Abstract: A predictive calculation method for calculating the shape of a cross-section of an engagement ridge of an ophthalmic lens obtained by beveling the lens with a beveling grindwheel driven in accordance with an initial path setting. The method includes the following steps: acquiring the initial path setting for the beveling grindwheel relative to the lens; determining at least two approximations (Sii, Sij) of the shape of the cross-section under consideration of the engagement ridge, the approximations being deduced from the intersection between the beveling grindwheel and the ophthalmic lens when the beveling grindwheel is situated at two distinct positions of the initial path setting; determining the intersection between these two approximations; and deducing therefrom the shape (Si) of the cross-section under consideration of the engagement ridge.

Abstract: A predictive calculation method for calculating the shape of a cross-section of an engagement ridge of an ophthalmic lens obtained by beveling the lens with a beveling grindwheel driven in accordance with an initial path setting. The method includes the following steps: acquiring the initial path setting for the beveling grindwheel relative to the lens; determining at least two approximations (Sii, Sij) of the shape of the cross-section under consideration of the engagement ridge, the approximations being deduced from the intersection between the beveling grindwheel and the ophthalmic lens when the beveling grindwheel is situated at two distinct positions of the initial path setting; determining the intersection between these two approximations; and deducing therefrom the shape (Si) of the cross-section under consideration of the engagement ridge.

Abstract: A hardened asbestos-free, porous, calcium silicate filler material for an acetylene storage vessel is made by mixing quicklime with water to form a first mixture. Then ground quartz silica is added to form a second mixture. A fibrous reinforcing material is blended in to form a third mixture. A precipitated silica (or synthetic silica) is added and homogenized to form a fourth mixture. The fourth mixture is transferred into a cylinder to be filled and is cured under saturated steam pressure. Thereafter, the cylinder is dried. A gas storage cylinder so formed has a monolithic dry mass filling a metal shell. The mass has a porosity of about 88 to 92%, a density in the range of 250 g/l to 350 g/l, and a crush strength of 250 to 550 psig.