Patent ID: 9027717
Filing Date: 2015-05-12
Classification: E21B,F04C,F16D

Abstract:
1. A centrifugal brake system for retarding backspin comprising: a main rotatable shaft extending axially through a brake housing; a hub supported for co-rotation by the shaft and rotatable concentrically in the brake housing; two or more brake shoes supported by and distributed circumferentially about the hub, each brake shoe movable radially outwardly under the influence of centrifugal force, between a biased, radially inward disengaged position, the brake shoes retained thereat when the shaft, hub and the two or more brake shoes rotate in a forward direction, and an engaged position in braking engagement with the brake housing, when the shaft, hub and the two or more brake shoes rotate in a backwards direction under the influence of centrifugal force; and a cam arrangement acting between the two or more brake shoes and the hub comprising: