US3748694A

US3748694A - Drafting system having a supporting roll for offset top feed roll

Info

Publication number: US3748694A
Application number: US00195160A
Authority: US
Inventors: S Staneff
Original assignee: Industriewerk Schaeffler OHG
Current assignee: INA Waelzlager Schaeffler OHG
Priority date: 1971-11-03
Filing date: 1971-11-03
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31

Abstract

The axially aligned top roller pairs of adjacent drafting units of a spinning, twisting or roving machine are journaled on respective shafts, and that top roller pair which serves as the top feed roll of two adjacent drafting units is positioned in nipping relation to a corresponding bottom feed roll, but the top feed roller pair is offset rearwardly of the bottom feed roll. Therefore, in order to prevent the top feed roller pair from tilting excessively about the point at which the load is being applied to the shaft therefor, an idler supporting roll is positioned beneath and in nipping relation to the top feed roller pair and is rotatable by the top feed roller pair and the strands passing between the same and the idler roll.

Description

Unite States Patent 1191 Staneff 1451 July 31, 1973 4] DRAFTING SYSTEM HAVING A SUPPORTING ROLL FOR OFFSET TOP FEED ROLL [75} Inventor: Stefan Staneff, l-lerzongenaurach,

Germany [73] Assignee: lndustriewerk Schaetfler, OHG,

Herzongenaurach, Germany 22 Filed: Nov. 3, 1971 211 Appl. 190.; 195,160

Related US. Application Data [63] Continuation-in-part of Ser. No. 153,615, June 16,

[52] US. Cl. l9/258, 19/293 [51] Int. Cl D0lh 5/70 [58] Field of Search 19/236, 244, 246-261,

[56] References Cited UNlTED STATES PATENTS 3,537,145 11/1970 Meert et al. 19/258 FOREIGN PATENTS 0R APPLICATIONS 500,677 11/1954 Italy 19/261 Primary Examiner-Dorsey Newton Attorney-Donald M. Seltzer [57] ABSTRACT The axially aligned top roller pairs of adjacent drafting units of a spinning, twisting or roving machine are journaled on respective shafts, and that top roller pair which serves as the top feed roll of two adjacent drafting units is positioned in nipping relation to a corresponding bottom feed roll, but the top feed roller pair is offset rearwardly of the bottom feed roll. Therefore, in order to prevent the top feed roller pair from tilting excessively about the point at which the load is being applied to the shaft therefor, an idler supporting roll is positioned beneath and in nipping relation to the top feed roller pair and is rotatable by the top feed roller pair and the strands passing between the same and the idler roll.

5 Claims, 3 Drawing Figures PATENTED L 3 1 975 SEEN 2 BF DRAFTING SYSTEM HAVING A SUPPORTING ROLL FOR OFFSET TOP FEED ROLL This application is a continuation-in-part of my copending application, Ser. No. 153,615, filed June 16, 1971 and entitled HIGH DRAFT TEXTILE DRAFT- ING SYSTEM AND METHOD.

The drafting system of said copending application includes a driven bottom feed roll which is offset upwardly out of a plane passing through the axes of the other bottom drafting rolls by an amount about equal to one-half of its own diameter, and a top feed roll, in the form of a pair of axially spaced cots or rollers journaled on a roller neck shaft, is offset rearwardly with respect to the bottom feed roll in such a manner that the textile strands, upon passing through the nips formed by the top feed roller pair and the bottom feed roll, are looped about the bottom feed roll through an arc of about 90 to 110 as they pass through the respective breaker drafting zones in their course to the next succeeding set of top and bottom drafting rolls. The total length of the path of each strand of textile fibers between the nips of the feed rolls and the next succeeding set of drafting rolls is greater than the maximum staple length of the fibers in the strands, and the uncontrolled length of the path of each strand between the bottom feed roll and said next succeeding set of drafting rolls is less than the average staple length of the fibers, thus providing a highly effective control of the fibers in the strands passing through the breaker drafting zones. Such fiber control in the breaker drafting zones permits substantially higher break drafts and substantially higher total drafts than drafting systems which do not have such fiber control.

Since the top feed roller pair is rearwardly offset considerably with respect to the bottom feed roll and the downward pressure or load is applied to a relatively narrow medial portion of the roller neck shaft of the top feed roller pair, the top feed roller pair tends to tilt about the medial portion of the roller neck shaft due to the differing tensile forces of the textile strands acting on the two cots or rollers thereof as caused by the normal differences in the tension in the strands in the breaker drafting zones forwardly of the feed roll nips and as by the parting of one or the other of the strands. Thus, the axis of the top feed roller pair may not extend parallel with the axis of the bottom feed roll. This problem is even more critical in relatively wide gauge spinning, twisting or roving machines. For example, the gauge or distance between the spindles of a spinning machine may be up to 100 to 260 millimeters (about 3 /16 inches to 10 A inches), and the relatively narrow control of the top feed roller pair by the top roll holders or carriers of the usual loading arms engaging the medial portion of the roller neck shaft will not prevent, with certainty, the tilting of the top feed roller pair if it is set back in the manner described with respect to the bottom feed roll.

It is therefore an object of this invention to provide means for preventing the two rollers or cots of the top feed roll from tilting excessively relative to the bottom feed roll when the top feed roll is offset relative to the bottom feed roll in a direction parallel to the travel of the textile strands between the feed rolls.

In the disclosed and preferred embodiment there is provided an adjacent pair of three-roller drafting units of the type disclosed in said copending application, but wherein an idler supporting roll is positioned beneath and in nipping relation with the top feed roller pair for the two adjacent drafting units, which idler supporting roll is rotated solely by the top feed roller pair and the strands passing therebetween to the nips between each top feed roller and the bottom feed roll. Thus, the idler supporting roll stabilizes the top feed roller pair relative to the bottom feed roll and substantially eliminates any tendency for the top feed roller pair to tilt relative to the bottom feed roll regardless of whether the load or downward pressure is applied to the roller neck shaft of the top feed roller pair in a direction perpendicular to the mean plane of the paths of the strands through the drafting units or in a direction inclined thereto. By utilizing the idler supporting roll of this invention, the load on the top feed roll can be effected at a right angle to the mean drafting plane so that practically any known form of weighting arms may be used with the drafting system.

Some of the objects of the invention having been stated, other objects and advantages will appear as the description proceeds, when taken in connection with the accompanying drawings, in which-- FIG. 1 is a schematic side elevation of one of a pair of drafting units embodying the invention and showing a top roll loading device in association therewith;

FIG. 2 is an enlarged view of the drafting unit shown in FIG. 1, but omitting the roll stand and the top roll loading device; and

FIG. 3 is a schematic plan view taken substantially along line 33 in FIG. 1, and showing both of the drafting units.

Referring more specifically to the drawings, the drafting system is embodied in a pair of side-by-side, three-roller, double apron drafting units including three sets or pairs of top and bottom drafting rolls common to both drafting units. The top and bottom rolls of the first set serve as feed rolls and are broadly designated at 11, 11a, the top and'the bottom rolls of the second pair serve as middle, intermediate or apronsupporting drafting rolls and are indicated at 12, 12a, and the top and bottom rolls of the third pair serve as delivery rolls and are indicated at 13, 13a.

Each top drafting roll includes a pair of axially spaced cots or rollers a, b journaled or rotatably mounted on opposing end portions of a corresponding roller neck shaft 0, and strands l4, 15 of textile staple fibers; e.g., rovings, pass from suitable sources through openings or passages in respective laterally reciprocating guide members, trumpets or

condensers

16, 17 and beneath the respective rollers a, b of top feed roll 11. Each roller a, b of top feed roll 11 forms a nip 20 with a corresponding boss of bottom feed roll 1 1a, and each strand l4, 15 extends upwardly through nip 20 and partially around the bottom feed roll 11a and into a respective breaker drafting zone A defined between the nips 20 of feed rolls 11, 11a and the trips 21 formed by intermediate drafting rolls 12, 12a and by respective draft aprons 12b, 12c looped thereover. The proximal reaches of

aprons

12b, 12c of the double apron draft mechanism extend into a main or secondary drafting zone B defined between the intermediate nips 21 and front nips 22 formed by

delivery rolls

13, 13a.

Although top feed roll 11 is slightly lower than the succeeding

top rolls

12, 13, the axes of all of the top drafting rolls 1 1-13 are disposed in a substantially common plane which is substantially parallel to the mean plane of the draft path of each of the strands l4, 15 of textile fibers through the drafting unit. The intermediate and delivery bottom drafting rolls 12a, 13a also have their axes disposed in a plane extending substantially parallel with the plane through the axes of the top drafting rolls l1l3. However, the axis of the bottom feed roll 1 la is offset upwardly, out of the plane passing through the axes of the bottom intermediate or apronsupporting roll 12a and the bottom delivery roll 13a, by a distance equal to about one-half the diameter of bottom feed roll 11a, so that the upper portion of bottom feed roll 11a is disposed above the plane of the imaginary straight line extending between the lowermost surfaces of the first and second top drafting rolls 11, 12. Thus, top feed roll 11 is considerably set back or rearwardly with respect to bottom feed roll 11a, and the nip 20 between each roller a, b of top feed roll 11 and bottom feed roll 11a is located rearwardly of the axis of bottom feed roll 11a with respect to the direction of movement of

strands

14, 15 through the drafting unit.

Consequently, each

strand

14, 15 is fed into the corresponding breaker drafting zone A by being directed upwardly and forwardly through the respective nip 29, and a break draft is imparted to the strand in its course to nip 21 while each strand is partially looped over and partially around bottom feed roll 11a. The relative positions of feed rolls 11, 11a, apron supporting rolls 12, 12a and the

aprons

12, 12c thereover are such that, although the angle between nip and thepoint of tangency of bottom feed roll 11a may be as low as 85, each strand is looped in moving engagement with the upper surface of the bottom feed roll through an arc in the range of about 90 to 110 from and forwardly of nip 20 as the strand passes out of engagement with roll 11a at a point forwardly of the point of tangency of bottom feed roll 11a and to nip 21.

It is preferred that the arc of contact of each

strand

14, 15 with bottom feed roll 11a is about 100 with respect to the axis of bottom feed roll 11a. Additionally, the relative positions of the drafting rolls are such that each strand passes through the main or secondary drafting zone B in a different angular plane than that of each such strand between feed roll 11a and intermediate rolls 12, 12a. The relationship of such relatively different planes of the passage of each strand and the diameters and relative positions of rolls 11a, 120 are such that each strand also is partially looped around the respective top draft apron 12b between a point rearwardly of the point of tangency of apron 12b and the nip 21 through an arc of no more than about 25 and preferably in the range of about 18 to 25.

The total length of the actual path of each strand l4, 15 between the hips 20, 21 is longer than the longest fibers in the strands while the unguided length of the path of the strand between the bottom feed roll 11a and top apron 12b is no greater than the average staple length of the fibers being drafted.

Although

aprons

12b, 120 are preferred, it is to be understood that they may be omitted, if desired, in which instance all of the top rolls 11-l3 may be cushion rolls all having the same diameter of cots a, b thereon, and the bosses of all of the bottom rolls 11a, 12a, 13a then should be of the same diameter with respect to each other. Such bosses usually are fluted as shown in FIG. 3.

As is conventional, bottom delivery roll 13a is supported for rotation in suitable bearings carried by the front portions of a plurality of spaced roll stands 25,

only one of which is shown in FIG. 1. Also, bottom feed roll 11a and intermediate bottom roll 12a are mounted in suitable bearings positioned in slide blocks 26 carried by the roll stands 25. The bottom drafting rolls Ila-13a are driven by suitable connections to a drive means 27 (FlG. 3) to, in turn, drive the rollers a, b of top drafting rolls, 11-13 through the

strands

14, 15 passing therebetween so as to impart the desired draft to the textile strands, as is well known.

Any suitable loading or pressure means may be provided for maintaining top drafting rolls Ila-13a in the desired spaced relationship and for applying the desired load or yielding downward pressure thereto. By way of example, a loading device 30 is provided which is of a type such as is disclosed in my said copending application, Serial No. 153,615.

Briefly, loading device 30 comprises a releasable loading arm or weighting arm 31 pivotally mounted on a bracket 31 carried by a fixed frame member 32 spaced rearwardly of the drafting rolls 1 1-13, 1 la-l3a. A suitable spring 34, acting through linkage 35 and a releasing lever 36, imparts downward pressure to the forward portion of weighting arm 31, which forward portion overlies the medial portion of the roller neck shafts c of top drafting rolls 11-13.

The forward portion of weighting arm 31 has a plurality of inverted substantially U-shaped top roll holders or carriers 40 projecting downwardly therefrom and adjustably mounted thereon, there being one of the top roller holders 40 for each of the top rolls 11-13. The top roll holders 40 are relatively narrow and each of them receives and engages a relatively small medial portion of each respective roller neck shaft 0, thus transmitting downward pressure from loading or weighting arm 31 to relatively narrow medial portions of the roller neck shafts c of top rolls 11-13 so that the rollers a, b of top feed roll 11 and top delivery roll 13 press the

respective strands

14, 15 against the respective bottom rolls 11a, 13a and so that the top aprons 12b press the

textile strands

14, 15 against the respective bottom aprons 12c under predetermined pressures during operation of the drafting units. Since the drafting units and loading device 30 are disclosed in said copending application, a further description thereof is deemed unnecessary.

Since the nips between the top feed roller pair a, b and bottom feed roll 11a are located rearwardly of the axis of bottom feed roll 11a with respect to the direc tion of travel of the

textile strands

14, 15 through the drafting unit, it follows that the axis of top feed roll 11 is spaced a considerable distance rearwardly of the axis of bottom feed roll 11a. Consequently, the force of the downward pressure acting on only a relatively narrow medial portion of the roller neck shaft c of top feed roll 11, the differing tensile forces of the

textile strands

14, 15 acting on the top feed roller pair a, b the spacing between the latter rollers and the spacing between the

adjacent textile strands

14, 15 are factors which separately and collectively tend to tilt the top feed roll 11 in a direction transversely of the direction of the paths of travel of the

textile strands

14, 15 through the drafting units and about the point at which the pressure is being applied to the top feed roller neck shaft c.

It should be noted that, if top feed roll 1 1 is permitted to tilt excessively, the axis of top feed roll 11 will be inclined relative to the axis of bottom feed roll 11a and thereby cause variation in the distance between the nips at the top feed roller pair a, b and the nips 21 at the respective pairs of draft aprons 12b, 12c. Also, this may vary the effective widths of the two nips 20 such that each strand l4, 15 might not be equally restrained across its entire width by the top and bottom feed rolls 11, 11a and repeated variations in the position of the top feed roll 11, as caused by tilting the same, will increase the temperature of the rollers a, b thereof, cause the latter rollers a, b to become damaged or worn excessively in less than their normal useful life, and reduce the quality of the textile strands l4, 15 being drafted.

According to the invention, however, an idler supporting roll 45 preferably of substantially lesser diameter than either of the feed rolls 11, 11a, is positioned beneath and in nipping relation with top feed roll 11, and is rotatable solely by top feed roll 11 and the strands passing therebetween so as to prevent top feed roll 11 from tilting excessively relative to bottom feed roll 11a under the force of the loading device 30. The idler supporting roll 45 preferably has a smooth peripheral surface and is loosely or freely rotatably mounted in suitable bearings 46, preferably roller bearings, mounted in the slide blocks 26 carried by the roll stands (FIG. 1).

It is preferred that the supporting roll 45 is relatively short and, accordingly, it may be made of a length about equal to the distance between the centers of adjacent roll stands 25 so that the top feed roll 11 need overcome relatively little inertial force in order to transmit rotation to the corresponding idler supporting roll 45. It is to be noted that idler supporting roll 45 forms an additional pair of nips with the two rollers a, b of top feed roll 11 with such additional pair of nips as illustrated in FIG. 2, being about 90 from the nips defined by the feed rolls 11, 20, with respect to the axis of top feed roll 11, so as to cause the textile strands to arcuately engage about one quarter of the surface of top feed roll 11. To facilitate guiding the

strands

14, 15 into the respective additional pair of nips and the threading of the strands therethrough and upwardly through the feed roll nips 20, the trumpets or

strand guide members

16, 17 are positioned rearwardly of and closely adjacent the respective pair of additional nips and the openings or passages through strand guide members l6, 17 are substantially tangentially aligned with the proximal portions of idler roll 45 and the top feed roller pair a, b forming the additional pair of nips.

it is thus seen that the supporting roll 45 supports the rearwardly offset top feed roll 11 by its nipping relation with the top feed roller pair a, b thereof in the adjacent pair of side-by-side drafting units thereby providing stabilizing means preventing the top feed roll from being tilted excessively about the relatively narrow medial portion of the respective roller neck shaft c being enga'ged by the respective top roll holder 40 of the loading or pressure means 30. Thus, the tilting of the top feed roll relative to bottom feed roll 11a as by differing tensile forces of the strands l4, l5 acting on the top feed roller pair a, b, is eliminated except for slight fluctuations of the top feed roller pair which may be effected by variations in mass and/or density of the strands l4, 15 being fed to the next succeeding set of drafting rolls [2, 12a and the

aprons

12b, 12c thereon. Also, it is to be noted that the idler supporting roll 45 facilitates positioning the trumpets or guide members l6, 17 so that an operator may easily thread the strands through the

guide members

16, 17 to the feed rolls 11, 11a in a direction generally parallel to the mean path of travel of the strands through the drafting units.

in the drawings and specification, there has been set forth a preferred embodiment of the invention and, although speeific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

1. A textile drafting system comprising a pair of sideby-side drafting units for drafting respective spacedapart textile strands therethrough, a series of sets of drafting rolls common to both drafting units and including a set of top and bottom feed rolls, a set of top and bottom intermediate rolls and a set of top and bottom delivery rolls, the top roll of each set comprising a roller neck shaft having a pair of axially spaced rollers thereon forming a respective pair of nips with the corresponding bottom roll through which the respective strands pass during drafting thereof, said bottom feed roll being offset upwardly by about one-half of its diameter with respect to a substantially common plane through the axes of said bottom intermediate roll and said bottom delivery roll, said top feed roll being offset rearwardly of said bottom feed roll whereby the nips of the bottom feed roll and the pair of rollers of said top feed roll are offset rearwardly of the axis of said bottom feed roll, pressure means engaging relatively narrow medial portions of said roller neck shafts between the respective pairs of rollers and applying a downward force thereto, stabilizing means preventing excessive tilting of said rearwardly offset top feed roll about the engaged medial portion of the roller neck shaft thereof by differing tensile forces of the strands acting on the respective rollers of said top feed roll during drafting, said stabilizing means including an idler roller positioned beneath said top feed roll and forming an additional pair of nips with the respective rollers thereof, said idler roll being so positioned relative to said top feed roll that the additional pair of nips formed therewith cause the textile strands in their path of travel to said first recited nips to arcuately engage about one quarter of the surface of the top feed roll, means supporting said idler roll for free rotation by the rollers of said top feed roll, and means guiding the strands into the respective additional pair of nips to facilitate threading the strands therethrough and upwardly through the nips of said feed rolls.

2. A drafting system according to claim 1, wherein said pressure means is provided with inverted substantially U-shaped holders thereon engaging the respective roller neck shafts at points about halfway between the respective pairs of said rollers.

3. A drafting system according to claim 2, wherein said idler supporting roll is of substantially less diameter than said feed rolls and has a substantially smooth peripheral surface engaging said strands.

4. A drafting system according to claim 3, wherein said strand guiding means includes a pair of guide members positioned rearwardly of and closely adjacent said additional pair of nips and having openings therethrough for guiding the respective strands into said additional pair of nips.

5. A drafting system according to claim 4, wherein the openings in said guide members are positioned in substantially tangential alignment with the proximal portions of the peripheral surfaces of said rollers of said top feed roll and said idler roll forming said additional pair of nips.

Claims

1. A textile drafting system comprising a pair of side-by-side drafting units for drafting respective spaced-apart textile strands therethrough, a series of sets of drafting rolls common to both drafting units and including a set of top and bottom feed rolls, a set of top and bottom intermediate rolls and a set of top and bottom delivery rolls, the top roll of each set comprising a roller neck shaft having a pair of axially spaced rollers thereon forming a respective pair of nips with the corresponding bottom roll through which the respective strands pass during drafting thereof, said bottom feed roll being offset upwardly by about one-half of its diameter with respect to a substantially common plane through the axes of said bottom intermediate roll and said bottom delivery roll, said top feed roll being offset rearwardly of said bottom feed roll whereby the nips of the bottom feed roll and the pair of rollers of said top feed roll are offset rearwardly of the axis of said bottom feed roll, pressure means engaging relatively narrow medial portions of said roller neck shafts between the respective pairs of rollers and applying a downward force thereto, stabilizing means preventing excessive tilting of said rearwardly offset top feed roll about the engaged medial portion of the roller neck shaft thereof by differing tensile forces of the strands acting on the respective rollers of said top feed roll during drafting, said stabilizing means including an idler roller positioned beneath said top feed roll and forming an additional pair of nips with the respective rollers thereof, said idler roll being so positioned relative to said top feed roll that the additional pair of nips formed therewith cause the textile strands in their path of travel to said first recited nips to arcuately engage about one quarter of the surface of the top feed roll, means supporting said idler roll for free rotation by the rollers of said top feed roll, and means guiding the strands into the respective additional pair of nips to facilitate threading the strands therethrough and upwardly through the nips of said feed rolls.