US 2930541 A
Description (OCR text may contain errors)
March 29, 1960 E. J. cRuM UNCOILERDEV Filed Feb. 28. 1957 ICE FIG. 1
INVENTOR. EBEN J. CRUM ATTORNEY UNCOILER DEVICE Eben Jelferson Crum, Baltimore, Md. Application February 28, 1957, Serial No. 643,137 3 Claims. (Cl. 242-128) 'This invention relates to wire or strand. handling and it is more particularly concerned with the uncoiling of wire or similar strand material from a coiled state.
Wire and other similar types of strand material hav- Sing a substantial modulus of elasticity are conventionally :stored in the form of coils wound on reels, spools, or :other holding devices. If the coil in any particular case is stationary, pulling on the strand in a straight line perpendicular to :the coil axis. The only feasible method of unwinding such a stationary coil is by pulling the strand in the direction of the axis of the coil. When this is done, the :strand as it becomes unwound from the coil, develops a :torsional twist with each turn or loop unwound. When :the strand material is of wire or other elongated material having a "substantial modulus of elasticity, such torsional :twisting tends tocause snarls in the loops.
From a comprehensive study of the phenomena of rsnarling, it appears that any torsion in a freely suspended vertical coil of wire by the application of a twisting force :about the longitudinal axis of the wire, imparts a tendency .for the loops of the coil to turn over. When a loop thus "turns over,-its relation to an adjacent loop is changed by :a crossing of the wire and hence a snarl is formed.
The tendency of a loop to turn over by the application of a twisting force about the longitudinal axis of the wire is resisted in the case of any given loop of the sus- ;pended coil by the moment defined by the product of :the weight of the loop and its effective moment arm ithrough which the'loop acts. This moment arm is about one-half the diameter of the loop. When the torsion :about the longitudinal axis of the wire is great enough :to overcome this weight moment and any other forces of resistance, the state of equilibrium is destroyed and um loop turns over.
Another factor tending to oppose the turning over of 'a loop is the pitch of the coil helix. In order for a loop to turn over it must close the gap between one point of the loop and another point of an adjacent loop, because of the crossing of the wire that results from the turning over. In a freely suspended coil, the distance between consecutive loops is a function of the weight acting on any given loop and the modulus of elasticity of the wire. Consequently, with a coil of uniform wire having a uni- :form modulus of elasticity throughout its length, the loops at the top of the suspended coil will be spaced farther apart than those at the bottom, because of the greater amount of weight acting on them. It follows, therefore, that with a given torsional twist in the wire about its longitudinal axis, the resistance to turning over is less at the bottom of the suspended coil than at the top and is, in fact, the place where turning over is found to occur most frequently in stretching out a flat coil of wire.
In industrial uses of wire supplied in coil form, it is important that it be possible to draw out the wire from its coiled form very rapidly. Under rapid conditions of drawing out, loop surging is experienced. This is due to the fact that as the loops become elevated from the the uncoiling thereof cannot be effected by m 2mm Patented Mar. 29, 1960 reposing coil residue, they ride beyond the initial equilibrium position because of the momentum. The elastic strain in the wire, however, reverses this movement, but again the loop overrides the equilibrium inthe opposite direction. This is repeated and thus provides a vibrational effect in the wire which at one point in thecycle' brings some of the loops farther apart and in another part of the cycle, brings them closer together. When the latter point in the cycle is reached, the resistance to the tendency to turn over for the reasons set forth above, is diminished, thereby presenting an unfavorable condition in the system.
The general solution to this problem heretofore has been to coil the wire about a spool or core of some kind, whereby turning over is effectively prevented because the spool acts as a barrier interposed in the path of the loop where the tendency to turn over is greatest. However, the use of such spools, cores, and similar devices for supporting the coil has the very serious drawback that it takes up a great deal of space and is expensive as an added deadweight item that must be stored and transported along with the coils. In the case of expensive spools, they are also transported back to the original loading station which involves other elements of cost, handling, storage and transportation problems.
It is for this reason that there has been a need for some improvement in the handling of wire and other such strand material that would overcome these difiiculties.
In my copending application for patent, Ser. No. 591,- 230, filed June 13, 1956, I have described a method of coiling Wire in such a way that it requires no lateral sup port, such as spools, etc., the method comprising generally the formation of a series of continuous consecutive loops and depositing these loops in horizontal layers one above the other, the while arranging the loops of each layer in consecutive overlapped relation.
Although said copending application discloses a means for uncoiling wire arranged in such a manner, supported wholly on a horizontal member, an object of this invention is the provision of a simpler and more universally applicable means for accomplishing this purpose.
Because of the eccentric arrangement of the coil loops, the possibility of developing kinks and snarls in the wire is reduced to a minimum, if not entirelyovercome, until the wire is uncoiled, at which timefin the'fcondition jreferred ,to above there is'a tendency tojsnarling just as the loops of the coils are being elevated, and it is the general object of this invention to provide a means for reducing this tendency to an ineffectual point.
Another object of this invention is the provision of such means which are simple, inexpensive and which require substantially no moving parts.
Other objects and advantages of the invention will apmore fully from the following description, considered together with the accompanying drawing.
In the drawing:
Fig. 1 is a side elevational view of an embodiment of the invention, partly broken away. i
Fig. 2 is a sectional view along the line 2-2, Fig. 1.
Fig. 3 is a diagrammatic sketch in elevation of a vertically suspended coil of wire to which a hollowcone has been applied to illustrate the principle of this invention.
Fig. 4 is a diagrammatic sketch -in elevation of a vertical coil of wire freely suspended for purposes of comparison with Fig. 3.
Referring with more particularity to the drawing in which like numerals designate like parts, the embodiment illustrated in Figs. 1 and ,2 comprises generally a horizontal base member 11 to which is secured an upright post 12. A hollow tubular member or slide 13 is slidably mounted on the post 12 and it is pro vided with a set screw 14 for holding it in selected positions of elevation on the post.
The tubular member 13 has secured to it an outwardly projecting arm 15 at the top, to the outer end of which there is rotatably mounted a sheave 16. Below the sheave 16 there is dsposed a hollow empty cone 17 which is secured to the member 13 by upper and lower arm brackets 18 and 19, respectively. The tip of the cone at the top is cut off to provide an opening 20 for the wire 21 of a coil 22 as it is unwound and passes over the sheave 16.
Between the upper arm bracket 18 and the arm 15, there is disposed a wire guide in the form of a small cylindrical tube 23 and through which the wire 21 passes as it proceeds from the top of the cone 17 to the sheave 16. The tube 23 is disposed substantially at the virtual apex of the truncated .cone 17 and is held inthis positionby a forked portion 24 of the arm 15.
Below the cone 17 there is disposed a skid 25 or other suitable horizontal support for the coil 22. An essential characteristic of this'support for the purpose of this invention is the fact that it does not include any spool, core, or other lateral support means on the inside of the coil. Such lateral support means interferes with the natural uncoiling of the wire, which should, for optimum results, proceed vertically upward from the coil or coil residue 22 in its reposed position. Also, contact of. the wire with such support surfaces tends to roll the wire and adds additional torsional stresses to it. This introduces unequal twisting in the wire. Also, the loops of the coil 22 may be disposed on the skid 25 either concentrically as shown, or eccentrically 'in accordance with my said prior application for patent. I A properly uncoiled wire of this kind, after it passes the sheave 16, should'have a uniform permanent twist in it throughout its length to the extent of only one twist or turn per coil length. This twist develops in the wire as it unfolds fromthe coil. If the force of contact between the wire and the sheave is too great for any reason, such as by the weight of the wire acting at that point, the twisting of the wife will have a tend-- ency to back up as in the case of a flat ribbon. This would have the undesirable effect of increasing the'tendency to turning over of loops at the bottom of the suspended portion of the coil, as well as inducing irregular twisting of the wire. This is overcome to a very large extent by positioning the guide tube 23 at the virtual, apex of thecone 17, because at this point the wire 'just beginning to move fully in the direction of the longitudinol axisof the cone and the radius of gyration of the coil is equal to that of the wire itself, thereby creating the most favorable condition for the wire to pass over the sheave without a backing up of torsional twists therein.
The cone 17 itself provides several functions. In the first place, it reduces the number of .loops under suspension and hence decreases the total torsional stress in the suspended portion of the wire because of the reduced weight action at any given point of the suspended portion. This may be readily seen by comparing the diagrams of Figs. 3 and 4, Fig. 4 being a freely suspended coil and Eig. 3 being the same coil suppressed by a cone 17, in accordancewith this invention. This therefore, reduces the tendency to snarling at the bottom loops of the suspended portion of the coil.
In addition to this advantage, the cone also acts to suppress surging or vibrations in the suspended portion last carried 1,87 ,42 K l r 112,157,347 T 12,390,157. Kramer of the coil under conditions of rapid uncoiling. This vibrational efiect may be further suppressed by a pair or flat parallel aprons 2-6 and 27 hingedly suspended from a pair of arms 28 and 29 extending outwardly from the tube 13 directly below cone 17.
The aprons 26 and 27 are hingedly attached to the arms 28 and 29 by means of pintles 30 and 31 passing through apertures in the arms and loops 32 and 33, respectively of the aprons.
The distancebetween the upper ends of the aprons 26 and is substantially equal to the diameter of the bottom of the cone 17. Consequently, when the skid 25 is placed between the aprons, below the cone 17,'the aprons will contact the upper end of the coil 22, as shown, and this contact will be maintained as the coil is being unwound, thereby assuring the necessary contact of the inner surfaces of the aprons with the wire loops .as they leave thev coil 22 and move upwardly into the cone 17, the contact being effective to prevent surging under rapid uncoiling conditions to which the device is adapted.
On the post 12, below the slide 13, there is provided another sheave 34, on one side, and a sheave 35,, on the opposite side, about one of which the uncoiled wire from the sheave 16 passes. This arrangement permits a constant angle'of take-off of the uncoiled wire from the apparatus, irrespective of the position of the slide 13 on the post 12. The sheaves 34 and 35 are used selectively depending upon whether the loops of the coil 22 are clockwise or counter-clockwise.
Having thus described my invention, I claim:
1. Apparatus for uncoiling a free coil of wire comprising a base member, a post on the base member, ,a movable member slidably mounted onthe'post, a hollow empty frusto-conical member supported by the movable member, means for removably securing the movable member to the post in different relative positions, a sheave above the conical member, means for rotatably supporting the sheave on the movable member and a pair of apron members secured to the movable member below said trusto-conical member, said apron members having portions vertically aligned with the coil to slidably contact loops of wire passing upwardly from the coil.
into the frusto-conical member.
2. Apparatus as defined by claim lin .which the aprons are hinged tothe movable member about axes parallel to each other. i i
3. Apparatus for uncoiling a free coilof wire comprisin fm au o ppoums th s i in fiat h rizon a position, a base member, a post secured to the base member alongside said coil supporting. means, a slide memby said .post, means 'for securing said slide member in different vertical positions on said post, arms secured to the slide member extending outwardly therefrom, a sheave and ahollowernpty truncated cone supported by said arms, said sheaveibeingabove said cone, and asheavecarried by the post below said slide memher and a pair of aprons 'hir gedly suspended to one of sa d was e e said wa a d sa d co uppo t ans 'luletererices Cited in thef ile ofthis' patent U I E rArges rescues