English to Japanese Tech/Engineering Engineering: Industrial Device for centering clamping

The above-described bell clamp method reaches its limits in the case of lenses with only slightly curved optical surfaces. Below a certain value of the angle, also designated as the ***centering angle***, formed between a tangent to the edge of the one optical surface of the lens at the clamping point (= contact point of the bell clamp) and a tangent to the edge of the other optical surface at the clamping point when viewed in radial section, self-locking arises, which prevents transverse movement of the lens relative to the bell clamps.