US2022030A - Signaling system - Google Patents

Description

NW. 2%, i935. "r. L. DIMOND 2,

' SIGNALING SYSTEM FiledFeb. 16, 1935 FIG. I

A TTORNE Y Patented Nov. 26, 1935 UNITED STATES SIGNALING SYSTEM Thomas L. Dimond, Rutherford, N. J assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application February 16, 1935, Serial No. 6,784

9 Claims.

This invention relates to signaling systems and particularly to systems in which automatic switches are directively controlled by current impulses in a direct current signaling circuit.

The object of the invention is to provide an improved impulse circuit arrangement which is capable of responding to impulses incoming over lines of high resistance and over lines having a low insulation resistance.

In an impulse receiving device arranged in accordance with this invention, one three-element gas-filled tube is energized in response to the closing of a direct current signaling circuit to operate an impulse receiving relay and another threeelement gas-filled tube is energized in response to the opening of the signaling circuit to operate a second impulse receiving relay, the operating circuits for each one of the impulse receiving relays being controlled by the other of these relays. The impulse receiving relays may be effective to control an impulse register or to control a circuit by directively operating an automatic switch.

A feature of the invention is an impulse receiving device comprising a transformer, two threeelement gas-filled tubes, a relay operativelycontrolled by one of the tubes for responding to the closing of an incoming impulse circuit which includes a winding of the transformer, and a relay operatively controlled by the other of the tubes for responding to the opening of the impulse circuit. The control element of one of'the tubes is connected to one secondary winding of the transformer and the control element of the other tube is connected to another secondary winding of the transformer. The anode of one of the tubes is connected to the winding of the relay which responds to the closing of the incoming impulse circuit and the anode of the other tube is connected to the winding of the relay which responds to the opening of the incoming impulse circuit; the operating circuit for each one of the relays is controlled by the other.

A more complete understanding of the invention may be obtained by considering the specific embodiments of the invention shown in the drawing which forms a part of this specification. The

invention is not, however, limited in its application to these specific arrangements and is, in general, applicable to any signaling system in which selective signals are created by the opening and closing'of a signaling circuit.

Referring toeach of the three figures of the drawing, A represents a subscribers station in an automatic telephone system and IR represents impulse receiving means.

The apparatus at station Aincludes a dial H], or an equivalent impulse sender, and is connected by line H to a central ofiice or exchange in which automatic switching equipment is provided for establishing a connection between the line H and an idle impulse receiving means IR in response to the removal of the receiver at station A to originate a call. The impulse receiv-- ing means IR may be used to directly control in succession each of a train of selective switches 10 to complete a desired connection or may be used to operate a register which thereafter controls the various switches through which a desired connection is established. Reference may be had to chapter III of the second edition of Automatic Telephony by Smith and Campbell for a description of an automatic telephone system comprising switches of the well-known Strowger type controlled by the dial impulses when dialed. Reference may be had to: Patent No. 1,395,977 granted to F. A. Stearn et al. on November 1, 1921 for a description of a system comprising switches of the power-driven type which are revertively controlled by a register-controller, set in accordance with trains of impulses created by the operation of the dial at any calling subscribers station to which the register-controller is connected. The impulse receiving means IR, in Fig. 1 comprises the transformer it, the two three-element hot-cathode gas-filled tubes i5 and I5 and the two relays H and 58. The transformer has three windings, the primary winding being connected in series with the central office battery and the line i i The inner ends of the secondary windings of the transformer are connected to the 85 negative pole of the central ofiice battery; the outer end of the upper winding is connected to the grid or control element of the tube l5; and the outer end of the lower winding is connected to the grid or control element of tube it. The cathode of. each tube is connected to the negative pole of central ofiice battery so that there is normally an insufficient difference in potential between the grid and cathode to cause ionization of the gas. If necessary, batteries is and it may be connected in series with the secondary windings of the transformer to normally maintain the grid elements at a proper potential level. The anode of tube 55 is connected in series with the winding of relay H and through the back contact of relay 58 to ground, the positive pole of the central office battery also being connectedto ground. The anode of tube It is connected in series with the winding of relay It to the lower armature of relay l1.

Each of tubes [5 and. I6 are filled to a low pressure with a gas such as neon, argon or helium; and the electrodes of each tube are so designed that the gas becomes ionized upon impression of the required potential across the cathode and grid, whereupon the tube becomes a conductor between the cathode and anode. Although the potential normally impressed across the cathode and anode is insufilcient to cause the breakdown of the tube, the tube remains energized even though the grid element is restored to its normal negative potential, until the cathode to anode circuit is opened or short-circuited.

Upon extension of line I l to the impulse receiving means IR, a circuit is closed from battery, through the primary winding of transformer l2 over the lower conductor of line H, through the telephone instrument and dial H! at station A, back over the upper conductor of line H to ground. The closing of this circuit induces an electromative force in the upper and lower secondary windings of transformer l2, thereby temporarily rendering the grid element of tube l5 less negative and the grid element of tube I 6 more negative. The tube It does not respond; but the temporary change in the potential of the grid of tube I5 causes the ionization of the gas and the tube becomes a conductor, so that relay i1 is operated by the current in the cathodeanode circuit. In operating, relay ll closes at its upper contacts a circuit which controls an impulse register or a selector switch. Relay I! also connects ground through its lower contacts to the winding of relay l8, but relay 58 cannot immediately operate since the tube 13 is not energized.

When the subscriber at station A operates the dial I Q, the line I I is interrupted by the dial contacts in usual manner. At the first opening of the line H, an electromotive force is induced in the secondary windings of transformer I2, thereby temporarily rendering the grid of tube l5 more negative and the grid of tube 15 less negative. The temporary change in the potential of the grid of tube It causes the ionization of the gas and the tube becomes a conductor, so that relay [8 is operated by the current in the cathodeanode circuit of tube IS. The change in the potential in the grid of tube It does not cause its deenergization; but, when relay l6 operates, tube [5 is deenergized and relay l1 releases, thereby opening the outgoing impulse circuit in response to the opening of the line H at dial Ill. The release of relay l1 causes the deenergization of tube 15 and the release of relay l8. As soon as the line i l is again closed at dial ID, the electromotive force induced in the secondary winding of transformer It causes the reenergization of tube l5 and reoperation of relay l1, thereby again closing the outgoing impulse circuit at the pper contacts of relay i7, Thus, each opening and closing of the line i l at the contacts of dial It! causes a corresponding opening and closing of the outgoing impulse circuit at the impulse receiving means IR.

The impulse receiving means IR shown in Fig. 2 is the same as that shown in Fig. 1, except that relay 2'! which is substituted for relay I! of Fig. 1 has an additional set of contacts to provide a locking circuit for this relay. When relay 21 operates, the anode of the tube is short-circuited so that the tube is immediately deenergized.

36, and the relays 3! and 38. The primary winding of the transformer is connected in series with the central ofiice battery and subscribers line. One end of each of the secondary windings is connected to ground, the other ends being con- 5 nected to the grid elements of tubes 35 and 36. The anode element of tube 35 is connected through the winding of relay 3! to the positive pole of battery 34, and the anode element of tube 36 is connected through the winding of relay 38 10 to the positive pole of battery 34, the negative pole of battery being connected to ground. The cathode of tube 35 is normally connected through the back contact of relay 38 to the negative pole of battery 33, the positive pole of bat- 15 tery 33 being connected to ground. The cathode of tube 35 is connected to the lower front contact of relay 31. When the line is closed and connected to the primary winding of transformer 32, the electromotive force .induced in the secondary windings causes the breakdown of tube 35 and the operation of relay 31. Relay 3'! closes at its upper contacts the outgoing impulse circuit and at its lower contacts connects the cathode of tube 36 to the negative pole of battery 33. When 55 the subscribers line is opened by the dial, the eleotromotive force induced in the secondary windings of transformer 32 causes the breakdown of tube 35 and operation of relay 38. The operation of relay 38 causes the release of relay 3'! 80 thereby opening the outgoing impulse circuit. The release of relay 3? causes the release of relay 38. When the line is again closed, at the end of the dial impulse, the tube 35 and relay 3'! are reenergized, thereby again closing the outgoing impulse circuit.

What is claimed is:

1. In combination, a first circuit, a second circuit, a first three-element gas-filled tube, a second three-element gas-filled tube, a first relay, 40 means including said first tube for operating said first relay in response to the closing of said first circuit, a second relay, means including said second tube for operating said second relay in response to the opening of said first circuit, and 45 means including said tubes and relays for closing said second circuit in response to the closing of said first circuit and for opening said second circuit in response to the opening of said first circuit.

2. In combination, a transformer, an impulse circuit including the primary winding of said transformer, two three-element gas-filled tubes, the control element of one of said tubes being connected to one secondary winding of said trans- 55 former, and the control element of the other of said tubes being connected to another secondary winding of said transformer, a relay for operation in response to the closing of said impulse circuit, another relay for operation in response 60 to the opening of said impulse relay circuit, the operating circuit for each one of said relays being controlled by the other of said relays, and another circuit controlled by one of said relays.

3. In combination, a circuit, means for opening 05 and closing said circuit, two three-element gasfilled tubes, two relays, the winding of one of said relays being connected to an element of one of the tubes and the winding of the other of said relays being connected to an element of the 70 other of said tubes, and circuit means for operatively associating said signaling circuit with the control element of each of said tubes, the closing of said circuit being effective to cause the breakdown of one of the tubes and operation of one 75 of the relays, and the opening of said circuit being efiective to cause the breakdown of the other of the tubes and the operation of the other of the relays.

4. In combination, a circuit, means for opening and closing said circuit, two three-element gasfilled tubes, two relays, the winding of one of said relays being connected to an element of one of the tubes and the winding of the other of said relaysbeing connected to an element of the other of said tubes, and circuit means for inductively connecting said signaling circuit to the control element of each of said tubes, the closing of said circuit being effective to cause the breakdown of one of the tubes and operation of one of the relays, and the opening of said circuit being efiective to cause the breakdown of the other of the tubes and the operation of the other of the relays.

5. In combination, a circuit, means for opening and closing said circuit, two three-element gas-filled tubes, two relays, the winding of one of said relays being permanently connected to an element of one of the tubes and the winding of the other of said relays being permanently connected to an element of the other of said tubes, and circuit means for operatively associating said signaling circuit with the control element of each of said tubes, the closing of said circuit being effective to cause the breakdown of one of the tubes and operation of one of the relays, and the opening of said circuit being efiective to cause the breakdown of the other of the tubes and the operation of the other of the relays.

6. In combination, a circuit, means for opening and closing said circuit, two three-element gasfilled tubes, two relays, the winding of one of said relays being connected to an element of one of the tubes and the winding of the other of said relays being connected to an element of the other of said tubes, circuit means for operatively associating said signaling circuit with the control element of each of said tubes, the closing of said circuit being effective to cause the breakdown of one of the tubes and operation of one of the relays, and the opening of said circuit being efiective to cause the breakdown of the other of the tubes and the operation of the other of the relays, contacts on each of said relays for controlling the other of the relays, and other circuit controlling contacts on one of said relays.

7. In combination, a circuit, means for opening and closing said circuit, two three-element gas-filled tubes, two relays, the winding of one of said relays being connected to an element of one of the tubes and the winding of the other of said relays being connected to an element of the other of said tubes, circuit means for operatively associating said signaling circuit with the control element of each of said tubes, the closing of said circuit being effective to cause the breakdown of one of the tubes and operation of one of the relays, and the opening of said circuit being eifective to cause the breakdown of the other of the tubes and the operation of the other of the relays, and means for holding said one of the relays operated and for causing the deenergization of said one of the tubes.

8. In combination, an impulse circuit, two three-element gas-filled tubes, circuit means for operatively associating said tubes with said circuit, a relay for operation in response to the ionization of one of said tubes, a relay for operation in response to the ionization of the other of said tubes, and means for alternately connecting each of said relays to its associated tube for operation in response to impulses in said circuit.

9. In combination, an impulse circuit, two three-element gas-filled tubes, circuit means for operatively associating said tubes with said circuit, a relay for operation in response to the ionization of one of said tubes, a relay for operation in response to the ionization of the other of said tubes, and means for-alternately connecting each of said relays to its associated tube for operation in response to impulses in said circuit, the cathode-anode circuit of each of the tubes being under the control of the relay associated with the other of the tubes.

THOMAS L, DIMOND.

Images