1. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (25) that is derived from the first longitudinal profile (27);
wherein the method includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (25) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) at which the second longitudinal profile (25) presents a radius of curvature that is at a minimum or less than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the section of the engagement ridge (24) is reduced in width or height over said singular portion (Z1-Z5).
2. The method according to claim 1, wherein said determination step excludes searching for said singular portion (Z1-Z5) of the second longitudinal profile (25) as a portion that presents a singular point (P1-P5) that is a geometrical singularity, i.e. an angular point or a cusp.
3. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (25) that is derived from the first longitudinal profile (27);
wherein the method includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (25) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) whose distance from an axis of the ophthalmic lens (20) passing inside the second longitudinal profile (25) is at a maximum or greater than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the section of the engagement ridge (24) is reduced in width or height over said singular portion (Z1-Z5).
4. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (25) that is derived from the first longitudinal profile (27);
wherein the method takes into consideration a third profile (60; 61; 62) derived from the first or the second longitudinal profile (25, 27) in application of a given derivation rule, the third profile being distinct from said first and second longitudinal profiles (25, 27) and each point thereof being associated with a point of the second longitudinal profile (25) in application of a given correspondence rule, and it includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (25) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) for which the associated point on said third longitudinal profile (60; 61; 62) is angular or presents a radius of curvature that is at a minimum or that is less than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the section of the engagement ridge (24) is reduced in width or height over said singular portion (Z1-Z5).
5. The method according to claim 1, wherein the width or the height of the section of the engagement ridge (24) are, at at least one point of each singular portion, reduced by at least 0.05 millimeters.
6. The method according to claim 5, wherein the width and the height of the section of the engagement ridge (24) are, at each point in each singular portion, reduced by at most 0.3 millimeters.
7. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (26) that is derived from the first longitudinal profile (27);
wherein the method includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (26) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) at which the second longitudinal profile (26) presents a radius of curvature that is at a minimum or less than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the second longitudinal profile (26) is derivable from the first longitudinal profile (27) by a mathematical relationship that, over said singular portion (Z1-Z5), differs from the remainder of the second longitudinal profile (26) in such a manner that the mean radius of curvature of said singular portion (Z1-Z5) of the second longitudinal profile (26) is increased relative to the mean radius of curvature that said singular portion (Z1-Z5) would have presented if the given mathematical relationship had been the same over said singular portion (Z1-Z5) as for the remainder of the second longitudinal profile (26).
8. The method according to claim 7, wherein said determination step excludes searching for said singular portion (Z1-Z5) of the second longitudinal profile (26) as a portion that presents a singular point (P1-P5) that is a geometrical singularity, i.e. an angular point or a cusp.
9. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (26) that is derived from the first longitudinal profile (27);
wherein the method includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (26) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) whose distance from an axis of the ophthalmic lens (20) passing inside the second longitudinal profile (26) is at a maximum or greater than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the second longitudinal profile (26) is derivable from the first longitudinal profile (27) by a mathematical relationship that, over said singular portion (Z1-Z5), differs from the remainder of the second longitudinal profile (26) in such a manner that the mean radius of curvature of said singular portion (Z1-Z5) of the second longitudinal profile (26) is increased relative to the mean radius of curvature that said singular portion (Z1-Z5) would have presented if the given mathematical relationship had been the same over said singular portion (Z1-Z5) as for the remainder of the second longitudinal profile (26).
10. A method of preparing an ophthalmic lens (20) for mounting in a surround of an eyeglass frame (10), the method comprising:
an acquisition step of acquiring a first longitudinal profile (27) of said surround;
a blocking step of blocking the ophthalmic lens (20) in support means (31); and
an edging step of edging the ophthalmic lens (20) by shaper means (32), during which the support means (31) or the shaper means (32) are controlled in such a manner that the ophthalmic lens (20) is edged to have an engagement ridge (24) on its edge face (23) that is generally profiled with a desired section and that extends along a second longitudinal profile (26) that is derived from the first longitudinal profile (27);
wherein the method takes into consideration a third profile (60; 61; 62) derived from the first or the second longitudinal profile (26, 27) in application of a given derivation rule, the third profile being distinct from said first and second longitudinal profiles (26, 27) and each point thereof being associated with a point of the second longitudinal profile (26) in application of a given correspondence rule, and it includes a determination step of determining at least one singular portion (Z1-Z5) of the second longitudinal profile (26) as a portion that is situated at less than 5 millimeters from or that contains a singular point (P1-P5) for which the associated point on said third longitudinal profile (60; 61; 62) is angular or presents a radius of curvature that is at a minimum or that is less than a threshold; and
in that during the edging step, the support means (31) or the shaper means (32) are controlled in such a manner that the second longitudinal profile (26) is derivable from the first longitudinal profile (27) by a mathematical relationship that, over said singular portion (Z1-Z5), differs from the remainder of the second longitudinal profile (26) in such a manner that the mean radius of curvature of said singular portion (Z1-Z5) of the second longitudinal profile (26) is increased relative to the mean radius of curvature that said singular portion (Z1-Z5) would have presented if the given mathematical relationship had been the same over said singular portion (Z1-Z5) as for the remainder of the second longitudinal profile (26).
11. The method according to claim 7, wherein the singular portion (Z1-Z5) of the second longitudinal profile (26) presents, relative to the shape that said portion would have presented if the mathematical relationship had been the same over the singular portion (Z1-Z5) as for the remainder of said second longitudinal profile (26), a departure at at least one point that is greater than 0.05 millimeters.
12. The method according to claim 11, wherein the singular portion (Z1-Z5) of the second longitudinal profile (26) presents, relative to the shape that said portion would have presented if the mathematical relationship had been the same over the singular portion (Z1-Z5) as for the remainder of said second longitudinal profile (26), a departure that is less than 0.3 millimeters.
13. The method according to claim 7, wherein the shaper means (32) or the support means (31) are controlled in such a manner that at the end of the edging step, the engagement ridge (24) presents a section of uniform shape along the second longitudinal profile (26).
14. The method according to claim 4, wherein said third longitudinal profile is a polygon that is circumscribed (60) or inscribed (61) relative to the first or second longitudinal profile (25; 26, 27).
15. The method according to claim 4, wherein said third longitudinal profile is a proportional transformation (62) of the first or the second longitudinal profile (25; 26, 27).
16. The method according to claim 1, wherein said threshold is less than 20 millimeters, and is preferably equal to 10 millimeters.
17. The method according to claim 1, wherein said threshold is a function of the shape of the first or the second longitudinal profile (25; 26, 27).
18. The method according to claim 1, wherein, during the determination step of determining each singular portion (Z6) of the second longitudinal profile (25; 26), an image of the second longitudinal profile (25; 26) is displayed together with an image of a cursor (50) having at least one dimension that is a function of said threshold, and at least one singular portion (Z6) is selected manually in which the shape of the cursor and the shape of the second longitudinal profile (25; 26) match.
19. The method according to claim 1, including, after the determination step, a step of searching in a database registry in which each record is associated with a reference type of eyeglass frame (10) and contains the shape of the second longitudinal profile (25; 26), for a record corresponding to the frame in question, and a step of writing the positions of each of the singular portions (Z1-Z5) on the second longitudinal profile (25; 26) into said record.
20. The method according to claim 1, wherein, for the second longitudinal profile (25; 26) including at least two singular portions (Z1-Z5) including a first singular portion (Z2) that is the closest to a temple portion of the second longitudinal profile (25; 26), the support means (31) or the shaper means (32) are controlled in such a manner that the section of the engagement ridge (24) is reduced locally in width or in height at least in the first singular portion (Z2) or in such a manner that the second longitudinal profile (26) is derived by said mathematical relationship that is different at least in the first singular portion (Z2).
21. The method according to claim 1, wherein each singular portion (Z1-Z5) of the second longitudinal profile (25; 26) is centered on said singular point (P1-P5) and presents a length of less than 10 millimeters.
22. The method according to claim 1, wherein during the edging step, the support means (31) or the edging means (32) are controlled in such a manner that each longitudinal profile of the engagement ridge (24) extends continuously along the edge face (23) of the ophthalmic lens (20), without any point that is an angular point or a cusp.
23. The method according to claim 1, wherein during the acquisition step, a record is read in a database registry in which each record is associated with a reference type of eyeglass frame (10) and contains the shape of the first longitudinal profile (27) corresponding to the reference type of eyeglass frame.
24. The method according to claim 23, wherein, during the determination step, said record is read that contains not only the shape of the first longitudinal profile (27), but also the shape of said second longitudinal profile (25; 26) and the positions of said singular portions (Z1-Z5).
25. The method according to claim 1, including steps of blocking and edging a second ophthalmic lens in order to enable it to be mounted in a second surround of said eyeglass frame (10), by forming an engagement ridge on its edge face that is generally profiled and that extends with a given longitudinal profile that is symmetrical to said second longitudinal profile (25; 26), and in which each section presents a width or a height equal to the width or the height of the symmetrical section of the engagement ridge (24) of the edged first ophthalmic lens (20).
26. The method according to claim 1, implemented by means of a system comprising firstly a client terminal installed beside a client and including computer means for recording and transmitting order data concerning the ophthalmic lens (20), said order data including data relating to the frame, and secondly a manufacturer terminal installed beside a manufacturer and including computer means for receiving and recording the order data transmitted by the client terminal, and a shaper device for edging said fabricated ophthalmic lens, the device being designed to implement said blocking and edging step, said acquisition step comprising:
a determination step of the client determining the first longitudinal profile (27) of the surround of the eyeglass frame (10); and
an ordering step of the client terminal sending order data and of the manufacturer terminal receiving said data, said data incorporating said first longitudinal profile (27).
27. The method according to claim 1, implemented by means of a system comprising firstly a client terminal installed beside a client and including computer means for recording and transmitting order data concerning the ophthalmic lens (20), said order data including data relating to the frame, and secondly a manufacturer terminal installed beside a manufacturer and including computer means for receiving and recording the order data transmitted by the client terminal, a shaper device for edging said fabricated ophthalmic lens, the device being designed to implement said blocking and edging step, said acquisition step comprising:
a determination step of the client determining a reference of the eyeglass frame (10); and
an ordering step of the client terminal sending order data and of the manufacturer terminal receiving said data, said data incorporating said reference; and
a searching step of the manufacturer terminal searching, in a database registry in which each record is associated with a type of eyeglass frame (10) and contains a reference for said frame and the first longitudinal profile (27) of the surround of said frame, for a record associated with the frame reference in question.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for passivating a surface of a dehydrochlorination reactor comprising: stopping a flow of hydrochlorofluoropropane to a reactor, passing a gas mixture comprising hydrogen gas through the reactor at a temperature of at least 25\xb0 C. for a period of time sufficient to restore the selectivity of a dehydrochlorination reaction, stopping the flow of the hydrogen gas mixture, and resuming the flow of hydrochlorofluoropropane to the dehydrochlorination reaction, wherein the gas mixture further comprises an inert diluent gas, and wherein the concentration of hydrogen gas in said gas mixture is at least 0.5% by mole percent.
2. The process of claim 1, wherein the concentration of hydrogen gas in said gas mixture is at least 3% by mole percent.
3. The process of claim 1, wherein the concentration of hydrogen gas in said gas mixture is at least 10% by mole percent.
4. The process of claim 1 wherein said inert diluent gas is nitrogen, helium, argon or neon and mixtures thereof.
5. The process of claim 1, wherein the process is maintained at a pressure of at least one atmosphere.
6. The process of claim 1, wherein the reactor is maintained at a temperature of at least 200\xb0 C.
7. The process of claim 1, wherein the selectivity for dehydrochlorination is increased to at least 90%.
8. The process of claim 1, wherein the selectivity for dehydrochlorination is increased to at least 95%.
9. A process for producing a fluoropropene of formula CF3CX\u2550CX2, wherein each X is F or H, at least one X is H and at least one X is F, comprising:
pyrolyzing a hydrochlorofluoropropane of formula CF3CXYCX2Y, wherein each X is F or H, at least one X is H, and at least one X is F and one Y is Cl and the other Y is H, in the gas-phase in the absence of a catalyst in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrochlorofluoropropane to said fluoropropene, and wherein said reaction vessel is periodically subjected to a passivation step to passivate the inner surface of said reaction vessel, wherein said passivation step comprises
(i) stopping the flow of hydrochlorofluoropropane to the reaction vessel, passing a gas mixture comprising hydrogen gas through the reactor at a temperature of at least 200\xb0 C. for a period of time sufficient to restore the selectivity of a dehydrochlorination reaction, stopping the flow of the gas mixture, and resuming the flow of hydrochlorofluoropropane to resume the pyrolysis reaction, or
(ii) introducing a flow of a gas mixture comprising hydrogen gas into said reactor while the flow of hydrochlorofluoropropane is continuing, for a time sufficient to maintain the selectivity of the dehydrochlorination reaction, and then discontinuing said flow of said gas mixture comprising hydrogen
wherein the gas mixture further comprises an inert diluent gas, and wherein the concentration of hydrogen gas in said gas mixture is at least 0.5% by mole percent.
10. The process of claim 9, wherein the inert diluent gas is nitrogen, helium, argon or neon.
11. The process of claim 9, wherein the passivation step is performed after 2000 hours of operation.
12. The process of claim 9, wherein the passivation step is performed after 50 hours of operation.
13. The process of claim 9, wherein the hydrogen gas in said gas mixture is at least 3% by mole percent.
14. The process of claim 9, wherein the selectivity of said dehydrochlorination reaction is increased to at least 90%.
15. The process of claim 9, wherein the selectivity of said dehydrochlorination reaction is increased to at least 95%.
16. The process of claim 9, wherein said passivation step (ii) is conducted at a temperature of at least 400\xb0 C.
17. A process for producing a fluoropropene of formula CF3CX\u2550CX2, wherein each X is F or H, at least one X is H and at least one X is F, comprising:
pyrolyzing a hydrochlorofluoropropane of formula CF3CXYCX2Y, wherein each X is F or H, at least one X is H, and at least one X is F and one Y is Cl and the other Y is H, in the gas-phase in the absence of a catalyst in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrochlorofluoropropane to said fluoropropene, and wherein said hydrochlorofluoropropane comprises less than 300 ppm of hydrogen fluoride.
18. A process for passivating a surface of a dehydrochlorination reactor comprising:
stopping a flow of hydrochlorofluoropropane to a reactor,
passing a gas mixture comprising a reducing agent comprising carbon monoxide (CO) and optionally other reducing agents selected from NH3, CH4, hydrogen and combinations thereof, optionally mixed with one or more inert diluents, through the reactor at a temperature of at least 25\xb0 C. for a period of time sufficient to restore the selectivity of a dehydrochlorination reaction, or (ii) a reducing agent comprising NH3 optionally mixed with one or more inert diluents, through the reactor at a temperature of at least 430\xb0 C. for a period of time sufficient to restore the selectivity of a dehydrochlorination reaction,
stopping the flow of the gas mixture, and
resuming the flow of hydrochlorofluoropropane to the dehydrochlorination reaction.
19. The process of claim 18 wherein the NH3 is mixed with nitrogen.
20. The process of claim 1 wherein the concentration of hydrogen gas in said gas mixture is 0.5 mole percent to 30 mole percent.
21. The process of claim 20 wherein the concentration of hydrogen gas in said gas mixture is 3 mole percent to 30 mole percent.