Abstract:
A dispensing cap is provided for a container and includes a body portion having a formed sliding track thereon. An opening is provided in the body for providing access through the body. A retention slot is formed adjacent the sliding track. A slider is moveably positioned within the sliding track for selectively opening and closing the body opening. A frangible tab is initially formed as part of the slider and engaged within the retention slot to fix the position of the slider within the sliding track. Removal of the frangible tab permits the slider to move relative to the body opening. The cap is formed by an injection molding process, in conjunction with an in-mold assembly of the slider.

Description:
[0001]    The present application claims the benefit of the filing date from U.S. Provisional application No. 61/173,712, filed Apr. 29, 2009. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a cap or closure to be applied to a container, with the closure forming means for controlling the discharge of a quantity of material retained within the container. 
       BACKGROUND OF THE INVENTION 
       [0003]    A number of forms of caps and closures are known for covering the upper end of a container and for selectively controlling the discharge of material from the container. One form of cap includes a sliding member retained by guide rails. The sliding member covers an opening in the cap and is moveable between an open position and a closed position. 
         [0004]    U.S. Pat. No. 4,592,480 to Hart et al. shows a tamper-evident cap having a two-part construction with a connecting tearaway tab or strip. In one embodiment, the tearaway tab is formed on one side of the cap and is connected to the slider and to a base portion. The tab can be removed so that the slider may be moved relative to the cap to control discharge from the container. 
         [0005]    U.S. Pat. No. 3,355,069 to Miles shows a slideable closure that is retained within rails on a cap. The slider includes an end portion that forms a cutter for shearing off projections in the upper surface to open the cap. In one embodiment shown, a knife edge is fixed on the slider as part of an overmolding process. 
         [0006]    U.S. Pat. No. 4,925,067 to Zemlo et al. shows a dispensing cap having a slider secured by rails and moveable in opposite directions to access openings in the surface of the cap. The slider and cap may be made of different materials to control friction between the moving parts. 
         [0007]    U.S. Pat. No. 6,102,259 to Tsamourgelis et al. shows a cap for a container having an integrally formed slider that sits between rails on the upper surface of the cap. A pair of elastic arms connect the slider to the cap and serve as a spring that moves the slider to a normally closed position. The slider has a T-shaped end that creates a limit stop for the slider as it moves toward the normally closed position. 
         [0008]    In addition, it is known to overmold parts within a plastic structure made of dissimilar materials, such that the final assembly permits the parts to functionally fuse, but not materially fuse. An integrally-molded bearing block assembly formed by an in-mold assembly process is shown in U.S. Pat. No. 5,049,341 to Rubinstein. 
       SUMMARY OF THE INVENTION 
       [0009]    A dispensing cap for a container is provided, with the cap adapted to close the open end of the container so as to retain a quantity of material therein and to selectively discharge the material. The cap includes a body portion having a formed sliding track thereon. The sliding track may be defined by a pair of parallel rails, projecting from or otherwise formed on the body. An opening is provided in the body for providing access to the quantity of material within the container. A retention slot is formed adjacent the sliding track. A slider is moveably positioned within the sliding track. A frangible tab is formed on the slider and is engaged within the retention slot to fix the position of the slider prior to removal of the tab. A stop member may be positioned at one end of the sliding track. The stop member serves to engage the slider to prevent movement of the slider within the track, past the stop member. The retention slot may be formed in the stop member. The retention slot may alternatively be formed within one of the rails, with the frangible tab extending from the slider in a direction transverse to the rail. 
         [0010]    A method of forming a cap for a container is also contemplated, comprising the steps of forming a container body having a sliding track thereon. The sliding track may be defined by a pair of rails positioned on opposite sides of the body portion. The upper surface of the body is formed with an opening for providing access to a quantity of material within the container on which the cap is to be positioned. A retention slot is formed adjacent the sliding track. A slider is moveably positioned within the sliding track for selectively opening and closing the body opening. A frangible tab may be formed on the slider at a position for engagement within the retention slot to fix the position of the slider. The body of the cap may be formed by an injection molding process. Further, the slider may be molded by an in-mold assembly within the formed body portion. The frangible tab is integrally formed with the slider and may be formed during the in-mold assembly of the slider within the retention slot. 
         [0011]    Other features of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For the purpose of illustrating the invention, the drawings show forms that are presently preferred. It should be understood that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings. 
           [0013]      FIG. 1  shows a dispensing cap embodiment as contemplated by the present invention. 
           [0014]      FIG. 2  shows the dispensing cap of  FIG. 1  wherein a frangible tab is removed from its connection to a slider. 
           [0015]      FIG. 3  shows the dispensing cap of  FIGS. 1 and 2  wherein the slider is provided in a dispensing position. 
           [0016]      FIG. 4  shows the dispensing cap of  FIGS. 1-3  wherein the slider is shown in an alternate dispensing position. 
           [0017]      FIG. 5  is a cross-sectional view of the dispensing cap taken along line  5 - 5  in  FIG. 1 . 
           [0018]      FIGS. 6A and 6B  graphically show the molding of the dispensing cap portion and its corresponding slider of the type contemplated by  FIGS. 1-5 . 
           [0019]      FIG. 7  shows a second embodiment of a dispensing cap having a slider positioned within a sliding track thereon. 
           [0020]      FIG. 8  shows the dispensing cap of  FIG. 7  wherein a frangible tab is separated from a slider portion. 
           [0021]      FIG. 9  shows a further embodiment of a dispensing cap of the type contemplated by the present invention. 
           [0022]      FIG. 10  shows a top view of the dispensing cap of  FIG. 9  wherein a frangible tab is separated from a slider portion. 
           [0023]      FIG. 11  shows a bottom view of the dispensing cap of  FIGS. 9 and 10  wherein the slider is positioned in a first open position. 
           [0024]      FIG. 12  shows a bottom view of  FIGS. 9-11  wherein the slider is positioned in a second open position. 
           [0025]      FIG. 13  shows the dispensing cap of  FIGS. 9-12  wherein the slider is positioned in a closed position. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In the figures, where like numerals identify like elements, there is shown a number of embodiments of a dispensing cap for a container or the like (not shown). It is contemplated that the container may be separately formed from the dispensing cap, with structures provided on the cap for adhering the cap to the open end of the container and to retain the quantity of material to be stored within the container. Alternatively, the cap may be integrally formed with the container body or otherwise secured to the container. 
         [0027]    In  FIGS. 1-5 , there is shown an embodiment of a dispensing cap, which is generally identified by the numeral  10 . The cap  10  comprises a rectangular body portion  12  and slider  14 . Side rails  16  and  18  are formed parallel to one another and project from opposite sides of an upper surface  20  of the body  12 . As illustrated in cross section in  FIG. 5 , the rails  16 ,  18  have an inwardly projecting portion, which overlaps with a portion of the slider  14  to retain the slider within an elongated sliding track on the upper surface  20  of the body  12 . An opening  22  is provided in the body  12  for access to the interior of the container (not shown) to which the cap  10  is to be attached. As shown in  FIG. 5 , a downwardly projecting flange  24  is formed on the bottom of the body  12 . The flange  24  is used to secure the cap  10  to the upper rim of the container to enclose the opening formed thereby. 
         [0028]    The slider  14  is normally positioned within the sliding track formed by the rails  16 ,  18 . A frangible tab  28  is positioned at one end of the slider  14 , as shown in  FIG. 1 . Separation of the frangible tab  28  from the slider  14  permits the slider to move away from a stop member  26  formed at the end of the body  12  (see  FIG. 2 ). The frangible tab  28  is positioned within a retention slot  30  provided in the stop member  26 . 
         [0029]    As shown in  FIGS. 3 and 4 , the slider  14  is moveable along the sliding track and covers at least a portion of the body opening  22 . The slider  14  may be moved into a number of positions, as represented by  FIGS. 3 and 4 , to adjust the size of the opening  22 . Changing the size of the opening  22  serves to control the flow of material from the container through the dispensing cap  10 . Further movement of the slider  14  to increase the exposed opening permits greater flow of material through the opening  22 . 
         [0030]    As graphically shown in  FIGS. 6A and 6B , the body portion  12  and slider  14  may be formed in an injection molding process. A number of mold parts  32 ,  34  and  36 , as illustrated in  FIG. 6A , combine to form a cavity for molding of the body portion  12 . In this figure, a simplistic formation of the mold is illustrated. After molding the body portion  12 , mold parts  32  are moved inwardly to clear the formed rails and then moved upwardly to move out of the way. 
         [0031]    As illustrated in  FIG. 6B , a further mold part  38  is positioned over the formed body portion  12 , creating a cavity for molding the slider  14 . The cavity for the slider  14  is in-part defined by the formed portions of the body  12 . Thus, the slider is formed in an in-mold assembly process. 
         [0032]    An in-mold assembly of the cap  10  is accomplished by a strategic resin selection for the body portion  12  and the slider  14 . For example, the material of the body can be chosen to have a melt temperature higher than the material of the slider. Thus, the slider material does not fuse with or chemically bond to the material of the body, or its associated rails, during the molding of the slider. It is contemplated that the body portion of the cap may be formed from polypropylene, which may have a talc filling therein. This type material will assist in marrying the cap with the container and allow for the use of ultrasonic bonding of elements, if desired. This type material is also compatible with various type spices and other products. The talc is used to deter excessive shrinkage and can contribute to proper adhesion. The slider is preferably made from a crystal polystyrene. This type material is compatible with the polypropylene of the cap in the in-mold assembly process. Polystyrene and polypropylene tend to not create a molecular bond when molded against one another. Although the melting temperatures of these materials are relatively close, the lack of a molecular bond during the molding process is contemplated to produce the desired freedom between the body and slider for in-mold assembly. In addition, the use of a polystyrene for the slider is contemplated to provide the tab portion of the slider with the appropriate level of stiffness so as to be easily broken off when opening is desired. 
         [0033]    In the in-mold assembly of the cap  10 , the frangible tab  28  of the slider  14  is formed within the retention slot  30  of the stop member  26 . The tab  28  is integrally formed with the slider  14 . A frangible extension connects the tab  28  forming a T-shaped projection. The slider  14  is formed under the rails  16 ,  18  during the in-mold assembly process and the tab  28  is formed on the opposite side of the stop member  26  from the slider  14 . Thus, deformation of the slider  14  is not required in order to assemble the cap  10 . A destructive force is required to remove the tab  28  in order to free the slider  14  from a locked position stop member  26 . The tab  28  is preferably formed in this manner to identify tampering. 
         [0034]    In  FIG. 7 , a dispensing cap  110  is illustrated having a generally cylindrical body  112  with a slider  114  positioned in a sliding track formed within the body upper surface  120 . As shown in  FIG. 8 , the slider  114  is moved away from a stop member  126 , positioned at the end of the side rails  116 ,  118 . The side rails  116 ,  118  form a sliding track on the upper surface  120  of the cap  110 . A retention slot  130  is provided in the stop member  126  for receipt of a frangible tab  128 , which is connected to the slider  114 . Removal of the tab  128  permits the slider  114  to move within the sliding track to expose the body opening  122 . The dispensing cap  112  and its constituent parts may be formed by an in-mold assembly as described above with respect to the embodiments of  FIGS. 1-5 . 
         [0035]    In the embodiment shown in  FIGS. 9-13 , a dispensing cap  210  is illustrated having a body  212  and a slider  214  positioned between two parallel rails  216 ,  218 . In  FIG. 9 , the slider  214  is locked in a closed position by tab  218 , which is positioned within a retention slot  230  formed in one rail  218 . As shown in  FIG. 10 , removal of the tab  228  from the slider  214  permits the slider  214  to move within the sliding track formed by the rails  216 ,  218 . Movement of the slider  214  within the sliding track exposes the upper surface  220  and its corresponding opening  222 . 
         [0036]    In  FIGS. 11-13 , the cap  210  is shown from underneath, illustrating the bottom surface  232  of the slider  214  and the bottom surface  234  of the body  212 . On the bottom surface  232  of the slider  214  is provided a stop member  226 . The stop member  226  is a downward projection which is normally positioned within the opening  222  of the body  212 . In  FIG. 11 , the stop  226  engages with one end of the opening  222 . The engagement of the stop  226  defines the maximum open area for the opening  222 . In  FIG. 12 , the stop  226  is positioned in engagement with the opposite end of the opening  222 . In this position, the slider  214  exposes a plurality of secondary openings  236 , which are provided at the opposite end of the body  212  from the position of engagement of the stop  226 . The secondary openings  236  serve as a sifting-type mechanism, as an example, for powdered or granular material retained within a container (not shown). In  FIG. 13 , the slider  214  is centered over the openings  222  and  236 , placing the cap  210  in a closed position. The stop  226  is centered within the opening  222  in the cap body  212 . 
         [0037]    The cap  210  of  FIGS. 9-13  is contemplated to be made by an in-mold assembly process as described above. As such, the stop member  226  as well as the frangible tab  228  may be integrally formed with the slider  214  as part of the molding process. Further, because the slider  214  is molded within a cavity that is in-part defined by the body  212  of the cap  210 , deformation of the slider  214  is not required in order for final assembly to be accomplished. Thus, the tab  228  is preferably formed within the retention slot  230  within the rail  218  and the stop  226  is projected into the opening  222  formed in the body  212  upon molding. Additional structures may be added to the slider and the body by the in-mold assembly process whereby separate assembly may require deformation of the parts if a separate assembly process is required after molding. 
         [0038]    The present invention has been described and illustrated with respect to a number of exemplary embodiments thereof. It should be understood by those skilled in the art from the foregoing that various other changes, omissions and additions may be made therein, without departing from the spirit and scope of the present invention, with the scope of the present invention being described by the foregoing claims.