Abstract:
A closure for a container having a lever-openable plug wherein the lever is attached to other parts of the closure by a frangible member which must be broken to permit actuation of the lever to open the plug, thus indicating to a subsequent observer that either the closure had been open or an attempt had been made to do so.

Description:
BACKGROUND OF THE INVENTION 
     Containers of the type under consideration include a cylindrical body with either an integral or seamed bottom and have a domed or narrow upper end with a neck which is associated with a closure. 
     Various closures for the small diameter neck are available. Such closures are shown in U.S. Pat. Nos. 3,251,499, 3,999,678 and 4,149,651. 
     DESCRIPTION OF THE PROBLEM 
     After considering various types of snap-in closures of the types heretofore discussed, a number of problems were noted. Some of the most objectionable problems have been the lack of consistent positive closure under pressure and which is also relatively easy to open and simple to adapt to high speed manufacture and application and are easily detectable as having been opened. Structures of the general type under consideration have been heretofore made, but are more costly and the best references require a closure which must be torn open to reveal pilferage. 
     SOLUTION OF THE PROBLEM 
     The snap-close closure of the instant invention has been made not only to minimize the amount of material used but also provides a novel combined venting and opening-facilitating leverage structure with enhanced sealing integrity as well as an indication of pilferage. The pilferage indicator is associated with the opening lever structure such that once the lever is lifted, it breaks apart a readily apparent nonrepairable frangible tie or tether of the indicator and forms a hole through the center of the lever. Tampering is thus readily evident. The lever is formed to spring up when it is broken away from the indicator and thus the apparent tampering is readily perceivable by the customer. 
     SUMMARY OF THE INVENTION 
     This invention is directed to closures and, more particularly, to a pilfer indicator for such closures. 
     A main object of the invention is to provide a closure which may be easily manufactured in a simple single molding operation and may be machine-folded and the lever portion thereof tethered prior to application to the container. 
     A further object is to provide a novel closure having several parts tethered to each other and which are recloseable and in which the structure indicating tampering also holds the uppermost or lever portion of the closure tightly against the top of the closure plug. 
     Another object is to provide a plastic closure which is made as a single unit in a simple molding operation. 
     Another object is to provide a novel opening lever arrangement which first breaks the tamper-indicating indicia, then opens a vent and then pries the closure open with relatively small effort. 
    
    
     These and other objects inherent in and encompassed by the invention will become more apparent from the specification and the drawings wherein: 
     FIG. 1 is a perspective view of a container with a closure incorporating the invention; 
     FIG. 2 is an enlarged fragmentary top plan view; 
     FIG. 3 is a fragmentary vertical cross-sectional view taken substantially on line 3--3 of FIG. 2; 
     FIG. 4 is a sectional view similar to FIG. 3 but showing the parts with the pilfer-indicator broken preparatory to opening the closure; 
     FIG. 5 is another sectional view similar to FIG. 3, and shows the parts reclosed; and 
     FIG. 6 is an enlarged top plan view of a portion of the handle showing the pilferproof structure. 
    
    
     DESCRIPTION OF THE INVENTION 
     The invention is shown applied to a container 2 made of metal such as aluminum and comprising a cylindrical body 3 with an integral outwardly convexed bottom 5 which is provided with outwardly protruding dimples 6 upon which the container rests. It will be understood that the invention is applicable to other types of containers. 
     The upper open end portion of the body 3 has a necked-in portion 9 which fits into an annular skirt portion 10 of a dome member 12 which forms the upper end of the container. A suitable adhesive 13 bonds the portion 9 to the skirt 10. The dome member 12 is formed with a stepped neck 14 and a toroidal section 18. The member 12 provides at the upper end of the container on neck 14 a shoulder 20 and an access opening 22, the neck 14 terminating in a curl 24. 
     A closure 25 formed of thermoplastic materials is provided at the upper end of the container and comprises a tubular neck or sleeve portion 26, a closure plug portion 28 and a venting portion 30 to which is attached a finger grip lever or handle 32. 
     The neck portion 26 is a cylindrical member which at its lower end is tapered at 36 and is tightly wedged through the opening 22 (FIG. 3) and then expands radially outwardly and engages its shoulder 38 under the lower edge of shoulder 20 of the neck 14. 
     The neck portion 26 has an upper outwardly projecting annular flange 40 which engages the top edge of the curl 24 and provides a fluid-tight pressure seal with the shoulder 38. 
     The interior bore surface 50 of the neck portion 26 provides a pour and fill opening within which there is located a locking ring member or annular shoulder 52 with a bottom locking surface 60 which extends normal to the axis of the neck portion. 
     The plug 28 has a cylindrical side wall 65 which adjacent to its lower edge is provided with an annular locking ring or rib 66 which is of generally triangular cross-section having a lower downwardly tapered pilot surface 67 which is adapted to be guided with the inner face 56 of the neck or sleeve locking ring 52 when the plug or cap is pressed into the neck opening or bore 50 whereupon the apical edge 68 on ring 66 is deflected and the locking ring or shoulder 66 on the cap or plug slips under the shoulder 52 of the neck and a flat radially outwardly extending surface 69 at the upper side of the shoulder 66, normal to the axis of the neck or sleeve, locks under the face 60. 
     The plug or cap 28 has a top wall 70 integral with the upper end of the side wall 65, the wall 70 extending beyond the perimeter of the side wall and forms an annular rim portion 72 which on its underside is pressed in position against the top surface 75 of the annular flange 40 integral with and extending radially outwardly from the upper end of the neck portion 26. The bottom side 77 of flange 40 presses against the crest 78 (FIG. 5) of the curl 24 of the metal neck 14. 
     A tether in the form of a narrow strap 80 connects a peripheral edge of flange 72 with a peripheral edge of portion 40 of the neck portion 26. 
     The wall 70 is provided close to its marginal edge with a vent opening 84 in an area diametrically opposite to the tether 80 adjacent to the interior surface of the wall 65 of the plug. 
     A frusto-conical pilot cavity 86 is formed at the upper end of opening 84 for guiding the male venting closure pin or element 30 which in the closed position extends into the opening 84. 
     The upper end of the closure element or vent pin 30 depends from and is integrally connected with the lever member 32 intermediate its ends. The lever or handle 32 has a fulcrum end 96 which engages with the top edge the thickened portion of a combination pouring lip and fulcrum rim 97 formed on the top side of the flange 40. The lever 32 is connected below the fulcrum end 96 to one end of a narrow strap 108 which is folded and which has its other end connected to the outer edge of flange 72 in an area diametrically opposite the strap 80. 
     A feature of the invention is the provision of a pilferproof structure 150 which comprises a post 152 which is formed integral with the top wall 70 and projects upwardly therefrom through an opening and is heat-bonded at 152 to a disk 156 which is formed in the intermediate portion 158 of the handle 32 in the plane thereof. The disk 156 is connected by a series of frangible straps or tethers 162 to the depressed body edge section 164 of the handle portion 158. The handle has a peripheral reinforcing rib 160 and a lift tab 161 facilitating entry of a finger thereunder. 
     Thus, to open the closure shown closed in FIG. 3, the user lifts on portion 161 diametrically opposite the strap 108 and breaks the straps 162 and lifts the fulcrum end portion 96 outwardly and withdraws the vent plug 30 from opening 84. Continued rotation of the lever or handle engages the fulcrum portion 96 against the rim or ledge 97 and further pivotal movement rightwardly (FIGS. 3 &amp; 4) pries the plug 28 out of the sleeve portion 26. Removal of the pin or plug 30 enhances the flexibility of wall 70 and the plug wall 65 in the immediate area and thus the flexure of that portion of the wall 65, that is, in the region of the vent opening whereby as the lever is fulcrummed, it pulls on the tether 108 which, in turn, curls the adjacent portion 72 of the top wall 70 upwardly and causes the portion of the wall 70 contiguous to the vent opening to warp radially inwardly thus facilitating partially unhooking of the ledge or shoulder 66 from under the shoulder 52 and disengaging the locking face 69 from face 60. The plug 28 then easily lifts out of the neck or sleeve opening and with the handle or lever portion 30 lays to one side of the pour opening 50 and may be grasped by the user so as not to obstruct pouring. 
     To reclose the closure, the plug 28 of the closure is pressed into the sleeve opening until the shoulder 52 snaps under the shoulder 66. Then the handle or leve is folded over the cap 28 and the vent plug or pin 30 is pressed into the vent opening 84. Since the pilfer-indicating straps 162 have been broken, it will be apparent to the observer that there is a strong probability that the closure has been previously opened. However, the pilferproof feature in no way interferes with the reclosing of the closure. The lever is so molded that when tacked down as in FIG. 3, it is stressed and biased upwardly so that when released by breaking stops 162, it will assume the position shown in FIG. 5 which brings attention to the possible pilfering.