Tamper evident cap

Abstract

The present invention is an integrated hinged cover and locking snap to detect tampering of the bung plugs on plastic drums. The locking snaps will break upon an unauthorized attempt to remove the cap from the drum finish. The hinged cover also provides an annular locking ring on the inside surface for engaging an annular ring on the plastic drum finish. The living hinge allows the cap to fit over the annular ring on the drum finish. The living hinge also provides a tear tab member (pull-tab) to remove the cap from the annular locking ring.

1 . A cap that fits over and around a bung plug, said cap comprising:
 a) two opposing semi-cylindrical flaps connected together by and pivoting around a living hinge, such that the two semi-cylindrical flaps can be brought together to form an annulus, wherein each semi-cylindrical flap comprises
 a semi-circular top surface, 
 a semi-cylindrical surface comprising a side, top and bottom, said semi-cylindrical surface integrated at its top with the semi-circular top surface, and 
 an annular section locking groove or lock rim integrated with the semi-cylindrical surface at the bottom of said semi-cylindrical surface; and 
   b) two lock mechanisms each comprising an arrow shaped male tongue and corresponding female groove,
 wherein the arrow and the tongue of each lock mechanism are integral to the semi-cylindrical surface of each of the opposing semi-cylindrical flaps, 
 such that when the two semi-cylindrical flaps are brought together, the male tongue of each lock mechanism inserts and locks into place in the corresponding female groove, thereby locking the two semi-cylindrical flaps together. 
   wherein the two semi-cylindrical flaps are free to pivot around the living hinge, and can be brought together to fit over and around the bung plug and locked into place thereupon.   
     
     
         2 . The cap of  claim 1  wherein the two semi-cylindrical flaps are free to pivot around the living hinge from an angle of 0° to approximately 210°. 
     
     
         3 . The cap of  claim 1  further comprising an element that permits a user to pry open the cap, thereby disconnecting the two semi-cylindrical flaps from each other. 
     
     
         4 . The cap of  claim 2  further comprising a pull-tab. 
     
     
         5 . The cap of  claim 1  wherein removal of the male tongue from the female groove of either lock mechanism causes the tongue to break.