CA1285976C - Double lens electric shield - Google Patents
Double lens electric shieldInfo
- Publication number
- CA1285976C CA1285976C CA000548534A CA548534A CA1285976C CA 1285976 C CA1285976 C CA 1285976C CA 000548534 A CA000548534 A CA 000548534A CA 548534 A CA548534 A CA 548534A CA 1285976 C CA1285976 C CA 1285976C
- Authority
- CA
- Canada
- Prior art keywords
- lens
- face
- lenses
- circuit
- assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000004033 plastic Substances 0.000 claims description 18
- 229920003023 plastic Polymers 0.000 claims description 18
- 125000006850 spacer group Chemical group 0.000 claims description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 8
- 239000004020 conductor Substances 0.000 claims description 7
- 230000001681 protective effect Effects 0.000 claims description 7
- 230000005540 biological transmission Effects 0.000 claims description 5
- 238000012216 screening Methods 0.000 claims description 5
- FERIUCNNQQJTOY-UHFFFAOYSA-M Butyrate Chemical compound CCCC([O-])=O FERIUCNNQQJTOY-UHFFFAOYSA-M 0.000 claims description 3
- FERIUCNNQQJTOY-UHFFFAOYSA-N Butyric acid Natural products CCCC(O)=O FERIUCNNQQJTOY-UHFFFAOYSA-N 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims description 3
- 230000001070 adhesive effect Effects 0.000 claims description 3
- 239000012212 insulator Substances 0.000 claims description 3
- 239000012530 fluid Substances 0.000 claims 3
- 230000002093 peripheral effect Effects 0.000 claims 3
- 229920006397 acrylic thermoplastic Polymers 0.000 claims 2
- 230000000903 blocking effect Effects 0.000 claims 2
- 239000007767 bonding agent Substances 0.000 claims 2
- 238000000576 coating method Methods 0.000 claims 2
- 230000002939 deleterious effect Effects 0.000 claims 2
- 239000003595 mist Substances 0.000 claims 2
- 239000013618 particulate matter Substances 0.000 claims 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims 2
- 239000004417 polycarbonate Substances 0.000 claims 2
- 229920000515 polycarbonate Polymers 0.000 claims 2
- ISXSCDLOGDJUNJ-UHFFFAOYSA-N tert-butyl prop-2-enoate Chemical compound CC(C)(C)OC(=O)C=C ISXSCDLOGDJUNJ-UHFFFAOYSA-N 0.000 claims 2
- 239000011324 bead Substances 0.000 claims 1
- 150000004648 butanoic acid derivatives Chemical class 0.000 claims 1
- 239000011521 glass Substances 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000010257 thawing Methods 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A42—HEADWEAR
- A42B—HATS; HEAD COVERINGS
- A42B3/00—Helmets; Helmet covers ; Other protective head coverings
- A42B3/04—Parts, details or accessories of helmets
- A42B3/18—Face protection devices
- A42B3/22—Visors
- A42B3/24—Visors with means for avoiding fogging or misting
- A42B3/245—Visors with means for avoiding fogging or misting using means for heating, e.g. electric heating of the visor
Landscapes
- Helmets And Other Head Coverings (AREA)
Abstract
ABSTRACT
The invention provides an improved double lens electric face shield for use in combination with a helmet.
The invention also provides for goggles having a double lens arrangement therein. In the case of both the goggles and the shield, there is imprinted, on the inner surface of one lens, an electrical circuit in a pattern of generally parallel, horizontal lines, said pattern printed with con-ductive ink capable of generating sufficient heat to ef-fectively de-ice or de-fog the exterior surface of the other lens when the electrical circuit has electrical power running therethrough.
The invention provides an improved double lens electric face shield for use in combination with a helmet.
The invention also provides for goggles having a double lens arrangement therein. In the case of both the goggles and the shield, there is imprinted, on the inner surface of one lens, an electrical circuit in a pattern of generally parallel, horizontal lines, said pattern printed with con-ductive ink capable of generating sufficient heat to ef-fectively de-ice or de-fog the exterior surface of the other lens when the electrical circuit has electrical power running therethrough.
Description
9~
DOUBLE LENS ELECTRIC SHIELD
The present invention relates to the arrangement of adjacent lenses, with air space therebetween, in either a face shield or eye goggles, and incorporating electric circuitry for effectively defogging or de-icing the shield or the goggles.
The arrangement of sheets of glass or plastic, adjacent one another with an air space therebetween to act as an insulator and thereby reduce condensation and fogging, is well known. An example is the use of windows in houses and buildings which have two panes of glass separated by an air space. This same arrangement has been incorporated into face shields used by snowmobilers and the like for at least ten years. The prior art double lens face shields are typically made of plastic.
It is also known to screen print on to glass for use in automobile rear windows, horizontal parallel lines for effectively defrosting, defogging and de-icing the window when necessary.
It is also known to minimize fogging and icing of face shields and goggles by applying a protective film to the lenses therein. Some of these lenses are known to contain electrically conductive films, but¢the films themselves usually reduce light transmissio~ with consequential diminished visibility by the user thereof.
The present invention is directed to a double lens face shield or eye goggles providing means for effectively defogging or de-icing the shield or goggles when necessary, qP
.
~s9~
without affecting light transmission through the lenses so as to diminish visibility of the user.
Accordingly, the present invention provides 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.
The present invention also provides 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 - - . : - . :
. -'. : , , . , :
'' ' " '"' :' : ~ ' ' ~2~3597~
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.
The present invention also provides 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 - 2a -, .
' ' .
.
~59~
through said shield.
The present invention also provides 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.
The present invention also provides 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 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 enter of each line or ribbon, said circuit having - 2b -" ,, ., , -~3SS~
sufficient electrical resistance to create heat effective towarml the other lens when connected to a 12 volt a.c. or d.c.
power source.
The present invention further provides 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 space~ apart, a distance ranging from 0.3 to 1.0 inches measured .` : ' ` , ' " ' . - .
: : . ,, : ~ - ' ' ` ;
97~
from the center of each line or ribbon.
The following is a description, by way of example, of certain embodiments of the present invention, reference being had to the accompanying drawings in which:
Figure 1 is a frontal view of a face shield ac-cording to the present invention, Figure 2 is a side view of the face shield of Figure 1 attached to a helmet, Figure 3 is a plan view of the electrical circuit pattern printed on to a lens according to the present invention, Figure 4 is a perspective view of a pair of goggles according to the present invention, Figure 5 is a cross-sectional view of the double lens arrangement taken along the lines 2' - 2' of Figure 1, Figure 6 is a perspective view of a double lens shield without electrical circuitry printed thereon, Figure 7 is a perspective view of the double lens shield of Figure 6 with the shield portion rotated above the vlsor portion, Figure ~ is an exploded view of the double lens shield of Figure 6.
Referring to the figures and, in particular, Figure 1, reference numeral 2 designates a face shield having double lens arrangement 4 housed in a frame 28 and pivotally connected at 12 to a sun visor portion 6. The lenses 4 have printed thereon a substantially parallel, horizontal pattern 10 of electrically conductive ink which .
. .
1~3597~
via connecting wire 8 may be plugged into electrical source means.
Referring to Figure 2, the face shield 2 is releasably attached (via snap fit as at 18) to a helmet 14 and the shield except for the visor is pivotally moveable in relation thereto. The helmet 14 has a neck strap 16.
Referring to Figure 3, there is illustrated the pattern of electrically conductive ink as printed on a plastic lens 4 laid out flat. The pattern of electrically conductive ink has generally parallel, horizontal lines 10 separated by spaces lOa with a border 20 across the bottom of the lens and along the two sides of the lens, said border comprised of electrically conductive ink, The arrangement of printed lines and borders as depicted in Figure 3 comprises the printed electrical circuit according to the present invention. Of course, there are many variations possible in the arrangement of the pattern, all of which would serve the purpose of defogging and de-icing the shield. For example, the width and thickness of the ink lines 10 as well as the thickness of the spaces lOa are variable within reason, as long as the field of vision of the wearer of the shield is not unreasonably obstructed or hampered. Furthermore, if the lens has a field of view governed by its entire surface area, it is logical not to have an electrical circuit pattern printed thereon with coverage of a per unit surface area which would obstruct the vision of the wearer of the shield.
The width of the line 10 can range anywhere from .008 to .03 inches. The width of the spaces lOa can range anywhere from . ~...
, ~
. .
~359~fi -.3 to 1.0 inches.
The thickness of the ink whether on the lines 10 or the border area 20 can range frorn less than 0.0005 to 0.010 inches. The total surface area (including the bordar) of the conductive ink (which itself is not transparent) should not occupy more than about 20% per unit area of the field of view of the face shield. Preferably, the coverage of the conductive ink is no more than about 8%, per unit area, of the field of view of the face shield.
The lenses are made of synthetic plastic materials such as butyrate. The thickness of the lenses may range from 0.02 to 0.1 inches. The lenses 4a and 4b have a space therebetween, identified by numeral 22 in Figure 5, said space providing thermal insulation between lenses 4a and 4b.
Referring to Figure 5, lens 4a is the outer (weather) lens and lens 4b is the inner (face) lens. The lenses 4a and 4b sit in grooves 24 in the frame 28 of the face shield 2.
Spacing means 26 act to maintain a gap or space 22 between the lenses 4a and 4b. The grooves 24 run along the entire perimeter of the frame 28 so as to provide strength to the lenses 4a and 4b when inserted therein. The spacer means 26 can assume any other suitable desired shape or form as long as it serves the functlon of maintaining the desired spacing between the respective lenses. The air gap 22 between the lenses should preferably range from 0.05 to 0.25 inches. The lenses 4a and 4b are sealed via an adhesive in the grooves 24 , .
-- --. .
~2~3597~
so as to ef~ectively seal the space 22 between the respective lenses.
The electrically conductive circuit is printed via silk screening or comparable method upon the surface of either lens 4a or lens 4b adjacent the gap 22. This surface is referred to herein as the inner surface of the respective lenses. The conductive circuit is printed in a pattern of generally horizontal, parallel lines 10 spanning the face shield and joining broader border areas of printed material 20. The electrically conductive circuit is printed using a conductive ink such as HYSOL (trade mark) No. 140-18-Q.
This is an acrylic based conductive ink formulated for air drying and for use on a variety of plastics. It has excellent adhesion to phenolic, urea, polystyrene, treated polyethylene vinyl and butyrate. The printed circuit, when connected to an electrical source, generates heat in the air space 22 keeping the respective lenses 4a and 4b free of fog created by the breath of the wearer thereof. The combination of the adjacent lenses and the insulating air gap reduces loss of heat to the atmosphere. The printed border area 20 completes the electrical circuit which is connected to insulated conductors 42 and 44 respectively. A variety of switch means may be connected to the electrical circuitry so as to have "on" and "off" positions or, in the alternative, a variety of settings indicating different levels of defogging capacity.
Figure 4 discloses the present invention as applied to a pair of goggles 30. The goggles 30 have straps 32 for ' ' . ; ' ' ' ~ : .
. . . - . .
;97S~
fastening around the user's head. The goggles have a pair of lenses generally indicated by numeral 36 which lie in the frame 34 of the goggles in the same fashion as the lenses sit in t:he frame of the face shield and previously described herein. Numeral 40 designates the wiring attached to the printed electrically conductive ink on the inner surface of one of the adjacent lenses in the goggles 30. The goggles rk in the same fashion as does the face shield previously described.
Figures 6 to 8 depict a prior art double lens shield which it may be noted, does not have electrical circuitry printed thereon. The reference numerals in Figures 6 to 8 correspond in description to the identical reference numerals used in Figures 1 to 5.
.~
.
DOUBLE LENS ELECTRIC SHIELD
The present invention relates to the arrangement of adjacent lenses, with air space therebetween, in either a face shield or eye goggles, and incorporating electric circuitry for effectively defogging or de-icing the shield or the goggles.
The arrangement of sheets of glass or plastic, adjacent one another with an air space therebetween to act as an insulator and thereby reduce condensation and fogging, is well known. An example is the use of windows in houses and buildings which have two panes of glass separated by an air space. This same arrangement has been incorporated into face shields used by snowmobilers and the like for at least ten years. The prior art double lens face shields are typically made of plastic.
It is also known to screen print on to glass for use in automobile rear windows, horizontal parallel lines for effectively defrosting, defogging and de-icing the window when necessary.
It is also known to minimize fogging and icing of face shields and goggles by applying a protective film to the lenses therein. Some of these lenses are known to contain electrically conductive films, but¢the films themselves usually reduce light transmissio~ with consequential diminished visibility by the user thereof.
The present invention is directed to a double lens face shield or eye goggles providing means for effectively defogging or de-icing the shield or goggles when necessary, qP
.
~s9~
without affecting light transmission through the lenses so as to diminish visibility of the user.
Accordingly, the present invention provides 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.
The present invention also provides 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 - - . : - . :
. -'. : , , . , :
'' ' " '"' :' : ~ ' ' ~2~3597~
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.
The present invention also provides 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 - 2a -, .
' ' .
.
~59~
through said shield.
The present invention also provides 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.
The present invention also provides 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 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 enter of each line or ribbon, said circuit having - 2b -" ,, ., , -~3SS~
sufficient electrical resistance to create heat effective towarml the other lens when connected to a 12 volt a.c. or d.c.
power source.
The present invention further provides 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 space~ apart, a distance ranging from 0.3 to 1.0 inches measured .` : ' ` , ' " ' . - .
: : . ,, : ~ - ' ' ` ;
97~
from the center of each line or ribbon.
The following is a description, by way of example, of certain embodiments of the present invention, reference being had to the accompanying drawings in which:
Figure 1 is a frontal view of a face shield ac-cording to the present invention, Figure 2 is a side view of the face shield of Figure 1 attached to a helmet, Figure 3 is a plan view of the electrical circuit pattern printed on to a lens according to the present invention, Figure 4 is a perspective view of a pair of goggles according to the present invention, Figure 5 is a cross-sectional view of the double lens arrangement taken along the lines 2' - 2' of Figure 1, Figure 6 is a perspective view of a double lens shield without electrical circuitry printed thereon, Figure 7 is a perspective view of the double lens shield of Figure 6 with the shield portion rotated above the vlsor portion, Figure ~ is an exploded view of the double lens shield of Figure 6.
Referring to the figures and, in particular, Figure 1, reference numeral 2 designates a face shield having double lens arrangement 4 housed in a frame 28 and pivotally connected at 12 to a sun visor portion 6. The lenses 4 have printed thereon a substantially parallel, horizontal pattern 10 of electrically conductive ink which .
. .
1~3597~
via connecting wire 8 may be plugged into electrical source means.
Referring to Figure 2, the face shield 2 is releasably attached (via snap fit as at 18) to a helmet 14 and the shield except for the visor is pivotally moveable in relation thereto. The helmet 14 has a neck strap 16.
Referring to Figure 3, there is illustrated the pattern of electrically conductive ink as printed on a plastic lens 4 laid out flat. The pattern of electrically conductive ink has generally parallel, horizontal lines 10 separated by spaces lOa with a border 20 across the bottom of the lens and along the two sides of the lens, said border comprised of electrically conductive ink, The arrangement of printed lines and borders as depicted in Figure 3 comprises the printed electrical circuit according to the present invention. Of course, there are many variations possible in the arrangement of the pattern, all of which would serve the purpose of defogging and de-icing the shield. For example, the width and thickness of the ink lines 10 as well as the thickness of the spaces lOa are variable within reason, as long as the field of vision of the wearer of the shield is not unreasonably obstructed or hampered. Furthermore, if the lens has a field of view governed by its entire surface area, it is logical not to have an electrical circuit pattern printed thereon with coverage of a per unit surface area which would obstruct the vision of the wearer of the shield.
The width of the line 10 can range anywhere from .008 to .03 inches. The width of the spaces lOa can range anywhere from . ~...
, ~
. .
~359~fi -.3 to 1.0 inches.
The thickness of the ink whether on the lines 10 or the border area 20 can range frorn less than 0.0005 to 0.010 inches. The total surface area (including the bordar) of the conductive ink (which itself is not transparent) should not occupy more than about 20% per unit area of the field of view of the face shield. Preferably, the coverage of the conductive ink is no more than about 8%, per unit area, of the field of view of the face shield.
The lenses are made of synthetic plastic materials such as butyrate. The thickness of the lenses may range from 0.02 to 0.1 inches. The lenses 4a and 4b have a space therebetween, identified by numeral 22 in Figure 5, said space providing thermal insulation between lenses 4a and 4b.
Referring to Figure 5, lens 4a is the outer (weather) lens and lens 4b is the inner (face) lens. The lenses 4a and 4b sit in grooves 24 in the frame 28 of the face shield 2.
Spacing means 26 act to maintain a gap or space 22 between the lenses 4a and 4b. The grooves 24 run along the entire perimeter of the frame 28 so as to provide strength to the lenses 4a and 4b when inserted therein. The spacer means 26 can assume any other suitable desired shape or form as long as it serves the functlon of maintaining the desired spacing between the respective lenses. The air gap 22 between the lenses should preferably range from 0.05 to 0.25 inches. The lenses 4a and 4b are sealed via an adhesive in the grooves 24 , .
-- --. .
~2~3597~
so as to ef~ectively seal the space 22 between the respective lenses.
The electrically conductive circuit is printed via silk screening or comparable method upon the surface of either lens 4a or lens 4b adjacent the gap 22. This surface is referred to herein as the inner surface of the respective lenses. The conductive circuit is printed in a pattern of generally horizontal, parallel lines 10 spanning the face shield and joining broader border areas of printed material 20. The electrically conductive circuit is printed using a conductive ink such as HYSOL (trade mark) No. 140-18-Q.
This is an acrylic based conductive ink formulated for air drying and for use on a variety of plastics. It has excellent adhesion to phenolic, urea, polystyrene, treated polyethylene vinyl and butyrate. The printed circuit, when connected to an electrical source, generates heat in the air space 22 keeping the respective lenses 4a and 4b free of fog created by the breath of the wearer thereof. The combination of the adjacent lenses and the insulating air gap reduces loss of heat to the atmosphere. The printed border area 20 completes the electrical circuit which is connected to insulated conductors 42 and 44 respectively. A variety of switch means may be connected to the electrical circuitry so as to have "on" and "off" positions or, in the alternative, a variety of settings indicating different levels of defogging capacity.
Figure 4 discloses the present invention as applied to a pair of goggles 30. The goggles 30 have straps 32 for ' ' . ; ' ' ' ~ : .
. . . - . .
;97S~
fastening around the user's head. The goggles have a pair of lenses generally indicated by numeral 36 which lie in the frame 34 of the goggles in the same fashion as the lenses sit in t:he frame of the face shield and previously described herein. Numeral 40 designates the wiring attached to the printed electrically conductive ink on the inner surface of one of the adjacent lenses in the goggles 30. The goggles rk in the same fashion as does the face shield previously described.
Figures 6 to 8 depict a prior art double lens shield which it may be noted, does not have electrical circuitry printed thereon. The reference numerals in Figures 6 to 8 correspond in description to the identical reference numerals used in Figures 1 to 5.
.~
.
Claims (53)
1. 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.
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.
2. The assembly of claim 1, in which the lenses are coextensive and the region between the spaced lenses defines an air space.
3. The assembly of claim 1, in which the circuit is printed upon an inner surface of one of said lenses.
4. The assembly of claim 3, in which the circuit is printed upon the inner surface of the face lens.
5. 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.
6. The assembly of claim 5, in which the seal means includes an elongated peripheral spacer formed integrally with one of said lenses.
7. The assembly of claim 6, in which the seal means comprises a combination of said spacer and a suitable adhesive or bonding agent.
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.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. The assembly of claim 13, in which one insulated conductor is replaced partially by an extension of one bus bar.
16. 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.
17. 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.
18. The face shield of claim 17, in which the spacer means defines a peripheral bead formed integrally with said weather lens.
19. 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.
20. 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.
21. The face shield of claim 17, in which the lenses are spaced apart a distance ranging from 0.050 to 0.250 inches.
22. 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.
23. The face shield of claim 17, 20 or 21, in which the lens printed with said circuit is said face lens.
24. The face shield of claim 18 or 19, in which the lens printed with said circuit is said face lens.
25. 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.
26. 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.
27. 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.
28. 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.
29. 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.
30. 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.
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.
31. The assembly of claim 30, wherein said field of view is otherwise free of coatings or films.
32. The assembly of claims 30, in which the lenses are coextensive and the region between the spaced lenses defines an air space.
33. 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.
34. 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.
35. The assembly of claim 34, in which the seal means includes an elongated peripheral spacer formed integrally with one of said lenses.
36. The assembly of claim 35, in which the seal means comprises a combination of said spacer and a suitable adhesive or bonding agent.
37. The assembly of claim 30, in which the circuit is printed upon an inner surface of one of said lenses.
38. The assembly of claim 37, in which the circuit is printed upon the inner surface of the face lens.
39. The assembly of claim 38, in which the printed electrical circuit develops sufficient resistance to electrical current to create heat in said air space.
40. 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.
41. 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.
42. 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.
43. 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.
44. 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.
45. The assembly of claim 44, in which one insulated conductor is replaced partially by an extension of one bus bar.
46. 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.
47. 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.
48. A face shield of claim 17, in which the lens printed with said circuit is said face lens.
49. 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.
50. 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.
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.
51. The assembly of claim 50, wherein said field of view is otherwise free of coatings or films.
52. 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.
53. 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.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000548534A CA1285976C (en) | 1987-10-02 | 1987-10-02 | Double lens electric shield |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000548534A CA1285976C (en) | 1987-10-02 | 1987-10-02 | Double lens electric shield |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1285976C true CA1285976C (en) | 1991-07-09 |
Family
ID=4136575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000548534A Expired - Lifetime CA1285976C (en) | 1987-10-02 | 1987-10-02 | Double lens electric shield |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1285976C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5694650A (en) * | 1995-04-13 | 1997-12-09 | Hong Jin Crown America, Inc. | Heated double lens face shield with passive defogging |
-
1987
- 1987-10-02 CA CA000548534A patent/CA1285976C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5694650A (en) * | 1995-04-13 | 1997-12-09 | Hong Jin Crown America, Inc. | Heated double lens face shield with passive defogging |
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| Date | Code | Title | Description |
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| MKEX | Expiry |