention,

shaft' Ina of December is, 1943, Serial Ne.514,4e3 6 Claims. (01. 192- 31) 2 as to its organization and W 7 together with further ob Scots and advantages thereof, will best be under-,- st-oo-d by reference to the following specification taken in connection with the accompanying drawings, in which: f :1

Fig. l'is a fragmentary plan view illustrating improved control apparatus characterized by the features of the present invention;

' Fig. 2 is a fragmentary end viewpartially in section of the apparatus shownin Fig. 1;

. Fig. 3 is an edge sectional viewillustrating' the parts of one of the control units providedin' the control apparatus shown in Fig. 1; i T

Fig. 4 is a side view of the control unit shown in'Fig. 3 withiiarts thereof broken away to show the driving relationship between certain of the elementsof the mechanism;

Fig. 5 'is an exploded perspective View of the parts making "up one-half of thecontrol unit shown in Fig; 3;

The invention, both method of operation,

.Fig. 6 is a diagrammatic view illustrating the 'manne'r'in which the rotary control'shaft of the control. apparatus may beactuated through a driving connection provided by the parts of one of thepontrol units; Y

Fig.7 is a circuit diagram illustrating the mannor of. electrically energizing the electromagnets and driving motor of the apparatus shown in Fi zlyand "1 i' 1' Fig. 8 is a sectional detailed view of'certain of, the parts includedinthe apparatus shown in i' F- 1 ,Referringnowto the drawings, and more particularly to Figs. land 2 thereof,the improved control apparatusthere illustrated is adapted'to "a radio receiving system {or the ingthe frequency changing means '10 of thesystern-to idifferentipredetermined settings respectively corresponding todifferent desired signal channels.- More'specifically,-the tuning or frequencychanging' meanslfl of the receiver: is adapted to be actuated to anyone ofa plurality of" different settings, respectively corresponding to different stations, by a single driving motor 13. This motor is arranged to rotate the settable vthe tuning means 10 throughany driving connectionstwhich commonly include the

gears

11 and 12,, a .rotary control' shaft" '15; an elongated driving gear 22, and the two meshing motor driven gears Sand one of a plurality of 23: These :driving connections alsoindividually "include" control units 14 which are axially disposedalong the rotary control shaft liand' are arranged to be selectively clutched to the elongated driving gear 22 by means of clutching units 5'! individually associated therewith.

More specifically considered, all parts of the control apparatus are supported between or upon two spaced-apart parallel extending frame members I6 and I1. These members have suitable tie rods I 8 and at extendin therebetween and anchored thereto at the end portions thereof for the purpose of enhancing the rigidity :of the structure. The motor I3 is mounted upon the frame member I! at the inner side thereof and is provided with a rotor shaft 9a which extends through an opening in the frame member I1 and carries the driving gear 9. the drawings, the projecting end of the shaft I311 is of reduced section and is formed with a fiat I 3b near the outer extremity thereof. The shoulder portion I 30 of the shaft serves as a stop or abutment for a washer 8 of a clutch assembly I through which the shaft I3a and gear 9 are slip connected. More specifically, this assembly comprises .a stressed dish-shaped sprin washer 5, the gear '9, a friction washe 4 and a collar 3. The parts .of this assembly are maintained upon the shaft end, with the washer 5 pressing the gear 9 against the friction washer 6, by means of a set screw 2 which is threaded through the collar 3 to engage the fiat portion I30 of th shaft end.

The gear 23 which meshes with the driving gear 9 is preferably formed of fiber or other like composition material, and is arranged to drive the elongated gear 22 through :a spring connection which includes the coil spring 26. More spe- .cifically, the gear 23 is rotatably supported by a f retaining bushing '24 which is rigidly mounted upon the shaft end of the elongated gea 22. A steel washer 25 abutting against a shouldered portion of the bushing 24 holds the gear 23 loosely upon the hub or bushing 24 so that it is free to rotate relative to the hub within the limits imposed by the spring 26. One end of this spring is looped about a friction screw 21 which holds the bushing 24 in a fixed position upon the shaft end of the gear 22. The opposite end of the spring 26 is hooked into an aperture formed in the face of the gear 23. Thus, a flexible drive between the motor shaft I3a. and the elongated gear 22 is provided which serves to prevent any possible locking of the clutch units to the driving gear 22 in the manner more fully explained below.

As best shown in Fig. l of the drawings, the several control units I 4 are arranged between the two frame members I6 and I! and each includes parts carried by three parallel extending shafts I5, 20 and 2|. The tw shafts '20 and H are fixedly supported by the members I6 and I! at the respective ends thereof in the manner pointed out below. The third shaft I 5, as indicated above, constitutes the rotary control shaft and carries stepped spacing sleeves 49 which are journaled in the frame members I 6 and I 1 in an obvious'manner; This shaft has the gear I I set screw mounted thereon at the end thereof which is adjacent the settable element Iila of the tuning means II]. The several control units, which are axially disposed along the three shafts I5, *20 and Y21, are of identical construction and arrangement. Accordingly,

the arrangementof these units will be readily understood from a consideration of the control unit the parts of which are detailed in Figs. 3, .4

and -5 of the drawings.

In brief, this control unit comprises an actuating element 30 which is mounted for rotation with the rotary control shaft I5 and to which rotation As clearly shown in Fig. 8 of may be imparted in different directions through two driving connections which respectively include the driving elements 4| a and 4Ib and two combination speed reducing and lost-motion mechanisms. Each combination speed reducing and lost-motion mechanism comprises a pair of relatively movable pinion gears 32 and 33, the first of which is mounted for rotation with the shaft I5 and the second of which is rotatable relative to thisshaft and the :other g ar32 an orbital or planetary gear 36 which is pivotally mounted by means of an axis pin 31 upon the associated driving element 4| for meshing engagement with the associated gears 32 and 33; a camming element in the form of a ring 40 which is welded or pinned to the associated gear 33 for rotation therewith about the shaft I5 and is provided around its outer periphery with a cam lobe 42; a cam follower 38 which is pivotally supported by means of a pin 43 at the outer periphery and to one side of the actuating element 30 for engagement by the associatedcam lobe 42 when predetermined relative positions. of the two associated gears 32 and 33 are established through operation of the associated driving element 4-I and a stop or projection 34 which is pinned by means of pins 35 to the associated driving element II and is provided with a projecting port-ion 44 adapted to be engaged by the associated cam follower 38 when this ;cam follower is actuated by the associated cam lobe 42. Each gear 33 of the control unit is provided with -a different number of teeth than the associated gear 32 so that during operation of the associated driving element 4I, it is rotated relative to the associated driving element but at a much slower speed. For example, if the gear 33a is provided with sixty-one teeth and the gear 32a is provided with sixty teeth, a 60:1 drive ratio is provided between the driving element 4 la and the gear 3.3a, such that the latter element and the cam ring a connected thereto are rotated one revolutionfor each .sixty revolutions of the driving element II a. Thus, the four elements 4| a, 36a, 32a and 33a combine to form i an exceedingly compact differential gear assembly'through which the cam ring 40a may be rotated at slow speed in response to high speed rotation of the driving element a. The other differential mechanism of the control unit, i..e., that comprising the 'four elements Mb, 36!), 32b and 33b, is an exact duplicate of that described and utilizes the same drive ratio between the driving elementi4Ib and the gear 331) thereof.

In' the assembly of the control unit l ia, two shouldered bushings 28a and 28b and two inner spacing rings 29a and 2% are utilized to provide the required bearing surfaces for those elements 4!, 33 and 43 which are rotatable relative to the control haft I5. The four identified supporting members, together with the actuating element 33 and the two gears 32, are arranged in a stack, with the elements M, 33 and 40 assembled thereon, in the manner just illustrated in Fig. 3 of the drawings. Assembly pins 3| extending through the stack at several positions about the axis of the stack are utilized to provide clam-pingengagement between the parts 28, 29, 39 and 32, thereby to maintain the enumerated parts of the control unit in their assembled relationship. In

this regard, it is pointed out that each bearing ring 29 has a thickness which is slightly greater than the combined thicknesses of the two elements 33 and 40 which it supports, whereby these two elements are permitted to rotate freely about the bearing ring 29 without 'bindingengagement -the setting of the V semblyrcornprises a1 camming member 53 having In its engagement with and as'best shown..in-.FigI

withthe'adjacem elements and 32; Springs 39 are utilized to bias the lobes 46 of the cam followers 38 into engagement with the peripheral surfaces of their respective associatedcamming elements 49. More specifically and as best shown in Fig. 5 of the drawings, that peripheral portion of the actuating element 3|] which is disposed adjacent the free end of the camming element 38a'is cut away'to provide a space within which the coilspring 39a; may be connected at opposite ends to the free end of the cam follower 38a and the actuating element 30. This spring connection serves'at all times to bias the lobe 46a of the cam follower 38a into engagement with the outer peripheral surface of the camming ringlfla. 'An identical arrangement is utilized to bias the lobe 46b of the cam follower 3811' into engagement with the outer peripheral surfaces of the camming ring b, it being noted in this regard that the two cam followers are disposed upon opposite sides of the actuating element 30.

' From the above explanation it will be clearly apparent that each control unit is exceedingly compact in arrangement and is entirely self-contained, such that it maybe removed from the rotary control-shaft l5 without disassembly of the'parts thereof. .As' best shown in Figs. land 3 of the'd rawings, bushings 48 are utilized fixedly to support each control unit l4 upon the rotary control shaft l5 and to maintain the required axial spacing between each adjacent pair of controlunits." Morespecifically, the inner peripheral por'tion'of the'supporting stack of each control unitii's clamped between the oppositely arrange shoulders of two shouldered bushings 48, these bushings being provided with. inner flatted surfaces which are adapted .toengage the flat lea of the shaft l5 to provide a fixed. mechanical connection betweenthe shaft andthe control unit which the bushings support. At the ends of the control shaft I5, the, stepped spacing sleeves 49 are provided, each of which includes a'portion 49a of reduced diameteriwhich is journaled within'a opening provided in the adjacent one of the two framemembers l6 and-l1; v Y g In order-frictionally to clamp the control units M between the shouldered portions of the bushings 48 upon which they are respectively sup ported spring washer assembly comprisingthe two bushings 5G and?! and the spring washer52,

and a clamping assemblyicomprising the three

parts

53, and 56 are provided. More specifically, the dish-shaped spring washer. 52 is disposed between thetwo bushings 50 and 5 to-re tain a-slight clamping pressure againsttheas- I tionallyengageable with their respective'associated shafts by means of friction screwsf86. .The threaded ends-cf thetwo shafts 2B and-2| are held by nuts 88 to tie plates '81, and extend throughthefr'ame members l6 and 11, the nuts 88 serving to hold the tie plates against the pinion assembly and to'space the pinions from the frame members it "and I'L Nuts 89 located upon the outside of the" frame members 16 and I1 aregutilized; fixedly to mount the shafts 253 and 2! thereon. a For the purpose of elongated gear 22 in selectively connecting the driving relationship with any onerof the control units l4, clutching units 51 are provided individual to the control units. Each clutching unit comprises an idler pinion B0 pivotally supported by means of a pivot pin 6| upon an L-shaped rocker arm '62 whichis loosely mounted upon the shaft 2|; Each idler pinion 60 is in meshing engagement with its associated pinion 58. At its projecting end, each rocker arm 62' carries an armature piece 63 which is adapted to be attractedinto engagement withthe' projecting core end 68 ofan electromagnet G'L-thereby to move the idler-pinion 6!! into meshing engagement with the elongated drive gear 22 in response to energization' of'this magnet. Inorder nor,- -ma1 ly tobias the rocker arm ,62 of each clutch assembly 51to a position wherein the idler pinion 60' 'is disengaged'from the gear 22, each rocker arm is spring connected through a coil spring 'to'thetie rod 65." Movement of the rocker arms 62funder the influence of their respective associated-retracting springs 65-is limited by the tie rod "18 which is positioned in the paths of movement of the rocker arms'and is provided with'a sernbly;stackof each-control unit regardless of clamping. assembly. Thisascamming ides 54 which engage a pin 55 extend ing through the shaft; 1 and is provided with a cross bar which'is threaded to receive a screw.56. the shaft l5, this screw may be utilized to .move

ofthe shaft for the purpose of exerting an axial clamping pressure upon the-parts '49, 48,: 50,15! 1 thefmember 53 radially and bi-Yin the manner morefully explained; V

below. Q'I'helgd ivin trol unit-J4 are vin meshing engagement with pinions fiaanclja respectively carried by the two shafts, -2l and 20. More specifically stationary .1 of the drawings the elements-Ha .andfdlb of each con- I H; and is anchored 'thereof.--This crossbar also supports a terminal- The motor may'beso arrangedthat cushioning sleeve" it formed of rubber or other softi flexible material; The electromagnets- 61 are ,all bolted to a crossbar-69 which extends transtwo frame members It; and to these members at the ends versely. between the strip T6 formed of Bakelite or other-suitable -insulating material having terminal elements suitably mounted "thereon for connection with the wind- :ing terminals of the electromagnets 61. ii 1 i3 is ofthe unidirectional :type and its rotor is rotated in a counterclockwise direction as viewed in Fig, 6

gof the' drawings' With the driving gear 22 thus rotating ina clockwise direction-theidler pinions areadapted for counterclockwise rotation when engaged with thedriving pinion 22.1, Accordingly,

when any selected idlerpiniontfl is actuatedinto meshing engagement withthe driving gear 22, the

meshing engagement of the geartn with its assopinionsr58 and 5Sthrough'their meshing engagement withea'chother, are so arranged that they rotate the drivingelements Ala and; 4lb inopciated' pinion 58 produces "pull the pinion tointomeshing engagement .with the driving-gear 22,

ationg Since this-meshing. engagement h01ds;th e. armature p ece .63 in itsattractedposition against properly a forcewhich acts to thereby tOfilQCk the pinion I -'and-'driving gear in mesh during the tuning oper the magnet core 68, a mechanical pressure urging the armature piece 63 toward the magnet core occurs concurrently with the electrical attraction of this piece by the core, whereby the magnet is aided in operating the movable parts of the clutch assembly. The magnets 51, therefore, need only be large enough to attract their associated armature pieces into engagement with the magnet cores. This utilization of the mechanical reaction between any one of the pinions 60 and its engaged pinion 58 provides for the use of relatively small magnets 61, since each magnet merely functions to initially engage the idler pinion with the driving gear; the pulling of the pinion into meshing engagement with the gear being sufiicient to maintain the geared or interlocked engagement between the two elements so long as the driving gear is rotating. The coil spring 26 through which the gear 22 is driven by the motor 93 insures positive disengagement of the idler pinion 60 embodied in any actuated clutch unit when the electromagnet 67 of the unit is deenergized upon completion of a tuning operation.

For the purpose of energizing the motor I 3 and selectively controlling the energization of the clutch magnets 5! individual to the several control units M. the control circuit illustrated in Fig. '7 of the drawings may be employed. Briefly considered, this circuit comprises a transformer 75 having a primary winding a adapted to be connected to a suitable commercial frequency source of alternating current and a secondary winding T57) from which current is delivered for energizing the motor l3 and selectively energizing the magnets 51. The transformer 15 also includes a low voltage winding 50 for supplying cathode heating current to the heaters of the tubes provided in the radio receiver equipped with the illustrated control apparatus. Two additional secondary windings 15d and 15e are provided, which are included in the illustrated full wave rectifying circuit, this circuit being utilized to supply the screen and anode potentials required for operation of the various tubes provided in the receiver. In order selectively to control the energization of the motor l3, the magnets 61, the cathode heating circuit, and the rectifying circuit, switching equipment is provided which includes off switch 8-3, push button switches 84 individual to the various magnets 61, and a relay switchin unit indicated generallyat 95. This unit includes two mechanically interlocked

magnets

76 and 78, the second of which includes an armature l9 interlocked with the armature 11 of the magnet 16 and arranged to control three sets of

contacts

83, 8| and 82. The magnet 76, together with the armature and contact spring assemblies thereof, are shown in Fig, 1 of the drawings as being mounted upon an assembly plate 96 which is rigidly secured to the frame member IT.

In considering the operation of the control apparatus as described above, it may be assumed that this apparatus is to be utilized to actuate the tuning means I!) of the receiver to the particular setting corresponding to the control unit Ma, thereby to tune the receiver for the reception of signals radiated at the particular carrier fre quency to which the control unit Ma corresponds. In order to initiate the operation of this control unit, the push button switch 34a, associated with this control unit is actuated to its close-d circuit position, thereby to complete a circuit for energizing the clutch magnet 61 individual to the control unit 14a in series with the driving motor I3 and the winding of the magnet 16. When energized in this circuit, the magnet 16 attracts its associated latching armature 11, thereby to release the spring biased armature 19 of the magnet 18. The armature 19 in moving to its retracted position, closes the contacts to complete the cathode heater circuit, and at the contacts 8i and 82, completes the high voltage rectifying circuit in an obvious manner.

When the electromagnet 61 individual to the control unit Ma is thus energized, the armature piece 63 of the clutch unit 51 associated with this control unit is attracted, whereby the rocker arm 62 0f the clutch unit is pivoted about the shaft 2! against the bias of its retracting spring 65 to move the idler pinion 60 into engagement with the driving gear 22. Thus, a driving connection is established between the motor 13 and the driving elements 41a and 41b of the control unit Mo. As will be seen-from Fig. 6 of the drawings, when the motor I3 is energized in the manner just explained, it rotates the gear 9 in a counterclockwise direction through the slip clutch connection provided between this gear and the motor shaft l3a. Accordingly, the gear 23 is actuated to rotate the elongated drive gear 22 in a clockwise direction through'the resilient connection provided by the spring 26. As a result, the two

pinions

58 and 59 are respectively rotated in clockwise and counterclockwise directions through the driving connection afforded by the idler pinion Ell in its engagement with the driving gear 22. Thus, driving connections are provided, whereby the driving element Ma is rotated in a counterclockwise direction and the driving element Mb in a clockwise direction relative to the rotary control shaft 15.

During rotation of the driving element lla, the planetary gear 360, is rotated about the two

gears

32a, and 33a and, due to the tooth differential between these two gears, the gear 33a and the camming element 46a connected thereto are rotated in the same direction as the driving element Ma, i. e., in a counterclockwise direction about the rotary control shaft IS. The driving element 4!]; similarl functions to drive the camming elements 481) in a clockwise direction relative to the rotary control shaft l5 through the driving connection provided by the diiferential gears 32b, 33b and 36b. During such rotation of the two camming elements 49a and 4% the actuating element 3!! for the rotary control shaft l5 remains stationary until the cam lobe 42 carried by one of the two cammin elements is positioned to actuate its associated cam follower 38 into engagement with the associated stop 34 carried by the associated driving element 4 I. With the camming element 40b rotating in the direction indicated, i. e., in a clockwise direction, the cam lobe 42b thereof will engage one of the camming surfaces of the lobe 46b when it is moved to the proper position relative to the actuating element 30. After such engagement, and during continued rotation of the camming element 4%, the two engaged lobes 42b and 45b coact to pivot the cam follower 38b in a counterclockwise direction about its pivot pin 43h so that the stop engaging head 45b thereof is moved radially outward from the shaft I5. Approximately when the lower knife edge of the lobe 46b is moved to bear against the upper knife edge of the lobe 426, the locking head 45b of the cam follower 38b is positioned to be engaged by the projection 44b of the stop element 34b. The engaged surfaces the stop 34a are cut at an of the two 'engagedelements 34b and 441 are cut on a bias so that the continued; movement of the driving: element 4] b, following engagement of the two elements, provides a solid mechanical interlock therebetween. 1

In a manner entirely-similar tothatjust described, the camming element 40a is rotated until the cam lobe 42a thereof is moved into engagement with the lobe 46a of the--cam follower 38a. Here. again, when the two

lobes

42a and 46a are relativelyso positioned that, when their knifeedges are engaged, the head 45a of the cam follower 38a is positioned for engagement by the projection Ma of the stop. element 34a. In this case also, the engaged edges of the head 45a and angle such that the two elements areinterlocked by continuedoperation of the driving element 4 lb.

From the above explanation it will be understood that when the cam follower 38a is engaged by the stop 34a, a direct mechanical connection is provided between'the driving element Ma and theactuating element 30. When this connectionis established, rotation of the planetary gear 36a about the two

gears

32a and 33a is obviously arrested with the result that relative movement between the

parts

30, 40a, 33a, 32a, 36a and Ala is entirely discontinued. In a similarmanner, relative movement between the parts Mb, 36b, 32b, 33b, 40b and 30 is arrested when the cam follower 38b is moved to a position for engagement by the stop 44b carried by the driving element llb. a v I From the above explanation it will be apparent that depending upon the initial setting of the control unit Ma, the rotary control shaft 15 and the actuating element 30 will be rotated in one direction or the other by one of the two driving elements Ma or Mb. Thus, if the stop 34a engages the cam follower 38a before the stop 34b engages the cam follower 381), the actuating element 30 and control shaft l will be rotatedin a counterclockwise direction to the predetermined setting to which the control unit [4a corif the stop 34b is moved to responds. Conversely, v

38b before the stop 34a engage the cam follower engages the cam follower 38a, the actuating element 30 and the control shaft 15 will berotated in a clockwise direction to the predetermined setting corresponding to the control unit Ma. In either case, the actuating element 30 and the shaft l5 are rotated at the speed of the driving element 4| with which they are mechanically connected until the nonengaged stop and cam follower are brought into engagement. When both of the two stop'elements 34a and 341) are moved into engagement with the

cam followers

38a and 3%, respectively, a locking connection is obviously established which prevents continued rotation of the parts I5, 30, M, 58, 59, 60, 22, 23 and 9. Thus, the entire gear train extending back to the motor driving gear 9 is locked up when the shaft [5 is rotated to the predetermined setting corresponding to the actuated control unit Ma. After this train has been locked'up, continued rotation of the motor shaft He is permitted through the slip clutch connection between this shaft andthe'gear 9. Y

When the new setting of the settable element Inc for the tuning'means I0 is established in the manner just explaned, the operator will be apprised of this fact through reception of the'desired station and may release thepush button switch 84a to deenergizethedriving motor 13,

the energized electromagnet 61 and the winding 1.0 of the magnet, 16 in an obvious manner. When the, magnet 16 is thus deenergized, its spring biased armature 11 is retracted to a position beneath the armature 19 of the magnet 18, but this operation is obviously without effect, and the power circuits of the receiver remain energi'zed. When the electromagnet 61 of the clutching. unit associated with ,theflcontrol unit I4a is deenergized, its associated rocker arm 62 is spring actuated by the associated spring 65 to its normal position wherein the idler pinion 60 of the actuated clutching unit 51 is disengaged from the driving gear 22. vIn this regard it is noted that upon deenergization of the driving motor 13, the coil spring 26 connected between the gear '23 and the driving gear Z2'provides a kick-back action to insure release of the idler pinion 60. by .the driving gear 22. The manner in which the remaining control units l4 may, through selective energization of, the magnets 61 by the push button switches 84, be actuated for the purpose of driving the settable element we to its other predetermined settings, will be clearly apparent from the above explanation with reference tothe operation of the control unit Me. If at any time it is desired to turn off the receiver after a period of operation, the off switch 83 may be momentarily operated to its closed circuit position thereby to complete an obvious circuit for energizing the winding of the, magnet 18. This magnet, in attracting its associated. armature 19, opens the contacts to deenergizethe cathode heaters of the tubes provided in the receiver. At the contacts 8| and 32, the magnet 18 opens the Bsupplycircuitsto the tubes and deenergizes the cathode heaters 0f the full waverectifying tube provided; in the rectifying circuit. As the armature 19 is moved to its attracted position, the free end thereof rides over the locking portion of the armature 11. After the switch .83 is released to deenergize the winding of the magnet 18, therefore, the armature .19 is held in its attracted position by the latching armature 11 of the magnet 16. During the above described movement of the shaft. [5 to the particular setting corresponding to the control unit Ma, the movable parts of the nonactive control units are also moved to produce unlatching relative movement between the cam and cam follower parts of one of the lost-motion mechanisms provided in each unit. In this regard it will be understood that as the control shaft 15 is rotated, all of the actuating elements 30 individual to the various control units are rotated therewith. The action which occurs in the nonactive units will be more fully apparent from the following explanation relating to the movement of the parts provided in the control unit I la when the control shaft 15 is driven to another predetermined setting by another of the controlunits. Thus-it may be assumed that after the rotary control shaft [5 is operated to the setting corresponding to the control unit I la, such that the cam followers 38a and 381) are respectively in engagement with the stops 34a and 3%, the shaft I5 is rotated by a second control unit in a clockwise direction. During such rotation of the shaft 15 the cam follower 38a remains in engagement with the stop 34a to prevent relative movement between the

parts

41a, 36a, 32a, 33a, -40a and 30 of the control unit. Thus, the driving gear 41a which is rotating in 'a clockwise direction, is ren-. dered operative to drive the driving element 41b in a clockwise direction through the driving connection afforded by the meshing pinions 58 and 59. The relative movement thus produced between the driving element MI) and the actuating element 39 by rotating these two elements in opposite directions causes the stop 34b and the cam follower 38b to be disengaged in a manner which will be clearly apparent from the following explanation.

Assuming now that the rotary control shaft I5 is rotated in a counterclockwise direction away from the predetermined setting corresponding to the control unit Ma, the actuating element and driving element 41b of this unit are rotated in the same direction due to the engagement between the cam follower 38b and stop 34b respectively carried thereby. The gear 32a is also rotated in a counterclockwise direction with the two elements 39 and 4| b. Also, and due to the driving connection afforded by the

pinions

59 and 58, the driving element lla is rotated in a clockwise direction relative to the shaft I5. With the two elements 4 la and 3211 thus rotating in opposite directions and with the element lla rotating in a direction opposite the direction of rotation of the actuating element 30, the planetary gear 36a functions to rotate the gear 33a and camming element 49a in a clockwise direction relative to the actuating element at. Thus, the cam lobe 42a is withdrawn from beneath the lobe 46a of the cam follower 33a to prevent reengagement of the stop 34a with the cam follower 38a after the two elements Ma and 30 have been relatively rotated through one revolution. As relative movement between the two elements 4 Ia and 30 continues, the cam lobe 42a is gradually backed away from the lobe 46a until these two lobes are separated by a distance which is determined by the amount, of movement required to actuate the shaft I 5 to its new setting.

From the above explanation apparent that the rotary control settable element moved to any desired setting through operation of a particular control unit without any interference whatever from the nonactive control units. This is due-to the fact that during operation of any one of the control units to establish the de sired setting for the shaft I5, the parts of the nonactive units are so moved relative to each other as. to prevent a locking connection from beit will be clearly shaft I5 and the ing established through any one of these units.'

Thus, the two combination speed reducing and lost-motion mechanisms as provided in each control unit, permit the rotary control shaft I5 to accurately and positively driven in either direction to any one of the predetermined settings respectively corresponding to the several control units.

In order individually to adjust the various control units relative to the rotary control shaft I5, thereby to provide for operation of this shaft by the various control units to the desired predetermined settings, the screw 56 in the clamping mechanism is withdrawn until the control units are freed for rotation relative to their respective associated supporting bushings 48. The shaft I5 is then adjusted to a desired control position or setting by a suitable manual control knob (not shown) provided for manually actuating the settable element Illa of the frequency changing means I0. During such rotation of the shaft I5 the spring washer 52 serves to maintain sufficient clamping pressure against the elements 28 of the respective control units to prevent the shaft from being moved relative to the control units, the movement of the rotary control shaft Illa actuated thereby may be' I said actuating element being taken up within each control unit in "a manner which will be clearly apparent from the above explanation. While the shaft I5 is held in the position to which it is adjusted, by manually gripping the control knob of the manual actuating means, the switch 84 associated with the particular control unit which is to be utilized in operating the rotary control shaft to the manually established setting, is operated to energize the driving motor I3. and to engage the idler pinion 66. of the clutching unit individual to the control unit with the driving gear 22. The motor I3 is thus rendered operative to drive the movable parts of the selected control unit until these parts are lockingly engaged in the manner explained above. During the final portion of the operation of the selected control unit and more particularly after one of the cam followers 38 is engaged by its associated stop 34, all parts of the control unit are rotated relative to the shaft I5 and the bushings 48 upon which the control unit is supported. Thus, the selected control unit is actuated to a position relative to the rotary control shaft I5, such that when the shaft and control unit are subsequently looked together, the control unit can thereafter only operate the rotary control shaft to the particular setting which it occupies when the locking operation is completed. The above described procedure may be repeated for each of the other control units I4, in order to establish the other predetermined settings desired for the rotary control shaft I5. During each setting operation, the control units which are not being adjusted are maintained in adjustment because of the fact that their frictional engagement with the bushings 48 is suificient to maintain their established positions relative to the shaft I5. When all of the control units I4 have been adjusted, the screw 56 may be tightened to frictionally look all of the control units I4 in fixed positions relative to the shaft I 5, in a manner which will be clearly apparent from the foregoing explanation.

been disclosed, modifications may be made therein, which are within the true spirit and scope of the invention.

I claim:

1. In combination, a rotatable actuating element, a second element movable in a path extending radially of the axis of rotation of said actuating element, lost-motion means operative to actuate said second element along said path, and a differential gear mechanism operated by and operative to take up the free travel in said lost-motion means and to then operate said second element through said lost-motion means.

2. In combination, a rotatable actuating element, a camming element rotatable about the same axis as said actuating element, speed reducing means connecting said actuating element in driving relationship with said camming element, and an additional element actuated by said camming element when said camming element is operated to a predetermined angular position.

3. In combination, a rotatable actuating element, a second element movable in a path extending radially of the axis of rotation of said actuating element, a camming element operative to actuate said second element when moved into a predetermined position, and a speed reducing gear mechanism connecting said actuating means in driving relationship with said camming element.

4. In combination, a pair of relatively rotatable gears having different numbers of teeth, a rotatable actuating element, a planetary gear rotatably supported upon said actuating element for meshingengagement with said pair of gears, whereby relative rotation actuating element to rotate said planetary gear about said pair of gears, a controlled element, and means responsive to the operation of said pair of gears into predetermined relative positions for actuating said controlled element'from one position to a different position.

5. In combination, a pair of relatively rotatable gears having different numbers of teeth, a rotatable actuating element, a planetary gear rotatably supported upon said actuating element for meshing engagement with said pair of gears, whereby relative rotation between said pair of gears is produced in response to operation of said actuating element to rotate said planetary gear about said pair of gears, a controlled element,

between said pair of gears is produced in response to operation of said gears is produced in response and means comprising a camming element rotatable with one of said pair of gears for actuating said controlled element from one position to a different position in response to the operation of said pair of gears into predetermined relative positions.

6. In combination, a pair of relatively rotatable gears having different numbers of teeth, a rotatable actuating element, a planetary gear rotatably supported upon said actuating element for meshing engagement with said pair of gears,

whereby relative rotation between said pair of tooperation of said actuating element to rotate said planetary gear about said pair of gears, said actuating element and pair of gears having a common axis, a controlled element movable in a path extending radially of said axis, and means comprising a camming element rotatable with one of said pair of gears about said axis for moving said controlled element along said path in response to the operation of said pair of gears into predetermined relative positions.

HAROLD F. ELLIOTT.