US2110286A - Teletypewriter equipment - Google Patents

Description

March s, 1938.

Filed Aug. 8. 1936 5 Sheets-Sheet l A TTORNEV Mam 8, 1938, A. A. EURGESS H0286 TELETYPEWRITER EQUIPMENT. .v

rFiled Aug. 8. 195e 3 sheets-sheet 2 ATTORNEY Mmh s, 1938.

A. A. BURGESS TELETYPEWRITER EQUIPMENT Filed Aug. 8. 1936 3 SheetsSheet 3 /NVEA/TOR BURGESS 5 WMM ATTORNEY field, the-top row of limit of'her lreachj UHowever, the 'effectiveness of her reachis limited by-theheight of herteletype#4 Patented Mar. 8, 1938 PATE-NT oF-Fl-ca This inventionrelates 'to' anfimproved tele typewriter exchange switchboard of thetype shown in Patent 2,037,193 granted'Aprn -14 1936 teletypewriter' are separated, or

,y to' A, A. Burgess et al,and,"moreparticularly; to

means'ffor increasing the area;l available'to Van operator, of'- the jack-held Y of `the switchboard multiple: A"

The' *practices usedA `in operating telephoneief change switchboard cannot' all be followed in op; eratingteletypewriter exchange *switchboards For example, a telephone 'operator canjplace her chairclose to the switchboard multiple and the4 of thejackeldfthen avail-; able to h'er will be limited Y'Dythe `lengthoff'her` extent of' the area telephone 5' switchboard practice.

and height of the rvt'eletypewriter;

reaches dup V'above ,her yteletypewriter to the jack which is determined -by `vthe writer sincethe heighti'ofv the jack-iielljl vail-'- able'` to her is roughly equal tothe length "reach minusithe height of her teletypewrite The teletypewriters ordinarily employed at tele` typewriter'- exchange` s'witczhboard's'*are f usually inches Ihigh. These tele*- placed` justl belowH "the- -frontof the switchlznoard multiple with the result that the multiple'commences about ten and enea half 1 inches above 'fthe possible operating level which is 'at the keyboardsof the teletypewriters'vy`v Thus, the numberofrows of jacks that can bem about-:ten and one-half typewriters are generally "reached by anoperator is distinctly-limited by this construction sincethe totalnumber of mul`-'- operator is able {toreachis-"j less than if-her teletypewriterwere-"`1ower=in--.ofthe steadily'increasinaderand'for'teletypef v Writer exchangefacilities, this increasleyinr the capacity of the operators positions become of in creasing importance.- Furthermoregthis lowering the Leffective height; fof the operatrs; teletype Write soasto jenabletheyoperator to reach ya I gretrlamount-loffthe @jack-acidi oftheswitch-c Accordingly, it is an object of thisinventiontoy increase the area of the-jackfield availableto`4- offthe bottom-of the'jackleld of the switchboard f multiple decreases an' object of this inventionto-provide-r a teletypewriter exchange" switchboard *withAv a ing'theamountbf timf'reqlird'to answer and" novel teletypewriter table *and assembly; f f These objects arek accomplished by decreasing in both time and fatigue,A the operators `will be'fincreasedf* board mg1tj1p1e. To obtain-Emis' "decrease Ain the eifectiveheight'of the operators teletypewriter,

the usual keyboard and typing mechanism ofthe' dissociated, and the keyboard vmechanism isfthen plac'edupon the topof the operators table while the typing mechanism, instead of being located above the key? I board'-v mechanism as underneath on a'shelf below'theltop of the table.

it usuallyy is, is *located Thefelect'rical connection betweenffthe units andl the-switchboard-and Abetween the units themselves.vv

is accomplished-by means -of yflexible-cords ter'- minating in plugs and jacks to facilitate disso-f V ciatng thel units for maintenance purposes.-

Sincel the tape is associatedwith theunit comprising the typing mechanism, it is also located benaththe top of the operatorstable and is," in itsnew? location, obscured; from direct fview. Therefore, a mirror-'mounted alongside thetyping' mechanism is employd'to' reflect the characters typed on the'tap'e to a second'mirror, mounted at table topLv level,- in which thel characters are viewed by'the?operator.j A length "of tape about four inches'lcri'g'which is more'than suflicient to meet viewedin thisv manner.

As'ifthe'unit comprising the keyboard mechanism'is only Vabout `live' inches high,r by lplacing multipler of about five and'one-'half inches is obtained in which additionaldine circuitsmay bev terminatdfi in -fjacks 1 'placed` in this ladditional space in 4the multiple'. Thus,- the/separation -of the keyboard and typing mechanisms-enables the' andl one-half -inches toprovide, on -a siX-panel multiple,r space for approximately 720 additional the capacity vof fthe operators) positions. `Inview theA average amountfo'f reachinanswering and completingcalls thereby`1jeduccomplete'calls andlikewisereducing,the amount of'fat'igue experienced by the-operatorsV iny doing' thistype ofv efficiency of the# work." Asfaresultfof thisreduction mum length of switchboard to' serve a .particularv number o f subscriberlines.

A modication of the invention is arranged with the teletypewriter motor located on a shelf" below the shelf on which the typing unit is lo-l cated. This increases the amountof knee room available to an operator. 'Italso permits thef table to be made narrower 'toenable the operator to sit closer to the jack-field. f Another modification of the invention incorpoi rates features described above into a switchboard section,V such as. somewhat by mounting the Vteletypewriter in a switchboardv f disclosure of Patent 1,867,333 grantedduly 12, 1932 to E. M. Smith.: f v

' `The above features and other` novel features of this teletypewritertableand assembly will be explainedinmiore detail in connection with the typewriter assembly together Vwith its- `table and asesociatedapparatus; f i

drawinssin whichf e Fig. y1 is a threedimensional view of a portion of a teletypewriter-central omceihaving a small teletypewriter exchange switchboard with Vtwo operators tables `and teletypewriters arranged `in front of Ait andconstructed in accordance with the invention;-

Fig. 2 is a cross-sectional side viewof one` ofA the operators. teletypewriters mountedupon its Figs-31s viewv of this operators teletype-v 1 writer mounted upon its table and located be neath the key-shelf of'the,switchboard;=y Fig-iis a three-dimensional view of the tele- Fig. 5`isja modication'of theinvent'ion'in which the teletypewriter motor is located on a shelf which is beneath the shelf upon which the typingunit is located; Y Y Fig .`6 is somewhat similar toa portion of Fig. 5

but shows the motor inverted and suspended from Y i i is Smounted uponthetop of theoperators tablev the bottom of the.shelf;',

Fig.g'1 Vis a modiication of the invention'in whichV switchboard itself; and g Fig. 8 is a, cross-sectional view of a portion of the switchboard, vshownin Figq, together with oneof its teletypewriters,

^ Fig, 'Lrepresents a smallte'letypewriter ex-v changeswitchboard- I similar tothat disclosed in Patent`=2',0 37,193 *granted April 14, 1936 to A.V A. Burgesslet al. v. Ihej disclosure of this Burgess et al patentfis incorporated hereinj by reference 'as Y apart of this specification. f Returning now to the consideration of Fig. 1, the upper front portion of the teletypewriterv exchange switchboard l has a' jackfield 24 comprising rows of jacks 25, Just above the ljack-ield 24 are busy Vtest lamps 2 0 and ticketboxes'2l forl storing message Vrate tickets A 22. Immediately below` the jackileld 2 4 are thev .position :splitting keys .llix e v r Slightly lower downon the' switchboard |1-is i suitably @Omleted t0, the. Other. unit such as the arrangement in 5,;maybeused if def,`

theprojectingforoverhanging, keyshelf 4 hav- VingarovIrOf calling and'answeringv plugs 28, a

row of supervisory lamps 29, and a rowofsupervisory keys` 30. Behind the lower portion of each section jof.,swi tchboard I is position relay equipnient (not shown) whichis wiredjtoterminal yjackfie`1d124 for efficient operation.

patent is the `teletypewriters are mounted in the f 4| The frontof cover 4I hasa hole 88 ,metes beiowftte tot vtif., table 3.

the

l to permit a teletypewriter and its table 3 to flt underneath tothe extent of about half their widthtoenable the operators to sit close to the Tables 3 maybe readily moved up and down the length of .the switchboard Vl Thefeet of each' table3 are provided with a base composed of non-resilient material, such in accordance with different trafc requirements.

as hard rubber. 'I 'o insure that the top `of table.A

3 will belevel and toobviate jiggling otftable), .v

the bases `66'jmay be removedto permit the in,-

sertion of afstabilizing device, afterwhich bases 65 m ay be replaced.: -Anfalternative means of stabilizing table 3 over an uneven oor surface is to use basescomposed of resilient or compressible. 'zx`iia;t e ri al,`.V such as a `rubber composition. which isdesigned to be compressiblein accor-d ance withthe unevenness of thesurface ofi the ping or jigglingnotfV ,theV table 3. ofl theswitchboard. room is sufficiently level. thenthe legs of these tables 3 maybe provided -f with cup-shaped feet of hard brass to facilitate sliding the tables 3upand do wn the length ofthe switchboard in accordance withdi ierent traffic requirements.

-Each operator's teletypewriter includes a keybeard trapsmitter unitfz which is similar to that is ishownQ-,ttrbe operatedfbyamotor 6 9y which is also. DoS/ltinadfupg 'the ten, of .table 3f- AS1-s' also shown inthe drawings,theL keyboard'unit 2 This cover has surface to the Afthe switchboard room vto reduce tipv` If the floor f.

^ described in Patent 1, 59 5 ,4 72granted/August 10, 1926 rto H. L. 'Ifhedisclosure-of this Krum incorporated herein by reference as a message rate i viewed.' A t theieft or the keyboard iseeentrei switchr 4 5- for controlling .current supplied from Y, .i

thelocal source of power supplyl lThe mechanism? `Whih ,fzlvnprisesl unit ,5l vof each operators, teletypewriter is:

the i' typing".

mountedupon shelf 52 which is locatedabout ten unit 5I is shown to be operated by a motorji which is also mounted upon shelf 52. 1 Although inK this ,embodiment l Off the invention.4 it is to e be that-e singiemeterieeeted with either unit end sited" i ,f The operators. positionl equipment is locatedA f at thefieft ef the keybeerdunit :rend is mounted upon a readily remoiiablexpnell tvvrwllitate 375-Y removal for maintenance. or modiiication to meet different requirements of different installations. This position equipmentincludes an electric calcuiagraph41 used by the operators to time messages as a basis for determiningv the amount to be charged for a particular call. .Calculagraph 41 is provided with levers 31, one of which. is used to indicate on a message rate ticket 22 y.the time when the message began, andthe'other to indicate on ticket 22 the timethe message ended. The position equipment alsoy includes the operators position keys 46 for performing the supervisory functions of ringing on the answering cord, cord circuit splitting, recall, and recall-release. These keys46 are connected by leads (not shown) to a connecting block. 82 located on the underside of the table top near the jack panel 61.

This positionequipment lis connectible to the switchboard I by the line cable 8 and the power cable I2. Line cable 8 has a plug 9 which is adapted to fit linto any of the outlets 1, at the base of switchboard I, leading to the position relay equipment (not shown) inside switchboard I. Power cable I2 has aplug I3 which is adapted to be inserted into any of the power outlets II, at the base of switchboard I, leading to the local source of power supply (not shown).

i Just to ith'eright of panel 68 and immediately to the leftvof the typing unit 2 is a smalljack panel 61 mounted in' the top of table 3. This jack panel 61 is connected by leads (not shown) tothe keys 46 and is providedfor receiving the plugs 38, 39, 48, and49. Attached to the plugs 48v and 49.are the teletypewriter line cord 88 and power cord `8l which passbehind the mirror 68 and theninto the keyboard unit 2. These cords 88 and 8| form a link in the electrical connection between the keyboard unit 2 and the connecting block 82 to permit ready removal of the keyboard unit 2 if desired. A cord 83 is attached to plug 38 for connecting the power supply to motor 56 of typing unit 5I. Another cord 84 is connected to plug 39 for forming the electrical connection between the keyboard unit 2 and the typing unit 5I through the connecting block 82. These cords. 83 and 84 permit ready removal of the typing unit 6I if desired.

Table 3 is also equipped with a telephone I6 which is mounted on the right end of cover 4I of thekeyboard unit 2. -Thistelephone I6 is connected to the switchboard I byl a cord I1 which passes through a hole 42 in theright end panel of table 3 and then to the connecting block 82. The. telephone circuit then passes from connecting block 82 over a conductor in cable and through jack 1 to the relay equipment'inside switchboard I. y e

The line circuit passes from the position relay equipment inside switchboard I, through outlet 1 and plug 8, over cable 8, through the connecting block 82, jack panel 61, line plug 48, line cord 88 which goes behind mirror 68 and then through a hole in cover 4I to the keyboard unit 2, back over another conductor in cord 88 and plug 48, through connecting block 82 and jack panel 61 to plug 39, over cord 84, through a hole in thetop of table 3 to the typing unit 5I, and then back over another conductor in cord 84 to cable 8. Likewise, the power circuit leadsfrom the local 4source of power supply over a conduit (not shown) inside switchboardV I, through outlet II and plug I3, over` cable I2, and then to the connecting block 82. Here the power circuit divides, one path 4passing through the jack panel 61, power plug 49, overpower cord 8| which passes vided with slots to facilitate uncovering the typ-I ing unit 2 when desired.

Since the tape 48 must pass through the typing unit 5 I, the tape reel 53 is conveniently mounted on the right end of Athe typing unit 5I. To facili` tate insertion and removal of the tape reel `53, the front -side' panel 54 of table 3 is mounted4 upon hinges 55 to act asI a hinged door so that it may be pulled outward. One end of a chain 63 is attached to the underside of the table top and the other end isl attached to the inside topportion of panel 54. Chain 63 is provided forthe purpose of preventing panel 54 from dropping down when opened and, instead, to` hold it out'in the manner cfa shelf for the convenience of a maintenance man. It is to be understood 'that this' is merely the preferred embodiment o f the invention andthat other arrangements may be constructed. For example, the right end panel of table 3 may be .arranged to drop, or slide downward. Alsothe tape reel 53 need notv be mounted directly on the typing unit 5I Ibut may be placed in other locations, such as upon the side panel 54. j

The tape 48 passes from the supply reel 53, through the typing unit 5I, through a slot 51 in shelf 52, and then to the used tape storage receptacle, or container, I4 with which each table 3 is provided. Panel 54 has a cut-out portion, indicated at64, for enabling an operator to quickly insert her hand therein to free the tape 48 if it becomessnarled or` tangled priorkto its passage through slot 51. ,Y

In orderfor the operator to see conveniently what is typed upon the tape 48, it is advisable to cut out a portion of the top of' the` table 3 as indicated at 6I and to employea small lamp 58 and two adjustably mounted mirrors 59 and 68. The tape illuminating lamp 58 has a shade which is designed to concentrate the light upon the printed portion of the tape 48. This light then shines upward to the mirror 59 which is so adjusted as to reflect it to the mirror 68 which, in turn, is adjusted to reflect the image of the printed tape 48 to the eyes ofthe operator indicated at 62. The line of. vision from the operators eyes 62 to the printed tape L48 is indicated in Fig. 2 by the broken line. If desired, the in terior of table 3 may be-painted white to reduce absorption of the: light rays.

It is to be understood that this is the preferred form of the tape projecting means andthat various modifications may readily be made to suit the requirements of a particular installation. A lengthv of tape about four inches long, more than suiiicient to meet operators typing requirements may be viewed in this manner. `In the event that it should become necessary for .an operator tol read back used tape 40 which has passed by the mirror 59, she may conveniently do so by reaching through the cut-outportion 64 of thepanel 54 and pulling tape 48 out of the slot 51.l She may then readily pull as much of tape 48 out of the used tape container I4 as may be necessary.l

A modification of the inventio-n is shown in Fig..A 5 in which a single motor 18 is yused to -,operate,

typing 'unit 5| andkeyboard unit2. Shaft 12 v is connected to the typing'unitl'5l by gears 14 and tokeyboard unit 2 by gears 15. 'Ihe rest of the construction of this modification is practically the vsame as that described above'.

The advantage of thismodiiication of the inventin resides yin the fact that, since the motor 51 need not be on the top of table 3, table 3 may be made narrower to enable'the operator to sit closerl to thev jack-field24` of switchboard Likewise, since motor 56 need not be placed on y shelf 52, shelf 52 may be made 'narrower thereby providingfmore knee-room for the operator. v Anothermodiiication of 'the invention is illustratedv in Fig. 6 which shows a single motor 10 AinvertedV and suspended by any Vsuitable means, l

such as screws 11, from the underside of shelf 52 for operating both the' keyboard unit and the typing lmit by means of gears -13'-14 and drive shaft 12. The advantages inherent in thismodiliication are that better ventilation is obtained for-motor V10 and more foot-room is provided for the operator. 1

Still another modification of this invention is shown in Figs. 7 and 8. In Fig. 7, a switchboard l |00 is shown provided with teletypewriters 0| partially built into, or mounted in, the switchboard |00. I'hese teletypewriters |0| are the same type as the teletypewriters shown in the other figures of the drawings. Although two separate motors have been shown in this embodiment of the invention, itis' to be understood that this is a matter of choice and that a single motor located with' either unit and suitably connected to the other unit may be used if desired.

:It can be'seen in the drawingsv that, with the switchboard constructionv employed, the tops of the teletypewriters are almost on the same level as the top of the key-shelf |03. vantage of` this construction resides in the fact that it enables the jack-field |04 to be extended vdownward further, than would otherwise bepossible. l This, of course, increases the number of subscriber lines available to the operators.

As can be seen in Fig; 8,y ateletypewriter |0| is provided with two motors |05 and |06. -Motor |05 operates the keyboard unit |01 and motor |06 operates the typing unit |08. Power for operating motor |05'comes in from conduit |00 and the power for operating motor |06 comes in over conductor I0. The typing unit |08 is electrically controlled by the keyboard unit |01 overY a conductor which leads from the conducting block |2 in the keyboard unit |01 through a connect! ing block ||3 in the typing unit |00. Since the tape H4, which comes from a supply rolly |53,

is inside the switchboard |00, it is made visible` to an operator by being illuminated by a source of light, such as lamp H5, and is then reflected tothe eyes of the operator by mirrors H6 and ||1. The line of vision is indicated. by the dotdash line in Fig. 7.

It can thus be: seen that the invention is not restricted to teletypewriters mounted upon movable'tables but is equally applicable to teletype- ,rwriters built into a switchboard In both types,

The ad-V the invention effects a decrease in the eective height of an operators teletypewriter which results in an increase inthe area of the jack-field available to the operator. 'I'his enables the operators tov make more efllcient use of the switchboard multiple. Since the switchboard multiple is an expensive item, ythe 'initial and overhead costs of a switchboard multiple having the bottom of its jack-field .lowered by means of these teletypewriter andtable assemblies are considerably less than they would be for an ordinary switchboard multiple having an equal number of jacks; It is to be understood that additional modica.- tions within the scope `of the principles herein outlined are `within the scope of the invention as herein set forth and claimed.

What is claimed is:

1. A teletypewriter central o iiice comprising in combination a teletypewriter exchange switch'- board including a switchboard multiple having a jack-field, an operators teletypewriter mounted beneath the jack-field of `'the switchboard mul- Y tiple, said teletypewriter having a. keyboard unit anda typing unit, means for' reducing the etfective height of the operators teletypewriter for increasing theeffective height of the jack-field, said means including first supporting means for supporting the keyboard unit below the jack-field and second supporting means for supporting the typing `unit beneath thefkeyboard unit.

2. A teletypewriter central cnice comprising in combination a teletypewriter exchange switchboard having a jack-'field and a projecting keyshelf, an operators teletypewritermountedvupon a table locatedunderneath thekey-shelf, said tablev being adapted for movement up and down( the length of the switchboard `for readily varying the location of the operators position in accordance with different trame" requirements, and means for increasing the area of the jack-field available to the reach of an operator, said means comprising a teletypewriter keyboard mounted on top of the table anda teletypewriter typing unit located underneath thetop` or the table .whereby the effective height'of the 'operators teletypewriter is lowered.

3. In a teletypewriter central omce having in combination a teletypewriter exchange switchboard and-an operators Vteletypewriter having a keyboard unit and a typing unit, said switchboard including a switchboard multiple having a Jackfield, the method of increasing the area of vthe jack-field accessible toan operator, said method comprising separating the keyboard mechanism of the operators teletypewriter from the typing mechanism, mounting the keyboard unit beneath the jack-field, and positioning the typing unit beneath the keyboard unit. Y l

4. In combination, an operators teletypewriter and table including a keyboard unit and position equipment mounted upon the top ofy the table, said table having a shelf, a typing unit mounted upon the shelf, a motor mounted upon the' shelf for operating the typing unit, and an electrical connectionbetween thekeyboard unit and the typing unit f or enabling theoperation of the typing unit to 4be controlled by the keyboard unit.

5. In combination, an operatorsteletypewriter and table includinga keyboard unit and position equipment mounted upon the top of the table; said table having a shelLva typing unit mounted upon the shelf, a first motor mounted upon the shelf for operating the typing unit, a second motor mounted upon the top of the table for operating thevkeyboardunit, and an electrical connection between the keyboard unit and the typing unit for enabling the operation of the typing unit to be controlled by the operation of the keyboard unit.

6. In combination, an operators teletypewriter and table including a keyboard unit and position equipment mounted upon the top of the table, said table having a shelf, a typing unit mounted upon the shelf, a motor, a plurality of gears for mechanically connecting the motor to both the keyboard unit and the typing unit for enabling the motor to operate both the keyboard unit and the typing unit, and an electrical connection between the keyboard unit and the typing unit for enabling the operation of the typing unit to be controlled by the operation of the keyboard unit.

7. In combination, an operators teletypewriter and table including a keyboard unit and position equipment mounted upon the top of the table, said table having an upper shelf and a lower shelf, a typing unit mounted upon one of the shelves, a motor located upon the other shelf,

means for mechanically connecting the motor to the keyboard unit and to the typing unit for enabling the motor to operate both the keyboard unit and the typing unit, and an electrical connection between the keyboard unit and the typing unit for enabling the operation of the typing unit to be controlled by the operation of the keyboard unit.

8. In combination, an operators teletypewriter and table including a keyboard unit and position equipment mounted upon the top of the table, a typing unit mounted beneath the top of the table, a motor for operating the typing unit, a supply of paper located beneath the top of the table for being printed upon by the typing unit, a source of light located beneath the top of the table for illuminating the printed portion of the paper, and a plurality of mirrors for enabling the printed portion of the paper to be viewed by an operator.

9. In combination, a teletypewriter exchange switchboard having a key-shelf, an operators teletypewriter built into the switchboard and having a keyboard unit and a typing unit, the keys of the keyboard unit being on a level with the key-shelf and the typing unit being located inside the switchboard on a level below that of the key-shelf and keyboard unit, a motor located inside the switchboard for operating the typing unit, andan electrical connection between the keyboard unit and the typing unit'for controlling the operation of the typing unit from the keyboard unit.

10. In combination, a teletypewriter exchange switchboard having a key-shelf, an operators teletypewriter mounted in the switchboard and having a keyboard unit and a typing unit, the keys of the keyboard unit being on a level with the key-shelf and the typing unit being located inside the switchboard on a level below that of the'key-sheli and keyboard unit, a iirst motor located inside the switchboard on a level with the key-shelf for operating the keyboard unit, a second motor located inside the switchboard beneath the level of theVkey-shelf for operating the typing unit and an electrical connection between the keyboard unit and the typing unit for controlling the operation of the typing unit by the operation of the keyboard unit.

l1. In combination, a teletypewriter exchange switchboard having a key-shelf, an operators teletypewriter mounted in the switchboard and having a keyboard unit and a typing unit, the keys of the keyboard unit being on a level with the key-shelf and the typing unit being located inside the switchboard on a level below that of the key-shelf and keyboard unit, a motor located inside the switchboard for operating the typing unit, an electrical connection between the keyboard unit and the typing unit for controlling the operation of the typing unit from the keyboard unit, a supply of paper located inside the switchboard for being printed upon by the typing unit, a source of light located inside the switchboard for illuminating the printed portion of the paper, and a plurality of mirrors for enabling the printed portion of the paper to be viewed by an operator.

l2. A teletypewriter central oflice comprising in combination a teletypewriter exchange switchboard including a switchboard multiple having a jack-held, an operators teletypewriter mounted beneath the jack-field of the switchboard multiple, said teletypewriter having a keyboard unit and a typing unit, means for reducing the effective height of the operators teletypewriter for increasing the eiective height of the jack-held, said means including rst supporting means for supporting the keyboard unit below the jack-held, second supporting means for supporting the typing unit beneath the keyboard unit, an electrical connection between the keyboard unit and the typing unit for enabling the operation of the typing unit to be controlled by the operation of the keyboard unit, a supply of paper leading through the typing unit for being printed upon by the typing unit, a source of light located beneath the keyboard unit for illuminating the printed portion of the paper, and a plurality of mirrors located in viewing relation with the printed portion of the paper for enabling the printed portion of the paper to be viewed by an operator.

ALFRED A. BURGESS.

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