Patent ID: 9623196
Date: 2017-04-18
CPC Classifications: A61M,B01D

Claim:
1. An air trap comprising: a body having a sealed interior space with an inner cylindrical wall, a center axis, and an inlet and an outlet on the center axis, wherein the inlet and outlet each have a diameter; a clear passage through the interior space that extends along the center axis from the inlet to the outlet, the clear passage having a diameter that is greater than or equal to the smaller of the inlet and outlet diameters; and at least one projection disposed within the interior space and coupled to the inner cylindrical wall, the at least one projection extending toward the central axis from the inner cylindrical wall to the clear passage and having a surface configured to substantially retain air bubbles on the surface, wherein the at least one projection comprises a spiral shelf having an inner edge, and wherein the inner edge is spaced away from the center axis along the entire length of the spiral shelf by a first gap, so that the inner edge defines a perimeter of the clear passage from the inlet to the outlet along the axis and wherein a portion of the inner cylindrical wall forms a hollow cylinder having, in cross-section, substantially straight parallel sides that extend in a direction along the central axis, for at least one complete rotation of the spiral shelf.