US2331043A

US2331043A - Ribbon shift mechanism

Info

Publication number: US2331043A
Application number: US372718A
Authority: US
Inventors: Louis M Potts
Original assignee: Teletype Corp
Current assignee: AT&T Teletype Corp
Priority date: 1941-01-02
Filing date: 1941-01-02
Publication date: 1943-10-05
Anticipated expiration: 1960-10-05

Description

Get. 5, 19430 L. M. POTTS 2,331,043

RIBBON SHIFT MECHANISM Filed Jan. 2, 1941' 4 Sheets-$119911 INVENTOR. LOUIS M. POTTS ATTORNEY.

Oct. 5, 1943.

L. M. POTTS RIBBON SHIFT MECHANISM Filed Jan. 2 1941 4 Sheets-Sheet 2 FIG.3

INVENTOR. LOUIS M. POTTS TTORNEY.

Oct. 5, 1943. -rs 2,331,043

RIBBON SHIFT MECHANISM Filed Jan. 2, 1941 4 She et s-Sheet :s

68 a INVENTOR LOUIS M. POTTS ATTORNEY.

Och 1943 L. N; Pom 2,33 ,04

RIBBON SHIFT MECHANISM Filed. Jan. 2, 1941 4 Sheets-Sheet 4 FIG. 8

INVENTOR. vLOUIS M. POTTS J 1 d r I v I Patented Oct. 5, 1943 mason smr'r MECHANISM Louis M. Potts, Evanston, 111., assignor to Teletype Corporation, Chicago, 111., a

Delaware corporation of Application January 2, 1941, Serial No. 372,718

11 Claims.

This invention relates to printing telegraph apparatus and more particularly to apparatus for selectively determining the transverse portion of.

having a plurality of bandsof different colors which is selectively operable in response to transmitted and received messages to produce a, multicolored record in which transmitted or received messages may be instantly recognized as such by the color of the message on th record.

A further object of this invention is to provide Q in a printing apparatus simple and inexpensive mechanism for equalizing wear on the inking ribbon.

In printing telegraph systems, there is generally provided at each substation a transmitter for sending messages and a receiver which may act to produce a home record for transmitted messages and a printed record of received messages. In order to be able to distinguish upon inspection of a printed copy the messages transmitted from those received, this invention features apparatus to produce a printed record in a color which is selectively determined by the transmitter associated therewith.

- One printing apparatus with which this particular invention finds utility comprises 9, type wheel, movable in the course of each printing cycle from a withdrawn position to a printing position. This movement may be imparted to the type wheel through the agency of a cam controlled bail, and the contemplated ribbon shift mechanism comprises a shift frame, movable by such a bail concurrently with the type wheel to interpose a predetermined color band of an inking ribbon, comprising a plurality of color bands, between the type element and the platen for printing. Following the printing step, the type wheel and the ribbon shift frame return to withdrawn position, and thus is provided visible printing, The ribbon shift frame, when recording characters received from a distant substatiomis elecam on a shaft in the transmitter to be elevated to a different height to present another color band a detailed description to be interpreted to the type element when the printing apparatus acts as a home recorder to record transmitted messages.

In each cycle of the printing apparatus the ribbon shift frame is latched in position to permit the inking ribbon to be elevated to present'to the printing point that color band from-which received signals are printed. If the next succeeding character to be printed is received from a distant station, the ribbon shift frame is properly conditioned. However, if the next succeeding character originates in the local station the ribbon shift frame must be shifted, and, for this purpose, a cam located on the cam shaft in the local transmitter operates a, latch release to shift theribbon frame.

Depending upon the character of the message material there occurs a preponderance of characters on one level or the other of the type elements and, consequently, one transverse half of the inking ribbon is normally subjected to greater wear than the. other half. Another feature of this invention obviates this unequal ribbon wear by providing a, ribbon shift frame automatically positioned in each printing cycle to present alternately the upper and lower transverse halvesbf the inking ribbon to the printing point. For the accomplishment of this result, the ribbon shift frame carries a stop projection extending through a stepped aperture in a cooperating sto'p member, which is cyclically conditioned by the print-' ing apparatus to alternately place the step in and out of the path of the stop projection, thereby permitting the ribbon frame totravel alternately to two different elevations.

As a still further feature, this invention provides means for manually controlling the travel of the ribbon shift frame to produce equalized wear by providing a manually operated cam to condition the stop member and the ribbon shift frame in either of their two operative positions.

The telegraph apparatus upon which this ribbon shift mechanism has been illustrated is disclosed in Patent No. 2,247,408, granted July 1, 1941, to Albert H. Reiber, which is incorporated herein by reference and resort may be had to that application for a morecomprehensive description of the structural details and the mode of operation of the printer apparatus whic described herein only generally.

For a more complete understanding 0 this invention, reference may be had to the following withthe accompanying drawings wherein,

Fig. 1 is a fragmentary front elevational view of a printing telegraph apparatus embodying one specific application of this invention:

Fig. 2 is a side elevational view, partially broken away, of the apparatus disclosed in Fig. 1;

Fig. 3 is a detailed perspective view of the type wheel shifting frame and ribbon shifting frame of Fig. 1 showing their nested relation to one another;

Fig. 4 is a fragmentary side elevational view of a. printing apparatus provided with mechanism for automatically shifting the inking ribbon to equalize wear;

Fig. 5 is a fragmentary plan view of the apparatus disclosed in Fig. 4;

Fig. 6 is a detailed perspective view of the slidable stop member of Fig. 4 and its operating mechanism;

Fig. 7 is a fragmentary side elevational view of a printing apparatus equipped with manual means for shifting the ribbon frame to equalize wear; and

Fig.8 is a fragmentary plan view of the apparatus of Fig. '7.

Referring now to the drawings and more particularly to Figs. 1, 2, and 3, there is indicated at H a casting for supporting a printing apparatus of the type described in the above-identified patent which casting is provided with a vertical supporting column l2 equipped at its upper extremity with a raceway i3 for supporting the roller bearings M of a movable carriage structure i 3 in which is rotatably supported a platen H on a shaft I8. An additional raceway i8 completes the supporting and guiding structure for the movable carriage iii. The carriage structure l3 also supports a paper guiding plate extending beneath the platen i! which serves to guide paper to the printing point and a plurality of extending fingers 2| integral with plate 20 functioning to maintain the paper in engagement with the platen.

The type wheel is mounted on a shaft. 23 and comprises a plurality of radially disposed type elements mounted for reciprocal movement in radial slots provided in the type wheel frame structure. A print hammer 21 is provided to move a selected type element toward the platen II to effect printing. Secured to the hub 23 of the type wheel 25 by means of a clamping nut 29, there is provided a radially extending arm 3| having a depending portion 32. An additional radially extending arm 33 is provided and is secured by a clamping bushing 34 toshaft 23. At

its distal end, radial arm 33 is bifurcated and the depending portion 32 of arm 3i projects through the bifurcation in a freely slidable manner. Through this mechanism, the driving torque of shaft 23 is transmitted to the type wheel 25 and the sliding engagement of projection 32 with radial arm 33 permits type wheel 25 to be elevated with respect to its driving member 33 while still maintaining driving relation therewith. At 33 there is indicated a portion of the receiving mechanism comprising a plurality of code discs and selecting mechanisms for selectively engaging a stop arm (not shown) in response to a received permutation code signal combination to arrest the type wheel 25 in the desired position to print the character corresponding to the received code signal combination. The structural details, as well as the mode ratus embodies no features of the present invention.

The apparatus disclosed herein provides for visible printing; that is, the type wheel is elevated into the printing position and after the printing has been effected, the wheel is returned to its lower position uncovering the printed character. Accordingly, a lifting bail 42 is rotatably mounted in a supporting structure 4| by means of trunnions 43 and is yieldably articulated to a type wheel shifting frame 43 to elevate that frame and the type wheel in the course of a printing cycle in a manner to be described hereinafter.

Frame member 43 is provided with a vertically disposed slot (not shown) through which a stud 41 carried by the supporting structure of the printing apparatus projects in order to support the frame member 43 in a slidable manner. Frame member 43 is provided with a horizontally extending portion 43 provided centrally with an aperture through which the type wheel shaft 23 projects and in which it is rotatably supported by means of the hub 28 of the type wheel 25. Horizontal portion 48 is perforated at each of its ends to receive guide pins 48 and 5| mounted in a vertical portion 52 of the printing apparatus frame. The guide pins fit freely within the apertured frame member 48 of the type wheel shifting frame 43 so that the latter is freely slidable. A spring 53, see Figs. 2 and 3, extending between bail 42 and a spring post 58 carried by frame 43, provides a yieldable connection between the bail and type wheel shifting frame so that as the bail rotates upon its trunnions under the influence of cams to be hereinafter described, the type wheel will be elevated.

The height to which the type wheel is elevated to determine-whether printing is to be effected in upper or lower case characters, is determined by a stop member 54 provided with a stepped aperture 55 and a stop projection 53 carried by frame member 43 and extending through the stepped aperture 55 in member 54 (see Fig. 3). Stop member 54 is provided with horizontally slotted

portions

51 and 58 through which

studs

59 and 33 carried by the printing apparatus frame project and provide supporting and guiding means for the stop member 54 which accordingly may be shifted horizontally. The position of stop member 54 is determined by the operation of function levers 33 which position stop member 54 through a pair of levers 3| and 32 pivotally supported by stud 41 and engaging respectively at their upper and lower ends the stop member 54 in a manner clearly disclosed in Fig. 5 of the above-identified patent. When the apparatus is conditioned for operating in unshift condition, the shoulder portion 34 of the stepped aperture in stop member 54 is in alignment with the stop projection 53 on frame member 43 and accordingly, whenthe ball 42 is rotated counterclockwise about its trunnions 43 under the control of the cam shaft of the printing apparatus, the spring 53 will cause the frame 43 to be elevated untitstop projection 53 engages the shoulder portion 34 of the stepped aperture 55 and arrests the elevation of the type wheel. In response to the selection of the shift function bar. the stop member 54 is shifted leftwardly, as viewed in Fig. 3, removing the shoulder portion 34 of the stepped aperture from alignment with projection 53 and in this condition when the frame member 43 is elevated, the arrestment of the frame will be delayed until stop projection 56 has passed the shoulder portion of the step and come into esngagement with the upper limit of the aperture 65. In other words, when typing from one-half of the type wheel, the carriage is arested by means of the step of aperture 55 and when operating from the other half, the step is ineffective and the carriage travels until arrested by the stop member 54 at the upper extremity of aperture 55.

The printing apparatus is provided with two cam shafts (see Fig. 2) represented at 66 and 61 with their associated drivinggears 88 and 69, respectively, which are caused to rotate for a single revolution in response to the reception by the magnet of the receiver of a code signal combination, whether it be received from a distant station or from the transmitter, to be described hereinafter, associated with the particular printing apparatus. n cam shaft 66 is an elevating cam II which operates through a follower I2 to rotate lifting bail 42 counterclockwise about its trunnions 43 to elevate the type wheel shifting frame 46 and, consequently, the type wheel. An internal cam I3 on cam shaft 61 and follower I5 are effective to provide the return of the bail 42 and the type wheel 25 to normal at a controlled speed. Also carried by cam shaft 61 is a cam 14 which is engaged by a cam follower 16,.

pivoted on member 11 to which member is also pivoted lever I8 which operates the print hammer 21. Accordingly, in response to the reception of a start impulse of a code signal combination, a cycle of operations is initiated in which both cam shafts 66 and 6'! are successively released. In the rotation of shaft 66, cam II is operative to elevate the bail 42 and to thereby elevate the shift frame 46 and type wheel 25, while internal cam I3 of shaft 61 is effective to maintain a controlled return of bail 42, frame 46, and type wheel 25. At the same time, through the rotation of cam shaft 61 the cam I4 operates its follower l6 and lever 18 to operate the print hammer in timed sequence with respect to the elevation of the type wheel.

A pair of inking ribbon spools 8| are provided which operate alternately as paying-out and take-up reels, only one of which is disclosed in the drawings for'the sake of structural clarity of those elements constituting the invention here involved, and the spool is rotatably supported by a stud shaft 82 provided with a driving gear 83. There is indicated at 84 a lever operated in response to the selection of the ribbon feed function bar to feed the ribbon from one spool to another.

The apparatus described up to this point is common with that disclosed in' the above-identified patent, and reference may be had to that patent for a more complete understanding of the apparatus herein described above only generally.

The ribbon in passing from. one spool to the other is guided around the type wheel 25 by an arcuate guide plate 85, provided with horizontally extending fingers 86 which direct the vertical displacement of the ribbon. The ribbon guide 85 is suspended from a horizontal portion of a ribbon shift frame 81. The ribbon shiftv frame 81 has a contour very similar to that of the type wheel shift frame 46 and is likewise slidably supported on stud 41 being provided with a vertically disposed slot 88, and being provided in its horizontal portion with two apertures through which guide pins '49 and 5| extend so that this shift frame 81 is mounted -frame 81 is through the agency of a spring 90 distended between a projection 69,0n the frame member 81 and the ball 42. The ribbon shift frame also carries a stop projection 9| for determining the height to which the ribbon shift frame and consequently the inking ribbon is elevated.

The mechanism provided for determining the height to which the ribbon shift frame 81 is elevated comprises a principal slide 92 which is slotted at 93 and 94 and supported by a pair of

studs

96 and 41 suitably carried by the frame structure of the printing apparatus. The dimensions of the studs and slots are such that member 92 is freely slidable in a horizontal direction. A spring 98 extending from the frame structure of the printing apparatus to the slide 92 tends to hold the slide in its leftward position, as viewed in Fig. 3. Slide member 92 is provided also with a pair of studs 99, only one of which appears in thedrawings, which extend through horizontally disposed slots IOI provided in an auxiliary slide member I02. A spring post or projection I03 is formed at the leftward extremity of slide I02 and a spring I04 is distended between the projection and one of the studs 99, preferably the rightward stud, to provide for a yieldable articulation between the two slide elements to permit a relative.

sliding of one with respect to the other should the other be maintained against movement at the time it is desired to move one of the slides. This condition which may exist will be explained in detail hereinafter. Slide member I02 which is L-shaped has in its vertical portion a stepped aperture I05 through which the stop projection 9| on the ribbon elevating frame 81 protrudes.

The principal slide 92 is provided with a look ing shoulder I01 into which a pivoted locking pawl I08 is adapted to be inserted to normally hold the slide 92 in its rightward position, as ilshown but is adapted to be rotated about its pivot III carried by the printer frame, by the operation of a cam follower I I2 and its cam I I3 in a manner to be hereinafter described. When pawl I08 is released from engagement with the locking shoulder I01, slide 92 is moved leftwardly under the influence of spring 98 and is subsequently restored by means of a cam I I4 carried on cam shaft 66 and engaged by a follower roll II5 on a pivoted lever II'I pivoted at II8 to the printer frame and extending into the path of a projection II9 on the slide 92.

Cam I I3 is carried on a transmitting cam shaft of a transmitter associated with the printing apparatus and indicated generally II 8 (see Fig.

2). Thetransmitter employed is the customary start-stop permutation code transmitter, such as that disclosed in the above-identified patent to Albert H. Reiber and since the transmitter is not new, and constitutes no part of this invention, it will not be described herein any more than to indicate it generally and to say that the cam I I3 is located as an additional cam upon the conventional transmittin cam shaft which is set into operation cyclically for the transmission of code signal combinations.

The operation of the printing apparatus to provide for a color differentiation between the printed record of messages received and messages transmitted is as follows: Slide member 92 .is normally locked by pawl I08 as disclosed in Fig.

2, placing spring 98 under tension and aligning the shoulder portion I06 of the step in aperture I05 with the stop projection 9| on the ribbon shift frame 81. With the apparatus in this condition, when a message is being received by the receiving apparatus 36 from a remote station, the local transmitter H8 is inoperative and slide 92 remains locked in its rightward,position, so that as the lifting ball 42 operates under thecontrol of the cams located on

cam shafts

66 and 61, as indicated above and as described in detail in the patent aforementioned. it will elevate both the type wheel shifting frame 45 and the ribbon shifting frame 81 until the stop projections of these frames come into abutting relation with the stepped apertures in the members 54 and I02, re-

spectively. Stop projection 55 on the type wheelshifting frame 46 will engage the shoulder portion 64 of stepped aperture 55 or proceed to the upper portion of that aperture in accordance with whether the apparatus is conditioned for printing in the upper or lower case position. The stop projection 9|, however, carried by the ribbon shift frame 81 is in alignment with the shoulder po'rtion I06 of the step of aperture I05 and accordingly, will engage therewith whether the type wheel frame member 46 travels to the shift or unshift position. In other words, irrespective of the elevation of the type wheel, during the condition of the apparatus now under consideration, the received message will always be recorded from the upper half of the inking ribbon because the stop projection will always abut against the shoulder portion of the step of aperture I05, limiting the elevation of ribbon shift frame 81 and positioning the upper portion of the inking ribbon in the path of the type elements.

When transmitter H8 is operative and the printing apparatus is employed for producing a home record of messages transmitted by the local transmitting equipment, the transmitting cam shaft rotates once for each signal combination transmitted and during the operation of the transmitting camshaft, cam I I 3 operates the follower I I 2 to rock locking pawl I08 clockwise about pivot III, releasing it locking engagementwith shoulder I01. Spring 98 is thereby rendered effective to draw the slide 92 leftwardly, as viewed in Fig. 1, and through the connection between slides 92 and I02, the latter slide member and, of course, the stop aperture I05 will likewise be positioned leftwardly. Shifting slide member I02 to the left removes the shoulder portion of stop aperture I05 from alignment with the stop projection 9| on the ribbon shift frame and under this condition, as the lifting bail 42 operates under the control of the

cam shafts

66 and 61, it will elevate the ribbon shift frame 81 to its uppermost limit; that is, until stop projection 9| abuts.

against the upper portion IIO of aperture I05 which positions the lower transverse portion of the inking ribbon in alignment with the type element. The inking ribbon illustrated at I20 comprises two color bands, the upper of which may be assumed to be blue and the lower assumed to be red. With such a ribbon, the received messages are printed in blue, that is, from the upper transverse half of the ribbon, and the transmitted messages are recorded in red from the lower half of the inking ribbon. During the operation of bail 42, the pins 49 and 5| serve to guide accurately frame

members

46 and 81.

As described in detail in the above-identified patent. when the printing apparatus herein disafford overlap in the printer.

closed is operating as a home recorder, in response to the depression of a key lever in the keyboard, the transmitting cam shaft, shaft 66. and shaft 61 are released in the recited order to The release of these shafts is such that when the shaft in transmitter IIB has completed about two-thirds of a revolution, shaft 68 is released and for approximately one-third of a revolution these shafts rotate concurrently. In order to assure the proper operation of the ribbon shift mechanism, cam I I4 is oriented on shaft 66 with its lobe engaging follower II5 within the first few degrees of rotation of shaft 65, and cam H3 is oriented on the cam shaft of transmitter II8 so that its lobe will engage follower 2 within the last few degrees of a cycle of revolution; that is, during the interval in which the transmitter cam shaft and shaft 68 rotate concurrently and after cam II4 has operated to latch slide 92 in its rightward position, as viewed in Fig. 3. With the cams oriented in this manner, in each cycle of the printing apparatus cam II4 will operate its follower I I5 to rock lever II1 counterclockwise and through its engagement with projection H9 position slide 92 to its rightward position if it should not already be so positioned. Spring I09 -is then effective to rock latching pawl I 08 counterclockwise to engage locking shoulder I01 and retain slide 92 in its rightward position. If the incoming signal combination originated at the local transmitter,

. cam II3 will operate after cam H4 and release pawl I08, permitting slide 92 to shift to its leftward position and condition the apparatus to record the transmitted character in its proper color.

Having provided a yieldable connection between the principal slide 92 and the auxiliary slide I02. it is not necessary to maintain a close timing relation between the restoring operation of the slide 92 and the return of the frame member 81. That is, if, assuming that the apparatus is printing a record of messages transmitted from the local transmitter, cam I I 4 should operate lever II1 to restore the slide 92 to normal, while stop projection 9I is still in the upper portion of the aperture I05 abutting against horizontal portion H0, the stop projection would also be in abutting relation with the vertical face of the step in aperture I 05-and, accordingly, would prevent slide I02 from following the return of slide 92. Since provision has been made for a relative sliding movement between members 92 and I02, cam II4 would return slide 92 to normal and lock it in that condition and spring I04 would be distended so that when the bail 42 finally had progressed sufficiently on its return movement, to retract the stop projection 9| from engagement with the vertical portion of the step, spring I04 would be effective to cause slide I02 to follow the positionment of slide 92 and accordingly, return the entire ribbon shifting mechanism to normal.

The apparatus disclosed in Figs. 4, 5, and 6 is identical with that of Figs. 1, 2, and 3, with the exception of the operating mechanism for the slide members of the ribbon shift mechanism, and accordingly, the parts common to the two groups of figures bear corresponding numerals. A plate I2I which supports spools 8I for the ribbon I20 is secured to the frame of the apparatus. An elongated stud I22 is substituted for the stud 96 of Fig. 2 and a ratchet I23 and a multi-lobed cam I24 have been added, mounted on stud I22. The ratchet and cam are integrally connected for rotation on stud I22. Also. rotatably mounted with ratchet I23 by a spring I32. Slide member 92 is provided with a cam projection I33 maintained in contact with em I24 by the spring 98 of the slide member 92.

In employing the ribbon shift mechanism disclosed in Figs. through 6, a solid color ribbon I20 is to be employed and the mechanism will operate as follows to assure equalized wear throughout the ribbon length: A received code signal combination, whether received from the line or from the transmitter associated with the particular printing apparatus, causes cam shafts 66 and 6! to rotate for one revolution. With each rotation of cam shaft'6'l, a cam I34 carried thereon is rotated and operates a bell crank follower I36 pivoted to the printer frame at I31.

The end of the bell crank not engaged by the cam is in the path of the spring-urged crank I26 and as the bell crank I36 is rocked about it's pivot in a counterclockwise direction by cam I34, it rocks crank I26 in a counterclockwise direction about stud I22, and feed pawl I28, which by virtue of spring I29 is in engagement with a tooth of ratchet I23, steps the ratchet counterclockwise about the stud I22. The jockey I3I is then positioned into the next recess on .the ratchet and serves to hold the ratchet as positioned while spring I2'I returns crank I26 to its normal posi-' tion for a subsequent stepping operation.

There are provided twice as many teeth in the ratchet as lobes on the. multi-lobed cam I24, and accordingly, it requires two operations of the stepping pawl I28 to travel from one lobe to the next succeeding one. When the ribbon shifting mechanism is conditioned as illustrated in Fig. 4 with the cam projection I33 engaging a lobe of multi-lobed cam I 2-4, slide member 92 and auxiliary slide I02 are conditioned in their rightward position, aligning the shoulder portion I06 of the step of aperture I05 with the stop projection 9| so that as the ball 42; operates under the control of

cam shafts

66 and 61, ribbon shift frame 81 is elevated to its lower position inasmuch as its movement is arrested by the abutment of stop projection 9| against the shoulder portion I06 of the step. The upper portion of the ribbon, accordingly; is presented to the printing point for the printing'operation and at the completion of that particular cycle, cam I34 will rock bell crank I36 and step ratchet I23 .in the manner above described and present a nadir to cam projection I33. Spring 98 will then be effective to draw the slide 92 to the left and through the following arrangement of slides 92 and I02, the auxiliary slide I02 will likewise be positioned to its leftward position.

In this condition, the stop projection 9I will not be in alignment with the shoulderporti'on of the. step of aperture I05 and will be permitted on Toward the completion of that cycle, cam I34 again will step ratchet I23 to present a lobe of cam I24 to cam projection I33 and position the ribbon shift mechanism again to the right to present the upper half of the ribbon to the printing point on the succeeding printing cycle. Accordingly, through the operation of cam I34, stepping ratchet I23, cam I24, and cam projection I33, the ribbon shift mechanism is positioned in alternation in its rightward and leftward position, causing printing from the upper and lower transverse halves of the ribbon, successively. Since the ribbon shift frame 81 travels to present the various portions of the ribbon to the printing point, it is immaterial that printing be from the upper or lower case; that is, from the upper or lower level of type elements on type wheel 25 and, accordingly, there will be a uniform wear on the ribbon since the ribbon will be presented in alternation for printing from-the upper and lower transverse portions thereof.

There is disclosed in Figs. 7 and 8 manually operated mechanism applied to the apparatus disclosed in Figs. 1, 2, and 3, for controlling ribslotted portion 93. An additional cam I40 provided with a projection I42 to facilitate the manual operation of the cam is rotatably supported on stud 96 for cooperation with projection I4I. With cam I40 in the position shown in Fig. 7, the ribbon shift mechanism is held, through the engagement of cam projection I M and cam I40, in its rightward position wherein the shoulder portion I06 of the step in aperture I05 is in alignment with the stop projection 9i carried on the ribbon shift frame 81 to limit the elevation of the ribbon shift frame to its lower position. With cam I40 rotated from the position illustrated in Fig. '7, spring 98 is effective to draw the principal slide 92 to its leftward position and through the following connection afforded by spring I04 and stud 99, the auxiliary slide member I02 is likewise positioned in its leftward position in which condition the stop projection 9| is not in alignment with the shoulder portion of the step in aperture I05 but is permitted to travel the entire length of the aperture I05 to abutment with horizontal portion IIO before being arrested thereby.

With this particular embodiment of the invention, the cam I40 and projection I M are conditioned to position the slide members 92 and I02 in either their rightward or leftward position, as desired, and are maintained in that condition to thereby effect printing from the same transverse half of the inking ribbon for approximately the entire ribbon length. Thereafter, cam I40 is rotated manually 180 shifting the slide members 92 and I02 to their alternate position topresent the alternate transverse half of the ribbon to the printing point for the following printing operations, wherein the printing is effected for approximately the entire ribbon length from the alternate half of the inking ribbon.

Although specific embodiments of the features of this invention have been disclosed and described in detail, it is to be understood that the invention is not limited to those specific disclosures but is capable of modifications and reribbon carrying mechanism into alignment with said platen for printing, means for varying the degree of shifting of said type wheel by said shifting means, and separate means for varying the degree of shifting of said ribbon carrying mechanism by said shifting means whereby the character of the printing is varied.

2. A printing telegraph apparatus comprising means to transmit code signal combinations, means to receive code signal combinations, means to record characters corresponding to code signal combinations received or transmitted, said recording means including a platen, a type wheel, a ribbon carrier, a multi-color band ribbon on member and position the step alternately into and out of the path of said stop projection.

6. In a printing apparatus, a type carrier having a plurality of rows of characters, means to shift the type carrier effective in each recording cycle to bring one row of characters into printing position, means to vary the rows of characters selected in accordance with the character to be printed, an inking ribbon. means to shift said ribbon from-a retracted position to the printing position in each cycle, means to maintain the shift of said inking ribbon to a predetermined degree irrespective of the shift of said type carrier, and means to determine the shift of said ribbon for different operating conditions.

7. In a printing apparatus, a ribbon shift mechanism comprising a shiftable ribbon carrying frame, means to shift said frame, means for said carrier, cyclically operable means to elevate said type wheel to alignment with said platen, cyclically operable means to elevate said ribbon carrier to present a given color band to said type wheel and said platen for recording characters corresponding to received code signal combinations, and means controlled by said transmitter to cause said ribbon carrier to be elevated to a different height to present a different color band to said type wheel and said platen for recording characters corresponding to transmitted code signal combinations.

3. In a printing apparatus, a ribbon shift mechanism comprising a shiftable ribbon carrying frame including a stop projection, means to shift said frame, means for varying theshifting of said frame comprising a principal sliding member, an auxiliary sliding member supported by said principal sliding member and having a stepped aperture through which said stop projection extends, and means to selectively position said sliding members to determine the degree of shifting of said frame through the engagement of said stop projection with the aperture in said auxiliary sliding member.

4. In a printing apparatus, a ribbon shifting mechanism comprising a shiftable ribbon carrying frame, means to elevate said frame to present theribbon to the printing point, means for limiting the elevation of said frame including a slidable stop member provided with a stepped stop aperture engaged by said frame, means for normally retaining the step of said aperture in a position to allow a predetermined elevation of said frame, means to shift said slidable stop member to allow a different predetermined elevation of said frame, and means to restore said slidable member from its shifted to its normal position at the beginning of each printing cycle.

5. A ribbon shift mechanism for printing apparatus to align the upper portion of an inking ribbon and the lower portion of the ribbon'at the printing point alternately, comprising a ribbon shift frame, a stop projection on said frame, means to elevate said frame, a slidable stop member having a stepped aperture into which said stop projection extends to limit the elevation of said frame, a cam following projection on said slidable stop member, a multi-lobe cam, means for urging said cam following projection into contact with said cam, means to step said cam in each printing cycle to slide said slidable stop varying the shifting of said frame including a principal sliding member, an auxiliary sliding member carried by said principal sliding member, a plurality of stopping devices carried by said auxiliary sliding member for engagement with said frame to determine the degree of ribbon shift, and means to selectively position said sliding members whereby a predetermined one of said stopping devices is rendered eflective to arrest the travel of said frame and determine the degree of ribbon shift.

8. In a printing apparatus, a ribbon shift mechanism comprising a ribbon carrying frame, means to shift said frame to present the ribbon to the printing point, means for limiting the degree of shifting of said frame including a slidable stop member having a plurality of stopping devices for engagement with said frame, means for normally retaining one of said stopping devices in operative relation with respect to said frame to allow a predetermined degree of ribbon shift, means to condition said slidable stop member to position another of said stopping devices in, operative relation with respect to said frame to allow a different degree of ribbon shift, and means to restore said slidable stop member to its normal position in each cycle of the printing apparatus.

9. In a printing telegraph apparatus, a printer for recording local and remote signals including a platen, a movable type member, an inking ribbon having a plurality of color areas, a movable ribbon carrier, cyclically operable means to elevate said type member to the printing position, cyclically operable means to elevate said ribbon carrier to interpose said inking ribbon between said type member and said platen for printing, means under the control of local signals for enabling said ribbon carrier to be elevated to a predetermined position to present a predetermined color area to the printing point, and means under the control of remote signals for causing said ribbon carrier to be elevated to a different predetermined position to present a different color area to the printing point.

10. In a printing apparatus, a cyclically operable ribbon shift mechanism including a ribbon carrier movable to different predetermined positions, a stop engaging means carried thereby, a reciprocating slide having a plurality of stops for cooperating with said stop engaging means to determine the elevational positionment of said carrier, and means for shifting said slide at the end of each printing cycle to alternately present one or the other of said stops to said stop engaging means to thereby enable said carrier to be alternately raised to a different predetermined position for each successive printing operation.

11. In a printing apparatus, a cyclically operable ribbon shift mechanism including a ribbon carrier movable to different predetermined positions, a stop engaging means carried thereby, a

reciprocating slide having a plurality of stepped apertured stops for cooperating with said stop engaging means to determine the elevational sive printing operation.

I able said carrier to be alternately raised to a different predetermined position for each succes- LOUIS M. PO'II'S.