A cutting method for an inner circumferential face or an outer circumferential face of a work using a cutting tool projecting from a main shaft which turns around a predetermined position serving as a center and for which a turning radius is adjustable, wherein a table that supports the work is set in a rotating central axis that is coaxial with a turning central axis of the main shaft, and the table is rotated in a direction opposite to a turning direction of the main shaft to increase a cutting velocity. The cutting method allows an increase to the cutting velocity under simple control.

A cutting method for an inner circumferential face or an outer circumferential face of a work using a cutting tool projecting from a main shaft which turns around a predetermined position serving as a center and for which a turning radius is adjustable, wherein a table that supports the work is set in a rotating central axis that is coaxial with a turning central axis of the main shaft, and the table is rotated in a direction opposite to a turning direction of the main shaft to increase a cutting velocity. The cutting method allows an increase to the cutting velocity under simple control.

A cutting method in which, in cutting a circumferential face of a work, control is enabled to make a cutting velocity constant accurately by using a cutting tool projecting from a main shaft which turns around a predetermined position serving as a center and for which a turning radius is adjustable, wherein, in the case that a turning angular velocity of the main shaft is represented as , a distance from a turning center to a tip of the cutting tool is represented as R, and a cutting velocity of the tip of the cutting tool is set to a constant value C, making the cutting velocity of the cutting tool constant by performing control such that 0 changes in association with a change in the distance R so that
=(C.sup.2{dot over (R)}.sup.2).sup.1/2/R
is formulated (where {dot over (R)} denotes a time differential of the distance R), thus providing an even cut face.

A cutting method in which, in cutting a circumferential face of a work, control is enabled to make a cutting velocity constant accurately by using a cutting tool projecting from a main shaft which turns around a predetermined position serving as a center and for which a turning radius is adjustable, wherein, in the case that a turning angular velocity of the main shaft is represented as , a distance from a turning center to a tip of the cutting tool is represented as R, and a cutting velocity of the tip of the cutting tool is set to a constant value C, making the cutting velocity of the cutting tool constant by performing control such that 0 changes in association with a change in the distance R so that
=(C.sup.2{dot over (R)}.sup.2).sup.1/2/R
is formulated (where {dot over (R)} denotes a time differential of the distance R), thus providing an even cut face.

The invention relates to a machine for processing plastic workpieces. A machine housing surrounds a working chamber located between a workpiece spindle for rotationally driving the workpieces about a workpiece axis of rotation and a fast tool servo for producing an oscillating feeding movement of a rotary tool in the direction of the workpieces. The workpiece spindle is provided with a carriage which can be driven and is guided on at least two guide surfaces of a guiding arrangement in order to produce a relative advancing movement between the workpiece and the rotary tool. The advancing movement runs transversely with respect to the feeding movement and defining therewith a processing plane in which during processing the rotary tool engages with the workpiece. The guiding arrangement is mounted on the machine housing such that the processing plane extends between the two guide surfaces.

The invention relates to a machine for processing plastic workpieces. A machine housing surrounds a working chamber located between a workpiece spindle for rotationally driving the workpieces about a workpiece axis of rotation and a fast tool servo for producing an oscillating feeding movement of a rotary tool in the direction of the workpieces. The workpiece spindle is provided with a carriage which can be driven and is guided on at least two guide surfaces of a guiding arrangement in order to produce a relative advancing movement between the workpiece and the rotary tool. The advancing movement runs transversely with respect to the feeding movement and defining therewith a processing plane in which during processing the rotary tool engages with the workpiece. The guiding arrangement is mounted on the machine housing such that the processing plane extends between the two guide surfaces.

A polygon machining method whereby first polygon machining using a polygon cutter is carried out on a workpiece, followed by machining using tools other than the polygon cutter, then second polygon machining using the polygon cutter again. The polygon machining method comprises: a first polygon machining step in which a main axis and a tool main axis are synchronously rotated such that the rotation speed of the main axis and the tool main axis are at a ratio required for the first polygon machining, and polygon machining is carried out; a machining step in which the ratio is changed to a second synchronization ratio such that the main axis rotates at a rotation speed required for machining after the first polygon machining, the main axis and the tool main axis are synchronously rotated, and machining is carried out on the workpiece that has received the first polygon machining; and a second polygon machining step in which the main axis and the tool main axis are synchronously rotated such that the rotation speed of the main axis and the tool main axis are at a ratio required for the second polygon machining, and polygon machining is carried out.

A polygon machining method whereby first polygon machining using a polygon cutter is carried out on a workpiece, followed by machining using tools other than the polygon cutter, then second polygon machining using the polygon cutter again. The polygon machining method comprises: a first polygon machining step in which a main axis and a tool main axis are synchronously rotated such that the rotation speed of the main axis and the tool main axis are at a ratio required for the first polygon machining, and polygon machining is carried out; a machining step in which the ratio is changed to a second synchronization ratio such that the main axis rotates at a rotation speed required for machining after the first polygon machining, the main axis and the tool main axis are synchronously rotated, and machining is carried out on the workpiece that has received the first polygon machining; and a second polygon machining step in which the main axis and the tool main axis are synchronously rotated such that the rotation speed of the main axis and the tool main axis are at a ratio required for the second polygon machining, and polygon machining is carried out.

A subassembly with a supporting element for a machine bed of a lathe, and of a machining unit which is arranged on the supporting element and has a machining axis, wherein a solid-body joint, via which the machining unit is arranged in a movable manner on the supporting element, is provided. A lathe for plastics spectacle lenses, having a machine bed, having a tool mount or workpiece mount which is arranged at least indirectly on the machine bed, and having a subassembly which is arranged at least indirectly on the machine bed, wherein the workpiece and the tool can be oriented in relation to one another via the solid-body joint.

A subassembly with a supporting element for a machine bed of a lathe, and of a machining unit which is arranged on the supporting element and has a machining axis, wherein a solid-body joint, via which the machining unit is arranged in a movable manner on the supporting element, is provided. A lathe for plastics spectacle lenses, having a machine bed, having a tool mount or workpiece mount which is arranged at least indirectly on the machine bed, and having a subassembly which is arranged at least indirectly on the machine bed, wherein the workpiece and the tool can be oriented in relation to one another via the solid-body joint.