A cutting insert for a tool for machining a workpiece. The cutting insert comprises a rake face with a chip shaping geometry which is particularly suitable for machining titanium and titanium alloys. The chip shaping geometry is designed in such a way that the chip lifted from the workpiece is deformed comparatively strongly about its longitudinal axis. The chip shaping geometry is arranged at least in a rear area of the rake face, which is laterally bounded by a first concavely curved portion and a second concavely curved portion of the minor cutting edges of the cutting insert. The chip shaping geometry projects upwardly beyond a cutting plane in which the main cutting edge of the cutting insert and two rectilinear portions of the two minor cutting edges are arranged and comprises at least two elevations so that the rake face in the rear area in a further cross-section parallel to the main cutting edge comprises two high points and an intermediate second low point which has an equal third distance from the first concavely curved portion and the second concavely curved portion. A rake angle along the main cutting edge varies such that the rake angle γ1 at a center of the main cutting edge, which has an equal second distance from a first end and a second end of the main cutting edge, is greater than the rake angle in the area of the first and/or second ends.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

A turning method for a computerized numerical control lathe performs the steps of: providing a cutting tool including a coupling portion, an intermediate portion and a cutting portion, a longitudinal center axis of the coupling portion defining a tool rotational axis, the cutting portion including a top surface, a first nose portion, the first nose portion including a first cutting edge, a second cutting edge, and a convex nose cutting edge connecting the first and second cutting edges; providing and rotating a metal work piece around a work piece rotational axis, which is set perpendicular to the work piece rotational axis; making a first pass where the first cutting edge is active and the second cutting edge is inactive; making a second pass where the first cutting edge is inactive and the second cutting edge is active; and rotating the turning tool around the tool rotational axis.

A curtain assembly comprises a rotatable drive element wherein at least one helical guide structure is formed on, or into, the outer surface of the drive element. A drive attachment element having a structure that communicates with the helical guide structure to move the drive attachment element axially along the drive element when the drive element is rotated. Specific embodiments incorporate either a manual or motor-driven rotation assembly for rotating the drive element. Further specific embodiments involve a helical guide structure that comprises a helical groove and a structure that comprises a tooth that engages with the helical groove.

A cutting tool includes a cutting chip and a chip holder. The chip holder includes: a body part having a height dimension larger than a width dimension, the body part including a first attachment face that intersects with a cutting feed direction, and a second attachment face that intersects with the first attachment face; a chip support part whose base end portion is connected to the body part and in which the cutting chip is attached to the upper end portion in the height direction of a tip end portion of the chip support part such that the cutting chip projects to one side in the width direction of the chip support part; a reinforcement part provided along the height direction of the chip support part; and a chip receiving part that supports the cutting chip projecting from the chip support part.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

A motorized drapery system having an elongated rotating drive element that has a non-circular cross-sectional shape such as square, rectangular, trapezoidal, cross shaped or any other non-circular shape that is twisted. In one arrangement the drive element is twisted in one direction along its entire length. In another arrangement the drive element is twisted in one direction in a first section and twisted in an opposite direction in a second section thereby providing a center opening/center closing drapery. A plurality of rings are positioned around the drive element including at least one driver ring that includes a feature that connects to the drive element and is configured to facilitate movement along the drive element, and a plurality of idler rings that are configured to slide along the drive element. A curtain is connected to the rings and opens and closes as the rings move along the drive element.

A method for machining grooves in the surface of a workpiece in which a dummy groove is machined in the surface of the workpiece by moving a cutting tool relative to the workpiece in a first machining direction of the workpiece, then orienting the cutting tool 180 degrees as compared to the first machining, and subsequently second machining the dummy groove by moving the cutting tool in a second direction opposite to the first direction. A displacement of a cutting edge of the cutting tool, caused by the first and second machining of the dummy groove is measured. A groove is machined with the cutting tool in a forward stroke and then a return stoke with the cutting tool rotated 180 degrees between the strokes. A relative position between the workpiece and the cutting tool during the forward and return strokes is corrected so as to eliminate the displacement.

An exemplary hand-held, power operated rotary knife dermatome comprises a blade housing assembly and a depth gauge assembly. The blade housing assembly includes an annular blade housing and a blade lock ring for rotatably supporting an annular rotary knife blade. The annular blade housing includes a shield extending radially inwardly from a blade receiving body and including an inner wall defining a tissue directing surface, the tissue directing surface including a first tissue guide surface extending upwardly from a lower end of the shield, the first tissue guide surface extending substantially parallel to the blade housing axially extending center line. The blade receiving body includes an annular blade channel extending axially upwardly from a lower surface of the blade receiving body, a bearing surface axially spaced from a lower surface of the blade receiving body, and a threaded portion formed on the outer surface of the annular blade housing.

A tool insert includes first, second, and third teeth arranged on a surface of the tool insert. The first tooth is arranged at a proximal end of the tool insert surface and has an angled leading end and a first tooth height. The second tooth is spaced from the first tooth by a first distance along the surface of the tool insert and has a second tooth height greater than the first tooth height. The third tooth is spaced from the second tooth by a second distance along the surface of the tool insert and has an extending angled portion. The first tooth forms a first groove in a bore surface. The second tooth increases the depth of the first groove. The third tooth provides at least one micro-scratch to one of the first groove and the bore surface.