US 3,938,735 AGranted

Capping assembly for thin all centrifuge tubes

AssigneeBeckman Instruments, Inc.

InventorsHerschel E. Wright, Kenzo Ishimaru

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Abstract

A centrifuge test tube cap assembly for a thin flexible test tube including a stem member having a stud adapted to extend out the mouth of the test tube and having a cylindrically shaped skirt dimensioned to fit snugly within the inner surface of the mouth of the test tube, the stem member also having a slanting annular surface between the skirt and the stud, slanting outwardly in the downward direction, and the assembly also including a crown member having a depending outer lip, the outer diameter of which is substantially the same as the outer diameter of the thin flexible tube and having an annular inner surface slanting outwardly in the downward direction, the slanting surface of the lip conforming to the shape and slant of the slanting annular surface of the stem member so that when the crown is positioned over the stem and tightened axially on the stem member the upper edge of the flexible tube is deformed inwardly to squeeze the upper edge of the tube between the respective slanting surfaces of the stem member and the crown member to effect a fluid-tight seal.

Claims4

Dependent claims

A centrifuge test tube cap for a thin flexible test tube comprising:

a stem member including a stud adapted to extend out of the mouth of the tube, said stem member including a cylindrically shaped skirt dimensioned to fit snugly within the inner surface of said test tube, said stem member also including an annular surface between said skirt and said stud slanting outwardly in the downward direction;
a crown member having an opening therein said stud of said stem member and having a depending lip, the outer diameter of which is adapted to be substantially the same as the outer diameter of said flexible test tube, said lip having a wedge-shaped cross-section with an annular inner surface outwardly in the downward direction and substantially conforming with the shape and slant of said annular surface on said stem member, said wedge-shaped lip of said crown member being positioned over said stem member and being thereby adapted to cause the upper edge of said flexible tube to be deformed inward against said annular slanting surface of said stem member;
and
means for clamping together said stem member and said crown member whereby said upper edge portion of said flexible tube is squeezed between said respective slanting surfaces of said stem and said crown member.

1 more element

Dependencies are inferred from the claim text.