Hauni-werke Korber & Co Kg.

Korber Ag

Uwe Uhlig

Werner Redeker

Heinrich Mushardt

Ralf Bleich

Reinhard Janutta

Horst Beyer

Peter Lutjens

Peter Oppelt

Frank Matysick

Werner Peschik

The sharpness profile of the working surface of a grinding wheel is determined in the course of a dressing operation by controlling the velocity of movement of the point of contact between the dressing tool and the grinding wheel. The velocity of such movement can be varied by changing the velocity of movement of the grinding wheel in a direction at right angles to its axis and/or by changing the velocity of movement of the dressing tool in a direction which is parallel to the axis of the grinding wheel. The velocity of the point of contact is varied as a function of changes of the inclination of various sections of the working surface relative to the axis of the grinding wheel. This influences the depth of notches or grooves which are formed by a rounded portion of the dressing tool in the working surface of the grinding wheel. The depth of such notches determines the sharpness of the corresponding sections of the working surface.

Method of dressing grinding wheels

When a cast metallic fixture for holding workpieces in a grinding machine, it is broken up by subjecting its walls to bending and tensional stresses to destory webs which connect two walls of the fixture to each other, whereupon the walls are moved apart to afford access to the workpiece. The webs can be destroyed as a result of the application of mechanical stresses to the walls of the fixture by a breaking device which is inserted into a compartment of the fixture and is movable relative thereto in order to destroy the integrity of a connector between the walls.

Apparatus for breaking up cast fixtures

A cast metallic fixture for workpieces including twin turbine blades has two spaced-apart walls which surround portions of the exterior of a workpiece and several webs which connect the walls to each other. The fixture is made in a casting mold which has one or more inserts extending into the interior of a workpiece which is placed into the cavity of the mold preparatory to pouring of a molten alloy which is then caused to harden and to thus form the fixture. When the fixture has served its purpose of holding the workpiece in a grinding machine, it is broken up by subjecting its walls to bending and tensional stresses to destroy the webs, whereupon the walls are moved apart to afford access to the workpiece. The webs can be destroyed by melting simultaneously with or in lieu of the application of mechanical stresses to the walls of the fixture.

Cast fixture for holding composite workpieces

A surface grinding machine wherein the grinding wheel is partially surrounded by a hood which can be turned about the axis of the grinding wheel in dependency on the shape and level of that part of a workpiece which is then treated by the grinding wheel. The hood carries coolant discharging nozzles which are continuously directed toward the location of contact between the grinding wheel and the workpiece. For this purpose, the nozzles are adjustable relative to the hood by discrete motors so as to compensate for wear upon and the resulting reduction of the diameter of the grinding wheel, or the hood is movable with the nozzles radially of the grinding wheel. The angular movements of the hood are shared by a dressing apparatus which is movable radially of the grinding wheel so that the dressing tool can treat the grinding wheel while the machine is in actual use.

Grinding machine with protective hood for the grinding wheel

A grinding machine wherein a column supports a vertically movable holder for the spindle of a grinding wheel and the dressing apparatus is mounted on the holder. The dressing apparatus has a carriage disposed at a level above the grinding wheel and movable up and down radially of the grinding wheel. The carriage has a forward extension for a follower which supports a pivotable carrier for two parallel or nearly parallel spindles each of which carries one or more dressing tools. The carrier is pivotable relative to the follower between a first position in which the first dressing tool is ready to treat the working surface of the grinding wheel and a second position in which the second dressing tool is ready to treat the working surface. Separate motors are provided to move the follower along the carriage, to move the carriage along the holder, to drive the spindles for the dressing tools, as well as to pivot the carrier relative to the follower. The dressing tools have different profiles and the axial distance between such dressing tools can be a small fraction of the axial length of the grinding wheel. The axis of at least one dressing tool is inclined with reference to the axis of the grinding wheel.

Apparatus for dressing grinding wheels

At least one end portion of a grinding or dressing wheel has a frustoconical projection with a relatively short frustoconical external surface extending into a frustoconical recess which is provided therefor in one end portion of a rotary tool supporting spindle. The wheel is formed with an end face which is located in the region of the maximum-diameter portion of its external surface and abuts against a complementary end face on the spindle to fix the wheel in a preselected axial position wherein the wheel is held by a tension rod which extends into an axial passage of the spindle. The positions of the projection and recess can be reversed.

Mounting for rotary grinding and dressing tools

Apparatus for supporting, locating and transferring plate-like or disc-shaped workpieces between several stations or between several machines where each of two plane parallel surfaces of each workpiece is subjected to one or more treatments has at least two partially overlapping plate chucks. A workpiece which is introduced by one chuck into the space where the two chucks overlap is released by the one chuck and is then attracted by the other chuck so that the previously exposed surface of the workpiece becomes concealed and vice versa. The chucks can transport workpieces between successive stations of a series of stations where the surfaces of the workpieces can be subjected to a coarse and thereupon to a precision or final treatment such as grinding and polishing, lapping or honing. If the chucks are installed in a separate frame, they can be rotated through 180.degree. about an axis which is parallel to their work-contacting surfaces so that a workpiece between such chucks is inverted, i.e., its upper side becomes its underside and vice versa. The chucks may be equipped with permanent magnets and/or electromagnets to selectively attract and release the workpieces.

Apparatus for manipulating workpieces having plane parallel surfaces

Apparatus for supporting, locating and transferring plate-like or disc-shaped workpieces between several stations or between several machines where each of two plane parallel surfaces of each workpiece is subjected to one or more treatments has at least two partially overlapping plate chucks. A workpiece which is introduced by one chuck into the space where the two chucks overlap is released by the one chuck and is then attracted by the other chuck so that the previously exposed surface of the workpiece becomes concealed and vice versa. The chucks can transport workpieces between successive stations of a series of stations where the surfaces of the workpieces can be subjected to a coarse and thereupon to a precision or final treatment such as grinding and polishing, lapping or honing. If the chucks are installed in a separate frame, they can be rotated through 180.degree. about an axis which is parallel to their work-contacting surfaces so that a workpiece between such chucks is inverted, i.e, its upper side becomes its underside and vice versa. The chucks may be equipped with permanent magnets and/or electromagnets to selectively attract and release the workpieces.

A surface grinding machine wherein a tool holder is mounted on an upright feed screw which is in mesh with a rotary spindle nut. The latter is held against axial movement in the column of the grinding machine and is normally driven by a torque transmitting unit having an endless toothed belt trained over a first pulley which is coaxial with the nut and a second pulley mounted on the output shaft of an electric motor. A gear train is installed in parallel with the torque transmitting unit to prevent automatic lowering of the tool holder when the belt breaks. The gear train has a first gear coaxial with the first pulley, a second gear coaxial with the second pulley and an additional gear meshing with the first and second gears. The tension of the belt is monitored by a detector which transmits a signal when the belt breaks, and such signal is used to immediately arrest the motor.

Machine tool feed screw drive

A double head grinding machine for the roots of turbine blades or similar complex workpieces with concave and/or convex surfaces has two parallel horizontal spindles the upper of which carries a single grinding wheel and the lower of which carries two coaxial grinding wheels. The base of the machine frame supports a table which is movable by a first motor in a direction at right angles to the axes of the spindles, tangentially of the grinding wheels and along a horizontal path below the spindles. A work holder on the table is movable by a second motor along a sloping path in a direction making an angle of 30 degrees with the axes of the spindles and at right angles to the direction of movement of the table in such a way that the workpiece which is held in the holder can be moved toward or away from the grinding wheels. The movements of the table and work holder in the two directions are controlled by discrete circuits or by a computer so as to impart to the workpiece a composite movement having a component in the direction of movement of the table and a component in the direction of movement of the work holder with reference to the table. At least one of the grinding wheels has a frustoconical working surface section whose inclination with reference to a plane that is normal to the axes of the spindles is also 30 degrees. The grinding machine renders it possible to treat or form arcuate surfaces whose radii of curvature greatly exceed the radii of the grinding wheels.

Grinding machine

A grinding machine with two parallel horizontal spindles which are movable radially of toward and away from each other and wherein each spindle carries a set of several coaxial grinding wheels having different outer diameters. The smaller wheels are nearer to and the larger wheels are more distant from the outer end portions of the respective spindles which are mounted, in cantilever fashion, in vertically movable carriers guided by vertical ways at the front side of an upright column forming part of the machine frame. The dressing mechanism for the grinding wheels has discrete coaxial or angularly staggered dressing discs for the respective grinding wheels, a common dressing disc for the grinding wheels on each spindle, or a single dressing disc for all of the grinding wheels. One or more workpieces are mounted on a holder which is rotatable relative to a support which, in turn, is rotatable relative to a table which is movable in parallelism with the axes of the spindles as well as tangentially of the grinding wheels so that each workpiece can be moved into engagement with a selected grinding wheel. The dressing disc or discs has or have different profiles, one for each grinding wheel, and the profile of each dressing disc is complementary to the profile of the peripheral working surface on the associated grinding wheel.

Growing community of inventors

Buchholz, Germany

Uwe Uhlig