Tool turret for a machine tool and lathe with such a tool turret

Lathe comprising a machine bed, at least one tool spindle mounted for rotation about a spindle axis defining the direction of a Z-axis of said lathe, said tool spindle being provided at its one end with a tool clamping device for holding a workpiece to be machined, at least one compound slide system with at least one Z-slide guided for displacement in the direction of the Z-axis and an X-slide guided for displacement in the direction of an X-axis extending perpendicularly to the Z-axis, and further comprising a tool turret carrier mounted on said compound slide system for rotation about a B-axis extending perpendicularly to the Z-axis and to the X-axis and hence held for displacement in the direction of the Z-axis and the X-axis, said tool turret carrier being provided with a tool turret comprising a turret head mounted on a turret head carrying device of said tool turret for rotation about a turret indexing axis and lockable by means of a turret head locking device relative to said carrying device in a predetermined number of indexing positions which are equidistant with respect to angle of rotation in relation to said indexing axis, said turret head tapering on both sides of a diameter plane of said turret head extending perpendicularly to said turret indexing axis, and said turret head having on each side of this diameter plane a circular ring-shaped row of tool stations which are equidistant with respect to angle of rotation, said row of tool stations being concentric with said indexing axis, and each of said tool stations having a tool receiving means associated with one of said indexing positions for clamping a toolholder for a machining tool, wherein

• (a) at least two of said tool receiving means are designed for clamping a tool rotatably drivable about a tool axis, the toolholder of said tool having a tool drive shaft for engaging the respective tool receiving means, and a tool driving device is provided for said tool drive shafts;
• (b) each tool station has as part of an interface between the toolholder and turret head a planar contact surface formed by the outer surfaces of said turret head for the respective toolholder;
• (c) the contact surfaces of a first row of tool stations define a first regular pyramid, and the contact surfaces of the other, second row of tool stations define a second regular pyramid, both pyramids having the same shape and apexes pointing away from one another, and the axis of each pyramid coinciding with said turret indexing axis so that the two Pyramids adjoin one another at said diameter plane of the turret head, said pyramid apexes being equidistantly spaced from said diameter plane;
• (d) each row of tool stations has at least one tool receiving means for a drivable tool;
• (e) each of said tool receiving means for drivable tools has an axis extending perpendicularly to said contact surface of the respective tool station;
• (f) two adjacent tool receiving means for drivable tools belong to different rows of tool stations and are offset from one another with respect to angle of rotation in relation to said turret indexing axis, the axes of these tool receiving means penetrating said diameter plane of said turret head at points which lie on a circle concentric with said indexing axis;
• (g) said tool driving device has at least one drive shaft extending perpendicularly to said turret indexing axis, said drive shaft being displaceable in the longitudinal direction thereof for coupling with and uncoupling from a tool drive shaft of a drivable tool.

Lathe comprising a machine bed, two coaxial workpiece spindles mounted for rotation about a common spindle axis defining the direction of a Z-axis of said lathe, and each provided with a workpiece clamping device for holding a workpiece to be machined, said workpiece spindles being arranged opposite each other with workpiece clamping devices facing one another, and further comprising two compound slide systems, each of which has a Z-slide guided for displacement in direction of the Z-axis and an X-slide guided for displacement in the direction of an X-axis extending perpendicularly to the Z-axis, wherein each of said two compound slide systems carries a tool turret comprising a turret head mounted on a turret head carrying device of said tool turret for rotation about a turret indexing axis and lockable by means of a turret head locking device relative to said carrying device in a predetermined number of indexing positions which are equidistant with respect to angle of rotation in relation to said indexing axis, said turret head tapering on both sides of a diameter plane of said turret head extending perpendicularly to said turret indexing axis, and said turret head having on each side of this diameter plane a circular ring-shaped row of tool stations which are equidistant with respect to angle of rotation, said row of tool stations being concentric with said indexing axis, and each of said tool stations having a tool receiving means associated with one of said indexing positions for clamping a toolholder for a machining tool, wherein

• (a) at least two of said tool receiving means are designed for clamping a tool rotatably drivable about a tool axis, the toolholder of said tool having a tool drive shaft for engaging the respective tool receiving means, and a tool driving device is provided for said tool drive shafts;
• (b) each tool station has as part of an interface between the toolholder and turret head a planar contact surface formed by the outer surfaces of said turret head for the respective toolholder;
• (c) the contact surfaces of a first row of tool stations define a first regular pyramid, and the contact surfaces of the other, second row of tool stations define a second regular Pyramid, both pyramids having the same shape and apexes pointing away from one another, and the axis of each pyramid coinciding with said turret indexing axis so that the two pyramids adjoin one another at said diameter plane of the turret head, said pyramid apexes being equidistantly spaced from said diameter plane;
• (d) each row of tool stations has at least one tool receiving means for a drivable tool;
• (e) each of said tool receiving means for drivable tools has an axis extending perpendicularly to said contact surface of the respective tool station;
• (f) two adjacent tool receiving means for drivable tools belong to different rows of tool stations and are offset from one another with respect to angle of rotation in relation to said turret indexing axis, the axes of these tool receiving means penetrating said diameter plane of said turret head at points which lie on a circle concentric with said indexing axis;
• (g) said tool driving device has at least one drive shaft extending perpendicularly to said turret indexing axis, said drive shaft being displaceable in the longitudinal direction thereof for coupling with and uncoupling from a tool drive shaft of a drivable tool.