Apparatus for coloring articles, for instance lens for spectacles

Claim 3

An apparatus according to claim 1, wherein said element is formed of a potentiometer, and wherein said photometric control device comprises a photocell, said potentiometer being preset by hand upon sensing said sample lens throgh said photocell.

Claim 4

An apparatus according to claim 2, wherein said operable means comprises a shifting member shiftable between two different positions, said member having a pair of seats, one of which is loaded with a transparent lens and the other with the sample lens said member when in one of said positions locating said transparent lens in correspondence with said photocell, when in the other of said positions locating said sample lens in correspondence with said photocell.

Claim 5

An apparatus according to claim 1, wherein said comparing circuit Comprises a threshold circuit, which operates said control means to switch off said heating means.

Claim 6

An apparatus according to claim 1, wherein said heating means comprises a resistor, and a variable transformer controlled by a wattmetric control circuit connected to said resistor for causing said transformer to supply a constant power to said resistor.

Claim 7

An apparatus according to claim 5, comprising a reversible motor connected to said transformer and operable in a first direction to increase the power supplied by said transformer and in a second direction to decrease said supplied power, said wattmetric control circuit causing said motor to be rotated in said first direction, said wattmetric control circuit comprising a second comparing circuit for comparing a predetermined electric current with a current proportional to the electric power absorbed by said resistor to stop said motor when a predetermined power is absorbed by said resistor.

Claim 8

An apparatus according to claim 6, wherein said second comparing circuit comprises a first threshold circuit for operting said motor in said first direction, said predetermined electric current being produced by a potentiometer preset so as to generate a corresponding threshold voltage when said predetermined power is absorbed.

Claim 9

An apparatus according to claim 7, wherein said control means comprises a second threshold circuit to cause said motor to rotate in said second direction, said first and second threshold circuits operating said motor by means of two corresponding relays.

Claim 10

An apparatus according to claim 1, comprising a pair of crucibles, one of which is loaded with said coloring material, the other of which is loaded with an antireflective material, a common support for carrying both said crucibles, and means for alternately shifting said crucibles in correspondence with said resistor.

Claim 11

An apparatus according to claim 9, wherein said common support comprises a shaft rotatable stepwise 180* and a transverse bar carrying said crucibles at the two ends thereof and having the middle portion secured to said shaft.

Claim 12

An apparatus according to claim 10, comprising a program control unit for sequentially controlling the operations of said motor and the stepwise rotation of said shaft, said control unit controlling also at least a vacuum pump and high voltage discharge means inside said chamber.

Claim 13

Apparatus for coloring articles, for example lens for spectacles, by evaporating a coloring material under vacuum, comprisng a vacuum chamber where both an article to be colored and said coloring material are introduced, and heating means located inside said chamber for heating said coloring material so as to evaporate this latter, wherein the improvement comprises comparing means for comparing the intensity of coloration of the article being colored with a predetermined intensity of coloration, control means conditioned by said comparing means for controlling said heating means, said comparing means comprising a comparing circuit for comparing a current proportional to the luminous intensity of the article being colored and generated by a photometric control device, with a current generated by an element preset according to said predetermined intensity, said articles being made of glass, and a shifting member shiftable between two different positions, said member having a plurality of seats, one of which is loaded with a transparent article and another with the sample article, said member when in one of said positions locating said transparent article in correspondence with said photometric control device and when in the other of said positions locating said sample article in correspondence with said photometric control device, whereby said predetermined intensity may be determined by sensing the sample article through said photometric control device.

Claim 14

Apparatus for coloring articles, for example lens for spectacles, by evaporating a coloring material under vacuum, comprisng a vacuum chamber where both an article to be colored and said coloring material are introduced, and heating means located inside said chamber for heating said coloring material so as to evaporate this latter, wherein the improvement comprises comparing means for comparing the intensity of coloration of the article being colored with a predetermined intensity of coloration, control means conditioned by said comparing means for controlling said heating means, said comparing means comprising a comparing circuit for comparing a current proportional to the luminous intensity of the article being colored and generated by a photometric control device, with a current generated by an element preset according to said predetermined intensity, said articles being made of glass, and a shifting member shiftable between two different positions, said member having a plurality of seats, one of which is loaded with a transparent article and another with the sample article, said member when in one of said positions locating said transparent article in correspondence with said photometric control device and when in the other of said positions locating said sample article in correspondence with said photometric control device, whereby said predetermined intensity may be determined by sensing the sample article through said photometric control device.