Abstract: The invention relates to a spectacle frame of the kind comprising a main structure (10) and, for each lens (11) to be mounted, a surround which is formed, on the one hand, from an upper rim (12), and, on the other hand, from a flexible rim cord (13).According to the invention, for at least one of the ends of the said flexible rim cord, four holes are provided in combination, two holes (14) being formed in the main structure (10), and two holes (26) being formed in correspondence in the upper rim (12), so that the said rim cord (13) fastens this upper rim (12) to the main structure (10).

Abstract: An eyeglass frame in which the rims are openable at their inner (nose) sides. A slot is defined between a pair of pins extending between the rims. A latching member is pivotally mounted on one of the pin and hooks onto the other pin in its closed position for closing the rims and clamping the associated lens therein. An overlay member may be provided on the visible side of the latching member.

Abstract: An eyeglass frame having open ended rims closed by screw assemblies for clamping lenses therein is disclosed. Each screw assembly comprises a machine screw having a head which defines a bearing surface, a nut threadedly engageable with the threaded shank of the screw, and integrally formed with a lug at one end of the open rim, and an insert member integrally formed with a lug at the other end of the open rim and having a cooperable bearing surface. Dog clutches are formed on the bearing surfaces and preferably comprise alternating projecting portions and recesses in an annular array. The dog clutches normally prevent loosening of the screw assembly by limiting the degree of relative angular displacement between the bearing surfaces, but the gap between the lugs and the resilience of the rims permits unscrewing of the assembly to remove the lens without damaging any of the parts of the assembly.

Abstract: The invention relates to a support adapted to receive, in movable manner, a glasses frame portion and comprising for this purpose assembly means of the push-button type. According to the invention, these assembly means are integral with the support in question (which is a horizontal bar in the embodiment shown by way of example), being moulded in one piece therewith; they comprise a support plate drilled with a hole and a hinged retaining tab provided with a projecting lug which fits the hole. Application particularly to glasses for use in sports, worn under a helmet.

Abstract: This is a method of decalcomania by thermic transfer, the pattern to be printed upon the substrate (10) to be decorated being produced by means of sublimable inks upon a flexible support skin (15) and the latter being applied to the said substrate (10) in a vacuum chest (20) with which heating means (38) are associated.According to the invention, the closure of the vacuum chest (20) is effected by the flexible support skin (15).Application particularly to the decoration of a spectacle frame front. FIGS.1 to 8 attached.

Abstract: A method and mould for moulding material requiring heat treatment for setting or curing, e.g., for making ophthalmic lenses. The mould comprises an annular gasket and two opposed die members which together define a moulding cavity. One of the die members is made in part of a fusible material, e.g. paraffin wax, which defines its moulding surface. After filling the mould the moulding material is subjected to heat treatment. The drop point or softening point of the fusible material falls within the range of temperatures of heat treatment so that in the course of such heat treatment of fusible material effectively releases the moulded material. This relieves stresses which would otherwise develop due to shrinking of the moulded material.

Abstract: An ophthalmic lens made of organic material has at least one layer of photochromic mineral glass within its mass to impart photochromic properties to the lens. This layer has a fibrous structure and may comprise a piece of woven fabric produced from fibres of photochromic mineral glass possessing a refractive index and a coefficient of chromatic dispersion which are equal to those of the constituent organic material of the lens.

Abstract: Method and apparatus for presenting test images to a subject at different distances and a constant visual angle. The test indicia are located at a single predetermined distance from the viewer. An optical system is provided between the test indicia and the viewer for including a lens system and at least one reflecting element or plane mirror. Displacements of the lens system along its optic axis and the plane mirror(s) along an axis parallel to a continuation of the lens system optic axis are coordinated so that the visual angle for the viewer remains the same regardless of the distance of the test image from the viewer. A single set of test indicia may be used for all potential image distances without having to vary the visual angle.

Abstract: A process of integrating a photochromic substance, especially a spiropyran or a metal dithizonate, into a transparent substrate of polymerized organic material such as poly [ethylene glycol di-allyl di-carbonate] by thermal transfer, comprising applying the photochromic substance alone or with a solvent and/or thickening agent to the surface of a transparent organic substrate such as a lens disc, and heating until the photochromic substance is sublimed and then diffused and anchored in the organic material of the lens, preferably just beneath the surface to which it is applied. Preferably, the photochromic substance is initially carried on a temporarily support for application.

Abstract: An ophthalmic lens is described having a front face which is a surface of revolution and is located entirely in front of the transverse plane tangential to its center. The curve representing the half-meridian of this front face corresponds to the following general formula:x=ay.sup.2 +by.sup..alpha. +cy.sup..gamma.in which the coefficient a is different from zero and negative, at least one of the coefficients b and c is different from zero and positive, .alpha. is a real number which is greater than or equal to 3 and less than 4, and .gamma. is a real number which is greater than or equal to 4.

Abstract: The invention relates to the production of spectacle frame parts of synthetic material and in particular to the moulding of spectacle frame faces of synthetic material, for example, of polyurethane.The faces are moulded between two casting half-moulds each comprising a plate having an impression on one surface thereof. Each plate has a substantially equal thickness at every point and is made of a polyolefine. Use of such half-moulds enables the faces of spectacle frames to be directly moulded into their final shape.

Abstract: A hub is disclosed for mounting the spindle of a rotary tool, particularly a grinding or polishing wheel for ophthalmic lenses. The hub comprises a cylindrical bore and a plurality of radial centering arms arranged around the bore with their free ends lying in a common circle concentric with the axis of the bore. The centering arms each have a hinge or pivot which may be formed by a portion of reduced section at their bases. The pivot or hinge axes of the centering arms are tangent to another common circle concentric with the bore. Each of the centering arms is of elastically deformable construction fixed, or formed in one piece, with the rest of the hub. The hub is divided by a radial groove into a rigid, one-piece part and a deformable flange formed by the centering arms. A tightening ring with a preferably planar thrust or engagement face is adapted to apply an axial force against the centering arms so that they come into retaining engagement with the spindle.

Abstract: Apparatus for machining, polishing and/or smoothing workpieces having curved surfaces such as optical or ophthalmic lenses. A bearing head maintains a tool against a workpiece. Pressure is applied by a pneumatic piston and cylinder unit for establishing contact pressure between the workpiece and the tool. An eccentric drive mechanism including a compound table generates relative displacement between the workpiece and the tool. The pneumatic piston and cylinder unit actually forms part of the tool holder spindle. The cylinder or piston rod of the unit is provided with a tool holder block mounting the tool and the other of the piston rod or cylinder is attached to the drive mechanism. The bearing head has a freely rotating position and a locked position preventing rotation.

Abstract: A method of marking an ophthalmic lens of organic material and the lens so marked. A marking substance containing an optical brightener which is a derivative of benzoxazolyls stilbenes, or benzotriazoles is mixed with a suitable binder and solvent and applied to a surface of the lens to be marked by thermal transfer from a transfer support. The marking substance is shaped to the desired configuration either when applied to the transfer support or by a mask defining the mark or indicia to be applied. Heat is applied to the marking substance and the lens which sublimes the optical brightener which then penetrates into the organic material of the lens to be anchored therein. The resultant indicia or mark provides a permanent marking of the lens and is only visible in ultra-violet light.

Abstract: The invention relates to a polishing material of the type containing powdered cerium oxide suspended in water.According to the invention, this polishing material also contains, in combination, a substance for use as a thickener and a substance for reducing the surface tension.The polishing material is particularly useful for polishing ophthalmic lenses made from organic materials.

Abstract: A molding assembly for casting soft contact lenses especially such lenses formed of hydrophobic material. Such a molding assembly comprises a molding cavity defined by the dies of the assembly and an annular gasket or sealing member joining the peripheries thereof. The perimeter of largest diameter of the molding cavity is defined by contact between a sealing ridge which is part of the concave die or the gasket or sealing member and a bearing surface which is part of the other of the concave die or the gasket or sealing member.The annular gasket or sealing member may have an annular skirt adapted to embrace the concave die in the closed position of the assembly.The gasket or sealing member is carried by the convex die and may be integrally formed in one piece with the convex mold.

Abstract: Two metallic half-moulds are produced from a prototype. The half-moulds have complementary mould faces which abut when the mould is closed, and moulding surfaces formed with annular rim depressions joined by a bridge cavity, each rim depression bordering a support surface for a false lens. A webbed frame front is moulded, false lenses are cut from that moulded front, and the mould faces which abut are set-back by a total amount corresponding to the shrinkage of the false lenses, so that the false lenses are gripped between the support surfaces and shape lens bezels in the rims when a frame front is moulded.

Abstract: A machine for the surfacing of ophthalmic lenses has a working head in which a supporting finger is axially mounted on a pivotable arm. Pivoting of the arm causes the supporting finger to approach a working station. The arm carries actuating means for the supporting finger which control the approach of the finger towards the working station and control the pressure applied by the finger at the working station. In addition, damping means are provided for damping oscillation and vibrations of said supporting finger.

Abstract: The invention relates generally to the production of ophthalmic lenses having, on one face, an active zone of progressively variable radius of curvature.According to the invention, when the blank from which such a lens is obtained is being cast, there is formed, on the periphery of its active zone, an edge region or facet extending continuously and circularly right round the said active zone for the subsequent support of the mould which is used to enable a gripper block to be cast on the face of the blank so as to enable a second machining operation to be carried out on the opposite face of the blank.

Abstract: A feeler for reading the contour of the rim of a spectacle frame has a reading head on a rod carried by a support which is linked by a ball joint to a fixed base. A cylindrical skirt on the support co-operates with the base and with a displacement detector which provides an indication which is employed to maintain contact of the rim with the reading head.