US Patent 7112021 Tool coupling for rotating tool

A tool assembly includes first and second tool bodies, a tool coupling interconnecting the tool bodies, and a drawing member for drawing the tool bodies together along a common longitudinal axis. The tool coupling includes a male portion disposed on one of the first and second tool bodies, and a female portion disposed in another of the first and second tool bodies and receiving the male portion. The tool coupling also includes a ridge disposed on one of the first and second tool bodies and a groove disposed in another of the first and second tool bodies and receiving the ridge for radially steering the first and second tool bodies during mating of the male and female portions.