US2411191A - Dial selective calling system - Google Patents

Dial selective calling system Download PDF


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US2411191A US561876A US56187644A US2411191A US 2411191 A US2411191 A US 2411191A US 561876 A US561876 A US 561876A US 56187644 A US56187644 A US 56187644A US 2411191 A US2411191 A US 2411191A
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Charles W Burcky
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AT&T Teletype Corp
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Teletype Corp
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    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. local area networks [LAN], wide area networks [WAN]
    • H04L12/40Bus networks


Nov. 19, 1946.
C. W. BURCKY DIAL SELECTIVE CALLING SYSTEM Filed Nov. 4, 1944 m9 WI W I- v KEV INV ENTOR CHARLES W. BURGKY ATTORNEY Patented Nov. 19, 1946 DIAL SELECTIVE CALLING SYSTEM Charles W. Burcky, Park Ridge, Ill., assignor ta.
Teletype Corporation, Chicago, 111., a corporation of Delaware Application November 4, 1944, Serial No. 561,876
v 1 Claim.
1 This invention relatesto telegraph switching systems and more particularly to station calling systems. The principal object of this invention is to provide an efficient and economical station selection system.
Another object of the invention is to provide a dial calling selective system which will operate on a minimum of power with the greatest simplicity of design.
Briefly, this invention relates to a station calling system employing at a transmitting station a manually operated dial mechanism which functions as a transmitter for sending signals, and a set of manually operable keys for permutably arranging signals generated by the dial mechanism for transmission over a line to a plurality of receiving stations associated with the line. Each of the receiving stations has an autoanatically operable mechanism acting as a receiving distributor for receiving signals, a set of manually operable selector elements associated with the automatic mechanism and being controllable by received signals for enabling the transmitting station to select a particular receiving station for operation upon an agreement between the permutative arrangement of the keys of the transmitting station and the permutative arrangement of the selector elements at the particular receiving station being called.
Specifically, the arrangement consists essentially of a selecting system wherein the transmitter distributor at the calling station is in the form of an ordinary telephone dial. At the calling station, there is provided a set of keys which are electrically connected to five segments transversable by a brush associated With the telephone dial. By means of these keys, various permutations may be set up in accordance with the five unit code in order to select a particular receiving station. At the receiving station, the receiving distributor, which i in the form of a tel'ephonedial, is released for operation upon the receipt of the start impulse and has associated therewith five segments similar to the five segments of the transmitting distributor. The five segments are connected to five slow-to-release relays each of which conditions a plug and jack arrangement to control marking and spacing signals. Connectible to the jacks are a set of plugs which may be connected either to the marking or spacing side of the jack in order to set up particular permutations at the receiving station. When the transmitting keys of the transmitting station are set in a permutation 2 similar to the permutations set up upon theplug and jack arrangement of the receiving station, .a circuit Will be completedto an output relay. At the receiving station there is provided a solenoid which is operable to perform the function of winding up the receiving distributor automatically after a signal has been received. The dial at the calling transmitter, however, is manually operated like the ordinary telephone dial, except thatthe same extent of movement is imparted upon each operation thereof, because upon each operation a five unit permutation code signal is transmitted, instead of a varying number of impulses.
Having reference to the drawing, the station li or central station is shown on the left-hand sideof the drawing and the station B or receiving station is shown on the right-hand side of the drawing. With the arrangement according to the present invention, the operator at the control station A, throughthe operation "of the five switches indicated generally as Il, may adjust these switches permutably in accordance with which one of a plurality of receiving stations he wishes to transmit to or to connect with. The station B is exemplary of a plurality of receiving stations which are identical in nature and wherein the plugs indicated generally as l2 may be inserted permutably into the jacks of a switchboard, indicated generally as 3, to correspond with the particular signal pertaining to the particular receiving station. In this manner, the signal which is transmitted from station A in accordance with the setting of switches II will be received by that-station B which has its plugs I 2 set in the same permutable manner intothe jack of switchboard l3, as will become more clearly apparent hereinafter. I
At the station A or calling station, the transmitting mechanism comprises a segmented transmitting disc l4 and a telephone dial device i5 associated with a common shaft I6. Thedisc H3 is fixed or stationary and the rotatable shaft 96 extends therethrough and carries a brush arm ll afiixed to the shaft. The disc 14 comprises a continuous inner ring 18 and a concentric se mented outer ring comprising a start segment l9, five impulse segments 2|, 22,23, 24, and 25, and astop segment 26. The brush arm I! is provided with arbon brushes 2'! and 28 adapted tocooperate with and bridge electrically the inner ring I8 and the outer segmented ring. The purpose of providing solid brushes is to facilitate rotation of the brush arm I! in both directions, as will hereinafter appear.
The telephone dial device I comprises a disc 29 fixed to the shaft I6 and provided with an aperture 3| for dialing the device. A fixed stop 32 is provided for limiting the rotational or clockwise movement of the dial 29. Also fixed to the shaft I6 is one end of a spiral spring 33, the other end of which is secured to a post 34 suitably mounted in the telephone dial structure. With this construction the shaft I6, When rotated clockwise through the instrumentality of dialing hole 3|, will cause spring 33 to be Wound up until the dialing'hole or finger has been stopped by the member 32, whereupon when the finger is withdrawn and the disc 29 allowed to be released, the shaft I6 will be rotated in a counterclockwise direction to its initial position under the control of the well known telephone dial governor (not shown). Also fixed to the shaft I6 is a disc 35 which is provided at suitable angular positions, radially directed from the periphery, with a pair of lugs or projections 36 and 31, which cooperate with a three-armed lever 38 :pivotally mounted on a shaft 39 suitably carried in the dial structure. Lever 38 is provided with an arm 4I which cooperate with the lugs 36 and 31, an arm 42 which cooperates with a contact 43, and an arm 44 which coacts with a detent spring member 45.
In accordance with thepresent' invention, the start segment I9 is connected by a conductor 46 to a bus bar 41. Also, segments 2| to 25 are connected by conductors 5| to 55, respectively, to the contacts 56 to 60 of five switches 6| to 65 which, in turn, are connected to the bus bar 41. A signaling line 66 is connected at station A to the bus bar 41 and at the station B to the winding of a relay 67. A plurality of similar receiving stations ID are also connected in the signal line 66.
The armature 68 of relay 6'! serves to complete a circuit, as will hereinafter appear, through contact 69 to start magnet II of station B. Start magnet II is provided with an armature I2 which is mounted on a pivot I3 and is biased in a counterclockwise direction against a stop 15 by a spring I4. The free end of the armature lever I2 is provided with a shouldered or hooked portion I6 adapted to cooperate with the end of a stop arm II secured to a distributor shaft I8,
Also fixed to the shaft I8 is a brush arm I9 which cooperates with a stationary face plate 8| of the receiving distributor of station B. An arm 82 is secured to the shaft I8 and cooperates with a pair of contacts 83 and 84 in a manner and for the purpose hereinafter described. Fixed to shaft I8 is one end of a spiral spring 85, the other end of which is fixed to a spring post 86. Spring 85 is normally in a wound condition tendmg to bias the shaft I8 in a counterclockwise direction, thereby holding the arm 'I'I against the shouldered portion I6 of armature I2, so that when the magnet His energized, as will appear presently, the armature I2 will be attracted to withdraw the shoulder I6 from the arm 11, thus releasing the shaft I8 for rotation by the spring 85, such rotation continuing until the arm 11 strikes a limiting stop 81. When this latter rotation occurs, a cord 88 will be wound around the shaft I3; Cord 88 is fixed at one end 89 to the shaft I8 and at the other end to a screw 9| secured to the plunger 92 of a solenoid 93. When the shaft I8 has been released for rotation to bring the stop arm 11 against the stop 81, the arm 82 will have been rotated to the position shown in dotted line, whereby contact 84 will be 4 closed, thus completing an energizing circuit for a relay 94, from grounded battery, through contact 84, over conductor 95, through the winding of relay 94, to ground. Relay 94 when energized will become locked up over a circuit extending from grounded battery 96, through a contact 91, over conductor 98, through a contact 99, then through the winding of relay 94 to ground. The energization of relay 94 also completes an energizing circuit for the solenoid 93 from grounded battery IIlI, through contact I02, over conductor I 03, and through the winding of the solenoid 93 to ground. Moreover, immediately after releasing shaft ?8 for rotation, contact 83 will close to control electrical circuits, as will hereinafter I appear.
When the shaft I8 has been released for rotation, the cord 88 will be wound around the shaft I8 thereby becoming taut between the shaft I8 and the screw 9 I. Then, when the contact has become closed and the relay 94 energized; as just described, whereby the solenoid 93 hasbecome energized, the plunger 92 will be drawn into the coil so that the cord 88 will become unwound from the shaft I8, at the same time rotating the shaft I9 in a clockwise direction bringing'the arm TI from the stop 81 to be re-engaged by the shoulder I6 of armature I2. During this rightward movement of the plunger 92 into the solenoid 93 a flange I04 on the solenoid plunger 92 Will operate to open the contact 91 to breakthe locking circuit for the relay 94, which in turn breaks the energizing circuit for the solenoid 93. Upon de-energization of the solenoid 93 due to the opening of contact I02 a spring I05 will act to withdraw the plunger 92 from the solenoid coil 93, thus slackening the cord 88 as shown in the drawing. r
Like the transmitting disk I4 at the transmitting station, the disk or face plate 8| at the receiving station B is similar thereto in the segmental arrangement. This face plate8| com prises a solid inner ring I66 to which is connected one end of a conductor III'I, the'o'ther" end of which terminates at the afore-mentioned contact 69. An outer concentric ring, comprising a plurality of segments is associated with the inner ring I66 and comp-rises, like the arrangement at the central station A, a. start segment I08, five segmentsI99, III, H2, H3, and H4 which constitute th code impulse segments, and a stop segment H5. The brush arm I9 is provided with a pair of carbon brushes, one cooperating with the inner ring I96 and the other with the outer segmented ring. The start segment I98is connected by a conductor II6 to the winding of the start magnet II. The segments I99, III, H2, H3, and H4 are connected by conductors H1, H8, H9, I2I, and I22, respectively, to the winding of relays I23, I24, I25, I26, and I21, respectively. The windings of slow-to-release relays I23 to' I21, inclusive, are connected also to a co'mmon'conductor I28 which terminates at the aforementioned contact 83. Relays I23 to I21 are each provided with a locking circuit which extends from grounded battery I29, over common conductor I3I, through individual contacts I32, through the-windings of the various associated relays I23 to I21, then over the common'conductor I 28 and through contact 83 to ground.
Each relay I23 to I2! is also provided with an armature I33 which cooperates with. a marking contact I34 and a spacing contact I35, individual thereto. When a relay is energized, a marking contact is closed;'' and when a relay is. de-
energized, a spacing contact is closed. Each marking contact I34 is connected to a marking jack I36, and each spacing contact I35 is connected to a spacing jack I31. Each armature I33 is electrically connected to the panel board I3 Five plugs I38, I40, I68, I69 and I19 are provided, one for each pair of jacks I36 and I31. Each plug is provided with a tip portion which is connectible with the jack I36 or I31, and a ring portion which connects with the panel board I3. The set of five plugs may be connected to either the marking jack I36 or the spacing jacks I31 to set up a particular permutation at the receiving station in accordance with its call signal. A series circuit through-the set of plugs and through an output relay I39 may be ultimately completed therefor only when the five relays I23 to I21 have been selected by a permutation code signal which matches the positions selected by the five line plugs. Initially, however, due to the fact that the attract time of the armature I6I of relay I39 is sufficiently long to permit the brush 19 to traverse several segments before the contact IE3 is closed, the lamp IE5 (or other apparatus to :be controlled) will not be operated until the entire code signal has been received. In
this way, a circuit through the output relay I39 upon the reception of any one of a plurality of difierent permutation signals, and the signal required to select any given station, may be changed at any time by inserting the line plugs in the jack in any one of said plurality of different possible combinations. It is understood, therefore, that the setting of the plugs at the stations B or similar stations will be characteristic of the calling signal for that particular station.
General operation The system according to the present invention is illustrated in the drawing in the normal stop position. In this position the brush arm I1 at the central transmitting station rests upon the stop segment 26, and the brush army 19 at the receiving station rests upon the start segment I88. The reason for this manner of connection is so that upon the initiation of the call at the station A the mechanism at the station B will be I in readiness to receive the start or initial impulse so as to initiate, in response to the start signal received from the calling station, the apparatus or mechanism at the called station. By means of the aperture 3I in the disk 29 the dial mechanism is rotated in a clockwise direction the full distance up to the stop 32. When this has been done the spiral spring 33 is wound and the disk 35 has been rotated to the position indicated by the dotted line positions 236 and 231 of lugs 36 and 31, respectively. At the initial portion of its rotation lug 31 of disk 35 acts upon arm II of lever 38 to rotate it to the dotted line position 24 I, thus opening contact 43 and causing detent 96 to hold arm 46 in a detented position. By this revolution, the brush arm I1 is rotated in a clockwise direction to bring the carbon brushes 21 and 28 into contact with the start segment I9 and the concentric solid ring I8 preparatory to transmitting the initial or start impulse upon the closing, subsequently, of the contact 43, as will appear presently. As the disk 35 was rotated, the lug 36 was carried past the dotted position 2 of arm 4i so that when the disk 29 was released upon withdrawal of the rotating instrumentality from the aperture 3I, the lug 36 acts to bring the lever 38 out of detented position to permit the closing of contact 43. As soon through contact 69, over conductor ring I86, through the brush arm 19, through start a permutative setting characteristic closed, a circuit is completed from battery I41 through contact 43, over conductor III, through ring I8, through carbon brush 21, over the brush arm I1, through the carbon brush 28, through start segment I9, over conductor 46, through bus bar 41, over the signal line '66, through the winding of relay 61, to ground. The re1ay61, upon being energized, pulls up its armature 68 to complete a circuit from grounded battery, through the armature 68, I 81 through as contact 43 has been segment I88, over conductor I I6, and through the winding of magnet II to ground. Upon the completion of this circuit, the rotation of the dial or receiving distributor at the receiving station is initiated due to the fact that the armature 12 is attracted. Upon attraction of the armature 12, the arm 11 is released for rotation, energy for rotating the shaft 18'being stored in the spring 66. The brush arms I1 and 19 are thus arranged to rotate in phase with each other under the control of the well known telephone dial governor (not shown) associated with each shaft. It is to be noted that the synchronism and phase conditions are required for only one revolution of the shafts I1 and 19.
The switch device I I comprising the switch arms 6|, 62, 63, 64, and is capable of being adjusted into any one of a plurality of permutable positions by employing various combinations of the switch arms in their two positions. These switches, of course, may be of any commercial form such that they may be manipulated to give of the station it is desired to call. Assuming that the switch arms 6| to 66, inclusive, are arranged in a permutative setting whereby the contacts 56,
58, and 68 are closed by the switch arms BI,
63, and 65, respectively, and it is desired to call a station having plugs I? arranged in this identical setting, the operator upon operating the dial at the calling station A will be connected to one and only one station B; namely, that which is connected in a predetermined manner with the same permutative setting, that is, marking impulses on the first, third, and fifth signal intervals of the code combination. At the receiving station B, plugs I38, I60, and I18 will have been inserted in the marking jacks, and plugs I40 and I68 will have been inserted infthe spacing jacks. As the brush arms I1 and I9 now rotate in synchronism they will traverse the corresponding code segments in proper timed sequence. For example, when the segment 2I is being traversed bythe brush arm I1, a signal impulse is transmitted from battery I41, through the contact 43, over conductor I4I, through ring I8, over brush arm I1, through segment 2|, over conductor 5|, through contact 66, over switch arm 6 I, through bus bar 41, over the signaling line 66, through the winding of relay 61, to ground. Whenever such a marking impulse is transmitted over the signaling line 66, the relay 61 becomes energized to attract its armature 68. As previously described, brush arm I1 passes over segment I9 as arm 19 passes over segment I88 to impress a start (marking) impulse upon start magnet 1I. Thereafter, brush arms I1 and 19 traverse substantially simultaneously with their respective segments ZI' and I89, then segments 22 and III, etc.
As the brush arm 19 passes over the start segment I88 the arm 132 permits the contact 83 to close, thus preparing the operating circuit and locking circuit for the slow-to-release relays I23 to I 21, inclusive. In the present instance, as the brush arm 19' passes over segment I I19, the brush arm I 1 is passing over the segment 2 I. Since the switch 6| isclosed, a circuit is completed to relay 61 from battery I41, through the contact 43, over conductor I4I, through ring I8, over brush I1, through segment 2|, over the conductor 5|, through contact 56 and switch BI to bus bar 41, whereupon the signal impulse is transmitted over the signaling line 36 to the relay 61 which becomes energized and attracts its armature 68. A'circuit is thereupon completed from grounded battery, over armature 68, through contact 69 (now closed), over conductor I01, through ring I06, over brush arm 19, through segment I09,
over conductor I I1, through the winding of relay I 28, through contact 83, to ground. Relay I23 becomes energized and attracts its armatures I 33 and I42. The closing of armature I42 closes its contact I32 to complete a locking circuit for relay I23 from grounded battery I29, over conductor I 3I, through the armature I42, through contact I 32 associated with relay I23, through the winding of relay I23, over conductor I28, through the contact 83 (now closed), to ground. The armature I33 of relay I23 is attracted (as indicated by dotted lines) and closes the marking contact I34 associated therewith, and since the plug I associated with the jack of the relay I23 is inserted in the marking jack position, a circuit will be prepared from ground, through the ring portion of plug I10, then through the panel board I3, over conductor I44, through the armature I33 of relay I 23, through the marking contact I34 thereof, over the conductor I to the marking jack I33 thereof, then over the tip side of plug I10 to the conductor I46.
As the brush arms I1 and 19 traverse further and contact the segment 22 at the central transmitting station and segment I I I' at the receiving station, respectively, a circuit is prepared from battery I41, through contact 43, over conductor I4I, through ring I8, over brush arm I1, through segment 22, and over conductor 52. But, since switch 52 is not closed, no circuit will be completed thereover, and hence, relay 51 connected to the line 65 will not be energized. Accordingly, the armature 68 will not be attracted, so contact 69 will not be closed. Therefore, no circuit is completed for relay I24, and armature I33 of relay I24 will be held at the spacing side I35 (as shown). The circuit previously described from ground .149, will be continued over the ring side of plug I38 associated with relay I24, then through the panel board I3 and through the armature I33 of relay I24, then through contact I35 and spacing jack I31 thereof. The circuit will then be completed over the tip side of plug I38 to conductor I46.
I 23, over conductor As the brush arms 19 and I1 traverse the succeeding segments, circuits for relays I25, I26 and I 21 will be completed depending upon Whether or not contact switches 63, 64, 65 are closed. In the present instance, it is noted that contacts 63 and 65 are closed and therefore, marking impulses will be transmitted over the signaling line when segments 23, H2, 25 and H4 are traversed, and relays I25 and I21 will become energized. The plugs I and I38 associated with relays I25 and I21, respectively, are connected to their respective marking jacks, and circuits will be completed therethrough. Since the switch :64 is not closed, the relay I 26 at the receiving station will'not'be energizedand the armature thereof will rest on the spacing contact I35 thereof.
The plug I49, therefore, will be inserted in the spacing jack.
5 With this arrangement it is seen that a series circuit is completed through the series of plugs, from ground, through the various circuits, as previously described, then through the winding of relay I39 to grounded battery. Since the output relay I39 is now energized it will attract its armature I5I and complete a circuit from grounded battery I52, through armature I5I, through contact I53 (now closed), over conductor I54 to (in the present embodiment) a signal lamp I55. Of course, it is understood that the output relay I 39 controls any sortof circuit such as a repeater or other electrical arrangement. For example, should it be desired to sustain the closing of the contact or contacts associated with relay I39 for a predetermined time, not less than a certain value, the relays I 23-I21 are made slow-to-release so that the rewind time of shaft 18 (that is, from the time contacts 84 are closed and relay 94 and solenoid 93 are operated until contact 83 is again opened) plus the slow-torelease time of relays I23-I21, plus the slow-to-release time of relay I 39 will give this value. For this reason, the relays I23-I21 are slo-w-to-release.
As the shaft 18 continues its rotation, the arm 11 will strike against stop 81, and the brush arm 19 will rest upon the stop segment I I5. On assuming this position the contact 84 will be, closed, as previously described, to introduce battery upon the circuit for the relay 94, which, as previously described, is effective to control the energization of the solenoid 93. Cord 88 which has just been wound up on the shaft 18, will be unwound by the pulling in of the solenoid 32, thus imparting clockwise rotation to shaft 18 until the 'stop arm 11 is locked behind the shoulder 16 of the armature 12 of the magnet H which is now deenergized. The dial at the transmitting station has been returned by spring 33 to its initial position so that now both the station A and station B are in their normal rest position preparatory to sending out another call signal which may be the same as previously described, or of any other'of a plurality of permutations which may be set up on the switches 6| to 65, inclusivait being understood that the signal transmitted from the station A will be received by and cause to operate the apparatus at that station B which has its plugs I38 set in the panel board I3 in a 55 permutative combination identical to the setting of the switches SI to 65.
Although the present invention has been described in connection with its specific embodiment thereof, it is understood that such application is merely illustrative and not restrictive, the scope of the present invention being defined only by the scope of the appending claim.
What is claimed is:
In a selective station calling system, a transmitting station, a plurality of receiving stations,
a signal line connecting said stations, transmitting means at said transmitting station comprisingpermutably settable switching elements and an impulsing device manipulable from a normal position to an ultimate position, said device effective upon return to normal position to impress through said switches start-stop permutation code signals upon said signal line, receiving means comprising a line relay responsive to signals impressed on said signal line, an automatically operable impulsing device normally tending to operate, storing relay means electrically associated with said impulsing device, electromagnetically controlled means effective normally to restrain said impulsing device against operation, said electromagnetically controlled means responsive to the start impulse of said permutation code signals to initiate operation of said automatically operable impulsing device to distribute the signal impulses of said permutation code signals to said storing relay means, a plurality of serially associated plugs, a corresponding series of jacks, one jack associated with each storing relay, a con-
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2441136A (en) * 1945-08-04 1948-05-11 Harold H Charles Keying device for aviation ground trainer signaling equipment
US2506429A (en) * 1946-05-31 1950-05-02 Bell Telephone Labor Inc Selective signaling system
US2906822A (en) * 1956-05-10 1959-09-29 Bendix Aviat Corp Code transmission systems

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2441136A (en) * 1945-08-04 1948-05-11 Harold H Charles Keying device for aviation ground trainer signaling equipment
US2506429A (en) * 1946-05-31 1950-05-02 Bell Telephone Labor Inc Selective signaling system
US2906822A (en) * 1956-05-10 1959-09-29 Bendix Aviat Corp Code transmission systems

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