Tamper evident cap wtih wavy ring seal

Abstract

There is a tamper evident cap of the type having a detachable annular band 7. The band is shaped to push fit over a shoulder 18 on the neck of a container 4 during initial sealing of the cap on the container. Subsequently the band 7 breaks away and stays with the container on removal of the cap to provide evidence of the removal. There is a shoulder engaging edge 13 of the band which is contoured to form resiliently deflectable undulations around the circumference of the band to engage over a range of shoulder diameters.

1 . A tamper evident cap of the type having connected thereto a detachable annular band, said band being shaped to push fit over a shoulder on the neck of a container during initial sealing of said cap thereon and to subsequently break away and stay with said container on removed of the cap to provide evidence of said removal wherein a shoulder engaging edge of the band is contoured to form resiliently deformable undulations around the circumference of said band to engage over a range of shoulder diameters.  
     
     
         2 . The tamper evident cap as claimed in  claim 1  wherein the band includes a main band portion and it locking ring with said shoulder engaging edge being a free edge of said locking ring.  
     
     
         3 . The tamper evident cap as claimed in  claim 2  wherein before the initial sealing of the cap on the container the locking ring extends downwardly and subsequently inverts about a hinge line during said sealing so that the shoulder engaging edge is directed upwardly to engage under the shoulder.  
     
     
         4 . The tamper evident cap as claimed in  claim 3  wherein the hinge line connects the locking ring to the main band portion.  
     
     
         5 . The tamper evident cap as claimed in  claim 4  wherein said hinge line is interrupted by spaced apart slits.  
     
     
         6 . The tamper evident cap as claimed ire  claim 5  wherein said slits are positioned to correspond with peaks of said undulations to assist compression of the locking ring as said locking ring passes over said shoulder during initial sealing.  
     
     
         7 . The tamper evident cap as claimed in  claim 6  wherein said band is detachably connected to a skirt of said cap by frangible angled ribs which extend between an upper edge of said band and a bottom edge of said skirt.  
     
     
         8 . The tamper evident cap as claimed in  claim 7  wherein shear forces acting between said skirt and bend during initial sealing are resisted by drive dogs on the lower edge of said skirt reacting against support pads on the upper edge of said band.  
     
     
         9 . The tamper evident cap as claimed in  claim 8  wherein said undulations are spaced apart by about 10 degrees around the circumference of said ring.  
     
     
         10 . The tamper evident cap as claimed in  claim 9  wherein said cap is a child resistant cap which includes a cowling fitted over the skirt and movable relative to said skirt between a first position wherein said cowling engages lugs on said skirt when turned in a rotational direction to screw said skirt onto said container and a second position at which said skirt is engaged by said cowling in the opposite rotational direction to enable said skirt to be unscrewed and a cam surface on one of said skirt and cowling which engages an inclined shoulder on the other one of said skirt and cowling whereby said cowling is biased to said first position.