US2825441A - Feed mechanism for perforated tape controlled apparatus - Google Patents

Description

-March 4, 1958 H. THOLSTRUP FEED MECHANISM FOR PERFORATED TAPE CONTROLLED APPARATUS Filed June 24, 1955 W m/, m mm m M 5m United States Patefit'G FEED MECHANISM FOR PERFORATED TAPE' CONTROLLED APPARATUS Henry 'L. TholstluliRochester, N. Y., assigrior, by riiesue assignments} to the United Statefs'jpf America-as represented by tlie Se'crtaryiif theNavy Applicationiune' 24,1955, Serial N 0. 517,949

This invention frelates "to feed 'mechanismsfemployed in perforated tape-controlled' apparatus, such as typewriters, computer input and output devicesf etc; and, more particularly, to such feed mechanism iitilizing a ratchet wheel in cooperation with a cam operated pawl for intermittently feeding perforated tape Perforated tape-controlled apparatusis well known in the art and a typical exampleof such apparatus is fully T disclosed in my -Patent';2,-448,842l The perforated tape Y feed mechanism disclosed in this patent; and shown in Figs. .2 and 4thereof, incorporates a relativelycompleX multiple linkage between the" cam'wheel and the pawl actuating the ratchet wheel. "In addition to this patent, other typestof feed mechanisms for advancing perforated I tape are shown in Fig. '3 of Pate:nt2,'346,267 issued to Mills et al., and in Figs. I and 2 of Patent 2,279,161, issued to DHumy. The feedi'rriechanism s disclosed in these-latter two patents also incorporate a multiple linkage between the cam wheeland thepawl actuating the ratch'etwhe'el. g

It is an object'of thisinvention to provide" a link'age between the cam wheel and the ratchet wheel which gives improved reliability of dperatiOfi-l 4 g It is a more 'specific object of this invention to provide a rigid one-piece link which: is integral-"with" the pawl actuating the ratchet wheelf Other objects and'r'nany er thefatteiidant" advantages of this invention will be readily app cia'ted as the becomes better 'understood by reference to metal m I detailed descriptioii'when considered in connection with the accompanying drawings-wherein: 5 k

Figf'l is an ele vatio'n'view' of a eed' iaeehamgmiiicorporating theprin'ciples'bf thisiriventipiiiand.

Ref'rrin'g now to, Pf'gs. 1 and"2; there isisliown highl point 'cam wheel 10 which is fiiredlyfi'ttacli dito drive :5 shaft 12. At a" distance from drivfejshaft 12, but disposed parallel-=theretoj is feedshaft 14. I Mounted' 'on feed-1f shaft 1'4, and coaxial therewith, is first ifieri'iber 16- which incorporates as an integral part thereof'r'atclie't wheel 18. Also included as parts of first member 16 are reduced diameter portion 20 located immediately adjacentratchet wheel 18 and shofild'er'21- located'ne'xt t'd r'e'dilc e'tl diameter portion 20. v a

Linking cam whe'l lti tdfa'tclit wheel' 18 issecond member 22. "Second memb'ei' 22'consist of a fifstf i'ela -ji may thin rigid fiat strip" 24. l A secoiid thin rigidfiat strip 26 is fixedly attached to first strip 24 and is oriented, as shown, with most of its length parallel to first strip 24. U-shaped slot 28 is cut in one end of each of first and second strips 24 and 26. Cam wheel 10 is disposed between strips 24 and 26, as shown, and drive shaft 12 is received on either side of cam wheel 10 by the respective slot 28 of each of first and second strips 24 and 26. Rotatably mounted on a pin passing between rivets 30 is cam follower 32. Cam follower 32 is positioned as shown to engage cam wheel 10.

At the other end of first strip 24 is slot 33. Slot 33 maintain feeds s be fqr fj l b vasls tsfilhatlv t i I;

the scope of the a'ppended claims the inyention may forated tapefa feedt mechanism for said tape go n I i 2,825,441

Ice fiat-enter! Ma 5 reeives reduced" diameter portion" 20, which has an]; axial extentjust suffici'ent' to accommodate the thickness of first strip 24, An extension from first strip 24 forms a short tab which is bent at substantially a right angle. The position of tab 34 on first strip 2fi'relative to the position of ratchetwheel 18 is such as to permit tab 34fto engage'a tooth of ratchet wheel jitt. f a

Also grouped on feedshaft l t, and coaxial therewith, are tdeten t' wheel and slew e38 which includes tap e" 1; feed ispro cket 40, Co op erating with detent wheel 36 is. k

Spring 4 2 connects second member 22 to a fiX edpoint e' s' atvsa In, P Ibn e fr h t i 19 d ive sh t' t 12 he. h pbihfiof af sl flsems i .9mm wit cam follower 3 2.? Ibis c ause s" second member22 to be reciprocated upward pushing tab 3 4 wh ich ,jacts as w pawl, f'agair st to9th,' of ratchet whe e s thereby push- Z inglr at chet wheel 18, dne' spac'e forwa rd. "Dete nt wheel 36; and'det eiit lj c'o a ct'in a conventional" manner to shaftl l t in its new position f'lfhis results} in sprocket 40 advancihgfthe perforated tape one space After thelhighj poihtl of cam wheel 10 passes earns follower "3 2, secondimerr b erf22jis recipro cated down-- M r e t am 4 wh as ra ,cam follower in "contact with cam wheel 10 and also' maintains-tab 34 contact with ratehetwheel It willreadily seenthatithe single"pi ece lin k -dis closed herein is much simpler than the :multiple link fcedingmechanisrns disclosed in the above-mentioned patents. Also the jplay ib'etween the: multiplex links is g eliminated, which resultshin afeedjmechanisinhaving an improved reliability of operation H A v p Obviously many rno difications triviasm of presenfinvention are possibl in the light of the above;

be practiced cinemas; than-as specifiEallydescribed."- T. I claim: 1, In combination P ii 1 Q 11$h e iil'ldtii e lif a dg'l hafis 2 a subs-taetially Para l ea h stee s-1 first 9 9mb? Y H A t tr i iiai wwdttsi have 2 sa srst 'ji rzrs g e-sn sifn eid fi st at a s d @9999 -str sbs s oriented parallel to said first strip and being spaced the M w m; y, P..,? !9 s sat ntli n W dth 2 set. cam wheel, means fixedly attaching said second strip to saidi first strip, said first and second strips each having a firstslot in said one end thereof and said first strip having a second slot in said other end thereof, said cam wheel lying between said first and second strips and said driveshaft being received on opposite sides of said cam wheel' by each of said first slots respectively, said first memberfurther including an extension coaxial with said feed; shaft having a reduced diameter portion immediately adjacent said ratchet wheel which is less than the width; of said second slot and a shoulder having a diameter which is greater than the width of said second slot terminating said reduced diameter portion, the axial: extent of said reduced diameter-portion being, just sufficient to 7 receive the thickness of said first strip and said reduced diameter portion being receivedby said second slot,

and said pawl portion' comprising a short ttablfix edly';

attached ne'ar said other end ofsaid tfirst strip and ex} 1 V tending at substantially a right angle vtherefrornrto cooperatively engage a tooth of said ratchet wheel t V, 2.The feeding mechanism defined in claim 1, further" comprising spring meansconnecting said second member to a fixed point, said spring means being oriented to apply'a force in a direction which urges saidtab into paratus employing a perforated tape, said tapefeeding V m'echanismcomprising': a'fe'ed shaft; a' drive 'shaft par:

' allel to said feed shaft; a first member including a ratchet wheel portion and a portion contiguous and coaxial therewith of smaller diameter and a shoulder terminating the free end of said'smaller. diameter portiomsaid first'member being mounted onsaid feed shaft coaxial therewithg a cam mounted on said drive shaft opposite i "to said first member; 'atrigidsecond member including a a first thin rigid flat strip, a second thin rigid'tflat strip of, a

shorter length than said first strip and securedjto said 1" t first strip whereby at least a portionof saidrsecfond strip a positive contact with a teeth of said rrat'chet whe el' and urges said cam follower into positivelcontact with said 7 7 t cam wheel.

3. In apparatus employing a perforated tape; a feed ing mechanism for said tape comprisinga feed shaft and V a drive shaft, said shafts being substantially parallel to each other, a first member including a' ratchet wheel mounted on and coaxial with said feed shaft, a high p'oint'cami'wheel mounted on. said drive shaft, and' a 'rigidvsecond member having a cam follower rotatably pinned toward one endthereof and a pawl portionintegral'withsaid second member toward the'othen end thereof, said second 'member being oriented withsaid cam follower in cooperative engagement with said cam with a tooth of1said ratchet wheel, whereby saidis econd member forms a single link between said cam wheel and said ratchet wheel, said second member including a first relatively thin rigid-flat strip, a second relatively thin rigid flat strip of shorter length'than said first strip'positioned to have one end thereof opposite said one end of said'first strip, said second strip being oriented par- "allel to said first strip and being spaced, therefrom by, an amount greater than the widthof said cam wheel, means fixedly attaching said second strip to said first? strip, said first and second strips each having a first'slot in said one end thereof and said first strip having a second: slot insaid other, end thereof, said can wheel lying between said first and second strips, and said drive shaftrbeing received on opposite sides of said canrwheel by each of saidjfirst slotsrespectively, said first member further including an extension coaxial with said feed shaft. having a reduced diameter po'rtionaimmediately adjacent said ratchet wheel which is lessthangthetwidth wheel and said pawl portion in cooperative engagement s is parallel to said first stripand whereby the free'iend of said' second stiip terminates adjacent one, end of; said.

first strip, said first and second strips being formed with aligned slots'in their iadjacent'endsf the other end of said first strip being formed with another slot,"and a.

cam follower rotatably joined to said first and second strips inwardly of the bottoms of saidaligned slots; said first strip having an integral pawl portion adjacent said other end thereof, the slotted other endv of saidf first strips-registering with the smaller diameter, portion of ,said first member for a sliding fit with the facin'gzsun faces of said ratchet wheel portion and said; shoulder, said, pawl portion engaging said ratchet wheel, 'the aligned slots in the adjacent ends of said-first and sec- 0nd strips registering with. said. driveshaft adjacent 0p- V posite sides of said'cam, "and'said cam follower engaging saidcam; and spring means connected to saidfsecond member and'tomeans that is. fixed relative to the axes of said'shafts to'urge saidpawl portion into contact 5 with a tooth of said ratchet wheel portion and to urge said ,cami follower into contact with'said cam; t 6. A step-by-step feeding mechanism comprisingr' a i of said secondslot and then ashoulder having a diam- V eter'which, is 'greater'thanrthe'width of said second slot terminating said reduced diameter, portion, the axial extent of said reduceddiameter portion being just sulficient'to' receive the thickness of said first strips and said reduced diameter portion beingreceived by said second slot, and said pawl portion comprising a short tab fixed- 7 1y attached neat, said other end of said first strip' and.

extending at substantially a right angle therefrom to co 'operatively engage a tooth of said ratchet wheel.

' 4;?I'he feeding mechanism defined in claim 3,'further comprising, spring means connecting said second membcrpto 'a fixed point ,tsaid spring means being orientedto apply a force in a dire'ctionto urge said tab into positive contact witha-tooth of. said-ratchet wheel and .to-

urge said cam follower into positive contact with said camwheel." V a LA tape feeding mechanism'adapted for use in ap-:

feedf shaft; a' drive shaft parallel'to said feed'jshaftgati sfirs'tlrne'mber including-a ratchet wheelf portion 'and a f portioncontiguous and coaxial therewith: of smaller 1 diametergand' a shoulderj terminating the free end of' s said: smaller diameter *portionpsaid first member being .40

the othenslot; the said oneslotted end registering with the smaller diameter portion of said firstmeinb'e'r for a sliding fit with the facing surfaces of said ratchet wheel a iportionand'said shoulder, said pawl'portion engaging said ratchet wheel portiomtheother slotted end ofsaid second member registering with said drive'shaft adjacent said cam, and said cam followerengaging said cam;

and spring means connected to said. second member and to meansthat is, fixed relative to the axes of said shafts a to urge 'said pawl portion intocontact withia tooth of 1 said ratchetwheel portion and to urge said cam follower a into c ontact with said cam.

321 References Cited in file of this patent V: 7

UNITED STATES PATENTS c 334,337, Kienast Apr. 7, 19os' 2,247,275 Buckley June 24, 1941

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