Abstract: Method for manufacturing cervical prostheses with a concavity after grinding, having the following steps: positioning a grinding tool (2) in a resting position (X0, Z0), loading the part (1) to grind, displacing the grinding tool (2) relative to the part (1) to grind along an axis (Z) parallel to the tool's rotation axis, displacing the grinding tool (2) relative to the part (1) to grind along an axis (X) perpendicular to the tool's rotation axis, so as to bring the tool in grinding start position, grinding the concavity (100) by combining rotation movements of the grinding tool and rotation movements of the part (1) around the two axes (Z, C) parallel to each other.

Abstract: Method for manufacturing cervical prostheses with a concavity after grinding, having the following steps: positioning a grinding tool (2) in a resting position (X0, Z0), loading the part (1) to grind, displacing the grinding tool (2) relative to the part (1) to grind along an axis (Z) parallel to the tool's rotation axis, displacing the grinding tool (2) relative to the part (1) to grind along an axis (X) perpendicular to the tool's rotation axis, so as to bring the tool in grinding start position, grinding the concavity (100) by combining rotation movements of the grinding tool and rotation movements of the part (1) around the two axes (Z, C) parallel to each other.

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 assembly such as a tool head for a spark erosion profiling machine tool comprises an elongate tool holding member having first and second opposed lengthwise bearing surfaces and third and fourth opposed lengthwise bearing surfaces. By way of example the member can be square, the bearing surfaces then being the four long sides of the member. The member is partly housed in a housing wherein there are mounted bearings which support the member for movement in the direction of its length with respect to the housing. The bearings can comprise discrete circulating roller bearing shoes and they are in abutting contact with the member at five positions in the region of each of two planes spaced apart along the length of the member by a calculated optimum distance.