US1062387A - Measured-service telephone system. - Google Patents

Description

V J. nmcxson. MEASURED SERVICE TELEPHONE SYSTEM.

APPLICATION FILED NOV. 22, 1911.

Patented May 20, 1913.

8 SHEETFSHEET 1.

J. ERIOKSON.

MEASURED SERVICE TELEPHONE SYSTEM.

' APPLIGATION FILED NOV.22, 1911.

1,062,387. Patenfed May 20, 1913.

3 SHEETS-SHEET 2.

TTOE/YEYE J i ERIGKSON.

MEASURED SERVICE TELEPHONE SYSTEM.

APPLICATION FILED NOV. 22, 1911.

Patented May 20, 1913.

3 8EEBTB-SHEET 3.

UNITED STATES PATENT OFFICE.

JOHN EBICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR '1'0 AUTOMATIC ELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF"ILLINOIS.

MEASURED-SERVICE TELEPHONE SYSTEM.

Specification or Letters Patent.

Application filed'l'ovember 22, 1911. Serial No. 661,786.

To all whom it nag concern: I

Be it known that I, JOHN ERICKSON, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Measured-Service Telephone Systems, of .which the following is a specification. I

My invention relates to a check-controlled telephone system, and more particularly to an automatic system in which it is necessary to deposit a coin before the conversation can be carried on.

My invention relates especially to an mproved construction of. the coin-collecting device and the association of thisdevice with the telephone system, so that it is neces' sary to deposit a plurality of coins before the. calling subscriber can converse with the called subscriber.

Heretofore, in check-controlled systems, it has merely beennecessary to deposit a single coin to operate the coin-collecting device and to render the system operative for talking. It often happens, however, that the charge for a call does not correspond to the denomination of any one coin. It therefore becomes necessary to deposit a plurality of coins to correspond to a given charge.

An object of my invention is to provide such a coin-collecting device, in which it is necessary to deposit two or more coins before conversation can be carried on between a calling and a called subscriber.

These'and other objects of my invention will bemore readily understood by reference to the accompanying drawings, in which Figures 1 and 2 represent a complete connection between-a'calling substationA (Fig. l) and a called substation A (Fig. 2) in a system embodying the principles of my invention. In Fig. 1 there is represented an automatic substation A to the line conductors of which there is allotted at the central.

oilice an individual or line switch C. At D there is shown a master switch for controlling a'group of line switches C. The line switches of this group have common access to a number of trunk lines which lead to first selector switches A number of first selectors have common access to a number of second selectors F, which in turn have access to connector switches H (Fig. 2), by means of which latter connection may be completed with subscribers lines. Fig. 3 is a front elevation of my improved substation coin-collecting device. Fig. 4 is a side elevation of the apparatus shown in Fig. 3.

As thus illustrated, the construction and method of operation of the coin-collecting device is as follows:

In Figs. 3 and 4 a face plate 2 is shown to the front surface of which there is attached a coin chute 3. Also to the front of the chute 3 there-is attached the trigger 16 and ratchets 17 and 18. Upon the front of the plate 2, but insulated therefrom and from each other, there is mounted a group of contactsprings 4, 5 and 6. The lower end of the spring 4 carries a swinging arm 7. Back of the plate 2 there is mounted a polarized electromagnet comprising a permanent magnetS and two coils 9 and 10. The armature 11 of the electromagnet is provided with a downwardly-projecting arm 12. The lower end of the arm 12 is bent forward above the arm 7 When the armature 11 is tipped downward to the lef.t,'the lower' ,end of the arm 12 is carried behind the small lug 13 on the top of the arm 7. If the magnet then be energized in the opposite direction to tip the armature downward to'the right, the arm 12 engages the lug 13 andcarries the arm 7 'over with it. When the arm 7 is thus carried to the left, the springs 4, 5 and 6 are forced into contact and the end of the arm 7 is moved into the path of the teeth of the wheel 17 The spring 15 serves to hold the arm 7 up against. the end of the arm 12 .until it is forced oil by the wheel 17. The trigger 16 carrying the pawl 20 partly closes the lower end of the coin chute, so that if a coin is dropped, the trigger is momentarily forced to the left, and upon its return motion rotates the wheels 17 and 18 one step. The teeth of the wheel 17 are so spaced that when it is rotated two steps in this manner one of the teeth will force the arm 7 down off the arm 12 and allow the springs 4, .5 and 6 to separate. The dotted lines in Fig. 3 show the position of the trigger just as a coin is passing its lower end. After the arm 7 hasbeen released it cannot be drawn over again until the electromagnet has been energized in the reverse direction to bring the arm 12 behind the lug 13 again. The armature of the electromagnet is pivoted to Patented May 20, 1913. 4

comprise the usual receiver 25, switch hook 26, transmitter 27 induction coil 28, ringer 29 and condenser 30. In addition, the sub: station A is provided with the" impulse s rings 31'and 32 and an impulse wheel 33' he impulse wheel 33 carries upon its periphery the impulse teeth 34 and is secured to a shaft 35, to which latter there is also attached a dial (not shown) provided with finger holes, through the medium of which the impulse wheel may be rotated. As the impulse .wheel is returned to normal position by a spring (not shown) after it has been rotated for any digit, each of the teeth 34 which pass the end of the spring 31 forces said spring out of engagement with the spring 32. The number, of times these springs are separated depends upon the digit called. Connected to the line of the substation A there is also shownone of my improved coin-collecting devices. The coincollecting device is represented only diagrammatically in Fig. 1, and the parts are designated by the same reference numerals as in Figs, 3 and 4.

The line switch C, which is individual to the line of substation A, and the master switch D are modified forms of the general type of line switch and master switch disclosed in British patent to R. W. James, No. 26,301 of 1906, but of'the particular form shown in British patent to T. G. Martin, No. 1419 of 1910. As herein represented, the line switch C comprises, among other details, a plunger (not shown) attached to the end of a so-called plunger arm 39 which is controlled by the magnet 40'. The magnet 40 also controls the relay armatures 41 and 42 and is'composed of four windings, namel a pull-in winding 43, a holding ,or cut-o winding 44, a line winding 46. and an auxiliary winding 45. The core of the magnet is provided near the center of its length with a lateral projection 47 bymeans of which the magnet is mounted upon the bracket 48, upon which latter the armatures 39, 4L-a-nd. 42 are pivoted. With this method of mounting the magnet, the magnetic circuit of the windings 43 and 44-is maintained separate from that of the windings 45 and 46, so that the armatures atone end of the magnet are not affected by the energization of the windings upon the other end. Of the two windings upon the upper end of the magnet, only the winding 43 is strong enough to attract the plunger arm 39 from its normal position. The winding 44 is not strong enough to thus operate the plunger arm, but will hold it in an operated position after it has been. drawn down by the winding 43. When the plunger arm 39 is attracted by the magnet 40, the plunger of the switch is forced into a bank of contact springs, forcing the springs 49, 51, 53 and 55 into engagement with the springs 50, 52, 54 and 56, respectively. Although only one set of springs (4956) is shown, each line groups of springs, each grou forming the terminal of a trunk line leading to a selector E. Each trunk line is multiplied through the corresponding springs of all the line switches of the group which is con? trolled by the master switch D; Theplu'ngers of the line switches of this group normally engage a so-called plunger shaft (not shown) and, through the medium vof the master switch D, are normally maintained opposite the terminal of an idle trunk line. The master switch consists essentially of a.

motor magnet 58 for rotating the ratchet wheel 59. The ratchet wheel 59 is connected with the plunger shaft in such a manner that a rotary motion of the ratchet wheel is transmitted to the plunger shaft, imparting to it an oscillating motion, so as to move the idle plungers back and forth in front of their trunk terminals. To the plunger shaft there is secured a locking plate 62 provided near its outer edge with a number of open- .ings 63 which are adapted tobe engaged by the pin 64 upon the end of the armature 65' of the relay 66. The openings in the plate 62 are so spaced that the pin 64 can engage one of them only when the plungers thatv are in looking engagement with the plunger shaft are directly in front of the corresponding trunk terminal. The master switch is also provided with a bank of con tacts comprising a common segment 65 and one individual. segment a for each trunk to which the line switches have access. The wiper 66 always keeps the common se ment in electrical connection with the ind vidual segment corresponding to the trunk line before which the idle plungers are being held by the master switch- The selector E is of the general type of selector disclosed in United States Letters Patent No. 815,321, granted to Keith, Erickson and Erickson, March .13, 1906, being somewhat modified, however, so as to operate in a two-wire system, 6., a system. in

switch 0 is provided with a number of such which the central ofiice apparatus is controlled from the callin substation over the two sides of the line iii series, As herein represented, the selector E comprises the usual wipers 67, 68 and 69 carried uponva vertically and rotatably movable shaft (not shown) which is controlled by the vertical a current interrupter 93 and an magnet and the rotary magnet 71. The usual side switch comprising the wipers 72, 73, 'M and is controlled by the private magnet 76 in a well-known manner. The operation of the selector is controlled by the calling subscriber through the medium of to engage the spring 80. The mechanism of the selector E is released immediately upon the energization of the release magnet, rather than b its deen'ergization as shown in. the said sel 83 and 84 are slow acting relays, '4'. 2,, they are slow to deenergize after their energizing circuits have been broken. This slow action is usually accomplished by securing a heavy I ring of copper around one end of the core of the relay. The selector F is similar to the selector .E, with the addition of the side switch wiper '85.

The connector H is of the general type of connector switch\ disclosed in United States Letters Patent No. 815,176, granted March 13, 1906, to Keith, Erickson and Erickson, but, like the selectors, is modified in order to operate in a two-wire system. Like the selectors, the connector isprovided with a shaft (not shown) carrying the wipers 86, 87 and 88, and is controlled by the-vertical magnet 89 and the rotary magnet 90. The usual side switch is controlled by the private magnet 91 in the usual manner. The line relay 92 is connected with the line couductors through the springs of a reversing relay 93. The connector is provided with a so-called back-bridge relay 177, through which the called substation is provided with talking battery current, and with a ringer relay, through the medium of which ring ing current may beaapplied to the called line after connection is completed therewith,

The substation A and the line switch G aresimilar to the substation A. and the line switch C, respectively. At M there is shown a ringin current generator and at L is shown a usy signalmg machine comprising induction coil 94". For operating the cenltral oflicc apparatus and Vfor furnishing ta king current there is provided a battery B having I one pole, preferably the positive, grounded atG.

Having given a description of the apparatus, I will now explain in a general way the operations by which one subscriber estalflishes connection with another in a system embodying the principles of my invention. It will be explained how the substation A may obtain connection with the ector patent. The'relays 82,

substation A, the number of which latter is assumed to be 2220. When the calling subscriber removes his receiver preparatory to making a call, the switch hook rises, permitting the spring 95 to pass out of engagement with the spring 97 and into contact with the spring 96, whereby the circuit of, the ringer 29 and the condenser 30 is broken, and a bridge consisting of the substation transmitter, the primary winding of the induct-ion coil, the windings of the coin-colleoting 'device 'and the receiver is closed across theline conductors 98 and 99. The closure of this bridge across the line completes an energizing circuit through the line winding 46 of the switch C. This circuit extends from ground G through the springs 101 and 102, line 99, springs'95 and 96, primary winding of the induction coil 28, impulse springs 31 and 32, coils 10 and 9 of the coin-collecting device, line 98, springs 104, and 103 and the winding. 46 to the battery lead 100. The current through the coils of the coin-collecting device at this time flows in such a direction as to attract the armature toward the coil 10, as shown in Fig. 1, thereby bringing the end of the arm 12 into engagement with the lug 13 on the arm 7 The energization of the winding t6 serves to operate the line switch- C to select an idle trunk leading to the selector, E. This operation is well understood in the-art, and as it forms no part of my presentinvent-ion, it is not thought necessary to describe the same indetail. When the connection is extended to the selector E, its line relay 77, the windings of which are bridged across the line circuit in series with the battery B, becomes energized by reason of the closed bridge across the line through the transmitter and coin-collecting device at the calling substation. The calling, subscriber now operates his calling dial in the usual manner for the first digit 2 of the-desired number. As the impulse wheel 33 returns to normal position after being rotated for this digit, the impulse springs 31 and 32 are separated. twice momentarily. Each time the springs 31 and 32 are separated, the energizing circuit of the line relay 77 of the selector E is broken, allowing said relay to be momentarily 'denergized. Since therelay- '82 of the selector is slow acting, it does not have time to denergize= during the momentary interruption of its circuit at the springs 111 and 110. Consequently, the engagement of the springs 110 and 112 .closes an energizing circuit through the vertical magnet 7 O, which operates to raise the switch shaft and wipers twosteps to a ptsition opposite the second row or level of ank contacts. The private magnet relay 83,

' which is included in the energizing circuit oi the vertical magnet, is energized with the first but, being a slow acting .erates to close a circuit extending from ground Gr through the springs 124 and 125 and the private magnet 76 to the battery lead 100. When the relay 83 de energizes after the last impulse is transmitted to the vertical magnet, this circuit through the private magnet is broken. The private magnet thereupon deenergizes and allows the side switch to pass to second position. wiper- 74 from first to second position disconnects the battery from the vertical magnet and completes an energizingcircuit through the rotary magnet 71, which then operates to rotate the shaft wipers one step, to press down the armature of the private magnet 76 and to open the circuit. of its own magnet at the interrupter springs 120*. When the circuit of the rotary magnet is thus opened, its armature falls back and, if the first trunk line upon which the wipers have just been rotated is not already in use, the private magnet armature falls back and permits the side switch to pass to third position. If, however, the first trunk line of the second level is already busy, the private wiper 68 finds the first contact which itengages provided with a guarding ground potential. When the wiper 68 thus engages the grounded contact, a locking circuit is completed through the side switch wiper 75 (in second position) and the private magnet 76 to the battery lead 100. The private magnet thus becomes energized and locks 'the side switch in second position. As long as the side switch remains thus locked, the rotary magnet continues to operate in a manner similar to that of a buzzer to rotate the selector wipers step by step until an idle trunk line is found.

When the private Wiper 68 engages the non-grounded contact of an idle trunk, the private magnet 76 deenergizes and permits the side switch to pass to third position, thereby breaking the circuit of the rotary magnet. The movement of the side switch wipers 72 and 73 from second to third position disconnects the line relay 77. from the line and extends the line connection through the shaft wipers 67 and 69 to the second selector F. The line relay 127 in the selector F then becomes energized i the same manner in which the relay 77 O the selector E was energized when the connection was first extended to that selector. The energization of the relay 127 serves'to close an energizing circuit through the slow acting relay 128 in the same manner in which the circuit of the relay 82 was closed by the relay 77. The relay 128, upon energizing, extends the guarding potential from ground Gr through the side switch wiper 85 and the springs 129 The movement of the side switch and 130 and to the private bank cont-acts of the seizedtrunk in the banks of all the selectors E which have access to this trunk. A circuit also extends from ground Gr through the said selector private bank con tacts, private Wiper 68, side switch Wiper 75, springs 131 and 132 and relay 82 to the batterylead 100. This circuit prevents the relay 82 from deenergizing after its former circuit is broken by the deenergization of the relay 77, when theside switch of the selector E passes to third position. A short period of time elapses between the time when the side switch of the selector E passes to third position and the time when the relay 128 energizes to extend, a guarding potential back to the first selector private bank contacts from ground G". During this interval the trunk line leading to the selector F is guarded by a ground potential extending from ground G through the spring 133 and 131, side switch wiper 75 and the private wiper 68 to the private bank contacts. It

will be remembered that the relay 84 is included in the operating circuit of the rotary magnet 71, and, since it is a slow acting relay, it remains energized for an instant after the rotary magnet is energized for the lastv time. Thus the relay 84 is already energized when the side switch reaches third position, and a guarding potential is extended from ground G8 in the manner described. The relay 84 is quicker than the relay 82 and thus deenergizes in time to close the new'energizing circuit for the re lay 82 before it has time to :deenergize. The calling subscriber now operates his calling device for the second digit 2. The second selector F operates in response to the impulses for this digit in the same manner as explained for the selector E, and extends connection to an idle connector H over the trunk lines 134 and 135. When the connection is thus extended to the connector H, its line relay 92 becomes energized in the same manner that the selector line relays are energized. The relay 92, upon energizing operates to complete a circuit extending from ground Gr through the springs 137 and 138 and the slow acting relay 139 to the battery lead 100. The relay 139, upon energizing, extends the guarding potential from ground G10 through the side switch wiper 140, springs 141 and 142 and the conductor 136 to all the selector private bank contacts which belong to the trunk line leading to the connector H. The energization of the relay 139 of the connector also provides a new holding circuit for the release relays 128 and 82 of the selectors F and E, respectively. This circuit extends from ground G through the side switch wiper 140, springs 141 and 142, conductor 136, private wiper 143 of the selector F, side switch wiper 144 and springs 145 and 145 to the point 147. From the point 147" one branch of this circuit extends through the relay 128 to battery, while another branch extends through the side switchrwiper 85 (in third position) to and through the relay 82 of the selector E over a circuit which has already becn traced. The calling subscriber now operates his dial for thethird digit 2, momentarily separating the impulse springs 31 and 32 in the same manner as described for the first digit. Eachtime the impulse springs are separated for the third digit, the energizing circuit for the connector line relay 92 is broken momentarily. Since the relay 139 of, the connector is slow acting, it does not the momentary deenergization of the relay 92. Consequently, the engagement of the springs 137 and 146 completes, an energiz: ing circuit through'the vertical magnet 89. This circuit extends from ground G through the springs 137 and 146, springs 147 and 148, private magnet relay 149, vertical magnet 89 and side switch wiper 150 to the battery lead 100. I The vertical magnet receives two impulses over this circuit an operates to raise t e shaft wipers 86, 87 and 88 two steps. 7

The privatemagnet relay 149 operates in the same manner as the private magnet relay 83 of the'selector E to close the circuit of the private magnet while the vertical magnet is operating. the private magnet extends from ground G through the springs 151 and 152 and the private In et 91 to the battery lead 100. This circuit is broken shortly after the last impulse is delivered to the vertical magnet, whereupon the private magnet deenergizes and permits the side switch to pass to third position. The movement of the side switch wiper 150 from first to second osition transfers the battery connection om the vertical magnet 89 to the rotary magnet 90. The connector is then in position to receive impulses for the last digit 0. The operation of the substation calling device for this digit opens the circuit of the relay 92 ten times. Each time the relay 92 deenergizes it completes a circuit extending from ground Gr through the springs 137, 146, 147 and 148, relay 149,

springs 153 and 154, rotary magnet 90 and side switch wiper 150 (in second position) to the battery lead 100. The rotary magnet 90 receives ten impulses over this circuitand operates to rotate the wi rs ten steps onto the contacts of the line his 2220. The private magnet relay 149 is' energized by the first impulse to the rotary magnet and again closes the circuit of theprivate magnet 91. The circuit of the relay 149 is not opened long enough to permit itto deenergize until after the lastimpulse'has been delivered to the rotary magnet. The relay 149 then dehave time to denergize during The circuit through I energizes and breaks the circuit of the private magnet 91, which, if the called line is not already busy, in turn deenergizes and permits the side switch to pass to third position, whereby connection is completed between the calling and the called lines. T-lli side switch wiper 156 (in third position) extends the guarding. potential from ground G through the private wiper 87 to the connector private bank contacts of the called line, and also provides an energizing circuit .for thecut-ofi winding 157 of the line switch C. The winding 157, upon energizing, attracts the armature 158, which operates to disconnect thev line winding 159 and ground Gr from the called line, and to extend the line conductor 160 through the springs 162 and 163 to the connector bank contact which is engaged by the wiper 86. When theside switch wiper 150 ofthe connector reaches third position,'the energizing circuit is established for the ringer relay 164. This circuit extends from ground G through the interrupter 165, relay 164, springs 171 and 170 and side switch wiper 150 to the battery lead 100. Since this circuit includes the interrupter 165, the relay 164 is energized only intermittently. Each time the relay 164 is energized it operates to disconnect the calling line from the called line and to bridge the generator M across the called line to ring the bell 175. When the called subscriber removes his receiver, or as soon thereafter as if it happens to be energized at the time, the called substation is provided with talking battery current from the central office. The circuit over which this talking current flows extends from ground G to the side switch wiper 156, lower winding of the re lay 177', ringer relay springs 188 and 189, side switch wiper 187, shaft wiper 88, line 161, hook switch springs 186 and 185, primary winding of the induction coil 184, transmitter 183, impulse springs 182, coils 181 and 180 of the coin-collecting device, line 160, springs 162 and 163, shaft wiper 86, ringer relay springs 181 and 180, private magnet springs 179 and 178, upper winding of the back-bridge relay 177 and the side switch wiper 150 to the battery lead 100. The current through the coils 281 and 280 and the coin-collecting device of the substation A is in such direction at this time as to attract the armature toward the coil 281.

Vhen the connector back-bridge relay 17 7 is energized by the talking current, itoperates to close 93. This circuit extends from ground G through the side switch wiper 1'56, relay 93 and springs 288 and 289 to the battery lead 100. The relay 93, upon energizing,'operates to break the circuit- 164 at the springs 171 and 170, and to comof the ringer relay the relay 164 deenergizes,

the circuit through the relay the springs 166 and 172, respectively. By

this operation the connections between the windings of the relay 92 and the trunk coni ductors 134 and135 are interchanged. By

this shifting of the connections of the relay 92 the current in the calling line is reversed. This reversal of the current causes the polarized relay of the coin-collecting device at the substantion A to "attract its armature in the opposite direction-that is, toward the coil 9. When the armature is attracted in this direction, it carries the arm 7 to the left, forcing the springs 4, 5. and 6--into en --gagement, as was explained in connection with Figs. 3 and 4. Theengagement of the sprlngs 4, 5 and 6 short-circuits the transmitter 27 and shunts the secondary winding of the induction coil 28 with the resistance 190.1 The short-circuiting of the transmitter27 makes it, impossible for the calling subscriber to talk to the called subscniber through the medium thereof. The shunting of the secondary winding of the induction coil 28- does not prevent the calling subscriber from hearing the called subscriber answer, but ,does not allow him toconverse through his receiver. When the calling subscriber hears the called subscriber answer, he deposits two coins in the coin chute. These coins, in passing down the chute, cause the ratchet wheel 18 to be advanced two steps, thereby releasing the arm 7 from plained, thereby-allowing the springs 4, 5 and 6 to separate. The separation of these springs restores the talking circuit for the calling substation to normal condition. Then the two subscribers may converse over 'the circuits represented by heavy lines in the arm, 12, as has been previously ex the side switch Wiper 140 of the connector passes from second to third position, the holding ground of the release relays 128 and 82 of the selector switches is transferred from ground G to ground G through the springs 138 and 137 so that the circuits of allthe'release relays are controlled by the connector line relay. When the relay 139 of the connector denergizes, it completes a circuit from ground G through the springs 137 and 146, springs 147 and 191, release magnet 192 and off normal springs 193 and 194 to the battery lead 100. The energization of the magnet 192 immediately restores the mechanism of the connector to normal position, thereby breaking the connection at the called line and allowing the winding 157 of the switch C to dee'nergize. The deenergization of the release relays 128 and 82 of the selectors E an'd'F closes the circuits of their respective release magnets. The energizing circuit' for the release magnet 78 of the selector E extends from ground Gr through the springs 110 and 112, springs 121 and 123, magnet 78 and off normal springs 80 and 81 t0 the battery lead 100. The circuit of the release magnet 193 of the selector F is similar to that just traced for the magnet 78. The energization of the magnets 78 and 193 restores themechanism of theirrespective switches to normal position. When the shafts of the switches E, F and H reach their lowest positions, the energizing circuits of their respective release magnets are broken by the separation of the off normal springs. The denergization of the release relay 82 ofthe selector E also opens the holding circuit of the winding 44 in the line switch C, whereupon its plunger returns to normal position and all the apparatus employed in the connection is left in readiness for another call.

The foregoing is an explanation of the manner in which connection is obtained withan idle line. It will now be explained how the calling-subscriber is given the busy signal in case the called; line is already in use when called by the subscriber at substation A. In the foregoing description it has been explained how, whenever a line is busy, either by reason of having made a call or by reason of having been called, there is a guarding ground potential on the connector private bank contacts of the said busy line. Thus, if the wipers of the connector H are rotated onto the contacts of the busy line, a ground potential is extendedfrom the private bank contact in that line through the private wiper 87, side switch wiper 156 (which is then in second position), springs 195 and 19.6, relay197 and to the spring 198 of the private magnet relay 149. As

the relay 149 d'eenergizes after the last impulse has been delivered to the rotary magnet of the connector, the spring 152 engages sequent time substation A From the foregoing it will be seen that the spring 198 before it breaks contact with the spring 151. The circuit of the private magnet 91 is, therefore, maintained by the current extending from the private bank contact of the busy line through the relay 197, causing the side switch to be locked in second position and the relay 197 to be energized. The energization of the relay 197 disconnects the rotary magnet 90 from the impulse spring 146, and shifts the holding ground of therelay 197 and the private magnet 91 from the guarded private bank contact to ground G throu h the springs 196 and 199, springs 142 an 141 and the side switch Wiper 140. In its energized position the relay 197 also completes a circuit over which the busy signaling current flows from the busy signaling machine L to the calling substation. This circuitextends from the battery lead 100 through the secondary winding of the induction coil 94, springs 200, contact point 201, side switch wiper 187, ringer relay springs'188 and 189, condenser 202, thence over the heavy conductors shown in Figs. 2 and 1 to and through the substation A and back over the.

other side of the line to the upper winding of the connector line relay 92 to the battery lead 100. Although the wipers of the connector H are standing on the contacts of the called line while a calling subscriber isthus receiving the busy signal, there is no connection between the. two lines. nection is opened on one side of the line at the private magnet springs 178 and 179 and on the other side at wiper 187, which is locked in second position. The switches are released in this position by the hanging up of the receiver at the calling substation in practically the same manner as when an idle line is called. It will be seen that when a busy line is called, the current in the calling line is not reversed. Therefore, the armature of the coin-collecting device at the substation A is not attracted toward the coil 9 to close I the springs 4, 5 and 6, but remains in the position shown in Fig. 1 until at some subcalled from the:

an idle line is and the call is answered.

the calling subscriber s telephone set is rendered inoperative for talking when the called subscriber answers. The calling subscriber can listen and hear the response of the called subscriber, but cannot use have been deposited in the slot at the calling substation. This is the only way in which the calling subscriber can talk to the called subscriber. A further advantage of my improved system is as follows: In telephone systems giving so-called measured service it is very often desired that no charge shall be levied for .change attendants are called, etc.

system shown herein provision for free the springs The con the side switchhis transmitter until after two coins, or the like called subscribers line,

calling certain lines, such as lines which terminate at the central office over which operators or ex- In the service when certain lines are called can easilybe made. This may be done by making the lines,which are to be called free of charge accessible from special connector switches. These special connectors may be similar in all respects to the connector H, with the exception that the -1ine relay 92 should be connected with the trunk conductors 134 and 135 direct instead of through of the relay '93. In these special connectors the relay corresponding to the relay 93 would have no springs corresponding to the springs 166, 167, 168, 172, 173 and 174. Since the line relay of these connectors is connected directly to the line conductors, the current is not reversed in the calling line upon the removal of the receiver at a substation which has been called through one of the' special connectors. Since the current in the calling line is not reversed, thevcalling telephone is not made inoperative for talking, and consequently the calling subscriber does not need to deposit coins before he can talk.

While I have illustrated my invention in connection with a particular type of telephone system, it will be understood that I do-not wish to be limitedto such a system, as it is obvious that my improved coin-collecting device can be used in many other systems without departing in any way from the spirit and intent of my invention. Likewise, while I have illustrated my coin-collecting device as being operated by depositing two coins, it will be readily understood that, if desired, my device can be so regu lated as to be operated upon depositing any numberof ooins,it being only necessary to alter the space between the teeth on the wheel 17 By properly spacing these teeth it will be readily evident that one, two, three, or any number of coins could be employed to release the arm 7 instead of 'two coins, as illustrated.

What I claim. as my invention is 1. In a telephonesystem, a plurality of subscribers lines, means for, establishing a talking circuit between any two lines, a coincollect-ing device vupon one of said lines,- means for rendering said talking circuit inoperative, and means controlled by depositing a plurality of coins in said coin-collecting device for rendering said talking circuit operative. V

2. In a telephone system,

I means for establishing a talking circuit means on said calling line to render thecalling telephone inoperative for talking when a calling and a between? said lines,

the called subscriber answers, and means operated by a plurality of coins for rendering said telephone operative.

3. In a telephone system, a calling and a called ,subscribers line, means for establishing a talking connection between said lines, a coin-collecting device associated with said calling line, means controlled by said device for rendering said calling telephone inoperative when; the called subscriber answers,

and means for operating said coin-collecting device by depositing a plurality of coins therein to render said calling telephone operative'.

called subscribers line, means for establishing a talking circuit between said lines, a coin-collecting device. on said calling subscribers line, a magnet and anarmature controlled thereby in said coin-collecting device, means controlled by said armature for renderinginoperative said calling telephone, and means controlled by depositing a pinrality of coins in said device for again renderin said telephone operative I 6. n a telephone system,a calling and a called subscribers line, means forjestablishing a talking circuit between said lines, a coin-collecting device at said calling station including a polarized magnet and an armature controlled thereby, means for energizing said magnet in 'one direction when a call is initiated, means for energizing said magnet in the opposite direction upon response of the called subscriber, means controlled by energizations of said magnet for rendering said calling telephone inoperative, and means controlledby depositing a plurality of coins in said device for again rendering said telephone operative.

7. In a telephone system, a calling and a called subscribers line, means for establishing a talkingbircu'it between said lines, a coin-collecting device associated with said calling line, means controlled by said device for closing a shunt circuit about the transinitter on said calling line to render the same inoperative, and means controlledby depositing a plurality of coins in said device for breaking said shunt to thereby again render said transmitter operative.

, 8. In a telephone system,

a callin and a' called subscribers line, g

a coin-collecting device on said calling subscribers line, said device including a polarized magnet,an armature controlled thereby, an arm controlled by said armature, means controlled by said arm for rendering said calling telephone inoperative, a ratchet and pawl, means for operating said pawl to move said ratchet one Y step upon depositing a coin in said device,

and means for operating said ratchet a plurality of steps to render said telephone operative'.

9. In a telephone system, a calling and a called subscribers line, means for establishing a talking circuit between said lines, a coin-collecting device associated with said calling line, said device including a polarized magnet, an armature controlled thereby, an arm controlled by said armature, means controlled by said arm for closing a shunt circuit about the transmitter on said calling line to render the same inoperative, a ratchet and pawl, means for operating said pawl to move said ratchet one step upon depositing a coin in said device, and means for operating said ratchet a plurality of steps to break said shunt to thereby again render said transmitter operative.

10. In a telephone system, a'plurality of subscribers lines,'means for establishing a talking circuit between any two lines, a coincollecting device upon one of said lines, means for rendering said talking circuit inoperative, and means controlled by successively depositing a plurality of coins in said coincollecting device for rendering said talking circuit operative.

11. In a telephone system, a calling and a called subscribers line, means for establishing a talking circuit-between said lines,

.a coin-collecting device on said calling subscribers line, means for reversing the current upon said line upon the response *of the calledsubscriber, means controlled by said reversal of current for rendering said calling telephone inoperative, and means controlled by successively depositing a plurality of coins in said coin-collecting device for again rendering said calling telephone operative.

12. In a telephone system, a calling and a called subscribers line. means forvestablishinga talking circuit between said lines,

a coin-collecting device on -said calling subscribers.line, 'a magnet and an armature controlled thereby in said coin-collecting device. means controlled by said armature for rendering inoperative said calling telephone, and v means controlled by successively deposltmga plurality of coins in said device for again rendering said telephone operative.

13. In a telephone system, a calling and :1 called subscribers line, means for establishing a talking circuit between said lines. a com-collecting device associated with said calling line, means controlled by said device for closing a shunt circuit about the trans mitteron said calling line to render the same inoperative, and means controlled by successively depositin a plurality of coins in said device for breaiing said shunt to thereby again render said transmitter operative.

Signed by me at Chicago, Cook county, Illinois, this 16th day of November, 1911.

JOHN ERICKSON' Witnesses:

ARTHUR J. RAY, E. D. FALES.

Copies of this patent may be obti ined for five cents each, by

addressing the Commissioner of Patents,

Washington, D. G."

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