Patent attributes
A cannula hub includes a shaft mount segment and a cannula coupling segment. A set of coupling nubbins radially extend from the outer surface of the cannula coupling segment. The coupling nubbins are aligned with one another along a helical cannula coupling pathway on the outer surface and are adapted to be received within a cooperative helical groove on a transfer vessel. The coupling nubbins have a protrusion projection distance that is greater than the depth of the groove. When a sufficient rotational force is applied to the cannula hub, the coupling nubbins score the inside face of the groove which increases the groove depth and enables the coupling nubbins to advance along the groove while forming a tight compression fit of the coupling nubbins within the groove.
