US2595510A - Apparatus for transmission of music from a central studio to a plurality of subscribers - Google Patents

Description

M y 1952 J. L. BURNETT ET AL 2,595,510

APPARATUS FOR TRANSMISSION OF MUSIC FROM A CENTRAL STUDIO TO A PLURALITY OF SUBSCRIBERS Filed March 20, 1948 STATION I BY M 1 Gtfornegs i Patented May 6, 1952 APPARATUS FOR TRANSMISSION OF MUSIC FROM A CENTRAL STUDIO TO A PLU- RALITY OF SUBSCRIBERS.

John L. Burnett and Bert Smith, Kansas City, Mo., assignors to Modern Music, Inc., Kansas City, Mo., a corporation of Missouri Application March 20, 1948, Serial No. 16,096

This invention relates to apparatus-for transmission of music from a central studio to a subscriber having a plurality of receiving stations equipped for receiving transcribed music and for carrying on a conversation with the studio operator.

The principal object of the invention is to provide for operation of any one of the subscriber stations to carry on a conversation with the central studio operator without interference with any of the other stations reception of transmitted music.

Other objects of the invention are to provide separate transmission lines for music and conversation; to provide a single speaker at each station adapted to be connected with the transmission lines to serve as a microphone as well as a speaker; to provide for reversing voice input amplification; to provide each station with a coin operated relay for establishing connection through the conversation line with the central studio and which operate to open circuit of the other stations with the conversation transmission line without interference with music being received at the other stations; to provide coin operated relays so that when any one is operated the other relays function to open the conversation circuits of the other stations with respect to the conversation transmission line; and to provide means actuated by an operator at the central studio for re-establishing the coin operated relays to open a closed circuit and to re-establish the ability of the other coin operated relays to be operated by a patron at any one of the stations.

In accomplishing these and other objects of the invention we have provided improved electric circuits and controls thereof, the preferred forms of which are illustrated in the accompanying drawing wherein:

The single figure is a diagrammatic View of the electric circuits and associated apparatus embodying the features of the present invention.

Referring more in detail to the drawing:

I designates the circuits at a central studio, 2 control circuits at a, remotely located subscribers place of business which are connected by'separate conversation and music transmission lines 3 and 4 respectively and individual coin control station circuits '5 whereby a customer may insert a coin at any one of a subscribers stations and effect automatic connection with the central studio through the conversation transmission line 3 without interference by any other patrons station and without interference of the music trans.

scams.- (0!. re-63) mitted from the central studio through the music transmission line to the other patrons stations.

Connected in each station circuit 5 is a speaker 63, transformer I, a coil holder relay 8, a master relay 9, switches Ill-l I, a line busy signal [2, and a binding post strip [3. The master relay includes contact points Pl to PI2 inclusive which are operated by a magnet winding 14. The switch I0 is adapted to be operated upon insertion of a coin and includes contacts PIA, P2A and P3A. The binding post strip carries a plurality of binding posts B! to B9 inclusive which are interconnected to corresponding binding posts of the other stations. The contact PIA of the switch It] is grounded as at l5 and the contact PEA is connected through the magnet winding M of the master relay switch with the binding post B6 by means of a conductor [6. The other contact P3A of the coin control switch is directly connected with the binding post B! by a conductor H. The binding posts BI and B2 are connected with the busy signal l2 by conductors l8 and [9 which are energized upon closing of the switch I l. The coin holding relay 8 has one side grounded and the other side connected by a conductor 20 with the contact P6 of the master relay switch. The contacts Pl P2, P4, P5 and Pl are connected with the binding post B3, B6, B8, B5 and B4 by conductors 2|, 22, 23, 24 and 25 respectively. The contacts P3 and P10 of the master control relay are connected with the transformer l of the speaker by conductors 26 and 21.

In operation of the coin control circuits thus described, insertion of a coin closes the switch It to energize the master relay by current flowing between the binding post 6 through the conductor l6, contact PZA and PIA and ground l5. This actuation of the master relay closes contact P9 and P12. Simultaneously a circuit is closed to the studio circuits later described through a circuit comprising the ground connection PIA of the switch It! and contact P3A, conductor I! and binding post I. The impulse through the master relay. causes the master relay to stay in closed position as the contacts P9 and PH maintain flow of current through the magnet winding 54 after the switch II] is opened.

The coin stop or coin holding relay 8 of the other patrons stations are energized through the contacts P2 and P4 of the relay which was energized by insertion of a coin. The switches II of the other stations are closed by the coin stop relays of said other stations to energize the signals thereof to indicate that one subscribers station is being used for communication.

The binding posts of each patron station are interconnected by line conductors 28 to 35 so that all of the binding posts of the stations are connected in parallel.

The control station circuits include two telephone input circuits 36 and 3'! that are inductive- 1y coupled with the transmission lines 3 and 4. The input 31 supplies the music circuit 38 which includes a suitable stage amplification as indicated by the tubes VI, V2, V3 and V4. Amplified music impulses are passed from the transformer 39 of the final stage of amplification through a conductor 49 which leads to binding post B5 of a binding post strip 4| having binding posts Bl to B9 from which the lines 28 to 35 extend to the patrons stations 5.

The control circuits are also connected with the voice transmission line 3 through conductors 42 and 43 with switches 44 and 45 having con tacts PIB, P213 and P3B, P4B, P513 and PBB, re-

spectively. The switches are operated by a relay coil 46 and are connected with the binding posts 6 and I of the contact strips 4| by conductors 4! and 49. The contacts PIB and P4B are connected with a current supply of substantially 55 volts through conductors 49 and 50, the contacts P2B and P5B being connected with the conductors 42 and 43 previously described. The contacts P3B and PBB are connected by conductors 5| and 52 with a reversing switch having switch sections 53 and 54. The section 53 of the switch has contacts PIC, P20, P30, P40, P50 and P60. The section 54 of the switch has contacts P10, P80, P90, PIBC, Pl I and H20. The contacts P20 and P80 are connected by conductors and 52 and the contact PIC is connected with the contact P50 by a conductor 55. The contact P30 is connected with the contact P40 by a conductor 56. The contacts P and P90 are similarly connected with the contacts P|90 and P|20 by conductors 51 and 58. The contacts P50 and P||0 are connected with the binding and 66, the contacts 64 and 55 being connected with grounds and the contact 85 with the conductor 61 leading to the grid circuit 68 of a vacuum tube 59. The other grid of the tube is connected by a conductor that is connected with the B-voltage supply conductor 1| of the music circuit. The plate of the tube is connected with the primary of a transformer 12 and the secondary ol the transformer is connected with the contacts P30 and P90 of the switches 53 and 54. The grid circuit of tube 69 is also connected to a similar transformer 13 having its primary connected with the contacts P60 and P| of the switch sections 53 and 54. The switch 63 is operated from the studio through a signal circuit 14 that is connected with the input 36. The signal current is passed through a filtering circuit indicated at 15 and imposed on the grid of a vacuum tube 76. The plate terminals are connected with 2, relay winding 11 of the switch 63 by a conducor 8. plied with a B-voltage through a conductor 19 that is connected with the B supply conductor H of the music circuit.

Connected in the conductors 5| and 52 on the line side of condensers 80 and 8| that are con- The opposite side of the winding is supnected therein is a relay winding 82 for operating a switch 93, one contact of which is connected with a five ampere twenty-four volt current supply through a conductor 84 and the other contact is connected by a conductor 85 with the conductor 41.

The studio apparatus includes a coin registering mechanism 86, a studio voice amplifier 87, a studio amplifier for the subscribers voice 88, a music preamplifier 89, and a relay signal generator 90. The mechanisms 81 and 88 are connected with a switch 9| through conductors 92-93 and 94-95. The switch 9| includes contacts PID, P2D and P3D, P4D, P5D, PbD, P'ID, P8D, P9D, P|9D, PI ID and PIZD. The conductors of the voice transmission line 3 are connected with the contacts PID, PZD, P'ID, P8D, P9D and PI 0D. The signal generator 99 is connected with the contacts P||D and P|2D by conductors 96 and 91. a

The music preamplifier 89 is connected with the conductors of the music transmission line by conductors 98 and 99. The coin register mechanism 86 is connected with a transformer I90 through a switch |0| operated by an electromagnet I!) energized by a push button switch NH. The wires 94 and of the studio voice preamplifier are connected with the contacts P3D and P4D. The conductors 92 and 93 from the studio voice amplifier 81 are also connected with the music line through a switch I92 by conductors I03 and I04. Conductor I06 connects the contacts PlD and P9 with one side of the voice line 3 and a conductor I05 connects P8D and PIUD with the other side of the voice line.

Normally the switches 44 and 45 have the contacts P2B-P3B and P5B-P5B closed. The normal position of the reversing switch sections 53 and 54 are such that the P2C-P30, P5C-P50, P80-P90, and PI |0-P|20 are closed while the other contacts are open so that these switches are normally in condition to pass voice currents from any one of the patrons stations to the studio. The contacts of the switch 83 are normally closed and the contacts of the switch 53 are normally open. The normal position of the switches 9 at the patrons stations are such that the contacts P3 and P5, P4 and P6, and PH) and PM are closed so that the customers stations are all ready to receive music currents transmitted from the studio. The coin operated switches l0 and signal switches II are also normally open.

If desired a thank you signal I2 is connected across the relay windings 4 of the respective patrons stations to indicate that contact is made with the studio.

Assuming that the circuits and associated apparatus are connected as described and that all of the switches are in their normal position, a patron at one of the stations in the customers place of business may insert a coin to close contacts PIA, P2A and P3A so that there is a 24-volt current through conductor 84, switch 83, conductor 85, conductor 41, relay winding 46, conductor 48, binding post of the strips 4| and I3, conductor l1, contacts P3A and PIA to ground l5. This flow of current energizes the relay winding 46 to open the contacts P2B and P3B and P53 and P63 and momentarily close the contacts PIB, P2B and P43, P5B sending an impulse of current over'the line wires 3 to the studio to energize the coin register mechanism 86 so that the studio operator is advised that a patron desires to carry on a conversation. Closure of the contacts PIA, PZA, P3A also causes a flow in the conductor 41,

binding post I of the strip 4!; relay winding [4, conductor l6 and ground I5, which impulse of current operates the relay switch 9 to close the contacts P9 and H2 to ground thereby establishing a holding circuit for the relay 9. Upon operation of the relay switch 9 a current flows in conductor 23, contacts P2 and P4, conductor 22 to the other customers stations so that a current flows through the closed contacts P4 and P5 of the relay switches of the other stations to energize the coin holder windings 8 at those stations for closing the contact switches l I. Closing of the contact switches II at the other stations causes flow of current to signals of the other stations. Energization of the signals indicates that one of the stations is in communication with the central studio. Operation of the winding 8 also rejects any coins that may be inserted at those stations so that they will not be effective in actuating the switches l until the normal conditions of the circuits have been re-established by the operator of the studio as later described.

After the impulse of current has occurred in the relay 46, the switches 42 and 43 return to their normal operating condition so that contacts P23 and P3B are closed and contacts P53 and,

P63 are closed. The relay winding I4 remains energized to hold contact of PI in engagement with P3, P2 with P4, P1 with Pm and P9 with PIZ. Upon closing of the contacts Pl, P3 and P1, PH) of switch 9, the speaker 6 may be used as a microphone so that the customer may talk to the operator of the studio, the circuit being completed through the conductors 25 and 21, contacts P'I-PI U and contacts Pl-P3 of switch 9, conductors 25 and 2|, binding posts -3 and 4 of strips l3 and 4|, normally closed contacts of the reversing switch sections 53 and 54 and conductors 42 and 43 which connect with line wires 3.

The studio operator answers by actuating the reversing switch sections 53 and 54 so that voice currents from the studio will be passed in the proper direction through the amplifying tube 69. This is effected by the operator sending a low frequency current (60 cycles) over the voice line wires to the input 36 through the filters 15 to the amplifying tube 16 from where the amplified current passes through the relay 1! to close the contacts 66, 65, 52 and64. A twenty-four volt current then passes through normally closed switch 83, conductor 60, winding 59, contacts 62 and 64 to ground, thereby energizing the winding 59 to change the position of the reversing switch sections 53 and 54. The contact PIC will then engage the contact P20, P40 the contact P5C, contact PHJC the contact PHC, and contact P'IC the contact P80. The voice currents from the studio then pass to the input side of the tube 69 and the output side is connected with the speaker transformer winding 1.

The operator of the studio may then talk to the customer at the subscribers station. After the conversation has been completed between the studio operator and customer, the operator at the studio proceeds to re-establish the normal position of the switch 9. This is effected by pushing the button Nil" which sends a current impulse over the voice line wires of proper voltage to energize the relay 82 and momentarily open the switch 83 which interrupts the twentyfour volt current supply to the relay winding I4, thereby re-establishing the normal position of the contacts for switch 9. Return of the contacts of the switch 9 to their normal position reestablishes the coin holding mechanism and signals at the other stations and the voice line is again open to the studio.

The operator then transmits the desired musical composition record and connects the music amplifier in circuit with the line wires 4 and the music current will be received at the amplifying mechanism 38 of the control station and theamplified current will be carried by the conductor 40 to the binding posts 5 of all of the stations.

During playing of the composition, a customer at any one of the-stations may carry on a conversation with the studio operator without interfering with the music reception at the other stations since the relay switch for that station automatically opens connection with the music circuits and establishes voice connection with the studio through separate line wires.

What we claim and desire to secure by Letters Patent is:

1. In a voice transmitting and receiving system including a studio, a control station situated remotely from the studio and a plurality of patron stations at the control station, a single pair of line conductors composing a single telephone circuit connecting the studio with the control station for transmitting voice currents between the studio and any one of the patrons stations, a current operated speaker at each patron's station adapted to serve as a microphone, means at the control station for amplifying the voice currents over said line conductors in either direction, actuating means at each of the patron stations for sending a current impulse over said line conductors to the studio, holding means at the patrons stations adapted to be energized by said actuating means at any one of the patron stations to prevent the other stations from communicating with the studio, a switch mechanism at each patron station actuated by the current impulse for actuating the holding means at the other patron stations and to connect the speaker in circuit with the voice current amplifying means at the control station, current conducting means connecting the amplifying means with said line conductors, and means for sending current impulses from the studio over said single pair of line conductors for rendering the amplifying means efiective so that voice currents from the studio are adapted to be amplified by the amplifying means at the control station for re ception at a patron's station sending the current impulses to the studio.

2. In a voice transmitting and receiving system including a studio, a control station situated remotely from the studio and a plurality of patron stations at the control station, a pair of line conductors connecting the studio with the control station for transmitting voice currents between the studio and any one of the patrons stations, a current operated speaker at each patrons station adapted to serve as a microphone, means at the control station for amplifying the voice currents over said pair of line conductors, actuating means at each of the patron stations for sending a current impulse over said pair of line conductors to the studio, holding means at the patrons stations adapted to be energized by said actuating means at any one of the patron stations to prevent the other stations from communicating with the studio, a switch mechanism at each patron station actuated by the current impulse for actuating the holding means at the other patron stations and to connect the speaker in circuit with the voice current amplifying means at the control station, current conducting means connecting the amplifying means with said pair of line conductors including reversing switches for reversing flow of current through the amplifying means, a relay means for actuating the reversing switch, and means at the studio for sending current impulses over said pair of line conductors for energizing the relay means actuating said reversing switches so that voice currents from the studio are adapted to be amplified by the amplifying means at the control station for reception at a patrons station sending the current impulses to the studio.

3. In a voice transmitting and receiving system including a studio, a control station situated remotely from the studio and a plurality of patron stations at the control station, a pair of line conductors connecting the studio with the control station for transmitting voice currents between the studio and any one of the patrons stations, a current operated speaker at each patrons station adapted to serve as a microphone, means at the control station for amplifying the voice currents, means at the studio for sending and receiving voice currents over said pair of line conductors, actuating means at each of the patron stations for sending a current impulse over said pair of line conductors to the studio, holding means at the patrons stations adapted to be energized by said impulse actuating means at any one of the patron stations to prevent the other stations from communicating with the studio, a switch mechanism at each patron station actuated by the current impulse for actuating the holding means at the other patron stations and to connect the speaker in circuit with the voice current amplifying means at the control station, current conducting means connecting the amplifying means with said pair of line conductors including reversing switches for reversing flow of current through the amplifying means, a relay means for actuating the reversing switch, means at the studio for sending current impulses over said pair of line conductors for energizing the relay means actuating said reversing switches so that voice currents from the studio are adapted to be amplified by the amplifying means at the control station for reception by the speaker at a patrons station sending the current impulses to the studio, and means energized at the studio for re-establishing said mechanisms to normal position after completion of conversation between the studio and patrons station.

4. In a voice transmitting and receiving system including a studio, a control station situated remotely from the studio and a plurality of patron stations at the control station, line conductors connecting the studio with the control station for transmitting voice currents between the studio and any one of the patron stations, means connected with the line conductors for amplifying said voice currents, music current sending means at the studio, separate line wires connecting the music current sending means with the patron stations, and current direction changing means for rendering the amplifying means effective in either direction of voice current flow.

5. In a voice transmitting and receiving system including a studio, a control station situated remotely from the studio and a patrons station at the control station, a speaker at the patrons station, amplifying means at the control station, line conductors connecting the studio with the control station for transmitting voice currents through the amplifying means to and from the speaker, music current sending means at the studio, separate line wires connecting the music current sending means with the patrons station, and current direction changing means for rendering the amplifying means effective for amplifying the voice currents in either direction.

JOHN L. BURNETT. BERT SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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