US2882340A

US2882340A - Continuous or intermittent telephone traffic registering system

Info

Publication number: US2882340A
Application number: US356192A
Authority: US
Inventors: James S Murray
Original assignee: General Telephone Laboratories Inc
Current assignee: General Telephone Laboratories Inc
Priority date: 1953-05-20
Filing date: 1953-05-20
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14

Description

April 1959 J. s. MURRAY 2,882,340

CONTINUOUS OR INTERMITTENT TELEPHONE TRAFFIC REGISTERING SYSTEM Filed May 20, 1953 s Sheets-Shet 1' METERS (l-IO) F|(;.| V 'fl|.20) %2 /l5l. v 0N couu'r |1a I84 (X) (X) I14 uol-nm- I85 4 n I75 I sx 2m "manda "n53 ns m l54 ITI a| L ifun'r lao HK aux nz 7 R2 FIG.4 I60 .u

v 6 n R3 I79 RI METERS f7 INVENTOR.

- JAMES S. MURRAY ATTY.

April 14, 1959 J. 5. MURRAY 2,882,340

CONTINUOUS OR INTERMITTENT TELEPHONE TRAFFIC REGISTERING SYSTEM Filed May 20, 1955 s sheets shet 2 JAMES s. nun AY BY $1 ATTY.

April 14, 1959' J. 5. MURRAY 8 CONTINUOUS 0R INTERMITTENT TELEPHONE TRAFFIC REGISTERING SYSTEM Filed May 20. 1953 s sheets-sheets D Ill :3 z a a m a 2 O o I m 9 cc 5 in FIG. 3

SHINUTES INVENTOR. mass s. WRRAY United States Patent CONTINUOUS OR INTERMITTENT TELEPHONE TRAFFIC REGISTERING SYSTEM James S. Murray, Tampa, Fla., assignor to General Telephone Laboratories, Incorporated, a corporation of Delaware Application May 20, 1953, Serial No. 356,192 12 Claims. (Cl. 179-85) The present invention relates in general to trafiic registering equipment for telephone systems and, more particularly, to improvements in apparatus for automatically testing and registering the busy trunks in the trunk groups associated with this apparatus.

The object of the present invention is the provision of improved apparatus for registering the number of busy trunks in the associated trunk groups on a continuous basis on each cycle operation of the scanning switches for a predetermined time period or on an intermittent basis in which the busy trunks are registered periodically on only predetermined ones of the cycle operations of the scanning switches for a predetermined time period.

Another object is the provision of means for selecting the predetermined time period which the apparatus continuously functions to test and register the number of busy trunks after which the cycle operations of the scanning switches are stopped regardless of the operated or non-operated condition of the starting means.

Other features of the invention will be fully set forth in the following description.

The drawings, Figs. 1 to 4, when arranged with Fig. 1 to the left of Fig. 2 and Fig. 2 directly above Fig. 3, show by means of the usual diagrams sufficient of the circuits and apparatus to enable the invention to be readily understood.

Fig. 1 shows a plurality of trunk group meters 1 to 24 for registering the number of busy trunks scanned by the scanning switches T81 and T82. The relays F, G, H and I control the meter operating circuits. A non-locking start key SK controls a start relay A which locks operated to the release relay B. Relays C and D are interrupter relays for controlling the pulsing relay E. The relay D is a slow-to-release relay while the relay C is a slow-to-operate relay, and this combination of relays may be adjusted by varying the spring tension of their contacts to interact at a predetermined speed to cause pulse relay E to pulse at the desired speed. A locking homing key HK is provided to control the release B which, when operated, causes all of the apparatus to be restored to normal even if the start relay A is maintained operated by the continued operation of the start key SK.

Fig. 2 shows the two scanning switches T81 and T82, their operating magnets M1 and M2 and their wipers and associated bank contacts. The switches TS1 and T82 are of the well known rotary type in which the wipers are stepped upon the deenergization of their stepping magnets. Each wiper has access to twenty-five bank contacts. The first, or control, wipers of each switch are provided for controlling the relays F, G, H and I and the apparatus shown in Fig. 3. The remaining wipers, or trunk wipers, have access to bank contacts to which the test or control conductors of the trunks to be tested for idle or busy condition are connected, it being understood that a busy trunk will have its test conductor grounded. For example, the first sub-group of trunks 1- ice 10 are connected to the first ten bank contacts accessible to trunk wiper 202 while the second sub-group of trunks are connected to the thirteenth to twenty-second bank contacts accessible to trunk wiper 202.

Fig. 3 shows a ten-second register 108R, which is mechanically similar to the scanning switches T81 and T82, a five minute timer 5MT and a five minute register 5MR also mechanically similar to the scanning switches. The ten-second register is provided with a stepping magnet M3 for stepping

wipers

301 and 302 on deenergization. The bank contacts accessible to wiper 301 are multipled for controlling the restoration of the ten-second register. Some of the bank contacts accessible to wiper 302 are connected to the l, 2, 3 and 4 minute time terminals and to some of the contact springs of the two and three minute keys 2MK and 3MK. The two and three minute keys 2MK and 3MK are locking keys which remain locked in operated position until manually restored. These keys are provided to determine the periodicity of the meter registrations on certain of the cycle operations of the scanning switches. That is, if the two minute key 2MK is operated, then meter registrations take place on only which key is operated. The five minute timer 5MT has.

a motor magnet M4 which steps its wipers 311, 312 and 313 on deenergization. It should be noted that the wipers 312 and 313 are in engagement with their twentyfifth bank contact while wiper 311 is just one step from engagement with its first bank contact. The wiper 311 engages its bank contacts only on its first half revolution while the wipers 312 and 313 engage their bank contacts only on their second half revolution. The slowto-operate relay K and the stepping magnet MS of the five minute register is controlled by the wiper 313 when it reaches its fifth bank contact. The five minute register SMR is operated one step every five minutes by the five minute timer and the bank contacts accessible to wiper 322 are connected to five minute time terminals, such as 5, 10, 30, etc. Relay M has a plurality of movable

time terminal clips

354 and 355 which are connectable to the one minute, or five minute time terminals in accordance with the total time period the scanning operations of the scanning switches are to test the busy condition of the associated trunks. The relay M controls the operation of the stop relay B dependent upon its connections over the

terminal clips

354 and 355 to the various time terminals.

Fig. 4 diagrammatically shows the control panel and the mounting of the on and count lamps, the start key SK, the homing key HK and the two and three minute keys 2MK and 3MK.

Having given a general description of the apparatus a detail description of its operation will now be given.

Continuous count for a total time of one hour In case the attendant desires to take a continuous count for a total time of one hour the

terminal clips

354 and 355 are connected to the sixty minute terminal 60, shown in the lower right-hand corner of Fig. 3, after which the start key SK is momentarily operated. The operation of key SK completes an obvious circuit for operating relay A which at contacts 110 completes a locking circuit for itself from grounded contacts 121. At contacts 111 relay A grounds conductor 100 to light the on lamp and the count lamp over contacts 171. At contacts 113 relay A grounds conductor 157 to connect ground to the control wipers 201 and 211 of scanning switches TSI and T52 and at contacts grounds conductor 159 to ground wiper 313 of the five minute timer SMT. The grounding of conductor 100 also completes a circuit by way of contacts 103 for operating relay D. Relay D operates and at contacts 104 completes a circuit from grounded conductor 100 for operating slow-to-operate relay C and at contacts 105 completes a circuit by way of

contacts

101, 105 and 120 for operating pulsing relay E- before the slow-to-operate relay C opens contacts 101. After a short interval the slow-to-operate relay C operates to open the circuit of relay E at contacts 101 to terminate the .pulse to relay E and at contacts 103 opens the circuit to the slow-to-release relay D. Relay D after an interval restores to open the circuit to relay C which restores after a short interval to reestablish the circuit for relay D and relay D again operating reestablishes the pulsing circuit to relay E at contacts 105 and the circuit of relay C at contacts 104. This interaction of slow-tooperate relay C and slow-to-release relay D continues as long as conductor 100 is grounded to pulse relay E. Re lays C and D are adjusted so that pulse relay E is operated twenty-five times every ten seconds thereby causing relay E to transmit twenty-five pulses every ten seconds.

' Each time relay E operates a ground pulse is sent to the stepping magnets M1 and M2 of the scanning switches T81 and TS2. The ground pulse to the magnet M1 extends from grounded conductor 100, contacts 130 and over conductor 168 to M1, while the ground pulse to magnet M2 extends from conductor 100, contacts 131 and over conductor 169 to M2. These magnets restore when relay E restores to step the wipers of the scanning switches one step and since relay E transmits twenty-five pulses every ten seconds the scanning switches take twenty-five steps every ten seconds.

On the first step of the scanning switches the wipers 202 to 207 of the first scanning switch T81 and the wipers 212 to 217 of the second scanning switch T82 are in engagement with their first bank contacts which terminate the test, or control, leads of the indicated trunk groups, such as the trunk groups 1-10, 21-30, 121-130, and 221-230. As is well known in automatic telephone systems if a trunk line is busy the test lead is connected to ground. If the first trunk in any of the connected trunk groups are busy the corresponding trunk group meter is operated to record such busy condition. For example, assuming that the first trunk in trunk groups 1-10 is busy, then meter 1 is operated over the following circuit: ground on the test lead of the busy trunk, first bank contact engaged by wiper 202, conductor 182,

contacts

172 and 151, and winding of meter 1 to battery. In a similar manner if the first trunk in trunk group 121-130 is busy, meter 13 is operated from the ground on the busy trunk lead first bank contact and wiper 212, conductor 191, contacts 161 and 142 and through winding of meter 13 to battery. Similar circuits are completed to operate the corresponding trunk group meters through first bank contact terminating the other trunk groups.

On the next energization of relay E stepping magnets M1 and M2 energize and when the relay E restores the magnets M1 and M2 restore to step the wipers of the scanning switches T81 and T82 a second step into engagement with their second bank contacts. If any of the secondtrunks in these respective trunk groups are busy then similar circuits are completed to operate the trunk group meters as previously described. That is, if the second trunk in trunk group 1-10 is busy then trunk group meter 1 is again operated. This operation continues until all trunks in the respective trunk groups are tested to operate the corresponding trunk group meters. When wipers 201 and 211 engage their 11th bank contacts relays F and G are operated. The circuit for operating relay F extends from ground at contacts 113, conductor 157, wiper 201 and its 11th bank contacts, conductor 180 through the winding of relay F and resistance R to battery. The circuit for energizing relay G extends from grounded conductor 157, wiper 211 and its 11th bank contact, conductor 190, winding of relay G and resistance R1 to battery. Relay F at contacts closes an obvious locking circuit for itself and at back contacts such as 151 and 153 disconnects the first subgroup of trunk group meters such as 1 and 11. At make contacts, such as

contacts

152 and 154, circuits are prepared for operating the second sub-group trunk meters such as 2 and 12. Relay G at contacts 140 completes an obvious locking circuit for itself and in a similar manner disconnects the sub-group trunk meters such as 13 and 23 and connects the sub-group meters such as 14 and 24.

The wipers of the scanning switches T81 and T52 con-" tinue to step over their bank contacts as described. The 12th bank contacts of the scanning switches are dead and perform no operation at that time. When the wipers of the scanning switch engage their 13th bank contacts the first trunks of the second sub-group are tested for idle or busy condition. If the first trunk in the second trunk subgroup 11 to 20 is busy then meter 2 is operated as follows: from ground on the busy test lead 13th bank contact and wiper 202, conductor 182,

contacts

172 and 152, and through the winding of meter 2 to battery. In a similar manner the corresponding trunk group meters are operated for each busy trunk when the wipers of the scanning switches step over their 13th to 22nd bank contacts. When control wiper 201 of switch TSl reaches its 22nd bank contact the cycle count meter CC is operated from grounded conductor 157, wiper 201 and its 22nd bank contact and through the winding of the cycle count meter to battery. This meter counts the number of cycle operations of the scanning switches.

When wiper 201 reaches its 23rd bank contact stepping magnet M4 of the five minute timer SMT is energized over the following circuit: from grounded conductor 157, wiper 201 and its 23rd bank contact, conductor 220, winding of stepping magnet M4 to battery. Wiper 211 in its 23rd position grounds conductor 230 every ten seconds but is without effect at this time since neither the two minute key 2MK or the three minute key 3MK is operated.

When wiper 201 steps olf its 23rd bank contact motor magnet M4 restores and steps the wipers of the five minute timer SMT one step. Since conductor 220 is grounded every ten seconds over wiper 201 the five minute timer is stepped once every ten seconds.

When wipers 201 and 211 reach their 24th bank contact relays F and G are short-circuited to cause such relays to restore. The short-circuit of relay F may be traced from ground at contacts 150, winding of relay F, conductor 181, 24th bank contact and wiper 201, conductor 157, to ground at contacts 113. The shortcircuit for relay G extends from ground at contacts 140, winding of relay G, conductor 188, 24th bank contact, wiper 211 to grounded conductor 157. Relays F and G restore to disconnect the trunk groups meters such as 2, 12, 14 and 24 and reconnects the trunk group meters such as 1, 11, 13 and 23 over the back contacts of these relays. When wipers 201 and 211 reach their 25th bank contacts such wipers ground conductors and 240 without efiect at this time. One cycle of scanning operation of switches T81 and T52 have scanned the connected trunk groups and recorded the number of busy trunks on their associated trunk group meters. Successive cycles of scanning operations continue to take place as previously decribed until the five minute register SMR reaches its 12th position.

The five minute timer SMT takes one step every ten seconds as previously described when scanning switch TSl reaches its 23rd position. When the five minute timer has completed 30 steps, which is equivalent to five minutes, a circuit is completed for operating the stepping magnet MS of the five minute register as follows: from ground contacts 115, conductor 159, wiper 313 in engagement with its 5th bank contact (30th step), contacts 342 and winding of stepping magnet MS to battery- A branch of this circuit also extends through the winding ofthe slow-to-operate relay K and therefore the stepping magnet M5 operates'before relay K. Relay K, upon operating at contacts 342 opens the circuit of stepping magnet M5 tocause the five minute register to take its first step into engagement with its first bank contacts where wiper 322 is conneced to the five minute terminal. At contacts 343, relay K connects ground to the multiple bank contacts accessible to wipers 311 and 312 of the five minute timer to complete a circuit by way of either wiper through the interrupter springs of stepping magnet M4 and said magnet to battery for causing the five minute timer to restore to its normal position where the wipers 311 and 312 no longer engage one of the multiple bank contacts. At contacts 341 relay K completes a locking circuit for itself through either of the wipers 311 and 312 and the multiple bank contacts accessible thereto to ground at 343. When the five minute timer has been restored to its normal position, as shown in the drawing, the restoring circuit and the circuit to relay K is opened and relay K after a short interval releases. From the foregoing it will be seen that the five minute 'timer 5MT takes one step every ten seconds during the scanning operations and after making thirty steps the five minute register 5MR is operated one step and a relay K is operated to cause the five minute timer to be reset to normal. As the scanning switches continue to operate the five minutes timer is again started from normal for another five minute timing operation.

' In the same manner as just described the five minute register 5MR takes one step every five minutes under control of thefive minute timer 5MT. After the scanning'switches have operated for one hour, or sixty minutes, wiper 322 of the five minute register switch engages its 12th bank contact connected to the sixty minute terminal 60. It will be remembered that both

terminal clips

354 and 355 are connected to this sixty minute terminal and when the scanning switch TS2 engages its 25th bank contact a circuit is completed for operating relay M as follows: ground contacts 113, conductor 157, wiper 211 and its 25th bank contact, conductor 240, wiper 322 and its 12th bank contact, 60 minute terminal, terminal clip 354 and winding of relay M to battery. At contacts 352 relay M completes a locking circuit for itself from grounded conductor 159, and at contacts 351 relay M completes a circuit for operating relay B from grounded conductor 240, wiper 322 and its 12th bank contact, sixty minute terminal, terminal clip 355, contacts 351, conductor 167 and winding of relay B to battery. Relay B at contacts 120 opens the circuit to pulsing relay E to stop further pulsing by relay E at contacts 121 opens the locking circuit of relay A which restores and disconnects ground from conductor 100. Removing of ground from 100 stops the previously described interaction of relays C and D, extinguishes the on lamp and the count lamp, at

contacts

113 and 115 disconnects ground from conductors 157 and 159 to restore relay M and relay B. At contacts 114 relay A grounds conductor 158 to complete a self-restoring circuit through the multiple bank contacts engaged by wiper 321 of the five minute register, the interrupter springs 323 and magnet M5 to battery. The five minute register thereupon restores to normal in a well known manner. At contacts 116 relay A grounds lead 145 to complete a self-restoring circuit for the five minute timer switch through the multiple bank contacts accessible to wipers 311 and 312, the'interrupter contacts of magnet M4 and the winding of magnet M4 to battery. The five minute timer thereupon'restores to normal until the wipers 311 and 312 no longer engage a multiple bank contact.

The scanning switches T81 and TS2 are stopped in their 25th positions and the five minute timer and the five minute register are restored to their normal positi'ons and the apparatus remains in this condition until the startkey SK is again momentarily operated.

It should be noted that operated that the pulsing circuit to relay E is opened and relay E restores and therefore the scanning operations are automatically stopped even through relay A should not be released when relay B opens the locking circuit of relay A. If the start key should be maintained operated then of course relay A is maintained operated when release relay B operates. Relay B is maintained operated because relay M is maintained operated over its locking circuit as long as relay A is operated. Also, with relay A operated, the ten second register 108R, the five minute timer 5MT and the five minute register 5MR are not restored to normal because restoring

conductors

156, 158 and are not grounded as long as relay A is operated. Therefore, regardless of the operated condition of the start key SK and relay A the scanning operations are automatically stopped after the selected total time period when relay B operates and do not repeat their scanning operations until relay A is restored.

Count every two minutes for total time of one hour In case the attendant desired to take a busy count every two minutes of the number of busy trunks in the connected trunk groups for a total time period of one hour, the terminal clips 354 and 355 are connected to the 60 minute terminal of the five minute register and the twominute key 2MK is operated to close its contacts 361 to 366 after which the start key SK is operated.

The operation of the start key SK again operates relay A and relay A causes relays C, D and E to operate as previously described. Relay E is pulsed by relays C and D to transmit pulses to the stepping magnets M1 and M2 to step the scanning switches T31 and TS2 in successive cycle operations. Both the five minute timer 5MT and the five minute register 5MR are operated in the same manner as described.

On the first cycle operation of scanning switches T81 and TS2 the busy condition of the trunks in each of the connected trunk groups is recorded on the trunk group meters as described and when wiper 211 reaches its 23rd bank contact on this first cycle stepping magnet M3 of the ten second register 10RS is operated. The circuit for operating magnet M3 may be traced as follows: from ground contacts 113, conductor 157, wiper 211 and its 23rd bank contact, conductor 230, contacts 364 of the now operated two minute key 2MK, and winding of stepping magnet M3 to battery. On the twenty-fourth step of the scanning switches the relays F and G are shunted down as described and the circuit to magnet M3 is opened to cause the ten second register 105R to take its first step. When wiper 211 reaches its twenty-fifth contact on this first cycle operation a circuit is completed for operating relays J and H as follows: ground contacts 113, conductor 157, wiper 211 and its 25th bank contact, conductor 240, wiper 302 and its first bank contact, contacts 366 of ZMK, conductor 178 and through the windings of relays J and H in parallel and the resistance R3 and R2 to battery. Relay H at contacts 170 locks itself to grounded conductor 100 and at contacts 171 opens the circuit to the count lamp. When the count lamp goes dark the attendant may take the meter readings for comparison with future meter readings. Relay H also at contacts 172177 opens the circuits to the trunk meters to prevent successive cycle operations of the scanning switches from operating the trunk group meters for a two minute period. Relay I at contacts locks to grounded conductor 1.00 and at contacts 161-166 likewise opens the circuits to the remaining trunk group meters. During this first cycle operation of the scanning switches the number of busy trunks in the trunk group have been recorded on their associated trunk group meters, the ten seconds register and the five minute timer have each taken one step and the relays H and I have been operated to prevent meter. operations for a two minute period.

The scanning switches T81 and TS2, however, continue to step through successive cycle operations without as soon as release relay B is causing any meter operations but on each cycle operation, or every ten seconds, the ten second register 108R and the five minute timer MT are operated one step whenever the scanning switches reach their twenty-third positions. After two minutes of cycle operations of the scanning switches the ten second register has taken twelve steps to position wiper 302 on its twelfth bank contact and when wiper 211 reaches its twenty-fifth bank contact on this cycle operation of the scanning switches a circuit is completed for shunting down relays H and I by shortcircuiting the same. This short-circuit may be traced from grounded conductor 100 through the locking contacts 170 and 160 and the windings of relay H and I to conductor 179, through contacts 362 of 2MK, twelfth bank contact and wiper 302, conductor 240, twenty-fifth bank contact and wiper 211, conductor 157 to ground at contacts 113. Due to this short-circuit the relays H and I restore to relight the count lamp and prepare the meter operating circuits. On the next succeeding cycle operation of the scanning switches the number of busy trunks in the connected trunk group are recorded on the trunk group meters as previously described, the ten second register SR is stepped to its thirteenth position when wiper 211 reaches its twenty-third position, the five minute timer is likewise stepped to its thirteenth position by wiper 201 in its twenty-third position, and when wiper 211 reaches its twenty-fifth bank contact in this cycle of operation relays H and I are again operated. The circuit for reoperating relays H and I is as follows: from grounded wiper 211 and its twenty-fifth bank contact conductor 240, wiper 302 and its thirteenth bank contact, contacts 365 of 2MK, conductor 178, through the windings of relays H and I in parallel and resistances R2 and R3 to battery. The operation. of relays H and I again opens the meteringcircuits to prevent meter operations for another two minute period. Subsequent cycle operations of the scanning switches cause the ten second register 108R and the five minute timer to step every ten seconds.

At the end of the second two minute period wiper 302 of 108R engages its twenty-fourth bank contact and when wiper 211 reaches its twenty-fifth bank contact a circuit is completed for operating relay L. This circuit may be traced from grounded wiper 211 and its twenty-fifth bank contact, conductor 240, wiper 302 and its twenty-fourth bank contact, contacts 363 of 2MK and winding of relay L to battery. Relay L at

contacts

331 and 332 completes a locking circuit for itself through the multiple contacts engaged by wiper 301 and completes a circuit for operating stepping magnet M3 through its interrupter springs as long as wiper 301 engages one of the multiple bank contacts grounded by contacts 332 to cause the ten second register to restore to normal. At contacts 333 relay L completes a shunt circuit around relays H and I to cause these relays to restore. This shunt circuit may be traced as follows: ground contacts 333, contacts 361 of 2MK, conductor 179, windings of relays H and J and their locking circuits 170 and 160 to grounded conductor 100. Relays H and J accordingly restore to again prepare the metering circuits for the next cycle operation of the scanning switches. When the ten second register 108R restores its wipers to normal, or the position shown in the drawing, the locking circuit of relay L is opened and relay L restores to open the short around relays H and I which have released by this time.

On the next cycle operation of the scanning switches following the second two minute period the number of busy trunks are recorded on the trunk group meters, the ten seconds register is operated from normal to its first bank contact to again operate relays H and I as previously described. Subsequent cycle operations of the scanning switches step the ten second register and the five minute timer and cause meter recordings every two minutes until the five minute register wiper 322 reaches its twelfth bank contact to energize relay M as previously described at the 8 end of 'one hour of scanning cycle operations. Relay M- locks and operates relay B, which causes relay A to restore to stop the operations of relays C, D and E as previously described. The five minute timer and the five minute register are restored to normal as previously describedwhen relay A restores. Relay A at contacts 112 grounds conductor 156 to ground the multipled bank contacts accessible to wiper 301 to close a self-restoring circuit over wiper 301 and interrupter contacts 303 to operate stepping magnet M3 to restore the ten second register to normal. The apparatus is now restored to normal and remains in this condition until the start key is again momentarily operated.

Count every three minutes for total time of one hour In case the attendant desires to take a busy count every three minutes of the number of busy trunks in the connected trunk groups for a total time period of one hour, the terminal clips 354 and 355 are connected to the 60 minute terminal of the five minute register and the three minute key 3MK is operated to close its contacts 371 to 374 after which the start key SK is operated.

The operation of start key SK again operates relay A and relay A causes relays C, D and E to operate to transmit pulses to the stepping magnets M1 and M2 to step the scanning switches T81 and T82 in successive scanning operations. The ten second register 108R and the fivev minute timer SMT are operated one step every ten seconds by each cycle operation of the scanning switches and the five minute register 5MR is operated by the five minute timer every five minutes. In this case since the three minute key 3MK instead of the two minute key 2MK, is operated, the control circuits for operating and restor ing relays H and J and relay L are controlled through the operated contacts of key 3MK. On the first cycle operation of the'scanning switches T51 and T52 the busy condition of the trunks in each of the connected trunk groups are recorded on the trunk group meters and when grounded wiper 211 reaches its 23rd bank contact on this first cycle stepping magnet M3. is operated over conductor 230, contacts 373 of 3MK, instead of contacts 364 of 2MK. With wiper 304 in engagement with its first bank contact and grounded wiper 211 in its twenty-fifth position the circuit for oper ating relays H and J includes contacts 374 of 3 MK instead of contacts 366 of 2MK. When wiper 302 reaches its eighteenth bank contact, which it does after a three minute period, and with grounded wiper 211 in its twentyfifth position relay L is operated over contacts 371 of 3MK, instead of over contacts 363 of 2MK. Relay L locks, restores the ten second register to normal and restores relays H and J as previously described, the short circuit for relays H and I, however, including contacts 372 of 3MK instead of contacts 361 of 2MK. With relays H and .T restored the metering circuits are reestab lished after the three minute period to enable the next cycle operation of the scanning switches to again operate the trunk group meters. This cycle operation again oper-' ates the ten second register 108R to reoperate relays H and I so that only one busy count reading is taken every three minutes. In the same manner as previously described a busy count reading is taken every three minutes until the five minute register SMR engages its twelfth bank contact which it does after one hourof scanning operations. The relay M is then operated to stop further scanning operations as previously described.

Variable total time counts The total time period of the scanning operations can be varied by connecting the terminal clips 354 and 355 to the difierent time period terminals associated with the five minute register SMR or the ten second register R.

If it isdesired to have a continuous meter count for a total time period of two hours then

terminal clips

354 and 355 are connected to the 120 minute time period terminal connected to the twenty-fourth bank contact of the five minute register SMR. Since the five minute register takes one step every five minutes then the wiper 322 will engage its twenty-fourth bank contact after the scanning switches have been operating for one hundred and twenty minutes, or two hours. The relay M, as previously described, will be operated over wiper 322 and its twenty-fourth bank contact to stop the scanning operations. For a total time period of thirty minutes the terminal clips 354 and 355 could be connected to the thirty minute time period terminal.

In case a desired total time count period is not a multiple of five minutes then terminal clip 354 is connected to the desired time period terminal connected to the five minute register SMR and the terminal clip 355 is connected to the desired minute

time period terminal

1, 2, 3 or 4 connected to the bank contacts of the ten second register 108R. For example if a total time count period of twelve minutes is desired then terminal clip 354 is connected to the ten minute terminal accessible to wiper 322 of the five minute register SMR and the terminal clip 355 is connected to the two minute terminal accessible to the wiper 302 of the ten second register 105R. The two minute key ZMK or the three minute key 3MK is operated dependent upon whether a count every two minutes or every three minutes is desired. With this twelve minute total time period the relay M would be operated after ten minutes when wiper 322 engaged its second bank contact and would lock up to grounded conductor 159 over contacts 352. Contacts 351 would not complete the circuit for operating release relay B until the ten second register wiper 302 engages its twelfth bank contact two minutes later or twelve minutes after starting the scanning operations. The circuit for operating release relay B for a total twelve minute time period is as follows: ground contacts 113, conductor 157, wiper 211 and its twenty-fifth bank contact, conductor 240, wiper 302 and its twelfth bank contact, the two minute time terminal 2, terminal clip 355 connected thereto, contacts 351, conductor 167 to release relay B and battery. The operation of relay B stops and restores all apparatus to normal as described. In this connection just described for the total time period of twelve minutes it was assumed that either the two minute key 2MK or the three minute key SMK was operated so that during this time interval the meter count of busy trunks was taken every two or three minutes. However, if a continuous count for a twelve minute period is desired then the

contacts

364 and 363 could be short-circuited, or closed, without closing any other of the key contacts. With contact 364 closed the ten second register is operated every ten seconds from wiper 211, and with contacts 363 closed the relay L is operated to automatically step the ten second register from its twenty-fourth bank contact to its twenty-fifth bank contact, or to its normal position.

Release If the attendant at any time desires to immediately stop the scanning operations and return the apparatus to normal the homing key HK is operated to complete a circuit for operating release relay B when the scanning switch wiper 201 reaches its twenty-fifth bank contact. The circuit for operating release relay B under this condition is as follows: ground contacts 113, conductor 157, wiper 201 and its twenty-fifth bank contact, conductor 155, homing key HK now operated, and winding of release relay B to battery. Relay B restores relay A and stops operation of relays C, D and E to stop the scanning operation of switches T51 and T82. Relay A in restoring at contacts 111 removes ground from conductor 100 to restore relays J and H it operated, at contacts 115 removes ground from conductor 159 to restore relay M it T10 operated; at contacts 112 grounds'conductor 156 to re store the ten second register 108R to normal by connecting ground through the multipled bank contacts engaged by wiper 301, the interrupter springs 303 and stepping magnet M3; at contacts 114 grounds conductor 158 to restore the five minute register SMR by connecting ground through the multipled bank contacts engaged by wiper 321, the interrupter springs 323, and stepping magnet M5; at contacts 116 grounds conductor to restore the five minute timer 5MT by connecting ground through the multipled bank contacts engaged by wipers 311 and 312, the interrupter springs and stepping magnet M4, and at contacts 113 opens the circuit to relay B which restores. All of the apparatus has now been restored to their normal positions as shown in the drawings.

What is claimed is:

1. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for continuously operating said switch in successive cycle operations to scan successive trunks of said group during each cycle operation, a meter, means for operating said meter each time said switch scans a busy trunk of said group to provide continuous meter recordings on said successive cycle operations of said switch, disabling means operable for disabling said meter operating means during certain of said cycle operations of said switch and restorable for reenabling said meter operating means to provide intermittent meter recordings only on predetermined ones of said successive cycle operations, manual means operative for determining the operating and restoring periodicity of said disabling means with respect to said cycle operations, and means controlled by the cycle operations of said switch for operating and restoring said disabling means in accordance with the operated condition of said manual means.

2. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for continuously operating said switch in successive cycle operations to scan successive trunks of said group during each cycle operation, a meter, means for operating said meter each time said switch scans a busy trunk of said group to provide continuous meter recordings on said successive cycle operations of said switch, disabling means operable for disabling said meter operating means during certain of said cycle operations of said switch and restorable for reenabling said meter operating means to provide intermittent meter recordings only on predetermined ones of said successive cycle operations, manual means operative for determining the operating and restoring periodicity of said disabling means with respect to said cycle operations, means controlled by the cycle operations of said switch for operating and restoring said disabling means in accordance with the operated condition of said manual means, stopping means for stopping further cycle operations of said switch, and means controlled by said switch after completing a predetermined number of cycle operations for operating said stopping means.

3. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for continuously operating said switch in successive cycle operations to scan successive trunks of said group during each cycle operation, meter each time said switch scans a busy trunk of said group to provide continuous meter recordings on said successive cycle operations of said switch, disabling means operable for disabling said meter operating means during certain of said cycle operations of said switch and restorable for reenabling said meter operating means to provide intermittent meter recordings only on predetermned ones of said successive cycle operations, manual means opera tive for determining the operating and restoring peri a meter, means for operating said odicity of said disabling means with respect to said cycle operations, means controlled by the cycle operations of said switch for operating and restoring said disabling means in accordance with the operated condition of said manual means, stopping means for stopping further cycle operations of said switch, means controlled by said switch after completing a predetermined number of cycle operations for operating said stopping means, timing means having a plurality of positions, means for operating said timing means from one of its positions to its next position under control of the cycle operations of said switch, stop control means connectable to any of said positions, means controlled by said switch at a time when said timing means reaches a position to which said stop control means is connected for operating said stop control means, and stopping means operated in response to the operation of said stop control means for stopping further cycle operations of said switch.

4. In a telephone system, a scanning switch having a control wiper and a plurality of trunk wipers, bank contacts in said switch accessible to said wipers, a trunk line terminating in each of said bank contacts accessible to said trunk wipers, startingmeans, means responsive to the operation of said starting means for operating all said wipers simultaneously in successive cycle operations to successively engage their bank contacts, each trunk wiper simultaneously engaging a corresponding bank contact to scan the trunk connected thereto for its idle or busy condition, a trunk meter for each trunk wiper, normal connections normally connecting each trunk meter to its corresponding trunk wiper, means for operating each said meter each time its corresponding trunk wiper engages a bank contact terminating a busy trunk to provide continuous meter recording over said normal connections on successive cycle operations of said switch, disabling means for opening said normal connections and for restoring said normal connections to provide intermittent meter recordings over said normal connections only on predetermined ones of said successive cycle operations, means manually operative for determining the operating and restoring periodicity of said disabling means with respect to said cycle operations, and timing means controlled by said control wiper and its bank contacts during the cycle operations of said switch for operating and restoring said disabling means in accordance with the operated condition of said manual means.

5. In a telephone system, a first and a second group of trunks, a first scanning switch having access to said first trunk group, a second scanning switch having access to said second trunk group, starting means, means responsive to the operation of said starting means for simultaneously operating both said switches in successive cycle operations to simultaneously scan successive trunks of both said trunk groups, a first trunk group meter, means for operating said first trunk group meter each time said first switch scans a busy trunk in said first trunk group, a second trunk group meter, means for operating said second trunk group meter each time said second switch scans a busy trunk in said second trunk group, a first timer having a plurality of positions, means controlled by said first switch for operating said first timer from one position to its next position in response to a predetermined number of cycle operations of said first switch, means for automatically stopping further cycle operations of said switches irrespective of the operated condition of said starting means, a circuit for operating said stopping means, a stop control relay and a portion of said circuit being connected to a predetermined one of said first timer positions in case said meter operation is desired on each cycle operation of said switches for a corresponding desired number of cycle operations of said switches, said relay being operated under control of said second switch in response to said first timer reaching said one predetermined position, contacts operated by said relay for completingsaid circuit to operate said stopping means to prevent further cycle operations of said switches, a. second timer having a plurality of positions, manual means operative in case said meter operations are desired during only one cycle operation of each of a predetermined plurality of cycle operations of said switches to enable the operation of said second timer, means controlled by said second switch when said manual means is operated for operating said second timer from one position to its next position in response to each cycle operation of said second switch, disabling means for disabling said meter operations during all said predetermined plurality of cycle operations except said one cycle operation of each of said predetermined plurality, means dependent upon the operated condition of said manual means and controlled by said switches and said second timer for operating and restoring said disabling means during certain ones of said cycle operations so that said meter operating means is efiective during only said desired one cycle operation of each said predetermined plurality of cycle operations of said switches, said stop control relay being connected to said one predetermined position of said first timer to operate said relay in response to said first timer reaching its said one predetermined position, said portion of said circuit being connected to a predetermined one of said second timer positions to prepare said circuit for operating said stopping means over said contacts operated by said relay, and said second timer in response to reaching its said one predetermined position completing said prepared circuit to operate said stopping means.

6. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for operating said scanning switch at a predetermined speed in successive cycle operations to successively scan said trunks, said operating means adjusted to cause each cycle operation of said switch to be completed within a predetermined time period, a timer, means controlled by said scanning switch for operating said timer one step for each predetermined time period in response to each cycle operation of said switch, a time register operated one step each time said timer completes a predetermined plurality of stepping operations, a total time period terminal accessible to said time register, and means connected to said total time period terminal and operated in response to said time register reaching said total time period terminal for automatically stopping and preventing any further scanning operations of said scanning switch irrespective of the operated conditon of said starting means.

7. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for operating said scanning switch at a predetermined speed in successive cycle operations to successively scan said trunks, said operating means adjusted to cause each cycle operation of said switch to be completed within a predetermined time period, a step-by-step timer, means controlled by said scanning switch for operating said timer one step for each said predetermined time period in response to each cycle operation of said scanning switch, a time register operated one step each time said timer completes a predetermined plurality of stepping operations, a plurality of time terminals connected to said time reg-' ister, each time terminal corresponding to a different time interval, means for stopping and preventing any further cycle operations of said scanning switch irrespective of the operated condition of said starting means, means for selectively connecting said stopping means to any desired one of said time terminals, and means for operating said stopping means in response to said time register reaching said time terminal connected to said stopping means to stop the scanning operations within the corresponding time interval.

8. In a telephone system, a scanning switch having bank contacts, a first and a second group of trunks terminatingin said bank contacts, a wiper in said switch, means for operating said wiper to successively engage successive ones of said bank contacts to successively scan the trunks of said trunk groups, a first meter for registering the number of busy trunks in said first trunk group, a second meter for registering the number of busy trunks in said second trunk group, a first circuit normally connecting said first meter to said wiper for operating said first meter each time said wiper engages a bank contact terminating a busy trunk of said first trunk group, a relay, an operating circuit completed for operating said relay after said wiper has scanned said first trunk group to open said first circuit, a second circuit connecting said second meter to said wiper completed by the operation of said relay for operating said second meter each time said wiper engages a bank contact terminating a busy trunk of said second trunk group, and a restoring circuit for restoring said relay completed after said wiper has scanned said second trunk group to open said second circuit and reclose said first circuit.

9. In a telephone system, a scanning switch having bank contacts, a first and a second group of trunks terminating in said bank contacts, a wiper in said switch, means for operating said wiper to successively engage suc cessive ones of said bank contacts to successively scan the trunks of said trunk groups, a first meter, a second meter, a first circuit normally connecting said first meter to said wiper for operating said first meter each time said wiper engages a bank contact terminating a busy trunk of said first trunk group, a first relay, an operating circuit completed for operating said relay after said wiper has scanned said first trunk group to open said first circuit, a second circuit connecting said second meter to said wiper completed by the operation of said first relay for operating said second meter each time said wiper engages a bank contact terminating a busy trunk of said second trunk group, a restoring circuit for restoring said first relay completed after said wiper has scanned said second trunk group to open said second circuit and to reclose said first circuit, a second relay, timing means controlled by said switch for operating said second relay after said first relay is restored, contacts operated by said second relay for opening said first and second circuits to prevent operation of said meters during subsequent scanning operations of said switch, restoring means for restoring said second relay to reclose said contacts to prepare said first and second circuits, said timing means controlled by said switch after a predetermined number of said subsequent scanning operations for causing said restoring means to restore said second relay, and said first relay, said first and second circuits, and said first and second meters rendered effective by the restoration of said second relay to again register the number of busy trunks in said trunk groups on the next following scanning operation of said switch.

10. In a telephone system, a group of trunks, a scanning switch having access to said trunks, starting means, means responsive to the operation of said starting means for operating said scanning switch in successive cycle operations to successively scan said trunks, a meter, means for operating said meter each time a busy trunk of said trunk group is scanned by said switch in its first cycle of operation, means operated after the trunk scanning operation and during said first cycle operation for disabling said meter operating means to prevent meter operations during subsequent scanning cycle operations, means for restoring said disabling means, means controlled by said switch in response to completing a predetermined number of said subsequent scanning cycle operations for causing said restoring means to restore said disabling means, said metering operating means thereby enabled by the restoration of said disabling means to operate said meter each time a busy trunk of said trunk group is scanned by said switch in its next following scanning cycle operation, said disabling means again operated after the trunk scanning operation and during .said next fol lowing scanning'cycle operation, and said restoring meansagain operative after said switch completes another corresponding predetermined number of subsequent cycle operations to again restore said disabling means, a time register having a plurality of positions, means controlled each time by a predetermined plurality of cycle operations of said switch for operating said time register from one position to the next, and stopping means connected to a particular one of said positions and operated in response to said time register reaching said particular one of said positions for automatically stopping and preventing any further cycle operations of said scanning switch.

11. In a telephone system, a first and a second group of trunks, a first scanning switch having access to said first trunk group, a second scanning switch having access to said second trunk group, starting means, means responsive to the operation of said starting means for operating said switches in successive cycle operations to scan successive trunks of both said trunk groups, a first trunk group meter, means for operating said first trunk group meter each time said first switch scans a busy trunk in said first trunk group, a second trunk group meter, means for operating said second trunk group meter each time said second switch scans a busy trunk in said second trunk group, a first timer having a plurality of positions, means controlled by said first switch for operating said first timer from one position to its next position each time said first switch completes a predetermined number of cycle operations, a second timer having a plurality of positions, means controlled by said second switch for operating said second timer each time said second switch completes a cycle operation, main and auxiliary stop control means being connected to predetermined positions of said timers in accordance with the number of cycle operations desired, means for operating said main and auxiliary stop control means jointly under control of only said second switch and said first timer at a time when said first timer is in a predetermined position and then only in case both said main and auxiliary stop control means are connected to said first timer predetermined position, said last means operating said main and auxiliary stop control means jointly under control of said second switch and both saidfirst and second timers at a time when both said timers are simultaneously in predetermined positions and then only in case said main stop control means is connected to said last mentioned first timer predetermined position and said auxiliary stop control means is connected to said last mentioned second timer predetermined position, and means operated in response to the operation of both said main and auxiliary stop control means for stopping further cycle operations of said switches irrespective of the operated condition of said starting means.

12. In a telephone system, a first and a second group of trunks, a first scanning switch having access to said first trunk group, a second scanning switch having access to said second trunk group, starting means, means responsive to the operation of said starting means for operating said switches in successive cycle operations to scan successive trunks of both said trunk groups, a first trunk group meter, means for operating said first trunk group meter each time said first switch scans a busy trunk in said first trunk group, a second trunk group meter, means for operating said second trunk group meter each time said second switch scans a busy trunk in said second trunk group, a first timer, means controlled by said first switch for operating said first timer each time said first switch completes a predetermined number of cycle operations, a second timer, means controlled by said second switch for operating said second timer in response to each cycle operation of said second switch, means for automatically stopping further cycle operations of said switches irrespective of the operated condition of said starting means, and means for operating said stopping means under joint control of only said second switch and said first timer in response to the completion of a predetermined plurality of cycle operations in case only said predetermined plurality of cycle operations is desired and for operating said stopping means under joint control of said second switch, said first timer and said second timer in response to the completion of a different plurality of cycle operations in case said different plurality of cycle operations is desired.

References Cited in the file of this patent UNITED STATES PATENTS Ostline Jan. 22, 1946: