US3336740A

US3336740A - Low-tension strand-plying method and apparatus

Info

Publication number: US3336740A
Application number: US598578A
Authority: US
Inventors: Alfred W Vibber
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-10-31
Filing date: 1966-10-31
Publication date: 1967-08-22
Anticipated expiration: 1984-08-22

Description

g- 7 A. w. VIBBER 3,336,740

LOW-TENSION STRAND-PL YING METHOD AND APPARATUS Filed Oct. :51, 1966 4 Sheets-Sheet l INVENTOR.

, Aug. 22, 1967 A. w VIBBER 3,336,740

LOW TENSION STRANDPLYING METHOD AND APPARATUS Filed Oct. 31, 1966 4 Sheets-Sheet 2 is Q IN VENTOR.

, WMJJ Aug. 22, 1967 A. w. VIB BER 3,336,740

LOWTENSION STRAND-FLYING METHOD AND APPARATUS Filed Oct. 31, 1966 4 Sheets-Sheet 3 I a 6 c a; 1 I m a) 1 jf United States Patent 3,336,740 LOW-TENSION STRAND-FLYING METHOD AND APPARATUS Alfred W. Vibber, 560 Riverside Drive, New York, N.Y. 10020 Filed Oct. 31, 1966, Ser. No. 598,578 21 Claims. (Cl. 5758.86)

ABSTRACT OF THE DISCLOSURE A novel cord forming spindle of the skip-plying type, and a system having a plurality of such spindles and taking up the cords directly from such spindles on a common beam. In the spindle of the invention a first, outer singles strand is rotated in the form of a loop or balloon about a source of a second, inner singles strand. The spindle incorporates a feeding means which engages the first strand as it rotates in the loop or balloon and feeds it at substantially constant speed toward the point at which the two singles strands are plied together. The second, inner strand is fed under substantially constant tension to the plying point. The plied strand or cord is pulled away from the plying point under tension. The feeding means for the first, outer singles strand isolates loop or balloon tension from the plying point, permitting the plying to be carried out at a desirably low tension, and permitting the cords thus formed by a plurality of such spindles to be taken up, if desired, directly from the spindles by a driven common take-up beam.

This application is a continuation-in-part of application Ser. No. 531,914, filed Mar. 4, 1966, and of application Ser. No. 584,288, filed Aug. 15, 1966, both now abandoned.

This invention relates to a method of and an apparatus for twisting and/ or plying strands, and particularly relates to a method of and an apparatus for plying strands together by rotating a strand about a source of supply of another strand, and plying the strands together beyond such source of the other strand.

This invention relates to an improvement upon the method and apparatus disclosed and claimed in applicants prior Patent No. 3,153,893, dated Oct. 27, 1964. The present invention provides a more positive means for the control of the feeding of the outer ballooned strand to the plying point, and thus provides for the production of a two-strand cord which is particularly characterized by its symmetry of construction and thus its ability to distribute tensional forces imposed thereon equally between the two strands which form the cord.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a fragmentary view in side elevation of a first disclosed embodiment of .spindle for plying strands together to form a cord in accordance with the present invention;

FIG. 2 is a fragmentary view partially in side elevation and partially in vertical section of the balloon control means employed with the spindle of FIG. 1;

FIG. 3 is a fragmentary view on an enlarged scale of the inner constant speed capstan and of the drive therefor, such capstan feeding the outer ballooned strand toward the plying point of the spindle;

FIG. 4 is a view in side elevation of a second embodiment of plying spindle in accordance with the invention;

5 is a view in side elevation of the auxiliary flyer employed with the spindle of FIG. 4;

FIG. 6 is a view in vertical section through the auxiliary flyer employed as an element of the spindle of FIG. 4 the section being taken along the line 66 of FIG. 5;

FIG. 7 is a view in horizontal section through the auxiliary flyer, the section being taken along the broken section line 7-7 of FIG. 5;

FIG. 8 is a somewhat schematic view in perspective of a novel system for simultaneously winding plied yarns produced by a plurality of spindles in accordance with the invention onto a multiple end beam;

FIG. 9 is an end view of the plied yarn take-up of the system of FIG. 8;

FIG. 10 is a plan view of the plied yarn take-up of FIG. 8;

FIG. 11 is a schematic view in side elevation of one of a plurality of tension devices which may be added to the beam winder of FIGS. 8, 9, and 10 to provide increased winding tensions in the cords; and

FIG. 12 is a schematic view of a ply-wrapping spindle of generally the same construction as that of the first disclosed embodiment herein, but with a constant tension take-up device for the cord substituted for the constant speed cord take-up device of the first embodiment.

As apparent from the above, three embodiments of plying spindle are shown in the accompanying drawings: The first embodiment is shown in FIGS. 1, 2, and 3, wherein the plying point X is located generally within the main flyer of the spindle and generally at a point on the axis thereof. The second embodiment is shown in FIGS. 4, 5, and 6; in such second embodiment, the plying point is a generally floating one, that is, it is free to rise and fall within limits and has appreciable freedom to center itself with respect to the axis of the rotating balloon or loop. In such first two embodiments the plied strand or cord is withdrawn at substantially constant speed under tension from the plying point. In FIG. 12 there is schematically illustrated a third embodiment of plying spindle wherein the plied strand or cord is withdrawn from the plying point under constant tension.

Turning now to the drawings, the spindle of FIGS. 1, 2, and 3 is somewhat the same as that of applicants prior Patent No. 3,153,893, above referred to, with the exception that the capstan which feds the outer ballooned strand positively toward the plying point is located on the flyer immediately adjacent the plying point rather than being located in advance of the entry of such strand into the balloon. The balloon is controlled as to size by means which has no appreciable effect upon the plying action of the two strands but merely keeps the balloon within practical controlled limits. The same reference characters are used in the spindle of FIGS. 1, 2, and 3 as in the first disclosed embodiment of spindle in Patent No. 3,153,893, with the exception of those applied to the capstan which feeds the first or outer ballooned strand to the plying point, and those applied to the means for controlling the diameter of the balloon.

Thus in FIG. 1 there is shown a spindle generally designated 10 which has a main vertical driven hollow shaft 11. Such spindle is mounted upon a frame generally designated 12 in which the shaft '11 is suitably journalled in a housing 16, such shaft being driven by means of a belt 14 entrained over a pulley 15 secured to the shaft 14, such belt being connected to a suitable driving means (not shown). Mounted upon the shaft 11 is a flyer 19 which rotates with the shaft 11, and above the flyer and held from rotation therewith with cooperating magnets 20 and 21 there is a sub-frame 17. Upon such sub-frame there is mounted a support 22 within a cage 23, the support 22 carrying an inner package 24 which supplies an inner strand b to the plying point X. Such inner strand b is fed from the package 24 downwardly to an idle tensioning means generally designated 26, which may be the same as that similarly designated in applicants prior Patent No. 3,153,893. The tensioning device 26 includes a pair of staggered idle rollers 27 and 29 to which the strand 1; is directed by the guide roll 25. An adjustable leaf spring 30 is mounted to cooperate with the roller 29. From the tensioning device 26 strand b is delivered over a guide roll set 31 and thence to a canted roller 32 and thence downwardly into the vertical bore through the hollow shaft 11.

The outer ballooned strand a is supplied from a package 34 which is mounted upon a spindle 35, the strand progressing upwardly partially about a guide pulley 39 and thence to a further guide pulley 41 and upwardly to a pulley 42. From the pulley 42 the strand a travels to a further guide pulley 44 on an overarm 45, and thence to an apex guide device generally designated 49. Device 49 includes means whereby the speed of feeding of the strand a into the balloon is governed by balloon diameter detecting means, whereby to maintain the balloon within the balloon diameter within predetermined desired limits. From the apex guiding and balloon controlling means 49, which will be described hereinafter, the strand a issues into the balloon generally designated 50 and travels downwardly through the rotating balloon to the entrance end 51 of a generally radial passage 37 in the fiyer 19. From such entrance 51 the strand a travels generally radially inwardly to the plying point X where it meets the inner strand [2 and is plied therewith. The resulting cord c travels downwardly through the hollow shaft 11 to an idle guiding means 52 and thence upwardly to a constant speed capstan 54 which withdraws the cord c at constant speed from the plying point X. The capstan 54 includes a roller 55 which is driven in timed relation with the shaft 11 and an opposing idle pulley 56, the cord c being wrapped several times about the opposing rollers 55 and 56. In order to maintain a substantially fixed driving relationship between the capstan 54 and the cord 0, there is employed a spring biased idle roll 57 which pinches the multiple runs of the cord 0 between it and the roll 55. From the capstan 54 the cord c travels downwardly to a take-up means which is shown generally as being made up of a bobbin 59 which lies upon driven rollers 60 so as to be fricti-onally driven thereby.

The apex guide and balloon controlling device in the spindle of FIG. 1, which is shown more particularly in some of its details in FIG. 2, is generally similar to that shown in FIG. of applicants prior Patent No. 2,871,648. Such device includes an idle retarded capstan set 62 to which the outer strand a travels from the guide pulley 44. After travelling a number of times about two opposed rollers 72 and 73 making up capstan set 62, the strand a travels downwardly in a vertical run through the apex guide proper of device 49 from which it issues into the balloon 50. Rollers 72 and 73 are of the same effective diameter, and are geared to rotate in synchronism in the same direction by gears 79 on such rollers, such gears meshing with an intermediate pinion 80.

The construction of device 49, its connection to the balloon controlling bell 64, and the manner of interaction between device 49 and capstan 62 are illustrated in FIG. 2. As there shown, a hollow spindle 65 disposed coaxially of and a fixed distance from the main spindle shaft 11 is rotatably mounted on ball bearings in an upper fixed frame part fragmentarily shown at 66. Spindle 65 carries at its lower end inwardly thereof a central guiding eye or apex guide 67 for the free end of the balloon. The lower end of spindle 65 also serves as the support for bell 64. The upper end of the bell is provided with a central hole which recives the lower externally threaded end of the spindle, as shown. The bell may be integrally connected to the spindle, or may be clamped on the spindle, so as to be non-rotatable with respect thereto, by having its central upper portion gripped between an outwardly directed flange on the spindle and a nut screwed onto the spindle.

The spindle 65, and thus the bell 64, are yieldingly turned in the direction opposite from the direction of rotation of balloon 50 by a coil spring 69 disposed around a spindle 65 above frame part 66. One end of spring 69 is secured to frame part 66, and the other end is secured to a collar 70 adjustably held in a selected position around the axis of spindle 65 by a thumb screw as shown. By loosening the thumb screw and turning collar 70 around the spindle, the spring 69 may be wound to impose a desired initial torque on the spindle 65.

The upper end of spindle 65 is internally threaded. An inner sleeve portion of a brake-applying member 71 is externally threaded, and mates with the internal threads on spindle 65. The lower end of the sleeve on member 71 has an external cylindrical zone which slidingly engages the inner cylindrical surface of spindle 65 below the threads thereon, so as to aid in guiding such sleeve. The sleeve has a central axial bore which receives strand a therethrough in its passage downwardly from the lower roll of capstan 62 to the apex guide 67.

The sleeve on member 71 has integral therewith an upper outwardly directed flange which carries a downwardly directed short outer sleeve which surrounds and is spaced radially outwardly from the upper end of spindle 65. The outer surface of such short outer sleeve is vertically slidingly received in a bore in an upper fixed frame part 74, which is located spaced above frame part 66. The above described sleeves are prevented from rotation by the engagement of splines on one sleeve with grooves in the sidewall of the bore in frame part 74. The threads on spindle 65 and on the sleeve which is threaded thereinto are made of such hand that spindle 65 is turned in the direction of rotation of the balloon 50 by engagement of the rim 75 of bell '64 by the balloon, the member 71 rises, and when spring 69 turns the spindle 65 in the reverse direction the member 71 descends. Descent of member 71 is stopped by engagement of an adjustable stop stud 76 threaded into a radial arm on member 71. The lower end of stud 76 engages frame part 74 when member 71 fully descends. When the balloon 50 engages the rim 75 of bell 64 with sufiicient force to rotate the spindle 65 to raise member 71, gradually contracts as a result of the action of member 71, spring 69 turns spindle 65 in the reverse direction, causing member 71 to descend.

Member 71 carries on its upper end an upwardly open vertical walled cavity carrying a brake shoe 77 vertically reciprocable therein. The brake shoe is urged upwardly in the cavity by a relatively stiff coil compression spring acting between a shoulder on the brake shoe and the bottom of the cavity. Brake shoe 77 engages a brake drum affixed to the shaft carrying roll 72 of capstan 62. The parts of mechanism 49, including brake shoe 77, the spring backing up the brake shoe, and the brake drum are so dimensioned that in the normal operation of the spindle the strand a in the balloon 50 engages the rim 75 of the bell 64. It will he obvious that upon an increase in diameter of the balloon the brake shoe 77 will engage the brake drum more forcibly, thereby decreasing the speed of capstan 62 and causing strand a to be fed more slowly into the balloon. Thereupon the diameter of the balloon decreases so that the balloon eventually ceases to contact bell 64 so strongly, spindle 65 turns in a direction opposite the direction of rotation of the balloon, member 71 descends, and capstan 62 again resumes its predetermined desired speed to maintain the balloon with the desired diameter. It will be obvious that the reverse corrective action takes place when the balloon contracts unduly in diameter.

The means for driving the constant speed capstan which is mounted upon the fiyer of the spindle is generally similar to that shown in FIGS. 4 and 5 of applicants prior Patent No. Re. 24,483, with the exception that only one capstan roll is shown as being employed on the flyer. Thus the outer ballooned strand a in leaving the balloon 50 travels inwardly through the outer end 51 of the radial passage 37 in the flyer and thence to the capstan roll 81 which is journalled in the hub of the flyer 19 transverse to the axis thereto and spaced somewhat radially from such axis. The capstan roll 81 is driven in synchronism with the main shaft 11 of the spindle, and thus the flyer 19. The means for thus driving the capstan 81 includes a sleeve 82 which extends upwardly coaxially within the shaft 11, such sleeve being secured to the frame 12 by means of angular brackets 84 secured between the bottom of the sleeve and the frame 12. The upper end of the sleeve 82 carries a worm 85 which meshes with a Worm gear 86 journalled in the hub of the flyer, the worm gear in turn being connected to the capstan roll 81 by meshing pinions connected respectively to the worm gear 86 and capstan roll 81. It will thus be apparent that upon turning of the shaft 11 and the flyer 19 the capstan roll 81 is turned in synchronism therewith. Strand a is wrapped several times about capstan roll 81 so as to have substantially non-slipping engagement therewith. The capstan roll 81 thus feeds the outer ballooned strand a forwardly at constant speed to the plying point X of the spindle.

As above noted, the spindle and method of plying of the present invention divorce the control of the balloon and tension variations in such balloon from the action of the two strands a and b as they are being plied together to form cord c at the plying point X. Thus the cord formed by the spindle is particularly characterized by its symmetry, that is, the uniformity in the length of the two strands a and b in the cord c. This follows from the fact that the tension imposed upon the cord by the take-up capstan 54 tends to be equally divided between the two strands a and b immediately in advance of the plying point X. It should be noted at this point that the capstan 81 which forwards the strand a to the plying point is driven at a somewhat higher surface speed than that of the takeup capstan 54. Typical values in a spindle such as described would be a surface speed of 114" per unit of time for the capstan 81 and a surface speed of 100" per same unit of time for the take-up capstan 54. With such arrangement, if it were not for the feeding forward of the inner strand b to the plying point X, the capstan 77 would always deliver an excess length of the outer strand a to the take-up capstan 54. The strand b, however, supplies, in effect, an added factor which takes up the excess length of strand a delivered to the plying point by winding it about the strand a and thus absorbing it into the cord. There is thus never any question of exerting an excess tension upon the formed cord 0 or the strand a by the interaction of the take-up capstan 54 and the singles capstan 81.

As above noted, the tension in the cord 0 between the take-up capstan 54 and the plying point tends to be equally divided between the strand a and b immediately in advance of the plying point. If during operation of the spindle the tension in the outer balloon strand a should rise unduly, it tends to become the core so that less of such strand is absorbed into the cord and more of strand b is absorbed thereinto. As a result, the tension in strand a decreases and tends to equal that imposed upon the strand b by the constant tension-imposing device 26. The converse is true when the tension in strand a between capstan 77 and the plying point decreases unduly: The strand b approaching the plying point then tends to become the core, more of strand a than of strand b is absorbed into the cord, and the tensions in strands a and b approaching the plying point are rapidly equalized so that equal lengths of the two strands are absorbed into the cord.

The second embodiment of apparatus and method in accordance with the invention, which is shown in FIGS. 47, inclusive, employs an apparatus wherein the plying point floats to a substantial extent about the axis of the main shaft of the spindle and wherein the diameter and thus tension in the ballooned strand is controlled by a storage wheel. Generally the apparatus is similar to that shown in Klein Patent No. 2,811,012 with the exception that instead of positively synchronized capstans on the auxiliary flyer the one of such capstans engaging the outer, ballooned strand is positively driven but the other is idle and serves to guide the inner strand to the plying point. Such inner strand is subjected to a predetermined constant tension by a tension device associated with the supply package for the inner strand.

The spindle of the embodiment of FIGS. 4, 5, 6, and 7 is designated generally by the reference character 100. As above noted, such apparatus corresponds generally to that of Klein Patent No. 2,811,012 with the exceptions to be noted below. Such spindle has a main shaft 103 which is driven by a belt 101 generally indicated, such shaft having afiixed and rotatable therewith a flyer 102 in which there is incorporated as an integral part thereof a storage wheel 104. A first strand a fed from an outer package 105 is led past an idle constant tension imposing device 107 upwardly into the bore of the shaft 103 and thence outwardly to the outer surface of the storage wheel 104. From such storage wheel the strand a issues into a rotating loop or balloon 109, the diameter of which is controlled by the storage wheel 104 in a well-known manner.

The strand a adjacent the upper end of the balloon 109 is wrapped one or more times in non-slipping engagement about a capstan roll 110 which forms a part of an idle auxiliary flyer 111 constructed generally in accordance with that of the above noted Klein Patent No. 2,811,- 012. There is this important difierence, however, between the apparatus of the present invention and that of Klein: The opposite roll 112 of the auxiliary flyer 111 is idle and serves only to guide the inner strand b to the plying point X in a manner which is symmetrical to and opposite from that of the outer strand a. The auxiliary flyer 111 is mounted upon a hollow shaft 114 which is journalled in a housing 113 supported upon a bracket 115, as shown. As will be apparent hereinafter, during the rotation of the auxiliary flyer 111, the capstan 110 is driven in synchronism with the rotation of the balloon 109 and thus of the flyer 102 by a gear mechanism which is more particularly shown in FIGS. 5, 6, and 7. The opposite roll 112 of the auxiliary flyer 111 is idle, being driven only by the passage of the inner strand b thereover.

An inner supply package 116 is non-rotatably mounted through suitable bearings upon the main shaft 103 and the flyer 102 of the spindle, the strand b from package 116 passing through a constant tension device 117 which is non-rotatably mounted upon the spindle. From the tension device 117, the strand b passes to a guide 119 which is mounted on the upper end of the enlarged head 131 of the shaft 114 for the auxiliary flyer 111. The above-mentioned driven capstan 110 and the idle capstan 112 are rotatably mounted upon stub shafts 132 and 134, respectively, such shafts being disposed in the same vertical axial plane and projecting in opposite directions at equal shallow angles with respect to the horizontal. The rolls 110 and 112, as well as the other parts of the auxiliary flyer to be described, are so constructed and arranged that the auxiliary flyer is in dynamic balance.

As in the above Klein patent, the auxiliary flyer 111 is driven by and in timed relationship with the balloon 109. Such driving is effected by having the strand a of the balloon 109 pass through a pigtail 122 which is formed in the radially outer end of a wire arm 123 afiixed to the auxiliary flyer 111. During the-operation of the de: vice, the capstans 110 and 112 rotate as a whole with the auxiliary flyer 111 in synchronism with the shaft 103 and the flyer 102. The inner strand b is delivered to the plying point X under a constant tension imposed thereon by the tension device 117. The driven capstan 110, however, is causedto rotate at a constant linear speed which somewhat exceeds the constant linear speed of the taking up of the plied cord by mechanism to be described.

Turning to FIGS. 5, 6, and 7, the construction and manner of operation of the mechanism for rotating the capstan 110 at constant speed will be apparent. At its base the head 131 of the shaft 114 is extended forwardly (FIGS. and 7) in two laterally spaced similar L-shaped arms 135 and 136, and is extended rearwardly in a balancing portion 142. A worm 137 of shallow pitch is fixedly disposed on the housing 113 adjacent the upper end of the latter. A worn gear 139 which meshes with the worm 137 is disposed between the depending portions of the arms 135 and 136 which journal the shaft 140 upon which the worm gear 139 is mounted in suitable bearings. The shaft 140 projects laterally outwardly of the arm 135 and is provided on its outer end with a bevel spiral gear 141 which is fixedly connected thereto. The gear 141 meshes with a gear 121 which is integrally connected to the capstan 110. It will be apparent that as the auxiliary fiyer 111 rotates about its vertical axis it carries the worm gear 139 with it, the worm gear turning as it rotates about the worm 137. Such rotation is transmitted by the shaft 140 and the meshing spiral gears 141 and 121 to the capstan 110. By a suitable choice of pitch and diameters of the worm and worm gear 137 and 139, respectively, and of the diameters of the meshing spiral gears 121 and 141, the capstan 110 will rotate at such constant linear speed as to produce a cord having the required number of twists per inch.

Above the plying point X there is an apex guide in the form of a roll 124 over which the plied cord 0 passes. The plying point X, as can be seen, floats to a limited degree in that its location relative to the apex guide 124, as well as its radial distance from the axis of the balloon 109, can change as required. The apex guide 124 forms a part of a constant speed cord take-up device wherein the roll 124 is driven at constant speed, such roll cooperating wtih a large, idle roll 125 which is parallel thereto and spaced therefrom. The cord 0 after passing initialy partially around roll 124i travels in repeated laterally spaced runs 126 around rolls 125 and 124, finally being taken off in a run 127 which extends to a take-up bobbin 129. Such bobbin is dirven in a conventional manner by being mounted upon and frictionaly driven by a constant speed driving roller 130.

Many of the advantages of the present invention will be apparent from the above. However, it would be well to summarize here the novel functions of the apparatus of the invention and the improved results flowing therefrom.

(1) The constant speed singles-feeding capstan 81 of the first described embodiment and 110 of the second embodiment isolate the tension of the balloon from the plying or cording point.

(2) The portion of the outer, ballooned singles strand between capstans 81 and 110 and the respective plying or cording points is quite short in each case, and such portion lies close to the axis of rotation of such singles. Consequently the contrifugal force and the air resistance in the second embodiment operative upon such portion of the outer singles strand are small. It will be understood that such portion of the outer singles strand may be made substantially shorter than those shown in the drawings, as by locating the capstan 81 of the first embodiment closer to the axis of the spindle, or by appropriate changes in diameter of such capstan 81, and by similar changes in the roll couple, including the capstan 110 of the second embodiment.

As consequences of conditions (1) and (2), the plying of the two strands can be carried out under a low tension if desired, the tension imposed on the inner singles strand by tension means 17 in the first embodiment and the tension means 117 in the second embodiment determining the plying tension. With low tension plying the resulting cord has properties of elongation under load which are fully as good as those of cord produced by the ring twisting process. Such plying tension may be adjusted within a wide range by appropriately adjusting the tension means 17, 117. Further, because of the short length of the portion of the outer, ballooned singles strand between the capstans 81 and and the plying points in the respective embodiments, weight variations per unit length in the outer ballooned strand, as by changes in the moisture content of such strand, or even in the denier of the strand, have little effect upon the plying of the strands at the plying or cording point. Thus the apparatus and method of the invention may be employed successfully to ply even non-premium quality strands and/ or strands wherein the moisture content is not carefuly controlled.

Because of the isolation of the plying or cording point from the tension of the outer strand in the balloon, the spindle can be run faster than prior spindles. The highest speed at which the spindle can be run depends, of course, upon a number of factors, including the capacity of the bearings employed to run at sustained high speeds, the power requirements of the spindle, the maximum tension to which it is advisable to subject the outer strand in the balloon, and the length of time which is required to relax the strand from its high tension, and possibly stretched condition in the balloon to its low tension, virtually unstretched condition under which it is plied with the inner strand.

The transition from the high tension condition of the outer strand, in the balloon, to the low tension condition, under which it is combined with the inner strand at the plying point, is effected gradually in both disclosed embodiments of the apparatus. The outer strand enters upon the respective singles capstan 81, 110 from the balloon under the high tension of the balloon. During the travel of such strand through the several wraps or turns thereof about the capstan, the strand progressively creeps to a small extent upon the surface of the capstan as the strand is subjected to lower and lower tension. This is particularly true of strands made of material such as nylon which stretches appreciably under substantial tension. Thus even at high speed rotation of the spindle, and accordingly high speeds of travel of the singles strands to the plying point, there is afforded sufficient time for the outer, ballooned strand to adjust its length suitably before it reaches the plying point so that the resulting cord is of balanced construction. It is to be understood that, although the outer strand has been described as creeping upon the surface of capstan 81, 110, such effect is actually very small. Also, such creepage is virtually constant under a given set of conditions, and thus capstans 81 and 110 feed the outer ballooned strand at a constant speed, such speed being the proper one to supply the required length of such outer singles strand to the plying point.

With regard to the embodiment of the spindle of FIGS. l-3, inclusive, it is desired to point out that the balloon controlling device 49 may be replaced, if desired, by other known balloon controlling devices which maintain the balloon diameter within close limits. Also, if the space between successive spindles in a frame is not critical, the balloon controlling portion of device 49 may be replaced by a simple, constant tension-imposing means comparable to the device 107 of the second described embodiment. In this case, the balloon itself is self-compensating, the balloon expanding and contracting within limits as required to maintain the tension of the strand therein equal to that imposed by the above described constant tension-imposing device operative upon the outer singles strand prior to its entry into the balloon.

Although in both of the preferred embodiments illustrated herein and described above the plied strand or cord is pulled away from the plying point at substantially constant speed, a substantial part of the advantages of the present invention are realized when the plied strand or cord is merely fed away from the plying point under ten:

sion. Preferably, for reasons of uniformity of the plied strand, in this last embodiment the tension applied to the plied strand by the feeding means 200 therefor is uniform or constant. Such feeding means 200, for pulling the plied strand away from the plying point under tension, may, for example, be one such as that employed for the same purpose in Clarkson Patent No. 2,503,242 or Clarkson Patent No. 2,729,051, both of which subject the plied strand to a uniform tension. When the plied strand is to be symmetrical, that is, to contain substantially equal lengths of the two singles strands a and b, the tension Tc which the feeding means for the plied strand imposes on the plied strand 0 is slightly greater than twice the tension Tc imposed on the inner, non-ballooned singles strand b by the constant tension imposing means which engages it. The small amount by which tension T0 exceeds twice the tension Tc; is necessary in such case to overcome the friction in the strand system and to provide the force for pulling the plied strand from the plying point. The remainder, T0 of the constant tension T0 imposed on the plied strand is, of course, sustained by the final run 1 of the outer, ballooned singles strand which extends between the constant speed capstan, which engages and feeds such strand from its balloon or loop, and the plying point.

In FIG. 12, the outer strand a is fed into the outer end of the balloon 50 by a balloon control device 49, and is fed from the inner end of the balloon 50 by a constant speed capstan 84 on the fiyer 19, both as in the embodiment of FIGS. 1-3, inclusive. The inner strand b is engaged by a constant tension retarding device 26 also as in FIGS. 1-3, inclusive.

It will be seen that in the spindle of FIG. 12:

T0 substantially equals T0 Tc substantially equals Tc +Tc and T0 substantially equals 2Tc and substantially equals As a result, the plied strand or cord produced by the apparatus of FIG. 12 is characterized by its high degree of symmetry. As in the above two Clarkson patents, the cord is finally wound on a package 59, as in the embodiment of FIGS. 1-3, inclusive. The means for rotating and controlling the package 59 maybe that of either of such Clarkson patents; its construction is such that its operation does not disturb the constant tension with which the take-up device pulls the plied strand away from the plying point P.

It is to be understood, however, that in some instances it may not be desired that the plied strand be uniform, and/or it may not be desired that the plied strand be symmetrical as regards the lengths of the two singles strands which it contains. In such cases, (A) the tension which the feeding means for the plied strand imposes thereon need not be uniform, or may deliberately be made non-uniform, and (B) the tension imposed upon the plied strand by its feeding means need not be twice the tension imposed upon the inner, non-ballooned singles strand by the constant tension imposing means which engages it; both of conditions A and B may be present in some manners of practice of the invention. In condition B, to produce a plied strand without regard to its symmetry, the tension imposed on the plied strand by its feeding means needs only somewhat to exceed the tension imposed on the inner, non-ballooned singles strand by its constant tensioning means; the tension of the plied strand can be varied from such minimum value to and substantially above twice the tension imposed on the inner singles strand by its tensioning means. As is well known, in the making by the ply-wrapping process of a two-ply strand of two substantially identical singles strands, when one singles strand is subjected to a greater tension at the plying -or cording point than the other, the one singles strand tends to become the core and the other singles strand tends to wrap about it.

The last described embodiment of the invention, Wherein the plied strand is merely fed away from the plying point under tension (under uniform tension when a uni form plied strand is desired), has the same principal advantages as those set forth above in connection with the two embodiments illustrated herein and first described above. The constant speed capstan for feeding the outer, ballooned singles strand from the balloon or loop isolates the tension, and any variations therein, of the balloon or loop from the cording or plying point. The run of the outer singles strand from such constant speed capstan to the plying point may be made short, is located near, and at its inner end substantially on, the axis of the loop, and thus is subjected to a very small centrifugal force. The tension to which such run of the outer singles strand is subjected by reason of its own manner of travel and feeding is small. By far the predominant part of the tension to which such run of the outer singles strand is subjected comes from the tension imposed upon it by the tension in the portion of the inner singles strand approaching the plying point and the tension in the plied strand or cord leaving the plying point. As pointed out above, both such latter tensions may be made to be relatively low, with a consequent improvement in the properties of elongation under load of the plied strand.

FIGS. 8, 9 and 10 illustrate somewhat schematically a novel system for winding plied yarns or cords produced by a plurality of spindles made in accordance with the invention onto a multiple beam end. Such system, by reason of the use of spindles of the invention, permits the cords to be wound directly, and at low tension, upon the beam, without the necessity of a take-up capstan device, as is required between the spindles and the multiple end beam in prior systems of the same general type.

As shown in FIG. 8, a plurality (only six shown) of similar aligned ply-wrapping spindles, which are generally similar to that of FIG. 4 herein, feed the cords 0 formed thereby upwardly to individual guide rollers 151, and thence horizontally to a multiple end beam winding device, generally designated 152. It will be understood that in the making of fabric from the cords, as many spindles may be employed as are necessary to form the desired warp-like sheet. The take-up beam, with the warplike sheet wound thereon, is ready for use directly at a loom for forming fabric, such as tire cord fabric.

Each of the spindles 150 has a main hollow spindle shaft 214 which is rotated by a belt 215 driven by a power source (not shown). A first, outer singles strand a is fed upwardly into the lower end of shaft 214 after passing through a strand guiding and tensioning means which is not shown in FIG. 8. The strand a rises in shaft 214 to pass radially outwardly thereof through a passage 216 in the side wall of the shaft, the strand then being wrapped to a varying degree about a strand storage wheel 217. From the storage wheel the strand a passes into a balloon or rotating loop 219 which revolves about a stationary housing 220. Within the housing there is supported a strand package 221 for a second, inner singles strand b. Strand b travels upwardly from package 221 to pass through an adjustable strand tensioning device 222, which, when adjusted, imposes a predetermined constant tension on strand b as it passes therethrough.

The strand b meets the strand a at a plying point not specifically shown, which lies generally on the axis of the spindle shaft 214, such plying point lying above the location at which the rotating strand a is engaged and synchronously metered by a capstan roll 245 which is mounted on an auxiliary fiyer 224 which is rotatably mounted coaxially of the spindle shaft 214 on a suitable fixed support 225. The auxiliary fiyer 224 has a body 240 of downwardly open conical shape, as shown. The fiyer 224 is driven to rotate about its axis by, and at the same speed as, the ballon 219. The capstan roll 245 is driven to rotate about its own axis to feed the strand a to the plying point at the proper speed, in excess of the speed of withdrawal of the resulting plied strand or cord 0, by means not here specifically shOWn.

Such driving means may, for example, include a central fixed hollow shaft on support 225 and disposed coaxial of spindle shaft 214, said fixed hollow shaft conducting the cord away from the plying point. The auxiliary flyer 224 is rotatably mounted on suitable hearings on an intermediate portion of said fixed hollow shaft, the lower end of which projects into the upper end of the conical flyer body 240. A pinion coaxial of such shaft is aflixed to the lower end thereof within the upper end of the body 246'. A suitable speed reducing gear train, which may include a series of meshing gears, is mounted on the flyer body 240 within the cavity therein, and extends from the pinion on the lower end of the hollow shaft to the capstan roll 245. It will be apparent that, as the auxiliary flyer is rotated by and at the same speed as the balloon, the strand 0 when suitably Wrapped about the surface of the capstan roll 245 will be fed to the plying point at an accurate, predetermined desired speed. As with the similar Singles feeding capstan rolls of the embodiments of FIGS. 1-7, incl., herein, the capstan roll 245 isolates the tension of the balloon from that existing in the run of strand a between the capstan roll 245 and the plying point. Not only does this permit the plying of the strands to be carried out under a desirable low tension, but it permits the speed of feeding of the cord 0 to be varied slightly, as may be required by the apparatus of FIGS. 8-11, incl., in a manner now to be described.

The cords c are gathered into the relationship which they are to have on the beam as they are led thereto through spaced guides 154 on a fixed guide board 155.

The beam winding device 152, which is shown more particularly in FIGS. 9 and 10, has a carriage 156 with a horizontal bed 157, the carriage being supported for reciprocation transversely of the paths of the cords approaching device 152. In the embodiment shown, the carriage 156 is supported on a fixed table 159 through the medium of a plurality of sets of rollers 160, of which one set is shown in FIG. 9, distributed over the area of the carriage. The carriage 156 has upstanding parallel walls 161 at its opposite ends, such walls journalling horizontal spaced parallel rubber-covered rolls 162 and 164 therebetween. The roll 162, in this instance, is driven by an axially fixed shaft 165, and roll 164 is idle, although if desired both rolls may be driven. To permit the roll 162 to reciprocate axially relative to shaft 165, there is provided a splined coupling 166 between shaft 165 and the shaft 167 of the roll 162.

The rolls 162 and 164 support the flanged multiple end beam 169 upon which the cords c are wound, the rolls being received between the flanges of the beam, as shown. The driving roll 162, which is driven at a constant peripheral speed, drives the cord-receiving surface of the beam 169 at the same speed regardless of the diameter of the beam. Non-slipping contact between the cordreceiving surface of the beam and the surface of driving roll 162 is maintained by a hold-down device having arms 170 secured to a horizontal rock shaft 171 extending through the end walls 161 of the carriage 156. The forward ends of the arms 170 are provided with semi-cylindrical seats 172 which receive and partially journal stub shafts 174 which extend from the opposite ends of the beam 169 coaxially thereof. The arms 170 are urged downwardly to thrust the beam against roll 162 by double acting reciprocable fluid motors 175 which are pivotally mounted on the bed of the carriage 156. Motors 175 have pistons and piston rods, the latter being pivotally connected to a cross rod 176 extending between the arms 170 intermediate their lengths. The introduction of fluid under pressure to motors 175 through upper conduits 177 thrusts arms 170 downwardly; such arms are elevated by exhausting fluid from conduits 177 and introducing it under pressure into the lower conduits 179 of the motors.

The carriage 156, and thus the beam 169 and its supporting and driving rolls 162, 164, are reciprocated lengthwise of the beam so as to lay each of the cords c in crisscross manner upon its zone of the beam. It will be apparent that by reason of the reciprocation of the beam 169 rather than the plied strand guide board, the lengths of the path of travel of the cords c from their spindles to the beam 169 remains constant at all times. The reciprocating stroke of the beam 169 may be, for example, a small distance which is no greater than twice the spacing between successive cords in the warp-like sheet. The carriage may be reciprocated in a number of ways, of which one is shown in FIG. 10. As there shown, a rigid member 180 extends from one end of the carriage 156; such member 180 carries an upstanding rounded pin 181 at its outer end. Pin 181, which functions as a cam follower, is accurately received within the groove or cam track 182 of a traversing earn 184 which is fixed to a driving shaft 185. It will be apparent that with the proper configuration of cam track 182, and predetermined speeds of rotation of shafts 165 and 185, the device 152 will wind each cord 0 upon the beam 169 at an accurately maintained constant speed which is correlated with and its somewhat less than the surface speed of the constant speed singles feeding capstans of the spindles 150. Thus, in accordance with the above mentioned example, the speed of winding of the cords on the beam may be per unit of time when the surface speed of the singles feeding capstans of the spindles is 114 per same unit of time.

Because of the low tensions under which the cords c are formed and delivered by the spindles 150, there is not required any take-up device other than the multiple end beam itself. The ability to coil a plurality of cord 0 upon a common multiple end beam without the use of any other take-up means arises from the self-compensating characteristics of the spindles 150.

The spindles have an auxiliary flyer 224 which carries a singles feeding capstan 245 which is driven at a constant surface speed (114, for example), when the predetermined speed of coiling of the cords c on the beam 169 is 100. Under such conditions, the cord 0 is symmetrical, the two singles strands approaching the plying point are each subjected to the same tension, that imposed by the fixed tension device engaging the inner singles strand, and the cord 0 is subjected to twice that tension. If a condition should arise, such as a slight irregularity of the outer surface of the wound cord on its zone of the beam 169, whereby the speed of take-up of such cord should momentarily increase, the spindle supplying such cord automatically adjusts to supply the requisite length of cord to the beam. With the increase in the speed of pulling of the cord from the spindles, the tension in the portion of the outer, ballooned singles between its constant speed capstan and the plying point increases. Thus more of the inner singles strand than of the outer singles strand is absorbed by the cord, and the effective length of the cord increases. Should the speed of takeup of the cord momentarily decrease, the tension in the portion of the outer singles strand between its constant speed capstan and the plying point decreases. Now more of the outer singles strand than of the inner singles strand is absorbed by the cord, and the effective length of the cord decreases. It should be understood that the described deviations of the cord from the desired symmetrical or balanced condition thereof are small, and with proper design need be no more than those encountered in premium cord plied by optimum ring twisting practice, or in cord plied by prior ply-wrapping apparatus wherein the balloon is controlled at least in part by deliberately unbalancing the cord produced.

In many case, the desired low tension under which the singles strands are plied is also ideal for winding the cord on a beam. If it should be desired, however, to wind the cords on a beam under a higher tension than that employed in the plying operation, the take-up device 152 may be supplemented by a plurality of tension devices 186, shown in FIG. 11, each of devices 186 engaging its respective cord at a location in advance of the beam winder 152. Tension device 186 includes two fixed, nonrotatable bodies 187, 189, under and over which, respectively, the cord 0 passes, and a rotatable guide roll under which the cord passes. A leaf spring 191 having its root secured to a fixed support 192, has its free end overlying the body 189. The cord is nipped between the free end of the leaf spring and body 189, the force of such nipping being adjustable by the turning of a thumb screw 194 which is threaded into an overarm 195 afiixed to support 192.

With the apparatus of the invention, in any of the forms thereof illustrated and described herein, only one of the strands, the outer, ballooned singles strand need be subjected to more than moderate tension at any time, either in the forming or the coiling of the cord; the outer strand is subjected to a fairly high tension in the balloon for only a very short time. The plying spindles of the invention, as above explained, immediately permit such strand to assume a substantially relaxed low tension condition, in advance of the plying point. Thus there is no deterioration in the properties of the cord such as occur when strands are plied under high tension and/or are maintained coiled under substantial tension for extended periods of time.

Although a limited number of embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes in addition to those above described, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

1. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of supply of a first strand anda support carrying a let-off strand package for a second strand, a rotatable shaft operable to rotate a loop of the first strand about the let-0E package and also to ply the two strands together at a plying point, a first means for feeding the first strand into the outer end of the loop, a second means engaging the first strand as it rotates in the loop for feeding the first strand at substantially constant speed toward the plying point, the plying point being located adjacent the inner end of the loop, the second feeding means engaging the first strand in advance of the plying point, a third means for feeding the plied strand under tension away from the plying point, strand tensioning and retarding means engaging the second strand at a zone in advance of the plying point for subjecting the second strand to substantially constant tension, and means for conducting the second strand from the strand tensioning and retarding means to the plying point under substantially the tension imposed on the second strand by the strand tensioning and retarding means.

2. Mechanism as claimed in claim 1, wherein the second feeding means engages the first strand adjacent the plying point, and wherein the third means, for feeding the plied strand under tension away from the plying point, subject the plied strand to a tension which is approximately twice the tension which the strand tensioning and retarding means imposes upon the second strand in the run thereof extending from said tensioning and retarding means to the plying point, and comprising means for conducting the first strand from the second means to the plying point without the imposition of substantial added tension on the first strand as it approaches the plying point, whereby the plied strand contains approximately equal lengths of the first and second strands.

3. Mechanism as claimed in claim 2, wherein the first and second strands are presented to the plying point under equal tensions, and the third means subjects the plied strand to a tension which is twice the tension under which each of the first and second strands is presented to the plying point.

4. Mechanism as claimed in claim 1, wherein said two strands are substantially inextensible under the tensions encountered in the plying operation and are substantially identical, and wherein the second feeding means feeds the first strand at a speed which exceeds the speed of feeding of the plied strand away from the plying point by the third feeding means, whereby to compensate for the decrease in the effective length of the first strand in the plied strand caused by the twisting of the two strands together.

5. Mechanism as claimed in claim 1, wherein the third means, for feeding the plied strand under tension away from the plying point, feeds the plied strand at substantially constant speed.

6. Mechanism as claimed in claim 5, wherein said two strands are substantially inextensible under the tensions encountered in the plying operation and are substantially identical, and wherein the second feeding means feeds the first strand at a speed which exceeds the speed of feeding of the plied strand by the third feeding means,

whereby to compensate for the decrease in the effective length of the first strand in the plied strand caused by the twisting of the two strands together.

7. Mechanism as claimed in claim 1, comprising means mounting the second feeding means for rotation as a whole with the loop about the axis of rotation of the loop.

8. Mechanism as claimed in claim 7, wherein the second feeding means is mounted upon the said shaft.

9. Mechanism as claimed in claim 8, comprising a flyer mounted upon said shaft for generating said loop of the first strand, said second feeding means being mounted upon said flyer.

10. Mechanism as claimed in claim 7, comprising a first guide coaxial of and remote from the shaft for guiding the plied strand away from the plying point, a flyer engaging the rotating first strand, the flyer being located nearer to the first guide than to the loop generating portion of the shaft, said second feeding means being mounted upon said flyer.

11. Mechanism as claimed in claim 10, comprising a further guide means mounted upon the flyer for conducting the second strand from its let-off package and thence into contact with the first strand at the plying point.

12. Mechanism as claimed in claim 10, wherein the shaft is hollow, and comprising a storage wheel on the shaft, means for feeding the first strand under tension into the outer end of the shaft, around the storage wheel, and thence into the loop, the first strand leaving the loop proper by way of the second feeding means on the flyer and then travelling to the plying point at which it meets the second strand.

13. A method of twisting together two strands so as to form a two-ply strand, comprising rotating a loop of a first strand about a let-off package for a second strand and also plying the two strands together at a plying point, feeding the first strand into the outer end of the loop, engaging the first strand as it rotates in the loop with a feeding means lying adjacent the inner end of the loop and in advance of the plying point, feeding the first strand by said feeding means at substantially constant speed toward the plying point, feeding the plied strand under tension away from the plying point, engaging the second strand at a zone in advance of the plying point by a strand tensioning and retarding means which subjects such strand to substantially constant tension, and conducting the second strand from the strand tensioning and retarding means to the plying point under substantially the tension imposed on the second strand by the strand tensioning and retarding means. a

14. A method as claimed in claim 13, comprising engaging the first strand as it rotates in said loop by the said feeding means adjacent the plying point, conducting the first strand from the said feeding means therefor to the plying point without the imposition of substantial added tension on the first strand as it approaches the plying point, and feeding the plied strand away from the plying point under a tension which approximates twice the tension to which the second strand is subjected immediately in advance of and at the plying point.

15. A method as claimed in claim 14, comprising presenting the first and second strands to the plying point under equal tensions, and withdrawing the plied strand from the plying point under a tension which is twice the tension under which each of the first and second strands is presented to the plying point.

16. A method as claimed in claim 13, wherein said two strands are substantially inextensible under the tensions encountered in the plying operation and are substantially identical, and wherein the speed of feeding of the first strand by said feeding means exceeds the speed of feeding of the plied strand away from the plying point, whereby to compensate for the decrease in the effective length of the first strand in the plied strand caused by the twisting of the two strands together.

17. A method as claimed in claim 16, comprising feeding the plied strand at constant speed under tension away from the plying point.

18. An apparatus for forming a plurality of cords simultaneously and winding them on a common beam, comprising a plurality of similar cord forming spindles of the plywrapping type, each of said spindles comprising a source of supply of a first strand and a support carrying a let-01f strand package for a second strand, a rotatable shaft operable to rotate a loop of the first strand about the let-off package and also to ply the two strands together at a plying point, a first means for feeding the first strand into the outer end of the loop, a second means engaging the first strand as it rotates in the loop for feeding the first strand at substantially constant speed toward the plying point, the plying point being located adjacent the inner end of the loop, the second feeding means engaging the first strand in advance of the plying point, strand tensioning and retarding means engaging the second strand at a zone in advance of the plying point for subjecting the second strand to substantially constant tension, and means for conducting the second strand from the strand tensioning and retarding means to the plying point under substantially the tension imposed on the second strand by the strand tensioning and retarding means, means for gathering the cords formed by the spindles and conducting them away from the spindles in parallel spaced relationship to form a warp-like sheet, a common take-up beam for the warp-like sheet, said take-up beam constituting means for feeding the cords under tension away from the plying points of the respective spindles, and means for driving the take-up beam at a substantially constant surface speed which is appreciably less than the strand feeding speed of the second feeding means.

19. An apparatus as claimed in claim 18, wherein the second feeding means of each of said spindles is driven at a strand feeding speed which is higher than the surface speed of the take-up beam in an amount sufiicient to compensate for the decrease in the effective length of the first strand in the plied strand caused by the twisting of the two strands together.

20. An apparatus as claimed in claim 19, wherein the means for gathering and conducting the cords leads the cords to the take-up beam under substantially the tension under which the cords are withdrawn from the respective plying points of the respective spindles.

21. An apparatus as claimed in claim 19, comprising means engaging and additionally tensioning the cords between the respective spindles and the take-up beam.

References Cited UNITED STATES PATENTS 2,503,242 4/1950 Clarkson 571 2,811,012 10/1957 Klein 57-5836 X 2,871,648 2/1959 Vibber 5758.36 2,914,903 12/1959 Klein et al. 57-58.36 X 2,961,824 11/1960 Klein 57-5836 2,986,865 6/1961 Clarkson 57-583 3,153,893 10/1964 Vibber 5758.3

FRANK J. COHEN, Primary Examiner.

D. WATKINS, Assistant Examiner.

Claims

1. MECHANISM FOR TWISTING TOGETHER TWO STRANDS SO AS TO FORM A TWO-PLY STRAND, COMPRISING A SOURCE OF SUPPLY OF A FIRST STRAND AND A SUPPORT CARRYING A LET-OFF STRAND PACKAGE FOR A SECOND STRAND, A ROTATABLE SHAFT OPERABLE TO RATATE A LOOP OF THE FIRST STRAND ABOUT THE LET-OFF PACKAGE AND ALSO TO PLY THE TWO STRANDS TOGETHER AT A PLYING POINT, A FIRST MEANS FOR FEEDING THE FIRST STRAND INTO THE OUTER END OF THE LOOP, A SECOND MEANS ENGAGING THE FIRST STRAND AS IT ROTATES IN THE LOOP FOR FEEDING THE FIRST STRAND AT SUBSTANTIALLY CONSTANT SPEED TOWARD THE PLYING POINT, THE PLYING POINT BEING LOCATED ADJACENT THE INNER END OF THE LOOP, THE SECOND FEEDING MEANS ENGAGING THE FIRST STRAND IN ADVANCE OF THE PLYING POINT, A THIRD MEANS FOR FEEDING THE PLIED STRAND UNDER TENSION AWAY FROM THE PLYING POINT, STRAND TENSIONING AND RETARDING MEANS ENGAGING THE SECOND STRAND AT A ZONE IN ADVANCE OF THE PLYING POINT FOR SUBJECTING THE SECOND STRAND TO SUBSTANTIALLY CONSTANT TENSION, AND MEANS FOR CONDUCTING THE SECOND STRAND FROM THE STRAND TENSIONING AND RETARDING MEANS TO THE PLYING POINT UNDER SUBSTANTIALLY THE TENSION IMPOSED ON THE SECOND STRAND BY THE STRAND TENSIONING AND RETARDING MEANS.

18. AN APPARATUS FOR FORMING A PLURALITY OF CORDS SIMULTANEOUSLY AND WINDING THEM ON A COMMON BEAM, COMPRISING A PLURALITY OF SIMILAR CORD FORMING SPINDLES OF THE PLYWRAPPING TYPE, EACH OF SAID SPINDLES COMPRISING A SOURCE OF SUPPLY OF A FIRST STRAND AN A SUPPORT CARRYING A LET-OFF STRAND PACKAGE FOR A SECOND STRAND, A ROTATABLE SHAFT OPERABLE TO ROTATE A LOOP OF THE FIRST STRAND ABOUT THE LET-OFF PACKAGE AND ALSO TO PLY THE TWO STRANDS TOGETHER AT A PLYING POINT, A FIRST MEANS FOR FEEDING THE FIRST STRAND INTO THE OUTER END OF THE LOOP, A SECOND MEANS ENGAGING THE FIRST STRAND AS IT ROTATES IN THE LOOP FOR FEEDING THE FIRST STRAND AT SUBSTANTIALLY CONSTANT SPEED TOWARD THE PLYING POINT, THE PLYING POINT BEING LOCATED ADJACENT THE INNER END OF THE LOOP, THE SECOND FEEDING MEANS ENGAGING THE FIRST STRAND IN ADVANCE OF THE PLYING POINT, STRAND TENSIONING AND RETARDING MEANS ENGAGING THE SECOND STRAND AT A ZONE IN ADVANCE OF THE PLYING POINT FOR SUBJECTING THE SECOND STRAND TO SUBSTANTIALLY CONSTANT TENSION, AND MEANS FOR CONDUCTING THE SECOND STRAND FROM THE STRAND TENSIONING AND RETARDING MEANS TO THE PLYING POINT UNDER SUNSTANTIALLY THE TENSION IMPOSED ON THE SECOND STRAND BY THE STRAND TENSIONING AND RETARDING MEANS, MEANS FOR GATHERING THE CORDS FORMED BY THE SPINDLES AND CONDUCTING THEM AWAY FROM THE SPINDLES IN PARALLEL SPACED RELATIONSHIP TO FORM A WARP-LIKE SHEET, A COMMON TAKE-UP BEAM FOR THE WARP-LIKE SHEET, SAID TAKE-UP BEAM CONSTITUTING MEANS FOR FEEDING THE CORDS UNDER TENSION AWAY FROM THE PLYING POINTS OF THE RESPECTIVE SPINDLES, AND MEANS FOR DRIVING THE TAKE-UP BEAM AT A SUBSTANTIALLY CONSTANT SURFACE SPEED WHICH IS APPRECIABLY LESS THAN THE STRAND FEEDING SPEED OF THE SECOND FEEDING MEANS.