Patent ID: 8885288

Claim:
A shroud comprising: an arcuate edge surface sized to facingly engage an edge of a disc operably disposed in the shroud to define an edge-wise gap entirely along the arcuate edge surface; a plate having a plate surface extending from a proximal end that is contiguous to the arcuate edge surface to a distal end terminating at a plate edge nearer an inner diameter of the disc, a leading edge of the plate spaced from the disc by a first gap forming an upstream inlet with respect to a direction that the disc operably rotates; a first protuberant member depending from the plate surface and spaced from the disc by a second gap downstream of and smaller than the first gap the first protuberant member operably extending from adjacent the plate edge in a substantially radial direction across a portion of the disc; and a second protuberant member depending from the plate surface and spaced from the disc by a third gap downstream of the second gap and smaller than the first gap, the second protuberant member operably extending from adjacent the plate edge in a substantially radial direction across a portion of the disc and radially longer than the first protuberant member.