US2252546A - Sliver drawing mechanism - Google Patents

Description

Aug. 12, 1941.

E. E. BLAKE SLIVER DRAWING MECHANISM I Filed Oct. 29, 1956 .s Sheets -$heet 1 N TORJ 5am INVE ATTORNEY Aug. 12, 1941.. E. E. BLAKE SLIVER DRAWING MECHANISM 5 Sheets-Sheet. 2

Filed Oct. 29, 1936 I Aug. 12, 1941. j 'E, LAKE 5 Sheets-Shee t s Filed Oct. 29, 1936 ATTORNEY Patented Aug. 12, 1941 UNITED STATES PATENT OFFICE SLIVER DRAWING MECHANISM Edmund E. Blake, Saco, Maine, assignor, bymesne assignments, to Saco-Loweli Shops,

Biddeford, Maine, a corporation of Maine Application October 29, 1936, Serial No. 108,191

2 Claims. (Cl. 19-133) This invention relates to drawing mechanisms of the general type used in the preparation of slivers for spinning. ,While it will be herein disclosed in connection with adrawing mechanism designed more especially for use in handling cotton slivers, it will be understood that the invention is equally applicable to operation on slivers or rovings composed of other fibers.

Such mechanisms perform the functions of drawing the slivers in order to straighten the flbersand to dispose them in a more nearly parallel relationship to each other, which is esthe trumpet moves in advance of the rolls until the end of the traverse is reached, and then it pauses, waits for the rolls to catch up with it, and starts in the opposite direction ahead of the rolls. 'I'his necessarily involves complications which are undesirable.

The present invention. satisfactorily deals with the conditions above described, and provides a sential in the best preparation of the sliver for spinning. In addition, these mechanisms attenuate the sliver to a size suitable for the spinning operation. A long draft in a given machine is of advantage in producing the desired results Y with as few operations and as little handling of the fibers as possible. It has been found that such a draft is facilitated by folding the moving sliver laterally upon itself at an intermediate point in the drawing operation and thus bringing the fibers at the selvages, which tend to-stray in drafting, back into the line of, flow of the main body of fibers being drafted and producing a sliver of approximately uniform cross-section.-

It has also been found that control of the fibers at the folding point is improved by guiding the sliver through a trumpet as it is fed to those :drawing rolls which precede the folding operation.

In operating a machine organized in accordance withthe foregoing, it was found that wear tended to become localized on the drawing rolls, articularly the covered top rolls, and this suggested the desirability of traversing; the silver with aview to distributing the wear. While'this normally is" a simple operation, it involves un usual problems in a drawing mechanism of the character just described because of the factthat the sliver is in the form of a fiat ribbon from the time it passes through the first pair of rolls until.

it reaches the folding rolls. In addition, the

drafting between any pairs of rolls is disturbed if, in any such zone, an attempt is made to move the ribbon laterally by forcing .amember against the salvage ofthe ribbon. j V

A further diiiiculty found in attempting to traverse the sliver in any orthodox fashion was that both thetrumpet and the folding rolls also hadto be traversed, and in order to maintain thev sliver in proper alinement with said rolls, it was necessary to give the trumpet considerable "lead" with reference to the rolls. In other words, as the traverse occurs in one direction,

thoroughly practical solution for the problems presented by them. Stated more specifically, the

invention provides a thoroughly reliable traversing mechanism for handling a ribbon-sliver in a drawing mechanism 'of the type above described and in which the control of the edge fibers-is maintained practically as effectively as though the traversing motion were not used, which can be manufactured economically, and which. will require a minimum of care and attention in operation.

6 The nature of the invention will be readily; understood from the following description when parts shown at the lus'trated in Fig.3 and the parts immediately connected therewith; a

Figs. Sand 6 are sectional views, with parts in elevation, showing details of the traversing mechanism;

Fig. 7 is a diagrammatic, sectional view, on a larger scale, of the drawing mechanism shown in Figs. 1 and 2;

Fig. his a rear elevation of the folding roll illustrated in '1, showing the manner in which the silver is fed to them;

9 is a pe spective view of a portion of a sliver illustrating certain of the effects of the operations which it-goes through; and

Fig.10 is a transverse, sectional view of the folded sliver.

Referring first to Fig. 7, it will-be observed that thedrawing mechanism there shown comprises upper anddower rear rolls l-and 3, respectively, a second or intermediate pair of rolls 4 and I,

particularly of said rolls.

upper and lower folding rolls 6 and 1, and upper and lower front rolls 8 and 9. The bottom rolls may be driven in the usual manner and the folding rolls are positively connected together through the gears 6a. and 10,, Fig. 1. Immediately behind the first pair of rolls 2 and 3 is a trumpet In for guiding the sliver S into the bite The second pair of rolls 4 and 5 revolve at a higher peripheral speed than the rear rolls 2 and 3 in order to give the desired draft, and for the same reason the front rolls 8 and 9 revolve at a higher peripheral speed than do the folding rolls 6 and]. Usually, however, a. minimum draft occurs-between the second pair of rolls and the folding rolls, the latter rolls running at'a slightly higher peripheral speed, in order to pull the sliver into the folding roll definitely and under the desired control. This step in the feed of the sliver is utilized solely to perform the .folding operation. Thus the drawing operation is divided into two steps and the fold is produced between these steps.

In the usual arrangement, all of the lower rolls aredriven positively by gearing located at one end of the drawing frame, and the upper rolls are revolved solely due to their contact with their respective 'lower rolls, these upper rolls being made in sections which are removably supported for convenience in threading up, cleaning, and the like. The lower rolls may be either fluted or smooth, but the upper rolls customarily are smooth. Usually the upper rolls 2, 4 and 8 are covered, and saddles and weights are used with them to hold them downwardly against their respective lower rolls with the desired degree of pressure. As shown in Fig. 8, the upper folding roll preferably is grooved, while the lower roll I is made sufficiently thin to fit into the groove of the upper roll with only the clearance necessary for smooth running. It is desirable, also, to locate the two front pairs of rolls at a lower level than the two rear pairs in order to facilitate the folding operation. As a rule, the upper roll 6 is self-weighted.

The arrangement above described is know and has been used heretofore. In a drawing frame a series of units like that shown in Fig; 7 are arranged side by side with the lower rolls running from one end to the other of the frame and common to all the units, as illustrated in Figs. 1 and 3.

As above stated, it is desirable to traverse the sliver, and for this purpose. it is necessary to traverse both the folding rolls and the trumpet.

I have found that the difficulties above discussedin performing this operation can be avoided, and

the necessity for lead of the trumpet traverse eliminated by traversing both the trumpet and the folding roll in unison, but at a very low rate. In other words, if this rate is made slow enough, then any necessity for lead is completely avoided. The desirable condition is to make the speed of traverse as fast as possible while maintaining the movement of the sliver from the trumpet to its cooperating pair of folding rolls in substantially a straight line lying at right.

plete reciprocation in, say, four minutes to one in twice that period. While the latter limit can be greatly increased, there is always the danger of grooving the covered rolls if the sliver rests in one place longv enough to overcome the elastic limit of the covering. Inasmuch as it is usually more convenient to drive the traversing mechanism from the lower rear roll 3 than from any other roll, and since the front roll speed necessarily is determined by the spindle speed while the back roll speed is varied to suit the requirements of the draft, it necessarily follows that the speed of this rear roll will vary greatly with different conditions. Consequently, the time occupied in making a complete traverse will vary.

A further condition encountered in traversing the folding rolls is that the upper roll is made up of disconnected sections so that it is impractical. to traverse this roll directly. The lower folding roll, however, extends from one end to the other of the machine, although it may also be made of sections secured together, end to end.

1 have found, however, that it is entirely prac-.

tical and greatly simplifies the traversing mechanism to traverse the upper roll through its engagement with the lower roll. In other words, if the lower folding roll is reciprocated longi- .tudinally of its own axis, the upper folding roll will be compelled to move 'with it because of the nature of its engagement with the lower roll. However, there necessarily is some clearance between the opposite sides of the thin lower folding roll and the walls of the groove in its upper roll. Consequently, when the lower roll is being traversed rapidly in one direction, it crowds against one wall of said groove and all of the clearance is between its opposite side and the adjacent wall. There is a tendency for fibers to work into the crease or crevice so provided, and thus to produce a fuzzy edge on the folded sliver. The slow rate of traverse above described, however, not only avoids the problem of lead,

but also makes it possible to produce the traverse sliver than there would be if the traversing movement were absent.- Thus this slow traverse solves two problems which have been exceedingly troublesome in a drawing mechanism of this type. At the same time it permits the use of a single traversing mechanism to operate both the trumpets a'nd the folding rolls.

The mechanism at present preferred for producing this traversing motion is illustrated in Figs. 1 to 4*, inclusive. .Referring to them, it will be seen that the trumpets ill for the entire series of units are rigidly secured'to a bar 12 which is mounted toslide in a path parallel to, and immediately beside, the lower rear roll 3. Its rightthe lower folding roll shaft 1', and the upper ends of the two arms of this yoke are slotted to receive pins Ill-48, Fig. 3, projecting laterally from a collar 20 which is held between two thrust bearing members 2l2|, both of which are secured to the end I of the lower folding roll shaft.- The arrangement is such that the shaft and the bearin members 2l--2l can rotate freely relatively to the collar 20, but all of these parts are secured together for movement axially of the shaft. The pivots lB-IB are in line with the pivot 22 which connects the lever It with the trumpet bar l2. Consequently, if the lever is rocked on its fulcrum I5, itwill move both the bar l2 and the shaft 1' in a direction parallel to the drawing rolls and in unison with each other.

For the purpose of imparting this movement to the members l2 and I at the slow rate desired, an eccentric strap 24 is pivoted to the lever M at 25, this strap running on an eccentric 26 secured rigidly, but adjustably, to the shaft 21. A worm wheel 28, also fast on this shaft, is

' driven by a worm 3|! on a vertical shaft 3|, and

the latter is connected through worm gears 32 and 33 with the lowerrear drawing roll 3 which is driven by the usual gearing at the opposite end of the machine. Thus motion is transmitted positively from the roll 3 to the trumpet bar l2 and the lower folding roll shaft 1', and results in reciprocating these members in unison at a very slow rate, as above described.

'The length of stroke of the reciprocating movement so imparted to the parts 1' and I2 can be conveniently adjusted by the arrangement shown in Figs. 4 and 6 forvarying the throw of the eccentric strap. As shown-in said figures, the eccentric 35 is adjustably secured to the shaft 21 by a set screw 36 and this eccentric fits within an eccentric bushing 26, these two parts being secured together by a set screw 31 to form a compound eccentric unit. Several notches 38, Fig; 4, are .formed in the periphery of the cocentric 35 to receive the point of the set screw 31, and numbers are associated with the respective notches to designate the length of stroke that will be imparted to the trumpet rod and the lower folding roll by the relative adjustment of they gear (not shown) meshes with a pinion 40 which preferably is integral with a bearing sleeve. Both these members ar splined to the shaft 1' and the sleeve is mounted to revolve in a bearing member 42 which is secured to any'convenient part of the machine frame. Thus the shaft can slide freely longitudinally of its own axis without disturbing itsrelationship to the parts that support and drive it.

Having thus described my invention, what I desire to claim as new is:

. 1. In a machine of the character described,.the combination of a series of drawing uni-ts arranged side by side. each of said units including a plurality of pairs of drawing rolls arranged one in advance of another to feed and draw asliver,

. each pair-including an upper roll and a lower roll,

a trumpet mounted in position to guide a sliver into the bite of the rearmost pair of said rolls, another pair of rolls located between adjacent pairs of said feeding and drawing rolls for folding the sliver as it passes'from one of the latter pairs of rolls to the next, the lower rolls of said units being .common to the series and being driven, a bar on which the trumpets for said units rolls to traverse said bar and said lower roll in unison.

2. In a machine of the character described, the combination of a series of drawing units arranged side by side, each of said units including a plurality of pairs of drawing rolls arranged one in advance of another to feed and draw a sliver,

each pair including an upper roll and a lower roll, a trumpet mounted in position to guide a sliver into the bite of the rearmost pair of said rolls, another pair of rolls locatedbetween adjacent pairs of said feeding and drawing rolls for folding the sliver as it passes from one of the latter pairs of rolls to the next, the lower rolls of said units being common to the series and being driven, a bar on which the trumpetsfor said units are secured, means supporting said bar for reciprocating motion in a direction parallel to said rolls, a lever mounted at one end of said series of units, an eccentric strap connected with said lever to rock it, an eccentric for operating said strap. worm gearing driving said eccentric-

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