US1897106A - Telephone system - Google Patents

Description

Feb. 14. 1933.

H. M. BASCOM SENDER /NVE/vro'f? H. M; BASC'OM By ATTORNEY Patented Feb. 14, 1933 UNITED STATES PATENT OFFICE HENRY M. BASCOM, F BROOKLYN, NEW YORK, ASSIGNOR TO AMERICAN TELEPHONE ANI) TELEGRAPH COMPANY, A CORPORATION 0F NEVSVYORK TELEPHONE SYSTEM Application led January 18, 1932. Serial No. 587,370.

This invention relates in general to dial telephone systems and particularly to the illumination of the characters of the impulse senders employed inv such systems.

In order to minimize the probability of telephone connections being inaccurately established by a subscriber manipulating the impulse sender or calling dial in dimly lighted rooms, telephone booths and the like, it

has been suggested in the past that some means be provided for rendering the dial characters more readily discernible. Treating the dial characters with phosphorescent paint, placing a lamp in proximity with the dial, incorporating in the dial structure a translucent number plate beneath which a small lamp may be lighted constitute some of the sugU-estions proposed in the past. In cases where auxiliary lamps were proposed,

means were provided for placing the lamps under the control of the telephone receiver switchhook contacts to be lighted in a local circuit when the receiver was removed from its switchbook.

It is the object of this invention to improve the method of controlling the illumination of telephone calling dials.

This object is attained in accordance-with a feature of the invention by employing a glow discharge tube in the form of a neon lamp, suitably associated with the dial structure and operated by carrier frequency current from the central office.

Another feature 'of the invention resides in the use of the neon lamp, not only as a means for illuminating the dial, but also as a dialing signal to visually indicate to the calling subscriber when she may actuate the dial in establishing a telephone connection.

These and other features of the invention will be readily understood from the following detailed description made with reference to the accompanying drawing in which Fig. 1 is a somewhat skeletonized circuit diagram of an automatic telephone connection of the step-by-step type embodying t-he features of the inventionand Fig. 2 is a schematic diagram of an automatic telephone connection of the panel type embodying the features of the invention.

` to the bank of a line finder switch LF which is represented bythe brushes 6, 7 and 8. The line nder is connected by the tip and ring conductors 9 and 10 of th-e 'trunk T to an associated selector switch S which is represented by the brushes '11 and 12. The brushes 13 and 14 represent a connector switch C which is connected by the trunk 15 to the terminals with which the brushes of the selectorS are in contact. The` line 16' connects the terminals vwith which the brushes 18 and 14 are in contact, to the called subscribers station B.` v

The line finder LF is similar to that disclosed in United States Patent No. 1,711,682 issued to Hovland, May 7, 1929. The selector switch S and connector switch C are of the Strowger type; for a detailed description of their operation, reference may be had to pages 57 to 65 inclusive of the second edition of Automatic Telephony by Smith and Campbell. Only those portions of the various switches are shown as are required 75 in explaining th-e operation of systems in which this invention is embodied.

When a call is originated by the removal of the receiver from the receiver hook at the calling station A, the line relay 2O operates in the well known manner, thereby causing a linender switch, such Aas LF, to hunt for the calling line 1. When the linefinder LFy has found the calling line, the brushes 6, 7 and 8 will engage and remain in engagement with corresponding terminals of the calling line 1. 1

At this point in the connection, it is usua practice to cause a tone signal to be transmitted over the line l to inform the calling subscriber that the linefinder has found the calling line and that the connection is ready for the reception of dial pulses. Upon hearing this tone signal, the calling subscriber proceeds to Yactuate the calling `dial 30 to 95 transmit pulses in accordance with the number of the line with `which telephone connection is desired. It is common practice for the calling subscriber to dial immediately after removing the receiver from the switch- 100 u p stepupY transformer in orde-r to: provide 'suffihook without listening for the tone signal.

Suchagprocedure may result in the loss of pulses and the establishment oa wrongconnection. n

' 5 `It will Vbe noted that a sourcel of'carrier current is normallyassociatedwith the trunk T by wayv of. the-armatures and front contacts of .polarized relay 2l;` so that when the -trunk vTV isconnected tothe subscribers line 10 lg'carrier Vcurrent fromthe. source 3l Twill 4traverse a path includingthebaclrc'ontacts and armatures of--relay 2l,t`runk conductors 9V and 10, brushes 6 and 7 `of linenderLF -snbscribers substation yeou'lipmentfat station A. A neonlamp '23 isbridged across the secondarywinding ofthe transformerV 22, andV is ,energizedfaccordingly, by currentfrom thej source 3 1, VThe illumination of lamp 23 there- Vu .ponindicates to the calling subscriber thatv Shelmay proceed to dial.V Y

diait vcharacters.

and! the mechanismV of the, dial;y The char- `v actors: may-be stamped on ja'translucent ma- -teriall supported by a metal platewith per! Vforations, in it corresponding tothe location 3? ot the. characters toqperrnit thernjto be illnm'inatedrom the rear. `j v l V Theqlamp 23 is'showniconnected:witha.

cientyvoltage for propieroperation.` i, 4Q From the foregoing descriptiomit isfevi-y d entthat this invention provides not' only a "satisfactory *.metliodf: of illuminatingi agiteljefV phone calling dialbut alsolftirnishes a visual nali..

scriberi proceeds to Vdial thev desirednumber and the selector 'switch VSV andV cmancctorv c switch@ function in the Welt known manne-rrespOIlSc to the transmitted HPUJSQSim"` complete; the connection to" the! called `sta'- thepolarized relay-21 remains unoperated as it ispoled in'such a-rnannerthat current from;V Y i the-batteryconnected tothe connector circuit by wayofthe windings of relay 24;- zmdnor- @it malcontactsfoai :relay 25` does notcause it `to opera-te;v

` AThe called' subscriber ing' responding to` the 1 incoming signalremovejs the receiver at sta- Vtion B whereupon relayoperates over an Q65. obtiens circuitfand establishesfan obvious Up vnfreceiptvisual effected f by thefilltnfnination of neon lampi 23, thesubs'- noted that up until;thistime,x

circuit for reversing relay 25 which operates.

In operating, relay 25 reverses the leads from battery and ground associated with relay 24 to the tip and ringk conductors of the established connection. This elects a reversal of current through polarized, Vrela-y 2].. which operateszand removes-the source 31 of caris thereupon extinguished.

rier current from theV trunk T. The lamp 23 ft'Y thej termination of conversation be! tween "thef subscribers at stations A and B, the connection is released inthe well known lmanner. "l and thelr associated Vline terminals, p.r1mary n 15. winding of transforme'rQQl landthrough the In Fig;,2there isdisclosed diagrammatif cally,` one method ofapplying the present in-` vention toal panelty'pe syste-m. jIn this iigure, LF representsla, lineiinderT SS a sender "selector,y DS a district. selector', IStan income? ing selectorandFS atina-,lselector-V These.

switches; function. in a] wellknown vI nanner fand it:isbelievcdnnnecessary tof enter-finto. n

any detailed-descriptionof their operation inthisapplication Howevensuchj a systemV is Ldisclosedand described S. latent` '1,567,07252issued to W1 Matthiesgl-Decemb er 29,1- 9'25l`f 1 1 .n Itis well wn that infsuch panel,type systems-7 theA remoyaLf-otthe -receiver at a; calling; ',station such as station A causes a sender-selector switch to functiontoY select ani lle"^-seriderl such asis `diagranimatically gli shown atSrandrconnect itwith a lineiimder i snfch"as- LFy which is Vlinnting for the calling line-n ln 'ith-1s ycase,:the source' 3l of v carrier frequencyicur-rent 1s bridged across the sender conductorsV so? thatwhen the VseI-idergS isconncctedtoj-thecalling linel by way otlinefinder LEand sender selcctor SS,.Car-rier cur-- .7 rent from the Vsource 31 will-traverse. thepri# mary 'winding oi transformer' 22 over-'an ohnio'ns circuiti and the lamp, 23- w'illgbe energized to serve both, fas alk dialing, signaland aszafmean'sfor illuminatingthc gd-ial chari When-:the connection has beenk tothe ycalled sta-tion bytway of the'districtf `selector DS, 'incoming-'selectorgIS and sel'ector FS i and the vdistrict selector vhas causcd'thetalkingI connection to be established 'the sender Sj'is dismissed in a manner well knowntof those skilled in the art', The' disconnection vof the sender alsodisconnccts Y the cfurrentsource- Sl-k, from` the corinectionso that the lamp 23 is extinguished.V Y In' both stepfbyfstep andv panel type: systems,A this invention pro-vides Vforythe transl mission ot.. a visual,L signal; to indica? e toi the f cal-ling subscriber that vthe telephone; equipment ,is prepa-red iorzdialing and also. tol `ilhiminate' tl1e-dial 'charactersV v r v Wha-tis claimed; is:

1 ll., telephone system,l callingstation;- i

a- VdialV calling station, an aut@maticV switch controlled by the voperation etY dial, switching means responsive to the removal of the receiver at said calling station for connecting said station with said automatic switch, a visual signal at said calling station and means effective upon the connection of said automatic switch with said calling station for energizing said visualsignal.

2. In a telephone system, a calling station, dial at said calling station, an automatic switch controlled by the operation of said dial, switching means responsive to the removal of the receiver at said calling station for connecting said station with said automat-ic switch, a lamp at said calling station and means effective upon the connection of said automatic switch with said calling sta tion for causing said lamp to illuminate said dial and give a visual dialing signal.

3. In a telephone system, a calling station, a dial at said calling station, an automat-ic switch controlled by the operation of said dial, switching means 1responsive to the removal of the receiver at said calling station for connecting said staion with said automatic switch, a visual signal at said calling station and a source of carrier current effective upon the connection of said automatic switch with said calling station for energizing said visual signal.

4. In a telephone system, a calling station, a called station, a dial atsaid calling station, a plurality of automatic switches cont-rolled by said dial, switching means responsive to the removal of the receiver at said calling station for connecting said dial with the first of said automatic switches, a lamp located at said calling station, means effective upon the operation of said switching means for energizing said lamp and means effective upon the response of the subscriber at said called station when said automatic switch-es have completed the connection betweensaid called and calling stations under control of said dial, for extinguishing said lamp.

5. In a. telephone system, a calling station, a lamp signal thereat, alink circuit, switching means responsive to the removal of the receiver at said calling station f'or connecting said station to said link circuit, and means effective upon the connection of said station with said link circuit for energizing said lamp signal.

6. In a telephone system, a calling station, a neon lamp signal thereat, a link circuit, a source of alternating current normally connected to said link circuit and switching means respon sive to the removal of the receiver at said station for connecting said link circuit to said calling station to cause said neon lamp signal to he energized by current from said alternating current` source.

7. In a telephone system, a` calling station, a dial thereat, means for illuminating the characters of said dial, a link circuit, means responsive to the removal of the receiver at said calling station for connecting said calling station to said link circuit and means effective upon the connection of said calling station to said link circuit for energizing said illuminating means.

8. In a telephone system, a calling station, a dial thereat, a neon lamp associated with said dial for illuminating the characters of said dial, a link circuit, a source of alternating current associated with said link circuit, switching means responsive to the removal ofthe receiver at said calling station for connecting said calling station to said link circuit whereupon current from said source energizes said neon lamp.

9. In a telephone system, a calling station, a dial thereat, means for illuminating the characters of said dial, a link circuit, means responsive to the removal of the receiver at said calling station for connecting said station with said link circuit, means responsive to the connection of said station with said link circuit for energizing said illuminating means, a plurality of automatic switches, a called station, said automatic switches being edective upon the actuation of said dial for extending a connection from said link circuit to said called station and means responsive to the removal of the receiver at said` called station for causing the deenergization of said illuminating means.

10. In a telephone system, a calling line, a dial thereat, means for illuminating the characters of said dial, a link circuit, means responsive to the removal of the receiver on said calling line for connecting said line with said link circuit, a relay` in said link circuit, a source of current connected to said link circuit by way of the contacts of said relay from which said illuminating means is energized when said calling line is connected to said link circuit, a called line, switching means responsive to the actuation of said dial for extending av connection from said link circuit to said called station and means at said called station for causing said relay to operate and disconnect said current source from said link circuit.

1l. In a telephone system, a calling line, a dia-l associated therewith, a lamp for said dial, an automatic switch, means associated with said calling line for causing said automatic switch to hunt for and seize said calling line and means responsive to the seizure of said line by said switch for energizing said lamp to illuminate said dial.

In testimony whereof, I have signed my name to this specification this 15 day of January 1932.

HENRY M. BASCOM.

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