US1575312A - Automatic testing system for automatic telephone switches - Google Patents

Description

March 2 ,1926. 1,575,312

A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TE E HONE SWITCHE 'ile 8. 1923 15 Sheets-Sheet 1 March z,1 9ze. 1,575,312

A. s. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 1923 15 Sheets-Shet 2 Arna/a 5. Ber/e/s. Wye/773a. g W I Affy.

March 2 1926. 1,515,312

A. s. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 8, 1925 15 Sheets-Shet 5 A/fy.

March 2 1926. 1,575,312

A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Fil e Dec 8. 1923 15 Sheets-Shefi /s; fawr'rl 5 04 0. y 4/154.

March 2 .1926. 1,575,312

A. S. BERTELS El AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 19123 5 Sheets-Sheet 5 Arno/a 5. fier/eb. Cdwin (Trap March 2 1926. 1,575,312

A. S. BERTEL ET AL AUTOMATIC TESTING SYSTEM FOR: AUTOMATIC TELEPHONE SWITCHES i 1923 hets-Sheet' 6 A. s. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 8, 1923 15 Sheetg-Sheet 7 March 2 1926. 15575312 d W by March 2,1926. 1,575,312 l I A. 5. BERTELS tr AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 8. 1923 15 eets-Shet' s March 2 1926.

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Mlle/7mm 14/770/05. Ber/e/s. f dw/n f fm March 2 1926. 1,575,312 A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Fil e 8, 1923 15 Sheets-Shet' 1 Arno/a iBer/e/s. [aw/1; f. Trap z March 2 1926. 1,575,312

A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. a, 192::

15 Sheets-Sheet 11 March 2 1926.

A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 1923 l5 Sheets-Sheet! 12 March 2 1926. 1,575,312 A. s. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Deq. a, 192; 15 Sheets-Sheet 15 5:: m K5 g Q2 m g o o 0 o March 2 1926.

A. s. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE SWITCHES Filed Dec. 8, 1923 15 Sheets-Shet l4 Arm/d5 fier/e/s. //7l//7/0f5. Ltd/Win 7% A. S. BERTELS ET AL AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEPHONE ,SWITCHELJj March 2 1926.

Tiled Dec. 8, 192:

' fdW/h ffra r Patented Mar. 2, 1925.

UNHTE STATss ARNOLD S. BERTELS, OF TENAFLY, NEW JERSEY, AND EDWIN F. TRAPP, OF VALLEY STBEAIVI, NEW YORK, ASSIGNORS TO WESTERN ELECT-RIG COMPANY, INGORIPQ- RATED, OF NEW YORK, N. Y., A COREGRATION OF NEXV YORK.

AUTOMATIC TESTING SYSTEM FOR AUTOMATIC TELEEHONE SWITCHES.

Application filed December 8, 1923. Serial No. 679,312.

To (ZZZ whom it may concern Be it known that we. ARNOLD S. BnnrnLs and EDWIN l Tnarr, citizens of the United States of America, residing at Tenafly, in the county of Bergen and State of New Jersoy, and at Valley Stream, in the county of Nassau and State of New York. respectively, have invented certain new and useful Improvements in Automatic Testing Systems for Automatic lelephone Switches, of which the following is a full, clear, concise, and cit act description.

This invention relates to telephone exchange systems and more particularly, to a testing device for use in machine switching systems for testing selector switches.

One of the principal requirements in the operation of a telephone exchange system is that of maintaining the central office equipment in proper working condition. In case of a manual exchange, the central office equipment is relatively simple and its apparatus is kept in good condition without much trouble. However, in the caseof a mechanical oiiice. its equipment is much more complicated. The establishment of different classes of calls brings into operation various combinations of selector mecl'ianisms of various types. The amount of apparatus used in mechanical exchange systems is very large and much of it is made up of moving parts subject to loss of adiustiuent while in use. For this reason, apparatus of this nature,v such as relays, interruptcrs, sequence switches, clutches and selector mechanisms, must be carefully watched to detect such loss of adiustment due to wear or broken. parts which results from normal use or mistreatment.

Naturally. the failure of any piece of apparatus to function properly will result in the stopping; of the progress of. calls or in thefalse routing of calls. Such failures ordinarily would not be detected except wherecalls are repeatedly reported as incomplete, and suchservice interruptions, if frequent enough, would assume serious proportions from a service standpoint. It is therefore important that the apparatus of an exchange be regularly tested to detertermine if it is in suitable condition for rendering eff cient service; f rst, before its reported failure, and second, after the ap paratus has been withdrawn from service for repair or adjustment to determine if such repairs or adjustments place the particular apparatus in serviceable condition. After repair and adjustment, the apparatus should be'given vigorous and repeated tests under conditions simulating those under which it will function in actual service before it is again placed in service.

It is, therefore, the object of this invention to provide an improved testing device for applying tests to selector switches of a telephone exchange system.

More particularly, it is the object of this invention to provide a testing device for testing district selectors of the types disclosed in the patents to F. A. Stearn et al., no. 1,395,9Z7, issued November 1,1921. No. 1,504,261, granted AugustlZ, 1924, to E. H. Mills and No. 1.513.351, granted October 28, 19241, to 1.). M. Taggart and F. J. Scudd-er.

I While the invention'ha's been disclosed as particularly adapted for testing switches of the panel type, as disclosed in the aforesaid patent and applications. it will however, be apparent from the following description that the invention has a wider utility and that by slight modification it could be adapted for testing other types of selector switches.

A feature of the invention is the provision of means for operating, switches employed in the several selection stages of amechanical switching system in simulation of the manner in which such switchesfunction in actual service and for observing, through the medium of suitable supervisory apparatus, the accuracy with which the switches under test function.

A further feature of the invention relates to the provision of means for operating; a selector switch in the establishment of all of the different classes of connections for which such switch is designed.

A further feature of the invention relates to the provision of means for establishing a connection between the testing device and the selector to be tested.

A further feature resides inthe method of repeating' a test any number of times on the same selector.

.lllO

A further feature relates to the provision ot means for indicating the type of selector about to be selected and for ascertaining the.

1 tion of a talking path, and, second, to send a similar series oi impulses to wause a different talking path selection. I

Reference may now be had to the accompanying drawings. Figs. 1 to 10 and 16 show the arrangement of apparatus which is included in the district selector testing circuit, and Figs. 12, 13, 1d and 15 show son'ieot the types of district selector circuitswhich may be tested.

More in detail, Fig. 1- shows an arrangement of relays and interruptors of well known design for simulating actual service conditions to be'met by the district selector circuits under test. A' sequence switch for controlling the operation of this apparatus is also shown.

Fig. 2 shows additional relays and interruptors and also a register to record the number of times the test circuit comes to rest on a terminal which is connected to a district selector circuit which has been made busy by the insertion of a plug in the make busy jack. A lamp associated therewith is also shown as a visual signal of such con: nection.

In F: 3 is shown a key which may be operate; in order to test the district selector circuit for a false operation of its chargmg re iy. an an associated signal. Relays for simulating line conditions of the message rate and coin collect type are also shown. Fig. 3. also shows a key which upon its operatiomperiiits a second cycle of routine tests to be made. An arrangement is also shown h an associated signal for indicating that more than one master switch is off normal at the same time.

Fig. l shows two master switches and one group switch, all of the type disclosed in Patent- No. 1,4;72gi65 granted Oct. 30, 1923, by O. F. Forsber ind M. De Vignier.

Fig. 5 shows three group switches together with their associated apparatus.

In Fig. 6 two registers are disclosed. one to record the number of single tests and the other to record the number of con'iplete tests. Class relays operated in accoroance with the particular types of district selector circuits connected to the groups are also illustrated in this figure.

7 shows a class sequence switch which is arranged to'assunie a position determined by the class relays in the preceding figure; and also a dial pulse sequence switch which is arranged to simulate the action of a calling dial. The following keys are also shown in this figure; the start key, which must be operated to initiate a routine test; a control advance key, which may be operated to advance the testcircuit out of any posltion in which it has inadvertently come to rest; the particular circuit key, which must be operated in addition to the start key whenever it is desired to make a test on a particular circuit; a pass busy plug key, whose operation will cause the group switch to, advance to the next terminal upon encountering a district whichis busy due to the fact that a make busy plug has been inserted in the make busy jack; a pass busy test key, which may be operated when the group switch encounters a district which is busy in regular telephone trafiic; a returnto-normal key, whose operation causes the test circuit to be returned to its normal position; and a lamp key, which controls the illumination of all the lamps used as signals in the test circuit.

Fig. 8 shows a register sequence switch, register stepping switch and associated relavs for controlling the selection of a particular circuit. A stepping switch and associated apparatus which functions in conjunction with the class sequence switch in the preceding figure is also shown.

Fig. 9 shows a combined busy and trouble time alarm circuit and Fig. 16 shows an alternate arrangement which may be used when a separate trouble and a separate busy time alarm circuit is desired.

Fig. 10 illustrates the arrangement of four groupsot keys which are utilized in the selection of a particular circuit.

Fi 11 with slight. modifications is similar to that shown in Fig. 2 of Patent No. 1,395,- 977, issued November 1, 1921, to F. A. Stearn et al., illustrating a district selector circuit of the type used in connection with single party and'flat rate type lines.

Figs; 12 and 13 when placed side by side, Fig. 19 at thele'tt oil Fig. 13, show the arrangement ot a district selector circuit which functions in connection with a two-party message rate type line similar to that disclosed in Figs. 2 and 3 of Patent No. 1,513,- 351, granted Oct. 28, 192%, by l). M. Taggart and F. J. Scudder.

- Fig. 14L illustrates the type of district selector circuit which is used in conjunction ith coin collect type line and is similar to Fig. 2 of Patent No. 1,504,261, granted Aug; 12, 192% to E. H. Mills.

F ig. shows connecting conductors between the district selector circuits of Figs. 11, 12, 13 and 1e and senders 910, 1010, and

1110; Senders 910 and 1010 are of the type disclosed in the above mentioned Patent #1,895,977 and sender 1110 is of the type disclosed in the above identified patent of E. H. Mills.

Fig. 17 shows the manner in which the sheets are to be arranged with respect to one circuits to which this circuit has access, de-

presses a start key 1. Upon the operation of this key, a circuit is closed from grounded battery, winding of the power magnet of se quence switch 200, upper left contact of sequence switch spring 201, conductor 202, outer left armature and back contact of re lay 301, conductor 102, armature and back contact of relay 101, conductorG, contact of start key 1, to ground on the normal contact of key 2. The power magnet of sequence switch 200 is energized in this circuit, moving this sequence switch from position 1 in to position 2. A circuit is also closed from ground-ed battery, winding of time measure alarm rolay' l01, conductor- 102, brush arm 103 and its associated normal contact, conductors 40 1 and 18, to ground on the contact of start key 1. Relay 401 is energized in this circuit andhegins the measure of time. This feature will be more fully explained hereinafter.

The operation of the start key also completes a circuit from grounded battery, upper right contact of sequence switch spring 228, conductor 205, right armature and back contact of relay 302, conductor 30S, winding of relay 501, outer left armature and back contact of relay 502, lower contact of interrupter 1, conductor 505, right inner armature and back contact of relay 103, conductor 104, normal contact of key 2, front contact of key 1, normal contact of key 3, conductor 11, to ground through the normal contact of repeat key 12. Relay 501 is energized in this circuit and connects its winding through its armatureand front contact in series with the winding of relay 502, to ground over the following circuit: conduo tor 508, inner left armature and back contact of relay 509, conductor 510, left arma-.

cuit is completed from grounded battery,

right upper contact of sequence switch spring 228, conductor 205, winding of stepping relay 207, conductor 208, outer left armature and front contact of relay 502, to ground through interrupter 5041 over the path previously traced, energizing stepping relay 207. Relay 207 completes a circuit from grounded battery, winding of relay 307, left armature and back contact of relay 805, conductor 211, right armature and front contact of relay 207, to ground through the left upper contact of sequence switch spring 209. Relay 307 energizes. When interrupter spring 504 disengages its lower contact, relay 307 through its inner armature and front contact connects its winding in series with the winding of relay 305 to ground over conductors 312, 105 and 106, normal contact of return-to-normal key 13 to ground, energizing the relay 305. iVhile interrupter spring 50 1 is still engaging its lower contact, a circuit is completed. from grounded battery, winding of the master steppingmagnet 705, conductor 310, outer armature and front contact of relay 307, outer right armature and back contact of relay 305, conductor 703, master switch arm 702 and its associated contact, conductor 215, outer left armature and back contact of relay 213, left armature and front contact of relay 207, upper left contact of sequence switch spring 200 to ground. Magnet 705 is energized in this circuit. .Vhen interrupter spring 504 disengages its lower conact as before mentioned, the circuit for relay 207 is broken, causing this relay to be deenergizcd. The deenergization of relay 207 in turn causes the .deenergization of magnet 705 and the brush assembly of the first master switch is stopped to the first terminal in the well known manner. A circuit now extends from grounded battery, resistance element 609, brush arm (502 and its associated first contact (with which it is engaged at this time as will become apparent later), conductor 606, front contact of start key 1, conductor 14, lettcontact of sequence switch spring 216, conductor 218, inner right armature and back contact of relay 313, conductor 314:, brush arm 709 and its associated. first off-normal contact, conductors 711 and 712, winding of olfuiornial relay 713 to ground, energizing relay 713. The energizetion of the latter relay completes a circuit for off-normal lamp 711, causing its illumi- 'iaticn as an indication to the operator that the first master switch is in its off normal position. This circuit may be traced from grounded battery, lamp 714, outer left armature and front contact of relay 713, conductor 715, to ground through the right contact of lamp key 15 if the latter is operated. Upon the next engagement of interrupter spring 504 with its lower contact, stepping relay 207 is again energized over the path previously traced, completing a circuit from grounded battery, right upper contact of sequence switch spring 228, conductor 205, winding of relay 321, left armature and back Contact o rel y 3 7, nne r ght armat re and front contact of relay 305, conductor 211, right armature and front contact of stepping relay 207, upper left contact of sequence switch spring 209 to ground, energizing relay 321. Relay 207 also closes a path from grounded battery, winding of master stepping magnet 705, conductors 719 and 720, outer left armature and back con tact of relay 721, conductors 722 and 723, outer right armature and back contact of relay 335, conductor 724, brush arm 702 and its associated contact, conductor 215, to ground as previously traced on sequence switch spring 209. Relay 321 upon energizin connects its winding and the winding of relay 317 in series to ground through its left armature and front contact; and upon the disengagement of interrupter 504 with its lower contact, relay 317 is energized. Relay 207 deenergizes, openlng the circuit through stepping magnet 705 which releases, moving the brush assembly of the first master switch to the second terminal. The master switch is now set in position to test all the district circuits associated'with the first twenty group switches, tie first being shown at 726 and the twentieth. at 800. Groups 2 to 19 have been omitted for the sake of clearness in the disclosure.

in this position of the master switch, the class sequence switch 50 shown in Fig. 7 is set in position to test for the particular kinds of district to which the test circuit has access. The districts, as has been before noted, may be either the coin collect, flat rate, or message register one or two-party types. The setting of the class switch for single party district selector circuits will be described. Vhen interrupter spring 5504 engages its lower contact, stepping relay 207 is energized as previously described and a circu is completed from grounded battery, ding of class relay 108, conductors 109 and 612, right inner armature and front contact of relay 317 conductors 32 1 and 211,-to ground over the pathpre iously traced. Relay 108 is energized in this circuit. A path is also closed from grounded battery, winding of group switch stepping magnet 726, conductor 725, brush arm 702 and its associated second contact, conductor 215, to ground on sequence switch spring 209 as previously noted. 4 'agnet 726 energizes in this circuit and upon the disengagement of interrupterspring 50st with its lower contact, stepping rclay207 deenergizes and, as a result, stepping magnet 726 deenergizes movingthe brush assembly of thefirst group switch to its first terminal. Relay 108 deenergizes. lVhen interrupter spring 504: next engages its lower contact, stepping relay 207 again energizes, in turn energizing relay 108 and stepping magnet 726.

Relay 108 through its front contacts controls the operation of class relays. 119, 1.21,

1.23, 11.6 and 115. These relays are operated in groups as determined by the particular class of districts connected to the group switch associated with the test circuit.

It will be assumed that single-party district selector circuits are connected to the group switch selected for test. In that case,

A circuit then extends from grounded battery, brush arm 601 and its associated contact, conductors 118 and 134, winding ofrelay 123, conductor 133, left inner armature and front contact of class relay 108, conductors 111, and 735, brush arm 732 of the: first group switch and its associated contact, conductor 733, brush arm 706 of the first master switch and its associated contact, conductor 513, right armature and back contact of relay 512, conductor 327, outer right armature and back contact of relay 313, conductor 511, inner right armature and back contact of relay 509, conductors 326 and 325, outer right armature and front contact of relay 317, conductors 609 and 16, lower contacts of sequence switch spring 57, conductor 608, to ground through brush arm 603 and its associated contact. Relay 123 is energized in this circuit and completes a circuit from grounded battery, brush arm 604 and its associated contact, conductors 118, 128 and 127, winding of relay 126, conductor 125, outer left armature and front contact of relay 123, conductor 122, outer left armature and back contact of relay 121, conductor 120, outer right armature and back contactof relay 119, to ground. Relay 126 is energized. The energization of relay 126 opens the circuit at its armature and back contact for energizing class switch stepping. magnet 015, preventing the motion of this switch.

lVhen interrupter 504. disengages its lower contact, stepping relay 207 deenergizes, in turn causing the deen-ergization of class relay 108. Relay 123, it will be noted, is looked through its inner left armature and front contact over conductors 105, 106 and 107 to ground at the normal contact of the returnto-normal key 13. The deenergization of relay 207 cu es stepping magnet 726 to deenergizc, moving the brush assembly of the group switch to its second terminal in the well known manner. A circuit is also established from grounded battery, brush arm a and its associated contact. conductors 118 and 128, winding of re ay 131, conductor 130, outer right armature and front contact of relay 123, conductors 100 and 107, normal contact of key 13 to ground, energizing rclay 131, which looks through its inner left armature and front'ccntact, conductor 132 to ground, as previously mentioned, on the normal contact of key'13. The energization of relay 131 establishes a circuit extending from grounded battery, winding of the power magnet of sequence switch 50, lower right contact of sequence switch spring 53, conductor 14:3, inner right armature and front contact of relay 123, conductors 140 and 139, inner right armature and front contact of relay 131 to ground, for moving this sequence switch out of position 1 and into position 8, which is the position assumed by the class switch for testing single-party district selector circuits.

While sequence switch 50 is in motion, a circuit is in existence for energizing relay 509 from grounded battery, winding of relay 509, conductor 51 1, to ground over the circuit previously traced for sequence switch magnet 50. The energization of relay 5C9 opens at its outer right armature and back contact an energizing circuit for sequence switch magnet 200, thus preventing this sequence switch from moving out of position 2 until the class switch is properly set. Up 011 the setting of the class switch, the circuit of relay 509 is broken, allowing this relay to deenergize.

Upon the deenergization of relay 207 due to the action of interrupter spring 504, relay 108 and group switch stepping magnet 726 are deenergized, the deenergization of the latter causing the brush assembly of the group switch to step to the second terminal. A circuit also extends from grounded battery, winding of power magnet of sequence switch 200, lower left contact of sequence switch spring 201, conductor 219, left con tacts of sequence switch spring 613, conductor 614;, outer right armature and front contact of relay 131, conductor 145, outer right armature and back contact of relay 509, conductor 515, right armature and front contact of relay 321, conductor 328, left armature and back contact of relay 207, upper left contact of sequence switch spring 209, to ground for advancing this sequence switch out of position 2 and into position 3. Ground on sequence switch spring 210 advances the sequence switch to position 5. As this sequence switch passes through positions 3 and 4;, acircuit exists from the ground, lower contacts of sequence switch sprin 221, conductor 240, right armature and back contact of relay 213, conductor 2 1:1, upper contacts of sequence switch spring 57, conductor 20, left armature and back contact of relay 295, conduct-or 2&2, winding of class stepping magnet 615 to grounded battery, energizing this magnet. As sequence switch 200 leaves position 4:, this circuit is opened, deenergizing magnet 015 and moving the brush assembly of the class stepping switch to the second terminal. connected to the first terminal associated with brush arm 605 is extinguisl'ied, and the lamp associated with, the second terminal is The lamp illuminated in a circuit extending from grounded battery, lamp 617, terminal 2, brush arm 605, conductor 670, contact of lamp key 15 (if operated), to ground. It should be noted here that a lamp is connected to each terminal in thearc served by brush arm 605 and the progress of the switch from terminal to terminal may be followed by this means.

The test circuit is now prepared to test the condition of the district selector circuit to which it is connected. If the terminal of the group switch is spare, that is, no district selector circuit is connected thereto, test conductor 739 will be grounded and sleeve conductor 768 will be opened. yVVith sequence switch200 in position 5, a circuit is closed from grounded battery, winding of the power magnet of sequence switch 200, upper right contact of sequence switch spring 201, conductor 247, outer armature'and back con' tact of relay 516, conductor 517, right outer armature ,and back contact of relay 518, inner right armature and back contact of relay 520, conductor 251, right upper contact of sequence switch spring 237 to ground, for moving this sequence switch out of position 5 and into position 1. Sequencev switch 200 is then advanced out of position 1 into position 2 over a circuit from grounded battery, winding of the power magnet of sequence switch 200, upper left contactof sequence switch spring 201, conductor 202, outer left armature and back contact of relay 301, conductor 102, armature and back contact of relay 101, conductor 6, front contact of start key 1, normal contact of key 2, to ground. \Vhen interrupter spring 50st next engages its lower contact, stepping relay 207 energizes in the wellknown manner,

establishing a circuit, from grounded battery, winding of group switch stepping magnet 726, conductor 725, brush arm 7 02 and its associated contact, conductor 215, left outer armature and back contactof relay 213, left armature and front contact of relay 207, upper left contact of sequence switch spring 209 to ground, energizing the mag net. When interrupter spring 504,- disengagcs its lower contact, stepping magnet 7 26 dcenergizes, causing the brush assembly of the group switch to move'to the third terminal. If this terminal is also a Spare one, the above described cycle of operations is repeated and the brush assembly of the group switch is moved to the fourth terminal. If, however, a district selector circuit is connected to the second terminal, the test circuit will make one of the following described tests.

A district selector circuit may be in one ofthree conditions. It may be in a busy condition. due to the fact that a make-busy plug has been inserted in the make-busy ack of the circuit; it may be busy due to the

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