US1245481A - Selector-switch. - Google Patents

Description

M. K. MCGRATH.y

SELECTOR SWITCH.

APPLICATION FILED IuNE 23. |916.

1,245,481 Patented Nov. 6, 1917.

Maur/'ce K. M3. @raf/z.

UNITED STATES PATENT oEEIcE.

MAURICE K. MCGRATHV, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- PANY INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION 0F NEW YORK.

SELECTOR-SWITCH.

Specication of Letters Patent.

Patented Nov. 6, 1917.

i Application led J une 23, 1916. Serial No. 105,412'.

To all whom z't may concern.'

Be it known that I, MAURICE K. Mo- GRATH, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Selector-Switches, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic or semi-automatic telephone systems, and has as one object the securing of a preliminary location of a line when in a certain condition, and subsequent relocation and association of a calling line therewith.

Heretofore, when it has been desired to select a group of terminal sets and find one of that group which is in a given condition, as not busy, it has been customary to primarily step a brush set from group to group until the desired group has been reached. The brush set then remains stationary until a change in circuit conditions causes it to begin hunting over the group to find a terminal set in the desired condition. This seriously lilmits the present automatic systems using direct impulse control because the brush set has to wait at the selected group a suiliciently long time to determine that the last impulse has arrived, that is, it must wait for the change-over before it will begin to hunt in that group. It is essential that the terminal set be found and a distant machine placed in a receptive condition before the sender can originate another train of pulses; but it has been found in practice that, in the short time between series of impulses, the mechanism is often unable to complete its action, and that the next train of pulses will result in obtaining a wrong connection.

One of the objects of this invention is the utilization of this time interval, hitherto wasted,1in which the brush set stood still, t effect searching for the desired line, and thus the searching operation will be Completed before a succeeding series of impulses can be sent. This results in greater rapidity in securing the desired connection, thus increasing the eiiiciency of the system and making it ossible for the same number of trunks to handle an increased number of calls, with resultant saving 'of equipment.

A still further object is to effect preliminary hunting for a line at high s eed and, after the line is located, to researc for said.

line at a slower speed and connect therewith.

Referring to the drawing, Figure 1 shows 1n part the mechanical construction of the stop and brush-operating mechanism, and also shows diagrannnatically the circuits and apparatus which constitute one embodiment of the invention.

In the preferred form of the invention, the general operation is as follows. A stop 1s moved under impulse control to the deslred group. Movement of the stop releases a brush carriage which follows the stop by gravity. When the brush carriage is with- 1n one group or less of the position of the stop, a circuit is prepared through a test relay, so thatwhen a line in a desired condition is passed by the brush carriage, this prepared circuit is completed. The completion of this circuit switches in a return mechanism to cause the return of the brush set to `permanent 'connection with'the line previously located.

Referring first to the brush carriage which is normally in the position shown in Fig. 1, 1 is a brush support and carries a multiple brush set 2 which is moved on actuation of an elevator rod 3 over the sets of terminals of a contact bank 4, thel sets of contacts being divided into groups for a purpose to be later described. This elevator rod 3 has a series of openings therethrough corresponding in number to the number of rows in the terminal bank, and a locking pawl 6 to normally engage the lowermost of said openings. This lockingI pawl 6 is moved by an armature 7 under the control of a high-speed magnet 8. A gear wheel 9 has teeth also engaging the openings 5 and is rotatably mounted on a shaft 10 whichl carries a ratchet wheel 11. The wheels 9 and 11 are connected by a spring coupling 12 which normally tends to hold the wheels in the position shown in Fig. 1. A stop- .arm 13, secured to the ratchet wheel 11 and movable therewith, normally engages a stop 14 on the wheel 9 under the influence of the spring coupling 12. An insulating member 15 is secured on the wheel 9, and on this is mounted a commutator ring 16 of conducting material. This commutator ring has a conducting segment 17 adjacent the stop 14, of a length equal to the distance moved by the arm 13 on one step of the ratchet wheel- 11, and arranged to be wiped over by the arm 13. The purpose of this conducting segment is to prepare a circuit from grounded battery 18, brush 19, conducting shaft 10, conducting ratchet wheel 11 and stop-arm 13, segment 17, commutator ring 16 and brush 20, test relay 46 and other apparatus to be later described, when the wheel 9 and registering position.

The ratchet wheel 11 is normally held -against back movement by a catch pawl 21 controlled by an armature 22 of an escapement switch reset magnet 23. On attraction of the armature 22, the pawl 21 is drawn down and forced out of engagement with the wheel 11 by a pin 43 fixedly carried on the structure supporting the shaft 10. The wheel 11 is stepped forward on actuation of a primary or group stepping magnet 24 which pulls up its armature 25, forcing forward a pawl 26 to stop the wheel 11 one step on each actuation of said magnet 24. The updrive of the elevator rod 3 is accomplished by a secondary or clutch magnet 26 which, when energized, pulls up its armature 27 to force the elevator rod 3 against a constantly rotating updrive roller 28.

The operation of the device is as follows: The subscriber at station 100 removes his receiver from the hook and when his line 101, l02vis extended through a line inder or other suitable device to wires 103, 104, the line relay 29 is actuated to send current through and pull up the slow-break relay 31. When the first series of impulses is sent by dial 109, the circuit to the line relay is intermittently broken. Each time the armature 30 drops back, it completes a circuit from ground, back contact of armature 30, front contact of armature 32, and wire 36 to the group stepping magnet which steps the wheel 11 one step for each impulse. At the first break of the line relay` circuit, a circuit is completed through the slow release relay 33 vwhich pulls up its armature to completeia circuit to actuate the high speed magnet 8 to withdraw the locking pawl 6. This circuit is as follows: grounded battery 38, magnet 8, front contact and inner armature 34 of relay 33, conductor 39, rear contact and left-hand armature 40 of relay 46, conductor41, back contact and outer lefthand armature of relay 72,to ground. Relay 33 is unaii'ected by the short breaks incident to the sending of the grou impulses. On the movement of the stop an the withdrawal of the locking pawl, the brush carriage drops by gravity aided by the springcoupling 12. The actuation of the group stepping magnet will set the stop for a certain group and when the brush carriage gets within one step, the stop-arm 13 will engage the conducting strip 17 of the commutator and prepare a circuit from the battery 18,

brush 19, wheel 11, stop-arm 13, segment 17, commutator 16, brush 20, wire 45, relay 46, back contact and armature 48, side-switch wiper 49 to test brush 50 which, in passing over the group, completes the circuit from ground through a grounded contact 51 of the first idle trunk in the group. This actuates test relay 46, which locks itself up and energizes clutch magnet 26 to step said brush carriage back. The locking circuit extends from ground, battery 18, brush 19, shaft 10, stop-arm 13, segment 17, commutator 16, brush 20, conductor 45,-relay 46, conductor 54, front contact and left-hand armature 40 of relay 46, conductor 41, back contact and outer left-hand armature 42 of relay 72 to ground. The test relay 46 also prepares a circuit for the relay 61 which controls the circuit of the escape switch 63 and the updrive magnet 26. In'the bank 4, idle trunks or lines have ground placed on their test contacts. The test contact 51 belongs to an idle line and hasv ground thereon as shown. As the brushes passed rapidly over grounded contact 51, the relay 61 would not ordinarily be actuated. If, for any reason, the brush passed the contact 51 sufficiently slowly to energize relay 61, no harm would be done, as the relay 61 would at once pull up, thereby preventing current being furnished the clutch magnet 26 to step it back by completing a circuit for the escape magnet 63 which moves the side switch into its second position, and the brush would be left in engagement with the desired line. Assuming the brush has passed at high-speed, only the relay 46 would act, locking up its circuit and also completing a circuit for the clutch magnet 26. The high-speed magnet 8 would have been released and the carriage locked in place as soon -as the test relay 46 acted, the circuit of magnet 8 being opened at the back contact of armature 40. The updrive will continue until the grounded brush in the group is reached, when a circuit from ground, test contact 51, brush 50, arm 49, front contact of armature 48, wire 60, through relay 61, to grounded battery 62, would energize relay 61 to open the circuit of the clutch magnet and close a circuit for the escape magnet. The circuit for the escapeswitch magnet extends from grounded battery 65, escape magnet 63, front contact and outer armature 66 of relay 61, conductor 67, back contact andvouter armature 64 of `relay 33 (denergized by the long energization of the line relay 29 at the end of the first series of impulses), conductors 68, 41, and back contact and outer lefthand armature 42 of the release relay 72, to ground. The escape magnet, on energization, moves the switch arms to second or talking position.

Inertia of the carrier may carry it a few contacts below the contact initially located and, if any of these contacts are in the desired condition, the carrier will return until it reaches the rst of these contacts in that condition, whereupon relay 61 will act and associate the brush with that contact, as previously described.

Should the carriage havefound an idle trunk in a group before the completion of the sending of the group impulses, the stoparm would be moved a full step and the circuit between the stop-arm 13 and segment 17 to test relay 46 would be broken before the magnet 33 could have released the circuit to the magnet 8 controlled by armature 34. The high-speed magnet 8 would be held up and, on further movement of the stop, the carriage 9 would follow to relocate a terminal set in the proper group. In the second position of the side switch, the clutch magnet 26, line relay 29, group ,stepping magnet 24, and relay 33 have their circuits opened.

In the second position, the talking circuit is extended through wires 105, 106 and their brushes to wires 107, 108, leading directly or through intermediate selectors and connectors to the called party. Thereuponrelay 69 is energized to cut off ground from the test contact 51 by a circuit extending from battery 53, left-hand winding of relay 69, conductor 108, calling circuit, wire 107 and right-hand winding of relay 69 to ground. The relay 72 has its armatures 7 74 and 42 made slow to pull up to insu e the energization of rela 69 and consequent cutting oi of ground rom contact 51, before relay 72 could possibly act. Relay 69, on pulling up, prevents actuationof the relay 72 opening the circuit at the armature 52 and back contacty of rela 69.

magnet 72 through an off-normal contact 7 5.

This circuit extends from ground, armature 30 and back contact of relay 29, armature 32 and its back contact, conductor 44, sideswitch arm 80, oli-normal contact 75, and relay 72 to grounded battery. Magnet 72 locksitself up, and completes a circuit for the clutch magnet 26, from grounded battery 59, magnet 26, conductors 58, 77, 76, front contact and outer left-hand armature 42 of relay 72 to ground. This moves the vcarriage to normal, in which position the off-normal contact will be opened and the restoring magnet denergized. On energization of release relay 72, a circuit is comp eted for the release magnet 23 from ground, outer armature 42 and front contact of relay 72, conductors 76, 78, magnet 23 to grounded battery 79. The magnet 23 pulls up, withdrawing the pawl 21 from ratchet wheel 11, leaving it free to return to normal. On reaching normal, relay 72 is denergized, opening the circuit to magnet 23, which, on its back stroke, resets the switch arms to Vfirst position.

Should the` parts be in talking position and the receiver replaced, the trunk relay 69- is denergized and puts ground on test terminal 51, brush 50, side-switch armA 49 second position, 'wire 70, back contact of armature 71, restoring magnet 7 2, to ounded battery. Restoring magnet 72 will then pull up and restore the device to normal.

What is claimed is:

1. In an electric switching system, a plurality of contacts, lines individual to said contacts and connected thereto, a movable contact, a line connected therewith, means for establishing an initial connection between said movable contact and one of said plurality of contacts, and means operated by said initial connection for moving said movable contact to'effect a inal connection between said movable Contact and the contact initially connected therewith.

2. In an electric switching system, a plurality of contacts, lines individual to said contacts and connected thereto, a movable contact, a line connected therewith, means for establishing an initial connection between said movable contact and one of said plurality of contacts, means for establishing a final connection between said movable contact and a contact initially connected therewith, and means operated by the initial connection of said contacts for controlling the operation of the said last-mentioned means.

3. In an electric switchin system, a plurality of contacts, lines in 'vidual to said contacts and connected thereto, a movable contact, a line connected therewith, means to move said movable contact to initially locate a contact in said plurality of contacts, and means controlled by the initial location thereof to move the movable contact into association with the contact initially located.

4. In an electric switchi system, a plurality of contacts, lines in ividual to said contacts and connected thereto, movable means for establishing connection to any desired Contact, a line connected to said movable means, means to move said movable means at high speed until a desiredl contact is encountered, and means controlled by said l v means at a high speed until a desired contact is passed, and means controlled in passing a desired contact to return saidl movable means at a slower speed to engage a desired contact.

6. In an electric switching system, a plurality of contacts, lines individual to said contacts and connected thereto, movable means for establishing connection to any contact in a desired condition, a line connected to said movable means, means to move said movable means until a contact in a desired condition Yis passed, and means controlled in passing a contact in a desired condition to return said movable means and associate it with the first contact in a desired condition encountered on said return movement.

. 7. In an electric switching system, a plurality of contacts, lines individual to said contacts and connected thereto, movable means for establishing connection to any desired contact, a line connected to said movable means, means to move said movable means at a high speed until a desired contact is passed, means controlled in passing a desired contact to return said movable means at a slower speed to engage a desired contact, and means to lock said movable means when a desired contact has been engaged.

8. In an electric switching system, a plurality of contacts, movable means for establishing connection to any one of said contacts when in a desired condition, means to move said movable means at high speed until a contact in a desired condition is passed, means controlled in passing said contact to move said movable means at a slower speed to engage the contact in the desired condition, means to change the condition of said contact, and means to restore said movable means to normal on a second change of the condition of said contact.

' 9. In an electric switching system, a plurality of contacts, a movable contact carriage,- a contact thereon to engage any one of said plurality of contacts, a stop for said carriage, means including a circuit for controlling the movement of the carriage, and means to change the condition of said circuit when said carriage and stop are within a certain distanceof each other.

10. In an electric switching system, a plurality of contacts, a movable contact carriage, a contact thereon to engage any one of said plurality of contacts, a stop for said carriage, and means to cause the movable contact to begin searching for a contact in a desired condition when said carriage and stop are within a certain distance of each other.

11. In an electric switching system, a plurality of contacts, a movable contact carriage, a contact thereon to engage any one of said plurality of contacts, a stop for said carriage, means to search for a contact in a desired condition, and means to prevent the movable contact searching for a contact until said carriage and stop are within a certain distance of each other.

12. In an electric switching system, a plurality of groups of contacts,` a movable contact to engage any desired one of said plurality of contacts, an impulse mechanism associated with said movable contact, means to step said movable contact from group to group under actuation of said impulse means, and means to search for a contact in the desired condition within a group before the completion of the impulses actuating said stepping means.

13. In an electric switching system, a plurality of groups of contacts, lines individual to said contacts and connected thereto, a movable contact, a line connected therewith, means for moving said movable contact to any desired group, means for establishing an initial connection between said movable contact and a contact in said group in a desired condition, and means operating immediately thereafter for associating said movable contact with the contact initially connected therewith.

14. In an electric switching system, a plurality of groups of contacts, lines individual to saidvcontacts, a movable contact, a line connected therewith, means for moving said movable contact from group to group, and means operated by said movable contact engaging a desired contact in a desired group during said group movement for associating said movable contact with said desired contact.

15. In an electric switching system, rality of groups of contacts, a movable contact, an impulse mechanism associated with said movable contact, means for moving said movable contact directly from one group to another under control of said impulse mechanism, and means operated by said movable contact engaging a desired contact in a desired group during said group movement for stopping said movable contact upon said deslred contact.

16. In an electric switching system, a plurality of groups of contacts, a movable contact, means for locating contacts within said groups in a desired condition, means for associating said movable contact with a contact in a desired condition in any of said groups, and means to prevent location of contacts in non-desired oups.

17 In an electric switc ing system, a plu-y rality of contacts divided into a plurality of groups, a movable contact carrier, a contact thereon, a stop to insure stopping of the carrier on the proper group of contacts, means to move said stop to the desired posltion, means to cause said carrier to move toward its stop position, conducting means in engagement when the stop means and carrier are within one group of each other, a circuit including said conducting means, the contact of the carrier and a desired contact in the selected group, and means controlled thereby to effect association of said contact on the carrier with said desired contact.

18. In an electrically operated switch, contacts therefor, a movable contact carrier, a Contact thereon, a stop for determining the stopping position of said carrier, means to move said stop, means to move said carrier toward its set position, a segment engaged by said stop when said moving means 1s within a certain distance from said stop, means for locki said carrier, and a circuit adapted to have 1ts condition changed when said segment and stop are in engagement to control the means for locking said carrier.

19. In a telephone exchange system, a calling line, impulse means associatedtherewith, a contact bank divided into a plurality of groups of terminals, outgoing lines connected to said'termnals, a movable brush carriage, a brush thereon, means to normally hold said carriage in locked position, means to extendlthe calling line to said brush and establish a talking circuit between the callin line and an outgoing line, means to move said brush carriage to any desired group, circuits controlling said holding and moving means, relay means under cntrol of said impulse means to control said circuits, means to return said brush carriage to normal position, a test circuit completed when said brush encounters a terminal in the desired group in a desired condition, relay means in said test circuit acting on completion of said circuit to effect the movement of the carriage restorin means to associate said vbrush with a de sire terminal, and relay means to effect actuation of said carriage restoring means on breaking of said talkin circuit.

20. In an electric switching system, a line, a group of contacts, other lines connected to said contacts, a movable brush carriage, a brush thereon, means for connecting said first line to said brush, means to move said brush over said contacts, a relay, a circuit completed when said brush encounters a contact in a desired circuit condition, a relay in said circuit actuated thereby to extend control to said first relay, means to associate said brush with a desired contact, a circuit for said means, and a circuit closed to said second relay on associationof said brush with the desired contact, said rst relay changing the condition of the circuit for the means for associating the brush with the desired Contact.

21. In an electric switching system, a pluralty of contacts, lines individual to said contacts and connected thereto, a contact movable over said plurality of contacts to engage any desired contact, a line connected to said movable contact, means to move said movable contact at different' speeds to engage said plurality of contacts, and means operated by the engagement of said movable vcontact with a contact in a desired condition to move said movable contact at a different speed thereafter.

22. In an electric switch, a `plurality of groups of contacts, lines individual to said contacts and connected thereto, a movable contact to engage any of said plurality of contacts, a line connected to said movable contact, means to move said movable Contact at different speeds, and means operated by the movable contact, engaging contacts in a desired condition in a group to cause said movable contacts to move at a different speed thereafter.

23. In an electric switch, a plurality of groups of contacts, lines individual to said contacts and connected thereto, a movable contact to engage any of said plurality of contacts, a line connected to said movable contact, means to move said movable contact at different speeds and in different directions, and means operated by the movable contact initially engaging a contact in a desired condition in a group to cause said movable contact to move in a different direction and at a different speed thereafter to again engage said contact.

24. In an electric switching system, an electrically operated switch having a plurality of fixed contacts and movable contacts, means for causing said movable contacts to traverse said fixed contacts by movements of different characters, and means operative in response to the en agement of one of said movable contacts wit a desired fixed contact for altering the character of movement of all of said movable contacts.

25. In an electric switching system, a plurality of terminals, a movable contact to engage any of said terminals, means to move said contact at different uniform rates of speed to engageany desired terminal, and

means to automatically change the speed 'of said contact from one rate to another when group.

27. In an electric switching system, a plurality of terminals, a Contact to move over said terminals and engage any desired terminal, means to move said contact at different uniform rates of speed to engage any desired terminal, and electrical means for automatically effecting a change of speed of Said contact from one rate to another when Within a certain distance of a desired ter-v minal.

28. In an electric switching system, a plurality ,of terminals, a movable contact to engage any desired terminal, means to move said contact at a high speed, a circuit to op- Lawaai erate said means, means to move said contact at a Lower speed, a circuit to operate said last named means, a relay for controlling said circuits, and means to automatically operate said relay to effect change of speed of saidY 15 contact when it is Within a certain distance of a desired terminal. y

In Witness whereof, I hereunto subscribe my name this 22nd day of June A. D. 1916.

' MAURICE K. MGGRAIH.

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