Cutting method and apparatus.

摘要

This invention provides a method of and apparatus for cutting within the confines of a passage. The method comprises introducing into the passage a cutting apparatus, supplying to the cutting apparatus fluid under pressure, supplying separately to the cutting apparatus a particulate abrasive material suspended in a fluid, mixing at least part of the fluid under pressure with the particulate abrasive material suspended in a fluid, and directing the mixture of fluid and particulate abrasive material under pressure onto a surface to be cut. The apparatus comprises a body portion (1, 21), a head portion (2, 25) rotatable relative to the body portion (1, 21) and comprising at least one cutting nozzle (11, 25) means (3, 34) for connecting the apparatus to a source of fluid under pressure, means (5, 41) for connecting the apparatus to a source of particulate abrasive material suspended in a fluid, means (10 or 32, 37) for rotating the head portion, and venturi means (14 or 26, 30) for mixing the particulate abrasive material suspended in a fluid with the fluid under pressure. The apparatus preferably comprises drive nozzles (8, 53) whereby part of the fluid under pressure can be directed rearwardly and outwardly of the apparatus to impart drive to the apparatus and an inflatable collar (46) which can be inflated to locate the apparatus in a passage during a cutting operation.