Abrading – Abrading process – Glass or stone abrading
Patent
1997-04-18
1999-10-12
Morgan, Eileen P.
Abrading
Abrading process
Glass or stone abrading
451 57, 451256, 451325, B24B 914
Patent
active
059646470
DESCRIPTION:
BRIEF SUMMARY
The present invention concerns spectacle lenses made of rigid material.
In this context, the expression "spectacle lenses" refers in the usual way to positive or negative focal power blanks usually having a circular initial contour and which have to be trimmed to fit the specific contour of a spectacle frame to which they are to be fitted.
It applies equally to finished products, that is to say products both faces of which already have their final profile, and semi-finished products, that is to say products where at least one face has still to be worked until it has the final profile.
In all cases their edge surface or peripheral rim is globally cylindrical and each face intersects it along an edge which at present is a sharp edge and which is therefore relatively fragile, given the rigid material from which they are made.
Such spectacle lenses are usually subjected during production and before trimming, to be more precise before they are shipped to the practitioners who usually carry out such trimming, to a certain number of manipulations necessary, for example, for dipping them into various treatment solutions, for example washing and coating solutions and solutions of other types.
Given the fragile nature of their edges, in particular in the case of spectacle lenses made from organic materials, such manipulation almost inevitably leads to the separation of small flakes of material along these edges, often called "flashes".
Accordingly, at the present time spectacle lenses of this type are usually shipped to practitioners with edges that are chipped to a greater or lesser degree.
Of course, the visible damage to which these spectacle lenses are subjected in this way is in practise of no consequence for their subsequent use, since it affects a portion of them that is trimmed off.
From the commercial point of view, however, it is prejudicial to their esthetic appearance.
Moreover, and more importantly, the flakes that chip off the spectacle lenses in question when they are manipulated inevitably pollute the corresponding treatment solutions, in which they progressively accumulate.
These treatment solutions must therefore be renewed from time to time, which is detrimental from the cost point of view.
If they were not renewed from time to time, the flashes that they contain could find their way onto the spectacle lenses dipped in them.
The present invention consists firstly in a method and a device for avoiding these problems by remedying the fragility of at least one edge of a rigid material spectacle lens, in practise each edge; the present invention also consists in any rigid material spectacle lens in which the fragility of at least one edge has been remedied in this manner.
In accordance with the invention, an edge of this kind is replaced by a globally rounded connecting surface which preferably merges substantially tangentially with the edge surface at least of the spectacle lens and which, even more preferably, merges substantially tangentially both with the edge surface of the spectacle lens and with the corresponding face of the latter.
In practise this is effected by machining the lens, by applying a deburring tool to the edge to be treated, with the deburring tool rotating relative to the spectacle lens about the axis of the latter.
In use, deburring tool can preferably pivot relative to the spectacle lens about a pivot axis orthogonal to the axis of the lens, with this pivot axis displaced along a path contained in a plane passing through the axis of the spectacle lens and globally oblique to the latter.
Although extending only a short distance onto the edge surface of the spectacle lens and the face concerned of the latter, the connecting surface provided in accordance with the invention between the edge surface and the face advantageously provides a particularly simple and effective way of preventing flakes being chipped off the periphery of the spectacle lens during its subsequent manipulation.
Published French patent application No 2 184 473 discloses the application of a tool to the edge su
REFERENCES:
patent: 3528326 (1970-09-01), Kilmer et al.
patent: 3641991 (1972-02-01), Haber
patent: 3736115 (1973-05-01), Blum
patent: 3778936 (1973-12-01), Steadman
patent: 5056270 (1991-10-01), Curcher
patent: 5149337 (1992-09-01), Watanabe
patent: 5158422 (1992-10-01), Wagner
patent: 5299394 (1994-04-01), Surdacki
patent: 5454748 (1995-10-01), Gottschald
Essilor International "Compagnie Generale d'Optique"
Morgan Eileen P.
LandOfFree
Method and device for remedying the fragility of the edges of a does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for remedying the fragility of the edges of a , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for remedying the fragility of the edges of a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-646826