Extensible handle carton with leakage preventing flap structure
BACKGROUND OF THE INVENTION 
     This invention relates generally to leakage of particulate from cartons, and more particularly to flap and handle construction associated with such cartons which also prevent such leakage. While the description will make reference to detergent particles in such cartons, other particles are also contemplated. 
     In the past, it was found that detergent paticulate tended to leak or sift from cartons via openings in end flaps which carried handles attached to the flap or flaps. This problem becomes acute when an opening or openings must be provided in such flaps to store collapsible handles, which must be grasped and pulled out from such openings. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide a simple, effective solution to the above problem. Basically, the new and improved carton construction comprises: 
     (a) a carton having upright side walls and end walls, 
     (b) multiple inner flaps attached to multiple of said walls proximate to upper ends thereof to fold downwardly toward closed substantially horizontal positions, for retention in said positions, with junctions between said inner flaps, 
     (c) and an outer flap attached to one of said walls proximate the upper end thereof to fold downwardly toward closed, substantially horizontal position to cover said inner flaps in their downwardly folded position, and to cover said junctions between said inner flaps, 
     (d) there being an elongated opening through said outer flap, 
     (e) a substantially flat strip handle extending at least partly in said opening and having opposite end portions retained to said outer flap and extending beneath said outer flap, 
     (f) and substantially flat closure means closing said opening beneath said handle and isolating said handle from said inner flaps. 
     Further, and as will appear, the closure means may include a first closure sheet directly underlying the opening in the outer flap and supporting handle end portions, there being windows in that sheet through which the handle extends, one window together with the opening in the outer flap sized to accomodate storage of a Z-folded portion of the handle; a second closure sheet underlying the first sheet and attached to same so as to close the windows to access of particulate shifting between interlocking junctions of the inner flaps, the second sheet also retaining the handle end portions to the first sheet; and provision for grasping of the stored handle including a slit located in the first closure sheet extending between the windows, as referred to. 
     These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: 
    
    
     DRAWING DESCRIPTION 
     FIG. 1 is a perspective view of a carton, with attached pull-out handle; 
     FIG. 2 is an enlarged perspective view of the FIG. 1 carton, showing inner and outer flap construction; 
     FIG. 3 is an enlarged plan view of the outer flap, when closed and showing the handle; 
     FIG. 4 is a section taken on lines 4--4 of FIG. 3; and 
     FIG. 5 is a bottom plan view of the outer flap, and showing a closure partly broken away. 
    
    
     DETAILED DESCRIPTION 
     Referring first to FIGS. 1 and 2, a carton 10 typically of cardboard construction, has upright side walls 11 and 12 (i.e., front and back sides) and upright end walls 13 and 14, the carton being elongated between such end walls. The location of a bottom wall is indicated at 15. The carton may, for example contain flowable solid detergent particles (indicated for example at 16 below the broken away portion 18 of inner flap 20 in FIG. 2). Conventionally, there is a problem of such detergent product leaking or shifting through small openings formed at the top of the carton, when lift handles are employed. 
     As shown in FIGS. 2-5, multiple inner flaps are attached to multiple of the carton upright walls, and proximate the upper ends of such walls, to fold downwardly toward closed substantially horizontal positions, for retention in such positions, with junctions between such inner flaps. See for example major inner flap 20 attached along hinge 20a to side wall 11; minor inner flap 21 attached along hinge 21a to end wall 13; and similar minor inner flap 22 attached along hinge 22a to end wall 14. In FIG. 2, major inner flap 20 has been folded down to extend horizontally over the carton interior and it has peripheral edges indicated at 20b-20d proximate the tops of walls 12, 13 and 14. Minor inner flap 21 has also been folded down to extend horizontally generally beneath flap 20 and has a corner 21b extended adjacent and above a diagonal edge 24a of a cutout 24 in flap 20, for retention in down position. Cutout 24 is sized for ease of insertion of the corner 21b through the cut-out. Small gaps remain at junction locations 25 and 26 via which particulate in the carton can sift or leak outwardly. Minor inner flap 22 is shown in vertical position prior to down-folding along with flap 20 to the same position beneath major flap 20 as flap 21. Cut-out 27 is the same as cut-out 24, and located to pass the corner 22b of flap 22. Small gaps then remain at junction locations 28 and 29, the same as junctions 25 and 26, and via which detergent or other particulate can leak or sift. See also curved slits 30 and 31 in flap 20 which facilitate insertion of the flap corners 21b and 22b through the cut-outs, as described. Such slits also pose the problem of leakage of particulate therethrough. 
     An outer flap 33 is attached to one of the upright walls, proximate the upper end thereof, to fold downwardly toward closed, substantially horizontal position, to cover the inner flaps in their down-folded positions, and to cover the junctions between the inner flaps, as described. In this regard, the inner side of the outer flap may be glued to the upper sides of the inner flaps as for example along the borders bounded by folds 20a, 21a and 22a, to block lateral or horizontal escape of particulate. Flap 33 has fold edge 33a, and peripheral edges 33b-33d as shown, to extend proximate folds 20a, 21a and 22a. 
     To facilitate carriage of the carton, a handle 34 is provided to have a collapsed position, as indicated in FIG. 4, and an upwardly extended position indicated by broken lines 34a in FIG. 4, the handle typically consisting of a flat flexible strip of plastic material having sufficient tensile strength to support the filled carton. The handle in stored position (see FIG. 4) is associated with an opening 35 cut or formed in the outer flap 33, so as to at least partly extend in that opening, and may be completely pushed down in that opening so that cartons can be stably stacked on top of one another. Thus, the thickness of the handle strip is preferably substantially less than that of the outer flap, to enable such storage, with the handle preferably having a Z-folded portion at 36, which enables handle extension from collapsed position. Thus, a mid-portion of the handle between the Z-fold 36 and the opposite end 34b of the handle (near the end 35b of the opening 35) is extensible upwardly, from stored position in opening 35. The latter may be laterally enlarged as at curved concave edges 35c and 35d to enable finger access to opposite edges of the handles, and finger and thumb access to the underside of the handle in stored position in opening 35. 
     To prevent outward leakage or sifting of the carton contents (which have sifted through junctures 25, 26, 28, 29 etc.) into the space directly below the outer flap, and out through opening 35, the handle is isolated from that space by provision of substantially flat closure means closing opening 35 beneath the handle, the closure at the same time facilitating strong retention of the handle ends to the inner side of the outer flap. In the example shown, the flat closure means, generally indicated at 40 includes a first closure sheet 41, which may consist of strong relatively stiff paper or plastic material, directly underlying the opening 35 and attached as by gluing to the inner side of the flap 33, all around that opening 35. Also, sheet 41 may support the handle end portions 34c and 34b as by suitable bonding or adhesive retention to the inner side of sheet 41, to prevent shear failure therebetween under tension loading exerted by weight of the filled carton transmitted to the hand-held and extended handle. Windows 44 and 45 cut in the sheet 41 respectively receive or pass the handle Z-fold 36 and the handle end portion 34b, as shown; the window 44 in particular cooperating with opening 35 to assure complete storage (in down position) of the three Z-folded portions of the collapsed handle. A lengthwise slit 46 between the windows and in sheet 41 facilitates some downward deflection of the split sheet portions below the handle in response to downward finger pressure applied during grasping of the handle. 
     To prevent outward shifting of detergent or other particulate via windows 44 and 45, and slit 46, a second closure sheet 50 is provided to underlie the first closure sheet and cover the windows 44, 45 and slit 46, the second sheet bonded to the first sheet rectangularly about those apertures, to block access of particulate thereto. Thus, sheet 50 may be bonded to sheet 41 near the edges of sheet 50, indicated for example at 50a-50d in FIG. 5. Sheet 50 may consist of paper and be quite flexible. 
     Accordingly, a sturdy, simple, effective means to completely prevent escape of particulate is provided in a carton structure employing interlocked inner flaps as described, and a pull-out handle which is stored below the outer surface plane of the outer flap.