Tamperproof Cap For Sealing Bottles Using A Stretchable Plastic Polymer Membrane On A Hollow Frame Within A Preformed Rigid Cover

Abstract

A cap for the hygienic sealing of bottles for drinkable liquids, which in one embodiment includes a closed bottom cylindrical, i.e. cup-shaped, aluminum sleeve, an insert composed of a lower hollow cylindrical base, a truncated cone also having a hollow shape, and a tapered wall having two or more elongate and vertical apertures formed therein. Said cap is further characterized by a stretchable plastic membrane that is stretched to externally cover the truncated cone-shaped section of said insert as well as its top opening, by an elastic plastic ring for clamping said membrane against the insert, and by an additional plastic structure concentric with the sleeve that sealingly occupies at least its closed bottom and acts as a seal.

1 . A cap for hygienic sealing of a bottle, the cap comprising:
 a cylindrical sleeve having a closed end and an open end, the open end having an inwardly projecting edge;   an insert disposed for at least partially within said sleeve, the insert comprising a lower hollow cylindrical base extending to form a truncated cone also having a hollow shape, the truncated cone tapering upwards and inwards a tapered wall of the truncated cone having two or more elongated longitudinal apertures formed therein, that delimit sectors having surfaces of rectangular or trapezoidal parallelepiped shapes, the sectors having at least one end integral with the lower hollow cylindrical base, the sectors being further configured to elastically open and assume an angular position from a longitudinal axis of the cap;   a membrane stretchable to externally cover the truncated cone and an opening formed at a narrower end of the truncated cone;   an elastic ring configured for clamping the membrane against a housing complementary to the ring, the housing being formed in an outer wall of the lower hollow cylindrical base;   a structure sealingly disposed within the sleeve at least at the closed end, such to provide adhesion against the sleeve and liquid tightness of the cap; and   means for securing said cap to the bottle, the means for securing being located at and/or near the closed end and between the closed end and the insert.   
   
   
       2 . The cap as claimed in  claim 1 , wherein the narrower end of the truncated cone is dimensioned to contact a neck of the bottle by contacting an annular sub-neck of the bottle that surrounds an outer portion of the bottle and that is integral with the neck of the bottle, the lower hollow cylindrical base of the insert having an end that lays against the inwardly projecting edge of the sleeve. 
   
   
       3 . The cap as claimed in  claim 1 , wherein the cylindrical sleeve comprises embossments forming a screw thread complementary to a screw thread of the bottle, and wherein the structure is configured as a sealing disk or ring provided against the closed end of the sleeve to ensure liquid tightness of the cap. 
   
   
       4 . The cap as claimed in  claim 1 , wherein an outer wall of the cylindrical sleeve comprises recesses extending towards the inside of the sleeve, the recesses being configured for holding the structure within the cylindrical sleeve. 
   
   
       5 . The cap as claimed in  claim 1 , wherein the structure comprises a screw thread complementary to screw thread on the bottle. 
   
   
       6 . The cap as claimed in  claim 1 , further comprising a circular weakened area formed by discontinuities along a circumference surrounding the cap, the circular weakened area providing an anti-tampering function. 
   
   
       7 . The cap as claimed in  claim 1 , wherein the structure comprises a plurality of multi-lateral elastic flaps which are radially movable and which are connected along a circumferential segment of a cylindrical wall of the structure and integrated at least along one edge with the cylindrical wall of the structure, the cylindrical wall of the structure having suitable apertures to allow radial motion of one of more free portions of the flaps, and
 wherein the flaps each have an inwardly protruding ridge of essentially triangular section disposed essentially perpendicularly to the longitudinal axis of the cap.   
   
   
       8 . The cap as claimed in  claim 7 , wherein the flaps have longitudinally disposed upper and lower sides integral with the cylindrical wall of the structure. 
   
   
       9 . The cap as claimed in  claim 1 , wherein a free edge of the cylindrical base of the insert comprises a plurality of teeth having tapered distal ends, wherein the teeth are configured to engage protrusions on a neck of the bottle, and wherein the protrusions are substantially as wide as gaps between the teeth thereby preventing the insert from rotating about a longitudinal axis of the bottle when the insert is in inserted position within the cylindrical sleeve. 
   
   
       10 . The cap as claimed in  claim 1 , wherein the narrower end of the truncated cone comprises a circumferential band integral thereto, and wherein the band has a wavy profile, causing a longitudinal development of the band to be longer than the circumference of the narrower end of the truncated cone. 
   
   
       11 . A neck of a bottle comprising;
 a first sub-neck disposed adjacent to an opening rim of the bottle and comprising,   an annular thicker portion or protuberance on an outer wall of the neck; and   a lower edge section configured to be compatible with the triangular ridges of the flaps of  claim 7 ,   wherein the neck has a height sufficient for engaging said flaps.   
   
   
       12 . The neck of a bottle as claimed in  claim 11 , further comprising one or more sub-necks longitudinally spaced from the first sub-neck or from threads on the cap, one of the one or more sub-necks being configured to lock the narrower end of the truncated cone of  claim 1  and another one of the one or more sub-necks being configured to lock a free end of the cylindrical base of the insert of  claim 1 . 
   
   
       13 . The neck of a bottle as claimed in  claim 11 , further comprising protrusions or protuberances having a shape of a parallelepiped, lateral walls of the parallelepiped being configured to engage the teeth of  claim 9 . 
   
   
       14 . The cap as claimed in  claim 7 , wherein the essentially triangular section of the ridge has a first side forming an inward angle of about 90° with the cylindrical wall of the structure and a second side forming an angle of about 35° with a plane perpendicular to the longitudinal axis of the cap.