Machine tools

A machine tool comprising, a hollow cylindrical body, a rotary driven tool mounted within said body for axial movement in use towards and away from a work surface, a suction chamber disposed about said tool and having means defining a central aperture for passage of the tool and a forward abutment surface for abutment against the work surface, means mounting said chamber for axial movement relative to said body and said tool, means resiliently biasing said chamber in a direction corresponding to a direction towards the work surface, stop means defining a forwardmost position of said chamber relative to said tool, said suction chamber comprising a plurality of complementary chamber sections each extending about a given portion of the circumferential extent of said chamber, means removably securing said chamber sections together and to said mounting means to allow removal of said chamber sections from said mounting means by a generally radial outward movement of said sections relative to said tool, said mounting means including an annular member mounted for axial movement relative to said body and said tool and subjected to the action of said biasing means, said annular member having an externally screw-threaded outer face and a lower edge with an outwardly-facing circular groove, said chamber sections when assembled having a circular upper edge with an inwardly-directed circular flange which rests in said groove of the annular member, and a screw ring threadably engaged on said outer face of the annular member, said screw ringn having a non-threaded clamping portion engageable about said upper edge of said chamber sections.