US2491808A - Multichannel radio and television receiver - Google Patents

Description

Dec. 20, 194-9 G. w. FYLER MULTICHANNEL RADIO AND TELEVISION RECEIVER 5 Sheets-Sheet l Filed Aug. 6,, 19

AWE/VIVA EM. ANTENNA MANUAL Tum Ms CONTROL FOR s.w. AND BROADCAST BANDS Invehtor Geof-ge W y F1. Fer,

His Attorney Dec. 20,1949 G. w. FYLER MULTICHANNEL RADIO AND TELEVISION RECEIVER 5 Sheets-Sheet 2 Filed Aug. 6, 19 42 Pig. 5.

F1 M. AND

VIDEO LFZ AMPLIFIER FREQUENC Y CON VERTER 0 J w W (.12.. s .q. B. m i, 8 M m a Q fHCW G t l e /A m v r m n m- .m WH 22 b m/ FIG. 3.

FIG. 2.

FIG- I.

POSITIVE /5us LOCAL OSCILLATOR Dec. 20, 1949 G. w. FYLER 3 9 MULTICHANNEL RADIO AND TELEVISION RECEIVER Filed Aug. 5, 1942 5 Sheets-Sheet 3 TO HIGH VOLTAGE g 3 TELEVISION PICTURE SUPPLY I VIDEO 1F AMPLIFIERS 95 AND DETECTOR POSITIVE Bus TELEVISION NEGATIVE B08 4 5 SYNC. PuLsz /00 .CLHfFERgA/VD H SEHARATOR 4 F J02 l VERTICAL SWEEP CIRCUITS HORIZONTAL ,//06 SWEEP c/Rcu/rs 97 TELEVISION NEGATIVE BUS inventor: George \MFgler',

a H ztborriey.

Dec. 20, 1949 G. w. FYLER 2,491,808

MULTICHANNEL RADIO AND TELEVISION RECEIVER Filed Aug. 6, 1942 5 Sheets-Sheet 4 "Fi .4. 55 g li'U'Ul.!|.ll|- A58 v a L59 SIG/VAL /4I /59 AUDIO LF. F. M LIM/TER DE TECTOR AMPL/Fum AMPLIFIER v I /40b Y I32 POSITIVE FZM. NEGATIVE Bus BUS 4 AUDIO AND POWER 37 AMPLIFIERS 4 sou/v0 257 g 5 REPRODUCER PHo/voafiAPH g "TURN-TABLE Y DRIVE MOTOR 27 POSITIVE I 35 BUS s4 I l 59 T w W 40 'L COMMON POWER T0 0/ maps T0 A-C. POWER SUPPLY MA INS HEATER CIRCUITS SUPPLY RECTIFIER -inventor-i George W. Fg ler,

by 79 a His Attorney Dc'.'20,- 1949' G. w. FYLER MULTICHANNEL RADIO AND TELEVISION RECEIVER Filed Aug. 6, 1942 5 Sheets-Sheet 5 R {\l/cn M5 5 MW. ma 7 MR V 0 MM 3 CC M2 n m RT 7D CMVERTER GRID 45 AFC. c/Rcwr l 6.

1.0041. OSCILLAwR PRESET TIMI/A6 IN 55:! FOR TELEv/s/o/vmrw/ms wscmmmwn cums/110x204 mum.

CAPACITOR 282 7D CONVERTER GRID 69 2 5a L BR mm 5 m Inventor: George \N. Fgler, by WW5 AMZM His Attorney.

Patented Dec. 20, 1949 MULTICHANNEL RADIO AND TELEVISION RECEIVER George W. Fyler, Stratford, Conn, assignor to General Electric Company, a corporation of New York Application August 6, 1942, Serial No. 453,821

12 Claims. 1

liy invention relates to radio receivers and especially to such receivers adapted for household reception.

It has for one of its objects to provide a radio receiver capable of the different types of radio reception now common in household reception and which may be produced at reduced cost.

Another object of my invention is to provide such a receiver capable of these different desired types of reception and which may be operated by the unskilled housewife to select the different desired types of operation with a minimum of confusion and error.

At the present time the different signals commonly radiated for home reception include television signals comprising a carrier wave modulated in accordance with the transmitted picture image and a carrier wave modulated, usually with respect to frequency, in accordance with the sound to accompany the picture reproduction. Signals comprising programs of music or speech are also commonly transmitted by frequency modulation of very short waves, amplitude modulation of waves of lower frequencies, commonly known as short waves and which I sometimes refer to herein as waves of intermediate wave length, and by amplitude modulation of long waves, as those in the broadcast band of frequen ies extending, for example, from 540 kilocycles to 1750 kilocycles.

An object of my invention is to provide a receiver capable of reception of any such signals and which is economical in its construction and simple in its operation.

In present day receivers stations in the broadcast band are commonly selected either by operation of push buttons corresponding to the different stations to be selected or by manually varying the unicontrolled tuning condensers to tune the receiver over the band to select the desired stations. An object of my invention is to provide a receiver in which such push button and manual tuning may be efiected and in which certain of the push buttons may also be utilized to select desired television stations, and to connect the receiver for reception of short waves or frequency modulated waves.

Another object of my invention is to provide improved and simplified selective switching mechanism for selecting the operations desired including switch numbers each of which may be operated from a normal position to either of two other positions to select, for example, a broadcast station or a television station dependent upon the position to which it is operated.

2 Still further objects of my invention relate to different circuit connections which may be employed with such switching means for effecting the different types of operation desired with a minimum number of electron discharge devices,

with a minimum number of switching operations, and with a maximum of economy in the equipment employed.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which Figs. 1, 2, 3 and 4 taken together represent an embodiment of my invention; Fig. '5 illustrates the manner in which Figs. 1, 2, 3 and 4 may be oriented with respect to each other properly to illustrate the invention; Figs. 6, '7 and 8 represent the circuits of the local oscillator employed for television and frequency modulation reception, short wave reception, and broadcast reception, respectively; Fig. 9 represents the detector circuit employed for broadcast reception; Fig. 10 represents the mechanical structure of the switching mechanism employed; and Fig. 11 shows such structure mounted in the chassis of the radio receiver.

General Referring first to Figs. 1 to 4, I have shown in the lower left hand corner of Fig. 1 a number of antennae I0, ll, l2. The antenna It is employed for the reception of frequency modulated signals and accordingly bears the legend F. M. antenna. Beneath this antenna, I have shown a second antenna I l, which is used for television reception, and which bears the legend Television antenna. A further antenna I2 is employed for reception of carrier Waves in the broadcast range of frequencies, and short waves of frequency higher than the broadcast band but lower than those used for frequency modulation or television. I have also shown, conventionally, a piezoelectric crystal l3 which may be taken to represent the pickup device of an ordinary phonograph the recordings of which are to be reproduced by the receiving equipment to be described.

Just at the right of these different antennae I9, I] and i2 is shown a switching mechanism comprising a plurality of switch members I l, l5, l6, H, 18., I9, 25 each of which has a normal position and which may be operated to either of two other positions. For example, the switch members I5, I6, 11 and I8 may be operated downwardly to effect reception from a desired station operating at a frequency in the broadcast band, as indicated by the legends on the drawing, or upwardly to effect reception of a desired television station, as similarly indicated. The switch member I is shown in such upward position. All of the remaining switch members are shown in the intermediate or normal position.

Switch member it may be operated upwardly to connect the receiver for reception of frequency modulated signals extending over a band over which the receiver is tunable by manual tuning. When so operated the receiver may be tuned over the band of frequencies by manipulation of knob 21. This switch member may also be operated downwardly to select a broadcast station.

Similarly switch member I9 may be operated upwardly for operation at any frequency in a short wave band of frequencies over which the receiver is tunable by manipulation of a knob 22, or downwardly for operation in the broadcast band of frequencies over which the receiver is tunable by manipulation of this same knob 22.

Similarly switch member 26 may be operated upwardly for phonograph reproduction and downwardly to deenergize the entire receiver.

Suitable labels, or legends, 5 may be appropriately placed on the panel of the equipmen adjacent the corresponding switch members to indicate the operation obtained by operation of each of the different switch members to their different positions.

All of these switch members, which may be in the form of push buttons, are biased, by means not shown in Fig. 1, but which are later described in connection with Fig. 10 to the intermediate position which is the position in which members A M and IE to 20 are illustrated, and when any switch member is operated to either of its two other positions, means are provided whereby the switch member is locked in such other position and whereby any other switch member is restored, by such operation, to its intermediate position. One such means is conventionally represented by the locking member I of Fig. 1, which for convenience of illustration, is represented as comprising, very simply, a plate through which the switch members extend and which is biased to the left by means of a spring 2 against the different switch members I i, I5, I6, I'I, etc. Each of these switch members may be considered as provided with two pawls I4 and I4" in the case of member I4, and I5 and I5" in the case of switch member I5, etc., which engage the plate I to retain the switch member in either of its two operating positions against its bias. Thus, the pawl I5" is illustrated as engaging the plate I to hold the switch member I5 in its upper position. If this switch member be grasped and forced downwardly, plate I is operated to the right to permit pawl I5" to pass and hence releases any other switch member which may be in one of its two extreme positions.

The preferred mechanism for accomplishing these results is more particularly described in a later portion of this specification in connection with Figs. 10 and 11. For the present it suffices to state that each of these switch members operates a plurality of movable contacts whereby various switching operations are effected. These contacts are each designated on the drawing by intermediate frequency amplifier 82.

' ducing device 96.

the same reference numeral as the respective switch member followed by a reference letter corresponding to the respective contact.

The antennae Ill, II and I2 are connected in accordance with the operation of these switch members through respective transformers 50, Ma, til), 4 to, did, illustrated in Fig. 1, to a conductor M, shown at the left of Fig. 1, which leads to the control electrode 46 of a converter shown in Fig. 2 whereby signals received on any antenna, so connected, are supplied to the converter. This converter operates in association with a local oscillator 52, of Fig. 2, to produce an intermediate frequency wave having a frequency corresponding to the reception determined by the operated switch member.

All of the connections necessary to operation of the local oscillator at the frequency required for production of the desired intermediate frequency and all of the other connections necessary to energization and selection of those parts of the equipment and those discharge devices the operation of which is required for the reception determined by the operated switch member, are effected through appropriate contacts on the operated switch member.

If the operated switch member selects a television station, for example, two intermediate frequency waves are produced, as is usual in television reception, one modulated in accordance with the image to be reproduced and having a range of frequencies extending, for example, from 8.5 megacycles to 13.25 megacycles, and the other having a frequency which is modulated in accordance with sound, which accompanies the picture reproduction, and which may have a frequency of 8.25 megacycles plus, of course, the frequency modulation side bands. These intermediate frequency waves are amplified by the The picture modulated wave is then transmitted over conductor 90, through equipment 95 of Fig. 3, which may comprise discharge devices 9|, 92 and 93, to the grid 94 of the television repro- The output from equipment E5 is also supplied over conductor I00 to the apparatus 9?, which selects and separates the horizontal synchronizing pulses from the vertical synchronizing pulses and which may comprise discharge device IOI. The horizontal synchronizing pulses are then supplied over conductor I02 to the horizontal sweep circuits I03 comprising discharge device I04, and over conductor I to the vertical sweep circuits I06 comprising discharge device IO'I. These circuits supply the deflection voltages to the coils I08 and H29, respectively, to control the deflection of the cathode ray in a manner that is well understood in the art.

The intermediate frequency wave, which is modulated in accordance with the sound to accompany the picture is reproduced upon the inductance 85, which is coupled to the output transformer 84 of intermediate frequency amplifier 82,

and is supplied over conductor I 20 through intermediate frequency amplifier I23 and limiter I 26 to the frequency modulation detector circuit which comprises diodes I32 and I33. The audio signal is reproduced upon resistances Mile and I402) of this circuit and is supplied over conductors 3t and 3'! to audio equipment 38 whereby iateis amplified and reproduced by a loud speaker This latter signal channel is also employed for 5. reception of frequency modulated signals when not accompanied by television signals.

During reception of signals in the broadcast band, or short wave signals having frequencies higher than the broadcast band but lower than frequencies employed for frequency modulation or television, the intermediate frequency may be of the conventional 455 kilocycle frequency,'for example. This intermediate frequency wave is produced upon secondary winding 222 and supplied through coil 85, which has low impedance at this frequency, to the intermediate frequency amplifier I23 by which it is amplified and reproduced upon the coil It'd, the latter of which is connected in series with the diode I32 whereby these voltages are rectified and reproduced upon resistance Idea and thence supplied through the audio. frequency equipment 33 to the loud speaker 39.

Of course, for phonograph reproduction only amplifier 38 and loud speaker 39 are utilized to effect the required translation of the signal to be reproduced.

Having now generally indicated the character of the equipment to be described, I shall now proceed with a more detailed description of its structure and operation.

Power supply circuits The equipment is illustrated as adapted for energization by means of alternating current through a common power supply rectifier 35. At 30 I have represented a plug which may cooperate with an ordinary household wall outlet to supply voltage of the commercial frequency,

usually 60 cycles, to the input of the rectifier This circuit may extend from one side of the rec-- tifier input over conductor 29, plug so, conductor 3!, fuse 32, conductor 33, contact 200. and conductor 34. The cathode heaters of the different discharge devices employed may be connected between these conductors 29 and 34 as indicated at 23 and 24. The output voltage from rectifier 35 appears between ground, indicated at i and a positive bus which bears the legend Posi ive bus, on Figs. 2, 3 and 4 of the drawings. positive bus is connected to the anodes of all of the discharge devices illustrated on the drawings. The negative terminal of the rectifier is connected to the metallic chassis on which the discharge devices are mounted and which may be us.

considered as ground.

The cathodes of certain of the discharge devices, as, for example, the cathodes of discharge devices I42, I i-5i and I44 of the audio amplifier 38, which are employed whenever the equipment is in use, are connected directly to the chassis ground so that anode voltage is applied thereto Whenever the plug 3!! is inserted in the wall outlet. The discharge devices of Fig. 3,. which are employed only during the television reception have their cathodes connected to a bus designated on the drawing Television negative bus which is grounded to the chassis only during television reception. Thus these devices are energized only during television reception. Certain further discharge devices, such as the discharge device I26 of Fig. l, of Fig. 2, and Hit of Fig. 2 which are employed only during frequency modulation reception have their cathodes connected toe. bus, which is designated F. M. negative bus on the drawing,

and which connected to ground only during frequency modulation reception. These connections are effected by the selective switching mechanism in a manner presently to be described.

Discharge devices 52 and 45 of Fig. 2 and I23 of This Fig. 4 are employed whenever the systemv is utilized for radio reception. Their cathodes are therefore connected to the receiver chassis so that these devices are energized whenever the plug as is inserted in the wall outlet. This is true even tho-ugh these devices are not utilized during phonograph reproduction. This simplifies to some extent the switching required and the anode current taken by these devices during phonograph reproduction is not objectionable.

Television reception Let us suppose that switch member, or push button, It is operated to its upper position as illustrated in the drawing, thereby to select television station No. 1. This push button I5 carries movable contacts I5a, I51), I50, and I 5d, which establish the connections required for reception of signals from television station No. 1. The contact I51) connects the television antenna, II directly across the primary winding of television input transformer l Ia. One terminal of the secondary winding of this transformer is grounded and the opposite terminal is connected through contact I 5a, in its upper position, to conductor M,

which leads to the input electrode 46 of the converter d5 of the receiver.

Since switch members Iii, Ill and it are in their neutral positions, the secondary windings of corresponding television transformers lib, sic and did are all short circuited by the respective contacts Idle, i'ic and 58b of the switch, whereas the primary windings of these transformers are open circuited. Similarly the secondary winding of frequency modulation transformer 58 is short circuited by contact ME) and its primary winding is open circuited. Accordingly, television signals from antenna i I are supplied only through transformer i i a to the converter input electrodes.

Contact 5503 in its upper position connects to ground at 60 the M. negative bus and since this bus is now connected through contact ltd and conductor to to the Television negative bus, it grounds that bus also. This means that all of the discharge devices utilized for either television reception or frequency modulation reception are energized.

The local oscillator 52 on Fig. 2 is provided with an oscillating circuit which. is used for television or frequency modulation reception and which comprises an inductance 58. having an intermediate point connected to the cathode of the discharge device. The upper terminal of this inductance is now connected through con:

, ductors and as and contact I50, in its upper position to ground through trimming inductance and also through conductor 54, and grid condenser to the grid electrode SI of the discharge device. The lower terminal of this inductance is connected to ground through conductcr contact Edd and conductor and thence through condenser 49 back to. the anode of the discharge device 52'. Thus coil 58, shunted by trimming inductance 55a, is connected directly between the grid and anode of device 52, and

conjunction with trimming inductance 55d detel-mines the frequency of oscillation of the local oscillator for reception on television channel No. l.

Oscillations of this frequency, produced by the local oscillator on the coil 58', are supplied through the condenser El to the control electrode db of the converter. Thus, the required intermediate frequencies are produced by the con.-

verter and amplifiedby the. amplifier 82, and the television intermediate frequency wave is sup--' plied through transformer 84 to the equipment of Fig. 3 for control of the picture reproduction and the sound modulated intermediate frequency carrier wave is supplied over conductor I20. through amplifier I23 and limiter I25 to the discriminator I32, I33 whereby the voice waves are reproduced and amplified by the amplifier 38 and supplied to the loud speaker 39.

The circuits of the discriminator detectors I32, I33 include the transformer windings I38 and I3'l, both of which are tuned to the frequency of the intermediate frequency carrier wave. The upper terminal of the primary winding I38 is connected through condenser I30 to the midpoint on the winding I31 thereby dividing that winding into an upper section and a lower section, each of which is in series with the respective diode I33 and I32. The lower terminal is connected to ground through by-p-ass condenser I30. The cathode of the diode I33 is connected to ground through the resistances I40?) and MM, and the cathode of the diode I32 is connected to ground through a circuit I35 and I35, which is tuned to the intermediate frequency of 455 kilocycles, for reasons later to be indicated, but which for audio and radio frequency waves and direct current may be considered as a direct connection to ground and to the lower terminal of the resistance I40a.

When the received carrier wave is of the desired intermediate frequency, the voltage on the secondary winding I3! is in quadrature with the voltage on the primary winding, with the result that the radio frequency voltage on the two diodes is equal and the direct current voltage produced on the two resistors Him and I401) are equal and of opposite polarity. When the frequency shifts, however, as by reason of signal modulation or otherwise, the voltage on one half of the secondary winding I3I becomes more nearly in phase with the voltage on the primary and that on the other half of the secondary winding becomes more nearly in opposed phase relation with the voltage on the primary winding, with the result that the radio frequency voltage on one or the other of the two diodes increases while that on the other decreases dependent upon the direction in which the frequency change occurs. Thus, the voltage on resistance I401) may increase while that on resistance Mild decreases, with the result that the cathode of diode I33 becomes positive with respect to ground, or the opposite effect may occur, with the result that this cathode becomes negative with respect to ground. Thus the audio frequency voltages appear between the cathode of the diode I33 and ground and are supplied over conductor 33 and amplifier 38 in the loud speaker.

Means are also employed, during television and frequency modulation reception, to maintain the oscillator 52 automatically at a fixed difference in frequency from the received signal modulated carrier wave irrespective of undesired effects such as change in temperature, power supply voltages, etc. This means comprises the discharge device I50 of Fig. 2, the cathode of which is connected through condenser I52 to ground and the anode of which is connected through condenser II to the upper terminal of the oscillator inductance 58. Thus, oscillations which appear on the inductance 58 are supplied through condensers I5I and I52 between the anode and cathode of discharge device I50. These oscillations are also supplied through the inherent capacity between the anode and control electrode of discharge device I 50 to a network comprising resistance I54 and condenser 8 I49. These oscillations appear on resistance I54 in quadrature with the voltage on the anode and, acting on the grid of the discharge device, cause current to flow in the discharge device I50 having a phase relation with respect to the voltage between the anode and cathode such that this dis charge device simulates an inductance. The magnitude of this inductance is determined by the unidirectional potential on the control electrode. This unidirectional potential is derived through resistance I54, conductor IEI, resistance I60, conductor I50, and resistances I55 and MI from the cathode of diode I33. Thus, if the received carrier wave shifts undesirably in frequency in such a direction that the cathode of diode I33 becomes positive with respect to ground, the grid of discharge device I50 is driven positively thereby to cause this device to draw more current and to appear as a smaller inductance, whereas if the frequency of the carrier wave shifts in such a direction that the cathode of diode I33 becomes negative with respect to ground, then the grid of discharge device I50 becomes negative and the discharge device I50 appears as a larger inductance. The variations of this inductance control the frequency of the oscillator 52 to maintain the intermediate frequency constant irrespective of shifts in the received carrier frequency or shifts in the frequency of oscillations produced by the local oscillator and which may occur, for example, during the warm-up period, or by reason of changes in power supply voltage.

This device I50, however, does not respond to shifts in the intermediate frequency produced in accordance with the desired audio signals since signal variations in the potential on the cathode Of diode I33 are filtered out by means of resistance I55 and capacity I51 and by resistance I60 and capacity I49 and are thereby prevented from affecting discharge device I50.

The same operation as that above described occurs if any of the other push buttons I5, I7, and I8 be operated to the upper position, the only difference being that a different input transformer M1), M0 or 4Id is connected in circuit in place of transformer Ma, and in addition a different trimming inductance 55b, 550, or 55d is connected between the oscillator grid and ground rather than the inductance 55a thereby to select the frequency of the corresponding television station.

Frequency modulation reception Now let us suppose that push button I4 is operated upwardly for frequency modulation reception. Push button I5 is immediately restored to its normal position thereby disconnecting the television negative bus from ground at contact I5d. This deenergizes all of the discharge devices of Fig. 3. The F. M. negative bus remains grounded through contact Md and conductor 50.

Frequency modulation antenna I0 is now connected directly across the primary winding of transformer 50 by means of contact Ma, and the ungrounded terminal of the secondary winding of this transformer is now connected through contact M1) to the conductor 44 and hence to the input of the converter.

The local oscillator 52 operates exactly as previously described, the lower terminal of inductance 58 being connected to ground and to the anode of the discharge device through conductor 59, contact I4d, conductor 60, ground and condenser 49 back to the anode of the discharge device. The upper terminal of inductance 58 is connected to the control electrode through con- 'ductors 51 and 56, contact I4c, conductor 54 and grid condenser 53, and it is shunted by the-variable oscillator tuning capacity 254, the ungrounded terminal of which is connected through contact Me in its upper position and conductor 54 to the control electrode 5I. This condenser thus serves to tune the oscillator over the range of frequencies corresponding to the range of frequencies in which frequency modulated signal are broadcast.

This condenser is unicontrolled with a condenser 205, as indicated by the dotted line 205, the latter of which tunes the input transformer over the frequency modulation range of frequencies. This latter range may extend from 42 to 50 megacycles. These tuning condensers 254 and 255 are provided with the knob, or control handle, 2| which may be mounted on the panel of the equipment for manipulation by the operator.

Dial lights indicated at 64 are employed to illuminate the dials associated with the tuning controls 2I and 22. These lamps are now energized through a circuit extending from the positive bus through conductor 65, lamps 64, conductors ZID, 2H and 2I2, choke coil 2I-3, contact Me in its upper position, conductors 56 and 51, inductance '58, conductor 59, contact I4d in its upper position, and conductor 60 to ground.

Short wave reception Now let us suppose that switch It is operated upwardly for short wave reception with manual tuning. Switch I4 is, Of course, immediately restored to the normal position. thus removing ground from the F. M. negative bus. Thus, discharge devices I50 and B2 of Fig. 2, discharge device IZG of Fig. 4 and all of the discharge devices of Fig. 3 are now deenergized. The intermediate frequency channel for the 8.25 megacycle wave used in frequency modulation reception is now disabled at two separated points, viz. discharge device 82 and limiter I25. This is desirable because of the high gain in this channel.

Antenna I2 is connected to the input of the converter through transformer 2I5, across the secondary of which is connected a trimmer condenser 2I5. One terminal of the secondary of this transformer is grounded, and the other terminal is connected through contact I9a, in its upper position, to the converter input bus 44 and also to the ungrounded terminal of tuning condenser 233, the latter of which is variable to tune the secondary of this transformer over the short wave range of frequencies. This short wave range of frequencies may be any desired range above the broadcast band over which tuning may be effected with the use of any single transformer 2I5. It may, for example, comprise the band commonly known as the D band in household receivers and which extends from the neighborhood of 5.5 megacycles to the HGigI'JibOIhOOd Of megacycles.

In this range of frequencies the oscillator coil 58 has insufficient inductance, and accordingly a different coil 11 is employed, this coil having an intermediate point connected through conductor 18 and the lower portion of the coil 58 to the cathode i! of the discharge device 52. The lower portion. of the coil 58 has negligible inductance at the frequencies at which the coil TI operates.

The lower terminal of the coil ii is connected to the anode of device 52 through conductor 248 and contact llib to ground and then through condenser 45 to the anode of the discharge device.

The upper terminal of this winding TI is con-.

,cuit I35, 55.

nected through condenser 243, conductor 246 and contact I90 to the ungrounded terminal of oscillator tuning condenser 232, the opposite terminal of which is grounded. These tuning condensers 232 and 233 are arranged for unicontrol, as indicated by the dotted line MI, by means of the handle 22 arranged on the panel of the apparatus. They, of course, tune their respective circuits for operation of the receiver over the desired short wave band of frequencies.

The oscillations produced on inductance 11 are supplied over conductor IE to the suppressor grid 53 of the converter 45, to combine with the signals received from the antenna on the control grid 45 thereby to produce the intermediate frequency wave in the output of this device.

The intermediate frequency wave, which now has a frequency of 455 kilocycles, appears on the secondary winding 222 of transformer 220 the lower terminal of which is grounded through condoctor 22!! and contact i917 and the upper terminal of which is connected through circuit and conductor 525 to the control electrode of the intermediate frequency amplifier I23.

This discharge device has in its anode circuit primary of transformer I27 which is tuned to the previously mentioned 8.25 megacycles wave and, in addition, it has the tuned circuit I24, tuned .to this 455 kilocycle intermediate frequency wave. This latter circuit is inductively couoled to the circuit !35, I35, similarly tuned, which is in series with the diode detector I32. Thus oscillations having the 455 kilocycle frequency de- Veloped. on circuit I24 are supplied through circuit I35, I35 for detection by the diode I32. This circuit may be traced as follows: circuit I35, I36, diode :32, lower half of the intermediate frequency transformer secondary winding I31, which is of substantially zero impedance at this frequency, conductor 5 and resistance I400. to ground and back to the grounded terminal of the cir- The inductance of the lower half of winding I3! is negligible at 455 kilocycles as is also the inductance of primary winding I38. Thus condenser I39, wh ch may be a large capacity, is connected directly in shunt with the resistance Idea, and in cooperation with that resistance acts as an audio frequency load for the diode I32. The voltage on this resistance is supplied through resistances IdIlb and MI and conductor3'i to the audio frequency amplifier of the loud speaker.

The dial lights are now energized through a circuit extending from the positive bus through conductor 55. lamps 54, conductors BIO, 2H and 225 and coil- 223 and conductor 224, to ground at contact I 91).

Broadcast reception manual tuning whereby this transformer 2M may be tuned over the broadcast band. The inductance of the primary winding of short wave transformer 215 is negligible at frequencies in the broadcast band.

The inductance of the coil'll of the local oscillator isn-ow too lowfor use in the broadcast band accordingly a third inductance I5 is now employed, this inductance having its lower terminal permanently grounded and hence connected to the anode fdevice 52. It has an intermediate terminal connected through coil 14 and lower sections of coils l1 and 58 in succession to the cathode of the discharge device. These lower sections of coils l1 and 58 have negligible inductance at the frequency of the local oscillator when adjusted for operation in the broadcast band.

The coil 14 is inserted in this connection to prevent any effect of coil 15 upon the operation of coil 1! during short wave reception. Coils l5 and 11 may be wound upon the same form and thus some inductive coupling may exist between them. During short wave reception conductor 248 is grounded, and thus, were it not for coil 14, a short circuit would exist across the lower part of coil 15. This raises the resonant frequency of coil up into the range of the oscillator during reception in the D band and thus produces undesired absorption of short wave energy from the local oscillator in the coil 75. This effect is prevented by the use of coil 14 which reduces the resonant frequency of coil 15 to a frequency lower than any frequency that the local oscillator operates at during short wave reception.

The local oscillator tuning condenser 232 is connected across the coil 15 through contact lfid, in its lower position, conductor 21'! and padder condenser 19, and it is shunted by the trimmer condenser 80. The ungrounded terminal of this condenser 232 is also connected through the contact H141 and conductors 2l9 and 54 to the grid of the oscillator. Thus, the local oscillator and antenna transformer are now in condition for tuning by their respective condensers 232 and 233 over the bands of frequencies for reception in the broadcast range.

The lower portion of inductance I5 is con- 'nected between the cathode of the converter 45 and ground this connection including bias resistance 12 which is by-passed for radio frequency currents, conductor 13 and inductance 14 which is of low value at the frequency of the local oscillator. Thus the oscillations produced by the local oscillator are combined in the converter with those received from the antenna to produce the 455 kilocycle wave at the output of the converter. The intermediate frequency wave is supplied through the channel, as previously described to the diode detector I32.

The dial lights are now lighted through a circuit extending from the positive bus through conductor 65, lamps 64, conductors 2l0, 2! I and 225, coil 223, conductor 224, and contact I90 in its lower position to ground.

Broadcast reception predetermined station selection Now let us suppose that switch i8 is operated 'to its lower position to select broadcast station No. 5. Antenna I2 is connected through broadcast transformer 2l4, conductors 209 and 208 and contact IBc, in its lower position to the converter input bus 44. It is also connected by this same contact lBc to the trimmer condenser a which tunes the transformer to the desired station.

The local oscillator circuit is exactly as pre- .vlously described, but the tuning condenser 232 is now disconnected therefrom and trimming 'plied to the intermediate frequency amplifier I23 of Fig. 4. It is desired, however, that this intermediate frequency channel be now somewhat more broadly tuned than was the case when the receiver Was tuned by manual tuning thereby to assure desired transmission of the required band of frequencies even though there be some alignment of the circuits. Such misalignment occurs frequently due to variations in the trimming condensers, etc. This broadening of the intermediate frequency channel is effected by removing the ground from conductor 224, which is connected to the lower terminal of coil 222 and by connecting this lower terminal through coil 223, conductor 225, and contact I822 to ground. This latter coil 223 is more closely coupled to the primary winding of transformer 220 than is coil 222, and thus produces a flattened top on the resonance curve of this circuit thereby broadening the range of frequencies efficiently passed.

If any other of the switch members M to ill be operated to the lower position, the operation is exactly the same except that trimmer condensers 25a, 25b, 25c and 25d are connected to the transformer 2|4 rather than condenser 25c, and similarly the oscillator broadcast trimming condensers 26a, 26b, 26c, and 26d are connected across the oscillating circuit in place of the condenser 25c.

When any of these switch members 14 to It are operated downwardly the dial lights are energized by a circuit through conductor 65, dial lights 64, conductor 210 and one of the contacts, [4a, I5a, l6b, Ila or l8b, as the case may be, to ground and hence to the negative side of the power supply source.

Phonoyraph reproduction Now let us suppose that switch member 2i! is operated to its upper position for phonograph reproduction. The motor of the phonograph is indicated at 21 as having a winding which may be connected across the power plug 3i) through a conductor 28, contact 20a, in its upper position, and conductor 33. Thus, this motor immediately starts to rotate and voice or music modulated electromotive force produced by the crystal I3 is supplied through conductor 42, contact 2012, in its upper position, and conductor 31 to the input of the audio amplifier. As previously mentioned this amplifier is energized whenever the plug 30 is inserted in the wall outlet, if the switch Local oscillator In Fig. 6 I have shown the circuits of the local oscillator 52 which are employed during television or frequency modulation reception, segregated from the rest of the apparatus. It will be seen that it comprises only inductance 5S shunted either by condenser 204 for frequency modulation reception, or by one of the tuning inductances 55 a, b, c, or d for television reception. The upper terminal thereof is connected to the control electrode through condenser 53, and the lower terminal is connected to ground and thence through condenser 49 to the anode of the discharge device. The upper terminal of the inductance 58 is also permanently coupled to the converter grid 46 through condenser 6|.

The circuits of the frequency control tube I50.

emos 13 the anode and cathode of which are connected across the oscillating circuit or the oscillator, have previously been described and will not further be explained here.

Fig. 7 illustrates the circuits of the local oscillator for short wave reception, as, for example, in the band extending from 5.75 megacycles to 18.3 megacycles. The upper terminal or inductance is now open circuited and the lower portion of this inductance is included. in circuit between the cathode ll and an intermediate point on short wave inductance 11, this lower portion of inductance 53 having negligible impedance at the short wave frequency. The lower terminal of the inductance H is connectedv to ground and hence through condenser to the anode of the discharge device. its upper terminal is connected through trimmer condenser 243 to the variable tuning capacitor 232, the latter of which is shunted by the trimming capacitor 2%. The upper terminal of the inductance ll is permanently connected to the converter suppressor grid 69.

In Fig. 8 is shown the circuits as. they are employed for broadcast reception. It will be seen that the cathode of the oscillator is connected to ground through the lower portions of the inductances 58, Ti and I5, in the order of the, frequencies at which these inductances operate. 6f

course, the portions of the inductances 58 and ll,

which are included in circuit are negligible at the frequency of the local oscillator for broadcast reception. The lower terminal of the inductance is is grounded and connected through capacitance 38 to the anode id. The upper terminal of inductance i is connected to the grid of the discharge device through condenser 19. The tuning condenser, which may be the condenser 232, or one of the trimming capacitors 2500 too, is

connected in shunt with the oscillatory circuit to determine the frequency thereof.

The lower portion of the inductance "I5 is connected in the cathode lead of the converter #5, this circuit extending from ground through the lower portion of inductance l5, inductance "I 4 and conductor it to the cathode of the converter. This forms a third permanent coupling between the local oscillator and. the converterihus, it will be seen that irrespective of the operation of the oscillator, its circuits are permanently coupled to the converter, there being no switching required in these coupling circuits, the only switching being that necessary to adapt the oscillator to its operation at the required frequency.

Amplitude modulation detector Fig. 9 shows the effective circuits of the detector I32 for reception of amplitude modulated waves in either the short wave or broadcast band of frequencies. As previously described, the intermediate frequency during such reception is of 455 lrilocycles and appears on the circuit comprising inductance It'd and condenser I35. This circuit is effectively connected through the diode it; directly across the resistance Edda, the latter which is eiiectively shunted by the capacitance which is proportioned relative to resistance to develop the audio signal voltages theren. Audio frequency voltages which appear on the resistance Hitler and capacitance I39 are supplied through resistances Idtb and MI to the audio output circuit.

Of course, the unidirectional voltage produced by the diode I32 and which appears on resistance o i i chassis of the apparatus.

through resistance Hill to the control grid of amplifier I23. This circuit may be. traced in Figs.

1 and 2 through resistance 23, conductor 23L winding 2E4, conductor 2-519 and thence through that. one of the switch contacts by which this latter conductor is connected to the bus M and hence to the converter grid.

Switch structure In Fig. 10 l have shown the mechanical structure of the switch mechanism illustrated in Fig. 1. This switch comprises a plurality of switch members It and it, represented in the form of hell crank levers, bearing those reference numerals in the drawingof these levers may be reciprocated between two positions about an axis HE. These levers are mounted in an angle shaped frame member Hi and carry at one end a handle IIE, and at the other end a projection lit, the latter of which may extend through respective movable contact carriers lit. These contact carriers are reciprocated longitudinally of themselves by the respective levers It, IS and carry contacts indicated at Md, and ltd, I50, I52), for example, which cooperate with stationary contacts H5, as indicated on the drawing, to effeet the different circuit connections described in connection with Figs. 1 to l- These latter contacts I. it are. mounted upon. a fixed non-conducting panel board iifi suitably mounted on the These levers M, I5 are biased to the position shown in the drawing by means of springs. Ill mounted upon oppositely extending. arcuate members H8 which project from the respective levers I4, 15 through openings H9 in either side of the angle of the frame member HI in which the different levers are pivoted. v Mounted. in this frame member iII is also a locking member IE4 which is adapted for reciprocati'on longitudinally of itself, but which is biased to its left hand position by means of a spring I65. This locking member is provided with a pair of projections sec for each of the levers I4 and I5 one of which is engaged by the corresponding lever I4, I55, when operated from the neutral position. to one of its opposite posi tions, thereby to operate locking member I6 1 to the right until the hook member 16'! of the respective projection ltd falls into an aperture I58 in the respective lever. When this happens the locking member holds the lever in its operated position.

For example, let. us suppose that the handle 'I I2 of lever It is pushed downwardly. The opposite end of this lever is operated upwardly and engages the ed-gewisev surface of the projection I66 pushing latchin member I to the right, whereupon on further movement of the lever It I the hooked portion It'll of projection I 66 falls,

under its bias,v into the aperture I68 in the lever I i thereby retaining the lever It in its downward posi ion. Now let us suppose that the corresponding handle, not shown, on lever I5 be pushed. either upwardly or downwardly. In its movement it engages one of the corresponding edgewise surfaces of the projections 5136 operating the latching plate I 66 tov the right, releasing lever I6 whereby that lever returns to its normal position under influence of bias springs II'I.. Lever I 5, however; is now locked in the position to which it is operated by the hook I61 of the respective projection I66 falling into its aperture I68.

This switch mechanism is designed for extreme compactness in its assembly and is of such a character that it may be readily mounted in a corner of the radio chassis where it requires a minimum of space. In Fig. 11, I have shown the mechanism so mounted. In this figure the chassis is indicated at I having the switch member I4 projecting therefrom, the latter being mounted in the angle member I I I. Plate I I6 carrying the various contacts I I5 is mounted across the corner of the chassis. In this way, in the practical assembly of the apparatus the switch is mounted beneath the chassis and well up into the corner out of the way and where any connections required thereto require a minimum of the useful space within the chassis.

This switch assembly and the circuit thus described comprises a receiver capable of the principal uses desired in reception in the home, and it accomplishes this result with a minimum of complication in both the switch and the circuit structure required. At the same time the extreme simplicity of push button operation is had, thus greatly lending to the reduction of confusion and error in the operation of various controls by the housewife, maid, or servant, who is unskilled and inexperienced in such matters. This advantage of the apparatus is enhanced by the fact that short wave, frequency modulation, and television reception is had by operating the push buttons upwardly whereas broadcast reception either by button selection or by manual tuning is obtained by operating them downwardly. Manual tuning in both the broadcast and short wave band is had by operation of a single switch member, upwardly for short wave reception, and downwardly for broadcast reception. At the same time the circuit structure is such that the number of switching operations required is minimized. The change, for example, from the detector for frequency modulated waves to the detector for amplitude modulated waves is made without switching other than the deenergization of discharge devices not required in amplitude modulation reception. The change in frequency of the oscillator is effected without any switching of the coupling circuits to the converter and with a minimum of other circuit connections. This is true, even though the oscillator operates at the comparatively low frequencies for reception in the broadcast band and also at the extremely high frequencies required for frequency modulation or television reception.

Also the maximum of utilization of the different discharge devices is had. The same local oscillator, converter, one intermediate frequency amplifier, one diode detector and all of the audio frequency amplifiers are employed in any radio reception that is had by the equipment, and no switching in the supply circuits of these devices is required. The energization of other devices, when required is effected in a way which does not undesirably complicate the switching required.

Another very important advantage resides in the character of the switch structure which results in extremely low stray capacity effects between ground and the grids of the converter and oscillator. Especially is this true when it is considered that these devices operate on all of the different types of receptions above described.

While I have shown a particular embodiment of my invention, it will of course be understood 16 that I do not wish to be limited thereto since many modifications both in the circuit structure and in the instrumentalities employed may be made and I contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination, in a radio receiver for frequency modulated carrier waves of short wave length and amplitude modulated. carrier waves of long wave length, of an electron discharge local oscillator, a converter, an electron discharge limiter, and a frequency discriminator including a pair of oppositely acting diodes, a switch having two positions, means responsive to operation of said switch to one of said positions to connect said oscillator and converter to convert short wave frequency modulated carrier waves of received frequency to a high fixed intermediate frequency wave and to supply said intermediate frequency wave through said limiter to said discriminator, and means responsive to operation of said switch to the other of said positions to connect said local oscillator and converter to convert received amplitude modulated broadcast waves of long wave length to a low intermediate frequency Wave and to supply said last wave to one of said diodes of said discriminator and to disable said limiter, and audio means connected to respond to the output of said diode or said discriminator.

2. The combination, in a radio receiver for television signals, audio modulated short wave signals and audio modulated long wave signals, of a television section, a radio section and an audio section, each section comprising electron discharge devices having cathode, grids and anodes and having permanently connected heater circuits, a source of anode operating potential having a positive terminal normally connected to the anodes of all of said discharge devices and a negative terminal normally connected to the cathodes of said discharge devices of said audio section, a negative television bus connected to the cathodes of said discharge devices in said television section and a second negative bus connected to the cathodes of discharge devices in said radio section, and switch means operable to energize the anode-cathode circuits of said discharge devices in said radio section in accordance with the reception desired, said switch means including means to connect one or both of said negative busses to said negative terminal in accordance with the reception desired.

3. The combination, in a receiver for frequency modulated short waves and amplitude modulated broadcast waves, of a converter for converting received frequency modulated waves of different frequencies to a common high intermediate irequency and for converting received broadcast waves of different frequencies to a common low intermediate frequency, three amplifiers connected in cascade for said high intermediate frequency, means selectivelyto connectsaid converter to convert either said short frequency modulated waves to said high intermediate frequency or said broadcast waves to said low intermediate frequency, said means being operative to disable the first and last of said amplifiers when operated to convert said broadcast waves to said low intermediate frequency, and means to amplify said low intermediate frequency in the intermediate one of said amplifiers.

4. The combination, in a radio receiver, of an electron discharge. converter, an electron discharge local oscillator separate from said electron discharge converter, said oscillator having" a phi-'- rality of oscillatory circuits corresponding to different' respective band's'of frequencies and each tunable to diiferent frequencies in'its respective band offrequencies, an individual permanent coupling'b'etween an ungrounded point on each of said oscillatory circuits and said converter,

5. The combination, in a radioreceivenof anelectron discharge converter; an electron discharge local oscillator, said oscillator having an oscillatory circuit corresponding to the broadcast band of frequencies, an oscillatory circuit corresponding to'a frequency employed for television reception and an oscillatory circuit corresponding to a frequency in a range intermediate said television and broadcast frequencies, each of'sai'd oscillatory circuits being individually and permanently coupledsoas to supply generated oscillations to'said converter; and svn'tching meansse lectively to establish operativecircuit relation between said 'electrondischarg-e' oscillator and one of said oscillatory circuits in accordance with'the" reception desired;to generate oscillationsof frequency determinedby said selected" one'of's'aid oscillatory circuits;

6, "The combination, in a superheterodyne multirange' receiver adapted" "for short wave, long wave and intermediate'wave" length receptiomof an electron discharge devicehaving a cathode and a plurality of'other electrodes,.a pluralityof oscillatory circuits; one for saidlong wave, onefl for'said short wave and one" for said intermediate 1 wave receptionyeach oscillatory circuit includ-f ing an inductance; theinductan'ce of sa'id long wave oscillatory circuit having a groundedl po int,

and a permanent'connectio'n fromsaid cathode to said point througha portion 'o'fJeach of said other inductances, and selective switchingmeans selectively .to establish an operative conneo'tiom from other of said electrodes of said discharge. device to different'points on any desired one of said inductances in accordancevwit'h the reception desired; sa'id switching means a establishing not more than" two connections for any desired -reception.

'7. The combinatiom in a multirange superhetrodyne receiver adapted foreshort Wave, longwave and intermediate wave length reception,-of arr-electron discharge device having a cathode, a control electrode and an anode, a plurality of oscillatory circuits, one for said long wave, one for said short wave and one for said intermediate wave reception, each oscillatory circuit including an inductance, the inductance of said long wave oscillatory circuit having a grounded point, and a permanent connection from said cathode to said point through a portion of each of said other inductances, and selective switching means to connect said anode and control electrode to different points on either said short wave or intermediate wave inductance and to connect said control electrode to a point on said broadcast inductance in accordance with the reception desired.

8. The combination, in a receiver operable over a plurality of bands of frequencies, of an electron quenci'es, of having an anode, a cathode, and two control electrodes, an electron discharge oscillator having discharge converter operable in all said bands and having an anode, a cathode, and a control electrode; an electron discharge oscillator having an anode; a cathode, and a control electrode, a

pluralityof oscillatory circuits, each corresponding'to'a respective one of said bands, a permanent connection from said cathode of said electron discharge oscillator to" intermediate ungrounded T points of all of said oscillatory circuits; a perma nent'coiinection from the cathode of said. electron discharge converter to an intermediate point on one of said oscillatory circuits and a permanent" coupling from said converter to an ungro'unded point on the other oscillatory circuit, and switching' means selectively to connect said oscillatory circuits tothe control electrode of said electron discharge oscillator.

9.'Th'e combination, in a superheterodyne receiver operable over a plurality of bands of frean electron discharge converter ananode, a cathode, and a control electrode, an oscillatory circuit for each of said bands, a permanent connection from the" cathode of said oscillator to an intermediate ungrounded point of all said circuits, a permanent connectionfrom the" cathode of saidconverter to an intermediate point of one of said'oscillatory circuits, a point removed from said intermediate point of each of the other of said oscillatory circuits being permanently;connected to a respective onev of said-control electrodes of said'converter whereby said'converter is permanently coupled to all of said oscillatory circuits,-and means selectively to connect said oscillatory circuits tonthe control electrodev of said electron discharge oscillator for excitation thereby.

10. The -C0-mbinati0n' -in" a signals representing a television image tobe reproduced and-a second carrier wave of long wave length modulatedin accordance with audible sig- I nals, ofla panel having two parallel rows of legplurality ,of switch operating members, each member correspondingto one pair of oppositely disposed legends and positioned therebetween and each member being movable from a neutral position to and from either of-said legends in accordance with the reception desired, the legends in one row corresponding to short wave stations to be received andthe legends in the other row corresponding to long wave stations to be received, an -electron discharge device, circuit connections for supplying said-first carrier wave to saicldevice and for causing said device to operate as a frequency converter for said first carrier wave, circuit connections for supplying said second carrier wave to said device and for causing said device to operate as a frequency converter for said second carrier wave, an output circuit for said discharge device, means responsive to currents in said output circuit to reproduce said television images and said audible signals, and switch means responsive to operation of each of said switch members for establishing said first named circuit connections when the respective switch member is operated in the short wave di rection and for establishing said second named circuit connections when said member is operated in the long wave direction.

11. The combination in a radio receiver I radio receiver adapted for receptionof a first'carrier wave of short-wave length modulated in accordance with adapted for reception of a first carrier wave of short wave length modulated in accordance with signals representing a television image to be reproduced and a second carrier wave of long wave length modulated in accordance with audible signals, a switch assembly, said assembly comprising a plurality of interlocked switch members each having a neutral position and two opposite positions, one of said opposite positions corresponding to reception of carrier waves of short wave length and the other corresponding to reception of said carrier waves of long wave length, an electron discharge device, circuit connections for supplying said first carrier wave to said device and for causing said device to operate as a frequency converter for said first carrier wave, circuit connections for supplying said second carrier Wave to said device and for causing said device to operate as a frequency converter for said second carrier wave, an output circuit for said discharge device, means responsive to currents in said output circuit to reproduce said television image and said audible signals, and switch means responsive to operation of each of said switch members for establishing said first named circuit connections when the respective switch member is operated to the short wav position and for establishing said second named circuit connections when said member is operated to its long wave position.

12. The combination in a radio receiver adapted for reception of either a composite television signal comprising a first short wave carrier amplitude modulated in accordance with television image signals and a second short wave carrier frequency modulated in accordance with television sound signals or a third short wave carrier frequency modulated in accordance with broadcast signals or a long wave carrier amplitude modulated in accordance with broadcast signals, of an electron discharge device, first circuit connections for supplying said first and second carriers to said device and for causing said device to operate as a frequency converter for said first and second carriers, second circuit connections for supplying said third carrier Wave to said device and for causing said device to operate as a frequency converter therefor, third circuit connections for supplying said long wave carrier to said device and for causing said device to operate as a frequency converter therefor, an output circuit for said discharge device, means responsive to currents in said output circuit to reproduce said television image and sound signals said short wave carrier broadcast signals and said long wave carrier broadcast signals, a switch assembly, said assembly comprising a plurality of interlocked switch operating members each having a neutral position and two opposite positions, one of said opposite positions corresponding to reception of said first, second, or third short wave carriers and the other position corre sponding to reception of said long wave carrier, and switch means responsive to operation of said switch members for establishing said first circuit connections when one of said switch members is operated to the short wave carrier position and for establishing said second circuit connections when another one of said switch members is operated to the short wave carrier position and for establishing said third circuit connections when any of said switch members is operated to the long wave position.

GEORGE W. FYLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 931,331 McIvavie Aug. 17, 1909 1,008,514 Armstrong Nov. 14, 1911 1,431,308 Jones Oct. 10, 1922 1,602,735 Davis Oct. 12, 1926 1,618,388 Rinker Feb. 22, 1927 1,704,754 Marvin Mar. 12, 1929 1,741,485 Taylor Dec. 31, 1929 1,768,658 Balsey July 1, 1930 1,979,588 Vreeland Nov. 6, 1934 2,024,807 Reid Dec. 17, 1935 2,062,259 Thomas Nov. 24, 1936 2,062,379 Silver Dec. 1, 1936 2,068,002 Batchelor Jan. 19, 1937 2,149,231 Reid Feb. 28, 1939 2,154,778 Schnell Apr. 18, 1939 2,167,605 Carlson July 25, 1939 2,183,741 Grundman Dec. 19, 1939 2,186,208 Reid Jan. 9, 1940 2,186,455 Goldmark June 9, 1940 2,209,959 Chittick et a1 Aug. 6, 1940 2,211,041 Albright Aug. 13, 1940 2,223,822 Grundman Dec. 3, 1940 2,230,557 Babik et al Feb. 4, 1941 2,245,383 Brokaw June 10, 1941 2,245,804 Mitchell June 17, 1941 2,258,599 Carlson Oct. 14, 1941 2,270,652 Epsley Jan. 20, 1942 2,272,050 Horowitz Feb. 3, 1942 4 2,289,000 Faudell July 7, 1942 "2,289,147 Shea July 7, 1942 2,296,092 Crosby Sept. 15, 1942 2,301,504 Batchelor Nov. 10, 1942 2,354,959 McCoy Aug. 1, 1944 2,443,935 Shea June 22, 1948 FOREIGN PATENTS Number Country Date 22,649 Australia Sept. 25, 1929 153,113 Austria Apr. 11, 1938

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