Abstract: An abrasive grinding machine wherein the periphery of a rotatable grinding wheel always is returned to, and during grinding maintained at, a constant and precise workpiece grinding position irrespective of the reduction of the diameter of the wheel from wear and/or dressing. The grinding wheel is mounted rotatably on the distal end of a rockable pivot arm which, during grinding, is actuated periodically to retract the wheel from and return it to workpiece grinding position. A control mechanism, constituted by a fixed stop on the pivot arm, a moveable cam for the stop and a programmable drive motor for the cam, is operative periodically, in harmony with the reciprocable movement of the pivot arm, to adjust the cam relative to the stop to permit controlled, incremental increases in the distance over which the grinding wheel is periodically retracted from and returned to workpiece grinding position. The invention finds particular use in conjunction with dressing tools or wheels for a grinding machine.

Abstract: A self-contained, mobile refractory apparatus for repairing interior refractory walls of high temperature industrial ovens and furnaces by spraying fluent refractory slurry mixes to seal cracked and spalled areas thereof. The apparatus is mounted on a vehicle, and includes a base, a rotatable, articulated support mounted on the base, a pivotal gunning lance support secured to the articulated support, an elongated gunning lance mounted on the gunning lance support with capacity for selected reciprocal axial movement, a slurry pipe mounted rotatably within the lance and a spray nozzle affixed to the slurry pipe for spraying slurry. Reversible hydraulic motors impart selected reciprocal movement to the lance and selected rotary movement to the slurry pipe and its nozzle. The lance is constituted by a pair of elongated, concentric tubes having elongated supporting ribs interposed therebetween, to provide high strength and rigidity with minimum deflection in use.

Abstract: A high speed hydraulically actuated rotatable chuck for machine tools, permitting the high pressure clamping of elongated work pieces with capacity to be machined simultaneously at opposite ends. Two separate, axially aligned hollow work holding elements are provided, each having capacity to contract diametrically to work clamping condition, and to expand diametrically to work releasing condition. Annular actuators are mounted externally about the work holding elements, with capacity for axial movement relative thereto. A plurality of hydraulically actuated pistons are provided to advance the annular actuators, under a high, uniformly applied working pressure, to contract their work holding elements into work clamping relation. Quick-acting release means retract the actuators, upon deactivation of the pistons, to permit the work holding elements to expand to work releasing condition.