US2674110A - Warp tension control means - Google Patents

Description

April 6, 1954 Filed 001;. 23, 1948 R. H. ROUGHSEDGE ET AL WARP TENSION CONTROL MEANS 3 Sheets-Sheet l INVENTORS. ROBE RT H.ROUGHSEDGE 1 April 6, 954 R. H. ROUGHSEDGE ETAL 2,674,110

WARP TENSION CONTROL MEANS Filed Oct. 23, 1948 3 Sheets-Sheet 2 INVENTOR S. ROBERT H.ROUGHSEDGE HANS G. LUSTIG ATTORNEYS.

WARP TENSION CONTROL MEANS 3 Sheets-Sheet 3 Filed Oct. 23, 1948 INVENTORS. ROBERT H. ROUGHSEDGE @EQNS G. LUST 1G 1 I 4 A O Patented Apr. 6, i954 WARP TENSION CONTROL MEANS Robert H. Roughsedge, Ramsey, N. J., and Hans G. Lustig, New York, N. Y., assignors to Celanese Corporation of America, a corporation of Delaware Application October 23, 1948, Serial No. 56,172

13 Claims. (01'. 66-146) This invention relates to textile apparatus, and relates more particularly to warp tension control means and to warp-knitting machines in connection with which said warp tension control means are employed.

In the usual method of producing warp-knitted fabrics, that is, fabrics in which a number of warp threads are knitted together in each course; a number of warp threads are drawn from any suitable source of supply such as a warp beam or a number of sectional warp beams and are passed over a warp tension control means on their way to a knitting station. The tension control means generally comprises a movable tension bar, over which the warp threads are trained, carried by one or more pivotally mounted arms. The tension bar is spring-loaded and as the tension on the warp threads increases the tension bar moves in one direction stressing the loading springs, and as the tension on the warp threads decreases the tension bar moves in the opposite direction under the urging of the same springs. The movement of the tension bar is used to control the rate of let-off of the warp threads from the warp beam or beams, thereby insuring that the warp tension will not vary beyond a predetermined range.

In prior warp-knitting machines, helical springs were employed in compression to load the tension bar and it was found that the warp tension varied excessively when the speed of the warp-knitting machines was increased beyond a certain point, thus not only producing a defective fabric but also causing rapid wear of the machine parts. The excessive variation in warp tension apparently resulted from internal oscillations set up in the loading sprin s at high knitting speeds, and from the large effective inertia of springs employed in compression which made it difficult for said springs to ad ust themselves to a rapidly varyin warp tension. This limited the speed of the warp-knitting machines to a maximum of about 400 to 500 courses per minute.

It is an important object of this invention to overcome the foregoing and other disadvantages of the warp-knitting machines hitherto employed, and to provide a warp-knitting machine capable of being operated at substantially higher knitting speeds.

A further object of this invention is to provide a warp tension control means in which the material of the loading springs absorbs the stresses applied to said springs in tensile and compressive strains.

Another object of this invention is to provide a warp tension control means in which a spring is employed in torsion to load the tension bar. I

Other objects of this invention, together with certain details of construction and combinations of parts, will be apparent from the following detailed description and claims.

Our invention comprises a warp tension-control means in which the loading springs are em ployed in torsion rather than in compression as has hitherto been customary. We have found that a warp-knitting machine incorporating this novel warp tension control means may'be op-' erated at substantially higher knitting speeds ranging from 600 to '700 or more courses per minute without excessive variation in the warp" tension. Even at these higher knitting'speeds; loading springs employed in torsion show no' tendency to develop internal oscillations and ex{ hibit a lower effective inertia as compared with springs employed in compression. As a result, loading springs employed in torsion can accommodate themselves readily to rapidly varying warp tension.

Springs employed in torsion and springs employed in compression differ from each other in A tain improved results by employing the loading springs in other arrangements wherein the material in said loading springs absorbs the 'ap-" plied stresses in tensile and compressive rather than in torsional strains.

The number and the specific design of the load ing springs will depend in lar e part on the lay out of the warp tension control means and of the warp-knitting machine in which it is employed. However, in a warp tension control means having'auxiliary loading sprin s between and in addition to the main loading springs adjacent the ends of the tension bar, it has been found that the best results are obtained when the auxiliary loading springs are employed in symmetrically positioned pairs, and each of said auxiliary loading springs has only one-half the stiffness of the main loading springs. in addition, if helically wound loading springs are employed, it is preferred that all of the loading springs be positioned in the warp tension con-' trol means so that their direction of winding alternates. While other arrangements with loading springs employed in torsion will give results superior to those obtainable with loading springs employed in compression, this particular arrangement permits the highest knitting speeds to be attained without an excessive variation in warp tension.

Various expedients may be employed to produce auxiliary loading springs having one-half the stiffness of the main loading springs. For example, a spring wire of larger diameter maybe employed in the main loading springs, or the auxiliary loading springs may have twice as many turns as the main loading springs-when a spring wire of the same diameter is. employed.

Means may be provided in the warp tension control means of this invention to vary the loading on the tension bar by altering the stresses applied to the loading springs. This permits of the adjustment of the. warp tension for different types' and weights ofwarp threads, for different fabric constructions, or for any other purpose.

The motion of the-tension bar which results from ,the'variations in warp tension may be-employedto control therate at which the-warp threads are let oil from the'warp beam or-beams; For example; themotion'ofthe tension bar may control a. positive let off of the. type shown in theFuhr-eretal. U. S. Patent No. 2,486,525, issued November-.1, 1949, to produce-a warp-knitting. machine capable of operating at the highest knitting speeds. The motion of the tension bar mayalsocontrol other types of apparatus for regulating; therate-at which the warp threads 811871813" off from the warp beam or beams such as brakesoperatingv onthe warp beam or beams, clutches through-which saidiwarp'beam or beams are driven;- etc. in a manner well understood in the-art.-

Ihe warp tension: control means of this in.- vention is particularly adapted for use withwarpknitting machines: ofall typesand-will be described in connection therewith. Ittmay, however, alsoibe used with other typesof textile apparatusrin which-it is necessary to control thewarp tension, such as slashers, for example. With such other types of-apparatus the motion of the tension: bar may control the rate at which the warp-threads-are taken up aswell as the rate at, which they are let off the warp-beam or beams.

A- preferred embodiment of our. invention is illustrated in the accompanying drawings, .in which;

Fig; 1* is a front. elevational view, partly in section of-awarptension control means embodying; this invention 1011: one .bar of. .atwo-bar warp-knitting machine;, with the other bar omitted'intheinterest ofclarity,

Fig; 2 is-a view, partly-in section, taken on line 2,-.-2of Fig. 1 in, thev direction ofthe arrows, with .certainparts omitted in the interest of clarity,

Eig.,3; is a:v-iew, partly-insection, taken generally on. line 3r 3=of Fig.1 1 in the direction of the. arrows, with certain-parts omitted in the interest=ofclarity, and.

Fig. 4 isyadetail. view,,part1y in section and on, an'enlarged scale, taken on line 4-4 of Fig.- 3 imthe-direction of the arrows.-

Like reference numerals indicate like parts throughout vthe several views of the drawings.

Referring nowr-to .thedrawings-for a detailed description of, our invention there is shown a portion-era two-bar-warp-knitting machine-comous machine elements.

prising a right-end main frame member H and an auxiliary frame member l2. In addition to the frame members H and i2, the warp-knitting machine will have a left-end main frame member and as many additional auxiliary frame members as are needed to support the various machine elements adequately. The left-end main frame member and the additional auxiliary frame members have been omitted from the drawings in the interest of clarity since they are identical in structure to the frame members H and 12, respectively. It is to be understood that the auxiliary frame members may be completely dispensed with when the warp-knitting machine is narrow enough so that the main frame members can provide adequate support for the vari- In Fig. 1 of the drawings, one of the two warp tension control means which are needed in a two-bar warp-knitting machine has been omitted since both are of identical structure.

The warp tension control means comprises a shaft l3 extending through openings M and 16 in' bosses Hand Win the frame members H and [2, respectively. At its-right end the shaft 13. is journa-lled' for free rotation in ball bearings I 9 and2l which are separated fromeach other by means of an annular spacer 22. The ball bearing I9 is retained in position by means of an annular disk 23 which is-fastened'to the. frame member H with screws 24 engaging threaded apertures 25 in the boss IT. The disk 23 is provided with a centrally-located aperture 21 through which the shaft 13 extends. An' annular disk 28011 the other side of the frame member I I retains the ball bearing 2! in position, and like the disk 23 is provided. with a centrally'located aperture 29 through which the shaft l3 extends. The disk 28. is also provided with an integral circular bearing ring 3| extending into the opening' 1:4, which bearing ring permits the disk 28 to be rotated without seizing or binding the shaft l3. The disk 28 is retained'in position by means of sleeves 32 which abut the boss I! at one end and which are provided with enlarged collars 33 spaced from said boss at their other end. The spacing between theboss i1 and the collars 33 somewhat greater than the thickness of the disk28; permitting the disk to rotate freely about an axis extending in the direction of the shaft [3. The sleeves 32 are fastened to the boss [1 bymeans of bolts 34 extending therethrough and engaging threadedapertures 36 in said boss.

At thev auxiliary frame member 12, the shaft 13. is journalled for free rotation in a ball bearing 3.1 which is'seatedin the opening. Hi; The ball. bearing 31 is retained in position by means of two identical annular disks 38' which are disposed: on each side of the auxiliary frame memher [2. Eachofthe disks 38 is provided with a centrally located aperture39' through which the shaft" l3" extends and, like the disk 28, is also provided with an integralcircular bearing ring 4| extending into the opening [6. The di'sks'38' are -heldin'positionby-means of sleeves 42 which are fastened to the boss I8 with bolts 43 that extend through said sleeves and engage threaded aper tures Minsaid' boss. Each of thesleeves 42 abuts the boss l8 and'is provided with'an enlarged collar 46, spaced from said boss, thespacing being somewhatgreater than thethickness of the disks 38 .to permit said disks to rotate freely'about an axis extending in the direction of the shaft i3.

A tubular tension bar 41 over which warp threads 48 are trained is positioned in front of 5. and parallel to the shaft I3. At its right end the tension bar extends through a sleeve 49 which is integral with one end of main pivot arm The other end of the pivot arm 5| encircles the shaft I3 being fastened thereto by means of set screws 52. Adjacent to the auxiliary frame member I2 the tension bar 41 extends through a sleeve 53 which is fastened to a pair of auxiliary pivot arms 54 positioned on each side of said auxiliary frame member. The pivot arms 54 are in turn fastened to sleeves 56 which encircle the shaft I3 and are fastened thereto by means of set screws 51. As is shown in Fig. 2, each of the pivot arms 54 is cut away at 58 to clear the head of the bolts 43. The shaft I3 and the pivot arms 5| and 54 rotate as a unit during operation permitting the tension bar 41 to move under the influence of changing warp tension.

The tension bar 41 is spring loaded by means of a main helical loading spring 59 positioned adjacent to the main pivot arm 5|, and auxiliary helical loading springs 6| and 62 positioned adjacent to the auxiliary pivot arms 54. Each of the auxiliary loading springs 6| and 62 has sixteen turns, whereas the main loading spring 59 has only eight turns so that the auxiliary loading springs 6| and 62 have only one-half the stiffness of the main loading spring 59. The exact number of turns in the loading springs will depend upon the properties of the material making up the springs and the design of the warp tension control means and the warp-knitting machine in which said springs are employed. In all cases, however, each of the auxiliary loading springs 6| and 62 should have only one-half the stiffness of the main loading spring 59. Both the main loading spring 59 and the auxiliary loading springs 6| and 62 are preferably positioned in the warp tension control means with their windings disposed in alternately opposite directions. Thus, the auxiliary loading spring 8| has its winding disposed in a direction opposite to that of the main loading spring 59, the auxiliary loading spring 62 has its winding disposed in a direction opposite to that of auxiliary loading spring 6|, and so forth'to the left-end main loading spring (not shown).

The main loading spring 59 is supported on an oil-impregnated bushing 63 provided with shoulders 64, which bushing is mounted concentrically of the shaft I3. During operation, the bushing 63 provides a film of lubricant over the surface of the main loading spring 59 to reduce the frictional forces thereon. One end 66 of the main loading spring 59 is looped around a sleeve 61 which is provided with a collar 68 that is cut away at 69 to clear said spring. The sleeve 61 is fastened by means of a bolt 1| extending therethrough to a lug 12 integral with a ring 13 which encircles the shaft I3 and is fastened thereto with a set screw 14. The other end 16 of the main loading spring 59 is looped around a sleeve 11 (Fig. 4) provided with a shoulder 18 that is cut away at 19 to clear said spring. The sleeve 11 is fastened by means of a bolt 8| extending therethrough to a strap 82 which is in turn welded to the ring 28. Both the main loading spring 59 and the bushing 83 are omitted from Figs. 3 and 4 of the drawings in the interest of clarity.

The main loading spring 59 may be adjusted for a wide range of operating conditions by means of an adjusting assembly indicated generally by reference numeral 83. The adjusting assembly 83 comprises" a'socket 84 fastened to the frame member II in any desired manner, in which socket 84, a rod, indicated generally by reference numeral 86, is secured by means of a bolt 81. The rod 86 has a straight section 88 connected to a;threaded section 89 of larger diameter by means of a tapered intermediate section 9|. A sleeve 92 fits loosely over the rod 86 and has adjacent to its lower end a shoulder 93 which bears against the strap 82. Adjusting nuts 94 and 96 in engagement with the threaded section 89 of the rod 86 abut against the sleeve 92 permitting said sleeve to be forced downwardly by rotation of said nuts. This in turn forces the strap 82 downwardly rotating the disk 28 and varying the torsion in the main loading spring 59.

The auxiliary loading springs 6| and 62 are supported on oil-impregnated bushings 91 provided with shoulders 98 which are mounted concentrically of the shaft I3. Like the bushing 63, the bushings 91 provide a film of lubricant over the surfaces of the auxiliary loading springs 6| and 62 to reduce the frictional forces thereon during operation. Ends 99 and I9I of the auxiliary loading springs 6| and 62, respectively, are looped around sleeves I82 which are provided with shoulders I83 that are cut away at I84 to clear said springs. The sleeves I92 are fastened by means of bolts I96 extending therethrough to lugs I91 integral with rings I88 which encircle the shaft I3 and are fastened thereto with set screws I89. The other ends III and H2 of the auxiliary loading springs 6| and 62, respectively, are looped around sleeves II3 (Fig. 2)

* provided with shoulders II4 that are cut away at 6 to clear said springs. The sleeves I I3 are fastened by means of bolts 1 extending therethrough to straps II8 which are secured as by welding to the disks 38 on each side of the auxiliary frame member I2. The straps II8 are fastened together to rotate as a unit by means of an end strap II 9 and bolts I2I. The auxiliary loading springs 6| and 62 and the bushings 91 are omitted from Figure 2 of the drawings in the interest of clarity.

The auxiliary loading springs 6| and 62 may be simultaneously adjusted for a wide range of operating conditions by means of an adjusting assembly, indicated generally by reference numeral I22. The adjusting assembly I22 comprises a socket I23 integral with the auxiliary frame member I 2, in which socket a rod, indicated generally by reference numeral I24, is fastened by means of a bolt I26. The rod I24 is similar in construction to the rod 86 having a straight section I21, a tapered intermediate section I28, and a threaded section I 29 of larger diameter than the straight section I21. A sleeve |3I fits loosely over the rod I 24 and is provided with a shoulder I32 adjacent to its lower end which bears against the straps II8. Adjusting nuts I33 and I34 in engagement with the threaded section I29 of the rod I24 abut the sleeve IBI permitting said sleeve to be. forced downwardly rotating the disks 38 and simultaneously varying the torsion in both of the auxiliary loading springs 6| and 62.

During operation, the Warp threads 48 are trained over the tension bar 41 on their way from the warp beam or beams to the knitting station. As the tension on the warp threads 48 increases the tension bar 41 will be forced downwardly rotating the shaft I3 in one direction and stressing the loading springs 59, 69 and 6| in torsion. Conversely, as the tension on the warp threads 48 decreases the shaft l3- will be rotated-fin the-"oppo= site direction'un'der the urging of the stressed loading springs 59, 61 and 62th'ereby raising the tension bar- 41. The rotation of the shaft l3 and/or'the motion of the tension bar'fl may, as pointed out above, be employed to control the let off of the war threads 48 from the warp beam or beams. The spring loading upon the tension bar GI may be readily varied by means of the adjusting nuts 94, 9B, 33 and 134 for different types of warp threads 48, for different fabric constructions, or forany other purpose.

It is to be understood that the foregoing detailed descriptionis given merely by way of illustration and that many variations may be made therein without departing from" the spirit of our invention.

Having described our invention, what we desire to secure'by Letters Patent is:

1. In a warp tension control means, a movable tension bar" over which the warp threads are trained, main spring loading means operatively connected to said tension bar" adjacent the ends of said tension bar, and auxiliaryspring' loading means operatively connected-to said tension bar intermediate saidmain" spring loading means, each of said main spring loading means comprisi'ng a single-loading spring, and each of 'said auxiliary spring loadingmeans comprising a pair of loading springs;

2. Inawarp' tension control means, a movable tension bar over which the warp threads are trained, spring loading means absorbing the stresses appliedthereto in tensile and compressive strains operatively connected to said ten sion bar adjacent the ends of said tension bar; and auxiliary spring loading means absorbing the stresses a pued thereto in tensile and compressive strains ope'ratively connectedto said tension bar intermediate said main spring loading means, each of said main spring" loading means comprisin a single-loading spring; and each of said auxiliary spring loading means" comprising a pair of loading springs.

3. In a warp tension control'means, a movable tension bar over which the warp threads are trained, and a plurality of spring loading means absorbing the stresses applied thereto in tensile and coinpressives'trains; saidspring-means having one end fixed and theother end operatively connected to said tension bar, the springs in said spring loading means having windings disposed in alternately opposite directions.

4; In a warptension control means, a movable tension bar over which the warp threads are trained, main spring loading means employed in torsion operatively connected to said tension bar adjacent the'ends of said tension bar, and auxili ary spring loading means employed in torsion operatively connected to said tension bar-intermediate said main spring loading means, each of said main spring loading means comprising a single-loading spring, each of said auxiliary spring loading means comprising a pair of loading springs and all of said loading springs having windingsdisposed in alternately opposite directions.

5. In a warp tension control means, a movable tensionbar over which the warp threads are trained, main spring loading means operatively connected to-saidtension bar adjacent the ends of said tension bar, and auxiliary spring loading means operatively connected to said tension bar intermediate said main spring loading means,

each ofsaidmain spring loading meanscompris- 8., ing a'- single" loading spring, each of said auxiliary spring loading means comprisinga pair of loadirig springs, and each of the loading springs in said auxiliary springloading means having one half the stiffness of the loading springs in said main spring loading means.

6. In a warp tension control means, a movable tension bar over which the warp threads are trained, main spring loading means absorbing the stresses applied'thereto in tensile and compressive strains operatively connected to said tension bar adjacent the ends of said tension bar, and auxiliary spring loading means absorbing the stresses applied thereto in tensile and compressive strains operatively connected to said tension bar intermediate saidmain spring loading means, each of said main springloading means compris irig a single'loading spring, each of said auxiliary spring loading means comprising a pair of loading springs, and each of the loading springs in said auxiliary springloading means having one half the stiffness of the loading springs in said main spring loading means.

7. In a warp tension control means, a tension bar over which the warp threads are trained, main arms adjacent the ends of the tension bar for pivotally'supporting the tension bar, auxiliary arms intermediate the main supporting arms for pivot'ally supporting the tension bar, a helical spring employed in torsion adjacent each of the main supporting arms for loading the tension bar, and pairs of helical springs employed in torsion positioned on each side of the auxiliary supporting arms for loading the tension bar.

8. In a warp tension control means, a pair of main frame members, auxiliary frame members intermediate saidmain frame members, a tension bar over which the warpthreads are trained, main arms adjacent the'mairi'frame' member for pivotally supporting the ends of the tension bar, auxiliary arms intermedi'ate the main supporting arms and adjacent the auxiliary frame member for pivotally supporting the tension bar, a helical spring employed in torsion adjacent each of the main supporting arms for loading the'ten sionbar, and pairs of helical springs employed in torsion positioned on each side of the auxiliary supporting arms for loading the tension bar,one ehd of each of said loadingsprings being operatively fastened to the supporting arm adjacent thereto, an'dthe other end of each of said load' ing' springs being adjustably fastened to the frame member adjacent thereto.

9. In a warp tensicncontrol means, a pairof main frame members, auxiliary frame members intermediate'said main frame members, a rotatable shaft mounted between said frame members, a tubular tension bar over which the warp threads are trained positioned in-front of and parallel to said shaft, main arms fastened to said shaft adjacent the main-frame members for pivotally supportingthe tension bar, auxiliary arms fastened to said shaft on each side of the auxiliary'frame members for pivotally supporting'the tension bar, a helical spring employed in torsion encircling the shaft adjacent each of the main frame membersfor loading said tension bar, said springhaving one'end fastened to said shaftand the other end adjustably fastened to the main frame member adjacent thereto, pairs of helical springs employed in torsion encircling the shaft on each side'of th'e auxiliary frame members for loading said tension bar, said springs having one end fastened to said shaft and theother end ad-' justablyfastened to the auxiliary'frame member,

each of the loading springs adjacent said auxiliary frame members having twice as many turns as the loadin springs positioned adjacent the main frame member, all of the loading springs having their windings disposed in alternately opposite directions, and oil-impregnated bushings mounted on said shaft internally of each of the loading springs for lubricating the loading springs.

10. In a warp tension control means, a movable tension bar over which the warp threads are trained, main spring loading mean operatively connected to said tension bar, and auxiliary spring loading means operatively connected to said tension bar, each of said main spring load ing means comprising a single loading spring, and each of said auxiliary spring loading means comprising a pair of loading springs.

11. In a warp tension control means, a rotatable shaft, spaced arms mounted on said shaft, a tension bar over which the warp threads are trained carried by said arms, and a helical spring encircling said shaft having one end fixed and the other end operatively connected to said shaft for loading said tension bar whereby the motion of the tension bar will ap ly a torsional stress to said spring.

12. In a warp tension control means, a rotatable shaft, supporting means fixed to said shaft, a tension bar over which the Warp threads are trained carried by said supporting means, a helical spring encircling said shaft having one end operatively connected to said shaft for loading said tension bar whereby the motion of the tension bar will apply a torsional stress to said spring, a. member engagin the other end of said spring and screw means for moving said memoer for adjusting the loading of the tension bar.

13. In a warp tension control means, a rotatable shaft, supporting means fixed to said a a tension bar over which the warp threads are trained carried by said supporting means, a plurality of helical springs encircling said shaft and having their windings disposed in alternately opposite directions, each helical spring having one end fixed and the other end operatively comiected to said shaft for loading said tension bar whereby the motion of the tension bar will apply a torsional stress to said springs, and screw means for shifting the relative position of the ends of the spring for adjusting the loading of the tension bar.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 410,505 Eck Sept. 3, 1889 671,534 Bartlett Apr. 9, 1901 745,240 Rolland Nov. 24, 1903 745,449 Mayo Dec. 1, 1903 1,790,201 Davis Jan. 27, 1931 2,308,430 Bolden Jan. 12, 1943 2,327,747 Sirmay Aug. 24, 1943 2,448,035 Lambach Aug. 31, 1948

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