Abstract: A machine tool comprises a spindle stock (12), a tool magazine (20) in which a plurality of grippers equipped with tool holders are arranged to travel along an endless track, and two gripper arms (25, 26; 28, 29) arranged for moving the tool holders between a common pick-up and/or mounting position at the tool magazine and a spindle position at the spindle nose of the spindle stock (12), which has a vertical spindle axis (23, 24). In order to achieve the narrowest possible arrangement for the transfer movement between the pick-up and mounting position and the spindle position, it is provided that both gripper arms (25, 26; 28, 29) operate simultaneously and in opposite directions between their spindle positions and their pick-up and/or mounting positions, which are located on one side of the spindle stock (12), moving along geographical curves evading each other.

Abstract: A machine tool (10) comprises a revolving spindle (11). A plurality of tool holders (14) each of which is provided with a taper (13) and can be transferred by means of a gripper arm (20) from a magazine position remote from the spindle (11) and mounted by their tapers (13), one by one, in the spindle (11) in a machining position, while the other tool holders (14) remain in the magazine position. In order to avoid that metal chips may get into contact with and stick to the tapers (13) of the tool holders (14) while the latter are in the magazine position the tool holders (14) are accommodated in a cavity (40) providing a closed cover at least for the tapers (13).

Abstract: A toolholder is provided for a machine tool where a plurality of standardized toolholders, in particular steeptaper toolholders, can be picked up from a tool magazine by means of grippers and can be introduced into a spindle of a spindle stock. The toolholder comprises an annular flange having an upwardly converging outer conical surface. The gripper can be provided with an inner conical surface widening towards the top. The two surfaces come into frictional engagement with each other under the action of the own weight of the toolholder, during introduction of the toolholder into the spindle, while the surfaces are lifted off from each other when the toolholder occupies its fully engaged position in the spindle.

Abstract: A machine tool comprises a motion unit that can be displaced relative to a work table along a horizontal axis. Guide rails extend in the direction of the axis, being fixed against movement in this direction. Supporting guide elements of the motion unit run on the guide rails in axially offset arrangement. A drive motor serves for effecting a relative movement between the motion unit and the guide rails.In order to reduce the overall depth of the machine tool in the direction of the axis and to improve the accessibility of the drive elements, the drive motor has its stator rigidly connected to the said motion unit and is arranged in substantially axial orientation between the said guide elements.

Abstract: A gripper for tools of a machine tool is provided with a hand with at least one moveable jaw arranged thereon for form-locking engagement of the tools.In order to enable the tools to be automatically gripped in form-locking engagement, without any supply of auxiliary energy, the hand is provided with an actuating element that can be moved by means of a stationary stop provided on the machine tool to move the jaw into a spread-apart position for introducing the tool, and into a closed position for gripping the tool in a form-locking manner.

Abstract: A methode serves for producing bores in wheels of motor vehichles, in particular for producing mounting bores (14) in a wheel disk (12) or valve bores in a rim of the wheels. The bore has a larger diameter (D.sub.1, D.sub.3) in the area of the surfaces (135, 136) of the wheel disk than in the area between these surfaces.In order to enable a countersunk portion to be produced in the area of the bore also in the surface opposite the machining surface, with the wheel in a signle mounting position, a tool (160) is employed whose bottom face exhibits a hook-like configuration (162, 163, 164, 165) and which can be passed through the bore in vertical direction (170), in axially displaced relation. Thereafter, the tool (160) is returned to a position in which it is aligned with the axis (15) of the bore, then rotated and retracted. whereby a countersunk portion (144) of larger diameter is produced. Finally, the tool can be removed from the bore by carrying out the described steps in the reverse order.

Abstract: A machine tool is provided with an enclosure with a charging door (10) arranged therein. In a first end position, the charging door closes the enclosure against the outside while in a second end position it occupies a position in which it is pivoted substantially about a horizontal axis in its upper portion. In this latter position, the lower rim of the charging door (10) is displaced into the interior of the enclosure. The charging door (10) is guided during its movement in such a manner that its lower edge is located at a higher level between the two end positions than in the said end positions.In order to facilitate opening and closing of the door for an operator, a power-operated drive (95, 100, 101) is arranged in a lateral bay (90) in the enclosure for opening and closing the charging door (10).

Abstract: A machine tool comprises a spindle stock and a worktable having an upper surface thereon for mounting and machining workpieces. The worktable and the spindle stock are alternatively displaceable relative to each other in a plane parallel to the upper surface from a first position at which a first portion of the upper surface is disposed proximate the spindle stock and serves as a processing area and a second portion of said upper surface is disposed distal to said spindle stock and serves as a mounting area, to a second postion at which the upper surface second portion is disposed proximate the spindle stock and serves as a processing area and the upper surface first portion is disposed to the spindle stock and serves as a mounting area. A splash guard wall is provided for separating the processing in the mounting areas. The splash guard wall is attached to the table upper surface by means of a hinge defining a first pivot axis.

Abstract: A machine tool comprises a spindle stock that can be moved along several axes. A work table can be rotated alternately in opposite directions by an angle of, preferably, 180.degree. about an axis extending perpendicularly to the table surface in such a manner that the halves of the table surface form alternately, at any given time, a processing area located in the working area of the spindle stock and a mounting area located at a distance from the working area. At least one line leads from a stationary part of the machine tool to the work table for transmitting signals and/or supplying energy.In order to simplify the arrangement of the line, in particular if a plurality of such lines is provided, the line is connected above the said work table to a point on the said stationary part of the said machine tool and, hanging down loosely between the two parts, on the other hand to a connection box of the said work table.

Abstract: A protective covering for a machine tool where work pieces can be mounted on a worktable comprises a loading door which can be pivoted between two end positions and which in a first end position closes the protective covering while in the second end position it clears an opening in the protective covering providing access to the work piece. The bottom of the loading door describes during this movement an upwardly curved locus extending above and across the work piece. It is proposed for this arrangement that the loading door be provided on its inside with a device for diverting liquid flowing down its inside towards the lateral edges and that the said loading door does not project beyond the outer contour of the said protective covering during its movement.

Abstract: A machine tool comprises a tool exchange mechanism for transferring various tool holders from a magazine position into a working position of a rotating spindle of the machine tool. In order to minimize tool change times for standardized and non-standardized tool holders, frictional means between the tool holders and grippers of the tool exchange mechanism are provided as well as locking mechanism for maintaining a predetermined rotational position of the tool holders in the tool exchange mechanism. Thus, the tool holders may be inserted into the rotating receiving opening of the spindle with a predetermined rotational position or, if the tool holder rotational position deviates from another predetermined rotational position of the rotating spindle, the search time for establishing a form-locking driving relation between the spindle and the tool holder is minimized.