Abstract:
Winding cores for the paper industry are restored by removing the metal tips from the ends of the core, trimming the core to eliminate the crimped end portions of the core, providing complementary male and female joint ends to the core, grinding the outer surface of the core to a constant outer diameter less than the industry standard outer diameter to accommodate a finishing layer. The cores with the complementary joints are pressed end to end to form a core master prior to its being ground and then picking up the core masters one by one and bringing them into proximity of a web of liner board material having a length which corresponds to the length of the core master and a width which corresponds to the circumference of the core, contacting the glue bearing liner board web with the core and rotating the core to wrap the web of liner board about the core to provide a finished restored core. The core master is then cut into suitable length winding cores.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 09/041,682, filed Mar. 13, 1998, now U.S. Pat. No. 6,051,092, issued Apr. 18, 2000, which is a divisional application of U.S. patent application Ser. No. 08/639,483, filed Apr. 29, 1996, now U.S. Pat. No. 5,845,871, issued Dec. 8, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method and apparatus for restoring cores, and more particularly, cores utilized for accommodating a roll of paper. 
     2. Description of the Prior Art 
     Newsprint and other paper used for printing is generally shipped from the paper mill in large rolls. When the rolls are made up at the paper mill, they are wound on a tubular core. Typically the cores are made of liner board and are usually provided with metal caps of the type described in U.S. Pat. No. 5,271,258, issued Dec. 21, 1993 to Bernier et al. 
     In the press room or other printing plant, the roll is mounted on an unwind apparatus with the core of the roll journaled on mandrels. Once the web of paper has been unwound from the core, the core is generally discarded or returned to a paper mill to be recycled as waste fiber. The core caps are first removed and restored for further use or sold for scrap. 
     The paper rolls are wound and unwound at high speeds and are, therefore, susceptible to misalignment while being wound, resulting in improper registry on the printing press, requiring constant alignment correction. A slight inconsistency in the outer diameter of 0.25 inches will cause the paper web, when being wound, to move away from the end of the core that includes the portion with the larger diameter. It is important, therefore, that the outer diameter be constant and retain its circular cylindrical configuration. Likewise, the inner diameter must not vary so that the axis of rotation is at the true center of the core and thus the roll of paper. Any out-of-center rotation will cause similar winding and unwinding problems. 
     Thus, it has not been contemplated to reuse a winding core once it has been utilized once other than to cut the core down to a smaller size. It has been found that after a single use, the winding core has been somewhat damaged. Even though such damage may appear negligible, the distortions in the outer diameter or center of rotation are usually unacceptable. Thus, the practice in industry is to discard the winding cores once a roll of paper web has been unwound therefrom. The discarded single use winding core is then returned to the paper mill as scrap liner board to be recycled as paper fiber. 
     SUMMARY OF THE INVENTION 
     It is an aim of the present invention to reclaim discarded winding cores and to restore such cores to acceptable standards such that the restored winding core can be reused as a winding core. 
     It is a further aim of the present invention to provide a method for restoring winding cores. 
     It is a further aim of the present invention to provide an apparatus to economically restore such discarded winding cores. 
     It is a still further aim of the present invention to provide an improved winding core with superior dimensional parameters compared to conventional winding cores. 
     A method in accordance with the present invention comprises the steps of collecting used winding cores, passing each core through a station for trimming the ends of each core, passing each core through a coning station for centering the core in relation to its outer diameter, grinding the outer surface of each core to a constant diameter equivalent to an outer diameter standard less the thickness of a finishing web of fiber material, providing a finishing web of fiber material with a length corresponding to the length of the winding core being restored and having a width equal to the circumference of the core being restored, and wrapping the finishing web of paper about the core being restored. 
     In a more specific embodiment of the present invention, the method includes the steps of recuperating used cores, selecting the winding cores by grade and length, passing each core through a core tip puller station for removing the steel tips from the ends of the cores, trimming the ends of the cores to remove crimping portions thereof, passing each core through a coning station for centering the cores in relation to their outer diameter, forming a female joint socket at one end thereof and a complementary male joint socket at the other end thereof, joining the cores end to end with adhesive to form an elongated multiple-length core master, grinding the outer surface of the core master to a constant diameter equivalent to a predetermined outer diameter standard less the thickness of a finishing web of paper, providing an elongated web of finishing material equivalent to the length of the multi-length core master, and wrapping the web about the core with adhesive so as to provide a constant outer diameter equivalent to the predetermined standard, and then cutting the multi-length core master to desired core lengths. 
     An apparatus in accordance with the present invention comprises a cutting table for trimming the ends of each winding core wherein saw means are provided for cutting off the ends of each core in order to remove any crimping marks, a coning station downstream of said cutting table wherein coning means are provided for centering the individual cores in relation to their outer diameters, grinding means for grinding the outer surface of the core to a predetermined constant diameter, and means for wrapping a finishing web of paper on the ground surface of the core, including a table for laying an elongated web of finishing paper having a length corresponding to the length of the core and a width corresponding to the circumference of the core, and means for wrapping the finishing web of paper on the core with adhesive. 
     An apparatus in accordance with a more specific embodiment of the present invention comprises a cutting table having a pair of spaced-apart cutting saws whereby the distance between the cutting saws can be adjusted to the equivalent of the length of the core being trimmed less the accumulated length of the portions of the ends to be trimmed, a coning station including a pair of spaced-apart heads each adapted to engage opposite ends of a trimmed core for the purpose of forming complementary female and male joints on the opposite ends of the core, means downstream of the coning station for joining the cores end to end to form a master core of a predetermined length representing multiple cores, a grinding station being arranged downstream thereof and including feeding means for feeding the so-formed master core by a rotating grinding wheel for grinding the core to a predetermined constant outer diameter, and the means for wrapping a finishing web of paper including a skiver for skiving the longitudinal edges of the web of finishing paper, means for applying glue to one surface of the web to be in contact with the core, the web wrapping station including a table, a web feeder for feeding a predetermined length of web onto the table from a continuous roll, means for picking up and laying the core master on the web, means for wrapping the length of web about the circumference of the core master with the skived edges overlapping, and means for cutting the core master into predetermined core lengths. 
     In another aspect of the present invention, there is provided an apparatus for wrapping a layer of material about a cylinder including an elongated frame, a material web feeding means at one end of the frame for feeding a predetermined length of web of material horizontally and longitudinally of the frame, the web having a width equal to the circumference of the cylinder, glue means for applying adhesive to the web, means for picking up and positioning a cylinder over the web of material on the elongated frame so that the axis of the cylinder is parallel to the longitudinal axis of the web of material, means for bringing the web of material and the cylinder into contact such that the adhesive will engage the surface of the cylinder, and means for rotating the cylinder so that the web of material is wrapped completely about the cylinder. 
     A winding core for transporting a web of paper in accordance with another aspect of the present invention comprises a circular cylindrical tube having ends and a predetermined circumference, the tube having a first spiral fiber board substrate and a web of fiber board material having a length equal to the length of the tube and a width corresponding to the circumference of the tube, the web of material having skived longitudinal edges, wherein the web of material is wrapped about the tube and forming a longitudinal seam made up of the longitudinal skived edges of the web that have been overlapped. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration, a preferred embodiment thereof, and in which: 
     FIG. 1 is a side elevation showing a series of stations for partially restoring a winding core; 
     FIG. 2 is a top elevation of the apparatus shown in FIG. 1; 
     FIG. 3 is a top elevation of a station shown in FIG. 1; 
     FIG. 4 is a side elevation of a further station shown in FIG. 1; 
     FIG. 5 is a top plan view of the station shown in FIG. 4; 
     FIG. 6 is a fragmentary top elevation of a further station in the restoring of the winding core which would be downstream of the apparatus shown in FIGS. 1 and 2; 
     FIG. 7 is an elevation of the station shown in FIG. 6; 
     FIG. 8 is a side elevation of a further station utilized in the restoring of the winding cores downstream of the station shown in FIGS. 6 and 7; 
     FIG. 9 is a fragmentary top plan view of the station shown in FIG. 8; 
     FIG. 10 is a top elevation of a further station associated with the station shown in FIGS. 8 and 9; 
     FIG. 11 is a fragmentary perspective view of a detail of the station shown in FIG. 10; 
     FIG. 12 is an enlarged fragmentary view of a detail of the station shown in FIG. 8; 
     FIG. 13 is a transverse cross-section of the station shown in FIG.  8  and taken along line  13 — 13  of FIG. 8; 
     FIG. 14 is an enlarged fragmentary elevation, partly in cross-section, of a detail of the station shown in FIG. 8; and 
     FIG. 15 is a block diagram showing the steps in accordance with the method of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIGS. 1 and 2, there is shown a core preparation table  10  having an inlet table  22  on which previously used or discarded cores C can be stored after they have been sorted according to grade and length. 
     For instance, the winding core C, which is normally made of a fiber board material, can come in different crush resistant categories, such as 400 lbs., 500 lbs., or 750 lbs. Eighty per cent of the winding cores are in a range of 55 inches, but this might vary. Most cores will have metal end caps at each end of the core C. Thus, a preselected batch of discarded used cores C are located on table  22  upstream of metal tip puller station  12 . 
     Downstream of the metal tip puller station  12  is a trimming station  14  made up, in the present embodiment, of two identical but reversed saw tables for trimming the ends of the cores. The next downstream station is a coning machine  16  best seen in FIGS. 4 and 5. The coning machine  16  serves to form a male joint on one end of the core C and a female socket at the other end. 
     Station  18 , shown in FIGS. 1 and 2, serves to press a series of cores C together to form a core master C M . Downstream of the press machine  18 , as shown in FIGS. 6 and 7, is a grinder  20 . Finally, to complete the process, a core wrapping apparatus  100 , as shown in FIGS. 8 through 14, is located downstream of the grinder  20 . 
     Referring now to FIGS. 1 through 5, the inlet table  22  is provided with a hydraulically operated gate member  24  associated with a slightly sloped table surface to allow cores C to advance one by one towards the metal tip puller station  12 . As shown in FIG. 3, the metal tip puller station  12  includes track  28  and a carriage  30  which travels on the track  28 . Puller head  32  is located on one end of the frame, as shown in FIG. 3, and an identical puller head  34  is located on the carriage  30 . The carriage  30  will move towards the puller head  32  when a core is located on the frame  26  to engage the ends such that the puller heads will engage the metal tips, and the carriage  30  will retract to remove the metal tips from the core C. The metal tips will be dumped from the respective puller heads  32  and  34  into a storage bin  23  for restoration of these metal tips. 
     The core C then advances through to station  14 . As shown in FIGS. 1 and 2, one end of the core will be cut by saw  38  as it comes off feed table  36 . The purpose of the saw  38  is to remove one end of the core which may have crimp marks, such as from the metal tips or caps. The core then passes through the next saw  44  in station  14  to cut off the other end of the core in a like manner. These circular saws  38  and  44  are readily available. The core is trimmed on both ends to be reduced to 48.5 inches from an original 55 inches. 
     The core C then moves on feeding table  37  to be engaged by the coning station  16 . As shown in FIGS. 4 and 5, the coning station  16  includes a frame  48  having a track  60 . A track  50  is mounted at one end of the frame  48  on platform  49 . A carriage  52  travels on the track  50 , and the carriage  52  mounts a router  56 . Router  56  is the female router, and the carriage  52  moves towards one end of the core C which is held in a holder  58  near the end. Holder  58  is provided with measuring devices for measuring the outer diameter of the core. These measuring devices can measure the outer diameter of the core 300 times a minute. 
     A female socket C V  is formed by router  56  with reference to the outer diameter. A router  68  is mounted on a subcarriage  66  mounted on a subtrack  64 . The subtrack  64  is mounted on the carriage  62  which in turn travels on the track  60  of the frame  48 . An outer diameter measuring device and holder  58  is mounted on the carriage  62 . The router  68  forms the male joint C S  in reference to the outer diameter. 
     The core C is then delivered on table  69  and, in the present instance, is manually laid in the press station  18  in a V-shaped trough  72  on elongated frame  70 . A press head  74  travels on the track  76  towards the aligned cores C in the trough  72 . Adhesive is applied to the joints C V  and C S  of each core C. Several cores C will be located end to end on the trough  72 , and the press head  74  moves to press the core sections in order that the jointed ends C V  and C S  be coupled together to form a core master C M . 
     Typically, a core master C M  will measure 180 inches and will be handled in the remainder of the core restoring apparatus as cylindrical core master C M . 
     Referring now to FIGS. 6 and 7, the core master C M  is passed through a grinder  20  which includes a grinding head frame  80 . Adjustable grinding wheels  86  and  88 , as shown in FIG.  7  and partially in FIG. 6, are effective for grinding the surface of the core master C M . The grinding machine  20  may be a Cincinnati grinding mill of the type known as Milacron (trade-mark) Twin Grip Centerless Grinder. Each of the grinding wheels is mounted with anti-friction profile truing in order to precisely grind the outer surface of the core C M  to a constant outer diameter. Typically, since the finished core should have an industry standard of 4.010 inches outer diameter, the grinding mill  20  will provide an outer diameter of 3.985 inches on the cores C M . Once the finishing web of liner board has been wrapped around the core, the core should reach an outer diameter of 4.010 inches. 
     The core C M  is driven past the grinding wheels  86  and  88  by means of driven wheel assemblies  82  and  84 , and the core C M  is supported on idler wheel assembly  94 . 
     Cores that are provided with metal end caps generally have an internal diameter of 3.072 inches. If, however, the core is not intended to be used with a metal end cap, the internal diameter is 3.000 inches. 
     Once the core C M  has been ground to its outer diameter of 3.985 inches, it is then sent to the wrapping assembly  100 . Reference is made to FIGS. 8 through 14 with respect to the wrapping assembly  100 . 
     As shown in FIGS. 8 and 9, the core wrapping assembly  100  includes a frame  102 . A web feeder and glue assembly  104  is provided at one end of the elongated frame  102 . A web assembly  103 , as shown in FIG. 10, includes a roll of liner board web W being taken off by the feed assembly  104 , and the web W passes through a skiver  114  which includes skiving wheels  116  shown in FIGS. 10 and 11. The skiver, depending on the thickness of the web W, will remove from 0.020 and 0.010 off each edge W L  and W R . The skiving station is upstream from the feed and glue station  104 . 
     The web W moves through the feed assembly  104  and through glue bath  118  and eventually over tension roller assembly  119 , including a spring mounted lever, and through the pair of tension rollers  120 . 
     Frame  102  is provided with a cutting assembly  108 , as shown in FIG. 12, which includes a cutting knife  122  on a pivoting lever  126  which moves in association with anvil  124  in order to cut the web W the exact predetermined length. The length of the web W is determined by the length of the core master C M . 
     The width of the web W is slightly greater, with the skived edges W L  and W R , than the circumference of the core C M , to be wrapped, so that the skived edges W L  and W R  can overlap at least within the parameters of the skived portions. 
     As shown in FIGS. 8,  12 ,  13 , and  14 , the web support assembly  105  includes vacuum feed conveyor  106  having suction cups  130  mounted on a vacuum box  134  which in turn is mounted to a conveyor system which moves the vacuum box  134  with vacuum cups  130  along the longitudinal axis of the frame  102 . The vacuum cups  130  act on the web W to advance the web W to the full extent required to cover the length of the core master C M . Once the web W has been extended to the predetermined length, the knife assembly  108  is activated to cut the length of the web W. The web W is supported on the frame by the elongated narrow platform  110 , as shown in FIG. 13, and by the suction cups  130 . 
     Once the web W has been laid out on the frame  102  as discussed above, a core master C M , in the magazine  112 , is lifted by means of a core support assembly  142 . 
     The core support assembly  142  includes a beam  144  which can travel laterally of the frame  102  as will be described later. A pair of spindle assemblies  164  are mounted on the beam  144  for travel along the longitudinal axis thereof. Each assembly  164  includes a sleeve  156  adapted to slide longitudinally on the beam  144 , a bracket  158  extending downwardly, and the spindle housing  165  having a spindle head  166 . The head  166  is mounted for sliding movement on a sliding sub-housing  167  slidably mounted to the housing  165 . The head  166  is rotatable by means of a motor in the sub-housing  167 . The head  166  is frusto-conical, and the beveled portion is radially serrated. 
     The shafts  154 , as seen in FIGS. 2 and 3, are driven by motor  170  through the intermediary of shafts  154 . The shafts  154  each have a gear  152  which engages rack  150  on the top of the frame  102 . Thus, motor  170  is effective to move the core support assembly  142  laterally on frame  102 . 
     As seen in FIG. 13, the pickup assembly  164  is adapted to pick up a core master C M  from the magazine  112  and move it to a position above the lateral center of the web W. 
     As shown in FIG. 13, web support assembly  105  may be raised, by means of hydraulic jacks  140  in increments corresponding to the different core diameters. Since the web W has been provided with an adhesive on the top surface thereof, the web W will come into contact with the surface of the core master C M . The close contact of the web to the surface of the core master is effected by means of a slicker assembly  174  which is actuated to raise the edge W R . The core master C M  is rotated by the motor (in sub-housing  167 ) driving the spindle heads  166 , and the web W will thus be wrapped about the core surface. A pair of idler rollers  172  is provided to ensure the close contact of the web being rolled to the surface of the core master C M . The skived edges of web W will overlap but will not form a seam of greater thickness than the thickness of the finished web of liner board. 
     The completed core masters C M  are then removed from frame  102 , and the cycle is repeated. The cores C M  are then cut into preferred core lengths. Metal tips may also be added to the restored cores.