US2220940A - Telephone recording system - Google Patents

Description

NOV. 12, 1940. 1 M|HEL|N| 2,220,940

TELEPHONE RECORDING SYSTEM Filed June 7, 1959 2 She'ts-Sheet 1 INVENTOR. {w a. BY

A TTORNEY Nov. 12, 1940. L. A. MICHELINI TELEPHONE RECORDING SYSTEM 2 Sheets-Sheet 2 Filed June 7, 1959 INVENTOR.

ATTORNEY Patented Nov. 12, 1940 I UNITED STATES TELEPHONE RECORDING SYSTEM Leo A. Michelini, San Francisco, Oalii.

Application June 7, 1939, Serial'No. 277,767

exchange and hundreds, if not thousands, of connected subscribers telephones. Each telephone is provided with a dialling mechanism, and

through this mechanism it is possible forany.

subscriber to actuate switches in the central exchange which will connect his or her phone with any one of the hundreds or thousands of telephones connected with the central exchange.

When a subscriber calls a certain party, and no answer is received, it would be highly desirable if a record of the call could be made, or if the called party could be notified of such a call, so as to be in a position to make a return call. Several methods of accomplishing this have been proposed, but so far as is known, none has been applied, or at least put into practical use, due to the cost and complicated nature of such methods or apparatus.

The object of the present invention is generally to improve and simplify the construction and operation of recording systems of the character described, and more specifically stated, to provide a system in which, first, each telephone is provided with a recording mechanism, and sec-' ondly, each telephone is provided with a dialling mechanism whereby the recording mechanism ofany other telephone may be actuated when the party called is absent.

The invention is shown by way of illustration in the accompanying drawings, in which:

Fig. 1 is a wiring diagram showing'two subscribers telephones equipped with recording mechanisms, said view showing also the manner in which these telephones are connected with a central exchange and operated therethrough;

Fig. 2 is a diagrammaticcross-sectional view of the recording mechanism; and

Fig. 3 is another diagrammatic view of the recording mechanism.

The telephone recording system disclosed in this application employs the usual automatically controlled central exchange, indicated at A, with the exception that in addition'thereto an oscillator such as diagrammatically indicated at B will also be required, as a direct current is employed for ordinary operation of the telephones, while an alternating high-frequency current is required when the recording mechanism of, a phone is to be actuated. Any number of subscribers' telephones may be connected with the central exchange, but for the purpose of simplitying the illustration only two telephones are here shown, indicated at C and D. Each subscribefls telephone will be provided with the usual dialling mechanism 3, a transmitter 4, a receiver 5, and ringing, bells 6. In addition thereto, each subscribers telephone will be provided a with a'recording mechanism I, ,a dashpotecontrolled relay switch 8, and a manually controlled switch 9 wherebya circuit established by the dialling mechanism of telephone through the central exchange A to the telephone D may be in closed, and high-frequency alternating current supplied, to permit actuation of the recordin mechanism.

If a person at the telephone C .desires to call the subscriber at telephone D, this is accomplished in the usual manner. that is, by removing the receiver 5 from the hook. when this is done, a circuit'is established through the hook switch I0 andthe dialling mechanism to the central exchange A, which can be traced as follows: D. C. current is supplied to the central exchange, and the flow of current through this circuit will first pass through wire H and wire l2, which connects to one side of the bell-ringing circuit 6.

From here the current flows through wire it,

through the receiver, then through wire I to the transmitter, then back through wire I! and the upper contact of the hook switch 10, as this I switch is closed. It then passes through wires l6 .and I! and a pair of contacts I8 01 the manual-' 80 1y controlled switch 9, then through wire I! to the dialling mechanism, then through wire 20 to wire 2|, which completes the circuit to the central exchange.

The person atstation C will next actuate the 8d diallingmechanism 3 in the usual manner, and in doing so will actuate switches in the central exchange A, which in turn will establish a circuit through the ringing mechanism of the telephone D. This circuit can be traced as follows. Before tracing this circuit it might be said that in addition to establishing a circuit through the hell or ringing circuitot the telephone D a circuit is alsoestablished through the coil 23 of a relay switch 8'. Commencing with wire 24, the current passes through said wire and the wire 25 to the dialling mechanism, then through said mechanism and out through wire 26, contacts I! of the manually controlled switch 9', wires 21 and 28, the lower side of the hook switch Ill, then through wire 29, the'coil of the-relay switch 23; then through a choke coil 30, the. magnets 01 the bell circuit 6, andwires 3i and 32, back to the central exchange.

mechanism in the central exchange will immediately commence operation, and the bells will ring.

If the subscriber at station D is at home and answers, the receiver will naturally be removed from the hook l8, and the circuit through the coil 23 of the relay switch will be broken. The voice or speaking circuit is established through the transmitter 4' the moment the receiver is removed, and conversation will proceed in the usual manner. On the other hand, if the subscriber is not at home, no answer will be received. The bells, or the ringing circuit, will continue and will repeat a predetermined number of times, for instanc six bells may be given, when the ringing circuit will be automatically broken by the action of the relay switch 8'. This switch, by the way, is here illustrated as of the solenoid type. When coil 23 is energized, the armature 33 will tend to move in an upward direction within the coil. Connected or extending through the coil is a rod 34. On its upper end is a switch bar 35, and at its lower end are a pair of switch bars 36 and 31; below the same is a dashpot 38. The dashpot controls the time the ringing circuit is maintained; for instance, after six rings have been given, the dashpot will have moved, due to the pull of the coil 23, to a position where the bars 35, 36 and 31 close circuits through the respective sets of contacts shown. Bar 35, in engaging its contacts, shunts the bell circuit, while bars 36 and 31 close a circuit through the recording mechanism, indicated at I, of the telephon D. The circuit closed by the switch bars- 36 and 31 isan alternating current circuit, as that is required for the operation of the recording mechanism indicated at 1', as has previously been stated. The moment the person at station C hears that the bell circuit has ceased ringing, he or she grasps th handle of the manually 40 controlled switch 9 at telephone C, and throws it to the dotted line position shown. This switch, by the Way, has three contacts, one of which engages the contacts l8, the second of which engages contacts 40, while the third engages contacts 4|. In throwing the switch from the full line position 9 to the dotted line position shown, a circuit is established through the contacts 41, while the circuit through the contacts l8 and 49 is broken. It should however beunderstood that the circuits through the contacts 40 and 18 must not be broken until the circuit through the contacts 4| is made, as even a momentary breaking of the circuit through the contacts l8 and 48 would break the circuit through the central exchange.

The throwing of the manually actuated switch from the full line position to the dotted line position transfers the dialling mechanism from the D. C. circuit-of the central exchange to the A. C. 30 circuit B, and as such permits the dialling mechanism to send alternating high-frequency current impulses through the oscillator B to actuate the recording mechanism 1' of the telephone D. As this is the case, the operator or individual at 5 the telephone C will now dial his or her own number on the dialling mechanism 3, and this number will be recorded by the mechanism indicated at 1', in the form of printed letters or numerals on a tape in the recording mechanism;

. 70 this number will be viewed .by the subscriber of the telephone D when he or she returns, and the subscriber will thereby .know that the person whose number is recorded on the tape has called and desires a return call.

' 7 When the person at telephone C operates the dialling mechanism 3 for the purpose of transmitting the telephone number to the recording mechanism of the telephone D, impulses of A. C. current are sent over the connecting wires or lines, and. the number of impulses produced each time the dial is operated will depend upon the distance the dial is rotated. For instance, if the number 5 is to be transmitted, the dial is rotated until it registers with the numeral 5. The dial is then released, and during the return movement, five interruptions or impulses are sent over the line. These impulses actuate a magnet 44, causing it to be alternately energized and deenergized, and as such, to actuate a lever 45 and a pawl 46 to rotate a ratchet gear 41 a distance of five teeth. On the ratchet gear is mounted a segment 48 and a contact arm 49. This arm moves over a series of stationary contacts F. The ratchet gear comes to a rest after reception of th fifth impulse, and during this rest period a circuit is closed through the segment 48, the contact arm 49, and the contact which it engages. It should and will engage the contact 59, the fifth from the top. This contact is connected through a wire 5| with a magnet 50', causing energization thereof. This magnet in turn actuates a pivoted type bar 52, causing it to strike a platen 53 over which is automatically fed an ink ribbon 54 and a paper tape 55. This type bar carries the numeral 5, and this numeral is thus imprinted on the tape.

During the period of time that the five impulses are received, or in other words, while the contact arm 49 is moving over the stationary contacts F, no current must fiow through the contact arm, but after it comes to reston the selected contact, or that indicated at 58, a. circuit is closed. Before describing this circuit, it should be noted (see Fig. 3) that two additional magnets are employed in conjunction with the magnet 44, to wit, the magnets 58 and 59; Both of these magnets are of th electro-magnetic type, and are instantaneously energized when a circuit is closed through them, but vwhen the circuit is broken, they will retain their magnetic field for a predetermined period of time, this being accomplished by the introduction of copper in the magnetic circuit; In other words, thes magnets are sluggish, as they are slow to release once they are energized. Another factor that should be considered is that when relay switch 8' closes, the contacts 36 and 31, as heretofore described, and magnets 44, 58 and 59 are energized, as a circuit through them is closed by the contacts 36 and 31. The circuit through the magnet 44, however, is interrupted by the impulses sent over the circuit bythe dialling mechanism of the telephone C. Magnet 44 controls the circuit through the magnet 58, as it opens and closes a switch 69 during each impulse. The opening and closing of the circuit through the magnet 58, through switch 60, is-however very rapid, and as the magnet 58 is sluggish, it retains its magnetic field and holds switch 6| open and switch 62 closed during the period when the impulses are being received; and as magnet 59 iscontrolled by the switchGZ, this also remains energized during the ,period 01'. impulse reception. thereby maintaining a pawl 63 in holding position to prevent return of the ratchet gear 41 during the impulse period. However, when the last impulse has been received, magnet 44, remains energized, thereby holding switch open, and breaking th circuit through magnet 58. Switch 6| will then close, and current will flow through the brush 6l', segment 48, contact arm 49, and contact 50.

This energizes the magnet 50, which causes the type arm 52 to strike the platen and thereby print the numeral 5. During the printing period, magnet 59 retains pawl 63 in holding position; that is, the circuit through magnet 59 is broken when switch 62 opens, but magnet 59 is so sluggish as to retain pawl 63 in holding position sufficiently long to permit energization of magnet 50' and actuation of the printing mechanism. When the printing operation is completed, magnet 59 releases the holding pawl 63, and at the same time breaks the circuit through the magnet 50' by opening switch 65, and as the ratchet gear is released it, together with the contact arm 49, will return to normal position, this return movement being insured by the employment of a spring such as shown at 66. In this position it is ready for actuation when the next series of impulses comes over the line circuit.

Each operation of the dial 3 will interrupt the alternating current flow through magnet 44, or in other words, cause a series of pulsations to flow through said magnet, but the number of interruptions or impulses obtained by the operation of the dial will depend upon the number which is being dialled and transmitted. The first operation described was the dialling of the number 5;

. the next and following operations will in all likelihood be other numbers, and the contact arm 49 will accordingly assume a different position after each operation of the dial, thereby causing energization of one or another of the printing magnets generally indicated at G, which are positioned adjacent the magnet 50'.

When the last number has been dialled,'the operator merely hangs the receiver 5 on the hook, and in so doing breaks the circuit through the central exchange. Thereafter the operator returns the manual switch 9 to normal position, and the telephone is then ready for normal operation. Simultaneously with the breaking of the circuit through the telephone C, the direct current circuit through the coil 23 of the relay switch 8 is broken. This switch will open, and the alternating current circuit previously established thereby through the recording mechanism 1' is also broken, thus restoring telephone D to normal operation.

It will be noted that a number of condensers and choke coils are shown in the several circuits.

. These are merely employed for the purpose of keeping alternating high-frequency current out of the direct current circuits, and vice versa, for keeping direct current from flowing through the alternating current circuits. As the function 01' choke coils and condensers for the purpose described is common knowledge, further description thereof is thought unnecessary.

By reference to Fig. 2 it will be noted that the tape is automatically advanced after each printing operation, by means of a magnet I0 and a ratchet mechanism H actuated thereby. The same is true of the ink ribbon, as it is operated by a magnet 12' and .a pawl-and-ratchet mechanism 13. These magnets are again shown in Fig; 3, and the circuit through them is believed to be clearly illustrated. Suiiice it to say that with the energization of any one of the printing magnets indicated at G, magnets 10 and I2 are also energized, causing automatic advance of the ink-ribbon and the tape 55 to be printed upon.

There are instances in which some telephone are not equipped with a dialling system. In such instances, when a person calls another telephone recording mechanism of the called telephone. In

other words, all telephones will be equipped with a recording mechanism; hence if a calling telephone has no dialling mechanism, the calling party can ask the central operator to dial the caller's number when the called telephone is not answered.

While certain features of my invention have been more or less specifically described and illustrated, I nevertheless wish it understood that changes may be resorted to within the scope of the appended claim.

Having thus described and illustrated my invention, I claim: I

In a telephone system having a central automatic exchange and a plurality of connected subscribers telephones, a dialling mechanism on each telephonei'or connecting a calling telephone through the central exchange with the ringing circuit of a called telephone, a relay switch in the ringing circuit of each telephone, said relay switches being dashpot controlled and closing only after the ringing ci cuit of a called telephone has rung a predetermined number of times, a

nism on the calling telephone with said'circuit,

so that the recording mechanism on the called telephone may be operated by the dialling mechanism on the calling telephone.

\ LEO A. MICI-IEIJNI.

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