Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B9/00—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor
  • B24B9/02—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground
  • B24B9/06—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain
  • B24B9/08—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass
  • B24B9/14—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms
  • B24B9/144—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms the spectacles being used as a template

Definitions

• a lens thus machined has a contour that rarely corresponds exactly to the outline of the bezel of his entourage. It may then be too large, which forces the optician to perform a tedious recovery of the machining of the nesting rib, too small.
• the shapes acquired in the database are generally slightly different from the actual shapes of the bezel crates selected by the wearer.
• the lenses machined according to these acquired shapes are not always mountable in the surroundings of the selected frame, so that it is often necessary to resume the machining of their interlocking ribs.
• the difference between the maximum value and the minimum value is less than 0.3 millimeters.
• FIGS. 7A and 7B are sectional views of the slices of two ophthalmic lenses cut in two different embodiments;
• FIGS. 8A and 8B are sectional views of a nesting rib of an ophthalmic lens fitted into a bezel of an eyeglass frame at a bearing section and at a singular section; of freedom ;
• a horizon line A3 (FIG. 6) which is substantially horizontal when the spectacle frame 10 is carried by the wearer in the orthostatic position, that is to say when the wearer is standing and holding his head upright.
• the horizon line A3 here corresponds more particularly to the straight line which passes opposite the two pupils of the wearer. It is characteristic of the orientation of the spectacle frame 10 and the ophthalmic lens 20.
• the ophthalmic lens 20 has a front optical face 21 convex and a concave rear optical surface 22, and a peripheral edge 23 whose initial contour 27 (Figure 6) is generally circular.
• This longitudinal profile 25 corresponds to a line running along the song
• a box frame 26 can be defined relative to the longitudinal profile 25.
• a frame 5 In the space left visible by the upper central opening of the cover 2, a frame 5 is visible.
• a plate (not visible) can move in translation on the frame 5 along a transfer axis D1.
• On this plate is rotatably mounted a turntable 6. This turntable 6 is therefore able to take two positions on the transfer axis D1, opposite each of the two surrounds 11 of the spectacle frame 10.
• the contour reading apparatus 1 comprises actuating means (not shown) adapted, firstly, to slide the support rod 8A along the lumen 7 in order to modify its radial position R with respect to the B1 rotation axis of the turntable 6, a second part, to vary the TETA angular position of the turntable 6 about its axis of rotation BI, and, thirdly, to position the probe finger 8B of the probe 8 at a greater or lesser altitude Z relative to the plane of the front face of the turntable 6.
• actuating means (not shown) adapted, firstly, to slide the support rod 8A along the lumen 7 in order to modify its radial position R with respect to the B1 rotation axis of the turntable 6, a second part, to vary the TETA angular position of the turntable 6 about its axis of rotation BI, and, thirdly, to position the probe finger 8B of the probe 8 at a greater or lesser altitude Z relative to the plane of the front face of the turntable 6.
• the contour reading apparatus 1 furthermore comprises an electronic and / or computer device 9 making it possible, on the one hand, to drive the actuating means of the contour reading apparatus 1, and, on the other hand, to acquire and record the coordinates rai, tetaai, za ⁇ of each point palpated of the bezel 13.
• such a trimming apparatus 30 generally comprises support means here formed by shafts 31 for holding and rotating the ophthalmic lens 20 around a locking pin A1 coincides with the central axis of the lens.
• Such a trimming apparatus further comprises trimming means here formed by a machining tool 32 rotatably mounted about an axis of rotation A2 which is here substantially parallel to the locking axis A1, but which could also be inclined relative to this axis.
• the machining tool 32 and / or the shafts 31 are provided with two relative mobilities, including a radial mobility that makes it possible to modify the spacing between the axis of rotation A2 and the blocking axis A1, and translational mobility. axial along an axis parallel to the blocking axis A1.
• the constant k is calculated conventionally according to the architectures of the contour reading apparatus 1 and the contouring apparatus 30, as well as to the shapes of the cross sections of the bezel of the surround of the frame and the bevelling groove of the main grinding wheel 33.
• This constant k makes it possible in particular to take into account the fact that, once the lens is nested in the surrounding area, the top of the interlocking rib (corresponding to the longitudinal profile deduced 25) is never in contact from the bottom of the bezel (corresponding to the acquired longitudinal profile 12) but is slightly offset relative to the latter (FIGS. 8A and 8B).
• the points of support are points where the interlocking rib 24 will be machined in a conventional and uniform manner, so that the nesting rib fits into the bezel 13, and that the singular points of freedom are points where the interlocking rib 24 will be machined in a particular and non-uniform manner, such that the interlocking rib does not fit completely into the bezel 13.
• the calculation means can select a larger number N of singular points of freedom P17-P20 regularly distributed along the longitudinal profile deduced 25, that is to say, separated from each other. others of the same length d in curvilinear abscissa.
• the starting singular point of freedom P7 of this distribution can be chosen randomly by the calculation means or can be predetermined. Its angular position can for example be set at 240 degrees. Once positioned on the longitudinal profile deduced 25, this singular point of freedom P17 allows the computing means to position the twenty-six other singular points of freedom P18-P20 on the longitudinal profile.
• said singular points of freedom are chosen to be spaced at most twenty millimeters in curvilinear abscissa along the interlocking rib 24 or at most thirty degrees around the central axis A1.
• the calculation means can select a very large number of singular points of freedom P37-P40. For the sake of clarity, only three of these singular points of freedom are referenced in this figure.
• the calculation means can determine the total length of the longitudinal profile deduced 25, then divide this length by thirty in order to regularly spacing the thirty singular points of freedom along this longitudinal profile.
• Each singular portion of freedom is then defined as being centered on a singular point of freedom and having a length equal to one thirtieth of the total length of the longitudinal profile deduced.
• the calculation means may regularly space the thirty singular points of freedom around the central axis A1 with an angular spacing of 12 degrees.
• Each singular portion of freedom will then be defined as being the portion of the longitudinal profile deduced 25 centered on a singular point of freedom, the ends of which are angularly spaced from each other by 12 degrees.
• the calculation means can randomly select at least fifteen singular points of freedom P41-P55 on the first longitudinal profile 25. More particularly, the number N of singular points of freedom being fixed, by example equal to 15, the calculation means may randomly choose fifteen points from the 360 points of the longitudinal profile deduced 25. This choice may, however, be made provided that these points are spaced from each other by a separation angle greater than 5 degrees.
• the calculation means then define as singular portions of freedom Z41-Z55 of the longitudinal profile deduced 25, the parts of this profile which are centered around these singular points of freedom P41-P55 and which have predetermined lengths, for example equal to 12 millimeters.
• the calculation means can then select the sixteen singular points of freedom P72-P87 of the longitudinal profile deduced 25 located on half-lines of the plane of the boxing frame which are born at the geometric center C1 and which are inclined by 4 or 12 degrees by relation to the four half-lines which are born at the level of the geometric center C1 and which pass through the remarkable points H1-H4. At least half of these sixteen singular points of freedom are then located within 5 millimeters of the remarkable points.
• the electronic and / or computer device of the trimming apparatus 30 will control the radial mobility of the grinder and / or the shafts 31 to position a second conical end portion 38 of the grinder 37 against the slice. the lens, on the side of its back side. Then, the grinder 37 and the support shafts 31 of the lens will be driven to form the trailing edge of the engagement rib 24.
• this steering will be realized so that the trailing edge of the interlocking rib is located at a constant distance from the front face of the lens, except in the singular portions of freedom where it will approach the front face.
• the nesting rib of the Ophthalmic lens will thus present a local narrowing of height and / or width in each singular portion of freedom.
• the electronic and / or computer device of the trimming apparatus 30 may control the radial mobility of the machining tool and / or the shafts 31 so as not only to reduce in width and / or height the section of the engagement rib 24 on each singular portion of freedom but also to machine the feet of the engagement rib 24 (by determining the shape of a new longitudinal profile from the longitudinal profile deduced, according to a method of type of that mentioned above).
• this ophthalmic lens Following the shaping of this ophthalmic lens, it will be possible to trim a second ophthalmic lens for mounting in a second surround of said spectacle frame 10, forming on its edge a generally profiled nesting rib. This rib will then be made so that it follows a symmetrical longitudinal profile of the longitudinal profile deduced 25 and so that each of its sections has a shape identical to that of the corresponding section (by symmetry) of the interlocking rib 24 of the first lens.
• a client terminal installed on the customer's side for lens control
• a manufacturer's terminal installed on the side of a lens manufacturer for lens manufacturing and trimming.
• the manufacturer determines on this longitudinal profile deduced 25 at least fifteen singular portions of freedom, then it diverts the lens specifically in these fifteen singular portions of freedom.
• the lens will be easily mountable "first time" in the frame selected by the wearer.
• the lens should not be returned to the manufacturer for resumption, which is always long and expensive.
• provision may be made for the acquisition step of the longitudinal profile acquired by the manufacturer-terminal to comprise two steps, including a first step of determining by the customer the shape of the acquired longitudinal profile 12, for example by probing the surrounding of the eyeglass frame, and a second step of transmission-reception of control data comprising the shape of the acquired longitudinal profile 12.
• the determination of the positions of the singular portions on the acquired longitudinal profile 12 may indifferently be carried out by the manufacturer or by the customer.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Eyeglasses (AREA)
• Prostheses (AREA)

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• 2008
  • 2008-01-28 FR FR0800451A patent/FR2926897B1/fr not_active Expired - Fee Related
  • 2008-12-24 AT AT08872556T patent/ATE515368T1/de not_active IP Right Cessation
  • 2008-12-24 WO PCT/FR2008/001824 patent/WO2009103910A2/fr active Application Filing
  • 2008-12-24 EP EP08872556A patent/EP2247408B1/de active Active
  • 2008-12-24 US US12/864,569 patent/US8672479B2/en active Active

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