Child proof screw cap

#The invention concerns a childproof screw-cap for such containers as bottles, pillboxes or the like, consisting of an inside-threaded closure cap for screwing on an external thread of the container and which can be opened only by additionally exerting an axial pressure on the cap.

#In known closure means of this sort the screw-cap is provided with an inside cap relatively rotatable to it and comprising the inside thread. An indexing junction is provided between the outer and inside caps, by means of which on one hand the inside cap is carried along only when the outside cap is rotated in the direction of closure, while on the other hand for normal handling and when rotating in the direction of opening the inside cap will not rotate along and the closure means accordingly remains closed. The connection between the outer and inside caps during a rotation in the direction of opening is implemented by a simultaneous pressure on the outside cap, so that opening requires the simultaneity of rotation and axial pressure.

#It is a drawback in this regard that opening such a closure means requires considerable manual dexterity which cannot always be provided, especially where the elderly are involved. On the other hand the possibility cannot be dismissed that a child at play may open such closure means when experimenting over a substantial time with the opening of such a closure means.

#The invention is discussed more comprehensively below in relation to the illustrative embodiments of the drawing.

#FIG. 1 is a perspective of an embodiment of the screw-cap of the invention seen obliquely from below;

#FIG. 2 is a sideview cross-section of the screw-cap of FIG. 1 for a somewhat modified embodiment during the closing motion;

#In FIG. 1 a container 11 is provided of which the neck 10 comprises an outside thread 7. A closure cap 1 provided with an inside thread 20 can be screwed onto the container neck 10. The inside thread 20 is interrupted by two grooves 5 in the inside wall of the closure cap 1, the grooves 5 receiving two stakes 3 mounted in a common cover plate 2 and pointing to the container 11. The stakes 3 are provided on their inside with the threads 3a matching the inside thread 20 of the closure cap 1. The outside thread 7 at the container neck 10 is provided with clearances 6 parallel to the closing axis 21 and of a width B exceeding the width of the stakes 3, whereby the closure cap 1 can both be moved within the clearances 6 when the stakes 3 are inserted and, with respect to their thread positions, offset. The upper side of the closure cap 1 is provided with the upwardly directed hollow cylindrical rim 1a (FIGS. 14 and 15) engaged by the cover plate 2 for the inserted condition, the inside wall of the hollow cylindrical rim 1a of the closure cap 1 being provided with projections or recesses 14 and 15 at a spacing of half a pitch which engage corresponding projections or recesses at the rim of the cover plate 2. The circumferential rim of the cover plate 2 also itself can form the projection engaging the indexing grooves.

#Two indexing positions are created in such a manner, in the first of which the threads 3a in the stakes 3 mesh with the threads of the inside thread 20 in the closure cap 1, while in the second one they are relatively offset by half a pitch. The first indexing position is brought about by axial pressure on the cover plate 2 in the direction of the container 11. To bring about the second indexing position and as regards the embodiment of the FIG. 1, cogs 8 are arranged on a circumferential flange 22 of the container neck 10, these cogs being in the area of the clearances 6. The cogs 8 comprise bevelled surface 8a extending as seen in the direction of closing toward the closure cap 1 and acting on the free ends of the stakes 3.

#Also, that side of the cog 8 which is away from the container 11 is provided with a flat surface 8b on which the free ends of the stakes 3 can rest in the closed state.