US927395A - Telephone-transmitter. - Google Patents

Description

C. ADAMS-RANDALL.

TELEPHONE TRANSMITTER.

APPLIUATION FILED APR. 16. 1907.

927,395. Patenteq July 6,1909.

2 SHEETS-SHEET 1.

(id/5&6 (4%1116 :Rarula 73 G. ADAMS-RANDALL.

TELEPHONE TRANSMITTER. Arrmoxnon FILED APR. 16. 1907. 7

927,395. Patented Ju ly e, 1909.

2 SHEETS-SHEET 2.

Eben fan I o an induction adapted, as is well known, to the use of hightageously therethrough a current of To all whom it may concern:

CHARLES ADAMS-RANDALL, OF NEW YORK, N. Y.

PATENT OFFICE.

TELEPHONE-TRANSMITTER.

Be it known that I, (hm-anus AnAMs-RA-N- BALL, a. citizen of the United, States residing at New York, in the county" of New York and State of New York,'have invented new and useful I1n rovenients in Telephone- Tran-sniitters, o specification. i, r

In telephony, telephone transmitters, as now generally constructed and used in a local circuit with the battery and primary coil or transformer, are not tension currents, or currents of high Voltage,

} the ractical' maximum voltage therethrough six voltsat an amperage usually very small, determined by the re-' rare y exceeding sistance ofthe circuit of which. the trans mitter is a{ part. This low voltage hasbeen found to be absolutely necessary to overcome the troubles arising from the use of too high voltage which causes arcing, frying and heating in and of the variable resistance of thetransmitter, creating disturbing noises in the receiver, affecting the articulation, the adjustment and reliability of the transmitter, and destroying the efiicienc of the variable resistance in' a-very short t me.

The object of the present invention is to produce a telephone transmitter havin and novel means and general construction t0 adapt the same to carry and vary advanhigh voltage, as compared with the voltage'heretofore used and without the above noted dis' advantages and defects,

and especially overcoming deterioration of the variable resistance, such-telephone transmitter, becaus of' the greatly increased voltage carried and varied thereby,beiug applicable for practical use on longer line and cable circuits than has heretofore been possible with transmitters as now constructed. ,7

To this end the in vention generically consists in obtaining greatly increased voltage or watts through a telephone transmitter, by

having a variable resistance conductor of and large CQHdllCtlVltY low norlnal resistance or current carrying capacity; supporting said variable resistance cw, 'rzmssc directly upon a suitable vibrator, such as a diaphragm, or upon or within some part se-i cured to the diaphragm and vibrated thereby} holding and confining en masse under pressure, said variable resistance having a materially increased of low resistance Specification of Letters Patent. Application filed April 10, 1907. Serial No. 368,467.

which the following is a Patented July '6, 1909.

. and large conductivity within a suitable receptacle and coveringthisresistance with a.

thin yielding perforated plate or cover of anon-conducting material having a contact piece or electrode, or electrodes, preferably adjustable, in electrical contact with i the mass of resistance granules through a pen foration, or perforations, in the said'nonconduct'in plate or. cover; and having a single lead or connection from one pole or battery or other source of electrical energy, such as an other source contact pieces are the transmitter.

in a mass over a comparatively large sur ace covering, preferably at a suitable uniform depth or thickness, almost the entire surface and'if such support be used it the granu es,

the diaphragmand vibrated is attached to thereby.

,w-i-th the part carrying the same and being the means for making electrical connection to thegranules from the battery or other side, face, or surface of the granules is covpoint or points of conered except at the tact therewith, by a thin yielding or pliable perforation, or a ni'iinber of perforations, formed therein, and further covered by a suitably supported or preferably adjustable contact piece'or pieces arranged over the cover andv granules and resting on the edge of the perforation or perforations therein, whereby the granulesarc entirely covered, confined and held, under pressure in a mass, the contact piece or pieces being in proper trical connection or connections from the or two or more transformers if two or more used in the construction of V 0f the diaphragm or other support carrying source of electrical energy. The opposite plate of mica, paper, rubber, or other similarnon-conducting material havlng a central electric light current supply, to the mass of confined granules, and therefrom such circuit including, if

.Toobtaiu the increased conductivity of the 1 variable res stance, the granules are arran ed .80

\8'5 The granules are suitably held in W place by an annular body, preferably ofsomeas leather,-paper, soft or surface of the granules bemg in electrical contact ioo engagement therewith and forming the elecbattery to the adjacent side or surface of the granules.

In the drawings: Figure 1 represents a transverse vertical section of the transmitter and the circuit connections in diagrammatic plan. Fig. 2 is a top plan view of a portion of the transmitter. Figs. 3, t and'5 are detail views of the .transmitter. Fig- 6 is a plan View, partially in diagram, of a modification of the transmitter. Fig. 7--is a detail 'plan view of a portion of the transmitter shown by Fig. 6.

Similar characters I of reference are? employed to indicate corresponding parts in the several views.

, The numeral 1 represents the case or body as at 5 and fitting in and engaging the inner screw-threaded surface 6 of the case or body 1. The ring 5 is provided with three or more lugs 0r projections 7 which bear upon the peripheral edge of the diaphragm at different portions of the latter and by means of which greater freedom of vibration of the diaphragm is obtained than when a clamping means is employed completely engaging the peripheral edgeof the diaphragm. An annular receptacle or body 8, formed of suitable pliable material such as soft leather, rubber, felt or the like, is secured to the diaphragm by means of glue. orotherwise, and preferably has an outer diameter nearly equal to that of the diaphragm, the inner diameter of this annular receptacle or body being greatly in excess of the diameter or area of the face of the electrode or electrodes employed in the organization of the transmitter. The body 8 forms a cup, chamber, or holding means having a "comparatively large superficial area of such suitable depth as to permit the use of a mass of granular variable resistance material of large conductivity and low normal resistance.

The variable resistance9, preferably composed of carbon granules, is arranged within the annular receptacle or body 8, the said granules in a' mass entirely filling the body or receptacle at a uniform depth. This variable resistance is held and confined under pressure within the annular receptacle or theannular receptacle or body 8 by means of shellac, glue, or other material and is also held close to the resistance material by a contact piece 11, as shown by Fig. l, the said contact piece resting upon the cover 10 over a perforation 12 in the center of the cap or cover, the said contact 11 positively engaging the granules 9 at all times and completing the -inc1osure for the variable resistance to confine the latter within the receptacle provided by the body 8. The contact piece 11 is carried by a suitable arm' 13 attached to the case or body 1 at its outer extremity, as at 14, and having a slight adjustment through the medium of a stiff arm or member 15 also fixed to the case 1 andextending over the arm 13 and carrying an adjusting screw 16 which bears on the inner end or extremity of the arm 13. By adjusting the screw 16 the engaging pressure of the contact piece 11 with relation to the cap or cover 10 and the. variable resistance granules 9 may be modified.

' A mouth piece 25 is provided which is secured to the case 1 by a screw-thread upon the same fitting into the screw-threaded central opening 26 of the said case.

-A suitable cap or cover 27 is applied over the transmitter opposite the mouth piece so that all the parts of the transmitter are fully inclosed, the cover being removable through the medium of screw-threads formed in a portion thereof and engaging corresponding threads on the exterior surface of the case of body 1, as at 28.

The circuit connections with the battery B to and from the transmitter are shown by Fig. 1, and are as follows: A wire 'w runs from the positive terminal of the battery to the primary coil of an induction coil 17, the said primary coil also being connected to the diaphragm 4 and variable resistance 9 by a wire 18 passing through an opening 27 in the center of the transmitter cap or cover 27. The secondary coil of the said induction coil 17 is connected to line L in the usual manner, as shown by Fig. 1, and also to ground by a wire 'w. A switch S is used to determine and change the voltage of the current through the transmitter and has thereon a series of buttons A, C, D and E with which a switch arm S is adapted to cooperate, and between the pivotal extremity of this latterv arm and the arm 13 carrying the contact piece 11 a wire 19 runs to setup the proper electrical connection between-the switch and the said contact piece.v The but- I 'v0lts,as shown, or up to the the arm or support 13 andby wire 19 to the through the granules composing the variable reslstance to thecont'actpiec'e 11, through switch S and from the latter back to the bat tery in accordance with the button engaged by theswitch arm S.

a As before indicated, the switch S provides convenient means for changing the voltage from maximum or twenty-four volts, for instance, when the button A engaged by the switch arm S; eighteen volts when the but-. ton (l is included in the circuit; twelve volts when the buttonD has the switch arm thereon andtosix volts when the button E is in the circuit, or. per contra, increased from the minimum to the maximum, twenty-tour reatest possible maximum that may be used with a transmitter constructed in accordance with-the princi'ples'of the improved transmitter.

The switch S, as shown, has-but four'contact buttons; but it will be understood that the same may have a "greater number it required for st ll further sub-dividing the bat-- tery or for use with a battery having a larger number of cellsand .a greater number of sub-divisions than'illustratedby Fig. 1. The

desired.

invention is not limited to the use'of a switch, the latter being shown asa simple illustration of one means for sub-dividing the battery, but in -lieuof theswitc'h other means,either automatic or semi-automatic, maybe used without departing from the principle involved or to control the sub divisions of the battery. to determine the vgltagethrough the transmitter as may be Tlie transmitter shown by Figs. 1, 2, 3, 4 and 5, illustrates the-simplest and preferredform of the invention. Thissimplified form of the inve1ition may, however, beyaried in many ways, one modification being shown by Figs. (3

just dtscribed and as and 7 and consisting in providing more than one perforatlonm the cover or cap 10, the

latter in this modified construction having a,

series of three openings 29 therein to accommodate acorresponding number of electrodes or contact; pieces 11, 11"v and 11 carried by supporting arms 13, 13? and 13 secured to the case 1,. as clearly shown byFig. 6. In i connection with this modified formof the invention it is preferred to employ three induction coils 17, 17".and 17, connected respectively from one side of theprimary coils to the arms 13, 13, 13", and the electrodes 1,1", 11, 11, the granules 9, the diaphragm 10, and by wire' 31to the battery B,

the opposite ends of the primary coils being connected in multiple by a wire 30" to'the switch arm S and from the buttons A, C, D and E to the battery B by wiresQQ, '21, 22

to the construction shown by Fig. 1. The in-'. side and outside wires 0* the secondary coil of and 23 in all respects similar in'arrangement' 1 As heretofore indicated, the important features of the present invention to be particularly noted and compared with other granular transniitteis are the extendcdor increased mass of granules of low normal resistance and increased current carrying or 1 conducting capacity, means for'holdingand confining the granules. in a mass under pressure, and the largely increased surface of the granules ascompared with the actual variable surface of the contact .or contacts 00- operating therewith and in electrical contact with the granulesat the contact surface thereof of smallest area. These particular es 'sential features of theiinvention permit of the eil'ective use of a current of minimum yoltage, or a low voltage of .six volts or'less as generally employed as a jmaximum in known granulartransmitters, and also per hit of the practical commercial useof a current at a voltage many times greater than the minimum specified u ith'correspoiicliiigincreased results, of benefits and advantages hereinbefore noted and'particularly producing a greater volume of tone at the receiver and the operation of more difficult circuits, andcircuits of greater length than hereto fore possible and without the detrimental effects of arcing frying undue heating or deterioration "ofthe variable resistances heretofore experienced in theoperation of telephone transmitters.

Having thus described the mvention, what is claimed, is: I

- A telephone transmitter constructed and adapted to carry and vary high or low tension currents therethrough comprising a diaphragm or other vibrating medium in electrical contact with; andcarrying or supporting a confined variable resistance con dnctor of'uniform depth and large conduct ring capacity, the conductor being held upon the diaphragm .or vibrating medium in a mass under ressure, acoiiperating electrode or contact means .in adjustable"electrical contact with the variable resistance conductor, a source of current supply, and connections therefrom to thevariable resistance conductor and to "the cooperating electrode.

*QQA telephone transmitter constructed andi'adapted to carryand vary high or low tension currents therethrough,comprising a diaphragm or other vibrating medium car- .rying or supporting a confined variable resistance of uniform depth, low resistance and large conducting capacity held in a confined mass under pressure in direct contact therewith, a cooperating electrode in adjustable electrical contact with the variable resistance, and a source of current supply having connections with the variable resistance conductor and the cooperating electrode.

3. A telephone transmitter constructed and adapted to carry and vary high or low tension currents therethrough, comprising a diaphragm or other vibrating medium in electrical contact with and carrying or supporting a confined variable resistance granular material of uniform depth, low resist ance and large conducting capacity held confined thereon in a mass under pressure, the variable resistance granular material directly contacting with the diaphragm or other vibratingmedium, a cooperating electrode in adjustable electrical contact with the variable resistance, a source of current supply having connections with the variable resistance conductor and the cooperating electrode, an induction coil having its primary in circuit-with the current supply and the transmitter and its secondary in circuit with the line, and means in circuit in series with the current supply, thetransmitter, and the induction 0011 primary for increasin and decreasing the current supply in sald circuit.

4. A telephone transmitter constructed and adapted to carry and vary high or low tension currents passing therethrough, comprising in combination, a diaphragm or other vibrating medium, a variable resistance conductor, a receptacle on the diaphragm or vibrating medium and having a non-metallic cover which is partially open and containing the said variable resistance conductor-in a confined mass under pressure, an electrode means in electrical eontact with the variable resistance conductor through the partially open non-metallic cover and cooperating therewith and with the diaphragm or vibrating medium, a source of current supply, and connections from the source of current supply to. the variable resistance conductor and to the cooperating electrode and increased current carrying or conduct" iug capacity and having direct contact with the vibrating medium, an electrode or contact piece in electrical contact with the portion of the resistance medium through the cover opposite the portion of said medium with which the vibrating medium is in direct contact, the resistance medium having a surface largely in excess of that of the electrode or contact piece, a battery means having one pole connected to the electrode or contact piece, and means for connecting the other pole of the battery means with the surface of the variable resistance medium opposite the electrode or contact piece.

6. A telephone transmitter having in combination a vibrating medium, a receptacle on tl e medium provided with a non-metallic eovei'which is partially open, a variable resistance medium confined in the receptacle under pressure and exposed to the partially open portion of the cover, the receptacle and variable resistance medium being vibratingly movable with the vibrating medium, one or more electrode devices in direct electrical contact with the variable resistance through the partially open portion of the cover, a battery, and electrical connections between one pole of the battery and theone or .more electrode devices and the remaining pole of the battery and the opposite side of the variable resistance.

7. A telephone transmitter having in combination, a vibrating medium, a receptacle held by the vibrating medium and provided with a cover of mica having one or more openings therein, a variable resistance means confined in the receptacle in direct engagement with the vibrating medium, one or more adjustable spring supported electrodes in pressure contact with the variable resistance means through the open cover, a battery or other source of electric energy supply, and means for electrically connecting the variable resistance and the one or more electrodes to opposite poles of the battery.

8. A telephone transmitter having in combination a diaphragm, a receptacle supported and in part formed by the diaphragm and consisting of an annular pad or washer and a perforated non-metallic cover, a variable granular resistance means confined in the said receptacle, an electrode means in con tact. with the variable; resistance means through the perforated cover, a source of electric energy, and electrical connections between the source of electric energy and the variable granular resistance and electrode means, the variable granular resist-' ance having a larger surface area than the electrode means in contact therewith.

9. The combination, in a telephone transmitter, of a diaphragm having a receptacle thereon, a variable resistance material held in a mass within the receptacle and in direct contact with the diaphragm, a perforated cover of nonconducting material on the receptacle. an adjustable electrode in variable electrical contact with the variable resistance material and slightly impinging or hearing on the cover around the perforationand acting with the cover to completely confine the variable resistance material Within the receptacle, and a source 0f-e1ectric energy supply in electrical connectionwith the electrode and variable resistance material. I

10. In a telephone transmitter, a vibrating means, a granular variable resistance conductor held confined under pressure, electrode means in contact with said conductor,

and means inde endent of the electrode means and the vi rating means for placing pressure on the resistance conductor.

duct'or, a yieldin or pliable non-conducting co'ver confin1ng 1e resistance conductor un der initial pressure, and electrodemeans in 'co1itactxvith the resistance conductor and having a smaller area than that of the said resistance conductor. 7 In testimony whereof I have hereunto setmy hand in presence of two subscribing witnesses. v

CHARLES ADAMS -RANDALL. Witnesses:

DANIEL D. LOVELACE, AnG. HETHERLIN.

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