US2247408A - Printing telegraph apparatus - Google Patents

Description

y 1941 A. H. REIBER 2,247,408

PRINTING TELEGRAPH APPARATUS Fil ed March 5, 1958 5 Sheets-Sheet 1 FIG. 1

no r IIIITII] ZZZ INVENTOR. ALBERT H. REIBER ATTORNEY.

y 1 A. H. REIBER 2,247,408

' I PRINTING TELEGRAPH APPARATUS Filed March 5, 1938 5 Sheets-Sheet 2 FIG. 2

INVENTOR. ALBERT H. REI BER ATTORNEY.

July 1, 1 A. H. REIBER I ,247,408

PRINTING TELEGRAPH APPARATUS INVET/TOR ALBERT H. R EIBER July 1, 194-1. A RElBER 2,247,408

' PRINTING TELEGRAPH APPARATUS Filed March 3, 1938 5 Sheets-Sheet 4 INVENTOR.

ALBERT H. REIBER ATTORNEY.

FIG. 4 BY' July 1, 1941.. REIBER 2,247,408

PRINTING. TELEGRAPH APPARATUS Filed March 3, 1938 5 Sheets-Sheet 5 INVENTOR. ALBERT H. REIBER' ATTORNEY Patented July 1 1941 UNITED STAT 1 ram Albert H. Reiber, Evanston,

Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application March 3, 1938, Serial No. 193,642

25 Claims.

This invention relates to printing telegraph apparatus and particularly to printing telegraph apparatus in which the characters are printed in page form from type elements carried upon the periphery of a rotatable and selectively arrestable wheel.

An object of the invention resides in the provision, in a printing telegraph receiving unit embodying a selectively rotatable type wheel, of instrumentalities for effecting printing therefrom independently of a succeeding selective operation for determining a subsequently selective position of the type wheel.

Another object of the invention is to render each character visible immediately after it is printed and further to render all of the printed material at the printing level visible when the receiving unit is at rest. 7

Another object of the invention is to provide separate terminal blocks and slip connection blocks for the electrical apparatus included in each assembly of apparatus that is removable as a unit from the receiving printer, so that partial dismantling of the apparatus may occur Without interfering with the circuits to apparatus not involved in the dismantlement.

The invention features, in a printing telegraph receiving unit embodying a type wheel, independently driven instrumentalities for setting the final selector mechanism and for printing, which instrumentalities operate successively to accomplish the printing of a character in response exclusively to the control signal representing the particular character.

Specifically, the invention features a division of the transfer and printing control operation between two cam assemblies that are independently driven, the establishment of a driving connection for one of the cam assemblies being controlled by the other cam assembly.

The invention also features an arrangement for oscillating the type wheel, whereby it is projected into position for printing just prior to theprinting operation and is retracted from that position following the printing operation, so that a character which has been printed becomes immediately visible after printing and all of the characters previously printed in a line are brought into view at the same time.

In a copending application Serial No, 77,796 filed May 4, 1936 by Albert H. Reiber, there is disclosed a type wheel printer with reference to which the present invention stands as an improvement. According to the disclosure of that application, the transfer operation, by which the rest.

code discs of a code disc selector are set in accordance with a new signal combination and the type wheel is released for rotation to a new position of arrestment corresponding to the transferred signal, is performed by a cam included in a cam assembly which also includes the cam for performing the printing operation. The printing operation is timed to precede the transfer operation, the reason for this being that the interval of time which it is necessary to allot to rotation of the type wheel to a new position of arrestment might be longer than the interval of time between the transfer operation and the end of the cycle of the camassembly which includes the transfer and printing cam, so that the printing operation could not be timed to be performed before the end'of the cycle in which the transfer occurred. Consequently, the printing operation is timed to occur substantially immediately after the beginning of the next cycle of operation of the cam assembly, and the result is, as described in the copending application, that the printer always comes to rest with a signal combination stored in the code disc selector mechanism which would not be cleared out until the next cycle of operation of the cam assembly. If the signal combination which is stored represents the last character of a message, it is necessary to introduce an idle operation of the printer in order to print the character for the selection of which the type wheel has been rotated in response to the signal combination stored in the code disc selector.

According to the present invention, the cam which effects the transfer has been removed from the cam assembly which includes the print cam and has been included in an extra cam assembly carried by' an extra power driven shaft located at the front of the machine. A clutch is provided for connecting the front cam assembly to the shaft by which it is carried, and this clutch is tripped by a cam projection included in the selector cam assembly, the function of which in the receiving mechanism, disclosed in the copending application, was to trip off the clutch for the main cam assembly, The cam assembly carried by the front shaft includes a cam for tripping the clutch through which rotation is imparted to the cam assembly on the main shaft, which includes the print cam. The front cam assembly, when it has effected the transfer and has come to rest, has set in operation the main or inner cam assembly and the printing of the character represented by the signal which has been transferred occurs before the main cam assembly comes to Thus a complete cycle of operation of the receiving mechanism, which begins with the reception of the start impulse of a signal combination and which terminates when the main cam assembly comes to rest, occupies a greater interval of time than does a cycle of operation of the receiving mechanism shown in the copending application, but there is no storage of a signal combination necessitating the introduction of an idle cycle, and signal combinations may be received and rendered effective for the printing of characters or the performance of functions as rapidly as in the printing mechanism according to the disclosure of the copending application.

.An arrangement for rendering each character visible immediately after printing is included in the present invention, the immediate visibility of the character being accomplished by normally holding the type wheel below the printing line, lifting it into printing position just prior to the performance of the printing operation and lowering it to the normal or rest position thereafter. The lifting and lowering of the type wheel is controlled by two cams, one included in the cam assembly on the front shaft and the other included in the cam assembly on the main or inner shaft. The cam on the front shaft operates in advance of the tripping off of the clutch through which the cam assembly on the main shaft is driven, to elevate a frame which holds the type wheel hub until the frame is arrested under the control of a mechanism which is controlled in accordance with letters or figures printing selection, a selected peripheral arrangement of printing elements being aligned with the printing level when the frame is arrested. Just before the elevating cam comes to rest it loses control over the type wheel supporting frame, but by this time a cam carried by the cam assembly on the main shaft has been rotated into position to assume control over the frame and hold it elevated until the printing operation occurs. After the character has been printed, this cam controls the lowering of the type wheel frame to its normal or rest position.

The type wheel which is included in the printing telegraph apparatus according to the present invention may be generally of the type disclosed in copending application Serial No. 77,794 filed lit/lay i, 1936 by Howard L. Krum et al. The type wheel has two rows of type pallets having character faces arranged around the periphery of the type wheel. The type pallets are held in the type wheel structure by springs and are arranged to be driven radially of the type wheel by a print hammer. When the type wheel is elevated preparatory'to printing, one or the other of the two rows of type pallets is brought into position level with the offset end of the print hammer, so that when the print hammer is operated, it will drive the particular type pallet which is in direct alignment with it radially of the type wheel to strike a message receiving page carried by the printing platen. The print hammer is reciprocated to effect printing by operation of the print cam act" ing through a cam follower arm and a bail.

Certain features of invention disclosed but not claimed herein are also disclosed and are claimed in copending applications Serial No. 208,761, filed May 19, 1938, by Edward S. Larson, Serial No. 204,038, filed April 25, 1938, by Carl A. Levin, Serial No. 203,021, filed April 20, 1938, by Berthel F. Madsen, Serial No. 210,816, filed May 31, 1938, by Carl W. Swan, and Serial No. 211,436, filed June 3, 1938, by Herman Lotterman.

For a complete understanding of the invention reference may be had to the following detailed description, to be interpreted in the light of the accompanying drawings, wherein Fig. 1 is a perspective view of the combined transmitting and receiving mechanism according to the present invention, certain portions being broken away to clarify the showing;

Fig. 2 is a front elevational View of the receiving and printing mechanism;

Fig. 3 is an elevational View of the receiving printer taken at the right-hand side thereof;

Fig. 4 is a view taken from the top showing sections taken on various planes to show constructural details, and

Fig. 5 is an exploded View in perspective of the type wheel oscillating mechanism and the relationship of the shift and unshift function mechanism thereto.

Referring now to the drawings and particularly to Fig. 1, the reference numerals l6 and l! designate generally the typing unit and keyboard transmitter unit, respectively, of a printing telegraph apparatus embodying the present invention. The keyboard transmitter unit 17 is generally similar to the transmitter disclosed in copending application Serial No. 77,796, filed May l, 1936 by Albert H. Reiber, and typing unit 16 embodies improvements on the typing unit disclosed in the copending application.

The foundation of the keyboard transmitter unit is the base casting i3 to the forwardvertical wall of which is secured a slotted comb I9. A plurality of key levers 2! are pivoted Within the casting it for rocking movement in a vertical plane, and these key levers protrude from the interior of base It through a slot in comb IS. The key levers 2i are provided with keytops 22 and are arranged to impart characteristic settings to permutation code bars contained within base 13 as fully disclosed in Patent No. 1,595,472 granted August 10, 1926 to Howard L. Krum. To the code bars are articulated lock levers 23 pivotally supported intermediate their ends and prov jecting above the upper surface of base casting l8 through apertures therein. The lock levers 23 are therefore subject to permutative setting by the code bars under the control of key levers 2|.

The upwardly projecting portions of the lock levers 23 are disposed between brackets 24 and 26 secured to base 18, and aligned with each of the lock levers 23 is a contact controlling lever 27., the levers 27 being pivotally supported by a pivot rod (not shown) extending between brackets24 and 26. A transmitting contact spring 28 individual to each of the levers 27 is mounted between insulating strips upon laterally extending portions of brackets 24 and 28, as indicated at 29. The upper end of each contact spring 28 engages a gooseneck portion of lever 27 and the flexing of contact spring 23 into and out of engagement with a shorter associated contact spring is controlled by gooseneck lever 27. The rocking of the gooseneck lever 27 is, in turn, controlled by the lock levers through blocking lugs (not shown), a lever 27 being unblocked when its corresponding lock lever is presented in extreme clockwise position and being blocked when its corresponding. lock lever is in extreme counterclockwise position.

Bracket 24 and another bracket designated by the reference numeral 3! rotatably support a signal transmitting distributor shaft 32. Near one end shaft 32 has secured thereto a gear 33 to which rotation is continuously imparted by another gear aswill presently appear. Adjacent to gear 33, shaft 32 has secured thereto the driving element 3d of a jaw clutch. A driven clutch element 36, slidable upon shaft 32, is keyed to a cam sleeve 3'! and is urged toward clutch driving element 34 by a compression spring 38. A pivoted clutch throwout lever 39 normally holds driven clutch element 36 out of engagement with driving element 34 against the force exerted by comression spring 38. Clutch throwout lever as has an arm ii which terminates substantially in engagement with an abutment screw 42 carried by a clutch tripping bell crank d3. A depending arm i l of bell crank 43 has its outer end disposed in the path of a lug liS carried by a link ll which enters the keyboard base l8 and is there connected to a universal bail (not shown). When link l? is shifted forwardly of the keyboard transmitter base by operation of the universal bail under the control of one of the key levers 2!, it rocks bell crank d3 clockwise which, in turn, trips clutch throwout lever 39 and permits spring 38 to shift driven clutch element 35 into engagement with driving element St. As link Q7 is moved forit is cammed downwardly by cooperation of a cam projection db with the head of a screw ii carried by a forwardly extending portion of bracket 25. The camming of link l! downwardly permits the free end of arm as of bell crank it to from lug lit so that bell crank d3 may return immediately to its extreme counterclockwise position and permit clutch throwout lever 39 to return immediately into position for arresting the clutch comprising elements 3d and 38 at the conclusion of one revolution thereof, even though a key lever should be held depressed and link l"; retained in its forward position for a prolonged interval of time. Thus the operation of cam sleeve Ill by the jaw clutch is confined to single revolution in response to each operation of a key lever. A tension spring 5i maintains engagement between cam projection iii of link i? and the head of screw 49.

The cam sleeve 3? carries a lock bail operating cam 52 and a plurality of impulse timing cams 53. Cam 52 controls the operation of a lock bail 5 3 pivotally supported by brackets 2 and 25, lowering the bail into blocking relation to the lock levers 23 as the cam sleeve 3? begins to rotate, and lifting it at the end of a cycle. The function of the lock bail Ed is to prevent the shifting of lock levers 23 during a cycle of rotation of the impulse timing cams 53 and thus preventing mutilation of a signal combination established by the depression of a key lever 2 l. Each of the earns 53 is aligned with one of the transmitting contact control levers 2'! and is engaged by a portion of the aligned lever. Each of the cams 53 has a notch 5t in the periphery thereof which, when presented to the associated transmitting contact control lever 2i, releases that lever for rocking movement in counterclockwise direction, and the lever 2? rocks unless restrained by its associated lock lever 23. The recesses 56 in the several cams 53 are arranged spirally about the cam assembly so that the levers 27 are released for rocking movement successively. When a lever El is permitted to rock counterclockwise by its cam 53, its contact spring 27 flexes into engagement with the associated short contact spring and a current impulse is impressed upon the telegraph line, the duration of which corresponds to the interval in which the lever 21 remains in its counterclockwise position. The cams 53 thus distribute to the telegraph line the signal impulses corresponding to a character represented by a key lever depressed. One of the contact controlling levers 27 has no lock lever associated with it and operates invariably once in each cycle of operation of the transmitting cam for impressing on the line the stop impulse.

The principal foundation element of the typing or receiving unit is a casting which mounts on the keyboard base #8 and has a portion 64 located centrally or the base it? and a portion 62 extending transversely of the base E8 in proximity to the rear edge thereof. Thumb screws are employed for securing the casting comprising portions 6i and 62 to the base l8, one of those screws being indicated at 63. A secondary casting 64 extends transversely of the keyboard base l8 and is secured to portion 82 of the primary casting by any desired means, such as screws. The primary casting supports all of the power driven shafts, the operating cam assemblies, the selector mechanism, the printing mechanism, and the ribbon feed mechanism. The secondary casting 64 supports the platen carriage and associated mechanism, the signal bells, and a set of levers by which various functions are performed.

The primary selector mechanism which integrates the signal combinations generated in the keyboard. transmitter mechanism, hereinbefore described, or in a remote transmitter, is indicated generally by the reference numeral 65 and is generally similar to the primary selector mechanism disclosed in the hereinbefore identified copending application of Albert H. Reiber. The principal elements of the selector mechanism (iii are a selector cam assembly 67, a selector magnet t8, and a sword and T-lever assembly 89, the last mentioned assembly as well as the selector being supported by a mounting plate it carried by the forwardly extending portion 6! of the primary casting. The selector cam assembly bl is carried by the upper end of a vertically positioned shaft which is rotatably supported in bearing blocks '52 and iii. The selector cam assembly 5? has flanges it secured thereto at opposite ends, and in spaced relation to each flange id is a flange 36 secured to the shaft which supports the cam assembly 8'1. A friction disc H occupies the space between each of the flanges it and the adjacent flange lti. Considerable friction is generated between the discs TI and those positioned on either side of them so that selector cam assembly til will rotate with its supporting shaft except when restrained under the control of selector magnet 68, as is well known in this type of single magnet selector mechanism.

Just above the point at which it enters lower bearing block it, the shaft has secured thereto a gear '58. An electric motor (not shown) drives a pinion which meshes with gear "l3 so that the shaft to which the gear i8 is secured is continuously rotated. It may be added at this point that a gear is carried by a stub shaft meshes with gear is and that a spiral gear 8E also secured to the stub shaft meshes with gear 33 carried by the transmitter shaft 32. Thus rotation is imparted to the transmitting distributor shaft 32 from the motor pinion through gears l3, it, 8 I, and 33.

The sword and T-lever mechanism 69 is actu ated under the joint control of selector cam,

assembly 6'? and the selector magnet E8 to interpret or integrate a series of impulses representing a signal combination preparatory to setting T-levers. 82 in accordance with the signal combination. Each of the T'-levers 82 engages one arm of a transfer bell crank 83, the other arm of which is articulated to one of the notched code discs of a code disc selector mechanism indicated generally by the reference numeral 84.

The code disc selector mechanism 84 has a circular arrangement of vertically positioned stop pins 86 which project through slots in the topmost plate of the mechanism. Stop pins 86 are biased inwardly radially of the code disc selector mechanism and near their upper ends they rest against the edges of shiftable notched code discs as is fully disclosed in the copending application of Albert H. Reiber. The notching of the code discs is such that for any permutative setting of the discs under the control of T-levers 82 one only of the stop pins 8% finds presented to it an alignment of notches, whereupon the pin therefor enters the alignment of notches under the influence of its biasing spring, its upper end moving inwardly. A type wheel stop arm Bl clamped. to type wheel shaft 88 is of such length that in revolving, it just clears those of the stop pins 36 which are held in their outermost positions by the code discs, but finds blocking its path any pin 86 which has entered an alignment of notches in the periphery of the code discs. The type wheel shaft 538 extends downwardly through the code disc selector mechanism il l coaxially thereof and receives a continuous torque from the driving motor through any convenient means, such as a gear carried by the shaft 83 and connected thereto by friction discs, the gear being continuously in mesh with the motor pinion. With this arrangement, the shaft 83 is always rotate and is free to do so when any stop pin 8%; which had been previously selected is moved out of the path of the stop arm 8'? upon the resetting of the code discs. With this arrangement, shaft 83 may be arrested in any angular position in which stop arm 81 encounters a stop pin B6.

The setting of the T-levers 82 according to the operation of the sword lever mechanism S9 is controlled by a transfer bail Si which is cam operated as will presently appear. ransfer bail Qi is pivotally supported by an upper mounting screw 92 and by a lower mounting screw which does not appear in Fig. 1. Transfer bail BI is biased in counterclockwise direction by tension spring at and has oppositely extending arms 94 and 95. the former of which is only partially indicated in Fig. 1 but which supports transfer springs, as is clearly indicated in the copending application of Albert H. Reiber, and the latter of which carries a locking blade 9'5 that cooperates with extensions 93 of T-levers 32. Looking blade 91 ordinarily blocks the extensions 93 of T-levers 82 whether they be presented in extreme clockwise or counterclockwise position. The rocking of transfer bail 95 in clockwise direction to effect the resetting of T-levers 82 is accompanied by withdrawal of locking blade 91 out of the path of movement of T-lever extensions 98. When the transfer has been completed, transfer bail 9i returns to its extreme counterclockwise position and locking blade 9'! is restored to locking position with respect to extensions 98.

The front portion of the primary foundation casting for the typing unit has secured thereto spaced brackets IM and I92. A shaft I83 is rotatably supported in vertical position between brackets if}! and I832. Shaft I03 has secured thereto near the lower end a gear W4 which permanently meshes with a gear I186 supprepared to ported by gear 18 and secured thereto by any desired means, such as screws. The hub of gear I04 has secured thereto the driving portion it! of a positive engagement clutch mechanism, the driven portion of which is indicated by the reference numeral I08. The driven element I98 may be of the type disclosed in copending application Serial No. 165,437, filed September 24, 1937, by B. F. Madsen, having in its periphery a groove designated I09 in the present application, which receives the portion III of the clutch throwout lever H2. The portion III of the clutch throwout lever H2 confines driven clutch element let to substantially complete engagement with driving element It! during a cycle of operation following the tripping of the clutch, and prevents acceleration of the driven element of the clutch from the speed imparted to it by the driving element Ifl'l, should any torque generated by negative load resulting from the interaction of a cam follower and its cam be applied to the driven clutch element I98. Driven clutch element I08 is slidably splined or keyed to a cam assembly sleeve H3 andis urged into engagement with driving element it? by compression spring IE4.

Clutch throwout lever H2 is carried by the lower end of a pivoted bail l I6, the upper pivot of which is indicated Ill. At its upper end, bail H6 is provided with an arm H5, the free end of which is disposed in the path of the lowermost cam projection I26 of selector cam assembly 6?. Bail I Iii is biased in counterclockwise direction by tension spring I21. When cam projection i263 on selector cam assembly I5! encounters arm N5 of bail I Hi, the bail is rocked in clockwise direction, thus withdrawing clutch throwout lever I i2 from restraining engagement with the driven clutch element 568 of the clutch on the front shaft, and permitting driven element 08 to move into engagement with driving element iii'i whereby rotation is imparted to cam sleeve i It.

Cam sleeve 5 l3 supports three cams designated IE8, IE9, and I25. Cam H is engaged by a follower roll I22 carried by an arm i23 secured to transfer bail SI. The direction of rotation of cam sleeve H3 is counterclockwise and cam H9, in being rotated, imparts clockwise rotation to arm I23 and therefore to transfer bail 9 i Transfer bail 9i, as previously set forth, effects the permutational rearrangement of T-levers 82 and therefore the notched code'discs in the code disc selector mechanism 8 3 in accordance with a signal combination which has been integrated in the sword lever mechanism 69.

As previously set forth, there is a shaft rotatably supported in vertical position by bearing blocks 12 and T3 to which the gear iii is secured. Below bearing block 13 the shaft has secured thereto the driving element 224 of a positive drive clutch, the driven element of which is indicated I29. Driven element I29 is slidably splined or keyed to a main cam assembly 839 and is urged into engagement with driving element I2 5 by a compression spring I26. The engagement and disengagement of the elements ltd and 52% of the main cam assembly driving clutch mechanism is controlled by apivoted clutch throwout lever 52? to which is secured an arm E23 that extends forwardly of the typing unit and terminates in the path of the apex of cam i it carried by cam sleeve M3 on the front shaft. As indicated in Fig. 1, in which the clutch mechanism on the shaft and on the main cam driving shaft are shown in their rest positions, the rest position of the apex of cam II8 is a small angular distance in counterclockwise direction from the end of arm I23 which effects the tripping of the main cam clutch comprising elements I24 and I29. Since, as previously stated, cam cylinder I I 3 rotates in counterclockwise direction, it will be apparent that cam II8 operates upon arm I28 to effect the tripping of driven clutch element I29 just before cam IIB reaches the end of a cycle of operation.

The bracket IIJI which rotatably supports the upper end of shaft I533 pivotally supports a bail I3I, the pivot being indicated I32. The bail I3l supports a cam follower arm which has been omitted from the showing of Fig. 1 for the reason that it would conceal substantial portions of the main cam assembly I36 carried by the rotatable shaft which is supported in bearing blocks 12 and 13. The cam follower arm carries at its free end a follower roll which engages cam I25 at a point between cam assemblies H3 and I 24. The contour of cam I25 comprises a smooth gradual rise and a sharp drop-off, the drop-off being indicated by a reference numeral I33. As cam I25 rotates counterclockwise, it shifts its follower roll away from the axis of shaft Hi3 and thus imparts a counterclockwise rotation to bail I 3 I. In the rest position of cam I 25, the drop-off I33 is a small angular distance beyond the point of engagement of the cam follower roll with cam I25. The tendency of the cam I25 therefore is to permit bail I 3 I to return sharply to its extreme clockwise position just before cam I25 reaches its rest position. However, as will presently appear, a cam included in the cam assembly I30 assumes control of bail I3I just before the sharp drop-off I 33 in cam I25 is presented to its follower, and the cam in cam assembly I 30 holds bail I BI in extreme counterclockwise position for a predetermined interval and thereafter controls the restoration of bail Iti to its extreme clockwise position.

Bail II'II has integral therewith an arm I t-i which extends toward the rear of the typing unit and terminates in a spring hanger hook I 36. Hook I36 supports one end of a tension spring I31, the opposite end of which is connected to an arm I 38 of a type wheel supporting frame I 39.

Frame I39 is provided with. a vertically disposed slot I II through which extends a stud M2 supported by a portion of the frame of the typing unit. At the top, frame I33 has a horizontally extending portion M3 through which type wheel shaft 88 passes and in which is rotatably held the hub of a type wheel IM. Vertically disposed guide pins I46, only one of which appears in Fig. 1, are supported by a stationary bracket It? at the top of the typing unit and pass through apertures in the horizontal portion Hit of type wheel supporting frame I39. The pins I46 and the cooperating elements comprising slot I4! and stud I42 permit oscillatory movement of frame I 39 vertically, and guide the frame in that movement. Frame I 39 is provided with an abutment screw I48 against which arm I34 of bail IBI rests when the bail ISI is in extreme clockwise position and frame I39 is in the lowermost position. When bail I3I is rocked in counterclockwise direction by cam I 25, bail arm Itt tends to move out of engagement with abutment screw Hi8 and spring I31 tends to be distended. Spring I31, in turn, lifts frame Hit, and thus type wheel M4, the normal position of which is below the printing line, is elevated so as to bring character elements carried upon the periphery of the type wheel into position to effect printing in line upon .upper and lower arms Ill-'5 and IN,

a page carried in engagement with cylindrical platen Hi9. When bail I3I is restored to its extreme clockwise position, arm I3 3 engages abutment screw M8 and restores frame I39 to its low" ermost position which, in turn, restores type wheel IM to its lowermost position, whereby each character becomes visible immediately after being printed.

As previously set forth, main cam sleeve I310 is set in operation by the tripping of clutch throwout lever I27 by cam IIB included in front cam assembly I I3 just before cam H8 reaches its rest position. The uppermost of the cams carried by cam assembly I30, designated I 5I, is engaged on the periphery thereof by a follower roll I 52 carried at the end of a lever I53 which is pivoted at Ififl. Lever I53 has integral therewith an arm I56 which is provided near its outer end with a plurality of spring connection apertures I57. Any one of the apertures I5! is adapt ed to receive one end of a tension spring I53, the other end of which is supported by a spring post I59. Spring I58 biases lever I53 in counterclockwise direction, thus urging cam follower roll I52 into engagement with the periphery of cam I5I. The several spring mounting apertures I57 in arm I 55 of lever I 53 are at different distances from spring post I59 so that the tension exerted by spring I58 and therefore the torque applied to lever I 53 may be varied.

A print hammer operating bail IIiI is pivotally supported by pivot I 54 and coaxially mounted pivot I52. At its lower end, bail IEiI is provided with an arm I53 which supports adjustable abutment screw IM and also one end of a tension spring I 66. The inner end of abutment screw I66 engages an arm I5? of lever I53 and the rearmost end of tension spring M55 is also connected to arm It"! of lever I53. With this arrangement, bail It! tends to occupy extreme clockwise position with respect to lever I53, the extremity of the position being determined by abutment screw IM.

Print hammer operating bail IIiI has integral therewith at its upper end a lever arm I68. At its free end, lever arm I68 is loosely articulated to a print hammer I88. Print hammer I59 extends between ribbon spools II I, rotatab-ly mounted upon a ribbon feed mechanism supporting plate I12. Print hammer I59 is provided with respectively, which are disposed in the same vertical plane. Lower arm. I'IIi enters a slot in a bracket I16, carried by ribbon feed mechanism foundation plate I12, and by means of slotted bracket IIB, print hammer I59 is held in a vertical plane and is guided in reciprocatory motion imparted by arm Isl of bail IEI. The upper arm N3 of print hammer IE9 is longer than the lower arm I74 and extends across the periphery of type wheel I46 and across the upper end of type wheel shaft it. At its free end, arm I73 is provided with 21. depending portion III which, in turn, is provided with an arm I78, the location of which is in alignment with the foremost portion of platen M9, which portion is at the level where printing occurs. Print hammer I69 is provided in its lower edge with a shallow recess I 'III, the base of which rests upon and slides upon a retainer Ibar I'IE secured to ribbon mechanism base plate I72. The motion of print hammer I69 to effect printing is limitedby engagement of one end of recess I 'II] with bar I i5, and the restorational motion may, if desired, be limited by engagement of the other end of recess I'm with bar I75.

The print hammer I59 may be lifted out of its position above the type wheel IM to permit adjusting or changing the type wheel, by springing the free end of print bail arm upwardly until the rearmost end of recess I19 clears bar I15, whereupon arm I14 of the print hammer may be drawn clear of slotted bracket I16, and the print hammer may be rotated upwardly in a vertical plane about its pivot of articulation with ball arm I58.

Type wheel I44 may be generally similar to the type wheel disclosed in the herein before identified application of Albert H. Reiber, and also in application Serial No. 17,794, filed May 4, 1936, by Howard L. Krum et al. As shown in those copending applications and as clearly indicated in Fig. 1 of the present application, type wheel IN is provided with a plurality of radially disposed type pallets I19 which are reciprocably mounted in radial slots in type wheel IM, and are provided at their outer ends with type elements IBI. There may be two superposed rows of type pallets I19, and by means of the lifting of type wheel supporting frame I39 by lever I34, either of the rows of type pallets may be brought into alignment with rearwardly presented portion I18 of print hammer I59. For any angular position of arrestment of type wheel IN by the cooperation of type wheel stop arm 81 with a selected stop pin 86, two of the type pallets I19 will be directed toward platen I49 in the same vertical plane as print hammer I159. According to the distance that type wheel IM has been lifted by lever arm I 3 8, the distance being controllable, as will appear later, one or the other of the type pallets I19 will be disposed directly in the path of portion I18 of print hammer I59.

Cam ItI, in its normal or rest position, holds print bail operating lever I53 in extreme clockwise position in opposition to the tension of spring I59. Spring I65 holds print hammer bail IBI in extreme clockwise position with its abutment screw I64 in engagement with arm I61 of print bail operating lever I53. Thus, print hammer I69 is held in retracted position. At a predetermined time in the operation of cam II, a sharp drop-off is presented to follower roll I52 of print bail operating lever I53. When the dropoif is encountered, lever I53 is rocked sharply in counterclockwise direction by spring I58. Lever I53 imparts counterclockwise movement to bail IBI through abutment screw I64. The angular distance through which lever I53 rocks, as cam follower I52 descends to the lowest or innermost point on the periphery of cam I5I is just short of sufficient to drive print hammer I69 positively against the type pallet I19 aligned therewith. However, the inertia of bail IBI and print hammer I99 causes spring I55 to yield and abutment'screw Nit to move out of engagement with arm IE1. Thus print hammer I69 overtravels or moves a greater distance than it would if positively interconnected with lever I53, the overtravel being caused by the inertia of bail I6I and print hammer I69, and being permitted by spring I66.

As soon as the energy generated by the inertia of bail ISI and print hammer I 69 has been expended, spring I56 withdraws print hammer I69 in the direction of its retracted position until abutment screw ltd returns into engagement with arm I61 of lever I53. The remainder of the movement of print hammer I69 to its rest position is effected by the restoration of lever I53 to its extreme clockwise position by cam I5I. The

uvertravel in the movement of print hammer I69 is sufficient to reciprocate the aligned type pallet I19 radially of type wheel IM- to effect printing. During the period of overtravel and restoration, the free end of arm I19 of print hammer I69 is presented between the type pallets adjacent to that which is being operated, so that the type wheel I ls could not be rotated, even if permitted to do so by arm 81, due to the fact that interference between arm I13 of print hammer I99 and adjacent unoperated type pallet would occur. Spring I65 withdraws print hammer I59 from a position of interference with unoperated type pallets much more rapidly than it could be withdrawn if positively connected to print hammer bail operating lever I53. Thus, with the arrangement hereinbefore described, the print hammer IE9 is projected and retracted in the shortest possible interval of time so that more time may be allowed for the rotation of type wheel I44 to the position corresponding to the next selection.

In a preceding paragraph, the lifting of the type'wheel to bring either of its two rows of type pallets into printing position was described. The lifting is accomplished by the counterclockwise rocking of bail ItI which has an arm I3 interconnected with the type wheel supporting frame I39 by spring I31. It was stated that the lifting of the type wheel supporting frame I39 is effected by a cam I25 on the front shaft. It was also stated that the lowering of type wheel supporting frame I39 is controlled by a cam included in the cam assembly I59 on the main shaft. This cam is indicated by the reference numeral I86, and is of the internal species having its cam surface on the inside of a depending peripheral flange. The internal cam surface is engaged by a follower roller carried at the free end of an arm I81, secured to type wheel lifting bail I3I. Spring I31 biases bail I3I in clockwise direction as previously set forth and, in so doing, urges the follower roller carried by arm I91 to seek engagement with the internal cam surface of cam I85. Cam I86 does not have a restricting channel, so that the follower carried by arm I81 is free to be moved away from engagement with the interior of the depending flange of cam I95 when bail I 3| is rocked in counterclockwise direction by cam I25. During the initial stages of the lifting of frame I39 by cam I25, cam I95 may be stationary.

About the time that cam I25 has rocked bail I3I to its extreme counterclockwise position, and before the drop-off of the cam is presented to its follower roller, the innermost portion of the cam surface of cam I86 is presented in engagement with the follower roller carried by cam follower arm I81. During the engagement of the follower roller carried by arm I81 with whatever dwell there may be at the innermost portion of the internal cam surface of cam I86, bail I3I will be held in extreme counterclockwise position and lever arm I34 will be held in a corresponding position. As cam I96 continues to rotate and the receding cam surface is presented to its follower (the recession being radially away from the axis of the cam), bail I3I will be restored by a controlled motion to its extreme clockwise position, and type wheel supporting frame I39 will be restored to its lowermost position to render visible the character just previously printed. It will be apparent that when the type wheel frame I39 is being elevated, the cam follower, by means of which the lowering of the frame will subsequently be controlled, is moved out of engagement with its cam surface, and that when the frame I39 is being held in elevated position, and is being lowered, the cam follower by which its elevation was accomplished will be held out of engagement with the elevating cam.

Of the principal mechanisms of the typing unit It, there remains for consideration only the function mechanism. This mechanism is, in general, similar in construction and operation to the function mechanism disclosed in the copending application of Albert H. Reiber, hereinbefore identified. The function mechanism may be understood to include those mechanisms by which such operations shift, unshift, carriage return,

line feed, signal bell operation, and transmitter disablement are selected and accomplished. Those functions which are materially diiferent from the corresponding functions, as disclosed in the copending application of Albert H. Reiber,

and which will be described in detail, are shift 1 and unshift, by means of which selection of characters in the letters or figures bank of type pallets is accomplished.

The selection of a function is accomplished by means of a testing mechanism which is cam controlled. Since the testing operation can be conveniently performed by a groove or channel earn, a channel I9I is provided in the upper surface of print'bail operating cam IEI. A cam follower, which could not be shown in Fig. l, is fitted into the groove or channel II]! in cam IEI, and the follower arm is part of a bail I92 which is operated to test for the selection of functions, and to condition in accordance with the selection one or more of a plurality of function bars, indicated generally by the reference numeral I93. The manner in which the presence of a function is tested and in which the function bars I93 are conditioned is fully disclosed in the copending application of Albert E. Reiber.

The function bars I93 are pivotally mounted upon rod Iil l. Rod I99 is supported between spaced arms and Hill, which comprise a function bail pivoted upon pivot rod I99. The lower arm I97. of the function bail has integral therewith an arm I99 at the free end of which is supported a cam follower roller 29L A function cam 292, carried by the main cam sleeve I39, has its periphery engaged by roller 29L and when cam 292 occupies rest position, arm I99 and the function bail comprising arms I99 and I 9'! are disposed in extreme clockwise position.

At their free ends, the arms I99 and I91 support a spring post 299 to which is hooked one end of each of a 2912-. Each of the springs 29 has its other end connected to one of the function bars I93. Thus, the function bars I93 are biased in counterclockwise direction, and movement of any of them in clockwise direction is opposed by its particular tension spring 299.

The conditioning of function bars I 93. under the control of bail I92 in response to a function selection, is manifestedby rotation of one or more of the function bars I93 through a small angular distance in clockwise direction. Such rotational movement brings the conditioned function bar out of alignment with the unselected function bars and into position to initiate or perform its assigned function. I after the conditioning of one of the function bars I93, earn 292 rocks its follower arm 29! and the function bail comprising arms I99 and iii? in counterclockwise direction. Since the function bars I99 are pivotally mounted upon plurality of tension springs 4- Immediately rod I94, carried by bail arms I95 and I97, they are moved endwise toward the rear of the printer as cam follower roller 29I is moved to its outermost position with respect to cam 292. Those of the function bars I99 which have not been conditioned by being rocked in clockwise direc-' tion are reciprocated idly while one conditioned function bar I93 initiates or performs the assigned function as a result of the reciprocatory movement. The rod I94, carried by function bail arms I96 and I9], also is pivotally engaged by a spacing pawl 296 which is reciprocated to effect spacing of the platen carriage as the function bars I99 are recipro cated rearwardly of the printer. The spacing operation and the performance of the several functions excepting shift and unshift are sufliciently similar to those dieclosed in the lcopending application of Albert H. Reiber, that it is considered unnecessary to describe them in detail here. However, the shift and unshift functions will now be described.

The hereinbefore identified stud I 32, which guides the type wheel supporting frame I39 in its upward and downward movements, extends through a horizontally extending slot in a slide member 291. The slide member 29f is also provided with an open ended slot 298 through which extends a screw 299, carried by the frame of the typing unit. The stud I42 and screw 299 support the slide member 291 and guide it through out a limited sliding movement forwardly and rearwardly of the typing unit.

The slide member 291 has integral therewith a vertically extending arm 2I I. The arm SZII is provided near its upper end with a step out aperture 2I2. By virtue of the stepcutting, two abutments or stop surfaces are provided, the lower of which is indicated by the reference numeral 2I3, and the upper of which is indicated 2M and is the upper end of the aperture 2i2. The type wheel supporting and lifting frame :99 has adjustably secured thereto a bracket 2ft, which has an arm 2, extending into the aperture 2I2 of the slide member 297. When the type wheel lifting frame I39 is lifted by bail arm I34, operating through spring I31, arm 2!! of bracket 2IB may encounter either of the stop surfaces 2I3 or 2M, depending upon whether the slide member 297 is presented in its rearmost or foremost position, and thereby the type wheel lifting frame I99 will be arrested in either of two positions of elevation while bail arm I39 continues to be rocked to its extreme counterclockwise position. Fhen the type wheel lifting frame I39 is arrested by the lower stop surface N3 of slide member 29?, the upper row of type pallets carried by type wheel M4 is presented in alignment with the operating extension ill! of print hammer I99, and when the frame I39 is permitted to be lifted until its arm 25? encounters the uppermost stop surface 254, the lower row of type pallets will be presented in alignment with the print hammer I 99, and with the character impression level of the platen i229.

The movement of slide member 253'! from one to the other of its two positions is accomplished by two levers pivoted upon stud I42, one of the lovers being pivotally supported between slide member 291 and 'the frame elements which sup-- port stud I92 and which, therefore, is behind slide member 291 and cannot be seen in Fig. 1. and the other of which is pivotally supported between slide member 29? and type wheel lifting frame I39 and is indicated by the reference numeral 2I8 in Fig. 1. A screw 2I9 establishes a pivotal interconnection between the slide member 201 and its operating lever 2H3. Lever 2I8 is provided with a depending finger 22 i. The first and second of the function bars 5%, counting from the top, each have extending laterally therefrom a lug, one of which appears in Fig. 1 and is indicated by the reference numeral 222. The depending finger ZZI, of lever 21s, occupies a position directly in the path of lug 222 when the function bar which carries lug 222 has been conditioned for function performance by being rocked in clockwise direction preparatory to being moved endwise by cam 2832, operating through arm 21H and bail arms I95 and Isl. When lever 2I8 is in its extreme counterclockwise position, which is the condition when slide member 291 occupies the rearmost of its possible positions, finger 22I is disposed substantial- 1y at the limit of movement of lug 222 so that it will not be affected if the function bar by which lug 222 is carried is conditioned and reciprocated. When, however, the slide member 21!! occupies the foremost position, lever 2H8 will be presented in extreme clockwise position and its depending finger 22I will be positioned to be engaged by lug 222, early in the cycle of move ment of that lug rearwardly of the typing unit. Under these conditions, counterclockwise movement of lever 2I8 by lug 222, as it moves rearwardly of the typing unit, will result in rearward movement of slide member 2M which is articulated to lever 2I8 by screw 25 whereby slide member 2'9? will be shifted to its rearmost position with stop surface 2I3 in the path of arm 26 I carried by type wheel lifting frame ass. It will be understood that the timing of the apparatus is such that type wheel supporting frame I39 is. held lowered by bail arm ltd when slide member 291 is shifted so that there shall be no interference between arm 2%! and the step-cut portion of aperture 252 during the movement of slide member 2931.

The restoration of the slide member Zil'l to its forward position is accomplished by the lever which corresponds to lever 218 and which is pivoted between slide member Bil! and the frame member which supports stud I22 so that it does not appear, in Fig. l. A screw 22% establishes a pivotal connection between this lever and the slide member 281. This pivotal interconnection is above stud I 52 so that when the lever is rocked in counterclockwise direction, the slide member 201 will be moved forwardly of the typing unit to its foremost position. The lower end of the lever which is pivoted to slide member 2M at 223 may be similar to the lower end of lever 2H8 so that when it is in extreme clockwise position, it will be disposed in the path of the laterally extending projection of that one of the function bars its, the function of which is toshift the slide member '20! to its foremost position to permit the type wheel lifting frame I39 and the type wheel Ifi to be lifted to their uppermost position whereby printing may be effected from the lower row of type pallets. v

It will be apparent from the foregoing description of the levers which control the shifting of slide member 28? that both of htese levers effect control by being rocked in counterclockwise di rection, one being operative to shift the slide member 253? rearwardly and the other being operative to shift it forwardly. It will also be apparent that as either is rocked in counterclockwise direction by its assigned function 'bar I83,

aaimoe the motion which it imparts to the slide member it? will cause the other lever to be rocked in clockwise direction so that they will be presented alternately in position to be operated by their respective function bars.

In addition to operating the function levers I83 and the spacing pawl 25%, the function bail also operates a ribbon feed lever 226. This lever is pivoted upon a stud 2721 fixed to a stationary portion of the typing unit and its lower end engages the arms I96 and Id? of the function bail. At its upper end, lever 22% is articulated to a link 2.23 which has a slot in which is disposed one end of a ribbon feed lever 229. The ribbon feed mechanism which is operated by lever 229 may be substantially identical with that disclosed in the copending application of Albert H. Reiber "The ribbon feed mechanism supporting plate I72 supports pairs of vertically disposed pins 23I which serve as guides for the inked ribbon 232, and there is also a semicircular ribbon guide which is supported by the type wheel lifting frame E39 in spaced relation to the type wheel lit between the type wheel and the platen I45. Thus, the ribbon guide 233 is lifted each time the type wheel Hid is lifted, and a portion of the ribbon 232 is always positioned between the type wheel Md and the platen IE9 o that inked type impressions may be produced upon a page carried by platen ms.

The platen I59 is rotatably supported by the opposed ends of a carriage 236. The carriage is supported for movement transversely of the typing unit by rails, one of which is indicated as 231, secured to the rear casting member 64. The casting lit also supports near the top thereof a bracket 238 which has a threaded aperture in coaxial relation to the platen I58. A bushing 239 threadedly engages the aperture in bracket 238 and rotatably supports a square rod 2M which enters platen M19 through one of the hubs therein and passes through a square portion of a tube which extends from end to end of the platen I39. The square shaft? is of sufficient length that it may extend into or through the square portion of the tube on the interior of platen I49 in any position which carriage 236 may occupy in its travel back and forth upon its supporting rails. Square shaft 2M has secured thereto a crank 2 32 which may be rotated manually to impart rotation to square shaft 2 and, through its cooperation with the square portion of the tube into which it extends, rotation may be imparted to platen Hi9.

Carriage 253 also supports a paper guiding plate or basket 243 which is disposed below the platen for guiding a page in the printing position and which, in turn, supports pressure rolls 2M and paper guide fingers 246. Carriage 236 may have associated therewith character spacing mechanism and line feeding mechanism in accordance with the disclosure of the copending application of Albert E. Reiben, A rotatable drum Zd'i is provided for housing a carriage return spring. A carriage return belt 248 has one end secured to the periphery of drum 2M and the other end secured to carriage 236.

Terminal blocks and slip connections are provided for connecting the various electrical circuit elements in the keyboard transml ter mechanism and the typing unit to external circuits. The reference numeral 25I indicates a terminal block which is mounted on the keyboard case casting I3 behind. the typing unit. Terminal block Z5I has terminals 252 individually engaged by slip connection tongues 253 carried by a slipconnection block 254. Slip connection block 254 is secured to the rear portion 62 of the primary typing unit casting below the secondary or carriage supporting casting B4. The contacts 252 and tongues 253 may form electrical connections between the electromagnet 68 carried by the typing unit and the transmitting contact springs 21 carried by the keyboard base and between the selector magnet and external circuit. Thus, the secondary casting and all of the elements which it supports may be removed from the typing unit without disturbing the electrical connection between the selector magnet 68 and the transmitting contacts and beween the exernal circuit and both the selector magnet and the contacts. Also the entire typing unit may be removed from the keyboard base by removal of the thumb screws 53 whereby the slip connection tongues I 253 will be removed from engagement with contacts 252 without disturbing the electrical connections between the transmitting contacts and external circuit.

The general operation of the typing or receiving unit hereinbefore described is as follows-:- Permutation code signals impressed upon a telegraph line to which the receiving unit is connected enter the receiving unit at terminals 252 and slip connection 253 and are impressed upon the selector magnet 68. Gear 18 and the shaft which it drives being in operation, selector assembly t'l which is friction driven is released for a cycle of operation by the start impulse of a signal combination in accordance with the wellknown practice employed in the operation of single magnet selector mechanisms controlled by start-stop signals. As the selector cam assembly 61 rotates, the sword levers contained in the sword lever mechanism 69 are set in characteristic positions according to the signal combination received. Just before the selector cam assembly 61 completes a cycle of rotation, its cam projection I26 engages arm- II of bail H6 and rocks the bail in clockwise directionwhereby clutch throwout lever I i2 is withdrawn from restraining engagement with driven clutch element I08, carried by the front shaft, whereupon the driven element its is shifted into engagement with driving element I01, and cam sleeve H3 is set in operation for a cycle comprising one revolution.

The first operation performed after cam sleeve I I3 is set in operation is the clockwise rocking of transfer bail 9!, by transfer cam H9, operating through cam follower roller I22 and follower arm I23. Transfer bail 9| operates to set the code discs contained in the code disc selector mechanism 04 in correspondence with the setting of the sword levers. The shifting of the code discs to accomplish the selection of a new stop pin 83 is accompanied by the camming of the previously selected stop pin into unselected position whereby the restraint upon type wheel stop arm 07 is removed and shaft 84 and type wheel I4 3 rotate to seek a new stop position. At this time, the type wheel I44 is. held in its lowermost position by the type wheel lifting bail t3I and ball arm I 34.

As soon as the transfer has been accomplished,

the selector cam barrel 6'! may be released for rotation to effect the setting of the sword levers according to a new signal combination. The timing of the operation of selector cam. assembly 61 and of cam sleeve II3 carried by front shaft I03 is such, with respect to the speedof operation of transmitting apparatus, in response to which. this receiving mechanism is intended to operate, that the transfer has been effected before the selector cam barrel is released by the start impulse of the next signal combination.

A predetermined interval after the transfer operation has been performed, cam I23 begins to rock type wheel lifting bail I3I in counterclockwise direction and the type wheel I44 is elevated into printing position. The position in which the type wheel will be arrested will be determined by the position occupied by slide member 267. Bail i3I will, however, be rocked to extreme clockwise position regardless of the position in which type wheel I44 is arrested, spring I 37 yielding to permit the motion of bail I3I to be completed.

A short angular distance before cam I25 has rocked bail I3I to extreme counterclockwise position, cam I58, carried by cam sleeve H3, engages clutch throwout lever I28 of the clutch which comprises driving element I24 and driven element I29 on the main shaft or inner cam shaft, whereby the main assembly I30 is. set in operation. By the time cam I25 has rocked type wheel lifting bail It! to extreme counterclockwise position, internal cam I83, included in the main cam assembly I30, has assumed control of its follower arm I81, which is carried by bail I3I, so that type wheel lifting bail I3I is held in extreme counterclockwise position after cam 525 has come to rest and has relinquished control over bail I3I.

The front shaft may be rotated at the same speed as the main shaft so that in the reception of signals continuously transmitted, the cam sleeve H3, carried by the front shaft I03, will have a rest period between cycles of operation equal to the rest period of selector cam assembly 07 between successive code combinations. Cam sleeve H3 may, therefore, begin its next cycle of rotation before the cam assembly I30, carried by themain or inner shaft, has completed much of its cycle of operation. While cam I86 is holding type wheel HM elevated, and before cam sleeve II3 can have rotated sufliciently far inthe next cycle to operate the transfer bail, the print cam I5I brings its sharp drop off into alignment with roller I52, carried by the print bail operating lever I53, whereupon spring I58 rotates lever I53 sharply in counterclockwise direction and this movement is imparted to print bail I51, which drives print hammer I 69 into engagement with the selected type pallet and which overtravels sufficiently to produce an impact between the selected type pallet and a message page carried by platen I49. At substantially the same time that print cam I5I permits print bail operating lever I53 to be rocked counterclockwise by its spring I58, cam groove 95, in the upper surface of cam I5I, operates its associated bail I92, which tests for function selection as disclosed in the copending application of Albert H. Reiber. The effect of such testing is that a function bar I93, which corresponds to a function that may have been found to be selected is rocked clockwise through a small angular distance in opposition to its biasing spring 204, to bring it into position to initiate or perform its function.

Since tension spring I63 is effective substantially instantaneously after the printing of a character to withdraw print hammer I69 to its retracted position, which operation can be per' formed much more rapidly by spring "it than it could be by cam I5I, operating through bail operating lever I53, the transfer of the next signal combination can be performed sooner after the print operation than it could be with positive printing and retraction of the print hammer. The sooner after the printing operation that the transfer of the next signal combination may be performed, the greater is the interval of time that may be allotted for rotation of the type Wheel into a new stop position correspondingto the new selection and, therefore, the slower can be the speed of rotation of the type wheel shaft 88. The maintenance of minimum rotational velocities consistent with emcient operation is desirable in order to minimize inertia effects.

Internal cam I89 is required to hold type wheel IM' elevated only until the print operation has been performed. As cam ISI continues to rotate and restores print bail operating lever I53 to itsextreme clockwise position, cam I86 permits bail..I3I and bail arm I3; to return to extreme clockwise position, the restoration not being abrupt nor violent but rather being controlled and gradual.

As set forth in the description of apparatus, cam 292 operates function bail lever arm I99 to reciprocate the spacing pawl 296 and the function bars I93. Immediately after the printing of a character has been accomplished, the carriage 296 may be spaced to bring a blank portion of the page into position to receive the next character. If instead of a character having been selected for printing a function has been selected, and the selection evidenced by the clockwise rocking of the particular function bar by operation of bail I92 substantially simultaneously with the operation of print bail lever I53, the apparatus is conditioned for the performance of the function. The operation of lever I99 by cam 292 is gradual so that there is no abruptness in the performance of the function. As the function bars I193 are moved rearwardiy of the typing unit by operation of function lever I99, the one of the function bars I93, which has-previously been rocked into effective position initiates or performs the function such as shift, unshift, line feed, carriage return, and'various other desirable functions as disclosed in the copending application of Albert H. Reiber. The operation of function bail lever I99 is the last operation performed by the cams on cam sleeve I24 before the cams return to rest position, at which point, clutch throwout lever I21 separates driven clutch element I29 from driving element I24. 7

From the foregoing it will be observed that during the reception of isolated or widely separated signal combinations, there occurs a train of operations for each signal combination which begins with the setting in rotation of selector cam cylinder 61 and which ends with the arrestment of main cam assembly I30. The selector cam cylinder cooperates with the selector mechanism to set up the signal combination received, trips off the cam sleeve II3 on the front shaft, and comes to rest. The cams carried by sleeve H3 transfer the signal combination to the code disc selector, elevate the type wheel to printing position under the control of the shift and unshift slide member 201, trip off the main cam assembly on the inner shaft, and come to rest. The cams on the main cam sleeve I39 effect the operation ofprint hammer I69, test for the presence of a function selection, control the lowering of the type wheel to its idle position, effect character because the description was restricted to Fig. 1

spacing and the performance of any function se-' lected, andcome to rest.

When, however, signal combinations are being received at substantially maximum frequency, as is the case when the transmitter from which the signals are being received is operated by a perforated tape, or if it is a keyboard transmitter, beingroperated by a skillful operator, the stop time between cycles of operation of selector cam assembly 61 will bevery brief. The stop time between successive cycles of the front cam cylinder I I3 and the main cam cylinder I39 will be correspondingly brief, but definite phase relationships between all of the cam assemblies will be maintained. Thus, all of the cam assemblies may be rotating simultaneously, and not two of them may be at rest at the same time. However, the operations which they control will proceed in orderly fashion exactly in accordance with the planned timing of the receiving mechanism. Any signal combination introduced at the selector magnet 68, whether relating to the printing of a character or to the performance of a function, will have become effective for the purpose for which it was introduced before the completion of the operation initiated by the selector cam assembly 91, and there will be no storage of a signal combination requiring an additional cycle of operation of the selector cam barrel for its clearing out, as is the case in some printing telegraph mechanisms, in which the transfer and printing operations are not assigned to be performed by cams included in separate cam assemblies, but are performed by cams included in a single .cam assembly, and in which there is insufficient time between the transfer operation and the end of the cycle of the single cam assembly for the completion of rotation of the type wheel or other conditioning of the printing element and the actual printing operation. In some printing telegraph I receiving apparatus having a single operating cam assembly, such for example, as that exemplified in the copending application of Albert H. Reiber, the printing operation is timed to precede the transfer operation in each cycle of the cam assembly so that the printing operation always lags one cam cycle behind the transfer operation, and at the completion of any message, the signal combination for the last character or function remains in storage in the code disc selector mechanism and necessitates the introduction of an idle cycle of the selector cam assembly for its clearing out. In the printing telegraph receiver mechanism according to the present invention, the printing operation and also the operation of the function mechanism follows the transfer operation in the general cycle of operation of the mechanism which may be considered as beginning with the starting of the selector cam assembly 6? into rotation and terminating with thearrestment of the cam assembly I35) carried by the main or inner operating shaft. It will thus e apparent that the printer always clears out and prints in accordance with the last signal combination received and no signal combination is ever left in storage in .the selector mechanism. In the foregoing general description of the printing telegraph apparatus in accordance with the invention, certain details were not described in which those details could not be clearly shown. They are, however, shown in Figs. 2 to 5, inclusive, and will now be described, having reference particularly to the detailed showings.

Type wheel supporting and driving mechanism Type wheel I44 comprises upper ring element 26I and lower ring element 262 joined by a web portion which has radial slots in which type pallets I19 are slidable. As indicated in Fig. 2, the type pallets are recessed, recesses in those of each row opening toward the recesses of those in the other row, and seated in the recesses of all of the type pallets I19 in a row is a garter spring 263 which biases all the type pallets it engages to their innermost position. The lower ring 262 of type wheel I44 has a cylindrical upset portion 264, the upset portion being coaxial with the type wheel.

The upset portion 264 of type wheel I44 rests on the top of a hub 266, which is slidable upon type wheel shaft 88. At one point in the periphery of type wheel hub 266, there is a notch or recess 261 which receives a pin 268 secured to and depending from the upset portion 264 of type wheel M4. Pin 268, cooperating with slot or recess 261, enables the fitting of a type wheel I44 to hub 266 and, therefore, to shaft 88-, in the correct angular position with respect thereto, so that the type wheels may be interchanged without adjustment or the checking of alignment. A plurality of clamping screws- 269; which may also be seen in Fig. 4, are employed for rigidly securing type wheel I44 to hub 266.

Hub 266 is supported by type wheel lifting frame I39, and to this end hub 266 is grooved as at 21I to provide a portion of reduced diameter between flanges or shoulders. Intermediate the apertures, through which extend the guide pins or screws I46, frame I39 is provided with a recess which extends inwardly from the foremost edge thereof. This recess is of such width that its defining edges enter the groove 2H, and substantially engage the reduced portion of the hub, thereby being disposed between the spaced shoulders. The recess in frame I39, which is entered by the reduced portion of hub 266, need have no closure to insure the retention of the hub, as the location of the type wheel shaft 98 is established, and the position of frame I39 1s definitely established by pins I46. From the foregoing it will be apparent that hub 266, while being slidable upon shaft 88, is secured to type wheel shifting frame I39, and in turn has secured to it type wheel I44. Thus, any motion which frame I39 undergoes is imparted to type Wheel I44.

Hub 26.6 has secured thereto, by means of clamping nut 212, a radially extending arm 213 at the free end of which is a depending arm 214. Type wheel shaft 88 has secured thereto, by means of clamping screw 216, a split bushing 211. Bushing 211 has integral therewith a radially extending arm 2-18, the free end of which is slotted to receive depending arm 214' of type wheel hub arm, 213. Rotation is imparted from shaft 88 to hub266 by means of arm 2 18 of bushing 211 through the engagement with depending arm 214 of radial arm- 213 of hub-266. Arm 214 of hub arm 213 fits freely into the slot in driving arm 218, so that when hub 266 is lifted by frame I39, arm 214 may slide in the slot in arm 218 and thus rotation may be imparted by shaft 88 to type wheel I44 while the type wheel is in motion upwardly or downwardly under the control of frame I39, or while the type wheel is being held in any predetermined; horizontalplane. 7

Function suppression mechanism In the copending application of Albert H. Reiber, it is disclosed that under certain circumf stances, it may be desirable to suppress functions which would otherwise be selected. For example, it has sometimes been the custom to cause the printing of a letter character in response to a particular signal combination if the last preceding case shift signal was an unshift or letters signal, and to cause a function to be performed in response to the same signal if the last preceding case shift signal was a. shift or figures signal. It is a simple matter to prevent the printing of a character in response to such signal combination when preceded by a shift or figures combination, it being necessary merely to provide. a blank type pallet in the lower row of type pallets at the point where pallet actuation will occur when the print hammer is operated, but it is necessary to suppress the function when printing of a character is :to occur from the upper: row of type pallets in response to the signal combination when preceded by the letters or unshift signal combination. In the apparatus according to the disclosure of the copending application of Albert H. Reiber, the shifting of the type wheel to its letters and figures positions was accomplished by a type wheel supporting frame which was movable upwardly under the control of the shift or figures function bar, and which remained in that position until restored to its lowermost or letters position by the unshift function bar.

According to the present invention, shift and unshift selections are controlled by the slide member 291. which is slidable horizontally. As indicated in Figs. 1, 3, and 5, slide member 291 has integral therewith a depending arm 213i which terminatessubstantially adjacent to the lowermost of thet function bars I93. Those function bars which relate to the performance of functions which under certain circumstances it may be desired to suppress may be provided with laterally extending projections 262. Depending arm 281 of slide member 291 has secured thereto a. function suppression plate 283, which may be step out on one end and square cut on the other end. When the function suppression plate 283 member 291 is in the unshift or right-hand position, the function suppression plate 283 will block the upper of the projections 282 and will prevent the rocking of the next to the lowest function bar I93 into position to be effective. When, however, the slide member 291 is shifted to its extreme left-hand position, as viewed in Fig. 3,, in which position it permits type Wheel I44 to be lifted to its uppermost position for figures selection, neither of the projections 282 on the lower function bars I93 will be blocked. The blocking of the projections 282 may be reversed by reversing the function suppression plate 293. so that the edge which is now the upper edge, as. it appears in Fig. 3, becomes the lower edge, such reversal being effected without reversing the plate end for end. With this arrangement, the function suppression plate 283 will block neither of the projections 282- when slide member 291 is in position for figures selection, and will block the lowermost of the projections 292 when slide member 291 is, positioned for letters selection, If

the plate 233 is reversed end for end so. that the square cut end is at the right as viewed in Fig. 3, both of the projections 282 will be blocked when slide member Ziil is positioned for letters selec tion, and neither will be blocked when the slide member is positioned for figures selection.

In the copending application of Albert H. Reiber, there is disclosed apparatus for and a method of suppressing the carriage spacing operation so that when certain functions are selected for performance, the spacing pawl will be prevented from performing a spacing operation. When, however, the space suppression operation is associated with a function which may itself be suppressed under certain conditions, as for eX- ample, functions for the suppression of which a function suppression plate 283 may be provided, it may be desirable to prevent the operation of the space suppression mechanism when the performance of the function is suppressed. The reference numeral 284 in Fig. 3 indicates the ends of two levers which, when moved outwardly from the plane of the drawing toward the observer, effe-ct a space suppression operation. Slide member 261 is provided with an arm 286 extending rightwardly, as viewed in Fig. 3, and terminating in a blocking projection 281 and a depending U-shaped portion 288. When slide member 28! is in extreme right-hand position, as viewed in Fig. 3,'blocking projection 281 is disposed in the path of movement of the upper of space suppression levers 284 so that, when an attempt is made to operate the upper of levers 284, it will be blocked and spacing pawl .235 will not be disabled. When slide member 201 is shifted to its extreme left-hand position, as viewed in Fig, 3, the right-hand leg 289 of depending U-shaped portion 288 will be disposed in the operating path of the lower of space suppressionl levers 284 so that it cannot be operated, but blocking projection 281 will have moved out of the path of operation of the upper space suppression lever 28d, and it will not be disabled.

Operating cam and follower arrangement In the general description which had reference particularly to Fig. 1, certain cam followers and their follower arms could not be particularly pointed out and identified due to the fact that it was necessary to omit them from Fig. 1 in order that other elements might be more clearly shown. The cam roller which is disposed in channel IilI of cam II appears in Fig. 4 and is indicated by the reference numeral 29L The arm by which it is carried and which imparts motion to function selection testing bail I 92 is indicated 292. Reference numeral 293 designartes the roller which is operated by type wheel elevating cam I25, and this roller is supported by the free end of arm 294 which is secured to type wheel oscillating bail I 3|. The arm by which the lowering of the type Wheel is controlled is identified, as previously set forth, by the reference numeral I81, and the free end of this arm supports a cam follower roller shown in dotted lines in Fig. 4, and identified by reference numeral 296. This follower roller is engageable with and operable by the internal cam surface afforded by the depending flange of cam I86.

Terminal block and slip connection arrangement The rear portion 62 of the primary casting BI is shown in section in Fig. 4 as is also the secondary casting 64. One of the screws by which casting 64 is secured to portion '62 of casting GI is indicated L The method of mounting slip connection block 254 upon portion 62 of the primary casting is shown in detaii in Fig. 4 and is observed .to comprise screws 392 which extend through slip connection block 254 and threadedly engage portion 62?. of the primary casting, spacer bushing 3% being employed to space slip connection block 25% from primary casting portion 62 a distance substantially equal to the thickness of the lowermost portion of secondary casting 64.

A slip connection block 3%, which may be similar to slip connection block 25 5, is secured to the lowermost portion of secondary casting 54 by screws 3H4 which threadedly engage that casting, but which do not extend into nor engage portion 62 of the primary casting. Slip connection block 3% supports a plurality of slip connection tongues 36%, which individually engage terminal contacts 3M, carried by a tennin'al block 388, similar to terminal block ZEI and similarly secured to the keyboard base casting l8. Electrical circuit apparatus which may be supported directly or indirectly by secondary iii).

casting to may be connected by conductive wires to the slip connection tongues 3% at their point of support by slip connection block 363. Tongues 3B5 connect such conductive wires to terminals 38'! of terminal block 388 and communication or control circuit wires may be connected to terminals 301 as desired. Thus, electrical connections to apparatus supported by the secondary casting will be confined to blocks 333 and 308. Similarly, electrical circuit apparatus supported directly or indirectly by primary casting BI may be connected by conductive wires to tongues 253 which, in turn, extend the conductive paths to terminals 252, at which point connection may be made to communication or control circuits. Also, conductive wires may extend from any of the terminals 252 or 391, to electrical circuit apparatus which is supported directly or indirectly by the base casting I3, such as the transmitting contacts. ratus supported by primary casting cl will be confined to blocks HI and 254. If for any reason it is desirable to remove the secondary casting 64 from rear portion 82 of the primary casting, this may be accomplished by removal of the screws 30!. Such removal will result in disengagement of tongues 3% from contacts 391, but the conductive paths which include the slip connection tongues 253 will not be disturbed, as

1 they would be if instead of employing separate slip connection blocks 254 and 393, a single slip connection block had been employed. Similarly, the primary casting 6| may be removed from base casting I8 by removal of thumb screws '63 with or without previous removal of casting 64 from casting portion 62, the result being that all of the slip connection tongues 253 and 395 will be removed from engagement with their corresponding terminals 252 and 39'! without disturbing the circuits to the transmitting contacts.

Letters and figures shift mechanism Fig. 5 discloses in detail, by means of anexploded perspective View, the instrumentalities for shifting the slidable member 23? forward and back under the control of the topmost bar I 93 which performs the shift function and of the bar immediately below it which performs the unshift function. In the general description jwhichhad reference particularly to Fig. 1, the

Thus, electrical connections to appashifting of slide member 207 to its rearmost position was described as being under the control of lever 2ft pivoted upon stud I42, which slidably supports slide member 261, the screw 2I9 having been identified as the pivotal interconnection be-' tween lever M8 and slide member 261. Refer ring particularly to Fig. 5, it will be observed that lever 2I8 is provided near its lower end with an elongated slot 3, which is adapted to re ceive the reduced portion 3 I 2 of a cylindrical boss 3I3, the reduced portion 3 I2 having parallel sides whereby boss 3I3 is prevented from rotating in slot 3. The slot may be longer than reduced portion 3I2 of boss 313 to provide for adjustment of the boss with respect to lever 2I8. Screw 2I9 threadedly engages boss 3I3 and rigidly clamps it to lever 2I8.

In a direct line below slot 316, by which the slide member 201 is slidably supported upon stud I42, the slide member is provided with an open ended slot 3I6, the slot opening downwardly. Slot 3I3 is dimensioned to receive cylindrical boss 3I3 and to permit rotation of the boss within the slot or movement of the boss longitudinally thereof while alfording substantially no lost motion of boss .3i3 transversely thereof. Boss 3I3 constitutes an articulation between lever 2I8 and slide member 267 so that when depending finger 22I of lever 2 I6 is engaged by laterally extending projection 222 of the second function bar I 93 from the top and lever 2I8 is rocked counterclockwise, slide member 291 will be shifted to its rearmest position. I

For the restoration of slide member 23'! to its foremost position, there is provided a lever 3" which is pivotally supported by stud I42 on the opposite side of slide member 201 from lever H8, and is provided at its upper end with an open ended slot 3I8. Slot 3I8 is adapted to receive the cylindrical portion of a boss 3l9' which is similar to boss 3I3 and which has a reduced portion 32I which enters an'elongated slot322 in slide member 207, located just below aperture 2I2. Screw 223 threadedly engages boss 3I9 and adjustably secures the reduced portion thereof in slot 322. Boss 3| 9 constitutes an articulation between lever 31'! and slide member'ZO'I, and when counterclockwise rotation is imparted to lever 3|! by laterally extending projection 222 of the topmost function bar I93, slide member 291 is shifted from its rearmost to its foremost position. Screw 209, which, as previously described, passes through slot 208 in slide member 201 and guides it in the sliding movement which it is intended to receive, is engaged by a spring biased jockey 323 which is pivotally supported by slide member 20'! at 324 and which is provided in its lower edge with spaced notches 326. Notches 326 in jockey detent 323 engage the shouldered portion of screw 209 and prevent accidental movement of slide member 26'! out of a selected position to which it has been shifted. Since levers 2I8 and 3H are both pivoted on stud I42, and pivotally engage slide member 201 atpoints in opposite direction from stud I42, it will be apparent that each of the levers, upon being rotated by its associated function bar I93, imparts an opposite rotation to the other. The angular position of each of the levers with reference to slide member 207 in a predetermined position thereof may be varied by loosening the screws 2 I 9 and 223 and shifting the reduced portion of the bosses 3I3 and 3I9 in the slots 3 and 3221'sspectively.

r in the position shown in Type wheel oscillating mechanism Fig. 5 shows in complete detail the dual cam arrangement for controlling bail I3I. The cams I25 and I86 are shown in their rest position, cam follower roller 293 engaging cam I25 at the minimum distance from the axis thereof, and cam follower roller 296 engaging the internal cam surface of cam I86 at the maximum distance from the axis thereof, so that ball I3I is in extreme clockwise position and type wheel supporting frame I39 is at its lowermost position. It being remembered that cam I 25 rotates in counterclockwise direction and cam I86 in clockwise direction, when cam I25 begins to rotate, it shifts its follower roller 293 outwardly from the axis of shaft I03 and through arm 294, counterclockwise rotation is imparted to bail I3I. Bail I3I has been rocked to extreme counterclockwise position as drop-off I33 of cam I25, which is a sharply descending cam surface, approaches follower roller 293. Before roller 293 moves down the drop-01f I33, the clutch through which rotation is imparted to cam I86 is tripped off ina manner previously described, and cam I86 rotates in a clockwise direction through a sufiicient angular distance to bring the cam surface portion which is at minimum distance from the axis of cam I 86; which portion is identified by the reference numeral 33I, into engagement with follower roller 296, whereby bail I3I is held in the position to which it had been rocked by cam I25. If cam I25 is not immediately set in rotation by the tripping of its driving clutch, it will remain Fig. 5 with cam follower roller 293 held out of engagement with cam I25 by the internal surface of cam I86. As cam I 86 continues to rotate, the point of engagement of follower roller 296 with its internal cam surface recedes from the axis of the cam, thus controlling the return of bail I3I to extreme clockwise position. In this way, the control of bail I3I is transferred from one cam to the other in timed relation to the cycles of the two cams, and neither, cam interferes with the operation of bail I3I by the other cam.

Cam assembly brake mechanism In the lower portion of Fig. 5 there is shown in exploded perspective a series of elements which, when assembled, comprises a roller bearing grip clutch. Interposed between the main cam sleeve I30 and the shaft by which it is supported, there is a sleeve 33I which is fixed to sleeve I30 and is threaded at its lower end. The inner member 332 of a roller bearing grip clutch is threadedly secured to the lower end of sleeve 33L Member 332 fits into the central aperture of ring gear I 06 and is retained in close proximity to the hub of gear 18, as shown in Fig. 3. Member 332 has a plurality of substantially right angled notches cut in the periphery thereof, the faces defining these notches being of unequal length, the shorter of the two faces of each notch designated by the reference numeral 333 extending substantially radially of the member 332. The angularly disposed faces of the notches and the adjacent arcuat-e inner surface of ring gear I06 define recesses that are generally triangular, being bounded by two plane surfaces and a curved surface. Each of the short faces 333 of the notches in member 332 is recessed to receive and support one end .of a compression spring 334. An axially drilled roller bearing 336 is disposed in each of the generally triangular recesses and the compression spring 334 tends to wedge the roller bearing between the long face of the notch and the arcuate internal surface of ring gear I96. The lower end. of cam sleeve I30 is undercut to provide a shoulder 331 against which a retainer ring 338 is placed before member 332 is secured to sleeve 33I. Retainer ring 338 fits loosely on the undercut portion of sleeve I30 and and is not clamped in place, but is free to rotate. The purpose of ring 333 is to cover, at least partially, the rollers 336 and to prevent them from escaping from their respective recesses. There is a further purpose of ring 333, which will be described hereinafter.

Since roller bearings 336 cannot be inserted into their recesses after member 332 has been placed in position in ring gear I96, the retainer ring 338 preventing this, it is necessary to work the member 332 and rollers 336 into position in ring gear I06 at the same time. Springs 334 tend to complicate the bringing of the member 332 and rollers 336 into final positionv together, by urging the rollers 336 out of the positions in which they must be held in order to be inserted with member 332 into gear I06. The insertion of the rollers 336 and member 332 has been simplified by providing clearance recesses in ring gear I06, the recesses being cut partially into the inner surfaceof ring gear I06 and partially into the upper face thereof, thus providing inwardly sloping cam surfaces. With the assistance of the clearances 339, the rollers 336 may be worked partially into position individually, whereupon member 332 may be lowered into position in gear I06,

the ring 333 urging rollers 336 down into position and the sloping cam surfaces of clearances 339 assisting in the insertion of the rollers.

Further simplificationof the insertion of member 332 and rollers 336 into the recess in ring gear I06 has been aiforded by the provision of depending fingers 34I, integral with retaining ring 338. The axial bores of rollers 336 fit loosely on the depending fingers 34d of retainer ring 333, and when a roller 336 has been placed upon each of the fingers 34 l all of the springs 334 may be partially compressed by rotating ring 338 in clockwise direction. Fingers 34I place restraint upon the movement of rollers 335,whereby they may be more easily cammed into position in their respective recesses by means of the clearances 339. An understanding of the exact nature of the clutch by which cam sleeve I30 is driven is prerequisite to an understanding of the utility of roller bearing grip clutch consisting of member 332, rollers 336, and ring gear I06, the roller bearing clutch being used in the present invention as a brake. Cam sleeve I30 is driven by driving clutch element I24 and driven element II29 as previously described. This clutch mechanism is of the well-known one-way driving construction. Each tooth of both elements of the clutch has one surface substantially in a plane passing through the axis of the clutch, and the other surface oblique thereto. Should any torque be applied to the driven element I29 of the clutch which exceeds the torque applied to the driving element I24, the sloping surfaces of the teeth of one clutch element may tend to slide upon the sloping surfaces of the teeth of the other clutch element, thus shifting driven element I29 axially away from driving element I24 and compressing spring I26. If the differential between the two torques is appreciable, the driven element may be rotated ahead of the driving element a distance equal to the extent of several teeth of the clutch members. A torque of suflicient magnitude to cause driven clutch element I29 to rotate more rapidly than driving element I23, and thus to gain upon it, may be generated by a heavily biased cam follower such as the function cam follower I99 and roller 20I or the print cam follower I53 and roller I52 riding down a sharply descending slope of their respective cams and thus becoming a negative load upon the driven clutch element I29.

The roller bearing grip clutch hereinbefore described serves as a brake to prevent acceleration of cam sleeve I30 under the influence of negative load upon any of its cams. Whenever cam sleeve I30 is stationary and the gears '58 and I06 are rotating, inner roller bearing clutch member 332, which is secured to sleeve 33I and, therefore, indirectly to cam sleeve I30, is also stationary, and the frictional engagement between the inner surface of ring gear I06 and rollers 333 tends to move the rollers into the widest portion of the recesses in which they are seated, the rollers thus being moved substantially free of inner clutch member 332 so that there is no tendency of gear I06 to impart rotation to the inner clutch member. When cam sleeve I30 is released for rotation and is rotating at the same speed as gear I06, there is no relative movement between roller bearing clutch member 332 and ring gear I06, and the springs 334 tend to wedge rollers 336 between the long faces of the notches in inner clutch member 332 and the inner surface of gear I06. If cam sleeve I30 should be subjected to a torque which tends to rotate it faster than gears I8 and I06, the frictional engagement of rollers 336 with member 332 tends to increase the wed ing of the rollers between member 332 and gear I06 so that a positive lock between inner roller bearing clutch member 332 and gear I06 is established and cam sleeve I30 is prevented from accelerating in response to the locally applied torque and is held to the speed of rotation of gear I8.

Although specific embodiments of the features of invention have been disclosed and described herein, it will be understood that the invention is not limited to such specific embodiments but is capable of modification, reorganization, rearrangement and substitution of parts and elements without departing from the spirit of the invention and within the scope of the appended claims.

What is claimed is:

1. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, means for arresting said type wheel in selected positions, signal responsive means for controlling said arresting means, means for timing the control of said signal responsive means over said arresting means, means for printing from said type wheel, means for controlling said printing means, and means actuated by said timing means for setting in operation said controlling means.

2. In a printing telegraph apparatus, a type wheel, means for rotating said type Wheel, means for arresting said type wheel in selected positions, signal responsive means for controlling said arresting means, means for effecting the control of said signal responsive means over said arresting means, means for printing from said type wheel, power drivenmeans for controlling said printing means, and means actuated by said control effecting means for setting in operation said power driven means.

3. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, means for arresting said type wheel in selected positions, signal responsive means for controlling said arresting means, power driven means for conditioning said arresting means to arrest said type wheel, power driven means for controlling printing from said type wheel, and means operable during a cycle of operation of said conditioning means for setting in operation said printing controlling means.

4. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, permutation code means for arresting said type wheel in selected positions, means for receiving and storing permutation code signals, means for transferring the setting of said signal storing means to said type wheel arresting means, power driven means for actuating said transferring means, means for printing from said type wheel, and power driven means set in operation by said first mentioned power driven means after the operation of said transferring means for controlling said printing means.

5. In a printing telegraph apparatus, a type wheel, means for rotating said type Wheel, a signal receiving selector, a type wheel controlling selector, means for printing from said type wheel, independently driven means for setting said "type wheel controlling selector and for controlling said printing means, one of said driven means being set in operation by said signal receiving selector and in turn setting in operation the other of said driven means.

6. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, a signal receiving selector operable in cycles, a type wheel controlling selector, means for printing from said type wheel, individually driven means set in operation by said signal receiving selector for setting said type Wheel controlling selector,

and individually driven means set in operation by the last mentioned means for controlling said printing means,

7. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, a signal receiving selector, a type wheel controlling selector, means for printing from said type wheel, means effective when set in operation by said signal receiving selector for setting saidtype wheel controlling selector, and means effective when set in operation by said last mentioned means for controlling said printing means. i

8. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, a signal receiving selector mechanism, a type wheel arresting selector mechanism, means for printing from said type wheel, a power driven distributor operable in cycles in said signal receiving selector mechanism, power driven means for setting said type wheel arresting selector mechanism, means power driven independently of said first mentioned power driven means for controlling the operation of said printing means, means controlled by said distributor in each cycle thereof for setting in operation the first mentioned power driven means, and means controlled by said first mentioned power driven means in each cycle thereof for setting in operation the second recited power driven means.

9. In a printing telegraph apparatus, a type wheel, a rotatable shaft, means for slidably supporting said type wheel upon said shaft, means for printing from said type wheel, power driven means for shifting said type wheel into printing position before a printing operation, means for retracting said type Wheel, and means power driven independently of said first mentioned power driven means for controlling the retraction of said type wheel by said retracting means after a printing operation.

T0. In a printing telegraph apparatus, a type wheel, an oscillatable support for said type Wheel, a printing member mounted to be substantially immovable in the direction of oscillation of said type wheel support, power actuated means for moving said support to bring said type wheel into position to be acted upon by said printing member, and other power actuated means for positively and unyieldably imparting retracting movement of controlled velocity to said support.

11, In a printing telegraph apparatus, a type wheel, an oscillatable support therefor, power driven means for shifting said support with controlled velocity in one direction and thereafter relinquishing control over said support, and other power driven means for assuming positive control over said support after the movement thereof in one direction and for controlling unyieldably the velocity of movement of said support in the opposite direction.

12. In a printing telegraph apparatus, a type wheel, a shiftable support for said type Wheel, a shifting bail connected to said support, a plurality of cam followers carried by said bail, and a plurality of independently driven cams to be engaged by and control said followers individu'ally,

13. In a printing telegraph apparatus, a type wheel, a shiitable support therefor, a shifting bail connected to said support, a plurality of cam followers carried by said bail, a plurality of independently driven cams for controlling said cam followers individually, and means for setting said cams in operation successively in overlap relation.

14. In a printing telegraph apparatus, a type wheel, a shif-table support for said type wheel, a shifting bail connected to said support, a plurality of cam followers carried by said bail, a power driven mechanism including a cam for controlling one of said cam followers, an independently driven mechanism including a cam for controlling another of said cam followers, and means included in the first mentioned power driven mechanism for setting in operation the second mentioned mechanism.

15. In a printing telegraph apparatus, a type wheel, a type wheel shaft, means on said shaft for supporting said type wheel, means accessible from the top of said type wheel for removably securing said type wheel to said supporting means, means for printing from said type wheel reciprocably supported above said type wheel, means for actuating said printing means, and means for articulating said printing means to said actuating means having a horizontally disposed axis, whereby said printing means may be rocked in a vertical plane away from said type wheel for permitting access thereto.

16. Ina printing telegraph apparatus, a type wheel, means for printing from said type wheel, and means for reciprocably supporting said printing means, said supporting means including a pivotal articulation having its axis substantially normal to the axis of said type wheel and to the direction of reciprocation of said printing means, whereby said printing means may be rocked out of printing position for permitting access to said type wheel.

17. In a printing telegraph apparatus, a type wheel, means for rotating said type wheel, a signal receiving selector operable in cycles. a

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