Abstract: The machine tool is provided for working ring-shaped workpieces (1), in particular one-piece turbine wheels, so-called “bladed rings”. It has a rotatable chucking device (2) for a workpiece (1). Said chucking device is mounted on a carrying part (4), which in turn is supported by a supporting component (5). In order to keep the dimension (14) of the length by which the carrying part (4) projects beyond the workpiece (1) on the side facing the supporting component (5), as low as possible, the carrying part (4) protrudes into the chucking device (2) to such an extent that it projects at least through the boundary surface (7) of the workpiece (1) facing the supporting component (5). A saving of space is achieved in this way and, therefore, enhanced accessibility is obtained for the tool to the side of the workpiece (1) facing the supporting component (5).

Abstract: The machining center serves for grinding workpieces with complex shaped surfaces, such as turbines or jet engine blades. One or several workpieces are clamped in a workpiece chucking device. The latter is displaceable along an X and a Y axis. Additionally, each workpiece is clamped rotatably around its longitudinal axis. A support device is disposed on a stand, and is displaceable along a vertical Z axial direction. One or several automatically exchangeable grinding attachments are inserted in support device. Each grinding attachment comprises grinding means driveable from support device. The support device is inclinable around an axis of inclination, which runs parallel to the Y axis. Each grinding attachment is rotatable by any angle around a grinding attachment longitudinal axis, which runs parallel to the Z axis when the support device is in the uninclined state. All said axes are numerically controlled.

Abstract: A controllable electrochromic indicator device is disclosed which includes two electrodes, an electrochromic layer and an adjacent charge-carrier-transmitting insulator layer situated between the two electrodes and at least one of the electrodes being deposited on a supporting plate and at least one of the electrodes being transparent. The charge carrier transmitting insulator layer is a good ion conductor and functions to almost completely block the flow of electrons. At least one of the electrodes is non-polarizable and is disposed in direct contact with the ion conductor.

Abstract: A hoist system for a power shovel having a main frame, a boom connected at a lower end thereof to the main frame, a dipper handle pivotally connected to the boom and a dipper pivotally connected to the dipper handle, including means for varying the pitch of the dipper, generally including a hoist mechanism mounted on the main frame, a first hoist line operatively connected at one end thereof to the hoist mechanism, passing over a point on the boom and operatively connected at the opposite end thereof to the dipper handle, a second hoist line operatively connected at one end thereof to the hoist mechanism, passing over a point on the boom and operatively connected at the opposite end thereof to the dipper, and means for selectively varying the effective length of one of said hoist lines relative to the other thereof.