Eyeglass Lens Blank Machining with Cured Connecting Material
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Solution Overview
Problem
Existing methods for supporting spectacle lens blanks during machining, such as using plastic block pieces, face issues with inadequate holding power and deformation of the lens, which affect the geometry and machining precision.
Innovation Solution
A machining method that involves reducing the size of the spectacle lens blank and connecting material during machining processes, allowing for almost complete support by the connecting material, with the diameter of the sealing or support means being independently selected to maximize support and maintain precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If plastic block pieces are used to support spectacle lens blanks, then the block pieces provide sufficient support, but the adhesive materials lack holding power and require pressing that deforms the lens
Solution Approach 1:
The patent changes the physical state of the connecting material from solid adhesive to liquid form that is subsequently cured. The connecting material is applied in liquid form, allowed to flow and conform to the lens surface, then cured to achieve strong bonding without requiring pressing that would deform the lens, thereby resolving the contradiction between holding power and manufacturing precision
Solution Approach 2:
The connecting material undergoes a phase transition from liquid to solid through curing. In liquid form, it can flow and adapt to the lens geometry without pressure; after curing, it achieves high strength bonding, thus eliminating the need for deforming pressing while maintaining both ease of application and strong holding power
2Ease of manufacture
If plastic block pieces are used to support spectacle lens blanks, then the block pieces are easy to manufacture, but they have very low strength affecting holding position in machine tool chuck
Solution Approach 1:
The patent uses a composite system combining a plastic block piece with a specialized connecting material. The block piece provides ease of manufacture and basic support structure, while the connecting material (which may be metal alloy or other high-strength material) provides the necessary holding strength for machine tool chucking, thus resolving the contradiction between ease of manufacture and strength
3Strength
If spectacle lens blank is supported only in area that will not be machined, then the connecting material provides support, but the blank cannot be reduced to final diameter until block piece and connecting material are removed
Solution Approach 1:
The patent extracts the connecting material from the final product by designing it to be removable after the lens is machined to final diameter. The connecting material provides support during machining but is then removed, allowing the lens to be fully machined including reduction to final diameter, thus resolving the contradiction between support strength and machining efficiency
Solution Approach 2:
The block piece and connecting material are attached to the lens blank before machining begins, providing preliminary support and positioning. This allows the lens to be securely held during all machining operations including diameter reduction, and the block piece is removed only after machining is complete, improving productivity by enabling complete machining before removal
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
Ensures optimal machining of spectacle lens blanks with almost 100% support, maintaining precision and preventing deformation, while allowing for the production of various shapes and sizes, including non-round forms.
Implementation Method 1
the connecting material is filled into the cavity or the connecting material is already provided in the cavity and is subsequently cured
Data Source
AI summary
A machining method for an eyeglass lens blank in which a bock piece is connected, by way of a connecting material, to a first side of the eyeglass lens blank for holding and supporting the eyeglass lens blank in a processing machine, wherein to this end a cavity is made between the block piece and the first side, at least using a sealing or supporting means, wherein the sealing or supporting means has an inner diameter Dd, Ds and sits against the first side in a sealing manner, the connecting material is filled into the cavity or connecting material is provided in the cavity and then the connecting material is cured, the eyeglass lens blank is placed into a milling and/or turning or grinding machine by way of the block piece cast on by way of the connecting material, wherein the eyeglass lens blank is supported on the first side by the connecting material across a diameter Dv that corresponds to the diameter Dd, Ds and wherein the blank and the connecting material are worked off in one of the following machining processes. An eyeglass lens blank having a diameter Dr, said blank being fastened to a block piece through the cast-on connecting material, wherein the connecting material has an outer diameter Dv. The diameter Dv is at most 2 mm to 6 mm, in particular at most 4 mm and is less than diameter Dr.