US1493254A - Automatic telephone system - Google Patents

Description

May 6 1924. 1,493,254

J. ERICKSON AUTOMATIC TELEPHONE SYSTEM Filed Oct. 21, 1918 2 Sheets-Sheet l Julm EZEKSUTZ.

'HZTH:

May 6 1924.

J. ERICKSON AUTOMATI C TELEPHONE SYSTEM Filed Oct. 21, 1918 2 Sheets-Sheet 2 Juhn .ErzcKsuz'z.

Patented May e, 1924.

UNITED STATES 1,493,254 PATENT, OFFICE.

JOHN ERICKSO'N, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

-AUTOMATIC TELEPHONE SYSTEM.

Application filed October 21, 1918., Serial No. 259,062.

To all whom it may concern:

Be it known that I, JOHN ERIoKsoN, a citizen of the United States of America, and a resident of Chicago, county of Cook,

State of Illinois, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

My invention relates in general to auto- 1 matic telephone systems and more specifically to an improved type of automatic switch to be used in a system of this type for extending connections from one subscribers line to another. One of the objects of my invention is to provide a mechanism for extending the lines of a subscriber in the simplest manner possible and to provide such a mechanism which is novel in action and which while meeting all the requirements ofsuch service, has a much longer life than mechanisms previously employed and has a centainty of action which is very desirable.

In the well known Strowger type of automatic switch which has been used in the past one of the chief objections has been to the use of the ratchet and pawl action for raising and rotating the w1pers. This action is quite noisy and at the same time is apt towear out on account of the jar and rubbing action of the pawls against the ratchet, also the impulses from the subscriber must'be of a certain length and strength and the magnets for operating the pawls must be strongand therefore use up considerable current.

In order to overcome these difliculties I have devised an improved and novel switch operating mechanism and method of control therefor which is highly efiicient and which at the same time operates accurately to control the movement of the wipers of a switch, whether the controlling impulses are uniform in strength and speed or not,'thus preventing a great deal of the trouble in getting false connections and wrong numbers, when the impulses vary from standard due to leakage or'too much capacity or resistance in a line circuit.

Having described my invention in general I will now describe the operation of one embodiment of my invention as shown in the accompanying drawings, in which,

Figure 1 is a side view of an automatic switch operated in accordance with my invention.

Figure 2 is a front view of the apparatus shown in Fig. 1. I

Figure 3 is an enlar ed view showing the operating magnets an their special armature more clearly. G 1

F i 4 is a cross section along the line A- in Fig;

3. w Figure 5 s owsa circuit diagram of-the switch as used in establishing a connectionfnom one substation to another. The switch H, Figure 5, has an operating mechanism such as shown in Figures 1, 2, '3, and 4.

Fig. 6 shows the arrangement of the contacts in the bankof the switch.

Referring now to Figure 1, in order to simplify the ex lanation of the mechanism I have shown t e same in connection with a simple one motion rotary switch such as might be used in an installation of a P. A. X. of from 25 to 50 lines. The type of switch shown is that having a plurality of wipers which rotate over a series of contact sets, one after the other, until a desired line is located and which ,are then released and returned, to normal by. means of a spiral spring. The leads or connections to the wipers consist of brushes which 'rub on the center portion of each wiper.

In order to operate these wipers I provide a gear wheel 2, rigidly mounted on the shaft carrying the wipers and cooperating with a worm gear 3 which drives the gear wheel. This worm gear 3 is normally in mesh with the teeth of gear 2 and is pivoted at one end in the armature 4 of a release magnet 5 and at the other end has a flexible connection with the armature of a pair of op erating magnets 6. Any rotary movement of the worm gear 3 drives the wipers forward toward another set of contacts.

The operating magnets 6 with their armature are shown more; clearly in Fi res 3 and 4. These magnets are mounted e tween a pair of brassbrackets 7: and 8, each magnet having a pair of pole pieces 9 and 10 and 11 and 12, respectlvely, the inner ends of which are bent toward each other as shown. The armature of these two magnets is of peculiar design and is pivoted at points 13 and 14 in the brass plates 7 and 8. This armature consists of a shaft 15 having a brass piece 16 fastened to one side thereof by means of holes in its bent over end, and

oured to the ends of the brass piece 16 is an iron part 18 which is so formed that one edge of its outer surface is very close to the pole pieces 11 and 12 or 9 and 10 when rotated, while its other edge is much farther away from the pole pieces, as shown in Figure 4. This whole armature being of a cylindnical shape, may revolve inside the curved pole pieces 9 and 11 at one end and 10 and 12 at the other end.

Now assume. the armature to be resting as shown in Figs. 3 and 4 with the iron part 18 thereof close to the pole pieces 11 and 12. It will be seen that the thinner edge thereof is nearest to the left hand magnet 6. Now when the left hand magnet is energized the armature will be rotated in the direction of the arrow in Fig.4. As the armature turns it will be seen that the thicker part of the part '18 gets nearer to the pole pieces so that the magnet always has something to pull against and will continue to draw the armature around a complete half turn until the part 18 stands with its thick edge flush with the upper or back edge of pole pieces 10 and 9, Figs. 3 and 4, so that the thin edge will now be closer to pole pieces 11 and 12 than the heavy edge. Then if the right hand magnet 6 be energized it will be seen that the armature will again be drawn about its axis in .the direction of the arrow. The armature is therefore given one full turn by the energization of first one and then the other of its controlling magnets. The worm gear 3 and the gear wheel 2 are so. related thatone comple'teturn of the armature of the magnets 6 moves the wiper of the switch, through the worm and gear, one step onto the next set of contacts so that 4 impulses will send the wipers 2 steps, that is,4 impulses delivered alternately to the operating magnets.

As the wipers are thus advanced by the worm 3, tension is stored up in the spiral spring 19 which winds around the wiper shaft. After the wipers have been rotated in this manner they may be released by the operation of the release magnet 5. This magnet 5, as explained, has an armature one end of which acts as a pivot for the worm 3.

4 Now when magnet 5 is energized the worm 3 is carried away from the teeth of the gear 2 and the spring 19 acts on the shaft, to rotate the wipers back to normal position. An arm or normal post 20 is rigidly secured to the wiper shaft and controls the off normal springs. As the wipers advance this arm 20 leaves said springs and allows them to come into'contact in pairs and again forces them apart when the wipers are released. It will switch operating motor mechanism which moves the wipers always in one direction in response to impulses without jar or noise and consequently with very little friction or wear on the parts. Also that the worm gear 3 acts as a driving gear to advance the wipers, holds them in their advanced position, and is again operated to release the wipers.

:thus be seen that I have provided a novel Referring now to Figure 5, I will explain 7 the operation of a system using a switch such as shown in Figs. 1,2, 3 and4. When the subscriber at substation A removes his receiver a circuit is closed for the line relay 25 in series with the calling line. Relay 25 energizes and closes a circuit from ground through springs 26 and 27, relay 31, and springs 32 and 33 to battery. 7 Relay 31 connects ground throughsprings 34 to the private normal conductor 37, and prepares a circuit for slow relayt38 and magnet 41 at sponds to the left hand magnet 6 in figures 2, 3 and 4. Magnet 41, upon energizing, draws the armature around one half turn as explained in connection with Figure 3 and thereby rotates the worm 3 (Fig.1)

sufliciently to move the wipers 47, 48 and- 49 half wa to 'the first set of contacts in the bank 0 the switch. As a result of this movement of the shaft and wipers, the off normal post 20 is moved away from the off normal springs 50 and 51 which close contact and prepare circuits for the release magnet 5 and switching relay 52, respectively. Now as relay 25 again energizes, a

circuit is closed from ground through springs 26 and 27, springs 53, springs 54, springs 55 and 56, and magnet 42 to battery. As before pointedout, magnet 42 draws the armature around anotherhalf turn until the iron portion thereof lies against its pole piece, and thereby, through the action of worm gear 2, drives the wipers 47. 48 and 49 onto the first set of bank contacts. It will therefore be seen that one deenergization and energization of the line relav 25 in response to a single impulse from the calling device, operates to send two impulses to the operating magnets of the switch, one to one magnet. and one to the other, and that these two impulses operate the switch to step the wipers one step. It will be understood that the relays 31 and 38 being slow acting, remain energized during the operation of relay 25. As soon as relay 25 comes to rest energized, relay 38 will fall back. Relay 38, while energized, maintains the circuit of relay 43 open at springs 58, opens the circuit from the private wiper 49 at springs 59, maintains the circuit of magnet 42 closed at springs 53, and completes a circuit of the slow relay at springs 61, extending from ground through springs 62, springs 61, springs 63 and 64, springs 65, and relay 60 to battery. Relay 60 now energizes over this circuit to prepare a circuit for relay 66 at springs 67, opens the circuit of relay 52 at springs 68, opens one point at springs 69 in the circuit of the lower windingof the back bridge relay 73, prepares a locking circuit for itself through springs 70 in case the called line is busy, opens springs 71, and closes one point in the busy signalling circuit at springs 72.

Assuming now that any lineis called whose number is less than 10, then the first series of impulses will operate the magnets 41 and 42 to step the wipers 47, 48 and 49 into engagement with the contacts connected to that line. Relay 60, being slow acting,

remains energized for a time after the impulses cease and after relay 38 opens the springs 61, so that, in case the called line is busy, and a ground is present on the contact with which private wiper 49 connects,

an energizing circuit will be closed from ground through wiper 49, springs 59, springs 74 and 75, springs 67, and upper winding of relay 66 to battery. Relay 66 energizes and locks itself to ground through springs 76, closes one point in the circuit of relay 73 at springs 77, closes another point at springs 78 in the locking circuit of the relay 60, and connects the busy tone circuit from springs 72 to one side of the talking circuit. As a result of this operation it will be seen that relays 60 and 66 remain locked up and a busy tone is connected to the calling subscribers line circuit.

Assuming, however, that the called line is idle, then as soon as the impulses cease and relay 38 falls back, relay 66 not having energized in this case, relay 52 will be energized over a circuit. extending from battery through said relay, ofi' normal springs 51,

springs 79, springs 68, and ground through springs 80. Relay 52 opens the circuit of relay 60 at springs 65, connects ground to the private wiper 49 through spring 74 and its front contact, opens the circuit of the operating magnets at springs 46 and 54 and connects the called line to the ringing circuit through springs 81 and 82 and springs 83. Ringing current will now flow from the ringing interrupter R through springs 84 and 85, through springs 86, springs 81 and 82. wiper 48, through. the bell of the called substation, back over wiper 47, springs 83,

springs 87 and 88, and upper winding of ring out off relay 66 to battery. As soon as the called subscriber answers, relay 66 energizes over this circuit in series with the talking circuit of the called line, and disconnects the ringing circuit from the called line and cuts the line through to the back bridge relay 73. Relay 66 also closes a locking circuit for itself at springs 76, to ground through springs 80, and connects ground through spring 78 and its front contact to the holding circuit of relay 52 and through spring 74 and its frontcontact to the private wiper. Back bridge relay 73 now energizes in series with the called line and opens springs 79. Conversation may now be carried on over the heavy conductors shown and when the conversation is com pleted, the release is accomplished as follows: Relay 25 deenergizes and opens the circuit of relay 31, which in turn falls back to close the circuit of release magnet 5 over a circuit from ground through springs 26 and 45, through springs 39 and 89, off normal springs 50 and relay 5 to battery. Release magnet 5 attracts its armature to draw the worm gear 3 out of engagement with the gear 2. As shown in Fig. 1, this worm gear has a flexible joint or spring joint which permits it to be thus moved by the armature 4. As. soon as the worm disengages gear 2, said gear is drawn back to its norma position by the spiral spring 19 and upon reaching normal the normal post 20 engages and operates the springs 50 and 51 and thereby opens the circuit of magnet 5. A further result of the operation of magnet 5 is the opening of springs 55 and 56 and closing of springs 55 and 57. This closes the circuit of operating magnet 42 and if the armature has by any chance been left in half wayposition, this insures that it will always rest at normal so that the initial impulse of the next call which always comes to magnet 41, will always be effective to move the wipers the desired half step.

So far I have explained the operation of the switch when from one to ten impulsesare sent to operate the same. As it is well known that-the usual calling device is of the ten impulse type it will be understood that some method must be devised for taking care of the calls up to No. 25 as this will necessitate more than "one operation of the dial. I have shown the arrangement of'the contacts in the bank of the switch in Fig. 6. Now if it is desired to call the number 12 contact or line then first ten impulses will be delivered to the switch to step the wipers to the contact marked 0 or tenth contact and then two impulses will be sent to step the switchto the second contact beyond the 0 contact, or if the twenty second contact or line is desired two sets of ten impulses are sent to the switch to step it first to the 0 contact and then to the 00 contact and then two impulses step the switch to the second contact beyond the 00. The Wipers normally stand on the first contact shown and in order to prevent wrong numbers because'of an extra impulse transmitted by the receiver hook when the receiver is removed I have connected the second contact to the busy signaling machine so'that if a single impulse is sent in the switch will stop on the contact marked 1 and give the calling subscriber a busy signal.

Referring now to Fig. 5, I have shown the method by which I prevent the operation of the relay 52 and the subsequent cutting ofi' of the operating magnets when the switch stops between series of impulses on the'O or 00 contacts. I have shown just below the wiper 48 one of the line contacts of the O and 00 contacts which is connected through a resistance to ground. Now when the wipers come to rest'between the series of impulses and wiper 48 rests upon the contact 90, then a circuit is closed from ground through resistance 91, contact 90, wiper 48, spring 81.and its back contact, springs 71, springs 92, and through the upper winding of relay 73 to battery. Relay 73. now energizes and opens the springs 79 in the circuit of relay 52, so that relay 52 will not energize and open the circuit of the operating magnets at springs 46 and 54.

As soon as the next series of impulses come in the circuit of relay 73 is of ..c ourse broken at wiper 48 and if ten more impulses are sent thev circuit of relay 73 will again be closed at the 00 contacts. I It will be seen therefore that I have provided a novel and eflicient switch operating, mechanism which is in the nature of a motor operated by impulses and having a pair of operating magnets operated alternating to rotate a shaft always in the same direction to step a series of wipers step by step over a series of contacts. Also the gear or stepping armature which is used to rotate the wipers is used both as a holding and a release pawl. It will be understood that I have shown only one modification of my invention to illustrate the same and that other modifications in the method of control will readily suggest themselves to those skilled in the art and come under the scope of my invention.

'Having fully described and ascertained the features and aspects of my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, an automatic switch, wipers for said'switch, a motor for driving sald wipers consisting of a pair of operating magnets ,having a; common rotatable armature, and means for energizing said magnets alternately to move said armature always in one direction to move said wipers. I

2. In a telephone system, an automatic switch, wipers for said switch, a motor for driving said wipers consisting of a pair of operating magnets having a common rotatable armature, and means forenergizing said magnets alternately to move said ar-' driving said wipers consisting ofa pair of operating magnets having a common rotatable armature, and means for energizing said magnets alternately to move said ar- 'mature always in one direction to move said wipers in response to a single" series of impulses.

5. In a telephone system,-an automatic switch, wipers for said switch, a motor for driving said wipers consisting of a pair of operatmg magnets having a common rotatable armature, and means for energizing said magnets alternately to move said ar-v mature always in one direction to move said wipers in response to a plurality of series of impulses.

6. In a telephone system, an automatic switch, wipers for said switch, a motor for driving said wipers consisting of a pair of operating magnets having a common rotatable armature, and means for energizing said magnets alternately to move said armature always in one direction to move said wipers step by step in response to a plurahty of series of impulses.

7. In a telephone system, an automatic switch having wipers, a shaft for moving said wipers, a pair of magnets having a commonrotatable armature for driving said shaft, and means for operating said magnets alternately to move said armature always in one direction to operate said shaft in a step by step manner to drive the Wipers.

8. In a telephone system, an automatic switch having wipers, contacts accessible to said wipers divided into groups, a motor for driving said wipers over said contacts, said motor consisting of a'pair of magnets having a common rotatable armature,

means for delivering a series of impulses to said motor, and for causing each successive impulse to operate alternate ones 'of'said magnets, and means controlled by the alternate operation of said magnets to move said common armature to which said shaft is geared, and means for transmitting an impulse to first one and then the other of said magnets to step said shaft one step.

10. In a telephone system, an automatic switch, wipers for said switch, a motor consisting of a pair of magnets for operating said wipers, a common-armature for said magnets, a shaft geared to said armature, said wipers directly controlled by said shaft, and means for operating first one magnet and then the other to rotate'the shaft and move the wipers one step.

11. In a telephone system, an automatic switch having wipers, a gear for driving said wipers, a motor for driving said gear always in the same direction consisting of a pair of magnets, means for delivering a plurality of impulses to said motor to operate said magnets alternately and means controlled by the alternate operation of said magnets for operating said gear to drive the wipers in a step by step manner.

12. In a telephone system, an automatic switch having wipers, a gear for driving said wipers, a motor for driving said gear consisting of a pair of magnets, means for delivering a plurality of impulses to said motor to operate said magnets alternately means controlled by the alternate operation of said magnets for operating said gear to drive the wipers in a step by step manner, and means for disengaging said gear from the wipers to release the wipers.

13. In a telephone system, an automatic switch having wipers, a worm gear for driv- :ing said wipers normally ,in engagement with said wipers, a pair of magnets for driving said gear, means for operating said magnets alternately to drive said gear in one direction and a. magnet for removing said gear from engagement with the wipers to release the wipers from an advanced position.

- 14. In a telephone system, an automatic switch having a line relay and wipers, a motor for driving said wipers consisting of a pair of magnets having a common rotatable armature, means for operating said line relay in response to impulses to control said motor, each energization of said line relay causing the operation of one of said magthe medium of sai nets and each .deenergization of said relay causing the energization of the other of said magnets, the energization of both magnets causing a single ste of said wipers through armature.

15. In a telephone system, an automatic switch, a wiper carrying element therefor,

and motor for moving said element, a shaft for said motor, said shaft in continuous engagement with said element while the element is moved a plurality of steps and said motor operated by impulses of direct current to' move the element in its steps, and means for disengaging said shaft from said element to release the switch.

16. In a telephone system, an automatic switch, having an operating magnet consisting of a pair of magnets having a common armature which is rotatable always in one direction, and carrying -a worm gear on one end thereof, means for operating the'switch through the medium of said magnets and gear, and means for disassociating said Worm gear from the switch to release the switch. Q

17. In an automatic switch, a motor magnet comprising two coils, a line relay for transmitting impulses to said coils alternately, an armature rotating continuously in the same direction responsive to the alternate energization of said coils, a wiper supporting element for said switch, and a reduction gear coupling the said armature and element together.

18. In an automatic switch, a motor magnet comprising two coils, a line relay for transmitting impulses to said coils alternately, an armature rotating continuously in the same direction responsive to the alternate energization of said coils, a rotatable wiper shaft for said switch, and a reduction gear coupling the said armature and shaft together.

19. In an automatic switch, a motor magnet comprising two coils, a line relay for transmitting impulses to said coils alternately, an armature rotating continuously in the same direction responsive to the alternate energization of said coils, a rotatable wiper shaft for said switch, a spring tending to maintain said shaft in a fixed position, and a worm gear coupling the said armature to said shaft to rotate the same against the tension of said spring, the said worm gear serving to prevent retrograde movement of the shaft when said coils are not energized.

20. In an automatic switch, a motor magnetcomprising two coils, a line relay for transmitting impulses to said coils alternate ly, an armature rotating continuously in the same direction responsive to the alternate energization of said coils, a rotatable wiper shaft for said switch, a spring tending to maintain said shaft .in a fixed position, a worm gear coupling the same armature to said shaft to rotate the same against the tension of said spring, the said worm gear serving to prevent retrograde movement of the shaft when said coils are not energized, and electro-magnetic means for separating the elements of the worm gear when the switch and shaft together. 1

22. In an automatic switch, an individual motor magnet, a llne relay for transmitting impulses to said magnet, an armature for sa1d magnet revolving contlnuously 1n the same direction responsive to said impulses, a rotatable wiper shaft for said switch, and

" means for coupling said armature to said shaft, said means comprising a worm gear ,which operates to drive the shaft when the armature is revolving and to prevent the return movement of the shaft when the armature is standing still.

23. In an automatic switch, two rotatable shafts disposed at right angles to each other,

wipers mounted on one of said shafts, a mo-.

tor for driving the other shaft, said motor comprising magnets and an armature mounted on said shaft for rotation between the poles of said magnets, a line relay for transmitting impulses to'the motor magnets to rotate the armature shaft, and means for causing the armature shaft to rotate the wiper shaft.

Signed by me at Chicago, Cook County, State of Illinois, this 19th day of October,

JOHN ERIG'IKSON.

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