US 3258221 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
J1me 1966 M. o. DERRICKSON ETAL 3,253,221
STRAP DISPENSER 2 Sheets-Sheer. 1
Filed July 1'7, 1964 June 1966 M. o. DERRICKSON ETAL 3,253,221
STRAP DISPENSER 2 Sheets-Sheet 2 Filed July 17, 1964 3,258,221 STRAP DISPENSER Michael O. Derrickson and Harry E. Pape, Norwood, Pa., assignors to FMC Corporation, Philadelphia, Pa., a corporation of Delaware Filed July 17, 1964, Ser. No. 383,420 2 Claims. (Cl. 242128) This invention relates to a strap dispenser which, while useful for dispensing strap from a ribbon wound coil, is most advantageously useful for dispensing strap from a mill wound coil.
' Strap for binding boxes, bales, bundles and the like is commonly packaged or supplied in coils known as mill wound and ribbon wound. A mill wound coil is an annulus having a thickness greater than the strap Width, usually not more than about six times the strap width, wherein the strap convolutions crisscross so that the strap is evenly distributed throughout the coil. A ribbon wound coil is one wherein the thickness of the coil is equal to the width of the strap, that is to say each convolution of the strap exactly overlies the previous convolution. Both types of coils are supplied without cores, the windings being held in annulus form during shipment by wires, straps or the like extending thereabout radially of the bundle. Due to the fact that a mill wound coil of any A given diameter obviously contains more strap and is heavier than ari-bbon wound coil of similar diameter, the various problems involved in providing a suitable dispenser for the strap are exaggerated or intensified when dealing with mill wound coils. Unwinding the strap from a mill wound coil is more difficult, particularly when the strap is withdrawn at high speed, due to the crisscrossing of the strap convolutions. As mentioned, the present invention may be used for dispensing strap from a ribbon wound coil but its greatest utility is in connection with mill wound coils.
With coreless coils, the strap may be withdrawn from either the inside or the outside of the coil, provided the coil is mounted or positioned so that the inner end of the strap is available. While many dispensers provide for mounting the coil in such manner that the inner end of the strap is not available, it is not uncommon to mount the coil on a platform in such manner that access may be had to the inner end of the strap. If the strap is withdrawn radially of the coil fromeither the inner or outer-end, provision must normally be made to allow the coil to rotate whenever strap is being withdrawn. If the coil of strap is allowed or forced to remain stationary, the strap may be withdrawn perpendicular to the plane of the coil but this method will normally cause a twisting of the strap, that is. the strap will twistthrough 360 for each convolution removed from the coil. Such twisting is highly objectionable when the strap is used for binding large objects and is completely unsatisfactory when the strap is being used with automatic equipment.
In US. Patent No. 2,844,334 there is described a dispenser wherein a mill wound coil of strap is mounted upon a rotatable support and the strap is taken from the center of the coil and formed into a ribbon wound coil which'is located coaxially with the mill wound coil and carried on the same rotatable support. The strap is withdrawn from the center of the ribbon wound coil and as the strap is so withdrawn more strap is pulled from the center of the mill wound coil and wrapped around the outside of the ribbon wound coil. The dispenser of said patent is so arranged that the ribbon wound coil rotates independently of the rotatable support until there are sufficient wraps or windings on the ribbon wound coil that friction-a1 forces interfere with the free rotation of said coil, at which time the rotatable support and the mill wound coil also are caused to rotate when the strap is United 1 States Patent "ice pulled. Since the strap is actually pulled out from a rotating coil, no twist is introduced into the strap and as long as the ribbon wound coil is free to rotate independently, only a low inertia needs to be overcome when the strap is pulled. However, it has been found that with the dispenser of the patent, only a few wraps on the ribbon wound coil are required to cause rotation of the entire apparatus including the heavy mill wound coil and thus very frequently a pull on the strap isrequired to overcome the inertia of the mill wound coil. This is objectionable, particularly when the strap is being'used by an automatic strapping machine and the present invention is intended to overcome this drawback.
It is an object of this invention to provide an improved strap dispenser capable of continuously or intermittently dispensing strap from a mill wound coil without introducing a twist into the strap and wherein the coil remains stationary most of the time so that only infrequently does the inertia of the coil need to be overcome.
More specific objects of the invention will become apparent as the description of a preferred embodiment thereof proceeds.
Referring now to the drawings:
FIG. 1 is a top plan view of the dispenser, with one of the parts removed for clarity of illustration;
FIG. 2 is a sectional view taken along the line IIII of FIG. 1; and I FIG. 3 is a perspective view showing the dispenser in use.
According to a preferred embodiment, the rotatable part of the dispenser is formed of a plurality of wires. Each wire has a vertically extending segment 12 at one end adjacent which is a horizontally extending segment 14. Segments 12 are arranged in a circle and a wire ring 16 is welded to the upper ends of said segments. .A wire ring 18 is welded to the underside of horizontal segments 14 and said horizontal segments extend radially inward from the circularly arranged segments 12. At the inner end of segment 14, the wire is bent upward at an angle of approximately 60 to the horizontal to provide a sloping segment 20 from the upper end of which the wire is bent at 22 out of alignment with segment 20 to provide a terminal segment 24.
The sloping segments 20 of the various wires together or as a group form a truncated cone or frustum of a cone extending axially of the circular base provided by the horizontal segments 14, with the larger base of the frustum lying in the plane of the horizontal segments. The smaller base of the frustum formed by segments 20 is parallel to the larger base and lies in the plane of the bends 22. A wire ring 26 is welded to sloping segments 20 to retain said segments in this overall frusto-conical configuration. The terminal segments 24 of the wires also form a frustum of a cone, said frustum being smaller than the one formed by segments 20. The smaller frustum is inverted and its smaller base is coincident with the smaller base of the larger frustum. At the outer ends of segments 24 a wire ring 28 is welded thereto and another ring 30 is also welded to the terminal segments 24 to give addition-a1 rigidity to the structure.
Extending diametrically across ring 30 and welded or otherwise secured to the under side thereof is a plate 32 and extending perpendicularly to said plate and secured to the under side of ring 26 is a plate 34. A spindle 36 extending vertically from a collar 38 secured to the upper ends of a plurality of legs 40 has -a bearing in the plates 32 and 34 whereby the wire framework is rotatably mounted. A coil spring 42 loosely surrounding spindle 36 bears at the lower end against plate 34 and at the upper end against a collar 44 axially adjustable along said spindle and held against rotation by a set screw 46 of spring 42 against plate 34 constitutes a drag brake to prevent free rotation of the wire framework and the amount of drag may be varied by adjustment of collar 44 to'vary the tension in the spring. The purpose of the brake will be explained later.
If desired, a pan 50 for holding seals, tools or the like may be secured to upper plate 32 as by means of screws 52.
In use, as shown in FIG. 3, a coil, for example a mill wound coil 54 of strap is placed in the basket formed by the lower portions of the wires and a length of strap is unwound from the inner portion of the coil and arranged in the form of a generally conoidal roll 56 by winding the same a few times about the conically arranged segments 20. The conoidal roll 56 of strap is indicated in FIG. 2 and it will be observed that the windings of the roll are laterally displaced and of ever decreasing diam- .eter from "bottom to top.
When the strap is pulled from the dispenser, win-dings are removed from the top of roll 56 and since in any particular operation the strap is being pulled in a particular direction, that is, to a particular point of use, the roll must of course rotatein order to pay out the strap. The upper windings of roll 56 cannot move up any further than the wire bends 22 because these upper windings are too small in diameter to pass about the outwardly directed wire segments 24. Thus, the small end of the cone frustum formed by the strap in roll 56 is restrained by the inverted cone frustum formed 'by the terminal portions 24 of the wires from moving away from the plane of mill wound coil 54. As roll 56 rotates due to removal of strap from the smaller end thereof more strap is withdrawn from mill wound coil and begins to progress helically upwards about the frusto-conically arranged segments 20. There is no fixed guide for the strap in the vicinity of coil 54 so that it is not necessary for the coil to rotate in order for the strap to move from said coil onto the large lower end of rotating roll 56. The actual point where the strap first begins to engage the wire segments 20 continually shifts around the base of the cone in the direction opposite to the longitudinal movement of the strap.
As the wrappings or convol-utions forming roll 56 move upward they begin to overlap, as best shown in FIG. 2, but never to the extent that one convolution directly and entirely overlies the preceding one. This overlapping provides a snub'bing action requiring a positive pull on the strap to remove it from the dispenser but so long as there is room at the bottom of the conical roll to accommodate another convolution the strap may be pulled quite easily and the drag brake prevents rotation of this wire framework. When the cone frustum becomes filled, the windings bind sothat it is no longer possible to rotate roll 56 independently and at that time any further pull on the strap results in rotation of the wire structure and the mill wound coil 54 supported thereby, so long of course as the pull is sufliciently strong to overcome the brake and the inertia of the mill wound coil. It should be pointed out that because of the close overlapping of the convolutions, a considerable length of strap can be accommodated on the conically arranged wire segments 20 and since strap is 'being withdrawn from the top of the cone at the same time that it is being wound onto the bottom of the cone a much more considerable length of strap may be withdrawn before rotation is imparted to the structure than can actually be accommodated at roll to rotate freely while a considerable length of strap is removed.
The amount of pull required to cause the wire framework to rotate, that is, to overcome the inertia of the mill wound coil and the effect of the brake, is generally sufficient to cause a small amount of overrunning, it being desirable to set the brake so that this may happen. However, the brake should be adjusted so that the amount of overrun is less than a full turn of the wire framework because each full turn of overrun will result in a turn of twist being inserted into the strap, assuming of course that the pulled end of the strap is not permitted to twist or rather more properly put, to untwist. Preferably, the brake is adjusted so that about a quarter turn of overrun is permitted. The actual setting of the brake to permit this amount of overrun will of course depend somewhat upon the weight of the mill wound roll but since the exact amount of overrun is not critical, the brake setting need be changed only when making a basic change in initial weight of the mill wound roll. As previously indi cated, the strap has a particular point of departure from the dispenser. The overrun temporarily carries this point of departure away from its natural position and when the strap is next pulled the movement of the strap back to the normal point of departure results in a further loosenin the windings of the conoidal roll 56, that is, a loosening in addition to that caused by removal of the windings during rotation of the framework. It has been found that with the dispenser hereinabove described, a considerable length of strap may be removed without further turning of the wire framework, once it has been caused to rotate through a relatively few turns. Thus only infrequency is it necessary to overcome the inertia of the mill wound coil and cause rotation of the framework.
Having thus described a preferred embodiment of the invention, what is claimed is:
1. A dispenser for dispensing flat strap from the center of a millwound coil of strap without inducing a twist into the strap, said dispenser comprising a horizontally disposed substantially circular platform for supporting a mill wound coil of strap, frusto-conical means extending axially above said platform, said frusto-coni'cal means having a large base lying in the plane of said platform and a small base parallel to the large base, said frustoconical means providing a guide whereby strap withdrawn from the center of the mill wound coil may be formed into a conoidal roll thereabout which conoidal roll will rotate freely so long as the strap forming the conoidal roll does not completely cover said frusto-conical means, means for preventing the loops of the conoidal roll from moving above the small base of said frusto-conical means, means supporting said holder for rotation, and brake means effective to prevent a pull on the strap from rotating said holder so long as another loop of strap can be accommodated on said frusto-conical means.
2. The dispenser set forth in claim 1 wherein the means for preventing the loops of the conoidal roll from moving above the small base of said frusto-conical means comprises a second frusto-conical means having a small base coincident with the small base of said frusto-conical means.
References Cited by the Examiner UNITED STATES PATENTS 315,707 4/1885 Briggs 242-128 377,422 2/1888 Bindeman 242-12s 856,761 6/1907 Bourne 242-128 2,286,460 6/1942 Brown 242-428 2,s44,334 7/1958 Luth 242-405 X 2,957,643 10/1960 Bosworth et al. 242-128 M ERVIN STEIN, Primary Examiner.
N. L. MINTZ, Assistant Examiner.