US1343256A

US1343256A - Selectively-operated circuit-controlling device

Info

Publication number: US1343256A
Application number: US98384A
Authority: US
Inventors: Joseph C Field
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1916-05-18
Filing date: 1916-05-18
Publication date: 1920-06-15
Anticipated expiration: 1937-06-15
Also published as: FR541180A; GB117170A; US1478005A; US1378943A; FR25866E; DE371358C; FR25557E; DE445968C

Description

1. c. FIELD.

SELECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE.

APPLICATION FILED MAY I8, 1916. 1,343,256. Paten edJune 15, 1920.

3 SHEETSSHEET I.

/m/en for: Joseph 6. Pie/d I Affy.

J. C. FIELD.

SELECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE.

APPLICATION FILED MAY 18, 1916.

1,343,256. Patented June 15, 1920.

3 SHEETS-SHEET 2.

Fig; a

lnven/or: Joseph F/e/d' y I. C. FIELD.

SELECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE.

' Patented June 15, 1920.

APPLICATION FILED MAY I8, 1916.

3 SHEETSSHEET 3.

n mm J J'OSEPH C. FIELD, OF ORANGE, JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED. OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SELECTIVELY-OPERATED CIRCUIT-CON TROLLIN G DEVICE.

Patented June 15, 1920.

Application filed May 18, 1916. Serial No. 98,384.

To all whom it may concern Be it known that I, Josnrn' C. FIELD, acitizen of the United States, residing at Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Selectively- Operated Circuit-Controlling Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to selectively operated circuit-controlling devices and more particularly to such circuit controlling devices of the step-by-step type.

It is the object of this invention to provide new. and improved selectively operated circuit controlling devices.

In accordance with one feature of this invention, there is provided a selectively operated circuit controlling device of few and simple parts and sturdy construction which will operate rapidly, accurately and efficiently in response to alternating current impulses.

In accordance with another feature of this invention, there is provided means in a device of this character whereby a plurality of separate circuits may be selectively controlled by a single device over the same operating circuit with other devices of the same type without mistakes or confusion of signals.

In accordance with another feature of this invention. there is provided a step-bystep element having cooperating therewith a single stepping or actuating pawl which is operated by the armature of a polarized electromagnet to cause said step-by-step element to be advanced one complete step in response to eachhalf cycle of alternating current through the winding of the electromagnet.

In accordance with another feature of this invention. means are provided for advancing the step-by-step element; of each selective device through different stages of movements and holding it in such advanced positions for a period of time during which the electromagnet of the selective devices is deenergized. This may be accomplished by attaching to the step-by-step element a contact member or segment carrying a plurality of projections or pins adapted in certain positions of said step-by-step element to be engaged by a holding member when the electromagnet is de'energized. The holding member is preferably controlled by the armature of the electromagnet.

Other features of the invention relate to the details of construction and combination of parts whereby the minimum number of parts are used, all of which may be easily formed and assembled.

In the drawings, Figure l is a front view of a device embodying the features of this invention; Fig. 2.is a side view; Figs. 3,

' 4 and 5 are detail views illustrating the different positions the mechanism assumes in its operation; Fig. 6 is a perspective of the device. with the frame carrying the moving parts separated from the electromagnet; Fig. 7 is a diagram of the apparatus and connections of a circuit equipped with the device of this invention; Fig. 8 is a side VleV from a position to the left of Fig. l,o f a section of the step-by-step element showlng an elongated holding pin; Fig. 9 1s a bottom view of the same section of the step-by-step element showing the manner in which the elongated holding pin is mounted thereon; and Fig. 10 is a View of the stepby-step element when in position for receiving time signals.

As shown in the drawings, 5, 5 designate the windings of an electromagnet controlling a centrally pivoted armature 6, which is polarized b means of a permanent magnet 7. Attac led to the armature 6 is an elongated S-shaped arm 8 carrying at its free end a pin 9 and at a point intermediate its ends a pin 10, both pins being adapted to engage a pivoted lever 12 carr ing at its upper end a stepping pawl 13. he coils 5, 5 and the cores on which they are wound are supported in a bracket 19 mounted on a base 1-, preferably of insulatin material. Carried by the supporting brac et 19 is a frame composed of front and back members or

plates

14 and 15 fastened together, between which'there is a pin 16 upon which the lever 12 is pivoted in position to move the stepping pawl 13 into engagement with a ratchet wheel 17 mounted upon a shaft 18 journaled in the

frame members

14 and 15. By means of a spring 15 the ratchet wheel 17 is normally retained in a position with a pin 56 therein in engagement with a stop member 57. The stepping pawl 13 is normally held against a stop pin provided in the back frame member 15 by the action of aspring 51 attached at one end to the pawl 13 and at the other to the pivoted lever 12. An adjustable pin 52 mounted in a projection of the front frame member 14 limits the forward travel of the pawl 13. By means of a spring 43 secured at one end to the lower end of lever 12 and at the other to an arm 36 mounted on the back frame member 15 (see Figs. 1 and 3) the lever 12 is normally held in the position shown in Figs. land 5 with the stepping pawl out of engagement with the ratchet wheel 17. The

pins

9 and 10 engage the pivoted lever 12 upon opposite sides of the pivot axis or pin 16 and upon opposite faces in such a manner that with each movement of the armav ture 6, in either direction, the stepping pawl 13 will cause a one-step movement of the ratchet wheel 17.

Mounted upon the shaft 18 carrying the ratchet wheel 17, and movable therewith, is a contact carrying member 20-carrying a contact spring 53 in the free end of which is a contact 21 adapted to coiiperate with a pluralit of

contact springs

22, 23, 24 and 25 mounte upon an insulating plate 26 secured to the back frame member 15.

Holding pins

27, 28 and'29 carried by the contact carrying member 20 are adapted to cooperate with a holding spring 35 mounted on the frame member 14. The holding pin 29 is located in a definite position on the contact carrying member 20, while the

holding pins

27 and 28 are made removable so they may be secured in any two of the

holes

54, 54 drilled in the contact carrying member 20, depending upon the code of impulses to which the particular selector is to be made responsive. The spring 35 normally bears against an insulating knob or roller 37 carried by the lever 12. The spring 35 is so tensioned or bowed that in the neutral position of the armature the free end of said spring, which is provided with .a curved projection 38, extends inside the circumference of a circle described by the holding pins 27 28 and 29 in the movement of the contact carrying member 20. As the armature 6 moves, however, in response to current impulses throu h the

windings

5, 5 of the electromagnet, t e

movements of the lever 12 will move the projection 38 at the free end of said spring 35 outwardly beyond the margin of the contact carr ing member 20. When the ratchet tail of pawl 40. As the arm 8 moves in the this pawl 40 is pivotally mounted upon the 7( pin 16, and is ada ted to be moved into engagement with t e ratchet wheel 17 by means of a spring 41 secured at one end to the tail of the holding pawl 40, and at the other to an arm 39 mounted upon the back frame member 15 (see Figs. 1 and 3). and to be moved out of engagement therewith by a pin 42 in one end of the lever 12. The pin 42-normally'keeps the holding pawl 40 out of engagement with the ratchet wheel 17 against the action of spring 41. It will be noted by reference to Figs. 3 and 4, (the right hand end of armature 6 being attracted in Fig. 3 and the left hand end in Fig. 4) that at the time the lever 12 5 is moved by the arm 8 into position to bring the steppingpawl 13 into engagement with the ratchet wheel 17 the pin 42 will be separated a distance from the end of the reverse direction and the lever 12 is moved about its pivot pin 16 by the spring 43, there will be a short interval of time before the projection 42 will engage the holding pawl'40. While the holdmg pawl 40 will actually be moved out of engagement with the ratchet wheel 17 before the reengagement therewith of the stepping pawl 13, the time intervening is so short that it will not be suflicient for the spring 45 to overcome the inertia of the ratchet wheel 17 andits associated parts.

For the purpose of providing for the simultaneous reception of time s1 als at all stations of a selective signaling system equi ped with selectors embodying features of t e present invention, the contact carrying member or step-by-step element 20 is provided with a holding member 55 so positioned that its curved end will be engaged by the curved projection 38 of the 'holdmg spring 35 (as shown in Fig. 10), when the element 20 has been advanced in response to twenty impulses of current through the

magnet windings

5, 5. The holding member 55 has a tail piece havin two

lugs

108 and 109 bent at substantia ly right angles thereto by means of which the holding member 55 is secured to the lower side of the element 20, as clearly shown in Figs. 8 and 9. The curved endof the holding member 55' corresponds to any of the pins 27 28 and 29 positioned in the element 20, that is, in so far as its function of holding the stepby-step element in advanced position is concerned. The tail iece of the holding member 55' is provide so that after the projection 38 of the holding spring 35 engages 'the curved end of the holding member 55, v the advancement of the element 20 in re deenergization of the selector magnets will not permit the return of the element 20 to normal position; for the projection 38 of the holding spring 35 in moving in toward the element 20 will strike the tail piece of the holding member 55 which due to the action of the spring 45 will be rotated with the element 20 until the curved end of bold ing member 55 engages the projection 38.

i The element 20 will therefore be held in advanced position with the movable contact 21 thereof within one step of the stationary contact 25 or five steps beyond the station contact 22, as shown in F ig. 10. The length of the tail piece of the holding member 55 is such that, after the curved end thereof is engaged by the projection 38, the element 20 must be advanced at least four steps more before the projection 38 in moving in toward the element 20 will clear the end of the tail piece and permit the spring 45 to return the element 20 to normal position. Contact 25, which may be considered the time receiving contact, is connected with the station contact 22 by means of a strap 58.

\Vlien projection 38 on spring 35 engages the pin 29, contact 21 carried by member 20 is in engagement with contact 22 mounted on the insulating plate 26, so a circuit 1s completed which includes the frame of the selector, member 20, spring 53 and

contacts

21 and 22, and may include a signaling device as will hereinafter more fully appear. The selector may control two other signaling devices, and each of the

contacts

23 and 24, provided on the insulating plate 26, may be in the circuit of each additional signaling device. Two additional holding pins and 61 may be provided on contact-carrying member 20, these two pins being positioned two steps apart, pin 60 being two steps from pin 29, and pin 61 four steps from pin 29. In other words, if a given number of complete or full steps are required to advance the ratchet wheel 17 to a position where, when the selector magnet is deenergized, the projection 38 will engage pin 29, only two additional steps would be required to advance the ratchet wheel 17 to a position to permit engagement of projection 38 and pin 60, and only four additional steps would be required to advance the ratchet wheel 17 to a' position to permit engagement of projection 38 and pin 61.

When projection 38 and pin 60 engage,

contacts

21 and 23 will be in engagement, and when projection 38 and pin 61 engage,

contacts

21 and 24 will be in engagement. -Wherever the term complete or full step is used in this application it is to be considered as meaning the advancement of the ratchet wheel 17 to a distance equivalent to a tooth of the ratchet wheel.

In order to bring about the control of a large number of circuits for each of a large number of stations, the selective circuitcontrolling devices of this invention are so constructed and arranged that they may be operated on the group or code plan. According to this plan of operation, the selectors are arranged in groups along the line, each group including a plurality of selectors. The selectors of each group are so equipped that it will require three different sets of operations to establish a signaling circuit with any selector of any group. The first set of movements or operations will be one in which all of the selectors on the line are advanced to a position where, when the selector magnets are deenergized, the selectors of a particular group will be held in advanced position, while all of the selectors of all of the other groups will be returned to normal position. The second set of movements of the selectors will cause an advancement of all of the selectors to a position where, when the selector magnets are deenergized, one selector of the previ-' ously selected group will be held, while the remaining ones of the group will return to normal position. Succeeding impulses sent over the line will move all of the selectors, but only the one of the particular group last held will be moved by these last impulses to a position to bring its circuit closing contact 21 into engagement with the

contacts

22, 23, 24 or 25. While it may be that certain selectors of groups not first selected may be advanced to the first or second holding position by the second operation which weeds out all but the desired selector of a chosen group, these will not be moved far enough to close the first signaling contact before the device of the selected group has been moved into contact with the last signalin contact controlled thereby.

In ig. 6 there is shown the selector with the frame comprising front and

back members

14 and 15 separated from the bracket 19. It will be seen that all moving parts of the selector are mounted in the frame which is easily and readily removable from the bracket, this being accomplished by -merely removing the two screws shown.

Such a construction facilitates the making of repairs, which may be done without removing the line connections to the selector magnets, which is very undesirable.

In Fig. 7 there is shown a selective signaling system to which may be connected a very large number of waystations at each of which is a selector selectively responsive to a definite combination or code of impulses, but for convenience only two waystations are illustrated. In this figure there is illustrated the application of the group-signaling feature, the feature of combining a timesending circuit with a selective signaling system, the feature of selecting a groupof waystat-ions to the exclusion of all other stations, and the feature of calling all stations at the same time.

In this figure, 70 and 71 designate line wiresextending from a central transmitting or despatchers station A to a plurality of receiving or waystations B and C. At each waystation there is a selector 72, the

windings

5, 5 of which are connected in bridge of the line wires and in serieswith a condenser 7-l and two

impedance coils

75, 75. Each waystation is also equipped with a signaling bell 76 under control of the selector thereat and a tele hone set 77 included in a normally open ridge of the line wires. A single battery 78 at each Waystation may serve for operating the signal bell 7 6 and for furnishing current for talking purposes. At each station there may be two

additional signaling devices

79 and 80, which may be exactly like the signaling bell 76, controlled by the selector and operated from the local battery 78 thereat.

At the transmitting station A there is a main battery 85 for supplying current for operating the selectors at the waystations. This battery is normally disconnected from the line wires and may be connected therewith by the operation of a relay 86. A polechanging relay 87 is provided for reversing the connections from battery 85 to the line wires. The relays 86 and 87 are connected in parallel and in circuit with a local battery 88, and are controlled by the

impulse transmitters

89, 90, 91, 92 and 93. The transmitter 89 is for callin waystation B, 90 for calling waystation 91 for calling a group of stations, 92 for calling all of the stations, and 93 for preparing the apparatus at all stations for the simultaneous reception of time signals. The transmitters are provided with teeth, certain ones of which may be blocked out by one or both adjust 'able cams 94 and 95 to obtain the particular number and combination of effective teeth for calling purposes. Each transmitter is adapted to rotate in the direction of the arrow, and the teeth thereof are adapted to' control contact springs 96 and 97 in circuit with the pole-changing relay 87. The free end of contact spring 97 of transmitters 89 and 90 is bent downward, and carries at the- ..extremity thereof an insulating roller 98 which, as the transmitter rotates, is'

of the cam 95 and adapted to ride on top separate contacts 96 and 97 during the time of the passage of cam 95.

The contact spring 96 of each transmitter is normally out of engagement with the rotatable disk thereof. During the revolution of the disk of each transmitter, contact spring 96 is in engagement with the disk,

maintaining the circuit of relay 86 closed to connectbattery 85 to the line wires arrange the first set of.which is made up of three and 71. Assuming that transmitter 89 is operated as the disk thereof. starts to rotate, the circuit of rela 86 is completed, operating this relay ant connecting .battery '85 to the-line .wires. As contact spring 96 rides upon the first tooth, it also engages spring 97 to actuate the pole-changing relay 87 by current from battery 88 to reverse the connection of battery 85 to the line wires. .When spring 96 drops between two teeth, relay 87 will be deenergized, and during the time sprin 96 is passing over the cam 94, relay '87 Wlll be energized to furnish a prolonged impulse of one polarity, for example, negative. As the disk continues to rotate, alternating "impulses are sent over the line, and when the cam 95 is reached, the insulating roller 98 on spring 97 rides thereon and raises spring 97 to keep it out of reach of spring 96, so that during the time the insulating roller 98 is riding over the cam 95, a prolonged impulse of opposite or positive polarity is sent over the line wires. As the disk continues to rotate, additional alternating impulses are sent over (the line wires, and when the spring 96 rides on the cam surface 100, a prolonged negative impulse is sent over the line wires to provide a ringing period. When the spring 96 drops onto the cam surface 101, a prolonged positive impulse is sent over the line wires to release the selector at the selected station. When spring 96 is out of en agement with the toothed wheel, relay 86 1s re- %eased and battery 85 is removed from the me.

Assuming that the selector at waystation B is arranged to respond to a code of impulses represented by 39-3, when the transmitter 89 is operated it will send out. the first set of three impulses of alternate charged, whereupon the flow of current through the selector magnets ceases and the selector magnets release. Those selectors, includin the one at station B, which are to respond to codes of impulses,

impulses, will in releasing, cause the curved en 38 of the contact springs 35 to engage the holdmg-pm 27 in the contact-carrying member 20, so that the contact-carrying member 20 at these'stations will be held in advanced position. All other selectors on quiring a different number of current impulses to bring their

pins

27, 27 into engagement with the projection 38, will be dropped back to normal position. Nine imthe line, including the one at station C, re-

position, where, when. the selector magnets are denergized, due to the'extended duration of the ninth impulse, projection 38 will engage the pin 28 at station B, thus holding the selector .thereat'in advanced position, while the selector at stationC will return to normal position. The selectors at all stations connected to the line, which are arranged to respond to a code of impulses, the sum of-the impulses in the first two sets of which totals nine, and those arranged to respond to a code of impulses, the first set of which is of nine impulses, will also be held in advanced position, while all other selectors, which were held in advanced position at the end of the first set of impulses transmitted, will be returned to normal position. line circuit will cause the engagement of contact 21 with the contact spring 22 at station B to close anenergizing circuit for the signaling bell 76, but no other station on the line will have its contact 21 in engagement with it's cont-act 22. During the operation of the signaling bell 76 resulting from the closure of its energizing circuit, a local circuit through the windings of

theselector magnets

5, 5 is intermittently established. This circuit may be traced (referring to Fig. 7) from the upper pole of battery 78, through armature 69,

contacts

68 and 67, answer-back resistance 66, windings of the

magnets

5, 5, contact spring 35, holding pin 29 and the contact-carrying element 20 to the lower pole of the battery 78. The closure of this circuit is of such short duration, the resistance of the answer-back resistance 66 and the windings of the

selector magnets

5, 5 so high and the voltage of the bat tery 78 so low that the closure of this circuit does not affect the operation of the selector. Any one of aplurality of

other signaling devices

79 and 80 at station B may have been operated by a proper number of impulses sent over the line after the selector thereat had been moved into its second holdin position.

13y selecting fifteen as the number of steps required to close the first signaling contact of any selector, there are fifty-five different combinations possible, and with a selector responsive to each of these combinations, it is possible to equip a line with fifty-five selectors and operate them successfully without interference. of thirty holes 54:, 54 in the contact-carrying member 20, as shown in Fig. 1, it is possible to choose thirty-two as the number of steps required to close the

first signaling contact

22, 21 of any selector. This may be done by merely shifting the position of the contact-carrying member 20 on the shaft 18, so that the contact 21 1s moved farther Three impulses now sent over the With a total number to' the right. If thirty-two be chosen as the number ofsteps required to close the

first signaling contact

22, 21 of any selector, there are three hundred and seventy-eight different combinations possible, and with a selector responsive to each of these combinations, it is possible to equip a line with three. hundred and seventy-eight selectors and operate them successfully without interference.

When fifteen is chosen as the number of steps required -to close the first signaling contact 22 of any selector, the following table represents the different combination or code of impulses for the total number of fifty-five separate stations:

2- 2-11 3- 2-10 4-2-9. 5-2-8 6-2-7 2- 3-10 3- 3- 9 4-3-8 5-3-7 6-3-6 2- 4- 9 3- 4- 8 "4-4-7 5-4-5 5-4-5 2- 5- s a- 5- 7 4-5-6 5-5-5 6-5-4 2- e- 7 3- 6- 6 4-5-5 5-5-4 6-6-3 2- 7- 5 a- 7- 5 4-7-4 5-7-3 5-7-2 2- s- 5 3- s- 4 483 582 7- 2- 6 a- 2- 5 9-2-4 10-2-3 11-2-2 7- 3- 5 sa- 4 9-3-3 10-3-2 It will be seen that the second signaling contact 23 of any selector may be engaged by contact 21 by sending, as the third or last set of impulses, two more than is enumerated in the above table, and the third signaling contact 24 of any selector may be made by sending as the third or last set of impulses four more than is enumerated in this table.

It will also be seen that if it is desired to select any group of stations (the first signaling contacts thereof) in which the first set of impulses is of the same number, for

example, the group containing station 13,,

this may be done by sending a code of impulses represented by 3-12, the second group of twelve impulses being obtained by adding together the impulses of the second and third sets. In the selecting of a group of stations, only the first removable holding pin 27 is used. The transmitter 91 at the transmitting station A is arranged to send this code of impulses 3-12, and may be used to select this group of waystations, which includes B. Station B may also be included in another group in which the last set of impulses is ofthe same number, responsive is arranged to send out a single set of fifteen impulses for calling all stations. All stations may be prepared for receiving time si 'nalsover the line wires 70 and 71. Forthls purpose the transmitting station is equipped with a transmitter 93 provided with a series of teeth arranged so that when the transmitter is set in operation an uninterrupted set of twenty impulses of current 10 of alternate polarity will be transmitted over the line wires. These impulses in traversing the

magnet windings

5, 5 energize the selector magnets, causing the advancement of the element 20 to a posltion where upon the cessation of the twentieth impulse the deenergization of the selector magnets permits the projections 38 of the holding springs 35 v to engage the curved ends of the holding members 55 thereby to hold the elements in such advanced position. When the projection 38 and the hooked end of the holding member 55 are in engagement, the contact 21 on member 20 is within one step of the contact 25, so that an additional one-step ad- 25 vancement of the ratchet wheel, in response .to a single impulse of current through the windings of the selector magnets, will advance contact 21 one step into engagement with contact 25. Upon the deenerglzation of the selector magnets following their energization by the single impulse of current, the projection 38 will again engage the I hooked end of holding member 55, and contact 21 will be out of engagement with con- 85 tact 25. During the time of engagement of

contacts

21 and 25, the signaling bells 76 at all stations will be ringing. advancement of the ratchet wheel at all stations is controlled by a relay 105 located in 40 a separate circuit 106, which may be controlled from the transmitting station or from some oflice located at a distance from the transmitting or despatching station. Preferably, this circuit 106 is connected on the standard time wire or telegraph line over which time impulses are sent from the National Observatory at Washington, D. C.

Just prior to the time when the time signals are to be received, the transmitter 93 is operated to send out twenty current impulses of alternate polarity to step all selectors into position where, when the selector magnets are denergized, the

projections

38, 38 engage the hooked ends of the

holdin members

55, 55, and the

contacts

21, 21 wi I be one step from the respective contacts 25 25. When transmitter 93 has returned to normal position of rest, relays 86 and 87 will be deenergized. A switch 107 is now closed to operate relay 86- to hold current of one polarity on the line. Now, as impulses are sent over the standard time wire to which circuit 106 is connected, relay 105 is energized by each impulse to close its contact, and operate The one-step the pole changing relay 87, which in reversing the polarity of current connected with the line wires, causes the energization of all selector magnets, whereupon the step-bystep

contact carrying elements

20, 20 are advanced one-step to close

contacts

21 and 25 at all way-stations. Upon the engagement of the

contacts

21 and 25 at each way-station, an energizing circuit for the vibrating .bell 76 thereat is closed to cause the operation thereof. Upon the cessation of the impulse over the line wires, the selector magnets are deenergized, and due to the action engagement and the bells will be tapped but once or twice. When the contact of relay 105 is opened, due to the cessation of the impulse over the time circuit, the pole changing relay 87 is denergized, whereupon an impulse of opposite polarity from the sending battery 85 is transmitted over the line wires causing the energization of all selector magnets to again advance the

elements

20, 20 and close the contacts 21 and i 25 as before. Upon the cessation of the impulse over the line wires the deenergization of the selector magnets causes the disengagement of the

contacts

21 and 25 and the return of the

elements

20, 20 to the former position with the

projections

38, 38 engaging the hooked ends of the holding

members

55, 55. For each impulse over the time circuit, the

contacts

21 and 25 at each station are brought into engagement twice. After the time signals have been received, all selectors may be returned to normal position by opening switch 107 and operating any transmitter, which will send out at least four impulses to'move the elongated holding member 55 beyond the point where it will be engaged by projection 38.

It will be obvious that there may be used a sending circuit, by means of which current is removed from the line wires at the end of each set of impulsesto denergizev the electromagnets of the selectors at all stations. When using such a sending circuit, the. relay 86 is made slow-releasing and included directly in series with relay 87, and the condensers 74, 74 at the waystations would be left out.

What is claimed is:

1. In a selectively o erated circuit controlling device, a stepy-step element, an actuating pawl therefor, a polarized electromagnet, and means responsive to succeeding [80 impulses of alternating current through said electromagnet and" co'dperating with and causing said pawl to advance said stepby-steplelement one complete step in re-- sponse to each half cycle of alternating current through the electromagnet.

'2. In a selectively o erated circuit controlling device, a stepy-step element, an actuating pawl therefor, a polarizedelectromagnet, an arm carried thereby, and. connection between said arm and said pawl whereby the movement of said arm in response to one complete cycle of alternating current through the electromagnet will cause said pawl to move said step-by-step element two full steps in the same direction.

' 8. In a step-by-step circuit controlling device, a step-by-step. element, an actuating pawl therefor, a centrally pivoted arm upon .one end of which said pawl is mounted, a

polarized electromagnet, an armature therefor, and an arm carried thereby and .engaging said pivoted arm to move said pawl into engagement with said step-by-step element twice in response to each complete cycle of alternating current through the electromagnet.

4. In a selectively operated circult controlling device, a step-by-step element, an actuating pawl therefor, a centrally pivoted arm upon one end of which said pawl is mounted, a polarized electromagnet, an armature therefor, and means carried by said armature adapted to engage said pivoted arm alternately upon opposlte faces and upon opposite sides of the pivot pomt to move said pawl into engagement with said step-by-step element upon each attraction of said armature.

5. In a selectively operated circuit con-. trolling device, a step-by-step element, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, a single stepping pawl operated by said armature and engaging said element to advance it step by step in response to the impulses through said electromagnet, and means controlled by and effective during the movement'of the armature from one extreme position to the other for retaining said element in ad vanced position.

6. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, a centrally pivoted armature responsive to alternating current impulses throu b said electromagnet, an arm carried by said armature, a single stepping pawl operated by said arm and adapted to engage said step-by-step element in the operation of said armature to advance it step by step, and a holding member moved into and out of engagement with said step-bystep element at each change in polarity of by-step element in advanced position dur-' ing a change in polarity of the stepping current. I

7. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, a centrally pivotedarmature responsive to alternating current impulses through said electroma et, an arm carried by said armature, a single stepping pawl controlled by said arm adapted to engage sai step-by-step element in the operation of said armature, and a pivotally supported member controlled by said armvand moved into and out of engagement with said stepby-step element at each change of polarity of the stepping current.

8.'In a selectively operated'circuit controlling device, a step-by-step element, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, a stepping pawl, a centrally pivoted member upon one end of which said stepping pawl is mounted, a holding pawl controlled by said pivoted member, and means carried by said armature adapted to engage said member alternately upon opposite faces and upon oppo site sides of the pivot point to move the said stepping pawl into engagement with said step-by-step element upon each attraction of said armature and ,to" move said holding pawl into and out of engagement with said step-by-step element at each change of polarity of the stepping current. 1

9.. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, a centrally pivoted member, a stepping pawl mounted on one end thereof, a centrally pivoted holding pawl controlled by said pivoted member, an

arm carried by said armature, and two pins carried by said arm adapted to engage said current to retain said element in advanced position during a change in polarity of the stepping current.

10. vIn a selectively operated circuit controlling device, a step-by-step element, a contact and a plurality of holding members carried thereby, a plurality of stationarycontacts corresponding respectively to the holding members, each stationary contact adapted to be engaged by the movable contact when the corresponding holding memof the contact carried thereby an any one of the stationary contacts, and a holding member controlled by said armature and brou ht into engagement with the holding member correspon ing .to the engaged stationary contact upon the deenergization of the electromagnet to hold said step-by-step element in contact engaging position.

11. In a selectively operated circuit controlling device, a step-by-ste element, a contact and a plurality of 1101 ing pins carried thereby, a plurality of stationary contacts corresponding respectively to the holding pins, each statlonary contact adapted to beengaged by the movable contact when its corresponding holding pin is effective for holding the step-by-step element in contact engaging position, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, stepping means controlled by said armature to advance said step-by-step element to cause enga ement of the contact carried thereby an any one of the stationary contacts, and a holding member controlled by said armature and brought into engagement with the holding pin ,corresponding to the engaged stationary contact upon the deenergization of the electromagnet to hold said step-by-step element in contact engaging position.

12. In a selectively operated circuit controlling device, a step-by-step element, a contact and a plurahty of olding plns carried thereby, a plurality of stationary contacts corresponding respectively to the holding pins,'each stationary contact adapted to be engaged by the movable contact when its corresponding holding pin is efiective for holding the step-by-step element in contact engaging position, an electromagnet, an armature responsive to current impulses through said electromagnet, steppin means controlled by said armature to a vance said step-by-step element to cause engagement of the contact carried thereby and any one of the stationary contacts, and a holding member controlled by said armature and brought into engagement with the holding pin corresponding to the engaged stationary contact upon the de'nergization of the electromagnet to hold said step-by-step element in contact engaging position.

13. In a selectively operated circuit controlling device, a step-b -step element, a contact and a'plurality o holding members carried thereby, a plurality of stationary contacts corresponding respectively to the holding members, each stationary contact adapted to be engaged b the movable contact when the correspon ing holdin member is effective for holding the stepy-step element in contact engaging position, an

electromagnet, an armature res onsive to current impulses through said e ectromagnet, stepping means controlled by said armature to advance said step-by-step element to cause engagement of the contact carried thereby and any one of the stationary contacts, and a holding member controlled by said armature and brou ht into engagement with the holding mem er corresponding to the engaged stationary'contact upon the deenerglzation of the electromagnet to hold said step-by-step element in contact engaging position.

14. In a selectively operated circuit controlling device, a step-by-step element, a contact carried thereby, a plurality of statlonary contacts, an electromagnet, a centrally pivoted armature responsive to alternatlng current impulses through said electromagnet, stepping means controlled by sa1d armature to advance said step-by-step element to cause engagement of the contact carried thereby and any one of the stationa'ry contacts, and means independent of the stepplng means and controlled by said step- "by-step element and said electromagnet to hold said'step-by-step element in contact-engagmg positlon.

15. 'In a selectively 0 rated circuit controlling device, a stepy-step element, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, stepping means controlled by said. armature and engaging said element to advance it step-by-step in response to alternating current impulses through said electromagnet, a holding member carried by said step-b'y-step element, a holding spring controlled by said armature adapted, after the advancement of said stepby-step element to-a predetermined position and thedeenergization of said electromagnet, to engage said holding member to hold said stepy-step element in such advanced position, a stationary contact, and a contact carried by said step-by-step element and brought into engagement with said stationary contact by a one-step advancement of said step-by-step element from the predetermined position due to subsequent energization of said electromagnet, said holding spring moving out of engagement with said holding member and thereafter moving into engagement therewith upon the deenergization of said electromagnet.

16. In a selectively operated circuit controlling device, a step-by-step element, contacts controlled thereby, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, stepping means operated by said armature and engaging said element to advance it step-by-step in response to a definite number of impulses through said electroniagnet to cause the engagement of said contacts, the first impulse being of either polarity, and means for returning said element to normal position after the further advancement thereof in response to a single impulse of either polarity through said electromagnet.

17. In a selectively operated circuit controlling device, a. step-by-step element, contacts controlled thereby, an electromagnet, a centrally pivoted armature responsive to alternating current impulses through said electromagnet, stepping means operated by said armature and engaging said element to advance it step-by-step in response to a definite number of impulses through said electromagnet, the first impulse being of either polarity, means controlled by said element and said electromagnet for holding said element in contact-engaging position, and means for returning said element to normal position after the further advancement thereof in response to a single impulse of either polarity through said electromagnet.

18. In a selectively operated circuit controlling device, a step-by-step element, contacts controlled thereby, an electromagnet, an armature controlled by said electromagnet, stepping means operated by said armature and engaging said element to advance it step-by-step in response to succeeding current impulses of opposite polarity through said electromagnet to close said contacts, and holding means controlled by said element and said armature to hold saidelement in a predetermined intermediate position after said element has been advanced to such position.

19. In a selectively operated clrcuit controlling device, a step-by-step element, contacts controlled thereby, an electromagnet, a, centrally pivoted armature respons ve to succeeding current impulses of opposlte polarity through said electromagnet, a stepping pawl operated by said arlnature and engaging said element upon each lmpulse of either polarity to advance 1t step-by-step 1n response to impulses through said electromagnet to close said contacts, and means controlled by said element and said armature to hold said element in a predetermined intermediate position after said element has been advanced to such position.

20. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, an armature responsive to current impulses through said electromagnet, stepping means controlled by said armature and engaging said element to advance it step by step in response to impulses through said electromagnet, means for holding said step-by-step element in'a predetermined advanced position,-a stationa contact, and a contact carried by said e ement brought into momentary engagement with the stationary contact by each one-step advancement or said element from the predetermined position in response to current impulses through said electromagnet.

21. In'a selectively operated circuit controlling device, a step-by-step element, an electromagnet, an armature responsive to current impulses through said electromagnet, stepping means controlled by said armature and engaging saidelement to advance 1t step by step in response to impulses through said electromagnet, means for holding said step-by-step element in a predetermined advanced position, a pair of contacts brought into momentary engagement by each one step advancement of, said element from the predetermined position in response to current impulses through said electromagnet. v

22. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, an armature responsive to current impulses through said electromagnet, stepping means controlled by said armature and engaging said element to advance it step by step in response to impulses through said electromagnet, a pair of contacts controlled by said step-by-step element, and means for holding said element in a predee tel-mined advanced position and cooperating with said element upon each subsequent one step advancement thereof from the predetermined posltion to cause the closure of the contacts.

23. In a selectively operated circuit controlling device, a step-by-step element, an electromagnet, an armature responsive to current impulses through said electromagnet, stepping means controlled by said armature and engaging said element to advance it step by step in response to impulses through said electromagnet, a pair of contacts controlled by said step-by-step element, means for holding said element in a predetermined advanced position and cooperating with said element upon each subsequent one step advancement thereof from the predetermined position to cause the closure of the contacts, and means controlled by said electromagnet for returning saidstepby-step element to its normal position.

24. In a selectivelv operated circuit-controlling device, a step-by-step element, an-

contacts by the advancement of said element, and means for holding said element in a predetermined advanced position and cooperatinto engagement with one of the stationary contacts by the advancement of said element,

' mediate position.

means for holding said element in a predetermined advanced position and cooperating therewith upon each subsequent one step advancement thereof from the predetermined position to cause the movable contact to engage the other stationary contact, and means controlled by said electromagnet 'for returning the step by step element to normal position. a

26. A code device of the character described comprising a step-by-step element, electromagnetic means including actuating pawls responsive to impulses of opposite polarity to actuate said element, means controlled by said element and electromagnetic means and rendered operatively responsive thereby when said element is actuated into a predetermined position, and means independent of the actuating pawls controlled by said element and electromagnetic means to retain said element momentarily in a predetermined intermediate position when said element has been actuated into said inter- 27. A code device of the character described comprising a step-by-step element,

electromagnetic means including actuating pawls responsive to impulses of opposite polarity to actuate said element, means controlled by said elementand electromagnetic means and rendered operatively responsive thereby when said element is actuated into a predetermined position, and means including an element movable with the step-bystep element controlled by said element and electromagnetic means to retain said element momentarlly in a predetermined intermediate position when said element has been actuated into said intermediate position.

28. In a selectively operated circuit controlling device, a step-by-step element, an actuating pawl therefor, a polarized electromagnet, an armature responsive to succeeding current impulses of alternate polarity through the electromagnet, and means controlled by the armature in its movement and cooperating with the pawl to adtrolling device, a step-by-step element, an

electromagnet, an armature responsive to current impulses through the electromagnet, stepping means controlled by the armature for advancing the element step by step into a predetermined position, a stationary contact, a contact moved into engagement therewith by each onestep advancement of the element from the predetermined position in response to impulses through the electromagnet, and means controlled and rendered efiective by the deenergization of the electromagnet for returning the element to its normal position.

31- In a selectively operated circuit-controlling device, a step-by-step element, an electromagnet, an armature responsive to current impulses through the electromagnet, stepping means controlled by the armature for advancing the element step by step into I a predetermined position, a stationary contact, a contact moved into engagement therewith by each one step advancement of the element from the predetermined position inresponse to impulses through the electromagnet, means for restoring the element to 'normal position, and means controlled by the element and cooperating with the restormg means for moving the element back into the predetermined position after each one step advancement thereof.

32. In a selectively operated circuit controlling device, a step-by-step element, a polarized electromagnet, a centrally pivoted armature having its free ends in operative relation to the respective poles of the electromagnet, stepping means operated by the armature for advancing the element step by step into a predetermined position in response to succeeding impulses of opposlte polarity through the electromagnet, a stationary contact, and a contact moved into engagement therewith by each one step advancement of the element from the predetermined position in response to impulses throu h the electromagnet.

33. n a selectively operated circuit controlling device, astep-by-step element. a polarized electromagnet, a centrally pivoted armature having its free ends in operative relation to the respective poles of the electromagnet, stepping means operated by the armature for advancing the element step by step into a predetermined position in response to succeeding impulses of opposite polarity through the electromagnet, a stationary contact, a contact moved into engagement therewith by each one step advancement of the element from the predetermined position in response to impulses through the electromagnet, and means for returning the element to the predetermined position after each such one step advancement.

34. In a selectively operated circuit controlling device, a step-by-step element, a polarized electromagnet, a centrally pivoted armature having its free ends in operative relation to the respective poles of the electromagnet, stepping means operated by the armature for advancing the element step by step in response to succeeding impulses of opposite polarity through the electromagnet, a plurality of stationary contacts, a contact moved into engagement with any one of the stationary contacts by the advancement of the step-by-step element, and means jointly controlled by the element and the electromagnet for holding the contacts in engagement.

35. In a selectively operated circuit-controlling device, a step-by-step element, a polarized electromagnet, a centrally pivoted armature having its free ends in operative relation to the respective poles of the electromagnet, stepping means operated by the armature for advancing the element step by step in response to alternating current impulses through the electromagnet, a stationmy contact, a contact moved into engagement therewith by the advancement of the step by step element, and means jointly controlledby the element and the electromagnet for holding the contacts in engagement.

In Witness whereof I hereunto subscribe my name this 17th day of May, A. D. 1916.

JOSEPH o. FIELD.