US1161411A - Telephone-exchange system. - Google Patents

Description

L. POLINKUWSKY.

TELEPHUNE EXCHANGE SYSTEM. APPLICATION FILED AUG. I7. I9I4.

l 1 6 1 ,411 Patented N ov. 23, 1915.

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UNITED sTATEs rrENT oEEioE. `p

LIPA POLINKOWSKY, 0F BRUSSELS, BELGIUM, ASSIGNOR TO WESTERN ELCTRIO COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

TELEPHONE-EXCHANGE SYSTEM.

Application filed August 17, 1914. Serial No. 857,130.

line, and relates more particularly to thecontrol of certain of such switches of the general type, which operate to select or seize certain electrically distinguished circuits from a plurality of equivalent circuits or equipments not so distinguished. Switches of this general type are employed in automatic systems for the purpose of selecting' and seizing an idle connecting or trunk line from a plurality of such trunks, for selecting and seizing a calling line from a plurality of such lines, or in general whenever it is desired to select and seize a particular circuit or equipment from a plurality of such circuits or equipments.

More specifically the invention relates to a test circuit or system for switches ot the type referred to above. It is usual in connection with such switches to provide a test circuit which includes a device such as a test relay which is responsive to an electrical condition individual to the terminals of the lines which it is desired to seize, and to provide devices set in operation by the response of such test relay to cause'the stopping of the switch and the opening of the test circuit, the opening of the test circuit rendering the switch ineffective for seizing other lines. It is also usual to arrange the circuits and apparatus so that the switch will again start in motion if the test relay does not remain energized a substantial time, but ordinarily no provision is made to prevent the opening of the test circuit in such event, so that the switch may be again started in motion, but will be, due to the opening of the test circuit, thereafter ineffective to seize a line.

VIt is thereforean object of the present invention to not only prevent the stopping of the switch by a momentary energization of the test relay, but to also provide means for preventing the-switch from being thereafter rendered ineffective for yseizing other lines. lVith this object in view, and inaccordance with this invention, circuits and. apparatus are provided for introducing a.

denite and substantial time interval be-v tween the initiation of the operationof the] test relay and the opening of the' test .cir-

cuit, so that a momentary energizationy of f ,f i Y. the test relay will notv alter the test "circuit, i i

and the test relay may thereafter Yoperate to cause the switch to seize a line.

Specincation of Letters Patent. i Patented NOV, 23,

In systems employing switches of thetype' under consideration, a momentary energization of the test relay may occur from various causes other than the contacting ofthe-fswitch with an electrically distinguished line,-for instance, causes such as grounds,

crosses or short circuits; but the most frequent cause is due to two or more switches f attempting to simultaneously connect to the same electrically distinguished line. In case this should occur in a system employing the 'l test circuit of this invention, not only will* more than one switch be prevented from'i tion, which is hereinafter disclosed, thereV is associated with each switch, in addition t0 a test relay, a power control relay and a' sequence switch. The circuits are so arranged that the operation of the test relay will cause the operation of the power control relay, which will in turn open the circuit ot the motor magnet of the switch to. stop the switch, and also to establish a` cir-Y cuit for the sequence switch to drive the same through two or more adjacent positions. The sequence i switch contacts are so arranged that the test circuit will not be opened by the sequence switch until after the sequence switch has moved through two or more adjacent positions, and as the circuit for the sequence switch will be maintained only as long as the test relay remains s energized, it follows that if the test relay fails to remain energized long enough for the sequence switch to move through at least two positions, the test circuit will not be'V opened. momentary energization of the test --relay By virtue of this arrangement, a

, magnet is energized.

can do no more than drive the sequence switch through one position, and hence the test circuit will not be opened by such a momentary energization, and the switch will not be rendered ineffective for thereafter seizing other lines.

The invention 1s diagrammatically shown in the drawing as employed in connection` tical in construct-ion, a description Vof one will suflice for both. 0n selector switch 1 there is shown a brush carriage carrying brushes 3, 4 and 5, which are adapted to sweep over, make contact with and test the rows lof terminals of the group of lines in which an idle line is located. The terminals of only two such lines are diagrammatically shown in the drawing, such rows being indicated at G and 7, it being understood, however, that in such switches as actually constructed, as many rows of terminals are provided in the switch as there lare lines which it is desired to reach. Also associated with the brush carriage is a brush 3 which in its normal position makes contact with the normalfcontact 9, but which is adapted when the carriage is being moved to make and break contact with the interrupter plate 10 to ground, such brush making contact with the interrupter plate at all times, except when the brushes 3, 4 and 5 are exactly centered upon a row of terminals.

The brush carriage is driven from the constantly rotating power shaft 11 through the agency of two friction disks 12 and. 13, the friction disks being coupled together' by means of the power magnet 14 when such A holding magnet 15 is also provided which acts, when energized, as a magnetic brake to stop the rotation of the brush carriage.

Associated with the selector switch 1 and individual thereto is a sequence or steering switch 16. The construction of sequence or steering switches of the type indicated is well known in this art and need not be herein further described. The purpose of the sequence switch 16 is, in its successive positions, to establish the various circuits by means of which the setting and restoration of the selector switch 1 may be controlled.

The sequence switch 16 is indicated as being capable of. stopping only in its first or normal position and in the 7th, 8th and 18th positions, for the reason that it is only necessary for the understanding of this invention that the sequence switch should stop in such positions; however, it is obvious that between its 1st and V7th positions the'sequence switch may stop as desired to control the selection of the necessary group of vlines in which the idle line is to be selected in any wellknown manner, and also that between its*l 8th and 18th positions it may stop to control the establishment of the through or talking` connection, to initiate the restoration of some other switch,or .to bring about other circuit changes.

The selector 2 is provided with brushes 17, 18 and 19 which vare adapted to travel y over rows of contacts, twoof such rows being indicated at 20 and 21. rlhe interrup'ter' brush is indicated at 22, the interrupter plateV at 23, and the normal contact at 24. vThe power magnet of the selector 2 is indicated Y at 25 and the holding magnet at 26. The sequence switch which is individual to selector 2 is indicated at 27. `8.51.V i

individual to the Selector l is the test relay 28, which is provided with two` windings, and the power control relay 29. Ak similar test relay 30,and power control relay 31 is associated with the selector 2.- AConnected with the row Vof terminals 6 in selector 1 and the row of terminals 2O in@ selector' 2 are three conductors, comprising a line 32. and connected to the row of terminals 7 of selector 1 and row 21 of selector 2y 9.5 Y 'Y are'three conductors comprising line 33. A relay 34 individual to the line 32 is shown connected in the test conductor of such line" and a relay 35 individualfto the line 335 is shown connected in the test conductor of such line. Y

The invention, however, will bevbetter un'- derstood from the description of the'operation thereof which follows: yAssume thatV Y the sequence switches 16 and 27Vhave been icl-5:

magnets 14 and 25v are energized over se`1-15k quence switch springs 160 and 270'to start 'f the brush carriages of selectors 1 and 2 in: motion, toV hunt for an idle line. Y Assuming y that'both the lines 32 and 33 are idle, a characteristic potential lwill be placed on the terminals 6, 7, 2O and 21, such terminals being connected to battery through the relaysA 34 and4 35. If selector 1, for instance," reaches the row of terminals r6 before se-` j lector 2 reaches the row of terminals 20, 125 which are associated xwith sameV line, namely line 32.-the relay 28'will be energized over a circuit which may be traced from battery through therelay 34, terminal 6, brush 5,

sequenceswitclr spring 16.1, left-hand wind-l 1123i l ing of the test relay 2S, sequence switch spring 162 to ground, provided the sequence switch 16 is in either of positions 7 or 8. The test relay 2S will close its front contact and establish a circuit, which will include the right-hand low resistance winding of the test relay, and the Winding of the power control relay 29 to ground. vA branch of the circuit last traced includes the sequence switch spring 163, interrupter brush 8 and interrupter plate 10 to ground, which branch circuit will shunt the relay29 and prevent it from operating until such shunt circuit is opened by the brush 8 falling in between two teeth on the interrupter plate 10 which will occur when the brushes 3, @L and 5 are accuutelv centered on the row of terminals 6. The relay 29 will then operate and kopen the circuit for the power magnet 1a and also close at its front contact a circuit for the holding magnet 15,y including sequence switch spring 164, thus causing the energization of the holding magnet and the stopping of the brush carriage on the rowof terminals 6. The relay 29 will also close at its front contact a circuit through the power magnet of the sequence switch 16, and will drive the sequence switch Jfrom position 7 to S, and if the test relay remains energized a sufficient time, the relay 29 will hold up long enough to drive the sequence switch through position 8. It will be observed that in both positions 7 and 8 of the sequence switch 16, the test relay 2S will be associated with the test circuit of the selector and will be in position to respond when such selector makes contact with the terminals of an idle line, and that a mo` mentary energization of the test relay will not drive the sequence switch through both positions 7 and Q It may easily happen that the selectors 1 and 2 may be simultaneously hunting for an idle line in a group of lines appearing in both of such selectors and therefore that the movable brushes of both selectors may simultaneously reach terminals associated with the same line, for instance, the brushes 3, 4t and 5 may make contact with the row of terminals 6 at the same time that brushes 17, 18 and 19 make contact with row of terminals 20, the row of terminals 6 as well as the row 20 both being connected to line 32, in which case the test relay 28 may be energized over the circuit previously traced and the test relay 30 may be energized over a circuit including the relay 34C, a test conductor of the line 32, terminal 20, brush 19, sequence switch spring 271, lefthand high resistance winding of the test relay 30, sequence switch spring 272 to ground. Therefore there will be a tendency for both of the relays 28 and 30 to operate, but owing to the fact that they must both be energized over their high resistance windings, the potential'ot1 the battery associated with the test conductor or" line 32 will be insutlicient to maintain both of the said relays energized, so that one of said relays will fall back, or in exceptional cases both of said relays may fall back. However, it may easily happen that both of said relays may have been energized long enough to close their front contacts and operate their respective power control relays 29 and 31, in which case the sequence switches 16 and 27 would be driven out of position 7 to position 8 and the motor magnets of the selectors 1 and 2 would be denergized. ln the case of the relay 28 which we will assume held up, this would be the normal operation and the circuit of the power control relay 29 would be maintained long enough to drive the sequence switch not only from position 7 to position S, but also through position S. rlhe brush carriage of selector 1 would therefore stop with the brushes 3, L1 and 5 centered on the terminals 6.

In the case of relay 36 which we will assume has fallen back, the momentary energization thereof in addition to momentarily energizing the power control relay 31 ,and driving sequence switch 27 to position 8 also opened the circuit of the motor magnet' 25. The motion of the brush carriage of the selector 2 may have actually been stopped but when relay 30 falls back relay 31 also falls back, and the brush carriage selector 2 will again start in its hunting movement. However, the test relay 30 was not energized long enough to cause the sequence switch 27 to move out of position 8, so that the test circuit of the selector is still maintained and the selector may still seize an idle line. It is obvious, therefore, that had the test circuit been closed only in the seventh position of the sequence switch 7 instead of in both the seventh and eighth positions, the selector 2 would have returned to normal without being able to seize another idle line and the call associated with such selector would have been lost. The selector 2 having again been started in motion as above described with the sequence switch 27 in position 8, and having reached the row of terminals 21 associated with idle line 33, the test relay 30 will again operate, and in this case remain energized over a circuit which may be traced as follows: battery, relay 35, line 33, terminal 21, brush 19, sequence switch spring 271, left hand high resistance winding of relay 30, sequence switch spring 272 to ground. closes a circuit for itself including its right hand low resistance winding and power control relay 31 to ground. Vhen the shunt around the relay 31 is removed when the brushes are accurately centered on the terminals 21 by the opening of the interrupter circuit, the relay 31 will operate denergiz- The relay 30 ing the magnet 25, energizing thev holding magnet 26 and driving the sequence switch 27 out of position 8. The brush carriage of selector 2 will thereforefstop and connection to the idle line will have been made. Both selectors will therefore have seized idle lines and neither call would have been lost. In case both of relays 28 and 30 should fall back, both selectors l and 2 would `be again started and with their sequence switches in position 8 and unless they should both again attempt to simultaneously seize the same line which is extremely unlikely` neither call vwould be lost. Still another condition under which the test relay associated with a selector switch, of the type herein disclosed, may become momentarily energized without the switch seizing aline may be brought about by the failure of the holding magnetto bring the brush carriage to a stop vbefore the brushes have overrun the terminals-'in otherv words, the momentum of the brush carriage may be 'sufficient to carry the brushes beyond a row of terminais before the motion of the brush carriage is stopped. In this case, assuming that the brushes havevcontacted with the terminals of an idle line, and have not been stopped until after they have traveled beyond such row of terminals, the line and power control relays will have been momentarily energized, in which case the sequence switch will have moved only from position 7 to position 8, because as soon as the brushes leave the row of terminals the line and power control relays will become denergized. The momentary energization of the test relay therefore would not render the switch ineffective for seizing other lines for the reason that as soon as a line relay is denergized the switch will again start on its hunting movement with the test circuit closed in the eighth position of the sequence switch.

It is obvious that because two test posi tions are provided on the sequence switch a momentary energization of the test relay from any cause will not disable the selector from thereafter selecting an idle line. The function therefore of the double test position of the sequence switch may be stated to be the provision of a time interval between the initiation of the operation of the test relay and the opening of the test circuit at the sequence switch, whereby the test circuit is not altered by a momentary energization of the test relay.

I claim:

l. Ina telephone exchange system, the combination with a selector, of a driving circuit and a test circuit therefor, a test relay in said test circuit, means controlled by the response of said relay to open said driving circuit and to disable the test relay for further testing, and means for interposing a time interval between the opening of the.

driving circuit and the disabling of the test relay. Y

2. In a rtelephone exchange system, the combina-tion with a selector, of a driving circuit and a test circuit therefor, a relay in said test circuit and means controlled by said relay when actuated to o-pen the driving circuit, Vandl means operated onlyin case said relay remains actuated a predetermined in- 'i Y Y `terval to disable the selector forV further test-` ing. x 3. In a telephone exchange system, the

combination with a selector, of a driving cir-V cuitJ therefor, a test circuit, a relay con` trolled lthereby which when actuated-opens so .c

the driving circuit, and means operated only L in case said relay remains actuated a predejk termined interval to open the test circuit.

4. In a telephone exchange system, the

combination with a selector, of a` sequencel switch associated therewith, a test circuit for said selector maintained closed by said c sequence switch in a plurality of successive positions, and a circuit for advancingy said sequence switch maintained closed as long as said test circuit is closed, wherebytrol of said driving circuit and adaptedfonly in case it remains actuated a predetermined interval to cau'sesaid sequence switch to open said test circuit.

6. In va vtelephone exchange system, theV positions indiioo combination with a selector, of a sequence;`

switch associated therewith, a `driving cirilo two successive positions of said sequence.' switch, a test relay therein, anda relay con-1 cuit for the selector, a test circuit closed lin trolled by said test relay andwhich when actuated upon the energization of said test relay when the selector connects with an" idle line is adapted to open the driving circuit and onlywhen maintained energized a predetermined interval, to advance the sequence switch through both positions individual to the test circuit.

7. In a telephone exchange system, the combination with a selector, of `a-'sequence switch associated therewith, a driving'cir-r cuit and a test circuit for the selector, said test circuit being closed through a plurality of successive positions of said sequence switch, and a test relay in said test circuitv adapted upon its vresponse toA move said sequence switch throughv a plurality of positions individual to the testvcirc'uit and if re stored prematurely to hold the sequence switch in one of the succeeding test positions and to reclose the driving circuit of the selector for further testing movement.

8. In a telephone exchange system, the combination with a selector, of a sequence switch associated therewith, a driving circuit and a test circuit for the selector, said test circuit being closed through a plurality of successive positions of said sequence switch, and a test relay in said test circuit adapted when energized to movesaid sequence switch through a plurality of positions individual to the test circuit and if restored prematurely to hold the sequence switch. in one of the succeeding test positions and to reclose on its back contact the driving circuit of the selector for further testing.

9. In a telephone exchange system, the

combination with a plurality of automatically operating switches, a plurality of lines multiplied thereto, a driving circuit and a test circuit for each such switch, and a relay controlled thereby adapted when actuated upon connecting with an electrically distin guished line to open the driving circuit and, if maintained actuated sufficiently long, to render ineffective the test circuit, the potential on such line being insufficient to maintain more than one relay excited sufficiently long to render its testing circuit ineffective.

In witness whereof, l hereunto subscribe my name this 28th day of July A. D., 1914.

LIPA POLINKOWSKY. Witnesses:

F. T. WOODWARD, H. TUCK SHERMAN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. G.

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