Abstract: This device includes a cylinder head stand mounted so that it can pivot tugh at least 180.degree. about a horizontal axis and capable of rigidly holding a cylinder head and a valve lifter. A plurality of blocks in the form of plates which are flexible and elastic and each of which has, on the one hand, a central hole of non-circular transverse section allowing it to be engaged, with rotational connection, on a horizontal support rod and, on the other hand, a perimeter allowing part of its edge face to be applied against at least one valve head.

Abstract: The method centers a guide rod, which is inserted in a valve guide of a valve seat to be machined and which serves as a guide rod for a shaping tool. By hand, or with a mechanical, pneumatic, hydraulic or electro-mechanical device, the guide rod is centered in the valve guide by means of a pivoting ball which is mounted in a manner such that it can pivot in all directions between two clamping plates and which is held with the possibility of translation between the clamping ring and the bottom of a housing. For this purpose, the pivoting ball is displaced circularly such that the guide rod sweeps all around the valve guide. By means of the follower levers, the shape of the valve guide is determined and, by means of a precise mechanical device, the pivoting ball is placed at the center of the swept shape, where it can be fixed by means of plates and of the clamping ring.

Abstract: A device for grinding the head of a valve, especially of an internal-combustion engine, has a rigid stand, a structure for supporting the valve stem in terms of rotation that is arranged fixedly and vertically on the stand, a stop for rotational bearing against the valve tail, and a drive mechanism for driving the valve in rotation by the front face. The drive mechanism is arranged vertically below the structure for supporting the valve stem in terms of rotation with a coupling to compensate for any misalignment between the axis of rotation of the drive mechanism and the axis of rotation of the valve stem. A machining station is mounted on the stand having a machining tool mounted thereto in an orientable manner so that the machining axis may be adjusted in relation to the fixed and vertical reference system of the valve stem.

Abstract: The present invention relates to a machine for the machining of a metal bk, especially for boring and facing.The machine according to the invention comprises a laser sighting system making it possible to bring the component to be machined into coincidence with an axis (X) or a reference plane (XY). This system makes it possible, by means of removable optoelectronic sensors, to obtain a control signal allowing the holding table to be positioned in an assisted manual way or automatically, for example with a numerical control.

Abstract: The present invention relates to a tool for precision machining, for exam for the grinding of thermal-engine valve seats. The tool according to the invention comprises a housing (2), a sleeve (3) equipped with a spherical orientation plug (3a) mounted inside the housing, a one-piece machining shaft (6) mounted freely in terms of rotational and translation motion in the sleeve, and a means for adjusting the height of the shaft (6), comprising a means for fixing said shaft in terms of rotation to a bush (17) movable in terms of translational motion relative to the sleeve.