Closure and sifter assemblage having automatically releasable, interlocking bead retainer structures

A closure and sifter assemblage for use with a container having a lip with an external undercut, comprising in combination:

• a) a screw cap having a threaded skirt and a closure wall spanning said skirt, and
• b) transferrable sifter means in said screw cap, comprising a sifter member having a central apertured portion spanning the skirt of the screw cap,
• c) said sifter member comprising a peripheral annular band-like rim having upper and lower back-to-back yieldable annular attachment beads,
• d) said closure wall of the screw cap having an integrally molded radially outwardly extending annular bead disposed adjacent to and lying radially inwardly of said skirt of the cap,
• e) said upper bead of the sifter member, when the latter is assembled to the screw cap, resiliently and releasably interlocking with an interference fit to the said annular bead of the screw cap,
• f) said lower attachment bead of the sifter member being frictionally engageable with said external undercut in the lip of the container when the screw cap and sifter member are screwed onto the container,
• g) said container lip being sized to effect a radially outward stretching of the band-like rim of the sifter member through contact with said lower attachment bead of the sifter member and a corresponding radially outward stretching of the said upper yieldable attachment bead thereof thereby to reduce the interference fit existing between said upper attachment bead of the sifter member and the bead of the screw cap so as to facilitate by-pass of said beads whenever the screw cap is removed, with the end result that the sifter member is thereafter always left in position on the lip of the container upon complete removal of the screw cap from the container.