US Patent 7475948 Pick with a bearing

In one aspect of the invention, a degradation assembly comprises a holder. The holder is attached to a driving mechanism and comprises a longitudinal central bore. A pick comprises a body intermediate a shank and an impact tip, and the shank is disposed in the central bore of the holder. The impact tip comprises an impact surface diamond or cubic boron nitride. At least one rolling element is disposed intermediate an inner bore surface and the shank, and is adapted for low-friction rotation with respect to both the inner bore surface and the shank.