Multi Part Blocking Piece

Abstract

The invention refers to a blocking piece, comprising at least two parts, at least one part being designed for multiple use and at least one part being designed for single use, wherein a surface for supporting one face of an optical article to be blocked is constituted at least in part by the reusable part and at least in part by the single use part.

1 . A blocking piece for blocking an optical article, comprising at least two parts, at least one reusable part being designed for multiple use and at least one single use part being designed for single use, wherein a working surface for supporting one face of an optical article to be blocked is constituted at least in part by the reusable part and at least in part by the single use part, wherein the reusable part has a reusable part top surface and the single use part has a single use part top surface, wherein the reusable part top surface and the single use part surface form the working surface, and
 wherein the reusable part has a first annular peripheral surface with a first annular diameter, the first annular peripheral surface extending from the reusable part top surface towards a bottom of the reusable part, and a second annular peripheral surface with a second annular diameter, the second annular surface extending from the first annular surface towards a bottom of the reusable part, the second annular diameter being larger than the first annular diameter, thereby forming an abutting shoulder for the single use part.   
     
     
         2 . The blocking piece according to  claim 1 , wherein the working surface is a continuous and step free surface. 
     
     
         3 . The blocking piece according to  claim 1 , wherein the reusable part top surface and the single use part top surface have the same curvature. 
     
     
         4 . The blocking piece according to  claim 1 , wherein the reusable part and the single use part are arranged concentrically with respect to each other, in particular wherein the single use part is a ring shaped outer part and the single use part is a central block designed to be engaged with the ring shaped part. 
     
     
         5 . The blocking piece according to  claim 1 , wherein the reusable part is configured and arranged with a chucking engaging portion for engagement with a chucking tool as used in a device for generating, polishing, coating etc., wherein the chucking engagement portion is located on an opposite side to the single use part top surface 
     
     
         6 . The blocking piece according to  claim 1 , wherein the reusable part and the single use part comprise at least a mating surface section, in particular the reusable part and the single use part being designed to cooperate snugglingly, by a form fit and/or using connecting means such as thread or clipping means. 
     
     
         7 . The blocking piece according to  claim 1 , wherein the single use part has a third peripheral annular surface extending from the single use part top surface towards a bottom of the single user part, and a fourth annular peripheral surface extending from the third peripheral annular surface towards a bottom of the single use part, wherein the third annular surface cooperates with the first annular surface, and the fourth annular surface cooperates with the second annular surface. 
     
     
         8 . The blocking piece according to  claim 1 , wherein at least one of the first, second, third and fourth peripheral annular surfaces is provided with at least one of a surface characteristics for light scattering or focusing, and of an alternating pattern of reflective elements and non-reflective elements. 
     
     
         9 . The blocking piece according to  claim 1  wherein the reusable part and the single use part have tolerance coping means, in particular a gap design to be filled with a bonding material, in particular the bonding material used during blocking of the optical article. 
     
     
         10 . The blocking piece according to  claim 1  wherein the single use part has axially extending reinforcing ribs. 
     
     
         11 . The blocking piece according to  claim 1  wherein the reusable part is provided with a over-moulded glass insert for strengthening the reusable part. 
     
     
         12 . The blocking piece according to  claim 1  wherein the reusable part comprises and preferably is composed of translucent, in particular transparent material, and wherein at least the single use part is made of plastic material, being translucent and more preferably transparent. 
     
     
         13 . A set of blocking pieces, composed of respectively at least two blocking pieces according to  claim 1 , wherein a first blocking piece is comprised of a reusable part and a single use part, both parts having corresponding surface characteristic with respect to the surface portion intended to support the optical article to be blocked whereas a second blocking piece of said set is composed as a reusable part and a single use part, both having corresponding surface characteristics, different from the optical characteristics of the first blocking piece so as to be suitable for accommodating and supporting optical articles of a family having different shape and/or configuration. 
     
     
         14 . The set of blocking pieces according to  claim 13 , wherein the optical articles to be blocked are optical lenses and wherein the reusable part and the single use part define a common base curve adapted for at least some of the lenses of a lens family, respectively. 
     
     
         15 . The set of blocking pieces as defined in  claim 13 , wherein the set is comprised of five to seven different blocking pieces and/or of blocking pieces being different with respect to each other by at least one dioptre. 
     
     
         16 . The method for manufacturing spectacle lenses using a blocking piece according to  claim 1 , comprising the steps of:
 i. blocking a spectacle lens blank with its blocking face on the working surface of the blocking piece using a blocking material,   ii. processing the blocked spectacle lens blank on the second face and optionally the edge to obtain a processed spectacle lens, and   iii. releasing the processed spectacle lens from the block piece, wherein the spectacle lens blank remains on the proposed block piece throughout the whole processing stage or step (ii).   
     
     
         17 . The method for manufacturing spectacle lenses using a set of blocking pieces according to  claim 13 , comprising the steps of:
 i. blocking a spectacle lens blank with its blocking face on the working surface of the blocking piece using a blocking material,   ii. processing the blocked spectacle lens blank on the second face and optionally the edge to obtain a processed spectacle lens, and   iii. releasing the processed spectacle lens from the block piece, wherein the spectacle lens blank remains on the proposed block piece throughout the whole processing stage or step (ii).