Abstract: To prepare an essentially toroidal surface (7) on a workpiece (1) by machining, rotation of the workpiece around a first axis of rotation (3) and at the same time a rotation of the cutting tool (8) used for this machining around a second axis of rotation (10) are provided, wherein the second axis of rotation passes through the predetermined center (4) of the circular surface of the torus, which yields the surface (7) to be machined of the workpiece (7) during the rotation of the workpiece (1) around the first axis of rotation (3).

Abstract: In a notching machine using a blade assembly of upper and lower knives mounted respectively on a vertically moving ram and a machine table and each comprising two individual blades forming with their cutting edges a coinciding vertex angle which may be changed by turning the blades relative to each other around a vertical axis of rotation that extends in parallel with the ram near the noses of the knives, a third blade component is provided at least for the upper knife for forming its nose portion with a unitary cutting edge that complements the cutting edges of the two other blades of the upper knife for confining its vertex angle.

Abstract: In a notching machine an upper knife is attached by an upper set collar to the head of a vertically moving ram for being turnable around an axis of rotation lying near the nose of the upper knife. The upper set collar is connected through a fixed axis parallel to the axis of rotation with a lower set collar for a common turning around the same axis of rotation. The lower set collar being provided for the attachment of a lower knife and serving as an auxiliary table for workpieces to be notched. The two knives have an equal minimum vertex of, for example, 30.degree. so that with a first working stroke of the ram in a first turning position of the upper and lower set collars and their knives, respectively, this minimum vertex may be notched into the workpieces lying on the auxiliary table and afterwards with a second working stroke of the ram this minimum vertex may be enlarged to any desired larger notching angle up to for example around 120.degree. in a second turning position of the knives.

Abstract: A table stop for a machine for cutting sheet material, more particularly a notching machine, comprising a double acting pressure cylinder for each the adjustment of the stroke of a stop rail along the blade of the cutting tool and its angular adjustment about a vertical pivot axis. The two pressure cylinders being coupled for a trailing movement of the one pressure cylinder provided for the angular adjustment by the other pressure cylinder being provided for the adjustment of the stroke. The relatively movable working members of the two pressure cylinders being connected with the stop rail through pivots.

Abstract: Punching press having a top cutter which is vertically movable by an axially guided ram. The top cutter extends beyond the cross-sectional surface area of the ram and cooperates with a bottom cutter mounted on the machine table. The ram is constructed as an angle section, particularly as an equal-limbed L-section, at least on the place of mounting for the top cutter and at least over an axial length corresponding to the length of stroke of the top cutter. The axial guiding system for the ram comprising a pin-and-bush guide which is disposed on the cutting clearance and comprising at least two pins and associated guide bushes situated at a distance from each other on the ram and on the machine frame in an axially parallel configuration.