Patent ID: 11897158
Assignee: URSCHEL LABORATORIES, INC.
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 10:
11. An impeller adapted to be coaxially mounted within a cutting head for rotation about an axis of the cutting head, the impeller comprising:
a lower plate having an upper surface, a lower surface, and a perimeter;
paddles configured with the lower plate to direct material placed on the lower plate in a radially outward direction of the impeller when the impeller is rotated, at least one of the paddles having an outer radial extent that is adjacent the perimeter of the lower plate; and
at least a first exit hole located in the lower plate, the first exit hole having a wall section that completely closes the first exit hole along the perimeter at the upper surface of the lower plate, the first exit hole extending through the lower plate to define a passageway connected to the upper surface to enable foreign debris at the upper surface to exit the impeller through the passageway;
wherein the first exit hole has a radially outermost wall that is not perpendicular to the upper surface of the plate; and
wherein the radially outermost wall of the first exit hole is inclined to slope radially inward from the upper surface to the lower surface of the lower plate at an angle of not greater than 25 degrees to vertical.