US2217041A - Measured service telephone system - Google Patents

Description

Oct. 8, 1940. H. P. BoswAU MEASUEED SERVICE TELEPHONE SYSTM Filed- Dec. 24, 193s Patented Oct. 8, 1940 UNITED STATES PA'rlszN'rA OFFICE MEASURE!) SERVICE TELEPHONE SYSTEM Application December 24, 1938, Serial No. 247,618

20 Claims.

The present invention relates in general to measured service telephone systems, and more particularly to improved circuits for use in connection with paystation calls.

The principal object of the invention is to provide novel circuit arrangements for generating and transmitting a paystaton tone to indicate that the calling party is a paystation subscriber. The paystation subscribers are equipped with the socalled post-pay stations which require the deposit of a coin when the called party answers in order to permit the calling party to talk to the called party. A post-pay station of this type is shown and described in the Riebe Patent No.

i 1,844,684, issued February 9, 1932. When a paystation subscriber calls a local line the tone is transmitted to both the calling and called subscribers when the called subscriber answers. This tone informs the called local subscriber that a paystation is calling and that he should wait long enough to allow the calling subscriber to deposit a coin. The tone informs the calling subscriber that the called party has answered and that he should deposit a coin. When a paystation subscriber originates a long distance call, which must be completed by an operator in a distant exchange, the tone is started in response to the ,operator answering to inform the operator that a paystation subscriber is calling so that the proper fees may be collected.

Ordinarily this new and novel tone generating and transmitting circuit is connected to the paystation lines at the local exchange between the line and its individual line switch. However, this circuit is such that it can be installed in the bell box at the subscribers residence since it is operated over the line conductors and does not require any additional battery connections. It is therefore possible to group both regular (non-pay) and paystation subscribers on the same party line and a tone will only be generated and transmitted when a paystation line is calling.

In the accompanying drawing are shown only such circuits of a local automatic telephone system and a distant manual exchange as are considered necessary to clearly'illustrate the invention.

In Fig. l the substation A is provided with the usual receiver, transmitter, switchhook, induction coil, bell, calling device, substation circuit, and coin collect mechanism as shown and described in the Riebe Patent No. 1,844,684. The line switches and switching through connector are somewhat similar to the line switch and connector shown in Fig. 9 of the Saunders Patent N0. 1,805,725, issued May 19, 1931. The line switches are the well known plunger type, and the connector is of the well known Strowger vertical and rotary type. In the connector onlyv the normal post springs 933 and switch-through relay 92 I the back-bridge and line relays, 922 and 923, are shown. y

The repeater diagrammatically shown terminates the incoming trunk conductors 43 and 44 eX- tending from the distant exchange and is accessible from the switch-through levels of the connectors. Repeaters of this type are well known and therefore only the circuits necessary to describe and understand the invention are shown.

The trunk conductors 43 and 44 extend to the distant exchange to the well-known ring-up and cut-off interlocking relays and jack J. The cord circuit may be any wellknown type of cord circuit Which closes a bridge across the tip and ring conductors of the trunk line to answer or originate trunk calls.

Fig. 2 shows a slight modification of the tone generating and transmitting device shown in Fig. 1.

Fig. 3 diagrammatically shows a party line wherein only one of the subscribers, subscriber D, is a paystation subscriber, the remaining subscribers on this line being regular or non-pay sub'- scribers. The tone generating and transmitting device is shown mounted in the bell box 9D indicated by the dotted rectangle.

A general description of the apparatus having been given, a detail description of its operation will now be proceeded with. For this purpose it will be assumed that the paystation subscriber A desires to converse with subscriber B.

When the receiver is removed at substation A a bridge is closed across the line conductors I and 2 to cause the operation of the lineswitch in the well-known manner. This circuit may be traced from ground at the line switch, main distributing frame jumper 6, Vthrough resistance R and the lower dry disc rectifier I2 in parallel, jumper 4, line conductor 2, substation A, line conductor I, main distributing frame jumpers 3 and 5 to the line relay and battery in the line switch. Assuming that the connector shown is the connector seized by the operation of the line switch, then the battery and ground connections through line relay 923 is substituted for the battery and ground at the line switch. The circuit for line relay 923 extends over the previously traced subscribers loop by way of contacts I5 and I6, back 'contacts I1 and I8 and through the normally closed springs controlled by contacts I9 and 20 to the winding of the line relay.

Subscriber A now dials the digits corresponding to the telephone number of substation B to cause the connector wipers 25 and 26 to engage bank contacts 29 and 39 of the called line and to ring the called party in the well known manner or as described in the Saunders Patent No. 1,805,726. Contacts 23 and 24 were closed during the operation of the connector and when subscriber B answers the ring-cut-oi relay operates to disconnect ringing current and complete the circuit for back bridge relay 922 at contacts 2| and 22 over the called subscribers loop. Back bridge relay 922, upon operating, at contacts I9 and reverses battery back over the calling subscribers loop. This reversal of battery now causes the operation of relay III over a circuit including dry disc rectier I I and the lower winding of relay I0. Relay Il) operates its armature contact 'I causing it to` strike contact spring 9 to which a weight 8 is attached. Due to this striking action, weight 8 and spring 9 are vibrated for a predetermined time and during this vibration contacts 'I and 9 are intermittently closed and opened to produce a tone which is audible to both calling and called subscribers. Eventually, the vibrating contact 9 comes to rest in engagement with contact 'I, thereby stopping the tone and continuously connecting the upper non-inductive winding of relay I0 in the loop circuit in parallel with resistance R to reduce the total series resistance therein. The called party is informed by the audible tone that a paystation subscriber is calling him and that he should wait a sufficient length of time to allow the calling subscriber to deposit the required coin. The calling party is informed by the audible tone that the called party has answered and he must deposit a coin before he can talk to the called subscriber as described in the Riebe Patent No. 1,844,684.

After conversation and in response to either subscriber replacing his receiver relay I0 restores. In case the calling subscriber hangs up rst then the circuit through the lower winding of relay I0 is opened, and in case the called subscriber hangs up iirst the back bridge relay 922 restores and reverses the battery connections to normal in which case the dry disc rectier II blocks the passage of current through the lower winding of relay ID.

On local calls to the paystation the current over the called line conductors is not reversed and therefore relay I0 does not operate. The resistance R connected in shunt of the lower winding of relay I0 is suiciently low to prevent operation of relay I0 by ringing current, part of which ows through rectifier II and the lower relay winding.

Having described the operation which takes place when a paystation subscriber calls another local subscriber, a description will now be given of a call in which the paystation subscriber desires to make a long distance call which must be completed by a manual operator in the distant exchange.

Assuming now that subscriber A desires to make a long distance call and in response to the removal of the receiver the line switch has operated and seized the switch through connector as previously described. Calling subscriber A now dials the digits necessary to trunk the call to the distant exchange and in response to dialling the first digit the connector wipers are positioned opposite the trunk level and the normal post` springs 933 are operated. The second digit rotates the connector wipers to the desired group after which the connector hunts for an idle trunk extending to the distant exchange. Assu-me now that the connector seizes, over bank contacts 21 and 29, the repeater shown terminating the rst idle trunk line. In response to this seizure switch-through relay 92I is operated to substitute battery and ground through the winding of the repeater line relay 49 for the connector line relay 923. This circuit extends from battery and ground through the windings of line relay 40, normally closed springs controlled by contacts 31 and 38, conductors 35 and 36, bank contacts 2'I and 28, wipers and 26, front contacts II and I8 of switch-through relay 92|, and thence over the calling subscribers loop.

In response to the operation of line relay 40 in the repeater, a relay operation (not shown) takes place to operate contacts 43 and 44 to cause a splash of ringing current to be transmitted over the trunk conductors 45 and 46 to the distant exchange after which contacts 4I and 42 are operated to disconnect the ringing current and prepare the circuit for reversing relay 39.

In the distant exchange, ring-up relay 53 is operated by the momentary splash of ringing current and mechanically locks up. The ring-up relay 53 and cut-olf relay 54 are interlocking and are well known, having been usedextensively in manual telephone systems. At contact 5I ringup relay 53 lights the call lamp L to signal the distant exchange operator whereupon the operator inserts the plug of her cord circuit into jack J and throws her answer key K. Cut-01T relay 54 is operated over the sleeve of the jack through resistance Sil to battery, thereby connecting the bridge 6I in the cord circuit across the trunk conductors 45 and 46 to operate reversing relay 39. Relay 39 is operated over the following circuit: ground and battery through both windings of relay 39, front contacts 4I and 42, trunk conductors 4-5 and 46, front contacts 5I and 52, tip and ring of jack J, tip and ring of the plug of the operators cord circuit and through the bridge 6I.

Reversing relay 39, upon operating, at contacts 3l and 38 reverses battery back over conductors 35 and 33, wipers 25 and 26, front contacts I'I and I8, and thence over the subscribers loop. Dry disc rectifier I I permits current to flow in the lower winding of relay I0 and due to this reversal of current relay I0 is operated as previously described. The tone generated by the vibration of spring 9 and weight 8 is audible to both the calling subscriber and the operator at the distant exchange. On receipt of this tone the operator at the distant exchange is advised that the calling party is at a paystation and that the proper fees should be collected for the connection when completed. The operator at any time can check the call and restart the tone by simply removing and replacing her plug to cause the restoration and reoperation of reversing relay 39 which will release and reoperate tone relay I0 as previously described.

Fig. 2 shows a slight modification over the tone relay circuit shown in Fig. 1. The only difference being that the lower dry disc rectifier, such as rectifier I2, has been omitted from Fig 2. This circuit results in only a slightly higher transmission loss on paystation calls and would not be objectionable on certain lines.

The paystation tone relay circuit shown in Fig. 3 shows a somewhat similar circuit to the one in Fig. l except that a condenser C is used in place of resistance R. This circuit provides more operating current for the relay 8 and is, therefore, suitable for long subscribers loops. In order to keep the total series resistance sufficiently low, the resistance of the upper non-inductive winding of relay 80 is reduced from that shown in Fig. 1 so that the relay will hold up with this reduced shunt, inasmuch as the resistance R of Fig. 1 is replaced by condenser C'.

One of the features of the invention is shown in Fig. 3 wherein the tone relay 80 is mounted in the bell box at the subscribers residence. Fig. 3 represents a party line in which only one of the parties, or party D, is a paystation and all of the remaining parties C, E and F are regular or nonpay party line subscribers. Since this tone relay is operated over the two line conductors and does not need any additional source ofbattery or connections it is possible to provide one or more paystations on any party line. In the example shown in Fig. 3 tone relay Bil is only operated by reversal of current when subscriber D initiates a call, since the relay is only cut into the line circuit when the receiver is removed at substation D. Since it is obvious how relay 80 is operated in view of the foregoing description, its detail operation will not be described.

Having described the invention and what is considered new and desired to be protected by Letters Patent is set forth in the following claims.

What is claimed is:

1. In a telephone system, a calling and a called subscribers line terminating in a local exchange, means at the exchange for establishing a connection between said lines, a tone generating device located at said exchange individual to the calling line, and means for operating said device upon the response of the called line to transmit an audible tone to both the calling and called subscribers.

2. In a telephone system, a calling and a called subscribers line terminating in a local exchange, means at the exchange for establishing a connection between said lines, a tone generating device individual to each said line and located in said local exchange, and means for operating only the tone generating device individual to the calling line in response to the called line answering the call to transmit a tone to both the calling and called subscribers.

3. In a telephone system, a calling and a called line terminating in a local exchange, means at said exchange for establishing a connection between said lines, a tone generating device individual to the calling line and located at the local exchange, means responsive to the called subscriber answering for reversing battery back over said connection, and said tone generating device operated in response to said reversal for transmitting a tone to both the calling and called subscribers.

4. In a telephone system, a party line, paystations and regular non-pay substations on said party line, a tone generating device connected to said party line at each paystation, a called subscribers line, means for establishing a connection between a calling paystation on said party line and said called line, and means responsive to the called subscriber answering for operating the calling paystations tone generating device to transmit a tone to both the calling and called parties.

5. In a telephone system, a party line, paystations on said party line, a tone generating device at each paystation, a called subscribers' line, means for establishing a connection between a calling paystation on said party line and said called line, and means responsive to the called subscriber answering for operating the calling paystations tone generating device to transmit a tone to both the calling and called parties, said tone generating devices at each paystation being normally inoperative and become effective for operation only in response to a call from the corresponding paystation,

6. In a telephone system, a party line, paystations and regular non-pay telephones on said party line, a tone generating device individual to each paystation on said party line, a called subscribers line, means for establishing a connection between a calling party on said party line and said called line, and means responsive to the called subscriber answering for operating an individual tone generating device to transmit a tone to both the calling and called subscribers only in case the call originated from a paystation on said party line.

'7. In a telephone system, a party line, a plurality of subscribers substations on said party line, some of said substations on said party line being of a different character than the remaining substations on said line, a tone generating device individual to each of said some substations of a different character, a called subscribers line, means for establishing a connection between said party line and said called line, and means responsive to the called subscriber answering for operating an individual tone generating device to transmit a tone to both the calling and called subscribers only in case a substation of said different character originated the call.

8. In a telephone system, a local exchange, a calling line terminating in said local exchange, a distant exchange, an operators position in the distant exchange, a trunk line interconnecting said exchanges and terminating in said operators position, means for establishing a connection between said line and said operators position over said trunk line, a tone generating device individual to said calling line and located in said local exchange, and means in said trunk line for operating said tone generating device in response to the operator answering the establishment of said .connection to transmit a tone to the operator over said trunk line.

9. In a telephone system, a local exchange, a party line terminating in said local exchange, paystations and regular non-pay substations on said party line, a distant exchange, an operators position in said distant exchange, a trunk line interconnecting said exchanges and terminating in said operators position at the distant exchange, means for establishing a connection'between said line and said operators position over said trunk line, a tone generating device individual to each paystation on said party line, and means responsive to the operator answering the establishment of said connection for operating a tone generating device only in case a paystation on said party line originated the call.

10. In a telephone system, a plurality of party i lines, paystations and regular non-pay substations on each of said party lines, a tone generating device at each paystation, means for establishing a connection between a calling party on one party line and a called party on anothery party line, said tone generating devices at each paystation being normally inoperative, means at each paystation for rendering its tone generating device effective for operation only when the receiver is removed from such paystation, and f means responsive to the called party answering for operating only the .calling partys tone generating device.

1l. In a telephone system, a local exchange, a

calling line terminating in said local exchange, i'

a distant exchange, an operators position in the distant exchange, a repeater in the local exchange, a trunk line interconnecting Said exchanges terminating in said repeater at the local exchange and in said operators position at the distant exchange, means including `automatic vswitches for establishing a local connection between said calling line and other local lines terminating in said local exchange, means including said automatic switches, said repeater, and said trunk line for establishing a trunk connection between said calling line and said operators position, a tone generating device individual to said Acalling line operative to transmit a tone to both the calling and called parties on local connections and to both the calling party and the operator on trunk connections, means in one of said automatic switches for operating said device on local connections when the called local subscriber answers, said last means ineffective von trunk connections, and means in said repeater .for operating said device on trunk connections yWhen the operator answers.

- l2. In a telephone system, a telephone line, a

vpaystatio-n on said line, a relay and a rectifier individual to said paystation and connected to said line, means including said rectifier for operating vor preventing the operation of said relay dependent upon the direction of flow of current over said line, and a tone producing circuit individual to said paystation and connected to said line for transmitting a tone over said line indicatve of said paystation in response to the operation of said relay when current i'iows over said ,line in the proper direction to operate said relay.

13. In a tone generating device for a paystation telephone subscribers line, a relay, an operating winding of said vrelay and a rectifier in series connectedto said line, means including Asaid rectiiier for operating or for preventing the operation of said relay dependent upon the direction of current flow over said line, a tone producing circuit including vibratory springs on said relay connected to said line for transmitting a tone over said line indicative of said paystation,

and means for operating said relay in response to the properdirection of current flow over said -line to vibrate said springs'thereby causing said tone producing circuit to generate said tone.

14. In a paystation substation comprising a paystation circuit and a tone generating device, said tone generating device comprising a relay vand a rectifier connected to said substation telephone circuit, said rectifier rendering said relay inoperative when current flows over said substation-telephone circuit in one direction but operative When 4current ows in the opposite direction, and a tone producing circuit in said device controlled by the operation of said relay when operated by cur'rent flow over said substation circuit in'said opposite direction for transmitting a tone indicative of a paystation substation.

15. In a telephone system, an exchange, a line terminating in said exchange, a paystation subscriber on said line, a tone generating device individual to said line, a relay and a rectifier included in said device and connected to said line, means including said rectier for rendering said relay inoperative when current flows over said line in one direction but operative when current .flows over said line in the opposite direction, and .a tone producing circuit included in said device and connected to said line for transmitting a tone over said line indicative of a paystation substation when said relay is operated by current iiow over said line in said opposite direction.

16. In a paystation substation comprising a paystation telephone circuit and a tone generating device, said tone generating device normally inoperative when current iiows over said substation circuit in one direction, and means for operating said tone generating device for only a predetermined time in response to current flow over said substation circuit in the opposite direction to transmit a tone indicative of a paystation substation.

1'7. In a tone generating device, a relay, an operating circuit for said relay, a rectier and an operating winding of said relay included in said operating circuit, said rectifier blocking current ow over said operating circuit when current flows in one direction, a resistance connected in shunt of said operating circuit for partially restricting current flow in either direction over said operating circuit, means for operating said relay over said operating circuit when current flows in the opposite direction, a vibratory spring operated for a predetermined. time in response to said relay operation, and a second circuit intermittently closed and opened by said vibrating spring for generating a tone, said second circuit including said springs and a second winding of said relay connected in shunt of said operating circuit.

18. In a tone generating device, a relay, an`

operating circuit for said relay, a rectier and an operating Winding of said relay included in said operating circuit, a second rectifier connected in shunt of said operating winding for bypassing current flow over said operating circuit when such current flows in one direction, an impedance connected in shunt of said operating circuit for partially restricting the current flow in said operating circuit, means for operating said relay over said operating circuit when the current ows in the opposite direction, and a second circuit intermittently closed and opened for a predetermined time in response to said relay operation for generating a tone, said second circuit including a second winding of said relay connected in shunt of said operating circuit.

19. In a tone generating device, a relay, an operating circuit for said relay, a rectifier and an operating winding of said relay included in said operating circuit, said rectifier blocking current flow over said operating circuit when current flows in one direction, means for operating said relay over said operating circuit when current iiows in the opposite direction, and a tone producing circuit controlled by the operation of said relay for generating a tone 20. In a telephone system, a subscribers line terminating in an exchange, a tone generating device individual to said line, a relay in said device, an operating circuit for said relay connected to said line, a rectifier and an operating winding of said relay included in said operating circuit, said rectier blocking current flow over said operating circuit when current iiows in one direction over said line, means for operating said relay over said operating circuit when current flows in the opposite direction over said line, a tone producing circuit controlled by the operation of said relay for transmitting a tone over said line, and means controlled by the operation of said relay after a predetermined time for reducing the total line resistance in said subscribers line loop extending to said exchange.

l HANS P. BOSWAU.

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