US1296679A - Telephone system. - Google Patents

Description

J. L. McQUARRIE & H P. CLAUSEN. THEPHONE SYSTEM 1 296 679 APPLICATIGN men mm. m1. Pat nted Ma 11.1919

lm/en fora: James L. MUuarn'e. Henry 1? Clause/v. by

QR .L m w mrnufm 7 ing the flow of ringing current.

UNITED STATES PATENT OFFICE.

J AMES LFMOQUARRIE, OF MONTCLAIB, NEW JERSEY, AND HENRY P. CLAUSEN, OF

MOUNT VERNON, NEW YORK, ABSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- POEATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Mar. 11, 1919.

Application filed August 2, 1917. Serial No. 184,028.

To all whom it may concern:

Be it known that we, JAMES L. MCQUAR- IIIE and HENRY P. CLAUSEN, citizens of the United States, residing at Montclair, in the county of Essex and State of New Jersey, and at Mount Vernon, .in the county of Westchcsterand State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems, and particularly to systems wherein machine-ringing of called subscribers is employed.

It is the practice to signal a called party by intermittently ringing the bell at the substation. This is'done automatically b'y a ringin maghin'e at the connector, such machine aying a commutator on the shaft or equivalent means for intermittently break- It frequently happens that the brushes of a connector are set on the terminals of a wanted line during what is known as thesilent interval of the ringing machine, that is, during the interval when ringing current is cut ofi from the line, and battery current is substituted. This results in loss of time and is considered a disadvantage in commercial systems.

The object of-this invention is to provide a cireuitarrangement whereb ringing cur- ,rent is applied to'the called line for a short.

interval immediately after the connector is set thereon, and intermittently thereafter, if the called subscriber does not respond to such reliminary signal.

A eatureof the present invention is a ringing. relay arranged to release slowly when energized over one circuit, and to release quickly when energized over another circuit. According to this feature, therelay is initially energized, immediately after the called line is seized, in such a manner that it will release slowly, and thereby apply ringing current to the called line for a definite interval. When, thereafter, it is enerized over a circuit including an interrupter, 1ts: energization is such that it releases quickly and moves its armatures in synchronism with the interrupter.

It is thou ht the invention will be better understood y reference to theaccompanying drawing in which a connection between two substations, through the use of a conthrough the apparatus of the subscribers substation S, the upper limb of the telephone line, the upper armature and normal contact of the line relay LR the upper winding of line relay LR, to battery and groundv The line relay LR attracts its armature and establishes a circuit from ground, the armature and alternate contact of relay LR the winding of first slow relay FS, to battery and ground.

The first slow relay FS attracts its arma tures and laces a ground on the third conductor of t e seized connector switch, whereby other selector switches are prevented from extending connections thereto. This ground, extends through the contact and outer armature of relay FS to the terminal t. v

At the same time, a circuit is prepared for slow relay, being slow to release, remains energised. throughout the sending of the impulses, but the primary magnet PM not having such characteristics, responds to each separate impulse, and, through its actuation, drives the brushes-b, b and b into association with the group of terminals in which are included those connected to the substa tion S. The actuation of the second slow relay SR establishes a circuit from ground, the ih'matm-e and alternate contact of relay SR, the winding of escape magnet E, to battery and ground, whereby the relay E is energized.

l'pou the termination of this series of impulses. the second slow relay SR is d energized, due to the. comparatively have interval during which the line relay LR holds its rmature in the attracted position. The consequent. det nergization of the escape magnet E causes the movement of the side switch wipers into their second position.

It should be noted at this point that. upon the first movement of the brushes caused b the primary ma net PM, the primary normal contacts ..()N are actuated, and the release magnet RM connected with the normal contact of the inner left-hand armature of relay FS so that, if, at any time after the connector switch (S has been seized, the relay LR retracts its armature for a sufficient length of time to allow the first low relay F8 to del nergizc, the release magnet will be energized and cause the restoration of the connector switch.

The last set of impulses sent out by the dial switch D causes the energization of the secondary magnet SM and the second slow relay S through a circuit extending now from the winding of second slow relay SR through the a per contact and armature of the test reniy R, winding of secondary magnet SM. second position contact and side-switch wiper W to battery and "round. Since the functioning of the test relay TR forms no part of the present invention, and since its operation is well known and can be easily followed from the drawing. no further description will be given. Responsive to the impulses flowing through the circuit just described, the secondary magn SM moves the brushes 1) to I) inclusive into association with the tel inals t to t inclusive. whereby the lines leading to substation S (assumed to be idle) are seized: At the termination of this series of impulses. the escape magnet E is again dei nergized and the side switch wipers are movedinto their third positions.

In the third positiifh, a circuit is established from ground, side-switch wiper WV and its third p ition contact. wim ing of relay 1, battery and ground, whereby relay 55 1 is energized nd attracts its armatures to ,extend the talking conductors, ieadin from the armatu'res of the ringing relay R, to

the b shes b" and b respectively.

Ifiph uld be noted that while in the secand position the side-switch wiper W entended a connection from ground through the upper winding of relay RR, to battely anl, ground. The upper winding of relay RR is s'd'wolmd thaheg ufh current flows 66 through the circuit just s lfibed tqnot only energize the relay but to cause it to be slow to release when this current ceases to flow. As the side switch is moved into the third position, a circuit is then established, by the energization of relay 1, extending from ground, the ringing current generator G, the alternate contact and upper armature of the relay RR. the upper armature and contact of relay 1, brush 1), terminal t, to and through the call bell of the substation S terminal f brush b the contact and lower armature of relay 1, the inner lower armature and alternate contact of relay RR. to ground. The relay RR. being slow to release, maintains this circuit for a definite interval.

ytT-ythe third position of the side switch is reac ed a circuit is also establishetl from ground, the side-switch wiper W and it third position contact, outer lower armature and contact of relay RR, the side-switch wiper \V and its third position contact, the winding of escape magnet E, to battery and ground. When the relay RR finally releases its armatures. the described circuit for the energization of escape magnet E is opened, the escape magnet deinergizes, and the sideswitch wipers more into-their fourth position.

In the fourth position, a circuit is established from ground, the interrupter I, the lower winding of relay RR, contact and upper armature of the clay 2. the fourth position contact and si e-switch wiper \V{, to battery, and round. The lower winding of release re ay RR is so proportioned that the current flow in this circuit, while sutlicient to cause its energization. is insutiieient to impart the slow releasing characteristic, this bein a function of the ampere turns, as is we known. Through this circuit. relay RR is intermittently energized and tit-energized. and. in response. it intermittently attracts and retracts its armatures. When, in res onse to the-summons of his callbell, the su scriber at substation S remores his receiver from the hook and the relay R-R next becomes deenergized, a circuit is established from ground, the lower winding of relay LR, the lower talking conductor of the connector switch, the normal contact and inner lower armature of relay RR, the lower armature and contact of relay 1, the brush teianinal t, to and through the apparatus-of the substation S", the terminal t. brush 1), contact and upper armature of relay 1, the upper armature and normal contact of the relay RR, the upper talking conductor of the connector switch, the upper winding of relay LR, to battery and ground. Relay LR attracts its at-matures and establishes a circuit from ground, the lower contact of PON, the lower armature and contact of relay LR, the windingof relay 2, the fourth position contact and sideswitch wiper W, to battery and ground. The consequent energization of relay 2 opens the energizing circuit of the relay RR at the upper armature and contact of relay :2, and closes a holding circuit for itself through its contact and lower armature in parallel with the contact and lower armature of relay LR.

The relay 1 is maintained energized, during the conversation, through a circuit extending from ground, fourth position contact and side-switch wiper W, the armature and contact of escape magnet E, the

winding of relay 1, to battery and ground.

At the close of the conversation, the deenergization of relay LR causes the deiinergization of the first slow relay FS, which establishes a circuit from ground, armature and normal contact of relay LE inner armature and normal contact of the relay FS, upper contact of PON, through the winding of the release magnet RM, to battery and ground, whereupon the connector switch is released in the well known manner. The removal of the ground potential from the terminal at through the deiinergization of the first slow rela FS allows the release of the selector switc SS.

What is claimed is:

1. In a telephone system, the combination with telephone lines, a call bell associated with each of said lines, switching means for interconnecting said lines and a source of ringing current for actuating said call bells, of a slow-releasing relay having two windings included in said switching means for controlling the application of said ringing current to said lines, a transient circuit including one of said. windings for the energization of said relay established upon the seizure of one of said lines as a called line by said means, and a circuit including an interrupter and the other of said windings for the subsequent energization of said relay.

2. In a telephone system, the combination with telephone lines, a call bell associated with each of said lines, a connector switch in which said lines terminate, means for setting said connector switch on said lines and a source of ringing current for actuating said call bells, of a relay having two windings for controlling the application of said ringing current to said lines, a transient circuit including one of said windings for the initial energization of said relay, and a circuit including an interrupter and the other of said windings for the subsequent energization of said relay.

3. In a telephone system, the combination with telephone lines, a source of ringing current and switching means for interconnecting said lines, of a slow-releasing relay for controlling the application of said current to said lines, a transiently-established circuit for the initial energization of said relay, a circuit including an interrupter for the sub sequent energization of said relay, and means included in said last circuit for reducing the flow of current therover for causing said relay to be quick to release.

4. In a telephone system, the combination with telephone lines, a source of ringing current, switching means for interconnecting said lines, of a relay for controlling the application of said current to said lines, a transientl -established circuit including means for t estrong energization of said relay and a circuit including an interrupter means for the weak energization of said relay.

5. In a telephone system the combination with telephone lines, a call bell associated with each of said lines, a connector switch in which said lines terminate, means for setting said connector switch on said lines and a source of ringing current for actuating said call bells, of a relay having a high resistance and a low resistance winding for controlling the application of said ringing current to said lines, a transient circuit including the low resistance winding of said relay, for the initial energization of said relay, and a circuit includm an interrupter'and said high resistance winding of said relay for the subsequent energization of said relay.

In witness whereof, we hereunto subscribe our names this 1st day of August-A D., 1917.

JAMES L. MCQUARRIE.

HENRY P. CLAUSEN.

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