US1156636A - Telephone-repeater. - Google Patents

Description

11.5, SHREEVE.

TLPHONE REPEATER.

Mmc/111011 men MA1/25,1911.

HERBERT E. SI-IREEVE, QF SHORT HILLS, NEW JERSEY, A.SSIG-NOR T WESTERN ELECTRIC COMPANY, 0F NEW YORK, N. Y., A CORPORATION 0F ILLINOIS.

TELEPHONE-REPEATER.

Specification of Ietters Patent. Patented 001;,` `12, 1915,

Application tiled May 25, 1911. Serial No. 629,261.

To all whom t may concern:

Be it known that I, HERBERT E. SHREEVE, a subject of the King of Great Britain, residing at Short Iilills, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Telephone-Repeaters, of which the following is a full, clear, concise, and exact description.

This invention relates to telephonie apparatus such as telephone repeaters and its objects are to provide a structure adapted forready replacement in telephone circuits, to provide simplified automatic means for maintaining adjustment of the working parts of such instruments, and in general to simplify and improve their mechanical construction.

In accordance with -one feature of the invention there is provided a receiver and transmitter mounted as a unit and having v terminal connections which may beV readily and quickly madev or severed without disturbing the fixed wiring of the circuit. More particularly the receiving and transmitting elementsV are each individually removably mounted end to end upon a tubular block. Terminals extending through the block from one end thereof to the other for the receiver and from one electrode of the transmitter arm are arranged to coperate with spring clips upon a base or socket part adapted to receive the bloc'k. The vibratory member of the transmitting element when thus assembled is inclosed within the cylindrical block and thus wholly removed from outside disturbing sounds and protected from mechanical injury. The block supporting the elements may be likened to a cartridge which by a simple movement may be withdrawn from its socket and immediately replacedby another similar structure. The block surrounding and supporting the elements is -provided with holes running from one end thereof to the other, which serve as air passages for ventilation and heat radiation. Preferably the base part is provided with heat radiating plates, which serve to quickly dissipate the heat conducted from the cartridge part to the base part and to that end the surface contact between these parts is made quite cally relieving the pressure upon the granuby packing of the granular carbon is prevented. The transmitter -element is provided with a thermostatic diaphragm and is connected in -circuit with the. receiver, the diaphragm being arranged -to bow outwardly to relieve the pressure in the transmitter upon an increase of current in the circuit, the receiver being also adapted by magnetic attraction to bow the diaphragm outwardly upon an increase of current in the circuit.

The invention will'be' more fully understood by reference to the accompanying drawings, wherein- Figure 1 is a transverse section on the line 1-1 of Fig. 2, and F 2 is a rear view of a telephone repeater embodying features of the invention; Figs. 3 to 9 inclusive are detail views of separate. parts of the repeater; and Fig. 10 is a diagram showing'` of the base piece. Fitting over the exposed end of the block 2 is a cap l having ventilating perforations 5, the'purpose of which will be more fully explained hereinafter. The cap is adapted to be held vin place by screws .6, engaging the ends'of elongated bolts 7 extending outwardly from lthe block 2. Interposed between the heads of the screw 6 and the cap 4'is a fiat ring 8 and a 'distance piece 81 which together form a frame for a number or instruction card to be placed between it and the cap. The heads of the screws 6 are perforated tol receive" a wire 7 8 which may be tied or sealed midway between the heads by a' lead seal 79. Formed integrally with thebase piece l are a series of heat radiating plates 9 and upon the rear side of the base are three contact springs l0, 11 and 12 mounted upon insulating blocks 13. Circuit connections to the frame and to the three contact springs 10, 11 and 12 are made Athrough the binding post's 38, 39,40 and 41, respectively, these being mounted uponsegments; of insulating material as 42 (Fig. 8), and the latter three .thereof being4 insulated from the frame by suitable bushings. Binding post 38 is in direct contact with the frame. The base has an overhang# ing flange 14 extending beyond the level of the contact springs and their retaining screw heads, this flange, however, being partly open at 15 to permit free circulation of air. The three contact springs 10, 11 and 12 eX- tend inwardly to points in line with the Y socket opening and are each provided with a contact surface 16, preferably of platinum. Coperating with the contact springs, when the block 2 is in place in the socket of the base piece l, are three contact rods 17 18 and 19. Rods 18 and 19 extend through the `bloclr 2 from one end to the other and are yto end serve as'air passages for ventilation.

The plate 24 has a central opening through which the. contact rod 17 extends, this rod serving to support an electrode plate 26, on the inner surface of said plate 24. The electrode 26 and rod 17 are insulated by sheets of mica 27 and 28 and held in place by a nut 29 and washer 80, the nut engaging threads on the rod 17. `This rod 17 serves also to electrically connect the electrode with the contact spring 10.' The electrode plate 26 has a facing o-f carbon 30. Formed integrally with the plate 24 is an externally threaded flange 31 which forms the side walls of a granular carbon transmitter button. The inner surface of this flange is coated with insulating enamel.

The opposing electrode of the transmitter button is a vibratory diaphragm formed of two thinplates of metal, the inner one,'32,

of gold and the outer one, 33, of iron. These plates are clamped together at their outer edges by an internally threaded flanged ring 34 engaging the flange 31 of the plate 24. Centrally mounted. upon the diaphragm is an iron rod or pole piece 35 held in place by a gold plated screw 36. The transmitter button thus constructed is partly filled as shown with granular carbon 37, the circuit through it passing fromthe spring 10 to the contact 17 and thence by way of the electrode 26 through the granular carbon 37, and the vibratory diaphragm 32, 33 to the frame v1 and binding'post 38.

The receiving element of the repeater comprises a. cylindrical iron or steel shell 43 fitting snugly within the block 2 and held in place by a set screw 44, a compound magnet sppol 45 of brass or other non-magnetic maferial, windings 46 and 47 thereon and an iron head 48. The spool is held in place by a screw 49 passing through the side of the shell 43, and the head 48 is held in place against the outer end of thecshell" 43A by scr/ ews 50, 50. Extending centrally throilgh tht*l head 48 is a pole piece 51, the end of which is presented toward and lies close. to the end of the opposing pole piece 35. The pole piece 51 is enlarged and threaded where it passes through the head 48 and is provided with a hexagonal head 52 and a nut 53 by means of which the air gap between pole pieces 51 and 35 may be adjusted. One terminal wire of each of the windings 46 and 47 is connected to the central part of the spool head and is thus metallically connected to all parts of the frame of the-instrument. The other two ends 54, 55 of the windings are brought through to the outer end of the spool and thence to the outside of the head 48, being insulated therefrom by rubber bushings 56. These terminal wires 54 and 55 are connected to the outer ends of the contact rods 18, 19 by means of terminal clips 57 and screws 58. The winding 47 being farthest away from the air gap between the electrodes is the ma gnetizing winding, while the winding 46 is the receiver winding. 1t will be noted that the electrode rods 35 and 51 extend freely through a central opening in the spool 45. With this construction the shell 43 may, if desirable, be ofsteel and forma permanent magnet, in which case the magnetizing winding would be omitted.

A suitable circuit arrangement for the telephone repeater herein described is shown vin Fig. 10, wherein 59 and 60 are the main winding 62 is included directly in the two line wires 59, 60 and from a central point in this winding in each wire and bridged across the circuit isa condenser 63 in series with one winding of an input repeating coil com prising the windings 64, 65. The winding 65 is in a local circuit which includes a condenser 66 and the receiver winding 46 of the repeater, this circuit passing from the condenser 66 to the frame 1, thence to block 2 in contact withv .the spool 45, winding 46, contact rod 19, contact spring 12, and input repeating coil winding 65. The connection from the block 2 to the spool 45 is indicated in the circuit diagram by a dotted line 67. A local circuit is also provided for the transmitter button and the magnetizing winding 47 as follows: Afrom the grounded battery 68 to the resistance 69, primary output repeating coil Winding 61, COntact spring 10, contact rod 17, electrode 26, carbon granules 37, vibratory diaphragm 32, 33, block 2, spool 45, winding 47, contact rod 18, contact spring 11 and impedance coil 71 to ground lll@ limit the flow of current in this local circuit vand that of the condenser 72 to localize the microphonic currents in the transmitter button and'to exclude such currents from the magnetizing Winding 47.

In operation vbice currents coming over the circuit of line wires 59, 60 from either direction will, by -induction through the windings 64, 65, cause variations in the attractive forces between the pole pieces 5l and 35 of the receiver, thereby causing corresponding variations 4in the resistance of the transmitter button land of current inthe local transmitter circuit. This local circuit includes the primarv winding 61 of the output repeating coil which thus causes a rein- 1forcement of the telephonic currents in the The action of the .gold and iron diaphragm of the transmitterbutton is such that any tendency of the carbon granules to pack will cause said .diaphragm to move away lfrom the opposing electrode, thereby relieving the pressure and maintaining the transmitter button in a sensitive state or condition. Gold has a higher coefficient of expansion than iron and gives a good contact surface for the carbon granules, while iron serves as an element of the thermostat and as a part of the magnetic. circuit of the receiver. Other metals of like characteristics may be used in. place of gold and iron, if desired. The gold plate lying next to the granules and expanding more rapidly than the iron, the diaphragm bows inwardly upon any increase in temperature in the granular chamber and conversely bows' outwardly upon a vdecrease in the temperature. The granular button being connected "in circuit through a resistance, there is at rst a gradual increase in temperature in the granular' carbon which continues until a fairly uniform temperature is reached. During this period there is therefore a gradual inward bowing ofthe diaphragm. This action is, however, followed by a tendency of the granules to pack, whereupon the heating decreases due to the lowered resistance of the granular button. This decrease in temperature resultsin a cooling of the diaphragm and'thus a movement 'of the diaphragm outwardly, whereupon the granules are relieved of pressure, the resistance and temperature are increased and thediaphragm is again moved inwardly. It has been found in practice that a`.diaphragm constructed in this manner has a periodic movement forward and backward, the period being of about thirty to forty seconds duration. The movement, although extremely slight and vimpossible of direct observation is sui'licient to keep the carbon granules in a free and sensitive state. It may be made manifest by placing a' milammeter in the local transmitter circuit. With a current ofabout400 mil-amperes in the circuit the needle shows a periodic movement of about twenty milamperes, that is to say, from about 380 to 400 mil-amperes.

not only by heat generated in the granules, but also by magnetic pull of the magnetizing winding of the receiver. These two forces in fact work together or cooperate to relieve the pressure on the granules upon any tendency thereof to pack. v

It is in practice frequently found desirable to replace one instrument with another and by the arrangement herein described,

ythis can be readily done without disturbing the circuit connections other than to separate the contact rods of the removable partfrom the fixed contact springs ofthe base.

The thermostatic diaphragm being partly of iron, is acted upon- It is only necessary that the transmitter and e receiver elements be removed as a unit from the frame l, the connections being broken at four points, three being between the contact rods 17, 1 8 and 19, and the contact springs 10,11 and l2, and the fourth between the block 2 and the frame l. The parts thus removed comprise the transmitting and receiving elements ltogether with the mounting block 2. Either of these elements may be separately removed from the block and replaced by a like element. The transmitter may be removed upon loosening the bolts 7, and likewise vthe receiver upon loosening thevset screw 44 and the connecting screws58. The locking pin 3 serves to locate the removable elements in their proper position so that it is impossible to make incorrect connections when replacing one in-v strument with another.

When assembled complete'. as shown in Figs. land 2 and mounted upon a wall or other support the heat generateolV in the l transmitter and' receiver elementsis dissipated partly by means -of the radiating plates 9 and partly by the free circulation of air through the openspaces at l5 in the base 1, the holes 25 1n the block 2, and the holes 5 in the, capfl.

I claim:

l. In a telephone repeater, the lcombination of a frame comprising contact springs and binding posts, of a block, transmitting and receiving elements mounted therein,

2. In a telephone repeater, the combination with a frame comprising a base and socket, contact springs and Abinding posts,' of a cylindrical block, transmitting and receiving elements secured to sairr block, terminals for said elements mounted upon said block, said block being adapted for kinsertion in the socket of said frame in position for engagement, of said terminals with said contact springs,l and a pinfcarried by said block and registering with a slot in said socket to lock said block Within said socketf` 3. In a telephone repeater, the combination of a frame having contact springsand a heat radiator, of a block adapted toengage said frame, transmitting and receiving elements mounted upon saidjblock and ter. minal connections upon said block for said elements adapted to engage said contact springs.

f1. In a telephone repeater, the combination of an electromagnetic receiver "and a granular transmitter placed lin operative relation to said receiver, said transmitter having a thermostatic diaphragm and being connected in circuit with said receiver, said diaphragm being arranged to bow outwardly and thereby to relieve the pressure on the granules in said transmitter upon an increase of current in said circuit and said receiver being also adapted by magnetic attraction to bow said diaphragm outwardly upon an increase of current in said circuit.

5. In a telephone repeater, the combination of a receiver having a magnetizing winding and a granular transmitter in operative relation* to said receiver, said transmitter having a thermostatic diaphragm forming one Wall Aof the granular chamber, and a local circuit including said magnetizing Winding and said transmitter, said thermostatic diaphragm and said magnetizing Winding being arranged and adapted jointly to relieve the pressure on the granules of said transmitter upon a tendency thereof topack by causing said diaphragm to bow inwardly.

6. In a telephone repeater, the combination with an electromagnetic receiver and agranular transmitter in operative relation thereto, the Winding upon said receiverbeing connected in series with said button andV a thermostatic diaphragm adapted under the influence jointly of the heat generated in said transmitter and ofthe magnetc pull of said receiver to relieve the transmitter granules of pressure upon a tendency thereof lto pack.

7. In a telephone repeater, the combination with an electromagnetic receiver and a granular transmitter in operative relation thereto, th Winding upon saidv receiver being connected in series with said button and a` thermostatic diaphragm, onej element of which is iron, adapted under the influence jointly of the heat generated in said transmittcrfand of the magnetic pull of said receiver to relieve the transmitter granules of pressure upon a tendency thereof to pack.

8.-.Ina telephone repeater, the combination with a transmitterv and a receiver, of a tubular block within which saidtransmitter and receiver are mounted, a lgsupporting' base, and a cap, said base and cap forming a lcomplete inclosure for said ;block, and said block having holes extending from said base to said cap, for the free circulation of air and dissipation of heat.

9. In a telephone repeater ,fthe combination of a granular transmitterfhaving as one wall of the granular chamber a thermostatic diaphragm composed in part of iron,

and an electromagnetic receiver arranged in operative relation to said diaphragm.y

10. In a telephone repeater, the combination with a base part, of a block, and a transmitter and a receiver mounted on said block, said block, transmitter andk receiver forming a unit removably mounted on said base, and said transmitter. andreceiver being separately and independently removable from said'block. A

11. 4In -a telephone repeater,theA combination with a socket base part, of a plug, and a transmitter and a receiver mountcd in said plug inoperative relation, tofy each other,

i said plug, transmitter and receiver forming a unit removably mounted in said socket base part, and said transmitter,l and receiver being separately and independently removable from said plug. j

12. In a telephone repeater, :jthe combination with a base part having terminal c0n tacts, of Aa block having coperating contacts and arranged to-be removably supported upon said base part, a transmitter and a receiver, said transmitter' and receiver being connected to said coperagting contacts and being separately and removably mounted on-said blockin operative relation to each other.

In witness whereof, I hereunto subscribe my vname this 23rd day of May,l A. D. 1911.

HERBERT E. sHZREEvE.

Vlfitnessesz IRVING MACDONALD, y FRANK A. FLEISCHMAN.

Images