US3549819A - Control device for operating an automatic current-pulse emitter for telephony or like installations - Google Patents

Description

United States Patent Inventors August Gaisser Ehingerstrasse, Aach, Hegau; Anton Schaumanu, Reuteberg; Willi Weber, Boerisriedstrasse Volkertshausen,

Germany App]. No. 771,048 Filed Oct. 28, 1968 Patented Dec. 22, 1970 CONTROL DEVICE FOR OPERATING AN AUTOMATIC CURRENT-PULSE EMITTER FOR TELEPHONY OR LIKE INSTALLATIONS 90ADO, 5; 340/357, 358; 178/17 NO REFERENCES CITED Primary Examiner-Kathleen I-l. Claffy Assistant Examiner-Tom DAmico 4 3 num/l/l! Attorney-Jeffers and Rickert ABSTRACT: An apparatus for controlling an automatic pulse transmitter for telephony, tele writer, or similar installations with address number selection wherein the address store is represented by a plurality of selector discs rotatable by a power accumulator on which the individual addresses are represented by selector cams which through the intermediary of selector bars individually control, during one revolution, a current pulse generator. A selector key :is associated with each selector bar so that it is moved from a resting position into an operating position before the initiation of a selection event and therein held during rotation by a locking bar and thereby starts the power drive which after completion of the selection event is automatically stopped after which the selector bar is returned to its starting position. A first gear train is provided for driving the selector discs at normal operating speed, a second gear train with a lower total transmission ratio is provided for driving the selector disc at a higher speed and which is connectable in circuit by means of a clutch coupling activated by a reset key whereby the reset key simultaneously with the engagement of the clutch interrupts emission of the current pulse trains.

SHEET 1 0F 5 PATENTEU UEC22 lsm PATENTEU DEE22I97U 3549,1319

sum s or s P. Fig.9.

automatic current-pulse emitter for telephony, teletype or similar installations with a number-address selector in particular f for such pulse emitters in which the address store compris'esa plurality of power-driven, rotatable selector discs on which'the individual addresses are indicated by control cams controlling a pulse generator during one revolution through bus-bars individually associated with the selector disc(s)and a jack associated with all the said bus-bars, wherein a particular event moved out of its resting or neutral position into its working position, and held therein during' one revolution by a locking catch and which releases or initiates the power-drive andon completion of the selecting event is automatically released after which the selector bar returns into its'starting position.

, Such a current-pulse transmitter not onlyallows the selection of subscriber numbers in a telephone or teleprinter network for local and trunk connections but is also suitable for preselecting and programming data-evaluation in installations in the so-called on-line method for a telephone or telewriter subscriber system.

In such appliances the selector discs perform a complete revolution during each individual selecting event for dialling the required subscriber number and on completion thereof are returned again to their starting position, ready for any further selecting event. Thus, the time of rotation of the said selector discs is governed by the highest number of places in the subscriber numbers to be selected, and the standard pulse frequency used, each place in the number to be selected, requiring the same time as the longest number to be selected.

This means that, irrespective of whether a long or a short subscriber number is to be selected, the time for completing one selecting operation is the same.

In order that the caller need not have his finger on the corresponding key during the whole selecting operation, means are provided in such systems in order that on depressing a particular key the drive is started and remains operative until the selector discs have after performing a complete revolution returned to their starting positions, after which the drive is then automatically cutout. The caller consequently has no means of influencing an initiated selecting event until it has been completed. This has the disadvantage that if the caller selects a wrong numeral before the whole selecting event has been completed, he is nevertheless unable, having noticed the mistake, to interrupt the already initiated selecting event for correction.

It is consequently theobject of the present invention to provide in such current-pulse transmitters a possibility for prematurely interrupting a selecting event and return the selector discs rapidly to their starting positions in order that the user shall not have the necessity of awaiting the normal completion of the selecting event before initiating a new such event.

The, solution provided by the present invention is characterized in and by the provision for the drive of the selector discs, in addition to a normal gear train, of a further auxiliary gear train with a smaller total transmission ratio, operating the selector-disc drive at an accelerated rate and connectable by a coupling actuated by a return key. thesaid return key interrupting the emission of the current-pulse train simultaneously with the engagement of the coupling.

Thisnot only affords the advantage that the caller can at any time interrupt an initiated selecting event and reset the appliance rapidly for a new selecting sequence; but also the further advantage that the accelerated drive of the selector discs for their return to the starting position can be effected not only by means of the. same drive, but also by a drive running with a constant single speed. It would of course also be possible to use a drive with two separate running speeds, but such power units are both expensive and of greater bulk for their accommodiation in. the appliance. A further ad ,bus-bar associated with a selectorkey isbefore each selecting vantage of the solution according to the invention is, that the quick-retum motion is equipped with elements other than those for the normal drive, and that such elements for normalspeed operation can be designed for relatively low running speeds, i.e., they have a relatively higher transmission ratio so that a cheaper high-speed driving motor can be used, and they are thus unsuitable for highspeed operation in view of the greater wear involved. I

In further development-of the inven'tionprovision is made for a-freewheel clutch to be incorporated in the normal-speed gear train which affords the adgantage that any harmful reaction of the high-speed drive on the normal-speed gear train is avoided and that the high-speed driveshall not encounter any higher frictional resistance as would be the case if, for instance, a slipping clutch were to be provided instead of a freewheel element. Having regard to the expenditure of manufacturing means and the attainable functional advantages and.

in further development of the present invention, the freewheel gear is designed as a pawl clutch.

In order to damp the inevitable acceleration shock occurring when the high-speed stage is engaged, and thus protect the gear from overloading, it is important to provide an elastic driving link in the high-speed gear train this elastic driving link suitably having the form of a rubber belt drive.

Such a rubber-belt drive isexceedingly quiet running, as well as being simple and cheap to make. in addition, it can ab,- sorb very high acceleration shocks without harm since the rubber belts are comparatively long and consequently highly elastic, and since they are only in frictional linkage with the belt pulleys they are at the sametime capable of acting as an overload safeguard.

In order to ensure that the clutch in the gear train of the high-speed stage is easily engaged by operating the reset key, and remains in gear until the selector discs have returned to their starting positions and are automatically reset it is ad vantageous to provide a springloaded control lever which is held in its inoperative position by a movable stop in driving connection with the reset key and which is in the working position returnable by the action of a cam associated with the selector discs into the inoperative position. As a consequence, the clutch in the gear train of the high-speed gear stage requires to incorporate, besides the reset key, only three essential components, viz: the control lover, the movable stop,

and the cam corotating with the selector discs, this ensuring not only a manufacturing advantage but also a number of functionally advantageous features.

The emission of a pulse train is suppressed during the action of the high-speed stage by a further feature in the development of the invention, which is likewise particularly simple,

viz, that the movable stop, until it has returnedto the inoperative position, holds the control lever against the force of a spring in a switching position in which it can influence a circuit-breaking element in the pulse-train circuit. It is in'this regard particularly advantageous that simultaneously with the engagement of the clutch in the high-speed gear train, the current circuit in question is broken, and is restored when the clutch is again disengaged; so that whenthe selector discs are returned to their starting positions the system is again ready for a new selecting event.

It will be advantageous in this regard, to provide for the inclusion of an electromagnetic clutch in the gear train of-the high-speed stage controlled by a switching element actuated by the control lever. v I

It is, however, cheaper and simpler to form the clutch in the gear train of the high-speed stage of a belt pulley in the rubber-belt drive, and a spur wheel, both located in a common point, and one element whereof is axially displaceable with ing position during operation of the high-speed gear train, it will be found advantageous to provide electrical switching means influencing the reset key incorporated in the actuating circuit of the electromagnet controlling the aforesaid locking catch.

In order to obtain perfectly accurate engagement and disengagement of the driving motor is such manner that the said driving motor is started by actuating any one selector key, and the stopping of the driving motor takes place when the selector discs have attained or regained their starting positions even while operating with the high-speed gear stage, it is advantageous both from the manufacturing and the functioning aspect, to provide a switching disc running-synchronously with the aforesaid selector discs and actuating the controlling switch of the driving motor, and associated with a second auxiliary switching disc rotatable with reference to the preceding through a predetermined angle and of the same shape or profile which is held in its resting position against the force of a return spring by the action of a locking catch easily released by acting on one or any selector key, and which under the action of a spring runs at a predetermined angle of advance with reference to the selector disc during the rotation of the latter and actuates the switching means at the start of its rotation.

Further features of this arrangement will be apparent from the following description of an exemplary embodiment thereof.

In order to make the range of applications of the high-speed gear stage more extensive and more rational, a further development of the invention provides for the selector discs each to have between any two control earns, a radial notch, and the circuit of the driving motor incorporates a motor switching element in series with an auxiliary switching element which when one of the control bus-bars actuated by a locking lever through a control link, drops into the said radial notch of the selector disc can be closed again by the action, either of the reset key or by a special switching key.

This affords the advantage that, in particular in the case of multifigure call numbers formed .of a prefix and a subscriber number a signal can be received during the selection event from the telephone or telewriter network indicating whether the subscribers linecalled is in factfree. This arrangement in particular introduces a deliberate pause in the selection sequence itself, during which either the engaged or the line clear signal is heard. Should the engaged tone be heard, for instance after dialling the prefix number, the caller can, by actuating the resetting key, immediately cancel the selection event, while in the other case, when the line clear signal is heard, by actuating the switching key the selection sequence started can be resumed in the normal manner.

However, this arrangement not only provides advantages in telephone and telewriter traffic, but can also be usefully applied for preselection and/or programming in data processing and computing machines using the on-line method, in which it is frequently desirable to divide the entire selection or programming number into distinct groups of figures, between which a selection pause is interposed,-for the possible reception of a feedback control signal.

When using the instrument in telephone and telewriter circuits it is advisable, as has already been mentioned, to arrange the radial notch in the selector discs always between two control cams the one of which represents the last figure of a prefix number and the other, the first figure of the subscriber number.

The arrangement becomes particularly simple and reliable if the locking lever is actuated by a control cam common to all scanning elements also controlling. the pulse-train emitter and in its inoperative position holding the control link of the auxiliary switching device against the force of a spring in the auxiliary switching device against the force of a spring in the auxiliary-switch-closed position. This ensures that the auxiliary switching element can be controlled by means of the normal selector bus-bars scanned by the control cams on the selector discs so that the auxiliary switching element can be precisely controlled in accordance with the positions of the selector discs.

In order that the auxiliary switching element can be controlled besides by the switching key, also by the reset key when changing to the high-speed gear and resetting, the actuating lever of the auxiliary switching element is also linked through a stop controlled by the reset key, with the value indication. By this means, when the resetting key is operated, the auxiliary switch which has cutout the driving motor, is reset, and the high-speed gear started without any delay.

The invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic view of the control mechanism of the current-pulse emitter;

FIG. 2 is a diagrammatic perspective view of the most important, manually operated elements of the arrangement;

FIG. 3 is a side view of the on-off switching mechanism for the driving motor;

FIG. 4 is a partial plan view of FIG. 3;

FIG. 5 is a side view of the resetting and drive gear with the principal control elements;

FIG. 6 is a section along A-A of FIG. 5;

FIG. 7 is a partial top view of FIG. 5;

FIG. 8 is a section B-B of FIG. 7; and

FIG. 9 is a block diagram of the electrical control circuits.

The principal elements for generating the current pulses representing the separate figures of the number to be selected are shown in FIG. I. In this device, each selector key 1 (FIG. 2) is associated with a selector bar 2 and a selector disc 3. The selector discs 3 are fitted coaxially on a selector shaft 4, and are fixed against rotation thereon, the shaft performing a complete revolution during a selection cycle. The selector shaft 4 is driven by a motor 5, through a worm gear 67 and a pair of worm wheels 8 and 9 (see also FIG. 5, 7 and 8). The worm wheels 7 and 8 are carried on a single shaft 10 the ends whereof run in fixed bearings 11 and 12. The rotary displacements of the selector discs 3 are performed always in the same direction shown by the arrow 13. Each such selector disc 3 has on its periphery a number of selector cams 14 of varying length along the periphery corresponding to varying numbers of current pulses.

Upon actuating one of the selector keys 1, the corresponding selector bar 2 is displaced with respect to the combined pawl catch 15 in the direction of the arrow 16 so that the key pin 17 of the combined pawl catch 15 is no longer opposite the notch 18, but opposite the nose 19 of the selector bar 2 (see FIG. 2). During the rotation of the selector disc 3 in the direction of the arrow 13, the feeler cam 20 on the selector bar traces the circumference of the selector disc 3 and each time that the cams l4 thereon pass underneath the pawl bar 15 rises and swings radially about the axis of its carrying shaft 21. This motion of the pawl bar 15 is transmitted to a twoarmed control lever 22, pivoted at 23 and influenced by a spring 24. The vertical arm 25 of the control lever 22 engages with its lower end 26 in radial slits 28 of a locking disc 27, as represented in FIG. 1. This locking disc 27 is rigidly connected with the pulse-release disc 29 and rotatably carried on the shaft or spindle 10. The locking disc 27 together with the pulse-release disc 29 are driven through a friction clutch, of which FIG. 1 shows only the compression spring 30.

Each time that the selector bar 2 when passing over a selector cam 14 raises the joint pawl bar 15, the control lever 22 is swung against the force of the spring 24 in the direction of the arrow 31 so that the end 26 of the vertical lever arm 25 rises out of the slit 28 in the locking disc 27 when this locking disc 27 together with the pulse-release disc 29 are actuated by the shaft 19 through the friction clutch. Thereby, a control cam 32 on the arm 25 of the control lever 22 closes the pair of contacts nsa and during the rotation of the pulse-release disc 23 releases at the contact pair nsi a number of current pulses corresponding to the length of arc of the selector cam 14.

As soon as the feeler cam 20 on the selector bar 2 has again moved radially off the selector cam 14, the spring 24 draws the end 26 of the control lever 22 into the next slit 28 in the locking disc 27 and thereby holds both the locking disc 27 and the pulse-release disc 29 while at thesame time openingthe two pairs of contacts nsa and nsi.

The worm wheel 8 fitted on the shaft 10, is in mesh with the helical gear wheel 9 which is driven in the direction of the arrow 13. The helical gear 9 carries on a pin 33 a follower pawl 34 which is influenced by the spring35to remain in mesh with a ratchet wheel 36 rigidly connected with a gear wheel 37 which in turn is held against rotation on the control spindle 4.

This selector shaft 4 is thus not driven directly by the worm wheel 9 which is loosely carried on the selector shaft 4, but is driven through the intermediary of a freewheel gear consisting of the ratchet wheel 36 and the follower pawl 34.

In addition to this first gear train consisting of the spiral gear 6,7 and 8,9 with the freewheel clutch consisting of the ratchet wheel 36 and the follower pawl 34, a second gear train is provided, likewise driven by the motor 5,This second gear train consists of two twin- belt pulleys 38 and 39, of which the twinbelt pulley 38 is rigidly coupled with the shaft 5' carrying the spiral gear 6. This second gear train further includes the gear wheels 40 and 41 meshing with each other, and of which the gear wheel 41 meshes with the gear wheel 37. The two twinbelt pulleys 38 and 39 are interconnected by means of the two elastic rubber belts 42. This gear train also incorporates between the twin-belt pulley 39 and the gear wheel 40, a releasable coupling 43 which is shown in FIG. 6 in cross section.

The belt pulley 39 is rotatable on the shaft 44 and axially slidable, and has on its outside a conical projection or boss 45 acting on a control lever 46 to produce an axial displacement of the twin-belt pulley 39 on the shaft 44. v

The inside of the twin-belt pulley 39 is formed with a recess 47 open towards the gear wheel 40 and incorporating a hub element 48 over which a compression spring 49 is fitted. The same recess 47 contains a coupling pin 50 coacting with a coupling pin 51 seated in a boss 52 on the gear wheel 40 and projecting into the recess 47 of the twin-belt pulley 39. The boss 52 contains a similar recess 53 into which the hub 48 can enter.

The gear wheel 40 with the boss 52 is not axially slidable on the axis 44, but is pinned thereon. The shaft 44 is rotatable, but not axially slidable and carried in bearings not represented herein. 1

The control lever 46 is pivoted on a fixed point 54 and the end 55 of its longer lever arm 56 bears against a stop 57. A second shorter lever arm 58 of the said control lever 46 has attached a tension spring 59 in such manner that the end 55 of the lever arm 56 bears on the stop 57, thus exerting on the control lever 46 a clockwise torque. The lever arm 58 further carries a roller 60 coacting with a switching cam 61 carried on a stub shaft 62 of the selector shaft 4 and rotating synchronously with the selector discs 3; I

The stop element 57 consists of an angled lug 64 fitted on the shaft 63 (see also FIG. 2) and longitudinally movable on a link 65. This lever 65 is pivoted on a fixed pivot pin 66 and connected with the shaft or bar 63 by'means of a hinge pin 67. On the side opposite to the stop element 57, the shaft 63 is hinge-connected with a cranked lever 68 This cranked lever 68 has one switching arm 69 acting 'onya resting contact al. fixed against rotation on a shaft 70. This shaft 70 is itself rotatable in a bearing 71 and carries at its other end a rigidlypinned lever 72, the one arm 73 whereof engages with a step 74 on the shank 75 of a resetting key 76 and carries a setting pin 77 (see FIG. 2, 5 and 7). The shank75 is equipped with a return spring 78 in such manner that the key 76 after being operated returns automatically into its initial position.

A second arm 79 of the lever 72 acts on a switching contact 80 controlling an electromagnet 81 (FIG. 3). This electromagnet 81 is fitted with a rocking armature 82 coupled through a switching pin 83 with a locking bar 84. The locking bar 84 has a locking lug 85 extending transversely to the longitudinal direction of the selector bars 2 and is common to all these bars. The locking bar 84 is influenced by a'tension spring 86 and is carried on a rotatable shaft 87..The locking catch coacts in the working position of the selector disc 2 with a locking nose 88 when the electromagnet 81 is activated. The activation (excitation) of the electromagnet 8 is efiected by means of a switch 89. The on-and-off switching of the driving motor 5 at the beginning and the end of one revolution of the selector discs 2 is effected with the parts in the positions shown in FIG. 3 and 4.

On the side of the selector shaft 4 opposite to the stub shaft 62 (FIG. 7) a further stub shaft 90 is fitted, rigidly fixed on the shaft 4 and supported in a bearing plate 91 of the apparatus. Outside the bearing plate 91 a fixed switching disc 92 is pinned on the stub shaft 90 associated with an auxiliary selector disc 93. This auxiliary selector disc is rotatable on the stub shaft 90 and operatively linked with the switching disc 92 by a pin 94 seated in the switching disc 92 and passing through a slot 95. A spring 97 is fitted between the pin 94 of the switching disc 92 and a pin 96 fitted in the auxiliary selector disc 93.

The switching disc 92 and the auxiliary selector disc 93 both have on their periphery radial slit 98 and are together scanned by the feeler roll 99. This feeler roll 99 is rotatably pivoted on the pin 100 of a cranked lever 101 which swings on a bearing pin 102 in the bearing plate 91 and is influenced by a tension spring 103. On the free end 104 of the cranked lever 101 a setting or adjusting screw 105 is fitted, coacting with the contact pin 106 of the switching element 89.

On its other end face the auxiliary selector disc 93 carries a pin 107 the motion path whereof is obstructed by a latch bar 109 guided in a longitudinal slotted bar 108. The latch bar 109 is hinged at its other end to a lever arm 110 which is fixed on a shaft 111 which carries a similarly fixed switching rail 112 infiuencing in common all the selector bars 2.

The selector shaft 4 is further associated with a cam plate 113 which is scanned by a lever arm 114 carrying a roller 115 and has a radially extending peripheral notch 116. The cam plate 113 and the lever arm 114 controlled by the former do not influence the switch element 89 I or the starting and stopping of the motor 5, but are there for the purpose of lifting all the selector bars 2 by means of the common lifting rail 117 in such manner that their feeler noses 20 are raised out of the range of the selector cams 14 on their respectively associated selector discs 3. The selector bar 2 displaced in the directionof the arrow 16 by depressing the corresponding selector key 1 is not affected by the lifting rail 117 while rotating in the direction of the arrow 118 since the earn 119 cannot then come within range of the said lifting rail 117.

The stopping and restarting of the driving motor 5 can be effected, apart from the arrangement shown in FIG. 3 and 4, also by means of the following arrangement which is shown in FIG. 2.

As will later be described in connection with FIG. 9, an auxiliary switch 120 is provided in the circuit of the driving motor 5 in series with the aforesaid switch 89. This auxiliary switch 120 is actuated by a lever arm 121 of a cranked lever 122 which is secured on a shaft 123 and influenced by a tension spring 124. The second arm 125 of this cranked lever 122 carries a pin 126 coacting with a locking lever 127. This locking lever 127 has a locking notch 128 within range of the pin 126 and is pivoted on a pin 129. The locking lever 127 engages with its arm 129 underneath a tongue 130 on the joint pawl bar 15 and is further influenced by a spring 131. The selector disc 3 has between the fourth and fifth the selector cams 14 a deep radial notch 131 which is deeperthan the normal gaps between the selector cams 14. The shaft 123 further carries, keyed fast thereon, a switching arm 132 and a further such arm 133. The switching arm 132 projects within the range of action of a key bar 134 of a starting key 135 which is further equipped with a return spring 78.'The switching arm 133 projects into the path of the setting pin 77 on the lever 72 which is controlled by the resetting key'76.

The manner of action of the arrangement just described, is as follows:

STARTING AND STOPPING OF THE DRIVING MOTOR 5.

At the end of each selection event the auxiliary switch 120 inthe circuit of the switch 89 is closed so that the driving 'motor can now be started by depressing the switch 89. When one of the selector keys 1 is actuated, the corresponding selector bar 2 is displaced in the direction of the arrow 16 when the lower end of the selector bar 2 strikes the switching bar 112 causing it to swing the lever arm 110 in the direction of the arrow 136 (FIG. 2 and 3). This rotation of the lever arm 110 withdraws the latch bar 199 out of the circular motion path of the pin 107 on the auxiliary selector disc 93 so that the said auxiliary selector disc rotates by the action of the tensioned spring 97 through the length of arc of the slit 95 with reference to the switching disc 92 and thereby lifts the feeler roll 99 on the cranked lever on to its outer circumference. The resulting pivoting motion of the cranked lever 101 causes closure of the switch 89 and thereby of the circuit of the driving motor 5 (see also FIG. 9). The driving motor 5 starts and sets in rotation the selector shaft 4 with the selector discs 3 and the two stub shafts 62 and 90.

As will be seen from FIG. 2 and 3, when the selector key 1 is depressed the selector bar has first to travel a certain distance before it can actuate the switching rail 112. When the selector key 1 is released a spring 137 draws the selector bar 2 back again through a shorter distance so that the latch bar 109 can again come within the circular path of the pin 107, i.e., into its locked position when the selector key 1 is released.

Simultaneously with the starting of the driving motor by actuating the switch 89, as will be seen from FIG. 9, the electromagnet 81 in series with a rectifier 138 and the switch 80 is energized. The rocking armature 82 of the electromagnet 81 now swings the locking catch 85 on the locking bar 84 behind the locking nose 88 on the selector bar 2 and thus holds the latter against the action of the tension spring 137 in the operating position of which the feeler or key pin 17 on the joint pawl bar is no longer opposite the notch 18, but over the nose 19 on the selector bar 2.

The driving motor 5 thus remains switched on until either the switch 89 or the auxiliary switch 120 interrupt a corresponding circuit.

The switch 89 is in any case only opened again after the switching disc 92 has completed a full revolution. Already before this switching disc 92 has completed its revolution, the pin 107 on the auxiliary selector disc 93 again makes contact with the latch bar 109, so that the motion of the auxiliary selector disc 93 is arrested, while the switching disc 92 runs on for the full length of arc of the slot 95 and thereby again tensions the spring 97. The feeler roll 99 can only again enter the notch 98 of the auxiliary selector disc 93 when the notch 98 of the switching disc 92 after completing one revolution again registers with the notch of the auxiliary selector disc 93. Only then the switch 89 opens and switches off the driving motor. The opening of the switch 89 also simultaneously interrupts the circuit of the electromagnet 81 so that the rocking annature 82 of the latter releases the locking bar 84 against the pull of the spring 86 which releases the locking nose 88 on the selector bar 2 whereupon the latter can return to the inoperative position. At latest simultaneously with the entering of the feeler roll 99 into the notches 98, the roller 115 of the lever arm 114 also enters the notch 116 on the cam plate 113, so that the lifting rail 117 no longer prevents the return motion of the selector bar 2.

INTERMEDIATE STOP If the selector disc 3 associated with the particular actuated selector bar is provided with a deep radial notch 131 as shown in FIG. 2, after the fourth selector cam 14 has been scanned the feeler nose can drop into this deep notch 131, swinging out thereby in such manner that the joint pawl bar bearing under spring tension on the nose 19 of the selector bar 2 likewise swings out and by means of the tongue 1311 turns the locking lever 127 clockwise until its locking notch 128 moves away from the pin 126 on the cranked lever 122 which then swings by the action of the spring 124 thus opening the auxiliary switch in the circuit of the driving motor 5 and stopping the said driving motor 5. The caller can now wait until a signal is heard in the handset. If this signal is line clear the caller can by actuating the starting key 135, restart the driving motor. This takes place by the following events:

Pressure on the starting key causes its shaft 134110 move downwards and thereby by means of the switching arm 132 to swing the lever 122 again in the opposite direction so that its 121 again closes the auxiliary switch 120 and thereby start the driving motor 5. When the driving motor 5 is switched on, the selector disc 3 is again rotated further so that the feeler nose 20 again moves out of the deep notch 131 and the locking lever 127 with its locking notch 128 does not move in front of the pin 126 so that when the starting key 135 is again released the auxiliary switch 120 remains closed and the selector event can be continued to the end in normal operation, i.e., at normal speed.

RESETTING THE SELECTOR SHAFT 4 FOR HIGH- SPEED GEAR If, during the intermediate stop, instead of the line-clear signal the engaged tone is heard, the caller can be actuating the resetting key 76 interrupt the initiated high-speed selection event.

Thus, instead of the starting key 135, the reset key 76 is now actuated. Consequently, the key shank 75 swings the lever 72 in such manner that on the one hand the cranked lever 122 through the setting pin 77 and the switching arm 133, now closes the auxiliary switch 120 in the same manner as when the starting key 135 was actuated and on the other hand through the shaft 70 and the locking lever 68, causes the bar 63 to withdraw the locking catch 64 from under the switching lever 46,.when the latter, drawn by the spring 59, performs a switching motion in the clockwise direction (referred to FIG. 5) and its arm 56 at the same time couples the twin-belt pulley 39 with the gear wheel 40, by means of the conical projection or boss 45. The downward motion of the lever arm 56 of the switching lever 46 now displaces the twin-belt pulley 39 axially on the shaft 44 towards the gear wheel 40 thus allowing the two coupling pins 50 and 51 to come into engagement. The drive of the selector shaft 4 is now performed by the second gear train with the lower transmission ratio, and the gear wheel 37 is driven in the high-speed gear stage through the belt drive 38, 39 and the two gear wheels 40 and 41. The stopping of the driving motor is effected after completed revolution of the selector shaft 4, in the manner explained above under reference to FIG. 3 and 4.

When the reset key 76 is depressed the lever arm 69 also opens the contactor switch al. (FIG. 5 and 9), in the circuit of the electromagnet 81. The contactor switch al. is connected in series with the current current-pulse switch nsi, so that during operation of the high-speed gear stage, the emission of current pulses is interrupted. The contactor switch al. at the same time performs the duty of the usual cradle switch in the ordinary telephone handset, so that on completion of the selection event initiated and conducted in the high-speed stage, it is no longer necessary to return the handset to the cradle before initiating the next selection event.

In order that the contactor switch al. may remain open also after release of the reset key 76 and until completion of a full revolution of the selector shaft 4, the stop together with the cranked lever 68 is prevented from following the pull of the spring 138 which is suspended from the lug 65, by the fact that the end 55 of the lever arm 56 of the switching lever 56 moves in front of the flat part 64 of the stop 57.

Thus, as soon as operation of the reset key 76 has caused the stop 57 to withdraw from underneath the arm 56 of the switching lever 46, the contactor switch as will remain open until the revolution of the selector shaft 4 has been completed. The switch 80 also remains open.

During the operation of the high-speed gear stage and owing to the action of the freewheel clutch formed by the ratchet wheel 36 and the follower pawl 34, the gear wheel 37 overruns the wormwheel 9, sothat the normal-speed gear train remains practically idle during theaction of the high-speed stage.

Shortly before completion of the full revolution of the selector shaft 4 the selector cam 61 on the stub shaft 62 makes contact with the roller 60 on the lever arm 58 of the switching lever 46 and during its further rotation swings the switching lever 46 back into its starting position so that the twin-belt pulley 39 similarly returns to its initial position and the two coupling pins are no longer in contact, i.e., the coupling 43 is cut out. Since this cutting out is completed before the selector shaft 4 has reached its starting position, the last few degrees of angle of rotation are again performed by the first gear train of the normal-speed stage driving the selector shaft 4 and the returning of the switching lever 46 into its normal position is performed as shown in FIG. 5.

1 As soon as the bottom edge of the arm 56 of the switching lever 46 has been lifted over the stop 57, the spring 138, through the lug 65 and therod 63, again draws the cranked lever 68 to the left with reference to the position shown in FIG. 5, and simultaneously the contactor switch 21 is again closed.

On completion of the revolution of the selector shaft 4, the driving motor is restarted in the manner described above, and all components of the arrangement move back into position for a further selection event. a

As the exemplary form of embodiment described above shows, the invention provides an arrangement which is extremely reliable in operation and relatively easy to manufacture, which lacks any complicated components and canbe operated in the simplest manner possible, while ensuring the quickest possible functioning. The apparatus is, moreover, capable of very wide application.

We claim:

l. A control device for operating an automatic currentpulse transmitter for telephony, telewriter and similar installations with address-number selection and in particular for such a current-pulse emitter in which the address store is represented by a plurality of selector discs rotatable by a power accumulator on which the individual addresses are represented by selector cams which through the intermediary of selector bars individually associated with the said selector discs and a common pawl bar for all such selector bars control during one revolution a current-pulse generator, wherein any one of the said selector bars with each of which aselector key is individually associated is before the initiation of a selection event moved from a resting position into an operating position and therein held during rotation by a locking bar and thereby starts the power drive which after completion of the selection event is automatically stopped after which the selector bar is returned to its starting position characterized in that in addition to a geartrain providedfor driving the selector discs at normal operating speed a second gear train with a lower total transmission ratio is provided for driving the selector discs at a higher speed and which is connectable in circuit by means of a clutch coupling actuated by a reset key whereby the said reset key is simultaneously with the engagement of the aforesaid clutch interrupts the emission of the aforesaid current-pulse trains.

2. A control device in accordance with claim 1 characterized in that the gear train for normal-speed operation incorporates a freewheel clutch.

3. A control device in accordance with claim 2 wherein said freewheel coupling consists of a pawlclutch.

4. A control device in accordance with claim 2 characterized in that the gear train for high-speed operation incorporates elastic driving means.

5. A control-device in accordance with claim characterized in that the elastic driving means consist of a rubberbelt drive (38,39,42).

6. A control device in accordance with claim 1 characterized in that the coupling (43) in the high-speed gear train is operated by a spring-loaded switching lever (45) which in its inoperative position is held by a movable stop (57) operatively linked with the reset key (76) and from its operating position is returned by a switching cam (61) rotating with the selector discs (3) into its resting position.

7. A control device in accordance with claim 6 characterized in that the stop (57) actuated by the reset key (76) is held by the switching lever (46) until returned into the inoperative position thereof against the force of a spring (138) in a switching position in which it actuates a circuit-breaker (al) in the current-pulse circuit through a lever (68).

8. A device in accordance with claim 1 wherein the gear train of the high-speed stage incorporates an electromagnetic clutch controlled by a switch actuated by the switching lever.

9. A control device in accordance with claim 1 wherein the clutch in the high-speed gear train is formed by a belt pulley and a spur wheel carried on a common shaft and wherein one part is axially slidable with reference: to the other part both being equipped with engaging and disengaging, axially movable follower elements.

10. A control device in accordance with claim 1 characterized in that the locking bar for the selector bar is actuated by .an electromagnet, and that the resetting key (76) is associated with an electric switch (80) connected in circuit with ry disc (93) rotatable with reference to the first through a predetermined angular distance which is held in 'its resting position by a key-operated latch bar (109) against the force of c a spring (97) and is made to advance with reference to the switching disc (92) during the rotation thereof through a particular angular distance whereby it performs the operating of the switch (89) at the start of its rotation.

12. A control device in accordance with claim 10 characterized in that the switching disc (92) and the auxiliary switching disc (93) are intercoupled by pins (94,95) between which the spring (97) is stretched in the peripheral direction.

13. A control device in accordance with claim 11 characterized in that the latch bar is released from its locking position by overrunning when the selector bar is actuated by depressing a selector key and thereby frees the auxiliary switching disc.

14. A control device in accordance with claim 1 characterized in that the selector discs (3) have between each two selector cams 14) a deep radial notch (131) and that the circuit of the driving motor (5) has in series with the switch (89) an auxiliary switch which is opened by the joint pawl bar (15) when the selector bar (2) drops into the deep radial notch (131) of the selector disc (3) and thus stops the driving motor.

15. A control device in accordance with claim 14 characterized in that the said auxiliary switch (120) is reset by a starting key (135). i

16. A control device in accordance with claim 14 wherein the auxiliary switch is actuated by a lever mechanism which is in operative linkage both with the starting key and the reset key.

17. A control device in accordance with claim 14 wherein the deep radial notch in the selector disc is in each casearranged between two selector cams the one of which represents the last figure of a prefix number and the other the first figure of a subscriber call number.

18. A control device in accordance with claim 16 wherein the lever mechanism actuating the auxiliary switch is held in the closed position by means of a locking lever which is actuated against the force of a spring by the joint pawl bar of the selector discs.

19. A control device in accordance with claim 18 wherein the lever mechanism of the auxiliary switch is in operative

Images