US1543937A - Automatic telephone-exchange system - Google Patents

Description

June 30, 1925. 1,543,937

J. L. MCQUARRIE AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed Nov. 28, 1921 Awe/fian- James 1. M al/(rifle.

and a secondary line switch.

Patented June 30, i925 1 UNITED STATES PATENT OFFICE.

JAMES L. TJIGQUARBIE, 0F NEVJ YORK, N. Y., ASSIGNOR- TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, H. Y., A COR-POEATION OF NEW YORK.

AUTOMATIC TELEPHONE-EXCHANGE SYSTEIVI.

Application filed November 28, 1921. Serial No. 518,326.

T 0 all whom it may concern:

Be it known that I, Jeans L. LICQUARRIE, a citizen of the United States of America,

residing at New York, in the county of New 5 York, State of New York, have invented certain new and useful Improvements in Automatic Telephone-Exchange Systems, of

which the following is afull, clear, concise,

line to an idle one of a large number of common trunks by means simple in construction, positive and speedy in action,

which permits of very efficient trunking, and in which first cost and maintenance charges shall below.

In accordance with this invention a unitary switching structure is provided having extensions of each incoming line located in proximity to link conductors, these latter conductors being located in proximity to trunk conductors, means being provided within said unitarv switching structure for connecting an incoming set of, line conductors on which a call has arrived instantaneously to an idle trunk through the intermediation of a set of link conductors, an idle set of trunk and link conductors being preselected in readiness to extend the call by suitable mechanism.

In machine switching telephone exchange systems it has been found that by making all the first selectors accessible to all the subscribers lines, more efficient trunking is obtained than by making groups of first selectors individual to groups of subscribers lines.

Various schemes have been devised to accomplish this purpose, one of the well-known arrangements providing primary and secondary line switches whereby any subscribers line can be connected to an idle one of all of the first selectors by the successive operations of a primary line switch This arrangement and others heretofore known to me req ire senarates r ctures for aocomplis'lr ing the primary and secondary trunking functions.

The invention contemplates providing a simple unitary switching structure to accomplish both primary and secondary switching operations. I

In the present embodiment of the invention, a connection between a subscribers line, upon which a call has been initiated, and one of the common outgoing trunks is instantaneously effected by intersecting movable bars which cooperate under the control of suitable magnets to bring contact sets or extensions of the calling subscribers line and contact sets or extensions of an idle trunk into contact with contact sets of an idle link or transfer circuit, the trunk and link used being predetermined by allotters.

More specifically a single unitary switching structure is provided in which conductors forming extensions of the subscribers lines of a given group intersect or .7 cross conductors forming link or transfer circuits, these link conductors being indi-. vidual to this group of lines. The conductors forming the link circuits individual to a number of groups of subscribers" lines in turn intersect conductors of all the trunks or outgoing lines which may terminate in first numerical switches. At the intersection of the line and link conductors and at the intersection of the link and trunk conductors contact sets are provided, certain predeteunined contact sets being automatr cally instantaneously interconnected upon the initiation of a call to extend a calling line to an idle trunk by means of'electromagnetically actuated operating bars arranged in intersecting relation so as; to co operate to interconnect said preselected contact sets.

three allotting switches for preselecting links from each group and outgoing trunks for use. The structural features are not shown in detail since there are in the art structures which may be used in carrying Out th w a A examp of @"Sflii able switching structure is shown in Patent 1,323,318 to J. N. Reynolds, issued December2, 1919. V

Inasmuch as the invention does not lie in the switch structures per se which is fully to advance in search of an idle link or transfer circuit to preselect the same in readiness for the next call, and shown in the drawing, the link circuit in question is the one at the extreme right. It will of course be understood that although only two subscrib ers lines A and B of one line group, and only two link circuits 4'and 5 individual to that group, and only two-subscribers lines G and D of another group and two link circuits 80, 83 individual to that group are illustrated, to simplify the disclosure, each line group may contain a hundred subscribers lines and each link group may comprise ten link circuits. The number of link circuits serving a given line group depends upon the trafiic in the line group which they serve; and the number of trunks depends upon the traiiic in all of the groups of lines which they serve,

It will be assumedthat the next call is initiated at substation A. This causes the relay 6 individual to such line to operate. In attracting its upper armature this relay closes acircuit to operate magnet 7 of the link circuit 4 which was preselected by the link circuit allotter 3 when substation B was extended to trunk 1. This circuit is as follows: grounded upper armature of relay 6, conductor 8, armature and normal contact of slow release relay 9, brush 10 of link circuit allotter 3, terminal 11, conductor 12, magnet 7 to battery and ground. Magnet 7 in attracting its right armature rotates av bar, the pivot pins 13, 14, whereof only. are shown, to position the multiple contact sets of the conducting strips 4, which maybe carried bythe bar, in operative relation to multiple contact sets of the conducting strips 15, 16, etc. of lines A and B, etc, and to multiple contact sets of the conducting strips 17, 18, etc, of trunks 1, 2, etc. Mag net 7, inattract-ing its left armature, closes a circuit to operate the trunk bar actuating magnet 19 of the trunk 2 preselected by the trunk allotter 20. This, allotter moved its brush 21 from engagement with terminal v22- connected to the bar actuating magnet 24 of trunk l and into engagement with terminal 23 connected to bar actuating magnet 19 of trunk 2 when substation B was extended to trunk 1. The circuit for operating magnet 24 is as follows: ground, left armature and alternate contact of magnet 7, conductor 25, armature and normal contact of slow release relay 26, brush 21, terminal 23, mag

net 19 to battery and ground. Magnet 19 in attracting its right armature first rotates a trunk bar, the pivot pins 27, 28 only whereof are shown, until the multiples 29, 3Q, 31 of the trunkconducting strips 18, which may be carried by the bar, are in operative relation to multiples 32, '34 ofthe link conducting strips 4-. Upon further attraction of the right armature of magnet 19 the trunk bar is forced to the left, moving multiples 29, 30, 31 into engagement with multiples 32, '33, 34 respectively, and also moves the remaining multiples of the trunk conducting strips 18 to a position where they will not be engaged by the multiples of a subsequently operated link bar.

Magnet 19 in attracting its left armature closes a circuit to operate the bar actuating magnet 35 of the calling line A. This circult is as follows: ground, left armature and alternate contact of magnet 19, conductors 36,37, 38, lower armature and alternate contact of relay 6, right winding of magnet 35 to battery and ground. Magnet 35 in at tracting its right armatures cuts off the line relay (5 and in attracting its left armature first'rotates the line bar, the pivot pins 40, 41 only whereof are shown, until the multiples 42, 43, 44, of line conducting strips 15 which may be carried by the bar, are in operativerelation to multiples 45, 46, 47 of the link conducting strips 4 to which the trunk 2 is already connected. Upon further attraction of the armature of magnet 35 the linebar is forced to the left. moving multiples 42, 43, 44 into engagement with multiples 45, 46, 47, respectively, and a.so moves the remaining multiples of the line conductin strips to a position where they will not be engaged by the multiples of a subsequently operated link bar. 7 a

The incoming line A is now the outgoing trunk 2 and relay 48 new operates in series with the substation equipment of the calling line A. The circuit is as follows: free pole of battery, lower left winding of repeating coil 53, relay 48, trunk conductor 49, middle strip of the trunk conducting strips 18, trunk multiple 30, link multiple 33, middle strip of the link conducting strips 4. link multiple 46,1ine mul tiple 43, middle strip of the line conducting strips 15, line conductor 50, the telephone apparatus (not shown) at substation A, line conductor 51, upper strip of the line conducting strips 15, line multiple 42, link mulextended to i IOU tiple 45, right strip of the link conducting strips 4, link multiple 32, trunk multiple 29, upper strip of the trunk conducting strips 18, trunk conductor 52, upper left winding of the repeating coil 53, to ground.

Relay 48, in attracting its armature, closes a circuit for test relay 54 of the link allotter 3 to cause it to advance and preselect an idle link in readiness for the next call. The circuit for relay 54 is as follows: ground, armature and alternate contact of relay 48, conductor 55, lower strip of the trunk conducting strips 18, multiple 31 thereof, multiple 34 and the left conducting strip of the link strips 4, conductor 56, brush 57, relay 54 to battery and ground. Relay 54 in attracting its armature closes the circuit of stepping magnet 58 of the link allotter 3. The attraction of the'armature of magnet 58 prepares, through the pawl 59 and ratchet 60, for the rotation of the shaft carrying the brushes 10 and 57 to move the said brushes over their terminal rows 61 and 62 respectively upon the subsequent deenergization of magnet 58. As long as wiper 57 encounters test contacts of busy link circuits upon which ground is present, the circuit of test relay 54 will remain closed, thus holding closed the circuit of self-interrupting magnet 58. As soon as wiper 57 is centered on a test terminal of the row 62 corresponding to an idle link circuit. no ground will be present thereon, since relay 48 thereof is inert and test relay 54 will release, opening the stepping circuit including magnet 58. release relay 9 is provided to prevent the operation of any of the link bar operating magnets 7 during the operation of the allotter 3. This relay is operated in parallel with test relay 54 from the grounds on the busy test terminals of the row 62. As soon as brush '10 leaves terminal 11 to which. the magnet 7 is connected, the circuit of this magnet'is opened and it releases and allows the link bar carrying the conducting strips 4 to return to its normal position. The set of multiple terminals 32, 33, 34 engaging the set of multiple terminals 29, 30, 31, respectively, remain in contact,however, due to the flexibility of said terminals. The other sets of terminals of the link conducting strips 4 are rotated in a counter clockwise direction to place them in a position where they will not be engaged by terminals carried by the bars of subsequent calling lines.

Relay 48 in attracting its armature also closes a circuit for test relay 63 of the trunk allotter 20 to cause it to advance and preselect an idle trunk. The circuit for relay 63 is as follows: ground, armature and alternate contact of relay 48, conductor 55, lower strip of the trunk conducting strips 18, conductor 64, terminal 92, brush 65, test relay 63 to battery and ground. Relay 63in attracting itsarmature closes the circuit of stepping magnet 66 of the trunk allotter 20. The attraction of the armature of magnet 66 prepares, through the pawl 67 and ratchet 68, for the rotation of the shaft carrying the brushes 21, to move the said brushes over their terminal rows 69, 70, respectively, upon the subsequent deenergization of magnet 66. As long as wiper 65 encounters test contacts of busy trunk circuits upon which ground is present, the circuit of test relay 63 will remain closed, thus holding closed the circuit of self-interrupting magnet 66. As soon as wiper 65 is centered on atest terminal of the row 70 corresponding to an idle trunk circuit, no ground will be present thereon and test relay 63 will become inert, opening the stepping circuit including magnet 66. A slow release relay 26, similar to slow relay 9, is provided to prevent the operation of any of the trunk bar operating magnets 24, 19, during the operation of the trunk allotter 20. This slow relay is operated in parallel with test relay 63 from the grounds on the busy test terminals of the row 70. As soon as brush 21 leaves terminal 23 the circuit of magnet 19 is opened, but due to the operation of relay 48 a circuit was already closed for magnet 71 which magnet holds armature 72 attracted to hold the trunk bar carrying the conducting strips 18 set to maintain trunk multiples 29, 30, 31 in contact with link multiples 32, 33, 34. The ground applied to the lower conducting strip of the strips 18 is extended over multiples 31, 34, the left strip of the conducting strips 4, multiples 47, 44, the lower strip of the conducting strips 15, to the left winding of the line bar operating magnet 35 whereby this magnet maintains its left armature attracted to hold the line bar set to maintain the multiples 42, 43, 44 in contact with multiples 45, 46, 47 after the circuit through the right winding of magnet 35 is opened by the retraction of the lower armature of the line relay 6 when it is cut off from the line due to the operation of magnet 35. This circuit for the left winding of magnet 35 is closed before the circuit including the right winding of said magnet is opened by the release of the line relay 6. The mechanical construction for accomplishing this function is not shown since such arrangements are well known. The ground applied by relay 48 to the lower conducting strip 18 and over the path traced to the holding winding of magnet 35 is extended by conductor 74 to the called multiples of line A to cause the line to test busy at such multiples in the wellknown manner.

The calling line A is new extended to trunk 2 and the allotters .3 and 20 have preselected idle link and trunk circuits respectively in readiness for the next call. The calling line A may now be extended in the direction of the called line over the trunk 2 in any suitable manner. For example, the

. theline circuit A causes the release of magnets 71 and 35. The deenergization of magnet 71 and consequent retraction of its right armature releases the trunk bar carrying the conducting strips 18 which bar is returned to its normal position by springs (not shown).

The'rele'ase of the armature of'relay '48 also removes ground fromthe terminal 92 of row 70 of the trunk allotter 20 to indicate the idle condition of the used trunk in the trunk allotter 20; The release of the armature of relay 48 also removes ground from the second terminalin row 62 of the link allotter 3 to indicate the idle condition of the used link in the link allotter. The deenergization of the line bar operating magnet 35 and terminals.

position by springs (notshown).

consequent retraction of its left armature releases the line'bar carrying the conducting strips 15 which bar is returned to its normal The deenergization of the line bar operating magnet 35 causes the retraction of its right armatures, reconnecting the line relay 6 to theline A.

When the relay 48 removed ground from conductor 55 and released magnet 35, the removal of this ground from the third wire 74 leading to the called multiples of line A causedthis line to test idle at such called hen line A is seized as a called line, ground is placed on conductor 74 completing a circuit for the left winding of magnet 35. The winding'is constructed and. arranged to magnetize the magnet sufficiently to cause it to attract its right armatures to cutoff the associated line relay 6, but insufficiently to cause it to actuate its left armature to move the bar carrying the multiple sets of contacts on the conducting strips 15.

As previously indicated, another-group of subscribers lines of which only two, C and D, are shown, is indicated at the left of the drawing. Each line of this group. is similarly provided with threeconducting strips '75 which may be carried by a bar, the pivot pins 76, 77 only whereof are shown. These strips are similarly provided with sets of multiple contacts 78, 81, for engagement with sets of multiple contacts 79, 82 respectively of link conducting strips 80, 83,

provided with aline relay 84 and a line bar operating magnet 85. The link circuits and 83 are similarly provided with a link allotter 86 for preselecting an idle link circuit. In the drawing the idle link circuit is shown as the first to the left, the operating magnet 87 of this link circuit being connect ed by'the brush 88 to the conductor 89 extending to the upper armatures of the line relays of the subscribers lines of this group.

In view of the operations already described it is thought unnecessary to describe in detail the operations involved in establishinga connection from line C or D toone of the trunk circuits. The initiation of a call in line C, for example, operates its line relay 84 which energizes magnet 87 to position multiples 79 and 90 of the preselected idle link circuit 80 in operative relation to multiples 78 and 91 respectively of the line and trunk conducting strips, so thatupon the operation of magnets 87 and 85 and the trunk magnet such as magnet 24, the connection is extended to the trunk preselected by trunk allotter 20.

It will be noted that the link conductors 4, 5, 83, 80, etc., of both line groups intersect all the trunk conductors 17, 18, etc. and

that each set of link conducting strips has a set of multiple contacts adapted to cooperate with a set of multiple contacts on each set of trunk conducting strips, whereby through the cooperation of the line and trunk bars any subscribers line of any group may seize any trunk; in other words, by virtue of the present invention a unitary structure is provided in which trunks common to all the subscribers lines termi' nate, and if any trunk is idle any line in any group may seize it.

7 It is to be understood that although the incoming lines are shown and described as subscribers lines, these lines may thClTlSBlVG: be incoming trunk lines to be extended by the switching unit of this invention to one of a number of trunks 1, 2, etc., whereby the connection may be extended in the direction of the called line.

That is claimed is: V

1. In a switching system, a unitary switching apparatus comprising sets of incoming line conductors, sets of link conductors primarily accessible from said sets of incoming conductors, sets of outgoing conductors, means for preselecting an idle set of link conductors, means for preselecting an idle set of outgoing conductors, and means for connecting any set of incoming line conduc' tors with an'idle one of any of said sets of outgoing conductors through an idle setof link conductors. a Y

2. In a switching system, a unitary switching apparatus comprising sets of incoming line conductors, sets of link conductorsprimarily accessible from said sets of incoming line conductors, sets of outgoing trunk conductors, line bars serving said line conductors, link bars serving-said link conductors, trunk bars serving said trunk conductors, means for pr'eselecting an idle link bar and an idle trunk bar, and electromagnetic means for actuating said bars to connect a set of incoming line conductors with an idle one or any of said set of trunk conductors through an idle set of link conductors.

3. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, trunk circuits, contact sets, incoming circuit bars serving said incoming circuits, link bars individual to said links, trunk bars individual to said trunks, magnets for causing the joint actuation of an incoming circuit bar, a link bar and a trunk bar, said bars cooperating with each other to actuate predetermined contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available one or" said trunk circuits, and circuits for said magnets closed upon the closure of one of said incoming circuits.

4. The combination, in a switching system, of incoming line conductors, a central ofiice, a switching apparatus thereat wherein said conductors terminate in groups, extensions of said conductors mounted on said apparatus, a group of sets of link conductors for each incoming line group mounted on said apparatus intersecting the extensions of its incoming line group and primarily accessible therefrom, a group of sets of trunk conductors intersecting theconductors of all of said link groups, and means for connecting a set of incoming line conductors to any set of idle link conductors of its group and to connect such set of link conductors to any available one of said sets of trunk conductors.

5. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a plurality of switching bars cooperating with each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit.

6. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a V plurality of intersecting switching bars act ing jointly and cooperating with each other for actuating said contact sets to connect any incommg circuit with a link circuit and 1 to connect such link circuit to any available outgoing circuit.

7. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, a plurality of switching bars cooperating with each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit, and means for restoring one of said bars without releasing the established connection.

8. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, a plurality of switching bars cooperating with each other and actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to an idle one of any of said outgoing circuits, and means for preselecting the link circuits and outgoing circuits.

9. The combination, in a switching system, of line circuits, link circuits primarily accessible from said line circuit-s, trunk circuits, contact sets, line bars serving said lines, link bars serving said links, trunk bars serving said trunks, and means for causing the joint operation of a line bar, a link bar and a trunk bar, said bars cooperating with each other for actuating said contact sets to connect a line to a link and to connect such link to any available trunk.

10. The combination, in a switching system, of incoming circuits divided into subgroups, a group of link circuits individual to each sub-group of incoming circuits and primarily accessible from the subgroup of incoming circuits to which it is individual, outgoing circuits common to all link circuits, a plurality of switching bars cooperating with each other, and means for operating the same for connecting an incoming circuit to a link, and for connecting said link to any available one of said outgoing circuits.

11. In a switching system, a unitary switching apparatus comprising sets of incoming line conductors, sets of link conductors primarily accessible from said sets of incoming line conductors, sets of outgoing conductors less in number than said sets of incoming conductors, means for preselecting an idle set of link conductors, means for preselecting an idle set of outgoing conductors, and means for connecting any set of incoming line conductors with an idle one of any of said sets of outgoing conductors through an idle set of link conductors.

12. In a switching system in which a unitary switching apparatus is employed for establishing connections between incoming circuits and outgoing circuits through the intermediary of link circuits, the method of establishing connections which consists in preselecting an idle outgoing circuit, preselecting an idle link circuit, making each link circuit primarily accessible from each incoming circuit, c0unecting 'any preselected outgoing circuit to any. preselected link circuit, and then connecting such preselected link-circuit to an incoming circuit.

Inna switching system in which a unitary. switching apparatus is employed for establishing connections between incoming circuits of a plurality of groups and outgoing circuits of a group common thereto through the intermediary of link circuits of groups individualrespectively to the groups of incoming circuits, the method of establishing connections Which consists in prese lecting an idle outgoing'circuit,preselecting an idle link circuit in each of the groups of link circuits, making each link circuit of a group primarily accessible from each in coming circuit of the; group to which that group of link circuits is individual, connecting any incomingcircuit With any preselected link circuit of the group accessible therefrom, and then connecting such link circuit With the preselected outgoing circuit. y In Witness whereof, I hereunto subscribe my name this 23rd day of November A. D.,

JAMES L. LMCQU RRIE.

DISOLAEMERB 1,543,937.James L. McQmmw'e, New York, N. Y. AUTOMATIC TELEPHONE-EX- CHANGE SYSTEM. Patent dated June 30, 1925. Disclaimer filed October 22, 1926, by the patentee, assignee, W eszfem mama Company, Incorporated, consenting. 4 Hereby enters this disclaimer to the said claims of said Letters Patent which are in the following words, to wit:

5. The combination, in a switching system, of incon'iing circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a plurality of switching bars cooperating with each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit.

6. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a plurality of intersecting switching bars acting jointly and cooperating with each other for actuating said contact sets to connect any incoming circuit with a link circuit and to connect such link circuit to any available outgoing circuit.

7. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, a plurality of switching bars cooperating with each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit, and means for restoring one of said bars without releasing the established connection.

[Oficc'al Gazette Nooember .76, 1926.]

DISCLAIMER 1,543,937.Ja71ws Z. McQuwrfic, New York, N. Y. AU'roMA'rIo TELEPHONE-EX- CHANGE SYSTEM. Patent dated June 30, 1925. Disclaimer filed April 4, 1928, by the assignee, W estem Electric Oompany, Incorporated.

Hereby enters this disclaimer to that part of the claims in said specification which are in the following words to wit:

5. The combination, in a switching system, of incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a plurality of switching bars cooperating With each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit.

6. The combination, in a switching system, of incon'iing circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, and a plurality of intersectin switching bars acting jointly and cooperating with each other for actuating said contact sets to connect any incoming circuit with a link circuit and. to connect such link circuit to any available outgoing circuit.

7, The combination, in a switching system, o1 incoming circuits, link circuits primarily accessible from said incoming circuits, outgoing circuits, contact sets, a plurality of switching bars cooperating with each other for actuating said contact sets to connect an incoming circuit to a link circuit and to connect such link circuit to any available outgoing circuit, and means for restoring one of said bars without releasing the established connection.

[Ofiicz'al Gazette May 1, 1928.]

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