US2003177A - Shift control for telegraph printers - Google Patents

Description

May 28, 1935.

R. F. DIRKES.

SHIFT CONTROL FOR TELEGRAPH PRINTERS Filed sept. 2, 1952 Fas.

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INVENTOR A R. F. DIRKES ATT RNEY Patented May 28, i935 UNIT-ED `STATES PATENT OFFICE SHIFT CONTROL FOR TELEGBAPH PRINTERS Robert F. lDir-kes, Jamaica, N. Y., assignor to TheA Western Union 'Telegraph Company,

New

. 10 Claims.

This invention relates to a printing telegraph system and more particularly to a method of and apparatus for controlling the shift mechanism. of a receiving printer.

` In printing telegraph systems used in certain types of service, particularly quotations involvingv the price of various stocks, commodities, etc., it is necessary to print in both upper and lower case positions and to change from one case to the 10 other frequently, that is, every'few characters. A Heretofore three general schemes have been used for this purpose. The first involves the use of a ve unit permutation code giving thirty-two distinct combinations, two of which are employed to operate the shift mechanism to either upper or lower position, thereby enabling substantially twice this number of characters to be printed. The shift mechanism is locked in each shifted position until the opposite shift combination is received. This system has the advantage of employing only a ve unit code but where case shifts Aoccur frequently considerable line time is lost in transmitting the shift and unshift combinations. The second scheme involves the addition of a case shift impulse to each code combination, the added impulse serving to operate the, shift mechanism to the proper case position as earch code combination is received. This latter scheme, while a considerable improvement on the rst method has the disadvantage that the characters are equally divided betweenv lower and upper case position. Since the upper and lower case characters are printed on diiferent levels on the ticker tape, the former comprising the letters f the alphabet and certain added symbols and the latter the numerals and fractions, it would be more advantageous in certain instances if the number of characters in the letter or lower case position could be increased beyond the available 40 thirty two. On the. other hand the entire thirty two characters are not required in or upper case position.

The third method of upper and lower case -control overcomes this ditlicul'ty by using a jumbled six unit code giving sixty two distinct combinations, each of which selects an individual type bar, noshift mechanism being employedl The disadvantage of this latter scheme is that it complicates the printing mechanism by doubling the number of type bars, pull bars, etc., in the ticker, thereby rendering the machine expensive and more diiiicult to obtain properly aligned printing.

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rihe present invention has for its object to prothe numerals unequal distribution of characters in either shift position may be obtained.

Another object is to provide a method of and apparatus'for controlling the shift mechanism of the telegraph printer by predetermined sub-combinations or impulses used in each character code.

A still further object is to provide a method of and means for controlling two separate selectable elements of a printer by a single code combination and a sub-combination occurring therein.

Other objects and advantages of the invention will hereinafter appear.

In accordance with my invention Ifemploy a' six unit code-giving sixty-four distinct combinations and I utilize certain sub-combinations occurring in the main combinations to control the lshift mechanism and any other auxiliary mechanism of the printer. For instance, in the embodiment described hereinafter, I,have utilized all combinations in which the 3rd and 4th impulses or the 4th and 5th impulses are both marking for characters occurring in the upper case position .and the remaining combination or characters occurring in the lower case position. This "gives a distributionof twenty four upper case characters and forty lower case characters. By choosing other controlling sub-combinations dif'- ferent distributions of the upper and lower case characters can be obtained.

The invention will best'be understood by reference to the accompanying drawing in which Figure 1 shows an exemplary arrangement of the marking and spacing impulses of the letters and gures code combinations;

Figure 2 is a vertical sectional view of a receiving printer embodying the presentA invention; Figure 3 is a fragmentary plan view ofthe printer; and

Figure .e is a diagram showing, a possible arrangement of the code bars of the receiving., printer. s

Referring first to Figure'l, have shown in '45 the left hand column the code combinations used for the letters or lower/ case characters, and in the right hand column the figures or upper case character combinations. The blank spaces represent spacing impulses and the numerals repre-A sent the numbers of the marking impulses of each combination. It willbe noted that each of the gures or upper case combinations employs either the 3rd and 4th impulses marking or `'the 4th and 5th impulses marking, whereas in the 5f I tion in which printing occurs.

sub-combinations occurs to retain it in lower case position.

Referring to Figures 2 and 3, I0 designates the code bars of a receiving printer, six of which are provided, notched so that for every code combination a single row of notches in the six barswill be aligned. A group of typ'e bars i I (one only being shown) are pivoted on an arcuate rod I2 and normally rest in a vertical position againstan arcuate pad I3. The type bars strike downwardly against the tape (not shown) arranged to pass from right to left horizontally across the revolving platen I6. Each type bar may carry a lower case character i5 and an upper case character I6. The type bars are provided with individual pull .bars il, having a rack I6 engaging a pinion I9 on the type bar. The pull bars are held against the edges of the code bars I3 by individual springs 2G, but are normally prevented from entering thenotches of the code bars by the staggered or unalined relation thereof. ln each position of the code bars, however, as stated, one row of notches-will be in alignment, permitting one of the pull bars to move inwardly soas to bring the shoulder 2l thereof into the path of 'a reciprocating bail 22, so as to be engaged thereby to move the pull bar upwardly and thus throw the type bar against the paper. y

The platen I4 compris'es a roller mounted upon a horizontal shaft 23 and arranged to be shifted longitudinally thereof so as to rest beneath either the upper or lower case character to permit printing from one or the'other of these characters. The tape ordinarily remains stationary so that the lower case characters are printed adjacent one edge thereof and the upper case characters adjacent the' other edge.

The printing mechanism sto far described is well known in the art and therefore has not been illustrated in detail.

The platen I4 is carried by a U-shaped frame 24 guided on a pin 25 and normally held in the lower or letters case position by a spring 26. It is adapted to be shifted towards the front of the machine by a U-shaped bell crank lever 2l pivoted on posts 28, 29 and having a vertical arm 3l engaging a rearward extension 32 of the frame 24. The lever 21 is actuated by one or both of two shift bars, 35, 36 having hooked lower ends 31 extending beneathone end 38 of the lever 21. The upper ends of the shift bars 35, 36 rest against the code bars IIl, shift bar 35 being arranged to nation are marking and shift bar 36 similarly entering the alined notches whenever the 3rd and 4th impulses are marking. Whenever one of the shift bars is so selected the shoulder 2! -thereof is brought into the path oi' the bail 22, thereby being raised to effect the platen shift. This occurs simultaneously with the operation of one of the type bars and determines the case shift posi- At the-end of each printing stroke, as the bail 22 moves downwardly, the platen is released and moved backward to lower case position by the spring 26,

amarrar'J` If the code combination being received does not' contain either the 8rd and 4th or 4th and 5th .35, 36 and the pull bars I1', it will be noted that in a position shown with all of the code bars in their normal or left hand position, the notches (represented by the dark portions of the bars) are not in line beneath either of the shift bars 35 and 36. However, if the 3rd and 4th code bars are shifted to the right, the notches will be alined beneath the bar 36 and if the 4th and 5th. code bars are shifted to the right the notches will be alined beneath the shift bar 35. Consequently, any code combination involving either of these sequences of marking impulses will actuate the shift mechanism to the upper case position.

` Referring back to the code shown in Figure l, the letters and figures characters shown in the same horizontal row are carried by the same type bar as, for instance, the ,characters A and I, B and 2, etc. Consequently, it is necessary that eachtype bar-carrying two such characters must be selected by two entirely distinct code combinations. If the type bars are designated forv convenience by the lower case character carried thereby, the A type bar will b e selected by either the l, 2, 3 marking combination or by the I, 2, 3, fl marking combination. This' is readily accomplished by proper arrangement of the notches or code bars. By reference to Figure 4 again, it will be noted that if either the 1st, 2nd and 3rd or the lst, 2nd, 3rd and 4th code bars are shifted to the'right, notches will be alined beneath the A code bar. In the first case,- however, the notches will not be alined beneath either of the shift bars 35, 36 `so that printing will occur only in the lower case position. Whereas in the second case, the shift bar 36 will be operated to effect printing in the figures case position. Simycombinations listed therebelow in Figure 1 contain but a single character and, therefore, must be selected by a single combination. Referring again to Figure 4, if the Y selection comprising l, 2` and 6 impulses marking is received, the notches will be alined beneath the Y pull bar, but this will occur for no other combination.

It `will be noted, therefore, that while certain of the type bars are selected by either of two combinations, others are selected by only a single combination.

While in the particular embodiment shc wn the 3rd and 4th or 4th and 5th marking impulses areused to control the shift mechanism, it is obvious that any other suitable combination of impulses of elements by which various other distributions Cil of uppen and lower case charactersl may be obtained.

, Number oi Number of characters in characters in sequegge of] ma'kmg upper case lower case pu ses 32 32 2, 3; 3, 4 0l 4, 5 28 36 1, 2 0l' 3, 4 24 40 3, 4 0l 4, 5 20 44 l, 2, 3 0l.' 3, 4 16 48 3, 4 14 50 1,2,3or3,4,5

In the case of equal divisionof upper and lower case characters, 32 in/ each case, three shift bars would be required, one for the 2nd and 3rd marking sequence, one for the 3rd and 4thA marking sequence and for the 4th and 5th marking sequence. In `the distribution of 16 lower case and 48 upper case characters a single shift bar would be required and in the remaining distributions, two shift bars are needed. Other distributions may be obtained by selecting the proper controlling sub-combinations of the main code groups.

While this arrangement ofl sub-combinations of certain impulses hasY been described herein as controlling a case shift mechanism in a printer, it is understood that it can be asreadily adaptable to control some other function of mechanism within a printer. Such functions, for

example, might be extra spacing ofthe tapel ing to lower or letters case position following each selection. It is evident, however, that it might be locked in upper case position when so actuated and returned to lower case shift position by one or more separate shift pull bars selected when-- ever the 3rd and 4th or 4th and 5th impulses are not marking. This mechanism is shownlin dotted linesin Figures 3 and 4 and comprises a pair of unshift pull bars 4 l, 42 controlled by the opposite ends of the code disk ,I0 from the shift pull bars 35, 3S. The pull bars 4l, 42 operate a.4 lever 33 which operates the bell crank lever'21 in the opposite direction from that produced by the shiftpull bars 35, 36. The shift bars Il, 42, as an inspection of Figure 4' will show, are arranged to enter aligned notches in the code bars whenever the 3rd and 4th or 4th and 5th code bars remain unshlfted -While the invention has been illustrated par.-

4ticularly with reference to type bar printers, it

is obvious, of course, that it is equally applicable to type wheel or other types of printers using upper and lower case positions. Therefore, I do not desire to be limited to the specific details shown and described herein but contemplate all such modifications and variations thereof as will occur to those skilled in the art, as coming within the scope -of the` appended claims.

What I claim is:

1. In a telegraph printer, a printing mechanism, a selecting mechanism, a case shift mechanism.

means responsive to a code combination for selecting said printing mechanism and meansy responsive to any one of a plurality of predetermined sub-combinations of two or more impulses occurring in said combination for controlling'said .case shift mechanism.

2. In a telegraph printer, a plurality of code bars, a. `plurality of character controlling pull bars, a plurality of shift pull bars, anda plurality of unshift pull bars, said code elements being notched so asto select a predetermined character controlling pull bar in a plurality of positionings thereof and yto select said case shift pull bar in one only of said plurality of positionings, and case shift mechanism actuated by said case shift pull bar.

3. In a. telegraph printer, a printing mechanism, mechanisms for accomplishing other functions,

means responsive toa complete code combination of marking and spacing conditions for selecting a particular character for printing, andmeans controlled by any one of a plurality of sub-combinations of two or more like Vconditions of said complete combination for effecting operation of character Ain a different case position, a plurality of actuating bars controlling'said type bars, a paper feed mechanism co-acting with said type. bars, aplaten moveable independently of said paper feed mechanism to determine the character on a selected type' bar to be printed, and a selecting mechanism responsive to six unit permutation code signals for simultaneously controlling lsaid type bars and said platen.

- 5. A printing telegraph receiver comprising a plurality of character carrying elements greater in number than 32, provided with a nonshift character, a number thereof less than 32 also being provided withl a shift character, a printing mechanism arranged to co-act with either of said characters on said character elements, means responsive to a six unit code combination of received impulses for selecting one of said character clements and for operating said printing mechanism to co-act with either the shift or nonshift character. 5

6. A printing telegraph receiver comprising a plurality lof character carrying elements greater in number than 32, a shift mechanism and per- .mutationjmeans on said receiver responsive to are transversely' offset with relation to each other. l

8. In a printing telegraph receiver, a plurality of type bars having letters and figures case characters, the letters case characters being greater in number than 32 and the flgures" case charactersbeing less in number than 32 and arranged on the same type bar with certain of said letter case characters and means whereby'the letters case characters are printed in one line and the flguresfcase characters are printed lin another oiset line.

9. In a printing telegraphreceiver, a plurality of character elements, a plurality of permutation members responsive to code combinations of impulses for selecting one of said character elements, a plurality of additional members each arranged to respond to a diierent impulse of each of said code combinations of impulses, a shift mechanism and a member operated by said additional mem-` bers when operated singly or together for moving said shift mechanism.

10. In a printing telegraph receiver, a plurality `of character' selecting elements greater in number than 32, a rst character corresponding to each of said elements, a second character correspond-A ing to predetermined ones of said elements, means responsive to a six unit permutation code combination of impulses for choosing one of said character selecting elements, and means also responsive to said permutation code combination of impulses and acting when the chosen character selecting element has more than one .character corresponding thereto, for selecting for printing ROBERT F. DIRKES.

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