Abstract: The frame holder for prescription glasses (24) of the type featuring two jaws mounted in such manner that they slide in relation to each other so that they can move toward or away from each other, and also featuring a device (22) to center the frame (24) between the jaws (12) so as to hold said frame (24) in a reference plane (P), characterized by the fact that it features a device (30) to support frame (24) approximately in the reference plane (P) before the frame (24) is clamped inside the jaws (12).

Abstract: The invention provides a machine for grinding and bevelling ophthalmic glasses of the type comprising a carriage (1) mounted to be movable in translation and in oscillation in a direction parallel with and perpendicular to a shaft (5) carrying at least one grinding wheel (4, 4A), and means for measuring the distance (L1) between the plane (PO) tangent to the pole (0) of the convex face of the glass (3) and the edge of the convex face, characterized in that the measuring means comprise means defining a reference surface (S) which is connected to move axially in translation with the grinding wheel, extends in a radial plane perpendicular to the axis of rotation of the grinding wheel and with which at least one point of the edge (A) of the convex face of the glass (3) is brought into contact by a movement in translation of the carriage (1), a sensor (18) for measuring the movements in translation of the carriage (1) relative to the grinding wheel (4) and means (12) for analyzing and processing signals from the s

Abstract: Machine for grinding and bevelling ophthalmic lenses of the type comprising a carriage movable in translation and in oscillation in directions parallel to and perpendicular to a shaft carrying grinding wheels for edge trimming (4) and bevelling, and a follower (7) for measuring the distance between the plane tangent to the pole of the convex surface of the lens and the edge of the surface and for measuring the value which corresponds to the width of the edge surface (12) of the lens (3). The follower (7) has a surface (8) having a convex curvature identical to that of the grinding wheel and which comprises a matrix of detection elements which cooperate with the edge surface (12) of the lens. Each of the detection elements is connected to a corresponding portion of a sensor (14) to which it transmits a signal representing the passage of a part of the edge surface (12) of the lens in front of the corresponding detection element.

Abstract: The apparatus comprises a device which explores without contact the inner contour of the frame rim (16) and employs an optical device (30) for sensing the image of characteristic points of the rim inner contour, an analyzer for analyzing the sensed images for determining the spatial coordinates of the characteristic points, and a calculating device for reconstituting the shape and/or the profile of the contour of the frame rim from these spatial coordinates.

Abstract: In a method employed by the device, the distance between a shaft (14) of a grinding wheel (13) and a shaft (5) carrying a finished glass (7) in contact with the grinding wheel, is measured by means of a microprocessor (18) controlling a shifting device (11), by bringing a tracer member (9) in contact with a template (8) mounted on the shaft (5), a standard disk (20) being mounted on the shaft (14) coaxial with the grinding wheel (13) for measuring the distance between the shaft (14) and the shaft (5) by bringing the standard disk in contact with the finished glass.

Abstract: A machining and bevelling tool, which is adaptable to a standard grinding machine for ophthalmic glasses, includes a metal body (1) having in its periphery a V shaped groove (2) and at least two teeth (3) each in the form of a small inserted plate (4) presenting a notch of corresponding V shape which protrudes in said groove (2), a shallow adjacent recess (8) being provided in front of each tooth (3), considering the direction of rotation of the tool. The diameter of the tool is larger than that of an ophthalmic glass, and substantially equal to that of a standard grinding wheel for ophthalmic glasses.

Abstract: A glasses frame carrier for a reproducing machine, of the type comprising a base plate (1), two parallel strips (8, 9) slidably mounted on the base plate are relatively movable toward and away from each other, and a device for centering the glasses frame between the two strips. The strips are respectively fixed to opposed parallel portions of a cable (16) forming a loop around two spaced-apart pulleys, one pulley (14) constituting a cable-driving element (16) and including a braking device (21, 23, 24) which is adjustable and constituted by an elastic element (23) which biases the pulley (14) in contact with a friction element (21).