US1836084A - Tension device - Google Patents

Description

H. PARKER TENSION DEVICE Filed March 12, 1929 2 Sheets-Sheet I fade I LIWJ H. PARKER TENSION DEVICE Dec. 15, 1931.

Filed March 12, 1929 2 Sheets-Sheet 2 Patented Dec. 15, 1931 'UITED STATE nowann PARKER, or BERL N, NEW HAMPSHIRE; ASSIGNOR To BROWN oomranYjor BERLIN, NEJV HAMPSHIRE, A oonronA'rroN or MAINE a TENSION nEvIcE Application filed March 12,1929. Serial No. 346,477.

This invention relates to mechanism'for automatically controlling the tension on sheet material as it is being drawn from a roll. In the many instances where paper or other sheet material is operated on byautoinatic machinery, the material is usually supplied inrolls which are made as large as practicable to minimize the, frequency of renewals of the'supply. In order to avo d breakage of the material from excess tension. and to det material is taken therefrom, andfric'tional variations inthebearingswhich support the roll. It is an object of'the invention to provide a tension mechanism which is relatively simple, is sensitive to small changes in the tension of the sheet and which acts promptly and automatically to check'incipient variae tions in tension. The invention is particularly applicable to machines for operating'on paper supplied from successive rolls of paper which may be mounted on a plurality'of spindles carried by a rotary frame and swung into place one after the other. By my invention each roll-carrying spindle may be provided with its own tensioning device controllable by mechanism responsive to tension on the paperin the machine itself just as itis about to be operated on. As each: roll .is moved into feeding position, the tensioning mechanism of its spindle automatically comes into operative relation with'the controlling mechanism Without requiring any action on the part of an operator to connect these mechanisms or to adjust theoonnectio'n'." Other advantageous features will be' apparent to one skilled in the art from the disclosure of the invention in the description which follows and the drawings, of which,

Figure 1 is a side elevation of mechanism embodying the invention; Figure 2-is a plan'view of thesame' Figure 3 is an elevation of a multiple spindle support'for rolls of's'heet material.

Figure 4 is a fragmentary side elevation v of ratchet mechanism employed infthe apparatus. i

Figure 5 is an endelevation ofthesame.

Y Figure 7 is'a fragmentary View of a tam member cooperatlng-wlth the elements:shoy vn in Figure6. J r I vReferring to the drawings in'detail, a ma- OFF CE Figure 6' is a perspective View of ajpair of pawls used in the apparatus. Y

chine foroperating-on a strip of paper or j thelike may be suitably positioned to draw a strip of sheet material from a supply roll mounted on a suitable standard adjacent thereto. I As shown 'in'Figures land 21a portion of the framework of sucha machin e :is indicated at '10. Spaced ther'efrom may be a standard 11 rising froma suitable base, J zl2,"the standard 11 pivotally supporting a number of arms 13 which maybe arranged in the form of a star wheel, as shown in Figure 3. Ea ch'of the'arms 13suppfortsaspin dle 1e capable of rotjatjably carrying ra roll 15Vof paper or other sheet materialwhich' is to be fed to the machine 10. Forsuc'cessful operation of most machines which operate on a paper strip, it is important'that the strip be supplied thereto under-a relatively uniforin tension. In 'order'to regulate the. tension automatically as it enters the machine 10, each: spindle 14 may be supplied with suitable'retarding meanswhich may include 7 abrake drum 16 havinga brake'band 1-7 Y, engaging a portion of it's peripheralfsurface. One end of the brake'band'lf may: beadjustably anchored as at 18, a wing nut .19 or threadedhand wheel being supplied to facili tate man ualadj ustnientof the minimum tenj sion :on the f brake. band 17,. As shown in Figure '1, the otherl end of the brake' band' may bews'ecured to the periphery of a takeup drum 20, this drum being fixedjto mock; shaft 21 having a crank arm 22-secured thereto. M i f I Apitman 23 may be pivotally connected. to, the crank arm 22,. the pitman' being suitspacing lugs to the arm 13, [These partsfare to increase the tension on the brake band i 17 and thus to -increase the retarding efiect;

. ably guided as by a member 24 bolted through i ii i v on the spindle 14. In order to actuate the rocking the bar on'its pivot 26causes a thrust on-the pitman 23 which, in turn, varies the braking'el'lect on the spindle 14 from which the sheet isbeing fed; v

7 Suitable mechanism't'or automatically regulatingthe axial. thrust on the rod 27 may be mounted onthe machine frameflO, as illustrated in Figures 1 and 2. This mechanism may comprise a rack 28 securedto or formed on the rod '27, this rack being meshed with a pinion"29. The-pinion 29 maybe mounted on a suitable shaft 30 on which is also mounted a ratchet wheel '31 the teeth of 'whichare engageable by one of a pair of pawls'32, 33. fThese'pawls are normally held out of 'operatve relation with the teeth of the ratchet wheel 31 by a sector-shaped member 34 having a pair of auxiliaryoffset arcu'a.teedges 35, 36'concentric; withthe shaft 30 and 'rockabfleabout the shaft as .an axis. ,On'these edges respectively ride teeth 320 and 'i3 30-of 'thepawls 32, 33. The tooth 330 is ensetfrom'the tooth 320- so as to clearthe icam This tooth'extends over'laterallyto have aportion engageablexfwith the ratchet Wheel 31. -A similarextension 321 is provided'with the tooth 320, but spaced therefrom to provide clearance for the" cam 36. A pair of 'flat sp'rings 300 maybe employedto keep the teeth 32 0 and 330' pressed respectively against the cams and 36. During the operation of the machine which operates on the sheet material,'thepawls32 and 33'are constantly reciproca-ted vertically. Forthis purpose, theymay be mounted upon a common supporting rod 37wlii'ch is reciprocated as by an eccentric 38 carried'byj a suitable gear 39 ldrivenlby a pinioni 40 mounted: on 'a driven feed roll 41 which assists in feeding the sheet to the machine 101 The sheet is preferably passed "over-the feed roll 41 in contactwith f a sufiicient portion of the periphery thereof to provide a desired amount of traction 'member wi-34 resumes its neutral position as ."between'the roll and the sheet, and' at' the same time to permit slippageto relieve differences of tension on the portio-ns'of the sheet approaching and leaving thefeedroll, the surface: of "the roll being su'i'li'ciently smooth for this purpose. 7

As the pawls reciprocate verticallyutheir :teeth'320 "and "330 ride ottthe edges "ofthe respective surfaces 35 and'36, so thatthe teeth u'emainder of the stroke of the pawl.

results in a small axial movement of the push rod 27 Which, inturn, increases or decreases the tension on the brake band 17 and hence 'fromtheroll 15. her 34 maybe governed'by suitable connec- "tions-witha roll 42-whichrides on a stretch of "the f sheet 'material between the feed roll 32l and 330 of the pawls are successively in 2 position to engage a tooth of the ratchet -or-the other about the shaft 30, this permits one-of-the pawls to drop behind atooth of the :ratchet wheel kll so that the wheel is.

rotated through a slight angle during the This the tension'on thesheet which is being fed The-position ofthe mem- 41 and the operatingelementso'f='the machine 10. Thus the tensiomng mechamsm is.re-

'sponsive-tothe' tension of the sheet as it actually reaches the operating mechanism.

As shown in Fi-gures 1 and 2,Jthe roll 42 may-dependfrom a pair of rock arms 43, 44"bysuitable-Jinks 45,' the:upper ends of the links being connected together as by a cross bar 46-to-maintain 'the roll 42'horizontal. 'A

suitable weight may be mounted on the cross bar' 4'6 to adjust :the pressure of the roll 42 on the sheet of material passing: thereunder.

48,-the latter-being pivot a'lly connected at its otherend to antextension 49 of the member 34' Through this linkage, any rise or fall of the roll :42's'will result in a rocking .move- ;ment. ofthe:-member 34. Hence a slackening otthetension ofthe sheet passing under the roll 42 will result'inailoweringof this roll. anda-rocki-ng of thezmember34 which'will -.permit:theipawlx32 to engage one i of the teeth "ofithe ratchet-wheelfil:so-as to rotate this .wheel through'a small angle. ':axial'motioniofttheepush rod'27'toward the I right which increasesthe-tension onthe, brake band 17=and hence increases the tension on thesh'eet ;from {the ;roll 15. crease ofitensioniisincreased bythe engagement ofz-t-h-epawl-32 with successive teeth of "theratchet wheel 3l until-the tension-of the sheetis asulficiently increasedto raise the roll This results in 42 to :its normal position, whereupon the shown in rEigure 14. "Agreater than normal tension on the sheet will raise the roll 42, thus rocking-the member 34 so as topermit -thexpawl;33 to engage successive teeth of the ratchet wheel- 3'1; and thereby to diminish This slight -into momentary fluctuations in the tension of the sheet such as, for example, might be caused by an eccentric winding of the roll 15, I may provide a dash-pot which may be connected to the rock arm 43 so as to prevent any violent oscillation of the roll 42. The dash-pot 50 be of any suitable construction, devices of this kind being well known in the art. 7

in operating the mechanism shown, each spindle may be supplied with a full roll of paper or other sheet material as it reaches the loading station. After each roll 15 is unwound the arms 13 may rotate so as to bring the next spindle with a full roll into feeding position, the spindle which is moved from feeding position being supplied with a fresh roll of material so as to be ready to resume feeding position in its turn. As each roll is swung into feeding position the pitman 23 of its tensioning mechanism automatically engages the bar 25. If the tension on the sheet as it starts feeding is not as desired,

the automatic mechanism quickly varies the tension to the proper magnitude, after which is kept thereat automatically as herein- ;ef-ore described.

l vvi'ng thus described an embodiment of this invention, it should be evident to thoseslzilled in the art that various changes and modifications might be made therein without departing from its spirit or scope as defined by the appended claims.

I claim:

1. Mechanism of the class described comprising a rotatable spindle for a roll of sheet material, means for retarding the rotation of said spindle, power means for adjusting said retarding means, including a rack operatively connected with said retarding means and a pair of opposed pawls adapted to engage said rack for movement thereof to adjust said retarding means, and means responsive to the tension on the sheet material at a point remote from the roll for controlling the operation of said power means, said controlling means including a cam member normally holding both said pawls out of operative engagement with said rack, said cam member being movable in response to variations of sheet tension to permit engagement of one pawl or the other with said rack.

2. Mechanism of the class described comprising a rotatable spindle for a roll of sheet material, a brake-drum thereon, a brake-- band engaging a portion of the periphery of said drum, adjustable anchoring means for one end of said band, a rotatably mounted crank-arm and axially movable to tension.

said brake-band, and means controlled by the tension of the sheet material from the roll for moving saidrod to regulate the brake-band tension.

3. Mechanism of the class described comprising a spindle fora roll of sheet material, a frame supporting said spindle and actuable to move said spindleiinto and out of sheetfeeding position, sheet tensioning means carried by said frame,'reversible'power means for actuating said tensioning means, and means directly responsive to changes of tension in the sheet for controlling the operation of said actuating means, said tensioning means being arranged to automatically move into operative relation with said actuating means when said spindle is moved intosheetfeeding position and to move out of operative relation with said actuating means when said spindle is moved out of sheet-feeding position.

4. Mechanism of the class described comincluding mechanism carried by said frame I and movable with said spindle and' other mechanismoperatively engageable by said movable mechanism .when the spindle moves into sheet-feeding position.

5. Mechanism of the'class described comprising a spindle for a roll of sheet material,

a frame supporting said spindle and actuable to move said spindle into and out of'sheetfeeding position, meanscarried by said frame for retarding the rotation of said spindle, and means for actuating said retarding means in response to variations inthe tension on the sheet fed from the roll, said actuating means including a reciprocable member presenting aface toward said frame, said retarding means having'an element movable into operative engagement with said face. when said spindle moves into sheet-feeding position. i In testimony whereof I have aflixed'my signature. 7

HOWARD PARKER,

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