Ophthalmic Lens Peripheral Rib for Frame Fit

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Solution Overview

Problem

Existing methods for mounting ophthalmic lenses in frames, particularly for strongly arched lenses, result in bevels that are thinner on the edges, leading to poor fit and aesthetics, with visible spaces between the frame and lens, and require multiple finishing wheels for varying relief heights.

Innovation Solution

A method and apparatus for forming a peripheral interlocking rib on the lens edge with a front flank continuous with the lens face and a rear flank, allowing for adjustable height and no rib foot, using tools with or without grooves, to ensure precise fitting and aesthetic alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional finishing wheel with a ribbing groove is used to form a bevel on strongly arched lenses, then the bevel can be formed, but the bevel becomes thinner on the strongly arched parts of the edge of the lens, which penalizes the quality and precision of the mounting

Engineering Contradiction:
Improvemounting precisionVSAvoidbevel thickness uniformity
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The invention changes the geometric parameters of the finishing wheel by providing a specific difference in diameter on either side of the ribbing groove. This parameter modification allows the wheel to compensate for the curvature of strongly arched lenses, maintaining uniform bevel thickness across the lens periphery and ensuring precise mounting quality.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple finishing wheels with different diameter differences are provided to achieve different relief heights, then various relief requirements can be met, but the device complexity and number of tools increase

Engineering Contradiction:
Improverelief height adjustabilityVSAvoidnumber of finishing wheels
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention introduces adjustability to the finishing wheel system, allowing the wheel to be dynamically adjusted to provide different diameter differences on either side of the ribbing groove. This dynamic adjustment capability enables a single wheel to perform the function of multiple fixed wheels, reducing device complexity while maintaining versatility for different relief heights.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the lower part of the flank of the bevel is not covered by the rim of the frame, then the bevel structure is simplified, but there is a visible space between the rim of the frame and the front face of the lens, which is unsightly and conducive to fouling

Engineering Contradiction:
Improvebevel structure simplicityVSAvoidvisible gaps and fouling
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by providing a cylindrical surface called the bevel foot that extends from the front or rear flanks of the bevel to the edge of the lens. This localized structural enhancement at specific areas (the feet of the bevel) ensures coverage by the frame rim, eliminating visible gaps and preventing fouling, while the rest of the bevel structure remains simple.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution ensures a flush fit of the lens within the frame, eliminating visible gaps and the need for multiple tools, improving both the precision and aesthetics of the lens mounting, and simplifying the machining process for strongly arched lenses.

Implementation Method 1

a grinding machine, called a grinder, which has a train of main grinding wheels and locking and driving means

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2046529B1Pair of ophthalmic glasses and method for forming a peripheral mounting rib on the edge of a lens
Publication Date: 2012.04.25 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP2046529B1 patent drawingFigure 1
  • EP2046529B1 patent drawingFigure 2~3
  • EP2046529B1 patent drawingFigure 4~5

AI summary

This pair of glasses comprises : - a frame (200) provided with at least one rim (201) having an inner groove (203), - a lens (100) mounted in said rim (201), the lens (100) having a front surface (101), a rear surface (102), and on its edge, a peripheral mounting rib (120; 130) having a rear flank (122; 132) located on the side of the rear surface (102) of the lens (100) and a front flank (121) located on the side of the front surface (101) of the lens, the front and rear flanks (121, 122; 132) being inserted into the inner groove (203). The front flank (121) of the peripheral mounting rib (130) has at least first order continuity with the rest of the front surface. The edge of the lens has a rear base or shoulder (124). The radial height of the peripheral mounting rib (130), measured between the top of said peripheral rib and the base (124), varies along the periphery of the lens.