US2690628A

US2690628A - Glass fiber drawing mechanism with means for accentuating strand discharge

Info

Publication number: US2690628A
Application number: US225883A
Authority: US
Inventors: Joseph F Courtney; Adelbert C Radtke
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1951-05-11
Filing date: 1951-05-11
Publication date: 1954-10-05
Anticipated expiration: 1971-10-05

Description

Oct. 5, 1954 J. F. COURTNEY ETAL ,6 GLASS FIBER DRAWING MECHANISM WITH MEANS FOR ACCENTUATING STRAND DISCHARGE Filed May 11, 1951 5 Sheets-Sheet 1 Pa be 0 W 5327/7 1 Uct. 5, 1954 J, COURTNEY ET AL 2,690,628

GLASS FIBER DRAWING MECHANISM WITH MEANS FOR ACCENTUATING STRAND DISCHARGE Filed May 11, 1951 3 Sheets-Sheet 2 Oct. 5, 1954 Filed May 11-, 1951 J. F. COURTNEY ET AL GLASS FIBER DRAWING MECHANISM WITH MEANS FOR ACCENTUATING STRAND DISCHARGE 3 Sheets-Sheet 3 Patented Oct. 5, 1954 UNITED STATES PATENT GLAS S FIBER DRAWING MECHANISM- W ITH. MEAN SFOR ACCENTUATING STRAND DIS-- CHARGE Joseph" F. Courtney; Evanston, and- Adelb'ert 'G.

Radtke, Chicago, 111., assign'orstoInternational: Harvester: Company, a corporation of New.

Jersey Application May-11, 1951, Serial ,No. 225,883

7 Claims;

This invention relates to'a novel apparatus for.

attenuating a thermoplastic material and has specific reference to the manufacture of glassfibers in the making of glass strands and the'like. Elemental glass fibers are characterized by low tensile strength, susceptibility to abrasion and fracture and extreme fragility and brittleness.

Due to this nature of the material and the-high speed for drawing the materialinto fiber form, extreme difficulty has beenexperienced-in pro viding a satisfactory drawing mechanism which will afford a positive grasp on the strand with? out deformation and provide a sustained substantially even pullon the strand to obtain ap-- proximately uniform characteristics with regard to flexibility, diameter, texture, etc. throughout its length.

A generalobject of the invention is to-devisea novel drawing mechanism which obtains a gentle grasp on a substantial length of astranol and eifects an approximately uniformpull on the strand without imposing high transverse stresses thereon.

A further object is to obtainanarrangementwhich provides a grasp on the strand-by continuously moving opposed endlesssurfaces-moving about predetermined axes in such manneras to utilize the centrifugal forces thereon tobias the surfaces towards each other and produce a grasping efiect onthe strand;

A more specific object is to provide a drawing device presenting opposed continuous surfaces receiving an extensive length of the strand there-- between, at least one of these surfaces beingdirectly actuated andat least' one-of these'sura faces being yieldably urged. against the strand: by impressing a centrifugal and/or. other force thereagainst.

In several arrangements, a pluralityof opposed belts are employed and arranged toutilize the centrifugal force to grasp the strand andinseveral of these embodiments the grasping action is accentuated by causing the strand andbeltsto move at their graspingareasalong a curved or sinuous path.

A more specific further. object is toprovide sucha strand attenuating device withnovel means for accentuating discharge of the strand from the device.

These and other objects of the invention will become more apparent from the specification-and drawings wherein:

Figure 1 is a side elevational view of one embodiment of the invention.

Figure 2 is a side elevational view of a still.

further embodiment of the invention.

Figures 3to 5 illustrat -another modifications Figure 3 iscomparable to Figures hand- 2; Figure dis a radial'sectionai viewon-the 1ine-5 5 of-' Figure- 3; and Figure 5-.is-a. f1'agmentary edge' view thereof.

Figures 6 and '7 illustrate-a still further em'-- 4 assembly against a=side of sheave M through=a- V-groove Id therein, the filaments discharging from the gathering sheave incompacted' form and'forming thestrand 8 The strand l8- isthen' pulled downwardly and a direction-to-' wards the sheave and then passed through' the' rotating drawing" mechanismgenerally indicated" lfi'if, said -mechanism including-anendless drive" belt- 02 and an" idler: belt l W4, disposed in a 1 substantially vertical plane;

The drive belt W2 is looped undera pulley which isdriven through a:sha-ftLI98 by-a motor 1 I'Q'L The-supper extremityof the: belt-"is trained over a: pulley I I-2." Similarly, the: idler belt: Isa-11s looped over a pulley: l li 'and -unden" The axes of 'rotatio'rrof allof these pulleys are substantially: parallel and pref a pulley H erably horizont'al; The-belts I02 and lll l 'are" arranged in: the form: of ovals and disposed' witli l i the advance" flights- I I8 and im respectively alongside each otherand with the outer sur-- faces thereof in J facing relationship for receiving the strand thereb'etween, said strand being' guided to the drawingmeans bys a centering'fork 122 or grooved idlerr guide sheave; rotation-of the pulleys lfi fi and! l iii are prefer ably fixed'sandrtheaxes ofrotation' I M- and: I25 ofthe. pulleys H2 and; H4: areadjustable- As shown in-Figure-Z a pulley or roller l28bearsx "againstthe backside of flight i IBzand is journaied'l as at 132 on a. substantially horizontal axis-(tow the IOWBl'iEIldOf an armliitw'hichnis pivoted on a preferably fixed horizontalzaxis iSBwintermedi-s ate the ends: thereof.- The arm: lt lz rot'atably supports at its upper. endon a=substantial1y hori- I zontal axis asat I38 aroller-lflfinvhich isenzgaged w-iththe-backside of. the: advance: flight:

1290f the belt M4.- The rollers I28 land ll-l0 are biased contra-directionally? with respect-to the; vertical plane passingtherebetween in'zorder;

The axes: of

to deflect the advance fiights from normally vertical lines to a sinuous or curved path whereby the strand between the advance flights and the grasping lengths of the belts are caused to move or sinuate along a gentle sinuous or curved route. This arrangement permits the application of light transverse clasping or grasping pressure against the strand along an extended length thereof and at the same time affords an efficient frictional engagement between the strand and the belts which is amplified by the wedging tendency between the belts and strand such that sufficient force is applied along a continuous length to provide for effective drawing of the strand. It will be noted that the belts rotate in the direction of the arrows.

The arm or lever 34 is biased in a direction urging the rollers 128 and I30 against the respective flights by means of a tension spring I40 which at one end is hooked as at I22 to the arm I34 intermediate points I32 and I35 and at the other end is fixed as at I44 to the right of lever I 34. The pulleys and rollers are disposed far enough apart to admit a workmans hand between flights [I8 and I25 without inury.

It will be understood that all of the strand which discharges from the drawing means H prior to the attainment of desired drawing rate is preferably discarded and that when a strand is of correct dimension, it is passed through the blower 46 as in our companion application for Glass Fiber Drawing Mechanism and Process, Serial No. 221,596, filed April 18, 1951, said blower being supported immediately below the discharge of the drawing means and depositing the strand I8 into the canaster 58. The blower d6 pulls at the strand IS in excess of the discharge rate of the drawing means but with slipping eifect so as not to break the strand. In addition, the rotation of the belts develops centrifugal forces which tend to throw the advance flights of these belts towards each other whereby producing a gentle grasping eifect along an extensive length of a strand. Static electricity dischargers I39 may be provided.

Referring now to Figure 2 the drawing means generally designated 200 comprises an entry zone 202 between the upper ends of advance flights or sections 204 and 206 of belts 208 and 2H) which on their outer or opposed sides are arranged in contact with a vertical length of strand I8 which adjacent to the entry zone is guided by a centering fork 2I2, the lower end of the strand discharging below the belts through the nozzle 45 which is applied to the strand after it attains a predetermined size as in all of the previous embodiments. The belt 263 is looped over a pulley 2M and passes under a pulley 2I6. Similarly, the belt 2I0 is trained over a pulley 2I8 and looped under a pulley 220. The belts and pulleys are disposed in a common generally vertical plane. The pulleys are rotatable on substantially parallel preferably horizontal axes and the pulleys 2I8 and 220 are preferably vertically offset with respect to the pulleys 2M and ME and arranged in partially vertical overlap therewith so as to produce a curved or sinuous path to which the strand is caused to conform as it travels along the belts. This arrangement effects a gentle gripping action on the strand which is augmented by centrifugal force tending to throw the belts toward each other at their leading lengths. To make this action more aggressive especially at the entry zone both belts are driven through pulleys 222 and 224 and connected to pulleys 2M and 2I8 respectively. The pulleys 222 and 224 are driven by a belt 226 which is trained on a pulley 228 driven by a motor 230, said belt 228 having its upper flight passing over the top of an idler pulley 232 and then continuing around the far side of pulley 222 and continuing into the lower flight 234 of the belt which passes over the pulley 224 and then joins around the far side of pulley 228 with the other end of top flight 23B of the belt.

Referring now to Figures 3 through 5, the strand 3% may be guided within a transaxially diagonal groove 302 in the periphery of a guide wheel 304 rotatably mounted as at 306.

The strand is directed downwardly to an entry zone 383 of a drawing mechanism generally designated 310.

The mechanism 310 comprises four intercallated pulleys or wheels 3I2, 3M, 3I5 and 3I8. A flat belt 320 is trained around the peripheries of pulleys BIZ and 3H; and another flat belt 322 is trained about pulleys 3M and 3I8. Due to the arrangement of the pulleys, the advance flights 324 and 326 of

belts

320 and 322 are caused to substantially assume the form of a sinusoidal curve to afford a grasping zone for engaging the strand 300 entered at one or upstream end of the mechanism between the belts at the entry zone at the pulleys 3I6 and 3H], and discharging at the other downstream end at the discharge zone 323 from between the segments of the belts on pulleys M2 and 3M. It will be observed that the strand 3651 which may be a composite of several strands is thus sinuated through the drawing means and grasped along an extensive length thereof. The present design, as heretofore stated, utilizes preferably flat belts. In order to retain these belts on the pulleys 3H5 and 358, the outer peripheries of these pulleys are crowned convexly outwardly, however, the crest of the crown is formed cylindrical about the axis to provide a width coextensive with the lateral extent of groove 392 in the guide sheave, the groove shifting the strand laterally across the belts to prevent the development of a single track depression in the belts. It will be understood that the axes of rotation of pulleys 3l2 and 3H! are preferably mounted on tensioned adjustable axes and the pulleys 3M and 316 on fixed axes.

The specific feature of this design is to pass the strand through a surface area of substantially maximum curvature and is especially desirable for drawing several strands simultaneously which requires maximum grasping and pulling eifort.

Each pulley is preferably designed to have a peripheral extent of about one foot in length and to be rotated at the peripheral speed of approximately 10,000 feet per minute. Thus intense centrifugal force is developed to bias the advance flights of the belts toward each other to accentuate the grasp on the strand. In addition, the tremendous speed of the pulleys tends to discharge the strand tangentially to the peripheries of the segments of the belts trained about pulleys 3 I2 and. 3M.

The stripping means in the present embodiment comprises a series of alternating flat areas or facets 33S and cylindrical segment areas 332 on the outer peripheries of pulleys 3I2 and 3M. The arrangement of these areas develops transverse oscillation of the belts at the discharge zone which serve to cast off the strand from the belts. Furthermore, the sharp change of direction of the belts from the projected path of the strand also disengages the strand therefrom so that the strand may discharge directly into container 334.

The drawing mechanism may be suitably powered from a motor 336 through a belt and sheave linkage 338 driving sheave 3.

Referring now to the modification in Figures 6 and 7, it will be seen that the general concept is the same as in the previous embodiments but provides a more compact arrangement and an intermediate grasping intensity.

The strand 600 is guided by a sheave 402 (similar to sheave 304) to shift or play transversely of the grasping width of belts 404 and 486 which are looped at their upper extremities about sheaves 408 and 610 respectively, and at their lower portions under sheaves M2 and 414.

It will be noted that all of the sheaves are of the same diameter and that the upper sheaves are spaced radially and rotate on substantially coplanar horizontal axes M6 and H 8. Similarly, the lower sheaves are spaced radially and are rotatable on axes 42c and 422 arranged in substantial horizontal alignment. The sheave 4|2 extends partially between sheaves 410 and 414 and 403 and M0. The arrangement of the sheaves deflects the advance flights 424 and 426 of the belts to form a modified S-shaped grasping zone which at its downstream end terminates at the discharge zone 428 of the mechanism.

The drawing assembly may be shielded by a member 439 which may have a slit 432 in alignment with the intake between the upper ends of the advance flights to guide the strand into the drawing mechanism when the process is first begun.

The drawing mechanism may be driven by a motor 434 connected to sheave M2.

In each of these designs the centrifugal force together with the initial tensioning adjustment grasps the strand, and the strand is drawn on a curved surface over an extensive length thereof. A gentle grasp is achieved together with the requisite frictional development to obtain the desired pull on the material without deforming the material or fracturing the same.

It will be understood that the guide wheel shown in the latter two embodiments may be substituted for the centering fork shown in the first several embodiments.

What is claimed is:

1. Apparatus for attenuating strands of material comprising a pair of belts having opposing strand-grasping sections transversely deflected to produce a flowing approximately S-shaped grasping zone terminating in a discharge end, said belts arranged to rotate about axes to develop centrifugal forces biasing the belts towards each other, and discharge accentuating means for casting of said strand loose from said belts at said discharge end of said grasping zone and comprising a sheave rotatably supporting at least one belt and provided with a non-round peripheral surface tracking said belt thereabout for oscillating the belt transversely and guiding the belt to move sharply away from the strand so as to cast loose therefrom.

2. In an apparatus for drawing glass strand, a pair of flat belt loops, a sheave disposed within each end of each loop and provided with a crowned peripheral surface in contact with the internal surface of the associated loop, said loops having corresponding lengths disposed in pressing contact with each other along complementary grasping surfaces defining an intake at one end and a discharge at the other end, and strand guide means comprising a sheave with a peripheral transaxially diagonal groove adapted to receive the strand at said intake and pursuant to rotation thereof to course the strand laterally on said belts as said strand is being drawn between said grasping surfaces, all of said sheaves mounted on parallel axes and said groove having a lateral traverse less than the Width of said belts.

3. In an apparatus for drawing glass strand a pair of belt loops, rotatable support means disposed within each end of each loop in contact with the internal side of the associated loop, said loops having corresponding lengths disposed in pressing contact with each other along complementary grasping surfaces providing an intake at one end and a discharge at the opposite end, and vibrating means operatively associated with at least one of said loops for oscillating the same sharply transversely at said discharge for stripping the strand therefrom.

4. Apparatus according to claim 3 and said vibrating means comprising a nonround face on the rotatable support means associated with said one loop at said discharge, said rotatable support means movable at a substantial speed suflicient to obtain a rapid oscillatory effect on the belt loop.

5. Apparatus according to claim 4 and said nonround face comprising a series of flats and intervening crowned surfaces continuous between adjacent flats disposed about the periphery of said rotatable support means.

6. Apparatus according to claim 5 and driving means directly connected to said rotatable support means comprising said nonround face to accentuate oscillation thereby of the related belt loop.

7. A glass fiber drawing apparatus comprising two flat belt loops each passing about a wheel at each end, said loops engaging each other at a determined region and having an intake at one end and a discharge at the other, said wheels rotatable on generally horizontal axes, each wheel comprising a cylindrical periphery crowned at its axial extremes to retain the belt thereon, and only noncylindrical spots on the cylindrical periphery of the wheels at said discharge of said region.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 109,430 Leavitt Nov. 22, 1870 461,855 Thompson Oct. 2'7, 1891 1,092,631 C'asablancas Apr. 7, 1914 1,443,514 Williams Jan. 30, 1923 2,067,251 Taylor Jan. 12, 1937 2,239,863 Schlipp Apr. 29, 1941 2,335,135 Staelin Nov. 23, 1943 2,348,182 Slayter May 2, 1944 2,418,873 Fletcher et a1 Apr. 15, 1947 2,448,499 Swann Aug. 31, 1948 2,497,511 Neisler, Jr. Feb. 14, 1950 FOREIGN PATENTS Number Country Date 16,297 Great Britain 1898 22,127 Great Britain 1892 525,283 Great Britain Aug. 26, 1940