US1801931A - Telephone system - Google Patents

Description

April 21, 1931. U D T 1,801,931

TELEPHONE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 2 Inventor 735% ELM-m5? April 21, 1931. F. A. LUNDQUIST TELEPHONE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 3 u an 01" Frank E.Lundqu1si 7 I April 21, 1931. F. A. LUNDQUIST TELEPHONE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 4 Iu usn or Frank flLum'l uzs Eff-7.

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April 21, 1931. F. A. LUNDQUIST TELEPHONE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 5 Inuan or Frank HLunclnms flm HTT April 21, 1931. F. A. LUNDQUlST TELEPHONE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 6 8 Sheets-Sheet 7 F. A. LUNDQUIST TELEPHONE SYSTEM Filed Nov 26, 1928 Apr-i121, 1931.

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tat-h W5 k April 21, 1931. F. A. LUNDQUlST TELEPHdNE SYSTEM Filed Nov. 26, 1928 8 Sheets-Sheet 8 IHI'JIE-ZL 01" Frank HLund-EFZ' imm 0253M Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE FRANK A. LUNDQUIST, F GAL-VA, ILLINOIS, ASSIGNOR TO RESERVE HOLDING COM- PEJNY, OF KANSAS CITY, MISSOURI, A CORPORATION OF DELAWARE TELEPHONE SYSTEM Application filed November 26, 1928. Serial No. 321,801.

This invention relates to telephone systems in general, but particularly to automatic telephone systems in which cheapness of construction permitting low cost of manufacture without a sacrifice of accurat eness and dependability is the principal ob]ect.

Another object is the conservation of space in a telephone exchange by providing mounting racks and switches which take up only a small fraction of the space taken up by the present day automatic telephone equipment.

In furtherance of the principal obj ect, substantially all the pieces of equipment have been made of pressed sheet steel thus insuring cheapness of manufacture of the parts by low cost of material and a small requirement of labor. The requirement of comparatively few relays for the operation controlassists 1n the attainment of the principal ob ect.

Another object of the invention is the provision of a common motor driven arrangement for the return of the switches from their operated positions to their normal positions.

The features of the invention pertaln principally to the improvements in operation over systems now generally in use.

One feature is the movement of the wlpers in one plane, a horizontal plane, under the control of a single operating magnet.

Another feature is the arrangement whereby only two relays, those providing talking battery in a system employing first selectors, second selectors, and connectors, are causing a drain upon the battery during the talking period.

Another feature is the escapement sprlng arrangement for the movement of the wiper carriage and the auxiliary switch.

Still another feature is the operation of the auxiliary switch to control the direction of movement of the wiper carriage and to control the various operating circuits.

Other objects and features will be evident and a complete understanding of the construction and operation of the system may be had from a perusal of the description in conjunction with the accompanying drawings in which:

Fig. 1 is a front View of a section of the switch mounting rack showing three connector switches in place on the rack.

2 is a rear View of the same rack showing the bare wire multiple banks which are mounted thereon.

Fig. 3 is a view of the right side of the mounting rack showing the relays mounted tl ereon and the switch restoring mechanism.

Fig. 4 is a top view of one of the selector switches removed from the rack.

Fig. 5 is a top View of one of the connector switches shown mounted in the rack, the rack being shown in cross section.

F ig. 6 is a view of the switch carriage moving mechanism, taken along the line 66 of Fig. 5, looking from the left.

Fig. 7 is a top view of the side switch operating mechanism of one of the connector switches. a

Fig. 8 is a perspective view of the connector switch showing only the details of the wiper carriage and the carriage operating mechanism.

Figs. 9 and 10 show a diagrammatic circuit representation of a system employing the switches of my invention.

The construction of the mounting rack will now be explained, reference being had particularly to Figs. 1, 2 and 8. The rack comprises four uprights, two of which are small angle irons 1 and two of which are small steel bars 2. The angles 1 are used as the rear uprights while the bars 2 are used as the front uprights, the narrow edges of the bars being towards the front.

The angles and the bars are oined together by smaller angles 3, that is, one angle and one bar on each side are joined by the smaller angles. The angles 3 are placed one above each other at specified intervals and are secured to the uprights by means of screws. The open sides of the angles face upwards and towards each other.

Cross pieces, or bars, 4 are used to connect the two sections of the frame together across the front and those pieces are spaced equally with the smaller angles 3. They are fastened to the horizontal flanges of the anQles by means of screws.

The brackets 5 are used in the rear to connect the two angles 1 together. These brackets are also employed for mounting the bare wire multiple banks 6, of which there are ten.

hen the frame is so constructed it has a rectangular horizontal cross section. Ten sets of smaller angles 3 are used as are ten pieces 4 and ten brackets 5. These, when placed at equal intervals provide ten spaces for switches. Two opposite angles 3 act as a trough in which the switch will slide and remain held when inserted. The front uprights are made of bars so as to leave the front of the rack open for the insertion of the switches.

The bare wire multiple banks are similar in construction to that shown and described in Patent No. 1,369,680, issued to me on February 22, 1921.

The circuit controlling relays and operating magnets for the switches are mounted on the outside of the rack in the most convenient location and in any suitable manner.

On the right side of the rack at the front is mounted the switch restoring apparatus. This apparatus consists of the vertical shaft 7. This shaft at the ends is held in place by two journal bearings in which the shaft rotates. I These bearings are mounted in brackets which are securely fastened to the rack. A collar securely fastened to the shaft above the upper bracket prevents the shaft from falling downward. These brackets, bearings and collar have not been shown in the drawing forit is thought that the arrangement is well known. Mounted on the shaft opposite each space in the rack for a switch is a ratchet gear 8 which is rigidly secured to the shaft by set screws. The bushing 9, which is rotatable on the shaft, rests upon the upper surface of the gear 8. Bigidly secured to the bushing 9 is the pawl carrying member 10 carrying the pawl 11 which is so positioned or shaped that it will engage the teeth of gear 8. The disc 12 is also rigidly fastened on the bushing 9 above the member 10. This disc on its upper side carries the screw and roller 15 and on the under side, the screw and roller 13. The disc 12 and rollers are more readily seen in Fig. 5. A. bracket 16 fastened to the rack supports the relay 18 having an armature 19, and acts as a support for the member 14 which is pivotally mounted at 17. A spiral spring about the pivot 17 holds the member 14 against the shaft 7 in its normal position. The member 14 is of the general shape shown in Fig. 5. The armature of relay 18 when in its detracted or normal position holds the pawl 11 out of engagement with teeth of ratchet gear 8 and when attracted allows the pawl to engage the teeth. The operation of this apparatus will be explained in detail as the description progresses.

A bracket 20, mounted on the rack, carries the ack spring assemblies 21 and 22. These assemblies cooperate with ack assemblies on the switch when the switch is in place in the rack to complete circuit connections.

The selector and connector switches are similar in construction, differing only in the auxiliary switch arrangement and the oilnormal spring arrangement. It is thought, therefore, that a description of a connector switch and a description of the auxiliary switch of a selector will suflice for a complete understanding of the two switches. As an aid to an understanding of a selector switch from the description of a connector switch, the equivalent parts of the selector switch in Fig. 4 have been given primed characters of reference corresponding to those of the connector switch. Accordingly, the description of a connector will be given in detail, reference being had to Figs. 5, 6 and 8.

The base of the connector is made of a flat, rectangular piece of sheet steel, 23, of such a size as to fit into the rack in the angles 3. Upon this plate 23 is mounted all of the operating mechanism of the connector, including the auxiliary switch.

The wiper carriage is mounted towards the rear part of the switch on the brackets 24 and 25 which are placed directly opposite each other on the base 23 as shown. These brackets are substantially T-shaped, bracket 24 having the cross bar 26 and bracket 25 having the cross bar 27. The ends of bars 26 and 27 are bent inwards at 90 degree angles to the bars. The bent ends, or ears, are provided with hushed holes in which the rods 28 and 29 of the wiper carriage are slidably fitted. Rod 28 fits and slides in the ears of bar 26, while rod 29 fits and slides in the ears of bar 27. Cross connecting rods 30 and 31 are fastened to rods 28 and 29 to form a complete unit.

Connecting the two cross rods 30 and 31 is the member 33 which is also substantially T-shaped. This member is also provided with ears having bushed holes therein which receive the rod 30. The opposite end of member 33 has the tail piece 35, which is provided with a hushed hole for receiving rod 31. This arrangement allows member 33 to slide across the switch on rods 30 and 31. To member 33 are fastened the private wipers 54 and the line wipers 55 in any convenient manner so that those wipers are insulated from member 33.

Rotatably mounted in the brackets 24 and 25 is the rod 32 which is provided at its ends with segmental gears 51, only the gear 51 adjacent bracket 24 being visible in the drawings. These gears cooperate with teeth on the under sides of rods 28 and 29 to translate the rotary motion of rod 32 to straight line motion for the wiper carriage to move the wipers into engagmeent with the bank contacts as will be evident from the complete description.

ment with teeth 42.

A U-shaped member 34 is slidably mounted onrod 32. This is accomplished by pro vi'ding a bashed hole in the base of the and by turning downward the end of the upper side of the member and providing a bushed hole in the turned down portion. T prevent rotary motion of member abou rod 32, the lower side of the member is provided with a projecting piece which its in the slot 38 in plate 23. The projecting piece is not Visible in the drawings.

Fastened to the lower side of member 34 is a pin which carries roller 36. The open portion of forked member 39 fits about roller 36. Fastened to the upper arm is the guide piece 37 which is also substantially U-shaped and whose sides are spaced wide enough apart so that member 33 will fit between them.

The fork-shaped lever 39 is pivoted at 63, (Fig. 5), and moves in a clockwise direction about that pivot when released under the influence of a clock-spring about its axis. Movement of the lever 39 in a clockwise direction moves the member 34 to the right. This movement of 34, because of member 37, will move the member 33 to the ight also, member 33 sliding upon rods 30 and 31. Member 37 also acts as a guide for member 33 when the carriage, comprising the rods 23, 29, 30 and 31, is moved forward due to the rotation of rod 32.

Fastened to the end of rod 29 is the long member 52 which is provided with the slot 53. A pin 54 fastened to bracket 25 acts as a guide for member 52 by fitting in the slot 53. Member 52 will move with the wiper carriage.

Lyingflat uponthe base plate 23 is tie member 40 which is substantially T-shape-c The screw 41 serves as a guide pin, movement being allowed to member 40 because of the slot. The base of member 40 is tapered to a smaller size so as to fit in the guide member 64 which is fastened to the base plate 23. The cross section of the member 40 is provided with steps as shown in Fig. 8. These steps limit the movement of member 34 on rod 32. hen the carriage is in normal position, position shown in Fig. 5, a projection piece on the under side of the lower side of member 34 cooperates with the steps to control the movement of 34 as will be subsequently eX- 'plained.

The member 40 is provided with teeth 42 on its one side The lever 44 which is centrally pivoted at 46 carries a pawl 43 which is pivotally mounted at 45. The spring about the pivot screw holds the pawl 43 in enga se- The lever 49 is ri angular shaped and pivoted at base of the angle. This lever is employed to move operating pawl 43 and holding pawl 48 out of engagement with the teeth 42. TVhen the pawis are so out of engagement, the member 40 will move towards the back of plate 23 because of the ratchet gear 57.

the spring 50 which is made of clock-spring steel.

Referring for the moment to Fig. 6, the means for rotating rod 32 will now be 6X- plained. At the end of rod 32, is fastened Approximately only two-thirds of periphery of the gear 57 is provided with teeth. That arrangement is such because it provides a definite starting place for the movement and because it is not necessary to have teeth all the way around the gear as it does not make a full revolution. A clock spring about the rod 32 rotates it in a counter-clockwise direction. A double dog 58 cooperating with ratchet gear 57 provides an escapement arrangement so that the rod 32 will be rotated step-by-step. A spring about the pivot pin 59 holds the pawl in the ratchet teeth to prevent rotation of the rod 32 when the switch is at rest. The dog 58 is provided with pin 61 to which is connected the piece 60. The function of the piece 60 will be explained subsequently.

The construction of the auxiliary switch will now be explained. Mounted on the same axis as lever 39, is the member which projects on both sides of the axis 63, having the bent over portion 91. Member 7 O is also provided with the arm 71 to which the wiper assembly 72 is insulatedly fastened. Assembly T2 may consist of any number of wipers. Rigidly fastened to the arm 71 is the dog 73 which is adapted to engage the notch in the armature 74 of relay 75 when that armature is in its attracted position. Connecting rod 76 connects member 70 to toothed member 77, 76 being fastened at 78 and 78. Member 7'? slides up a rod in the same manner as does member 34, the rod being invisible in the drawing as it lies directly beneath member 77. It will be noted that the teeth 85 on one side of member 77 have slanting sides and are fewer in number than the teeth 86 on the opposite side which have one edge which is perpendicular to the edge of member 77. Pivotally mounted at 82 on the small frame 88 which carries the rod up which member 7'? slides is a U-shaped member 79. This member lies upon the member 77 and has the end of its side arm 89 bent downward. Pivoted on member 79 at 81 is the member which is held against the side of member 7 9 to form an arm corresponding to arm 89. Piece 80 is held by the spring about its pivot at 81. The end of member 80 is bent downwards in a way similar to that of arm 89, to form a holding pawl which engages the flat side of the teeth 86. A clock spring about the axis of member 70 at 63 rotates member 70 in a clockwise direction unless movement is hindered by pawl 80 which, by holding memher 7 9, prevents member 70 from rotatin Thus the member 7 9 carrying the two pawls 89 and 80 acts as a double dog and the movement of member 7 0 might be termed an escapement arran ement since the clock spring is always under tension. When, through the action of armature 83, member 79 is rotated in a clockwise direction (Fig. 7) about its pivot 82, pawl 80 will disengage tooth 86 and member 7 7 will move slightly to the right until tooth 85 engages pawl 89. Then on the reverse action of armature 83, pawl 89 will disengage tooth 85 and member 77 will move a greater distance to the right until pawl 80 engages the next tooth 86. In this manner, the movement of the wiper assembly 72 is controlled and the wipers are positioned upon the sets of bank contacts of bank 90 through the action of members 77 and 7 9.

The bank assembly 90 is comprised of a row of contacts for each wiper of the wiper assembly 72. Each row of contacts comprises sets of individual contacts of two in a set. The contacts of each set are separated by insulating material. Circuits are completed from one contact through the wiper,

Y which wipes both contacts simultaneously,

to the other contact. No wires are directly connected to the wipers, they merely act as circuit closing devices.

Mounted also upon the same axis as lever 39 and member 70 is the restoring lever 65, which has one of its ends formed in the shape of a cam, 66, so that when lever 65 is rotated about axis 63 in a counter-clockwise direction, the member 49, one end of which rides upon the periphery of the cam, will be rotated in a counter-clockwise direction to remove the pawls 13 and as out of engagement with the teeth 42, to allow spring to return member 40 to its normal position, that position in which member 40 is shown in Fig. 5. The long arm of lever 65, that diametrically opposite cam 66, engages the bent over portion 91 of member 70 and the bent over portion 67 of lever 39 in its counterclockwise motion, to rotate the members 7 O and 39 in a counter-clockwise direction also about axis 63 to restore them to their normal positions.

The lever 68, which at its one end is rotatably connected to lever at 69, has its other end formed into a hook which is adapted to engage the roller 13 which is on the under side of disc 12. About the axis 69 of lever 68 is a spring which tends to rotate lever 68 in a counter-clockwise direction so as to hold the opposite end of the lever against the upright 2. A small bracket 92 secured to the upright 2 holds the free end, or hook end, of lever 68 up so that the hook will always be in position to catch the roller 13.

' Thus it can be seen, that when the disc 12 rotates in a counter-clockwise direction, the roller 13 will engage the hook of lever 68 and pull the lever to the right thus rotating the arm 65 in a counter-clockwise direction to perform the restoring operations. Still further rotation of disc 12 will move roller 13 out of engagement with the hook. This will allow the spring about the axis of lever 65 to rotate it in a clockwise direction until it engages the stop 93. This rotation will move lever 68 to the left.

The wiper cords are encased in a spiral spring tube 94. so as to prevent the cords from becoming entangled in the apparatus and to keep them from being bent, thus prolonging the life of the cords. A fiat, wide strip of fibre is placed across the switch and fastened to the brackets 24 and 25. This strip provides a support for the tube 94 and a smooth surface upon which it can slide as the wiper carriage is moved.

As previously stated, the circuit controlling relays and operating magnets, with the exception of relay 7 5, are mounted upon the mounting rack. Those consist of the line relay 95, operating magnet 96, slow relay 97, slow relay 98, and release magnet 18.

Referring to relay 96 in detail it will be seen that this relay has an armature 99 which is pivoted at 100 and which has the pawl 101 pivotly connected to its free end. A spring about the pivot of pawl 101 holds its opposite end against the stop 102 which is connected to the toothed member 77. The pawl 101 has a projecting piece 103 which is bent downward. lVhen the switch is in normal position, the member 77 will be in the position shown in Fig. 5 and the stop 102 will be in such a position as to hold the piece 103 of pawl 101 in operative relation with the left end of member 44.- so that when armature 99 is attracted, pawl 101 will rotate member 44 through a small angle in a clockwise direction about its axis 16, thereby causing the member 40 to be moved a corresponding amount in a straight line motion through the action of pawl 43 and teeth 42.

hen member 77 is moved a step to the right, the stop 102 is also moved to the right. This movement places the projecting piece 103 in operative relation with the piece 60 of dog 58. An attraction and following detractionof armature 99 will rock the pawl 58 on its axis 59. This action of pawl 58 allows the movement of ratchet 57 through a certain angle and thus the movement of the wiper carriage a certain amount.

It will be noted that the relay 98 has an armature 104 which has an extension 83 connecting the armature with member 79. It can be seen, therefore, that each attraction of armature 104 will rotate member 79 in a clockwise direction about its pivot 82 and that each retraction of the armature will allow the member 79 to rotate in the reverse direction under the influence of the spring about the pivot 82. This movement of member 79, as explained, controls the movement of member 77. It will be noted and remembered that the teeth on member 77 are so placed and of such a number as to allow the first two number of attractions.

movements upon the retraction of armature 104 and the two subsequent movements upon the attraction of armature 104. As member 77 controls the movement of the wipers of the wiper assembly 72, it can be said that the wipers are advanced the first two times upon the retraction of armature 104 and the next two times upon the attraction of armature 104.

A detailed description of a connector switch having now been given, a general description of the mechanical operation of the switch will now be given.

In positioning the line and private wipers of the connector upon the bank contacts of any desired line, the wipers must first be moved from their position of rest to the right to place them opposite the row in which the contacts are located in the bank, it being remembered that there are one hundred sets of contacts accessible to the wipers, arranged in ten rows of ten contact sets. This movement is necessary except when a contact set in the first row is desired because the wipers are normally opposite the first row. The next movement of the wipers is into the bank.

lVhen the connector switch is seized as the last switch in the switch train, there remain only two more digits to be transmitted to complete the connection to the desired line. Line relay 95 and magnet 96 will follow the impulses of each digit as transmitted by the calling subscriber, that is, relay 96 will energize with each impulse and deenergize with the termination of each impulse. Relays 97' and 98 because of the copper slugs on their cores will energize with the first impulse of a series and remain energized until the completion of the series.

Accordingly, when the first digit is transmitted to the connector, the relay 96 in following the impulses will attract and detract its armature 99 a corresponding number of times. Each attraction of armature 99 causes the pawl 101 to rotate member 44 to move member step by step according to the The first step of member 40 will place the projecting piece on member 34 in such a position that the second step of member 40 will release it and the member 34 will be moved to the right until that projecting piece engages the edge of the second elevation. Thereafter each step of the member 40 will allow the member 34 to be moved to the right a distance corre sponding to the width of each elevation or the distance between each row of bank contacts. It has been necessasry that member 40 be stepped twice before member 34 is moved to the right for the reason that the wipers are standing opposite the first row of contacts in their normal position and if only an impulse comprises the first digit, it is not desired to move the wipers out of line with the first row of contacts.

Relay 98 also energizes upon the first im= pulse and attracts its armature 104 and holds it attracted throughout the first impulse series, or during the time the wipers are being moved across the switch. At the termination of the series, relay 98 detracts its armature and allows member 77 with stop 102 to move to the right to advance the wipers of the auxiliary switch to the next set of contacts. The movement of stop 102 shifts the pawl 101 so that upon the next series of impulses, the pawl will operate the dog 58 to rotate the shaft 32 to advance the wipers into engagement with a set of contacts in the row opposite which the wipers were standing.

The subsequent retraction of armature 104 at the termination of the second impulse series moves the member 77 and the stop 102 to the right again, thus advancing the wipers of the auxiliary switch and allowing the pawl 102 to move out of engagement with member 60 of dog 58 so that any further operation of the calling device at the sending station clannot move the wipers 54 and 55 any furt 1er.

Further operation of relay 98 to move the wipers of the auxiliary switch depends upon the condition of the called line and this op eration will be brought out in the description of a telephone system employing switches of the type which has just been described.

The return of the switch to normal after the parties are through conversing will now be described.

Shaft 7 being motor driven, is continuous- 1y rotating at a desired rate of speed. As the ratchet gear 8 is rigidly fastened to the shaft 7, it will be revolving continuously.

When the calling party hangs up, certain circuits are completed to bring about themomentary operation of relay 18 which upon operating allows the pawl 11 to engage the teeth of ratchet 8. This pawl and ratchet engagement causes the disc 12 to be rotated with the shaft 7 As disc 12 rotates, roller 15 will engage the end of arm 14 and rotate arm 14 about its axis 17 in a counter-clockwise direction. That rotation of 14 causes its notched end to enter the slot 53 of mem ber 52 and engage the member to pull the wiper carriage away from the bank, the re turn of the carriage rotating the rod 32 in the reverse direction from which it was first rotated, to wind up the spring attached to it. When the carriage has been moved back as far as it will go, the roller 15 will have moved far enough to disengage the arm 14 and that arm will return to normal. lVhen this disengagement occurs, roller 13 will just be engaging the hooked end of lever 68 to complete the restoration of the switch apparatus to normal as has been explained. When the restoration is complete, the pawl 11 will have rotated far enoiwh to again encounter the armature 19 of reliiy 18, whereby the pawl 11 will be moved out of engagement with the ratchet and the rotation of disc 12 will be stopped.

Theselector switches are the same in construction as the connector switch just described with the exception of a few minor details. The selector switch doesnot have the relay and the auxiliary switch is different in that it does not have as many positions for the wipers. The movement of the wipers is regulated through the piece similar to member 77 of the connector, which has fewer teeth than the member 77. The wipers of the auxiliary switch advance on only the retraction of the armature similar to armature 104 It will be remembered that, in a system employing switches of the type described, all the connector switches will be grouped together on racks and all the selector switches will be group together on other racks. Al though the racks are identical and will carry either kind of switch, it is not desirable to have more than one type of switch on a rack because of the bank arrangement.

With reference particularly to Figs. 9 and 10, a detailed description will be given of the operation of a telephone system employing first selectors, second selectors and connector switches of the type herein disclosed.

It will be assumed that the system is a 10,000-line system, that is a system employing first and second selectors and connectors and in which the telephone numbers comprise four digits.

In Fig. 9, there is diagrammatically represented a calling subscribers station A, a line switch LS, a first selector E, and a second selector E. The substation A has the usual talking, signalling and impulse transmitting instrumentalities usually found in a substation in an automatic telephone system. The substation is connected to the central exchange by the line conductors 111 and 112 which terminate in a rotary line switch individual to that line. The line switch is of the type whose wipers move in one direction only and have no normal position. Line switchesof that type are well known and need not be further described. Conductors 162, 163 and 164 connect the substation A to the connector switches, being multipled to the banks thereof.

Fig. 10 is a diagrammatic circuit represen tationv of the connector switch and of the called subscribers substation A which is similar to the substation A.

It will be assumed that the subscriber at substation A desires to converse with the subscriber at substation A. Accordingly, the subscriber at substation A will remove the receiver from the hook, thereby completing the loop circuit over conductors 111 and 112 to the line switch LS which rotates-its wipers 116, 117 and 118 in the well known manner to a trunk leading to an idle first selecselected digit.

tor switch. It will be assumed that the selector E is the first idle selector encountered by the line switch, therefore when wipers 116, 117, and 118 engage the contacts 113, 114 and 115, the line switch LS stops rotating its wipers and connects the conductors 111 and 112 to wipers 116 and 118, respectively. This connection completes the circuit of the line relay 95 of the selector E, which circuit is traceable from ground, lower winding of relay 95, upper bank contact 127, auxiliary switch wiper 109, lower contact 128, bank contact 115, wiper 118, thence through the loop circuit to wiper 116, contact 113, lower contact 120, auxiliary switch wiper 106, upper contact 119, upper winding of relay 95 to grounded battery. Relay 95 energizes in that circuit and moves its armature into engagement with its alternate contact, thereby completing the energizing circuit of slow-to-release relay 97.

Relay 97 accordingly energizes and moves its armatures to connect the release trunk con ductor 130 to ground on the upper one of the armatures and to prepare a series circuit for magnet 96 and relay 98 through the lower one of its armatures.

The subscriber at A will now operate the calling device S in accordance with the first digit of the called subscribers number. This operation will interrupt the circuit of relay 95 a number of times corresponding to the Relay 95 will deenergize with each interruption and move its armature into engagement with its back contact thereby opening the circuit of slow-to-release relay 97 and closing the circuit including magnet- 96 and relay 98. Relay 97 being slow acting will hold up during the series of impulses. Magnet 96 will energize a number of times corresponding to the number of deenergizations'of the line relay 95. Relay 98 energizes with the first impulse and remains encrgized throughout the series.

With each energization of magnet 96, the wiper carriage carrying wipers 133, 134. and 135 is stepped sideways to position it in front of a row of bank contacts to which are connected a group of trunks terminating in second selectors.

At the completion of the transmission of the first digit, relay 95 will remain energized. Relay 98 will deenergize after an interval and in so doing will. move the member 77 one step, as has been explained, to move the wipers 106 to 109, inclusive, of the auxiliary switch to shift the pawl 101 (Fig. 5) into operative relation with double dog 58 (Fig. 5). After wipers 106, 107 and 109 have been moveda step they maintain the same cirtacts 125 and 126 to complete the following circuit: ground, winding of relay 98, winding of magnet 96, upper contact 125, wiper 108, lower contact 126, off-normal springs operated by rod 28, armature and make contact of relay to battery and ground. Relay 98 will .nergize and magnet 96 will energize to rotate the rod 32 (Fig. 8) to move the wipers 133, 13 1 and 135 into engagement with the first set of contacts in the row. The movement of the wiper carriage which includes rod 28, opens the off-normal springs controlled by rod 28, thereby opening the circuit of relay 98 and magnet 96. The relay 98 will remain energized for an instant but magnet 96 will deenergize. Further movement of wipers 133, 13 1 and 135 depends upon whether or not the trunk associated with the first set of contacts is busy.

If the trunk is busy wiper 13 1 will encounter a grounded private contact. A circuit will, therefore, be completed for relay 136 from grounded wiper 13 1, off-normal springs 137, winding of relay 136, lower contact 123, wiper 107, upper contact 122 to grounded battery. Before relay 93 has had time to deenergize, relay 136 will complete another circuit for relay 98 in series with magnet 96 by moving its armature into engagement with its make contacts, connecting lower contact 126 to grounded battery. Magnet 96 will, therefore, energize again to set the wipers 133, 13 1 and 135 onto the next set of contacts. The stepping of those wipers opens the circuit of relay 136 which in turn opens the .Zrcuit of magnet 96 and relay 98. If wiper 134: again encounters a grounded contact, relay 136 will again ener 'ize to once more complete the circuit of magnet 96. The same cycle of operations will continue until the wipers 133, 131 and 135 encounter the contacts of an idle trunk, which in this case it will be assumed, is the trunk connected to bank contacts 150,151 and 152.

When no ground is found by wiper 131 on contact 151, no circuit will. be completed for relay 136. Theref no circuit will be completed or magnet 96 and relay 98. After an interval relay 98" will deenergize and again move the member 7 7 to move the wipers 106 to 109, inclusive, to the next position. Wipers 106 and 109 in moving out of engagement with upper contacts 119 and 127, open the previously traced circuit for relay 95' which relay deenergizes and opens the circuit of relay 97 Relay 97 deenergizes after an interval and moves its armatures out of engagement with their make contacts to preare a circuit at the lower armature for reease magnet 18 through the off-normal spring 132, which spring and off-normal spring 131 were moved into engagement with their make contacts when member 77 was moved on the first deenergization of relay 98. Ground is maintained on release trunk conductor 130 through off-normal spring 131 to maintain energized the cut-off relay of the line switch LS.

Wipers 106 and 109 engage the upper con tacts 121 and 129, respectively, to connect them in circuit with lower contacts 120 and 128, respectively, thereby transferring the subscribers loop circuit to the windings of relay 95 of the second selector E. l Viper 107 by engaging contact 12 1 connects g to the winding of relay 136 for a purpose which will be described later. l' iper 108 is advanced to a free contact and in so doing allows othnormal spring 110 to engage its alternate contact, thereby opening one circuit for release magnet 18 and preparing another circuit therefor.

The subscriber at A will now operate the calling device S in accordance with the second digit of the called subscribers number. The second selector E will operate in exactly the same manner as the selector E to position the wipers opposite a group of trunks leading to a group of connectors having access to station A and to then position the wipers on the contacts of an idle one of said trunks. In this case it will be assumed that the idle trunk encountered is that attached to contacts 200, 201 and 202. The auxiliary switch wipers 153 to 156, inclusive, will have been moved to their last position and the line relay 95 of the connector H will have had its windings connected to the loop circuit through selectors E and E. Relay 95 energizes when so connected and operates its armature to complete the circuit of relay 97. Relay 97 energizes and operates its armature to prepare a series circuit for magnet 96 and relay 98.

The subscriber now operates the calling device S in accordance with the third digit of the called number to interrupt the circuit of relay 95 a number of times. Upon each interruption of its circuit, relay 95 deenergizes and completes the circuit for magnet 96 and relay 98 from grounded battery armature and resting contact of relay 95, armature and front contact of relay 97, magnet 96, relay 98 to ground. Relay 97 remains energized throughout the series of impulses to maintain the circuit of magnet 96. Magnet 96 operates with each impulse to move the wiper carriage to place the wipers opposite the row of bank contacts in which those of the called line appear. Relay 9S energizes on the first impulse and remains energized throughout the series.

An interval after the termination of the impulse series, relay 98 deenergizes and moves the member 77 one step, thereby allowing the wipers 201 to 209, inclusive, of the auxiliary switch to be advanced to the No. 1 position. Member 77 in moving allows spring 232 to engage its contact to prepare a circuit for release magnet 18. No circuits s round are effected when the auxiliary switch wipers are moved to position No. 1.

The subscriber now operates the calling device S in accordance with the last digit of the called number. Relays 95 and 98 and magnet 96 respond as before. This time, however, the operation of magnet 96 moves the wipers 218, 219 and 220 into the bank to engage contacts 221, 222 and 228, respectively.

If the called subscribers line is busy, ground will be present on conductor 228 and therefore on bank contact 222, having been connected thereto by the cut-oil relay of the line switch associated with the called subscribrrs line. Accordingly, when wiper 219 encounters ground upon contact 222 the following circuitwill be completed: grounded contact 222, wiper 219, conductor 225, spring 210 and its resting contact, conductor 288, winding of relay to battery. Relay 75 energizes in the circuit and exerts a pull upon its armature 74;. Armature 74 cannot move to its attracted position until the dog 78 enters into the notch in the armature.

hen relay 98 deenergizes an interval after the completion of the impulse series, and after relay 75 has energized, the member 77 is again moved to move the wipers. Non mally this movement is enough to move the wipers 204 to 209, inclusive, from position 1 to position 8. However, since relay 75 is exerting a pull upon armature 74, the dog 78 will enter the first notch of armature 7 1 and stop the wipers in position 2. This operation connects a busy tone to the calling subscribers line to inform the subscriber that the desired line is busy. The busy tone source is connected to the calling subscribers line by way of conductor 280, position 2 contact of wiper 208, wiper 208, conductor 285, wiper 208, position 2 contact of wiper 208, conductor 216, and thence through the condenser to the substation A.

The calling subscriber hearing the busy tone will hang up the receiver and thereby open the loop circuit. Relay 95 accordingly deenergizes and opens the circuit of re y 97 which also deenergizes. The deenergization of these two relays completes the circuit for release magnet 18 and also for release hack relay 157 of the selector E. This circuit may be traced as follows: ground, battery, armature and back contact of relay 95, armature and resting contact of relay 97 to conductor 281 where ti circuit divides, part going by way of spring 282 and its contact to release magnet 18 and ground and the other going by way of contact 20', wiper 159 of selector E, spring 161 and its contact, winding of relay 157, lower last posltion contact of wiper 15 1, wiper 15 1-, upper contact to ground. Magnet 18 and rela Y 157 ener ize in that multiple cir- I I b o L curt. Relay 157 in so doing operates its armature to complete the circuit through spring 162 and its alternate contact for release magnet 18 of the selector E. Magnet 18 enei gizes to operate its armature to complete the circuit for release back relay 186 of: selector E from grounded battery, alternate contact of re and armature of release magnet 18, contact 151, wiper 181 of selector E, spring 187 and its contact, winding of relay 80, low r contact 128, wiper 107, upper contact 12 1 to ground. Relay 186 energizes in that circuit and operates its armature to complete the circuit through spring 110 and its alternate contact for release magnet 18 oi the selector E. Release magnet 18 therefore energizes.

Release magnets 18, 18 and 18 energize in the order in which their circuits are completed and each magnet operates its armature to allow the associated pawl 11 to engage the associated ratchet 8 to return the switches to normal under the power furnished by rotating shaft 7, as has been explained. The return to normal of the switches disconnects ground from the relase trunk 180 to allow the line switch LS to release also. When the members 11 associated with the selectors are ioved from their normal positions,theyallow springs 187 of selector and 161 of selector E to disengage their contacts, those springs being held against their contacts under tension. The circuits of relays 186 and 157 will therefore be opened and the relays deenergize to open the circuits of release magnets 18 and 18". The circuit of release magnet 18 is opened and the busy tone is disconnected when the member 77 and the auxiliary switch wipers 201- to 209, inclusive, are returned to normal.

t will be assumed, however, that when wipers 218, 219 and 220 come to rest upon contacts 221, 222 and 228 that the called subscribers line is idle. Therefore, wiper 219 finds no ground on contact 222 and no circuit is completed for relay 75. Accordingly, when relay 98 deenergizes, the wipers 20 1 to 209, in elusive, will be moved to position 8.

l Viper 205, in moving into position 3, enspring 210 and moves it out of engeinent with its resting contact and into engagementwith its grounded make contact.

is movementconnects ground to conductor 22) and thence to conductor 228 to operate the cut-off relay of the line switch associated with the station A for disconnecting all. attacnments from the line and to place ground upon the private contacts in the banks of other connector switches having access to the station A.

lVith the wipers in position 8, ringing current is applied to the substation A to ring the bells thereat over the following circuit: ringing current generator, conductor 212, position 8 contact of wiper 206, wiper 206, conductor 28 1, wiper 20 1, position 8 contact of wiper 20 1, position 1 contact of wiper 204 by way of wire connecting position 3 contactwith position 4 contact, conductor 224, wiper 218, contact 221, conductor 227, condenser and call bells at station A, conductor 229, contact 223, wiper 220, conductor 226, position 4 contact and position 3 contact of wiper 209, which contacts are wired together, wiper 209, conductor 235, wiper 208, position 3 contact of wiper 208, position 4 contact which is wired to position 3 contact, conductor 214, lower winding of cut-cit relay 203 to ground. Ring cut-ofl relay 203 is so constructed that it will not operate on alter nating current. .The bells at station A will ring to inform the subscriber thereat that a call is'incoming to the station.

When the receiver is removed from the hook switch. by the called subscriber, the transmitter and receiver are included in series in the circuit in place of the condenser and the call bells. This will complete a circuit for the ring cut-ofi relay from grounded battery at the generator. The ring cut-oil relay 203 will therefore energize and move the upper of its two armatures into engagement with its make contact. The upper armature will connect battery to the winding of relay 98. Relay'98 will energize to move the member 77 and the wipers 204 to 209, inclusive, from position 3 to position 4.

With wipers 204 to 209, inclusive, in position 4, the stations A and A are connected in a talking circuit, talking battery to station A being supplied through the windings ofthe line relay Lwhile talking battery to station A is furnished through the windings of the cut-oil relay 203 over the following circuit ground, lower winding of relay 203, conductor 214, position 4 contact of wiper 207, wiper 207, conductor 235, wiper 209, position 4 contact of wi er 209, conductor 226, wiper 220, called su scribers p circuit,wiper 218 conductor 224, position 4 contact of wiper 204, wiper 204, conductor 234, wiper 206, position 4 contact of wiper 206, conductor 213, upper winding of relay 203 'to battery and ground.

When the upper winding of relay 203 is included in the circuit, the lower of the two armatures will be operated. This operation completes the circuit for relay 75 and relay 75 energizes and attracts its armature 74. -With the attraction of armature 74, the spring controlled thereby will be allowed to disengage its make contact. This disengagement opens the circuit of relay 98 and that relay deenergizes.

" The talking circuit includes the condenser, conductor 217', position 4 contact of wiper 205, conductor 234 and thence through wiper 204- and the above trained circuit through wiper 209 to conductor 235, then through wiper 208, position 4 contact of wiper 208, conductor 216, the condenser and thence over the calling subscribers loop circuit. The

equipment will remain in this position throughout the conversation.

When the parties are through talking, they will hang up their receivers. If the subscriber at substation A hangs up first, the relay 203 will deenergize with no other effect than the opening of the circuit of relay 75 which will deenergize and retract its armature 7 4. Then, when the calling subscriber hangs up his receiver, the circuit for relay 95 will be opened and that relay deenergizes and opens the circuit of relay 97. Before relay 9? has had time to deenergize, it being slow to release, an impulse is transmitted to magnet 96 and relay 98. Magnet 96 and relay 98 energize without any effect at this time. Relay 97 deenergizes after an interval, opening the circuit of the relay 98 and closing the circuit for release magnet 18. From this stage on, the release operations are as have been described.

If the calling party is the first to hang up, relay 95 will deenergize first. An interval after the deenergization of relay 95, relay 97 deenergizes to complete the circuit of release magnet 18 and the release back relay 157 of the second selector. The switches will then be returned to normal as in the previous case. When the wipers 204 to 209, inclusive, are removed from position 4 to their normal position, the circuit of relay 203 is opened and that relay deenergizes.

Although I have chosen the foregoing example as an illustration of my invention, I do not intend to be limited to the exact dis- 1 closure as there are adaptations and modifications which can be made by those skilled in the art without departing from the scope or spirit of the invention.

And having so described my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What is claimed is:

1. In a telephone system, a switch mounting rack, a switch mounted therein, said switch having wipers normally in one position, means for operating said switch to move said wipers in one direction from their normal position, means cooperating with said first means for thereafter moving said wipers in another direction, a constantly rotating shaft on said rack, and means operated by said shaft for moving said wipers in the two opposite directions to return them to their normal position.

2. In a telephone system, a switch mounting rack, a switch mounted therein, said switch having a carriage with wipers there- 12 on and an auxiliary switch, both having normal positions, means on said rack for operating said switch to move said carriage and said auxiliary switch from their normal positions, and means on said rack for returnmg said carriage and said auxiliary switch to their normal positions.

3. In a telephone system, a switch mount- ;ing rack, a switch mounted therein, said for operating said switch to move said carriage and said auxiliary switch from their normal positions, a constantly rotating shaft on said rack, a ratchet gear rigidly mounted on said shaft, and means cooperating with said shaft and gear for operating means to return said carriage and said auxiliary switch to their normal positions.

5. In a telephone system, a switch mounting rack, a switch mounted therein, said switch comprising wipers and an auxiliary switch, each having a normal position, means on said rack for moving said wipers in one direction from their normal position, means cooperating with said first means for thereafter moving said wipers in another direction, additional means for operating said auxiliary switch each time the wipers are moved, a constantly rotating shaft, and means controlled by said shaft for returning said wipers and said auxiliary switch to their normal positions.

6. In a telephone system, a switch mounting rack, a switch mounted therein, said switch comprising wipers and an auxiliary switch, each having a normal position, means on said rack for moving said wipers in one direction from their normal position, means cooperating with said first means for thereafter moving said wipers in another direction, additional means for operating said auxiliary switch'each time the wipers are moved, a constantly rotating shaft on said rack, a ratchet gear rigidly mounted on said shaft, means controlled by said ratchet and shaft for operating means to move said wipers in a direction reverse to said other direction and for thereafter operating means to move said wipers and said auxiliary switch to their normal positions simultaneously.

7. In a telephone system, an automatic switch having a wiper carriage adapted to move in straight line motion in a plurality of directions in one plane, separate escapement spring means for moving said carriage in each direction motion, a single operating magnet, subscriber controlled means for operating said magnet to operate one of said spring means to move said wiper carriage in one direction, and means for thereafter operating said magnet to operate another of said spring means to move said wiper carriage in another direction.

8. In a telephone system, an automatic switch, a wiper carriage thereon, means for moving said carriage in one direction, means for moving said carriage in another direction in the same plane, an operating magnet for controlling both of said means 111 the movin of the carriage, means for associating said magnet with said moving means one after the other, subscriber controlled means for operating said magnet to control said first moving means to move said carriage in one direction, said associating means operative responsive to said movement for associating said magnet with said second moving means, said magnet again operated to control said second moving means to move said carriage in said other direction.

9. In a telephone system a switch mounting rack, a switch mounted therein said switch having a carriage having a normal position and having wipers thereon, means for moving said carriage from its normal position in two directions to place said wipers in a certain position, a constantly rotating shaft on said rack, a ratchet gear carried by Said shaft and mtegral therewith, a disc loosely mounted on said shaft and carrying a pawl adapted to engage said ratchet but normally held out of engagement therewith, said disc rotatin with said shaft when said pawl engages said ratchet, and means operated by the rotation of said disc for returning said carriage to its normal position.

10. In a telephone system, a switch mounting rack, a switch mounted therein, said switch having a wiper carriage having a normal position, means for moving said carriage from its normal position in two directions, a constantly rotating shaft on said rack, a ratchet gear carried by said shaft and integral therewith, a disc loosely. mounted on said shaft and carrying a pawl adapted to engage said ratchet but normally maintained disengaged therefrom, said disc rotating with said shaft when said pawl is in engagement with said ratchet, a pair of pins on said disc, and means operated by said ins when said disc rotates for returning sai carriage to its normal position.

11. In a telephone system, a switch mounting rack, a switch mounted therein, said switch having a wiper carriage having a normal position, means for moving said carriage from its normal position in two directions, a constantly rotating shaft on said rack a ratchet gear carried by said shaft and mvtegral therewith, a disc loosely mounted on said shaft and carrying a pawl adapted to engage said ratchet but normally maintained FRANK A. LUNDQUIST.

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