US2049322A - Method and apparatus for stabilizing the pressure of the drawing rolls of textile machinery - Google Patents

Description

July 28, 1936. w H, SANDERS 2,049,322

METHOD AND APPARATUS FOR STABILIZING THE PRESSURE OF THE DRAWING ROLLS OF TEXTILE MACHINERY Filed Oct. 18, 1933 2 Sheets-Sheet l A TTORNE Y.

2 2 2 3 w m 5 2 t e R 8 U h YS R EE2 N PI H July 28, 1936. w SANDERS METHOD AND APPARATUS FOR STABILIZING THE OF THE DRAWING ROLLS OF TEXTILE MAC Filed Oct. 18, 1933 I N VEN TOR.

ATTORNEY.

Patented July 28, 1936 :f

UNITED STATES PATENT OFFICE QMETHOD AND APPARATUS FOR STABILIZ- ING THE PRESSURE OF THE DRAWING ROLLS OF TEXTILE MACHINERY s William H. Sanders, Gastonia, N. 0., assignor to Parks-Cramer Company, 'Fitchburg, Mass., a

corporation of Massachusetts Application October 18, 1933, Serial No. 694,181

7 18 Claims. (01. 19-137) This invention relates to pressure stabilizing mechanism for the feed rolls'or so-called draft 7 rolls of the general type used in textile spinning machinery and preparatory machinery for drawi5 1r ing out and. delivering continuous strands of textile fibres in the form known as roving, sliver,

or yarn, and other analogous machinery.

In mechanism of thisgeneral class the material travels between the cooperatingsurfaces of one or more pairs of rolls or their equivalent. One roll of each pair is usually fluted and posi tively driven, and the other, usually the upper roll, is covered with a resilient material, such as leather or cork, and is subjected to sufiicient pressure to cause the material to be grasped by the rolls with suflicient firmnessto insure positive and continuous delivery-of the material.

In certain other analogous mechanisms each roll in a pair may be uncovered in which case 20 the material usually travels between the surface of one roll, usually the upper of the two, and the surfaceof a continuous apron composed of resilient material, such as leather, which also runs between the two rolls and beneath the material. The 25 apron used in this case'is the "counterpart of a resilient roll covering in that it serve's the same purpose of providing aresilie'nt cushion for'the material which protects it frominjury' by'the pressure to which the upper rolltis subject. 30 In all such mechanisms. there is'a marked tendency for chattering or vibratory motion of the upper roll to occur with consequent variation in the pressure effective between the rolls whenever the upper roll rises or falls, as it must, in re- 35 sponse to inequalities in the material.

Such vibration is largely due to the resilient nature'of the'roll covering or the apron, as the case may be, coupled with such other causes 'as the. inertia of the weights or the elasticity of 40 springs used in the pressure applying mechanism and to sympathetic vibration. due to vibrationof the machine as a whole, orto' vibration of the factory floor. i

Such oscillation or vibratory motion of 'the'top 45 roll weighting mechanism'is clearly observable and is generally recognized in" the art as being one of the principal causes of unevenness in yarn, roving, and sliver, and" of end breakage and consequent waste of material'and reduced pro- 50 duction. 9

I have discovered that such vibration'fand consequent unevenness in, orbreakage of; thematerial may be minimized and'practicall'y eliminated and that uniformity "of the qualityfl amr fathe quantity of product may be correspondingly initproved and increased by maintaining substantially uniform elastic pressure on the top rolls and retarding or dampening the movement of the top rolls when displacement occurs by reason of variations in thickness of the traveling material or by oscillations otherwise produced.

I have selected for illustrative purposes a preferred embodiment of the invention as applied to a common form of draft roll mechanism that is in wide use on cotton textile spinning machinery. l0 In this construction the draft roll mechanism comprises a set of lower fixedly journaled fluted rolls which are positively driven at such different speeds as effect proper drawing of the material and coopcrating upper draft rolls, commonly known as top 5 rolls, covered with a resilient material to cooperate with the fluted surfaces of the respective lower draft rolls. Two or more of the successive top draft rolls are subject to pressure applied through devices known as saddles which are supported upon the top roll journals and cause the rolls to grasp the strand of material passing between them and the lower rolls with sufficient firmness to accomplish properly the process of drafting.

The saddles are subjected to pressure by means of a link known as a stirrup which is suspended on an adjustably positioned seat on the saddle and depends therefrom between adjacent pairs of top rolls and lower draft rolls, the lower end of the stirrup being connectedwith mechanism forapplying tension to said stirrup to produce the required pressure.

The mechanism hitherto commonly used for this particular purpose comprises a lever which is seated in the lower eye of the stirrup, the longer arm of the lever being loaded with a weight at the outer end thereof, and the shorter arm of the lever being anchored by an eye-bolt to a girder extending lengthwise of the machine and known as the roller beam which girder carries longitudinally spaced upright supports known as roll stands in which the lower rolls are journaled.

V In such usual type of top roll weighting mechanism it is necessary to use heavier weights thanwould be required for generating only the pressure essential to normal operation of the rolls in order that the additional weight may resist elevation of the rolls both by additional pressure and by the inertia of the weight as a whole, but when the rolls are returned to their normal position, after being raised by the passage of thicker material'than normal, the inertia of the weight and the resilience of the top roll coverings operate ogous to those herein described are usedin which saddle and stirrup in oppositionto the resistance due to the weight and to its inertia. The sudden lifting impulse thus imparted to the weight often causes it to be carried upward too far by its own inertia and thus produces, first, momentarily 3 excessive pressure followed f by a momentarily deficient pressure. a

Upon the subsequent descent of the weight its inertia again causes a sudden increase inpressure Y that amounts to an actual blow delivered upon the top roll. The resulting impact and compression of the resilient material with which t'h'e top' rolls are covered causes the weight to rebound after its sudden fall and causes further persistent vibra;

*tion and variations-in pressure;- It thus :develops that the natural variations in thevmaterial imparts'sudden'and viol'entoscillation and vibration to thefvarious' parts of the vweighting mechanism and correspondingalternations of excessiveiand deficient pressurethat tend to injure the material 'in process, and also to cause rapid deterioration oft'he top roll covering by frequent andpersistent eXc'essive -shock-and'pressure." e T a v I Deficient pressure frequently reaches'so low a valuethat' the tension due .to'the' winding action of'the spinning mechanism causes the thin strand of'untwist'ed material to slip through the last pair of draft mills and thus breaks down the strand. Thevalue and uniformity of the pressureimposed upon the top rolls are of major importance for the-saddleandtop rolls are :subject'to change irrvertical position as above' described in response to 1 inequalities in the material passing beneath them and any variation in pressure due to their sudden displacement 'orto their vibratory motion caus'e'suneven drafting which results infrequent --in jury-andbreakage of the "attenuated material beneath eithem th consequent interruption of production, loss by waste, and the necessity for correspondingincreased attention upon the part or theimachine tenders for the piecingi-up ofrthe brokenends. t 1 "Furthermore, uniformity .in' pressure will-in? er-ease *the-life of the covering of :the "top-rolls which because of: their resilient nature are "particularly subject to vibration and to, consequent deterioration. z r r The-scope of m y 'invention is, however, not

limitedto its use upon machines for cotton manu- 1 facturing as herein disclosed in the preferred embodiment-of the invention. 7 3

' Closely analogous mechanisms are .w-idelyused in'other branches of the textile industry and notably in the woolen and worsted industries; in certain of these industries 'top draft 'r'olls covered with resilient material are used and are subject in s'omecasesito pressure applied: by weights; and in other cases to pressure applied by springs; 'In certain-other instances drafting mechanisms anal- 'there'are'cooperating pairs'of rolls both of which are-fluted. In such cases the resilient covering of 'thetop roll has its counterpart inaleather apron which runs between the fluted *rolls'and thus provides a :resilient cushion: for .the material which passes beneath; the lower s'urface of the upper roll' and' the upperrsurface' of the apronwhi'chruns abovethelower fluted roll; 1 In 'all;- such cases there are-- present the T "same analogous features of a movable roll subject to pressure and to motion, a companion rollrin fixedly positioned bearings, and a continuous surface of resilient material between which and the a surface of the movable feed roll the material is '5 being processedand delivered. I 7 1 111 311 such cases vibration and chattering are l 3 the main causes of unevenness in the product and v injury and breakage of the material in'process,

and of rapid deterioration of either the resilient 10 rollcovering or theapron as the case may be.

My invention is equally'applicable-toall such analogous mechanisms. The distinguishing characteristic of myinvention is the provision of means for applying elastic pressure and dampen- 15 mg 'orrshock absorbing means acting conjointly to maintain the cooperating rolls of a drafting 'mecha'nismofanyof the classes described in non-vibratory operating engagement with the material -passing therebetween. V 1 V V The-primary object, therefore', of theinvention iszx-to provide a textile machine: having draft mechanism including atop draft roll or rolls with means for applying uniformrpressure to the top roll: er -rolls and. dampening or shock'absorbing 25 means vac'ting in.'con-junction=with said pressure applying means .to :prevent vibration of the top roll o-rrirolls, whereby-the'top rolls arepermitted to undergo gradual vertical: displacement from V and'to return to their'normal position in accordance with inequalities in' the material in'process V r e without sudden-or vibratory-motion of said-rolls :and"vvithout,.substantial.variation in the value of V pressureappliedp .f 3 r furtherobjectiof thezinvention is'to provide 35 a mechanism of the; character described having a minimum number'ofzpaits and including means attached to the structure-10f the machinefor applying uniform 'elasticipressure tdthe'saddIes in a predetermined desirableiidirection, and also 40.

and direction in. combination 1 with hydraulic 50- 7 means for controllably dampening and retarding the longitudinal movement ofrthe stirrup, whereby the top' rolls are'subject only to gradual displacement from theirnormal position without sudden or vibratory motion.

r r w 55 A' further object'of the inventionisto provide a I self-contained mechanism assembled inf'co m pact form'= as an article :of "manufacture adapted to beapplied tothe saddle" mechanism of a usual construction] and comprising spring-operated 60 means :adapted .Jto apply substantially uniform pressure to" the-top rolls "in a'predeterminedv direction by connection with'thestir'rup; and also including hydraulic dampeningsor' shock absorbing meansfor retarding :the motions-of said 'springeoperated me'ansito prevent: vibratory motion =th'ereof;r:or'ofsthe parts'o'perated thereby.

:An i1lu'strativerembodiment'oftheinvention is shown in; the accompanying drawings, in which,

Fig. 1 is a fragmentary front elevational view of arollstand whose-upper feed-r0lls are equipped with; pressure mechanism constructed accord-'- an'ceivith the :presentfinvention; j

: iFigi Q: an enlarged :vertical section on line :Fig. 3is an enlarged fragmentary .vertical sec tion on line 33 Fig. 1; a Fig. 4 is a section on line 4-4 Fig. 3 viewed downwardly.

A preferred embodiment of the invention is illustrated in the drawings as applied to a cotton spinning machine of a-usual type 'in' which hydraulicallyl controlled spring pressure mechanism has been substituted for the weighted arm mechanism commonly employed in machines of this type. a

Referring in detail to the drawings, the ma chine frame or bed 5 carries a roller stand 5 which is provided with a plurality: of series of lowerfeed rolls 1 and upper feed rolls 8. A saddle 9 is shown resting upon two of the upper feed rolls of each series or set as is common in the art, but it will be understood that a pairof overlapping saddles may be employed as is also common in the art when it is desired to maintain pressure upon all of the upper feed rolls of each seriesor set. I I

The preferred embodiment of the invention shown'in the accompanying drawings comprises a combined springtension device and a hydraulic dampening or shock absorbing mechanism consisting of a cylinder with a piston re'ciprocable therein adapted to be connected to the movable rolls or the saddles for such rolls, with a spring interposed between the piston and the adjustable upper end ofthe cylinder. Suitable means are provided to permit a" restricted flow of the fluid from one side of the piston to the other thereby to resist the movement of the piston in either direction so that the spring'and dampening device act conjointly to maintain a predetermined substantially uniform pressure upon the movable feed "rolls and to minimize and effectively prevent vibration thereof. As shown, this combined device includes a cylinder- Iii rigid with a forwardly and downwardly extending standard I I having a wide flat base I2 resting flatly upon the upper surface of the machine frame or bed 5 and rigidly'secured to the latter by means of a bolt 13 passing through an opening in the machine frame or bed 5 and threaded into an axial bore or socket provided in the lower end of the standard ll, said opening in the machine frame or bed 5 being the one ordinarily provided'to receive the stem of an eye bolt by which the weighted lever of the ordinary pressure mechanism is usually pivotally anchored to the machine frame. It will be noted by this means the cylinder I8 is supported at an inclination so as to be axially alined with the associated stirrup l4 when inuse, whereby a true straight line 'pull will be exerted upon said saddle link as and by means to'be presently described, thereby placing the upper feed rolls under a uniform even pressure at all times. Loosely and slidably fitted in the cylinder ii! is a piston l5 which works in a body of viscous fluid, such as oil, l6 that is placed within the cylinder Ill. The loose fitting I of the piston l5 within the-cylinder it) provides for restricted passageof the oil or other fluid pastsaid piston, so thatmovement of the latter will be dampened and retarded in a manner generally similar to dash pot or shock absorbing constructions of the hydraulic type. y l The terms dampening and shock-absorb ing. are herein used'to-specifically describe the absorption and final dissipation of kinetic energy by the application of "resistance inopposition to motion. The aforesaid .terms are herein used in specific contra-distinction'to the cushioning action of springs, which, when used in opposition to motion, merely accumulate potential energy by their distortion, which is subsequently delivered as kinetic energy by the recoil of the spring. It is to be especially observed that such cushioning action not only fails to prevent or minimize vibration but often tends, on the contrary, to promote and to amplify and prolong vibration, while the dampening or shock-absorbing action that is an outstanding characteristic of the means employed for the purposes of my invention effectively minimizes or prevents vibratory motion.

Again, it is to be particularly noted that the dampening means employed for the purpose of my invention are strictly non-elastic and serve a novel and entirely different purpose from the elastic means such as springs of various types which are so commonly used in the art for cushioning and which because of their elastic nature are incapable of producing true dampening, as hereinbefore explained.

The effective dampening of roller and saddle motion as accomplished by my invention and the non-elastic means employed to effect such dampening are therefore outstanding and distinguishing characteristics of my invention. This provides for slow even movement of the piston in either direction and obviates sudden movement thereof in opposition to vibration or the like, for a purpose which will presently become apparent. Threaded into the upper end of cylinder it for adjustment longitudinally of the latter is a head I! having a central opening through which slidably projects a rod 18 rigid with and extending upwardly from the piston IS, the upper projecting end of rod l8 being formed as at is for connection with the lower end of stirrup l4. Surrounding the rod l8 within the cylinder IO and between the piston l5 and plug I! is a compression spring 20 by which a downward pull is exerted upon the rod l8 and stirrup l4 in a straight line to subject the upper feed rolls 8 to a uniform pressure which may be varied to suit requirements .by adjustment of head ll longitudinally of cylinder I!) so as to vary the normal tension of spring 20 when the device is in use. The use of a spring tension device alone or in angular relation to the stirrup I4 is open to the objection that the same would not provide for a straight line pull upon the saddle link and would not successfully oppose sudden movement thereof due to a sudden jerk or vibration, and the result would be lack of uniform pressure attendant with frequent end breakage and the production of threads which would vary considerably in thickness. I overcome these objections by supporting the cylinder l0 at an inclination so that the piston rod I8 is in direct line with the saddle link I l, and by providing the rod l8 with a piston l5 operating in the thick fluid l6 so that the action of the spring 20 is retarded. In other words, sudden expansion and compression of spring 2|] is opposed by this hydraulic dampening or shock absorbing means so as to eifectively prevent sudden movement or vibration of rod l8 and saddle link I l. Obviously, downward movement of rod I 8 is controlled and retarded by compression of the fluid l6 beneath the piston l5, and due to the fact that such fluid is restricted in its upward passage past the piston l5 at such time. In a like manner, upward movement of rod l8 and saddle link I4 is controlled and retarded because the corresponding upward movement of piston spring-upon the upperrolls is efiec'tively'insured without permitting excessive vibration and the like. I have found that in actual practice and as a result ofext'ended use, the present pressure mechanism enables the production of 'thre'ads of substantially uniform thickness, and-practica1ly eliminates the occurrence of end breakage The mechanism for applying pressure to and for dampening the 'vibration'of the top rolls of drawing mechanism above described is of .a simple character and "may be conveniently constructed as an article of manufacture adapted to be substituted for the pressure applying means of spinning Inachines and analogous machines'of the prior art without modification "or substantial change in the construction of such machines. It, of course, may be readily incorporated in new machines'without substantial modification of the saddle mechanism or other structure of the machine.

While I have illustrated'the pressure applying means and the mechanism for minimizing and practically eliminating vibration of the top roll mechanism as a unit construction, similar .operating hydraulic mechanism or its equivalent may be independently applied to the usual type of lever and weight mechanism,'or to usual types of spring pressure applying mechanism, and various changes in form,-construction and arrangement 7 of parts may also be made within "the scope of I 1. A textile machine having means for-continuously drafting a moving strand composed of textile fibres comprising cooperating relatively movable drawing members, yieldable means act ing upon said drawing members'to'apply pressure to the material being drawn therebetween, and

non-elastic dampening means cooperating with said pressure-applying means to resist sudden movement of said movable members and dissipate energy expended in overcoming said resistance. Y r

Y 2. A textile machine having means for con-- 'and non-elastic means acting conjointly with said pressure applying means to dampen sudden or vibratory movements thereof, therebytostabilize the pressure effective upon'the material.

3. A textile machine having means for continuously drafting :a moving strand composed of textile fibres comprising cooperating relatively movable drawing 'membersiyieldable means actin'giupon said drawingmembers to apply pressure to the material beingtdrawn therebetween,

and hydraulic means associated with said yieldable pressure applying means and acting con jointly therewith to retard and dampen sudden or vibratory movements offsaid relatively movable drawing members, thereby to stabilize the I pressure effective-upon the-material.

' 4. A textile machine having means for continuously drafting a moving strand composedof textile fibres having cooperating lower and top drawing rolls, yieldable means acting upon said top rolls to apply pressure to the materialbeing drawn between said rolls, and non-elastic dampening means acting conjointly with said pressure applying means to minimize oscillatory move-' ments of said top roll;by:retardation of sudden and vibratorymovements thereof, thereby to stabilize-the'pressure effective upon the material, 5. A textile machine having ;mechanism for continuously drafting -a movingstrand composed of textile fibres comprising aset of fixedly journaled rolls, a set of relatively movable rolls cooperating therewith, a saddle for said movable rolls, yieldable means for :applying pressure-to said saddle, and dampening means operable to. apply non-elastic resistance to any sudden motion of said movable rolls and acting conjointly withvsaidpressure-applying means-to subject said material to substantially uniform pressure by preventing vibratory motion of said movable O rolls. a

6. A textilemachine having 'means for continuously drafting a moving strandcomposed of textile fibres having -a set of fixedly journaled 7 lower draftrolls, a'set of cooperating top draft rolls,'a saddle mechanism supported on the jour nals of said top rolls, a. stirrupsuspended from a seat on said saddle, means for applying. tension to said stirrup including a spring acting down 7 j wardly upon said stirrup in axial alinementtheres with, and hydraulic means associated with said pressure applying means and acting 'conjo'intly therewith to dampen suddenor. vibratory movements of said top rolls, thereby to stabilize the pressure effective upon the material. 7

we 7. A textile machinehaving means for co tinuously draftingamoving strand composed of textile fibres having a set of fixedly journaled'low er draft -rolls,-a set-0f cooperating top draft rolls, a saddlemechanism supported on thejournals of said top rolls, a stirrup suspended from a seat on said saddle,means for applying tension to said stirrup including la spring' acting downwardly upon said stirrup in axial alinement therewith, 5 and hydraulic dampening means also acting upon said stirrup in axial alinement therewith and 'tud e -o'f movement of said top'rolls and to prevent sudden and vibratory movements thereof, there:

by to stabilize the pressure eifective upon the material.

8; In a device of the character described, in combination,'a roll standbed, a roll stand 'm'ount ed upon saidbed, feed rolls in'said roll stand, a saddle bearing on certain of saidfeed rolls, a"

stirrup connected with said saddle and extend- 65 ing between said feed-rollstoward said roll stand bed, a hydraulic dampening device, means mounting the same upon said roll stand bed in an inclined position longitudinally alined with said stirrup, said dampening device having a piston provided with an axial upwardly "projecting rod connected to said stirrup, and a "spring exerting adownward pullupon saidstirrup.

9. In a device of the character described, in

combinatioma roll stand bed,:azroll= stand mounted 55 conjointly with said spring to restrict the ampliupon said bed, feed'rolls' in. said rollstand, a saddle bearing on certain of said feed rolls, a stirrup connected with said saddle and extending between said feed rolls toward said roll stand bed a hydraulic dampening device, means mounting said dampening device] upon said roll stand bed in an inclined position longitudinally alined with said stirrup, said dampening device having a piston provided with an axial upwardly projecting rod connected to said stirrup, and a spring exerting adownward pull upon said stirrup, said dampen ngdevice further including'a cylinder having anaxially adjustable head in the upper end thereof through which said" piston rod 'slidably extends, and said. spring being of the compression type and encircling said rod within said cylinder, between said head'and said piston, whereby the tension of said springmay be adjusted by longitudinal adjustment'of'the head relatively to said cylinders 10. A textile machine of the character described having drafting roll mechanism comprising a set of lower draft rolls, a set of top draft rolls resting thereupon in operative engagement, a saddle bearing upon the journals of said top rolls, a stirrup positioned at its upper end in an adjustable seat on said saddle, a fixture positioned below said rolls comprising a hollow cylinder disposed beneath said saddle in axial alinement with said stirrup seat, a piston movable lengthwise within said cylinder having a piston rod connected with said stirrup in axial alinement therewith, an apertured head adjustably positioned in said cylinder and surrounding said rod, a spiral spring disposed in compression between said head and said piston, and a body of viscous liquid filling the lower portion of said cylinder to above said piston acting conjointly with said spring to maintain uniform elastic pressure upon said saddle and top rolls and to retard the movements of said piston and thereby to minimize the vibration of said saddle and top rolls.

11. As an article of manufacture, a device for applying elastic pressure to the top rolls of the drafting mechanism of a textile machine and to dampen the vibratory movement thereof comprising a cylinder closed at its lower end and having an apertured head at the opposite end, a piston movable lengthwise within said cylinder having a piston rod extending through said aperture and provided at the outer end thereof with means for operative connection to the top rolls of said machine, means for securing said cylinder to the frame of the machine, a spiral. spring disposed within said cylinder for compression between said piston and said head, and a body of liquid filling the lower portion of said cylinder to above said piston.

12. As an article of manufacture, a device for applying yielding pressure through a saddle and stirrup to the top rolls of the drafting mechanism of a textile machine, comprising relatively movable members adapted to be attached respec tively to'a rigid part of the machine and to the top roll stirrup, a spring of predetermined strength intermediate of said relatively movable members, and supplemental dampening means operable to apply non-elastic resistance to the relative movement of said movable members in response to displacement of said top rolls and acting conjointly with said spring to maintain substantially uniform pressure on said top rolls by preventing vibration thereof.

13. As an article of manufacture, a device for applying yielding pressure through a saddle and stirrup to the top rolls of the drafting mech anism of a textile machine, comprising relatively movable members one of which is adapted to be anchored to a stationary part of the machine and the other of which is adapted to be detachably connected to the top roll stirrup, a spring of predetermined strength intermediate of said relatively movable members, means for varying the initial force applied by said spring to said stirrup, and supplemental dampening means operable to apply non-elastic resistance to the relative movements of said members and cooperating with said spring to stabilize the pressure applied to said top rolls and prevent vibratory motion thereof.

, 14. As an article of manufactura'adevice for applying yielding pressure through a saddle and stirrup to the top rolls of the drafting mechanism of a textile machine, comprising relatively movable members adapted to be attached respectively to a rigid part of the machine and to the top roll stirrup, a spring of predetermined strength disposed to react upon said relatively movable members, and hydraulic dampening means also interposed between said relatively movable members acting conjointly with said spring to restrict the relative movements of said members, and thereby to stabilize the pressure applied to said top rolls.

15. As an article of manufacture, a device for applying yielding pressure through a saddle and stirrup to the top rolls of the drafting mechanism of a textile machine, comprising a cylinder closed at its lower end and having means for attachment to the frame of the machine, an apertured head closing the other end of said cylinder, a piston reciprocable in said cylinder operable to resist the passage of surrounding liquid upon reciprocation of the piston and having a piston rod extending through said head and provided with means detachably to engage the top roll stirrup, a compression spring of predetermined strength interposed between said piston and said head, and a body of liquid filling said cylinder to above said piston and acting upon reciprocation of the piston to restrict the amplitude of movement of the top rolls, thereby to prevent vibration thereof.

16. As an article of manufacture, a device for applying yielding pressure through a saddle and stirrup to the top rolls of the drafting mechanism of a textile machine, comprising a cylinder closed at its lower end and having means for attachment to the frame of the machine, an apertured head adjustably mounted upon the other end of said cylinder, a piston reciprocable in said cylinder operable to restrict the passage of surrounding liquid upon reciprocation of the piston and having a piston rod extending through said head provided with means detachably to engage the top roll stirrup, a compression spring of predetermined strength interposed between said piston and said head, and a body of liquid filling said cylinder to above said piston acting upon reciprocation of the piston to restrict the amplitude of vibration of the top rolls thereby to dampen the vibration thereof, and means whereby the position of said cylinder head may be adjusted to determine the value of the force exerted by said spring upon said stirrup.

17. As an article of manufacture, a device for applying pressure through a saddle and stirrup to the top rolls of the drafting mechanism of a tex- V tile machine, comprising aicylinder' closedi at; it's lower end and having? means for attachment to the frame of the machine,.a,n.apertureds'headsclosing theother end of said cylinder, a pisto'nz recip rocable in said cylinder having fa'predetermined' clearance relative to thecyli nder bore and? having a piston rod extending through said head pro vided with means detachably to engage thefftop roll stirrup', a compression spring ofpredetermi'n'ed strength interposed between. said pistonandsaid head, and a'body of suitable liquid' fillingsaid cylinder to above said piston operable upon 'reciproa cation of the piston to restrict the amplitude of movement of the top rolls'and'thereby todampen vibration thereof. a

18. As an article of manufacture, a; device for applying yielding pressure through a saddleand stirrup to the top rolls of the drafting mechanism of a textile machinejcornprising a cylinder closed} at its lower end and having means for ateg onegaze tachment to theaframe of the machine; an apestured head-constituting: the up per end of said i cylinder, a pistofri reciprocable within said" cy1tind'er operable tefiestrict' the passage thereby of surrounding liquid uponreciprocation of the pi ston, said piston having a piston rod extending through said apertured head and adapted fornona Iii the piston to resist displacement of the toprolls and thereby to: prevent vibration thereof 'by' the dampening. action oi isaidc fluid;v upon the movementsofsaidipistoru fl SANDERS.

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