Abstract: The invention relates to a position drive for a tool head for use in machine tools. The tool head comprises a base body (12), a tool shank (16) which protrudes axially over the base body (12) and is coupleable to a rotating machine spindle (14), and a thrust member (18) which is movable with respect to the base body (12) and which serves to move at least one tip holder or cutting tool (76). Further, an electric motor arrangement (24), which is coupleable to the thrust member (18), and a power supply device (26) for the motor arrangement (24) are positioned on the base body (12). In order to ensure a compact construction having an efficient motor arrangement, a hollow shaft (50) is borne rotatable about an axis of the base body (12), which is concentric with respect to a displacement axis (52) of the thrust member (18), and the hollow shaft (50) has an internal thread which engages in an external thread (42) of the thrust member (18).

Abstract: Methods and apparatus for on-site machining are disclosed. The internal portions of devices such as turbine valves must be machined in place, but present certain areas, such as the valve seat, that cannot be readily accessed from an external surface. The present invention provides methods and apparatus whereby such surfaces can be machined using a fixture to which a milling head or other machine tool is attached. In a preferred embodiment, a mounting plate is provided that contains holes or other features that cooperate with the structure to which the plate attached, thereby providing a rigid base for the machining operation. The present inventions also preferably uses a tool bar that has a cutting head that retracts and swivels. In its initial position the cutting head is swiveled inside the tool bar and the assembly can be inserted into a structure. Once inside, a threaded push rod is turned and manipulated to cause the cutting head to swivel, and then it is locked in place.

Abstract: A machine tool comprises a support structure having first and second opposite ends spaced apart along an axis, a drive assembly mounted on the support structure at the first end thereof, the drive assembly comprising at least one drive motor, and an output drive shaft coupled drivingly to the drive motor. The machine tool also comprises a machining head mounted on the support structure at the second end thereof, a tool support member mounted on the machining head and movable relative thereto, and a transmission shaft coupling the output drive shaft to the tool support member to effect movement of the tool support member. The transmission shaft extends parallel to the axis of the support structure over at least a substantial part of the distance of the first end of the support structure from the second end thereof.

Abstract: Machine for precision machining, with a rod for the determination of the ctical mean axis of a hole of cylindrical general contour. The present invention relates to a machine for precision machining, in particular for the grinding of valve seatings of heat engines, which is in accordance with the described in the European Patent EP-B-No. 0,022,796. According to the invention, the pilot rod (11) comprises various annular recesses (11a), in which various rings (13) which are resiliently deformable in the radial direction are respectively mounted. The invention is applicable to all types of machines for machining necessitating the presence of a pilot rod.

Abstract: An apparatus and method for forming a valve seat while the valve body is positioned in-line are disclosed. The valve reseater apparatus (25) includes stabilizers (27) for positioning the valve reseater (25) near the valve seat (21) to be repaired, as well as a cutting tool (42) mounted on a tool head (41) which is rotated by means of a revolution shaft (44) interconnected with a motor (34). The cutting tool (42) is simultaneously translated by means of translation screws (66, 67) which are controlled by means of a rotatable hand knob (56). The circumference of rotation is automatically controlled by means of a star wheel arrangement.