US3169360A

US3169360A - Stranding apparatus and method

Info

Publication number: US3169360A
Application number: US206764A
Authority: US
Inventors: Roy E Corrall; George N Menasoff
Original assignee: Anaconda Wire and Cable Co
Current assignee: Ericsson Inc
Priority date: 1962-07-02
Filing date: 1962-07-02
Publication date: 1965-02-16
Anticipated expiration: 1982-02-16

Description

1965 R. E. CORRALL. ETAL 3,169,360

swamnmc APPARATUS AND METHOD 3 Sheets-Sheet 1 Filed July 2, 1962 ML .L mA mm v mm B Y O R GEORGE N. MENASO FF Feb. 116,.v 1965 R. E. CORRALL, ETAL S'IRANDING APPARATUS AND METHOD 3 Sheets-Sheet 2 Filed July 2, 1962 F C- m O TAW m M R V ON w 0E RG 17/5/19 Mil/i 6 R. E. CORRALL ETAL 3,

STRANDING APPARATUS AND METHOD Filed July 2, 1962 3 Sheets-Sheet 3 INVENTORS ROY E. COR R ALL GEORGE.N. MENASOFF United States Patent Our invention relates to strand twisting and particularly-to the twisting of strand with a false 'or reversing I twist.

In the stranding of insulated conductors there are certain advantages to twisting the strands in afalse twist with periodicreversals of direction of lay rather than twisting them in a continuous helix in the manner most commonly practiced. Amongfthese advantages are the 'facts that in applying a false twist it is not necessary to rotate the take-up or pay-off assembly and the expensive equipment necessary for the rotation of heavy reels can be eliminated. With the elimination of heavy rotating elements comes the additional advantage of increased speed of operation. There, are also advantages in the false twisted product itself in that slack can be generated in short lengths of such strand merely by untwisting a central length of it even when the ends are remote, without any necessity for cutting the conductors. A most important advantage, however, from the vantage point of this invention, is that when strands are twisted with a false twist the stranding operation can be part of a continuous process involvingsteps both downstream and upstream of the twisting where the ends of the'strand are not available for rotating. Such a process would occur for instance where conductors are insulated in an extruder, twisted into pairs, and combined to form a cable. In contra-distinction to such a proposed process it is present commercial practice to insulate conductors individually and take them up on reels. The insulated conductors on two of the reels are then twisted into pairs and taken up on reels again. Finally the pairs on a plurality of these reels are stranded into a cable. It has been known to apply a false twist by passing filaments through a reciprocating lay plate but the angle of such twists has been limited to a fraction of a full turn because of the tangling of strands upstream of the lay plate and in no case has been able to exceed 540.

to advancing strand comprising means accumulating such strand which may be, but is not necessarily limited to,

a sheave, a roll supporting a plurality of turns or a pair of rolls supporting at least one loop and mounted in a cradle, and also comprising means for rotating the accumulating means, such as by rotating thecradle, so as an impart a twist of one direction to the strand leaving the accumulating means, and a twist of opposite direction to the strand entering the accumulating means. Our apparatus also comprises means for alternately restraining the accumulating means against rotating for a period sufficient to advance the twisted strand from it, and may also comprise means for binding the strand, preferably at reversal points while leaving the strand free from binding elsewhere. Such binding may be quicksetting cement such as but not limited to the hot-melt adhesive such as that described in application Serial Number 190,108, filed April 25, 1962, and assigned to the assignee of this invention.

Where reverse-lay or false twisting has been used 7 for the stranding of prior art electric cables it has not been known to twist more than a fraction of a turn between reversals. We have invented reverse twist cables with angles of twist in excess of 540 and even in excess of three or more complete turns. These may be but are not limited to telephone conductor pairs of two insulated wires or multi-pair cables comprising a plurality of such twistedpairs with a jacketoverall. Our cables may be made with reverse twistingof the strands, and binding at the points of reversal, the strands being free from bindingelsewhere along their lengths; and the binding may be a hot-melt adhesive;

I We have also invented a method of twisting a strand comprising continuously advancing it into an accumulated supply of strand while simultaneously paying the strand from the supply and periodically rotating the supply to impart a twist to the strand leaving the supply, and an opposite twist to the strand entering thesupply. In our method the supply is preferably alternately restrained against the rotating or rotated in the opposite direction until the twisted strand has paid from it and the angle of rotation is in excess of 540 and preferably encompasses a plurality of full turns. Our method also preferably comprises the step of binding the strand intermittently at reversal points as by a hot-melt adhe-v sive, which binding may advantageously occur as the first step in our process. A more thorough understanding of our invention can be obtained from a study of the appended drawing.

In the drawing:

. FIGURES 1a and 1b are perspective views of an apparatus made to our invention.

FIGURE 2 is a perspective view of an adhesive applicator used in one embodiment of our invention.

FIGURE 3 is a lengthwise view of a twisted strand of our invention. V

FIGURE 4 is a lengthwise, cut-away view of a cable of strands of our invention.

' Referring to FIGURES 1a and lb a stranding apparatus, indicated generally by the numeral 10 is mounted on a base 11. A strand 12 comprised of parallel insu

lated conductors

13, 14 is advancing from right to left as seen in the drawing from a supply source not shown. Our apparatus has particular utility for the twisting of telephone cable pairs such as may be made from the

insulated conductors

13, 14 but it can also be advantageously used for quads and for other types of strand comprising a greater or fewer number of conductors or other filaments; The strand 12 passes through a binding head 16 where it is bound together at fixed intervals along its length. We have shown a known type of commercially available binding head of which the wire andharness taper made by the Possis Machine Corp 825 Rhode Island Avenue, Minneapolis 26, Minn,

is an example. In this embodiment of the binding head 16 a gummed tape 17 feeds from a pad 18 and a short length of the tape is automatically wrapped around the strand at selected intervals. Since our strand 12 is continuously advancing we have mounted the binding head 16 on rails 19 so that it can be advanced at the speed of advancement of the strand 12 by the rotation of a worm 21 driven by a reversing motor 22. After the strand 12 has been bound at one point, the motor 22 reverses to turn the worm 21 in the opposite direction so that the head 16 is returned to its original position. This is quite feasible in our apparatus because the long lengthof strand between reversal points allows ample time for the return of the head 16, and it constitutes one of 'the advantages of our invention. Although we have shown a' binding head 16 which wraps gummed tape around the strand it will be readilyunderstood that we do not wish to be limited to this method of binding. For instance, in FIGURE 2, we have shown a binding means hereinafter to be explained in detail, which utilizes hot-melt or other quick-setting adhesive for bindingour strand 12. As the strand pays from the binding head 16 it passes through a hollow journal 23 which turns in a bearing 24 mounted on a pedestal 26, which is in turn supported on the base 11. Also mounted on the base 11 another pedestal 27 is surmounted by a bearing 28 in which another hollow journal 29 rotates in line ,with the journal 23. The journals 23, 29 support between them a cradle 31, which we prefer to form from a single bar 32 for ease in stringing, as shall be shown. The bar 32 mounts an upper rigid bearing 33 which supports a grooved roll 34 on a cantilevered shaft 36., The roll 34 is wide enough to contain a plurality of grooves 37 and it will be understood the greater the number of grooves 37, other factors being equal, the greater will be the storage capacity of our apparatus. It is, however, contemplated that for some applications the roll 34 may have a single groove and take the form of a simple sheave. Upstream and to the right of the bearing 33, a bearing 38 is mounted on the underside of the bar 32. The bearing 38 supports a light-Weight flanged roll 39 on a cantilevered shaft 41. The roll 39 is wide enough to accommodate all the turns of strand supported by the grooves 37 and the strand is formed in a plurality of loops 42 enclosing the two rolls 34, 39. The rolls 34 and 39 are of very light-weight construction so that they are easily turned by the forward motion of the strand 12 but it will be understood that where the strand might be broken or damaged by the load incurred in turning them, the rolls 34 and 39 may be driven by gear trains or other means known to persons skilled in mechanical arts.

Before entering upon the roll 39 the strand 12 passes through a pair of pinch rolls 43, 44 mounted on a bar 46 fixed to the base 11 by means of a pedestal 47. Thus the pinch rolls 43, 44 remain stationary and do not rotate along with the cradle 31 and are tight enough to prevent back twist in the strand 12. In the embodiment of our apparatus shown in FIGURES la and 1b the strand 12 makes one turn around the roll 39 adjacent to the near flange, and then passes around the grooved roll 34 and back to the roll 39 to form the series of loops 42. Leaving the roll 34 the strand passes over

guide sheaves

48, 49 through another pair of pinch rolls 51, 52 and thence to take-up means not shown, which may incorporate another processing step. The pinch rolls 51, 52 are fixed to a bar 53 rigidly mounted to the base 11 by means of a pedestal 54. A belt pulley 56 is locked to the journal 23 and is driven through a belt 57 by means of a drive pulley 58 and motor 59 which we prefer to be a high-inertia rotor motor. The pulley 58 is connected to a shaft 61 of the motor 59 through a clutch 62 and can be stopped by an electric brake 63. The clutch 62 and brake 63 are actuated by a limit switch 64 through brushes 66, 67 and slip rings 68, 69. The limit switch 64 is, in turn, actuated by a cam 71 driven at a selected reduction ratio from the roll 39. In the apparatus shown we prefer to employ a reduction ratio of 20 to 1, operating in a known manner so that the drive pulley 58 will be stopped by the disconnection of the clutch 62 and application of the brake 63 after twenty revolutions of the roll 39,

and will start again after another twenty revolutions, and so on. Thus the cradle 31 is caused to rotate for a period equal to twenty revolutions of the roll 39 and alternately to remain stationary for twenty revolutions. In this regard it should be particularly noted that in one method of operation of our apparatus the rolls 34 and 39 rotate continuously at a constant rate and the motor 59 runs continuously in the same direction; the cradle 31, although it stops and starts at regular intervals does not reverse its direction of rotation but rotates always in the same direction. In another method of operation the clutch 62 is a reversing clutch and the cradle 31 rotates alternately for twenty revolutions clockwise and counterclockwise.

A second limit switch 72 is connected through slip rings 73, 74 and brushes 76, 77 and

wires

78, 79 there- (it from to the binding head 16 so that the binding head applies binding to the strand once for every twenty revolutions of the roll 39. The switch 72 is actuated by a cam 75 driven by a reducing mechanism from the roll 39. The cams 71 and 75 turn at equal rates of speed but are out of phase to an extent selected so that a bound point in the strand 12 reaches the pinch rolls 43, 44

each time the rotation of the cradle 31 stops or starts.

It will be understood that although we have selected a length of twenty circumferences of the roll 39 as the length of strand between reversal points other lengths can also be chosen within the scope of our invention, but the length should correspond to the length of strand stored on the rotating cradle 31 between the pairs of pinch rolls 43, 44 and 51, 52. In the illustrated case this length is just twenty circumferences of theroll 39.

Although we have preferred to apply binding to our strand 12 upstream of its entrance into the storage rotating means our invention also will include apparatus Where the binding head is mounted downstream of the cradle and applies binding to strand emerging from the pinch rolls 51, 52. Such a binding might be applied continuously as by winding with a yarn or tape, or it might be applied only at points of reversal. The extent of binding required depends to some extent on the springiness of the strand being twisted. We have found that polyethylene-insulated, solid-copper telephone conductor pairs can be twisted very satisfactorily on the apparatus described and shown in FIGURES 1a and 1b. Where the springiness of the strand is such that the false twist tends strongly to unwind under very slight tension this unwinding might take place in the unsupported portions of the loops 42 between the rolls 34 and 39. This can be overcome at the expense of storage capacity by having only a single roll such as the roll 39 mounted on the cradle 31 so that the stored strand will, at all times, be restrained from unwinding by it's frictional contact with the surface of the roll. If the strand is then bound continuously as it leaves the cradle, even a springy strand will retain its false twist.

Operation grooves 37 in the roll 34 and also the roll 39 until all the grooves 37 have been used. This stringing of the strand 12 is greatly simplified by the cantilever mounting of the rolls 34 and 39. The threading of the strand continues over the sheave 48 and under the sheave 49, through the final rolls 51, 52 and downstream to the take-up apparatus, not shown. It will be understood that, in order to avoid waste, all or part of this threading may employ a piece of scrap lead-cord that can be discarded later.

The motor 59 is operated with the clutch 62 engaged and the brake 63 released so that the cradle 31 rotates as the strand 12 pays through the apparatus. As the cradle rotates it applies a twist to the strand 12 at the pinch rolls 51, 52 so that the strand advancing downstream of the apparatus is twisted. At the same time, the strand 12 entering the apparatus through the pinch rolls 43, 44 is given a twist in the opposite direction to the twist imparted by the pinch rolls 51, 52. As the stranding progresses the untwisted strand that was initially stored on the rolls 34, 39 is twisted as it pays off through the pinch rolls 51, 52 While the fresh strand being taken up in the storage is twisted at the rolls 43, 44 and stored in the twisted condition. When twenty circumferences of the roll 39 have been pair into the apparatus all the untwisted strand will have advanced from the storage and will have been replaced by twisted strand. At this point the cam 71 will actuate the switch 64 to disengage the clutch 62 and apply the brake 63 thus stopping rotation of the cradle 31.

However, the strand 12 will continue to pay through. the pinch rolls 51, 52, but since all the stored strand is twisted in a direction opposite to the strand already advanced there will be a point of reversal in'the strand passing through the rolls 51, 52 at the time the cradle stops rotating. As the twisted strand continues to advance from the stationary cradle it is replaced by untwisted strand passing through the rolls 43, 44. When the twisted strand is completely replaced by untwisted strand the clutch 62 will engage and the cradle will start to rotate and thus repeat the cycle. During this operation the binder head 16 is, applying a gummed-tape binding to points of the strand which correspond to points of reversal of twist with the result that the false twist does not unwind when the strand emerges from the apparatus. When, instead of remaining stationary at the end of each cycle, the cradle 31 rotates alternately clockwise and counterclockwise, the strand taken up in the storage is always twisted and an additional twist in the same direction is applied to the strand as it leaves the storage.

During the initial loading of the storage with twisted strand (and during each of the subsequent periods between reversal points) the cradle will make a plurality of complete revolutions: For example, if the length of twist-lay is six inches and the circumference of the roll 39 is one foot there will be forty full turns in the strand between reversal points. This large number of turns has a number of important advantages. For one thing it reduces the number of bindings required where the bindings are applied only at reversals. It provides ample time for the return of the binding head. It prevents the false twist being unwound by tension in the strand. And it reduces the frequency of starting and stopping of rotation of the cradle.

In a preferred embodiment of our invention, binding of the strand is accomplished by an apparatus 100 shown in FIGURE 2. In this apparatus the conductors l3, 14 pass through respective separating guide blocks 161, 102 mounted on a platform 103 on a pedestal 194 on the base 111. Also mounted on the platform M3 is a solenoidcnntrolled nozzle 105 to which is supplied a suitable hotmelt, or other quick-setting cement such as that hereinbefore described through an insulated pipe-line 106 from a source not shown. The nozzle W5 is activated by the switch 72 through the lead wires '78, '79 to apply a deposit of cement to the wire 14% at points corresponding to points of reversal of the twist, immediately after which, the conductors l3, 14 pass between grooved pinch rolls 187, MP3 where they are brought together and bound by the cement. From the rolls 107, 108 the strand passes through the hollow journal 23 and is processed as hereinbefore described.

The length of the conductor 14 to which cement canbe continuously applied by this method is not limited and this provides for some latitude in obtaining perfect registration between the point of binding and the point of reversal of twist. Alternatively, it is within the scope of our invention to mount the apparatus lltlil downstream of the cradle Fall to bind the strand after it has been twisted.

In FIGURE 3 we have shown a paired strand 110 twisted in accordance with our invention. The strand is comprised of

insulated conductors

113, 114 which can be seen to have a right-hand twist at a length 116 and a left-hand twist at a length 117. Reversal points occur at 11%, 119, 121 and in between these reversals the twist in the strand continues in one direction for a large plurality of turns. At the reversal points

bindings

122, 123, 124, which consist in this embodiment of hot-melt adhesive, prevent the strand from opening. Although we have shown binding only at reversal points in might be continued for a longer distance within the scope of our invention, and instead of a hot-melt cement might consist of other adhesive means, or of wraps of adhesive tape or continuous servings of yarn or tape.

6 In FIGURE' 4 a plurality of the paired strands have been formed into a cable 126 with a jacket 127.

We have invented a new and useful apparatus and method for which we desire an award of Letters Patent.

We claim: v 1. Apparatus applying a reversing twist to advancing strand comprising:

. (A) means accumulating said strand comprising (a) a sheave and V (b) a cradle mounting said sheave, said cradle being fixed against translation along the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand leaving said sheave and a twist of opposite direction to said strand entering upon said sheave, and

(b) restraining said cradle from rotation for a period sufiicient to advance said strand having said opposite twist around the circumference of said sheave.

2. Apparatus applying a reversing twist to advancing strand comprising: p g V (A) means accumulating said strand comprising (a) a'roll supporting a plurality of turns of said strand and (b) a cradle mounting said roll,'said cradle being fixed against translation along the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand leaving said roll and a twist of opposite direction to said strand entering upon said roll, and

(b) restraining said cradle from rotation for a period suflicient to advance said strand having said opposite twist around said plurality of turns.

3. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of rolls mounted on parallel axes and supporting at least one loop of said strand,

(b) a cradle mounting said rolls, said cradle being fixed against translation along the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand leaving said rolls and a twist of opposite direction to said strand entering upon said rolls, and

(b) restraining said cradle from rotation for a period sufiicient to advance said strand having said opposite twist from said rolls.

4. Apparatus applying a reversing twist to advancing strand comprising:

(b) a cradle mounting said rolls, said cradle being fixed against'translation along the axis of advance of said strand, and

(b) restraining said cradle from rotation for a period sufiicient to advance said strand having said opposite twist from said rolls, thereby imparting to said strand periodic points of reversal of twist, and

(C) means applying binding to said strand at said points of reversal, said strand being free from binding elsewhere along said strand.

7 5. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a sheave, ([2) a cradle mounting said sheave, and (c) a pair of pinch rolls mounted downstream of said sheave, said cradle and said pinch rolls being fixed against translation along the axis of advance of said strand, and (B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand between said sheave and said pinch rolls, and a twist of opposite direction to said strand entering upon said sheave, and (b) restraining said cradle from rotation for a period suflicient to advance said strand having said opposite twist around the circumference of said sheave. 6. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a roll supporting a plurality of turns of said strand, (b) a cradle mounting said roll, and (c) a pair of pinch rolls mounted downstream of said roll, said cradle and said pinch rolls being fixed against translation along the axis of advance of said strand, and (B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand between said roll and said pinch rolls and a twist of opposite direction to said strand entering upon said roll, and (b) restraining said cradle from rotation for a period sufiicient to advance said strand having said opposite twist around said plurality of turns. 7. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of storage rolls mounted on parallel axes and supporting a plurality of loops of said strand, (b) a cradle mounting said rolls, and (c) a pair of pinch rolls mounted downstream of said storage rolls, said cradle and said pinch rolls being fixed against translation along the axis of advance ofsaid strand, and (8) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand between said storage rolls and said pinch rolls and a twist of opposite direction to said. strand entering upon said storage rolls, and (b) restraining said cradle from rotation for a period suflicient to advance said strand having said opposite twist from said storage rolls. 8. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of storage rolls mounted on parallel axes and supporting a plurality of loops of said strand, (II) a cradle mounting said rolls, and (c) a pair of pinch rolls mounted downstream of said storage rolls, said cradle and said pinch rolls being fixed against translation along the axis of advance of said strand, (B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand between said storage rolls and said pinch rolls and a twist of opposite direction to said strand entering upon said storage rolls, and

(b) restraining said cradle from rotation for a period sufficient to advance said strand having said opposite twist from said storage rolls thereby imparting to said strand periodic points of reversal of twist, and

(C) meansapplying binding to said strand at said points of reversal, said strand being free from binding elsewhere along said strand.

9. Apparatus applying a reversing twist to advancing strand comprising:

(A) means continuously accumulating and paying oil supplies of said strand,

(B) means alternately rotating said accumulating means in one direction until one said supply has paid off and in the reverse direction until the next said supply has paid on thereby giving said strand periodic points of reversal of twist, and

(C) means applying binding to said strand at said points, said strand being free from binding elsewhere along said strand.

10. The apparatus of claim 9 wherein said accumulating means comprises at least one roll mounted in a cradle.

11. The method of twisting a strand comprising the steps of: I

(A) continuously advancing said strand into an accumulated supply of said strand,

(B) simultaneously paying said strand from said accumulated supply and (C) during said advancing, alternately (a) rotating said accumulated supply so as to (1) impart a twist to said strand leaving said supply, and (2) impart an opposite twist to said strand entering said supply, and (b) restraining said supply against said rotating until said oppositely twisted strand has paid from said supply.

12. The method of twisting a strand comprising the steps of:

(B) simultaneously paying said strand from said accumulated supply, and

(C) during said advancing, alternately (a) rotating said accumulated supply through an angle in excess of 540 so as to (1) impart a twist to said strand leaving said supply, and (2) impart an opposite twist to said strand entering said supply, and (b) restraining said supply against said rotating until said oppositely twisted strand has paid from said supply.

13. The method of twisting a strand comprising the steps of:

(B) simultaneously paying said strand from said supply, and

(C) during said advancing, alternately (a) rotating said accumulated supply through an angle in excess of 540 so as to impart a twist to said strand leaving said supply and an opposite twist to said strand entering said supply, and

(b) restraining said supply against said rotating until said oppositely twisted strand has paid from said supply, and

(D) binding said strand intermittently at points of reversal of said twist.

14. The method of twisting a strand comprising the steps of:

(A) applying binding to said strand at regularly spaced intervals while continuously advancing said strand,

9' I (B) collecting said strand in an accumulatedsupply thereof, (C) simultaneouslycontinuously paying said strand from said supply, (D) during said advancing, alternately (a) rotating said supply through an angle in excess of 540 so as to impart a twist to said strand leaving said supply and an opposite twist to said strand entering said supply,

(b) restraining said supply against said rotating until said oppositely twisted strand has paid from said supply,

(c) said restraining being instituted at thetime 'a bound portion of said strand is entering said supply whereby reversals of twist in said strand will occur at the bound portions of said strand.

15. The method of twisting a strand comprising the steps of:

(A) continuously advancing said strand into an accumulated supply of said strand, (B) simultaneously paying said strand from said accumulated supply, and (C) during said advancing, alternately (a) rotating said accumulated supply in one direction so as to (1) impart a twist to said strand leaving said supply, and (2) impart an opposite twist to said strand entering said supply, and

(b) rotating said accumulated supply in the opposite direction until said oppositely twisted strand has paid from said supply.

16. Apparatus applying a reversing twist to advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis of advance of said strand and (b) fixed against translation along said axis, and

(B) means periodically rotating said accumulating means so as to (a) impart a twist of one direction to said strand leaving said accumulating means, and

(b) a twist of opposite direction to said strand entering said accumulating means.

17. Apparatus applying a reversing twist to advancing strand comprising:

(B) means alternately (a) rotating said accumulating means so as to impart a twist of one direction to said strand leaving said accumulating means and a twist of opposite direction to said strand entering said accumulating means, and

(b) restraining said accumulating means from said rotating for a period sufiicient to advance said strand having said opposite twist from said accumulating means.

18. Apparatus applying a reversing twist to advancing strand comprising:

(b) restraining said accumulating means from said rotating for a period sufiicient to advance said 19 strand having said opposite twist from said accumulating means, and (C) means applying binding to said strand, thereby restraining said twist. 19. Apparatus applying a reversing twist to advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis of advance of said strand and (b) fixed against translation along saidaxis, and (B) means alternately a (a), rotating said accumulating means so as to impart a twist of one direction to said strand leaving said accumulating means and a twist of opposite direction to said strand entering said accumulating means, and (b) restraining said accumulating means from said rotating for a period sufiicient to advance said strand having said opposite twist from said accumulating means thereby giving said strand periodic points of reversal of twist, and (C) means applying binding to said strand at said points, said strand being free from binding elsewhere along said strand. 20. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand, (B) means alternately (a) rotating said accumulating means so as to impart a twist of one direction to said strand leaving said accumulating means and a twist of opposite direction to said strand entering said accumulating means, and (b) restraining said accumulating means from said rotating for a peniod sufiicient to advance said strand having said opposite twist from said accumulating means thereby giving said strand periodic points of reversal of twist, and (C) means applying a quick-setting adhesive binding to said strand at said points, said strand being free from binding elsewhere along said strand. 21. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of rolls mounted on parallel axes and supporting at least one loop of said strand, (b) a cradle mounting said rolls, and (B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand leaving said rolls and a twist of opposite direction to said strand entering upon said rolls, and (b) restraining said cradle from rotation for a period suificient to advance said strand having said opposite twist from said rolls, thereby imparting to said strand periodic points of reversal of twist, and (C) means applying a quick-setting adhesive binding to said strand at said points of reversal, said strand being free from binding elsewhere along, said strand. 22. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of storage rolls mounted on parallel axes and supporting a plurality of loops of said said strand, (b) a cradle mounting said rolls, and (c) a pair of pinch rolls mounted downstream of said storage rolls, (B) means alternately (a) rotating said cradle so as to impart a twist of one direction to said strand between said storage rolls and said pinch rolls and a twist of opposite direction to said strand entering upon said storage rolls, and

1 1 (b) restraining said cradle from rotation for a period suflicient to advance said strand having said opposite twist from said storage rolls thereby :imparting to said strand periodic points of reversal of twist, and (C) means applying quick-setting adhesive binding to said strand at said points of reversal, said strand being free from binding elsewhere along said strand.

References Cited in the file of this patent UNITED STATES PATENTS 1,030,426 Parsons et a1. June 25, 1912 1,960,426 Zundorf May 29, 1934 2,001,065 Klein May 14, 1934 Peterson Mar. 23, Berggren et a1. Oct. 12, Speekman June 19, Gillis Apr. 30, Bryan et a1. Apr. 21 Lilly Oct. 11, Lenk et a1. Oct. 25, Crosby et a1. Ian, 16, Cook Mar. 20, Henning Sept. 4, Bloch Nov. 6,

FOREIGN PATENTS Denmark Apr. 4,

Claims

1. APPARATUS APPLYING A REVERSING TWIST TO ADVANCING STRAND COMPRISING: (A) MEANS ACCUMULATING SAID STRAND COMPRISING (A) A SHEAVE AND (B) A CRADLE MOUNTING SAID SHEAVE, SAID CRADLE BEING FIXED AGAINST TRANSLATION ALONG THE AXISOF ADVANCE OF SAID STRAND, AND (B) MEANS ALTERNATELY (A) A ROTATING SAID CRADLE SO AS TO IMPART A TWIST OF ONE DIRECTION TO SAID STRAND LEAVING SAID SHEAVE AND A TWIST OF OPPOSITE DIRECTION TO SAID STRAND ENTERING UPON SAID SHEAVE, AND (B) RESTRAINING SAID CRADLE FROM ROTATION FOR A PERIOD SUFFICIENT TO ADVANCE SAID STRAND HAVING SAID OPPOSITE TWIST AROUND THE CIRCUMFERENCE OF SAID SHEAVE.