Abstract:
A method of affixing a sleeve to the neck of an aluminum container of the type having a tapered neck and wherein said sleeve has a complementary taper. The method comprises positioning said sleeve onto said neck wherein a portion of the neck extends beyond said sleeve and wherein said positioning causes said complementary taper of the sleeve and said taper of the neck to form a friction fit, said friction fit preventing rotation of said sleeve relative to said neck, wherein said friction fit is formed without expansion or deformation of said neck, and curling the portion of the neck extending beyond the sleeve so that the curl covers at least a portion of the upper end of said sleeve. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present invention is a continuation of pending U.S. application Ser. No. 10/282,652 entitled “A Method Of Manufacturing An Aluminum Receptacle With Threaded Outsert” filed 29 Oct. 2002, which is a divisional of U.S. application Ser. No. 10/005,044 entitled “A Method Of Manufacturing An Aluminum Receptacle With Threaded Outsert” filed 4 Dec. 2001, now abandoned, both of which are assigned to the same assignee as the present invention. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention is directed to aluminum receptacles and, more particularly, to aluminum receptacles having a threaded neck for receiving a cap.  
         [0003]     It is known in the art to form drawn, or drawn and ironed, cans from aluminum and steel for use in the packaging of beer, soft drinks, oil, and other liquids. Most metal cans for beer and beverages are adapted to be closed with relatively flat lids or ends which are secured on the cans by double seaming or a similar process. The lids may have tear strips formed in them and pull tabs attached to the tear strips to facilitate access to the tear strips to thereby provide an opening in the lid.  
         [0004]     Not all aluminum containers have flat tops. It is known in the art to use a series of necking dies on an aluminum container to form a neck on one end of the container. Threads may then be formed in the neck portion of the container by positioning first and second thread rolling tools adjacent to inside and outside surfaces, respectively, of the neck and rotatably moving the tools against the surface. Threaded aluminum containers have typically been made from relatively thick metal, i.e., at least 0.020 inches thick. The material is typically pure aluminum (99.5-99.8% aluminum) which is relatively soft and permits the forming of threads in the neck.  
         [0005]     The insides of aluminum containers are very often provided with a coating which prevents interaction between the raw aluminum and the contents of the container. The process of forming threads on the neck portion of the container may crack and/or dislodge portions of the coating thereby allowing the contents of the container to come into contact with raw aluminum. Furthermore, a coating which is cracked or otherwise damaged may work loose after the container is filled thereby contaminating the contents of the container.  
         [0006]     An improvement over forming the threads directly in the aluminum container is to secure a sleeve of plastic or other material around the neck of the aluminum container. Examples of the use of such a sleeve can be found in U.S. Pat. No. 5,713,235 entitled “Method and Apparatus for Die Necking a Metal Container,” U.S. Pat. No. 6,010,026 entitled “Assembly of Aluminum Can and Threaded Sleeve,” U.S. Pat. No. 5,718,352 entitled “Threaded Aluminum Cans and Methods of Manufacture,” U.S. Pat. No. 5,778,723 entitled “Method and Apparatus for Necking a Metal Container and Resultant Container,” U.S. Pat. No. 6,010,028 entitled “Lightweight Reclosable Can with Attached Threaded Pour Spout and Methods of Manufacture,” and U.S. Pat. No. 5,822,843 entitled “Method of Making Bottle-Shaped Metal Cans.” Very often, to prevent rotation of the sleeve on the container, small dents, ribs, slots or the like are provided on the container and/or the sleeve. The sleeve can also be adhesively bonded to the container to prevent relative rotation. However, forming of dents, ribs, slots, or the like in the container may damage the protective coating on the inside of the container. Therefore, the need exits for a method for securing a threaded sleeve to the neck of an aluminum container and the improved container resulting therefrom.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is directed to an aluminum container comprising a base portion, a substantially vertical wall portion extending upwardly from the base portion, a transition portion extending from the wall portion, and a neck portion extending from the transition portion. The neck portion is tapered and has an upper end having a wall thickness that is preferably less than the thickness of the wall of the remainder of the neck portion. The upper end of the neck portion may also be chamfered.  
         [0008]     The aluminum container of the present invention may be combined with a threaded sleeve to form a receptacle. The sleeve has an outer surface and an inner surface. The outer surface has threads thereon and the inner surface has a taper complementary to the taper of the neck portion so as to form a friction fit with the neck portion. The sleeve may also have a notch formed in the periphery of its upper outside surface. When the upper chamfered end of the neck is curled, the neck portion extends over a top end portion of the sleeve and terminates in the notch in the sleeve.  
         [0009]     The present invention is also directed to a method of affixing a sleeve to the neck of an aluminum bottle of the type having a tapered neck and wherein the sleeve has a complementary taper. The method is comprised of positioning the sleeve onto the neck such that a portion of the neck extends beyond the sleeve, and curling the portion of the neck extending beyond the sleeve so that the curl covers at least a portion of the upper end of the sleeve. The curling step causes the sleeve to seat on the neck so as to form a friction fit therewith.  
         [0010]     By providing the neck portion of the container with a taper, and providing the threaded sleeve with a complementary taper, a friction fit can be obtained without requiring any dimples, dents, or similar structure in either the neck portion or the threaded sleeve. Because of the taper, the threaded sleeve can be easily inserted onto the neck portion of the container. Thereafter, the curling process (which curls the end of the neck portion extending beyond the sleeve) pushes the threaded sleeve further down onto the neck portion of the container thereby causing an extremely tight friction fit. By controlling the amount of the neck portion which extends beyond the threaded sleeve, and therefore the amount of material available for curling, the threaded sleeve can be precisely positioned on the neck portion of the container. Additionally, by providing a notch in the upper outside peripheral surface of the threaded sleeve, the curled edge of the neck portion may terminate in the notch thereby covering the entire top edge of the threaded sleeve as well as providing a smooth profile for the finished receptacle. There is no exposed aluminum, and no possibility of damaging the protective coating on the inside of the container. Those, and other advantages and benefits, will become apparent from the detailed description of the preferred embodiments hereinbelow. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     For the present invention to be easily understood and readily practiced, the present invention will now be described, for purposes of illustration and not limitation, in conjunction with the following figures, wherein:  
         [0012]      FIG. 1  illustrates a container constructed according to the present invention;  
         [0013]      FIG. 2  illustrates the detail of the upper end of the neck portion of the container;  
         [0014]      FIG. 3  illustrates an exemplary necking die;  
         [0015]      FIG. 4  is a perspective view of the threaded sleeve;  
         [0016]      FIG. 5  is a side view of the threaded sleeve;  
         [0017]      FIG. 6  is a top view of the threaded sleeve;  
         [0018]      FIG. 7  is a cross-sectional view of the threaded sleeve taken along the lines VII-VII in  FIG. 6 ;  
         [0019]      FIG. 8  illustrates the combination of a container as shown in  FIG. 1  carrying a sleeve as shown in  FIG. 4 ;  
         [0020]      FIG. 9  illustrates an exemplary curling die;  
         [0021]      FIG. 10  illustrates a receptacle formed from the container and sleeve;  
         [0022]      FIG. 11  illustrates the detail of the neck portion carrying the sleeve;  
         [0023]      FIG. 12  illustrates a container not carrying a threaded sleeve; the container end has been curled to further illustrate the curl;  
         [0024]      FIGS. 13-16  illustrate other shapes for the transition portion of the container/finished receptacle; and  
         [0025]      FIG. 17  illustrates a cap. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]      FIG. 1  illustrates a container  10  constructed according to the present invention. The exemplary dimensions illustrated in  FIG. 1  are for purposes of illustration and not limitation. All dimension are in millimeters.  
         [0027]     The container  10  is comprised of a base portion  12  from which extends a substantially vertical wall portion  14 . A transition portion  16  extends from the wall portion  14  and a neck portion  18  extends from the transition portion  16 . It is anticipated that the container  10  may be fabricated using a well-known impact extrusion process. In the impact extrusion process, a slug of substantially pure aluminum (meaning aluminum having a purity of approximately 99.5-99.8%) is impact extruded to form a container of the desired diameter and having walls of a given height. After impact extrusion, the wall portion  16  may be lengthened using one or more dies. Thereafter, the container is trimmed to remove the uneven edges.  
         [0028]     After trimming, the interior of the container may be coated with a protective coating of lacquer which is then cured in an oven. Thereafter, graphics may be applied to the outside of the container  10 .  
         [0029]     The typical impact extrusion process used to produce, for example, aerosol containers, is modified after the neck portion  18  has been formed through the application of a series of necking dies according to known processes. After the neck portion  18  has been formed, the final necking die or dies imparts a slight taper to the neck  18 . An exemplary necking die  21  is illustrated in  FIG. 3 . As can be seen from the exemplary necking die in  FIG. 3 , upon insertion of the container  10 , the neck portion  18  is tapered such that the neck portion is approximately 26.6 millimeters at its top and 25.2 millimeters at its bottom. Although the taper in the preferred embodiment is approximately 1°, it is anticipated that tapers of other dimensions may be used. The dimensions shown in  FIG. 3  are exemplary only.  
         [0030]     After the neck portion  18  has been tapered, a portion of the material at an upper end  20  thereof is removed so that the upper end  20  of the neck portion  18  has a wall thickness that is less than the thickness of the wall of the remainder of the neck portion  18  as illustrated in  FIG. 2 . In the embodiment shown in  FIG. 2 , 20 mm of material has been removed from the topmost 4 millimeters of the upper end  20  of the neck portion  18 . Additionally, the end of the neck portion  18  has been chamfered at 45°. Although the detail shown in  FIG. 2  is not necessary to obtain a friction fit between a threaded sleeve  22  illustrated in  FIGS. 4-7  and the neck portion  18  of the present invention, removal of the material and chamfering of the edge provide advantages which will be described hereinbelow.  
         [0031]     Turning now to  FIGS. 4-7 , the threaded sleeve  22  is illustrated. As seen in  FIG. 4 , the threaded sleeve  22  has an outer surface  24  carrying threads  26  and an inner surface  28 . The inner surface  28  is provided with a taper complementary to the taper on the neck portion  18  of the container  10 . As seen best in  FIG. 6 , a top edge  29  of the threaded sleeve  22  may have notches  30  which are a remnant of the process used to manufacture the sleeve  22 . The exemplary dimensions illustrated in  FIG. 7  are for purposes of illustration only, and not limitation. The threaded sleeve  22  is preferably comprised of plastic but may be comprised of a number of other materials such as aluminum or other metals.  
         [0032]     As can be seen in  FIGS. 5, 6 , and  7 , a notch  32  is formed in the periphery of the upper outer surface  24  and at the top edge  29  of the sleeve  22 . The purpose of the notch  32  is described hereinbelow.  
         [0033]     Turning now to  FIG. 8 , a container of the type illustrated in  FIG. 1  is illustrated carrying a threaded sleeve  22  of the type illustrated in  FIG. 4  on the neck portion  18  of the container  10 . Approximately 2-3 millimeters of the upper end  20  of the neck portion  18  extends beyond the threaded sleeve  22 . The final seating of the sleeve  22  on the neck portion  18  can be controlled by the height by which the upper end  20  of the neck portion  18  extends beyond the threaded sleeve  22  as will be described.  
         [0034]     The container illustrated in  FIG. 8  is input to a plurality of curling dies  34 , one of which is illustrated in  FIG. 9 . The plurality of curling dies  34  is positioned around a centering mandrill, not shown. The upper end  20  of the container  10  is guided into the plurality of curling dies  34  through the use of the centering mandrill. Curling dies  34  cause the material of the upper end  20  of the neck portion  18  extending beyond the threaded sleeve  22  to be curled as seen in  FIGS. 10, 11 , and  12 . The dimensions illustrated in  FIG. 9  are exemplary only and are not limitations on the present invention.  
         [0035]     Turning now to  FIGS. 10, 11 , and  12 ,  FIG. 10  illustrates a completed receptacle  36 . As is seen, the completed receptacle  36  is comprised of the container  10  and the threaded sleeve  22  fastened thereto. In the present invention, the fastening mechanism is primarily by means of a friction fit.  
         [0036]     As seen in greater detail in  FIG. 11 , the upper end  20  of the neck portion  18  is curled so that it completely covers the upper edge  29  of the sleeve  22 . Additionally, the curl terminates in the notch  32  formed in threaded sleeve  22 . As can be seen in  FIG. 11 , by virtue of the reduced thickness of the upper end  20  and the chamfer, the curl terminates in notch  32  in a manner to provide a substantially unbroken profile for the top of the receptacle  36 . In addition, the curled portion is covered with lacquer so that there is no exposed aluminum. Finally, the curl completely covers the top edge  29 , and hence the notches  30 , in the top edge  29  of the threaded sleeve  22 . As with the other figures, the dimensions shown in  FIG. 11  are exemplary only and do not limit the scope of the present invention.  
         [0037]     In  FIG. 12 , a container  10  is illustrated which has been curled without the threaded sleeve. Thus,  FIG. 12  provides an additional illustration of the curl formed on the upper end  20  of the neck portion  18 . The dimensions shown in  FIG. 12  are exemplary only and are not intended to limit the scope of the present invention.  
         [0038]     It is anticipated that the container and resulting receptacle of the present invention may be formed in a variety of shapes and sizes. It is anticipated that the container and resulting receptacle may have a diameter of, for example, 35 mm-66 mm and a height of, for example, 70 mm-260 mm. The transition portion  16  illustrated in  FIG. 1  is referred to as a tapered shoulder. Other types of transition portions  16  may include a round shoulder as shown in  FIG. 13 , an oval shoulder as shown in  FIG. 14 , an ergonomic shoulder as shown in  FIG. 15 , and a flat shoulder as shown in  FIG. 16 .  
         [0039]      FIG. 17  illustrates a cap  38  which may be used to seal the receptacle  36  of the present invention. The cap  38  is preferably formed of aluminum. The cap  38  has at the top thereof a material, such as PVC, which is intended to act as a liner and create a seal. The cap  38  is positioned over the threaded sleeve  22  of the container  36 . Thereafter, pressure is applied, for example, a pressure of 35 inch pounds, in a downward manner to affect the seal. While the downward pressure is applied, thread rollers apply side pressure of, for example, 38 inch pounds, to cause the cap  38  to deform to thereby produce threads complementary to the threads carried by the threaded sleeve  22 .  
         [0040]     A tamper seal  42  is carried at a bottom edge  44  of the cap  38  by a plurality of breakaway members  46 . As is known in the art, as the cap  38  is applied to the receptacle  36 , the tamper seal  42  is bent inwardly. The inward bending of the tamper seal causes the tamper seal to be tucked under, for example, a bottom protrusion  48  of the threaded sleeve  22  best seen in  FIG. 11 . With the tamper seal  42  thus positioned, removal of the cap  38  will cause the break away members  46  to break away from the tamper seal  42  thereby leaving the tamper seal  42  on the neck of the receptacle while the cap  38  is removed. Cap  38 , being threaded, may then be replaced on receptacle  36  to reseal it. Other types of caps and tamper seals may be provided. For example, ratchet teeth (not shown) may be formed on the bottom of threaded sleeve  22  which meet with teeth held in the tamper seal, which is connected to a cap through break away members. Rotation of the cap in a clockwise direction allows the cap to be seated while rotation in a counter-clockwise direction causes the tamper seal to break away.  
         [0041]     While the present invention has been described in conjunction with preferred embodiments thereof, those of ordinary skill in the art will recognize that many modifications and variations are possible. Such modifications and variations fall within the scope of the present invention which is limited only by the following claims.