Abstract: An optical element unit including a first optical element module and a sealing arrangement is disclosed. The first optical element module occupies a first module space and includes a first module component of a first component type and an associated second module component of a second component type. The first component type is optical elements and the second component type being different from the first component type. The sealing arrangement separates the first module space into a first space and a second space and substantially prevents, at least in a first direction, the intrusion of substances from one of the first space and the second space into the other one of the first space and the second space. The first module component at least partially contacts the first space and, at least in its area optically used, not contacting the second space. The second module component at least partially contacts the second space.

Abstract: An optical element unit including a first optical element module and a sealing arrangement is disclosed. The first optical element module occupies a first module space and includes a first module component of a first component type and an associated second module component of a second component type. The first component type is optical elements and the second component type being different from the first component type. The sealing arrangement separates the first module space into a first space and a second space and substantially prevents, at least in a first direction, the intrusion of substances from one of the first space and the second space into the other one of the first space and the second space. The first module component at least partially contacts the first space and, at least in its area optically used, not contacting the second space. The second module component at least partially contacts the second space.

Abstract: An optical element unit includes a first optical element module and a sealing arrangement. The first optical element module occupies a first module space and includes a first module component of a first component type and an associated second module component of a second component type. The first component type is optical elements and the second component type being different from the first component type. The sealing arrangement separates the first module space into a first space and a second space and substantially pre-vents, at least in a first direction, the intrusion of substances from one of the first space and the second space into the other one of the first space and the second space. The first module component at least partially contacts the first space and, at least in its area optically used, not contacting the second space. The second module component at least partially contacts the second space.

Abstract: There is provided an optical element comprising an optical element body, a reflecting area and an optical passageway. The optical element body defines an axis of rotational symmetry. The reflecting area is disposed on the optical element body and adapted to be optically used in an exposure process. The optical passageway is arranged within the optical element body and allows light to pass the optical element body, the optical passageway being arranged eccentrically with respect to the axis of rotational symmetry.

Abstract: An optical element unit is provided comprising an optical element group; a housing receiving said optical element group and having an inner housing part and an exit end; and a purge unit connected to said housing and providing a purge medium to said inner housing part. The optical element group comprises an ultimate optical element. The ultimate optical element is located at the exit end of housing and separates the inner housing part from an environment external to the housing. The ultimate optical element and the housing define a sealing gap. The purge unit provides purge medium to the sealing gap to prevent intrusion of contaminants into the inner housing part.

Abstract: An optical element unit including a first optical element module and a sealing arrangement is disclosed. The first optical element module occupies a first module space and includes a first module component of a first component type and an associated second module component of a second component type. The first component type is optical elements and the second component type being different from the first component type. The sealing arrangement separates the first module space into a first space and a second space and substantially prevents, at least in a first direction, the intrusion of substances from one of the first space and the second space into the other one of the first space and the second space. The first module component at least partially contacts the first space and, at least in its area optically used, not contacting the second space. The second module component at least partially contacts the second space.

Abstract: An optical element unit is provided comprising an optical element group; a housing receiving said optical element group and having an inner housing part and an exit end; and a purge unit connected to said housing and providing a purge medium to said inner housing part. The optical element group comprises an ultimate optical element. The ultimate optical element is located at the exit end of housing and separates the inner housing part from an environment external to the housing. The ultimate optical element and the housing define a sealing gap. The purge unit provides purge medium to the sealing gap to prevent intrusion of contaminants into the inner housing part.

Abstract: In the case of a connecting chain link for link chains having two connecting-link parts (1, 2), their ends (4, 5), which are connected to each other via a respective longitudinal web (3), are held together in the closed position by means of a respective stub (6) gripping into a pocket (7). While each stub (6) is provided with an essentially U-shaped retaining web (19) which has clearances (22, 23) in the region of its limbs (20, 21) running parallel to each other, each pocket (7) is provided with a U-shaped retaining groove (25) whose one wall (24) has recesses (26, 27). The size and position of the clearances (22, 23) and of the recesses (26, 27) make it possible for the connecting-link parts (1, 2) to be joined together in a position in which their stubs (6) and pockets (7) partially overlap.

Abstract: In the case of a connecting chain link for link chains having two connecting-link parts (1, 2) which can be displaced by limited amounts in the longitudinal direction of the connecting link, in order to open and close the connecting link, and which are each provided with a stub (6) at one end (4) and at the other end (5) with a pocket (7) to hold the stub (6), in the closed position the connecting-link parts (1, 2) are locked in place with the aid of a central locking element (10) which rests in shell-shaped supporting surfaces (9) of two projections (8) which protrude into the clear interior of the connecting link.

Abstract: In the case of a connecting chain link having two connecting-link parts (1, 2) which are locked in place in the closed position by means of a bolt-shaped locking element (12) which rests in a holder (11) formed by the connecting-link parts (1, 2), the locking element (12) has, in addition to a central spring lock washer (19) which is used to secure its axial position, two further spring lock washers (23, 24) which are arranged in the region of its end and prevent tilting movements of the locking element (12) in the holder (11).