US3322361A

US3322361A - Low tension core adapter

Info

Publication number: US3322361A
Application number: US484865A
Authority: US
Inventors: Roger W Young
Original assignee: John Dusenbery Co Inc
Current assignee: John Dusenbery Co Inc
Priority date: 1965-09-03
Filing date: 1965-09-03
Publication date: 1967-05-30
Anticipated expiration: 1984-05-30
Also published as: GB1110186A

Description

y 1967 R. w. YOUNG 3,322,361

LOW TENSION CORE ADAPTER Filed Sept.' 13, 1965 2 Sheets-Sheet 1 FIG.5

INVENTOR ROGER W. YOUNG ATTORNEY May 30, 1967 R. w. YOUNG LOW TENSION CORE ADAPTER 2 Sheets-$heet 2 Filed Sept. 3, 1965 INVENTOR ROGE R W. YOU NG ATTORNEY narrow width, very thin films having a low United States Patent Oiifice 3,322,361 Patented May 30, 1967 3,322,361 LOW TENSIGN CURE ADAPTER Roger W. Young, Upper Montclair, NJ, assignor to John Dnsenhery Company, Inc, (Clifton, N.J., a corporation of New Jersey Fitted Sept. 3, 1965, Ser. No. 484,865 9 Claims. (Cl. 242-669) This invention relates to core adapters for use on web slitting and rewinding machines and more particularly to core adapters of novel construction for use in rewinding tensile strength. In slitting and rewinding machines, a relatively wide web of material, such as a plastic film, is slit into narrow strips, which strips are then rewound into roll form on individual cores mounted on a pOWer driven shaft, or mandrel. In order to provide a smooth rewinding of the cut strips, a certain amount of tension must be maintained on each individual strip during the entire rewinding operation. This is accomplished by rotating the mandrel at a higher speed than the cores, such arrangement being commonly referred to in this art as differential winding. As the diameter of the rewound rolls increases, the rotation of the cores decreases, since the strips are fed to the cores by a pull roll rotating at a constant speed. Accordingly, arrangements are provided to afford slippage between the cores and the supporting mandrel, which slippage increases automatically as the diameter of the rewound rolls increases.

A variable factor which effects the rewinding of the cut strips is the normal variation in gauge, or thickness of the particular material. Such variation results in the diameter of some rewound rolls increasing at a faster rate than others which often results in rewound rolls of inferior quality. To overcome this problem, it is the practice to provide an arrangement wherein each core can slip, relative to the mandrel, in correspondence with the tension of the associated strip and independently of the other cores. This is done by inserting core spacer rings over the mandrel and between each of the rewind cores. These core spacer rings are individually keyed to the mandrel and the assembly of spacers and cores is clamped, axially, by suitable loading means carried by the mandrel. Thus, the core spacers, are positively driven by the mandrel while each core is free to slip as the tension of the associate strip exceeds the frictional restraining force exerted against opposite ends of the core by the spacers.

Normally, a winding machine is provided with two spaced rewind mandrels, each mandrel carrying a plurality of alternately-disposed cores and spacer rings. Adjacently-disposed strips of the slit web are directed to different mandrels so that the spacing of the cores on each mandrel is equal to the width of the strips. Such spacing is maintained by the core spacers.

The cores upon which the slit strips of material are wound generally are formed of a plurality of convolutions of paper wound into a rigid tube, the inside diameter of which has a commercial tolerance of inch, or greater. Consequently, when the cores are mounted directly on the mandrel and axially clamped by intervening core spacers, there is no assurance each core will rotate concentrically with the shaft axis. Such non-concentric rotation of the core results in wound rolls of nonuniform tension, or density. In order to provide concentric rotation of all of the cores, it is the practice to mount the individual cores on the mandrel by means of core adapters, which adapters are in frictional engagement with the spacer rings.

In the case of very thin film, slit into narrow strips, the amount of tension which can be applied to the strips, during the winding operation, cannot exceed a relatively low, maximum value, otherwise the strip may be stretched and/or torn, particularly when the machine desirably is operated at high speeds. For operation with such films, the core adapters must be capable of maintaining a uniform low tension on the strips from the beginning to the end of the winding cycle, which tension is not subject to i sudden variations arising from frictional changes between the adapters and spacers. Also, the adapters must be constructed and arranged to receive cores having inside diameters which vary within commercial limits and to rotate such cores concentrically with the mandrel axis. Yet, the cores must readily be mounted on and removed from the adapters. Core adapters made in accordance with this invention meet all of these requirements.

An object of this invention is the provision of improved core adapters for supporting tubular cores on a mandrel, which adapters are particularly useful for the winding of narrow strips of very thin film into roll form.

An object of this invention is the provision of adapters for supporting cores on a mandrel for the purpose of winding strips of material on the cores, which adapters include means for retaining the cores concentric with the mandrel axis and means for maintaining relatively low, uniform tension on the material strips during the winding operation.

An object of this invention is the provision of an adapter for supporting a tubular core on a mandrel, which adapter comprises concentrically-disposed, spaced cylindrical members, bearing means disposed between the said members to afford concentric rotation of the members, and means for removably securing a core on one of the said members.

An object of this invention is the provision of a core adapter comprising concentric inner and outer cylindrical members, bearing means disposed between the said members, a reduced diameter portion formed on the outer cylindrical member and adapted for insertion into an end of a tubular core, and means carried by said reduceddiameter portion for preventing relative rotation between the core and the outer cylindrical member.

These and other objects and advantages of the invention will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a front elevational view of a core adapter made in accordance with one embodiment of this invention;

FIGURE 2 is a rear elevational view thereof;

FIGURE 3 is a central cross-sectional view taken along the line 3-3 of FIGURE 1;

FIGURE 4 is a front elevational view of a core adapter made in accordance with another embodiment of this invention;

FIGURE 5 is a central, cross-sectional view taken along the line 55 of FIGURE 4; and

FIGURE 6 is a fragmentary front elevational view showing the core adapters carrying cores and mounted on the mandrel of a rewinding machine, with portions drawn in cross-section.

Referring now to FIGURES 1-3, the core adapter 10 comprises a first outer cylindrical member 11 preferably made of aluminum and provided with an integral, reduced-diameter portion 12, which portion has an inner circular bore formed in the free end for receiving the outer race of a low friction bearing 13. The member 11 has a central hole 14 extending therethrough, which hole has a diameter slightly larger than that of the winding machine mandrel for which the adapter is designed. The

outer surface of the cylindrical member 11 is provided with a relatively shallow bore within which a smooth metal plate 15 is positioned, said plate havmg a central hole aligned with the mandrel hole 14. Rotation of the plate 15, relative to the cylindrical member 11, is prevented by two, axially-extending pins 16 which are driven into holes formed in the member 11 and extend through diametrically-opposed holes 17 formed in the plate.

A second outer cylindrical member 1?, made of aluminum, has an outside diameter corresponding to that of the cylindrical member 11, said member 18 being provided with an integral, reduced-diameter portion 19 having a circumferential groove 20 formed therein. The inner end of the member 18 is provided with two circular bores, one such bore receiving the reduced-diameter portion 12 of the outer cylindrical member 11 and the other such bore receiving the outer race of the bearing 13.

The two

cylindrical members

11 and 18 are secured together by the fastening screws 21, which screws pass through clearance holes formed in the member 11 and are threaded into holes formed in the member 18. In addition to conventional lock washers, flat washers 22 are associated with each of the fastening screws, said flat Washers having portions extending over the underlying plate 15. After the fastening screws are firmly threaded into position, the two cylindrical members 11 and 1&3 constitute a unitary structure which is secured to the outer race of the bearing 13.

The inner race of the ball bearing 13 is force-fitted over a tubular member 25, made of a material having a low coefficient of friction such as, for example, Teflon, having an inside diameter corresponding to that of the central hole 14 formed in the cylindrical member 11. It will now be apparent, that bearing 13 affords relative rotation between the inner tubular member 25 and the outer cylindrical structure consisting of the

members

11 and 18.

The reduced-diameter portion 19, of the cylindrical member 18, is adapted for insertion into an end of a tubular core. When the core is so mounted on the adapter, it is important that the core be restrained against rotation relative to the outer cylindrical structure of the adapter. For this purpose, a resilient O-ring as, made of rubber or other suitable material, is positioned in the bottom of the groove 20 and supports a closely-coiled garter spring 27. It will be noted that the encircling garter spring extends above the groove. As mentioned above, the tubular cores are made of paper and have diiferent inside diameters due to manufacturing tolerances. Thus, the outer peripheral surface of the garter spring is arranged to be somewhat larger than the maximum inside diameter of the commercially available cores of given, nominal size, while the diameter of the reduced-diameter portion 19, of the adapter, over which the cores are to be fitted, is somewhat less than the minimum diameter of such cores. When the end of the core is pressed onto the adapter and over the garter spring, the resilient O-ring compresses to accommodate the particular core. Under the combined force developed by the spring and the O-ring, there is exerted against the core a radial pressure, which pressure causes the spring convolutions to bite into the inner wall of the core, slightly, thereby preventing rotation between the mounted core and the outer cyclindrical structure of the adapter.

Reference now is made to FIGURES 4 and 5, which show a core adapter 30 of modified construction, FIG- URE 4 being a front elevational view and FIGURE being a central cross-sectional view taken along the line 55 of FIGURE 4. The outer cylindrical member 31, preferably made of aluminum, includes a reduced-diameter portion 32 having the same diameter as the reduceddiameter portion 19 of the adapter shown in FIGURES 1-3. An O-ring 26 and a garter spring 27' are disposed within the circumferential groove formed in the portion 32. The inner wall of the member 31 is provided with a bore receiving the outer race of the bearing 13', which bearing is retained in place by a conventional, split retaining ring 33. An inner, tubular member 35 is secured to the inner race of the bearing, such member corresponding to the member 25 (see FIGURE 3), and having an inside diameter slightly larger than that of the mandrel. The member 35 also is made of a material having a low coefficient of friction. It will be clear that the bearing 13 affords rotation of the outer and

inner members

31 and 35, respectively.

The assembly of a plurality of core adapters in operative position on a mandrel of a rewinding machine is shown in FIGURE 6, to which reference now is made. The mandrel 37 has a stop collar 38 inserted thereon and secured in place as by a set screw 39, which collar serves to position the adapters and cores in alignment with the incoming strips of material to be wound into roll form. The mandrel is loaded, alternately, with spacer rings 41 and pairs of

core adapters

10 and 30, each pair of core adapters carrying a core 41. These spacer rings are made of a material having a low coefiicient of friction and good compressive rigidity such as, for example, low friction nylon. As shown in the cross-sectional portion of FIG- URE 6, the reduced-diameter portions of the outer cylindrical members of the

adapters

10 and 30 are inserted into opposite ends of the core 41. Such core is rotatable with the outer cylindrical members of the adapters but is restrained against rotation relative to such members by the garter springs 27 and 27'. After the last core assembly has been loaded on the mandrel, a last spacer ring 4t} is inserted, followed by a thrust bearing assembly 42. The loaded mandrel now is installed on the machine.

Assuming, now, that ends of the strip material have been fastened to the cores, as by means of adhesive tape, a desired strip tension is obtained by means of a pistontype cylinder 45 which is secured in fixed position on the machine frame. By regulating the fluid pressure to this cylinder, a range of axial pressures can be applied to the thrust bearing 42 through the piston 46 and the lever 47, said lever being pivotally carried by the machine frame and having a bifurcated end spanning the mandrel 37.

It is here pointed out that the thrust bearing 42, the spacer rings 4-!) and the core adapter assemblies are free to slide axially along the mandrel. However, the spacer rings have secured thereto inwardly-extending metal keys slidably disposed within a keyway 418 formed in the mandrel. Consequently, the spacer rings rotate, at all times, at the same speed as the mandrel, which speed is such that the surface velocity of the core is somewhat greater than the linear speed at which the strips of material are fed to the rewind station. Since the strips of material are fed to the cores over a pull roll, not shown, rotating at a constant speed, a certain amount of slippage must take place between the core and the mandrel.

In prior core adapters, each of the circular members (which are inserted into opposite ends of the core) carries a central bushing made of a low friction material, which bushing has an inside diameter such that the adapter is slidably insertable on the mandrel. Thus, in operation, there are four friction surfaces which effect the tension of the strip of material being wound on the core, namely, the areas of contact between the mandrel and the two bushings and the areas of contact between each of the circular members and the adjacent spacer ring. As the downward weight of the wound roll increases, there is a corresponding increase in the frictional torque between the two bushings and the mandrel. Further, the axial pressure between the spacer rings and the circular members, of the core adapters, decreases in effect in a long stack of core adapters and spacer rings, due to the longitudinal, frictional resistance of the weighted cores and the torsional force of the keys, of the spacer rings, against the side wall of the mandrel keyway. These two factors militate against the maintenance of a relatively low, uniform tension on the strips of material being wound.

In core adapters made in accordance with this invention, it will be noted that the spacer rings each have one end in contact with the inner tubular member 35, of the adapter 30, and the other end in contact With the plate 15, of the adapter 10. Although there is an axial pressure applied between the spacer ring and the tubular member 35, no slippage occurs between these members as the ball bearing will rotate before such slippage can take place. Also, the rewound roll is carried by the bearing with but a negligible increase in radial friction as the weight of the roll increases to its maximum value. Thus, it will be apparent that there is only one friction surface for developing torque, namely, the area of contact between the plate and the engaged end of the proximate spacer ring. Therefore, in order to obtain the same winding tension, the axial pressure applied to the assembly of core adapters and spacer rings will be twice that required in the case of core adapters of prior construction. The axial pressure is attenuated, in a long stack of core adapters and spacer rings, and the attenuation effect is a function of :the torque and roll weight. Thus, it can be seen that by doubling the axial pressure, the percentage attenuation error is reduced by 50%, while maintaining the same torque output. This feature is of importance when winding narrow strips of very thin material, wherein it is essential to maintain a relatively low, uniform strip tension throughout the winding cycle.

Having now described the invention, those skilled in this art will be able to make various changes and modifications without thereby departing from the spirit and scope of the invention as recited in the following claims.

I claim:

1. An adapter for use in supporting a tubular core on a mandrel, which adapter comprises,

(a) a cylindrical outer member having a portion insertable into an end of the core,

(b) holding means carried by said outer member, said holding means cooperating with the core to prevent relative rotation between the core and said member,

(c) a tubular inner member concentric with said outer member and insertable over the mandrel, and

(d) bearing means positioned between the said outer and inner members to afford relative rotation therebetween.

2. The invention as recited in claim 1, wherein the said holding means comprises means forming a peripheral groove in the said portion of the outer member, a resilient ring member groove, and a coiled spring positioned in said groove and over the said ring member, said spring having convolutions normally extending radially outward of the groove.

3. The invention as recited in claim 1, wherein the said outer member includes a base portion provided with a central opening corresponding substantially to the inside diameter of the said inner member, and including a flat plate secured to the said base portion, said plate provided with a central opening corresponding to the central opening in the said base portion.

4. The invention as recited in claim 1, wherein the said inner member is made of a material having a low coefficient of friction.

5. The invention as recited in claim 1, wherein the said bearing means comprises a ball bearing having inner and outer races, the inner race being secured to the said inner member and the outer race being secured to the said outer member.

6. An adapter for use in supporting a tubular core on a mandrel comprising,

disposed in the bottom of the. 50

(a) a tubular inner member made of a material having a low coefficient of friction and having an inside diameter such that it is slidably insertable over the mandrel,

5 (b) a cylindrical outer member having a reduced-diameter portion for insertion into an end of the core and a base portion provided with a central opening corresponding to the inside diameter of the said inner member,

(c) a ball bearing having an inner race secured to the outer wall of the said inner member and an outer race secured to the inner Wall of the said outer member,

(d) a flat plate secured to the surface of the base portion of the said outer member, said plate provided with a central opening corresponding to the inside diameter of the said inner member,

(e) means forming a peripheral groove in the reduceddiameter portion of the said outer member,

(f) a resilient ring disposed in the bottom of said groove, and

jg) a coil spring disposed in said groove and over the said ring, said spring having convolutions normally extending radially outward of the groove.

7. An arrangement for winding a strip of material on a core which is frictionally driven by a mandrel, which arrangement comprises,

(a) a first adapter mounted on the mandrel and comprising concentric inner and outer members mechanically coupled to a ball bearing,

(b) a second adapter mounted on the mandrel and comprising concentric inner and outer members mechanically coupled to a ball bearing,

(c) a core carried by the outer members of both said adapters,

(d) holding means on each of the outer members of the adapters, said holding means preventing rotation of the core relative to the said outer members,

(e) a pair of spacer rings mounted on the mandrel 4 for positive rotation therewith, one spacer ring having an end in frictional engagement with the outer member of the said first adapter and the other spacer ring having an end in frictional engagement with the inner member of the said second adapter, and

(f) means applying an axial rings.

8. The invention as recited in claim 7 including a flat plate secured to an end of the outer member of the said first adapter, and wherein the end of the said one spacer ring is in frictional engagement with the said plate.

9. The invention as recited in claim 8, wherein the said holding means comprises complementary reduceddiameter portions formed on the outer members of both adapters, a peripheral groove formed in each such reduced-diameter portion, resilient ring members individually disposed in the bottom of each groove, and a pair of circular coiled springs individually positioned over the ring members and projecting radially outwardly of the grooves, the arrangement being such that the springs bite into the wall of the core.

pressure to the spacer References Cited UNITED STATES PATENTS 1,955,917 4/1934 Jung 2,833,488 5/1958 Kerber FRANK I. COHEN, Primary Examiner. 70 N. L. MINTZ, Assistant Examiner.

Claims

1. AN ADAPTER FOR USE IN SUPPORTING A TUBULAR CORE ON A MANDREL, WHICH ADAPTER COMPRISES, (A) A CYLINDRICAL OUTER MEMBER HAVING A PORTION INSERTABLE INTO AN END OF THE CORE, (B) HOLDING MEANS CARRIED BY SAID OUTER MEMBER, SAID HOLDING MEANS COOPERATING WITH THE CORE TO PREVENT RELATIVE ROTATION BETWEEN THE CORE AND SAID MEMBER, (C) A TUBULAR INNER MEMBER CONCENTRIC WITH SAID OUTER MEMBER AND INSERTABLE OVER THE MANDREL, AND (D) BEARING MEANS POSITIONED BETWEEN THE SAID OUTER AND INNER MEMBERS TO AFFORD RELATIVE ROTATION THEREBETWEEN.