US2268203A - Calculating machine - Google Patents

Description

Fla/ 1 4 Dec. 30,- 1941.

Original Filed April 28, 1934 W. W. CARPENTER EI'AL CALCULATING MAdHINE FIG.5 FIG. FIGQ FIG.6 FIGJZ FIG-7 IFIGA FIG.3 FIGJO FIGZM 14' Sheets-Sheet 1 git,

.WWCARPENTER WHMATTH/ES BY 6PM A T TORLVE if Dec. 30, 1941. w.,w. CARPENTER ETAL 2,268,203

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CALCULATING MACHINE Original Filed April 28, 1954 14 Sheets-Sheet s WWCARPENTER. WVEVTORS- WHMATTH/ES BY 6P6.M

A ORN Dec. 30, 1941 'w. w'. CARPENTER ETAL 2,268,203

CALCULATING MACHINE 'Ozigipal File'd April 28, 1934 14 Sheets- Sheet 4 WW CARPENTER W H. MA T TH/ES BY 'm ATTORNEY IN VEN TORS.

Dec. 30, 1941. w. w. CARPENTER ET AL CALCULATING MACHINE Original Filed April 28, 1934 14 Sheets-Sheet 5 um: CARPENTER WVFNTORS' WHMATTHIES )4 7' TORNEV Dec. 30, 1941. w. w. CARPENTEfi ETAL 6 CALCULATING MACHINE Original Filed; April 28,- 1934 14 Sheets-Sheet 6 W W CARPENTER E/v TORS- n; H. MA 7 7/1/55 BY @aw ATTORNEY Dec. 30, 1941 w. w. CARPENTER EIAL I 2,268,203

' CALCULATING MACHINE v Original Filed A ril 28, 1934 1'4 Sheet-Sheet"! In a O D In. K In G.

h! n! 01 RPEN 75/? i; 'lNVEA/TORS. 3 BY @am Dec. 30, 1941.-

w. w. CARPENTER ETAL CALCULATING MACHINE Original Filed April 28, 1934 14 Sheets-Sheet 8 WW CARPENTER INVEN TORS. W H MA 7771/55 A T TORIVEY w. w. CARIQENTER EI'AL 2,268,203

' 'Dec. 30, 1941.

r CALCULATING MACHINE 14 Sheets-Sheet 9 Original Filed April 28, 1934 n2! CARPENTER n. h. MA 7 TH/ES av M /NVENTORS:

Ad T TORNE Y Dec. 30, 1941- w. w. CARPENTER ET AL 2,268,203

CALCULA'I ING MACHINE Original Filed April 28, 1954 14 SheetsShet 10 QMQ wmv

. W W CARPENTER MEMO Wh. MATTH/ES A TTORNE V m w. w. CARPENTER ETAL 2,268,203

CALCULATING MACHINE Original Filed April 28, 1934 14 Sheets-Sheet 11 5 my CARPENTER WHMATTH/ES BY @m ATTORNE V N lNVEN 7'0 Dec. 30, 1941. 'w. w. CARPENTER ET AL 2,263,203

CALCULATING MACHINE Original Filed April 28, 1934 14 Sheets-Sheet 12 WW CARPENTER INVENTORS. W MATT/115$ A T TORNEY .FIG. /3

Dec.

w. w. CARPENTER ETAL 2,268,203

CALCULATING MACHINE Original Filed April 28, 1934 1 4 Sheets-Sheet l3 .ww CARPENTER Dec. 19415 w. w. CARPENTER ETAL 2,258,203

- CALCULATING MACHINE Original Filed April 28, 1934 14 Sheets-Sheet 14 W W CARPENTER W H. MATTH/ES INVENTORS ATTORNEY containing thereon nated. The ultimate Patented Dec. 30, 1941 OFFICE CALCULATING MACHINE Warren W. Carpenter, Garden City,

Matthies, Hac'kensack, N. J. ors to Bell Telephone Laboratories,

N. Y., a corporation of New William H.

rated, New York, York Original application 722,890, now Patent No. 5, 1938.- Divided and 1:11

her 6, 1937, Serial No.

N. Y., and

assi n- Incorpo- April 28, 1934, Serial No.

"2,112,951, dated April is application Novem- 9 Claims. (Cl. 23561.10)

This invention relates to a calculating machine and more particularly to one designed to produce a computed and translated record from another record which contains notations of connections and conversation times relating to calls completed from a subscriber's line in a telephone system. Specifically, sion of our Patent 2,112,951 issued April 5, 1938, which discloses the entire invention. The purpose ofthe present application is to more particularly describe and claim that part of the invention which has to do with the means and the method for producing a translated and computed record for each line from another record and necessary entries for call charging purposes such as, for example, calling and called line numbers and start andfinish times of conversations, all of which were entered on said record at the time that the several connections were being established and termipurpose of producing such a translated and computed record is, of course, to utilize ,it to operate well-known tabulating printers to produce the subscribers monthly bill.

At the present time it is well known that on some classes of subscribers lines of a telephone system such as, for example, individual message rate lines, charges for telephone service are usually made by operating a message register meter associated with the calling line regardless of whether the telephone system of which said this application is a dividiate toll area and'for which,the subscriber is to be billed in bulk; that is, billed for the entire service in terms of the local charge rate without difierentiating between local and toll calls.

This method of billing subscriber while practically satisfactory for local calls atoll calls as can be billed in bulk, is impractical cording position while of application where the equipment 01 the telephone plant can be extended to permit ,subscribers to dial directly other subscribers who are located in the more remote toll areas. As is well known, toll and long distance calls are timed and ticketed by a recording operator whose function is to record on a ticket the number of the calling line, the destination of the call and the duration of the conversation so that, when the monthly bill is prepared for the lin the entries on the toll tickets are included in the bill as separate items thereon.

As is well known, the operation of timing and ticketing involves considerable delays at the rethe handling of tickets slows up the efficiency of the commercial departments of an operating company to the point 1 where the gains from mechanical switching are line forms a part is manual, semi-automatic or automatic, and that said meter is operated whenthe called subscriber removes his receiver from the switchhook in response to the call.

Furthermore, recent advances in the telephone art make it possible, in automatic systems, for

the calling subscriber to dial directly the ofllce and number of a wanted subscriber who happens to be located in that section of the toll area which is immediately contiguous to the local area and for which the charge for the connection is a multiple of the base charge for a local call, strictly so-called. For such a connection, the' meter of the calling line is operated a number of times for the initial charge period when said charge is a multiple of the standard local rate and also a number of times thereafter for each period of overtime consumed depending upon the multiple of the local standard rate which is charged for each overtime unit. At the end of each month, or whatever the billing interval may happen to be, a reading of the line meter canceled to an appreciable extent. I

The invention is intended to overcome this obstacle by the use of a centralized recording mechanism which-is adapted to register on a permanent record the identity of all local and toll calls, the former automatically where the subscriber can dial the wanted station directly, and the latter manually by the recording operator whose only duty in this respect is to depress a number of keys appropriate to the designation of the call destination and\to the charge to be made therefor. More specifically, the invention, as adapted and'applied toua telephone plant, involves a system of .apparatus and cooperating circuits by which all local calls dialed by the is taken, and by subtracting this reading from "I First of all, it eliminates line meters -and the then, not only and for such attendant necessity of reading the fact that particular embodiment of our illustrated with reference calling line extension.- recording the called number, and the start and finishing time of any vice at the them; secondly, it places toll call recording on a more emcient basis by freeing the operator from the duty of writing out toll tickets, and thirdly, it preserves a record of all calls as made by the subscriber, thereby eliminating all possibilities of misunderstanding between the subscriber and the operating company. In other words, the value of our invention as applied to telephone billing practices, lies in the fact that it broadens the potential scope of mechanical switching and in it reduces the cost of operating the clerical branch of the telephone plant.

In the parent patent above referred to, the

invention as aptelephone system, is described and to a telephone system of the well-known panel type in which the calling subscriber establishes a connection with a called subscriber over panel type switching selectors although no limitation of our invention to any particular type of apparatus or any speciflc system is intended therein, the invention being readily adaptable by any one skilled in the art to any well-known apparatus used for establishing telephone connections.

The general principle upon which the invention operates is the making, upon a suitable meplied to a dium, of a record of each call made-by a, calling line of a group by means of a recording equipment common to the group. This record includes an identifying designation of the calling line, the code of the called ofdce, the number of the called subscriber, and the start and finishing time of I the connection.

' The recording equipment consists, in general, of a suitable recording apparatus that cooperates with a recording register which, at the appropriate moment, is operatively connected with a This register is used for office code, the called line particular connection.

For registration purposes one recording equipment is conveniently allotted to one group of subscribers who are, in turn, served by a particular group of switching trunks or, in the case where the lines terminate on line finder frames, to a group of lines on one line finder frame and served by a correlated group of line finder district selectors. However, should it be found that a single recording unit for a line finder group undesirably increases the holding time of the line finder district selectors serving the group, two or more such recording units maybe used for the group, each unit serving a proportionately smaller number of lines.

A register circuit is provided for various items required for billing the call and to further control the operation of the recording equipment. This register circuitcomprises a pulsing relay which responds to code impulses transmitted from-a sender, a group of registerin relays or their equivalent for recording the dialed office code and the number of the called subscriber, a timing device, other registers responsive to this timing device at the instant when conversation ensues between the called and calling subscriber over the established connection, and still other registers which respond to said timing detime the conversation between the two subscribers is completed.

For the purpose of illustrating the invention both in the parent patent'above referred to and in the present divisional application thereof, use

recording the V from the .sender.

is made of a recording apparatus of the perforator type common in printing telegraph systems which comprises a suitable number of punch magnets for perforating transversely across a tape of suitable size the codes of various items. Other recording apparatus such as that which is responsive to the setting of suitable light valves might be equally well used. The invention, however, is not limited to any particular type of recording apparatus, and the one herein shown and described is, therefore, only typically illustrative and not exclusive of the many equivalent mechanisms well known and available which could be used within the scope of the present invention. i

In general, the telephone system,

invention, when applied to a operates as follows: When the subscriber removes his receiver from the switchhook, a line finder district selector and a controlling device, such as a register sender, become connected to the subscriber's line in the wellknown manner. The subscriber, upon receiving dial tone, dials the called subscribers ofiice code and number. These are registered in the sender for the purpose of controlling theproper setting of the various switching selectors between the calling and the called line. When the sender has responded to the series of pulses which make up the code of the called office and the called numbenthe register circuit above mentioned, or tape register as it designated in the parent patent, is connected to the line ,finder district selector and placed in a responsive condition to code pulses subsequently to be transmitted to it That is to say, when the called offlce code and called oflice number have been registered in the sender, it becomes necessary to make a. record of this tape that will contain the record of the completed call. To do this, the tape register is operatively connected to the sender and a pulse code for each of the letters and each of the digits dialed by the to the tape register and perfo'rator is now opregister and a subscriber is transmitted recorded therein. A tape eratively associated with, the tape a the perforator is brought into play to translate the pulse codes into six-digit perforating codes for perforation upon the tape.

However, in advance of perforating the called ofilce code and number in terms of six-digit codes, it becomes necessary to perforate one or more of three special codec indicative of either one of three other notations. The first code is termed a switching" character code, the second a new call character code, and a third a calling line character code, this last to identify the calling line in the group of lines to which the registers and perforator are common. The reason for the use of the three special character codes will become apparent later on in the detailed description of the invention but it is plain at the present time that some means must be used to identify the relationship between the calling line and the succeeding called oflice code and number to which the line is establishing a connection.

If the call is a toll call which must be routed through an operator's position, the recording operator, instead of making the usual ticket for' the call, now causes the regular ticket information to be punched upon the recording tape bydepressing suitable keys on a teletype transmitter located at her position. In this case, however, the city or town to which the call is to be completed as well as the called office code and code and number on the number therein and the charge for the call in terms of dollars and cents will be punched by the operator on her key-set and subsequently recorded on the tape through printer pulses tranmitted to an auxiliary responsive device in the tape register which, in turn, causes the operation of the translating relays to record the information on the tape in the same code that is used for recording the notations of local calls. After the codes of the called office and number have been perforated on" the tape, the tape register and the associated tape perforator are disconnected from the line, ready to be used "by some other calling line in the group over which,

at this time, the called ofllce and number of another connection may have been completely dialed. Thus it is seen that the tape perforator and associated tape register are not held continuously to one line until the connection is established and conversation completed there over, but are associated only momentarily with any line in the group at the time the line and its associated equipment have enough of a record as the perforator are connected to this other line to record the information. But in this case, as already noted, the record belonging to this other line is not confused with the preceding record which belongs to the first line because the usual switching character code and the 'code designating a new call intervenes between the record for the first line and the record for the second. Or if, again, the new call should be a toll call and therefore is to be completed through an operators position, then whatever information the operator may desire to record on the tape is preceded by theswitching character followed by the code indicating a toll call which is then followed by whatever information the operator mayv have punched on theteletype transmitter associated with her position.

When the conversation starting time has been recorded on the tape, the tape register and the to be punched on the tape. The recording equipment, therefore, is used discontinuously by all lines in the group to which it has access. It now becomes evident why, prior to punching the called office code and number or any other notation relating to "a particular call, it is necessary to perforate an identifying character code which indicates the calling line from which the office code and number were dialed, and why, it is necessary to punch a further character code to indicate whether the record which follows relates to a new call started by another line or is merely a succeeding notation of a call made by a previous line for which other notations have already been recorded upon the tape. For reasons which will appear hereinafter should the call be a toll call, thatis, one which is to be completed through an operator's position, it will also be necessary to record another character in advance of any information to indicate that what follows is part of the record of a toll call and not of a local call.

perforator are'again disconnected from the line, but when the conversation is terminated and the called subscriber has restored his receiver, the tape register and associated perforator are. again connected to the district selector in order that the finishing time of the conversation may then be recorded on the same group of registers and in the same three separate designations as the starting time, preceded, as always, by the switching character code and by the calling line identification code.

Thus the iprimary" tape record made for a group of lines contains a series of disconnected code notations which relate to calls initiated from the lines in said group, The next step in our invention is to take this tape and produce from it one tape for each line containing thereon all of the notations belonging to the calls made by the line, with the notations arranged sequentially in the orderin which they would have When the connection to the called subscriber's line is 'completed and the called subscriber answers, an occurrence which marks the instant from which conversation time is to be measured, the tape register is once more connected to the district selector whereupon, under the control of a timing device, this instant is registered by setting the position of each of three switches, the first of which by its positionmarks a particular ten minute interval, the second a particular minute interval and the third a particular tenth of a minute interval. The positioned switches in the tape register .are now operatively associated with the translating relays for the purpose of translating said record in terms of the six-digit code used for punching each of the separate designatlons on the tape, and with the translating relays set in accordance with the position of the switches, the perforator is again operated to punch, first the usual switching character, second the identifying codeof the calling line and, third, each of the separate codes indicating the three separate notations of-the starting time as marked by the positions of the three switches. The tape register and the perforator are then again disconnected from the line. If at this time another line has started a call and the extension of said line has advanced to the point where the called office and numberhave been registered in a sender, the tape register as well been entered on the tape had they been recorded chronologically in the normal process of establishing" the call without interruption for recording the notations of other calls initiated by other lines in the group. That is to say, the order of the notations would be the calling oflice and number, the starting time and finishing times of the connection, followed by the called ofiice and number and the starting andvfinishing time ofthe next, call if this next call happens to be a local call, or of the city, ofilce and number and the toll charges if it happens to be a toll call, subject however to the condition that each of these groups of notations would be preceded and followed by the usual switching character code and by the new call code or by the code of an operator's call whichever the case might be.

The equipment for making an individual tape for each line from the primary tape is-completely disclosed in our parent Patent 2,112,951,

above mentioned, and it is sufiicient to note for the purpose of the present invention that said v equipment is adapted to produce an individual tape for each line which contains, in chronological order, all the recorded notations for each' local and toll call, each group of notations being preceded by a code which denotes whether sucha call is local or toll.

It will be observed that the individual tape 'rate bill form, the charge depending upon the distance of the connection and the duration of the conversation. Besides this, local calls must be added together and separated from toll calls which are also. added together and the two included as parts of the same bill. In our invention, duction from the individual tape of a or final tape for each this final tape through tabulating printers which add up the local calls, print the total charge therefor and further print, on the same or sepaand history of each toll call together with the total for all toll calls.

In order to achieve this next step, the individual tape is passed through the organization of circuits herein called the computer from which is produced a final tape for each line that contains for each call the directory abbreviation of the called oifice, the number of the called line and the computed charge in dollars and cents to be assessed for the call. In the case of the record of a toll connection included on the individual tape, the computer functions merely to transfer this record on the final tape inasmuch as all of the information in the form to be printed on the bill is already contained on the individual tape.

The more essential elements of the computer comprise a perforator and an impulse receiver, usually of thetype common in telegraph systems, a group of registers for recording the called oilice and number of a local connection thereon, another group of registers for recording the start and finishing time of a connection, a translator for translating the time of a connection and the called oifice name into a charge based upon standard charge units, and a group of adding registers which integrate the charges as the individual tape advances from one call to the next. After the record of the last call has: passed through the computer, the total sum recorded in the adding registers is perforated on the final tape, which tape is then passed through an ordinary page printer adapted to respond to the perf orations thereon for printing the final bill.

As said before, the present application is directed specifically to the computer. For the purcomputed pose of completely describing their equipment and operation, attention is directed to the following drawings in which Figs. 1 to 13 inclusive, when arranged as shown in Fig. 1A, disclose in schematic fashion the apparatus and circuits of the invention.

Fig. 14 shows the perforator code'used on the individual tape prepared by the mechanism disclosed in Patent 2,112,951 above mentioned;

Fig. 15 is a timing chart showing the operating sequence of the sensing pins of the mechanism 400 relative to one complete cycle of the distributor 445-449, the operation of switch and relays H2 and 422, all of said apparatus being shown in Fig. 4. The raised lines in the chart indicatethe operated condition of the apparatus designated except for the lines relating to switch 5 wherein each line represents the movement of the switch or the operation of its driving magnet 4 as indicated by the legend.

' Local call record ence is made to the above-named patents for 75 line, and the running of.

this requires the prov tape is interposed a more comprehensive understanding thereof. For the purpose of describing those elements of the invention which are intended to be covered by the present application, W4: may start by assuming that the primary tape has been produced for a certain group of lines, that it contains the perforated codes of each of the separate notations that relate to each of the calls made from each of said lines, recorded thereon separately at the time a particular function for a particular call is completed by any one of the lines in the group, and thatfrom this primary tape; a tape for each line has been produced which contains-thereon all code entries relating to calls completed from that line.

The next step in the operation of the invention is to take the individual tape and pass it through a computer which will make up the final tape that will operate an ordinary page printer or similar device for printing the bill. This final tape will contain the code of the called-omce and number of each call, the charge in money units for the call and, as a final entry, the total by another entry which likewise relates to thesame call. But whereas the primary tape from which all-the individual tapes are made contains all of the separate entries for the different calls more or less indiscriminately distributed throughout its length without correlation to the calls to which they pertain, the individual tape for a particular line in any group not only contains the separate entries for all calls made from that line, but has them arranged in the correct succession of time in which such entries would have been made for the particular call if the primary tape had been made continuous for one connection from the instant the call was initiated to the time it was terminated. In other words, while each group of between two, switching characters, yet all of the entries within the group are the entries of one call only. .For instance, immediately succeeding the first switching character code will be the new call code after which come the entries of the called subscribers line followed immediately thereafter by the switching character code and then by the entries of the beginning of the conversation time and followed again by another switching character code and then by the entries of the end of the conversation time. Although each of these separate entries may have been separated from each other on the primary tape by other entries appertaining all assembled together with respect to the call in the order of succession to whichthey appertain. Hence the individual tape passed through the computer has all entries relating to successive calls disposed on the tape in which these calls were made. 4

The individual tape is now passed through the sensing mechanism 400 of the computer which is entries on the individual similar in construction to the senser 200 in our above-mentioned Patent 2,112,951 except for the fact that interrupter 422 the shaft of which operates the tape advancing mechanism and the sensingpins depressinglever is driven by the same shaft which drives distributor brushes 445 and 449 and has a set of contacts which make at the beginning of the distributor brush -revolution, that is, in the blank interval immediately preceding segments I and remains closed for the entire revolution, that is, until the brushes have cleared segments 6. Distributors 445 and 449 are of the usual rotary types well known in telegraph systems and are typified, for instance, by the disclosure in Patent 1,311,915.

After the tape is inserted in the tape-slot (not shown), locking key 443 is depressed whereupon a circuit for the start magnet 444 is completed which extends from grounded battery, resistance 451, contacts of key 443, distributor brush 445 and the two normal segments of commutators 423 and 446, winding of magnet 444 to ground. Magnet 444 operates, unlatches the distributor brushes which now sweep along the segments of their respective commutators, brush 445 supplying impulse ground to the segments of com- 'mutator 446 as the brush comes into-contact with the segments of commutator 423 which are grounded in the manner described hereinafter. As the tape advances, the sensing pins l-8, inclusive, become aligned under the six holes of the first switching character code, pass therethrough and, as a result, the six segments of the commutator 423 are grounded by the bottom set of contacts carried on each sensing pins l-B inclusive, ofthe mechanism 400. As the -distributor brush 445 rotates along the surface of the commutator, said brush grounds, in succession, the six conductors 43| to 4315, inclusive. commutator brush 449 also receives these pulses and transmits them to coimnutator bar 448 but inasmuch as this bar is connected to the top middle armature of relay 425 which is normal at this time, the pulses transmitted by brush 449 will have no effect.

For reasons stated hereinafter, the brushes of switch 415, which is of the usual rotary back stroke type typically disclosed in Patent 1,472,465 issued to O. F. Forsberg and R. M. de Vignier on October 30, 1923, may be standing on'any set of terminals. Let it be assumed that the switch brushes are resting on the second terminal set; that is, the terminal set immediately succeeding the normal N terminal set. Hence, when the distributor brush 445 reaches segment I and grounds conductor 43l, a circuit is completed for relay 'l0l which extends from ground on conductor 43l, No. 1 contact set of relay 452', brush 6 and second cooperating terminal, upper winding of relay 10l to grounded battery. Relay 10l operates and locks over its lower winding and No. a contacts, conductor 421, bottom back contacts of relay 412, bottom inner contacts of relay 4, to ground. The grounding of conductor 432, when the distributor brush .4 5

reaches the second segment, causes a circuit to be completed which traces through the No. 2 contacts of relay 452, brush M8 and second cooperating terminal, upper winding of relay102, to grounded battery. Relay 102 also operates and locks over its-bottom winding and No. a contacts to ground on conductor'421. When the brush 445 reaches the third segment, ground is con.-

thesecond cooperating terminal, upper winding of relay 103 to grounded battery. Relay 103, like relays 10! and 102, operates and locks over its lower winding and No. a contacts to ground on conductor 421. When the distributor brush makes contact with the fourth segment, ground is connected to conductor 434 and a circuit is thereby completed over No. 4 contacts of relay 452, brush 439 and second cooperating terminal,

' erates and breaks its interrupter contacts but I nected to conductor 433 which is extended over the No. 3 contacts of relay 452, brush'4l1 and upper winding of relay 104 to grounded battery. Relay 104 likewise operates and locks over its lower winding and No. a contacts to ground on conductor 421. When the distributor brush reaches the fifth segment, ground is connected to conductor 435 and a circuit. is completed for relay-105 over the No. 5 contacts of relay 452, brush I and second cooperating terminal, upper winding of relay 105 to grounded battery, operating this relay which then locks in a circuit over its lower winding and No. a contacts to ground on conductor 421. Similarly, when the brush makes contact with the sixth segment, ground is connected. to conductor 436 and a circuit is thereby completed for relay 106 over the No. 6 contacts of relay 4'52, through brush 4| 9 and second cooperating terminal, upper winding of relay to grounded battery, operating said relay which then locks in a circuit through its lower winding and No. a contacts to grounded conductor 421.

Hence it is seen that the eifect of the first switching character code perforations ahead of the call entries of the first call is to cause the operation of any group of registers shown in Figs. 3 to '7, inclusive, with whose terminals on switch 415 the brushes of said switch may be connected contacts of relay 412, winding of switch magnet M4 to grounded battery. The switch magnet opsince the brushes are advanced on the release, or back stroke, of the switch magnet, the brushes of the switch are held on the terminals with which they are in engagement so long as the magnet circuit is maintained. At the end of the revolution, thecOntacts of interrupter 422 are opened, the circuit of switch magnet 4l4 is broken, the magnet releases and the brushes are advanced to the next terminal set. When the brushes have been disconnected from the preceding group. of terminals the register relays which had been pre viously locked up do not release inasmuch as the ground connected to conductor 421 is not disturbed.

The next series, of perforations on the individual tape will be those of the new call code lar set of contacts of operated sensing pins 2, 3,

4 andt, off-normal terminals of the terminal bank accessible to brush 420, winding of relay 4| 2 to grounded battery. Relay 2 operates, disconnects ground from conductor 421 causing thereby the release of the register relays previously operated and locked by the switching character code and disconnects the winding of magnet 4|4 from the contacts of interrupter 422.

X the called ofiice name.

In the meanwhile relay 2 closes a self-interrupting circuit for magnet '4 which extends from ground on the bottom inner contacts of relay 4| l, bottom front contacts of relay M2, interrupter contacts of. magnet M4 to grounded battery. The magnet now operates on self-interruptions until brush 420 is advanced to the normal terminal N whereupon relay 2 is released and the switch is stopped from further rotation. Inasmuch as the contacts operated by cam 422 are still closed, magnet H4 is again operated over the previously described circuit, causing the advance of the switch brushes to the first terminal of their respective arc.

Thus it is seen that the effect of the switching character code has been merely to operate and lock a group of registers which are subsequently released while the effect of the new call code is to return switch 5 to the first set of activeterminals on the switch arc;

If the brushes of switch 415 are already standing on the normal terminal when the sensing pins pass through the holes of the switching character code the commutator conductors will be grounded as already described, but since the brushes to which each of them is connected are positioned on vacant terminals, no register relays will be operated and the switch will be advanced to the terminals of the first register 100. Further, when the tape has been advanced to the new call code, the previously described operations following in response thereto will take place and the switch will be driven back to the normal terminals.

With the'switch H5 in its first position subsequent to the operations of the new call code "-cycle as above described, the computer is ready to proceed with the next entry on the tape. This entry, it will be remembered, will be, in the case of a local call, the code of the first letter of If the call is a local call, the name of the office and the number of the called subscriber will have been recorded on the primary tape and repunched on the individual tape in equivalent number codes. For illustration it may be assumed that the name of the local office is Halifax and that the number of the called subscriber 3678. The office name,-

however, like the called number, will have been recorded in the code of numerical characters corresponding to the letters. The name Halifax,

' minals.

on each of the segments is extended at the proper time to conductors 432, 434 and 436 in succession. Ground on conductor 432 closes the circuit of relay 102 as already described causing said relay to operate and lock to conductor .421; ground on conductor ,434 causes the circuit of relay 104 to be closed as previously described causing said relay to operate and lock to conductor 421; and the same is true with respect to relay 106 whose circuit is closed by ground over conductor 436, said relay also operating and locking The code perforations of theto conductor 421. digit 4, corresponding to the letter H of the called oflice name, cause, therefore, the operation and locking of the three above-mentioned relays in the register 10!]. At the end of the revolution, cam 422 opens its contacts thereby causing the release of magnet 4 which advances the brushes of switch 5 one step to the second set of ter- At the beginning of-the next distributor brush revolution, interrupter 422 again makes its contacts, closing thereby a previously .described circuit for switch magnet 4 which operates preparatory to advancing the brushes of the switch 415 to the next or third set of terminals. In the meanwhile the tape has been advanced tothe next set of perforations which, in the case assumed, are those of the digit 2 corresponding to the code of the numerical equivalent of the letter A of the called oflice name. The sensing pins, accordingly, pass through the holes made in positions I, 2, 5 and 6 of the tape which,

' in the manner previously described, cause the therefore, will have been recorded in the numerical code 425 the first digit of which is represented by a code that consists of a hole perforated in the second position of the tape, another in the fourth and another in the sixth; that of the second digit by a hole in the first, another in the second, another in the fifth and another in the sixth, while the digit 5 is designated by a code character consisting of a hole in the fifth and a hole in the sixth position of the tape (see Fig. 14)., When the distributor start magnet 444 operates to start the next revolution of the distributor brushes, interrupter 422 closes the circuit to the winding of switch magnet 4 over a path previously traced, causing said magnet to operate preparatory to advancing the brushes of the switch to the second terminal set. Hence when the tape has advanced to the position where the sensing pins are aligned under the holes of the code of the character 4,-the second, fourtlr and sixth pins will pass through said holes and close ground to the conductors connecting with com- . mutator segments 2, 4 and 6. Therefore, when grounding of conductors 43!, 432, 435 and 436 as the distributor brush 445 makes with the correspondingly numbered'segments of commutators 445 and 423. With the brushes of switch 5 on the second set ofterminals, the grounding of conductor 43| causes a circuit to be closed extending from said ground, No. 1 contacts of relay 452, switch brush 416 and second terminal on itsarc, upper winding of relay 1 to grounded battery, causing said relay to operate and look over its lower winding and No. 1 contact to ground on conductor 421. The ground on conductor 432 causes a circuit to be closed extending from said ground, No. 2 contacts of relay452, brush H8 and second terminal on the arc, upper winding of relay 1l2 to grounded battery causing said relay to operate and look over its bottom winding and No. 1 contact to ground on conductor 421. Ground on conductor 435 likewise causes a circuit to be closed from said ground, No. 5 contacts of relay 452, brush 421 and second terminal on its'arc, upper winding of relay 1l5 to grounded battery. Relay now operates and locks over its bottom winding and No.- 1 contact to conductor 421. Lastly, the ground on conductor 436 causes a circuit to be closed over the No- 6 contacts of relay 452, brush 41-9 and second terminal on its arc upper winding of relay'1l5 to grounded battery, causing said relay to operate and then lock 'over its lower winding and No. 1 contact to ground on conductor 421. Thus the perforations of the code of digit 2 have resulted in'the operation and locking of four re-

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