US Patent 7648210 Pick with an interlocked bolster

In one aspect of the invention, a pick comprises a front portion with an impact tip brazed to a carbide bolster. The carbide bolster comprises a cavity which is formed in the bolster's base end and which is adapted to interlock with a rear portion of the pick. The rear portion is adapted to be retained within a bore of a holder that is attached to a driving mechanism. The rear portion comprises a locking mechanism adapted to lock its first end within the cavity. The locking mechanism comprises a radially extending catch that is formed in the first end of the rear portion.