US1337309A - Telephone system - Google Patents

Description

'C. L. GOODRUM. TELEPHONE SYSTEM. APPLICATION FILED FEB.26, 191s;

Patented Apr. 20, 1920.

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C. L. GOODRUM. TELEPHONE SYSTEM. APPLICATION FILED FEB. 26, 1916.

2 SHEETS-SHEET 2.

Patented Apr. 20, 1920.

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UNITED STATES FATENT OFFICE.

CHARLES GOODRTTM, OF NEW YORK, N. Y., .ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Apr. 20, 1920.

Application filed February 26, 1916. Serial No. 80,690.

To all whom it may concern:

Be it known that I, CHARLES L. GooDRUM, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and usefullmprovements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems in which connections from calling to called subscribers lines are established by means of automatic or electrically operated switching devices.

The principal feature of this invention resides in the provision of means whereby a plurality of brush sets, which are provided as terminals of the same telephone circuit and are carried on the same movable switch element, are employed in simultaneously hunting for a desired line.

A further feature of the invention resides in the provision of means whereby the brush set which first engages the terminal to a desiredl'ne will be definitely associated with the tele hone circuit of which it is a terminal, and the remaining brushes will be maintained disconnected from said telephone circuit.

The present invention may be employed to decrease the time necessary to find and make connection to desired lines,or in certain'instances may be employed to increase the size of line groups. It may be used with switches arranged either to find and make connection to calling subscribers lines, or to find and make connection to idle trunk lines. In the present disclosure the invention is shown as applied to ajline finder switch, and to a trunk selecting switch. I

Referring to the drawings, Figures 1 and 2 with @Fig. 1 at the left diagrammatically indicate the apparatus and circuits employed in the present embodiment of the invention. Theswitch herein disclosed may be of the characterof that shown in patent to Oscar l1. Forsberg, No. 1,252,420, issued January 8, 1918, although obviously any switch which has a set of movable brushes may be employed. In the switch of the Forsberg application above referred to ten brush sets are shown, the several sets being spirally arranged about 'the shaft. A separate group of terminals is provided for each brush set, and the appropriate brush is brought into operative engagement with its particular series of contacts by rotating the supporting shaft.

As a series of ten contacts is provided for each of the brushes, the switch will have a capacity of 100 lines, In the present disclosure the number of brushes may bedoubled, or the number of rotary positions maybe made one half the number of the Forsberg switch. Whichever structure is employed, the sets of brushes will be arranged in pairs as 2-2, 33'. etc. The sets of brushes of each pair are arranged in alrnement, but the several pairs of sets are spirally arranged about the shaft. In case it is desired to employ the present invention to decrease the length of the hunting operation, but five contacts would be arranged in the series provided for each of the brush sets. and, if the number of rotary positions of the switch are decreased, it would result .in doubling the size of the line groups. In

the first instance only five vertical steps of the switch would be required in finding the last line of a group, whereas in the second assumption, while the number of steps, that is ten, for finding the last line would be the same, the size of the group would be doubled.

In the present disclosure the desired sets of brushes will also be brought into operative relation with their respective groups of terminals by rotary movement of the shaft 1. This rotary movement will be accomplished by means of the stepping magnet 5, to the armature 6 of which, is secured the stepping pawl 7. The pawl 7 is arranged to operatively engage the ratchet wheel 8 fixed to the rotatable shaft 9. Thespur gear 10 is also fixed to the shaft 9, and

when thebrush shaft 1 is in its lowermost position, gear 10 operatively engages the gear 11 fixed to shaft 1 near the lower end thereof. The coil spring 12 has its inner end secured to the shaft 9, and its outer end secured to the framework in any desired manner. Retrograde movement of the shaft 9 is prevented by means of the pawl 13, which projects from the yoke 14 p votally supported on the pin 15. Thus it will be seen that of the ratchet wheel 8 will be communicated to the shaft 1 so that a different pair of brush sets 2-2, 3-3, etc., will be brought into operative relation to their respective the step-by-step rotary movement contact groups upon each energization of the magnet 5.

The vertical movement of the shaft 1 is caused by the magnet 16, the armature 17 of which is provided with a pawl 18, which is arranged to cooperate with the circular ratchet teeth 19 on the shaft 1 to move the brushes from set to set of contacts upon successive energizations of the magnet 16. Downward movement of the shaft 1 is prevented by means of the pawl 20, which is carried by the yoke 21 pivotally mounted on the pin 15.

At the lower end of the shaft 1 is a spring detent 22, which, upon the first upward step of the shaft 1, is released and operatively engages the gear wheel 10. The release and return to normal of the switch is controlled-by the magnet 23, the armature 24; of which is fixed .to the yoke 14, which carries the pawl 13. The yoke 14 isprovided with a finger 25, so positioned adjacent to the finger 26 of the yoke 21 that, upon the attraction of 20, as well as the pawl 13, is retracted. The

reverse rotary movement of the shaft 9 at this time is prevented, however, by means of the detent 22, and the shaft 1 is maintained in a definite rotary position by the engagement of the brushes with the contacts. As the shaft 1 approaches its normal position, the gear '11 drops into mesh with the gear 10. At the same timethe detent 22 is retracted, and the switch is rotated to its normal position by means of the spring 12.

It is to be understood that the invention is not limited to employment with a switch of the type herein disclosed, as any other two movement switch, or in fact any other switch which is provided with progressively movable brushes, may be employed with the present invention.

The circuit changing device or side switch herein disclosed may be similar in character to that shown in the patent to Keith and Erickson No. 815,176 of March 13, 1906. The switch shown in this patent, however, will not operate in a manner necessary to fulfil the requirements of the present invention. A circuit controlling switch, such as employed herein, is shown in the above noted application to Oscar F. Forsberg. This side switch may be caused to move its wipers either upon the energization or upon the deenergization of its controlling magnet. This is accomplished by the omission from its escape wheel of the appropriate ratchet teeth.

the armature 24, the pawl terminates at the same time that the brushes 2' are passing over the contacts of the group in which the line A terminates. It will be further noted that only one connecting circuit or trunk is provided for the sets of brushes 2 and 2', the set of brushes which is operatively connected to said trunk being determined by the energized or deenergized condition of the auxiliary test relay 27 The brushes 2 are normally connected to the trunk, but upon the energization of the relay- 27 the'brushes 2 are cut oif and the brushes 2 are'connected to the trunk instead. It is to be understood that a plurality or group of lineifinder switches will be employed in the present invention in a manner similar to that disclosed in applicants application, Serial N 0. 35,326, filed June 21, 1915.-

It is believed that the invention will now be readily understood'from a description of the manner in which the switches operate in'establishi ng a connectio Assuming now that the subscriber having the line A initiates a call by removing his receiver from its hook; this will complete a circuit from battery through the left winding of line relay 28, back'contact and left armature of cut off relay 29 over the lower side of the subscribers line A, through the substation thereof, over the upper side. of the line At, through the right armature and back contact of relay 29 and the right winding of relay 28 back to batt'ery. Relay 28 attracts its armatures andputs potential on the right terminal of the set in which line A terminates, from the source'of current 30, through test relay 31, right contact and armature of relay 28. It also fig-{completes a circuit from battery through relay 32, back contact and left armature of relay 33, left armature and contact of relay 31, left contact and armature of relay 28 and the right Winding of relay 28 to ground. Relay 32 is energized and locks up through its left armature and contact.

net 5 is repeatedly energized and deenergized, thus stepping the sets of brushes 2-2', 23-3, etc., successively into operative relation to their rows of contacts, until the brush 36 carried at the top of the shaft 1 engages the contact 37 individual to the group of the calling line. A circuit will now be completed from battery through the escape magnet 38, side switch wiper 39, brush contact 37, outermost right armature andv contact of relay 32 and the right armature 30 rupted, stopping the vertical stepping acand contact of relay 31 to ground. Escape magnet 38 will be energized and will'move the side switch wipers to osition 2.

In position 2 a circuit is completed from battery through the vertical stepping magnet 16, its individual interrupter contact 4 side switch wiper 35, relay 33, innermost right armature and front "contact of relay 32, and right armature and contact of relay 31 to ground.' Due to the action of the individual interrupter 40, magnet 16 will be repeatedly energized and deenergized, thus stepping the sets of brushes 2 and 2 from set to set in their respective series of contacts. When the brushes 2' engage the contacts of the line A, a circuit will be completed from source of current 30, through test relay 31, contact and right armature of line relay 28, right contact and right brush 2, through condenser 41, side switch wiper 42, auxiliary test relay 27 tobattery and 1 ground. This will cause an impulse of current to pass through relays 31 and 127, and

both will attract their armatures. During the vertical stepping operation a circuit extend ed through escape magnet 38 and side switch wiper 39 in parallel with the vertical magnet 16 and wiper 35. Now, upon the attraction of the armature of relay 31,. the circuit for magnets 16 and 38 will be intertion and causing the de'nergization of the escape magnet 38, whicln'upon the retrac tion of 1ts armature, moves the side switch wipers to position 3. When the side switch goes to position 3, relay 27 is locked up by a circuit through its upper armature and contact and side switch wiper 42, which.

locking circuit will be maintained until the side switch is restored to its normal position upon restoration of the switch.

Had the subscriber of line A initiated the call instead of the subscriber of line A, the operation would have been exactly the same as just described, with the exception that the test circuit would have extended from the source of chrrent 30, through relay 31, contact and right armature of the line relay 28'- of line A to the right contact and the right brush 2. through the innermost lower armature and back contact of relay 27, wiper 43. condenser 44, resistance 45 to battery and ground. Relay 31 would have been energized and accomplished the same functions as previously described. As the side switch would move to position 3 immediately after the test, the energizing circuit for the relay 27 would be open, thus insuring that the lower armatu'res of this relay wouldremain retracted and thus maintain the brushes of the set 2 connected to the trunk. r

' As the side switch" moves to position 3, the starter wire 46 is extended through the back contact and innermost right armature of releft brush of the set 2 and the winding of the cutoff relay 29, to ground. e Relay 29 will be energized, thus interrupting the circuit of line relay 28, which, in retracting its ar-" matures, will return the common mechanism to its normal position.

In position 3 of the side switch, the side switch wipers 43 and 47 also extend the calling line through to the selector switch shown in Fig. 2. I

The calling subscriber may now operate his 'dial to send a series of impulses to the selector switch shown in Fig. 2. This switch may be of the same structure as that indicated in Fig. 1. Whenside switch wiper 43 reached its third position a circuit was completed from battery through the right winding of trunk relay 48, side switch wiper 49, the left Winding of relay 48, Wiper 43, innermost lower armature and frontcon tact of relay 27 right brush 2, the line terminal engaged thereby, front contact and.

right armature of cutoff relay 29 over the upper side of' the subscribers line A, through the substation thereof, back over the lower side of the subscribers line, through the left armature and front contact of relay 29, and through the winding of relay 29 to ground. This circuit causes the energization of relay 48, which in attracting its armature completes a circuit from battery, through the winding of relay 50, front contact and armature of relay 48, back contact and armature of relay 51, back contact and armature of release magnet 52 to ground. The subscriber now sends the se lecting series of impulses to operate the switch shown inFig. 2. The sending device may be of any desired and well-known construction which operates to produce a series of interruptions in the line circuit. With each interruption at the sending device, the circuit of relay 48 will be broken and it will retract its armature, completing a circuit from battery, through the rotary stepping magnet 53, side switch wiper 54, and also from battery through the escape magnet relay 55 in parallel with magnet 53, and thence through the front contact and innermost armature of relay 50, back contact and armature of relay 48, back contact and armature of relay 51 to ground, through the back contact and armature of release magnet 52. Relay 55, in attracting its armature,.will cause the energization of the esenergization of relay 18, the rotary stepping magnet 53 w1ll be repeatedly operated to step the switch shaft 57 of the selector switch around until the sets of brushes 58 In position 2a circuit is completed from battery through the "ertical stepping magnet'59, its individual interrupter 60, wiper 61, front contact and armature of relay 48, back contact and armature of relay 51 and back contact and armature of release magnet 52 to ground. It is to be understood that the test contact of idle trunks, that is, the right or under contact in Fig. 2, will be connected to ground throu h a resistance in any well-known manner. his ground connection may for example be made through a back contact of the first slow relay corresponding to relay 50. As this relay holds its armatures continuously attracted whenever its switch is in use, the ground is present on the test contact only when the switch is idle. We will first assume that the brushes 58 are first to engage thecontacts of an idle trunk. When this occurs, a circuit will be completed from battery, through the auxiliary test relay 62, the normal lower contacts of this relay, the right brush of the set 58 and the contact engaged thereby to ground through resistance 63. Relay 62, in attracting its lower armature, will complete a locking circuit for itself, which extends to ground through the front contact and outermost armature of relay 50. In attracting its innermost upper armature, it completes a circuit from battery through the test relay 51, innermost upper armature and front contact of relay 62, right brush of the set 58 and the terminal engaged thereby, to ground through resistance 63. Relay 51 in attracting its armature, will complete a circuit from battery through the escape magnet 56, front contact and armature of relay 51 and the back contact and armature of release magnet 52 to ground. Magnet 56 will be energized and move the side switch wipers to position 3.

At the time test relay 51 is energized the line relay and consequently the first slow relay at the second selector switch will also be energized which will operate to remove the ground from the test contact engaged by the right brush of the set 58, thus causing the immediate retraction of the armature of relay 51. As the relay 50 is slow to release,

62. In thecase now it will not drop off its armature during the momentary interruption of its circuit at the back contact of relay 51.

Had it happened that the calling line terminated in the series o f'contacts traversed by the set of brushes 58, the operation would have been the same as justdescribed with the exception that the operation of the test relay 51'would not have been preceded I by the operation of the auxiliary test relay assumed, the operating circuit for the relay 51 would extend from battery through said relay 51, the innermost upper armature and back contact of relay 62, the right brush 58 and the contact engaged thereby, to ground through the resistance 63. Thus it will be seen that, irrespective of which brush first engages an idle trunk, the switch will be stopped with said brush on the contacts of said trunk and the set of brushes on the idle trunk will be connected to the trunk circuit, the other'set of brushes being maintained disconnected from the trunk circuit.

As the side switch of the selector moves to position 3, thecircuit extending through the right winding of relay 48 will be interrupted, but as battery will be supplied at this time from the next selector switch to the contact engaged by the left brush 58 or 58, depending upon which has first found the idle trunk, this relay will not retract its armature, as a circuit will now exist from battery-through the left brush of the operative set to the uppermost armature of relay 62, wiper 49, left winding of relay 48, wiper 7 43, innermost lower armature and front contact of relay 27, the right brush of the set 2 and the contact engaged, the front contact and'right armature of relay 29, the upper side of the subscribers line A through the substation thereof, back over the lower side of the line A through the left armature and front contact of relay 29, to ground through the winding of relay 29.

The release of the line finder and the first selector switches at the termination of the conversation is controlled at the back contact and outermost armature of relay 50.

When the calling subscriber replaces his receiver upon the hook, the above traced C11- cuit through the left winding of relay 48 is interrupted and it retracts its armature, thus permanently opening the circuit for the relay 50 which in turn becomes denergized and completes a circuit from battery throng 1 the release, magnet 23 of the line finder switch, back contact and right armature of relay 33 and from battery through the release magnet 52 and off-normal contact 64 and thence to ground through the back contact and outermost armature ofrelay 50. The release magnet 23 thereupon locks up through a circuit including off-normal contact 65 and the contact 66, and remains said series of locked until contact 65 is opened as the switch reaches its normal position, litelease magnet 52 also looks upthrough oilnormal contact 64 and its armature and front contact, thus insuring the full return to normal oi the selector switch.

It will thus be seen that the arrangement herein disclosed provides means whereby two sets of brushes may each hunt over their respective series of contacts at the same time and whereby the brush set, which first engages the contacts of the desired line, will be maintained in engagement with said confacts and will also be connected to the trunk circuit, the other set of brushes being maintained disconnected from the trunk circuit. While the invention herein disclosed is applied to a two-wire multiple system, it is obvious that it is equally applicable to systems of other characters and that other means than those disclosed herein may be employed for determining which of the brush sets will be connected to the trunk circuit.

What is claimed is:

1. In a telephone system, a switch including a plurality of brushes, series of circuit terminal contacts, one for each of said brushes, each series being the terminals of a different group of circuits, automatic means for simultaneously moving said brushes over contacts, and a single test relay for stopping the movement of said switch when any one of said brushes engages the contact of a desired circuit.

2. In a telephone system, a switch including a plurality of brushes, series of circuit terminal contacts, one for each of said brushes, said series being the terminals of different groups, automatic means for si multaneously moving said brushes over said series oft contacts, a test relay, a circuit for said relay having branches including said said circuit when any one of said brushes, respectively and means for closing brushes engages a desired circuit terminal.

3. in telephone system, a switch including a plurality of sets of brushes, series of circuit terminal contacts, one for each of said sets of brushes, a telephone circuit, a single relay for joining said circuit to one or another of said brush sets, automatic means for simultaneously moving said brush sets over their series of contacts, and means operated when one or the other of said brush sets engages the contacts of a desired circuit for stopping the movement of said switch and joining the engaged brushes to said telephone circuit.

4,. In a telephone system, a switch including a air of brushes, a telephone circuit, a relay or connecting one or the other of said brushes to said circuit, a series of line terminal contacts, one for each of saidbrushes, automatic means for simultaneously moving said brushes over said series of contacts, and

ing a pair of brushes,

means controlling the operation. of said relay whereby the brush which first engages the contact of a desired line will e connected to said telephone circuit,

5. in a telephone system, an electrically phone lines terminating in said series or contacts respecti ely, means 'ierat on the initiation of a call on one of said lines for automatically and Sil'lilf" neously inov in said brushes over said series of contacts, an a single test relay to stopping the move ment of said switch when any one oi? said brushes engages the contact a calling line,

7. in a telephone system, a switch includ in a plurality of brushes, series oi contacts, one for each of said brushes, telephone lines terminating in said contacts respectively, means actuated upon the initiation of a call on one of said lines for automatically and simultaneously moving said brushes over said contacts, a test relay for stopping the movement of: said switch, a circuit for said relay having branches including said brushes respectively and the-contacts of said series and means for closing said circuit when any one of said brushes engages de sired line terminal,

7-8. In a telephone system, a switch includseries of contacts, one for each of said brushes, terminating in said contacts respectively, a telephone circuit, a relay for. connecting one or the other of said brushes to circu means responsive to the in 'ation of a call. on 'one of said lines automatically and simultaneously moving said brushes over said series of contacts, and neans control.- ling the operation of said relay whereby when. one or the other of said brushes en:

gages the contact said calling line, sic.

brush will be connected to said telephone circuit/ 7 7 9, In a telephone system, a switch having a plurality of brushes, series of contacts one tacts, and a single test relay for stopping the movement of said switch when any one ill:

of said brushes engages the contact of an" idle trunk.

10. In a telephone system, a switch .having a plurality of brushes, series of contacts one for each of said brushes, trunk lines pleting said circuit through any one of said brushes and the contact of the first encountered idle trunk.

11. In a telephone system, a switch having a pair of brushes, series of contacts one for each of said-brushes, trunk lines, terminating in said contacts respectively, a telephone circuit, a relay for connecting one or the other of said brushes to said circuit, automatic means for simultaneously moving said brushes over said contacts, and means controlling the operation of said relay whereby when one or the other of said brushes engages thecontact of an idle trunk, said" brush will be connected to said telephone circuit. i

12. In a telephone system, an electrically operated switch having two brushes, series of contacts one for eachof said brushes,

trunk-lines terminating in said contacts re-,

spectively, automatic means for simultaneously moving said ,brushes over saidcontacts, a telephone circuit, a test relay for stopping the movement of. said switch, a circuit for said relay having alternative branches extending through said brushes respectively, and a second relay, said second relay being operative to control the extension of said test circuit to the brush which first engages the contact of an idle trunk and to operatively associate said brush with said telephone circuit.

In witness whereof, I hereunto subscribe my name this th day of February A. D.,

CHARLES L. GOODRUM.

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