Abstract: A grinding machine that can continuously grind a rod-like object rotating around its axis supported by a head and a tailstock. Grinding tools are attached to a rotating circular plate which is provided on a carriage that moves along a bed adjacent the axis of the rod-like object at a constant rate to grind the outer surface of the rod-like object. The circular plate includes a front side on which a plurality of first and second grinding tools are mounted. The grinding tools include those for roughing and those for finishing and are mounted along imaginary circles of different radii according to their use in grinding. The plate can be moved up and down so that the rod-like object can be ground with the pertinent tools. That is, a different degree of grinding ranging from roughing to finishing can be performed with different tools in a continuous manner by only changing the height of the circular plate without exchanging the tools.

Abstract: This invention discloses a method and an apparatus for grinding and polishing up a rod-like object which has such a comparatively small diameter that the rod is pliable when subjected to usual grinding. Upon grinding, it is placed on a horizontal, rotatable roll with a surface having great frictional resistance and held by a pair of parallel, opposed guide plates on both sides, where it is made to rotate by the rotation of the roll while a rotating grindstone is being pressed on it. Uniform grinding can be made by moving the grindstone and the rod-like object relative to each other along a gap between the parallel, opposed guide plates.

Abstract: A roller used for a roller conveyor which includes an outer cylinder of the roller supported by a pneumatic bearing. The roller also includes a fixed shaft having a path for letting air pass through in the center thereof, and annular members fitted on the fixed shaft, the outer cylinder covering the shaft and annular members leaving a narrow gap around the annular members. The path for letting air pass through the shaft and the narrow gap communicate with each other by way of holes and a groove made on the annular members. Therefore, the introduced air can pass through the holes and the groove and then fill the narrow gap to such an extent that the wall of the outer cylinder never comes into contact with the annular members, the thin layer of air in the gap functioning as the pneumatic bearing.

Abstract: A grinder performs operations ranging from rough grinding to mirror-like finishing of the whole of an elongate peripheral surface of a work rotated around the central longitudinal axis thereof by pressing a grindstone to the work and by shifting the grindstone along the longitudinal direction of the central rotary axis of the work. By providing a rotor on the carriage adapted to move in parallel with the longitudinal axis of the work to be ground and by fixing grindstones different from each other in grain size to a plurality of rotating shafts fixed to the rotor, respectively, a grindstone in desired grain size is, upon rotation of the rotor, selectively brought into contact with the work. The grindstone that has been in contact with the work is rotated by a drive and, at the same time, the pressing force to act upon the work is imparted to the grindstone by a presser.