US1491154A - Line switch and connections - Google Patents

Description

April 22 1924. 1,491,154

F. A. LUNDQUIST LINE SWITCH AND CONNEGTINS Filed Oct. 23. 1918 lave/fof `terred to as motor 1.

Patented Apr. 22, 1924.

UNITED STATES FRANK. A. LUNDQUIST, OF

CHICAGO, ILLINOIS, AssIeNon, BY MnsNn AssIGNMnN'rs,

- T HENRY S. CONRAD, TRUSTEE.'

LINE SWITCH AND GONNECTINS.

Application led October 23, 1918.

To a-llwhom t may concern.'

Be it known that I, FRANK A. LUNDQUIs'r, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Line Switches and Connections, of which the following is a specification.

My invention relates to line switches and their' connections in automatic telephone exchanges, and has for its object improvements in such devices. :One object which may be mentioned as, a preliminary is an arrangement by which I dispense with the third wire normally used between the connector and the subscribers switch. Another 0b ject which I will mention in my preliminary statement is an arrangement by which I use the test magnet as a line relay.

The accompanying drawing is a diagram of a line switch and the connections leading to and from the switch as far as such connections are necessary to an understanding of the present invention. y

In the center of the drawing is a tube 1 which slides on a standard 2 when compressed air is admitted from pipe 3 to the interior of standard 2. These partsconstitute a pneumatic motor which will be re- On the top of motor 1 are some insulated wipers which are designed to make electrical connections with stationary contacts when the motor 1 is operated.

On one side of motor 1 are ratchet teeth Il adapted to be engaged by a pawl 5 to stop the motor at any desired position. A magnet having coils 6 and 7 acts upon its armature 8 to move pawl 5 into engagement with teeth 4. A spring 9 acts to move pawl 5 away from teeth 4.- and to move armature 8 to its retracted position.

Adjacent tothe magnet (i4-T is a valve 10 to which compressed air flows from a local supply pipe 11. The valve 10 is in the nature of a check valve which is normally held closed by the pressure of air in pipe l1. It has a st em12 which engages the armature 8 and acts to push said armature toward its retracted position. Back of armature 8 is a spring 13 which acts to push the armature 8 toward its attracted position and to hold said armature in Contact with stem 12. The combined force' of spring 9 and the air pressure on valve 10 is greater than the force Serial No. 259,398.

of the spring 13, so that armature 8 is normally held in its retracted position. But

when the magnet is energized, the attraction on .armature 8 plus the force of spring 13 is greater than the combined force olf' spring 9 plus the air pressure on valve 10, with the result that the valve is opened when the magnet is energized. When the valve 10 is opened, air flows from pipe 11 to pipe 111 and thence to a motor 15 which is of the same character as motor 1. yIn normal position, valve 10 permits air to exhaust from pipe 14.

At a convenient place is a magnet composed of coils 16 and 17 and armature 18. A spring 19 presses armature 18 against the stem of valve 20, but with a force less than enough to open said valve. But when the magnet 16-17 is energizechthe valve 20 is opened to permit compressed air to flow from pipe 11a to pipe 3. The pipe 11a is a branch of the supply pipe 11.

Pivoted at 21 to the frame of the switch is a bell crank lever 22, one arm of which rests on motor 15y so that when said motor is operated said arm is lifted to shift adjacentk contact springs. To the other arm of lever 22 is pivoted an arm 23 which vis pulledv upward hy a spring 241. W'hen motor 1 is in .normal position, a pin 25 on said motor engages the arm 23 to hold it in the posi# tion shown.

movement of lever 22 pushes arm 23 so as to shift the adjacentcontact springs to the right. But if motor 15 operates after mo-, tor 1 has ope-rated, then spring 24 has pulled arm 23 upward so that the said arm passes `over the adjacent contactsprings without touching them.

In addition to the parts so far described there are batteries X and X', a generator G, another motor and valve with levers and If the motor 15 operates when thelmotor 1 is in normal position, then the springs, certain contact springsand wipers a bridgeacross the contacts touched by the l bushes 40, 41, and when the selector is seized by the line switch the bridge is opened.

The consequent attraction oit the armature 8 throws the pawl 5 into the ratchet 4 and stops the motor 1 with its wipers in engagement with the stationary contacts which represent the found selector.` The armature 8 also opens valve 10 to admit air to motor 15, which motor tilts bell crank 22 to shift springs 37 and 44 from previous position to contact with springs 55 and 60. Motor also tilts bell crank 49 to open valve 50 and permit compressed air to lcw from pipe 3 thru pipe 51 to motor 52. This motor shifts springs 29 and 32 so as to break the circuit for magnet 16-17 and to connect the station wires and 31 to the wipers 57 and 62 as follows: 302953-54-3755- 56-57; and 3132-58-59-44-6U-61 62.y

When motor 15 moves lever 49 as before described, such movement ot 49 permits spring 63 to turn lever 64 on its pivot so that the catch 65 comes over the tail ot armature 18. As this occurs at the time, or slightly before, the circuit is broken thru magnet 16-17, the armature 18 is retained in its attracted position and the valve 2O is held open so that air remains on motors 1 and 52. l

The parts remain in this condition while the subscriber at the local station reached by wires 30 and 31 is talking to a called subscriber. When the calling subscriber hangs up his receiver he breaks the circuit for magnet 6-7 and this permits motor 15 to fall back. rThis in turn shuts air from valve 50 and permits motor 52 to tall back. The Same movement which permits valve 5() to close also turns arm 64 to release catch 65 from armature 18 so that said armature returns to normal position.v This l-ets valve 2O close, whereupon motor 1 falls back to normal position. y

When 15 first operated as previously described it was after motor 1 had moved. Consequently7 the tilting of bell crank 22 resulted in arm 23 passing over the adjacent contact springs and into a position which brought the hook 66 on arm 23 behind a stationary block or catch 67. When motor 15 released as described, spring 37 acting on bell crank 22 can return only part way to normal position until the i'all of motor 1 causes pin 25 to release hook 66 'from catch 67. What happens is that springs 37 and 44 are suspended between the upper and lower contacts with which they normally engage but from which they are wholly disengaged during release operations.

From the line switch wires 68 and 69 lead to contacts on connector switches, and when some other subscriber calls the. subscriber associated with this line switch he closes extensions of lines 68 and 69 whereupon a circuit is completed as follows: Xw35-6- the calling subscriber-69-72-73-597 48-X.

This actuates magnet 6 7 which throws pawl 5 into ratchet 4 so as to prevent motor 1 moving from normal position. The magnet valso opens valve 10 so as to admit air to motor 15. This motor acts on bell crank 22 and causes arm 23 to push the adjacent springs into engagement with other contacts, whereupon a current flows: generator G- 74-75-76-77-78-29-30-local station -31-32--79-80-81--82--83--Gr- This is a signalling circuit which calls the subscriber at the local station who rcmoves his receiver and thereby closes a circuit thru the magnet 1617 as in the previously described condition. The action of magnet 1617 opens valve 2O and admits air to motor 1, and, thru previously opened valve 50, to motor 52. Owing to the tact that pawl 5 had been previously thrown into ratchet 4, motor 1 accomplishes nothing. But motor 52 shifts the adjacent contact -springs to cut ott generator G and connect wires 30 and 31 to wires 68 and 69. These last may be traced as follows: 30-29-53- 54-70-71-68; and 31-32-5859-73- 72(i9.

From the description which applies to the line switch as a calling switch it will be seen that the magnet 6-7 becomes a line re` lay which remains energized in a bridge across the talking circuit. Vhen the line switch is a called switch, the magnet 6-7 is the test magnet which is energized over wires 68 and 69 leading back to a connector. lf the line switch is already acting as a calling switch, then the rise of motor 1 lifts part 84 and the terminals of wires 68 and 69 are disconnected from spring 7() and 73 so that a calling subscriber cannot find a busy line switch. But instead the wires 68 and 69 are switched to a pair of springs 85 and 86 which connect to a common buzz circuit (not shown) whereby the calling subscriber secures a busy signal.

When motor 52 operated to cut ott the generator G it also shifted the connections of wires 30 and 31 from the magnet 16-17 18, the valve is still held open and pressure is still on motorl. But when the circuit is broken thru magnet 6-'-7, motor 15 will fallback and this turn will release armature 18and permit valve 2O to close. The arrangement herein shown is such that the magnet 6-7 has its circuit closed thru both the calling and called station when the call comes from some station other `than the one associated with the line switch. As-a consequence of this, the circuit for magnet 6 7 can be broke-n only when both subscribers hang up their receivers at the end of a conversation. No special appliances or attachments are needed for preventing the line switch from making a trunk hunting movement when the called subscriber is the last to hang up. f

What I claim is: y e 1. In a line switch and connections therefor', a magnet serving as a line relay when the switch is a calling switch, and as a ring'-` ing relay when the switch is a called switch.

2. rIn a line switch and connections therefor, a magnet serving at one time as a line relay and at another time as a magnet for holding the line switch at normal position, a signaling generator, means controlled by the magnet for connectingthe generator to the connections leading from the line switch to the local station associated therewith, and meansby which such connections for the generatoris interrupted when' said magnet acts as a line relay. y

3. A line switchhaving a pair of wires leading to aconnector switchand a second pair of lwires leading to a local station, va signaling generator, means controlled over the irst pair of wires for connecting the generator to the second pair, and means for subsequently connecting the two pairs of wires to form a talkingcircuit;

4. A line switch having a pair of 1wires leading to a connector switch and a second pair of wires leading to a local station, a signaling generator, a pneumatic device for connecting the generator to the second pair of wires so as to call the subscriber at the local station. a magnetfor controlling the operation of the pneumatic device, means for controlling they magnet by an impulse liiowing over the first pair of wires, and

means by which the wires carrying such impulse are subsequently used in a talking circuit to the local station.

5. In a line switch and connections therefor, a line relay by which the line switch is controlled, and connections so arranged that upon a callcoming from a distant station to the station associated with the line switch said relay will have its circuit closed thru both the calling and the called stations.

6.*A line switch having a pair of wires leading to a connector switch and a second pair of wires leading to a local station, a magnet arranged to have` its circuit closed thru the first pair of Wires, and a pneumatic device controlled by said magnet for connecting the twopairs of wires to form a talking circuit.

7, `A line switch having a ypair of wiresk leading to a connector switch and a second pair of wires leading to a local station, a.

magnet bridged upon the talking circuitr formed by connecting the two pairs of wires together, and a pneumatic device controlled by said magnet for controlling the completion of the circuit upon which it is bridged.

8. In a line switch and connections therefor, a magnet servingfirst as a test magnet and then as a line relay when the switch is a calling switch, and first as a ringingjrelay and then as a line relay when the switch is a called switch. y

9. A line switch having a pair of wires leading to a connector switch and a second pair of wires leading to a local station, a signalling generator, means controlled over the rst pair of wires for connecting thegenerator to the second pair,y and means for subsequently disconnecting said generators from said second pair of wires and :tor subsequently connecting the two pairs of wires to form a talking circuit. e

l0. A line switch having a pair of wires leading to a connector switch and a second pair of wires leading to a local station, a signalling generator means controlled over said first pair of wires for connecting saidy generator to said second pair of wires to signal the subscriber at said local station, y

and a pneumatic device for subsequently connecting the two pairs of wires to form a talking circuit.

1l. A line switch having a pair of wires leading to a connector switch and a second' pair of wires leading to a local station, aik

magnet on said line switch havingtwo windings, one of said windings normally connected'to one of said iirst pair of Wires and to one pole of battery, the other windf ing normally connected to the other wire of said tirst pair of wires and to the other pole `or" battery, means for operating said magnet over said first pair of wires, and means for connecting said magnet to said second pair y oitwires.

l2. A Vline `switch having a pair of wires leading to a connector switch andasecond pair of wires leading to a local station, a

magnet normally connected to said first pair of wires, a relay normally connected to said second pair of wires, means operated in response to the operation of said magnet when said switch is a calling switch for disconnecting said relay from said second pair of wires, and said means operated in response to the operation of said relay when said switch is a called switch `for disconnecting said relaytrom said second pair of wires.

13. A line switch having a pair of wires leading to a connectorl switchand a second pair of wires leading to a localstation, a magnet normally connected to saidrfirst pair of wires, a relay normally connected to said second pair of wires, means operated in response to the operation of said magnet when said switch is a calling switch for disconnecting said relay from said second pair of wires and Jfor connecting said magnet thereto, and said means operating in response to the operation or" said relay when said switch is a called switch for disconnecting said rer lay from said second pair of wires and for connecting said magnet thereto.

14;. A line switch having apair of wires leading to a connector switch and a second pair oi' wires leading to a local station, a magnet normally connected to said first pair of wires, a relay normally connected to said second pair of wires, ay pneumatic device operated in response to the operation of said magnet when said switch is a calling switch for disconnecting said relay from said second pair of wires, and said device operated in response to the operation of said relay when said switch is a called switch for disconnecting said relay from said second pair of wires.

15.' A line switch having a pair of wires leading to a connector switch and a second pair of wires leading to a local station, a magnet normally connected to said first pair ot wires, a relay normally connected to said second pair of wires, a pneumatic device in said switch for disconnecting said relay from said second pair of wires and for connecting both said pairs of wires together so that said magnet is connected to both of said pairs, said device operated in response to the operation of said magnet when said switch' is a calling switch, and said device operated in response to the operation of said relay when said switch is a called switch.

16. A line switch having a pair of wires leading to a connector switch and a second pair of wires leading to a local station, a magnet normallyv connected to said first pair of wires, a relay normally connected to said second pair of wires, a device in said switch for disconnecting said relay from said second pair of wires and for connecting both said pairs of wires together so that said magnet is connected to both of said pairs,

said device operated in response to the op eration of said magnet when said switch is a calling switch, andsaid device operated in response to thev operation' of said relay when said switch is a called switch.

17. In a line switch a pneumatic device on said switch for disconnecting generator from the calledyline and for connecting the calling and called lines together to form a talking circuit, a magnet and a relay on said switch, a source ofair pressure, said relay partially completing an air passage from said source to said device and said magnet completing the air passage so as to cause the operation of said device when said switch is a calling switch, said magnet partially completing an air passage from said source to said device and said relay completing the air passage so as to cause the operation of said device when said switch is a called switch.

18. In a line switch, a pneumatic device on said switch for disconnecting generator from the called line and for connecting the calling and called lines together to form a talking circuit, a magnet and a relay on said switch, a source of air pressure, 4said relay partially completing an air passage from said source to said device and said magnet completing the air passage so as to cause the operation of said device when said switch is a calling switch, said magnet partially completing an air passage from said source to said device and said relay completing the air passage so as to cause the operation of said device when said switch is a called switch, and means controlled by said magnet for maintaining said device in operated position.

19. In a line switch, a pneumatic device on said switch for disconnecting generator from the called line and for connecting the calling and called lines together to form a talking circuit, a magnet and a relay on said switch, a source of air pressure, said relay partially completing an air passage from saidsource to said device and said magnet completing the air passage so as to cause the operation of said device when said switch is a calling switch, said magnet partially completing an air passage from said source to said devi-ce and said relay completing the air passage so as to cause the operation of said device when said switch is a called switch, and means by which either the calling or called line controls the release of said magnet to cause the release of said device.

FRANK A. LUNDQUIST.

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