Patent ID: 8215508

Claim:
A closure for attachment to a centrifuge bottle having a mouth, the closure having a thread for threaded engagement with the centrifuge bottle and comprising: an end wall; and a sidewall having an axial centerline and extending from said end wall, said sidewall comprising: a first terminal end opposite said end wall, said first terminal end having a first outer peripheral boundary at a first radial distance from said axial centerline; said first terminal end defining an opening for coupling the closure to the bottle; a second terminal end adjacent said end wall, said second terminal end having a second outer peripheral boundary at a second radial distance from said axial centerline, said second radial distance being less than said first radial distance; a first transition surface inclined at an angle relative to said axial centerline with said thread being positioned radially inwardly from said first transition surface; and a second transition surface inclined at an angle relative to said axial centerline, said second transition surface being configured to intersect a plane defined by the mouth of said centrifuge bottle when the closure is attached to the mouth; said first transition surface extending between said first outer peripheral boundary and said second transition surface; said second transition surface extending between said first transition surface and said second outer peripheral boundary.