US2709403A - Stranding machine - Google Patents

Description

May 31, 1955 R. HUNT STRANDING MACHINE Filed Sept. 21, 1950 3 Sheets-Sheet 1 t on mm m M a n m M 6 PA. L5;

y 1, 1955 R. HUNT STRANDING MACHINE I5 Sheets-Sheet 2 Filed Sept. 21, 1950 as 22. 2s 23 1' INVENTOR. LeonardRHum altar/my.

May 31, 1955 R. HUNT STRANDING MACHINE Filed Sept. 21, 1950' 3 SheetS-Sheet 3 y my W m r M wk m% 8 .L

United States Patent STRANDING MACHINE Leonard R. Hunt, Muncy, Pa., assignor to Jones &

Laughlin Steel Corporation, Pittsburgh, Pa., 2 corporation of Pennsylvania Application September 21, 1950, Serial No. 186,047 16 Claims. (Cl. 57-1) This invention relates to machines for stranding filaments of wire, vegetable fibers, and plastics or the like. It is directed more particularly to a machine for high speed stranding of relatively small wires, and throughout my specification and claims reference is made to the stranding of small wires, but it should be understood that the machine of my invention may also be used for stranding filaments of other materials.

Wire rope or cable is composed of individual wires laid or twisted together to form strands, the strands themselves being laid or twisted together to form a cable if desired. Machines for combining individual wires to form strands, and for combining strands to form cables, are well known in the art and embrace a variety of types designed for specific products. All such stranders operate on the same general principle, and embody a rotating structuref frequently called a ilyer, for twisting or laying the wires together to form a strand, and cradle means for one or more spools of wire mounted either on the rotating structure or within it. The speed with which wire can be stranded by such machines is, as a rule, limited by the maximum speed at which the fiyer or other rotating parts can operate. High speed stranders, prior to my invention to be described, were therefore made with rotating parts of relatively small diameter. Although stranders so constructed could operate at relatively high speeds, the amount of wire which could be held by the relatively small size spools this construction necessitated was small. The frequent shutdowns of. such machines for reloading with full spools thus tended to nullify the production advantage of high speed operation.

A further disadvantage of most known stranding machines capable of reasonably high speeds is the twist they impart to one or more of the wires before stranding, or to the strand, or both. Twist is imparted to a wire being stranded or a strand being formed when it.

passes through any guide or other meanswhich prevents it from rotating freely about its own axis. Thus, if a wire or strand coming from a rotating part passes through eyes or over pulleys which change its course more than about 90, or iswound up on the drum or spool, it is twisted. Twisting of individual wires or a strand is undesirable because it builds up localized stresses in the wire. If the -wire were perfectly uniform from end to end, the torsional stresses resulting from twisting would be distributed evenly along its length, but as perfect uniformity of wire is commercially impractical, these stresses concentrate at imperfeetions in the wire. The same is true of the twisted strand. Furthermore, the twist imparted to the wire or strand results in an unruly or wild product that does not lie fiat and is difficult to work with.

The principal object of my invention therefore is to provide a strander for fine wire capable of continuous operation at high speed. Another object is to provide such a strander which has spools accommodating a relatively large amount of wire. Another object is to provide such a machine which strands fine wires without twisting the wires individually before stranding, or twisting the strand after forming. Another object is to provide such a machine with automatic means for shutting it down upon the breakage of a wir Other objects will appear in the course of the description of my invennon.

l have discovered that the limitations of wire stranders known prior to my invention can be overcome to a large degree by constructing the machine so that it has no flyer or spool cradle in the accepted sense, but is provided with individual cantilevered rotating shells having cantilevered spool cradles journaled therein, these shells being independently but synchronously driven. The shells of my machine, synchronously rotating about a common axis, fulfill the functions of the conventional flyer but are unconnected except by the wires being stranded. The spool cradles are likewise entirely inde pendent of each other, but are likewise journaled about the common axis of the shells. By this construction I avoid entirely all problems of alignment. Furthermore, my shells and spools may be made large enough to accommodate a considerable amount of wire without detriment to the speed of the machine.

A present preferred embodiment of my invention is illustrated by the accompanying figures, to which reference is now made:

Figures 1A and 1B are plan views, partly in section through the plane II of Figures 2A and 2B, of a wire strander constructed according to my invention. The view is broken at the dotted line, the left hand end of the machine being shown in Figure 1A and the right hand end in Figure 1B;

Figures 2A and 2B are side elevations of the machine shown in Figures 1A and 1B, likewise broken at the same dotted line;

Figure 3 is a detail elevation, spool cradle and bearing plane TIL-Hi of Figure 1A;

Figure 4 is an end elevation of a rotor shell showing the eyes for guiding wires'therethrough and the location of wire passages in one of the-rotor. shafts;

Figure 5 is a detail drawing,.partly in' section through the plane V-V of Figure 4, showing the method of mounting an eye in a rotor shell; a

Figure 6 is another view, partly in section through the plane VI-VI of Figure 5, of the mounting shown in Figure 5;

Figure 7 is an end elevation of a wire bobbin'mounted in a bobbin cradlev showing the braking mechanismj Figure 8 is a detail cross-section of the automatic cut-otf mechanism, taken through.- the plane VIII'VIII' of Figure 2A; v. 1

Figure 9 is a detail elevation, partly in. section through the plane IXIX of Figure 1A, of a portion of a. rotor shaft and its associated automatic cut-off mechanism,

Figure 10 is a detail cross-section of a rotor pulley and drive belt, taken through the plane X--:X of Figure 2A.

My machine is mounted on a rigid horizontal base 1. At one end of this base 1 is located a split bear ing stand 2 provided with journal bearings 3 and 4,- which may be antifriction bearingsof the ball or roller type. In these bearings is journaled a shaft 5 'p1-ovided with a driving pulley 6 and carrying at its inner" end a shallow cylindrical shell 7. Centrally located in the inner end of shaft 5 is a journal bearing 8 jourf ualing a shaft 10. To the inner end of this shaft is fixed a cradle 11. On the .outer endof split bearing stand 2 is fastened a bracket 12 holding a cradle 13. The outer end of shaft 5 is provided with an axially partly in section, of a therefor, taken through the bored hole 14 which extends about half the length of the shaft and is met by the bored hole 15 which terminates on the outer surface of shaft 5 between the bearing 4 and the shell 7. The shell 7 is provided with a hole 16 through its end, this hole being aligned with the axis of the inclined bore 15. The shell 7 is likewise provided with an eye 17 on its inner surface near its open end, this eye 17 being aligned both with the hole 16 and the inclined bore 15. Although only one hole and eye are necessary for leading the wire through shell 7, as will appear, it may be desirable, to preserve dynamic balance, to provide three such holes and eyes in shell 7, spaced 120 apart. The cradle 11 has attached thereto an upstanding bracket 19 carrying an eye 20, this eye being aligned with the axis of shafts 5 and 10.

Aligned with the bearing stand 2 but spaced therefrom on the base 1 is a second and identical bearing stand 21 provided with journal bearings 22 and 23. In these hearings is journaled a shaft 24 provided with a driving pulley 25 and carrying at its outer end, that is, its end adjacent shell 7, a shallow cylindrical shell 26. Centrally located in the outer end of shaft 24 are journal bearings 28 journaling a shaft 29, and to the outer end of this shaft is fastened a cradle 39. The cradle shaft 29 is provided with an axial hole 31 which extends throughout its length. The shaft 24 is likewise provided with an axial hole 32 aligned with the hole 31 in shaft 29 and extending from the end of the recess enclosing journal bearing 28 inwardly to approximately the same point as is reached by the hole 14 in shaft 5. This hole 32 is intersected by a hole 33 which terminates on the exterior of shaft 24 beyond journal bearing 23. The shaft 24 is provided at its inner end with an annular projecting channel 35 having upstanding flanges 37 and 38 respectively, and terminates in a rotor mechanism 39 to be described. Three longi tudinal holes 40, 41 and 42, symmetrically spaced 120 apart about the circumference, traverse the shaft 24 from its outer end to its inner face as determined by flange 38. Only two of these are required to lead through the wires, as will appear, but it is desirable to drill the third hole to preserve the dynamic balance of the shaft 24.

The shell 26 is provided with bored holes in its end face corresponding to the previously mentioned holes 40, 41 and 42 in the shaft 24. The shell 26 is likewise provided around the interior of its flange with three pairs of eyes 43-43, 44-44 and 46-46 spaced 120 apart and aligned with the holes 40, 41 and 42 in the shaft 24 respectively.

The three cradles 11, 13 and 30 of my apparatus carry spools or bobbins 47, 48 and 49 respectively, which are identical in construction and hold the wire to be stranded. These bobbins are mounted in their respective cradles so that they can rotate freely about their axes, but their rotation is restrained and tension is applied to the wire as it unwinds by a braking mechanism which comprises a flat spring arm 59 holding a transverse member 51, which is faced on the side adjacent the wire with frictional material such as brake lining. The spring arm 50 urges the frictional material carried by the transverse member 51 against the surface of the wire 52 wound on the spool.

The bobbin 48 is mounted in the bobbin cradle 13 as shown, and the wire therefrom is introduced into the bored hole 14 in shaft 5 and led through intersecting bore 15, which brings it through bearing stand 2. From the end of the bore 15 the wire passes through the hole 16 in the shell 7 and eye 17 on the inside of the flange of this shell, and from there is carried across to shell 26 where it passes through the pair of eyes 43-43 on the inside flange. The wire thus clears both bobbins 47 and 49. ,From the pair of eyes 43-43 the wire is led into the bore 40 which extends through the shaft 24 and emerges at the face of the annular flange 38. The wire from the bobbin 47, which is held in the cradle 11, is led through the eye 20, carried by the cradle bracket 19, and from this point passes over to shell 26 where it is led through a pair of eyes 44-44 and into longitudinal bore 41 of shaft 24, emerging again at the outer face of flange 38. The wire from the third bobbin 49 carried in the third cradle 36 is led into the axial bore 31 of cradle shaft 29, from thence into the axial bore 32 of shaft 24 and the intersecting bore 33, emerging at the surface of shaft 24 between shaft bearing 23 and the flange 37. The wire is led through holes 36-36 in flanges 37 and 38 and so emerges, like the other wires, at the inner surface of flange 38. The three wires at this point are positioned around the circumference of the face of flange 33 at intervals of 120. They pass at the same relative spacing through the rotor 39 of the automatic cut-off to be described, and from this rotor enter the die 53.

The automatic cut-off is shown in detail in Figures 8 and 9. The rotor 39, as mentioned, is carried by the shaft 24. This rotor is surrounded by a concentric ring 55 of conductive material carried by the arm 56 mounted in an insulated bushing 57 in the bracket 58, which also supports the die 53. The rotor 39 is formed with an annular channel 59, the walls of which are pierced by three pairs of holes -60 disposed 126 apart. Through these holes the wires 63 pass. Within the annular channel 59 are pivotally mounted three arms 61 on pins 62. For clearness, only one such arm and pin are shown on the drawings. Each arm 61 is provided at the upper surface of its free end with a semicircular channel 64 aligned with the opening 68 through which the wire passes. The wire 63 is threaded through the pair of holes 60-60 over the arm 61 so that the outer end of this arm is prevented by the wire from moving up and making contact with the concentric ring 55. When the machine is operating, centrifugal force causes the arm 61 to swing outward about its pivot 62 and assume the position shown in Figure 8, the wire 63 being engaged between the intersecting arcs of the hole 60 and the semicircular channel 64. If the wire 63 should break while the machine is in operation, the restraint upon the arm 61' would be removed and the free end of the arm would be thrown outward by centrifugal force until it made contact with the concentric ring 55 as shown by the broken lines of Figure 8.

The three wires coming from rotor 39 pass through die 53 mounted on bracket 58, and at this point are laid up or stranded, passing to the haul-01f drums 6S and 66 as a three-wire strand. Haul-off drum is driven through gear reducer 67 as will be described. Drum 66 is an idler supported by bracket 68. The haul-off mechanism is conventional and will not be described further. From this mechanism fl1e strand passes through the level winder 69 driven through the reduction gear and cam apparatus 70, which also is familiar to those skilled in the art and requires no further description here. The strand is wound up on take-off bobbin 71, mounted on shaft 73, which is journaled in bearings 74-74 supported on bracket 75.

My apparatus is driven preferably by an electric motor or other source of power which may be mounted below the base 1 and is not shown in the figures. The drive from the motor or other power source to primary drive pulley 76 is preferably through a V-belt. Pulley 76 is rigidly attached to shaft '77, one end of which is coupled to the drive shaft of gear box 67. The other end of shaft 77 is journaled in bearings 78-78 and carries pulleys 79 and 8%) respectively. These pulleys are positioned opposite rotor pulleys 25 and 6 respectively, and all are provided with teeth 81 as shown more clearly in Figure 10, which mesh with corresponding teeth 82 of a flexible belt 83 of the type known as a timing belt. This belt is omitted from Figure 1A for clearness.

Shafts 5 and 24 are therefore synchronously but independently driven from drive shaft 77.

Gear box 67 is provided with a double-ended shaft 72, one end of which carries haul-off drum as has been mentioned. The other end carries a flat-faced pulley 84. Idler pulley 85 mounted on bracket 86 provided with adjusting screw 87 is aligned with pulley 84 and a second flat-faced pulley 88 mounted on the end of shaft 73. A flat belt, omitted from the figures for clearness, is looped around pulleys 84 and 88, and held taut by idler pulley 85. immediately behind pulley 88 is a pinion 89 also fastened to shaft 73, which drives a second pinion 91 attached to drive shaft 92 of level winder mechanism previously described.

The gear ratio of gear box 67 is such that shaft 72 turns at a fraction of the speed of shaft 77. Pulleys 79 and 25, likewise and 6, are conveniently made the same size so that rotors 7 and 26 rotate at the same speed as drive shaft 77. The rate of travel of the strand, and thus the rate of production for a given motor speed, is determined by the peripheral speed of haul-off drum 65. The pitch of the strand is determined by the ratio between this peripheral speed and the rotational speed of rotors 26 and 7. All these factors are considered in determining the gear ratio of gear box 67. The flat belt used to drive the pulley 88 from pulley 84 is adjusted to permit sufiicient slippage so that the strand is always tightly wound on spool 7 1. The level winder mechanism is directly driven from shaft 73 so that the strand is always wound level on spool 71 regardless of slippage of the belt driving pulley 88.

The operation of my apparatus has been explained in part in connection with the description of the foregoing paragraphs. As has been mentioned, spools or bobbins of wire 47, 48 and 49 are placed in cradles 11, 13 and i 30 respectively, and the wire from each spool threaded through my machine along the path previously described. The three wires emerge from the rotor 39 at apertures spaced apart around its circumference, and from here pass together through die 53. After the wires have been threaded through my machine, as has been mentioned, the motor is started and shells 7 and 26 begin to rotate. Cradles 11 and 30, however, being supported by shafts journaled for free rotation in rotor shafts 5 and 24 respectively, are restrained from rotation by gravity. Rotating shell 7 carries the wire from spool 48 around spool 47, and rotating shell 26 carries the wires from spools 47 and 48 around spool 49. The rotation of rotor 39 causes the three individual wires to be laid or wrapped around one another as they pass into die 53, and the strand so formed is wound about haul-off drums 65 and 66, and therefore prevented from itself rotating. The result is the formation of a three-wire strand with no twisting either of the individual wires themselves before stranding or of the strand itself after it is formed. The strand from haul-off drums 65 and 66 is wound through level winder 69 onto take-off spool 71 in the conventional manner.

No problems of alignment of rotating wire-carrying parts present themselves in the construction of my machine, which is thus freed from one of the limitations of high speed operation. Machines constructed according to my invention for stranding fine wire a few thousandths of an inch in diameter have been operated at speeds up to 7,200 R. P. M. with no ditficulty, which is appreciably faster than any other stranding machines with which I am familiar. The rotating shells 7 and 26, being light in weight and of low inertia, may be made large enough to accommodate sizable bobbins or spools holding substantial quantities of wire, enabling my machine to run for extended periods of time between shutdowns for reloading. As has been indicated, the shells 7 and 26, which are the largest rotating parts of my machine, should be dynamically balanced about their shafts for best results.

The spools of wire 47, 48 and 49 rotate in their cradles 11,. 13 and 30 as the wires are unreel'ed. The braking members 51, which have previously been mentioned, control the speed of these spools and maintain a desirable tension upon the wire. As has been shown, the braking member 51 engages the wire directly rather than the spool itself. This construction has been found desirable since it provides a diminishing braking force as the amount of wire on the spool decreases, and thus tends to maintain more uniform wire tension.

In my previous description of the automatic cut-off mechanism I have shown that upon breakage of the wire, the free end of pivoted arm 61 is thrown outward by centrifugal force, making contact with the conductive ring 55. I have also mentioned that this ring is insulated from the remainder of the machine structure. This ring and the remainder of the machine are electrically connected to a conventional relay mechanism, not illustrated, which breaks the circuit through the driving motor when energized by contact between arm 61 and ring 55. As such electrical mechanisms are well known and in themselves form no part of my invention, I do not describe them further.

The contact arm 61 may be spring biased or loaded so that upon breakage of its restraining wire, it is urged outwardly by the force of the loaded spring, as well as centrifugal force. A spring loaded arm is held steadily and without chattering against the ring 55 as the machine slows down. The choice between spring loaded arms and those without spring loading is of course governed by the nature of the electrical circuit actuated by contact be tween an arm and the ring.

The rotors of my strander may be independently but synchronously gear driven from the counter shaft, rather than belt driven as illustrated and described. Likewise, the drive motor may be directly connected to the counter shaft, or connected by gearing if desired. The haul-off drum and wind-up spool may also be driven by means other than here described, without departing from the I spirit of my invention.

Although I have described and illustrated the present preferred embodiment of my invention, it will be understood that the invention is not limited thereto but may be otherwise embodied or practiced within the scope of a my claims.

rotor members mounted on the first and second rotorv shafts respectively, first and second cradle shafts concentrically journaled in the first and second rotor shafts respectively, first and second cradles mounted on the first and second cradle shafts respectively, and wire carrying spools mounted for rotation in these cradles.

2. In a Wire stranding machine the combination of a frame, first and second rotor shafts journaled in the frame in spaced relation along a common axis, first and second rotor members mounted on the first and second rotor shafts respectively, first and second cradle shafts concentrically journaled in the first and second rotor shafts respectively, first and second cradles mounted on the first and second cradle shafts respectively, wire carrying spools mounted for rotation in these cradles, and means for driving the rotor shafts independently but synchronously.

3. In a wire stranding machine the combination of a frame, first and second rotor shafts journaled in the frame in spaced relation along a common axis, first and second rotor members mounted on the first and second rotor shafts respectively, first and second cradle shafts concentrically journaled in the first and second rotor shafts respectively, first and second cradles mounted on the first and second cradle shafts respectively between the rotor shafts, and wire carrying spools mounted for rotation in these cradles.

4. The combination of claim 1 having a third cradle fixed to the frame on the common axis beyond the first rotor shaft and a third wire carrying spool mounted for rotation in the third cradle.

5. In a wire stranding machine the combination of a frame, a rotor shaft journaled in the frame, a rotor member cantilevered from an end of the rotor shaft, a cradle shaft concentrically journaled in the rotor end of the rotor shaft, a first cradle positioned within the rotor member and cantilevered from the cradle shaft, a second cradle fixed to the frame, Wire carrying spools mounted for rotation in the cradles, and means for driving the rotor shaft.

6. The combination of claim 1 having first and second rotor members cantilevered from the inner ends of the first and second rotor shafts respectively, and first and second cradles cantilevered from the inner ends of the first and second cradle shafts respectively, the first rotor member and the first cradle being aligned with and immediately adiacent to the second rotor member and second cradle respectively but inde endent thereof.

7. The combination of claim 1 having first and second rotor members in the form of shallow cylindrical shells open at their adjacent ends and partially enclosing their respective cradles.

8. The combination of claim 3 having first and second rotor members in the form of shallow cylindrical shells open at their adjacent ends and partially enclosing their respective cradles, and wire guide means carried by the rotor shells comprisin eyes through which the Wire is passed, these eyes being attached to the inner circumference of the rotor shells and so arranged that the several eyes of the first rotor shell are aligned with those of the second rotor shell respectively.

9. The combination of. claim 3 having first and second rotor members in the form of shallow cylindrical shells open at their adjacent ends and partially enclosing their respective cradles, wire guide means carried by the rotor shells comprising eyes through which the wire is passed, these eyes being attached to the inner circumference of the rotor shells and so arranged that the several eyes of the first rotor shell are aligned with those of the second rotor shell respectively, and an eye carried by a cradle and positioned on the common axis between the first and second rotor members.

10. The combination of claim 1 having a third cradle fixed to the frame on the common axis beyond the first rotor shaft, a third wire carrying spool mounted for rotation in the third cradle, and wire guide mezms carried by the rotor members comprising eyes through which the wire is passed and wire guide passages in the rotor shafts so arranged as to thread a strand of wire from the third spool around the first and second spools and out through the second rotor member without reversing direction, and to thread a strand of wire from the first spool around the second spool and out through the second rotor member without reversing direction.

11. The combination of claim 1 having wire guide means carried by the rotor members and a Wire laying head on the second rotor shaft for laying the Wires from the spools over each other.

12. In a wire stranding machine, the combination of a frame, first and second cantilevered unconnected rotor members open at their adjacent ends rotatably mounted on the frame in spaced relation along a common horizontal axis, first and second cantilevered cradles rotatably mounted within the first and second rotor members respectively, wire carrying spools mounted for rotation in these cradles, and Wire guide means carried by the rotor members and cradles so arranged as to thread a strand of wire from the second spool out through the second rotor member and from the first spool around the second spool and out through the second rotor memher without reversing direction.

13. In a wire stranding machine, the combination of a pair of rotor members mounted in spaced apart relation for rotation about a common axis, a pair of spool cradle means one journalled at one end in each of said rotor members, and drive means for said rotors for drivin g the same in synchronism.

14. in a wire stranding machine the combination of a pair of rotor members mounted in spaced apart relation for rotation about a common axis, a corresponding pair of spool cradle means, each journaled at one end only in its corresponding rotor member, and means for driving the rotor members independently but synchronously.

15. In a wire stranding machine the combination of a pair of unconnected rotor members mounted in spaced apart relation for rotation about a common axis, a corresponding pair of unconnected spool cradle means, each journaled at one end only in its corresponding rotor member, and means for driving the rotor members independently but synchronously.

16. In a wire stranding machine the combination of a frame, first and second rotor members rotatably mounted on the frame along a common axis, cradle means supported by shafts concentrically journaled in the rotor members, said rotor members having the form of cylindrical shells open at their adjacent ends and at least partially enclosing the cradle means, and means for driving the rotor members independently but synchronously.

References Cited in the file of this patent UNITED STATES PATENTS 477,784 Sisum June 28, 1892 592,453 Sisum Oct. 26, 1897 2,0l0,888 Pool Aug. 13, 1935 2,277,102 Henning et al. Mar. 24, 1942 2,361,509 Steuber Oct. 31, 1944 2,406,530 Bruestle Aug. 27, 1946 2,499,246 Harmon Feb. 28, 1950 2,567,347 Pierce Sept. 11, 1951

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