Historical Document · 1929
Bulletin 1026: Strowger P-A-X
AE sales bulletin describing the Strowger private automatic exchange.
Historical Document · 1929
AE sales bulletin describing the Strowger private automatic exchange.
~ - - - STRDWG~lJt'!!JDMATI~~~~ G) " ~ C I A L.. &'~S TENt S 1! .( Bunetln 1026 Automatic Electric Inc. , CHICAGO. U.S.A. ?.... • >- • STRO~GER A private automatic telephone system of the Strowger Automatic Dial type, adapted to the interior communication needs of business and industrial organizations. Bulletin 1026 September 1, 19 29 Automatic Electric Inc. 1033 WEST VAN BUREN STREET . CHICAGO . U . S. A . Strowger P-A-X (Private' Automatic Exchange) ~~~~~~~~~~~~~~~~~=~ The Home of StJrowgeJr P=A=X Originators and Pioneer Manufacturers The factories of Automatic Electric Inc., in Chicago, are devoted exclusively to the design and manufacture of Strowger Automatic Dial telephone systems and other communication equipment. The annual output of the plant, for both public and private telephone systems, is sufficient to care for 300,000 telephone lines. Because of this large production capacity, quick service on repair parts and additions is assured. This pioneer organization is backed by more than forty years of experience in telephone design and manufacture. More than two thousand business and industrial organizations are now using Strowger Automatic Dial Systems for their interior communication needs, with complete satisfaction. STRD!!tlYTIlMATI[ CIAL. SYSTEM S Engineered, Designed and Manufactured by Automatic Electric Inc~ Factory and General Offices: 1033 West Van Buren Street, Chicago, U. S. A. -Sales and Service Offices in the Following Cities: Los Angeles Cleveland New York Kansas City Boston St. Paul Atlanta Detroit Philadelphia General Export Distributors The Automatic Electric Company, Ltd., Chicago In Canada-Independent Sales and Engineering Co., Ltd., Vancouver In Australasia-Automatic Telephones, Ltd., Sydney In Japan-Automatic Telephones Ltd. of Japan, Tokyo . Associated Companies American Electric Company, Inc. Chicago International Automatic Telephone Co., Ltd. London Automatic Telephone Manufacturing Co., Ltd. Liverpool The New Antwerp Telephone and Electrical Works Antwerp ParJe Tw o Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~=~ 'W"hat the Strowger P=A=X Is Strowger P-A-X (Private Automatic Exchange) is primarily a private automatic telephone system especially designed for the private communication needs of business and industry. It permits every man in an organization, in effect, to sit by the side of every other man ; places every department in direct communication with every other department ; and enables an executive, without personal effort, to keep in touch with every unit and every process in his organ ization . Telephone service is, however , only one of the many services which can be furnished by Strowger P-A -X. With many of the types, such special services as Code Call, Conference, and Emergency Alarm Service can also be suppliedand all without the services of operators or other attendants. Among the most common ly used special se rvices are the following : A Rapid and A ccurate Interior Communication System Interior Telephone Ser')l;ce Code-Call Service Through the P-A-X code-call feature (see description on page 16) , provision is made for the immediate location of. and conversation with, any executive, foreman, or other person it may be desired to find , no matter where in the plant he may be at the time . Conference Service This service provides for interconnecting any number of telephones for a conference, the conferees remaining at their desks. Code Call Conference Wire Emergency and Fire-Alarm Service An alarm service interconnected with the telephone facilities and offering to industrial plants and other establishments a protection that is highly effec tive and complete in every detail. Watchman' s Service This feature offers a means of supervising watchmen in industrial plants, and for a chief watchman or gatekeeper to keep in constant touch with his subordinates at all times-in emergencies as well as under normal conditions. Watchman Super')lis;on Executive Right-of-Way Enables an executive to place a signal tone in the telephone of the two parties engaged in a conversation, to inform them that he wishes to speak to one of them . This service saves the valuable time of important executives. Miscellaneous Services Although the above are the most important of the services rendered by Strowger P-A-X, it is an apparatus so flexible that it is capable of meeting, in a business or industrial establishment, every requirement that relates to commu nication or remote control. Features of Strowger P=A=X Strowger P-A-X Is Really Private On many " private" telephone systems, eavesdropping is so easy that really private, confidential information cannot be transmitted over the telephone. There is no such danger where Strowger P-A-X is employed. Connections made on the P -A -X are automatically locked against intrusion, and there is no operator to hear what is said . Page Three Strowger P-A-X (Private Automatic Exchange) ~,~~~~~~~~~~~~~~~~~~~ Strowger P-A-X Is Automatic Strowger P-A-X Is Fully Automatic None of its services is ever delayed or hampered because an attendant is Jbsent. The delays and errors that characterize human operation are eliminated . The services rendered by the P -A-X are rapid and accurate, and are available twenty-four hours a day . Strowger P-A -X Restricts Personal City Calls There are usually a large number of employees who need intercommunicating facilities, but not the public telephone service facilities . When P -A -X is used, such emp loyees are given P -A-X telephones only, the outside telephones being assigned only to those who need them . Strowger P-A -X Cuts Rental'Costs By reducing the number of outside telephones needed, P -A -X cuts telephone rental costs. Also, as it keeps the rented telephones free at all times for outside business calls, there are fewer busy signals on incoming ca lls, and more messages ca n be completed without increasing the number of trunks. Strowger P-A-X Betters Your Outside Telephone Service Your private branch exchange, free from handling interior calls, gives better service on public-exchange calls. Your operator can give all of her attention to incoming and outgoing calls. Busy signals, on incoming calls, are much less frequent , because the outside telephones are not used for interior calls . Strowger P-A-X Is Simple to Install, Maintain and Operate Simple to Install, Maintain and Operate It is built in compact units , easily mounted and wired. Metal covers protect the equipment from dust and dirt. Wearing parts hold adjustments over a long period of time, and such parts as do wear out are low in price and easily replaced. The dial used is the simplest and most convenient calling device yet invented . It requires little mental or physical effort and its operation is becoming universally known through its use on public telephone systems. S trowger P-A-X Is Used The convenience, privacy and reliability of Strowger P-A-X encourages the use of the telephone for internal business. This prevents the wasting of many hours of time by individuals who would leave their desks and walk, rather than use a manual system. ttDouble",Track~~ Telephone Service When P-A -X is installed and operated as a system entirely independent of the public telephones , the utmoSt usefulness is secured from both systems . The man who is supplied with both P-A-X and outside telephones enjoys the advantages of what is , in effect, a " double-track" telephone system . He has direct contact with every department of the organization through the P-A-X : he can deal with customers, or others outside the plant, through the public telephone system; and, when necessary, he can do both of these at the same time. This convenience of " double -track" service is of great value when he is asked for information which he does not have immediately available. Without leaving his desk, he can secure the desired information from any place in the plant. Instead of saying, ''I' ll look that up, and call you back," he says, "Wait a minute-I'l l find out." Then he dials over the P-A-X, and in a few moments is able to answer the calling party's question. The saying of time and annoyance on such calls constitutes one of the greatest advantages of the Strowger P-A-X. Page Four Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~==~ How §trowgeJr P",A",X Operates , In making use of any of the automatic services of the P -A-X. the teleph one IS operated as follows: the receiver is first lifted from the hook and the dial turned from the proper digits to the finger stop and released. As soon as the proper number. " 7-4" for instance . is called. the equipment begins to render the service required . If an interior telephone call is made. the bell at the cailed telephone ri ngs . or. if that line is busy. a buzz is heard in the receiver. If a code call is sent out. bells. buzzers. gongs. horns. etc .. sound th e proper code until the person desired calls the response number. If an alarm is sent. immediately the signals are heard throughout the establishment. All of the Strowger P -A -X services are automatic. immediate. and always available. All are controlled by the dial. over a single pair of wires. The operation of the mechanism may be understood in a general way by a consideration of a typical interior telephone call. The following description varies as to the type of installation . but it will give a general understandin g of the operation of the equipment . Suppose. for instance. Mr. X. whose P -A-X telephone is No. 25. wishes to call Mr. Y. at P -A-X telephone No. 74. Figure 1 Fig ure 2 Easy to Operate F igure 3 When Mr. X lifts the receiver of his telephone (Fig. I) the line switch or finder switch (depending on the type of switchboard installed) immediately operates to extend his line to an idle connector switch. He then turns the dial from the figure "7" to the finger stop and releases it (Figs. 2 and 3). The dial turns back to its original position of its own accord and transmits a series of seven electrical impulses to the connector switch . In a similar way. dialing th e second figure. "4." causes four impulses to be transmitted to the connector. Acting under the control of these impulses. the connector immediately establishes connection with the terminals of line 74. Without any further operation of the dial. the connector tests the line. rings lhe bell automatically and intermittently if the line is not in use. or sends th e busy signa l back to the receiver of the calling telephone if the called telephone is busy. When Mr. Y answers by lifting the receiver of telephone No. 74. the connection is ready for conversation . Replacing the receivers on the hook after conversation causes the immediate release of the switches. which are then ready for another call. Page Five Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~~~~ Strowger P=A=X Telephones Every public telephone company takes the utmost care in the selection and purchase of telephone instruments for its subscribers. They know that to buy cheap or unstandard telephones invites complaints, poor service, and unjustified repair and replacement expense. The conditions under which the Strowger P-A -X telephones are used are frequently more severe than those of public telephone systems. They must be able to withstand the most constant use over a long period of years without undue deterioration. Standard Type Instruments The telephones of Strowger P -A -X are built especiall y for such service. There is nothing cheap or flimsy in their construction . They are identical in design and construction with the telephones used for service in hundreds of large public automatic exchanges , and are built to meet the exacting needs of the world's most prominent telephone engineers. Th e Typ e I -A Monopho ne The Type 2 Monophone The P -A-X Monophone The P-A-X Monophone This beautiful telephone is now coming into wide use both by public telephone companies and for private service. The Monophone combines the compactness and efficiency of the conventional telephone with the additional advantage of having the transmitter and receiver in a single convenient unit. This transmitter-receiver unit is ruggedly constructed of bakelite and so shaped that no matter how it is placed on the rest, it will always slide into its proper position. Monophone desk stands are furnished in two different styles. The No. I-A type is designed for use with the usual type of ringer box mounted separately. The No. 2 type has the Monophone and ringer box in a single complete unit. Ji:ither type is very pleasing in appearance, and makes an attractive addition to the executive's desk . The Type I-A Monophone is now available in a variety of attractive colors, with gold or chromium plated fittings. The main parts of the telephone are made of solid colored bakelite; the finest is absolutely permanent. Color folder may be had on application . Page Six Strowger P-A-X (Private Automatic Exchange) ~'~~~~~~~~~~~~~~~~~~ P-A-X Wall Monophone This is a most compact and useful instrumen,t , designed for mounting on a wall or by the side of ' a desk . P -A -X Wall Monophone A Monophone of this type is made by mounting a Monophone cradle on a black-japanned steel ringer box, of the enclosed-gong type. The dial is mounted at a convenient angle on the cover of the box. The wall set, complete with the combination unit, measures 9 inches in width and 12 inches in height, and projects 5 Yz inches from the surface on which it is mounted . The P -A-X Desk Telephone A Con')'enient Wall Set The P -A -X Ringer Box The P-A-X Desk Telephone This instrument is identical in size and appearance with the conventional desk telephones used with large public automatic telephone exchanges. It embodies the most highly approved ideas in exterior design and interior mechanical and electrical construction. P-A-X Desk Telephone It is similar in style to the familiar manual telephone except for the addition of the calling dial, by the manipulation of which the user sele,cts and controls the P-A-X service it is desired to use . T he Ringer Box Associated with each desk telephone or Type I-A Monophone is a ringer box, which contains the ringer and condensers and the terminal block to which the telephone line is connected. The box is made of heavy steel, parkerized and japanned . It is 7 y,; by 9% by 4 inches in size. Page Seven Strowger P-A-X (Pri'Vate- Automatic Exchange) ' ~I~~~~~~~~~~~~~~~~==~ The P-A-X Wall Telephone P-A-X Wall Telephone This instrument is very compactly assembled and is sturdy in construction. The case is heavy steeL black enameled. All parts are easily accessible for adjustment or repair. Wherever it is desired to install J telephone that cannot conveniently be placed on a desk or stand, the wall 'type gives excellent service, and is frequently used in corridors, and on walls or columns in shops and factories . Dimensions of box same as ringer box shown on previous page . Overall width , 10 inches. The P -A -X Wall Telephone The P-A-X Flush Type Wall Telephone Telephones of this type are used principally in halls , corridors or in places where the usual type of wall instrument is not suitable. All working parts are mounted on a steel plate that has been given a durable black enamel finish . The front plate is mounted on a steel box that is first placed in the wall to protect the telephone parts . It is then held securely in place by four machine screws. The front plate is perforated to permit the ringer being heard distinctly . Each telephone is equipped with a standard type transmitter, dial and receiver. Flush Type Wall Telephone Dimensions of front plate 13 by 7% inches. Dimensions of inside box 11 - 13 / 16 by6 Y4 by 4 inches deep. The P-A-X F lush Type Telephone The P -A -X Mine Telephone The telephone shown on page 9 has been designed for use in mines , for police systems, street railways, quarries and various other outside uses . A cast iron case encloses all working parts. The door is fitted with a handle having a cy linder lock. When the outer door is open, only the parts actually used in making a call are exposed. All other parts are contained in a second compartment, so de_signed and constructed that is is airtight and waterproof. Page Eight Strowger P-A-X (Pri'JIate Automati,c Exchange) ~. ~~~~~~~~~~~~~~~===.~ "" The ringer h as three-inch loud -r ingin g gongs. mounted on top of the iron case and protected by an iron hood . Ringer coils are impregnated with a waterproofing compou nd and the wiring is carried in ru b ber -covered co nductors. On the back of the iron case are two horizontal mounting bars. Dimensions. 11 Yz, -inch es wide. 15 inches high . 12Yz inches deep. The P-A-X Mine Telephone Mine Telephone The P-A-X Dial The dial is a small . compact and sturdy device. 3 inches in diameter. mounted on th e telephone as shown in the illustrations . The rear of the dial is shown on this page with all its working parts. When the front disc is turned. the main spring is wound up and this returns the disc to normal when released . breaking the line circuit a number of times in quick succession. correspondin.g to the figure dialed . This. in turn . operates the switches and connects the calling party with the telephone desired . This dial is . the same as that used by all independent telephone ccmpanies operating Strowger Automatic Dial systems. The P -A-X Telephone Relay A Simple and Sturdy Dial The P-A-X Dial T he P -A-X Loud -Ringing Extension Bell Telephone Relay This relay makes it possible to increase the efficiency of a telephone system in noisy places by substituti ng for the usual ringer. a louder and more powerful signal. S pedal Signal Apparatus Loud-Ringing Extension Bell This loud-ringing extension bell is used in place of the regular bells on the ordinary P-A -X telephone. The telephone, located in a noisy part of the factory . is equipped with one of these loud-ringing extension bells and operates when that particular station is being called. Paae Ni~e Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~==~ The Type J[ P=A=X (Capacity 90 Telephones, One Conversation) (Special Seruices- --Code-Call, Private Line) For Small Organizatiorts Tbe Type I P-A-X is especially designed to meet the needs of relatively small organizations, where the needs of intercommunication are of a somewhat limited nature. It enables such organizations to take advantage of the quick , accurate and convenient service of the P-A-X, at the lowest possible cost. It consists of a single, standard, automatic switch; a vibrating ringingcurrent converter; and the necessary relays and fuses. This equipment is mounted on a small frame of angle steel. Type 1 P -A-X Unit, with Switch Covers Removed Type 1 P-A-X Unit, with Rectifier A common pair of wires is run to all of the telephones , and each telephone also has a single wire leading to it. This individual wire is for ringing the bell of the called station to the exclusion of all others. Since the telephones are all wired common to the one switch, this telephone has a capacity of only one conversation at a time. It is, therefore, seldom used for more than twenty or thirty telephones , although it has a capacity of ninety. Telephones are called by dialing two digits. Immediately after the last digit of the number is dialed, the called telephone will be given a single ring. To repeat the ring, it is necessary to dial the number again, but it is not necessary to replace the receiver first . The Type I P-A-X operates on 22 volts, direct current, supplied from an II -cell storage battery of twelve ampere-hours capacity. The battery is trickle charged by an electrolytic rectifier, at a rate just high enough to compensate for the normal current-drain. In this way, the battery is automatically kept in a tully-charged condition. A signal relay and buzzer are provided, to signal any failure of the charging current. The Type 1 P -A-X may, if desired , be equipped for code-call service with a maximum of 10 code combinations, and with a private line between 2 telephones. The equipment for these services is mounted on standard switch bases, for which space is provided on the switchboard . See illustration at left. Page Ten Strowg-er P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~=~ The Type :10 P=AcX (Ca pacity 10 Lines, Two Simultaneous Conversations) The Type 10 P-A-X is a full automatic. selective-ringing. secret-service Strowger Automatic Dial system having a capacity of 10 lines and 2 simultaneous local calls. Two telephones may be placed on each line. using code ringing , but the two cannot call each other. Type 10 P-A-X Unit The entire equipment. conslstmg of a combination of simple Strowger rotary switches and Strowger relays. is mounted on a frame together with the ringing-current generator. fuse block . and terminal block. as shown in the illustrations. The apparatus is normally protected with steel dust -proof covers. To make a call. the telephone number (1 digit ) is dialed first . and followed by the dialing of a single figure (usually "8") for ringing . To repeat the ring . the last digit must be dialed aagin. If the called line is busy, the usual " busy tone" is received at the calling station. A 10 Line Unit Complete Type 10 Installation in Cabi net The current supply of the Type 10 P -A-X is furnished by an II -cell storage battery of 12 -ampere hour capacity, the battery being floated from an electrolytic rectifier. In cases where commercial power of 110 volts D . C. is available, battery may be charged from this source through a resistance. The dimensions of the central unit are 2'8" long, 1'5" high . and 1'6" wide. Page Eleven Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~=~ The Type 2 P",A",X (CapacitCj 25 Lines, Three Simultaneous Conversations) A 25-Line System When a private telephone system reaches a size of approximately 25 lines. it is usually necessary to provide facilities for more than one or two calls at a time. The Type 2 P -A-X. a 25-line system. is therefore supplied with suffi cien t equipment to handle three simultaneous conversations. The switchboard equipment is assembled on a frame of angle steel. arranged to be .mounted either on the floor or bolted on the wall. At the top of this frame is a plate mounting a group of three finder switches. together with the necessary relays and power fuses . Below this are mounted three connector sw itches and a ringing co nverter of the vibrating-reed type. The Type 2 P · A · X Shown With and Without Switch Covers The connector switches are the "operators" of the P -A-X. and perform the work of making and releasing the connections. When a telephone receiver is lifted. preparatory to making a call. one of the finder switches automatically rotates to the line of the calling party . and connects it througl1 to a connector switch. _The connectio11- is then completed. under control o{ the- calling party's dial. by the connector swit'ch. All telephone numbers are 2-digit. Immediately after the last digit of the number is dialed. the called telephone is signaled automatically and intermitently. until the call is either answered or abandoned. If the telephone called is busy. the familiar busy tone is sounded in the calling party's receiver. The Type 2 P -A-X is operated on 48 volts. direct current. supplied by a 23-cell storage battery of 12 ampere-hour capacity. The battery is kept fully charged by an electrolytic trickle charger. and a signal buzzer gives indication of any failure of the charge. Page Twelve [ J Str-o wger P-A -x (Private A utoma tic Exchange) ~~~~~~~~~~~~~~~~~~~ The Type 5 pcAcX (Initia l Capacity Up to 100 Lines) t ! (Special Services---Code-Call; Watchman's Supervisory and Recording; Conference; Executive Right -of-Way ; Emergency or Fire Alarm) The Type 5 P -A-X is particularly adapted for use in large estab lishments where the telephone traffic is comparatively heavy and a number of simultaneous conversations must be accommodated . The lOO-Line P-A-X The switchboard equ ipment is mounted on a heavy steel frame , complete! y ('nclosed in a glass and steel cabinet. It consists of line switches ( one for each line in service) , connector switches (in number equal to the number of sim ultaneous calls required) , and the power and ringing-circuit equipment . The Type 5 P - A ~·X . Front View . Showing Line Switches The Type 5 P-A-X. Rear View. Showing Connector Switches The line switch of a line operates when the telephone receiver on that line is removed, and extends the line through to one of the connector switches. The connection is then completed by the connector. under control of the calling subscriber's dial. The number of connectors required depends upon the amount of traffic at the busiest time of the day . Seven connectors are usually furnished . although there is space for as many as 20 . Page Thirteen Strowger P-A-X (Private Automatic Exchange) ~I~~~~~~~~~~~~~~~~~ All telephone numbers are of 2 digits (00 to 99). Ringing commences automatically, after the second digit, and is cut off when the called party answers. The Type 5 P-A-X operates on 48 volts, direct current, supplied from two storage batteries, each consisting of 23 cells of 24 ampere-hour capacity. These batteries are installed in a wooden battery-rack; or, if they are to be installed in a place where appearance is important, a neatly finished steel batterycabinet, similar to the cabinet shown on page 11, can be supplied. The battery-charging control equipment of this P-A-X is contained in a metal cabinet designed for wall mounting. Three types of charging are available: Tungar rectifier for commercial alternating current; resistances for commercial direct current having positive side grounded; and motor-generator for direct current not so arranged. Floor plan is shown on page 27. The Type 7 P=A=X (Unlimited Capacity) Unlimited Capacity for Expansion The Type 7 P-A-X is an expansion of the Type 5, with selector switches added to select a connector in the called hundred-line group. If the traffic is light, the selectors are mounted on the rear of the line switchboards, with the connectors. If traffic is heavy, so' that connectors occupy the space, it is necessary to installed a separate unit for monnting the selectors. A Typical Type 7 P -A-X Installed. Capacity 300 Lines U nits for this purpose are furnished in 3 different capacities , depending em the ultimate number of line units that might be installed-namely 54, 100. an'd 200 selectors . The battery charging circuit of the Type 7 P-A-X may be arranged either for a voltage-controlled charging scheme whereby the charging device is started automatically whenever the voltage on the switchboard bus bars reaches the low limit and cut off whenever the voltage reaches the high limit, or a time-controlled scheme as described in connection with Type 5 . Page Fourteen Strowger P-A-X (Private Autom'atic Exchange) ~~~~~~~~~~~~~~~~~~ The Switches of Strowger P=A=X The Line Switch The P-A-X Line Switch The line switch is a simple selecting mechanism which automatically connects the calling line to an idle one of a common group of connectors or selectors, when the receiver is removed preparatory to dialing. As used in the Type 5 P-A-X and Type 7 P-A-X, the line switches are mounted one above another in groups of 25, and with 4 groups in each 1 00 line unit. The contact bank has a capacity of lO trunks to major switches. P-A-X Line Switch The Finder Switch The finder switch, used on P-A-X's Types 2 and 10, performs a similar function to that of the line switch except that the operation is reversed. That is, instead of the subscriber's line equipment operating to find an idle connector when the receiver of the calling station is lifted, as in the case of line switch systems, the finder switch associated with an idle connector rotates to find the line that is calling, and connects with it. It will be noticed that in the Type 2 P -A-X and Type lO P -A-X there is one finder switch for each connector. Finder Switch The P-A-X Finder Switch The Connector The connector is the "operator" of the P-A-X. It consists essentially of a shaft carrying 3 wiper springs at its lower end, so arranged that when the shaft is given first a step by step vertical motion and then a similar rotary motion , the wiper springs will be caused to rest on the contacts of the ca lled line. At the top of the switch is a group of control relays , Below this are the vertical and rotary magnets, the associated ratchet mechanism for lifting and rotating the shaft, and the release magnet for permitting the shaft to drop to normal, when conversation is finished, In the Type lO P-A-X the connector is of the rotary type of switch similar in design to the finder switch shown above. P-A-X Connector T he Selector The P-A-X Connector The selector is used in systems of more than lOO lines for selecting a connector serving the proper hundred groups. It is similar in general design to the connector, having the same shaft and contact springs with the same vertical and rotary motion . Page Fifteen , Str.owger P-A-X (Private Automatic Exchange) n ~~~~~~~~~~~~~~~~~==~ Strowger Code 'Call Service Code Call Signalling The Code Call service of the Strowger P-A-X completes and perfects the advantages of the P-A-X intercommunicating service. The P-A-X Code Call is more than a man finder . It makes possible not only immediate location of. but also conversation with any executive, foreman, mechanic or any other employeno matter in what part of the building or plant he may be at the time. ly o V For example, a customer calls in over the city telephone and asks for a definite delivery date for certain material he has ordered . You dial the number 'e! tc er e an ho of the P-A-X telephone at the production manager 's desk, and after hearing his telephone bell ring for a few seconds, decide he is not there-or perhaps his stenographer answers and says he is " somewhere in the factory. " You immediately momentarily depress the hookswitch , releasing the connection, and dial the code number assigned to the production manager. Immediately bells, buzzers, horns , whistles, etc. , begin to sound that particular code in. all parts of the plant, each signal device designed and adjusted to be suitable for the particular department in which it is used. m1 I a 111 : ( -:all\ , ru' ill' JO ve: The production manager hears the code signal , recognizes it as his own , and turns to the nearest P -A -X telephone , dialing the code call answering number. The code signal stops, and he is immediately connected to your own telephone, and you are able to secure the desired information for your customer at once . Page Sixteen is le~ Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~==~ , t The code call may be operated from any of the automatic telephones. The operatpr on the telephone company's private bran h switchboard may also use the code call service for locating persons when wanted on calls from the outside. For this purpose she is simply provided with a regular P-A-X telephone. by means of which she puts on the call in the usual way. When the party answers. the code stops. She may observe this without holding the receiver to her ear. How the Code Call Operates Most P-A-X units. when installed. are already wired for Code Call service. To take advantage of the service. it is merely necessary to install the Code Call machine as illustrated . and the necessary signal devices and WirIng. The Code Call machine consists of a combination of standard switches which operate under the control qf the P-A-X user's dial to generate. select. and send out the proper code ringing combinations. For example. on the Type 5 (l00 line) P-A-X. the preliminary calling code is "7 -0." To call a person whose code is " 2-1." a P-A-X user dials "7- 0-2 - 1." Dialing the "7-0" connects the line with the The P -A -X Code Call Equipment code machine.. Dialing the "2-1" causes the machine to generate and send out the "2-1" code to all of the signal devices. which immediately begin to sound the proper signal-" two strokes-pause-one stroke"the signal being repeated at regular intervals. The party called hearing his code being sounded. steps to the nearest P-A-X telephone and dials the common answering number ("79") . This stops the code and connects him with the person calling. In case the call is not answered. the calling party may stop the code merely by hanging up the receiver. If the plant in which the Code Call service is used is a large one. extending over many buildings or many floors. it may be advisable. to avoid confusion. to use several code machines. one for each section or floor. In this way it is possible to sound a code signal in anyone section or building and not in the others. In addition. another code machine may be used for sounding codes in all parts of the plant at once. Page Seventeen Strowger P-A-X (Private Automatic Exchange) ~~~~~~~~~~~~~~~~~==~ 'W'atchman's Se:rvice A Complete Waf hman's System In buildings or plants that are extensive or contain valuable equipment, it is customary to employ a watchman, or, in the larger plants, a staff of watchmen under .a chief or supervisor, who are, or should be, constantly patrolling the property during the night hours on the lookout for possible outbreaks of fire , attempts at burglary, or perhaps malicious damage by some disgruntled employe. In the P -A-X equipped plant, the Watchman's Service feature offers a ready means of keeping all watchmen in constant telephonic touch with the chief, and of automatically recording and supervising the movements of watchmen on their rounds . Properly adjusted to the conditions and requirements of each individual plant, it increases the efficiency of the staff and offers a protection that is most effective and complete in every detail. In the past, many variations of the Watchman's Service feature have been placed in operation in P -A -X equipped plants, all of them alike in their essentials, but differing in their details of application. The system described below represents what experience has shown to be the most typical and valuable in the average plant, but can, of course, be adjusted to meet conditions that may seem to require somewhat different treatment. Watchman's Seruice Equipment Eacn P-A-X telephone is potentially a watchman 's reporting station, and any or all of the telephones on a given route may be used as reporting stations, as conditions may require. The supervisor's equipment consists of a standard P-A-X telephone, an audible signal, and a lamp and key panel for purposes of supervision . The automatic recording of watchmen's movements is taken care of by an electric clock of the recording type , illustrations of which are shown . Page Eighteen Strowger P-A-X (Private Automatic Exchange) ~.~~~~~~~~~~~~~~~~==~ P -A -X W atchm an's Reco rdin g C loc k This clock gives clear and separate registrations for two -day periods with out changing the dial. The dial is of paper and is fastened over a corrugated hard rubber drum . Registration is made by means of needles, one for every station, which perforate the dial. the perforations showing both the numbers of the stations and the time of recording. 1. When a watchman calls in, a distinct tone is sounded in his receiver to notify him that his call has been recorded. 2. The supervisor is given audible and visual signals when a watchman lalls in . The number of the station from which the call is made is indicated on the lamp panel. 3. Means are provided whereby the supervisor may determine whether the proper party is operating the station equipment. 4 . Means are provided for permanently recording the number and time of each call. 5 . An alarm is given if more than a predetermined interval of time elapses between calls 'from consecutive stations. 6. An alarm is given if a watchman does not call in from his various stations in the prescribed order. 7. Arrangements may be made so that these alarms are given at a distant point, police headquarters, for instance. 8. Means are provided for the supervisor to communicate with such distant point. What the Watchman's System Will Do Operation of System When a watchman on his route arrives at the P -A-X telephone 'designated as his first station, he removes the receiver , dials a predetermined number, say 77 , and waits a few seconds in case the supervisor wishes to verify the fact that the proper party is calling in. The watchman receives a buzzing sound in his receiver indicating that his ca ll has been properly recorded . At the same time the lamp on the supervisor's panel. corresponding to the station calling, glows and shows up the station number. The lamp continues to glow until the watch man calls in from the next station . If the supervisor wishes to speak with the watchman, he may cut in on the station by pressing a key on his desk while the watchman is waiting, or by dialing the number of the station if the watch man has already hung up. Operation of Watchman's Service The lamps on the panel a.re divided into a number of groups , one group for each route. Pa ge Nineteen Strowger P-A-X (PriYate Automatic Exchange) ~~~~~~~~~~~~~~~~~~~~ If the watchman, for some reason , fails to call in from the next station on his route within the prescribed time intervaL a buzzer alarm is operated at the supervisor's' office. The supervisor, on hearing the buzzer, inspects the lamp panel to determine the meaning of the alarm . Finding that the lamp associated with the last station from which the watchman called in is still glowing, and is the only glowing lamp in the lamp panel. the supervisor tealizes that the next call-in is overdue. The glowing lamp in the lamp panel also indicates the location from which the last call-in was made , and the super visor may then make an investigation. If the watchman makes an error in the order in which he calls in from the stations on the route, or fails to report from one or more st~ tions, the buzzer at the supervisor's desk is operated . On hearing the buzzer. the supervisor inspects the lamp panel to determine the meaning of . the alarm. Finding two lamps glowing , he realizes an error has been made in the order of calling in, and gets in touch with the watch man , who goes back to the station (or stations ) overlooked and calls in from each station in order. P -A -X Watchman 's Service Equip ment. Equipped for Two Watchmen. Fire Alarm Service Fire Alarm Ser'JIice The special equipment for Strowger Fire Alarm service, used in connection with a supervised watchman 's system, consists of a number of closed circuit alarm boxes similar to those in. general use, placed ' at convenient points, a supervisory panel at the gate bouse or fire marshal's office, and a code sender. If, upon an outbreak of fire , a pull-box is operated , the code sender automatically sends out the fire code for that box to all of the code call signal devices. Experience has shown, however. that most fire alarms are turned in over the telephone. For this reason , in the P-A -X Fire Alarm system , a special telephone number is set aside for the fire marshal or chief watchman. If, in the event of an outbreak of fire , this number is dialed , a loud ringing bell is sounded in the fire marshal's office, the bell being associated with his telephone. He may then ascertain the exact location of the fire and he presses a key aSSOCiated with the fire box for that location, which operates the code sender exactly as if the corresponding pull box is operated. This avoids the confusion which results when a pull-