US2780840A - Roller arrangement for drafting systems of spinning machines - Google Patents

Description

H. L. P. UDE

Feb., 12, 1957 ROLLER ARRANGEMENT FOR DRAFTING SYSTEMS OF' SPINNING MACHINES Filed Jan. 19, 1953 2 Sheets-Sheet 1 Fell 12, 1957 i H. L. P. UDE 2,780,840

ROLLER ARRANGEMENT FOR DRAFTING SYSTEMS OF SPINNING MACHINES Filed Jan. 19, 1953 2 Sheets-Sheet 2 ROLLER ARRANGEMEN T FOR DRAFTING SYSTEMS OF SPINNENG MACHINES Haus L. P. Ude, Kaiserslautern, Germany, assignor to Schiess Aktiengesellschaft, Dusseldorf-berlrassel, Germany, a firm Application January 19, 1953, Serial No. 331,955

Claims priority, application Germany January 24, 1952 15 Claims. (Cl. 19-131) The present invention relates to spinning machines and, more particularly, to roller arrangements for drafting systems of spinning machines, especially speed frames and spinning frames.

With drafting systems, the fiber material is grasped by guiding and retaining members which move in the direction of movement of the sliver and are located between feed rollers and delivery rollers. The said sliver is pulled out from said guiding and retaining members by the front delivery roller. The said guiding and retaining members have the purpose of preventing accidental movement of the bers, particularly those fibers which are neither grasped by the feeding nor the delivery rollers, because such accidental movements affect the uniformity of the liber material during the drafting operation.

With all drafting systems it is desirable first of all to maintain the distance between the last guiding element in the drafting eld and the nip of the delivery rollers as small as possible in order to control the short fibers and to prevent them from floating The reduction of said distance, however, geometrically depends on the size of the surfaces of the elements involved so that certain limits prevail with regard to structural requirements which latter are due particularly to static and dynamic stresses of the elements involved. It has been attempted by various structural arrangements to circumvent those limits. However, such efforts have had no results of practical value.

It is an object of the invention to provide an arrangement for use in connection with spinning machines, especially drafting systems, which will make it possible to reduce the distance between the drafting guiding members to a minimum, to thereby materially increase the uniformity of the thread.

It is another object to provide a roller unit, especially for use in connection with spinning machines, especially drafting systems, which can easily be designed and installed and will materially increase the uniformity of the sliver, roving, or the like.

Still another object of the invention consists in the provision of a roller assembly, particularly for use in connection with spinning machines, especially drafting systems, which, while allowing the employment of return rollers for the drafting apron or aprons adjacent the delivery roller, will materially reduce the distance between the clamping line of such apron or aprons and the clamping line between the delivering rollers.

These and other obiects and advantages of the invention will appear more clearly from the following specication in connection with the accompanying drawings, in which:

Figure l illustrates a two apron drafting system of the heretofore customary type.

Figure 2 diagrammatically illustrates a rst embodiment of the invention.

Figure 2a is a longitudinal section through the arrangement of Figure 2.

Ptent Figure 3 represents another embodiment of the invention and illustrates the same in longitudinal section.

Figure 4 is across section through the arrangement of Figure 3.

Figure S is a perspective view of still another arrangement according to the invention.

Figure 6 represents a perspective view of a still further embodiment of the invention.

Figure 7 illustrates a front view of an arrangement according to the invention showing how it is journalled in the machine.

Figure 8 is a front View of an arrangement according to the invention and shows the same as an independent unit.

Figure 9 represents a side view of an arrangement according to the invention as used in connection with the front delivery roller of a drafting system.

Figure 10 shows the invention as used in connection with the front pressure roller of a drafting system.

Figure l1 illustrates an embodiment of the invention somewhat modified over the arrangement shown in Figure l0.

Figure 12 illustrates a drafting system in which the delivery as well as the conveying elements are designed according to the present invention.

Figure 13 diagrammatically illustrates a side view of a specific embodiment of the invention using the principle of Figure l2.

The invention is characterized primarily by the combination of at least two rollers which contact each other and of which one roller only, namely, the roller with the smaller diameter, grasps the liber material, whereas the other roller having a larger diameter serves as supporting element for the first-mentioned roller of smaller diameter. With this arrangement, the larger roller may simultaneously serve as driving and/or clearer roller for the smaller roller.

With other embodiments of the invention more than two, and more specifically, an odd number of rollers with decreasing diameter are arranged preferably one behind the other in one plane and have looped around them an endless belt in such a manner that only the rollers of the largest and smallest diameters are contacted by the belt. The guiding and supporting rollers may be journalled in bearing parts common thereto. Intermediate bearing parts may be maintained properly spaced from the lateral bearing means by tube-shaped roller elements. The bearing means may be rigidly interconnected by bars or the like.

Roller units of the above-mentioned type may selectively be employed as feeding members, delivery members, guiding members and/or pressure members. It is possible to journal at least two roller units or aggregates in the bearing means common to said two units or aggregates.

Referring now to the drawings in detail and Figure 1 thereof in particular, the structure shown therein illustrates a heretofore common arrangement and particularly clearly indicates the problem underlying the present invention. The arrangement shown in Figure 1 is a two apron drafting system (Casablanca drafting systems). For the reasons outlined above, it is desirable to maintain as small as possible the distance a between the line A along which the fiber strand F leaves the guiding element, in this instance, the aprons R1 and R2, and the clamping line B of the front delivery roller pair Z1 and Z2, because the shorter the Idistance a, the better will be the control of the fibers, especially of the shorter bers, and the less will be the proportion of the floating bers.

The possibility of bringing the guiding elements R1 and R2 closer to the front roller pair Z1 and Z2, i. e., to shorten the distance a, obviously depends geometrically ateos@ on the size of the circumferential surfaces of the bodies involved, i. e., practically on the four adjacent radii of curvature, namely: the radius r,L of the return for the lower apron; the radius r2 of the return for the upper apron; the radius r3 of the delivery roller Z2; the ra-dius r4 of the pressure roller Z1.

It will, of course, be understood that witlra single apron or roller drafting system, the radii of the corresponding bottom and top rollers are to be substituted for r, and r2. The diiculty encountered when attempting to reduce the radius r1 of the return for the lower apron consistsprimarily in that the lower apron is usually driven and is thus under mechanical stress. When employing a return roller journalled on each side,.the return roller is also subjected to bending stress. Therefore, while discarding a rotating return roller, the apron has at this point, as illustrated in Figure l, been looped around a stationary return edge, as a result of which it was possible to reduce the outer radius of curvature of the leather to a few millimeters in the desired sense. H owever, such an arrangement caused the drawback of having a slide friction return of the apron R1 around the sharply curved rigid edge. This is particularly undesirable since the lower apron is under driving tension.

The radius of curvature r2 of the upper apron which usually passes in slack condition and forward bulging around a likewise stationary edge has a magnitude of about four to live millimeters, a value which cannot be Ina-de smaller even when using an upper pressureroller in a single apron drawing frame.

With these expedients applied to the customary drafting systems, it was possible for purely geometrical reasons to reduce the distance a at best to about sixteen, mostly eighteen millimeters and more, as is shown in Figure l nearly to scale. This represents the optimum, even if the radii rc, and 11, of the front roller are dimensioned as small as illustrated in Figure l. It will be apparent that a further reduction in the distance a is `possibleonly when at least one of the radii rs or r4 is reduced. The fact that such reduction has heretofore not been effected in spite of the increase to be expected in the uniformity of the thread is due primarily to the following diiculties:

(l) The delivery cylinder Zz is driven and has to transfer forces which act tangentially thereon over the entire length of the machine, Consequently the delivery cylinder Zz must have the required torsional strength and rigidity; in other words, it must have a sufficiently great diameter. Furthermore, no torsional vibrations of the delivery cylinder must occur. i

(2) Thedelivery cylinder Z2 is at each spinning point subjected to bending stresses by the positively loaded pressure roller Z1. The delivcryroller Z2, therefore, must have the required moment of inertia in order to prevent a bending through beyond a predetermined extent.

(3) The reduction in diameter of the delivery roller Z2 and of the pressure roller Z1 rolling on the delivery roller Z2 is limited in view of the increasing lap danger which increases in Vproportion to the decreasing diameter.

(4) A possible further reduction in diameter of the front roller Z1 and/or Z2 must not affect the possibility of applying the required positive clamping pressure between said two roilers which is necessary lfor the drafting operation proper. v

The problem outlined above has been solved according to the present invention in avery simple manner while avoiding the above-referred-to difliculties. rl`hefinvention is primarily based on the principle of combiningat, least two rollers to one supporting roller aggregatezor unit, one of said rollers having a smaller diameter grasping the-liber material whilerthe other roller having. a "larger diameter lserves. as supporting element for the first-nientioned roller. Suchra unit oraggregate replaces vthe, heretofore used individualrollersin the drafting `system so thatrwhenever the new unit is vbeing used, the heretofore employed large diameter can be replaced by a materially smaller diameter.

Figures 2 and 2a illustrate the principle of the invention in its most simple embodiment. The delivery roller Z2 of Figure 1 has been replaced by the roller unit or aggregate 1, 2. As will be seen from Figure 2, the roller 1 has a smaller diameter than the roller 2 and has a considerably smaller diameter than the heretofore employed delivery roller Z2. The roller 1 having the smaller diameter grasps the liber material in a similar manner as was -done heretofore by the delivery roller Z2, whereas the larger roller 2 serves as supporting andy driving roller for the roller 1. The driving of the roller 1 by the roller 2 may be effected by purely rolling friction, but, if desired, this may also be effected Vby'providing the periphery of the rollers 1 and 2 Vwith a knurled surface or with teeth meshing with each other. The direction of rotation of the roller 2 is naturally opposite to the direction of rotation of the roller 1. Both rollers `are journalled, for instance, in bearing supports S common thereto which are prevented from rotating by means of abutments 5a, or the like.

As will be clear from Figure 2, by means of the roller units 1, 2, the distance a between the clamping lines of the drafting elements R1 and R2 on one hand, and Z1 and 1 on the other hand, can be considerably reduced over the heretofore customary distance a (Figure l).

Figure 2a furthermore indicates how the larger supporting roller 2 may simulaneously serve as clearer roller, i. e., for removal of the lap from roller 1. The roller 2 is below the clamping point of the ber material provided with at grooves which are provided with clearing elements 2a as, for instance, stripping materialfor clearer rollers, brushes or card wire band. In this way, lap about to form on the roller 1 will be taken olf after half a revolution of the roller 1. For the same purpose, also roller 2 may be provided with or without a groove and may consist of lap repelling material of any standard type. The two roller unit shown in Figures 2 and 2a and illustrating the principle of the invention in connection with delivery cylinders may also be used as pressure means instead of the roller Z1, while cooperating with a single roller Z2 or with a roller unit 1, 2. When using the roller unit as pressure means, the two lateral supports 5 of the unit are rigidly interconnected by means of a transverse bar.

In order to avoid the necessity of reversing the direction of movement of the driving roller 2, it is preferable to combine an odd number of rollers of decreasing diameter to roller units as has been illustrated in the following figures. It is most advantageous to combine three rollers to one unit of which each larger roller supports the adjacent smaller roller.

Figures 3 and 4 illustrate such a three roller unit. The rollers 1, 2 and 3 arranged in series in one plane have looped around a belt 4 which may be made of rubber, leather or other appropriate natural or synthetic material. The smallest roller 1 is supported by the adjacent roller 2, whereas the latter is supported by the roller 3. ln its most simple construction, the axes of the three rollers are located in one plane. The rollers l and 3 rotate in the same direction as the belt 4 looped therearound vwhereas the intermediate roller 2 rotatesA ina direction opposite to the direction of rotation of said belt 4, The diameters of the three rollers are so dimensioned that the roller 2 does not Contact the belt surface. Such a supporting roller arrangement affords the possibility of maintaining the radius of curvature r (Figure 4) small, which radius is influential in the dimensioning of the distance a, while the cross sections of the rollers may nevertheless be dimensioned in conformity. with the driving vrequirements and thev rigidity required in this connection.` The belt 4 not only aids the drive 4of the rollers of the unit but also considerably reduces the lap dangerQ The rollers are maintained relative to each `other by the end bearings 5. When rollers of relatively great length are being used, intermediate bearings 6 may be employed which may be located inside the belt 4, i. e., are embraced by the latter (Figure 4), but, if desired, such intermediate bearings 6 may also protrude between the belts 4- (Figure 6).

In order to be able, when installing the arrangement, to slip the intermediate bearing 6 upon the driving shaft 3, the bearing supports may either be divided or the shaft, as illustrated in Figure 5, may be composed of tubular sections 3a.

When the end bearings 5 are rigidly mounted, for instance, on the roller stands, the arrangement of intermediate bearings 6 will aid the entire aggregate against torsion. If desired, one or more portions or the entire length of the rollers 1 to 3 may be provided with teeth which, however, should be set back with regard to the belt supporting surface of the rollers so that the belt passing around the rollers 1 and 3 will not be bulged out by the teeth.

In order to increasel the rigidity of the aggregate, the intermediate and the end bearings 6 and 5, respectively, may be rigidly connected With each other, for instance, by connecting rods. Such connection is indispensable with aggregates having only two end bearings 5, as is illustrated at 410 in Figures 3 and 4.

Supporting roller aggregates according to Figures 2 to 6 may form independent units which may be handled as such and which can be built in as structural units into the drafting systems and so on in the same manner as individual cylinders.

The units according to the present invention operate in the following manner:

The tension of the belt, if a belt is being employed, is taken up to any desired extent by causing one roller to press against the other roller. In other words, the belt tension is taken up by the aggregate and thus does not cause any action toward the outside on any of the bearings.

A load P (Figure 4) which acts upon the roller 1 from the outside in the direction of the arrow is taken up entirely with increasing angle a of the attack of the load to a decreasing degree by the next supporting roller 2 and depending on the journalling in these supports, also from the supporting roller 3.

t is principally possible to drive all three rollers. Generally, roller 3 is driven because its diameter and thus the respective looping angle of the belt is greatest so that in this way the belt is best carried along.

Purely rolling friction prevails between the rollers 1, 2, 3 in view of the influence of the belt tension or outer forces, in the direction of the arrow P (Figure 4). Due to this rolling friction and the adhesive friction of the looping belt, for instance, when roller 3 is driven, the other rollers are carried along even when under load.

Whether and to what extent friction in the bearings of the rollers ll, 2, 3 will occur in the end and intermediate supports 5 and 6 (Figures 3 to 6) which may also in part be provided with roller bearings, will depend on the direction of the outer attacking force, i. e., on the angle a (Figure 4) and on the functions respectively to be performed by the supporting bearing aggregate. When the force P attacks at an angle or equalling zero, this force is practically completely taken up by the adjacent supporting rollers. The bearing portions of the end and intermediate supports 5 and 6, respectively, are then subjected to merely minor stresses which are produced by the arrangement of the individual rollers relative to each other, if roller 3 as indicated in Figure 7 is journalled, for instance, in the roller bearings of the machine-roller stands l5. If on the other hand, such an aggregate is used for instance as a pressure roller, while the outer force P is as shown in Figure 8, conveyed to the aggregate through the connecting member and end support 5, it will be clear that vthe force P will be passed to clamping line B in part through the bearings of the rollers 3, 2, and 1 and in part through the supporting rollers 3, 2, and 1. This branching 0E or split in the power distribution, which can be further influenced for instance by the shaping of the bearing bores in the supports 5, results in that first of all the smallest roller 1 is supported and secondly its bearing means in the end supports are less stressed than would be the case if the roller 1 were journalled merely in supports 5 without adjacent supporting rollers.

Such a supporting aggregate makes it possible to subject also rollers of smaller radius of curvature to positive clamping pressure without risking any undue bending through and with the possibility to drive such cylinders Without additional lap danger. The smooth outer' encircling surfaces ofthe aggregate oier good withdrawing possibilities. These supporting roller units may be mounted at the various points in the drafting systems of spinning machines and speed frames as shown for instance in Figures 9 to l2, in order to reduce the passage distance and thus the floating fibers.

For purposes of comparison, about the same scale and, as far as possible, the same dimensions as in Figure l have been employed. The resulting decrease in the distance a in these gures in only of relative, not absolute, importance. For other drafting systems, therefore, other absolute values are obtained for a, i. e., the obtained reductions in the distance a, depending on the geometric conditions.

Figure 9 illustrates a supporting roller aggregate used in a drawing frame as delivery roller. A comparision with Figure 1 will clearly show the decrease in a.

Figure l0 shows a supporting roller aggregate as pressure roller on a normal delivery roller, in addition to the delivery roller also shaft 3, i. e., the entire pressure roller being driven. Also in this instance, a decrease in the passage a is obtained over the application of normal pressure roller Z1, according to Figure l.

When employing supporting roller aggregates as pressure rollers with driven shaft, the possibility of removing the weight from the top roller and the possibility of clearing the respective rollers during the operation is of importance. Principally, two arrangements are possible. Figure l0 illustrates a pressure roller-supporting roller aggregate adapted to be detached during operation. The drive is effected through the continuous shaft la, each of several pressure rollers being driven through the intervention of a pair of gears 7, 8 or corresponding friction rollers. By means of the hook-shaped support 9, it is possible to support the pressure roller during operation above the shaft 1a whereby the meshing of the gears 7, 8 or the engagement of the friction rollers will be assured. The loading is effected in the direction of the arrow P.

Figure ll illustrates a pressure roller arrangement with four rollers of which the roller 3 extends over the entire length of the machine and is driven, whereas the remaining rollers are caused to rotate by rolling friction between the same and by adhesive friction with encircling belt 4. The pressure roller in the supporting roller aggregate is adapted to be tilted about the shaft 3 during operation. The loading is effected in the direction of the arrow P. The load is, in this instance, conveyed through `the bearing pivots of roller 2 unto the rollers 2 and 1. Also in this instance, reduction in the distance a is obtained. The supporting roller and pressure rollers according to the invention may, however, also be applied without special drive therefor, in the manner of customary pressure rollers. Rotation of such rollers is then effected merely by pressing the same against the lower roller.

Finally, Figure l2 illustrates the employment of four supporting roller units in one and the same drafting system, which results in a particularly short distance a.

The rollers 3 and 3a and, if desired, also the rollers 3b and 3c are driven. The replacement of the double apron R1, R2 with stationary ,returning edges. according,

to `Figure lyields, according to theembodiment shown in Figure l2, the greatadvantage that the belts are pulled around rotating rollers 1a and 1b respectively driven by rolling friction and rollers 2a and 2b. Slip and wear due to sliding friction is thus avoided.

The supporting bearings 4of the two rollers aggregates shown in Figure 12 may be combined to a single element 13 as illustrated in Figure 13 so that these two supporting roller aggregates will be safely suspended as to the two strongest driven shafts 3 and 3a. If desired, the lower belt, as shown in Figure 12, may also whenusing a supporting roller aggregate, be vprovided witha tension Vroller 12.

The invention is not limited to the particular embodiments shown in the drawing, butmay also be applied in connection with all types of drafting systems of spinning machines, especially speed frames .and spinning frames. The arrangement according to the invention may also be built into machines using the heretofore customary roller arrangements, in order to reduce the distance between the two drafting elements, especially where heretofore this was not possible due to constructive difficulties concerning the roller diameters. The subdividing of a large diameter intr,` a plurality of smaller diameters supporting each other is essentialin connection with the present invention. It is also to be understood that the present invention 1s not limited to the particular constructions shown inthe accompanying drawings but also comprises any modifications within the scope of the appended claims.

What I claim is: I

1. In a drafting system of spinning machines: an upper delivery roller, a lower v-delivery roller arranged Afor cooperation with said upper delivery roller so .as to forni a nip therewith for drafting fiber material and delivering drafted ber material to a bobbin, guiding means closely spaced from said delivery rollers and located on the approach side thereof for guiding ber material being drafted toward and between said delivery rollers, .and at least a further roller drivingly engaging one of vsaid delivery rollers and preventing the` adjacent delivery roller from bending toward said further roller, said further rolier being arranged positively to be driven, that delivery roller which is engaged by said further roller `in the form of a pin of a dia: eter considerably less than the diameter of said further roller.

2. in 'a drafting system of spinning machines: an upper delivery roller, a lower delivery roller in form'of .a pin arranged below and for cooperation `with said upper delivery roller so as to form a nip therewith for drafting fiber material and delivering drafted ber material to a bobbin, guiding means closely spaced from said delivery rollers and located on the approach side thereof for guiding fiber material being drafted ltoward and between said delivery rollers, and at least one supporting roller arranged below and drivingly engaging said lower delivery roller, the diameter of the rollers below said ,upper delivery roller increasing with each roller below said upper delivery roller and in the direction away from said upper delivery roller.

3. A drafting system according to claim 2, in which the supporting Vroller drivingly engaging said lower delivery relier is provided with a clearer cover for preventing accumulation of lap.

4. In a drafting system of spinning machines: a supporting roller arranged for positive driving connection, a lower deiivery roller in form of a pin having a diameter considerabiy less than the diameter of said supporting roller and having its peripheral portion arranged for frictional engagement with the peripheral portion ofk said supporting roller, said supporting roller supporting said lower delivery roller, an upper delivery roller arranged adjacentto and above said lower delivery roller for drafting ber material therebetween and delivering drafted bermaterial to a bobbin, upper and lower guiding members respectively arranged in closely spaced relationship `to the nip of said upper and lower delivery rollers for guiding material being drafted toward and between said upperand lower delivery rollers, and clearing cover means mounted on said supporting roller and adapted totcounteract lap accumulation on said lower delivery roller.

5. A roller arrangement according to claim 4, in which the clearing cover means are mounted in recessed portions of s-aid supporting roller.

6. Aroller arrangement according to claim 4, in which the peripheral portion of said supporting roller comprises ber repellent material.

7. In a drafting system of spinning machines: a supporting roller, alower delivery roller having a diameter considerablyless than the diameter of said supporting roller and having its peripheral portion arranged for engagement with the peripheral portion of said supporting roller, said supporting roller acting as support for said lower delivery roller, an upper delivery roller arranged fo cooperation with said lower delivery roller so as t0 form a nip therewith for drafting fiber material between said lower delivery roller and said upper delivery roller and for delivering drafted ber material to a bobbin, guiding means closely spaced from said delivery rollers andrlocated on the Iapproach side thereof for guiding fiber material being drafted toward and between said Vdelivery rollers, and supporting means common to said supporting roller and said lower delivery roller for supporting the same.

-8. `In combination in a drafting system for spinning machines yand the like: upper delivery means, lower delivery means arranged for cooperation with said upper delivery'means' for 'drafting fiber material and delivering drafted bcr material to a bobbin, one of said delivery means comprising at least one roller and the other vone of said delivery means including at least two superimposed rollers of different diameters having their peripheral portions arranged for engagement with each other so that the roller of smallest diameter of said superimposed rollers is supported byva roller of larger diameter while said roller of smallest diameter is closer to the other delivery'rneans than said roller of larger diameter, said roller of larger diameter supporting said roller of smaller diameteragainst bending and guiding means, respectively arranged in closely spaced relationship to the nip of said upperv and lower delivery means for guiding fiber material being drafted toward said upper and lower delivery means and therebetween.

'9.` 'An arrangementaccording to claim 8, which inoludes endless belt means looped around an uneven number of superimposed rollers of different diameters.

10. An arrangement according to claim 8, in which at least on'eiofsaid delivery means includes three superimposed rollers respectively and successively increasing in' diameter in the'direction away from the other delivery means, each of said superimposed rollers having its peripheral portion in engagement with the respective adjacent roller `of said superimposed rollers, and in which an endless belt is looped around4 said three superimposed rollers, the arrangement being such that only the rollers of the largest and smallestdiameter of ythe said superirn posed rollers are in 'engagement .with said belt.

ll. An arrangement according to claim l0, in which thesuperimposed rollers have their axes of rotation arranged in ya common plane.

' l2. An arrangement-according to claim 8, which includes first bearing 'means spaced from each other and common tothepsiuperirnposed rollers for supporting the same, intermediate bearing means spaced from said first bearing, means `'for .additionally supporting said superimposed rollers, `and tubeshaped spacer means between said intermediate bearingl means and said first bearing means for maintaining said intermediate bearing means spaced from said rst bearing means.

13. An 'arrangement according to claimv 8, in which each of said lower fand upper delivery means includes a roller unit comprising a plurality of rollers successively increasing in diameter away from the other roller unit, the rollers of smallest diameter of each roller unit being closest to each other, and a pair Iof endless belts respectively looped around said roller units `and forming a bite with each other.

14. An arrangement according to claim 13, which includes bearing means common to at least two roller units for supporting the same.

15. An arrangement according to claim 8, in which each of said upper and lower delivery means includes three superimposed rollers of different diameters having an endless belt looped therearound, the arrangement being :such that the rollers of the delivery means are arranged adjacent each other and that the belts respectively passing :around the same face leach other only over that respective portion of the belts which contacts the respective roller of smallest diameter', and in which each of the guiding means arranged in closely spaced relationship to the nip of said upper and lower delivery means includes a plurality of rollers successively increasing in Adiameter in a direction away from said delivery means, the rollers 4oi said guiding means having their axes arranged in substantially the same plane a-nd having endless belts respectively looped therearound, the rollers of said guiding means being arranged relative to each other so that the belts pertaining thereto face each other over -the distance extending from one point of contact thereof with the respective roller of largest diameter to one point `of contact of the same belt with the roller of smallest diameter of the ysame guiding means.

References Cited in the le of this patent UNITED STATES PATENTS 375,881 Lain Jan. 3, 1888 1,654,940 Lucas Jan. 3, 1928 2,178,627 Devaux Nov. 7, 1939

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