USRE13798E - To wireless - Google Patents

Description

` 40 less .telegraph receiving A of the present UNifrED STATES 'PATENT OFFICE;

,.GBEENLEAF -WHITTIEB PICKABD,

OF AMESBUBY, MASSACUSETTS, ASSIGNOB, BY

MESNE ASSIGNMENTS, TO.WIRELESS SPECIALTY APPARATUS COMPANY, OF BOS- TON, MASSACHUSETTS, A CORPORATION OF NEW YORK.

MEANS FOB RECEIVING 13,798.' Division of original Patent No.

reissue illed latch 9, 1912. Serial No. 682,829.

' To all whom it may concern:

Be it known that I, GREENLEAF Wnrr'rmn PICKARD, a citizen of theUnited States f America, and a resident of the town of Amesbury, State of` Massachusetts, have invented certain new and useful Impr'ovements in Means for Receiving Intelligence Communicated by Electric Waves, the princ iples of which are set forth in the follow- 1o ing specification and accompanying drawing, which discloses the form of the invention which I now consider to be the best of J the vario-'us forms in which the principles of the invention may be embodied.A

This invention relates to means forA receiving intelligence communicated by electric waves, and relates more particularly to improvements in detectors of the rectifier 2o pThe object of my invention is to provide improved commercially useful means for cperating a devicev for translating into intel igible form a relatively great art of f nergy of the high frequency oscillatory eurrents, such as generated at a receiving station by the transmitted electro-radiant energy or electric waves. i It-,isvmy objectto convert as much as possible -of the energy of the received oscillations into a form 'capable .of operating an vindicating device, such, for exam le, as a telephone receiver, preferably wit out the use of any auxiliary energy; and in any case without recourse to the effect of resistance due to conductor attenuation or imperfect contact; and without recourse to a vacuum tube. j Y, i Of the drawings,Figure 1 is a diagrammatic illustration of a well-known form of wirestation apparatus, -ths being t e apparatus with whichl the in- Yvention has been actually used. Figs. 2 and 3 are aside elevation and section respectively preferred embodiment of the detectorv em oyed in the invention i n` its p` nt` most eilicient form, Fig. 3 being a slightl' modiied form,

In ig.I the genera arrangementisawellknown. loop formv of wave-intercepter A, A'

i tion,

INTELLIGENGE communica-ran BY nnnc'rnic 'wavns Speciiication of Beissued Letters Patent.y Reissued Sept, 8, 1914.

838,531, dated November 20, 1906, and application Serial lo. 342,465, led November 8, 1906. Original No. 877,451, dated January 21, 1908, Serial No.

401,856.V Application for operatively7 provided with the usual ad usta le capacity C, inductance L, adjustabl bo tli the wave-intercepter and oscillation-receiving circuits, the inductance L', ad'ustable in the wave-intercepter circuit, an the cnnection of the latter circuit' to ground a In Fig. 1, the circuit L, T, J, C'-T, L receives the oscillations enerated in, the .wave-intercepting loop A,

L bein adjustable 1n the oscillation circuit cillation receiver ordetector of this invenas-it includes the adjustable condenser C and the indicating device T in' shunt 'to tliis'condenser. The device is preferabl a telephone receiver and may be an other orm of device such as a sensitive ga vanometer which will indicate an abrupt direct current. The receiver or 4vdetector .should in use be maintained in good elec# trical connection in the oscillation circuit,

the

.substantially per lead to the shunt-connected condenser C and the 'telephone T is taken from the lower end of the inductance L, s o that the telephone and itsparallel connected condenser are in series. between the detector and a part-of the inductance L which is at lower potential with respect to the ground.

The receiver or detector of this invention, roughly indicated atTJ in Fig. 1 is shown indetail in .Fig. 2. r'Ilo a wooden base L are secured-an angular metalsupport 2 and a metal plate 3, rovided with binding posts 4, 5 orthe lea s of'the oscillating circuit of Fig'. 1. thel chuck which is removabl the plate'3 by the art 6. Vsists ofa piece o 4soldered a ymetallic' i plating copper or silver, `which plating on the material N area of surface contact -between them, Aas compared with the area of the contact junction T `J. The dcpxosition may be b electro-plating or bysing a layer 0f e mascrewed into 'MR such as vis deposited terial N upon a metallic and the contact-'unction T J should be aect electrical contact. 'The v the inductance '60 which is well adapted for use with the osilo'w of A Onecelement of the detectoi is in order to provide a large i surface, or otherproperly with the member wise; and as shown in Fig. 3, it is suilicient to place the material N in a liquefiedl mass of fusible metal F M in a chuck-cup 18, provided with a screw 17, so that when the metal F M cools and-solidilics, the material N will be firmly embedded in, and in good electrical and large-.areaed contact with the metal F M.

They operative contact-junction (,T J 0f i Fig. 1) is located anale lower' end of the 1101- low metallic sleeve 7 of Fig. 2, which junction is of substantially less surface area than that of the contact between N and M- P. The sleeve 7 can slide along the metallic pro- 'ection 8, which depends from the metallic hall 9, the ball forming a ball-and-socket universal joint with the part 10 of thin metal, which is stamped to shape and secured to the metallic support 2 so as to complete the circuit. The member 7 of the receiver may be of any conductor which coperates N. The member N may be of the element silicon, which appears to be most useful either in the massive amor hous or graphitic solid#r form; or`it may bev a" suitable equivalent whiid accom- 'plishesthe objects of the invention, i. e., a conductor within the scope of the invention which possesses high resistivity and which when operatively in substantially perfect electrical contact with the other conductor, as 7, operates in coperation therewith to produce a direct current occurring intermittently, and charging one side of the conaddition to denser, the discharge-of which is suitable foroperating the indicating device. When the member h"7 is metallic, as of copper` in accordance with this disclosure, and therefore has low resistivity, there is a very substantial'diiference'in the degree of resistivity\possessed bythe two conductors. the member N has high power in coperation with the member 7, in high resistivity, or when there is a substantial difference in the resistivity of the two conductors, a considerable part 'of the ener centrate in the form of Joulean heat, at the contact junction, where it may be converted into a vdirect current owingto the cooperative thermo-electromotive power of the two conductors. The junction betweenthe massive conductors 7 and N should be a substantially perfect electrical contactand this i 1s secured by the spring 11, which presses lthek two conductors together with suiicient force to exclude substantially all contact resistance and action of a'loose-contactor coherer nature arising from the resistance of an imperfect contact, such as to cause the contact to be"v a substantially perfect one. Such a perfect contact not only accomplishes the objects of the invention, uncommereial instability of tacts. The 11 imperfect conserves to "make When thermoelectromotive of the received oscillations is conbut avolds the good contact between the part 7 and the good conducting part 8, and also presses the good conductin part 8 into good contact with the conducting part l0 which is secured to part 2, thus establishing a good electrical' connection between part 7 and its circuitterminal 4. No means for delicate adjustment of the spring-pressure, such as a line screw, is necessary, since operatively the spring is such as to pressure to insure a substantially perfect contact. The spring 1l however, coperatively with the movable part 8, permits the selection by manual adjustment of different locations of the contact T J, owing, in this disclosure, to inequalities of different parts of the operating surface of part N, whereby the pressure of the spring is slightly` varied within the limits of contact and the sensitiveness of operation lunder differentexternal conditions Aof use.

In no case, however, is it lnecessary to continuously move either 7 or N with respect to each other during operation. The device is most efficient in the form shown, as to the lower end ofl part 7 having a substantial rounded surface in physical contact of considerable area with part N, but having an extremely small electrical contact therewith. In no case need either member 7 or.

always exert suicient/ perfect contact pressure, so as to slightly vary tlie area of electrical N possess such attentuation as might therev by generate heat.

In order to obtain the best results, the above specification should be carefully followed. So -far I have been able to convert upward of ten percent. of the energy of the oscillations into direct current energy. The device is therefore an electricalconverter or rectifier. In the preferred form of this invention the action due to .the inherent properties of the silicon member or its equivalent is of extraordinary Icated by the fact that the ployed to commercially phone T only energy emoperate the teleduced to a minimum, as lby employing the `conductors in substantially massive form and in vsubstantially perfect contact with each other, because the energy of the oscillations should not be wasted without contributing substantially to elfective action.

The energy required to erate a telephone, Vthat is; clearly' defined dot, in, Morse code, is approximately one millionth (1 10") erg. The energy received in longdistance wireless communication is, vat the minimum, of the order of magnitude of one-thousand'th of an erg per dot. The elliciency of the apparatus of this invention, s l

demonstrated by trial under commercial conditions, is upward of ten percent. There is thus ample margin for commercial operais that of the, received oscillations. All resistance-varying action should be recommercially ,op-e to Aproduce in it a -for example, the

vigor, as is indiizo tiveness for the least sensitive form of this invention in the case of the present longest distance wireless telegraphy. l

The speed of reception with this invention is unlimited, since it is not only selfrestoring to its sensitive state, but this restoration is practically instantaneous be-v cause, so far as the thermo-electromotive action is concerned, the small quantity of heat which is generated by the received oscillations comprising a signal is rapidly conducted away, partly by thermal conduction to` the metal portion 7 and the nemainder bv the conversion into an electric current' which finally expends its energy in the indicating device.

The advantages of the new detector are as follows. It fulfils all requirements of commercial wireless telegraphy as to sensitiveness, speed, stability and freedom from delicate adjustments. I have found that the l continued .sensitiveness of the detector is in areaed perfect contact`with steel as setv no wise impaired by severe static discharges. It is also simple and cheap in construction. It is not affected by changes-in atmospheric temperature or humidity. Its sensitiveness so far has not been impaired bycontinuous and continued use.

I am aware of the existence in the prior art of a rectifier detector consisting of a pair of conductors which coperatively have high resistivity, or in'whi'ch atleast onevhas high resistivity, and in which suchI conductors are held in substantially perfect small areaed contact with each other. An example of such a rectifier detector is that of Hughes comprising carbon in small forth in a historyof wireless 'telegraphy by Fahe, 1901 Editionfpage 313.y A further prior disclosure of a rectifier detector is in U. S. lPatent No. 763,894 to Hogg, where the pair of conductors consists of steel or other metal in perfect smalllareaed contact with selenium, annealed selenium or selenids of metals, selenium in anyv conducting form and selends of metals having high resistivity. These rectiers of thev prior art may be;used either with or without a local source of energy. y y

While my invention relates to, a detector I of the rectifierclass, examples of which are referred' to above, my invention residesin improvements having the advantages hereinbefore set forth, and having a novel and -useful structure and association with other parts as set forth in the appended claims.

What I claim is:

l. Means for receiving intelligence communicated lby electromagnetic waves, which comprises two substantially .massive individual electrical conductors operatively in substantially4 perfect contact with each other,

said conductors having different degrees of resistivity, and coperatively having high supported at a said springV resistivity, atl least one of said conductors having high resistivity; in combination with a mass of fusible metal supporting said high resistance conductor, and a supporting receptacle for said fusible metal.

2. Means for receiving intelligence communicated by electromagnetic waves, which comprises two substantially massive individual electrical conductors of different degrees of resistivity, and coperatively having high resistivity, at least one ofl which conductors possesses high resistivity; in combination with a spring which operatively holds the said conductors `in substantially perfect small-areaed electrical contact with each other; and a freely movable, non-threaded support for said spring to ermit a variation of contact pressure witliin widelimits of substantially perfect Contact pressure, and thereby slightly vary the area of the minute electrical contact. 4

3. Means `for receiving intelligence communicated by electric waves, which comprises'a rectifying member in contact with a Vconductor of different material, in combinationV with a mass of readily fusible metal in which said rectifying member is firmly 'embedded and in good electrical and large-- arcaed contact.

4. 'Means for receiving intelligence communicated by electric' waves, which comprises afrectifyingmember in contactwith 4a conductor of different material, 'in combination with a mass of readily fusible metal in which said rectifying memberl is rmly embedded in good electrical and large-areaed contact, and a the same after it has cooled and solidified.

v5. Means for receiving intelligence Icommunicated by electro-magnetic waves, which comprises the combination with a rectifying conductor havin a contact surface consisting of a substantially plane area, of a Lmanuallyl movable contact-pointcarrier, having an end which is directed toward said contact surface, but which is structurally independent thereof, and has free transverse movement relative thereto; a. guide with which said carrier has movable relation under said manual control, said guide being movably point remote from the free end of the earner,

end of the carrier be moved into various different positions relative to said contact surface; and ahelical spring operatively mounted between said guide and carrier to press the latter toward said contact surface, being carried with said guide and carrier into theirvarious different positions.

6. In a converter ternating or oscillatory currents, nation withl a rectifying conductor,

the combiof a difreceptacle for. receiving the liquefied mass`of fusible 'metal and holdingV whereby the guide and carrier may be bodily moved,`and said free or rectifier for-feeble almunicated by electro-magnetic waves, which.

ferent conducto;` in Contact therewith, means `to per-v for supporting one of said members mit manual movement of it to select contacts between the two members on different parts of the rectifying member, and a helical spring mounted coaxially with said manual member and bodily 'movable therewith.

7. Means for receiving intelligence communicated by electro-magnetic waves, whichcomprises the combination with a rectifying conductor having a contact surface consisting of a substantially plane area, of a manually movable contact-point-carrier, having an end-Which is directed toward said contact surface, but which is structurally independent thereof, and has free transverse movement relative thereto; a guide with which said carrierhas movable relation under said manual control, said, guide having a ball joint remote vfrom the free end of the carrier whereby said free end may be manually moved into all positions relative to said Contact surface; and a helical spring operatively mounted between said guide and oarrier to press the latter toward said contact surface, said spring being carried with said guide and carrier into their various different positions.

8. Means for receiving intelligence communicated by electro-magnetic waves, which comprises the combination with a rectifying conductor having a contact surface consisting of a substantially plane area and possessingslight irregularities, of a contact point therefor, having an end which is directed toward said contact surface, butA which 4is structurally independent thereof; a helical vspring constructed and arranged to press the contact point against. the contact surface;

and means, combined with the spring, to permit the manual alteration of the contact junction from one-point to another of the irregular contact Lsurface of the -rectifying conductor.

9. Means for receiving intelligence co1n` municated by electro-'magnetic'waves, which comprises .the combination witha mass of fusible metal, vof a rectifyingA conductor mounted therein and having exposed therefrom a contact surface consisting of a substantially plane area; and a cooperating contact directed toward said contact surface; said fusible metal mass and said coperating contact having relative' movement permitting the manual alterationof the contact between the coperating contact and the surface of the rectifying'conductor.

10. Means Afor receiving intelligence comcomprisesthe combination with a mass of fusible metal, of a rectifying conductor embedded therein, but,V having exposedV therefrom a contact surface consisting of a substantially plane area possessin slight irregularities; a manually mova le contactrier'lnto various different positions relative t0 ,the rectiercontact surface; and a helical spring mounted between said guide and said carrier, permitting the carrier to `be slid away from -the irregular contact surface, and pressing the contact against said surface when the carrier is manuallyv permitted to return toward said surface.-

11. Means for-receiving intelligence communicated by electro-magnetic waves which comprises the combination Withfa rectifying conductor having a contact surface consisting substantially of a plane area; of a cooperating contact mem-ber therefor; means for movably vsupporting one of said members to permit the manual selection ofthe contact junction between them; and a helical spring, combined with said means, and bodily movable with one of said members and acting to press them intongood contact with each other. l Y

12. Means' for receiving intelligence communicated by/electro-magnetic waves, which comprises the combination with a rectifying conductor having a contact surface consisting substantially of a plane ayrea; 'of a co-' operating contact Amember operatively located substantially at right angles to said surface, one of said members being movably and resiliently mounted, whereby such member may'be removed from contact with the other, and replaced with a different contact junction, and in good contact therewith.

13. Means for receiving intelligence communicate'd by electro-magnetic waves, which comprisesthe combination with a rectifying conductor, having a contact surface consisting of a substantially plane area; of a cooperating contact p01nt therefor having an end which is directed toward said plane surface and which is structurally independent thereof to permit free relative transverse movement; and means to permit the manual los alteration of theA location of the contact junction of the two conductors in the lane of the contact surface of ,the rectiijying conductor. y

14. Means for receiving intelligence communicated by electro-magnetic waves, which comprises the combination with a rectifying conductor having a contact surface consisting substantially of a plane area; of a cooperating contact making small areaed electrical contact therewith; means for fixing one of said contacts from movement toward the other; and means, including a spring, to permit the other conductor to move to and from and transversely of the other.

15. Means for receiving intelligence communicated by electromagnetic waves, which comprises two individual massive electrical conductors of'dit'I'e-rent de rees of resistivity and cooperatively having igh resistivity, at. least one of which conductors having igh resistivity; yin. combination with a supporting member having a telescopic joint with one of said conductors; a spring operatively located within the telescopic joint to hold the two conductors in substantially perfect contact with each other; and means to permit the manual alteration of the location of the contact junctionv of the two conductors.

16,; In a detector device of the character described, a cup, a detector member, conducting material holding said detector member in said cup, a second detector member,

said rst detector member having a surface exposed toward second detector member, means for pressing saidv detector members A into substantially perfect Contact, and means.

` l GREENLEAF WHITTIER IICKARD.

Witnesses:

A. H, TEABURY, VILLIAM J. BRSLIN.

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