US1237476A - Electrical testing system. - Google Patents

Description

H. P. CLAUSEN & c. L. GOODRUM.

ELECTRIBAL TESTING SYSTEM.

V APPLICATION FILED DEC.21.1916- 1,23'7,;47& Patented Aug. 21, 1917.

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HENRY P. CLAUSEN, OF MOUNT VERNON, AND CHARLES L. GOODRUM, Q YORK,

I 'N. Y. ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK,

N. Y.,' A. CORPORATION OF NEW YORK.

ELECTRICAL TESTING SYSTEM.

Specification of Letters Patent. Patented Aug. 21, 1917.

Application fil ed December 21, 1916. Serial No. 138,169.

T 0 all whom it may concern:

. Be it known that we, HENRY P. CLAUSEN and CHARLES L. GOODRUM, citizens of the United States, residing at Mount Vernon, in

the county of Westchester and State of New.

York, and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Electrical Testing Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to electrical testing systems, and particularly to that class of ardconditions of a certain nature which are encountered.

After a connection has been established between two subscribers, and the calling subscriber has abandoned the call, but the called subscriber has failed to replace his receiver on its hook, the connector switch concerned.

in the connection, as well as the called line, are said to be in an unstandard condition. It is necessary to relieve, or remedy, this condition as soon as possible. Periodic manually conducted tests for detecting such held connectors are unsatisfactory, and result in a detriment to the service. 7

Automatic routine tests may be performed with the apparatus and means disclosed herein, with the result that, in most cases, the unstandard condition will be detected and remedied before a complaint can be lodged.

In the drawings, the part above the broken line diagrammatically represents the cir cuits of a well-known connector switch, and that part below the broken line diagrammat:

ically represents an arrangement of the testing and recording means.

In the preferred form of the invention there is provided a testing means whichis responsive to a changed electrical condition at one point only in the circuit of theCOnnector switch. If, during a routine test, an unstandard condition is encountered, the re sponse of the testing means places a how ler tone on the talking conductors of the held connector switch, which is intended to sumnoon the responsible party. If thisparty,

in response to such a summons, replaces his receiver on its hook, no record of the un standard condition is made. If,fonthe other hand, the unstandard" condition is not remedied 'within a predetermined length of time such condition is recorded, and the testing device is advanced into association with the next connector swltch.

There are three conditions in whichsuch an automatic connector switch as is shown in that part of the drawing above-the broken line may be found during an automatic routine test. It may be found: first, in an idle condition, second, 'in abusy condition, and

third, in a condition created by the abandon.- ment. of the call by the'calling party, where the called party has failed to replace his j receiver on its hook.

In the idle condition, the-switch will be substantially as shown in the drawing, that is, all side-switch arms will be in first position, and all magnets and relays de'elnergi'zed and the off-normal switch open.

With such a switch in a busy condition, the line relay LE under control of the calling line, will be energized; the slow relay 10,

controlled by the line relay LR, will be energized; relay 5,,whose function it is to extend the talking conductors through to the called party, will be energized, and the relay LE controlled by the called party,*will be energized.

These conditions may best be understood by the following short description of the operation of such switch in extendinga connection from the calling line to a called line.

Let it be assumed that the switch shown has been seized by a, selector switch in the. well-known manner. A path of low resist-' ance is thereby completed between conductors 1 and 2, which results in the establishment of a circuit from ground, battery, theleft-hand winding of relay LE the'normal contact and inner lower armature of line relay LR conductor 1, the path of low resistance mentioned, conductor 2, the innermost upper armature and normal contact of relay LE theright-hand winding of line relay 'LR and thence to ground. RelayjLR at tracts its armature and: establishes a circuit from ground, armature-and a-lternatecontact of relay LE the Winding of slow release relay 10, to battery andthence to ground. Slow release relay 10 is energized in this circuit and completes a connection from ground, contact and outermost armature of relay 10, test wire TVV, and thence over well- I known circuits, to the winding of a relay in the line switch concerned inthis connection (not shown), to battery, and thence to ground.

The calling party now dials to transmit a series of impulses, these impulsesbeing short openings of the path of low resistance spoken of. Line relay LE in response to such impulses, causes its armature to rapidly vibrate Magnet 11, however, is slow to release, and

does not respond to'the separate impulses transmitted through its winding and, therefore, remains energized until after such impulses have" ceased. On the other hand, magnet PM,being 'fas't,'responds to each separate impulse, and steps the brushes of the connector switch to the terminals of'the de sired group in the wellknown'manner.

The energizationof the slow release relay 11 results in the establishment of a circuit from ground, armature and contact of relay 11, the winding of relay 6, to battery and thence to ground. Relay 6 controls the movement of the side-switch arms, and, upon its energization, moves the side-switch arms into their second position. This occurs after the sending of this first series of impulses in response to the retraction of the armature of relay ll.

The subscriber now dials a second time 7 and the consequent vibration of the armature of line relay LE between its normal and its alternate contacts results in the transmission of impulses through the cir-' cuit described, except in this case such impulses travel through the WlDCllIlg of the secondary magnet SM mstead of the primary magnet PM, from thence'through the side-switch arm 4 in the second position, to battery and ground, over the circuit previously traced. -Under control of the secondary magnet SM, the brushes 8 and 9 are driven into contact with the terminals of the desired line.

The energization of relay 11 during the I sending of this, second series of-impulses energizes the relay 6 in the manner hereto-- fore described, and upon its dee'nergization at the end of the series of impulses, the sideswitch arms 8 and 4 are moved into third position. A circuit is thereupon established from ground, the side-switch arm 8,1the armature and contact of relay 6, winding of relay 5 to battery and ground. Relay 5 attracts its armatures and thereby extends the talking conductors of the connector switch to the brushes 8 and 9, and thence to the conductors of the called subscribers line.

At the same time a circuit is established from ground, interrupter I winding of realternate contact and armature of relay 7,

upper armature and contact of relay 5, the brush 9, through the conductors and signaling apparatus of the called subscribers substation, to the brush 8 contact and lower armature of relay 5, lower armature and alternate contact of relay 7 toa source'of ringing current. Through this circuit the bell of. the called subscribers substation is oper ated.

lVhen', in response to the summons of his telephone bell, the called subscriber removes his receiver from its hook, and when the interrupter I is in such a position that the relay 7 is deenergized, a circuit is established from ground, battery, the upper winding of relay LE the upper normal contact and armature of relay 7, upper armature and contact of relay 5, brush 9, through the lines and apparatus of the called subscribers substation, tothe brushS, contact and lower armature of relay 5, lower armature and nor mal contact of relay 7, lower winding of relay LR to ground. The relay LE is energized in this circuit and reverses the polarity of the current traveling over the conductors 1 and 2 of the calling subscribers substation in a manner and for a purpose well-known in the art. At the same time relay LR completes a circuit from ground, contact and outer armature of relay 10 test wire TlV, outermost upper armature of relay LE the winding of relay 13, to battery, and thence to ground. Relay 13 is energized in this circuit. and attracts its armatures and opens at its uppe armature and contact the circuit for relay 7. The energization of relay 18 also results in the establishment of a locking circuit for itself from ground at the contact and outermost armature of relay 10, contact and, lower armature of relay 13, winding of relay 13, to battery and thence to ground.

The relay 7 is not, therefore, again energized and the talking conductors ofthe con- "nector switch are maintained in steady connection with the brushes 8 and 9, whereby a conversation between the calling and the called subscriber may take place.

Suppose now that both subscribers hang up their receivers. The connection set up and switch, shown herein, will be ended and the switches concerned will return to normal in the well-known manner. In this case, the line relays LR and LE under the control of the two subscribers, as heretofore described, will be dee'nergized. The ground on the test wire TVV, at the contact and outermost armature of relay 10, under control of relay LE will be removed, thereby allowing the line switch and other selector switches to release. At the same time a ground will be placed on the release magnet 15 through a circuit extending from ground,

the armature andnormal contact of relay LE innermost armature and normal contact of relay v1O, the oif-normal contact12, the lowermost armature and contact of relay LE the windingof magnet 15, to battery and thence to ground, whereupon this connector switch will be released.

If, on the other hand, the called subscriber fails to replace his receiver on its hook, then only relay LE will retract its armature and the ground placed on the circuit just described will have to travel through the winding of relay 14 in series with the-windand thence'to ground. This ground also extends through thelower armature and contact of relay 13 to the test wireTW, thus holding the line switch and selector switches concerned in this connection.

The third condition in which this connector switch may be found is, therefore, apparent from the foregoing description. The ground exists on the circuit between the ofi-normal contact 12 and the winding of relay 14. Relay 14 and line relay LE are still energized under the control of a called subscriber. i I

Referring now especially to'the partof the drawing below the broken line, it will be seen that from each connector switch three,

conductors are led to afset of terminals t,

t and t the terminals t and leading to is energized. Therefore, the sequence switch 18 will pass all of its positions'as just de-' the conductors which extend through the armatures and contacts of relay 5' to the established through the connector brushes 8 and 9; the terminal t leading to the point in the circuit of the connector switch which, from the previous description, will be recognized as being connected to the ground only when the condition for which the test is being carried on occurs.

There is a set of brushes 6, b and b which are arranged to travel over and make contact with the terminals t, t and t These brushes are driven from one set of terminals to another by a stepping magnet 16, and extend the circuits from the connector switch to the testing apparatus through the contacts and armatures of relay 17.

The operation of this testing apparatus may be described as follows: I

A hand switch H is provided for putting such apparatus into operation. The lefthand member of this switch provides a circuit from ground through the interrupter I to the winding of the motor magnet of the sequence switch 18, to battery and ground. Through this: circuit the sequence switch is stepped forward one step at a time.

Suppose that the brushes 7), b and b first come in contact with a set of terminals t, t and 6 connected to an idle connector switch. Since no ground appears on the terminal If, neither relay 19 nor 20 will be energized in any position of the sequence switch during thiste'st. As position 1 is reached a circuit will be established from ground, battery, right-hand member of switch I-l, sequence switch contact 30, winding of relay 17, normal contact and armature of relay 21, to ground. Relay 17 will be energized in this circuit in position 1 only, and will attract its armatures 22, 23 and 24. When position 2 is reached a circuit will be established from ground, battery, the right-hand member of hand switch H, sequence switch contact 31, winding of relay 21, the normal contact and outermost armature of relay 19 to ground. Relay 21 is energized in this sequence switch contact 32, the right-hand member of hand switch H tobattery and thence to ground. Stepping magnet 16 advances the brushes 5, b and 79 into contact with the set of terminals connected with the next switch to be tested.

Let us assume that in thiscase the connec tor switch is involved in a through connection from acalling subscriber to a called subscriber. N0 ground in this case will be connected to the terminal-t since the relay 10 scribed, and the stepping magnet 16, will advance the brushes Z), t and b to the next set of terminals to be tested,

We will now assume that the connector switch is held by a called subscriber on a connectionwhich has been abandoned by the calling subscriber. A ground will be placed on terminal t from the armature and nor-.

mal contact of relay LE inner armature and normal contact of relay 10, olf-normal switch 12 to t.

I i-position 1 of the sequence switch 18 relay 17 will be energized as heretofore described. A circuit will also be established between the ground at terminal 't described, will now be found open at the outermost armature and contact of relay 19; hence relay 17 will maintain its armatures attracted throughout positions 1 to 12, inclusive, as indicated at sequence switch contact 30. As position 6 is reached a circuit is established leading from the middle armature and contact of relay l9, condenser C, sequence switch contact 35, armature 22 and associated contact of relay 17, brush Z2 terminal 6 normal contact and upper armature of relay 7, the upper armature and contact of relay 5, bush 9, through the circuit provided by the called subscribers substation apparatus, brush 8, contact and lower armature of relay 5, lower armature and normal contact of relay 7, terminal 25 brush 6 contact and armature 23 of the relay 17, sequence switch contact 34, contact and innermost armature of relay 19, secondary winding of transformer T, and thence to the middle armature of relay 19. The primary winding of transformer T provides a source of alternating current of such high fre quency that a current induced in the Secondary and flowing through the. circuit just described will so actuate the receiver of the called subscribers telephone set that a howl will be produced therein. This is designed to attract the called subscriber s at-.

tention, who may ceiver on its hook.

Should this happen the connector switch will be restored to its idle condition, whereupon relay 19 will be deenergized and in turn the relay 21 will be energized. The attracthereupon replace the retion of its armature by relay 21 removes, through the deenergization of relay 17 the. testing apparatus fromconnection with theconnector switch and Whfin the sequence As position 2 is reached the circuit for relay 21,.heretofore.

switch--18 finally arrives at the thirteenth position, thebrushes b, b and b are advancedv to a new set of terminals.

If, on the other hand, the subscriber should not replace the receiver upon its hook before position 12 of. the sequence switch 18 is reached, then accircuit will be provided from. ground at terminal 6.. through the 0rd of the condition in which the connector switch under test is found. When, an instant later, sequence switch 18 arrives in the thirteenth position, stepping magnet 16. is

energized, as heretofore described, and ad vancesthe brushes, I27, 6 and b to a new position. 7

What is claimed is:

1. In an electrical testing system, an arrangement for detecting unstandard conditions in an automatic selective switch, comprising a testing means responsive to an electrical, condition on the release wire of such automatic selective switch indicating an unstandard condition, a single link conductor extending between said release wire and said testing means, automatic means for associating said testing means with saidconductor, and means controlled by said testing means for indicating such unstandard condition.

2. An arrangement for detecting and recording. an unstandard condltlon in an automatic selective switch comprising a single relay responsive to a potential indicating an unstandard condition, a signaling apparatus' controlled by said relay for apprising the responsible person ofsuch unstandard condition, recording means responsive to a potential indicating an unstandard condition, and means for preventing the operation of the recording means in case the unstandard condition 1s eliminated in response to theoperation of such signaling apparatus.

3. An electrical testing system for detecting unstandard conditions created in an automatic selective switch through the failure of a called party to replace his receiver on its hook after the calling party'has abandoned the call, comprising testing, means .responsive to an electrical condition at one point in, the .circuit'of such a selective switch means for preventing the operation of said recording means.

4:. An electrical testing system for detecting and recording unstandard conditions in an automatic selective switch created through the failure of a called party to properly manipulate the apparatus connected with said switch, comprising testing means responsive to a changed electrical condition at one point in the circuit of such a selective switch indicating an unstandard condition, recording means also responsive to said changed electrical condition, signaling means controlled by said testing means for apprising the responsible party of such unstandard condition, and means controlled by said testing means for preventing the operation of said recording means responsive to the proper manipulation of said apparatus connected with said switch in response to said signalingmeans.

5. An arrangement for detecting an unstandard condition in an automatic selective switch, which is used in establishing telephonic connection and which unstandard condition is created by the improper manipulation of subscribers apparatus, comprising contacts connected to the talking circuits of said switch and a contact connected to the release circuit of said switch, testing means responsive to a changed electrical condition in such release circuit indicating an unstandard condition of said switch, automatic means for associating said testing means with said contacts, and means controlled by such testing means to indicate the existence of an unstandard condition.

6. An arrangement for determining unstandard conditions in an automatic selective switch used for establishing telephonic connection, comprising a single contact connected to the release circuit of said switch, testing means responsive to a potential on such release circuit indicating an unstandard condition, and means for automatically and successively associating such testing means with such contacts and with said testing conductor.

7. An arrangement for detecting and recording an unstandard condition in an automatic switch used for telephonic connection, comprising a single contact connected to the release circuit of said switch, contacts connected to the talking circuits of said switch, testing means responsive to a potential on said release circuit indicating an unstandard condition, a signaling means controlled by said testing means for apprising the responsible party of said unstandard condition, means for recording said unstandard condition, and means under control of said responsible party for rendering inoperative said recording means.

In witness whereof, we hereunto subscribe our names this 19th day of December A. D.,

HENRY P. CLAUSEN. CHARLES L. GOODRUM.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C.

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