Abstract:
An expandable core chuck includes a housing having a plurality of slots and a plurality of expansion plates movable radially outwardly from the housing to engage the interior surface of an article to be gripped. Outward movement of the expansion plates is effected by means of a camshaft and rotation of the camshaft.

Description:
TECHNICAL FIELD 
       [0001]    The present invention is directed to an expandable core chuck suitable for engaging the interior surface of a cylindrical core or other article having an inwardly facing cylindrical surface. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many products are manufactured from elongated sheet or stock material or wire that is shipped and stored in the form of a roll or coil. Continuous strips or webs of thin, flexible material or wire are commonly provided wound on cores to provide rolls of material. The rolls of material are subsequently unwound for production of items made from the materials. Examples of these materials are plastic film, metal foil, tissue, paper and wire. 
         [0003]    During the manufacturing process, the cores carrying the material are commonly transported to various stations within the manufacturing facility. For instance, cores of fresh material are received and transferred to unwind stations. Cores that have material removed are transported to storage facilities, core cleaning stations, or other processing stations. Core chucks are inserted into the opposed ends of the cores thereby allowing the cores to be lifted for transport and processing without damaging the sheet material contained on the core or the core itself. Different types of product have cores which have different inner diameters. In current practice, the manufacturing plant has core chucks of a variety of diameters designed to match the inner diameter of the cores. Thus, there is a need for an universal core chuck that can be used with cores having varying inner diameters of the inwardly facing cylindrical surface of the core. While this invention is described for use with cores carrying rolls of sheet material or wire, it is not intended to be so narrowly construed as to be limited only to that specific use. The present invention can be utilized to mate with a wide variety of articles having an internal cylindrical surface. 
         [0004]    A universal core chuck or arbor for securing the internal surface of a reel or other article may be found in U.S. Pat. No. 6,494,401. The &#39;401 patent includes a thorough discussion of prior art attempts to solve the problems of sizing chucks to cores having different inner diameters. An arbor disclosed in that patent application has a cylindrical axially extending tube with longitudinal slots. Blades are positioned in the slots and are movable radially outwardly from the tube to a position at which their outer surfaces extend slightly beyond the outer surface of the tube. The blades have an inner surface defining axially spaced apart first cam grooves having inclined wrap surfaces. A cam member includes spaced apart cam followers that include inclined ramp surfaces aligned with the first cam grooves. The cam is reciprocal via a pneumatic actuator from a first position in which the respective blades are retracted to a second position in which the blades are extended slightly outwardly from the outer surface of the tube. The present invention improves upon this complex mechanical structure. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides an expanding core chuck having a housing extending along an axis with a plurality of slots, preferably four, extending substantially parallel to the longitudinal axis of the housing. A camshaft having a plurality of lobes or cams is positioned in the housing and is rotatable with respect to the axis of the housing in clockwise and counterclockwise direction upon actuation by a pneumatic actuator. Each of the cams has a cam surface which extends at varying radial distances from the axis. Cam rollers or other actuators are attached to expansion plates such that, upon rotation of the cam shaft in one direction, the cam rollers will be actuated by the varying radial distance cam surfaces to move the expansion plates from a position within the housing to a position extending outwardly from the housing and into mating contact with the inner cylindrical surface of the core and, upon rotation in the opposite direction, move the expansion plates back within the housing. 
         [0006]    Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of the core chuck of the present invention with the expansion plates contracted. 
           [0008]      FIG. 2  is a view similar to  FIG. 1  showing the core chuck with the expansion plates expanded. 
           [0009]      FIG. 3  is a view similar to  FIG. 1  but with the outer shell removed for clarity. 
           [0010]      FIG. 4  is a sectional view of the core chuck of the present invention taken along the longitudinal axis. 
           [0011]      FIG. 4A  is an enlarged of a section of  FIG. 4 . 
           [0012]      FIG. 5  is a schematic view taken through line  2 - 2  of  FIG. 4 , showing the essential structure of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    Referring to  FIGS. 1 and 2  there is shown the expandable core chuck  10  of the present invention. The core chuck includes a housing or outer shell  12  extending along an axis A ( FIG. 4 ) from a first end on which is mounted an end cap  14  to a second end on which is fastened a mounting flange  16  (FIG.  5 ). The outer shell has four slots  18  extending longitudinally from a point slightly spaced from the end cap  14  to approximately midway between the end cap  14  and the mounting flange  16 . The outer shell  12  also has four openings  20  generally aligned with the slots  18  and spaced a short distance therefrom toward the end with the mounting flange  16 . The slots  18  and the openings  20  are positioned substantially 90 degrees from adjacent slots and openings. 
         [0014]    Referring to  FIGS. 3 ,  4  and  5 , housed within the shell  12  is a camshaft  22  extending along the axis A from a bearing  24  secured to the end cap  14  to a second bearing  26  fastened to a coupling  28 . The coupling  28  is also secured to a pneumatic cylinder  44  which, upon actuation, rotates the coupling  28  and the camshaft  22  alternately clockwise and counterclockwise. The cam shaft  22  a plurality of cam members  30  extending radially outwardly. Each cam member  30  has a cam surface  32  which follows a path in a circumferential direction, with the path being closer to the axis A in one area and extending along a smooth gradually outwardly path to other areas progressively further from the axis A. Cam rollers  34  mounted on each of four expansion plates are engaged with each of the cam surfaces  32 . Each expansion plate  36  has one or two radially extending support members  42 , each of which carries the cam roller  34 . Located on the outwardly facing ends of the expansion plates  36  are contact members  38  which engage the inner cylindrical surface of the cores or other articles to be cleaned. 
         [0015]    The expansion plates  38 , support member  42  and cam rollers  34  are slidably engaged with a mounting member  40  and are movable relative thereto in a radial direction from a retracted position shown in  FIG. 1  to an expanded position shown in  FIG. 2  in response to movement of the cam members  30  relative to the cam rollers  34 . The support members  42  and expansion plates  36  are urged outwardly when the camshaft  22  is rotating in a direction in which the cam surfaces  32  push the cam rollers  34  outwardly. Rotation of the camshaft  22  in one direction will force the cam rollers  34  engaged with the cam surfaces  32  to move radially outwardly away from the axis A. 
         [0016]      FIGS. 4 and 4A  show in detail the elastic members  37  that are engaged with the mounting members  40  and the support members  42  through slots  35 . As the cam surfaces  32  push the cam rollers  34  radially outwardly, the elastic members  37  are elongated. When the camshaft  22  is rotated in the opposite direction from that which moves the expansion plates  36  outwardly, the elastic members  37  pull the support members  42  and expansion plates  36  radially inward. Guides  39 , located on the support members  42  are engaged with an edge of the mounting members  40  to ensure that the support members  42  and expansion plates move in a non-skewed manner. 
         [0017]    Upon insertion of the core chuck into the end of the core, the pneumatic cylinder  44  is actuated to rotate the camshaft  22  in a first direction, for example clockwise, to urge the cam rollers  34  outwardly as a result of the outwardly extending cam surfaces moving thereagainst to thereby push the expansion plates  36  outwardly such that the contact members  38  firmly engage the cylindrical interior surface of the core. The expandable core chuck  10  may be removed from the core by actuating the pneumatic cylinder  44  to rotate the camshaft  22  in the opposite direction, for example, counterclockwise, to move the reduced sized portions of the cam surfaces relative to the cam rollers so that the springs of the expansion plates return them to a position within the housing or outer shell  12 . 
         [0018]    This invention has been described in considerable detail with reference to its preferred embodiments. However, as indicated previously, the invention is susceptible to numerous modifications, variations, and substitutions without departure from the spirit and scope of the invention as described in the foregoing detailed description and as defined in the following appended claims.