US1242384A - Automatic telephone system. - Google Patents

Description

A. B. SPERRY.

AUTOMATIC TELEPHONE SYSTEM.

,APPUCATION FILED JAN. 14. I916.

Patented Oct, 9, 1917. 2 SHEETS-SHEET 2 In yen for: A rzhur B Sperry.

" Amy.

ARTHUR BRUCE SPERRY, or NEW YORK, N. Y., ASSIGNOR To wnsfrnnn ELECTRIC COMPANY, INCORPORATED, or NEW YORK,1\T.Y.,A coaronn'rronor new YORK.

To all whom it may concern: Be it known that I, SPERRY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a full, clear, concise, and eXact description. v v

This invention relates to telephone systerms in which the talking connections are established, in part at least, by means of automatic or electrically actuated switching mechanism. I i

The invention is directed in general towardthe provision of a system of this charactor in which the impulses for controlling the switches used in establishing a connection, are transmitted over the third or nontalking conductor of the connecting circuits, and more particularly to a system of this character in which the test for idle trunks at the selector switches employed takes place through one of the brushes in the talking circuit.

In the drawings, Figures 1 and 2, with Fig. 1 at the left, diagrammatically indicate the circuits and apparatus employed with the present invention.

The switches employed inthe present invention may be of any desired kind, in which the switch brushes are firstmoved to select a group of contacts and are then moved over the contacts of the group to select a particular set of contacts in the selected group. A switch of this general character is shown in the patent to Keith ct aZ., No. 815,176. In the following description of the present invention, however, the rotary stepping magnet will be described asoperating first, that is, it is assumed that an around-and-up switch is em ployed in the present system instead of the up-and-around'switch shown in said patent. A switch of this character is shown in an application to Oscar F. Forsberg, Serial No. 6,302,. filed February 5,v 1915. The side switch employed in the present invention may also be of the type shown in said Forsberg application. .This side switch diifers from the one shown in the Keith patent, principally in that its wipers may be caused to move in certain instances upon the energization instead of upon the den ergization of its controlling magnet.

Specification of Letters Patent.

Application filed January 14, 1916. 7 Serial No. 72,139.

AR'rn R Biro on w armature of relay 11 to ground.

Patented Oct. 9,1917.

At the left in Fig. l of the drawings, the callingline 1 is shownjoined to theconnecting circuit 2 by means of. a line finder switch. diagrammatically indicatedby the brushes 3, land 5. It is immaterial, however, in what. mannerthe calling line is joined to the trunk circuit. This could as well be accomplished by means of a line or trunk finding switch or by means of a manually operated plug and jack switch, as the present invention may be as well employed in a semi-automatic telephone system as in a full automaticv system. Assuming now that the line finder brushes 8, A and 5 are positioned on the contacts of the calling line 1 and that'the side switch wipers 6, 7 and 8 have moved to position 41, the cutoff relay 9 will be energized by a-circuit extending through brush 3 and wiper 6, thus cutting off the line relay 10 of the calling now closed at the hook-switch, current will j flow from grounded battery through the right winding of impulse relay 11, wiper 7, brush 4:, the left side of the calling line, through the substation apparatus, back over the right side of the line, brush 5, wiper 8 and the left winding of relay 11 back to ground. Relay 11 will attract its armature completing a circuit for the slow-release relay 12. i

The calling subscriber will now operate his dial to send the first series of impulses. The substation sender circuit may be substantially of the character shown in patent to A. E. Lundell, No. 1,1418,912, issued Au gust 3, 1915. The sender arrangement disclosed insaid patent, causes a series of interruptions in the line circuit and during the timesuoh interruptions are being sent, short circuits the calling subscribers receiver. With the first interruption in the line circuit relay 11 will be deprived of our rent'and will retract its armature. completing a circuit from battery through the rotary stepping magnet 13 and the escape magnet relay 14 in parallel and thence through the contact and right armature of relay 15, side switch wiper 16, front contact and armature of relay 12, back contact and A circuit will also be provided for the relay 15, but due to the resistance 17 in series with the winding of this relay and also due' to the fact that its armatures are held. retracted by a relatively heavy spring, it will not be energized during the brief periods its circuit is. closed at the back contact of relay 11 during the operation of the sender. Relay 14 in attracting its armature completes a circuit from battery through the escape magnet 18, wiper 19 and the armature and contact of relay 14, causing the energization of the escape magnet. illelay-h is slow to release and, therefore, holds up its armature throughout the series of interruptions in its circuit caused by the subscribers sending device. The rotary stepping magnet 13 is, however, repeatedly energized and deenergized, thus stepping the selector switch brushes 20, 21 and 22 from group to group of the trunk lines terminating at said switch.

At the termination of the series of impulses, the circuit of relay 11 is maintained closed so that magnet 13 and relay 14 deenergize. The switch stops on the selected group of contacts, and as relay 1% retracts its armature due'to the prolonged interruptions of its circuit, the escape magnet 18 becomes deenergized and moves the side witch wipers to position 2.

In position 2 the test relay 23 is joined to the selector brush 21 through wiper 2%. A circuit is also established for the test relay 23 from battery through-relay 15, wiper 16, vertical ofi-normal contact 25, which opens on the first vertical step, and through the winding of relay 23 to ground. A circuit is now closed from battery through the vertical stepping magnet 27, off-normal contact 28, wiper 29 and interrupter 30 thus causing the- brushes 20, 21 and 22 to be stepped from set to set of the trunk contacts in the selected group. The test contact of busy trunks will be supplied with battery potential through the brush 21, wiper 2-1 and resistance 26 of the selector associated with said trunk at one of its multiple terminals and, therefore, the test relay will be held up while brushes 20, 21 and 22 pass over busy trunks. lNhen they engage the contacts of an idle trunk, battery will not be present upon the contact engaged by brush 21, and relay 23 will fall off closing at its left armature and back contact the circuit for the escape magnet 18. The escape magnet will be energized, and in attracting its armature will move the side switch to position 3.

The calling subscribers line is new connected through to the connector switch shown in Fig. 2. If desired, however, other selector switches, similar to the one shown to the right in Fig. 1, may be interposed between said selector switch and the connector switch of Fig. 2.

In the present disclosure, however, the calling subscriber will now operate his sending device to send out the next ortens series of impulses, each interruption at the sending device will cause the retraction of the armature of relay 11 as before. With the first retraction of the armature of relay 11, a circuit will be completed from battery through the rotary stepping magnet 101, wiper 102 and from battery through the escape magnet relay 103 in parallel therewith and thence through the left armature and back contact of test relay 10%, back contact and right armature of relay 105, brush 20, wiper 16, front contact and armature of relay 12 and the back contact and armature of relay '11 to ground. Magnet 10land relay 103 will both be energized. A circuit will also be established for relay 105, but as this relay is made slow to pull up by providing its armatures with relatively strong retractile springs, it will not be affected by the brief current impulses therethrough by the operation of the sending device. Relay 103 is made slow to release and holds up throughout the series of impulses thereby maintaining an energizing circuit through its armature and alternate contact for the escape magnet 106.- The rotary stepping magnet 101 isrepeatedly energized and deenergized, due to the impulses of current therethrough,- and steps the connectorswitch brushes 107, 108 and 109 from group to group of the subscribers line contacts terminating therein until the tens group in which the wanted line terminates isreached. The circuit for relay 11 will now be 1naintained closed, thus holding open the circuit, for stepping magnet 101 and relay 103; Relay 103 will then retract its'armature and interrupt the circuit for the escape magnet 106 causing the side switch to move to posi tion 2.

The subscriber now operates the sending device to send the final or units series of impulses. TVith the first retraction of the armature of impulse relay 11, circuits are closed through thevertical magnet 110 andthe escape magnet relay 103in a manner similar to that in which rotary magnet 101 and relay 103 were energized'when the tens series of impulses were sent. Relay 103 again closes the circuit for the escape magnet 106 and maintains said magnet energized throughout the series of impulses. Vertical stepping magnet 110 is repeatedly energized and deenergized, moving the brushes 107,108 and 109 from set to set of the line terminal contacts of the selected tens group.

When the connectorswitch brushes are positioned on the terminals of the called line, the calling substation circuit will re-- main closed at the sending device causing relay 11 to hold up its armature, thus holdin g open the circuit of magnet 110 and relay 103. Relay 103 will retract its armature, but as its contacts are of themake-beforebreak character, the circuit of theescape escape magnet 106 magnet 106 will be extended through the normal contacts of relay 103, testrelay 10 1 and its normal contact,wiper 112 and brush 107 to the test contact of-the wanted linen 'We will first assume that the wanted line is busy, in which case the test contact will be connected to earth through brush 107'and side switch wiper112 in positions 3 and 4: of the connector'switch associated with multiple contacts of the line. This beingthe case,'test-relay 104: will attract its armature, completing a locking circuit foritself .and in series through its right alternate contacts and side switch wiper 113 to ground. The escape magnet will. thereupon be locked up, and the side switch wiperswill remain in position 2 until the switch is released and returns to its normal position.

The escape magnet 106 being energized and the side switch being in position 2, the busy tone device 114: is joined to the upper talking strand. It will be noted that this busy tone device was connected to the upper talking conductor while the last series of impulses was being transmitted, but as the calling subscribers receiver is short-circuited duringthe sending of the impulses and as the connector side switch moves to position 3 simultaneouslywith the opening of this shunt circuit when the wanted sub- 'scribers line is idle, the calling subscriber in that case would not hear the tone.

" If the called line is busy, the calling subscriber will hear the busy tone, and upon rep'lacing his receiver on the hook will open the circuit-for relay 11. The armature of relay ll will' fall off" and will remainretracted completing a circuit from battery through the slow-to-pull up relay 105, brush 20 and wiper 16, also from battery through the slow-to-pull-up relay 15 and resistance 17, and thence through the front contact and its armature and front contact, thus insuring the return of the selector switch to nor- 'mal position. Relay 105 completes a circuit from battery through the release magnet 117, rotary ofi-normal contact 118, closed on first rotary step, front contact and leftarmature of relay 105 to ground. v Magnet 117 pulls up and locks through'cont'act 118 and its armature and contact, thus causing the restoration of the connector switch;

If the wanted subscribers line'isidle, the contact engaged by brush/107 will not be connected directly to groundas previously described and, therefore, relay 104 will not 1 be energized and magnet 106 will retract its armatures moving the side switch to position 3. A-circuitwillnow be completed from battery through the escape'magnet .106,= armature and contactof trip relay 119 and side switchwi'per 113 to ground. The escape magnet attracts its armature, and

closesa-circuit from generator l20-through trip relay 119,contact and right armature of magnetx106, wiper 121,: brush 108,- the right side of the subscribers line, through the sub-5 stationbell, back over the left side of the line, brush 109 and side switch wipers v122 and 113 to ground' This causes the bell o the called substation to ring.

Upon the response of the calledsub-' scriber, the bell is short-circuited causing an increased flow of current through relay 119,

which attracts its armature, thus interrupt- .ing the circuit for escape magnet 106 and plied tothe called subscriber throughresistances 26 and33. Y

The release of the-switches is controlled solely by the calling subscriber, and when he interrupts his substation circuit'by replacing his receiver upon the hook, relay 11 will fall off, after which release will take place in exactly the same manner as described in regard to an unsuccessful connection.

What is claimed is: a.

1. In a telephone'system, an electrically:

operated switch, a circuit extending to said switch, said circuit including a talking conductor and a non-talking conductor,means controllable over said non-talking conductor for actuating said switchin establishing a connection, and test means connected to said talking conductor. a

'2. In a telephone system, an electrically operated switch, a'connecting circuit extending to said switch, said connecting circuit comprising a pair of talking conductors and a third or non-talking conductor, means controllable over said third conductor for -actuating said switch in establishing a connection, and test means connected toone of said talking conductors.

3.111 a telephone system, an incoming line, means including an electrically operated switch for extending said line, a connecting circuit extending to said switch, said connecting circuit comprising a talking conductorand a. non-talking conductor, means controllable over said non-talking conductor.for'actuating said switch in establlshing and-1n disestabhsh-ing a connection, andtest means connected to one of said talking conductors.

4:. In a telephone system, an incoming line,- means including a selector switch for extending said line, a connecting circuit exten'dingto said switch, said circuit comprising a pair of talking conductors and a third or non-talking conductor, means controllable over said third conductor for causing the movement of said switch in establishing a connection, means for determining the busy or idle condition of a circuit connected to one of said talking conductors, and means for releasing said switch controllable over said third conductor.

5. In a telephone system, a subscribers line, means including a selector. switch for extending said line, a connecting circuit extending to said switch, said circuit comprising a talking conductor and a non-talking conductor, a stepping magnet for said switch, means for joining said magnet to said non-talking conductor, means for transmitting impulses over said third conductor to said magnet to cause-the movement of said switch in establishing a connection and means for determining the busy or idle condition of a circuit arranged to be connected with said talking conductor.

6. In a telephone exchange system, a con necting circuit, including a talking conductor and a non-talking conductor, a selector switch having brushes at which said conductors respectively terminate, groups of trunk lines having terminals arranged to be engaged by said brushes, means operable by impulses over said non-talking conductor for moving said brushes from group to group of said trunk line terminals, and means connected to said talking conductor for controlling the operation of said switch to select the terminals of an idle trunk line.

7. In a telephone exchange system, a con necting circuit, including a talking conductor and a non-talking conductor, a switch having brushes at which said conductors respectively terminate, groups of circuit terminals arranged to be engaged by said brushes, means operable over said non-talking conductor for moving said brushes from group to group'of said extension circuit terminals, and meansconnectecl to'said talking conductor for determining the busy or idle condition of a circuit having its terminals engaged by said brushes.

8. In a telephone exchange system, a connecting circuit, comprising a pair of talking conductors and a third or non-talking conductor, a selector switch having brushes at which said conductors respectively terminate, extension circuit terminals arranged in groups, means operable over said third conductor for moving said brushes to select a group of said extension circuit terminals, means for causing said brushes to move a from circuit to circuit in the selected group tor switch having brushes ,at which said conductors respectively terminate, groups of extension circuits having terminals arranged to be engaged by the brushes of said switch, means controllable over said non-talking conductor for moving said brushes from group to group of the terminals of said extension circuits, means for moving said brushes from setto set of the terminals in the selected group, a test relay, and a side switch having a wiper for oining said relay to one of said talking conductors during such last named movement.

10. In a telephone exchange system, a connecting circuit consisting of a pair of talking conductors and a third or non-talking conductor, .a selector switch having brushes at which said conductors respectively tern'iinate, groups of extension circuits having terminals arranged to be engaged by the brushes of said switch, means controllable over saidthird conductor for moving said brushes from group to group of the terminals of said extension circuits, means for moving said brushes from set to set of the terminals in the selected group, a test relay, means for joining said relay to one 01 said talking conductors during such last named movement and means controlled by said relay for causing said switch to stop from set to set of the terminals in the selected group, a side switch, a circuit for said magnet including a wiper of said side switch, a test relay, a side switch wiper for joining said relay to one of said talking conductors during such last named move ment, a magnet for operating said side switch and a circuit for said side switch. magnet controlled by said relay.

12. In a telephone exchange system, a calling subscribers line,'means including a selector switch for extending said line, a connecting circuit including a pair of talking conductors and a third or non-talking nals, means for moving said switch over conductor extending to said switch, groups the terminals in a group, a test relay and of extension circuit terminals, an impulse means for connecting said relay to said relay, means at the substation for controltalking conductors to cause said switch to 5 ling the operation of said impulse relay to stop when its brushes engage the terminals 15 transmit impulses over said third conducof an idle extension circuit. tor, an electro-magnet associated with said In witness whereof, I hereunto subscribe third conductor and arranged to be actumy name this 13th day of January, A. D.

I ated by said impulses for moving said 1916.

1o switch from group to group of said termi- ARTHUR BRUCE SPERRY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0.

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