US975933A - Telephone-repeater. - Google Patents

Description

s. .L. AMPBELL; TELEPHONE RBPEATER. I APPLIOATION FILED 001229, 1908. RENEWED HA3. 3, 1010.

Patented Nov. 15, 3919.

2 SKEBTFEZHEET l.

UNITED strn'rns PATENT OFFICE.

smart L. QAMPBELL, or PRAIRIE. cm, oaneon.

'rnnnrnonn-anrnarnn Application filed October 29, 1908, Serial No. 460,108. awed March a, 1910. Serial No. 547,125;

State ofOregon, have invented a new and useful Telephone-Repeater, of which the following is a specification. I

This invention has reference to improve- 'ments in telephonic repeaters and is designed to provide a means whereby the range of telephonic transmission may be Y lar ely. increased;

n accordance with the present inuention,

the transmitting, stationis provided with the ordinary microphonicfl unit and local circuit and by this means electrical impulses corres onding to sound waves aretrans-. to aline. At the distant end of the mitte line is a receiver element, to the armature of which is attached a microphonic element in a local microphonic circuit, which in turn is in operative relation, inductively, to another transmitting line leading to the dis: tant receiving point, ,where there is located a telephonic receiver. The distant receiving point is also transmitter in u'ctively related to another transmission line; leading to the original transmitting station, where there is also located a telephonic receiver. The system thus includes a complete. transmitting circuit and a complete receiving circuit at each station and at intermediate points these circuits include a telephonic repeater. If

the line be exoessively'long, then a number.

of 'repeaters'may be included one after the other at proper intervals in the line.

'The invention will be best understood from a consideration of the following detail description. taken in connection with the accompanying drawings forming a part of this specification, in which drawings,

Figure 1 is a diagrammatic representation of a complete transmitting and receiving circuit connecting two distant stations, and including in each circuit a telephonic repeater. Fig. 2 is'a central section throu h the repeater element or unit embodying t e invention. Fig.3 is a similarsection at right angles to that of Fig. 2'.

Referring to the drawing there is shown at 'one station, which for convenience will;

rovided with a telephonic Lby the reference numeral 2. The transmitter 1 is iu a local transmitter circuit 3 electrical energy, and a telephonic induction coil 5, the primary winding of which is in the circuit 3. The secondary winding of the coil 5 is in the line circuit 6, one branch 7 of which, leads to a common return conductor 8, if the system be an all metal system, or this conductor 8 may lead to ground. The otherbranch 9 of the circuit 6 includes the winding 10 of a telephonic receiverll, and this conductor 9 also leads to the common return 8 or to the ground as the case may be.

In operative relation to the receiver-magnet 11 is an ironarmature 12 controllin a micro honic element 13 of any suita le type, but particularly of a delicate type, re-

12. The microphonic. element is in a local circuit 14 including abattery 15 or other source of electric current, and the primary winding of a telephone induction coil 16. The secondary windingof the coil 16 is in a line circuit 17, one member 18 of which is connected to the common return 8 or is grounded as the casemay be, and the other member 19 of which includes a. telephonic receiver 20.

For convenience of description, the receiver 20 will be assumed to be at the receivin the drawings by the letter B. At station cluded in a local microphone circuit 22 which circuit is supplied with current from asuitable .source of electric energy such as the battery 23, and also includes the primary -winding of a telephone induction coil 24.

a line circuit 25, one side 26 of which,is connected to the common return 8 or to ground and the other side 27 ofwhich is ground and includes the coil 28 of a telephonic receiver 29. In ppe'rative relation to the active ends of the receiver magnet isan armature 30 controlling a micr'ophonicelv meat 31 in a local microphone circuit 32.15;: which is included a battery 33 or other winding of a telephone induction coil 34. The secondary winding of the coil 34 is in another line circuit 35, one side of which 1ssponsive to weak vibrations of the armature also connected to the common return 8 or source of electric current, and the primary- Specification of Letters Patent. Pat ented Ngw, 15 1910 including a battery 4 or other source of ing station, and this station is designated B there is a' microphonic transmitter 21in- The secondary winding of the coil 24 is in connected to the common return 8 or tothe I ground as the case may be, and the other side 37 of which is also connected to the common return or ground andinchides the receiver 2 before referred to at the station A.

The two stations A and B are thereby coupled together by two distinct circuits in each of which is a microphonic transmitter at one endand a telephonic receiver at the other end, and each of'tliese circuits includes a relay or repeater operative to telephonic currents. Let it be supposed that the dis tance'between the Stations A and B is so great that telephonic communication-is practically impossible because of the ivcalnqiing of the current over such long transmission lines. Let it also be assumed that the repeater circuit 14 or 32 is at an intermediate point between the two stations A and B. The distance'from station A to the repeater circuit 14, or from the station B to the re' peater circuit 32 is such that the receiver 11 or 29 as the case may, be is still vigorously actuated by the telephonic current coming from the respective stations. The currents actuating the receiver 11 or 29 as the case may be 'will cause fluctuations of the currents in the circuits 14 or 32, through the microphonic element 13 or 31, and since the batteries 15 or 33 furnish new or additional energy in the circuit 14 or 32 respectively, greatly strengthened telephonic currents are thrown upon the receiver circuit. 17 and 3.3.

and the result is that the receivers 20 or 2 as the case may be are strongly actuated and telephonic messages "WlllCl'l would be imperceptible or' heard with ditliculty over the distance between the stations 'A and B are heard at the receivers 2 and 20 strongly and distinctly. It will be understood of course, that ifthedistance betweeh the stations A and B 'be too great for proper transmission with a single repeater then additional repeater circuits may be interspersed between these stations. The arinatui'es 12 and 30 areof such thickness as to prevent any distortion or buckling of the metal, but move as a whole under the impulses of the receiver magnets, thus communicating all the movement to thefinicrophonic element. The armature isnot connected to any part of the mechanism other than the carbon box or variable resistance medium.

In Fi 's2and 3 there-is shown a practical form of telephone repeaters, In these figures the coils 10 are shown as of the type usually employed in connection with telephone receivers, and these coils'are provided with'soft iron pole'l pieces 88, connected to the polar end or a permanent magnet 39 by means of a screw bolt 40 of non-magnetic material, the pole pieces being held apart and in magnetic engagement with the polar ends of the magnets 39 by a. spacing of non-magnetic material. 'Betwesn the magnet 39 and the coils 10 the pole pieces wanes pass through slots in the base of a cup 42, designed to inclose and protect the. coils l0 and between the inner face of the base of the cup and the coils there is a dished supporting disk '3, resting on another disk 44 of some soft non-resonant material, such for instance as felt. Made fast to the ends of the blocks 41 remote from the coils 10,

this conducting strip also lies along the block 4l, from which, if the latter be of metal, the strip is insulated by a layer 49 of insulating material. The strip 48 is further held to the block 41 by a screw 50, which, when the block ,41 is of metal, is insulated from said strip. The strips 48 liebetween the legsot the magnet 39 and, the ends thereof remote from. the 'binding posts 46 are connected by conductors 51 to the respective ends of the coils 10, thiase'canductors being suitably insulated where necessary. The cup 42 is formed at its open end with an annular flange or ledge 52, over-- riding the free edge of an inwardly directed I annular flange on a ring 54. Extending diametrically across the ring 54 'is a bridge 55,

secured at each end to the ring and between this bridge piece and the ledge 52 of the cup 42 are spacing blocks 56, serving when the bridge 55' is in place, to firmly clamp the ledge 52 of the cup 42 against the tlange 53 of the ring The central portion of the bridge 55 is formed with a boss 57 receivimc, the stem 58 of the microphonic element 13 or 31, as the case may be.

The inicioplionic element is not shown in the "drawings in detail, since its structure be similar to that u'sually'eniployed in connect on with n crophonic transmitters, but it s powerful and delicate a type as po .0. The movable member of the Dll('i nic elenient cai'ries thedim. phi'agni 12 or 30, as the case iiia be, and this-diaphragm is made of a small but rigid piece of metal, only large enough to bridge 1.

erme'ee The cup 42 and the ring 54, as clamped together by the ring 55 and spacing blocks 56, form a rigid support for the coils 10 or 28, as the case may be, and the microphonic element may be very delicately adjusted into operative relations With the said coils and be ultimately clamped into position by aset screw 60 iiitlie boss 5'? and a clamp nut 61. In order to inclose the working parts of the repeater there he provided e cap 62, indicated in dotted lines in Figs. 2 and 3, and this cap is applied to the ring 54:. The cup 42-, together with the heavy ring 54 rind hridge'piece 55, forms a very rigid support for very accurately mainteinihg the receiver coils and the microphonic element in relative position one to the other during the operation ofthe structure.

hat is claimed is:

y l. A telephone repeater system comprising a local microphone circuit at one station, e line circuit in inductive relation to the mi crophone circuit, a repeater unit at a distent point in said circuit comprising receiver coils and a magnet, an inclosing cup carried thereby, a flanged ring receiving and engeged by the cup, a hri ge piece on the ring and clamping the cup to the ring, a microphonic element carried by the bridge piece, a free armature carried by the microphonic element in operative relation to the free ends of the receiver magnet pole pieces, a circuit controlled by the last named microphonic element, and a circuit in inductive relation tov the last named circuit and containing receiver.

2.v A telephone repeater unitcomprising receiver coils and a magnet, en inciosing cup carried thereby, a flanged rim receiving and engaged by the cup, at bri igc piece on the ring and clamping the cup to the ring, a microphonicielement carried by the bridge piece, and at free armature carried by the microphonic element in ope 'etive relation to the free ends of the receiver megnet pole pieces. v

In testimony that I claim the foregoing as my own, I have hereto efixed my signature in the presence of two witnesses.

SAMUEL L. CAMPBELL.

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