POLISHING DISC FOR A TOOL FOR FINE PROCESSING OF OPTICALLY EFFECTIVE SURFACES ON SPECTACLE LENSES

• US 20170246729A1
• Filed: 09/16/2015
• Published: 08/31/2017
• Est. Priority Date: 10/15/2014
• Status: Active Grant

• Current Assignee: Satisloh AG (EssilorLuxottica SA)
• Original Assignee: Satisloh AG (EssilorLuxottica SA)
• Inventors: Philipps, Peter, Kaufmann, Andreas, Wallendorf, Steffen, Schfer, Holger
• Granted Patent: US 10,569,387 B2
• Time in Patent Office: Days
• CPC Class Codes: B24B 13/012 conformable in shape to the optical surface, e.g. by fluid pressure acting on an elastic membrane
• CPC Class Codes: B24B 13/02 by means of tools with abrading surfaces corresponding in shape with the lenses to be made
• CPC Class Codes: B24D 13/147 comprising assemblies of felted or spongy material; comprising pads surrounded by a flexible material
• CPC Class Codes: B24D 9/003 Wheels having flaps of flexible abrasive material supported by a flexible material

Abstract

The invention relates to a polishing disc for a tool for fine processing optically active surfaces on spectacle lenses, having a main body which has a central axis and to which an intermediate layer that is softer than the main body and is made of a resilient material is secured, a polishing medium carrier resting on the intermediate layer. The intermediate layer has at least two regions with different degrees of hardness, said regions being arranged one behind the other in the direction of the central axis of the main body. The intermediate layer region adjoining the main part is softer than the intermediate layer region on which the polishing medium carrier rests.

Claims

1. A polishing disc for a tool for fine processing of optically effective surfaces on spectacle lenses, comprising a base body which has a center axis and to which is secured an intermediate layer, on which a polishing medium carrier rests, of a resilient material, the intermediate layer being softer by comparison with the base body, characterized in that the intermediate layer has at least two regions of different hardness arranged in succession in the direction of the center axis, wherein the region of the intermediate layer adjoining the base body is softer than the region of the intermediate layer on which the polishing medium carrier rests.

2. A polishing disc according to claim 1, characterized in that the at least two regions of the intermediate layer are formed by mutually different foam material layers, namely at least one softer foam material layer on the base body and at least one harder foam material layer under the polishing medium carrier.

3. A polishing disc according to claim 2, characterized in that the mutually different foam material layers are glued together.

4. A polishing disc according to claim 3, characterized in that the ratio of the substantially constant thickness of the harder foam material layer to the substantially constant thickness of the softer foam material layer is between 1 to 2 and 1 to 4, the thicknesses being measured along or parallel to the center axis.

5. A polishing disc according to claim 2, characterized in that as determined for the case of whole-area compression the static modulus of elasticity of the harder foam material layer is between 0.40 and 1.50 N/mm², whereas the static modulus of elasticity of the softer foam material layer is between 0.25 and 0.45 N/mm².

6. A polishing disc according to claim 2, characterized in that the softer foam material layer is made from an at least partly open-pore polyetherurethane elastomer, whereas the harder foam material layer is made from of a closed-cell polyetherurethane elastomer.

7. A polishing disc according to claim 1, characterized in that the base body has a substantially spherical end surface which faces the intermediate layer and to which the intermediate layer is secured, in particular firmly glued, wherein the end surface has a radius of curvature (R_G) of between 35 and 42 mm.

8. A polishing disc according to claim 7, characterized in that the base body has a diameter between 35 and 60 mm in the region of its end surface, wherein the substantially constant thickness of the intermediate layer is between 15 and 22 mm as measured along or parallel to the center axis.

9. A polishing disc according to claim 8, characterized in that the polishing medium carrier protrudes in radial direction with respect to the center axis (M) at all sides beyond the intermediate layer.

18. A polishing disc according to claim 4, characterized in that the ratio of the substantially constant thickness of the harder foam material layer to the substantially constant thickness of the softer foam material layer is approximately 1 to 3, the thicknesses being measured along or parallel to the center axis.

19. A polishing disc according to claim 5, characterized in that as determined for the case of whole-area compression the static modulus of elasticity of the harder foam material layer is between 0.80 and 1.00 N/mm², whereas the static modulus of elasticity of the softer foam material layer is between 0.35 and 0.45 N/mm².

20. A polishing disc according to claim 7, characterized in that the base body has a substantially spherical end surface which faces the intermediate layer and to which the intermediate layer is secured, in particular firmly glued, wherein the end surface has a radius of curvature of between 36 and 40 mm.

10. A tool for fine processing of optically effective surfaces at spectacle lenses, comprising a tool mounting head securable to a spindle shaft of a tool spindle to be capable of axial and rotational entrainment, characterized in that a polishing disc for a tool for fine processing of optically effective surfaces on spectacle lenses, said polishing disc comprising a base body which has a center axis and to which is secured an intermediate layer, on which a polishing medium carrier rests, of a resilient material, the intermediate layer being softer by comparison with the base body, wherein the intermediate layer has at least two regions of different hardness arranged in succession in the direction of the center axis, wherein the region of the intermediate layer adjoining the base body is softer than the region of the intermediate layer on which the polishing medium carrier rests is exchangeably mounted on the tool mounting head, wherein for mounting purposes the base body of the polishing disc and the tool mounting head are provided with complementary structures for axial detenting and rotational entrainment of the polishing disc with and by the tool mounting head.

11. A tool according to claim 10, characterized in that the tool mounting head has a ball joint with a ball head which is received in a ball socket and which is formed at a ball pin securable to the spindle shaft of the tool spindle, the ball socket being formed in a mounting plate with which the polishing disc is detentable.

12. A tool according to claim 11, characterized in that the ball head has a receiving bore for a transverse pin which extends through the ball head and engages on either side of the ball head in associated recesses in the ball socket so as to connect the mounting plate with the ball pin to be capable of rotational entrainment.

13. A tool according to claim 12, characterized in that the mounting plate is resiliently supported on a support flange at the ball-pin side by way of a resilient annular element so that the polishing disc detented with the mounting plate seeks to self-align by its center axis with the ball pin and thus the spindle shaft of the tool spindle.

14. A tool according to claim 13, characterized in that the base body of the polishing disc and the tool mounting head are each provided with a respective radially protruding collar, wherein the collars in the state in which the polishing disc is mounted on the tool mounting head are opposite one another and mechanically positively engaged over by a securing ring with a substantially U-shaped cross-section.

15. A tool according to claim 14, characterized in that the securing ring is formed by two half rings which are pivotably connected together on one side by use of a hinge and are releasably detentable together on the other side by way of a snap connection.

16. A tool according to claim 11, characterized in that the mounting plate is resiliently supported on a support flange at the ball-pin side by way of a resilient annular element so that the polishing disc detented with the mounting plate seeks to self-align by its center axis with the ball pin and thus the spindle shaft of the tool spindle.

17. A tool according to claim 10, characterized in that the base body of the polishing disc and the tool mounting head are each provided with a respective radially protruding collar, wherein the collars in the state in which the polishing disc is mounted on the tool mounting head are opposite one another and mechanically positively engaged over by a securing ring with a substantially U-shaped cross-section.