Abstract: A spindle liner for a turning machine has an elongated polymeric member sized to fit within the inner diameter of a spindle and further has a bore through the polymeric member sized and shaped to receive a given size bar stock. The spindle liner may be installed within a spindle and bolted to a spindle flange by an adapter fixed to the spindle liner so that the spindle liner rotates with the spindle. The spindle liner attenuates noise and vibration of the rotating bar stock and eliminates whipping of the free end of the bar stock.

Abstract: A bar feed mechanism for a machine tool comprising at least one cylindrical tube adapted to be aligned with a spindle of the machine tool, a piston movable in the tube, a shaft rotatably secured to the piston, a centering sleeve rotatably mounted on the shaft and axially movable thereon, center elements secured to the shaft at the end remote from the piston, a bushing at the end of the tube adjacent the machine tool having an orifice which permits passage of the center means therethrough but retains the centering sleeve, an hydraulic pressure inlet for admitting pressure fluid behind the piston to cause movement thereof in a feeding direction, apparatus to admit pressure fluid between the piston and centering sleeve, and pressure relief apparatus to permit discharge of pressure fluid from the tube between the piston and centering sleeve when the sleeve abuts the bushing, thereby permitting continued movement of the piston, shaft and center elements in the feeding direction.