CA2121273C - Tubular core assembly for winding paper and other small material including frustroconical core inserts - Google Patents
Tubular core assembly for winding paper and other small material including frustroconical core insertsInfo
- Publication number
- CA2121273C CA2121273C CA 2121273 CA2121273A CA2121273C CA 2121273 C CA2121273 C CA 2121273C CA 2121273 CA2121273 CA 2121273 CA 2121273 A CA2121273 A CA 2121273A CA 2121273 C CA2121273 C CA 2121273C
- Authority
- CA
- Canada
- Prior art keywords
- core
- insert members
- annular
- tubular
- core insert
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H75/00—Storing webs, tapes, or filamentary material, e.g. on reels
- B65H75/02—Cores, formers, supports, or holders for coiled, wound, or folded material, e.g. reels, spindles, bobbins, cop tubes, cans, mandrels or chucks
- B65H75/18—Constructional details
- B65H75/185—End caps, plugs or adapters
Abstract
The invention provides tubular core assemblies for winding or unwinding of sheet material, such as newsprint, wherein the opposed ends of an elongate cylindrical core are provided with core insert members securely attached by adhesive bonding to the inside and surfaces of the cylindrical core for reducing the inside diameter of the ends of the cylindrical core. The annular core insert members each include a substantially frustoconical exterior surface for joining to the inside periphery of the ends of the cylindrical core and the opposed ends of the cylindrical core have substantially frustoconical interior surfaces which match the substantially frustoconical exterior surfaces of the annular core insert members. The annular core insert members can readily be bonded to the ends of the main core body by axial insertion into the core because surface-to-surface contact of the bonding surfaces is improved and because adhesive bonding material is not scraped off during the insertion process. In addition, the core insert members have improved axial load capabilities.
Description
3 ~ !
- 2~21273 . ,~, TUBULAR CORE ASSEMBLY FOR WINDING
PAPER AND OTHER ~ '1' MATERIAL INCLUDING
FRUSTROCONICAL CORE INSERTS
Field of the Invention The invention relates to a tubular core of the type used for winding paper, such as newsprint, film and other sheet material. More specifically, the invention is directed to a tubular core assembly having annular core insert members for reducing the inside diameter of the tubular core.
Backqround of the Invention Tubes and cores are widely used in the film and paper industry for winding film and paper into roll ~orm. These cores are usually made of paperboard and are formed by a spiral or convolute wrap process.
Thus, one or more plies of paperboard are coated with adhesive and wrapped around a mandrel to seal each layer to the next in the structure. For lightweight uses, the tubes or cores are made of lightweight paperboard and may have only a few layers. However, for heavy duty uses, such as for winding and unwinding for newspaper and Rotogravure printing, the tubes are 20 usually very long, for example up to about 10 ft. ~;;
(3.08 m.) for U.S. Rotogravure printing and 10.5 ft.
(3.22 m.), for European Rotogravure printing. In view of the large size, these tubes must be of very heavy or thick construction to be able to carry the weight of a large roll of paper.
2~21 273 In use on winding and unwinding equipment, the tubular cores are mounted on stub shafts or chucks of standard size. U-shaped metal end caps are typically inserted into the open ends of the tube to assist in more positive mounting of the paperboard cores on the chucks or stub shafts of the winding and unwinding equipment.
Many paperboard cores used in film and paper processes have a three-inch inside diameter and much of the commercially used equipment have chucks and stub shafts designed to cooperate with three-inch inside diameter cores. Because of this equipment design, the user is limited to use of the three-inch inside diameter cores.
At times, printers and/or film manufacturers could obtain benefits from the use of a larger tubular core on equipment designed for use with a core of smaller diameter including improved vibration and dynamic strength performance. For example, many conventional cores have a six-inch inside diameter and it is clear that the use of six-inch inside diameter core with equipment designed to support a core having a three-inch inside diameter can significantly impact vibration during the winding and unwinding process.
U.S. Patent 4,875,636 to Kewin discloses a non-returnable newsprint carrier system in which the newsprint cylindrical core can be used without the need for metal end caps. The inside surfaces of the opposite end portions of the tubular core have substantially the same non-cylindrical configuration, profile and dimensions as the outside surfaces of the reel stub shafts of an offset printing press so that the tubular core and newsprint stub shaft will have a full profile fit in surface-to-surface contact over substantially the entire surface of the reel stub shafts inserted within the core during use thereof.
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2~2~2~3 U.S. Patent 4,874,139 to Kewin discloses tubular core assemblies which include an annular core insert member which may be made of a cellulosic material, permanently bonded to the inside end of a tubular paperboard core. The use of such an interior annular core insert can allow for the use of a smaller wall thickness paperboard tube. In practice, there is a problem with the annular core insert because it is fastened to the interior of the inside tube by an adhesive. The exterior of the core insert must have a tight fit with the interior of the core, inside the tube, to eliminate vibration and wobble in high speed winding and to try to keep the insert from breaking loose during sudden acceleration or deceleration of the unwind machine. Because of the relatively close tolerance fit between the annular core insert and the inside of the core, the adhesive, intended to bond the annular core insert to the core, is typically wiped out of the minimal space between the insert and the core during the axial insertion process. Moreover, unless the exterior surface of the annular core insert and the interior surface of the tube, are perfectly symmetrical ; -and circular, gaps can be left between the two surfaces where no bonding occurs. Thus, in practice, the annular core inserts are seldom adhered securely to the tube and very seldom survive the winding operation, much less the unwinding operation.
The elimination of metal end caps for the mounting of cores on winding and unwinding equipment would be highly desirable. However, in practice the proposed systems of the prior art include various disadvantages as discussed above, including the poor bonding between interior annular core inserts and the ends of the tubular core and/or the need to reduce the diameter of inside portions o~ the tubular core in order to provide a tube with an inside surface having a profile matching the exterior profile of the reel stub 21 2~ 273 shafts of winding and unwinding equipment. Moreover, there is no practical solution provided in the art for the recurring needs and desires of manufacturers to employ large diameter cores on equipment designed for use with smaller diameter cores.
Summary of the Invention According to the invention, a tubular core assembly including a cylindrical core having annular core insert members in each of its opposed ends is provided in which the core inserts can readily be securely attached by adhesive bonding to the inside end surfaces of the cylindrical core. Because the annular core insert members for the ends of the tube can be readily and permanently bonded to the inside end surfaces of the core, the invention provides a practical and readi.ly available means for reducing the inside diameter of large cylindrical cores so that the large cylindrical cores can readily be used with winding and unwinding equipment designed for use with smaller cores. In addition, the inside surfaces of the core insert members can be configured and profiled to match the outside dimensions of conventional stub shafts or chucks of conventional winding and unwinding equipment.
The tubular core assembly of the invention includes an elongate hollow cylindrical core, preferably a paperboard core formed by multiple wraps of a paperboard material, and having annular core insert members securely attached by adhesive bonding to the inside periphery of each of the opposed ends of the cylindrical core for reducing the inside diameters of the ends. The annular core insert members each.include a substantially frustoconical exterior surface for joining to the inside periphery of the ends of the cylindrical core. The opposed ends of the cylindrical core include substantially frustoconical interior surfaces which match the substantially frustoconical exterior surfaces of the annular core insert members and which taper from a larger diameter to a smaller diameter in the axially inward direction. Because of the frustoconical, i.e. tapered, exterior shape of the annular core insert members, the insert members can readily be adhesively bonded to the interior end surfaces of the cylindrical core by axial insertion. A
bonding material, such as an aqueous or solvent based glue, coated onto the outside surfaces of the insert members and/or onto the inside surfaces of the ends of the main hollow cylindrical core is not scraped off during the insertion of the core insert member into the main cylindrical core because of the tapered shapes of the core insert members and the inside surfaces of the ends of the main cylindrical core. In addition, after assembly, inward axial pressure on the frustoconically shaped annular core insert members results in radially outward force being exerted on the ends of the cylindrical core with the result that the annular core insert members have improved axial load capabilities.
The annular core insert members are readily formed from various cellulosic-based and/or polymer-based and composite materials including wood particles or chips, wood pulp, paperboard and/or liquid and solid polytners by conventional molding or winding operations.
The tubular core assemblies of the invention can be used without the need for metal end caps or inserts.
The annular core insert members additionally strengthen the ends of the paperboard cores by increasing the wall thickness of the core ends. The inside annular surfaces of the core insert members can be provided with shapes and profiles matching the exterior profiles of conventional chucks and/or reel stub shafts of winding and unwinding equipment so that such chucks and/or reel stub shafts can be inserted into the cores of the invention in surface-to-surface contact with the inside surface of the core assembly as disclosed in 2~ ~1273 .
U.S. Patent 4,875,636 to Kewin, which is hereby incorporated by reference. The tubular core assemblies of the invention can be used with conventional core plugs during shipping of empty cores and/or fully wound rolls of paper and the like.
Brief Description of the Drawinqs In the drawings which form a portion of the original disclosure of the invention:
Figure 1, is an exploded perspective view of one end portion of one preferred tubular core assembly of the invention, the other end being identical; and Figure 2, is a cross-sectional side view of a core assembly of the invention showing the annular core insert member positioned in, and bonded to one end of the tubular core.
Descri~tion of the Preferred Embodiment In the following detailed description, exemplary pre~erred embodiments of the invention are described to enable practice of the invention. It will ~
20 be apparent that terms used in describing the invention ~ -are used for the purpose of description and not for the purpose of limiting the invention. It will also be apparent that the invention is susceptible to numerous variations and modifications as will become apparent from a consideration of the invention as shown in the attached drawings and described herein.
Figure 1 illustrates an exploded perspective view of one end o~ a tubular core assembly of the invention. The opposed end of the tubular core assembly (not shown) is identical to the end shown in Fi~ure l as will he apparent. The tubular core assembly includes a main tubular core 10 and an annular core insert member 12.
The main core member 10 is defined by a cylindrical, hollow bodywall 14 which is preferably formed by multiple wraps of a paperboard material. As illustrated in Figure 1, the bodywall 14 is a spiral 2~ 21273 wrapped tubular body; however, a multiple paperboard layer tubular core can also be formed by employing a convolute wrapping process or alternatively the main core member can be formed of a single layer bodywall prepared for example of a plastic material by an extrusion or molding process. In preferred embodiments of the invention, the bodywall 14 will include multiple paperboard layers.
Both the spiral wrapping process and the convolute wrapping process are well known to those skilled in the art. In general, such processes involve the wrapping of one or more adhesive coated plys around a mandrel to provide a tubular body. The thickness of the bodywall and the density of the paperboard plies ;
used in the wrapping process are chosen to provide the desired strength in the resultant bodywall. For example, where the core is intended for light-duty or light-weight uses, the paperboard plles can have a light density and/or light weight and the bodywall thickness can be relatively low, for example, in the range of from about 0.125 inches to about 0.25 inches.
On the other hand, for heavy-duty uses, a thicker bodywall for example in the range of between about 0.5 inches and about 0.875 inches, is needed and typically a heavy and/or thick paperboard ply material is used.
A portion 16 of the interior periphery of the end of the main core body 10 is beveled in order to receive the external surface 18 of the core insert member 12 in surface-to-surface contact. The beveled interior surface 16 can readily be formed by processes known to those skilled in the art including burnishing processes, grinding processes and the like.
The annular core insert member 12 can be formed from any of various materials including cellulosic, plastic and composite materials but is preferably formed from a cellulosic-based material such as wood chips or wood particles, wood pulp, paper :- 2~2127~
and/or paperboard materials, including recycled paper materials, and the like. The annular core insert 12 can readily be formed by a molding process, for example, by molding wood particles, chips, wood pulp.
and/or liquid and solid polymer materials or the like into the desired annular shape according to well known processes. Alternatively, the annular core insert 12 can be formed by grinding or burnishing the exterior surface of a paperboard tubular member to achieve the desired exterior frustoconical shape.
The main paperboard tubular body 10 typically has an inside diameter of a few inches, e.g. three inches, up to 6-7 inches or greater. The main body member 10 generally has an extended length ranging from 15 one foot or more up to about 11 ft. or greater. The -annular core insert member 12 typically has a longitudinal length based on the desired end use of the tubular core assembly and preferably has a length about the same as or greater than the chuck or reel stub shaft intended to be inserted into the tubular core assembly. Typically, the length of the annular core insert member will range from about one inch to about 18 inches or more.
The wall thickness of the core insert member 12 is chosen based on the desired interior diameter reduction for main tube body 10. For example, when it is desired to convert a conventional tube having an inside diameter of about six inches for use with conventional winding and unwinding equipment designed to receive a tube having an inside diameter of about three inches, the core insert member 12 can have a wall thickness of about 1.5 inches or greater. In general, it is preferred that the core insert member 12 have an average wall thickness (averaged over the length of the insert) of greater than about 0.25 inches, preferably greater than 0.5 inches, in order to substantially strengthen the ends of the main core body 10.
-'' 2~21273 g The frustoconically shaped exterior surface of core insert member 12 can have a taper which typically ranges from between about 5 degrees to about 35 degrees or more. Preferably, the angle of the surface taper, A, (relative to the main core axis) as indicated in Figure 2, will be greater than about 10-15 degrees. It will be apparent that the specific surface taper angle will be chosen depending upon the thickness of the main bodywall portion 14 of the main core 10 and upon the longitudinal length and thickness of the core insert member 12 and upon other factors. It will also be apparent that when relatively long core insert members are used, only a portion of the exterior surface thereof will be frustoconical while the remaining exterior surface can be a cylindrical surface having the same out:side diameter as the inside diameter of the main core body 10.
In general, the frustoconical surface provides a number of significant advantages in the core assemblies of the invention. When an adhesive material such as a latex or solvent based or thermosetting glue is applied to either or both of surfaces 18 and 16, the insertion of core insert member 12 into the main body 10 results in an even pressure on the glue surface, substantially perpendicular to the wall surfaces 18 and 16; thus, the adhesive material is not scraped off as was the case with use of prior art core insert members.
In addition, the matching frustoconical interior surface of main core body 10 and the matching exterior surface of core insert body 12 cooperate during the insertion operation to assist in centering of the core insert member 12 radially within the main core body 10.
As a result, the core insert member 12 is securely attached to the main body 10 with adhesive spread evenly around the surface of the core insert and, in addition, the core insert is well centered in the main body wall. In use, axially inward slippage of the core 21~ 12 r~
,.
insert as a result of axially inward pressure on the core insert is prevented by the interaction between the exterior surface of the core insert and the interior surface of the main body core 10.
Although the core insert member 12 illustrated in Figures 1 and 2 is shown to have a substantially smooth, exterior frustoconical surface, it will be apparent that the exterior surface can be provide with splines and the interior surface 16 of the main core body 10 can be provided with matching grooves to receive such splines or vice versa. However, splines, grooves and the like are generally undesirable and unnecessary in the present invention and the use of a substantially smooth exterior surface on core insert member 12 is preferred because the smooth surface provides for joining of the core insert member to the main body without the necessity for matching of mechanical anchoring surfaces.
As indicated previously, in a particularly preferred embodiment of the invention, the interior peripheral surface 20 of core insert member 12 can be profiled to match the exterior profile of a reel stub shaft used in winding and unwinding equipment as disclosed in U.S. Patent 4,875,636. Thus, the interior surface of core insert member 12 can include a first portion located at position 20a which tapers radially outwardly in the axial outward direction, preferably at an angle of approximately 2~ with respect to the longitudinal central axis of the main core body, and a second portion at position 20b which extends axially outwardly from the first portion 20a and tapers axially outwardly at a second predetermined angle, preferably approximately 33~ with respect to the central axis A.
In addition, the inside surface 20 can include one or more grooves for receiving a spline or the like on the exterior of a reel stub shaft of conventional winding or unwinding equipment. Such preferred profiled 2 1 2 1 2 ~ 3 ,~
interior surfaces are discussed and illustrated in detail in U.S. Patent 4,875,636, which has been previously incorporated herein by reference.
The core assemblies of the invention can also be used with conventional metal inserts for receiving stubs shafts or chucks, however as discussed above such metal inserts are not necessary in preferred embodiments of the invention. As indicated previously, a conventional core plug can advantageously be incorporated into to the annular opening of the core insert member 12 during shipping and storage of the core assembly bodies of the invention in order to protect the ends thereof. Such core plugs are generally known to those skilled in the art and exemplary core plugs are also disclosed in the previously mentione.~ U.S. Patent 4,875,636.
The invention has been described in considerable detail with reference to its preferred embodiments. However, it will be apparent that variations and modifications can be made without departing from the spirit and scope of the invention as described in the foregoing detailed specification and defined in the appended claims.
PAPER AND OTHER ~ '1' MATERIAL INCLUDING
FRUSTROCONICAL CORE INSERTS
Field of the Invention The invention relates to a tubular core of the type used for winding paper, such as newsprint, film and other sheet material. More specifically, the invention is directed to a tubular core assembly having annular core insert members for reducing the inside diameter of the tubular core.
Backqround of the Invention Tubes and cores are widely used in the film and paper industry for winding film and paper into roll ~orm. These cores are usually made of paperboard and are formed by a spiral or convolute wrap process.
Thus, one or more plies of paperboard are coated with adhesive and wrapped around a mandrel to seal each layer to the next in the structure. For lightweight uses, the tubes or cores are made of lightweight paperboard and may have only a few layers. However, for heavy duty uses, such as for winding and unwinding for newspaper and Rotogravure printing, the tubes are 20 usually very long, for example up to about 10 ft. ~;;
(3.08 m.) for U.S. Rotogravure printing and 10.5 ft.
(3.22 m.), for European Rotogravure printing. In view of the large size, these tubes must be of very heavy or thick construction to be able to carry the weight of a large roll of paper.
2~21 273 In use on winding and unwinding equipment, the tubular cores are mounted on stub shafts or chucks of standard size. U-shaped metal end caps are typically inserted into the open ends of the tube to assist in more positive mounting of the paperboard cores on the chucks or stub shafts of the winding and unwinding equipment.
Many paperboard cores used in film and paper processes have a three-inch inside diameter and much of the commercially used equipment have chucks and stub shafts designed to cooperate with three-inch inside diameter cores. Because of this equipment design, the user is limited to use of the three-inch inside diameter cores.
At times, printers and/or film manufacturers could obtain benefits from the use of a larger tubular core on equipment designed for use with a core of smaller diameter including improved vibration and dynamic strength performance. For example, many conventional cores have a six-inch inside diameter and it is clear that the use of six-inch inside diameter core with equipment designed to support a core having a three-inch inside diameter can significantly impact vibration during the winding and unwinding process.
U.S. Patent 4,875,636 to Kewin discloses a non-returnable newsprint carrier system in which the newsprint cylindrical core can be used without the need for metal end caps. The inside surfaces of the opposite end portions of the tubular core have substantially the same non-cylindrical configuration, profile and dimensions as the outside surfaces of the reel stub shafts of an offset printing press so that the tubular core and newsprint stub shaft will have a full profile fit in surface-to-surface contact over substantially the entire surface of the reel stub shafts inserted within the core during use thereof.
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2~2~2~3 U.S. Patent 4,874,139 to Kewin discloses tubular core assemblies which include an annular core insert member which may be made of a cellulosic material, permanently bonded to the inside end of a tubular paperboard core. The use of such an interior annular core insert can allow for the use of a smaller wall thickness paperboard tube. In practice, there is a problem with the annular core insert because it is fastened to the interior of the inside tube by an adhesive. The exterior of the core insert must have a tight fit with the interior of the core, inside the tube, to eliminate vibration and wobble in high speed winding and to try to keep the insert from breaking loose during sudden acceleration or deceleration of the unwind machine. Because of the relatively close tolerance fit between the annular core insert and the inside of the core, the adhesive, intended to bond the annular core insert to the core, is typically wiped out of the minimal space between the insert and the core during the axial insertion process. Moreover, unless the exterior surface of the annular core insert and the interior surface of the tube, are perfectly symmetrical ; -and circular, gaps can be left between the two surfaces where no bonding occurs. Thus, in practice, the annular core inserts are seldom adhered securely to the tube and very seldom survive the winding operation, much less the unwinding operation.
The elimination of metal end caps for the mounting of cores on winding and unwinding equipment would be highly desirable. However, in practice the proposed systems of the prior art include various disadvantages as discussed above, including the poor bonding between interior annular core inserts and the ends of the tubular core and/or the need to reduce the diameter of inside portions o~ the tubular core in order to provide a tube with an inside surface having a profile matching the exterior profile of the reel stub 21 2~ 273 shafts of winding and unwinding equipment. Moreover, there is no practical solution provided in the art for the recurring needs and desires of manufacturers to employ large diameter cores on equipment designed for use with smaller diameter cores.
Summary of the Invention According to the invention, a tubular core assembly including a cylindrical core having annular core insert members in each of its opposed ends is provided in which the core inserts can readily be securely attached by adhesive bonding to the inside end surfaces of the cylindrical core. Because the annular core insert members for the ends of the tube can be readily and permanently bonded to the inside end surfaces of the core, the invention provides a practical and readi.ly available means for reducing the inside diameter of large cylindrical cores so that the large cylindrical cores can readily be used with winding and unwinding equipment designed for use with smaller cores. In addition, the inside surfaces of the core insert members can be configured and profiled to match the outside dimensions of conventional stub shafts or chucks of conventional winding and unwinding equipment.
The tubular core assembly of the invention includes an elongate hollow cylindrical core, preferably a paperboard core formed by multiple wraps of a paperboard material, and having annular core insert members securely attached by adhesive bonding to the inside periphery of each of the opposed ends of the cylindrical core for reducing the inside diameters of the ends. The annular core insert members each.include a substantially frustoconical exterior surface for joining to the inside periphery of the ends of the cylindrical core. The opposed ends of the cylindrical core include substantially frustoconical interior surfaces which match the substantially frustoconical exterior surfaces of the annular core insert members and which taper from a larger diameter to a smaller diameter in the axially inward direction. Because of the frustoconical, i.e. tapered, exterior shape of the annular core insert members, the insert members can readily be adhesively bonded to the interior end surfaces of the cylindrical core by axial insertion. A
bonding material, such as an aqueous or solvent based glue, coated onto the outside surfaces of the insert members and/or onto the inside surfaces of the ends of the main hollow cylindrical core is not scraped off during the insertion of the core insert member into the main cylindrical core because of the tapered shapes of the core insert members and the inside surfaces of the ends of the main cylindrical core. In addition, after assembly, inward axial pressure on the frustoconically shaped annular core insert members results in radially outward force being exerted on the ends of the cylindrical core with the result that the annular core insert members have improved axial load capabilities.
The annular core insert members are readily formed from various cellulosic-based and/or polymer-based and composite materials including wood particles or chips, wood pulp, paperboard and/or liquid and solid polytners by conventional molding or winding operations.
The tubular core assemblies of the invention can be used without the need for metal end caps or inserts.
The annular core insert members additionally strengthen the ends of the paperboard cores by increasing the wall thickness of the core ends. The inside annular surfaces of the core insert members can be provided with shapes and profiles matching the exterior profiles of conventional chucks and/or reel stub shafts of winding and unwinding equipment so that such chucks and/or reel stub shafts can be inserted into the cores of the invention in surface-to-surface contact with the inside surface of the core assembly as disclosed in 2~ ~1273 .
U.S. Patent 4,875,636 to Kewin, which is hereby incorporated by reference. The tubular core assemblies of the invention can be used with conventional core plugs during shipping of empty cores and/or fully wound rolls of paper and the like.
Brief Description of the Drawinqs In the drawings which form a portion of the original disclosure of the invention:
Figure 1, is an exploded perspective view of one end portion of one preferred tubular core assembly of the invention, the other end being identical; and Figure 2, is a cross-sectional side view of a core assembly of the invention showing the annular core insert member positioned in, and bonded to one end of the tubular core.
Descri~tion of the Preferred Embodiment In the following detailed description, exemplary pre~erred embodiments of the invention are described to enable practice of the invention. It will ~
20 be apparent that terms used in describing the invention ~ -are used for the purpose of description and not for the purpose of limiting the invention. It will also be apparent that the invention is susceptible to numerous variations and modifications as will become apparent from a consideration of the invention as shown in the attached drawings and described herein.
Figure 1 illustrates an exploded perspective view of one end o~ a tubular core assembly of the invention. The opposed end of the tubular core assembly (not shown) is identical to the end shown in Fi~ure l as will he apparent. The tubular core assembly includes a main tubular core 10 and an annular core insert member 12.
The main core member 10 is defined by a cylindrical, hollow bodywall 14 which is preferably formed by multiple wraps of a paperboard material. As illustrated in Figure 1, the bodywall 14 is a spiral 2~ 21273 wrapped tubular body; however, a multiple paperboard layer tubular core can also be formed by employing a convolute wrapping process or alternatively the main core member can be formed of a single layer bodywall prepared for example of a plastic material by an extrusion or molding process. In preferred embodiments of the invention, the bodywall 14 will include multiple paperboard layers.
Both the spiral wrapping process and the convolute wrapping process are well known to those skilled in the art. In general, such processes involve the wrapping of one or more adhesive coated plys around a mandrel to provide a tubular body. The thickness of the bodywall and the density of the paperboard plies ;
used in the wrapping process are chosen to provide the desired strength in the resultant bodywall. For example, where the core is intended for light-duty or light-weight uses, the paperboard plles can have a light density and/or light weight and the bodywall thickness can be relatively low, for example, in the range of from about 0.125 inches to about 0.25 inches.
On the other hand, for heavy-duty uses, a thicker bodywall for example in the range of between about 0.5 inches and about 0.875 inches, is needed and typically a heavy and/or thick paperboard ply material is used.
A portion 16 of the interior periphery of the end of the main core body 10 is beveled in order to receive the external surface 18 of the core insert member 12 in surface-to-surface contact. The beveled interior surface 16 can readily be formed by processes known to those skilled in the art including burnishing processes, grinding processes and the like.
The annular core insert member 12 can be formed from any of various materials including cellulosic, plastic and composite materials but is preferably formed from a cellulosic-based material such as wood chips or wood particles, wood pulp, paper :- 2~2127~
and/or paperboard materials, including recycled paper materials, and the like. The annular core insert 12 can readily be formed by a molding process, for example, by molding wood particles, chips, wood pulp.
and/or liquid and solid polymer materials or the like into the desired annular shape according to well known processes. Alternatively, the annular core insert 12 can be formed by grinding or burnishing the exterior surface of a paperboard tubular member to achieve the desired exterior frustoconical shape.
The main paperboard tubular body 10 typically has an inside diameter of a few inches, e.g. three inches, up to 6-7 inches or greater. The main body member 10 generally has an extended length ranging from 15 one foot or more up to about 11 ft. or greater. The -annular core insert member 12 typically has a longitudinal length based on the desired end use of the tubular core assembly and preferably has a length about the same as or greater than the chuck or reel stub shaft intended to be inserted into the tubular core assembly. Typically, the length of the annular core insert member will range from about one inch to about 18 inches or more.
The wall thickness of the core insert member 12 is chosen based on the desired interior diameter reduction for main tube body 10. For example, when it is desired to convert a conventional tube having an inside diameter of about six inches for use with conventional winding and unwinding equipment designed to receive a tube having an inside diameter of about three inches, the core insert member 12 can have a wall thickness of about 1.5 inches or greater. In general, it is preferred that the core insert member 12 have an average wall thickness (averaged over the length of the insert) of greater than about 0.25 inches, preferably greater than 0.5 inches, in order to substantially strengthen the ends of the main core body 10.
-'' 2~21273 g The frustoconically shaped exterior surface of core insert member 12 can have a taper which typically ranges from between about 5 degrees to about 35 degrees or more. Preferably, the angle of the surface taper, A, (relative to the main core axis) as indicated in Figure 2, will be greater than about 10-15 degrees. It will be apparent that the specific surface taper angle will be chosen depending upon the thickness of the main bodywall portion 14 of the main core 10 and upon the longitudinal length and thickness of the core insert member 12 and upon other factors. It will also be apparent that when relatively long core insert members are used, only a portion of the exterior surface thereof will be frustoconical while the remaining exterior surface can be a cylindrical surface having the same out:side diameter as the inside diameter of the main core body 10.
In general, the frustoconical surface provides a number of significant advantages in the core assemblies of the invention. When an adhesive material such as a latex or solvent based or thermosetting glue is applied to either or both of surfaces 18 and 16, the insertion of core insert member 12 into the main body 10 results in an even pressure on the glue surface, substantially perpendicular to the wall surfaces 18 and 16; thus, the adhesive material is not scraped off as was the case with use of prior art core insert members.
In addition, the matching frustoconical interior surface of main core body 10 and the matching exterior surface of core insert body 12 cooperate during the insertion operation to assist in centering of the core insert member 12 radially within the main core body 10.
As a result, the core insert member 12 is securely attached to the main body 10 with adhesive spread evenly around the surface of the core insert and, in addition, the core insert is well centered in the main body wall. In use, axially inward slippage of the core 21~ 12 r~
,.
insert as a result of axially inward pressure on the core insert is prevented by the interaction between the exterior surface of the core insert and the interior surface of the main body core 10.
Although the core insert member 12 illustrated in Figures 1 and 2 is shown to have a substantially smooth, exterior frustoconical surface, it will be apparent that the exterior surface can be provide with splines and the interior surface 16 of the main core body 10 can be provided with matching grooves to receive such splines or vice versa. However, splines, grooves and the like are generally undesirable and unnecessary in the present invention and the use of a substantially smooth exterior surface on core insert member 12 is preferred because the smooth surface provides for joining of the core insert member to the main body without the necessity for matching of mechanical anchoring surfaces.
As indicated previously, in a particularly preferred embodiment of the invention, the interior peripheral surface 20 of core insert member 12 can be profiled to match the exterior profile of a reel stub shaft used in winding and unwinding equipment as disclosed in U.S. Patent 4,875,636. Thus, the interior surface of core insert member 12 can include a first portion located at position 20a which tapers radially outwardly in the axial outward direction, preferably at an angle of approximately 2~ with respect to the longitudinal central axis of the main core body, and a second portion at position 20b which extends axially outwardly from the first portion 20a and tapers axially outwardly at a second predetermined angle, preferably approximately 33~ with respect to the central axis A.
In addition, the inside surface 20 can include one or more grooves for receiving a spline or the like on the exterior of a reel stub shaft of conventional winding or unwinding equipment. Such preferred profiled 2 1 2 1 2 ~ 3 ,~
interior surfaces are discussed and illustrated in detail in U.S. Patent 4,875,636, which has been previously incorporated herein by reference.
The core assemblies of the invention can also be used with conventional metal inserts for receiving stubs shafts or chucks, however as discussed above such metal inserts are not necessary in preferred embodiments of the invention. As indicated previously, a conventional core plug can advantageously be incorporated into to the annular opening of the core insert member 12 during shipping and storage of the core assembly bodies of the invention in order to protect the ends thereof. Such core plugs are generally known to those skilled in the art and exemplary core plugs are also disclosed in the previously mentione.~ U.S. Patent 4,875,636.
The invention has been described in considerable detail with reference to its preferred embodiments. However, it will be apparent that variations and modifications can be made without departing from the spirit and scope of the invention as described in the foregoing detailed specification and defined in the appended claims.
Claims (11)
1. A tubular core assembly for a roll of paper or sheet material comprising:
an elongate hollow cylindrical core having a substantially uniform outer diameter for winding said paper or sheet material and being formed by multiple wraps of a paperboard material and having opposed ends;
annular core insert members securely attached by adhesive bonding to the inside periphery of each of said opposed ends of said cylindrical core for reducing the inside diameter of said ends;
said annular insert members each comprising a substantially frustroconical exterior surface for joining to the inside periphery of said cylindrical core;
said opposed ends of said cylindrical core comprising substantially frustroconical interior surfaces matching the substantially frustroconical exterior surfaces of said annular core insert members and tapering from a larger diameter to a smaller diameter in the axially inward direction;
whereby said annular core insert members can readily be adhesively bonded to said ends of said core by axial insertion into said core and wherein said insert members have improved axial load capabilities.
an elongate hollow cylindrical core having a substantially uniform outer diameter for winding said paper or sheet material and being formed by multiple wraps of a paperboard material and having opposed ends;
annular core insert members securely attached by adhesive bonding to the inside periphery of each of said opposed ends of said cylindrical core for reducing the inside diameter of said ends;
said annular insert members each comprising a substantially frustroconical exterior surface for joining to the inside periphery of said cylindrical core;
said opposed ends of said cylindrical core comprising substantially frustroconical interior surfaces matching the substantially frustroconical exterior surfaces of said annular core insert members and tapering from a larger diameter to a smaller diameter in the axially inward direction;
whereby said annular core insert members can readily be adhesively bonded to said ends of said core by axial insertion into said core and wherein said insert members have improved axial load capabilities.
2. The tubular core assembly of Claim 1 wherein said annular core insert member are formed of a cellulosic-based material.
3. The tubular core assembly of Claim 2 wherein said annular core insert members are formed by molding said cellulosic material.
4. The tubular core assembly of Claim 3 wherein said cellulosic material comprises wood particles.
5. The tubular core assembly of Claim 1 wherein said annular core insert members comprise a profiled interior surface adapted to match the exterior profile of a chuck on a winding or unwinding apparatus.
6. The tubular core assembly of Claim 5 wherein said chuck is a reel stub shaft of a printing press.
7. The tubular core assembly of Claim 1 wherein each of said annular core insert members have an average radial wall thickness, averaged over the axial length of each said member, of at least about 0.25 inches.
8. The tubular core assembly of Claim 7 wherein each of said annular core insert members have an average radial wall thickness, averaged over the axial length of each said member, sufficient to reduce the inside diameter of a six inch inside diameter elongate hollow cylindrical core to an inside diameter of about three inches.
9. The tubular core assembly of Claim 1 wherein said annular core insert members have a frustoconical exterior surface tapering at an angle of at least 10 degrees with respect to the longitudinal axis of said annular core insert member.
10. The tubular core assembly of Claim 1 wherein said annular core insert members each have a length of between about 1 and about 18 inches.
11. The tubular core assembly of Claim 1 wherein each of said annular core insert members have a substantially smooth exterior surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US4997293A | 1993-04-20 | 1993-04-20 | |
| US049,972 | 1993-04-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2121273A1 CA2121273A1 (en) | 1994-10-21 |
| CA2121273C true CA2121273C (en) | 1999-01-19 |
Family
ID=21962724
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2121273 Expired - Fee Related CA2121273C (en) | 1993-04-20 | 1994-04-14 | Tubular core assembly for winding paper and other small material including frustroconical core inserts |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2121273C (en) |
| DE (1) | DE4413810A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006060924A1 (en) * | 2004-12-08 | 2006-06-15 | Abzac Canada Inc. | Restored winding cores and method for manufacturing the same |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE0102452L (en) * | 2001-07-05 | 2003-01-06 | Core Link Ab | Method and device for jointing |
| DE10148763A1 (en) * | 2001-10-02 | 2003-04-17 | Kunststoff Spritzguswerk Ing K | Coiling sleeve for coiling material sheets comprises an adapter which is nondestructively detachable from the sleeve body |
| US7204451B2 (en) | 2004-02-25 | 2007-04-17 | Sonoco Development, Inc. | Winding core and associated method |
| US10843892B2 (en) | 2017-09-12 | 2020-11-24 | Michael Van Deurse | Winding core end protector |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US411140A (en) * | 1889-09-17 | Shell for winding paper | ||
| DE1976889U (en) * | 1967-08-28 | 1968-01-11 | Georg Vogel | PLASTIC BUNG FOR THE SLEEVE OF ROTATING ROLLERS. |
| DE1982189U (en) * | 1967-11-20 | 1968-03-28 | Manfred P Dr Zeiser | PLASTIC BUNG FOR THE SLEEVE OF ROTATING ROLLERS. |
-
1994
- 1994-04-14 CA CA 2121273 patent/CA2121273C/en not_active Expired - Fee Related
- 1994-04-20 DE DE19944413810 patent/DE4413810A1/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006060924A1 (en) * | 2004-12-08 | 2006-06-15 | Abzac Canada Inc. | Restored winding cores and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2121273A1 (en) | 1994-10-21 |
| DE4413810A1 (en) | 1994-10-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20130415 |