Supporting cap for sealed centrifuge tube
AssigneeBeckman Instruments, Inc.
InventorsSteven J. Chulay, Steven T. Nielsen
Life of this patent
Estimating the term…
Abstract
A fluid-containing means for each bore of a centrifuge rotor is disclosed which combines a self-capped tube and a floating cap resting on the top of the tube and arranged to resist deformation of the tube by the centrifugal forces developed therein. The floating cap has an annular skirt which engages the top of the tube and which is sufficiently thick in cross-section to prevent deformation of the floating cap. The floating cap is formed from a relatively light plastic, having a density less than that of the centrifuged fluid, thereby preventing bottoming of the floating cap in the bore in the event of rupture of the tube.
Claims14
In a centrifuge rotor having at least one cylindrical bore for receipt of a fluid sample, sample retaining means comprising:
- a closed tube containing the sample and having a cylindrical body portion which generally conforms to the shape of the bore and an upper surface which has a generally dome-shaped center area;
- a cap extending into the bore to engage the top of the tube and having in the center of its lower surface a concave recess which engages and substantially conforms to the dome-shaped center area of the tube upper surface;
- the cap having an annular axially extending peripheral portion which encircles the dome-shaped area of the tube and which has sufficient cross-sectional area to prevent permanent deformation of the cap during centrifugation, said axially extending peripheral portion terminating in a substantially flat annular surface adjacent the tube;
- and
- the upper surface of the tube having a peripheral area around the dome-shaped center area, which peripheral area during centrifuge operation is pressed against the adjacent annular surface of the peripheral portion of the cap.
In a centrifuge rotor having at least one cavity for receipt of a fluid sample, sample retaining means comprising:
- a closed tube containing the sample and having a body portion which generally conforms to the shape of the cavity and an upper surface which seals in the fluid sample;
- a floating cap extending into the cavity to engage the top of the tube and arranged to substantially conform to the shape thereof;
- the cavity being at such an angle that centrifugal force tends to move the tube and the cap toward the bottom of the cavity;
- and
- the cap being formed of material of a density less than the density of a substantial portion of the fluid in the tube, thereby limiting outward movement of the cap in the event the tube bursts.
In a centrifuge rotor having at least one cylindrical bore for receipt of a fluid sample, sample retaining means comprising:
- a closed tube containing the sample and having a cylindrical body portion which generally conforms to the shape of the bore and an upper surface which has a generally dome-shaped area;
- and
- a cap engaging the top of the tube and having in its lower surface a concave recess which engages and substantially conforms to the dome-shaped area of the tube upper surface;
- the cap having an annular axially extending skirt which encircles the dome-shaped area of the tube and which has sufficient cross-sectional area to prevent permanent deformation of the cap during centrifugation, said axially extending skirt terminating in a substantially flat annular surface.
Dependencies are inferred from the claim text.