Abstract: The apparatus, especially a grinding machine, comprises a frame (14) on which two working planes (A, B) are used, at least two oscillating elements (11, 12) disposed on one of the planes and each including at least one tool device (15, 16), at least one further tool device disposed on the other plane, and at least one means for generating oscillating motion (20) whereby a reciprocating movement can be generated at the level of each of the oscillating elements, so that the resultant of the vectors representing the dynamic forces associated with the movement of each of the oscillating elements is substantially equal to zero. There is then little or no induced vibration.

Abstract: The single-motored apparatus includes a motor which rotatingly drives a main shaft and a correction shaft, the main shaft in turn rotatingly driving the diamond toolholder, a clutch for coupling and uncoupling the shafts, and a cam/feeler assembly for transforming the rotary movement of the correction shaft into longitudinal movement of the diamond toolholder. When the correction shaft and the main shaft connected by the clutch rotate simultaneously, the diamond toolholder executes solely an angular movement; when the two shafts are uncoupled and only one of the two shafts rotates, the diamond toolholder executes either solely a longitudinal movement or a longitudinal and angular movement at the same time.

Abstract: A toolholder turret (3) is movable in the X and Z directions relative to a work table (2) so that each of the grinding tools (9a, 10a, 11a 12a) can be presented to machine a surface of a workpiece (6). A support (20) of a truing unit (4) bears a rotary body (22), one arm (23) of which is provided at the end with a follower, while two vertical arms are provided with diamonds. The exact positions of the truing tools relative to a reference, which may be constituted by the detecting surfaces of the follower, are detected by means of a further follower (18) integral with a further table (13). Measurements taken by displacement of the latter follower are stored in a memory. Other measurements relating to the actual sizes and shapes of the grinding tools are likewise taken through displacement of the further table so that these tools are sensed by the detecting surfaces of the first-mentioned follower.

Abstract: An auxiliary device is disclosed for use with grinding machines to assist in clamping a workpiece and performing the grinding of an internal bore in the workpiece. The device has an exteriorily conical surface extending from an annular projection to one end of the device which inserts into the workpiece and the interior of the device also has a frusto-conical surface tapering outwardly to the opposite end.

Abstract: Two grinding-wheel spindles bearing grinding wheels are mounted on a table which undergoes an angular displacement for simultaneously grinding convergent internal and external conical surfaces of a workpiece, on the one hand, and for truing the grinding wheels by means of truing tools, on the other hand. The truing tools are so positioned that the grinding faces of the wheels are trued in a manner whereby the workpiece surfaces are then automatically ground with extreme precision and the exact desired diameter of the circular edge formed at the junction of the convergent surfaces is obtained.