Double lens electric shield

Claim 2

In a protective helmet and face shield assembly including fastener means for securing the shield releasably to the helmet and hinge means between the fastener means and the shield permitting relative motion between the shield and the helmet an improved face shield comprising: at least two spaced, plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, a surface of one of said lenses being printed with an electrically conductive circuit of an ink having a metallic content substantially throughout said field of view, said circuit being arranged upon said surface in accordance with a pattern of spaced, continuous, generally parallel lines, said lines at maximum width and minimum spacing occupying no more than about eight percent (8%), per unit area, of said field of view, said circuit having sufficient electrical resistance to create heat effective to inhibit formation of fog, ice or frost upon the face shield, and said pattern of lines being effective to provide maximum light transmission and visibility therebetween through said shield.

Claim 3

The assembly of claim 1, in which the lenses are coextensive and the region between the spaced lenses defines an air space.

Claim 4

The assembly of claim 1, in which the circuit is printed upon an inner surface of one of said lenses.

Claim 5

The assembly of claim 3, in which the circuit is printed upon the inner surface of the face lens.

Claim 6

The assembly of claim 2, in which the periphery of the coextensive lenses is provided with seal means protecting the air space against undesirable exterior fluid and particulate matter.

Claim 7

The assembly of claim 5, in which the seal means includes an elongated peripheral spacer formed integrally with one of said lenses.

Claim 8

The assembly of claim 6, in which the seal means comprises a combination of said spacer and a suitable adhesive or bonding agent.

Claim 9

8 The assembly of claim 4, in which the printed electrical circuit develops sufficient resistance to electrical current to create heat in said air space.

Claim 10

The assembly of claim 8, in which the printed circuit develops a power density throughout said one of said lenses when energized by a 12 volt a.c. or d.c. power source effective to create heat sufficient to eliminate for or mist and to melt snow, ice, slush and the like accumulating on the outer surface of the weather lens.

Claim 11

The assembly of claim 9, in which the material from which the lenses are fabricated and the power density are selected to optimize defogging and deicing without deleterious effect upon the lens material.

Claim 12

The assembly of claim 9, in which the power density ranges from 0.30 to 0.60 watts per square inch of face lens within said circuit pattern.

Claim 13

The assembly of claim 11, in which the material from which the face lens is manufactured is selected from the group consisting of polycarbonates, butyrate and acrylics.

Claim 14

The assembly of claim 1, in which the printed circuit includes opposed bus bars each connected to an insulated electrical conductor and the conductors lead to an a.c. or a d.c. power source.

Claim 15

The assembly of claim 2, in which the air space defines a thermal insulator blocking excessive heat loss through the weather lens and minimizing power consumption.

Claim 16

The assembly of claim 13, in which one insulated conductor is replaced partially by an extension of one bus bar.

Claim 17

The assembly of claim 1, in which a portion of the pattern includes spaced parallel lines having a width ranging from 0.010 to 0.030 inches, a thickness less than 0.0005 inches and which are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the center of each line.

Claim 18

A face shield comprising at least two plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, said lenses being coextensive and being separated by spacer means defining an appreciable air gap between lenses, the inner surface of one lens being printed with an electrically conductive circuit of an ink having a metallic content arranged in accordance with a predetermined pattern, said pattern defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0005 inches and are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the center of each line or ribbon, said lines at maximum width and minimum spacing occupying no more than about eight percent (8%), per unit area, of said field or view.

Claim 19

A face shield comprising at least two plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, said lenses being coextensive and being separated by spacer means defining an appreciable air gap between lenses, the inner surface of one lens being printed with an electrically conductive circuit of an ink having a metallic content arranged in accordance with a predetermined pattern, said pattern defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0005 inches and are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the center of each line or ribbon, said lines at maximum width and minimum spacing occupying no more than about eight percent (8%), per unit area, of said field or view.

Claim 20

The face shield of claim 17, in which the spacer means defines a peripheral bead formed integrally with said weather lens.

Claim 21

The face shield of claim 18, in which portions of the perimeter of said coextensive lenses are air closed by seal means protecting the inner surfaces of the lenses against entry of undesirable particulte and fluid matter.

Claim 22

The face shield of claim 17, in which the weather lens is of a thickness ranging from 0.050 to 0.100 inches and the face lens is of a thickness ranging from 0.020 to 0.040 inches.

Claim 23

The face shield of claim 17, in which the lenses are spaced apart a distance ranging from 0.050 to 0.250 inches.

Claim 24

The face shield of claim 21, in which the weather lens is of a thickness ranging from 0.050 to 0.100 inches and the face lens is of a thickness ranging from 0.020 to 0.040 inches.

Claim 25

The face shield of claim 17, 20 or 21, in which the lens printed with said circuit is said face lens.

Claim 26

The face shield of claim 18 or 19, in which the lens printed with said circuit is said face lens.

Claim 27

A face shield of claim 17, 20 or 21, in which the lens printed with said circuits is said face lens and said circuit has sufficient electrical resistance to warm said air gap and said weather and face lenses to keep said face lens free of fogging and inhibit formation of fog, ice or frost on said weather lens.

Claim 28

A face shield of claim 18 or 19, in which the lens printed with said circuit is said face lens and said circuit has sufficient electrical resistance to warm said air gap and said weather and face lenses to keep said face lens free of fogging and inhibit formation of fog, ice or frost on said weather lens.

Claim 29

The face shield of claim 17 or 21, in which the lens printed with said circuit is said face lens and said circuit has sufficient electrical resistance to warm said air gap and said weather and face lenses to keep said face lens free of fogging and inhibit formation of fog, ice or frost on said weather lens; said weather lens having a thickness ranging from 0.05 to 0.100 inches, and said face lens having a thickness ranging from 0.020 to 0.040 inches.

Claim 30

The face shield of claim 18 or 19, in which the lens printed with said circuit is said face lens and said circuit has sufficient electrical resistance to warm said air gap and said weather and face lenses to keep said face lens free of fogging and inhibit formation of fog, ice or frost on said weather lens; said weather lens having a thickness ranging from 0.05 to 0.100 inches, and said face lens having a thickness ranging from 0.20 to 0.040 inches.

Claim 31

A defogging and deicing shield structure in the form of goggles comprising at least two plastic lenses providing a field of view, defining an eye lens and a weather lens, spacer means for creating an air gap between lenses, an electrically conductive circuit of an ink having a metallic content printed on an inner surface of said eye lens effective to warm said air space and said weather lens when said circuit is connected to a 12 volt source of a.c. or d.c. current to inhibit formation of fog, ice or frost upon said weather lens, said circuit defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0005 inches and are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the centre of each line or ribbon, said lines at maximum width and minimum spacing occupying no more than about eight percent (8%), per unit area, of said field of view.

Claim 32

A defogging and deicing shield structure in the form of goggles comprising at least two plastic lenses providing a field of view, defining an eye lens and a weather lens, spacer means for creating an air gap between lenses, an electrically conductive circuit of an ink having a metallic content printed on an inner surface of said eye lens effective to warm said air space and said weather lens when said circuit is connected to a 12 volt source of a.c. or d.c. current to inhibit formation of fog, ice or frost upon said weather lens, said circuit defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0005 inches and are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the centre of each line or ribbon, said lines at maximum width and minimum spacing occupying no more than about eight percent (8%), per unit area, of said field of view.

Claim 33

In a protective helmet and face shield assembly including fastener means for securing the shield releasably to the helmet and hinge means between the fastener means and the shield permitting relative motion between the shield and the helmet an improved face shield comprising: at least two spaced, plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, a surface of one of said lenses being printed solely by silk screening with an electrically conductive circuit of an ink having a metallic content, substantially throughout said field of view, said circuit being arranged upon said surface in accordance with a pattern of spaced, continuous, generally parallel lines, said lines at maximum width and minimum spacing occupying no more than eight percent (8%), per unit area, of said field of view, said circuit having sufficient electrical resistance to create heat effective to inhibit formation of fog, ice or frost upon the face shield, and said pattern of lines being effective to provide maximum light transmission and visibility therebetween through said shield.

Claim 34

In a protective helmet and face shield assembly including fastener means for securing the shield releasably to the helmet and hinge means between the fastener means and the shield permitting relative motion between the shield and the helmet an improved face shield comprising: at least two spaced, plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, a surface of one of said lenses being printed solely by silk screening with an electrically conductive circuit of an ink having a metallic content, substantially throughout said field of view, said circuit being arranged upon said surface in accordance with a pattern of spaced, continuous, generally parallel lines, said lines at maximum width and minimum spacing occupying no more than eight percent (8%), per unit area, of said field of view, said circuit having sufficient electrical resistance to create heat effective to inhibit formation of fog, ice or frost upon the face shield, and said pattern of lines being effective to provide maximum light transmission and visibility therebetween through said shield.

Claim 35

The assembly of claim 30, wherein said field of view is otherwise free of coatings or films.

Claim 36

The assembly of claims 30, in which the lenses are coextensive and the region between the spaced lenses defines an air space.

Claim 37

The assembly of claim 32, in which the air space defines a thermal insulator blocking excessive heat lost through the weather lens and minimizing power consumption.

Claim 38

The assembly of claim 32, in which the periphery of the coextensive lenses is provided with seal means protecting the air space against undesirable exterior fluid and particulate matter.

Claim 39

The assembly of claim 34, in which the seal means includes an elongated peripheral spacer formed integrally with one of said lenses.

Claim 40

The assembly of claim 35, in which the seal means comprises a combination of said spacer and a suitable adhesive or bonding agent.

Claim 41

The assembly of claim 30, in which the circuit is printed upon an inner surface of one of said lenses.

Claim 42

The assembly of claim 37, in which the circuit is printed upon the inner surface of the face lens.

Claim 43

The assembly of claim 38, in which the printed electrical circuit develops sufficient resistance to electrical current to create heat in said air space.

Claim 44

The assembly of claim 39, in which the printed circuit develops a power density when energized by a 12 volt a.c. or d.c. power source effective to create heat sufficient to eliminate fog or mist and to melt snow, ice, slush and the like accumulating on the outer surface of the weather lens.

Claim 45

The assembly of claim 40, in which the material from which the lenses are fabricated and the power density are selected to optimize defogging and deicing without deleterious effect upon the lens material.

Claim 46

The assembly of claim 40, in which the power density ranges from 0.3 to 0.60 watts per square inch of face lens within said circuit pattern.

Claim 47

The assembly of claim 42, in which the material from which the face lens is manufactured is selected from the group consisting of polycarbonates, butyrates and acrylics.

Claim 48

The assembly of claim 30, in which the printed circuit includes opposed bus bars each connected to an insulated electrical conductor and the conductors lead to an a.c. or a d.c. power source.

Claim 49

The assembly of claim 44, in which one insulated conductor is replaced partially by an extension of one bus bar.

Claim 50

The assembly of claim 30, in which a portion of the pattern includes spaced parallel lines having a width ranging from 0.010 to 0.030 inches, a thickness less than 0.0005 inches and are spaced apart a distance ranging from 0.375 to 1.00 inches measured from the center of each line.

Claim 51

The face shield of claim 30 or 46, in which the weather lens is of a thickness ranging from 0.050 to 0.100 inches and the face lens is of a thickness ranging from 0.020 to 0.040 inches.

Claim 52

A face shield of claim 17, in which the lens printed with said circuit is said face lens.

Claim 53

A face shield of claim 48, in which said circuit has sufficient electrical resistance to warm said air gap and said weather and face lenses to keep said face lens free of fogging and inhibit formation of fog, ice or frost on said weather lens.

Claim 54

In a protective helmet and face shield assembly including fastener means for securing the shield releasably to the helmet and hinge means between the fastener means and the shield permitting relative motion between the shield and the helmet an improved face shield comprising: at least two spaced, plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, a surface of one of said lenses being imprinted solely by silk screening with an electrically conductive circuit substantially throughout said field of view, said circuit being arranged upon said surface in accordance with a pattern of spaced, continuous, generally parallel lines, said lines at maximum width and minimum spacing occupying no more than about twenty percent (20%), per unit area, of said field of view.

Claim 55

In a protective helmet and face shield assembly including fastener means for securing the shield releasably to the helmet and hinge means between the fastener means and the shield permitting relative motion between the shield and the helmet an improved face shield comprising: at least two spaced, plastic lenses providing a field of view, one lens defining a face lens and another lens defining a weather lens, a surface of one of said lenses being imprinted solely by silk screening with an electrically conductive circuit substantially throughout said field of view, said circuit being arranged upon said surface in accordance with a pattern of spaced, continuous, generally parallel lines, said lines at maximum width and minimum spacing occupying no more than about twenty percent (20%), per unit area, of said field of view.

Claim 56

The assembly of claim 50, wherein said field of view is otherwise free of coatings or films.

Claim 57

A face shield comprising at least two plastic lenses, one lens defining a face lens and another lens defining a weather lens, said lenses being coextensive and being separated by spacer means defining an appreciable air gap between lenses, the inner surface of one lens being imprinted with an electrically conductive circuit arranged in accordance with a predetermined pattern, said pattern defining spaced parallel lines or ribbons of printed indicia where the lines ranged in width from 0.010 to 0.030 inches and in thickness less than 0.0010 inches and are spaced apart, a distance ranging from 0.3 to 1.0 inches measured from the center of each line or ribbon, said circuit having sufficient electrical resistance to create heat effective to warm the other lens when connected to a 12 volt a.c. or d.c. power source.

Claim 58

A face shield comprising at least two plastic lenses, one lens defining a face lens and another lens defining a weather lens, said lenses being coextensive and being separated by spacer means defining an appreciable air gap between lenses, the inner surface of one lens being imprinted with an electrically conductive circuit arranged in accordance with a predetermined pattern, said pattern defining spaced parallel lines or ribbons of printed indicia where the lines ranged in width from 0.010 to 0.030 inches and in thickness less than 0.0010 inches and are spaced apart, a distance ranging from 0.3 to 1.0 inches measured from the center of each line or ribbon, said circuit having sufficient electrical resistance to create heat effective to warm the other lens when connected to a 12 volt a.c. or d.c. power source.

Claim 59

A defogging and de-icing shield structure in the form of goggles comprising at least two plastic lenses, defining an eye lens and a weather lens, spacer means for creating an air gap between lenses, an electrically conductive circuit imprinted on an inner surface of said eye lens effective to warm said air space and said weather lens when said circuit is connected to a 12 volt source of a.c. or d.c. current, said circuit defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0010 inches and are spaced apart, a distance ranging from 0.3 to 1.0 inches measured from the center of each line or ribbon.

Claim 60

A defogging and de-icing shield structure in the form of goggles comprising at least two plastic lenses, defining an eye lens and a weather lens, spacer means for creating an air gap between lenses, an electrically conductive circuit imprinted on an inner surface of said eye lens effective to warm said air space and said weather lens when said circuit is connected to a 12 volt source of a.c. or d.c. current, said circuit defining spaced parallel lines or ribbons of printed indicia where the lines range in width from 0.010 to 0.030 inches and in thickness less than 0.0010 inches and are spaced apart, a distance ranging from 0.3 to 1.0 inches measured from the center of each line or ribbon.