US2477702A - Backspacing mechanism - Google Patents

Description

Aug. 2, 1949. c. w. NORTON BACKSPACING MECHANISM s Sheets- Sheet. 1

Original Filed July 8, 1944 WM-rm V ATTORNEYS Aug. 2, 1949. c. w. NORTON BACKSPACING MECHANISM Original Filed July '8, 1944 5 Sheets-Sheet INVENTOR (fiarlar E Jlormz 5 Mn fm Mm A Patented Aug. 2, 1949 UNITED STATES PATENT OFFICE BACKSPACING MECHANISM Charles W. Norton, West Orange, N. J., assignor to Ralph C. Coxhead Corporation, New York, N. Y., a corporation of Delaware This invention relates to typewriting machines and as illustrated and described is embodied in a machine known in the art as a Varityper, in which a supporting anvil carries interchangeable type shuttles, so that various styles and sizes of type may be used at will. This application is a division of my application Serial No. 543,981, filed July 8, 1944, now issued as Patent No. 2,405,974.

Machines according to this invention are capable of producing typed sheets in simulation of ordinary printed matter which may be used as make ready for reproduction of photolithographic or other printing processes. The printing type, however, must be given various conventional dimensions as to width, and it is desirable that different styles and sizes of type, such as occur in ordinary printed matter in the way of headings, emphasis and the like, may be used. Means for attaining this result is disclosed in my Patent No. 2,298,805, issued October 13, 1942.

The invention disclosed herein is capable of producing a typed sheet in characters of conventional dimensions differentially spaced in many different fonts of type; to accomplish this result requires new structures in respect of some of the functions, and a novel coordination of the different mechanisms and'devices which must be conjointly employed; and it provides mechanism whereby the carriage feed may be advanced according to the varying width of the different characters, and at the same time affords means for appropriate back-spacing adapted to the requirements of such difierential spacing.

The object of this invention is to provide improved back-spacing mechanism whereby the carriage may be back-spaced different distances per stroke.

In the claims as well as in the description parts are identified by specific names for convenience, but such nomenclature is intended to be as generic, in its application to analogous parts, as the prior art will permit. The best form in which I have contemplated applying my invention is illustrated in the accompanying drawings forming a part of this application in which:

Fig. 1 is a plan view of a preferred form of typewriting machine with such parts omitted as are well-known in the art and may not be necessary to a complete understanding of the present invention.

Fig. 2 is a vertical section on the line 33 of Fig. 1.

Fig. 3 is a broken perspective view of the backspacing key and mechanism.

9 Claims. (Cl. 197-91) Fi 4 is a view in side elevation of the twobutton back-spacing key.

Fig. 5 is a side elevation of the back-spacing ratchet in the position taken in back-spacing four units.

Fig. 6 is a detailed view of the escapement dog and a portion of the escapement wheel that is acted upon by the back-spacing mechanism.

Fig. 7 is a plan view of the back-spacing ratchet shown in Fig. 3.

The machine herewith illustrated and described is of the key-controlled shuttle type, where the printing impression is formed by the impact of a.

printing hammer which forces the paper against the ribbon and type. The particular machine illustrated is known in the art as the Varityperi, Referring to Fig. 1, it comprises a main frame I which carries the mechanism of the machine.

Type keys 2 (only a few being illustrated) are mounted on a pivot bar 4 (Fig. 2) supported by the main frame l. These type keys 2 at their front ends carry finger buttons 5 and at the rear ends cooperate with the actuator bars 6 (one of which is shown in Fig. 2) to operate actuators 1. These actuators 1 swing the shuttle arm 8 (Fig. 1) so that it oscillates the shuttle 9 on an anvil 9a to bring the proper type to the printing point.

This mechanism is old in the art and will not be described in detail. See patent to Trego No. 1,880,592, October 4, 1932.

The paper carriage l6 (Fig. 2) is provided with antifriction rolls I! which travel upon the carriage supporting rod l8 as the carriage moves to the left under the influence of the carriage spring. This mechanism is also old and well-. known in the art and therefore will not be described in detail. The carriage is moved in letter space direction by a carriage spring which is mounted in a drum [9 (Fig. 1) that carries a band which is attached to the carriage, as is well-known in the art.

The carriage I6 is progressed from two to seven units of space upon the printing of a character or symbol, the exact spacing being dependent upon the width of thecharacter. For example, a lower case L is allocated three units of space, while the lower case M or W is allocated seven units. This variable spacing in accordance with the width of the letters occurs within the same font of type. The unit of space referred to is an arbitrarily selected unit which is an aliquot part of and smaller than any of the letter spaces. The term "letters as used herein includes the various symbols and figuresfound on a typewriter keyboard, as well as letters of the alphabet.

dotted-line position and contacts frame I of the machine, thereby preventing further downward movement. This limited movement is designed to effect only one backspacing unit. The button 5 312 is marked Back space 1.

The motion ,ofithe backspacing;-key 3' is communicated to the escapemenfmechanism-by shaft I3, mounted in the frame I. This shaft has rigidly secured thereto an arm carrying the roller and r space ni s r p iv lyyI =-llwtinacontaet with extension 3e on the backmechanism, escapement wheels I- IIf and IV-- are selectively or simultaneously-released for rotation of a single tootlf'upomd'pressiowof a printing key 5. The details of consh'uction bt spacing key. On the rear end of shaft I3 there isrigid1yi'secured4amarm I3b (see Fig. 3) connectedby;'a'1irrl:I3c7 with a bell-crank lever I3d freely mountedfor oscillation on escapement wh h h va a le sp azis a m s d are 'llifisha'ftt I Ii Theearmalsb and link I30 are biased set forth in detail in the above-reirredi'ttorparenti; application.

A system of variable letter spacing of the type above described requiress that the backspacing mechanismubencapable of backspacing the carriage IBfor any numherpfspace'unita In'order that the carriagermay be returnedifortherretyping ofiany characten or ,symbol whichmaybepoorly or illegibly printed, or forthe maintenance of an;

indented column, as well .asv for otherreasons;

it ;'is..essential Tto provide. backspacing mechanism which. is,capable .ofibackspacing; one unit only: Flor: greater .speediimbackspacing; it is desirable to also provide additional'mechanismior;back= b yia spring l 3d tending to draw them toward each other;the effect ot which is to bias shaft I3 in suchimanner as to maintain roller I3a in contact with the extension 36 on the back-spacing key, and to bias bell-crank lever I3d toward the positionshown'in'Fig; 3, which is the normal ordn-active:position'.of-th'e"mechanism.*

A pawl-i23is pivoted on-a pin-23a; rigidly-se cured*to:the-bell-'crank lever I3d1' 'Ihe-pawl n'! is 'spacedfrom' thebell crank I311 flay a sleeve 231), as is" shown in Fig. 7* (with the spring: 232% omittedd It is to-beobserved: that both b'ell I crank lever I 3d-and*escapement whee1-*-If are freelymounted on escap'ement shaft -4 I and that spafi gethemarriagea pl m y, of spacet nits: the -sleeve-23b serves-td-position 'pawl 23 for co=-- Toaneet this need therbackespacing kev 3"'(Fig; 1) hastworbuttons; 3Z1 and.3b3, one .,of i'which operates" toeliackspaceiour at each stroke, andlthe other; oftlwhiohloperatesato backespace: azsing1e;

actiorrwith the'teethon escapement wheel I -j. Toobtain--proper engagement b'etweem the pawl 23"and theteeth-of theescapement wheelI -f, sleever23b has"aprojecting pimfle *(Fig: 5-)"whic l'iunitonleaoh; stroke.. Itjisd-essentialfin, suclicase: 85 engages'pin 2311mmpawl23 and imparts thereto thatbackspacing befieeirom mechaniealerror; and; theback-spacing. mechanism is so con-1 stmotedcasctoesecune,exact spacing. ItLLisl com-- strueteditoact zuponaessapement .Wheel" I f.' It i the pressure-of springfl3e surrounding=sleeve 23band atta'ched' at one-= end to the belI- orank I 3?? arid" at the other" endto-"p in -23a Whicl'i'spring" tends to h'oldthepawlin engagement with z the willlb'e seen 'oru'efe'renceioiEig. 6 that the eescapee- 40" escapement wheel ment wheel 'I;'-f.- isrcontrolledr by, the actiornof; dogs I 05 and, I 06.1 The-action.of."typing a char: aeteroperatesrtoerelase dog l 05Ifromthe escapee meat wheels. When-.theldogd 05 is being released}.

However; in normal or='inactive=position (Fig. 3') pawl 23 isout of engagement witlr escape-"- ment Wh'eeI I- f: and it 'is'held -in"this inactive position by a pin" 43 secured on the: machine th'e-d0g=. l 061s; irmthecpafli ofianeoncomin stooth- 5- fr m -s Whichpin en a es a n0tch= 43a-:in-*p w ofi; the escapemen-t wheel-1 before thatwheeli. is: entirely =freeeffom.-theedog- 1 I 05; ,andithel-irelationl OffiOgJ flliandtdog l 05Tislsuch as .tmpermit a=.very;.. slight 'movement of the eseapemenLwheeL-after,

dege I llfiehasubeenldisengagedand beforeuth'eeescapemenit' wheelshass b'eenstopneiby, dog" !06.. Wh'emdog: I UBLrelasesthe escapemenhwheel, itfisrre=engaged by, dog I05; and therescapement wheel hasrturneioneltooth,ppogressingathel car:

23?- Ii'r this=posltion escapement wheel I 4; being under tlie infiiience of the -carriagedrive, is: controlTed -in its rotation partly-bycdog- Ifl5' and partly-by -*dog= I 86}. as *been explained."

Dog I05 carries=a-pif1 mm: which is engage abl=by wpih- IIISUwmlirr-k I30 wherr'in the-post tion shown 'inF'ig'r- 5? Ifvtliat positionthe *ex tension I3i on bell-cranklever' I3cl' contacts? stoppin=63 "on"-the machine =frame5 Thepurpose riageJtl'oneeunitd A-more. detailed-de'scription, of this contact is= to=take the-principal "shockof of: this escapementemechanism ia containedain, the above-mentioned; parent application. The. hackspacing mechlanismnof ;Eig,..3lis ,designed.'to actuate theeescapementfwhleel I;-f 'in .the reverse direction. 7

The.buttonsemiarid3bv (Eigsa3 and .4). arecarried. by a. member; pivoted) 0n..the key. 3;. member is. yieldably held" inl the. positiom shown imFZigbrllbyaatensionnspringjfil Itlh'asa .pointrorr the -back spacing stroke and-"th ns -:protect the dog I05 and the pins 15a and I05b as wellaszthew escapementrwheelffom excessive force arrd in- When the -keydi riS given'zai: fu1-1 wstrokersothat'. it contacts: the. stop: pina 3d= the backs-spacing: meehamsmwwillitakeethe position shown in Fig.7 5;- in= whichpin 15b contacts pinzIIISwand. so.holds-.- dogs, I 05am vcontact LWj-th ,artooth of ,escapement w g mcm dgwnwardmgyement ofj h key 65' wheel If. This wi1l.preventanyrfiirthenback=- lmpressureom button 3a issnotchangedjn pOSL:

tionbut clearsithejrame ,I landQpermitsthe key 3. tormove.downwardmntilitnontactsizheadjustable stope3da Thissmovement eflectsi an backespacingg ward .rotation ;of the escapement. wheel at the endof theofflllstrok'e; and the movement is such that theescapement'wheel has moved backward a" distance equal to four --andone=half fteeth beohfoumvunitmaanibuttonfid isimarkeareaea 'f0re farther nwvementi'issstopped. O -the re= space 4:." If,;,however, .the key. isoperated; by pressure .on-tbutton 3b.the.pivoted member, which. carriescthev operating buttons,. is first deflected against thertensionot-ithe spring BLandbnrdGWne turn of the mechanism, dog I05 will permit/ a forward rotation oftl'ie'escapement wheelfor-*a distance of half a tooth, when the next tootl'rwill be engaged'by'dog I 05: The resultant backward ward movement of'the key 3, toe 3?: takes the motion of the full baclr=spacing-stroke'is'a baclr ward movement of four teeth of escapement wheel 1-). This rotation transmitted through the train of escapement gearing (shown in Fig. 2) results in an angular rotation of shaft 4| which is the equivalent of four spacing units.

Obviously a backward movement of only one tooth would transmit to shaft 4| a movement of only one unit; and this is the backward movement occasioned by a stroke on button 31).

It is to be observed that when the back-spacing key is released and the pawl 23 returns to its normal position the spring 23c permits the pawl to move outward as it passes over the ratchet teeth; and as it approaches pin 43, notch 43a is in position to engage pin 43. Further return movement of the pawl completely disengages it from th teeth on escapement wheel 1- In order to avoid friction and noise on carriage return the escapement mechanism is provided with a construction that lifts the dog I of escapement wheel I-f at this time. I'his comprises a grooved wheel 13 around which is a bight of strand material, in this instance spring wire 13a, frictionally engaging the bottom of the groove and terminating in a bent end 13b (Figs. 3 and 5). The grooved wheel 13 is fixedly mounted on shaft 4| and turns counterclockwise on return movement of the carriage. The spring [30. rotates with the wheel I3 until the end of this spring engages pin I 05a (Fig. 5) and earns outwardly the pin a carried on the dog I 05, thus removing the dog I85 from engagement with the escapement wheel I-). When the carriage moves in letter space direction the spring 13a is carried along with wheel 13, restoring the normal action of dog I05. When the end 1312 of the spring engages the fixed pin I050 the spring tends to open around grooved wheel 13 so that no perceptible friction occurs during letter space travel of the carriage.

It is to be understood that while the invention is described herein as applicable to a typewriting machine of the kind known as a Varityper it is capable of use with typewriting machines of other kinds, and is not to be understood as limited in its scope other than is indicated in the claims.

What I claim is:

1. In a typewriting machine, in combination, a movable paper carriage, a spacing mechanism for controlling the movement of said carriage, a back-spacing key lever, an oscillator shaft, an arm rigid on said shaft adapted to contact said back-spacing key lever, a second arm rigid on said shaft, an escapement shaft, a member freely oscillatable on said escapement shaft, 3, link connecting said second arm with said member, a spring operative to hold said first mentioned arm in contact with said back-spacing key lever, an escapement wheel mounted on said escapement shaft and connected therewith, a pawl pivoted on said member for actuating said escapement wheel, and means controlled by said link for preventing overthrow of said escapement wheel at the end of its pawl-actuated movement.

2. In a typewriting machine, in combination, a movable paper carriage, a spacing mechanism for controlling the movement of said carriage, a back-spacing key lever, an oscillator shaft, an arm rigid on said shaft adapted to contact said back-spacing key lever, a second arm rigid on said shaft, an escapement shaft, a member freely oscillatable on said escapement shaft, a link connecting said second arm with said member,

a spring operative to" holdsaid first mentioned arm in contact with said back-spacing key lever, an escapement wheel mounted on said escapement shaft and connected therewith, a pawl pivoted on said member for actuating said escapement wheel, saidpawl being normally held out of contact with said escapement wheel, and means 1 controlled by said link for preventing overthrow of said escapement wheel at the end of its pawl-actuated movement.

3. Ina typewriting machine, in combination, a movable paper carriage, a letter spacing mechanism operable within the same font of type and including a plurality of interconnected escapements operable selectively or combinationally for variably controlling the carriage movement in accordance with the width of letters within a single font of type, one escapement being effective to space an aliquot amount of any of the carriage letter spacings, and backspacing mechanism for'backspacing said one escapement a like aliquot amount.

4. In a typewriting machine, in combination, a paper carriage, 'a letter spacing mechanism operable within the same font of type and includingthree interconnected escapement-s selectively operable for variably controlling the carriage movement, one escapement being effective to space an aliquot amount of any of the carriage letter spacings, and back spacing mechanism for backspacing said one escapement a like aliquot amount.

5. In a typewriting machine, in combination, a paper carriage, a letter spacing mechanism operable within the same font of type and including three interconnected escapements operable selectively or combinationally for variably controlling the carriage movement, one escapement being effective to space an aliquot unit less than any of the carriage letter spacings, and backspacing mechanism for backspacing said one escapement a like aliquot unit.

6. In a typewriting machine, in combination, a movable paper carriage, an escapement mechanism, including an escapement wheel, for controlling the spacing movement of said carriage, a backspacing key lever, a pawl oscillatable about the axis of the escapement wheel, said pawl being normally held out of engagement with said wheel and engageable therewith upon oscillatory motion of the pawl for backspacing the carriage, means operatively connected with said backspacing key lever for oscillating said pawl, and an escapement-wheel-engaging means actuated by said pawl oscillating means at the end of its carriage backspacing travel to prevent overthrow of the escapement wheel by said pawl.

'7. In a typewriting machine, in combination, a movable paper carriage, an escapement mechanism, including an escapement wheel, for controlling the spacing movement of said carriage, a backspacing key lever, a pawl oscillatable about the axis of the escapement wheel, said pawl being normally held out of engagement with said wheel and engageable therewith upon actuation of the backspacing key lever for backspacing the carriage, means operatively connected with said backspacing key lever for oscillating said pawl, and an escapement-wheel-engaging means actuated by said pawl oscillating means at the end of its carriage backspacing travel to prevent overthrow of the escapement wheel by said pawl.

8. In a typewriting machine, in combination, a movable paper carriage, an escapement mechanism, including an escapement wheel and a dog ammo normally engageditherewith, ior controlllng the spacing movement of -sazldearriage, a backspacing key lever, a pawl-'oscillatable about the-axis of the esc'apement WheeLsa-id pawl being normally held out ofengagement with said wheel and engageable therewith upon oscillatory'motion of the pawl to movethe iescapement wheel in reversedire'ction, said dog being displaceable by reverse movement of the escapement-wheel, and means operatively connected with said backspacing key lever for oscillating said pawl and restricting displacing movement of said dog at the end of the pawlsscarriage backspacing travel to prevent overthrow of the escapement wheel by'said pawl.

9. In a typewriting machineyin combination, a movable paper carriage, an escapement mechanism, including an escapement wheel and a dog normally engaged therewith, for controlling the spacing movement of said carriage, a backspacing key lever, a pawl oscillatableaboutthe axis of the escapement wheel, saidpawl being normally held out ofengagement with said wheel and engageable therewith upon oscillatory motion of the pawl to move-theescap'ement 'wheel in reverse direction, said :dog being displace'able by reversem'ovement or the escap'ement vwheel,

and-a link operatively connected with said backspacing key lever to cause oscillation of said pawl, said link being adapted to restrict the displacing movement of said dog at the end of the pawls backspacing. travelto prevent overthrow of the escapement wheel :by said pawl.

CHARLES W. NORTON.

REFERENCES CITED "Ihe following'refe'rences are of record in the fileofth'is patent:

UNITED STATES PATENTS Number Name Date 656,658 Phelps Aug. 28, 1900 604,073 Peterson Feb. 25, 1902 1,183,056 Wiley May 16, 1916 1,243,955 Krusius Oct. 23, 1917 1,918,304 Trego July 18, 1933 1,941,018 Murray Dec. 26, 1933 1,984,410 Hart Dec. 18, 1934 2,127,431 Schremp Aug. 16, 1938 2,224,766 Dodge Dec. 10, 1940 2,268,867 Gabrielson et a1. Jan. 6, 1942 2,294,721 'Dobson Sept. 1, 1942 2,364,653 Pollock et a1. Dec. 12, 1944

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