US1681510A - Telephone system - Google Patents

Description

Aug. 21, 1928.

M6 M9 m0 Aug. 21, 1928.

S. B. WILLIAMS TELEPHONE SYSTEM 6 Sheets-Sheet 3 1 Aug. 21, T928.

' 1,681,510 S. B. WILLIAMS TELEPHONE SYSTEM I Filed Oct. 22, 1926 6 shuts-sheet 4 IHI D CID El a Wye/#05 017/721/6/ 15 kl/f/mma Aug. 21, 1928. 1,681,510

S. B. WILLIAMS TELEPHONE SYSTEM Filed Oct. 22, 1926 6 Sheets-Sheet 5 U/776/8 ms.

' ing magnet Referring first to Fig. 1 the line switch is of the coordinate type and is one of a plu-' of group 104, while'each trunk may be reached through any link of the frame. The lines each appear in avertical row such as 108 and 109 andare controlled by the corresponding vertical magnets 128 and 111, to connect the Each line line with the links in the group. Y I I has a line relay 112 and a cut-oifrelay 113; each group of links has a start relay 114 and group relay 115, a busy relay 138 andabusy record relay 140; and each link has an operat- W hen a subscriber such as the subscriber at subestation 106 initiates a call, the removal of the receiver from the switch hook operates line relay 112. The'operation of relay 112 closes an obvious circuit for group start relay 114. Relay114 closes-a circuit from battery, back contact'of relay 122, which is common to the frame, left winding of relay 115, to ground at the left frontcontact ofrelay 114. Relay'115 closes a holding circuit for itself extending from ground at the contact of relay 114 through its right winding over a "chain circuit extending over the front contact of relay 115 and the back'contacts of other group relays in the same frame such as relay 123 to battery through the winding ofrelay 122. Relay 122 operates and opens the energizing circuit of relay 115' as well as the energizing,

circuit for other group relayson the frame and closes a circuit from ground at'its frontcontact 'over the left front contact ofrelay 115 to battery through the winding of relay 124. Relay124 is provided withaplurality. of armatures one for each horizontal group on the frameand in operating now extends a. cir-f cuit from ground on'the outer contact of re' lay 112, over a front contact of relay 124 through thelower winding of relay 125, which is individual to the vertical groupin which I line'106 appears, to battery at theleft back cont-act ofrelay 126'which is'commonto all vertical groups. Relay 125 closes a holding.

circuit for itself from ground at the front contact of relay 112througl'1' the upper wind ing of relay 125 and its front contact over the baokcontact of the other vertical group relays 127, etc to batterythroughthe windingof relay 126 Relay 126 operates opening the energizing circuit for all vertical group relays' of framejlOO, preventingthe operation of anyother vertical group relay until line 106 has been served. It also closes a circuit from 118 and 119 and a holding relay I ground at its front contact over the lower contacts of relay'125 to the winding of ver ticalmagnet 128 and battery and also to the armature of relay 129. If the first outgoing relay 1311t0 the winding of vertical mag- .net 132.:

v Assuming the trunk 133, controlled by magnet 130 is idle,the operation of magnets 128 and 130 will rotate the vertical bars to pro? pare for extension of line 106 to trunk 133.

The operation of magnet 130 closes a circuit from ground through the left winding of relay 134, left back contact of relay 135, front contact of magnet 130 over conductor 136, to

the corresponding district selector where it extendsover back contactof relay 402, back 1 contact of relay403, .to battery through the winding of pulsing relay 404 inthe sender. Relay 404 operates and closes an obvious circuit for relay 405 which in turn closes an ob viouscircuit for relay 403. The'operation of relay 403 connects ground to conductor 136 in place of battery. Relay 134 also operates in circuit as firsttraced and closes a locking circuit for itself from battery through its right winding and right front contact to ground at the front contact of magnet 130. It also closes an obvious circuit for relay 1 35. Relay 135 in operating disconnects conductor 136 from the winding of relay 134 and extends it to the front contact of relay 137. I

Magnet 128'in operating closes an obvious circuitfor relay 137 so that a circuit'is now extended from conductor 136 asabove traced relay'138' to battery. As soon as ground is connected to conductor136from the district.

selector, relay 138 operates,

When relay 114 operated as previously de- .scribed, it closed a circuit from ground over its rlght front contact, left back contact of relay 138 to battery through the winding of lock-'out'relay 139. When relay 137v operated it closeda locking circuit for relay 139. Therefore, the operation of relay 138, opening the energizing circuit 'forrelay. 139, does not cause that relay to release. .Relay 139 provides a lockmg ground for relay'138 :over the left front contact and left winding of. relay 138; The operation of relay 138 closes a circuitfrom battery through the left winding of horizontal magnet 118, inner back I 'contact o'f relay 120.com contactof relay 138, and thence over the energizing circuit for relay 138 to ground on conductor 1'36. "Magnet operates to cause the "engage-mentof the contacts of line 106 and trunk 133with the horizontal conductors of link 102 thus ex- 1 battery through the winding of relay trict selector.

tending line 106 to the district selector. The operation of link 102 extends a circuit from 113 over the sleeve. conductor of link 102 and trunk 133 to ground in the district selector.

Relay 11-3 operates and opens the circuit of.

t The horizontal magnet 118 in operating,

closed a circuit from "round at its front contact, throughthe winding of relay 120to bat tery, butrelay 120 was not able to operate since it was shunted by the energizing circuit of niagnet 118. VVhenthe energizing circuit of magnet 118 is opened by the release of. relay 138, relay 120' operates further opening the energizing circuit of magnet118. However, magnet 118 is held operated in a circuit from batterythrough both windings over the sleeve conductor of link 102 and trunk 133 to ground at the district selector.

If link 102 had been in use with another call at the time the call was initiated at substation106 the operated condition of relay 120 would have extended the horizontal magnet operating circuit oVer its inner right front contact and the inner right back contact of a subsequent relay of the group to the/ winding of the corresponding horizontal magnet to employ that link for the extension. of the connection; I If all of the horizontal links except link 101 had been in use when the call was inilay 121 operated a chain circuit is completed over the left front contacts of all the horizontal relays such as relays 120 and 121 through the winding and left normal contact of relay 140'to conductor141. A second chain circuit would beextended from battery through the middle winding of relay 138 over the inner right front contacts of the horizontal relays and the back contact of relay 140 individual tothe horizontal group 104 to conductor 142 and the Winding of relay 143 to ground; Relay 143 in operating closes a circuit from battery over its front contact, con- The release of magnet ductor 144, upper winding of relay 201 at the overfiowaindicator connector, back contact, of relay 202, to ground; Relay 201v locks in a circuit from battery through its lowerwinding and lower front contact,back contacts of other relays such as relays 290, through winding of relay 202 to conductor 204 which is grounded. in the printer shown diagrammatically in- Fig. 3. Relay 202 operates disconnecting ground from the windings of relays 201, 290, etc., and closing 'a circuit from ground at itsinner right front contact over the inner upper contact ofrelay 201 tothe winding of multi-contact relay 203. The operationof this relay extends conductors 141,144, 145, 146 to the grid wires of the overflow connector 200. Atthe same time, relay 202 closes a circuit from battery over its outer right contact, uppermost-contact of relay 201, back contact of-relay 20'5and'thence, assuming that the first indicator isbusy, over the upper front contact of relay 206, upper back contact of relay 207, upper back contact of relay 212, upper winding of relay 213,to ground at the upper back contact of relay 214. Relay 213 operates and extends a circuit from batter over conductor 209 lower windin and front contact of relay 213 to ground through winding of relay 214. Relay 214 in operatng closes a circuit from ground over its lower front contact, inner upperfront contact of relay 213 to thewinding of multi-contact relay.

211. overflow connector 200 to therecording relays Relay 211 extends the'grid wires of associated with the second overflow indicator.

Relay 214 in operating also closes a circuit a from battery through the'upper winding of o relay 212, to ground at the upper front'contactvof relay 2 14, and in parallel therewith over the middle upper contact of relay 213, winding of relay 205. opening the energizing circuit of relay 213 but-relay 213 isheld, operated as above de-, scribed,

Vith both relays 203 and, 211 operated, the

chain circuit previously traced to conductor 141 is-extended over contacts of relays 203.

Relay 205' operates e and 211- to the winding of relay 215, back con-tact of. relay 216, to grounded conductor 204. Belay 215 in operating closes a locking circuit for itself from. grounded conductor 204 through thewinding of relay 216, right 3 front contact and winding of relay 215, con- 203, conductor 141, to the winding of relay 140. Relay 'l40'is marginal and did not operate in series with relay 215 but now operates and looks over the chain circuit to groundat its left 'frontcontact. It also closes ground over itsj'right front contact and the second chain circuit to the middle Winding of relay lay 215 serves to identify group104 as that on which the overflow condition arose. Relay 143 is individual to the line switch frame 100 and in turn operates relay 201 which is also individual to line switchlOO. The frame is therefore identified by means of relay 219, the circuit for which maybe traced from battery over the contacts of relays 203and 211, conductor 217, left winding of relay'219, to

groundat the contacts ofrelays 211 and 203. The operation of any frame relay-such as relay 203 01'218 connects battery to conductor 21? The grounded contact of each frame relay is connected only with the indicator relay corresponding to the frame to be iden-' tified. Relay 219 locks from battery on 0011- 'ductor 217 through its right winding and right front contact to grounded conductor 204. Relays 215 and 219 light lamps 220 and 221 respectively to give a visual signal of the frame and group number. Relay 215 also connects ground to conductor 222 which completes a circuit for the No. 1 units relay 310 and 320 are simultaneously stepped to among those identifying the horizontal group to the printer '300.- In turn relay'219 connects ground to conductors 223 and 224. Conductor 224 extends to the winding ofthe No; 0' tens relay and conductor 223 extends to the No. 1 units relay among those identifying line switch frames. 1 I a As above indicated, the printer 300-may be of the type disclosed in the'Pfannenstiehl patent and may be controlled in the manner shown in the Potts patent. There. will be a group of relays for each indication desired, that is, a group for the line switch frame number, a group for horizontal group identification, etc. If there are more than 10 units ofany kind to be identified, there will be a series of units relays and a series of tens relays for each indication. Each relay will have contacts to control the code setting of the printer magnets and means Wlll be provided for progressivelyassociating the 'relays of each group with the printerand for advancing the control from group to group. Only those groups in which relays ha-ve'been operated will be effective. When the complete indication has been printed, ground will be removed from conductor 204 and all of the'relays of the overfioWindica tor andconnector will be released.

In addition toindica-ting the group of ap and for that purpose the timing arrangement shown in Fig. has been provided. 1 This timing arrangement is under the control of a master clock 350 having a contact 351 Wll'iCll closes at G-se'cond intervals. vWhen this contact is closed, an obviouscircuit is completed through the left winding of relay 352 and that relay operates. Relay352 closes aholding circuit for itself from battery through the right winding of relay 352, back contact of magnet 311 to ground at the front'ocontact of relay-352. This ground also completes'a circuit through the winding of magnet 311. This magnet operates opening the holding circuit of relay 352 and permitting that relay to release, in turn releasing magnet 311 and steppingswitch 310 to its first terminal. At

the end of 6 seconds the circuit ofrelay 352 is again closed and switch 310 stepped to its hen contact 352 closes, o

second terminal. stepping switch 310 from its tenthterminal wl'iich'will occur at the end of 60'seconds, the

- operation of relay 352 closes a circuit from I ground over its front contact, brush 324 of magnets 311 and 321 to step their-brushes simultaneously to the next terminals. 7 hen swrtch310 reaches its twentleth terminal, a

circuit is again closed over brush 324 and its" second terminal, twentieth terminal of brush 313 towindingof magnet 321, and switches their twenty-first and third terminals respectively. .An obvious self -1nterruptingcircuit is now closed for magnet 311 to bringswitch 310back to terminal 1.

Vhenrelay 352 is operated to step switch321 toits tenth terininaha circuit is closed from ground over I the front contact of relay 352, brush 334 of the second terminal of brush 334 andthe When relay 352 releases, magnet 331,

twentieth terminal of brush 323. Switch 320 c is then returned to its first terminal by a selfinterrup'ting circuit for magnet 321. When the circuit is closed forstepping switch 331 to its sixth terminal, a circuit is'closed from battery through the winding of magnet 341. Yof switch 340, brush 333'and its sixth terminal, brush 344 and its first terminal to ground at the front. contact of relay E352. .lVhen switch 331 is steppedto its'twelfth terminal, the circuit of magnet 341 extends overthe twelfth terminal of brush 333 and the sec- 1 on d terminal of brush 344. i From a considera- 'tion of the above descript on and the drawing it will be apparent that switch 310 makes one;

step every six seconds, switch 320 makes one step per minute, switch-33O every ten minutes,

and switch 340 every hour. These switches are; simple step-by-step sw'itches havmg 24 terminals. Switch 320 in each position prepares a Circuit for one ofnrelays such as relays 326, 327 etc, which correspond to the units digit of the minute. Switch 330 pl'epares a circuit for one-of the relays 336, 337 etc.,-;corresponding to the tens digit of the minute. Switch 340prepares a circuit for relays 346, 34'? etc.,corresponding to the'hour.- It likewise prepares a circuit from ground through brush 348 to relayl348 or relay 349 depend ing upon whether the hour-is a morning hour oran afternoon hour, a

When the overflowindicator' connector 200 operates, connecting battery to conductorz2l7, the circuits prepared by the timing mechanism at that moment are completedandthe corresponding relays operate to light lamps giving a visual indicationof the timeandto' operate. relays in the printer control mechanism to print the hour, minute and whether before or after noon. r a

If instead of the horizontal links being busy all the trunks outgoing to the district sclectorhad been busy, relays 129, 131,:etc., corresponding to the trunks would have been operated as above-described and a chain circuit closed from ground over the left from contact ofrelay 129, left front contact of relay 131 andother trunk relays to the winding of relay 147- and battery. Relay 147 connects battery over its outer front contact and the back contact of relay 148 to conductor 149 and thus to conductor 144 operating relay 201 in the same manner as did relay 143. The operation of relay 201 causes the connection of the conductors 141 144,145 and 146 to the overflow indicator in the same manneras be fore. Relay 147 also closes a circuit from battery over its inner'front contact, winding and normal contactof relay148, to conductor 146. W'ith relays 203 and 211 operated, this circuit will be extended over the contacts of these relays to the left windingofall trunks busytrelay 225 and ground. Relay 225 looks in a circuit frombattery on conductor 2.17, through its right Winding and rightfront Contact to ground on conductor 204. The operation of relay 225 lights all-trunks-busy lamp 226 and grounds conductor 227 to operate the all-trunks-busy relay in theprinter control circuit. As before, relay 201 operates.

- groups, a threeway test is performed to selectthe path to be used in completing thecon'nec-t r indicator relay 219 to identify the frame.

Referring now to Figs-4, 5 and 6, a skeletonized showing has been madeof an incom ing selector and a final selector together with a part of the control apparatus. Reference is made to the above identified patent of;

W. W. Carpenter for a complete showing and description of the means for extending a con nection from adistrictfselector to a called subscribersline. Briefly, whena connection is extended to an lncomlng selector such as 401, the tip and ring conductors areextended to a sender selector switch such as 406 and a sender 407. Here a registration is made of subscribers line appears. 1 g

It 18 then necessary to find a connecting unit including a horizontal link in both the incoming selector and the final selector anda trunk connecting these linksall of which are idle beforeithe connection can be established. The horizontal operating magnets of the incoming selector are associated with the marker by means of incoming selector frame connector 409; The multicontact relays 410 and 411 of connector. 409 are individual to the marker taken for use, while the relays 412 and 413 are individual to the incoming frame and one of them is operated by means of a circuit extending'through the marker and controlled byan identifying potential on the incoming frameitself. i

The trunks extending between the incoming selector and the final selector are connected with the marker for test by means of trunk connector 414,and a trunk group connecting a particular incoming selectorwith a particular final selector appearsin the contacts of a particular relaysuch as relay 415 in the trunk connector. The identity of this relay is determined by the joint action of the incoming frame connector 409 andthe trans lator connector 602. l p I The horizontal operating magnets for the horizontal group, in which the, called sub scribers line is located on the final selector, are connected with the marker by means of final frame connecto'rjI603. "The frame connector serves to extend the circuits of all horizontal magnets and discrimination between a the groups is brought about byimulti-contact relays 604, 605, etc, which form a part of the translator. l s

In order to extend a connectionitheremust be an idle path comprising anincoming link. a trunk and 'a'final'link. Since each trunk has accessto only one link in each of the incoming selector groups and finalv selector through the winding of the operatingmagnets, through the final frame connector 603' and the translator-relays 604 .or 605 depending onthe group, throughthe translator connector 602, to battery through the windings of another set of relays. In addition, circuits are closed from the sleeve conductors of the trunks, through the trunk connector to battery through the windings of a third set of relays. A busy linkor trunk is characterized by ground'at its sleeve wire or conductor and and therefore each final link test .relay is arranged to operate three trunk test relays. Therefore it is possible'that there may be no idle connecting path between the incoming selector and particular final selector although there may be idle links in either selector and idle trunks provided that these do not have access to one another. If this is the case, all. i of the trunk test relays 416,417, 418 and 119,

etc., will be operated anda chain circuit will be closed from ground over the front con tacts of these relays through the winding of relay 4:20 to battery. 0

Relay 4120 in operating closes, a circuit from battery at its inner right front contact to con ductor 423, upper winding of relay 506 of the final frame overflow connector, to ground at the back contact of relay 507. Relay 5060perates and locks in a circuit from battery on conductor 423, lower winding'and front contact of relay .506, thence over the back contacts ofrelays'such as relays 508 corresponding to other final frames throughthe winding of relay 507 to grounded conductor204c. The operation of relay 507.closes a circuit from ground at its inner front contact, inner upper front contact of relay 506, conductor 509, front; contactof relay-4e20, marker connector 4.08 to the sender to-indicate to the sender that it has been impossible to complete the connection and to cause the sender to signal thecalling subscriber and to release the apparatus. cuitfrom battery over'its outer front contact, upper front contact of relay 506, winding of multi-contact relay 510, conductor .609 to ground at the outer left front contact of relays 607, 608 or other relays eorrespondingto J the group in which the called subscribers line was located. Relay 510 operates and extends the indicating conductors to the grid Wires of the incoming connector 500. A circuit is also closed in parallelwith relay 510 extending over the back contact of relay 511, upper front contact of relay 512, assuming thatthe corresponding indicator is busy, up'-' per back contact of relay 513, upper back contact of relay 514, upper winding of relay 515,

upper back contact of relay .516 to ground. to conductors 421 or 422 etc.,faccording to Relay 507 .also closes a cir- The operationof relays 515,516, 514, and 511 is thesame as described in connection with the line finder overflow indicator connector and results in the'operation of multi-contact relay 517, to extend the grid conductors through to the indicator relays.

. Although it is possible to record all'the frames, groups, etc.,over which arconnection was attempted, in practice all of the incoming links couldlnot-be busy since there are more links than there areincoming trunks of the incoming circuit. Each group of trunks outgoing from an incomin selector terminates on a-particular final selector and therefore may usually be identified by the final frame. /Vhere it is necessary to employ more than one group of trunks for aparticular group of final lines, more than one incoming frame will be used and a group of trunks from each frame willbei terminated on the final frame having access to the particular group of subscribers. It is therefore-desirable to know the number of the final frame and the horizontal group of that frame where the overflow occurred together with :the number of the trunk group, provided'more than one group 'of trunksis used. To this end a circuit is provided from ground at the right front contact of relay420 through the translator connector to conductor 606. Conductor 606 extends to a part of the translator and likewise to incoming frame connector 409. The

tal group and relay'608'to contactsof relay 7 605 which: likewise identifies a particular horizontaligroup. Relays607 and 608 connect battery to conductors 610 and'611 respecti-vely, which completes circuits extend ing throughindicator connector 500 to the left winding of relays such as 518, i519 and 520, back contactof relay 521 to grounded conductor 204. These relays identify the horizontal-group on whichthe overflow oc- Since relays 607 and 608 are both individual tothefsame final selector and the opera-' tion' of either one causes the operation of relay-510, the circuit completed from ground over the contacts of relays 510 and 517 through the-left winding of relay v522 to batteryover contacts of relays 517 and 510 serves to identify the final frame on which the group is located. Another final frame would cause the operation ofrelay 523 which would in turn cause the-operation of relay 524'to indicate the identity of that other final frame. In order to identify thegroup of trunks among a plurality of. groups of trunks having access to a'given final selector, a circuit is likewiseextended from grounded conductor 606-through the incoming frame connector which frame has been employed. Connectnects battery to conductor 217 to complete the circuit of the time indicator relays.

At the right of the rectangle representing theprinter are shown three typical records. The first record shows that no connecting paths were available to reach a subscribers line appearing in group on final frame 22, overthe trunks of sub-group 2, at 12:51 p. m. The v.secondrecord shows that all the trunks outgoing from line switch frame 21 were busy at 12 :52 p. in. The third record shows that all-the links of group on line switch frame 21 were busy at 12:51 p. m.

It will be apparent from the foregoing description that by means of the apparatus of the present disclosure, a printed record may be obtained of every occurrence of a failure to complete a connection because all of the apparatus available was busy, whereby it is possible to study traffic conditions and to determine remedies at-leisure. 7

What is claimed is:

1. In a telephone system, a plurality of connective elements divided into groups, means to operate said elements, means common to said groups of elements for recording the simultaneous operation of all elements of a group, and means for selectively associating the recording means with said groups.

2. In a telephone exchange system, a plu- I rality of connective elements divided into groups, means for operating said connective (elements, a printer for printing a' record identifying said groups and means effective in response to the simultaneous busy condition of the elements of any group to associate the printer with that group.

3. In a telephone exchange system, a plurality of connective elements divided into groups and sub-groups, means for operating said connective elements, a printer device common to said connective elements, and means to operate said printer to record the simultaneous operation of all of the elements of a sub-group in any group and to control said printer to record the identity of said group and sub-group.

4. In a telephone exchange system,a plurality of connective elements divided into groups and sub-groups, means to operate said elements, means common to said groups 01": connective elements for recording the failure to establish aconnection by meansof anysubgroup in any group of elements because of the operated condition of all the elements of said sub-group, means to identify said group and sub-group, and means to record the time at which the failure occurs.

5. Inatelephone exchange system, a plurality of connective elements having different functions, said elements being divided into groups and sub-groups, means for operating said connective elements, a printing mechanism common to said connective elements, and

means to operate saidmechanism to record the simultaneous operation of the elements of any sub-group in any group and to cause said printer to record the function, group and subgroup of said connective elements.

6. In a telephone exchange system, a plurality of connective elements divided into groups, means-for operating said connective elements, a printer device common. to said connective elements, means to operate said device to'record the simultaneous operation of all the elements of any group andto control said-"printer to record the identity of the group, a timing device, and means controlled by said timing device to cause said printer to recordthe time of day at which saidsimultaneous operation occurred.

7 In a telephone exchangesystem, a plurality of connective elements having different functions, said elements being divided into groups and sub-groups, means for operating said connective elements, a printing mechanism common to said connective elements, means to operate said mechanism to record the simultaneous operation of the ele-' ments of any sub-group in any group and to cause said printer to record the function, group and sub-group of said connective elements, a timing device, and means controlled by said timing device to cause said printer to record the time at which said simultaneous operation occurred.

8. In a telephone exchange system, a plurality of line switches, each comprising a ,plurality of groups of switching elements, means for operating each switching element, a printing mechanism, means responsive to the simultaneous operation of all of said switching elements in any group to associate said printer with the line switch in which said group is located, and means to operate said printer to'record the identity of said switch and said group.-

9. In a telephone exchange system, line switches, final selectors, each comprising a plurality of groups of switching elements, a timing device, a printer mechanism common to said line switches and said final selectors, means responsive to the simultaneous operation of all ofthe switching elements of a group in either said line switches or said final selectors to cause the association of said printer with the line switch or final selector upon which said group appears, means-to cause said printer to identify said group and to make a printed record thereof, and means controlled by said timing device to cause said printer to record the time.

10. In a telephone exchange system, a plurality of connective elements divided into groups and subgroups, means to .7 operate said elements, means common to said groups of elements to record the simultaneous operation of the elements of any sub-group of any group and to recordthe identity of said group and sub-group, and means responsive to the operation of said recording means to prevent duplicate recording of any one simultaneous operation. p

11. In a telephone exchange system, a plurality of connective elements divided into groups and sub-groups, means to operatesaid elements,a recording device common to said groups of connective elements, means individual to each sub-group in each groupresponsive to the simultaneous operation of all elements in said sub-group to initiate the operation of said recording means toflrecord 12. In a telephone exchange system, a plu-c rality of connective-elements divided into groups and sub-groups, means to operate said connective elements, a chain circuit closed by said, operating means when all of said elements are simultaneously operated, a printing device common to said elements, means individual to each sub-group controlled by said chain circuits'to initiate the/operation or said printer and to control s'a1d Iprmter to record the identity of the group and subgroup,-and means responsive to the operation of said recording means to prevent the reoperation of said indivldual meanscas long as said, cha1n circultsare maintained.

In witness whereof, I hereunto subscribe my name this 18th day of October, A. D. 1926. i 1 i i SAMUEL B. WILLIAMS.

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