Block piece for blocking a lens

A kit comprising:

• a bottom part having a holding section formed by an annular wall surrounding a central, axially open recess for holding a block piece in a workpiece chuck of a processing device or a coating device and
• multiple upper parts for blocking an eyeglass lens by means of a block material, wherein
• only the upper parts have a block surface for at least one of the lens or the block material,
• the upper parts are different with respect to at least one of a diameter of the block surface, a curvature of the block surface, or a prismatic tilting of the block surface,
• the holding section of the bottom part is selectively connectable with any one of the upper parts by a press fit,
• the block piece formed by the bottom part and one of the upper parts is adapted to be held on the bottom part for at least one of processing or coating of an optically active surface of the lens, and
• a normal at a midpoint of the block surface of the upper parts is inclined relative to a central axis of the bottom part, and wherein the respective upper part is insertable into the bottom part only in one orientation in such a way that the normal at the midpoint of the block surface of the respective upper part and the central axis of the bottom part always span a same plane.

A method for blocking an eyeglass lens, wherein a block piece is provided which has a bottom part, the bottom part having a holding section formed by an annular wall surrounding a central, axially open recess with which the block piece can be held in a workpiece chuck of a processing device or a coating device, and an upper part for a fastening of the lens for at least one of processing or coating of an optically active surface of the lens, and wherein only the upper part has a block surface for at least one of the lens or a block material, wherein said upper part has the block surface for the lens or the block material, wherein a normal at a midpoint of the block surface of the upper part is inclined relative to a central axis of the bottom part, and wherein the upper part is insertable into the bottom part only in one orientation in such a way that the normal at the midpoint of the block surface of the upper part and the central axis of the bottom part always span a same plane, the method comprising:

• connecting the holding section of the bottom part with the upper part by a press fit,
• blocking the lens on the upper part by means of the block material,
• at least one of processing or coating the optically active surface of the blocked lens,
• and at least one of the following features:
• using the bottom part made of metal and the upper part made of plastic for said blocking of the lens on the upper part, or
• connecting the top and bottom parts in such a way that the normal at the midpoint of the block surface of the upper part and the central axis of the bottom part always span the same plane.

A block piece for blocking an eyeglass lens by means of a block material, comprising:

• a bottom part comprising a holding section, the holding section being adapted for detachably connecting the block piece with a workpiece chuck of a processing device or a coating device, wherein the holding section is formed by an annular wall surrounding a central, axially open recess, and
• an upper part for fastening of the lens for processing and/or coating an optically active surface of the lens, wherein only the upper part has a block surface for at least one of the lens or the block material,
• wherein the bottom part has a connecting recess for receiving the upper part, with a periphery of the connecting recess, when viewed in a top view of the bottom part along a central axis of the bottom part, having a rotational asymmetrical shape,
• wherein the upper part comprises a connecting portion that has a rotationally asymmetrical shape complementary to the rotational asymmetrical shape of the connecting recess, and
• wherein the connecting portion is or can be plugged into the connecting recess so that the bottom part and the upper part are fixedly connected to one another in a torque-proof manner that prevents rotation of the upper part relative to the bottom part in a circumferential direction and in a defined rotational position determined by the rotational asymmetry, and
• wherein the connecting recess and the connecting portion are non-circular, and wherein a normal at a midpoint of the block surface of the upper part is inclined relative to the central axis of the bottom part.