Abstract: A tool for removing a disk or cylindrical core from a workpiece which includes a shank, an extension piece and cutting elements, the extension piece being in the form of a hollow cylinder and including apertures in the wall thereof for the introduction therein of a coolant. An axially movable centering element is positioned with the extension piece, the centering element including a centering spigot which fits into a cup-shaped centering piston, plate springs within the piston and against which the centering spigot is movable, and an elastic ring therearound for contact against the inner wall of the hollow cylinder.

Abstract: A hammer drill is provided with an accessory that is rotatably supported on the chuck of the drill and has a handle fixed to the support rotatable on the drill chuck. Structure is provided forming a throughgoing passage extending from the tool through the handle to the outer end of the handle and a flexible conduit is connected to this handle at the outer end thereof for drawing gas and particles from the tool through the passage. The structure may surround an intermediate portion of the tool at the radial opening of an axial bore through the tool so that particles and the like can be aspirated directly through the tool. Alternately a telescoping tube is provided connected at its rear end to the passage at the support and at its front end to a cup through whose base the drill passes, so that this cup is pressed against the workpiece during the drilling operation.

Abstract: An apparatus in a machine tool controls the flow of coolant in accordance to tool contact with a workpiece. The preferred embodiment measures and stores a torque value exerted upon a spindle motor under no-load conditions and compares this value to an operating torque value upon the same spindle motor. When the tool contacts a workpiece and the operating torque exceeds the stored no-load torque value by a predetermined amount, a solenoid operated valve is opened and coolant is permitted to the area of tool engagement with the workpiece.

Abstract: A method to reduce the growth rate of localized tool wear at the depth-of-cut line by the enrichment of the cutting zone atmosphere with gaseous oxygen.

Abstract: A band saw is provided with rotary guides for changing the angle of the saw. While the part is rotated and linearly translated toward and away from the saw by the contouring apparatus, the saw cuts a peripheral shape on the part with the blade, changing its angular attitude where necessary. An air cushion support holds the edge of the part at the saw blade.