US1393521A - Machine-switching telephone system - Google Patents

Description

c. L. GOODRUM. MACHINE SWITCHING TELEPHONE SYSTEM.

APPLICATION FILED APR. 27 I9I7- v 1,393,521. Patented Oct. 11, 1921-.

2 SHEETS-SHEET I.

' lnwn for: Char/es L Gaadrum.

C. L. GOODRUM. MACHINE SWITCHING TELEPHONE SYSTEM.

APPLICATION FILED APR. 27,19]?- Patented Oct. 11, 1921.

2 $HEETSSHEET 2.

Mwnfar: (/1 dr/es L Goodrum.

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UNITED STATES PATENT OFFICE.

CHARLES I. GO ODRUM, OF'NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- IPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

MACHINE-SWITCHING TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Oct. 11, 1921.

Application filed April 27, 1917. Serial No. 164,870.

To all whom it'may' concern:

Be it'known that 1, CHARLES L. GooDRUM, 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 Machine- Switching Telephone Systems, of which the following is a full, clear, concise and exact description.

This invention relates to machine switching telephone systems, and more particularly to improvements in group selecting switches for use in such systems.

The object of the invention is to provide an arrangement for "eliminating the trunk hunting interval in the operation of a group of a selecting switch.

A feature of the invention is the use of switching means somewhat similar in construction to the well known Keith line switch (U. S. Patent No. 1,151,543), in a directively actuated selector switc Generally stated, the invention comprises a plurality of banks of contacts, each bank beingunder control of a plunger, means 'for keeping. the plunger-s always in operative relation with-sets of contacts which are connected to idle trunks'and 'a means 'for selectively actuatingany one of said plungers.

Through such means an idle trunk is instantly available for the extension of a connectionat the end o'f'the' group selecting operation, and the trunk hunting operation is entirely eliminated.

- In the drawings, Figure 1 is a diagrammatical perspective view of a structure embodying this invention showing in part the necessary elements forming two switching mechanisms; F ig.-2is a-diagrammatical representation of a path through which a connection between two substations may beestablished, showing an indicated calling subscribers substation, an indicated-line switch, a group selector embodying this invention, an indicated connector switch, and an indicated called subs'cribers substation.

Each group selector switch consist-s essentially of a plurality of plungers, such as P and P each place'd'in operative relation to a plurality of sets of contacts,such'as G and C or C and 0*. Certain contacts in e'ach set are common to the line L the other cor l'tacts being individual ito the trunks, such as T 21?, (I and I- so that the actuation of the plunger fl iiwei; the .liiig teithr trunk T or T operative relation with a pin 5 or 6 associated' respectively with the plungers P and P At the end of the rotating movement ofthe shaft 1, the magnet 7 is actuated, and,

through its armature 8, presses on, a disk 9 and moves the shaft 1 downwardly. A pin on the shaft, such as 3, is thereby brought into engagement with a pin, such as 5, as sociated with a plunger, such as P which, engaging the contacts, such as C connects the line L with the trunk T The trunk T now having been made busy, the magnet 10 will be actuated in amanner to be described hereinafter, and allows the rotation ofthe "plunger bar 11 on its axis, so'as to bring another plunger, such as P, still in engagement therewith, into operative relation with another set of contacts connected with an idle trunk. Whenthe plunger bar 11 has been rotated through its full arc, means, hereinafter to be .described, cause the energization of magnet N, whereby the bar 11 is returned to the position shown or normal.

It is thought that the invention may be more fully understood through a description of the establishment of a connection employing a group selecting switch of this nature.

Referring especially to Fig. 2, S represents the calling subscribers substation. hen the receiver is removed from its hook, the connection will be-extended to the group selector through a line switch indicated at LS in the well known manner, whereupon a circuit will be established from battery, the left-hand winding of relay LR, the normal contact of SON through the circuits of the line switch and the substation S to the normal contact of SON the right-hand winding of relay LR to ground. Relay LR becomes energized in this circuit and attracts its armature, whereupon a circuit is established for the energizing of the first 510W "M y zirom. ground, armature and manipulates his sender, the resulting series of breaks in the circuit through which relay LR is energized cause the lnterrnlttent deenergization and energizatlon of relay LR and a consequent vibration of its armature.

Upon the first retraction-acircuit is established from ground, the armature and normal contact of relay LR, the armature and alternate contact of relay FS, the lower armature and contact of relay 7 to a point where the circuit divides, extending in one direction through the winding of the second slow relay SS to battery and ground, and in the other. direction through the winding of primary magnet PM to battery and ground. Slow release relay SS becomes energized and holds its armature attracted until after the last impulse has been re ceived and its circuit is permanently opened. Relay PM, however, responds to each separate impulse, and, in the manner before described, rotates the shaft 1, whereby a group of trunks is selected.

Shortlyafter the receipt ofthe last impulse, the second slow relay SS retracts its armature and establishes a circuit from ground, the armature and contact of-relay SS, the primary off-normal contact PON through the upper winding of relay 7, the brush B, contact 12, upon which the brush B has been set by the rotation ofshaft 1, to the contact and right-hand armature of relay 10, the normal contact and left-hand armature of relay 13- to battery and ground.- Belay 7 becomes energized in'this circuit and causes the plunger to operate the contacts G in the manner heretofore described. Atthe same time relay 7 attracts its armatures, opening at itslower armature and contact the circuit through which relays SS and PM were energized, and completing throu h its inner armature a holding circuit or itself, extending from groundfbattery, the

lower winding of relay 7, the inner armature and contact of relay 7, the left-hand armature and contact of release relay R to ground. The movement caused by the energization of relay 7 operates the secondary off-normal contacts SON SON and SON', whereby the calling line is extended through the contacts C to thetrunk T, and thence to the connector switch OS. A further manipulation of the sender at the substation S directs the operation of a connectorswitch CS to the terminals of the called line S whereby the connection between these two substations is completed.

When the set of contacts (2 was operated a ground was extended through the springs 14 and 15' -to the conductor 16, and thence to the first contact 17 and brush 18, whereby it was further extended through the contact its next position,

left-hand armature of relay 10, Winding of relay 1O tothe normal contact and lefthand armature of, relay 13; to "batteryj'and ground. Relay 10 becomes energized in this circuitand escapesthe plunger bar 11 into whereby the brush 18 is brought into operative relation with the next contact 19; i

' The brushes 18 and 20 attached to the bar 11 form a master switch arrangement whose function is to keep the plungers P and P before an idle trunk. Thuswhen contact 17 is. connected to ground in the manner 'described, the brush 18'is caused to move into engagement with contact 19 which is associated through "a conductor similar to 16 with the next idle trunk; a

In the normal position of the plungerbar with the contact 23,- whereupon ground projected frornbrush 20 through. contact 23,

he winding of relay 13 to battery and ground. Relay 18becomes'energized in this circuit and establishes a holding'circuitfor itself from ground, thearmature and contact' of -relay 22, the right-hand armature and contact of'relay1-3, and. thence over the circuit previously traced. A connection is at the" same time established from ground, battery, left-hand armature and alternate contact'of relay 13,'the winding of magnet N to ground. Magnet-N is there uponheld energized until under its action the plunger bar 'll'has been'returned to its normal position. and brush 20' is again'brought into association' with contact 21. This actionresults in the' energization of relay 22, the consequent breaking ofpthe holdingcircuit of relay13, and the retraction of the armatures of relay 13.

- The release of switch is accomplished the shaftl has rotated. The retraction of its armatures by relay 7 allows the shaft 1 to move upward and removes the force which keeps the plunger, such as I, in association'wi-th the contacts such as C What is claimed is: I v 1.- In a telephone system, g up switches for interconnecting said lines and telephone lines, of extending circuits, selective said circuits comprising terminals in which said lines terminate, terminals arranged in operative relation to said line terminals in which said circuits terminate, a means for causing the operative interconnection of said line and said circuit terminals individual to each said group of extending circuits, means common to said groups for controlling said means and means for selectively operating said first means.

2. In a telephone system, a line, a plurality of groups of trunks, an automatic switch for establishing connection between said line and an idle one of said trunks provided with contacts in which said line and said trunks terminate, a series of members for operatively associating said line terminals with said trunk terminals, each said member being individual to one of said groups of trunks, trunk controlled means for operatively associating said members with sets of terminals connected to idle trunks, and line controlled means for selectively operating said members.

3. In a telephone system, a line, a plurality of groups of trunks, an automatic switch for establishing connections between said line and said trunks comprising terminals in which said line terminates, terminals arranged in operativerelationwithsaid line terminals in which said trunk terminates, means individual to each of said groups of trunks for actuating said terminals, trunk controlled means for automatically associating said means with an idle one of said trunks, and line controlled means for selectively operating said terminal actuating means.

4. In a telephone system, telephone lines, groups of extending circuits, automatic switches for interconnecting said lines and circuits, groups of spring contacts in which said lines and said extending circuits terminate, means individual to each said group for operatively actuating said spring con tacts to interconnect said lines and said circuits, means common to said groups for automatically associating saidmeans with contacts connected to an idle one of said circuits, and line controlled means for selectively actuating said contact actuating means.

5. In a telephone system, a selective switch comprising a plurality of groups of banks of contacts, means individual to each bank for operating the contacts thereof, means common to each group for controlling said first means and means individual to the corresponding bank of each group for selectively operating said first means.

In witness whereof, I hereunto subscribe my name this 26th day of April A. D., 1917.

CHARLES L. GOODRUM.

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