Abstract: Machine tools utilized in precision machine operations require tool support structures which exhibit minimal deflection, thermal expansion and vibration characteristics. The tool support structure of the present invention is a graphite fiber reinforced composite in which layers of the graphite fibers or yarn are disposed in a 0/90.degree. pattern and bonded together with an epoxy resin. The finished composite possesses a low coefficient of thermal expansion and a substantially greater elastic modulus, stiffness-to-weight ratio, and damping factor than a conventional steel tool support utilized in similar machining operations.

Abstract: The overhung ratio of a boring bar having a damper formed by a damper mass located in a cavity near the cutting tool, with a fluid-filled clearance between the mass and the cavity wall, may be increased by shrink-fitting a tungsten carbide core or bung into the root end of the bar and/or by fitting a second damper to the free end of the bar beyond the cutting tool.

Abstract: Disclosed is a method for suppressing the self-excited chatter vibrations in a machine tool of the type having a "non-rotating" tool or of the type having a "rotating" tool. According to this invention a chatter suppressing contact is provided to itself the tool of the non-rotating type machine tool or to the rotating spindle to which the tool is fixed in the rotating type machine tool in such a way that the chatter suppressing contact slidably reciprocates on the tool or the rotating spindle thus changing the contact point with time. As a result the natural frequency of the tool is changed while it is employed in machining, and the self-excited chatter vibration are suppressed. The chatter suppressor contact which is used in a non-rotating type machine tool is in the form of an auxiliary tool holder, whereas the chatter suppressor contact which is used in a rotating type machine tool is in the form of a ball or roller bearing.

Abstract: A power driven rotary tool having a specially constructed bearing ring spacer means adapted to oppose self-induced vibrations. The power driven rotary tool comprises an outer housing frame, a driven rotatable shaft, a set of antifriction bearings disposed between the outer frame and the rotatable shaft for support of the rotatable shaft, a bearing ring spacer means in solid contact with either the outer housing frame or the outer races of the antifriction bearing and between a set of antifriction bearings, longitudinal passageways provided in the bearing ring spacer means and rigid impact elements disposed in the passageway to oppose self-induced vibrations with a power driven rotary tool.

Abstract: The vibration damping construction for boring bars comprising a cutter insert holder bar cap rigidly mounted on the end of a boring bar having a rigidly anchored cantilevered internal bar extending back within a cylindrical cavity in the end of the boring bar on which an optional number of heavy reactors are assembled with optionally varied radial clearance for relative oscillatory movement, as well as axial clearance for free independent movement and with outer radial clearance relative to the inner wall of the boring bar exceeding the maximum oscillatory movement whereby reactive oscillatory damping impact transmitted to the cantilevered inner bar will in turn be transmitted to the anchor point of the inner bar and thereby concentrated near the axial location of the cutter insert.