US2218833A

US2218833A - Switching apparatus

Info

Publication number: US2218833A
Application number: US214721A
Authority: US
Inventors: Sengebusch Hans
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1938-06-20
Filing date: 1938-06-20
Publication date: 1940-10-22
Anticipated expiration: 1957-10-22

Description

Oct.- 22, 1940. H. ssNGEsuscH svn-caixa APPARATUS' Filed June 20, 1938 4 shuts-Sheet l Oct. 22, 1940.

H. sENGEBuscH 2,218,833

SWITCHING APPARATUS Filed June 20, 1938 4 Sheets-Sheet 2 28 INVENTOR HANS sE'NGEBuscH BY 49M@ dan@ ATTORNEYS Ot. 22, 1940. H. sENGEBuscl-l l '2218333 y 'S'ITCHING APPARATUS Filed June 2o. 1958 4 Smets-shut :s

HANS sENGEBuscH ATTORNEYS Oct. 22, 1940. H. sENGEBuscH swr'rcnrue APPARATUS' Filed June 20, 1938 4 Sheets-Sheet 4 umm.

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\W URN. Y Nm j kiff j@ INVENTOR.

` HANS SENGEBU SCH .iM/MVM l lll..

ATTORNEYS.

Patented Oct. 22, 1940 hUNITED STATES 2,218,833 swrromNG APPARATUS Bans Sengebusch, Villa Park, Ill.,asslgnor to l Associated Electric Laboratories, Inc., Chicago,

Ill., a corporation of Application `June 20,

41 Claims.

The present invention relates to switching apparatus and more particularly to improvements in switching apparatus of the form suitable for use in automatic telephone exchanges.

In an automatic telephone exchange, one of the major items of cost, both in the installation and in the maintenance thereof, is the multiples extending between the bank contacts of the various automatic switches. Switching apparatus comprising a plurality of automatic switching units and an associated conductor bank formed of uninsulated conductors which serve both as multiple conductors between the plurality of switching units and as wiper 4contacts for the wipers of the individual switching units has been proposed in order to reduce the item of cost mentioned above. In switching apparatus of this type, the individual automatic switching units` conventionally employed are of considerable size and of complicated construction, thereby detracting from the inherent economy of the apparatus.

Accordingly, it is an object of the present invention to provide an improved switching unit adapted to b'e used in'conjunction with a bare wire bank contact and multiple field which is compact and economical to manufacture, simple in arrangement, positive in operation, and includes a minimum number of'parts.

In general the object set forth. above is attained in accordance with the present invention by providing a switching unit which comprises a plurality of elementary switches; each of the elementary switches including a carriage movable in a first direction, an Velement carried by the carriage and movable in a second direction and a contact controlling member carried by the element; means for selecting any one of the elementary switches to be operated; means including a first operating member common to theelementary switches for moving the carriage of a selected one of the elementary switches; and means including a second operating member common to the elementary switches for moving the element of theselected elementary switch. More specifically, the rst operating member x is supported for both rotational and-longitudinal step-by-step movement and the second operating member is supported for rotational stepby-step movement.A The rotational step-by-step movement of the first operating member is effecy tive to select successively the elementary switches kto be operated, while the longitudinal -step-bystep rnovement'of the first operating member is effective to move the carriage 0i a selected one Delaware 1938, Serial No. 214,721

of the elementary switches step by step in the ber is effective to move the element of the A selected elementary switch step by step in the second-mentioned direction.

In accordance with a further feature of the y invention, an improved arrangement is provided for operating and controlling the switching unit, which comprises a mechanism selectively operable to impart to the first operating member both rotational and longitudinal step-by-step movements and to impart to the second operating member rotational step-by-step movement, means for controlling the selective operations of the mechanism and means including a lock-I ing mechanism for controlling the movements imparted to the first operating member.

The novel features believed-to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization andmethod of operation, together with further objects and advantages thereof, will best be understood by reference'to the following specifications taken in connection with accompanying drawings, in which Fig. 1 is an end elevational view of the front and rear frames of switching apparatus having embodied therein a plurality of switching units constructed and arranged in accordance with the present invention; Flg. 2 is a side elevational view of the front frame shown in Fig. 1; Fig. 3 is an enlarged side elevational view, partly in section, of a particular structural detail of the front frame, taken in the direction of the arrows 3 in Fig. 1; Fig. 4 is an enlarged sectional view of ,the particular structural detail of the front frame, taken along the'line 4-4 in Fig. 2;` Figs. 5A and 5B, taken together, are a fragmentary plan view of one of the automatic switching units of the switching apparatus; Fig. 6 is an end elevational view of the switching unit shown in Figs. 5A and 5B; Fig. 7 is a side elevational view of the switching unit; Fig. 8 is a diagrammatic illustration of the arrangement of the cam members in a lock and clutch controlA mechanism embodied in the switching unit; and Fig. 9 is an enlarged fragmentary end elevational view of the conductor bank and two of the switching units carried by the front and rear frames, shown in Fig. 1.

vReferring now more particularly to Figs. 1 and 2.0i the drawings, there is illustrated switching apparatus including front and

rear frames

20 and 2|, respectively, the frames being of simi- ,lar construction and each comprising a plurality of vertical and

horizontal members

22 and 23, respectively, secured together in any suitable manner. 'I'he

frames

20 and 2| are arranged back to back and secured together in spaced relation, a conductor bank 24 being arranged to occupy the space A between the backs of the frames. The conductor bank 24 comprises a plurality of vertically disposed conductors divided into ten spaced-apart groups; each group comprising ten subgroups or levels; each subgroup comprising ten lines; and each line including a positive and a negative conductor. Also each line may be provided with a control or private conductor in the event the switching apparatus is utilized in a telephone system wherein each line circuit includes a control or private conductor. Each" conductor in each group in theconductor bank 24 is uninsulated and serves both as a multiple conductor between the switching units and as av wiper contact for the wipers of the individual switching units. Also, each conductor is retained in position in its group by a plurality of spaced-apart insulating members 25. 'Ihe positive and negative line conductors in each group in the conductor bank 24 are segregated into two spaced-apart divisions which are arranged in the same manner. The line conductors in each subgroup in both the positive and negative divisions are arranged in .substantially the same vertical plane, each line conductor being spaced from the adjacent line conductor by a fixed distance; and the subgroups in each group are arranged in substantially parallel vertical planes, each subgroup being spaced from the adjacent subgroup by a fixed distance.

Each of the

frames

20 and 2| is adapted to support a group of identical automatic switching units in vertical alignment and in such a manner that each switching unit has access to each line in the conductor bank 24. This is accomplished by providing the front frame 20 with a plurality of sets of supported elements 26 and the rear frame 2| with a plurality of sets of supporting elements 2l. In each frame each set of supporting elements is spaced in a vertical direction a fixed distance from the adjacent set of supporting elements and comprises two horizontally alignedsupporting elements respectively secured to the vertical members 22 disposed at the right-hand and left-hand ends of the frame. In order to prevent the switching units supported by the rear frame 2| from' interfering with the switching units supported by the front frame 20, the sets of supporting elements 21 carried by the rear frame 2| are staggered in a vertical direction with respect to the sets of supporting elements 26 carried by the front frame-20. Thus, the switching units in one of the groups have access to sections of the conductor bank 24 disposed between the switching units of the other group, as illustrated in Fig. 9.

Each switching unit is provided with a base plate 28 which constitutes a shelf adapted to be supported upon one of the sets of supporting elements carried by one of the frames. As best shown in Figs. 3 and 4, the opposite ends of the base plate 28 of one of the switching units supported in the front frame 20 rest upon the upper surfaces of the supporting elements of one of the set of supporting elements 26. 'Ihe base plate 28 is provided with an upstanding ilange 29 extending along the front edge thereof which projects over the vertical members 22 disposed at the opposite ends of the front frame 20. The base plat@ 28 is secured in place at each end thereof by an arrangement including a screwl30 extending through an elongated opening 3| formed in the flange 29 and threaded intoan opening in the vertical member 22. Also an arrangement is provided'for locking each end of the base plate 28 securely in place, which comprises a pair of screws 32 threaded in openings formed in the iiange 29 and engaging the vertical member 22. The elongated openings 3| formed in the opposite ends of the flange 29 accommodate'adjustment of the switching unit in a longitudinal direction with respect to the ends of the front frame 20, and the

screws

30 and 32 accommodate adjustment of the switching unit in a lateral direction with respect tothe front andback of the front frame 29.

In placing a switching unit in the front frame 28 the base plate 28 of the switching unit is rst positioned upon the set of supporting elements 26 disposed at the desired level. The switching unit is then slid laterally into place and' adjusted so that the same is in proper alignment with respect to the conductor bank 24. The screws 30 are then inserted through the elongated openings 3| formed in the opposite ends of the flange 29 and tightened into snug-engagement with the flange 29. The screws 32 are then tightened into snug engagement with the vertical members 22 disposed at the opposite ends of the front frame 20, thereby securely retaining the switching unit in its adjusted position. The switching unit may be removed from the front frame 2l)v by withdrawing the base plate 28 after the screws 36 have been untightened and removed.

Referring now to Figs 5A, 5B, 6 and 7, there is shown a fragmentary portion of one of the automatic switching units of the switching apparatus,

which comprises ten elementary switches of identical construction respectively associated with the ten groups of lines in the conductor bank 24; the illustrated

elementary switches

33, 34 and 35 being associated respectively with the rst, second and tenth levels or groups of lines in the conductor bank 24. Each of the elementary switches comprises a carriage 36 individually provided with an element or slide 3l, upon which a contact controlling member 38 is mounted. The contact controlling member 38 carries two pairs of wipers or

contact members

39 and 40, respectively associated with the positive and negative divisions of the line conductors in the associated n group of lines in the conductor bank 24.l A terminal block 4| is also mounted on the slide 3l in order to extend electrical connections to the pairs of

contact members

39 and 40. The carriage 36 of each elementary switch is slidably mounted on two substantially parallel longitudinal guide bars 42 and 43, which are supported by two spaced apart brackets 44 and 45 carried by the base plate 28. Each of the carriages 36 is biased to a normal position and movable along a longitudinal path into ten oil-normal positions respectively corresponding to the ten subgroups or levels in the associated group of lines in the conductor bank 24. The slide 3l of each elementary switch is biased to a normal position and movable along a lateral path into ten oli-normal positions respectively corresponding to the ten lines in each subgroup or level in the associated group of lines.

An arrangement including an operating member or shaft 48, common to the elementary switches and. mounted for both rotational movement and movement in a longitudinal direction, is provided for selecting the particular elementary asiassa Y switch to be operated', and for moving the carriage 34 oi' the selected elementary switch into anyone of its'ten oli-normal positions. The'operating -shaft 48 is biased to a normal angular position 'a'nd rotatable in a counterclockwise direction, as

`viewed from the left-hand end thereof, into ten ofi-normal angular positions; and biased to a normal longitudinal position and movable toward the left into ten oil-normal longitudinal positions.

More particularly, the operating shaft 48 is ro-v tively associated with the elefentary switches 33,

34 and 35. Each of the cam members is provided with a first partor projection which is adapted to be moved into driving relationship with a second part or slot formed in the carriage of the associated elementary switch, the cam members 50, 5i and 52, respectively, being provided with projections 50, 5i, and 52* which are adapted respectively to be moved into slots 50h, Sib, and`52b formed in the carriages of the

elementary switches

33, 34 and 35, respectively.. The

cam projections 50, 5 i, etc., are successively displaced by a fixed angular distance about the operating shaft 48 and arranged in such a manner that the cam projection 5llEL is moved into the slot 5i)b formed in the carriage 36 of the elementary switch 33, when the operating shaft 48 is rotated from its normal angular position into its first o'- normal angular position; that the cam projection 50iis moved out of the slot 5i!b and the cam projection 5ia is moved into the slot 5ib formed in the carriage 36 of the elementary switch 34, when the operating shaft 4 8 is rotated into its second off-normal angular position; etc. When the cam projection 5i)EL occupies a position in the slot 50h, the carriage 36 of the elementary switch 33 is locked to the operating shaft 48 for movement in a longitudinal direction therewith, thereby rendering the elementary switch 33 operative to select a line from the first group of lines in the -conductor bank 24. rIn a similar manner, the

carriage of any one of the other elementary switches may be locked to the operating shaft 48, thereby lrendering the one elementary switch operable to select a line from the associated group of lines in the conductor bank 24. The arrangement of the cam members 50, 5|, 52, etc., on the operating shaft 48 permits only one of the elementary switches to be rendered operable or to be selected at any time; and any one of the elementary switches may be selected to be operated by rotating the operating shaft 48 to a corresponding off-normal angular position. At this time, the operating shaft 48 is retained in any predetermined off-normal angular position by an arrangement described subsequently.

After the operating shaft 48 has been rotated into a predetermined off-normal angular position to cause a corresponding elementary switch to be selected and locked to the operating shaft 48 for movement in a longitudinal direction therewith, the operating shaft 48 is moved from its normal longitudinal position into a predetermined ofi'- normal longitudinal position, causing the carriage of the selected elementary switch to be moved,

toward the left into a corresponding off-normal position, thereby to select a corresponding sub1 group or level from the associated group of lines. The carriage 36 of/the selected elementary switch is moved longitudinally against the bias of a coil spring 58 individual thereto, one end of the spring being secured to a lug 5,3 provided on the carriage 38, and the other end thereof being secured to a screw 51 carried by the base plate 28. At this time, the operating shaft 48 is retained in its predetermined off-normal longitudinal position by an arrangement including a ratchet 53 provided on the extreme right-hand end of the operating shaft 48 and an associated detent 54 pivotally mounted upon the guide bar 43; the carriage 38 of the operated elementary switch being retained in its predetermined ofi-normal position by the engagement between the projection on the cam carried by the operating shaft 43 and the slot formed in the carriage of the operated elementary switch. Also, an additional arrangement including a locking member or bar 31, individual to the operated elementary switch, is provided for retaining the carriage 36 thereof in its predetermined oif-normal position independently of the position of the operating shaft 48. Ten spaced apart notches are formed in the 'locking bar 31l and correspond to the ten off-normal positions of the carriage 36, the notches being adapted to engage a downwardly extending flange or member provided on the slide 31 carried by the carriage 36.

An arrangement including an operating member or shaft 58, common to the elementary switches and mounted for rotational movement, is provided for moving the slide 31 of a selected elementary switch in a lateral direction into any one of its ten off-normal positions. The shaft 58 is of tubular construction, having stub shafts 59 and 60 secured in the opposite ends thereof, the stub shafts 58 and 60 being rotatably supported in bearings provided in the brackets 44 and 45, respectively. The operating shaft 58 is biased to a normal position, and is rotatable in a counter-clockwise direction, as viewed from the left-hand end thereof, into ten off-normal positions against the bias of a coil spring 68. The spring 68 encloses the extreme right-hand end of the stub shaft 60, one'end of the spring 68 being secured in a notch 60* formed in the stub shaft 60, and the other end thereof being secured to the bracket 45. The operating shaft 58 carries ten cylindrical gears respectively associated with the slides carried by the ten elementary switches, the illustrated gears 6i, 62 and 63 being associated with the slides 31 carried by the

elementary switches

33, 34 and 35, respectively. As best shown in Fig. '7, the slide 31 of each elementary switch is of substantially channel shape having two downwardly extending flanges 64 and 65, and is retained in position by a bracket 66 secured to the carriage 36. The ange 64 of the slide 31 is provided with a plurality of teeth 61 which are adapted to engage the associated cylindrical gear carried by the operating shaft 58, thereby rendering the slide 31 a rack operated by the associated cylindrical gear.

When the carriage 36 of a selected elementary switch is moved to a predetermined off-normal position, thereby to select a corresponding subgroup or level in the associated group of lines, the teeth 61 provided in the slide 31, carried by the carriage 38, are brought into engagement with the associated cylindrical gear carried by the operating shaft 58. The operating shaft 58 is then rotated from its normal position into a predetermined oi'f-normal position, causing the slide 31, carried by the carriage 35 of the selected elementary switch, to be moved into a corresponding off-normal position, due to the driving engagement between the cylindrical gear and the associated slide, thereby to cause the pairs of

contact members

39 and 48 to select a corresponding line from the previously selectedsubgroup or level in the associated group of lines. The pairs of

contact members

39 and 48 respectively engage the positive and negative conductors of the selected line, a connection being extended thereto by way of the terminal block 4|. When the operating shaft 58 is rotated into its first o-normal position, the slide 31 is moved into its first ofinormal position. At this time, the forward edge of the ange 64 on the slide 31 engages one of the notches formed in the locking bar 31a and corresponding to the particular off-normal position of the carriage 36. The engagement between the slide 31 and the locking bar 81 retains the carriage 36 in its predetermined oli-normal position independently of the position of the operating shaft 48. Also, at this time, a lug, not shown, car-l ried by the under side of the operating shaft 58,

position by the operating shaft 58, the operatingl shaft 58 being retained in its predetermined oifnormal position by an arrangement described subsequently. The carriage 36 of the selected ele- 'mentary switch is retained in its predetermined off-normal position by the engagement between the slide 31 and the locking bar 318. In order-to restore the operated elementary switch to its idle position, the arrangement for retaining the operating shaft 58 in its predetermined o-normal position is released, causing the spring 68 to rotate the operating shaft 58 in a clockwise direction back into its normal position. As the operating shaft 58 is rotated back into its normal position, the slide 31 is moved back into its normal position, due to the driving connection between the cylindrical gear carried by the operating shaft 58 and the slide 31. When the slide 31 is moved back into its normal position, the ange 64 thereon disengages the notch in the locking bar 318, and the carriage 36 is moved back into its normal position by the spring 55.

In order to control the operating

shafts

48 and 58 in the switching unit, in themanner previously described, an arrangement including an operating motor 69 and a lock and clutch control mechanism 18 is provided. The operating motor 69 is of the electromagnetic type, comprising a frame 1|, secured to the base plate 28 by a plurality of screws 12, and a pvotally mounted armature 13 provided with an outwardly extending arm 14 adapted to carry a pawl, not shown, arranged \.in driving relationship with a ratchet wheel 15. The ratchet wheel is mounted for rotation upon a rotatable shaft 16, which is supported in a pair of spaced apart bearing housings 11 carried by a bearing bracket 18, secured to the base plate 28,by a plurality of screws 19. The'ratchet wheel is rigidly secured'to a clutch member 88, which carries two clutch plates 8| and 82 on the opposite ends thereof. The clutch member 88 is so constructedy and arranged that it is rotated step by step in a counter-clockwise direction, as viewed from the left-hand end thereof, by the ratchet wheel 15 and the operating motor 69. The clutch plates 8| and 82, carried on the opposite ends of the clutch member 88, are arranged respectively to drive two cooperatingl clutch plates 83 and 84, the clutch plates 83 and 84 being rigidly secured respectively to the shaft 16 and the stub shaft 59. 'I'he clutch plates 8| and 83 constitute a driving arrangement for rotating the shaft 16 step by step in a. counter-clockwise direction, while the clutch plates 82 and 84 constitute a driving arrangement for rotating the operating shaft 58 step by step in a counter-'clockwise direction., The shaft 16 is normally biased to a predetermined angular position by a `coil spring 85. The,coil spring 85 encloses the extreme lefthand end of the shaft 16, one end of the spring 85 being secured in a notch 16a, formed in the left-hand end of the shaft 16, and the other end thereof being secured to the base plate 28. Also, a gear 86 is rigidly secured to the shaft 16 and engages a gear 81 rigidly secured to a rotatable shaft 88, which latter shaft is supported in two spaced apart bearing brackets 98 carried by the base plate 28. Also, a spiral gear 9| is rigidly secured to the shaft 88 and engages a cylindrical spiral gear 92 rigidly secured to the operating shaft 48. The

gears

86 and 81, the spiral gear 9|, and the cylindrical spiral gear 92 constitute a driving arrangement for imparting both rotational and longitudinal step-by-step movements to the operating shaft 48.

The lock and clutch control mechanism 10 comprises a ratchet wheel 93 and two substantially disc-shaped

cam members

94 and 95 rigidly secured to a rotatable shaft 96, which is carried by the base plate 28. 'I'he ratchet wheel 93 is arranged to be driven by a pawl 91 pivotally mounted on an arm 98, carried by a. pivotally mounted armature 99 of an operating motor |88. The operating motor l 88 is of the electromagnetic type and includes a frame |8| carried by the base plate 28. The arm 98 is normally biased away from the ratchet wheel 93 by a leaf spring |82 and into engagement with a stop |83 carried by the base plate 28, the leaf spring |82 beingv secured to the base plate 28 by a plurality of screws |84. The pawl 91 is biased toward the ratchet wheel 93 by a coil spring |85 extending between the p awl 91 and the arm 98. The periphery of the cam member 94 is provided with a plurality of projections 94B, which are spaced apart by intervening depressions 94h. Associated with the cam member.94 is a clutch control lever |86, provided with two outwardly extending arms |81 and |88. The clutch control lever |86 is pivotally mounted intermediate the ends of the arms |81 and |88 upon a shaft |89, carried by the base plate 28, and is biased in a clockwise direction by a coil spring ||8 extending between the arm |88 and the bracket 44. 'I'he extreme outer end of the arm |81 is provided with a finger which rides upon the periphery of the cam member 94, while the extreme outer end of the arm |88 is provided with a tab ||2 which is disposed in an annular vrecess 88a formed in the clutch member 88 between the clutch pif+A and the ratchet wheel 15. 'I'he lock and clutch control mechanism 18 is so constructed and arranged that it is rotated step by step in a counter-clockwise direction by the ratchet Wheel 93- and the operating motor |88. As the lock and clutch control mechanism 18 is rotated sten by the periphery of the cam member 84, alternately engages one of the projections 84n and one of the depressions 84", disposed about the periphery of the cam member 84. When the finger engages one of the projections 84B, the clutch control lever |08 is rotated ina counter-clockwisel direction about the shaft |08.against the bias of the spring ||0, causing the tab ||2 on the arm |08 to move the clutch member 80 toward the left, thereby to engage the clutch plates 8| and 88; On the other hand, when the finger engages one of the depressions 84h, the clutch@ control lever |08 is rotated in a clockwisedirection about the shaft |08 by the spring ||0, causing the tab |I2 on the arm |08 to move the clutch member toward the right, thereby to engage the clutch plates 82 and 84.

The periphery of the cam member is provided with a plurality of projections 85, which are spaced apart by intervening depressions 85". Associated with the cam member 85 is a lock control member ||8 pivotally mounted upon a shaft ||4 supported in a pair of spaced apart brackets ||5, carried by the base plate 28., The lock control member ||3 is biased in a clockwise direction, as viewed from the left-hand end thereof, by a coil spring ||5 extending between the lock control member ||3 and the base plate 28. 'I'he lock control member ||3 comprises a forwardly extending locking edge ||1, having such a thickness that it is adapted to engage any one of a plurality of notches |I8 formed in the periphery of a locking disc |I8 rigidly secured to the operating shaft 48; a rearwardly extending projection |20 adapted to ride upon the periphery of the cam member 85; and a forwardly extending locking arm |2| provided with a notch |2|s therein adapted to engage a reduced annular portion 48'* on the operating, shaft 48. The lock and clutch control mecha'- nism 10 is so constructed and arranged that, as it is rotated step by step in a counter-clockwise direction, the projection |20 on the lock control member I3. alternately engages one oi the projections 'L and one of the depressions 85h, disposed about the periphery of the cam member 85. When the projection |20 engages one of the projections 85, the lock control member ||3 is rotated in a counter-clockwise direction about the shaft ||4 against the bias of the spring ||0, first causing the notch |2|* in the locking arm |2| to disengage the reduced annular portion 48" on the operating shaft 48, thereby to release the operating shaft 48 for movement ina longitudinal direction toward the left; and then causing the locking edge ||1 of the lock control member ||3 to engage one of the notches 8 formed in the periphery of the disc H8, thereby to lock the operating shaft 48 against further rotational movement. On the other hand, when the projection |20 engages one of the depressions 85",

the lock control member 3 is rotated in a clockwise-direction about the shaft ||4 by the .spring IIB, first causing the locking edge ||1 of the lock control member ||3 to disengage one of the notches ||8 formed in the periphery of the disc ||8, thereby to release the operating shaft 48 for rotational movement; and then causing the notch |2|'ai in the locking arm |2| to engage the reduced annular portion 48 on the operating shaft 48, thereby to lock the operating shaft 48 against movement ina longitudinal direction.

When the switching unit occupies an idle position, the operating shaft 48 is retained in its normal angular position by the engagement between a stop 48b carried by the operating member 48 and the guide bar 48 and in its normal longitudinal position by the engagement between the notch |2|* in the locking arm |2| and reduced annular portion 48 on the operating shaftv The arrangement of the cam members 84 and 85 on the shaft 88 of the lock and clutch control mechanism 10` is diagrammatically illustrated in Fig. 8. Referring to this figure, it will be observed that the finger on the arm |01 of the clutch control member |08 engages one of the projections 84* on the cam member 84, and the projection |20 on the lock control member ||3 engages one of the depressions 85b in the cam member 85, when the shaft 88 occupies its first angular position Pi, corresponding to the idle position of the switching unit. During the course of the operation of the switching unit to select a particular line in the conductor bank 24, the shaft 8B of the lock and clutch control mechanism 10 is successively rotated into its second, third, and fourth angular positions P2, P3 and P4, respectively, causing the finger successively to engage the same 'projection 84, the adjacent depression 84h and the same depression 84h; and causing the projection |20 successively to engage the adjacent projection 85, the same projection 85a and the adjacent depression 85h, in the respective angular positions of the shaft 86 of the lock and clutch control mechanism 10. In order to disengage the established connection to the selected line in the conductor bank 24 and to restore the operated switching unit to its idle position, the shaft 86 of the lock and clutch control mechanism 10 is rotated into its fifth angular position P5, corresponding to its first angular position PI, as is described more fully subsequently. In the fifth angular position P5, of the shaft 88 of the lock and clutch control mechanism 10, the finger |I| again engages a projection 84a on the cam member 84, and the projection |20 again engages a depression 85h in the cam member 85.

Referring now to the operation of the switching unit described, and assuming that the switching unit is to be operated to select a particular line from the conductor bank 24, such, for example, as the -fourth line in the third subgroup or level, in the second group of lines in the conductor bank 24, it will be understood that the switching unit is controlled by a suitable impulse transmitter connected and arranged in a control circuit, including the operating motors 68 and |00. In order to cause the switching unit to operate and select the line noted above, the impulse device is first operated to transmit `a first series of impulses, comprising two impulses, thereby to cause the operating motor 68 to be energized two times successively. The elements of the switching unitare in the positions shown,

corresponding to the idle position of the switch- The clutch member 80 is rotated two 10 clockwise direction by theshaft i6, due to the engagement of the gears 86 and 8l, causing' the spiral gear QI to exert a force upon the cylindrical spiral gear 92, thereby tending simultaneously to rotate the operating shaft d8 in a counterclockwise direction and lto move the operating shaft A8 in a longitudinal direction. As previously noted, at this time, the operating shaft 48 is locked against movement in a longitudinal direction, but is free to be rotated. Thus, the

operating shaft 48 is rotated from its normal angular position into its second off-normal angular position, causing the projection 5IEL on' the cam member 5I to be moved into the slot lb, formed in the carriage 36 of the elementary g5 switch 3 associated with the second group of lines in the conductor bank 2t. 'When the cam projection la is moved into the slot lb, formed in the carriage 36 of the elementary switch 3d, the elementary switch 33 is locked to the operating shaft 4B for movement in a longitudinal direction therewith. As previously explained, only the carriage of the elementary switch 36 is locked to the operating shaft it for movement in a longitudinal direction therewith, when the 35 operating shaft i8 occupies its second off-normal angular position.

At the end of the first series of impulses, a single energizing impulse is transmitted to the operating motor I. The shaft 95 of the lock and clutch control mechanism 'IG is rotated one step in a counter-clockwise direction into its second angular position P2, by the operating motor I through the pawl and ratchet wheel mechanism arranged therebetween, the ratchet wheel 93 being retained in its operated position by a detent, not shown. This rotation of the lock and clutch control mechanism l@ causes the projection I2@ on the lock control member I I3 to en gage one of the projections 95e on the cam member 95, thereby to rotate the lock control member IIS in a counter-clockwise direction against the bias of the spring IIS. When the lock control member H3 is rotated in a counter-clockwise direction, the locking edge I Il of the lock control member I I3 engages the second notch I I8, formed in the periphery of the disc IIQ, in order to lock the operating shaft i8 against further rotational movement. Also, the notch IZIa in the locking arm I2I disengages the reduced annular portion 6o d8a on the operating shaft t8, in order to release the operating shaft B3 for movement in a longitudinal direction toward the left. This rotation of the lock and clutch control mechanism l0 is not effective to rotate the clutch control lever IUS,

65 as previously explained. Accordingly, the clutch plates 8| and 83 remain in engagement, at this time.

The impulse device is then operated to transmit a second series of impulses, comprising three im- 70 pulses, thereby to cause the operating motor 69 to be energized three times successively. The clutch member 80 is rotated three steps further in a counter-clockwise direction, thereby causing the spiral gear 9| to exert a. force upon the cylin- 7-5 drical spiral gear 92, tending to rotate the operat- 2,21s,sss

ing shaft 43 in a counter-clockwise direction and to move the operating shaft 48 in a longitudinal direction toward the left, as previously explained. At this time, the operating shaft Il@ is locked against rotational movement, but is free to be moved in a longitudinal direction. Thus, the operating shaft i8 is moved from its normal longitudinal position into its third off-normal longitudinal position, causing the carriage of the selected elementary switch 3B to be moved against the bias of the spring 55 into its third olf-normal position corresponding to the third subgroup or level in the associated group of lines. As the carriage 36 of the selected elementary switch 34 is moved from its normal position into its first offnormal position, the teeth 6l provided on the flange 64 of the slide 3l, carried by the carriage 36, are brought into engagement with the cylindrical gear 52, carried by the operating shaft 58. At this time, the operating shaft 48 is retained in its second off-normal angular position by the lock and clutch control mechanism l0, and in its third off-normal longitudinal position by the engagement between the detent 56 pivotally mounted on the guide bar 43 and the ratchet 53 on Vthe extreme right-hand end of the operating shaft l. The carriage 36 of the operated elementary switch 3Q is retained in its third olfnormal position by the engagement between the projection lton the cam member 5i, carried by the operating shaft d8, and the slot 5Ib formed in the carriage 36.

At the end of the second series of impulses, a single energizing impulse is transmitted to the operating motor I, causing the shaft 96 of the lock and clutch control mechanism 'iii to be rotated one step further in a counter-clockwise direction into its third angular position P3. This rotation of the shaft 96 of the lock and clutch control mechanism It causes the finger I I I on the arm Ijl of the clutch control lever IUS to engage one of the depressions slib in the periphery of the cam member Effi, thereby to cause the spring IIU to rotate the clutch control lever IGS in a clockwise direction. When the clutch control lever IIi is rotated in a clockwise direction, the tab IIZ on the arm IBB of the clutch control lever IBS moves the clutch member 80 toward the right, thereby to disengage the clutch plates 3| and 83 and to engage the clutch plates 82 and 86. This rotation of the shaft 96 of the lock and clutch control mechanism 'I0 is not effective to rotate the lock control member I I3, as previously explained. Accordingly, the operating shaft 48 remains locked against rotational movement, at this time.

The impulse device is then operated to transmit a third series of impulses, comprising four impulses, thereby to cause the operating motor 69 to be energized four times successively. The clutch member 80 is rotated four steps further in a counter-clockwise direction, thereby causing the operating shaft 58 to be rotated in a counterclockwise direction from its normal position into its fourth off-normal position. Rotation of the operating shaft 58 into its fourth olf-normal position causes the slide 3l, carried by the carriage 36 of the operated elementary\switch 34 to be moved into its fourth off-normal position, thereby to establish connections between the pairs of

contact members

39 and 40, and the positive and negative conductors, respectively, of the fourth line in the previously selected subgroup or level of lines. When the slide 31 is moved into its first off-normal position, the flange 64 thereon is moved into engagement with the third time, a lug, not shown, carried by the operating shaft 58, engages the detent 54 pivotally mounted on the guide bar 43, causing the detent 54 to be moved out of engagement with the rack" 53 in order torelease the operating shaft 48 for movement in a longitudinal direction. The operating shaft 48 is restrained against movement in a longitudinal direction by the engagement between the projection on the cam member 5| and the slot 5U formed in the carriage 36, at this time. At this time, in the operated elementary switch 34, the carriage 36 is retained in its third. offnormal position by the locking bar 31, and the slide 31 is held in its fourth off-normal position by the clutch member 80,

At the end of the third series of impulses, a single energizing impulse is transmitted to the operating motor |00, causing the shaft 86 of the lock and clutch control mechanism to be rotated one step further in a counter-clockwise direction into its fourth angular position P4. This rotation of the shaft 86 of the lock and clutch control mechanism 10 causes the projection on the lock control member ||3 to engage one of the depressions 85b in the cam memberl 85, thereby to cause the spring ||6 to rotate the lock control member ||3 in a clockwise direction. When the lock control member ||3 is rotated in a clockwise direction, the locking edge ||1 thereof disengages the second notch ||8 formed in the periphery of the disc ||9 in order to release the operating shaft 48 for rotational movement. Also, the notch |2| in the locking arm |2| is moved into a position wherein it may engage the reduced annular portion 48` on the operating shaft 48, when the operating shaft 48 is returned to its normal longitudinal position. The operating shaft 48 is then rotated in a clockwise direction back into its normal angular position, by the spring 85 through the gears 88 and 81, the spiral gear 9|, and the cylindrical spiral gear 92, the operating shaft 48 being arrested in its normal angular position by the engagement between the stop 48b carried by the operating shaft 48 and the guide bar 43. The operating shaft 48 is then moved in a longitudinal direction toward the right back into its normal longitudinal position by the spring 85 through the

gears

86 and 81, the spiral gear 9|, and the cylindrical spiral gear 92. When the operating shaft 48 is moved back into its normal longitudinal position, the notch |2| in the locking arm |2| engages the reduced annular portion 48a in the operating shaft 48, therebyto lock the operating shaft 48 against movement in a longitudinal direction. Thus, the operating shaft 48 is restored to its -normal position corresponding to the idle position of the switching unit. This rotation of the shaft 96 of the lock and clutch control mechanism 10 is not effective to rotate the clutch control lever |06, as previously explained. Accordingly, the clutch plates 82 and 84 remain in engagement, at this time.

In order to interrupt the established connection to the particular selected line in the conductor bank 24 and to restore the switching unit to its idle position, it is only necessary to transmit a single energizing impulse to the operating motor |00, thereby causing the shaft 96 of the lock and clutch control mechanism 10 to be ro- .tated one step further in a counter-clockwise direction into its fifth angular position P5, which angular position corresponds to its first angular position Pl. This rotation of the shaft 98 of the lock and clutch control mechanism 10 causes the finger on the arm |01.of the clutch control lever |08 to engage one of the projections 84*l on the cam member 84, thereby to rotate the clutch control lever |06 in counter-clockwise direction against the bias of the spring I|0. When the clutch control lever |06 is rotated in a counterclockwise direction, the tab I2 on the arm |08 of the clutch control lever |06 moves the clutch member 80 toward the left, thereby to disengage the clutch platesv 82 and 84 and to engage the clutch plates 8| and 83. When the clutch plates 82 and 84 are disengaged, the operating shaft 58 is rotated in a clockwise direction back into its normal position by the spring 68. This rotation of the operating shaft 58 causes the slide 31 of the operated elementary switch 34 to be moved back into its normal position through the driving engagement between the cylindrical gear 62 and the third notch in the kicking bar 31a, individual V to the elementary switch 34, thereby to release the carriage 36 for movement in a longitudinal direction. The spring 55, individual to the elementary switch 34, then moves the carriage 36 back into its normal position. This rotation of the shaft 86 ofthe lock and clutch control mechanism 10 is not effective to rotate the lock control member H3, as previously explained. Accordingly, at this time, the operating shaft 48 remains locked against movement in a longitudinal direction. Thus, the switching unit is completely restored to its idle position and is again in condition to be reoperated to select any particular line in the conductor bank 24.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made in the structure thereof, and it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a iirst'direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; means for selectingany one of said elementary switches to be operated; means including a first operating member common to said elementary switches for moving the carriage of a selected one of said elementary switches; means including a second `operating member common to said elementary switches for moving the element of said selected elementary switch; and means for moving successively said iirst and said second operating members.

2. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; means for selecting any one of said elementary switches to be operated; a first operating member common to said elementary switches Aand supported for step-by-step movement;

dii

`means responsive to the step-by-step movement of said first operating member for moving the carriage of a selected one of said elementary tary switch stepby step in said second direction.l

3. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; means including a first operating member common to said elementary switches for selecting any one of said elementary switches to be operated and for moving the carriage of a selected one of said elementary switches; and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch.

4. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common to said elementary switches and movable in two directions; means controlled by the movement of said first operating member in one of said directions for selecting any one of said elementary switches to be operated; means responsive to the movement of said first operating member in the other of said directions for moving the carriage of a selected one of said elementary switches; and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch.

5. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common to said elementary switches and supported for both rotational and longitudinal movements; means controlled by the rotational movement of said first operating member for selecting any one of said elementary switches tor be operated; means responsive to the longitudinal movement of said first operating member for moving the carriage of a selected one of said elementary switches; a second operating member common to each of said switches and supported for rotational movement; and means responsive to the rotational movement of said second operating member for moving the element of said selected elementary switch.

6. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable -in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common to said elementary switches and movable step by step in two directions; means controlled by the movement of said first operating member step by step in one of said directions for selecting successively said elementary switches to be operated; means responsive to the movement of said first operating member step by step in the other of said directions for moving the carriage of a selected one of said elementary switches step by step in said rst direction; a second operating member common to said elementary switches and movable step by step; and means responsive to the movement of said second operating member step by step for moving the element of said selected switch step by step in said second direction.

7. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common to said elementary switches and supported for both rotational and longitudinal step-by-step movements; means controlled by the rotational stepby-step movement of said first operating member for selecting successively said elementary switches to be operated, means responsive to the longitudinal step-by-step movement of said first operating member for moving the carriage of a selected one of said switches step by step in said iirst direction; a second operating member common to said elementary switches and supported for rotational step-by-step movement; and means responsive to the rotational step-bystep movement of said second operating member for moving the element of said selected elementary switch step by step in said second direction.

8. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a rst direction, an element-carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; an operating membereommon to said elementary switches and movable in two directions; means controlled by the movement of said operating member in one of said directions for selecting anyone of said elementary switches to be operated; means responsive to the movement of said operating member in the other of said directions for moving the carriage of a selected one of said elementary switches; a mechanism operable to move said operating member in each of said directions; means including a locking mechanism for controlling the directions of movement of said operating member; and means for moving the element of said selected elementary switch.

9. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; an operating member common to said elementary switches and movable in two directions; means controlled by the movement of said operating member in one of said directions for selecting any one of said elementary switches to be operated; means responsive to the movement of said operating member in the other of said vdirections for moving the carriage of a selected one of said elementary switches; an operating mechanism tending to move said operating member in each of said directions simultaneously; means including a locking mechanism adapted alternately to lock said iirst operating member against movement in one and the other of said directions for controlling the directions of movement o-f said operating member; and means for moving the element of said selected elementary-switch.

10. An automatic switching unit comprising a plurality of elementary switches; each oi' said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; an operating member common to said elementary switches and supported for both rotational and longitudinal movements; means controlled by the rotational movement of said operating member for selecting any one of said elementary switches to be operated; means responsive to the longitudinal movement of said operating member for moving the carriage of a selected one of said elementary switches; a mechanism including a cylindrical spiral gear carried by said operating member and operable to impart to said operating member both rotational and longitudinal movements; means including a locking mechanism for controlling the movements imparted to said operating member; and means for moving the element of said selected elementary switch.

11. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a iirst operating member common to said elementary switches and supported for both rotational and longitudinal step-by-step movements; means controlled by the rotational stepby-step movement of said first operating member for selecting successively said elementary switches to be operated; means responsive to the longitudinal step-by-step movement of said first operating member for moving the carriage of a selected one of said switches step by step in said first direction; a mechanism operable to impart to said first operating member both rotational and longitudinal step-by-step movements; means including a locking mechanism for controlling the movements imparted to said iirst operating member; a second operating member common to said elementary switches and supported for rotational step-by-step movement; and means responsive to the rotational step-by-step movement of said second operating member for moving the element of said selected elementary switch step by step in said second direction.

12. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common tosaid elementary switches and movable `step by step in two directions; means controlled by the movement of said rst operating member step by step in one of said directions for selecting successively said elementary switches to be operated;` means responsive to the movement of said first operating member step by step in the other of said directions for moving the carriage of a selected one of said elementary switches step by step in said first direction; a mechanism operable to move said iirst operated member step by step in each of said directions; means including a locklplurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said elementfa iirst operating member common -to said elementary switches and movable in two directions; means controlled by the movement oi' said iirst operating member in one of said directions for selecting any one of said elementary switches to be operated; means responsive to the movement of said iirst operating member in the other of said directions for moving the carriage of a selected one of said elementary switches; a mechanism operable to move said iirst operating member in each of said directions; a locking mechanism operable to control the directions oi movement of said iirst operating member, said locking mechanism normally being operated to release said iirst operating member to be moved in said firstdirection and to lock said iirst operating member against movement in said other direction and being operated in response to the movement of said iirst operating member in said one direction to release said iirst operating member to be moved in said other direction and to lock said iirst operating member against further movement in said one direction: and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch.

14. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a'contact controlling member carried by said element; a first operating member common to said elementary switches and movable in two directions; means controlled by the movement of said iirst operating member in one of said directions for locking the carriages of said elementary Aswitches to said iirst operating member selectively and in a predetermined order, thereby to cause the carriage of a selected one of said elementary switches to be moved in said iirst direction when said first operating member is moved in the other of said directions; and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch in said second direction.

l5. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a iirst direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a iirst operating member common to said elementary switches and supported for bothv 1'0- tational and longitudinal step-by-step movements; means controlled by the rotational step- -rection when said rst operatingI member is moved longitiv iinally step by step; a` second operating member common to said elementary switches and supported for step-by-step movement; and means responsive to the step-by-step movement of said second operating member for moving the element of said selected elementary switch step by step in said second direction.

16. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a movable .carriage, a movable element carried by said carriage,

and a contact controlling member carried by said element; a rst movable member common to said switches; means for locking selectively and in a predetermined order the carriages of said elementary switches to said iirst member, thereby to cause the carriage of a selected one of said elementary switches to be locked to said first member for movement with said iirst member; and means including a second movable member common to said elementaryswitches for moving the element of said selected elementary switch.

17. An automatic switching unit comprising a plurality of elementary switches; each oi said elementary switches including a movable carriage,

a movable element carried by said carriage, and

a contact controlling member carried by said element; a movable operating member common to said elementary switches; a plurality of 4first parts carried by said operating member; a second part carried by the carriage of each one of said elementary switches and associated with a correspondingone of said rst parts; means for moving selectively corresponding ones of said iirst and second parts into engagement; means for locking engaging ones of said rst and second parts in engagement, thereby to lock the carriage of the corresponding one of said elementary switches to said operating member for movement therewith; and means for moving the element of said corresponding one of said elementary switches.

18. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a movable carriage, a movable element carried by said carriage, and a contact controlling member carried by said element; a movable operating member common to said -elementary switches; a plurality of rst parts carried by said operating member; a second part carried by the carriage of each one of said elementary switches and associated with a corresponding one of said first parts; corresponding ones of said first and second parts constituting sets of parts; means for moving selectively and in a predetermined order said sets of parts into engagement; said setsI of parts being so constructed and arranged that only one set of parts vcan be moved into engagement at any time;

means for locking the parts of any one of the engaging sets of parts in engagement, thereby to lock the carriage of the corresponding one of said elementary switches to said operating member for movement therewith; and means for moving the element of said corresponding one of said elementary switches.

19. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage supported for longitudinal movement, an element carried by said carriage and supported for lateral movement, and a contact controlling member carried by said element; a iirst operating memvber common to said elementary switches and supported for both rotational and longitudinal movements; means controlled by the rotational movement of said rst operating member for locking the carriages of said elementary switches to said rst operating member selectively and in a predetermined order, thereby to cause the carriage of a selected one of said elementary switches to be locked to said irst operating member for movement longitudinally with said iirst operating member; and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch laterally.

20. An automatic switching unit comprising a plurality of. elementary switches; each of said elementary switches including a carriage supported for longitudinal movement, an element carried by said carriage and supported for lateral movement, and a contact controlling member carried by said element; a rst operatingv member common to said elementary switches and supported for both rotational and longitudinal movements; a plurality of cam members carried by said rst operating member, each of said cam members being associated with a corresponding one of said elementary switches and provided with a first part adapted to drive a cooperating second part carried by the carriage of the associated elementary switch, said cam members being so constructed and arranged that said iirst parts are brought selectively and in a predetermined order into driving relationship with said cooperating second parts as said iirst operating member is rotated, thereby to cause the carriage of a selected one of said elementary switches to be locked t0 said rst operating member for movement longitudinally with said rst operating member; and means including a second operating member common to said elementary switches for moving the element of said selected elementary switch laterally.

21. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, a slide carried by said carriage and movable in a second direction, said slide being provided with a rack, and a contact controlling member carried by said slide; a iirst operating member common to said elementary switches and movable in two directions; means controlled by the movement of said iirst operating member in one of said directions for selecting one of said elementary switches to be operated; means responsive to the movement of said iirst operating member in the other of said directions for moving the carriage of said selected elementary switch in said iirst direction; a second operating member common to said elementary switches and supported for rotational movement; a plurality of gears carried by said second operating member, each of said gears being associated with a corresponding one of said elementary switches and adapted to engage the rack provided on the slide of the associated elementary switch; means responsive to the movement ofthe carriage of said selected switch in said iirst direction for moving the rack provided on the slide of said selected elementary switch and the associated gear carried by said second F operating member into engagement; and means for rotating said second operating member, thereby to cause the slide of said selected elementary switch to be moved in said second direction.'

22. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage 4movable in a longitudinal direction, a slide carried by said carriage and movable in a lateral direc- 55r tion, said slide being provided with a rack. and

a contact controlling member carried by said slide; a first operating shaft common to said elementary switches and supported for both rotational and longitudinal step-by-step movements; a plurality of cam members carried by said first operating shaft, each of said cam members being associated with a corresponding ,one of said elementary switches and provided with a first part adapted to drive a cooperating second part carried by the carriage of the associated elementary switch, said cam members being so constructed and arranged that said first parts are brought successively into driving relationship with said cooperating second parts as -said first operating shaft is rotated step by step, thereby to select successively said elementary switches to be operated; means for rotating said rst operating shaft a predetermined number of steps, thereby to select a corresponding one of said elementary switches to be operated; means for moving said first operated shaft longitudinally a predetermined number of steps, thereby to move the carriage of said selected elementary switch step by step in said longitudinal direction; a second operating shaft common to said elementary switches and supported for rotational. step-bystep movement; a plurality of gears carried by said second operating shaft, each of said gears being associated with a corresponding one of said elementary switches and adapted to engage the rack provided on the slide of the associated elementary switch after the associated elementary switch has been selected to be operated and the carriage thereof has been moved in said longitudinal direction; and means for rotating said second operating shaft a predetermined number of steps, thereby to move the slide of said selected elementary switch step by step in said lateral direction.

23. An automatic switching unit comprising ay said selected elementary switch; a second operating member common to each of said switches and supported for rotational movement; means responsive to the rotational movement of said second operating member for moving the element of said selected elementary switch; a mechanism selectively operable to impart to said first operating member both rotational and longitudinal movements and to impart to said second operating member rotational movement; means for controlling the selective operations of said mechanism; and means including a locking mechanism for controlling the movements imparted to said first operating member.

24. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; a first operating member common to said elementary -switches and supported for both rotational and longitudinal step-by-step movements; means controlled by the rotational stepby-step movement of said first operating member for selecting successively said elementary switches to be operated; means responsive to the longitudinal step-by-step movement of said first operating member for moving the carriage of a .selected one of said switches step by step in said first direction; a second operating member common to said elementary switches and supported for rotational step-by-step movement; means responsive to the rotational step-by-step movement of said second operating member for moving the element of said selected elementary switch step by step in said second direction; a mechanism .adapted to be connected selectively to said first operating member and to said second operating member, said'mechanism being operable to impart to said first operating member both rotational and longitudinal step-by-step movements and to impart to said second operating member rotational step-by-step movement; means for controlling selectively the connections of said mechanism; and means including a locking mechanism for controlling the movements impartedto said first operating member.

25. A switch comprising, in combination, a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, a contact controlling member carried by said element, a fixed locking member normally engaging said element, thereby to lock said element against movement in said second direction, means for moving said carriage and said element carried thereby in said first direction, said element and said fixed locking member being so constructed and arranged that they are automatically disengaged when said element is moved with said carriage in said first direction, thereby to unlock said element for movement in said second direction, and means -for moving said element in said second direction.

26. A switch comprising, in combination, a carriage movable in a first direction, an element carried-by said carriage and movable in a second direction, a contact controlling member carried by said element, a movable locking member carried by said element, a fixed locking member, said locking members normally being in engagement, thereby to lock said element against movement in said second direction, means for moving said carriage and said element carried thereby in said first direction, said locking members being so constructed and arranged that they are automatically moved into disengagement when said element is moved with said carriage in saidfirst direction, thereby to unlock said element for movement in said second direction, and means for moving said element in said second direction, said members being moved into engagement when said element is moved in said second direction, thereby to lock said carriage and said element carried thereby against further movement in said first direction.

27. A switch comprising, in combination, a carriage movable in a first direction, an element carried by said carriage and movable in a second direction, a contact controlling member carried by said element, a movable locking member carried by said element, a fixed locking member, one

Cil

of said locking members having an opening therein into which the other of said locking members is adapted to be inserted, said locking members normally being in engagement, thereby to lock said element against movement Iin said second direction, means for moving said carriage and. said element carried thereby in said first direction, the opening in said one locking member and said other locking member being moved into alignment when said-element is moved with said carriage in said first direction, thereby to unlock said element for movement in said second direction, and means for moving said element in said second direction, said other locking member being inserted into .the opening in said one locking member and said locking members being moved into engagement when said element is moved in said second direction, thereby to lock said carriage and said element carried thereby against further movement in lsaid rst direction. 28. A switch comprising, in combination, a carriage movable along a first path and having a normal position, an element carried by said carriage, said element being movable along a second path and having a normal position, a contact controlling member carried by said element, means for locking'said element in its normal position, means for advancing said carriage from its normal ,position along said first path, means responsive to the movement of said carriage from its normal position for unlocking said element for movement along said second path, means for advancing said element from its normal position along said second path, means responsive to the movement of said element from its normal position for locking said carriage against further movement along said first path, means for retracting said element along said second path to its normal position, means responsive to the movement of said element to its normal position for unlocking said carriage for movement along said rst path, and means for retracting said carriage along said rst path to its normal position.

29. An automatic switching unit comprising a plurality of elementary switches; each ofl said elementary switches including a carriage movable in a first direction, an element carried by said carriage and movable in a second direction,

and a contact controlling member carried by said element; means for selecting any one of said elementary lswitches to be operated; means for moving the carriage of a selected one of said elementary switches; normally ineiective means for moving the element of said selected elementary switch; and means controlled by the movement of the carriage of said selected elementary switch for rendering said last-mentioned means eiective.

30. An automatic switching unit comprising a plurality of elementary switches; each of said elementary switches including a carriage movable in a rst direction, an element carried by said carriage and movable in a second direction, and a contact controlling member carried by said element; means for selecting any one of said elementary switches to be operated; means including a rst operating member common to said elementary switches for moving the carriage of a selected one of said elementary switches; normally ineiective means including a second operating member common -to said elementary switches for moving the element of said selected elementary switch; means controlled by the movement of the carriage of said selected elecarried by said carriage and movable in a second direction with respect to said contact bank, and a contact controlling member carried by said element; means for selecting any one of said elementary switches to be operated; and means for moving the carriage and the element of a selected one of said elementary switches.

32. In a switching system including a contact bank; a switchingunit associated with said contact bank; said switching unit comprising a plurality of independently operable elementary switches; each of said elementary switches including a carriage movable in a first direction with respect to said contact bank, an element carried by said carriage and movable in a second direction with respect to said contact bank, and a contact controlling member carried by said element; and impulse responsive means for seleeting any one of said elementary switches to be operated and for moving the carriage and the element of a selected one of said elementary switches.

33. In a switching system including a contact bank; a plurality of switching units commonly associatedwith said contact bank; each of said switching units comprising La plurality of elementary switches; each of said elementary switches including a carriage movable in aVA first member common to said elementary switches for movngthe element of said selected elementary switch.

34. In a switching system including a contact bank; a plurality of switching units commonly associated with said contact bank; each of said switching units comprising a plurality of elementary switches; switches including a carriage movable in a rst direction with respect to said Contact bank, an element carried by said carriage and movable in a second direction with respect to said contact bank, and a contact controlling member carried by said element; means for selecting any one of said elementary switches to be operated; means including a rst operating member common to said elementary switches for moving the carriage of a selected one of said elementary switches; means including a second operating member common to said elementary switches for moving the element of said selected elementary switch; andmotor means for moving successively said first and said second operating members.

35. In a switching system including a contact each of said elementaryv bank divided into a plurality of groups of contacts; a plurality of switching units commonly associated with said contact bank; each of said switching units being operable independently of rthe other of said switching units and comprising a plurality of independently operable elementary switches respectively associated with the groups of contacts in said contact bank; each of said elementary switches including a carriage movable in a llrst direction with .respect to said contact bank, an element carried by said carriage and movable in a second direction With respect to said contact bank, and a contact controlling member carried by said element, andcooperating with the contacts in the associated group of contacts in said contact bank; means for selecting any one of said elementary switches to be operated; and means for moving the carriage and the element of a selected one of said elementary switches.

36. In a switching system including a contact bank divided into a plurality of groups of contacts; a switching unit associated with said contact bank; said switching unit comprising a plurality of independently operable elementary switches respectively associated with the groups of contacts in said contact bank; each of said elementary switches including a carriage movable in a first direction with respect to said contact bank, an element carried by said carriage and movable in a second direction with respect to said contact bank, and a contact controlling member carried by said element and cooperating with the contacts in the associated group of contacts in said contact bank; and impulse responsive means for selecting any one of said elementary switches to be operated and for moving the carriage and the element of a selected one oi' said elementary switches.

3'7. In a switching system-including a contact bank divided into a plurality of groups of contacts; a switching unit associated with said contact bank; said switching unit comprising a plurality of independently operable elementary switches respectively associated with the groups of contacts in said contact bank; each of said elementary switches being operative to control the contacts in the associated group of contacts in said contact bank; means for selecting any one of said elementary switches to be operated and for preventing the operation of the other of said elementary switches; and means for selectively controlling the operation of said selected elementary switch. y

38. In a switching system including a longitudinally extending contact bank and a frame associated therewith; a plurality of self-contained switching units removably' supported by said frame in spaced-apart relationship and commonly associated with said contact bank; each of said switching units being operable independently of the other of said switching units and comprising a plurality o1' independently operable elementary switches; each of said element-V ary switches including a carriage movable in a rst direction with respect to said contact bank,

an element carried by said carriage and movable in a second direction with respect to said contact bank, and a Contact controlling member carried by said element; means for selecting any one of said elementary switches to be operated; and means for moving the carriage and the element of a selected one of said elementary switches.

39. In a switching system including a longitudinally extending contact bank divided into a plurality of groups of contacts and a frame associated therewith; a plurality of self-contained switching units removably supported by said frame in spaced-apart relationship and commonly associated with said contact bank; each of said switching units being operable independently of the other of said switching units and comprising -a plurality of independently operable elementary switches respectively associated with the groups of contacts in said contact bank; each of said elementary switches being operative to control the contacts in the associated group of contacts in said contact bank; means for selecting any one of said elementary switches to be operated and for preventing the operation of the other of said elementary switches; and means for selectively controlling the operation of said selected elementary switch.

40. In a switching system including a contact bank; a switching unit associated with said contact bank; said switching unit comprising a plurality of independently operable elementary switches; each of said elementary switches including a carriage movable in a rst direction with respect to said contact bank, an element carried by said carriage and movable in a second direction with respect to said contact bank, and a contact controlling member carried by said element; impulse responsive means operative successively to select any one of said elementary switches to be operated, to move the carriage of a selected one of said elementary switches, and to move the element of a selected one of said elementary switches; and additional impulse responsive means for controlling the operation of said ilrst-mentioned impulse responsive means.

41.In a switching system including a contact bank divided into a plurality of groups of contacts; a switching unit associated with said contactA bank; said switching unit comprising a plurality of elementary switches respectively associated with the groups of contacts in said contact bank; each of said elementary switches being operative independently of the other of said elementary switches to control the contacts in the associated group of contacts in said contact bank; impulse responsive means operative successively to select any one oi' said elementary switches to be operated, and selectively to control the operation of said selected elementary switch; and additional impulse responsive means for controlling the operation of said rst-mentioned impulse responsive means.

HANS SENGEBUSCH.