US939756A - Telephone system. - Google Patents

Description

F. E. SUMMBRS.

TELEPHONE SYSTEM.'

APLICATION FILED MAR.10. 1908. w56, Patented Nov. 9. 1909.

3 SHEETS-SHEET l.

E. E. SUMMERS.

TELEPHONE SYSTEM.

APPLXGATION FILED MAR. 10, 1908,

939,756, Patented N0v.9,1909.

E'. E. SUMMERS.

TELEPHONE APPLIUATI SYSTEM.

ON FILED MAR. 10, 1908.

Patented Nov. 9, 1909.

3 MEETS-SHEET" A.but it will be evident to those skilled in the *UNITED sTATEs PATENT orifice- FRANK EZRA SUMMERS, OF SCOTLAND CQUNTY, MISSQURL TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Nov. 9, 1909.

Application led March 10,1908. Serial No. 420,188.

T o. all whom it may concern.'

Be it known -that I, Futuri E. Sonrisas, a Acitizen ofthe United States, residing in the' county ot' Scotland and State of Missouri, have invented a' ne f' and useful Telephone System. of which the follow-ing is a specification.

The primary object of the present invention is to provide, a novel, simple and eti'ective system l'or party lines that will permit two parties to communicate and prohibit any one,r else on the line or lines trom` overhearing the. conversation,.the system being such that th(` Vsystems now in nseniay .be readily modified to include the saine.

A further and important object is. to provide means whereby part-'ies along the line may communicate 'with those using the same, in order that the parties in communication may be notited oit' and give way to emergency calls. v

Astill further object is to provide in a system that will permit exclusive communication between two part-ies, means which will permit other parties along the line to connuunicate with each other without intertering or being interfered with by those who are using the system tor exclusive purposes.

Still another object is to provide in a system of this clntracter, means which will ett'ect the operation ot' any predetermined call at the exchange trom any instrument alonI the line, regardless ot vwl'lethcr other instruments are in use or not, such operation acting as a check to prevent unwarranted or malicious interferencewith the parties talking. l

Two embodiments ot the invention are illustrated in the accompanying drawings,

art and by reference to the appended claims that the: invention is not limited solely to the specilic arrangements disclosed.

yln said drawingsI-Figure 1 is a diagraimnatic view ot' a very simple form of the invention. Fig. 1Ll is a detail sectional view on the line .r--af of Fig. 1. F ig. 24 is a view partly diagrammatic in its character, showing a more involved embodiment ofthe' invention. Fig. 3 is a vertical sectional view substantially on the line 3-3 of Fig. 2. Fig. l is a detail sectional view on the linev t-4 ot Fig. 3. Fig. 5 isa sectional View on the line om?) ot' Fig. Fig. G is a detailv perspective view ot' the calling plunger.

phone instruments S are Fig. 7 is a similar View of the actuating plunger.

Similar reference numerals designate corresponding parts in all the figures of the drawings.

Referring first to the embodiment disclosed in Figs. l andnla, a plurality ot' teleline connects the various instruments, and

consistsof av plurality of entirely separate Sections 1+i extending respectively from 011e instrument S to the next. Each instrument is provided with a pair of terminal contacts 15 electrically connected to the line se tions 1l lead-ing thereto and therefrom. Electrically connected to the contacts l5, as shown at 16, is a switch comprising a contact 17 and a knife bar 18. The bar 18 of said switch is pivotally connected to an actuating rod 19, which is pivoted as shown at 20 to a swinging receiver supporting hook 21. the arrangement being such that when the hook is down by reason of the weight of the receivers placed thereon, the switch will be closed. Consequently the line sections will be electrically connected, forming in effect a continuous line through the various instruments.

The generator 13 has one pole grounded as shown at 22, while its other pole is electrically connected as illustrated at 23 to the bar 24 of a switch having a contact 25. This contact is electrically connected by a wire 26,

to the line 14, and the bar 24 is pivoted to lthe v actuating rod 19. The two switches l8and 24 are simultaneously closed, as will beievident byr reference to the right hand .,instru ment in Fig. 1, which illustrates the receiver holding hook in its depressed position,

the left Vhand instrument illustrating the Ijelation of the parts when the hook is elevated.

Thetransmitter 9 is located in a. primary circuit 27 that includes a suitable source of electrical energy 28, and also' includes a switch 29, the bar of which is connected to the actuating rod 19. -One of the receivers as shown at 11, has one pole 30 grounded, the other pole being in the secondary circuit 31 of the induction coil 32 that is included in g therefore cannot eavesdrop. It will, how

the primary circuit 27. This secondary circuit includes a switch 33, leading from which vis a wire 34 connected to` a switch bar 35 5 pivoted as shown at 3G and capable of swinging into engagement with either of the terminal contacts 15. The other receiver has one pole grounded, as illustrated at'37, while its other pole isl connected toa wire38 leading-through a switch 39., From this switch, extends another wire 40 Aconnected to a pair of contacts 41 disposed in the path of movement of a cross bar 42 movable with the bar k35, but insulated therefrom, Ias shown vat 43 in Fig, 1a. rlhe bar 42 also-engages a pair of contacts 44 connected to the contacts l5. The parts are so arranged that when the receiver supporting 'hook 2l is depressed, the switches 18 -and 24 will be closed, while the switches 29, 33 and 39 will be opened, as illustrated in the right'hand instrument of Fig. 1. On the.

vother hand, when the hook 21 is elevated, then the' switches 29, 33 and 39 will be closed, While the switches 18 and 24 will be opened. The operationof this embodiment of the invention may now be briefly outlined as follows: Assuming the switch bar 35 in its centralpositiom'as shown in Fig. 1 and the vari- Vous receiver supporting hooks 21 depressed with the receivers thereon, it will be evident that the line -sections 14 will all. be connected together, notl only bythe bars 42 engaging the 'contacts 44, but because the Vswitches 18 are closed. l If new any party on the line operatesthe generator 13, it will be evident' that the call bellsat the dii'erentinsti'uments and at the exchange will be operated, For the purpose of. explanation, let it be assumed that one vparty'on the line calls another party on the 'same line several instruments away. The party called removes his receivers from the hook 21, whereupon the switches 18 and 24 will be opened while the switches 29, 33 and 39 will be closed. Afterplacing the receivers to his `ears,he turns the switch barv 35 in one direction or the other, until-lie discovers in which direction the call has come. When said bar 35 is engaged with one of the 'contacts 15, -as` for instance, the one on the right, it will beevident that the' transmitter 9 and 'receiver 11 are electrically connected i to the 'portion of the line on the right handl side of the instrument, while the portion on' theleft hand side is entirely` cut oli' from said transmitter and thereceivcr ll. Therefore vthere'can be no interference by the-parties 'on the opposite sidey of the linstrument to that from which the call has come. Moreover, if yany party between the two talling, attempts 60 to over-hear the conversation,- he must remove his receiver from the liook,which -a's already eXplained,-opens the switches 18 and fiirt'her than this, he-must turn his switch 'in one direction or the other, thus breaking the lines *35 between'the two parties using-said line. He

'struinent,.the switch bar 42 will connect one communication with one of the parties using the line so that in case of an emergency, such parties using the hne can give way to those' Areceiving such call can by operating his As before described, cach of the trans- -niittcrs- M 'is located in the primary circuit -(3() of an`-indmtion coil.(31, said circuit inever, be noted that when the transmitter 9 andreceiver 11 is electrically connected to the portion of the line on one side of the inof the contacts 44 and one ofthe contacts 41, thus closing a circuit tlirough'tlie opposite portion of the line and'tl'irough the receivery 10. Consequently any party can get into requiring immediate attention. In other y Words, thel mechanism is so arranged thatthe' transmitter 9 'and receiver'll are in communication with one portion of the line when the receiver 10 alone is in communication with -the otherportion, and should a call come in through the receiver 1'0, the party switch 35, communicate with the person so calling, and ascertain what is wanted. 'The above describedmechaiiisni has been shown in connection with a single line, but the invention may be embodied in various ways. 'lhus in- Figs. 2-7 inclusive, a very involved systemi is disclosed by vnieans ot'l which certain advantages are secured.

'lwo instruments 45 are disclosed, though it will be understood that any number may be employed. lach of these yinstruments includes a suitable case 46 and employs a transmitter 47, two receivers 48 and 49, bell' mechanism 50, and a receiver supporting hook 51. A continuous party line' 52 is provided having branches 53 leading to the various instruments and terminating in contacts 54. )t privater secret line corresponding in all respects to'the former linev 14 is also provided, and it' consists therelore of separate sections 55 exteiiding'succcssively from one instrument to the next,

the sectionsleading to and from each in- 'A `branch (O'l'rom the linej, extends to `each instrument 45. l

of thc-induction 'coil 61 includes the receiverl 49 and a switch 66. 'Ihis switch 66 'has its lcontact v element' electrically connected, as 125 shown at 7 to a switch barB that is movable into engagement with the contacts 54 and 56. The'other receiver 48 is electrically connected as shown at 69 toa switch 70,

fumi/which leads a wire 71 connected to alS pair of contact elements 72 cooperating with a switch bar 73 that is connected toand operates with the bar 68, but is insulated therefrom.l This bar 73 alsocoperates with a Vpair of Contact elements 7l electrically connected as shown .at 75 to the contacts 56. Still another switch 76 is located in the circuit'77 that includes the bell 50, said circuit being grounded as shown at 7S. Another switch 7 9 has its elements connected as shown -f at 80 with the contacts 56 ot' the' private line sections 55.

The branch 'G0 from the ringing wire 67 at each instrument is connected to a switch plunger 87 has a 52 from which leads a wire 83 connected to a' spring circuit closer S11 arranged'within the instrument case 4:6. rIhis closer moves acter of the call that defines the particular instrument. This mechanically-actuated call mechanism is not herein claimed as part of the present invention.

.ciproca-ted.

same, when the plunger approaches its the switch bar 81 v v that'itthe bar a5.-

These lugs, as clearly shown -at the left hand of Fig. 2, are so arranged that they will strike the spring element Stand :torce it into engagement with the element when the plunger 87 is re- The speed at which said plunger operates -is determined by a rotary fan '90 having a pinion 91 in mesh with a gear wheel92 loosely journaled upon a shatt 93 and having` a dog and ratchet connection 94 with the shaft. This shaft 93 is provided with apinion 95 meshing with a rack 96 t'orined upon one side of the plunger. The said plunger also has an upstanding finger 97 disposed below and arranged to strike the switch bar 81 in order to elevate thc nppermost posit-ion. The plunger is also provided with an outstanding pin 98 that strikes in its downward movement to close the switch, it being understood that the frictionalv bearing of the bar S1 is vsuliicien't to .hold it wherever it is positioned. lith ,this construction, it will be evident 87 is moved from its uppermost position, as lshown in Fig. 2, down- `wardly7 the lugs S9 .will pass the spring "contact 84 and canse the same to engage and 'disengage the contact 85, but

-downward during this movement, the switch 81. 1s Also during the downward move opened.

. ment, the shaft 93 operates freely with respectto the gear wheel 92, inasmuch asthe dog will ride freely over the ratchet. Willen,

however,V the .plunger l87 reaches its; lower- .most positron, the pin J8-will iliav'e struck' bar 81 cooperating with a contact element.

l side, the number and chart acter of saidlugs depending upon the-charlhe switch bar 81 and lowered it sulticiently lo engage the contact clement 82. If now, the lrar 87 is released, it will be carried upwardly b v the spring at a .rate ot' speed, determined by the tan 90, and during this upward movement, the lugs S9 will again cause the springcontactto close and open' the circuit, thus automatically calling the central operator.

For thc purpose of actuating the plunger 87, another plunger 09 is provided that is located alongside the-.plunger 87, and has a stem 100 projecting from the case el" tlu` instrument. Pivotally mounted on thel plunger 99 is a dog 101 vhaving one end 102 arranged' to engage over a shoulder 10?, formed upon the plunger -87 when the plunger 90 is elevated. A stop 104e is, however,l located in the path ot movement of the tail 105 of 'such dog when the plunger 00 is in 'its lowermost position. The plunger 90 also provided near its upper end with a shoulder 106, and a spring pressed pawl 107,

pivoted `within the case is arranged to eligage over the shoulder 10G to, prevent upward movement of the plunger 09? when the plunger S7 is depressed. VSaid plunger S7 is, however, provided with a shoulder 10S arranged to engage the pawl 107 and carrv it away from the shoulder 100. as will be evident by reference to Fig. 2.

Referring now to F 2 and 3, it will be noted that a latch 109 is provided for holding the receiver supporting hook 51 'in its depressed position and against the action oli the elevating spring 11.0. This hook 10E) is pivoted hetweenits ends, as shown at 111. and has a right angularly disposed arm 112 ou the end of which is mountcda leali' spring 113. The'end of the spring is disposed in the path of movement of the pin 08, arranged upon the plunger 87, said pin passL ing the spring during the movement ot said pl ungcr. The operation o'l thisl embodiment of the invention is suliistantially as follows. Assuming the various receivers on the hooksc it will be evident that the sections of the private or secret line will be elect rically connected through the switch 70. lt'a call is sont over the line. it will pass through the line sections 55, thc switches 70 through the wire 77 and the bells 50 to theI ground. The party calledremoves his receivers from the hook, andplaces them to his cars. rlhe hook 51 still remains depressed, as itis held by the latch 100. The. party called then raises by means of the handle 100, the plunger SS-)nntil'the dog 102 .engages over the Ashoulder 103. He thenunoves said plunger 99to its lowerinost position, whereupon the tail 105 of said dog will strike-thc stop 10-l-, and consequently the dog will be swung out otengagement with the shoulder 103. This releases the depressed plunger 87, and in accordance with the above described mode ll t) ot operation, the plunger '87 will rise and cause the number of the instrument to be given at the exchange, showing the operator that the call has been answered. During this downward movement, the shoulder 106 of the plunger 87` havingy been carried away from the pawl T. said pawl will be forced y over towardthe plunger 99 by the spring,

a'ndwill. engage over the shoulder 106, preventing `the plunger 99 from being again raised until the plunger 87 has returned. Upon the return of the plunger, the shoulder 108 will againstrike the shoulder 107 and will cause it to disengage the shoulder 106. Furthermoreupon the downward movement of the 'plunger 87 it will be evident by reference to F ig. 3 that the pin 98 l will pass the spring 113 and upon the elevatio'n of suchplungcr, the pin 9S, striking the spring 113, will cause the latch 109 to disenga'ge the hook 51.' Said hook will thereupon be elevated by the spring 110,

l l closing the switches G3, '06 and 70, and opening the switches 76 and 79. Consequently it will be evident that the transmitter and receiver 49 will be in electrical communication with the switch bar GS, while the receiver 48 will be electrically connected to the contacts 72. The party `called can theieupon by turning the bar (S8 in one direction or the' other, ascertain in which direction thel interfering vwith or being interfered With by the partiesusing the secret line. With this mechanism, therefore, a secret service line is provided, and also one for general-conversation, one being independent of the other,A and being so arranged that the instruments can be employed on either. Moreover by having the means set forth for always ringing the call. -prior to establishing communicaiiuu over the lines, the operator atthe exchange knows whenever any instrument is used or whenever its' use isatteinpted,and

a material' checkis thus rovided against unwarranted or malicious interference with the legitimate users of the system. It will ci course he understood ,that the switches (5S aud 73 are located inside the instrument as ,will be evident by reference to Figs.` 2 and suitable shaft' 115' which projects'ffrom'tlie l front of the case, and has a pointer, 1116 co.

These switches are mounted 'on a `operatinwith indicating marks 1.17', by

means o which the positionsof the switches can be determined.

From the foregoing, it is thought that the construct-ion, operation, and many advantages of the herein described invention, will be apparent to those skilled in ,the art, without further description, andmit will be understood that various changes lin the size,l shape, proportion and minor details of con struction, mayy be resorted to Without de arting from -the spirit or sacriicing any o the advantages of the invention.

Having thus fully described my invention, t

what 1 claim as new and desire to secure by Letters Patent, is if 1. In a telephone syste-ni, the combination instrument located between adjacent sections and including a receiver and transof al line divided into scction s,"a telephone sa" f mitter'adapted to be connected in circuiti' f with either section ofthe line, a main signaling device at the instrument normal y connected in circuit with the line sections.

a second receiver at the instrument arrange to bc connected with one line section when the tii'st receiver is connected with the otherv section for conversation between subscrib' ers, said second receivergtormnig an einer-f' gency signaling device for ermitting a message to he received over tie idle section/inf the line while the main signaling device is .out of circuit, and a single manual/ ly con# trolled means whereby a called subscriber can connect his telephone'instr ment with one line" section or the sother/todetemine over which the call signal is received and to. converse with 'the calling scriber and at the same time connect the /idle -sectioi'iA ,ofthe line with the second rec iver. l,

2. In a 'telephone s s ein, the combination of a plurality of te ephone instruments, a

' calling signal device at each instrument noimally in circuit and automatically cut out of i' circuit upon removal yof the receiver.' from the hook of the instrument, a linedivided into sections with adjacent sections connect.;- ed with each telephone 1nstrument,an` einen.

gency 'signal device at each telephone instrument, and a single switch at each instru-fl ment for connecting the receiving and trans mittin devices thereof with fone line? sec,

with the emergency sivnaling device.

3. -In'a system of the character set forth, the combination with a 'plurality of tele" phone instruments including receivin mechiio ,tion w ile connecting the' other line sectione i aiiisimand contact point-s electrical y connected thereto, of a line comprising separate sections extending from one instrument to the next, the adjacent sections having vcontact points at each instrument, and a switch electrically connected t`o the receiving mechan'ism and movable into simultaneous engagement with either contact point ot he line sections and a point of the receiving the mechanism, and being also mov-able into simultaneous engagement with both of the line-section contact points to connectsaid line sections.

il. In a system of the character set forth, theI ,combination with a plurality of telephone instruments including transmittingy and,receiving mechanism, of a line comprising separate sections extending from one instrument to the next, the sections adjacent to each instrument having contact points at said instrument, signaling means at each instrument, a switch electrically connected to ying said transmitting and receivin the transmitting and receiving mechanism of each instrument and movable into engagement with either contact point, a movable receiver supporting hook, and a switch automatically controlled by the movement of thehook for connecting together and disconnecting the sections of the line Without including the signaling means in such con-l nection.

5. In a system of the character set forth,

the combination with a plurality of telephone instruments including transmitting y and receiving mechanism, of an electrically operated signal for each instrument, a line connecting the instruments and comprising separate sections extending successively from `one instrument to the next, a movable receiv'er support-ing` hook for each instrument, a switch operated thereby and connecting the line sections that' extend to and from the instrument When the receiver is on the hook and disconnectin the said line sections when the receiver is o the hook, a switch operated by said hook for cutting in and out the signal, and means for connecting the transmitting and receiving mechanism to either section independentlyV of the other when the sections are thus disconnected b the actuation of the hook operated switc 6. In a system oi the character .set forth, the' combination with a plurality of telephone instruments including transn'iitting and receiving mechanism, of. a line comprising separate sections extending successively from one instrument to the next, cachinstruinent having terminal contacts for the line sections leading to and from; the same, a movable receiver su porting hook for each instrument, a switch -or connectin and disconnecting the line sections associ ted with the instrument, an electrical signal for the instrument, a stvitch'controlling the signal, al common connection'between said switches and the receiver supporting hook, and a switch electrically connected to the transmitting and receiving means and coperating Tit/hthe terminal Acontacts for connectmechanismslto either line section vindepen ently of the other;V

i'. In alsy'stein ofthe characteriset forth,

combination with a plurality oi' telephone instruments, each having a transmitter and receiver` and ringing mechanism, oi a receiver supporting device, and a plurality of switches respectively electrically connected to thc receiver. the transmitter and the ringing mechanism, a common actuating rod connected to the receiver supporting` device and said switches. a line connecting the various instruureiusI and comprising sectionsI extending from one instrument tovthe next, a switch located at each instrument for normally connecting together the line sections leading thereto, said switch being operated by the receiver supporting hook, and a manually operated switch for connecting the receiver and transmitter ofeach instru.- ment to either line section when the sections are disconnected by the openingot the switch controlling the connections.

S. In a system of the character set forth,

the combination with a plurality of tele-` phone instruments, each including transmitting mechanism and two receivers, of a linel the connection between the line sections is broken.

9. In a system of the character set forth, the combination with a plurality ./oftelephone instruments, each including transmitting mechanism and two receivers, of a. line connecting the instruments and comprising separate sections extending from one instrument to the next, means at the instrument for connecting the line sections while the transmitting mechanisni and receivers are cut out of said line, means for breaking the connections between the line sections at each instrument, and switch mechanism for electrically connecting the transmitting mechanism and one receiver. to either line section and connecting the other receiver to the other line section at each instrument when the connection between the sections is broken.,

10. In a system ot' the character set forth,

.the combination with a plurality ot telephone instruments, each including transmitting means and two receivers, ot a. lin'e connecting the Vinstruments and comprising separate sections extending from one instrument to the next, means at each instrument for connecting the line sections While' the transmitting mechanism and receivers are c'xl-tfout'- of'such line, means for breaking ethe connections between the line sections at eat/ch instrument, and simultaneously opceiver to one line section and connecting the V other receivei to the otliei line section at each instrument. when the connection betiveeii the line sections i's broken.

11. In a system of the character set forth,

the combination. with a plurality of telephone instruments, each including transmitting mechanism and two receivers, of a line connecting the instruments and comprising separate sections extending from one instrument to the next, and movable switch mechanism comprising relatively fixed switch bars simultaneously movable to positions to connect the transmitting mechanism and one receiver to either line section and the other receiver to the other line section.

. 12. In a system of the character set forth, the combination with a plurality of telephone instruments including transmitting and receiving mechanism, of a party line' common to the instruments, a private line composed ot separate sections extendingv from one instrument to the next, a switch for electrically connecting the transmittingA and receiving mechanisml of each instrument to either section of the private line ex- .tending to and from such instrument, when the said sections are disconnected from each other and electrically connecting said transf initting and receiving mechanism to the party line irrespective of the connection and disconnection of the private line sections, and means operating with said switch to connect the private line sections when the transmitting and receiving` mechanism is connected to the party line.

13. In a system of the character set forth, the combination with a lurality of telephone instruments including transmitting and receiving mechanism, of a line connecting the instruments and comprising separate sections extendingy successively from one instru-ment to the next, -nieans at the different instruments for electrically connecting the sections together, a switch at each instrument for connecting the transmitting and receiving mechanism ot' such inlstrument to either line section associated with the same inde endentlyof the other, switch mechanism or electrically connecting the transmitting and receiving mech# anism to anddisconnecting it from the first mentioned switch, and calling means located at each instrument and constituting means for controlling the operation-,of the switch ing the instruments and comprising separate Yesente i sectionsu extending successively from one in strument to the next, means atthediiierent instruments for electrically connecting the' sectionsI together, a switch at each instrument for connecting the transmitting and receiving mechanism of such instrument to either line section associated therewithindependently of the other, switch mechanism for electrically connecting-the transmitting and receiving mechanism to and disconnecting it from the first mentioned switch, a latch for holding the switch mechanism against movement, and mechanically operated calling mechanism located at each instrument and constituting operating means for the latch of such instrument.

and receiving mechanism to and disconnecting it from the 'first mentioned switch, a

latch for holding the switch mechanism against movement, calling mechanism at each instrument, and manually operated mechanism at each instrument for successively operating the calling mechanism and the latch of such instrument.

16. In a system of the character set forth,

the combination witha plurality of telephone instruments including transmitting and receiving mechanism, of a line connecting the instruments and 4comprising separate sections extending successively -romone instriunent to the next, means at-,the ditferent instruments for electrically connecting the sections together, a switch at each instrunient for connecting the transmitting 'and receiving mechanism of such instrument to either line section associated with the saine independently'of the Jother, switch mechanism or electrically connecting the transmitting vand receivingi'nechanism to and disconnecting it .from the rst mentioned switch,

la receiver sup orting hook located at each instrument an constituting actuating means for the switch mechanism, a'latch engaging the hook, and calling mechanism including a reciprocatory plunger having a portie/n that 4engages the-latch to operate the sii/me, andl an actuating bar cooperating with/theplum" ger to move the same. j /J 17. In a system of the character set forth,

the combination with ay plurality of telephone instruments, eachincluding two-rethe combination with a ceivers and a singiemovable support for I switch mechanism associated with each inboth receivers, of a line comprising sections l 'strument for rconnecting one of the receivers leading from one instrument to the next, thereof to either iin'e section and the other switch mechanism for connecting one rereceiver to the opposite line section, and sepceiver to either line section and the lother rei arate switches operated by the receiver supceiver to the opposite line, section, and switch 5 porting hook of such instrument for connectmechanism operated by the receiver support i ing both receivers to and disconnecting them for connectingfboth receivers toand disconirom the iirst mentioned switch mechanism. necting them'from the iirst mentioned switch In testimony, that I claim the foregoing mechanism. l as my own, I have hereto affixed my signaf 1S. In a systemv of the character set forth, 5 ture in the presence of tWo Witnesses.

lura ity of tele- -1 phone instruments, each iiiiciuding two re- BRANK EZRA SUMMERS ceivers and a single supporting hook for Witnesses: both receivers, of a line comprising sections JOHN H. SIGGERS, leading from one instrument to the next, Lnwis EBERLY.

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