A device for ventilating a burning building that includes, a chassis; and a cutting assembly, mounted on the chassis. The cutting assembly is adapted to cut a ventilation hole in a roof or wall member of a building either autonomously or under remote control by an operator to allow smoke and/or hot gases to escape from the roof space.

A power tool system comprises (i) at least one power tool, in particular a circular saw, having at least one tool support unit for supporting a tool during machining and at least one displaceably mounted tool guiding unit, and (ii) at least one power tool separation device which is arranged on the tool guiding unit. The power tool separation device comprises at least one cutting unit and at least one guide unit for guiding the cutting unit.

A trenching device rotating a trenching chain through a substrate to form a trench. The trenching device including a power unit, a drive unit including a belt drive system, and a trenching unit including a trenching chain and configured to rotate the trenching chain about a trenching bar.