3.1 Snapped Bit Retainer System - WO2022171785A1:
Key Excerpt:
"However, the successive blows by the hammer to rear of the drill bit may cause the drill bit to fracture, which is known as "shanking" in the art. If the drill bit does fracture then part of the drill bit may remain in the bore hole and the operator may need to retrieve the fractured part from the bottom of the bore hole before drilling can continue. Such retrieval, known as "fishing", may be extremely difficult with deep boreholes and may consume valuable operating time."