Abstract:
A poster tube closure includes a plug member for locating within an end of a poster tube. The plug member has a substantially planar closure surface with upper and lower faces, wherein a perimeter wall extends downwardly from the lower face for gripping the wall of a poster tube when inserted. The upper face has a frangible or weakened area arranged in use to be broken by user action to permit removal of the plug member and a visible indication of the breakage.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a tube closure, for example a poster tube closure, and to a tube system. 
       BACKGROUND TO THE INVENTION 
       [0002]    Poster tubes are rigid tubes, usually cylindrical, within which posters, artwork or photographs are stored in rolled-up form for protection during transportation, e.g. when posted from a supplier to a customer. 
         [0003]    The tube is usually closed-off at each or one end by an end-plug or closure  1  of the form shown in  FIG. 1 . Conventional closures are circular, push-fit plugs that are shaped to snugly locate within the end of the tube, comprising a solid planar base  2 , with an upstanding perimeter wall  3  and a circumferential lip  4  inwards of the wall that allows the recipient to grip the closure to pull-it out of the tube to access the poster inside. 
         [0004]    Where the contents are of value, or liable to be tampered with, the closures are usually secured using adhesive tape or staples. Tape looks unsightly and can easily be removed and replaced. Stapling is more secure, but requires an air stapler to puncture the tube, and presents a problem in that a tool is needed to remove the staples which, if not properly removed, may damage the poster as it is drawn out of the tube. 
       SUMMARY OF THE INVENTION 
       [0005]    A first aspect of the invention provides a tube closure, comprising a plug member for locating substantially entirely within an open end of a tube, the plug member being provided with a breakable region configured in use to be broken by user action in order to enable access beneath to enable its extraction from a tube within which it is located. 
         [0006]    The tube closure is particularly a poster tube closure, e.g. comprising a plug member for locating within an open end of a poster tube, the plug member being provided with a breakable region configured in use to be broken by user action in order to enable access beneath to enable its extraction from a tube within which it is located. 
         [0007]    The closure therefore provides a neat and convenient way of closing a poster tube which provides a visible indication of tampering via the breakable region. It will be appreciated that the breakable region can be broken in part only to provide access and removal. 
         [0008]    A poster tube in this context can also be used for carrying similar articles such as artwork and photographs. 
         [0009]    The plug member may have an upper and lower surface, and wherein the upper surface is generally planar with no upstanding perimeter wall so that in use it fits flush with the end of a poster tube. 
         [0010]    The breakable region may be formed within the perimeter. 
         [0011]    The breakable region may be defined by a plurality of perforations. 
         [0012]    The perforations may define a tab-like breakable region part of which is not breakable, for example with the perforations not entirely bounding the breakable region so that part remains intact whilst still enabling removal of the closure and a visible indication of the break. 
         [0013]    A circumferential wall may be provided that extends downwards relative to the plug member&#39;s upper surface and is arranged in use to locate within a tube to provide a snug fit. 
         [0014]    One or more ribs may be provided on the circumferential wall, i.e. its outer side, to ensure the snug fit. 
         [0015]    The closure may be formed of polyethylene. 
         [0016]    A second aspect provides a poster tube closure, comprising a plug member for locating within an end of a poster tube, the plug member comprising a substantially planar closure surface with upper and lower faces, wherein a perimeter wall extends downwardly from the lower face for gripping the wall of a poster tube when inserted, and wherein the upper face has a frangible or weakened area arranged in use to be broken by user action to permit removal of the plug member and a visible indication of said breakage. 
         [0017]    A third aspect provides a poster storage system, comprised of a hollow tube with at least one open end, and a removable plug member shaped and dimensioned to close-off the open end in accordance with any preceding definition. 
         [0018]    A fourth aspect provides a poster storage system, comprised of a hollow tube with at least one open end, and a removable plug member shaped and dimensioned to close-off the open end, wherein the plug member on its external side has no upstanding projection or lip so that it can fit flush within the tube&#39;s open end, and has a breakable region accessible from the external side which is configured to be broken by user action to enable extraction of the plug from the tube from underneath. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: 
           [0020]      FIG. 1  is a perspective view of a known tube closure, which is useful for understanding the background of the invention; 
           [0021]      FIGS. 2 a -2 c    are different views of a tube closure according to the invention; 
           [0022]      FIG. 3  is a side sectional view of the tube closure of  FIG. 2  when located within a poster tube; 
           [0023]      FIG. 4  is a top plan view of a further embodiment tube closure according to the invention; 
           [0024]      FIG. 5  is a top plan view of a still further embodiment tube closure according to the invention; 
           [0025]      FIG. 6  is a side view of a still further embodiment tube closure according to the invention; and 
           [0026]      FIG. 7  is a side view of the  FIG. 6  closure when located within a poster tube, shown in section. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Embodiments described herein relate to a poster tube closure and poster tube system. In this regard, it is to be understood that the term ‘poster tube’ can also encompass tubes for storing flexible artwork and photographs that can be rolled for storage. 
         [0028]    Referring to  FIGS. 2( a )-( c ) , a first embodiment poster tube closure (hereafter “closure”)  10  is shown in different views. The closure is formed of plastics material, e.g. polyethylene (high or low density) but could be formed of any other plastic, metal, rigid cardboard or similar material. 
         [0029]    The closure  10  is a disk shaped member having a planar upper surface  12  and a lower surface (not visible). A side wall  14  extends downwards from the perimeter of the lower surface. Around the side wall  14  is or are formed one or more gripping ribs  16 , which is or are projections which in use are configured to firmly grip the inner surface of a poster tube to retain the closure  10  in position. Each rib  16  in this case is circumferential, but can be broken into several individual projections. A variety of rib arrangements could be used. 
         [0030]    The closure  10  is shaped and dimensioned to fit snugly within the open end of a poster tube, the or each rib  16  serving to maintain the tight fit. The product within the tube will therefore be well protected from the elements. The closure  10  in use locates entirely within the open end, or substantially so. 
         [0031]    The fact that the upper surface  12  is planar and has no projecting parts itself ensures that, when positioned within the tube, e.g. by a sender, the closure  10  is flush with the tube&#39;s terminating end. This makes it very difficult for the closure  10  to be removed, e.g. inappropriately in transit, and the closure can be put in place by the sender without using tape, staples or other specialist apparatus. 
         [0032]    To enable the end-user to remove the closure  10 , a breakable region  18  is provided in the closure  10 , as seen from the upper surface  12 . The breakable region  18  is formed by a line or boundary of weakness in the form of perforations or a score line which may or may not extend all the way through the closure&#39;s material. In the case of  FIG. 2 , the breakable region  18  is defined within a circular score line  19 , which could alternatively be a perforation line, and enables the end-user to remove the closure  10  by using their finger or thumb to break part of the scored or perforated boundary, and then they pull the closure upwards from its lower surface. 
         [0033]    Use of a score line instead of perforations is advantageous in terms of avoiding moisture entering the closed-off tube during storage or transit, which might damage its contents. 
         [0034]    The breakable region  18  also serves as a visible indicator of tampering. The end user can see very clearly if the breakable region  18  is in any way damaged. The breakable region in some embodiments is within, and spaced from, the outer perimeter of the closure, without extending all the way to the outer wall. This makes it straightforward to manufacture, amongst other advantages. In some embodiments, there is no external projection from the closure (other than the downwardly extending peripheral wall) and in particular nothing projecting upwards or sidewards from the upper surface so that the closure can fit entirely within the open end of the tube with nothing projecting out of the tube when it is closed, which might otherwise get caught or tangled with other things when stored or during transportation. 
         [0035]    In the case of the first embodiment, the shape of the closure  10  is circular. It can, however, be of any shape, e.g. square, rectangular, triangular and so on depending on the cross-sectional shape of the tube with which it will be used. Likewise, the shape of the breakable region  18  is in this case circular, but can be of any shape which is not dependent on the overall shape of the closure  10 . 
         [0036]      FIG. 3  shows in cross-section the closure  10  when inserted within one-end of a tube  30 . The flush arrangement is visible, as is the use of the ribs  16  to provide a tight fit. The closure  10  can be provided as a separate item for use by poster suppliers, or a set of tubes and closures can be supplied in a kit or pack. 
         [0037]      FIG. 4  shows a second embodiment closure  40  which is identical to the first shown in  FIG. 2 , but is marked by printing, embossing or any similar means to indicate how to use the closure. The outer ‘ring’  42  on the upper surface is indicated for the benefit of the person closing the tube  30  prior to sending, and ensures they do not accidentally break the inner breakable seal  44 . The breakable seal  44  is similarly marked to indicate how the end customer can access their product, and that damage to the seal indicates tampering which should alert them to contact the postal authorities or the sender. 
         [0038]      FIG. 5  shows a third embodiment closure  50 , which employs a different shape and style of breakable seal region  54  within the outer part  52 . Specifically, the breakable seal  54  is a narrow rectangle with one narrow end not perforated and the other indicated as the preferred push point. This arrangement maximises the surface area which the packer uses to locate the closure  50  within the tube open end, and, because one end is not perforated, the broken region forms a tab rotatable about a fold line that prevents its removal and potential littering. 
         [0039]      FIG. 6  shows a fourth embodiment closure  60  which in which a plurality of ribs  62  are provided on the external surface of the perimeter wall, extending vertically from a position between (but not necessarily from) the lowermost edge of the wall and the upper surface. The ribs  62  are distributed generally evenly around the perimeter wall, spaced apart from one another. The ribs  62  have a profile that tapers outwardly towards the upper surface to provide a wedge shape, as best seen with reference to the ribs on the opposite sides of the wall. The thickness of the ribs  62  at the point where they meet or reach the upper wall is arranged as to be the same, or just greater than, the internal diameter of a tube  30  (see  FIG. 7 ) within which the closure  60  is to locate. This ensures that the closure  60 , when inserted, wedges firmly within the tube  30  at the point where the closure&#39;s upper surface and the upper edge of the tube are substantially flush, as shown in  FIG. 7 . The closure  60  is prevented from moving further inside the tube  30 . 
         [0040]    This arrangement of ribs  62  is applicable to any previous embodiment, i.e. instead of using horizontal ribs. 
         [0041]    Otherwise, the features of the breakable region as previously described are present in the closure  60 . 
         [0042]    In summary, there is described a poster closure system that locates snugly within the open end of a poster tube in a flush-arrangement, making it very difficult to grip and remove. The only realistic way of removing the closure is to break the breakable region, offering an immediate visual confirmation that the contents may have been tampered with. 
         [0043]    It will be appreciated that the above described embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the present application. 
         [0044]    Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.