US 12,138,731 B2
Device for pneumatically blocking a semi-finished optical element
Sébastien Pinault, Charenton le Pont (FR); Luc Martin, Charenton le Pont (FR); Jérôme Moine, Charenton le Pont (FR); and Xavier Bultez, Charenton le Pont (FR)
Assigned to Essilor International, Charenton-le-pont (FR)
Appl. No. 16/612,027
Filed by Essilor International, Charenton le Pont (FR)
PCT Filed Jun. 12, 2018, PCT No. PCT/EP2018/065438
§ 371(c)(1), (2) Date Nov. 8, 2019,
PCT Pub. No. WO2018/229024, PCT Pub. Date Dec. 20, 2018.
Claims priority of application No. 17305706 (EP), filed on Jun. 12, 2017.
Prior Publication US 2020/0198085 A1, Jun. 25, 2020
Int. Cl. B24B 13/005 (2006.01)
CPC B24B 13/005 (2013.01) 17 Claims
OG exemplary drawing
 
1. A blocking device for pneumatically blocking a semi-finished optical element (11) having a first face (14) to which the blocking device (13) is to be attached and having opposite to the first face (14) a second face (15) to be surfaced in a surfacing machine (10) configured for holding the semi-finished optical element (11) via the blocking device (13), said blocking device (13) comprising:
a mounting portion (20) provided for mounting the blocking device (13) 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);
said blocking portion (21) comprising:
a support member configured for providing a rigid support to said semi-finished optical element (11), said support member having a contact face onto which said first face (14) of said semi-finished optical element (11) is to be applied; and
a pneumatic blocking member defining a cavity (30) configured to be closed by said first face (14) of said semi-finished optical element (11), said pneumatic blocking member being configured to sustain a vacuum inside said cavity (30) when closed by said first face (14) of said semi-finished optical element (11) so that said semi-finished optical element (11) is attached to said blocking portion (21);
wherein said support member includes a support element (23) made of a shape-memory material having a rigid state below a predetermined temperature and a plastic state above said predetermined temperature, said support element (23) assuming in the absence of external forces a predetermined memory shape when heated above said predetermined temperature, said contact face of said support member being a surface (25) of said support element (23), and
wherein said cavity (30) is annular and extends around said support element (23).