This invention relates to containers adapted to receive plastic closure fitments including fitments which are designed to resist opening by children.
A typical container-closure combination of this type is shown in FIG. 1. The container or can 10 includes an uppermost metallic panel 12 having an opening receiving a plastic filament 14. As illustrated, the fitment 14 is of the child-proof or child-resistant type so as to require a substantial torque about the axis of the closure (indicated by the arrow A) and a force upwardly and along the axis of the closure (as depicted by the arrow B). Many different types of products are kept in this type of container to protect young children from the harmful effects of these products.
An enlarged prior art child-resistant closure in combination with the metallic container panel 12 is shown in FIGS. 2 and 3. The closure 14 comprises an annular portion 16 extending generally downwardly in a direction substantially parallel to the axis of the closure x--x. The annular portion includes a radially outwardly extending protuberance 18 in the form of an annular ridge. The closure 14 further comprises a flange 20 extending radially outwardly from the annular portion above the protuberance 18. The flange 20 includes a downwardly extending projection in the form of annular ring 22 spaced radially outwardly from the annular portion 16 so as to form an annular groove 24 between a radially inwardly facing surface 26 and a radially outwardly facing surface 28. Generally speaking, the inwardly facing surface 26 and the outwardly facing surface 28 are concentric, generally cylindrical surfaces.
The closure 14 includes an annular neck 30 extending upwardly from the flange 20 where the central portion of the neck 30 includes one or more dispensing openings 32. The periphery of the neck 30 around the dispensing opening 32 comprises an annular lip 34 adapted to cooperate with a radially inwardly extending ridge 36 of a closure cap 38 so as to hold the cap 38 in place on the base of the closure 14. The ridge 36 extends around approximately 300.degree. of the cap periphery and includes two notches 40 adjacent the ends of the ridge 36. The base of the cap 38 includes a radially outwardly extending locking portion 39 located beneath the lip 34 which is adapted to extend into one of the notches 40 when the cap 38 is rotated by applying a torque A as shown in FIG. 1. In order to reach the notch 40, it is necessary to apply considerable torque A to the cap 38 so as to overcome the resistance offered by the ends 41 of the ridge 36 adjacent the notches 40. Once this resistance is overcome, the locking portion 39 snaps into place within one of the notches 40.
It will be understood that the notches 40 and the locking portion 39 are particularly important in the opening sequence for the closure. In this connection, it will be observed that the cap 38 includes an opening tab 44 which extends radially outwardly therefrom. The tab 44 is normally located above a pedestal 46 which extends radially outwardly from the neck 30 above the flange 20. By applying the torque A to the cap 38, the tab 44 is moved to a position circumferentially spaced from the pedestal 46 so as to allow a finger or thumb to be inserted beneath the tab 44. Once the finger or thumb is beneath the tab 44, the axially upwardly directed force B may be applied to the cap so as to push or pull the ridge 36 of the cap 38 upward over the lip 34 of the closure base.
In the prior art closure-container combination of FIGS. 2 and 3, the closure 14 is secured to the container by inserting a curl 48 at the edge of an opening 50 in the panel 12 into the groove 24 of the closure 14. As shown, the curl 48 extends upwardly and radially outwardly such that the edge of the curl is not in contact with the radially outwardly facing surface 28 of the groove.
It has been found that the curl 48 is easily damaged during insertion of the closure 14 into the groove 24 of the closure. Such damage can result in a leaky container. Furthermore, the curl 48 is not effective to provide a centering function during the insertion of the closure 14 nor can it effectively resist removal of the entire closure fitment.
Another prior art container-closure combination is disclosed in U.S. Pat. No. 3,128,900--Chaboche. As shown in FIG. 3a thereof, a curl or bead extends upwardly into a groove formed in a closure. Unlike the bead of the prior art container shown in FIGS. 2 and 3, the bead of the Chaboche container extends upwardly and then downwardly and inwardly. There is no suggestion that the edge of the curl is in contact with or in any way abrades the closure.