US1246881A - Telephone-exchange system. - Google Patents

Description

H. P. CLAUSEN.

TELEPHONE'EXCHANGE SYSTEM.

APPLICATION FILED 050.21. 1916.

Patented Nov. 20, 1917.

2 SHEETS-SHEET H. P. CLAUSEN.

'[ELEPHONE EXCHANGE SYSTEM.

' APPUCATION FILED DEC. 21,1916- I 1 ,2465881 Patented Nov. 20, 1917.

2 SHEETS-SHEET 2.

L J l /m/e/1/0/ Henry E C/ause/v.

HENRY P. CLAUSEN', 0F MOUNT VERNON, NEW YORK,

COMPANY, INCORPORATED,

ASSIGNOR TO WESTERN ELECTRIC OF NEW YORK, N. Y., A CORPORATION OF. NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Nov. 20, 1917.

Application filed December 21, 1916. Serial No. 188,170.

To all whom it may concern.

Be it known that I, HENRY P. CLAUsEN, a citizen of the United States, residing at Mount Vernon, in the county of Wcstchester and State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to systems of great capacity in which a connection may be established through the operation of an impulse transmitter.

The engineering profession has heretofore considered telephone exchange systems utilizing automatic'switches impractical for use in large cities or in localities Where service must be supplied to a large number of sub scribers. The difliculty encountered has been, in a sense, psychological and due to the well-established fact that very few persons are able to accurately remember a telephone number consisting of more than five digits.

The object of this invention-is to provide means whereby a very large number of subscribers may be served through an automatic telephone exchange system, without the use of unreasonably long call-numbers, or more specifically through the use of easilyremembered call-numbers.

In a system serving millions of subscribers through manually operated exchanges any one subscriber may be called by another through the use of a call-number which is almost in the nature of a formula, such, for' instance, as New York city, Riverside five one three four, party J, this-being due to the use of the decimal system of deslgnating telephone numbers.

In a system embodying this invention any one of several million subscribers may be called through the use-of a short and easily remembered call-number, such, for instance,

as Red, three A, B, four.

A feature of the invention is the use of other than the decimal system in an arrangement of call-numbers and apparatus. In addition to the usual ten number digits,

other symbols such as letters of the Roman alphabet, letters of the Greek alphabet or monosyllabic words may be used as digits, any combination ofwhich will represent a particular subscriber.

Another feature of the invention is the provision of means whereby the subscriber in operating his impulse transmitter will not be compelled to wait an unreasonable length of time between successive operations. This .may be accomplished in several ways, for

corded on a register in any well-known manner, such, for instance, as that disclosed in the application of James L. McQuarrie, Serial No. 131,455, filed November 15, 1916.

Through the use of short impulses of currents of different frequencies, the sending of impulses representing one of a large number of digital characters will take the same time as the sending of any other one. Here also the impulses may be recorded on air-egister which, in turn, will direct the setting of the various selectors and connectors.

Through the use of the third scheme, an impulse transmitter may be arranged to send more than the usual number of trains of impulses. All the digital characters of a call-number exce t the last would be selected from the first ten positions, and the last only would be composed of a greater number of impulses than ten. Thus, if tWenty positions were provided on the impulse sender and the call-numbers were limited to four digits, the first, second, and third might be selected in any one of ten different ways, and the fourth might be selected in any one of twenty ways, thus giving a capacity of 20,000 lines, or double the amount possible with the ordinary ten-position impulse sender.

Another feature of the invention is the ferred designations such as 3500, pronounced three, five, hundred, and the less regularly called subscribers are assigned a less preferable designation, such, for instance, as 7797, pronounced seven, seven, nine, seven.

According to this feature, the automatic switches are made responsive to the trains of impulses representing the digits to extend a connection "from a first selector to a second selector or from a second selector to a third selector in the usual manner. They are arranged, however, to be responsive to the trams of impulses representing the digital characters other than the digits to extend a connection in a different manner, that is, from a first selector to a third selector or from a second selector directly to a connector switch, thus eliminating a selector normally used in the establishment of. a connection.

With the use of a designation including digital characters other than the digits and an arrangement of apparatus contemplated by this invention, a smaller number of selectors is used in setting up a connection to a preferred subscriber, while the usual number is usedin setting up a connection to a common subscriber. Thus the preferred subscribers service is quickened and, therefore, enhanced in value.

-While this invention admits of the use of dial switches of any capacity, and selector and connector switches of corresponding capacity, it may best be exemplified by the following assumptions;

A system will be described in which a twenty-position dial switch may be used. The first ten positions may be designated by the ten digits, and the second ten may be designated by ten digital characters which may, as before stated, be either letters of the Roman alphabet, letters of the Greek alphabet or even short easily pronounced monosyllabic words. There may even be a double designation on the dials, that is, the name of an exchange may be set opposite a character so that the train of impulses representing a certain character may also represent a certain exchange. Thus we might have twenty diflerent exchange districts designated by twenty different names, such for instance, as *Worth, Main, East, Blue, Brown or John.

It will also be assumed that the automatic selector switches shall each be capable of making a selection in twenty diiferent ways, that is, there shall be twenty vertical steps and a sufiicient number of rotary steps. The connector switches may make a selection in a vertical direction in twenty ways, and a selection in a rotary direction in twenty ways. Thus the capacity of the latter shall be four hundred lines, and the capacity of the exchange shall be a function of the number of selector switches used.

If it be now assumed that no telephone number shall consist of more than five digits, it will be seen that the system is capable of serving twenty to the fifth power, or three million, two hundred thousand subscribers.

It should be noted that with the decimal system used hereinbefore, the ultimate ca pacity of an exchange where the call numbers are limited to five digits has been ten to the fifth power or one hundred thousand. Thus, by an increase of one hundred per cent. in the capacity of the impulse transmitters, an increase has been gained in the ultimate capacity of the system of three thousand, two hundred per cent.

In the drawings, Figure l is a diagrammatic representation of the arrangement of the switching mechanisms in a large non numerical" system; Fig. 2 is a detailed representation of the same; and Fig. 3 is a detailed representation of a modification of the same arranged for a division of service into two or more classes.

;Referring now especially to Fig. 1, the figures designated LE and so forth represent groups of line finder switches multiplied through cables 1, 2, 3 and so forth, to the connector switches C C and so forth. FS SS TS represent respectively first selectors, second selectors and third selectors.

Each connector switch, since it must be capable of making twenty selections in both rotary and vertical movements, will have a capacity of four hundred lines, and on a ten percent. basis, C will represent a bank of forty connector switches. Similarly, L'F will represent a bank of forty line finder switches.

LE to LB are banks of line finder switches constituting a major group serving one hundred and sixty thousand subscribers lines, there being twenty of such major groups. They may be entered by the sending of impulses corresponding to twenty exchange names, though it does not follow that they should be segregated in twenty exchange buildings. Each major group then comprises four hundred such groups as LF and is in turn divided into twenty minor groups, as represented by LF to L1 in one case and LF" to 'LF in another case, each of which minor groups in turn comprises twenty such groups as LF A subscriber having access to the system through the group. LF will, upon initiating a call, be served by a bank of first selectors represented by FS By then manipulating his dial switch, the subscriber may gain access to any one of the major groups of one hundred and sixty thousand subscribers lines by setting the first selector on the group of terminals leading to such major group. Assluning that the first of the twenty major groups is selected. the connection may. be traced over the line 11 representing the which the trunks leading from FS to each of the maor groups, then over the line 12 which represents the particular group of trunks leading to the second selector SS of the first major group, SS to SS represent part of the twenty groups of second selectors into minor group is divided.

Thesecond manipulation of the subscribers dial switch results in the selection of one of twenty groups of third selectors. It will be assumed that this selection leads to the third selectors TS, the connection therewith being traced over the representations of trunk cables 13 and 14.

The third selection made by the subscriber extends the connection through trunk cable 15 and, we will assume, through the particular conductors thereof represented by 16 to the group of connector switches C The last two movements of the dial switch result in the extension of the connection within the group C to terminals of the particular line wanted.

Referring now especially to Fig. 2; LF LF", LF and LF represent banks of line finder switches, in the same manner as LF in Fig. 1. FS, SS and TS represent respectively first selectors, second selectors and third selectors, in a manner also similar to that in Fig. 1. C C 0 and C represent banks of connector switches, and the line 17 represents the cable carrying the multiple conductors of lines terminating in the line finder switches LF, and so forth, and the connector switches C and so forth.

A line entering the system in, say, line finder L15" is switched to a first selector over one of the sets of conductors included in the cable 18. If now the dial switch at the substation is manipulated in a position designated by a digit, one of the first groups of levels indicated will be selected, and if it is manipulated in one of the positions designated by a character not a digit, it will be set on a line terminal in one of the upper sets of levels indichted. In either case the connection will be extended to the second selector. The next set of impulses will cause one of the second selectors represented by SS to be set on the terminals of a line leading to a particular one of the group of third selectors represented by TS. From the third selector, any one of the connectors represented by one of the group C to C is selected, and within this connector the particular line wanted is picked out.

Referring. now especially to Fig. 3, this represents a modification of the above and shows means whereby a divided service may be rendered subscribers.

Let it be assumed that the subscriber whose line enters the telephone system through the group of line finders LF is set upon one of the first selectors FS. Let

it be further assumed that the designation of the called telephone line in this case is three, A, four, six. i

The sending of impulses representing the character 3 will then selectively set the first selector F8 on one of the lower levels in the selector F8 thus picking out the terminals, of a second selector in the group represented by SS. The next series of impulses will represent the character A, and the sending of these impulses will result in the setting of the second selector on a level in the upper group of levels indicated. The result of such a setting extends the connection past the third selector TS", directly into one of the connector switches 0 C or C The manipulation of the dial in the last two digital positions results in the selection of the particular line wanted.

If it had been assumed that a designation composed entirely of digits had been selected, then the line entering the group of line finders LF would, in each case, have set the selector switches on one of the first group of levelsof each switch in turn, and the third selector TS would have been included in such connectio Let it be assumed, as another example, that a call for a prominent subscriber, or one to whom preferred service is supplied, is now initiated. Such a subscriber might have a telephone designation such for'instance as BF. Theaction of the line finder ELF results in the extension of the calling line to the first selector FS, and this first selector, in responding to the train of im pulses representing the character B, wouldset its brushes on terminals in the upper group of levels indicated, thereby selecting an idle third selector over the trunk cable 20. An idle third selector being selected, the impulses representing the character F would now be sent, and would result in the setting of the brushes of TS on one of the upper levels indicated in that group. Service of this nature is to be given only to users of a great volume, or in other words, to subscribers whose service demands a plurality of trunks. The third selector TS being set on one of the upper levels, will now be impelled to act in the same way as if a connector switch were to be selected, that is, after the particular level has been picked out, then an idle trunk in that level must be selected. In this case all trunks in one level lead to the same subscriber, and the action will be the same as if an idle connector switch were being hunted.

What is claimed is:

1. In a telephone exchange system, lines arranged in numerical order accessible to calling lines by a plurality of groups of paths, less in number than the number of lines, selector switches adapted to select a path by means of successive selections, the number of which is determined by the number of characters in the designation of the line to which such path is to be established, such selectors having access to more than ten groups of paths, whereby certain paths may be established by a number of selections less than the number of digits in the numerical designation of the line to which such path extends.

2. In a telephone exchange system, lines arranged in numerical order accessible to calling lines by composite paths composed oi a number of component paths arranged in groups, groups of component paths individual to each character of the maximum number of characters employed to represent such lines, groups of component paths individual to groups of more than one character of such maximum number, selector switches adapted to select and interconnect successive paths in groups of either character in a single selective operation whereby a composite path may be established to certain lines including component paths of a group of paths individual to a group of characters by a less number of selective operations than other component paths or groups of paths individual to a character.

3. In a telephone exchange system, lines arranged in numerical order accessible to calling lines by a plurality of composite paths including certain component paths arranged in decimal groups and other component paths arranged in other non-decimal groups, less in number than such decimal groups, selector switches for establishing such composite paths by successive selections depending in number upon the number of groups of such component paths, and means in such selector switches rendering both decimal and non-decimal groups of component paths accessible therein, whereby certain composite paths including component paths ofthe non-decimal groups may be established by means of a less number of selections than by composite paths including only component paths in the decimal groups.

4. In a telephone system, lines arranged in numerical order but desi ated on a nondecimal basis, said lines bemg accessible to calling lines by a plurality of groups of paths, less in number than the number of lines, selector switches arranged toselect a path by means of successive selection, the number of which'is determined by the number of characters in the designation of the line to which such path is to be established, such selectors having access to a plurality of groups of paths whereby certain paths may messes be established by a number of selections less than the number of digits in the numerical designation of the line to which such path extends.

5. In a telephone system, lines arranged in numerical order on a non-decimal basis, said lines being designated for purpose of calling by digits, and characters representing numbers consisting of more than one digit, whereby certain of said lines contain in their designation a less number of characters than is necessary to distinguish them in their numerical order.

6. in a telephone exchange system, lines arranged in non-decimal numerical order accessible to calling lines by compound paths composed of a number of simple paths arranged in groups, groups of simple paths individual to each character of the maximum number of characters employed to represent such lines, groups of simple paths individual to groups of more than one character of such maximum number, selector switches adapted to select and interconnect successive paths in groups of either character, whereby a composite path maybe established to certain lines including simple paths of a group of paths individual to a group of-characters by a less number of selective operations than other simple paths or groups of paths individual to a character.

7. In a telephone exchange system, telephone lines, means including automatic switches for interconnecting said lines, said switches being responsive to trains of impulses designated by digit to extend a connection over a path to a switch next in order and being also responsive to the trains of impulses designated by characters representing a combination of digits to extend a connection past a switch next in order to a switch second in order. 7

8. In a telephone system, telephone lines, means including automatic switches for interconnecting said lines, said switches being arranged in the order of first selectors, second selectors, and so on, said switches being responsive to trains of impulses designated by one group of characters to extend a connection over a path leading to a selector switch next in order and being also responsive to trains of impulses designated by another group of characters to extend a connection past a selector switch next in order to a switch second in order.

In witness whereof, I hereuntosubscribe nnnnx P. onausnn.

Images