US1489082A - Telephone exchange - Google Patents

Description

April 1 1924. I 1,489,082

F. A. LUNDQUIST TELEPHONE EXCHANGE Original i d Se t. 30, 1918 6 Sheets-Sheet 1 F. A. LUND'QUIST TELEPHONE EXCHANGE April 1 1924.

Original Filed Sept. 30, 1

6 Sheets-Sheet 3 jyala/gii Z66] April 1 1924. 1,489,082-

F. A. LUNDQUIST TELEPHONE EXCHANGE Original Filed Sept. 30, 1918 6 Sheets-Sheet i Cain's 551 I "Ira/(92%? 6 Sheets-Sheet 5 Original Filed Sept.

Ry g Patented Apr. 1, 1924.

UNITED ST ATESPATENT 0 FFICE.

FRANK A. LUNDQUIST, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO HENRY S. CONRAD, TRUSTEE.

TELEPHONE EXCHANGE.

Application filed September 30, 1918, Serial No. 256,188.

To all whom it may concern Be it known that I, FRANK A. LUND- UIs'r, a citizen of the United States of America, and a resident of Chicago, county of'Cook, and State of Illinois, have invented certain new and useful Improvements in Telephone Exchanges, of which the following is a specification.v

1y invention relates to automatic telephone exchanges and has for its object improvements in such exchanges. The line switch, shown in the lower part of the general diagram, has been described in detail in my pending application Serial Number- 248,104, filed August 3, 1918; and the selector switch, shown in the central part of the diagram, has been described in detail in my pending application Serial Number 250,873, filed August 21, 1918. The connector, shown in the upper part of the diagram, will be described herein.

In the drawings hereunto annexed- Fig. 1 isa side elevation of a connector; I Figs. 2, 3 and 4 are sections on lines 2-2, 3-3 and 4-4, respectively, of Fig. 1;

Fig. 5 is a partial elevation of some of the apparatus shown in Fig. 1, but from the opposite side; a

Fig. 6 is a diagram of two line switches, the one at the left being a calling switch and the one to the right being a called switch;

Fig. 7 is a diagram of the selector;

Fig. 8 is a diagram of the connector; and

Fig. 9 is a diagram showing the noninterfering connections between two connectors. 1

Fig. 6 at the bottom, Fig. 7 in the middle, and F ig. 8 at the top, taken together. represent one diagram covering a calling operation.

The frame of the connector is composed of a bottom bar 11, a top bar 12, and end bars 13 and 14.

Near the central part of this rectangular frame is a pneumatic motor which consists of a tube 15 arranged toslide on a standard lficarried in a small frame 17 (Fi s. 1,3, 4 and Compressed air entering t rough pipe 18 over the top of the standard 16 causes the tube 15 to rise.

Another pneumatic motor consists of a Renewed June 15, 1923.

that this weightdoes not put a strain on,

motor 19.

Supported in a bracket 24 on the bar 11 IS a gear 25 which meshes with a rack 26 on motor 19. On the same spindle with the gear 25 is a case 27 (Fig. 1) which contains a clock spring acting upon gear 25 in a direction to hold the motor normally to the left as seen in Fig. 1.

Supported on the bracket 24 is a magnet 28 whose armature 29 is connected to an escape lever 30 acting upon an escape wheel 31 secured to gear 25. If impulses flow through the magnet 28 at a time when compressed air is admitted to the motor 19, the

motor 19 will move the motor 15 step by 6n the motor 15 are racks 32 which engage gears 33 secured to a sleeve 34. The sleeve '34 is mounted to rotate in the frame 17 and to slide upon the square part of a shaft 35 which extends between and is supported by the bars 13 and 14. Supported on the bar 12 is a magnet 36 whose armature 37 is connected to an escape lever 38 operating upon an escape wheel 39 secured to shaft If impulses flow through mag net 36 at a time when compressed air is admitted to the motor 15, the. motor 15 will move upward step by step.

Supported at .a convenient place near magnet 36 is a small pneumatic motor 40. (Figs. 2 and 4.) A spring 41 acts to hold the motor 40 in normal position when not moved from normal position by compressed air.

Secured to the shaft is a wheel -l3 which has teeth equal in number to the teeth 01 wheel 89, and supported at ts is a pawl 45 adapted to catch in the teeth of wheel 5 and hold shaft in an advanced position after it has been moved from normal position. The pawl l5 has an extension M5 which bears against a collar a? on motor i0. lVhen the motor is in its normal position the pawl 4-5 is held from engagement with wheel d3, but when said motor has moved, said pawl falls into engagement with said wheel.

On the top of motor 19 is a ratchet bar and pivoted at l9 (Fig. l) is a pawl adapted to engage ratchet as and hold motor in advanced position when moved by compressed air. An extension 51 ot the pawl 50 rests on collar a7. lVhen motor it) is in normal position, the pawl 50 is held away from ratchet l8, but the pawl falls into engagement with the ratchet when the motor to is actuated.

Pivoted on pin (Fig. at) is another pawl adapted to engage ratchet 48. An extension 5-l of pawl projects upward and is engaged by an arm 55 secured on shat't 35. lVhen shaft 35 is in normal position. pawl 53 is held from engagement with ratchet 48. but when the shaft 35 is moved by an upward movement of motor 15. the pawl 53 l'alls into engagement with ratchet- 4-8.

Pivoted at 56 in the lower right hand corner of Fig. 1 is a disk 57 having ratchet teeth therein. Adjacent thereto is a motor 58 arranged to act upon a lever 59 pivoted at 60. A spring 61 acts to normally hold the lever 59 in the position shown. Pivoted at 62 on lever 59 is a pawl (53 which has an arm normally engaging a pin til to hold the pawl (53 trom engagement with the teeth in disk 57. lVhen motor 58 lit'ts lever 59, pawl (i -3 turns on its pivot to engage the teeth ot disk 57, and when motor 58 tails back the force of spring (31 acting on lever 59 ad vances disk 57 one step.

Pivoted at (35 is a catch 66 arranged to engage teeth on disk 57 and hold it in its advanced position when moved by pawl (33. Connected to an arm on the catch 66 is a rod 67 which extends to and is connected to a wing 68 on the frame 17. \Vhen the motor 19 is in its normal position the catch 66 is held free from disk 57. but as soon as the motor 19 has advanced one step the catch 66 drops to engagement with disk 57 and is in a position to act as a holding pawl.

Supported near the disk 57 is a valve 69, and pivoted at T0 is a lever 71 which has one arm engaging said valve and another arm with a cam 72 arranged to be engaged by an arm 73 secured to the (liS 57. The valve 69 is of the self closing kind (like a check valve), and when the disk 57 is in either its first or third position the *alve is closed. lint when the disk is in its intermediate position the arm 73 engages cam 72 to more lever 71 so as to open valve 69.

On the disk 57 are certain insulated wipers, and supported by a plate Tl are certain insulated contact strips. These parts correspond to the well known side switch and will be described in connection with the circuits to be given later.

Supported at a convenient place near the parts just described are two pairs of contact springs which are normally in the position shown in Fig. 1. A piece oli insulation 75 carried by the lever 59 shifts these springs to their alternative position whenever the motor 58 lifts said lever. These will he further described in connection with the circuits.

Supported on the bar 12 is a relay T6, and adjacent to the relay is a valve casing 77 to which compressed air flows from a source through pipe '78. The alve in this casing. which will hereafter be designated by the character applied to the casing. is in the nature of a check valve and held closed by the pressure of the air in the pipe 78. The stem 7.) of the valve extends beyond the casing and is engaged by an adjustable screw 80 in the armature 81 of the relay 76. A spring 82 normally acts to elevate the arnia ture but with a force less than that required to lift the valve from its seat. But when the arn'iature 81 is attracted by an impul e through relay 76, then the attraction plus the force of the spring 82 is sutlicicnt to open the valve. lVhen the circuit is broken through the rela 7c. the pressure of air in pipe 78 will close the valve and push arma ture 81 back against the action of spring 82. But it such break is followed quickly by a remake o'l the circuit as by the operation of the ordinary calling device at a local station. the armature 81 does not have time to tall back but remains attracted as in the case of an ordinary slow relay.

On the top oi motor 15 is a cross head 8 and on this cross head are arms Si and which carry insulated \Ylptl'S 86. 87. SS and 89. hen motor 19 operates. these wipers are moved step by step to the right. as shown in Fig. 1, and when motor 15 operates the wipers are raised step by step. By such movements the wipers are brought into engagement with desired contact points in a rectangular arrangement of such points.

011 the connector are certain contact springs which will be explained in connection with the circuits. From pipe T8 are branches to the different motors. These will be evident from the drawings and the description to follow.

In the diagrams the same battery is shown at a number of different places and is lows marked X, X and X with appropriate plus and minus signs to indicate positive and negative poles. .This repetition of the battery is to avoid long and confusing lines drawn upon the diagram. The line switch at the left in Fig. 6 has been advanced from normal position to engagement with an idle trunk leading to the selector in Fig. 7. In the line switch, three motors and one magnet are shown in operated position. At the time a subscriber begins a call these are all in normal position, and the operation of calling will now be described,

The first thing a calling subscriber does is to remove his receiver. This causes a closure, at the local station, of the following circuit: X-resistance R89 -90 91.- 92local station-9495 96X.

This causes magnet 96 to attract its armature and open valve 97 so as to permit compressed air to flow from a source to the motor 98, which immediately starts upward on a trunk hunting expedition. As soon as the wipers carried by motor 98 come to an idle trunk a new circuit is completed as fol- X99100101102103104- 105 105 106-107 (which is shown ad vanced, but is in normal position at th is, time) The impulse thru magnet 100 attracts its armature and causes pawl 110 to engage the teeth on motor 98 and arrest that motor with its wipers in engagement with the found trunk. The armature of magnet 100 also opens valve 111so as to admit compressed'air to motors 112 and 113. Motor 112 is used to prevent the line switch from moving from normal position, but as such movement has occurred before motor 112 acts, this motor accomplishes nothing at this time. Motor 113 throws another pawl 114 into engagement with the motor 98 and also shifts the adjacent contact springs into the position shown in Fig, 6. Shifting these springs connects wire 92 to wiper 117 by way of 91115 116, and connects wire 93 to wiper 121 by way of 94119 120. hen this is accomplished acircuit is completed for relay 118 of Fig. 7 as follows: X 1l8 122 117-116 115 -9192 local station93-94-119-120121 123 --resistanceX.

The shifting of the springs by motor 113 breaks for magnet 100 by moving 102 from 103, but immediately remakes by 103 engaging1241 from which the circuit continues-- 125126127128129130. This shift of the springs also breaks the circuit for magnet 96 and this results in air becoming exhausted from motorv 98.. .But pawl 114 is held against the ratchet teeth by motor 113 with sufficient force to prevent motor 98 from falling back when air is exhausted from it. f

The circuit just previously described thru of operations is a condensed one.

attracts armature 134 to open springs 135 and 136. The connections of relay 118 are such that it is a slow relay as far as armature 131 is concerned, and a fast relay as far as armature 134 is concerned.

lVhen armature 131 closed springs 128 129 as a result of the impulse thru relay 118 previously described, a circuit was completed as follows: X-130-129-128137 138139140141142143 (142 and 143 are closed in'normal position)-144 X". The current thru 139 attracts armature 145 which opens valve 146 to admit compressed air to pipe 147 and connections.

Air admitted to pipe 147 flows to motor 148 which moves lever 149 to advance ratchet 150 and its connected insulated wipers 107 and 151 from normal to midposition. Air also flows to motor 152, but this does not operate until an escapement permits it to operate as will be described.

The operations so far described all result automatically from the closure of a circuit at the calling station by the subscriber removing his receiver. The above statement In still more condensed form :-The subsciber removes his receiver, and this initiates automatic operations which connects him to the relay, 118 of an idle selector, the relay becoming energized from the common battery in the central office thru the sub-station.

Impulses thru magnet 157 operate escape wheel 158 and permit motor 152 to move the selector wipers step by step to successive rows of contacts.

At the first movement of the wipers to the right, the support 159 passes from under spring 142 so as to break the circuit for magnet 139, but the ratchet wheel 158 vibrates spring 142 in unison with the dial operations so that the armature 145 for mag net 139 (loes not have time to fall back. But at the end of the first dial operation the spring 142 rests at the position shown and this definitely breaks the circuit for magnet 189. Thereupon armature 145 falls back and valve 116 closes. This shuts air from motor 118 whereupon lever 149 falls back and opens valve 160 This admits air to motor 161 which immediately moves the wipers upward on a trunk hunting movement.

When an idle trunk is found a circuit is completed as follows :X1391291Q8- 13T138-139--1-101GQ163161165- 16616TX This operates magnet 139 to open valve 116 and permit air to flow again to motor 118 which advances wipers 197 and 151 to their final position,-that shown in Fig. T. In this movement, wiper 151 tilts lever 168 so as to permit the normally open valve 169 to close thus shutting otl the supply of compressed air which flows thru valve 16 to motor 161. Pawls indicated in vFig. T and described in my before men tioned apgli-ation, Number 259,873, hold motor 161 from falling back when the air is shut otl by valve 169.

It was previously described how the operation of the line switch extended the subscribers line to the wipers 117 and 121 in engagement with wires 12; and 12?). The last described movement of the wipers 15 and 19? extend these connections to found trunks and battery as follows: 1221T0 151 111 1T21T31T9180181 - X 3 and 123 1T5-19T1T6-1TT-1T81T1 .1t i616TX The relay 189 is like the relay 118 and has a "fast armature 182 and a slow armature 183 which acts to open the alve 181 to permit compressed air to flow from the general supply pipe 185 to the local supply pipe T8. The relay 189 is controlled from the local station in the same way as relay 118.

When the connector is in normal position the springs 161 and 165 are closed by a projection 186 carried by motor 19. In Fig. 1 this projection is shown attached to crosshead 82). (in trame 17 is a pin 187 which normally engages spring 196 so as to hold it in the position shown in Fig. 1, but when the motor 19 moves the frame 17 to the right, the pin 187 permits spring 196 to fall to the position shown in Fig. 8.

When the relay 189 is connected to the subscribers line in the manner described. it is energized from the battery by way of the local station. This attracts armature 183 to open valve 181 so that compressed air may flow to valves 69 and TT preparatory to future operationsv Armature 183 also closed springs 188 and 189, whereupon an impulse flows:X -181-188189-19O 191-76 19Q-wiper 193191-195196 197 19816616T[ As a result magnet 76 attracts armature 81 to open valve 77 so that compressed air may iiow thru the connecting pipes to motors 19 and 58. The motor 58 lifts lever 59 to open the adjacent contactsprings and to prepare pawl 66 for subsequent movement of ratchet wheel 57. The air acting on motor 19 moves it far enough to permit springs 161 and 165 to open but not far enough to permit spring 196 to move away from spring 197. This last occurs only when magnet 28 operates its escapement as before described.

When the subscriber next operates his calling device he breaks and remakes the circuit thru relay 180 whereupon an impulse flows :X'--181 188189190-wiper 199 OO- 291 28-2()229Z- -2()-i166-1 67 -X This operates the escapement to permit motor 19 to move the wipers 86 to 89 to the right, and is repeated at desired number of times to bring those wipers under the desired vertical row of contacts. Upon the first movement of the escapement for motor 19. the pin 187 leaves spring 196 and said spring drops to spring 295. whereupon the steady eurlent before described as passing thru magnet 76 is changed to a pulsating current as t'ollows:X -181-188189- 190--19176-192193-191195 196 2052O220320116616TX c When the subscriber pauses in the operation of his dial, springs 20;) and 201 remain open with the result that the. circuit is broken for magnets 28 and 76. Breaking for 28 simply arrests the forward movement of motor 19 and leaves wipers 86 to 89 under the desired row of contacts. Breaking the circuit for magnet 76 permits valve 77 to close and shut the air from motors 19 and Pawls previously described hold motor 19 so that nothing happens at this point, but motor 58 falls back and the wipers 193 and 199 carried by ratchet wheel 57 are advanced to their mid-position. In moving, the ratchet wheel 57 tilts lever 71 to open valve 69 and permit air to flow thru pipe 18 to motor 15.

\Vhen the subscriber operates his dial again to break and remake the circuit thru relay 180, impulses flow as follows :X 181-188 1S9'199wiper 199296-207 -362()22(W-2011 66-167X Magnet 36 is the vertical escape magnet which operates in unison with relay 180 and permits the motor 15 to move upward step by step. Magnet 36 also has a projection 208 on its armature, which projection closes springs 210 and 211 to send a pulsating current thru magnet 76 as tollows:-X"-181- 188-189-19019176192209 219 21121216616TX This circuit thru magnet 76 again opens valve 77 to again operate motor 58 and lift leve 59. At the end of the impulses sent by the subscriber, the circuit is again broken thru magnet 76 and lever 59 again falls back. This advances wipers 193 and 199 to their final position,

which is that shown in Fig. 8. In this final position a pin 213 on ratchet wheel 57 closes adjacent springs 214v and 215.

It was previously described that the selector connected the subscribers line to wires 173 and 178. The final movement of the connector extends these connections to the wipers 88 and 89 as follows :173-179 -22()22l22l-88; and 178216-217- 218-219-89.

At the left in Fig. 9 is a condensed diagram of the connector A which the calling subscriber is assumed to be using and get connection with some other subscriber. This connector is shown in its normal position. At the right in Fig. 9 is shown another connector B which some other subscriber has moved to find connection with some called subscriber. The purpose of Fig. 9 is to show what happens if the calling subscriber tries to get connection to the subscriber called by the connector I: to the right. Assume that the wipers 193 and 199 of connector A are in their mid-position, and that the calling subscriber attempts to stop his switch in connection with the bank contacts shown, which bank contacts correspond to the bank contacts engaged by switch B to the rigl'it. Under these conditions a current will flow as follows: X-181-to 188 of switch A189 190191--76 192193-- 222-223-87 224 225 to 224.- of switch B87223-226-215-214227167'-X. \Vith switch A stopping in this position a steady current is kept on magnet 76 which holds valve 77 open and keeps air on motor 58. As wipers 193 and 199 move tofinal position, and wires 173 and 178 are connected to wipers 88 and 89 only when motor 58. falls back. it will be seen that no connection will be made to a subscriber to be called if that subscriber has already been called by and is in connection with some other party.

It was previously described how the calling subscriber placed his connector on the contact terminals of a subscriber to be called when no other person is in connection with that subscriber. This position is shown in Fig. 8. Upon the stoppage of the connector in desired position a circuit is completed as follows: X-181-188189190-199 228--86--229 thru Fig. 7 to 100 in the line switch to the right in Fig. 6 99 X.

The impulse thru the magnet 1.00 of the called. line switch produces the same result as before described for the line switch to the left. to motors 112 and .113. Motor 112 permits pawl 230 to fall in over a collar 231 on Inotor 98 from moving from normal position if air should be admitted to motor 98'under conditions to be hereinafter explained. The

motor 112 has a check valve at 232 which acts to make this motor slow on release.

Motor 113 of called switch shiftsthe ad This is opening valve 111 to admit air jacent contact springs as was described for the calling switch. This shift connects the wires leading to the local station to the wipers ot' the line switch. In this case the wipers are in contact with only battery connections, but there are branches tapped from the wiper connections, and these branches are the normal wires whose terminals were connected to by the connector. Referring to Fig. 8 it will be seen that the wiper 88 is in contact with the terminal of wire 233 which may be traced thru Fig. 7 to Fig. 6 where it is found to be an extension of wire 120 described in connection with the other line switch as being connected to the local station. In the same way wiper 89 of the connector is in contact with the terminal of wire 234 which may be traced in the same way to the called line switch where it is found to be an extension of wire 116 which is connected to the local station.

'What has been so far described shows the calling station connected to a called station. There will, of course, be signaling apparatus for calling the called subscriber, but for simplicity of showing that is omitted from the present application and will be shown in another case. It will simply be assumed that the subscriber has been called, has talked and has come to the time of hanging up his receiver.

If the called subscriber hangs up first, then there are no complications. But if the calling subscriber hangs up first, 'he breaks the circuit he made for magnet 100 of the called line switch and this lets air escape from motor 113. The result is that the adjacent cont-act springs fall back to normal posit-ion and a circuit is completed formagnet 96 of the called switch because the called subscribe-r still has his receiver off its hook. This opens valve 97 to admit air to motor 98, but motor 112 is slow to exhaust, and pawl 230 is over collar 231 and the motor 98 cannot move on a trunk hunting operation. By observing the relationship of the pivot to pawl 230 to the direction of strain upon that pawl when the air is acting on motor 98 it will be seen that the arrangement is a self-locking one. The motor 98 cannot move upward no matter how long the called subscriber may keep his receiver off its hook. But when he hangs up the circuits are all broken and air is exhausted from all motors.

During talking the relays 118 and 180 are bridged on the talking circuit and are energized from battery by way of the calling station. \Vhen the calling'subscriber hangs up his receiver he breaks this circuit and relays 118 and 180 resume normal position. When relay 118 is de-energized, armature 131 falls back and permits springs 128 and 129 to separate. As these springs are in the circuit for magnet. 100 that magnet releases valve 111 so that air is shut otl' from motors 112 and 113. lYhen motor 113 falls back. the holding pa-wl 111 is withdrawn and motor 98 falls back.

Breaking the circuit thru relay 180 on the connector permits valve 18% to close and shut the air supply from pipe 78. A branch 235 leads from pipe T8 to motor 40. and when valve 184: was lirst opened air flowed to this motor to permit the holding pawls 45 and 50 to engage their ra-tchets. \Vhen valve 18st closes motor it) falls back and disengages these pawls. Releasing pawl 15 permits the vertical motor 15 to fall back, and as this motor reaches its normal position the arm 55 on shaft 35 strikes the extension 51- ot' pawl so as to release this pawl and permit the horizontal motor 19 to return to its normal position.

The release for the selector of Fig. 7 is very similar to that just described for the connector. It has been given in detail in my application previously mentioned.

Reviewing the operation in condensed form. the calling subscriber removes his receiver and thereby closes a circuit for the magnet 96 on his individual line switch. This admits air to motor 98 which immediately moves its wipers upward. When these find an idle trunk a circuit is completed for the magnet 100 which throws in the stopping pawl 110. and opens the valve 111 so as to admit air to motor 113. The motor 113 throws in the holding pawl 11st. and shifts contact springs so as to connect the station wires to the wipers and thin them to battery and relay 118- on idle selector.

Relay 118 opens valve 139 to admit air to the local pipe system. and closes a circuit for magnet 139 which in turn opens valve 116 to admit air to motors H8 and 152-. Up to this point all operations automatically result from lifting the receiver from its hook.

l'v hen the subscriber first operates his dial the selector of Fig. 7 moves to the right a number of steps which corresponds to the number indicated by the dial more ment. The impulses for this are relayed to magnet 15? which operates an escapement for this purpose. 'hen the first dial movementceascs the consequent pause in the [low of impulses brings about. thrn intermediate operations, an opening of valve 160 to ad init air to motor 161. This motor carries its wipers upward and when these wipers come to the terminals of an idle trunk, the selector is automatically stopped and the subscribers line is extended to the relay 180 on the connector.

The next two operations of the dial cause the connector to move step by step first horizontally and then vertically to the terminals of the line leading to the line switch belonging to the subscriber to be called. hen this point is reached, the connector automatically connects the calling line to the found terminals. If. however. the subscriber to be called has already been called by some other person. then the connector does not extend the calling line. In ex changes as ordinarily made. the connector extends the calling line to the terminals tound and then breaks the connection it the called subscriber is previously busy. In the present; case. if the subscriber to be called is previously called. then the connector never makes the movement necessary to extend the calling line.

hen the connector extends the calling line to the terminals of it called subscriber it closes a circuit which causes an operation of the line switch belonging to the called subscriber it such line switch is in its normal position. It. however, the line switch has been moved to make a call. then the contact springs 22-36 and 237 at the line switch are open and no circuit can be completed to magnet 100 ot the called line switch. It should be observed that the mag} net 100 of the alliiig switch acts as a trunk selector. and magnet 100 of the called switch acts as a connector by connecting the subscribers line to his normal wires and as a cut out by disconnecting the magnet 5 3 from the subscribers line.

In normal position the line switch wipers 117 and 121 engage contacts 238 and 1239 which are connected thrn resistances to a. battery. In the normal position of motor 113. the wipers 117 and 121 are disconnected at springs 11?) and 11!). and the battery is not employed. But when the line switch is called the wipers 117 and 121 are connected to the local station and the connected battery serves for talking nn-poses. The calling station is connected to battery X for talking purposes.

'hat I claim is:

1. In a telephone exchange. a line leading from a local station to wipers such as S8 and 8S). pneumatic motors for moving said wipers successively in directions perpendicular to each other, other wipers such as 198 and 199 serving in the electrical control of said motors, and a special motor serving to shift the last mentioned wipers and to temporarily break the connection between the lo *al station and the first mentioned wipers.

In a telephone exchange, a line leading from a local station to wipers on a connector. a line leading from a second local station to a line switch, a line leading from contact points on the connector to the line switch but normally disconnected from the line leading from the local station to the line switch, and means operating thru the conloo 1 ,csepez nector and involving a pneumatic device on the lin switch for connecting together the two lines leading to the line Switch.

3. In a telephone exchange, two line switches connected to corresponding local stations, connections extending from wipers on one line switch to normal wires on the other, and locking devices on the second line switch and a controlled over said connections by amagnet and pneumatic device 011 the switch.

said wipers, means by which the line is connected to the wipers for any talking circuit extending to said local station as a called station, and battery connections engaged by said wipers when in normal position but disengaged therefrom whenthe wipers have been moved. 1

5. In a telephone exchange, a line switch arranged to make connections for talking purposes either as a" callingor a called me dium, a line extending from said switch to a local station, and battery connections connected to said line at the line switch when said switch is a called medium but disconnected therefrom by the movement of the line switch when said switch is a calling medium.

6. In a connector switch, wipers for making telephonic connections, pneumatic motors serving to move said wipers in directions perpendicular to each other, an escapement for each motor, a relay arranged to control the operations of said escapements successively so as to permit said motors to move said wipers successively, and means for controlling said relay from a distant station.

7. In a switching mechanism having wipers, a pneumatic motor for moving the wipers in on direction, an escapement for per-' mitting the motor to advance step by step, a second pneumatic motor for moving the wipers in a second direction, an escapement for permitting the second motor to advance step by step, and electrical controlling means for causing the step by step movements in the second direction to follow those in the first direction.

8. A pair of wipers, a pneumatic motor, an escapement for permitting the motor to move the wipers step by step, a second pneumatic motor for moving the wipers in a second direction, a second escapement for per mitting the second motor to advance step by step, and electro-magnetic means for controlling said escapements in succession.

9. In an automatic telephone exchange having line switches and selectors, a pneumatic motor on each selector for moving it, a source of compressed air, and means by found selector.

10. In an automatic telephone exchange in which calls from a local station pass through primary and secondary switches, a pneumatic motor on each secondary switch for moving it, a source of compressed air, and automatic means for admitting compressed air to the motor of a secondary switch upon a subscriber closing an electrical connection at his local station.

11. Ina telephone exchange, a line lead ing from a local station through successive switches to a pair of wipers on a connector switch, pneumatic motors for moving said wipers step by step over a series of contacts to'a desired position,'and means for breaking the connection between the station and said wipers during the making of such movement.

12. In a telephone exchange, a calling and a called station, a line leading from a calling station to a pair of wipers on a connector switch, pneumatic motors for moving said wipers step by step into engagement with the contacts of the called station, other wipers serving in the control of said motors, a special motor which breaks the connection between the calling station and said first mentioned wipers when in operated position and which operates said other wipers when returning to normal position, and means controlled by the busy condition of the called station for maintaining said special motor in operated position.

13. In a telephone exchange, a calling and called line, a plurality of pneumatically operated switches and a pneumatic connector for completing connections between the call.- ing and the called line, a pneumatic side switch in said connector, and means in said connector for controlling said side switch to disconnect said calling line from said called line when said called line is busy.

14. In atelephone exchange, a calling and a called line, a plurality of pneumatically operated switches and a pneumatic connector for completing connections between the calling and the called line, a pneumatic side switch in said connector, and means in said connector for preventing said side switch to reach final position and for controlling said side switch to break the connection between the calling and called lines when said called line is busy.

15. In a telephone exchange a calling and a called line, electrically controlled and pneumatically operated line switches, selector and connector switches for completing a connection between the calling and the called lines, means for operating said switches to establish a connection between a calling and a called line, and a pneumatic side switch in said connector for preventing the establishment of said connection when the called line is busy.

ltl. In a telephone system, a calling and called subscriber each having pneumatic line switches individual thereto, pneumatic selector and connector switches, means controlled by the calling subscriber for actuating his individual line switch to seize an idle selector switch. and means controlled by the calling subscriber to actuate said selector switch to seize an idle connector switch and then to actuate said connector to seize said called suhscribers individual line switch.

17. In a telephone systei'u, a calling and a called subscriber each having pneumatic line switches individual thereto. pneumatic selector and connector switches, means controlled by the calling subscriber for actuating his individual line switch to seize an idle selector switch, means controlled by the calling subscriber to actuate said selector switch to seize an idle connector switch and then to actuate said connector to seize said called subscribefs individual line switch, and means for establishing talking circuits between said subscribers.

18. In a telephone exchange, two line switches connected to corresponding local stations, connections extending from one of said local stations through the wipers on one of said line switches to normal wires on the other. locking devices on the second line switch controlled over said connections by a 'magnet and pneumatic device on said second switch, and means for extending said connections to include said second station.

19. In a telephone exchange, a line switch having wipers for talking connections, a line leading from the line switch. to a local station but normally disconnected from said wipers, a pneumatic motor for connecting said line to said wipers, and battery connections tor talking purposes engaged by said wipers when in normal position but disengaged therefrom when said wipers have been moved.

20. In a telephone exchange having line switches and selectors, the combination with a pneumatic motor and a starting magnet on each line switch and on each selector, and trunk connections between line switches and selectors, of means by which upon closing a circuit for the starting magnet on aline switch the associated pneumatic motor and the starting magnet on the selector with its associated pneumatic motor will all be automatically operated.

21. In an automatic trunk selecting system having primary and secondary mecha nisms, a starting magnet and a pneumatic device on each primary mechanism, a pneumatic device on each secondary mechanism, and intern'iediate connections so arranged that upon a circuit being closed through the starting magnet ol the primary mechanism power will be automatically applied to the pneumatic device on the primary mechanism and then zuitomatically applied to the pneumatic device on the secondary mechanism.

22. In a telephone exchange having line switches and selectors, the combination with a pneumatic motor and a starting magnet on each line switch and on each selector, and trunk connections between line switches and selectors, of means by which upon closing a circuit for the starting magnet on a line switch the associated pneumatic motor and the starting magnet on the selector with its associated pneumatic motor will all be antomatically operated, of means for breaking the circuit of the starting magnet ot' the line switch when the line switch seizes said so lector, and of means for holding said line switch in operated position after the circuit of the starting magnet of the line switch has been broken.

In a switching mechanism. the cont bination with a carriage, motors for moving said carriage in dilferent. directions. means for operating said motors, ot escapements for restraining said motors from operation, a magnet, and means controlled through said magnet for operating said escapements.

FRANK A. LUNDQUIST.

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