вход по аккаунту


Патент USA US2137431

код для вставки
Nov. 22, 1938.
a. D. wxLLls
Filed Oct. ’7, 1935
5 Sheets-Sheet l
Nov. 22, 1938.
B. D. wlLLls
Filed oct. 7. 1935
s sheets-sheet 2
WL _.
NOV. 22, 1938.
B, D, w|L|_|S
Filed oet. 7, 1935
l3 sheets-sheet 5
1 U.)
ä S9;
0n S`
Patented Nov. 22, 193s
Bernard D. Willis, Oak Park, Ill., assigner, `by
mesne assignments, to Associated Electric Lab
oratories, Inc., Chicago, ‘I-ll., a corporation kof
Application October 7, 1,9135, Serial No. 43,903
17 Claims. (Gl. 179-18)
'I‘he Apresent invention relates in general to route, shown in Fig. 3, these switches vcomprise
automatic telephone systems, and more especially trunk iinders such as F', arranged in several
>to systems of lthe type which employ separate groups, ñrst selectors such as SI and second
setting and speaking routes, commonly known as _selectors such as S2. The selectors may be of
`5 by-pass systems. The object of the invention is the Strowger type, preferably, The trunk find- V5
to provide Aa new and improved system of this
character `which is better adapted to present
commercial requirements than those heretofore
r1.0 'The invention will be described hereinafter
erS. such as F’ may be rotary Single mOiiOrl iirld
ers, and if each ñnder has ecèess to ñftyirunks,
Áas is usual in the case of rotary finders, there
would be four groups required to take care of
two-hundred «trunk circuits TC.
with reference to the accompanying drawings,
Acomprising’Figs. 1, 2, and 3, which show by means
of the usual circuit diagrams suiiicient of the
equipment involved to enable the invention to
,lâ lbefexplained and understood.
Referring to the drawings, Fig. l shows at the
'rhe equipmentinvoived having been described,
‘the Operation Oi the system will be explained.
F01“ this pllrDQSe vit Will be assumed that the Sub
§criber ,et Steiifirl A desires t0 Set 11p e Connec
`tion to the Aline .of station B. Upon the removal :l5
10i the receiver at statiOn A a bridge iS ClOSed
left a subscriber’s station A, having a line ex-
eCrOSS lirle C_OildlleßOrS 2 .and 3 and the lirle relay
tending‘to the exchange and there equipped with 1.4 is energized. On energizetion. the line relay
`the usual line and cut-off relays.
The Aline of station A may be one of a group
of two-hundred lines which are accessible to a
groupof connectors and also to a group of iind-
connects'the cut-off relay 5 to multiple test con
lìdCÈS ‘Sllßll‘ es 3 in the finder banks and grOllrldS ‘.29
ille Start »Wireglì Through the medium of the
«diStriblltOr D er1 idle `iirider' iS 110W Started 11D iIl
ers, preferably ofthe Strowger type. Fig. l in-
¿Search 0f lille Calling line. Assuming the ñnder
dicates one iinder of the group, denoted by the
cs reference character F, and also a distributor D
which is common to the group. The ñnder and
distributor may have any well known circuit
arrangement and hence the detailed circuits are
not shown. The Saunders Patent No. 1,851,132,
¿30 granted March 29, 1932, shows a finder system
that maybe used.
Associated with the länder F is a, trunk circuit
F iS used, the Swifßeh .iS ñrSi Operated Virl its verti
>`@al motion under control of vertical test Wiper »2,5
itl, ‘end “Ellen irl its rOtery motion under the 60n
brel OfïitS files-.È Wiper ll, end iS SÈODPed When the
letter Wiper reaches test Contact 8 of the calling
line. At this point the ñrlder ’Cesi relay erler
gizes in series with the cut-0H relay 5, the latter 3.0
relay energizing also. On energizing, relay 5
locks itself to the test lead coming from the ñnd- ‘_
TCÍ which comprises the relays shown and a
step-b_y-step sender SD.
TheA trunk circuit TC is accessible to a number
er and also connects this test lead to the test
lead 6 extending to the connector banks, where
the calling line is made busy. Relay 5 also dis- ¿35
of so-called confluence switches such as CS,
connects the line relay 4, permitting it to deener- "
which are also preferably of the Strowger type.
The switch CS has access 'to two hundred trunk
circuits _such as TC. Assuming that sixteen trunk
4_0 circuits, or finders such as F, are required for
each group of subscribers’ lines, the arrangement
shown comprising a single group of conñuence
»switchesgives a capacity of twelve groups of
subscribers’ lines, _or 2400 lines, with eight trunks
A5 remaining which can be allotted to additional
_ñnders in busy groups if required.
Fig. 2 shows a connector switch C, having ac-
`cess rto two-hundred subscribers’ lines one of
The calling line conductors 2 and 3 are thus
extended through by way of bank contacts ‘l
and 9, and finder wipers lll and l2, to the line ¿4_0
relay l5 irl ille lil’lli'lk Circuit TC, Where the Said
relay I6 iS eCCOrdingly energized. Orl energiZiIlg,
line relay it grounds the conductor 25 at 21 to
provide a ‘holding circuit for the finder F and cut
Off relay 5, Connects the Clit-Off relay l1 130 the ¿155
test lead 33 at 2%, and at 29 grounds the finder
start lead 30. ‘
As a result of the grounding of the start lead
which is the line of station B. The connector
so c may be directly paired with the connuence
3G, the start relay IUI irl the trunk finder F'
pulls up. prepares the test circuit et |09, Closes e0
“ 4 switches CS, as 'shown in vthe drawings.
a circuit for the lower polarizing winding of test ` '
are, of course, as many groups of connectors as
relay |02 at the same point, and closes a circuit
there are groups of subscribers’ lines, and each
connector `has an associated conñuence switch.
for stepping Vmagnet H14 at IIU. On energizing,
the stepping magnet I 04 closes a circuit for
Considering Í,now the switches in the setting
stepping relay |03, which energizes and breaks 45,5
the circuit of magnet |04, the latter falling back
and advancing the ñnder wipers |05-|08 one
step. This interaction of magnet |04 and relay
|03 continues, and the ñnder Wipers are ad
vanced step by step, until the test Wiper |01 en
Y gages the test contact | |1, where it finds a bat
tery potential on conductor 33. As a result the
stepping relay |03 is held energized, and relays
| 02 and |1 are energized in series over a test
10 circuit which extends from ground at |09 by way
of |02, |03, |01, ||1, 33, contacts controlled byY
39, 28, and |1 to battery.
Considering ñrst the effect of energizing re
lay I1, this relay locks itself at 36, closes the
15 finder holding circuit at 35, opens the start cir
cuit at 31, and at its outer. contacts disconnects
the line relay |6, which falls back. By this time,
however, the lead 33 has direct ground on it, as
will subsequently appear, and the finder holding
20 circuit is maintained over 33, contacts controlled
by 39, 35, and 25.
At the finder F', the holding up of relay |03
prevents the possibility of reclosing the circuit
of magnet |04 and insures a positive stopping
25 of the finder. Test relay |02, on energizing,
breaks the circuit of magnet |04 at I |5, transfers
the finder start circuit at ||6, and closes its con
tacts ||3 and ||4. The effect of closing these
two contacts is to short circuit the upper wind
30 ings of relays |02 and |03 and to connect the
test lead 33 to test lead |23. Since the upper
windings ofrelays |02 and |03 are short-circuited
the test lead 33 will be grounded at |09 until
operates in buzzer fashion to rotate the wipers
|3l-|34 in search of an idle trunk line. When
an idle trunk line is reached, assumed in this
case to be the trunk line extending to the second
selector S2, the test wiper |34 will ñnd a battery
potential on test Contact |38 and the electro
polarized test relay |21 will energize in series
with the changeover relay |52 of the second se
lector. On energizing, relay |21 breaks the cir
cuit of the rotary magnet to stop the rotary 10
movement. Relay |21 also extends the holding
circuit forward by connecting conductor |23 to
the test wiper |34. This short circuits the upper
winding of relay |21 but the relay holds up by
means of its lower polarizing winding. In addi
tion, relay |21 extends conductor |20 forward
to wiper |33, and closes a bridge across wipers
| 3| and |32.
Upon the seizure of the second selector S2, as
described in the foregoing, the relay |52 energizes 20
as previously mentioned; The line relay |50
energizes also, due to the bridge across wipers
|3| and |32 at the i‘lrst selector SI. The line
relay closes acircuit for the slow-acting relay I5 I.
This is the usual release relay, but in the pres 25
ent case it does not ground the holding circuit
because ground is fed forward from the first
selector Sl.
The calling subscriber may now dial the second
digitV of the called number, causing a second series 30
of -deenergizations of the line relay |24. Each
time the line relay falls back it breaks the bridge
across wipers |3| and |32 at contact |39, and
the slow-acting start relay |0| falls back. Relay
thus the digit is repeated on to the second se
|02 ris held energized over its lower or polarizing
winding, which is able to maintain the relay after
lector S2 by producing a series of interruptions
in the circuit of line relay |50. Under control
of line relay |50 the selector S2 is operated and
the wipers IGI-|64 are first stepped up verti
it is once operated. Relay |03 falls back.
The test relay |02 also extends the line con
ductors 3| and 32 by way of wipers |05 and |06
and contacts ||| and ||2 to the windings of
the line relay |24 of the first selector SI. The
line relay accordingly energizes and closes a cir
cuit for the slow-acting release relay |25, which
cally and are then rotated in search of a trunk
line leading to an idle connector. Assuming that
‘the connector C, Fig. 2, is the first connector
found idle, when test wiper |64 reaches test con
tact |68 it finds a battery potential and the test
energizes in turn and places ground on the test Vrelay |53 energizes in series with relay 201 of
45 lead |23, thereby completing a holding circuit the connector C. On energizing, relay |53 opens
including conductors |23, 33 and 25. The release
relay grounds this circuit before relay |0| has
had time to fall back.
Due to ground on the conductor |23 the Slow
50 acting changeover relayv |26 also energizes at
this time, .and connects the dial tone circuit to
< the lower winding of line relay |24 in place of
direct ground. Upon hearing the tone` in his
receiver the calling subscriber knows that he can
55 proceed to dial the number of the desired line.
The general operation of selectors such as SI
and S2 is well known and hence may be ex
plained rather briefly. Responsive to the dialling
the rotary magnet circuit, extends the holding
circuit forward by connecting it to test wiper |64,
and locks itself to the holding circuit. Relay |53
also disconnects the line relay |50 and extends
the repeating loop forward to wipers |6| and |62.
Upon the seizure of the connector C, therefore,
the line relay 20| energizes, as well as relay 201,
its lower winding getting its ground connection
from the now grounded holding conductor 2|6,
and closes a circuit for the release relay 202. On
energizing, relay 202 prepares the vertical magnet
circuit at 225 and at 222 it connects another
ground to the holding conductor 2|6.
of the first digit the line relay |24 is deenergized
The calling subscriber may now dial the third
a number of times and sends a series of impulses
to the vertical magnet |28. . The magnet |29
digit of the number, which is repeated by the 60
line relay |24 of the selector S| to the line relay
20| of connector C. Line relay 20| accordingly
responds to theseimpulses and steps up the shaft
carrying wipers |3|--|34 until they stand oppo
site the level corresponding to the digit dialled.
65 At the first vertical step the off-normal contacts
deenergizes a plurality of times and sends a series
of impulses to the Vertical magnet 2|| over a
circuit extending from ground at 22| by way of
ON are shifted, one result being to open the
225, 216, 241, 239, and winding of 2|| to battery.
initial energizing circuit of relay |26, but this
relay is maintained during the vertical operation
by its lower winding, which is in parallel with
70 the vertical magnet |28.
At the end of the first digit the line relay |24
comes to rest in energized position and relay
The vertical magnet 2|| responds to the series of
impulses and steps up the shaft carrying the set
of wipers 282,-284 and the set of wipers 28E-_281.
|26 falls back, closing a circuit for rotary mag
net |29. The rotary magnet |29 therefore ener
gizes, and since it interrupts its own circuit, it
The connector C has a capacity of 200 lines and
has two sets of wipers. The slow-acting relay
205'is energized in parallel with the vertical mag
net 2|| and remains operated during the series
of impulses. Upon the first vertical step of the
switch the'oiî-normal springs are shifted, and
the initialenergizing »circuit of relay-f2 01, is broken.
The relay is held up, however-,overa circuit ex
tending from groundzby way .of v224, `123|, 232, l230,
»now vsends a seriesof impulses to fthe rotary mag
way, however, suñicient to close contact 215. Re
sistance 299 is high enough to prevent the ener
gization of relay 208 and to prevent the full opera
tion of relay 1203. At the end of the final digit
relay 205 .falls back, the resistance 289 in the
test circuit is cut out, and a branch circuit 25| is
substituted `for the resistance. This lowers the
.resistance ofthe test circuit suñicient to operate 10
`relays 208 and 203. The former relay is slow to
operate, however, and relay 203 operates and locks
itself ,at .2.14, breaking the >test circuit at the same
net 2|,2 .over the circuit-groundat 22|., 225,121.6,
time, before relay 208 can get started.
.241, 239, 26.2, 21 I, and 21.2 to battery. The rotary
magnet responds `and ,rotates the rtwo wiper .sets
gized position, relay 203 opens the impulse circuit
.and Winding .of 201 .to battery.
At the end-.oi >the verticaloperation, theslow
.acting relay '205 deenergizes, followed by thede
energization of relay 201. The‘latter relay trans
fers the .impulse circuit `.from vertical magnet -.2:|.|
to rotary magnet 2|2 vat 23.9.
be a ground potential .on test contact 29| and
. The calling vsubscriber may vnowdial .the fourth
digit of the called number, _and the digit .is re
peated as before to the 4line relay 20 I.. This relay
of the connector in on ,the .bank Vlevels .selected
by the vertical movement, the upper set of wipers
282---284` engaging the `contacts 29.0-292 of the
line of station B. Relay v205 energizes in Vparallel
with the rotary magnet, .and `closes a circuit for
relay '1203 will be energized, operating only part
In ener
at 2:16, andccnnects a source of busy signalling
current tothe talking conductor 2I5 at 213. As
will appear .subsequently the calling line has
4already or shortly will be extended through to the
4connector C. Inieither case he will hear the busy 20
signal and will understand that the called line is
relay 2|0, >said circuit lextending from .ground at. engaged.
Assuming now that the called line is idle, when
224 by .way of 26|, 232,238, resistance .288, .and
upper winding of 2|;0 to battery. Relay 2|,0 is .the test vcircuit is .established .as described in the
25 a two-step relay and only‘closes its .contacts 210
and 211 when energized over the above circuit.
At the end of the .rotary movement relay ..205 falls
back and closes acircuit for fully operating relay
2|0, the circuit extending from ground .at v221| by
way of 261|, contacts controlled by 232, `210, and
upper winding `of relay 2| 0 to battery. Relay
2|0 now operates fully, .locks itself at _265, Aand
at 211| `shiits the impulse circuit Vfrom the rotary
magnet 2I2 to the relay .209. ¿It will be Ynoted
also that relay 2z|0 disconnects the wiper >set
`202--284 and connects up wiper set 285-281.
The calling subscriber >may now dial Ythe ñnal
digit of the called number. The ñnal digit is
either thedigit one or vthe digit two, which re
spectively select the wiper sets 285----281 and
282-234. In .the present case the called line is
reached by way yoi? Wiperset 218.2-284 Vand >hence
the final digit is two. vWhen the line relay 20|
responds, the first impulse :is transmitted to ithe
-15 lower winding of relay 209, the impulse circuit
having been transferred from lthe rotary `magnet
by relay 240. Relay .209 is also a two-step relay
and only closes its contact ¿260 responsive to the
impulse. When the impulse is over, the :relay
A20.0 operates .all the way, due to energization `of
foregoing, the test relay 203 will not be energized, ._
due to absence of ground potential at test
contact 219|. When relay 205 falls back therefore
a circuit will »be closed which extends :from ground
at 223 by way of 2.1.5, 25|, upper winding of 208,
249, 254, 283, 29|, and winding of cut-,oiï relay 293 "30
to battery. Relays 208 and '293 energize inseries
over the above circuitand the latter relay discon
nects the :line >relay 291i. Relay :20.8 energizes over
4the series circuit sufficient to close its contact 245,
and then operates all the way due .to energization
of its lower winding. In `energized position relay
208 breaks the impulse circuit .at A221 .and grounds
the test wiper .283 at 2M. Relay 20S also closes
the ringing circuit at 24.! and 228, andat 242 con
nects a source of ring-back tone to the talking ,
Leaving `the connectorC in this condition, 4with
.the kbell at station B ringing, attention maybe
>directed tothe operation of the confluence switch
CS, which begins at the moment the `connector C .Ä i
is stepped oiï normal responsive to the third digit
dialled. When the oñî normal springs are shifted
on the `iirst vertical step of 'the connectora V.con
nectionisestablished between conductors I§I1I and
'219, com-pletinga circuit for relay I9 .of the .trunk
circuit "I‘C, which extends from `the grounded
both windings in seri-es, and `at 262 transfers the
impulse circuit to the `lowerwinding of `relay ¿21.0. . holding circuit including conductor 33 `.by way of
The second impulse now cornes in and .causes the
3_8, Winding of I9, 34, |03, |20, |33, |31, |63, |101,
deenergization of relay 2|0, due to vthe‘fact that
the two windings of the relay oppose each other.
Contacts 210 and ‘212 break at substantially the
`|"liI, off-normal contact, 2I.9, side-switch SS in
same time. With relay 2 I0 deenergized the wiper
set 282-284 is again connected. `It will be evi
`dent that if the last `digit had been one instead
of two, relay 2| Uwould have remained energized,
and wiper set ‘2357281 would have `remained
Relay 209, which‘is 'always-energized on the last
digit, disconnects ground from contact group
232 at 26|, and closes >a point `in the test circuit
at 249. Relay i205 isenergized during the dialling
of the last digitgand asjsoonas relay 209 operates,
thetestcircuit `iscompleted iirst to test wiper 286
and Athen to test wiper ’283, vthe latter test wiper
being substituted for lthe former by the falling
back ofrelay .2.I0 on-«the second impulse. The
test circuit may be traced from test wiper 283by
way'of 261|, 249,‘upperzwindingof‘relay `208, 23|,
resistance `209, and >winding of test relay 203 to
battery. .If äthe :line of .station Bis busy .therewill
-ñrst position, and winding of Vertical .magnet :60 „
to battery. Relay vI9 is energized over the above
circuit, ‘magnet 60 being unaffected due to the
relatively high resistance of relay I9. On ener
gizing, `relay .I9 locks itself Aat 4I and cuts `oit -its
original energizing circuit, which is connected to 60
contact spring 23 of the sender SD `at 42. Relay
:I9 also closes a circuit for the stepping magnet
20 ofithe sender at .40.
The stepping magnet 20 interrupts .its own-cir
cuit and accordingly begins to operate in the 65
manner of a buzzer to rotate the shaft carrying
the cams :2| and `22. On the first step cam 2|
shifts the spring .46, thereby lsubstituting ,a .local
ground connection for the circuit through-contact
_4.0 of relay I9. This operation insures that `the
sender magnet "20 will drive ¿the cams through a
complete revolutionand return `them to normal;
even if the calling subscriber should hang up.
Asrthe cam 22 rotates, thespring‘Zê-l ñrst en
counters ¿the :projections M, `which Lforce spring
23 twice into engagement with ground spring 44
and thus send two impulses to the vertical magnet
Iil!) of switch CS over the circuit: ground, 44, 23,
42, 34, |08, |20, |33, |31, |61, I1I, 2|9, SS, and
winding of 60 to battery. The vertical magnet
60 responds to these impulses and raises the shaft
carrying the two wiper sets 53-55 and 83-85
two steps.
Cam 22 continues its rotation and eventually
the 'spring 23 drops into the notch 48, which
causes it to momentarily engage spring 45.
_operation connects a source of alternating cur
rent A. C. to the impulse circuit and thus trans
mits an impulse of alternating current.
'I‘he cur
rent is of high enough frequency and the circuit
includes sufñcient resistance so that magnet 09,
is not affected, but the alternating current relay
58 responds to the impulse and operates the pri
vate magnet 62. The operation and release of
magnet S2 advances the wiper of side switch SS
one step by means of the usual escapement.
Further rotation of cam 22 causes projection
49 to engage spring 23, and another ground im
pulse is transmitted, causing the operation of the
25 y„rotary magnet 6|. Magnet 0| rotates the switch
shaft one step and brings the wiper set 53-55
into engagement with bank contacts SI1-«52.
As cam 22 continues its rotation, the spring 23
falls successively into the notches 1 I, sending out
30 two alternating current impulses.
These im
pulses cause two operations o_f relay 58 and pri
vate magnet 62, and the wiper of side switch SS
is advanced two steps so as to connect with relay
Further movement of the cam now sends a
35 single ñnal ground impulse by means of pro
jection 12, which operates relay 51.
Relay 51
is a connecting relay and extends the trunk con
ductors 2I5, 2 I6, and 2 I8 back to the wipers 53,54,
and 55. Relay 51 also locks itself to the holding
conductor 2I6 and disconnects conductor 2|0
from conductor |12.
The cams 2| and 22 reach their normal posi
tion shortly after the last impulse is transmitted
and spring 46 falls into the notch in cam 2 I, thus
45 stopping the operation of the stepping magnet
20. In the meantime relay I9 has fallen back,
so that the sender is not restarted. When relay
51 energizes responsive to the last impulse a cir
cuit is completed for relay I8, said circuit ex
tending from the grounded holding conductor
2|6, by way of contacts of 51, 54, 5|, and winding
of I0 to battery. Relay I8 energizes and com
pletes the final holding circuit at 39, disconnect
ing conductor 33at the same point. Relay I8 also
unlocks relay I 9 at 38, and at its upper and lower
contacts disconnects the conductors 3| and 32.
The latter operation initiates the release of the
switches in Fig. 2. The line relay |24 falls back
followed by relay |25. Thus a circuit is closed
60 for the release magnet |30 and the selector S|
is restored to normal. The deenergization of
relay |25 also removes ground from the holding
circuit and relay |02 of finder F’ falls back, also
relay |53 of selector S2. Relay |53 closes a cir
cuit for release magnet |56 and the selector S2 is
restored to normal.
It will be seen now that the calling line has
been extended to the connector C by means of
the confluence switch CS and that the switches
FI, SI, and S2, Fig. 3, have been eliminated.
The connection is held up by ground applied to
4holding conductor 2|6 by relay 202 of the con
nector C.
When the called subscriber at station B an
75 swers, the ring-cut-oif relay 206 energizes and
locks itself at 234. Relay 206 also closes a cir
cuit for relay 201 by way of 243 and 233, and
relay 201 energizes. By the operation of relay
201 the ringing circuit is broken and the talking
circuit is extended back at contacts 236 and 240,
and the ring-back tone circuit is opened at 231.
The back bridge relay 204 now energizes over the
called line. At 229 relay 204 opens the release
magnet circuit, and at.228 it gives its lower wind
ing another ground connection by way of 235
and 240. ` In addition, relay 204 disconnects the
line relay 20| from conductors 2|5 and 2|8 at
221 and 230 and substitutes for the line relay the
battery feed relay 200. This completes the talk
ing circuit, and also reverses the direction of
current flow in the calling line. Relay 200 en
ergizes and at 220 closes a local circuit for line
relay 20| in order to reoperate the same and
hold it and the release relay 202 energized.
The calling and called subscribers may now 20
converse as desired, transmitter current being
supplied through the windings of relays 200 and
204. These relays have ballast resistances 290
and 291 in series with them in order to main
tain a substantially constant current value re
gardless of the length of the subscribers’ lines.
When the subscribers are through talking they
will hang up their receivers. When the receiver
is' replaced at station A the battery feed relay
200 falls back, allowing the line relay 20| to fall 30
back also.
The release relay 202 then restores
after an instant and removes ground from the
holding conductor 2I6. This allows relays 51,
I8, and I1 to deenergize. The cut-olf relay 5 also
restores, and at the same time the ñnder F is 35
restored in the usual manner. At the connector
C the release of the switch depends on whether
the called party has hung up or not. When re
lay 202 falls back it opens the local holding cir
cuit at 224 and closes a point in the release cir 40
cuit at 226. If the receiver is still off at station
B the back bridge relay 204 will stay energized
and hold open the release circuit at 229. When
the receiver is replaced at station B, relay 204
deenergizes, removes ground from the locking
circuits of relays 200 and 208, permitting these
relays to deenergize to free the called line, and
closes the release circuit at 229. Release magnet
2|3 accordingly operates to restore the connector
C. The release magnet 63 of switch CS is also 50
operated, over conductor 2I1, and restores the
switch CS and its side switch SS to normal. All
the apparatus is thus placed in condition for use
in another call,
Some additional remarks may now be inserted 55
with a View to a fuller explanation of certain fea
tures than appeared advisable in the course of the
regular circuit explanation. To begin with, it will
be understood that the sender SD is individual to
the trunk circuit TC. Each' trunk circuit such 60
as TC has a sender SD and also has a code num
ber allotted to it which corresponds to the posi
tion of the trunk circuit in the banks of the con
ñuence switches and which the associated sender
is arranged to send out whenever it is operated. 65
Thus the code assigned to the trunk TC is 2 I2, the
sender SD always sends out this number, and any
ccniluence switch operated in accordance there
with will connect with the particular trunk cir
cuit TC and no other. If there are two-hundred 70
trunks such as TC there will be two hundred dif
ferent code numbers assigned. The cams 22 of
the senders are cut in accordance with the differ
ent code numbers. There would be for instance,
one-hundred cams arranged to send numbers 112 75
2,137,43 1I
to 002, one-hundred numbers in all, each cam
having two notches 'I I , providing for one hundred
numbers ending in the digit two. There would
also be one-hundred similar cams, except for hav
ing only-one notch 1I, providing for sending one
hundredA numbers ending inthe digit one. The
cams inl the two groups serve to operate switches
such as CS the same, except that those sending
out code numbers ending in the digit two operate
10 relays‘su'ch as 51, while those sending out code
numbers having the ñnal digit 1 operate relays
such as `56. This brings into play both wiper sets
of switches such as CS and gives‘the` switches
access to two-hundred trunk circuits such as TC.
As statedßearlier in the specification the capac
ity of a system having 200 trunk circuits TC is
about 2400 lines. The capacity can obviously be
increased by adding additional wiper sets to the
confluence switches CS. For instance the switch
20' CScould be provided with a` third set of wipers
and another relay similar to relays 56 and 51.
This would provide for another hundred trunk
time the holding time of the switches such as SI
and S2 in the setting route is reduced` to -a mini
The foregoing advantages, of course, could not
be secured if the connector were by-passed as well
as the selectors, which brings up an additional
advantage of the present system over those sys
tems which by-pass all the directive switches used
in the setting route. It is usually necessary in
automatic systems to provide for different types 1,0
of service among which may be mentioned regu
lar individual line service, selective ringing party
line service, code ringing party line service, and
trunk service to private branch exchanges. In
the ordinary automatic systems these different 1.5
types of service are furnished by providing dii
ferent groups of connectors such as individual
line connectors, selective ringing or code ringing
connectors, and rotary connectors. Thus the
connectors in each group are relatively simple 20
switches as each switch only has to give one type
of service. In by-pass systems where the final
switches are eliminated the advantage of group
circuits TC. The cams 22 ofthe senders SD as
sociated with the third hundred trunk circuits ing in accordance with service facilities has to be
251 would be the same as the others except that they - sacrificed because the called lines are extended 25
back to common talking links, and each link has
would each have three notches such as 'II.
There is a limit to the number of wiper sets to be of a universal type arranged to give the nec
essary type of service regardless of the line called.
that can be economically added to the coniiuence
switches and consequently for very large systems
30 a` diiîerentplan would be followed. An obvious
arrangement is to divide the conñuence switches
into groups and insert group selectors between
>the connectors and the conñuence switches. In
this. arrangement each connector would be paired
` with a` group> selector, and each group selector
would have access to confluence switches in each
group. The senders SD would also be arranged
so as to send out four digits instead of three, the
first digit serving to `operate a group selector.
In describing the operation of the system it was
assumed that the connector C was completely op
erated by series of impulses repeated by the‘line
relay |24 of‘selector SI. In actualpractice, how
ever, itis more or less a matter of chance that
45 the: connector is fully operated in this manner.
The operation of the coniiuence switch CS begins
substantially simultaneously with the operation
of the connector and each has to respond to three
digits. If the calling subscriber delays a little in
50i dialling, or if thelast three digits of the called
number are of high value, the confluence switch
may complete its-operation ñrst. If this occurs
the line relay 20| of the connector is controlled
over the talking path through the coniluence
55 switch CS to complete the operation of the con
The links, therefore, are excessively complicated.
In the present system the connectors are common 30
to the setting and speaking routes, that is., only
the selectors are by-passed, and the advantage
of grouping the connectors for different types of
service is retained. 'I'hus the connector C isone
of a group of connectors arranged to provide in 35
dividual line service. 'There ordinarily will be
other groups of connectors for party line service,
and one or more groups of rotary connectors.
'I’hese different types of connectors are well known
and consequently `it is not necessary to show them 40'
in the drawings.
the connectors are of
standard types,` retaining the functions of battery
feed, busy testing, ringing, etc., a. confluence
switch such as CS has no functions to perform 45
except that of completing the ñnal talking con
nection between the connector used to iind the
called line and the trunk circuit to which the
calling line is connected, and consequently these
confluence switches are ofrvery simple construc 50
As indicated hereinbefore, the connector C is
in general not new, but it has a special feature
involving the prevention of clicks at the calling
station which is believed to be novel. This fea 55
nector; On the other hand if the connector
should> complete its operation first, there is no
delay in transmitting the busy tone or ring back
tone to the calling party, as the repeating circuit
at Si is connected with the control circuit incom
ture may be regarded as an improvement on my
ingto the line relay I24‘by means of a small con
from the back bridge relay 204, and the provi
denserY IlII.
sion of contacts on the back bridge relay for con
There is a considerable advantage in starting
the operation of the coniluence switch before the
dialling is completed as compared‘to those by
pass systems in which the connection is extended
clear through tothe called line before the opera
tion of the‘switch or switches which complete the
talking path is started. By starting the opera
prior Patent No. 1,376,848, May 3, 1921. The ar
rangement involves the provision of a battery
feed relay 20B which is connected to the talking
circuit on the opposite side of the condensers 60
necting the incoming trunk conductors 2I5 and
253 to the battery feed relay in place of the line
relay. This circuit not only greatly reduces the
click or bang due `to reversal of current in the
calling line, a result obtained in my prior pat
ent, but it also eliminates the clicks due to the
action of the switching through and ring cut
off relays, one or the other'of which is present 70
tion of the, confluence switch at the time the op
eration of the connector is started the talking
connection through the conñuence switch is
in systems using standard connectors. The elim
ination of the ring cut-off and .switching through
usually established by the time the called line is
found, or perhaps before, and the delay which
clicks is due to the fact that in- the present cir
cuit the incoming trunk conductors 2 I5 and 2 I8
would otherwise occur is avoided.
are normally entirely separate fromrthe talking 75
At; the same
2,137,43 1
circuit in the connector and extend only to the
windings of line relay 201. When the back bridge
relay operates to disconnect the trunk conduc
tors from the line relay and connect them in
stead to the battery feed relay 200, it connects
these trunk conductors to the talking circuit at
the same time.
The invention having been described, what is
considered to be new and is desired to be pro
10 tected by Letters Patent will be set forth in the
following claims.
What is claimed is:
1. In a telephone system, means including a
finder, a ñrst selector, a second selector, and a
15 connector for’ extending a call from a calling
line to a called line, a confluence switch for by
passing both the first and second selectors,
thereby directly connecting the ñnder and con
nector, and means for releasing the first and sec
20 ond selectors while the calling and called lines
are maintained in talking relation through the
finder, the confluence switch and the connector.
2. In a telephone system, a trunk circuit,
means for extending a calling line to said trunk
circuit, means including selector switches and a
connector for selecting a called line, a confluence
switch for connecting the connector with said
trunk circuit, a sender individual to the trunk
circuit for operating said confluence switch to
30 connect the connector switch with the trunk cir
cuit and for maintaining such connection, and
means for releasing said selector switches after
the connector and trunk circuit have been con
3. In a telephone system, a plurality of serially
related automatic switches controlled over a call
ing line to select a called line, a confluence switch
for setting up a by-pass connection from the
calling line to the final switch, means for start
40 ing the operation of the confluence switch con
currently with the final switch, and_means for
completing the operation of the final switch over
the by-pass connection if said connection is es
tablished before the called line is selected.
4. In a telephone system, a setting route in
volving selector switches and a connector switch,
a speaking route excluding said selectors but in
cluding said connector, and operating means in
said connector controllable either over said set
50 ting route or said speaking route.
5. In a telephone system, a setting route involv
ing selector switches and a connector switch, a
speaking route excluding said selectors but in
cluding said connector, means Vfor starting the
55 operation of said connector over said setting
route, and circuit arrangements whereby the op
eration of said connector may be completed over
said speaking route.
6. In a telephone system, a setting route in
60 volving selector switches and a connector switch,
a speaking route excluding said selectors but in
cluding said connector, means for starting the
operation of said connector over said setting
route, means for concurrently starting the estab
65 lishment of the speaking route, and means for
completing the operation of said connector over
the speaking route in case the same is established
before the connector is fully operated.
'7. In a separate setting and speaking route
70 system, a coniiuence switch for completing the
speaking route, a control circuit for said switch
included in the setting route, and means for
transmitting both direct current impulses and
alternating current impulses over said circuit to
75 control the operation of said switch.
8. In a separate setting and speaking route
system, a confluence switch for completing the
speaking route, a control circuit for said switch
included in the setting route, said switch having
primary and secondary operating movements,
means for sending direct current impulses over
said circuit to control said switch in its oper
ating movements, and means for sending alter
nating current impulses over said circuit to con
trol the changeover in said switch from its pri 10
mary movement to its secondary movement.
9. In a separate setting and speaking route
system, a ñnal connector, a confluence switch
for completing the speaking route and individual
to said connector, an operating circuit for said 15
confluence switch, and means responsive to the
beginning of the operation of said connector for.
completing said operating circuit.
10. In a separate setting and speaking route
system, a connector switch for connecting with 20
a called line, means including a train of selector
switches for selecting and operating said connec
tor from a calling line, a confluence switch asso
ciated with said connector for connecting the
same with the calling line over a talking path 25
excluding said train of switches, means in said
connector for testing and ringing the called line,
and means in said connector for supplying talk
ing current for both the calling and called lines.
l1. In a telephone system, a setting route in 30
volving selector switches and a connector, a
speaking route involving a confluence switch and
said connector, a control circuit included in the
setting route over which a calling subscriber
transmits impulses to operate said connector, a 35
second control circuit included in said setting
route, and a sender operating concurrently with
the subscriber’s calling device to send impulses
over said second control circuit in the same di
rection as the impulses in said first control cir 40
cuit and effective to operate said confluence
12. In a telephone system, a setting route in
cluding a selector repeater and a connector,
means for operating said connector under con
trol of said selector repeater, a speaking route in
cluding said connector but excluding said selector
repeater, means for starting the establishment
of the speaking route while the connector is op
erating, and means effective if the operation of 50
the connector is completed before the speaking
route is established for transmitting tone cur
rents back over the setting route from the con
nector to the calling subscriber.
13. In a connector switch, talking conductors 55
each including a condenser, a battery feed relay
and a back bridge relay bridged across said talk
ing conductors on opposite sides of said con
densers, a line relay, incoming trunk conductors
normally connected to said line relay and dis 60
connected from said talking conductors, and con
tacts on said back bridge relay forvdisconnecting
said trunk conductors from said line relay and
for connecting them to said battery feed relay.
14. A connecting switch as claimed in claim 65
13, characterized by the provision of contacts
on the battery feed relay for holding the line re
lay energized after the trunk conductors have
been disconnected.
15. A connector switch as claimed in claim 13, 70
in which the battery feed relay and line relay
are so connected to the battery that the sub
stitution of the battery feed relay for the line
relay causes a reversal of current in the trunk
`16. In a telephone system, a connector switch
lincluding operating means, a setting route in
cluding selector switches and said operating
means, a speaking route including said operat
ing means and excluding said selector switches,
telephone system, a confluence switchV for com
pleting the speaking route, said switch having
primary and secondary movements, a control cir
cuit for said switch included in at rleast one of
said routes, means for sending current impulses
said routes being adapted-to be `completed fol- ‘ of one kind over said circuit to control said
lowing the initiation of a call thereover, means switch in its operating movements, and means
for starting the operation of‘said operating means
over said setting route, and means for complet
10 ing the operation of said operating means over
said speaking route. '
for sending current impulses of a different kind
over` said circuit to terminate one of said move
ments and to start theother of said movements. 10
17. In a separate setting and speaking route
Без категории
Размер файла
1 408 Кб
Пожаловаться на содержимое документа