US1372426A - Multiplex radiotelephony - Google Patents

Description

'1. H. HAMMOND, In.

- MULTIPLEX RADIOTELEPHONY. APPLICATIONYHLED MAY 2-9, 1912. RENEWED MAR. 15,1919.

1,372,426. Patented Mar.22, 1921.-

WITNESSE a MZE/VTOR V I A! izz' w" ORNEYS Mi i UNITED STATES PATENT OFFICE.

JOHN HAYS HAMMOND, J 3, OF GLOUCESTER, MASSACHUSETTS.

- MULTIPLEX nanio rnnnrnony.

'. Specification of Letters Patent -Pa tenf ed luau 22 19,21,

Application iiled I May 29, 1912, Serial No. 700,426. lienewed March I5, 1919. Serial No. 282,960.

To ditwhom it may concern:

siding at Gloucester, in the-State of Messachusetts-have invented certain -new and useful Improvements in. Multiplex Radio ficat-ioii. y y

My invention relates to systems for transmitting and receiving two or more telephoneconversations simultaneously by meansof electric waves; and relates more particularly to such systems where electric. ,waves having different lengthsai'e employed for this simultaneous or multiplex, te- Hei'etofoi'etwo oscillation genera-tors have been used at the transmitting station, each generating electric waves of a definite length, but by my inventionit is possible to use only one generator for generating any required number of sets of clectric waves, the waves in-each sethaving difierent-lengths from those in the other sets. v: This will be shown more fully by the following description,' reference be ng had to the accompanyingdrawings;

Figure l shows-atransmitting stationon my system of multiplex radio telephony I F 2 shows a corresponding receiving L station on'mysystem; a r y In 'Fig '1,' an oscillatory arc-O is suRpl iTd from a source of direct current shunted around Ozare two-oscillating cirij cuits O'L GandOL C containing the inductan'ce coilsL and--L ,and the condensers C and C respectively, which are in resonancewith the antenna circuits A L T E and A T 515, respectively,- towhich they .are v respectively: coupled through the coils- L 40 and L p; ,It is'well known that an electric arc of thetype shown comprises-two elec- 5: trodes, one of 'whiclnthe cathode, is always negative, and emits electrons when in op eration. J'The are 0 eonstitutes ajthermionic oscillator. i The antenna is grounded 1 atg E, and Jasthecircuits 0L G and 0 I30 have different osci llation' periods, the an tennal A--will radiate continuous unclam'ped In 2, B is-an antenna grounded at telephony. of which the followingis aspeci- E and having two circuits B Li C E and B L C E these circuits containing the inductancecoils, L and L, and the 3 condensers,'C ,and (3*,"respectively, and being coupled to the closedoscillation circuits L C and L 0? through the coils L and L, respectively. The. antenna circuit B L C and the oscillation -circuit L5 (3* are in resonance with each other and with one of 'the wave-frequencies of the transmitting rectifier will deliver, unidirectional cur-' i rent corresponding to the current"variations caused by the transmitter T, in Fig. 1,-to

the telephone receiver P where the sounds produced at will be reproduced. V In like" manner whenthe circuit L C is energized,

- the rectifier .R -w-i-ll deliver unidirectional current to thetelephone P which will thus Although in the particular embodiment 'of'my invention here shown there are only two sets of circuits,- and only two telephone conversations can be carried on vsirnultaneously. my invention is not limited to two sets,

of circuits, but may employ three or more sets of circuits, so that three. or more telephone conversations can be carried on simultane'ously. Instead. of "telephone appa 'ratus I canemploy telegraph apparatus at of two or' morextelegraph messages,- or- I canuse bothvtelephoneandtelegraph apparatus at both transmitting and'ireceiving."

9 stations andtransini't and receive telephone conversations and:telegraph messages Jsilmultaiieoiislyz And, "moreover; IFtlo not *confine myself to the particular a aratus or, circuits-here shown, but may em )loyany otlierapparatu s tor arrangement 9 circzuits' suitable forimy 'purpose: a

I iclaim as my invention I q f 1. In wa sysftem oi multiplex radio te le'p hony," e plurality of oscillation circuits connected with a: single-arc, said oscillation circuits haviingdiiferent periodicities, secondary circuitcoupled to each of said oscilla- 1 1 o t on oircuitsand connected to a s ngle antenna, a telephone transmitter in operativej' relation "to each of said secondary circuits,

and a receiving station comprising a plurality of circuits tuned to the dlflerent wave lengths-emittedby the transmitting station. 2. A system of multiplex radio telephony having a transmitting station comprising a single are connected with a source of en-- ergy, a plurality of circuits in. parallel conreceiving station comprising a plurality of circuits tuned to the wave lengths of the transmitting station, and operatively con- 6 nected with telephone receiving apparatus.

3. In a system of-electricwave transmission,'a plurality of oscillation circuits connected with a sin 1e arc, said oscillation circuits having di erent periodicities secondary circuits coupled to each of said oscillation circuits and connected to a single antenna, and a; receivingvstation co g; ing -P y of circuits tuned to they different wave lengths emitted by the transmitting station.-

4. In a system of multiplex radio telephony, the combination with a source of electroradiant oscillations, of means for simultaneously impressing'a plurality of series of undulations corresponding to sound waves upon the said oscillations, and receiving means includinga plurality of devices selectively responsive respectively to said plurality of series;

5. A transmission system for multiplex radio signaling, comprising a transmission circuit, a-plurality of secondary circuits connected to said transmission circuit, an electric arc, a source of electric energy connected to said are for energizing the same, and a plurality of oscillation circuits tuned to different frequencies respectively and respectively coupled to said secondary circuitsfand shunted around said are.

6. A transmission system for multiplex radio signaling, comprising a transmission circuit, a plurality of secondary circuits connected to said transmission circuit, an electric arc, a source of electric energy connected to said are for energizing the same, a lurality of oscillation circuits tuned to dili erent frequencies respectively and respectively coupled to said secondary circuits and shunted'around said arc, and a si aling-device arranged to act upon eac' of said secondary circuits.

7 A multiplex'system comprising a single are, a pluraht-y' of oscillation circults tuned to different frequencies respectively and connected to said arc, a single antenna operatively connected to said circuits and a Sig-- naling device arranged tocontrol each of said oscillation circuits whereby a plurality of messages may be simultaneously transmitted through said antenna.

8. A multiplex system comprising a single are, a plurality of oscillation circuits tuned to different frequencies respectively and connected to said arc, a single conductor operatively connected to said circuits and a sig-' vices associated with said circuits respectively whereby a plurality of different messages may be simultaneousl generated.

10. In a system of multiplex signaling, an oscillator having an electron emittin cathode a plurality of circuits associate with said oscillator and arranged to have simultaneously generated therein respectively, as

the result of the action of the oscillator, a plurality of series of periodic electrical impulses having diflerent frequencies respectively, and a plurality of signaling devlces associated with said circuits respectively whereby a plurality of different messages may be simultaneously generated.

11. In a multiplex system of signaling, the combination with an oscillator, of a plurality of circuits associated therewith and arranged to have simultaneously produced therein respectively as a result of the action of said oscillator, a plurality of series of periodic electrical impulses having different frequencies respectively, one of said frequencies being substantially outside of the range of audibility, and a plurality of signaling devices associated with said circuits "respectively whereby a plurality of diiferent messages may be simultaneously generated, one of said signaling devices associated with the circuit having-generated therein a frequency substantially outside of the range of -audibility, being a telephone transmitter.

12. A multiplex transmission system com prising a thermionic oscillator, a pluralit of circuits associated with said oscillator and arranged to have generated therein respectively as a result of the action of said oscillator a plurality of series of periodic electrical impulses of different fre uencies respectively, and a plurality of signa ing devices associated with said circuits respectively whereby a plurality of different messages may be simultaneously transmitted.

f ranged to have generated therein respectively as a result of the action of said oscillator, a plurality of substantially ultraaudible periodic electrical impulses of diiierent frequencies respectively, and a plurality of separately operated signaling devices as sociated with said circuits respectively whereby a plurality of different messages may be simultaneously transmitted.

14:. In a system of multiplex radiotelephony, a sending station comprising telephone transmitting apparatus; va plurallty of 0scillationcircuits connected with a single arc, sald osclllatlon circults generating a plurallty oi series of electric Waves of different frequencies respectively, each of said series of Waves having amplitude variations impressed thereon by said telephone transmitting apparatus, and a receiving station compr sing a plurality of circuits tuned respectively to said i requen'cies.

15. In a system of multiplex radio telephony, the combination with a source of electroradiant oscillations, of means for simul taneously impressing a plurality of series of undulations corresponding to sound waves upon the said oscillations, and receiving means including a plurality of devices selectively responsive respectively to said plurality of series. a

This specification signed and witnessed this 22nd day of May A. 1)., 1912.

JOHN HAYS HAMMOND, JR.

In the presence of- MABEL J. Coornn, OLIVE B. RING.

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