CPC B24B 13/005 (2013.01) [B24B 9/146 (2013.01); B24B 13/0052 (2013.01); B24B 13/012 (2013.01); B24B 41/061 (2013.01); B29D 11/0048 (2013.01)] | 19 Claims |
1. A blocking device for blocking a semi-finished optical element (11; 111) having a first face (14; 114) to which the blocking device (13; 113) is to be attached and having opposite to the first face (14; 114) a second face (15) to be surfaced in a surfacing machine (10) configured for holding the semi-finished optical element (11; 111) via the blocking device (13; 113), said blocking device (13; 113) comprising:
a mounting portion (20) provided for mounting the blocking device (13; 113) on a corresponding mounting member (17) of said surfacing machine (10) ; and
a blocking portion (21) configured for blocking said semi-finished optical element (11; 111) ;
said blocking portion (21) comprising a support member configured for providing a rigid support to said semi-finished optical element (11; 111),
wherein said support member includes a support element (23; 123) made of a shape-memory material comprising ferromagnetic elements (27), said support element having a rigid state below a predetermined temperature and a plastic state above said predetermined temperature, said support element (23; 123) assuming in the absence of external forces a predetermined memory shape when heated above said predetermined temperature, said support member having a contact face (25; 125) onto which said first face (14; 114) of said semi-finished optical element (11; 111) is to be applied;
wherein said blocking portion (21) includes a heating device (36) configured for heating said support element above said predetermined temperature,
wherein said ferromagnetic elements (27) configure said support element (23; 123) for being inductively heated above said predetermined temperature by the heating element (36),
wherein the blocking device is further configured to generate a magnetic retaining effect.
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