Method And Apparatus For Coreless Spool Production

Abstract

Coreless spools, alternately wound on two spindle mounted mandrels from a continuous web supply of thin sheet material, are jet propulsively ejected from the mandrels by pressurized fluid conducted thereto. Loose end portions of the completed spools are rewrapped about the spool body by bridging a gap between two conveyors and two air curtains.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the art of sheet material handling and more particularly to spool winding for the paper converting industry.

2. Description of the Prior Art

The use of spindle mounted winding mandrels for the production of coreless spools from thin sheet material such as "crepe" or "tissue" paper is a well established practice in the art.

To assist the starting wrap and spool removal, alternate communication of the mandrel surface with vacuum and pressure fluid sources has been taught by E. A. Link in U.S. Pat. No. 2,575,631.

Although such fluid assistance for starting and finishing a spool winding cycle as taught by Link is of value, manual removal of the finished spool is still necessary. Accordingly, if greater production rates from such spool winding devices are to be realized, such manual functions in the operation must be eliminated.

SUMMARY OF THE INVENTION

An objective of the present invention, therefore, is to provide a method and apparatus for rapid and positive ejection of a completed spool from the winding mandrel.

Another object of the invention is to teach a material flow strategy to a plurality of winding mandrels.

Another object of the invention is to teach a method and apparatus for rewrapping loose ends of ejected spools.

These and other objects of the invention may be accomplished by driving the web flow path into an oscillating deflector for chuting the web to one of a plurality of winding mandrels.

The leading edge of the web is drawn into a converging nip between the receiving mandrel and surface friction drive belts therefor. A vacuum bias applied to the surface of the mandrel serves to adhere the web leading edge thereto until the first full wrap is complete and assists with tight, smooth layering for wraps applied thereafter.

When the desired length of web designated to form a spool has passed, the web is transversely severed above the deflector which indexes to the next chute position for directing the new leading edge into the next winding apparatus.

Meanwhile, tail winding of the previous spool is completed.

Sequentially thereafter, the spool wrapped mandrel disengages from the surface drive belts for acceleration to a greater rotational velocity. The mandrel surface vacuum is then replaced with a pressurized fluid flow which expands the spool from the mandrel surface in such a manner as to either impulsively or reactively propel the spool over the mandrel end and onto a receiving conveyor. This receiving conveyor delivers the spool across an air curtain which presses any free end portions against the conveyor surface plane to be carried into a gap between the delivery end of the receiving conveyor and the receiving end of a delivery conveyor. The gap dimensions, however, are insufficient to accommodate the main spool body which bridges the gap in transfer from said receiving to said delivery conveyor. The transition causes the free end portion to be drawn from the gap and under the spool main portion.

A subsequent air curtain may be used to blow any remaining free end portion of the spool up and over said main body portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the present invention showing the spool winding operation on one of two mandrels.

FIG. 2 is a schematic representation of the present invention showing the spool winding operation on the other of the two mandrels with the cutting mechanism engaged.

FIG. 3a is a side elevation of the deflector apparatus.

FIG. 3b is an end elevational of the deflector apparatus.

FIG. 4 is an elevational detail of the mandrel, mandrel drive, ejected spool braking mechanism, and the receiving conveyor station shown in partial section.

FIG. 5a is a detail of the mandrel and drive mechanism during the spool winding process.

FIG. 5b shows the next sequential step from FIG. 5a in preparation of a wound spool for ejection.

FIG. 5c shows the pressurized expansion of a spool immediately antecedent to ejection.

FIG. 5d shows the initial ejective movement of a spool from the mandrel.

FIG. 6a schematically shows the spool receiving and delivery conveyors for rewinding loose end portions thereof.

FIGS. 6b and 6c sequentially show a spool bridging the gap between the two conveyor sections to illustrate a critical portion of the rewrapping process.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to the schematic of FIG. 1, a continuous web W of paper, foil or other thin sheet material of indefinite length is drawn from the active supply roll 20 and turned over one of bars 22 into the nip of the web pulling section.

This pulling section comprises pulling drums 23 which are driven cylinders having a traction belt 25 wrapped partially thereabout. For greater area distribution of the pulling section nip pressure, the portion of the belts 25 in actual contact with the web W is increased by turning the belts over idler rolls 24.

Since the web W path through the pulling section is vertical, supply rolls 20 and 21 may be positioned on either side thereof. Accordingly when the web material from one roll is exhausted, supply from a reserve roll 21 may be started immediately with minimum time loss.

Upon emerging from the pulling section nip, web W is passed betweeen cooperative cutting elements 80 and 82 held at the open position and deflected by the left face 31 of deflector 30 into the nip between winding mandrel 40 and winding belts 51.

Deflector 30, as further shown in FIGS. 3a and 3b is an elongated, hollow triangular body that is offset positioned from the axis of journals 33. Position control of the deflector is provided by means of an eccentric 34 driven connecting rod 35. Such position control comprises a small angle oscillatory movement of the deflector apex 39 from the position shown in FIG. 1 on the right side of the web path to the position shown in FIG. 2 on the left side of the web path.

Since, in many cases, the web W product comprises extremely thin material such as "crepe" or "tissue" paper, means are provided by the deflector 30 to prevent undesirable wrinkling and folding of the web as it turns from the straight line path out of the pulling section. Such means provided by the present invention comprises a plurality of low velocity air jets 37 emanating from the deflector body at a shallow angle from the plane of the deflector face 31. Moreover the axes 37a and jets 37 are respectively disposed in a radial array of planes emanating from axis 38 which is transverse of the web path W and remote from the deflector apex ridge 39. This radial or fan-like array of axes 37a provides a subtle but effective transverse and longitudinal smoothing of the web plane as it enters the nips between mandrel 40 and winding belts 51.

Air supply to deflector 30 hollow interior is conventionally provided through a flexible conduit 36 from a suitable pressurized source. Of course, the jets 37 are provided on both faces 31 and 32 of the deflector 30.

At this point in the machine cycle, mandrel 40 is internally evacuated causing an atmospheric draft radially inward through perforations 47 (FIG. 4) in the outer mandrel wall as will be described in greater detail relative to FIGS. 4 and 5.

As the nips between mandrel 40 and belts 51 press or wipe the web W into intimate contact with the mandrel 40 outer surface, the atmospheric pressure differential across the web thickness adheres the leading edge thereof to the mandrel surface for completion of the first full wrap after emerging from the nip between the mandrel and the belts 51. Thereafter, successive wraps of a continuous web length are wound thereon to complete a coreless spool.

Rotational force is provided to the mandrel 40 by surface friction drive from the belts 51 which, in turn, are driven by one of the turning rolls 50 and 52.

The length of web W wound upon the mandrel may be determined by any of several well known techniques including a gear mechanism or a timer. Although the details of a suitable drive mechanism for the web cutting mechanism shown are not illustrated, it should be understood that many such mechanisms are known to the prior art. Depending on the degree of precision desired for the cut length of web W, the rotational position of drum 81 may or may not be positively coordinated with the rotational position of cam 85. If the web W cut length may fluctuate within a tolerance defined by the circumferential arc of knife edge 80, the continuously rotating drum 81 may be free of any coordinating mechanism with cam 85. The particular technique selected for description herewith, however, is to cyclically coordinate, by means of chain drives, for example, the angular position of rotating knife drum 81 with that of cam detents 87. By making the speed of traction belts 25 independently variable of the cutting unit rotational speed, the desired length of web W to form a spool may be determined by the web W velocity.

When the desired length of web W has passed cam 85 is rotated so that one of the detents 87 thereon aligns with the bell crank 83 follower 84. Spring 86 provides the bias to urge the follower 84 into continuing contact with the surface of cam 85.

When the follower 84 drops into a detent 87, the bell crank 83 rotates the few degrees necessary to bring the anvil 82 into cutting position. When the rotating drum 81 mounted knife edge 80, traveling at a greater surface speed than the web W, reaches complimentary alignment with the anvil 82, the web W is sheared therebetween.

To prevent the leading edge of web W following a cut from momentarily adhering to the anvil 82, drum 81 is sheathed with a resilient foam material 88, the circumferential surface thereof radially projecting slightly beyond the edge of knife 80. At the moment of cut, the portion of the foam immediately behind the blade 80 presses the web leading edge against the upper surface of anvil 82 for a frictional grip on said leading edge to pull it off the anvil 82.

The remaining rotating surface elements of sheath 88 sustain touching contact with the web W as it passes thereby lending a positive control assist to the web path.

The rotational speed of cam 85 also provides a convenient timing reference for coordinating the cyclic activity of the deflector 30, mandrels 40 and 60, the several drive mechanisms and solenoid actuated fluid control valves as to be subsequently described. Accordingly, a multiple lobe cam shaft 65 is driven by a timing chain 66 from the drive shaft for cam 85 to selectively make and break electrical contacts 67 for each electrically actuated control mechanism appropriate for the functions hereinafter described.

After completely winding the tail of a cut length of web W, winding belts 51 and roller 52 are rotated about the axis of roller 50 to disengage the belts 51 from the wound spool of web W about mandrel 40. If desired, the machine may be designed so that mandrel 40 is displaced in an opposite direction away from the winding belts 51 for complete disengagement therebetween. At this point, the coreless spool of web W wrapped about mandrel 40 is ejected therefrom in a manner to be subsequently described in detail.

Meanwhile, deflector 30 has been rotated by eccentric 34 mounted connecting rod 35 from the position shown in FIG. 1 to that of FIG. 2 to chute the new leading edge of web W into the nip between winding mandrel 60 and belts 71. The following events pursuant to winding another coreless spool of web material are the same as previously described relative to mandrel 40.

When the web spool C.sub.1 (FIG. 6a) ejects from the end of mandrel 40, the speed thereof is first retarded by a breaking section comprising converging belts 90 driven by drums 91 over idlers 92 (FIG. 4). Here the spool is flattened to an oval and controllably placed on a receiving conveyor section 100 comprising a multiplicity of spaced belts 101.

Upon emerging from the braking section (FIG. 6a), the tails T of the spools C are uncontrolled and are likely to be lifted free and partially unwound from the spool body. To neatly rewrap the tails T onto the spool body C, the receiving and delivery conveyor sections 100 and 105, respectively, are provided with air curtains from upper and lower manifolds 103 and 104 extending transversely across respective conveyor sections. If the tail has come free from the spool body underside as shown by T.sub.2 in FIG. 6a, the tail T.sub.2 is blown by the air curtain from upper manifold 103 into the crevice 102 between the down stream end of receiving conveyor 100 and the upstream end of delivery conveyor 105. Since the radii of turning drums 106 and 107 are critically sized, as is the width of crevice 102, the spool body C does not follow the tail T into the crevice but is merely passed tangentially between the drums 106 and 107 across the crevice as illustrated by FIGS. 6b and 6c. Consequently, the free tail T.sub.2 is wrapped under the spool body C.sub.2.

In the extreme case, where a free tail T yet remains behind a spool C after bridging the crevice 102, the air curtain from lower manifold 104 blows same up and around to the top side of the spool C as shown in FIG. 6a relative to spool C.sub.3 and tail T.sub.3.

Accordingly, after passing the aforedescribed tail control section, the tails of such spools lay entirely in juxtaposition with the body and in immediate condition for final packaging.

Turning next to the internal details of the winding mandrels and the mechanics of coreless spool ejection, reference is first made to FIG. 4 where the mandrel 40 is shown as a closed, hollow cylinder rotationally mounted on a hollow spindle 41.

One end of the spindle 41 is rigidly secured to a swing arm 42 journaled about a bearing shaft 53. Conduit 45 is connected, alternatively, to positive and negative (vacuum) fluid pressure sources. Fluid communication between conduit 45 and apertures 47 through the shell of mandrel 40 is allowed via apertures 46 through the shell of spindle 41.

Integral with the swing arm 42 but opposite of the shaft 53 axis from the spindle 41 is a cam follower portion 43. The cam 44, in cooperation with the follower portion 43, is functionally effective to swing the mandrel 40 from the winding position of FIG. 1 to the ejection position of FIG. 2.

In the case of winding belt unit 50, 51 and 52, drum 50 enjoys a fixed axis about shaft 53 but idler drum 52 oscillates between winding and ejection positions. Winding unit 70, 71 and 72, on the other hand enjoys fixed axes for both drums 70 and 72. This distinction, however, is a mere designers choice and is not critical to the invention. Nevertheless, for power transmission convenience, drums 50 and 70 should be mounted on fixed axes and driven through a suitable, variable speed transmission 56. In the FIG. 4 embodiment, power is delivered from the input gear 55, through the transmission 56 and to the drum 50 via belt 57.

Experience with the present invention has found the variable speed transmission 56 extremely useful due to subtle distinctions in winding characteristics between different web materials. Even color differences between two, otherwise identical, webs of paper will require different winding speeds.

Although the web W winding drive is delivered by belts 51, mandrel 40 is also independently driven from a suitable, selectively engageable source, not shown, which delivers power to a transfer reduction sheave 54, also mounted on shaft 53, via an input 54b and and output 54a.

As indicated above, the shell of mandrel 40 is perforated by a multiplicity of apertures 47 drilled therethrough at an angle of approximately 20.degree. with and in radial planes of the mandrel axis.

The exact number, angle, and distribution pattern of apertures 47 optimum for a given core diameter and weight of particular wound web material are all variable parameters that are dependent upon the pressure and delivery characteristics of a working fluid source and upon the mechanical characteristics of the particular web material.

In a particular example, however, with a 2.75 inch OD and 20-1/2 inch long mandrel provided with 36, 3/32 inch diameter apertures 47, drilled at a 20.degree. angle with the mandrel axis in radial planes, and uniformly distributed around the mandrel circumference in eight symetrically offset rows, spools wound from 20 inch wide and 120 inch long webs of 0.002 caliper crepe paper were quickly and neatly ejected without axial or telescopic expansion with an 18 psi source of air pressure.

As described above relative to the winding operation, conduit 45 is connected to the vacuum source for the mandrel to receive the leading edge of the web W. This vacuum connection is continued throughout the winding process, FIG. 5a, and immediately after the wrapped mandrel has disengaged from the winding belts 51. When such disengagement is complete, power is delivered to the mandrel independent drive train 54 to rotationally accelerate the mandrel and wound spool C, the effect of which is to complete the tail wrap and draw the trailing edge T thereof next to the spool surface C as illustrated by FIG. 5b. Since the web is permeable, in the case of "crepe" or "tissue" paper, the slight pressure differential attraction attraction remaining through a multiplicity of wraps is sufficient to adhere the tail T against the cylindrical surface.

With the independent mandrel drive still engaged, conduit 45 is switched from the vacuum source to a pressure source causing an air blast from mandrel apertures 47 to expand and distort the cylindrical configuration of spool C to that exageratedly shown by FIG. 5c.

High speed photographs have shown that under the aforedescribed conditions, the wound spool assumes a bulb shape at the discharge end of the mandrel as evidence that the leading axial end L of the spool C is retaining a close circumferential proximity to the mandrel surface and the air discharged from the apertures 47 is forming a pressure chamber within the region B. This circumstance dictates a fluid flow bias in the reverse direction F (relative to the air discharge direction from apertures 47 and the consequent movement of spool C). Consequently, spool C is, at least partially, reactively propelled from the mandrel 40 by the fluid mass discharge in the direction F as shown by FIG. 5d just as any jet powered vehicle.

Although detailed theoretical and laboratory analysis may reveal that the cylinder C is also propelled impulsively to some degree, for the purpose of this disclosure and the claims appended hereto, the phenomena, whether impulsive, reactive or a combination of the two, will be characterized as "reactive propulsion."

It is to be understood that the foregoing description is of a preferred embodiment and that the invention is not to be limited by descriptions of incidentally disclosed machine elements and power transmission arrangement. Therefore, changes may be made in the described preferred embodiment without departing from the scope of the invention defined in the following claims.

Claims

I claim:

1. An apparatus for winding and ejecting coreless spools of thin sheet material comprising:

cantilever supported spindle means;

substantially cylindrical shell means rotationally secured to said spindle means about the axis thereof;

a plurality of adjacently unbonded wraps of a strip of thin, resilient sheet material coiled about said shell means;

a multiplicity of fluid conducting apertures in said shell means and in selective communication with pressurized fluid supply means, said apertures having a fluid discharge axis at an acute angle to said spindle axis and of such size and distribution about said shell to cause a greater radial expansion of said coil of sheet material at the supported end of said spindle than at the unsupported end thereof when pressurized fluid is conducted through said apertures whereby said coil of sheet material is reactively ejected from said shell means over the unsupported end of said spindle means.

2. Apparatus as described by claim 1 wherein said apertures are alternatively communicated with vacuum source means for reverse fluid flow there through whereby said thin sheet material is pressure differentially pressed against the outer surface of said shell means during the wrapping of said coil.

3. Apparatus as described by claim 2 wherein said shell means is rotatively driven at a first rotational speed by surface friction applied first drive means, the engagement of said first means being coordinated to the communication of said apertures with said vacuum source means.

4. Apparatus as described by claim 3 wherein said shell means is also driven by second drive means at a second, greater rotational speed, the engagement of said second drive means being coordinated to the communication of said apertures with said pressurized fluid supply means and the disengagement of said first drive means.

5. A process of winding and stripping a coreless spool of thin sheet material about an axially rotatable, cantilever supported, substantially cylindrical mandrel means comprising the steps of:

winding a length of thin, resilient sheet material about said mandrel means to form a substantially cylindrical coreless spool thereof;

conducting pressurized fluid between said coreless spool and said mandrel means;

radially expanding said spool from substantial contact with said mandrel means, said radial expansion being greater at the supported end of said mandrel than at the unsupported end thereof; and

reactively propelling said spool over the unsupported end of said mandrel means by discharging said fluid from the chamber of radial expansion between said spool and said mandrel at the supported end of said mandrel.

6. A process as described by claim 5 wherein introduction of fluid flow between said spool and said mandrel means is directed toward the unsupported end of said mandrel means.

7. A process as described by claim 6 wherein said winding comprises the step of reducing the environmental pressure surrounding said mandrel adjacent the surface thereof.

8. A process as described by claim 5 wherein said mandrel means is rotationally accelerated before said spool expansion.