Abstract: A rock boring device includes a rotary disc cutter. The disc cutter is driven in an oscillating manner and may be driven or free to nutate, and the device includes a mounting section for the rotary disc cutter and a driven section. The mounting section may be angularly offset from the axis of the driven section whereby the rotary disc cutter can oscillate and/or nutate.

Abstract: A rock boring device (10) including a rotary disc cutter (11). The disc cutter (11) is driven in an oscillating manner and also driven or free to nutate, and the device includes a mounting section (22) for the rotary disc cutter and a driven section (21), and wherein the mounting section (22) is angularly offset from the axis of the driven section whereby the rotary disc cutter will both oscillate and nutate.

Abstract: The invention provides a digital contract comprising a sealed package comprising: a header package comprising: rules defining any sealed packages to be included in said contract; a validating party who is to validate said header package; and a sealing party who is to seal said package; a body containing at least a portion of the content of the package; and a validating signature generated from said rules and said body according to a first key belonging to said validating party; any sealed packages defined in said rules; and a sealing signature generated from said header package and any of said sealed packages according to a first key belonging to said sealing party. Further provided is contract management software for generating, validating, exchanging and managing such contracts.