US2863613A - Strand reeling apparatus - Google Patents

Description

Dec. 9, 1958 "r. T. BUNCH STRAND REELING APPARATUS Filed Oct. 10, 1955 3 Sheets-Sheet 1 INVENTOR. 7'. 7'. BUNCH BY a ATTORNEY Dec. 9, 1958 T. T. BUNCH 2,8

STRAND REELING APPARATUS Filed Oct. 10, 19 55 3 Sheets-Sheet 2 INVENTOR. 7. 7'. BUNCH ATTORNEY Dec. 9, 1958 Filed Oct. 10. 1955 VELOCITY LINEAR T. T. BUNCH STRAND REELING APPARATUS 3 Sheets-Sheet 3 REVERSIING I02 VALVE /0 EXHAUST SUPPLY DC. SOURCE Q L c J COUN:TER /50 FIG. 3

CAM CYCLEQCHART OF CAM \40 ANGULAR ROTATION (RADIANS) Fla 4 INVENTOR. 7'. 7". BUNCH BY Wm ATTORNEY United States Patent OfiFice 1 2,863,613 STRAND REELING APPARATUS Tillman T. Bunch, near Ashland, Md., assignor to Western Electric Company, Incorporated, New York, N. Y., a

corporation of New York Application October 10, 1955, Serial No. 539,343 9 Claims. (Cl. 242-25) This invention relates to strand reeling apparatus, and more particularly to apparatus for controlling the tension in a strand as it is wound upon a takeup reel.

In the manufacture of plastic insulated wire the finished wire is delivered continuously from a plastics extruder to a takeup reel at a constant linear speed and under a substantially constant tension. As soon as a pre-' determined length of the wire has been wound upon a takeup reel, the wire is severed automatically and the new leading end of the wire is attached automatically to the empty winding drum of another takeup reel without interrupting the advance of the wire.

It is a common practice to employ strand reeling apparatus having two takeup reels which are driven by slipping-belts. When apparatus of this type is employed it is necessary to operate a drive pulley connected to the empty takeup reel, immediately before the transfer of the wire from the full takeup reel, at a rotational speed somewhat greater than is required for a match of the peripheral speed of the empty winding drum to the linear speed of the advancing wire. This actual mismatch between the linear speed of the wire and the peripheral speed of the Winding drum of the empty takeup reel is predetermined and consistent. V

The mismatch in speeds subjects the wire to a sudden shock, which occurs simultaneously with the attachment of the leading end of the wire to the winding drum of the empty takeup reel. This shock results because the wire, which at that instant is traveling at a speed slower than the peripheral speed of the winding drum of the empty takeup reel, attempts to decelerate the take up reel rapidly. It has been found that relatively fragile wires frequently break because they are unable to withstand the increased tensions accompanying the shock, thereby causing serious interruptions in the reeling operation. Hence, it is desirable to provide suitable means for eliminating, or reduc-.

ing materially, the shock which results from the mismatch in speeds between the takeup reel drum and the wire.

It is an object of this invention to provide new and improved strand reeling apparatus.

It is another object of this invention to provide new and improved apparatus for controlling the tension in a strand as it is wound upon a takeup reel.

A further object of the invention is the provision of a strand reeling apparatus for winding a strand, being delivered at a substantially constant predetermined linear speed, upon a takeup reel including a winding surface having a peripheral speed somewhat greater than the linear speed of the strand.

Apparatus for winding a strand being delivered at a substantially constant predetermined linear speed upon a takeup reel including a Winding surface having peripheral speed which is different from linear speed of the strand, which illustrates certain features of the invention, may include means for accumulating normally a length of the continuously advancing strand at a point removed from its leading end. Means are provided for changing the size of the accumulated length of the strand at a rate such as to match substantially the linear speed of' the leading end of the strand to the peripheral speed of the winding surface.

More specifically, such apparatus may include a pair of sheaves about which the continuously advancing strand forms a plurality of loops at a point intermediate of the leading end of the strand and a strand supply. A predeterminad length of the strand is accumulated in the loops formed between the sheaves. Means are provided for attaching the leading end of the strand to the winding drum of the takeup reel, the winding drum having a peripheral speed initially somewhat greater than the normal linear speed at which the strand is delivered from the supply. Means are actuated simultaneously with the strand attaching means for causing the sheaves to move relatively together to deliver at least a portion of the strand accumulated in the loops between the sheaves at a rate such that, when added to the rate at which the strand is supplied, it matches the linear speed of the strand between the leading end thereof and the sheaves with the peripheral speed of the winding surface.

Figs. 1 and 2 combined constitute a front elevation of strand reeling apparatus forming an illustrative embodiment of the invention;

Fig. 3 is a schematic representation of an electrical control circuit associated with the apparatus shown in Figs. 1 and 2, and

Fig. 4 is a cam-cycle chart of a cam forming part of the apparatus shown in Fig. 1.

Referring now to the drawings, there is shown in Fig. 2 strand take up apparatus, indicated generally by the numeral 10, for taking up, without interruption, a relatively thin and fragile strand 11. The strand 11 is delivered at a substantially constant rate from an insulating machine (not shown) by a conventional strand advancing capstan 14 (Fig. 1). The latter is driven rotatably at a constant speed by an electric motor 17.

The strand takeup apparatus 10 includes a frame 20 including two vertical end support members 21 and 23 and a vertical central support member 24. Rotatably journalled in suitable bearings on the end support member 21 and the central support member 24 are a pair of cooperating reel-supporting arbors 25 and 26, respectively. Similarly a pair of reel-supporting arbors 27 and 28 are journalled rotatably in suitable hearings on the end support member 23 and the central support member 24, respectively. Removably mounted on the arbors 25 and 26 is a takeup reel 31 and similarly mounted between the arbors 27 and 28 is an identical takeup reel 32, the takeup reels being positioned side-by-side (Fig. 2) for axial rotation about a common rotational axis.

The takeup reels 31 and 32 are of a conventional design and each includes a cylindrical winding drum 34 and a pair of flange-like reel heads 3535 secured fixedly at opposite ends of the winding drum. The reel-supporting arbors 25 and 28 are freely rotatable. The reel-supporting arbors 26 and 27 are provided with tail pulleys 38 and 39, respectively. The tail pulley 38 is connected operatively to a drive pulley 41 by means of a drive belt 42 to form a conventional slipping-belt transmission. Similarly the tail.

pulley 39 is operatively connected to a drive pulley 47 by means of a drive belt 48 to form a slipping-belt transmission. The drive pulleys 41 and 47 are driven rotatably by separate electric drive motors 51 and 52, respectively, having a predetermined, controlled, maximum speed.

Mounted between the central support member 24 and the adjacent inner reel heads 35-35 of the takeup reels 31 and 32, respectively, are snagger discs 55 and 56. The snagger disc 55 is keyed to the reel-supporting arbor 26 for rotation therewith and the snagger disc 56 is similarly keyed upon the reel-supporting arbor 27. Each of the snagger discs 55 and 56 are provided with a series of peripheral, projecting fingers 57 57 utilized for catching the strand 11 when the latter is transferred from one takeup reel 31 or 32 to the other during the operation 'of the strand takeup apparatus. A vertically positioned cutter 59 is mounted on the front of the central support member 24 and is designed to sever the strand 11 when the Patented Dec. 9, s-

3. latter is engaged between the fingers 57-57 during a transfer operation. Strand engaging and severing apparatus similar to that described hereinabove is described in Hosford Patent 1,393,286.

The strand 11 as it approaches the takeup reels 31 and 32 advances partly around a freely rotatable guide sheave 60 positioned on the top of the frame 20 as viewed in Fig. 2. From the guide sheave 60, the strand 11 is directed to and travels partly around a distributor sheave 62, which, in turndirects the strand'between a pair of forwardly projecting, spaced, cooperating guide fingers 6464 mounted at the lower end of a depending bracket arm 65. The guide fingers 64--64 direct the strand 11 to one or the other of the takeup reels 31 and 32.

The bracket arm 65 is a part of amovable distributor carriage, indicated generally by the numeral 70, which is slidably mounted for transverse movement along spaced, horizontally extending traverse rods 71 and 72 supported fixedly at their opposite ends on upright support members 7474. The distributor sheave 62 is rotatably journalled on and supported by the distributor carriage 70 for transverse movement therewith.

The distributor carriage 70 is connected to the outer end of a piston rod 76 of a hydraulically-actuated distributing cylinder 78 designed to reciprocate the distributor carriage to and fro with respect to the takeup reels 31 and 32. The distributing cylinder 78 is mounted slidably on the traverse rod 72 by virtue of sliding collars 81 and 82. The collar 82 is, in turn, attached fixedly to the outer end of a piston rod 84 of a pneumaticallyactuated stepping cylinder 85 which is designed to index the hydraulically-actuated distributing cylinder 78 alternately from one of two operating positions to the other. In one operating position, illustrated in Fig.2, the distributing cylinder 78 is located so as to cause the distribution of the strand 11 in smooth, even layers upon the winding drum 34 of the takeup reel 31. In the other operating position the distributing cylinder 78 is located so as to cause the strand 11 to be distributed similarly upon the takeup reel 32.

The reciprocation of the piston rod 76 of the distributing cylinder 78 is effected in a conventional manner, for example by hydraulic pumps (not shown) driven from the respective takeups 31 and 32. A pair of sensitive limit switches 88 and 89 are mounted on the frame 20 and are actuated, when the reel 31 is being wound as shown in Fig. 2, alternately by a cam 92 mounted on the distribu tor carriage 70 for movement therewith to effect the desired reversal of the piston rod 76 of the distributing cylinder at the end of each transverse stroke by operating a conventional, solenoid-operated reversing valve (not shown) which controls the direction of flow of hydraulic fluid supplied to the distributing cylinder 78. A second cam 91 is also mounted to the carriage 70 and is designed to actuate the switches 88 and 89 when the strand is being wound on the reel 32.

The operation of the stepping cylinder 85 is controlled by a conventional length counter 95 which is operatively connected to and. driven from the guide sheave 60'to register the footage of the strand 11 passing over the guide sheave. The length counterv95 may be preset to actuate and momentarily close a normally open contact 97 (Fig. 3) each time the counter registers the passage of a predetermined length of the strand 11.

The normally open contact 97 forms part of an electrical control circuit illustrated in Fig. 3, which includes a pair of operating solenoids 101 and 102 of a conventional, solenoid operated, four way, spool-type reversing valve 105 designed to control the operation of the stepping cylinder 85. When the operating solenoid 102 is energized momentarily it actuates the reversing valve 105 so as to cause compressed air from a suitable supply to be admitted into theright hand end of the stepping cylinder to force the. piston rod 84 to the left, as viewed in- Fig. 2, the left hand end of the steppingcylindenbeing connected to exhaust. Conversely, when the operating solenoid 101 is energized momentarily the reversing valve 105 is operated to throw the piston rod 84 of the stepping cylinder to the right.

The operating solenoids 101 and 102 of the reversing valve are connected in series with normally open, spring biased, contacts 114 and 112, respectively, of sensitive limit switches 116 and 115, respectively (Fig. 2). The limit switches 115 and 116 are positioned so asto be operated by a cam 117 secured to the collar 82 and are operated alternately as the piston rod 84 is indexed. The series connection of the operating solenoid 101 and the normally open contact 114 is, in turn, connected in parallel with the series connection of the operating solenoid 102 and the normally open contact 112. The latter parallel arrangement is, in turn, connected in series with a D. C. source of E. M. F. through the normally open contact 97 of the length counter 95.

Positioned between the strand takeup apparatus 10 and the strand-advancing capstan 14 is a pair of multigrooved, jockey sheaves 120 and 121. The strand 11 is directed to the jockey sheaves 120 and 121 by guide sheaves 122 and 123 and forms several loops about jockey sheaves 120 and 121 before advancing to the guide sheave 60. When the jockey sheaves 120 and 121are in their normal positions, as shown in Fig. 1, the thus formed loops contain an accumulated, predetermined length of the strand 11. The jockey sheaves 120 and 121 are mounted freely rotatably on movable, sheave-supporting mounts 125 and 126, respectively. The sheave-supporting mounts 125 and 126 are engaged slidably on a horizontally extending track 130 for longitudinal movement therealong. The track 130 is supported at its opposite ends by upright columns 133 and. 134.

The sheave-supporting mount 125 is located at the right hand end of the track 130, as viewed in Fig. 1, and is connected to the upright column 133 by means of a relatively strong tension spring 135. The sheave-supporting mount 126 is provided with a depending cam follower 137 which is slidably engaged in a cam slot 139 formed in an elongated, drum-type cam 140. The cam 140 is keyed upon a horizontally extending shaft 142, the opposite ends of which are rotatably journalled in the upright columns 133 and 134, respectively.

The shaft 142 and cam 140 are driven positively from a .jack shaft 148 through a chain and sprocket transmission 145 having a 1:1 train ratio. The jack shaft 148 is journalled rotatably on the upright column 134. A solenoid-actuated, single-revolution clutch 150 is pro vided for engaging the jack shaft 148 operatively to a continuously rotating output shaft 152 of a gear reduction unit 155 driven by the continuously operating motor 17. The motor 17, which drives the strand-advancing capstan 14, is connected to the latter through the gear reduction unit 155 and its output shaft 157.

The; single-revolution clutch 150 includes a springbiased, detent tripping lever, which is connected to a plunger 163 operated by a solenoid 165. When the solenoid 165 is energized momentarily, the detent tripping lever 160 is operated to actuate the clutch 150 so as to connect the jack shaft .148 to the continuously rotating output shaft 152 for rotation therewith' through a complete 360 revolution. At the end of this single revolution the clutch 150 operates to disengage the jack shaft 148 from output shaft 152 and to stop the jack shaft at its original starting position. Thus the cam 140 makes precisely a single, complete 360 revolution. As shown in Fig. 3 the clutch-operating solenoid 165 is connected in series with the normally open contact 97 of the counter 95.

During the single, complete revolution of the cam 140, the cam follower 137 engaged in the cam slot 139 causes the jockey sheave 121 to move through a complete operating cycle. The movement of the jockey sheave 121 relative to thetrack 130- and thejockey sheave 120 maybe visualized best by reference to a cam cycle chart ,illustrated in Fig. 4. Referring now to Fig. 4, it may be seen that instantaneously at the start of the cycle the jockey sheave 121 is' driven to the right, as viewedin Fig. 1, toward the jockey sheave 120 at a predetermined speed. As the jockey sheave 121 nears the jockey sheave 120, it decelerates and finally, upon reaching an extreme right hand position, as shown in dashed outlines in Fig. 1, it reverses its direction of travel and returns to its original starting position at a greatly reduced speed.

Operation Let it be assumed that the strand 11 is being taken up presently on the takeup reel3l, as illustrated in Fig. 2, and that the takeup reel is almost full. The motor 51 drives the takeup reel 31 at a speed such that the continuously advancing strand 11 is under a substantially constant, predetermined tension.

As the time for the transfer operation approaches, the motor 52 is energized also to drive the empty takeup reel 32 rotatably at a speed such that the peripheral speed of its winding drum 34 exceeds the normal linear speed of the strand 11 by approximately 8 to 10%. It will be understood that the normal linear speed of the strand 11 is the speed established by the strandadvancing capstan 14. A substantial overdrive of the winding drum 34 of the takeup reel 32 is necessary in order to avoid the frictional instability attending the threshold between static and moving conditions, which is a characteristic of a slipping-belt transmission.

As soon as a predetermined length of the strand 11 has been Wound upon the takeup reel 31, the counter 95 operates to close its normally open contact 97 momentarily, thereby energizing the operating solenoid 102 momentarily through the then closed contact 112 of the sensitive limit switch 115. When the solenoid 102 is energized, the reversing valve 105 is actuated to admit compressed air to the right hand end of the stepping cylinder 85 to force the piston rod 84 to its extreme left hand position, as viewed in Fig. 2.

The movement of the piston rod 84 to its extreme left hand position indexes the distributor carriage 70 to the left adjacent to the empty takeup reel 32, in which latter position the distributor carriage is set to distribute the strand 11 uniformly upon the winding drum 34 of the takeup reel 32. As the distributor carriage is indexed in this manner, the strand 11 is caught by a pair of projecting fingers 57-57 on the snagger discs 55 and 56, respectively, and carried against the cutter 59 mounted on the center support member 24 whereby it is severed. The new leading end of the strand 11 is held by the finger 57 on the snagger disc 56 and is wrapped on the drum 34.

Simultaneously with the closure of the contact 97 of the counter 95, the clutch-operating solenoid 165 is energized to operate the detent tripping lever 160 of the single revolution clutch 150. The operation of the detent tripping lever 160 instantaneously engages the jack shaft 148 to the continuously operating output shaft 152 for a complete 360 revolution of the latter shaft.

Instantaneously, the cam 140 commences its complete 360 revolution.

During the time interval that the new leading end of the strand 11 is seized by the fingers 57-57, severed and attached to the empty winding drum 34, the jockey sheave 121 is driven by the cam 140 and moves at a predetermined speed toward the jockey sheave 120. To insure the movement of the jockey sheave 121 instantaneously at the desired predetermined speed, it is important that the inertia of the system including the jockey sheave 121, the mount 126 and the cam 140 be relatively low in comparison with the inertia of the system including the shaft 152 and the motor 17. The predetermined length of the strand I1 accumulated previously in loops between the jockey sheaves 120 and 121 is dissipated match substantially the peripheral .speed of the empty winding drum 34.

At the time of the transfer of the strand 11 from the takeup reel 31 to the takeup reel 32 there is substantially no difference in speed between the leading end of the strand 11 and the empty winding drum 34. Hence,

the shock which would occur normally due to the speed mismatch is eliminated effectively because the inertia of the empty takeup reel system, which must be overcome in decelerating the takeup reel 32 to reduce the peripheral speed of its winding drum to its proper value, is dissipated smoothly over a greater length of time with an accompanying reduction in the tension created in the strand 11.

Sometime after the rightward movement of the sheave 121 commences and before it reaches the extreme right hand position, as illustrated in dashed lines in Fig. 1, the required deceleration of the takeup reel 32 is accomplished and the proper slip (no less than approximately 8 to 10%) takes place between the belt 48 and the drive pulley 47 to take up the strand 11 under normal tension. Thereafter, when the pulley 121 reaches the extreme right hand position, its direction of travel is reversed and it is returned at a reduced speed to its original starting position. Upon completion of the cycle of the cam 140, the clutch 150 automatically disengages and the apparatus is in readiness for the next transfer operation, which will occur when the now empty takeup reel 32becomes full. It will be noted that the manner in which the jockey sheave is mounted resiliently enables this sheave to absorb some of the shock to complement the action of the cam-driven jockey sheave 121.

It Will be understood that this invention is not limited to the specific embodiment of the invention hereinabove described. Manifestly, numerous modifications and variations of this apparatus may be made within the spiirt and scope of the invention.

What is claimed is:

1. Strand reeling apparatus for winding a strand, being delivered at a substantially constant predetermined linear speed, upon a takeup reel including a winding surface having a peripheral speed somewhat greater than the linear speed of the strand, which apparatus comprises means for accumulating a length of the advancing strand at a position removed from the reel, means for attaching the strand to the winding surface of the takeup reel, and means actuated simultaneously with said attaching means for dispensing at least a portion of the accumulated length of the strand at a rate such as to match substantially the linear speed of the strand as it approaches the reel with the peripheral speed of the winding surface.

2. Strand reeling apparatus for winding a strand, being delivered at a substantially constant predetermined linear speed, upon a takeup reel including a Winding surface having a peripheral speed somewhat greater than the linear speed of the strand, which apparatus comprises a pair of spaced rotatable sheaves about which the advancing strand forms at least one loop interme diate of the leading end of the strand and the strand supply, means for attaching the strand to the winding surface of the takeup reel, and means actuated simultaneously with said attaching means for causing a relative movement of the sheaves toward one another to dispense at least a portion of the length of the strand accumulated in said loop at a rate such as to match substantially the linear speed of the strand as it appreaches the reel with the peripheral speed of the winding surface.

3. Strand reeling apparatus for taking up a strand, delivered continuously at a constant predetermined linear -speed"from' a supply thereof, on a takeup reel with a winding drum having a peripheral speed initially somewhat greater than said linear speed of the strand, which apparatus comprises means for accumulating a length of the continuously advancing strand intermediate of the leading end of the strand and the supply thereof, means for attaching the leading end of the strand to the winding drum of the takeup reel, and means actuated simultaneously with said strand attaching means for causing the strand accumulation means to dissipate at least a portion of the accumulated length of strand'at a rate such that when added to the rate-at which the strand is supplied increases effectively the linear speed of the leading end of the strand to match the peripheral speed of the winding drum.

4. Strand reeling apparatus for taking up a strand delivered continuously from a strand supply at a constant predetermined linear speed, which apparatus comprises a slipping-belt driven takeup reel provided with a winding surface having initially when empty a peripheral speed somewhat greater than the linear speed at which a strand is delivered from a strand supply, strand collection means for storing a length of the continuously advancing strand intermediate of the leading end thereof and the strand supply, means for catching the leading end of the strand and attaching it to the empty winding surface of the takeup reel, and means actuated simultaneously with said last-mentioned means for operating the strand collection means to dissipate at least a portion of the accumulated length of the strand at rates that when added to the rate at which the strand is supplied establish effectively optimum linear speeds of the leading end of the strand which promote the transfer of the strand without attendant shock.

5. Strand reeling apparatus for taking up a strand delivered continuously from a strand supply at a constant predetermined linear speed, which apparatus comprises a slipping-belt driven takeup reel provided with a winding surface having initially when empty a peripheral speed somewhat greater than the predetermined linear delivery speed of the strand, a pair of spaced, rotatable, strand-engaging sheaves about which the continuously advancing strand forms a plurality of loops containing a predetermined accumulated length of the strand intermediate of its leading end and the strand supply, strand transfer means for catching the leading end of the strand and attaching the strand to the overrunning empty winding surface of the takeup reel, and cam means operated simultaneously With the strand transfer -means for moving the sheaves relatively together at a predetermined speed such as to deliver at least a portion of the strand accumulated thcrebetween at a rate such that when added to .the rate at which the strand is delivered from the strand supply tends to match the linear speed of the leading end of the strand with the peripheral speed of the winding surface to effectively eliminate the. shock on the strand due to a mismatch in the speeds.

6. Apparatus for transferring from one takeup reel to another takeup reel a strand delivered at a constant predetermined linear speed, the winding surface of the latter takeup reel having a peripheral speed initially somewhat greater than said linear speed of the strand, which apparatus comprises a pair of spaced rotatable sheaves about which the continuously advancing strand forms at least one loop normally containing a predetermined accumulated length of the strand intermediate of its leading end and the strand supply, strand transfer means for severing the strand adjacent to said firstmentioned reel and for simultaneously attaching the new leading end of the strand to the winding surface of the other takeup reel, and means operated simultaneously with the strand transfer means for moving the sheaves relatively together at a predetermined speed such as to reduce the length of strand accumulated between the "sheaves at-a rate such that when added to the rate-at which thestrand is delivered from the supply tends to match 'the'linear speed of the leading and of the strand withthe peripheral speed of the-winding surface.

7. In strand reeling apparatus including strand-advancingi means for delivering a strand from a supply thereof at a constant predetermined linear speed, a pair of takeup reels for winding the strand alterantely thereupon, slipping-belt drive means for driving the takeup reels rotatably, said drive meansbeing designed to overdrive the takeup reels when empty at speeds such that the peripheral speed of their empty winding surfaces exceeds the predetermined linear delivery speed of the strand by a predetermined amount, means for transferring the strand from a full takeup reel to an empty talteup reel and means operated simultaneously with said strand-transferring means for severing the strand and attaching the-new leading end thereof to the winding surface of theempty'takeup reel, the improvement which comprises means positioned intermediate of the strand-advancing means and the -takeup reels for storing a loop of the continuously advancing strand, and means operated simultaneously with said strand severing and attaching means for dissipating the strand accumulated in said loop at rates such that when added to the rate at which the strand is supplied establish effectively optimum linear speeds of the new leading end of the strand which promote the transfer of the strand to the empty winding surface without attendant shock.

8. In strand reeling apparatus including strand-advancingmeans for delivering a strand from a supply I thereof at a constant predetermined linear speed, a

pair of takeup reels for winding the strand alternately thereupon, slipping-belt drive means for driving the takeup reels rotatably, said drive means being designed to overdrive the takeup reels when empty at speeds such that the peripheral speed of their empty winding surfaces exceed the said predetermined linear delivery speed of the strand by a predetermined amount, means for transferring the strand from a full takeup reel to an empty takeup reel and means operated simultaneously 'with'said strand transferring means for severing the strand and attaching the new leading end thereof to the winding surface of the empty takeup reel, the improvement which comprises a pair of strand-engaging sheaves positioned intermediate of the strand-advancing means and the takeup reels, a track, a pair of sheave-supporting members, each-of'which is designed to support one of the sheaves rotatably and is mounted movably on the track for travel therealong, said sheave-supporting members being normally separated so that the sheaves are spaced apart by a predetermined distance and the continuously advancing strand forms a loop about the sheaves containing apredetermined accumulated length ,of the strand, and means operated simultaneously with said strand severing and attaching means for moving the sheavesupportinggmembers together at a predetermined speed to dissipate the length of the strand accumulated in the loop at a rate such as to increase the effective linear speed vof the new leading end of the strand sufficiently to match-substantially the peripheral speed of the empty winding surface.

9. The apparatus of claim 8 in which the means lastmentioned therein is also for subsequently returning the sheaves to their normal separated positions at a relatively slower'speed than the speed at which the sheave supportingmembers are moved together.

References Cited in the file of this patent UNITED STATES PATENTS

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