US3216065A

US3216065A - Resiliently mounted lower drafting rolls

Info

Publication number: US3216065A
Authority: US
Publication date: 1965-11-09
Anticipated expiration: 1982-11-09

Description

Nov. 9, 1965 B. c. GRIEB 3,216,065

RESILIENTLY MOUNTED LOWER DRAFTING ROLLS Filed Feb. 5, 1963 3 Sheets-Sheet 1 '21- INVENTOR:

K) BENIAMIN Cusans Qwes Nov. 9, 1965 a. c. GRIEB RESILIENTLY MOUNTED LOWER DRAFTING ROLLS 5 Sheets-Sheet 2 Filed Feb. 5, 1963 Nov. 9, 1965 B. c. GRIEB RESILIENTLY MOUNTED LOWER DRAFTING ROLLS 3 Sheets-Sheet 3 Filed Feb. 5, 1963 a E k R 5 mG w N s 5 E U N WE L. W C M T 4 N m A m M H .b H E Y 5 5 B MW 2 A. V0 a a? /0 H u u 1 MWTL M a A 2 //,m 4 I mm TML L l 5 .FI!|.TII 5 m I. 6 fi 5 w 7/ ,N/ l J Wu W! K E l 6 6 M7 United States Patent 3,216,065 RESILIENTLY MOUNTED LOWER DRAFTING ROLLS Benjamin Curtis Grieb, Rte. 2, St. John Lane, Charlotte, N.C. Filed Feb. 5, 1963, Ser. No. 256,469 9 Claims. (Cl. 19-494) This invention relates to improvements in a drafting frame, such as a spinning frame, roving frame, and the like, and relates particularly to an improved means for applying contact pressure between the sets of top and bottom drafting rolls through which fibrous material, such as sliver, roving or yarn, passes.

In drafting equipment, sets of alined top and bottom rolls are brought together into engagement under predetermined amounts of contact pressure to enable these sets of rolls, which are running at different speeds, to grip the fibrous material for the purpose of stretching or drafting the fibrous material as it passes through the sets of rolls. Heretofore, the desired contact pressure between the top rolls and the bottom rolls has been achieved by weighting the top rolls or applying pressure thereto. This has been done, for example, by applying saddles about the center sections of the top rolls with the saddles having weights attached thereto, or various arrangements of springs and arm members containing the springs where the arm members are secured to the roll stand beneath the sets of top and bottom rolls so that spring pressure is applied on the top rolls to draw them against the bottom rolls in engagement therewith for providing the desired contact pressures therebetween. Weighting of the top rolls or applying pressure thereto for maintaining the top rolls in engagement with the bottom rolls under desired contact pressures has also been accomplished by mechanisms which are operable by fluid pressure or magnetic means.

It is an object of the present invention to provide an improved means for applying contact pressures between sets of engageable top and bottom rolls in a drafting frame which relies upon resiliently biasing the bottom rolls in a direction toward the corresponding top rolls engaged thereby, rather than applying contact pressures between the sets of engageable top and bottom rolls through weighting of the top rolls or applying pressure thereto as is the conventional practice. My improvement eliminates obstructing mechanisms, which are associated with conventional weighting of the top rolls or application of pressure to the top rolls, from the drafting area and results in a more open drafting area significantly cleaner than heretofore known. This is accomplished in accordance with the present invention by incorporating resilient means in the roll stand beneath the bearings for the bottom rolls so as to bias the bottom rolls against the respective top rolls engaged thereby to establish the desired contact pressures therebetween.

My improvement offers other advantages over conventional forms of drafting equipment which provide for maintaining predetermined contact pressures between engaging sets of top and bottom rolls by weighting or applying pressure to the top rolls. In the latter respect, the bearings rotatably supporting each of the sectional bottom rolls which commonly extend across a plurality of roll stands must be accurately alined for proper drafting to take place. Because of various factors, these bearings frequently undergo limited movement relative to each other resulting in improper alinement. Variations in the alinement between the bearings supporting a sectional bottom roll are particularly troublesome when such bearings are of the anti-friction type-whose use for rotatably supporting bottom roll sections has been steadily 3,216,065 Patented Nov. 9, 1965 increasing in popularity. Even though the antifriction bearings so used may be allegedly self-alining, this selfalining feature is apparently incapable of compensating for variations in the alinement of bottom roll sections from one roll stand to another.

It is therefore another object of this invention to provide an improved means for applying contact pressures between sets of engageable top and bottom rolls in a drafting frame for maintaining engagement therebetween under predetermined contact pressures, the improved means comprising resilient means installed in the roll stands of the frame beneath the bearings supporting sections of the bottom rolls for biasing the bottom rolls against the top rolls engaged thereby to establish the desired contact pressures therebetween, wherein the sectional bottom rolls are resiliently supported on the roll stands to allow greater tolerance in accurately alining and leveling the bottom roll sections and more effective maintenance of proper alinement and leveling of the bottom roll sections as between the plurality of roll stands on which the sections of the bottom rolls are disposed.

As is well known, drafting of fibrous material in a drawing frame is greatest at the front pair of top and bottom rolls with the contact pressure between the engaged top and bottom front rolls being maintained at a greater magnitude than the contact pressures between the other sets of engaged top and bottom rolls. It is therefore another object of this invention to provide an improved means for maintaining an effective contact pressure between the engaged top and bottom front rolls in a drawing frame, which means resiliently supports the bearings for the sections of the bottom front roll in the roll stands of the frame and comprises a pair of spring-urged plungers installed in each of the roll stands at the opposite ends of a bottom front roll section for resiliently acting upon the bearings for the bottom front roll section in vertical and horizontal directions respectively, thereby accommodating alinement variations between the bearings to maintain accurate alinement between the sections of the bottom front roll along its extent.

It is yet another object of this invention to provide in a drawing frame having sets of top and bottom rolls, wherein the top rolls are releasably maintained in engagement with the bottom rolls corresponding thereto, a novel means for providing the desired contact pressures between the engaged top and bottom rolls comprising rcsilicnt means installed in the roll stand beneath the bottom rolls for biasing the bottom rolls against the top rolls to establish contact pressures therebetween, and a movable latching means operably associated with the bottom rolls for movement to a latching position to limit movement of the bottom rolls under the biasing action of the resilient means. The bottom rolls are thereby retained in a resiliently biased operative position with respect to the top rolls when the top rolls have been re moved from engagement therewith for clearing bunched or snarled fiber or piecing together broken fiber ends.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

FIGURE 1 is a fragmentary front elevational view of a drawing frame having a drafting roll assembly constructed in accordance with the present invention;

FIGURE 2 is a front elevational view of the drawing frame showing the sets of engaged top and bottom rolls, wherein the sectional bottom rolls extend across a plurality of roll stands;

FIGURE 3 is a transverse vertical sectional view taken substantially along the line 33 in FIGURE 1 and showing a latching bar in latched position with respect to the bottom rolls;

FIGURE 4 is a perspective view of the latching bar which comprises a component of the drafting roll assembly;

FIGURE 5 is a transverse vertical sectional view taken along the line 55 in FIGURE 1 and showing the latching bar in unlatched position with respect to the bottom rolls; and

FIGURE 6 is a longitudinal sectional view taken substantially along the line 6-6 in FIGURE 5.

Referring more specifically to the drawings, reference numeral 10 designates the roll stands of a drawing frame for supporting sets of alined top and bottom rolls. The sets of top and bottom rolls include top and bottom front rolls 11, 12, top and

bottom back rolls

13, 14, and top and bottom

intermediate rolls

15, 16 positioned between the top and bottom front and back rolls. As indicated by the bottom front roll 12 illustrated in FIGURE 6, each of the bottom rolls comprises a plurality of interconnected bottom roll sections the bottom front roll 12 of FIGURE 6, for example, including bottom

front roll sections

17 and 18 having their adjacent ends connected together by suitable means, such as the threaded reduced end portion 19 of the roll section 17 received within a complementary threaded bore 20 formed in the adjacent end of the roll section 18.

Each of the bottom rolls therefore comprises an elongated sectional shaft, the sectional shaft having a plurality of enlarged collars defining drafting rolls along its length to form axially spaced surfaces of enlarged diameter which are adapted to engage and draft fiber F (FIG- URE 5) or may be covered by fiber-engaging apron belts.

The bottom front roll 12 is shown as having fluted fiber engaging surfaces 21, while the bottom back and

intermediate rolls

14, 16 are shown as having plain surfaces 22 of enlarged diameter. Preferably, the enlarged collars forming the axially spaced plain surfaces 22 along the length of a bottom roll would comprise respective cots 23 of suitable material which have been pressed onto the sectional shaft of the bottom roll to be frictionally secured thereto. It will be understood, however, that the character of the enlarged collars and the surfaces thereon for the bottom rolls is merely descriptive of the illustrated embodiment of my invention, and that my invention is not to be necessarily limited to the specific type of enlarged collars and surfaces thereon for the bottom front, back, and intermediate rolls which are shown in the drawings.

Each of the top rolls is illustrated as being of the composite type comprising a plurality of axially spaced, horizontially alined separate units, wherein each unit includes rolls in the form of

cuts

24, 24 frictionally pressed onto the opposite ends of a relatively short shaft 25. As shown, corresponding top roll units of the front, back, and intermediate top rolls are carried by a top arm assembly 30. The top arm assembly 30 comprises a top arm 31 extending transversely to and straddling the relatively short shafts of the top roll units, with the shafts 25 being journaled in the top arm 31 for rotation with respect thereto. The top arm 31 is mounted for pivotal movement with respect to the roll stand 10 about an axle bar 32 fixedly mounted on the roll stand 10 above the top and bottom back rolls 13, 14 (FIGURES 3 and 5). The top arm 31 is equipped with a toggle lever 33 which is mounted for "pivoting movement about one end thereof and extends along the top arm 31 of the top arm assembly so as to be disposed thereabove. The toggle lever 33 when positioned in its lowered position, as illustrated in FIGURES 3 and 5, locks the top arm 31 in its lowered position with the rolls or

cots

24, 24 of the top roll units carried by the top arm 31 being disposed in engagement with the enlarged collars of the bottom rolls corresponding thereto. Upon raising the toggle lever 33, the top arm 31 is unlocked and may be pivoted about the fixed axle bar 32 to lift the top arm 31 to an open position in which the top rolls or

cots

24, 24 are disengaged from the bottom rolls. As illustrated, the top arm assembly 30 is similar to the type of top arm assembly known as a Tru-Set top arm assembly which was introduced by Saco-Lowell Shops of Boston, Massachusetts.

lt will be observed, however, that the top arm assembly 31 is not required to apply spring pressure or weights to the top rolls carried thereby for providing contact pressures between the top rolls and the bottom rolls when in engagement, although this may be done within the spirit of the present invention, if desired. It should be also understood that the top arm assembly 30 is merely representative of a mechanism associated with the top rolls for releasably maintaining the top rolls in engagement with the bottom rolls corresponding thereto, and that the present invention is not to be considered as being necessarily limited thereto, since any applicable means for inducing engagement between the sets of top and bottom rolls may be suitably employed.

As shown, the drawing frame employs the Casablanca system of drafting in that the top and bottom

intermediate rolls

15, 16 are respectively encircled by belt aprons 35, 36 for providing increased drafting in the Zone between the top and

bottom back rolls

13, 14 and the top and bottom

intermediate rolls

15, 16, and in the zone between the

intermediate rolls

15, 16 and the front rolls 11, 12. The bottom rolls are positively driven at progressively increasing speeds from back to front in the usual manner by a driving mechanism (not shown) of conventional character, while rotation is imparted to the top rolls through their engagement with the bottom rolls corresponding thereto.

In accordance with the present invention, the

sectional bottom rolls

12, 14, and 16 are resiliently mounted in the roll stands 10 of the drawing frame within bearing supports. In this respect, each roll stand 10 is provided with a bearing block 40 having a U-shaped bearing support slot 41 in which the front roll 12 is suitably supported, in a manner to be presently described. The rear and

intermediate rolls

14, 16 are suitably supported in rear and intermediate bearing supports 42, and 43, respectively. These bearing supports 42, and 43 are supported on the bearing block 40 and may be made adjustable by means (not shown) so as to be slidable with respect to each other to vary the distance therebetween. Referring specifically to the bottom front r011 12 and the bearing support slot 41 therefor, a substantially U-shaped or channel-shaped bearing carrier or liner 44 is movably mounted in the bearing support 41 for receiving a bearing 45 which rotatably supports the bottom front roll 12. The bearing 45 is illustrated as being of the antifriction type having an inner race 46, an outer race 47 and anti-friction ball elements 48 between the inner and outer races, with the opposite ends of the anti-friction bearing 45 being sealed by suitable means, such as

shields

49, 49. The inner race 46 of the anti-friction bearing 45 is pressed onto the bottom front roll section 17 adjacent the threaded reduced end portion 19, and the outer race 47 is pressed into the channel-shaped bearing carrier 44 to be seated therein.

Resilient means are installed in the bearing block 40 to flexibly support the bearing assembly for the bottom front roll 12 in the bearing support slot 41 and to bias the bottom front roll 12 toward the top front roll 11, thereby providing a desired contact pressure between the top and bottom front rolls 11, 12 when these rolls are in engagement with each other. The resilient means associated with the bottom front roll 12 preferably take the form of a pair of spring-urged

plungers

50, 50 particularly positioned in the bearing block 40 so as to exert biasing forces extending horizontally and vertically of the roll stand 10. Each of the spring-urged

plungers

50, 50 is slidably mounted in a cylindrical shell 51 which is pressed into a blind bore formed in the bearing block 40. The cylindrical shell 51 also contains a helical spring 52 whose opposite ends are seated against the rear closed end of the cylindrical shell 51 and an enlarged retainer collar 53 provided on the plunger 50 intermediate the ends thereof. The forward end of the plunger 50 protrudes outwardly of the shell 51 to engage the channelshaped bearing carrier 44 as the plunger is biased forwardly in the shell 51 by the spring 52. The enlarged collar 53 on the plunger 50 is adapted to abut an inturned annular flange 54 integral with the forward end of the shell 51 to limit forward movement of the plunger 50 under the biasing action of the spring 52.

As previously indicated, one of the spring-urged plungers 50 is disposed for lateral or horizontal movement in the bearing block 40, while the other spring-urged plunger 50 is arranged at right angles to the first plunger 50 so as to be disposed for vertical movement with respect to the bottom front roll 12. The bottom front roll sections comprising the elongate sectional shaft which forms the bottom front roll of the drawing frame are thereby rotatably supported by a bearing at each of the ends thereof in a flexible manner to compensate for horizontal and vertical variations in the relative positions assumed by the bearing assemblies for the bottom front roll sections along the length of the sectional bottom front roll 12, such variations being especially likely to occur where the sectional bottom front roll 12 extends across adjacent roll stands of the drawing frame.

The back and intermediate bottom rolls 14 and 16 are likewise flexibly supported, but it will be observed that the resilient means biasing the back and intermediate bottom rolls 14 and 16 toward the top rolls 13, corresponding thereto to provide the desired contact pressures therebetween are illustrated as taking a form different from the spring-urged plungers 50, flexibily supporting the bottom front roll 12. In this connection, the bottom back roll 14 is shown as being rotatably supported in its bearing support 42 by a channel-shaped bearing liner 60. The bearing support 42 is provided with an arcuate recess extending beneath the channelshaped bearing liner in which a mass of resilient material is disposed to act upon the bearing liner 60 and the bottom back roll 14 rotatably supported thereby for biasing the bottom back roll 14 toward the top roll 13 corresponding thereto to maintain the proper contact pressure therebetween.

The mass of resilient material carried by the bearing support 42 beneath the bearing liner 60 and the bottom back roll 14 comprises a substantially arcuate rubber pad 61 which is so dimensioned as to protrude outwardly of the bearing support 42 when in a relaxed state. The bearing liner 60 and the bottom back roll 14 when received in the bearing support 42 cause the arcuate rubber pad 61 to be placed under compression. The compressed arcuate rubber pad 61 resiliently biases the hearing liner 60 and the bottom back roll 14 in a direction toward the top roll 13 engaged by the bottom roll 14 for providing contact pressure between the top and bottom back rolls 13, 14 of a desired magnitude.

Similarly, the bottom intermediate roll 16 is flexibly mounted in its bearing support 43, being rotatably supported by a channel-shaped bearing liner 60 and resiliently biased toward the top intermediate roll 15 by an arcuate rubber pad 61 received in a recess provided in the bearing support 43.

Thus, all of the bottom rolls of the drawing frame are flexibly mounted on the roll stands 10 thereof and are biased by resilient means in directions toward the top rolls engaged thereby to provide the desired contact pressures between the sets of engaged top and bottom rolls. It will be appreciated that the spring-urged

plungers

50, 50 flexibly supporting the bottom front roll 12 could also be employed as the form of resilient means for supporting the back and intermediate bottom rolls 14, 16, while conversely the bottom front roll 12 could be flexibility supported by an arcuate rubber pad similar to the

pads

61, 61 flexibly supporting the back and intermediate bottom rolls 14, 16 within the spirit of the present invention. However, it is preferred that the

springurged plungers

50, 50 be used to flexibly support the bottom front roll 12, since it is the top and bottom front rolls 11, 12 which normally engage each other with the greatest contact pressure and the bottom front roll sections are more likely to encounter bearing alinement irregularities. In the latter connection, the biasing forces afforded by the spring-urged

plungers

50, 50 can be more readily controlled through substitution of springs having known strength characteristics, and the springs are less likely to assume a frozen or set state as compared to the

rubber pads

61, 61.

Latching members (FIGURE 4) are operably associated with the bottom rolls 12, 14, and 16, and each of the roll stands 10. In this connection, a latching member is mounted on each roll stand 10 for slidable movement between positions latching and unlatching sections of the bottom rolls with respect to the top rolls corresponding thereto. The latching member comprises an elongate bar 70 provided along its lower edge with a plurality of inclined cam surfaces 71, 72, and 73 corresponding to the bottom front, back, and

intermediate rolls

12, 14, and 16, respectively. The latching bar 70 is slidably received in

trackways

74, 74 formed on the roll stand 10, the

trackways

74, 74 being positioned on the bearing block 40 at opposite ends thereof above and below the bottom rolls. One end of the latching bar 70 is slidably received in the upper trackway 74, while the opposite end of the latching bar 70 extends outwardly through the lower trackway 74 and terminates in an enlarged key 75 having an outer concave surface generally conforming to a finger tip.

When the latching bar 70 is in the unlatched position illustrated in FIGURE 5, the cam surfaces 71, 72, and 73 along the lower edge thereof are out of engagement with the sections of the bottom rolls corresponding thereto. Upon manually pushing inwardly against the key 75 of the latching bar 70, the latching bar 70 will be slidably moved to its latched position (FIGURE 3) in which each of the cam surfaces 71, 72, and 73 is brought into abutting engagement with the bottom roll section corresponding thereto. It will be observed that the upper edge of the latching bar 70 includes a serrated portion 76 positioned slightly forwardly of the cam surface 71 on the lower edge thereof, the serrated portion 76 serving as an adjustable retaining means to be hooked onto the end edge of a member 77 forming part of the lower trackway 74 at various positions along the serrated portion 76 for retaining the latching bar 70 in an ad justed latching position so that the cam surfaces 71, 72, and 73 thereon will just abut the respective bottom roll section corresponding thereto. The fine adjustment of the latching bar 70 in its latching position permitted by the serrated portion 76 allows sections of the bottom rolls to remain in engagement with the top rolls under predetermined contact pressures therebetwecn, while these bottom roll sections are latched by the latching bar 70 to limit the movement thereof under the biasing forces of their respective resilient means toward the top rolls.

Should it be desired to remove one or more sets of top roll units as carried by respective top arm assemblies 30 from engagement with the bottom rolls to clear bunched or snarled fiber or to piece together broken fiber ends, the bottom roll sections corresponding to the set or sets of top roll units which have been removed are latched in a resiliently biased operative position with respect to the top rolls by latching

bars

70, 70. Subsequent raising of the toggle lever 33 to unlock the top arm 31 and lifting of the top arm 31 by pivoting it to an open position for releasing the set of top roll units from engagement with the bottom rolls does not affect the respective positions of the bottom rolls, in view of the fine adjustment of the latching bars 70, 70 in their latching position with the cam surfaces 71, 72, and 73 thereon lightly abutting the bottom roll sections prior to the release of the set of top roll units from engagement with the bottom roll sections corresponding thereto. It will be understood that each of the roll stands 10 is provided with a latching bar 70, and the latching bars 70, 70 at opposite ends of bottom roll sections will preferably be manipulated as a pair to evenly distribute the load imposed by the bottom roll sections when retained in a latched position between the pair of latching bars at opposite ends thereof to guard against the assumption of a misalined position by the bottom rolls where only one latching bar 70 is relied upon to retain the bottom roll sections in a resiliently biased operative position.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a textile drafting apparatus including a pair of top and bottom front rolls, roll stands on which said pair of top and bottom front rolls are mounted, said roll stands each including a bearing block having a bearing therein for rotatably supporting said bottom front roll, and means operably associated with said top front roll for maintaining said top front roll in engagement with said bottom front roll;

(a) a pair of springs mounted in said bearing block beneath said bearing rotatably supporting said bottom front roll, and

(b) said springs being disposed at right angles to each other in vertical and horizontal positions in said bearing block and resiliently biasing said bearing and said bottom front roll in a resultant direction toward the rotational axis of said top front roll to provide contact pressure between said pair of engaged top and bottom front rolls while resiliently mounting said bearing in said bearing block.

2. In a textile drafting apparatus having sets of top and bottom rolls, a roll stand on which said sets of top and bottom rolls are mounted, roll supporting means on said roll stand for rotatably supporting said bottom rolls, and means operably associated with said top rolls for releasably maintaining said top rolls in engagement with said bottom rolls corresponding thereto;

(a) means carried by said roll supporting means and resiliently biasing said bottom rolls in directions toward said top rolls corresponding thereto to provide contact pressures between said sets of engaged top and bottom rolls,

(b) latching means operably associated with said bottom rolls and being movable to a latching position to limit the movement of said bottom rolls under the biasing action of said resilient biasing means, and

(c) said latching means when disposed in latching position retaining said bottom rolls in resiliently biased operative position with respect to said top rolls upon release of said top rolls from engagement with said bottom rolls corresponding thereto.

3. In a textile drafting apparatus having many pairs of cooperating top and bottom front drafting rolls wherein the top rolls are arranged in longitudinally spaced apart units and all the bottom rolls are longitudinally interconnected. roll stands on which said top and bottom rolls are mounted, roll supporting means on the roll stands each having a bearing rotatably supporting said bottom front rolls, and means operably associated with the top front rolls for maintaining the same in engagement with the bottom front rolls;

(a) means carried by said roll supporting means resiliently mounting said hearings in said roll supporting means to compensate for variations in alinement between the bearings and biasing said bearings and said bottom front rolls in a direction substantially toward the rotational axis of said top front rolls to provide contact pressure between said engaged pairs of front rolls.

4. In a textile drafting apparatus having a plurality of top and bottom drafting rolls arranged in cooperating pairs to define many front, intermediate, and back pairs of rolls and wherein the top rolls are arranged in longi tudinally spaced apart units and all the bottom rolls are interconnected longitudinally, roll stands on which said top and bottom rolls are mounted, roll supporting means on each roll stand each having bearing means rotatably supporting said bottom rolls, and means operably associated with the top rolls for maintaining the same in engagement with the bottom rolls;

(a) means carried by said roll supporting means resiliently mounting said bottom rolls to compensate for alinement variations between the roll stands and biasing each of said bottom rolls in a direction substantially toward the rotational axis of its corresponding top roll to provide contact pressure between said pairs of rolls.

5. In a textile drafting apparatus according to claim 4 wherein said means (it) includes compressible spring means resiliently mounting, and biasing said bottom front rolls toward said top front rolls.

6. In a textile drafting apparatus according to claim 4 wherein said means (it) includes compressible pads resiliently mounting, and biasing said bottom intermediate and bottom back rolls toward said cooperating intermediate and back top rolls.

7. In a textile drafting apparatus including pairs of top and bottom front drafting rolls, roll stands on which said pairs of top and bottom front rolls are mounted, said roll stands including bearing blocks each having a bearing therein for rotatably supporting said bottom front rolls, and means operably associated with said top front rolls for maintaining said top front rolls in engagement with said bottom front rolls;

(a) a pair of springs mounted in each bearing block beneath said bearings rotatably supporting said bottom front rolls, and

(b) said springs being disposed relative to each other in said bearing blocks to resiliently bias said bearings and said bottom front rolls in a resultant direction substantially toward the rotational axis of said top front rolls to provide contact pressure between said pairs of engaged top and bottom front rolls and resiliently mounting said bearings in said bearing blocks.

8. In a textile drafting apparatus,

(a) a pair of engaging top and bottom front rolls,

(b) said bottom front roll comprising a plurality of interconnected bottom front roll sections,

(c) a plurality of roll stands on which said bottom front roll is mounted,

(d) means operably associated with said top roll for releasably maintaining said top roll in engagement with said corresponding bottom roll,

(c) said roll stands being respectively disposed beneath said bottom front roll at positions adjoining connected opposed ends of adjacent bottom front roll seiltions and the opposite ends of the bottom front ro (f) an anti-friction bearing carried by each of said roll stands for rotatably supporting said bottom front roll at a plurality of points therealong adjacent the connected opposed ends of adjacent bottom front roll sections and the opposite ends of the bottom front roll,

(g) a pair of springs mounted in each of said roll stands beneath said anti-friction bearing carried thereby, and

(h) said springs being disposed relative to each other to resiliently bias said anti-friction bearings and said interconnected bottom front roll sections in a resultant direction substantially toward the rotational axis of. said top front roll to provide contact pressure between said pair of engaged top and bottom front rolls and resiliently mounting said bottom front roll on said roll stands to compensate for variations in alinement between the bearings.

9. In a textile drafting apparatus,

(a) a plurality of sets of releasably engaging top and bottom rolls,

(b) each of said bottom rolls comprising a plurality of interconnected bottom roll sections,

(c) a plurality of roll stands on which said sets of bottom rolls are mounted,

(d) means operably associated with said top rolls for releasably maintaining said top rolls in engagement with said corresponding bottom rolls,

(e) said roll stands being respectively disposed beneath said bottom rolls at positions adjoining connected opposed ends of adjacent bottom roll sections and the opposite ends of the bottom roll for each of the sectional bottom rolls,

(f) bearing means carried by each of said roll stands for rotatably supporting each of said bottom rolls at respective points therealong adjacent the connected opposed ends of adjacent bottom roll sections and the opposite ends of the bottom roll,

(g) resilient means carried by each of said roll stands and positioned beneath each of said bearing means carried thereby, said resilient means respectively biasing each of said bearing means and said bottom roll corresponding thereto in directions toward said top rolls engaged thereby to provide contact pressures between said sets of engaged top and bottom rolls and resiliently mounting said bottom rolls on said roll stands,

(h) latching means operably associated with said bottom rolls and being movable to a latching position to limit the movement of said bottom rolls under the biasing action of said resilient means, and

(i) said latching means when disposed in latching position retaining said bottom rolls in resiliently biased operative position with respect to said top rolls.

References Cited by the Examiner UNITED STATES PATENTS 2,389,581 11/45 Tarr 19294 2,592,718 4/52 McGhee 19-294 3,035,314 5/62 Cotchett l9294 FOREIGN PATENTS 8,6l6 1903 Great Britain. 475,187 1l/37 Great Britain.

DONALD W. PARKER, Primary Examiner.

RUSSELL C. MADER, Examiner.

Claims

1. IN A TEXTILE DRAFTING APPARATUS INCLUDING A PAIR OF TOP AND BOTTOM FRONT ROLLS, ROLL STANDS ON WHICH SAID PAIR OF TOP AND BOTTOM FRONT ROLLS ARE MOUNTED, SAID ROLL STANDS EACH INCLUDING A BEARING BLOCK HAVING A BEARING THEREIN FOR ROTATABLY SUPPORTING SAID BOTTOM FRONT ROLL, AND MEANS OPERABLY ASSOCIATED WITH SAID TOP FRONT ROLL FOR MAINTAINING SAID TOP FRONT ROLL IN ENGAGEMENT WITH SAID BOTTOM FRONT ROLL; (A) A PAIR OF SPRINGS MOUNTED IN SAID BEARING BLOCK BENEATH SAID BEARING ROTATABLY SUPPORTING SAID BOTTOM FRONT ROLL, AND (B) SAID SPRING BEING DISPOSED AT RIGHT ANGLES TO EACH OTHER IN VERTICAL AND HORIZONTAL POSITIONS IN SAID BEARING BLOCK AND RESILIENTLY BIASING SAID BEARING AND SAID BOTTOM FRONT ROLL IN A RESULTANT DIRECTION TOWARD THE ROTATIONAL AXIS OF SAID TOP FRONT ROLL TO PROVIDE CONTACT PRESSURE BETWEEN SAID PAIR OF ENGAGED TOP AND BOTTOM FRONT ROLLS WHILE RESILIENTLY MOUNTING SAID BEARING IN SAID BEARING BLOCK.