Title:
Telephone system
United States Patent 2129332


Abstract:
My invention relates to telephonic or telegraphic connection between two points in which use is made, for a portion of the distance between said points, of any kind of conventional type of telephone network, for example, networks having local or central battery, or an automatic system, wireless...



Inventors:
Domenico, Mastini
Application Number:
US1534235A
Publication Date:
09/06/1938
Filing Date:
04/08/1935
Assignee:
Domenico, Mastini
Primary Class:
Other Classes:
340/286.01
International Classes:
H04W84/02
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Description:

My invention relates to telephonic or telegraphic connection between two points in which use is made, for a portion of the distance between said points, of any kind of conventional type of telephone network, for example, networks having local or central battery, or an automatic system, wireless transmitting means such as electromagnetic or light waves being used for the remainder of the distance between two points. My arrangement requires no change at the central telephone plant, the only change which is required being at the individual subscriber's stations where there is added what I call a "complex," which is used instead of the ordinary individual telephone instrument, there being a conversation connection combined with said "complex." In the accompanying drawing, by means of which I illustrate my invention, Fig. 1 is a schematic view exemplifying the general principles of my invention, and Fig. 2 is a diagram of the circuits which I may employ.

The principle of my invention is first explained with reference to Fig. 1, wherein a remote radio station I, either portable or stationary, is to be connected with a particular subscriber station 3 through a central station 5. The radio station 1, through radiated energy, effects the remote control of a complex 7, which is associated with a telephone sub-station. Under the actuation of this remote control, the complex 7 is connected with the central station 5, while the ordinary telephone apparatus 9 at the sub-station is disconnected from the network, and gives rise to operations in the network circuit of the central station similar to those which would have been produced had the apparatus 9 called the apparatus 3 directly. The radiant energy, modulated at the remote radio station I, passes to the complex 7, and the voice-modulated current passes over the previously established wire conversation circuit of the telephone network to the subscriber station 3.

Conversely, an incoming call made from any subscriber's station will actuate a transmitter in the complex 7 tuned to the receiver circuit of the remote radio station I, which transmitter, through the radiated energy, actuates a receiver in the remote station I and upon response of the latter, completes the conversation circuit 1-3.

My inventive concept is explained in greater detail with reference to Fig. 2 of the drawing.

This figure diagrammatically shows a combined radio-telephone network connection between a remote radio station I and any subscriber 3 of a telephone network, whether of dial or other type.

The diagram of Fig. 2 serves to explain the construction shown in Fig. 1. In Pig. 2 there is the remote, the stationary or movable radio station I, the interposed complex 7, the telephone apparatus 9 connected with the local station, and the telephone central 5. The station I consists of a transmitter 17 and a receiver 19, with the corresponding aerials. The complex 7 consists similarly of a stationary wireless transmitter 21 and a receiver 23, with the corresponding aerials.

Two cases are now possible: (1) The radio station I calls any subscriber's station 3.

(2) Any subscriber's station 3 calls the radio station I.

In case 1 the conversation circuit is established in the following manner: As long as a microphone 25 at the radio station I is hung up, the transmitter 17 of station I is inoperative, and both microphone and the transmitter circuits are open. Upon the lifting off of the microphone, however, both circuits are closed by the hook 27 and the transmitter begins to send a carrier wave and, so long as there is no modulation, continues sending this carrier wave which is received by the stationary receiver 23, is amplified in high frequency amplifier 29, and is passed on to a detector tube 31. In this case the detected high frequency oscillations produce a direct current and this will give rise to a potential at the ends of a variable potentiometer 33 in the cathode circuit of the detector. A portion of this potential is passed to a low frequency amplifier 35, while the total potential drop acts on the grid circuit of a subsequent tube 37. This tube 37 is directly coupled with an amplifying stage (tube 39), the function of which is to amplify both the modulated current and the direct current.

A bridge system is provided in the plate circuit of the tube 39 across the points (apices) of which there is connected an impulse relay 41 which is connected in series with a milliammeter 43. By suitably adjusting a regulating resistance 45 in the bridge, the latter, in the absence of a carrier wave, can be set to zero, or balanced.

On the other hand, if a carrier wave is transmitted, a potential variation will take place, the bridge is no longer in balance, the milliammeter indicates the passage of current, the relay 41 is excited and closes the feed circuit of a relay 47.

The relay 47, with the switches 49 and 51, shifts the telephone line, consisting of the wires 53 and 55, to the non-local circuit, these wires 53 and 55 being then connected through two transformers 57 and 59 with the output circuit of the stationary receiver 23 and with the input circuit of the stationary transmitter 21. The same relay 47, through a contact 61, also actuates the station transmitter 21. An armature 63 also closes the circuit to the central station 5 and opens a shunt circuit normally across the transformer 59.

Calling impulses coming in from station I may then be sent over the line to the central station. The oscillator grid circuit of the transmitter 17 is connected to the movable element 65 and to the upper contact 67 of a dialing device 69. A lower contact 71 is also associated with the element 65 and the terminals of a grid biasing battery 73 are connected, respectively, to the contacts.

The grid biasing battery, therefore, is intermittently interposed in the grid circuit of the oscillator by actuation of the dialing device, the polarity of the battery and its potential being such that the grid receives a blocking negative voltage when the said battery is in circuit. When the element 65 is in the position of rest, as shown in the drawing, the oscillator may function normally.

The interruptions of the oscillating current, or of the carrier wave, corresponding to the desired subscriber's number, operate, at the receiver 23, to cause the relay 41 to vibrate and thus impose upon the telephone lines 53-55 the number of pulses required for the calling of the desired subscriber 3.

When this is done and the subscriber's station 3 is not busy, conversation can be begun, as the modulations coming from the movable transmitter are sent into the wire circuit by the stationary receiver 23 and the coupling transformer 57, while the modulations emitted by the wire circuit pass through the coupling transformer 59 to the stationary transmitter 21 and from there, by wireless, to the movable receiver 19.

In the second case (2), when the call goes out from any subscriber 3 of the telephone network a slow release relay 75 is actuated thereby. This 50' relay is of the thermic type and, after being energized, holds the armature attracted for thirty seconds or for any other suitable period of time.

A contact 77 of this relay actuates the transmitter T and a contact 79 actuates a buzzer 81, in the grid circuit of transmitter 21. The transmitter 21, therefore, will send oscillations, which are modulated by the inherent frequency of the buzzer and which are received by the movable receiver 19 and passed to the associated telephone apparatus 83. There they produce a call and, if it corresponds to the number of the sta-. tion I and is answered, microphone 25 will be taken off. As a result, the movable transmitter 17 now sends a carrier wave which, after amplification and reception through the stationary receiver 23, actuates the relay 41 therein, which establishes the conversation circuit. Relay 41 actuates relay 47 which switches in the telephone line and at the same time closes the feed circuit of the stationary transmitter 21, which was previously closed for a short time through the relay 75. After these operations the wireless conversation circuit is estabilshed.

When the telephone network is manual rather than of the dial type, the plant is simplified, it being sufficient to establish connection with the central exchange in the manner described previously, and, in a central having local batteries, to send out another calling current.

The circuit described herein only by way of example may be modified in different ways. For example, other rays, for example, light rays, may be employed instead of radio connections.

I claim as my invention: 1. In combination, a remote radio transmitter, a local telephone sub-station, a central station, wire lines normally interposed between said local sub-station and said central station, local radio receiving apparatus and means whereby radio signals received by said local receiving apparatus from said remote radio transmitter cause the disconnection of the local sub-station from the wire lines and the connection of the radio receiving apparatus thereto instead.

2. In combination, a remote radio transmitter, a local radio transmitter, a local radio receiver, a local telephone sub-station, a central telephone station, wire lines normally connecting said substation to said central station, and means responsive to an incoming radio signal, from said remote station, for causing the sub-station to be disconnected from said wire lines and for causing the connection to said lines of said local radio transmitter and said local radio receiver.

3. In combination, a remote radio transmitter, a local radio transmitter, a local radio receiver, a local telephone sub-station, a central telephone station, wire lines normally connecting said substation to said central station, and means whereby a signal from said remote transmitter, after demodulation by said local receiver, causes the disconnection of said wire lines from said substation, the connection of said local radio receiver and said local radio transmitter to said wire lines and the energization of said local transmitter.

4. In combination, a remote radio transmitting and receiving station, a local radio transmitting and receiving station situated near a local telephone sub-station, a central station, wire lines normally interposed between said local substation and said central station, and means by which the local radio transmitting and receiving station, by the action of the energy transmitted from the remote radio transmitting and receiving station, is connected to the central station and the local telephone sub-station is disconnected.

5. In combination, a central telephone station, a telephone sub-station, two wire lines normally connecting the sub-station and the central station, a local radio transmitter and receiver associated with the sub-station, a remote radio transmitter and means for disconnecting said sub-station from said wire lines and connecting said local transmitter and receiver thereto in lieu thereof, said means being responsive to radiant energy received from said distant radio transmitter.

6. In combination, a central telephone station, a sub-station, two wire lines extending from the central station to the sub-station, a local radio transmitter and receiver disposed in proximity to the sub-station, a remote radio transmitter and receiver, means whereby a carrier wave received by the local radio receiver causes disconnection of the sub-station from the lines and connection to said lines of the local radio transmitter and receiver as well as energization of the local transmitter and means at the remote transmitter for producing calling impulses whereby said remote radio transmitter and receiver may be placed in communication with a predetermined sub-station associated with said central station.

7. In combination, a central telephone station a sub-station, a communication channel, constituted by at least two wires, extending from the central station to the sub-station, a local radio transmitter and receiver disposed in proximity to the sub-station, a remotely disposed radio transmitter and means associated with said local radio transmitter and receiver for operatively connecting both of them to said communication channel and for disconnecting the sub-station therefrom in response to the reception by said local receiver of a carrier wave from said remote transmitter, said means, upon cessation of said carrier wave, also functioning to disconnect said local transmitter and receiver from said communication channel and to reconnect the substation thereto.

8. In combination, a remote radio transmitting and receiving station, a local radio transmitting and receiving station situated near a local telephone sub-station, a central station, wire lines normally interposed between said local substation and the central station, means by which the local radio transmitting and receiving station, by the action of the energy transmitted from the remote radio transmitting and receiving station, is connected to the central station and the local telephone station disconnected, means for transmitting a calling signal, means responsive to said calling signal for producing momentary energization of the local transmitter, and a signal device at said local sub-station energized by said signal, said last-named means and said device being operative contemporaneously.

9. In combination, a remote radio transmitting and receiving station, a local radio transmitting and receiving station situated near a local telephone sub-station, a central station, wire lines normally interposed between said local substation and the central station, means, by which the local radio transmitting and receiving station, by the action of the energy transmitted from the remote radio transmitting and receiving station is connected to the central station and the local telephone station Sdisconnected, means for producing momentary energization of the local transmitter and for modulating the carrier wave of the local radio transmitter for sending to the remote radio receiver a calling signal, and a signal device at the local sub-station, both said device and said lastnamed means being activated by a calling signal coming from the central station.

10. In combination, a remote radio transmitting and receiving station, a local radio transmitting and receiving station situated near a local telephone sub-station, a central station, wire lines normally interposed between said local station and the central station, means by which the local radio transmitting and receiving station, by the action of the energy transmitted from the remote radio transmitting and receiving station is connected to the central station and the local telephone station disconnected, means for producing momentary energization of the local transmitter and for modulating the carrier wave of the local radio transmitter for sending to the remote radio receiver a calling signal, a signal device at the local sub-station, both said device and said last-named means being activated by a calling signal coming from the central station, and means for disabling said means for producing momentary energization in response to said energy received from the remote radio station. 11. In combination, a remote radio transmitting and receiving station, a local radio transmitting and receiving station situated near a local telephone sub-station, a central station, wire lines normally interposed between said local station, and the central station, means by which the local radio transmitting and receiving station, by the action of the energy transmitted from the remote radio transmitting and receiving station is connected to the central station and the local telephone station disconnected, means for producing momentary energization of the local transmitter and for modulating the carrier wave of the local radio transmitter for sending to the remote radio receiver a calling signal, a signal device at the local sub-station, both said device and said lastnamed means being activated by a calling signal coming from the central station, and means for disabling said means for producing momentary energization in response to said energy received from the remote radio station and means at the remote radio transmitter for producing carrier wave impulses which after demodulation by the local radio receiver are sent to the central station for selecting and calling the desired subscriberstation.

DOMENICO MASTINI.