U.S. patent application number 17/096331 was filed with the patent office on 2021-03-04 for grey compounded infrared absorbing spectacles, goggles, faceshields and hood windows used in personal protective equipment for arc flash hazards.
The applicant listed for this patent is Jack Bouton Hirschmann, Randell Bouton Hirschmann, Thomas E. Neal. Invention is credited to Jack Bouton Hirschmann, Randell Bouton Hirschmann, Thomas E. Neal.
Application Number | 20210063771 17/096331 |
Document ID | / |
Family ID | 1000005220407 |
Filed Date | 2021-03-04 |
United States Patent
Application |
20210063771 |
Kind Code |
A1 |
Hirschmann; Jack Bouton ; et
al. |
March 4, 2021 |
GREY COMPOUNDED INFRARED ABSORBING SPECTACLES, GOGGLES, FACESHIELDS
AND HOOD WINDOWS USED IN PERSONAL PROTECTIVE EQUIPMENT FOR ARC
FLASH HAZARDS
Abstract
An improved personal protective device and composition thereof.
The device comprises arc flash spectacles or goggles, an arc flash
faceshield or an arc flash hood window to provide optical clarity,
specifically color acuity. The spectacles or goggles, the
faceshield and the hood window include polycarbonate material for
high-impact, high-mass performance, and surface charring during arc
flash exposure and provides an arc flash protective rating of at
least 4 cal/cm.sup.2 (in the case of eyewear and face shields) or
at least 15 cal/cm.sup.2 (in the case of hood windows).
Inventors: |
Hirschmann; Jack Bouton;
(South Darmouth, MA) ; Hirschmann; Randell Bouton;
(South Dartmouth, MA) ; Neal; Thomas E.; (Bonita
Springs, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hirschmann; Jack Bouton
Hirschmann; Randell Bouton
Neal; Thomas E. |
South Darmouth
South Dartmouth
Bonita Springs |
MA
MA
FL |
US
US
US |
|
|
Family ID: |
1000005220407 |
Appl. No.: |
17/096331 |
Filed: |
November 12, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14722727 |
May 27, 2015 |
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17096331 |
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14525881 |
Oct 28, 2014 |
9498382 |
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14722727 |
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61896751 |
Oct 29, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 9/061 20130101;
A61F 9/065 20130101; G02C 7/108 20130101 |
International
Class: |
G02C 7/10 20060101
G02C007/10; A61F 9/06 20060101 A61F009/06 |
Claims
1. A faceshield for blocking arc flash thermal energy, the
faceshield comprising: a lens providing color acuity within the
visible light spectrum, the lens comprised of a particulate
consisting of antimony doped tin oxide that blocks infrared
radiation, and an optically clear plastic material, the-optically
clear plastic material and the particulate chosen and blended in
proportion so that the faceshield will block a range from 3 to 40
cal/cm.sup.2 of arc flash thermal energy, the lens further
comprising of: a) an optically clear plastic material selected from
the group consisting of but not limited to polycarbonate, acrylic,
cellulose propionate, cellulose acetate and cellulose acetate
butyrate; and b) a particulate of antimony doped tin oxide coated
with a dispersant; and c) the particulate described in b) dispersed
within said optically clear plastic material.
2. The faceshield of claim 1, wherein the particulate of antimony
doped tin oxide coated with a dispersant has a size range of about
0.1 to 15 microns per particle.
3. The faceshield of claim 1, wherein the leas provides at least
30% light transmission across the visible light spectrum.
4. A faceshield for blocking arc flash thermal energy, the
faceshield comprising: a lens providing color acuity within the
visible light spectrum, the lens comprised of a particulate
consisting of antimony doped tin oxide that blocks infrared
radiation, a dye of a color within the visible light spectrum, and
an optically clear plastic material, the optically clear plastic
material, the particulate and the dye being chosen and blended in
proportion so that the faceshield will block a range from 3 to 40
cal/cm.sup.2 of arc flash thermal energy, the lens further
comprising of: a) an optically clear plastic material selected from
the group consisting of but not limited to polycarbonate, acrylic,
cellulose propionate, cellulose acetate and cellulose acetate
butyrate; and b) a particulate of antimony doped tin oxide coated
with a dispersant and a dye of a color within the visible light
spectrum; and c) the particulate and the dye described in b)
dispersed within said optically clear plastic material.
5. The faceshield of claim 4, wherein the particulate of antimony
doped tin oxide coated with a dispersant has a size range of about
0.1 to 15 microns per particle.
6. The faceshield of claim 4, wherein the lens provides at least
30% light transmission across the visible light spectrum.
7. A hood window for blocking arc flash thermal energy, the hood
window comprising: a lens providing color acuity within the visible
light spectrum, the lens comprised of a particulate of antimony
doped tin oxide that blocks infrared radiation and an optically
clear plastic material, the optically clear plastic material and
particulate being chosen and blended in proportion so that the hood
window will block a range of 15 to 140 cal cm.sup.2 of arc flash
thermal energy, the lens further comprising: a) an optically clear
plastic material selected from the group consisting of but not
limited to polycarbonate, acrylic, cellulose propionate, cellulose
acetate and cellulose acetate butyrate; and b) a particulate of
antimony doped tin oxide coated with a dispersant; and. c) the
particulate described in b) dispersed within said optically clear
plastic material.
8. The hood window of claim 7, wherein the particulate of antimony
doped tin oxide coated with a dispersant has a size range of about
0.1 to 15 microns per particle.
9. The hood window of claim 7, wherein the lens provides at least
30% light transmission across the visible light spectrum.
10. The hood window of claim 7, where in the optically clear
plastic material of the hood window is polycarbonate and the
particulate of the lens is antimony doped tin oxide coated with a
dispersant and has a size range of about 0.1 to 15 microns per
particle, whereby the lens chars at arc flash thermal energy
exposures greater than 12 cal/cm.sup.2, and said charring decreases
the temperature of the surface of the hood window and increases the
blocking of arc flash thermal energy as exposures are increased up
to 140 cal/cm.sup.2.
11. Eyewear for blocking arc flash thermal energy, the eyewear
comprising: a polycarbonate frame, and a lens providing color
acuity within the visible light spectrum, the lens comprised of a
particulate of antimony doped tin oxide that blocks infrared
radiation and an optically clear plastic material, the optically
clear plastic will block at least 3 cal/cm.sup.2 of arc flash
thermal energy, the lens further comprising: a) an optically clear
plastic material, the optically clear plastic material consisting
of an optically clear plastic selected from the group consisting of
but not limited to polycarbonate, acrylic, cellulose propionate,
cellulose acetate and cellulose acetate butyrate; and b) a
particulate of antimony doped tin oxide coated with a dispersant;
and c) the particulate described in b) dispersed within said
optically clear plastic material.
12. Eyewear of claim 11, wherein the lens provides at least 30%
light transmission across the visible light spectrum.
13. Eyewear of claim 11, wherein the particulate of antimony doped
tin oxide coated with a dispersant has a size range of about 0.1 to
15 microns per particle.
Description
RELATED APPLICATION DATA
[0001] This application claims priority to patent application Ser.
No. 14/722,727, filed on May 27, 2015 which claims priority to
application Ser. No. 14/525,881 filed on Oct. 28, 2014 which claims
priority to provisional patent application No. 61/896,751, filed on
Oct. 29, 2013.
FIELD OF INVENTION
[0002] The present invention relates to improved personal
protective equipment for protecting electricians and electrical
workers from arc flash exposure. In particular, the present
invention is directed towards improved optically neutral
spectacles, goggles, faceshields, and hood windows with a true
color lens such that the user has color acuity, thus, eliminating a
key potential safety hazard in the presence of energized electrical
equipment with color coded electrical wiring or circuitry.
BACKGROUND OF THE INVENTION
[0003] When an electric current passes through air between
ungrounded conductors, or between ungrounded conductors and
grounded conductors, the temperatures can reach 35,000.degree. F.
Exposure to the arc flash thermal energy from these extreme
temperatures both burns the skin directly and causes ignition of
conventional work clothing, which adds to the severity of burn
injury. The majority of hospital admissions due to electrical
accidents are from arc flash burns, not from shocks. Each year more
than 2,000 people are admitted to burn centers with severe arc
flash burns. Arc flash events can and do severely injure and kill
workers even at distances of 10 ft (3 m).
[0004] Arc flash hazard exposure level is a function of a variety
of factors, including but not limited to fault clearing time,
magnitude of the arc current, the type of equipment in which the
arc is initiated and a worker's distance from the arc flash event.
Multiple techniques can be employed to limit risks related to such
exposures. Arc flash injuries, for instance, arc particularly
prevalent among electricians. A myriad of solutions have been
proposed to minimize such injuries.
[0005] One such method is through the use of Personal Protective
Equipment (PPE) by electricians, electric utility workers and
others at risk, including protective eyewear, faceshields, hoods,
shirts, pants, coveralls and arc flash suits. One of the common
ways to prevent eye and face injuries from an arc flash is
interposing a lens or transparent window between the wearer and the
arcing source. One such problem with PPE, however, is the
restrictions in movement and perception which they place upon such
workers. In the case of protective arc flash PPE eyewear,
faceshields and hood windows, it may be essential for such workers
to have full visual perception (including color acuity) in order to
perceive and conduct work on energized electrical equipment as may
be needed in the use of color coded electrical wiring and the like.
Working on an incorrect conductor due to the worker not being able
to perceive the correct color for color coded wires can be a
contributing cause for an arc flash event. As a result, there is a
need for arc flash PPE eyewear, faceshields and hood windows which
provides optical clarity, and in particular color acuity to the
user.
DESCRIPTION OF THE PRIOR ART
[0006] One example of a prior art approach U.S. Pat. No. 6,375,865
to Paulson purports to disclose compositions that block
electric-arc energy. Specifically, Paulson claims to disclose a
composition and process for manufacturing electric-arc resistant
objects that are at least partially transparent. As that patent
defines tire term, however "substantially transparent" means a
composition which allows the passage of a sufficient amount of
light to allow a person looking through the material to view
objects under normal working conditions. It does not, however,
teach or suggest color acuity for a user. Put another way, there is
a difference between transparency, i.e., being able to see objects,
as opposed to color acuity, i.e., seeing objects without alteration
in color versus the distortion in color perceived looking through
the material used.
[0007] U.S. Pat. No. 3,382,183 to Donoian et. al. teaches a plastic
optical filter related to the stabilization of infrared absorbing
organic dyes in plastic substrates. A problem arises due to the
degradation of the infrared dyes in sunlight and the fact that the
Donoian device is simply an optical filter and not an arc
shield.
[0008] A further approach is known to be offered through BSD
Bildungs--und Servicezentrum GmbH. BSD has offered a Bayer Plastics
product typically used in architectural or automotive applications
to protect against sun light. BSD's product, however, is a
faceshield with a laminate of protective film over the
faceshield.
[0009] Still another publication is shown in U.S. Patent
Application No. 2012/0086909 (Paulson), which discloses an arc
shielding lens or a laminate for such a lens with a mixture of
nanoparticles for thermal negation and absorption. However, nothing
in this application teaches or suggests the need for color acuity
to enable the wearer to better identify potential arc flash hazards
while still being protected from an arc flash occurrence.
[0010] A further reference regarding to charring of eye and face
PPE during arc flash exposure relates to polycarbonate faceshields
and is described in, R. L. Doughty, Dr. T. E. Neal, T. A. Dear and
A. H. Bingham, "Testing Update On Protective Clothing &
Equipment For Electric Arc Exposure," IEEE Industrial Applications
Magazine, Vol. 5, pp. 37-49, January/February 1999. The paper
describes a reduction of arc flash thermal energy transmitted
through clear polycarbonate faceshields at exposures of 21 to 25
cal/cm2 but the authors note that at the exposure level needed to
generate charring, sufficient energy has already been transmitted
through the faceshield to cause burn injury.
[0011] In sum, the prior art fails to teach the use of a
composition for a PPE eyewear, faceshields or hood windows which
enables color acuity by a wearer during use.
DEFINITION OF TERMS
[0012] The following terms are used in the claims of the patent as
filed and are intended to have their broadest plain and ordinary
meaning consistent with the requirements of the law.
[0013] "Arc flash thermal energy" means all forms of energy created
by an arc flash event including but not limited to infrared
radiation, ultraviolet radiation, visible light spectrum radiation,
convective energy due to hot gases and plasma, and conductive
energy due to molten metal and other heated debris.
[0014] "Color acuity" means the ability to discern and distinguish
between colors in the visible light spectrum.
[0015] "Eyewear" means spectacles and goggles used for protection
of the eyes.
[0016] "Hood window" means a faceshield that is fitted into a hood
to provide protection for the eyes, face, neck and head.
[0017] "Faceshield" means a device that protects the face and eyes
and is generally attached to a hard cap or hard hat.
[0018] Eye and face PPE consists of eyewear, faceshields and hood
windows.
[0019] "Optically neutral" means the near absence of any color
shift in the visible light spectrum.
[0020] "Charring" means the creation of a black porous material on
the surface of eye and face PPE which reduces light transmission
and heat transmission through the eye and face PPE.
[0021] Where alternative meanings are possible, the broadest
meaning is intended. All words used in the claims set forth below
are intended to be used in the normal, customary usage of grammar
and the English language.
OBJECTS AND SUMMARY OF THE INVENTION
[0022] The apparatus and method of the present invention generally
include eyewear, a faceshield or a hood window for blocking or
absorbing infrared radiation emanating from an are flash event. The
eyewear, faceshield and hood window are comprised of an infrared
absorber including but not limited to particulates of antimony
doped tin oxide, indium doped tin oxide, lanthanum boride or cesium
tungstate mixed with an optically clear plastic material for
providing a grey lens or shield which permits color acuity. The
eyewear further includes a frame or similar support structure for
the lens comprised of polycarbonate or similar non-conductive
material. The faceshield is mounted on a hard cap or hard hat, and
the hood window is inserted into a sewed pocket in the front of a
hood and secured with a grommet or the like.
[0023] The combination of a polycarbonate optically clear plastic
material and the selected particulate of the invention provides
blocking of infrared radiation by the particulate at lower exposure
levels that are insufficient to generate charring and provides a
significantly increased level of charring which very effectively
blocks higher exposure levels of arc flash thermal energy at or
above the level needed to generate the charring phenomenon. In
addition, the charring process removes heat Loin the polycarbonate
lens or shield material during the formation of the char, i.e. the
heated polycarbonate near the surface is removed from the surface
as it undergoes pyrolysis and is converted into a thick char on the
surface that very effectively blocks arc flash thermal energy.
Consequently, once the charring process is initiated, the level of
heat transmitted by the eye and face PPE surprisingly decreases
even as the infrared radiation is increased. The concentration of
particulate used in the polycarbonate optically clear plastic
material must be properly set to block infrared radiation at lower
exposure levels in order to avoid burn injury up to the exposure
levels at which the charring process is initiated. The combination
of infrared radiation blocking by the infrared absorbing
particulate at low exposure levels, the removal of heat flora the
polycarbonate lens or shield surface and the blacking of arc flash
thermal energy at higher exposure levels by the charring process
permits the use of reduced levels of infrared absorbing particulate
which in turn provides higher visible light transmission and
consequently higher visual acuity and color acuity for the user of
the eye and face PPE of this invention.
[0024] The immediate application of the present invention will be
seen in providing personal protective equipment for electricians
and electrical workers exposed to a wide range of arc flash
conditions whereby the workers have color acuity to recognize wire
color coding.
[0025] Thus it can be seen that one object of the present invention
is to provide electricians and electrical workers with eyewear,
faceshields or hood windows for preventing injury due to arc flash
thermal energy while at the same time providing workers with color
acuity in order to reduce the likelihood of working on an incorrect
wire or circuit, art due to color distortion.
[0026] A further object of the present invention is to provide
eyewear, a faceshield and a hood window which inhibits the tinting
or discoloration of objects being viewed therethrough.
[0027] Still another object of the present invention is to provide
eyewear and a faceshield which can block and dissipate up to 40
cal/cm.sup.2 and a hood window which can block and dissipate up to
140 cal/cm.sup.2 of arc flash thermal energy.
[0028] Yet another object of the present invention is to provide
eyewear, a faceshield and a hood window which includes an infrared
absorber for blocking infrared radiation.
[0029] Still another object of the present invention is to provide
eyewear, a faceshield and a hood window which provides an
electrical worker protection from arc flash events combined with a
superior ability to detect and address potential arc flash
conditions over prior faceshield compositions.
[0030] Yet another object of the present invention is to provide
eyewear, a faceshield and a hood window which includes a very thin
gold coating on the surface to reflect radiant heat in prolonged
exposures such as experienced by firefighters and some industrial
workers who deal with molten metals or other molten substances. The
gold coating reflects a substantial portion of the radiant heat
exposure and the grey eyewear, faceshield and hood window absorbs a
substantial portion of the remaining infrared radiation that is not
reflected by the thin gold surface coating.
[0031] It should be noted that not every embodiment of the claimed
invention will accomplish each of the objects of the invention set
forth above. In addition, further objects of the invention will
become apparent based the summary of the invention, the detailed
description of preferred embodiments, and as illustrated in the
accompanying drawings. Such objects, features, and advantages of
the present invention will become more apparent in light of the
following detailed description of a best mode embodiment thereof,
and as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 shows a perspective view of a faceshield according to
a first preferred embodiment of the invention.
[0033] FIG. 2 shows a perspective view of a hood according to a
first preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Set forth below is a description of what is currently
believed to be the preferred embodiment or best examples of the
invention claimed. Future and present alternatives and
modifications to this preferred embodiment are contemplated. Any
alternatives or modifications which make insubstantial changes in
function, in purpose, in structure or in result are intended to be
covered by the claims in this patent.
[0035] FIG. 1 shows a first preferred embodiment of a faceshield 10
constructed in accordance with the present invention. The
faceshield 10 is attached to a hard hat 12 or other type of
headgear and protects users from electric arcs while at the same
time allowing the user to view objects with color acuity. The
optically clear plastic material for this product is preferably
polycarbonate, but may also include acrylics, cellulose
propionates, cellulose acetates and cellulose acetate butyrate or
similar optically clear plastics known to those of skill in the
art. Similarly, a face shield 10 in accordance with the present
invention may be fitted into a hood 20 (as shown in FIG. 2), or
eyewear, like spectacles or goggles may be constructed in
accordance with the present invention.
[0036] In order to provide the necessary user protection for the
optically neutral faceshield 10 of the present invention, the
invention should further include a particulate comprised of
antimony doped tin oxide particles coated with a dispersant for
blocking infrared radiation associated with arc flashes and similar
events. Such particulate may be of a nanoparticle size. Such a
particulate for use with the present invention typically consists
of nanoparticles of antimony doped tin oxide that arc coated with a
dispersant to provide a dispersible powder with dimensions in a
range of about 5-15 microns, and most preferably about 10
microns.
[0037] A coating on substantially each antimony doped tin oxide
particle is important for it to disperse in the optically clear
plastic material, such coating being applied by fluidized bed,
sol-gel, sputtering, evaporation or other methods known to those of
skill in the art. Without the coating in the practice of the
present invention, the particles are difficult to disperse evenly
in the processing of the particles in mixing with the optically
clear plastic material and the molding of the plastic part. In the
absence of such a coating, the faceshield will have a haze that
will affect the visibility through the optical part (shield or
lens) and prevent or diminish the color acuity provided by the
present invention.
[0038] In an attempt to quantify the advantage of the present
invention, the following table compares several different models of
face shields in their ability to transmit the visible light
spectrum therethrough. That is, a goal of the present invention is
to provide both: 1) a higher level of transmission of visible light
across the visible light spectrum; and 2) a substantially
consistent transmission of light across the visible light spectrum
(i.e., so as to manna n color acuity). Specifically, the following
comparison shows: 1) a conventional green IR arc flash shield, 2) a
range of concentration of particulate plus dispersants as a weight
per pound of optically clear polycarbonate material manufactured in
accord with the present invention, and 3) a "clear" face
shield:
TABLE-US-00001 Concentration of Antimony Doped Tin Oxide with 0
grams/lb. .3 g Epolin 1125/lb. 5 grams/lb. 7 grams/lb. 9 grams/lb.
11 grams/lb. Oberon Clear Wavelength ClearPolycarbonate Clear
Polycarbonate Clear Polycarbonate Clear Polycarbonate Clear
Polycarbonate Polycarbonate (nm) % Trans. % Trans. % Trans. %
Trans. % Trans. % Trans. 760 nm 13.64% 44.83% 33.27% 25.36% 18.59%
90.20% 750 nm 15.95% 45.17% 33.82% 25.62% 18.96% 90.02% 740 nm
18.42% 45.19% 34.21% 26.07% 19.59% 90.07% 730 nm 21.01% 46.21%
35.32% 27.22% 20.58% 90.09% 720 nm 23.65% 47.77% 36.32% 28.40%
21.37% 90.04% 710 nm 26.19% 48.10% 36.75% 28.84% 21.85% 89.97% 700
nm 28.67% 48.03% 37.66% 29.17% 22.60% 89.95% 690 nm 31.00% 49.40%
38.54% 30.40% 23.63% 89.98% 680 nm 33.09% 50.67% 39.20% 31.58%
24.24% 89.82% 670 nm 34.96% 50.41% 40.07% 31.75% 24.81% 89.59% 660
nm 36.62% 51.15% 40.73% 32.47% 25.88% 89.20% 650 nm 38.09% 52.97%
41.96% 34.13% 26.79% 88.61% 640 nm 39.41% 53.03% 42.50% 34.66%
27.35% 87.93% 630 nm 40.90% 53.40% 43.32% 34.93% 28.32% 87.62% 620
nm 42.53% 54.85% 44.21% 36.48% 29.19% 87.70% 610 nm 44.21% 54.78%
44.65% 36.96% 29.62% 87.67% 600 nm 45.82% 55.43% 45.43% 37.16%
30.58% 87.37% 590 nm 47.42% 56.24% 46.13% 38.70% 31.29% 86.95% 580
nm 49.17% 56.49% 46.65% 38.93% 31.83% 86.91% 570 nm 50.96% 57.32%
47.51% 39.49% 32.83% 87.07% 560 nm 52.65% 57.46% 47.80% 40.74%
33.09% 87.22% 550 nm 54.07% 58.42% 48.62% 40.42% 34.03% 87.25% 540
nm 55.20% 58.25% 48.93% 41.91% 34.28% 87.30% 530 nm 55.63% 59.37%
49.37% 41.50% 34.96% 87.46% 520 nm 54.08% 58.89% 49.87% 42.56%
35.13% 87.61% 510 nm 47.60% 60.03% 49.98% 42.25% 35.61% 87.69% 500
nm 33.63% 59.34% 50.18% 42.96% 35.43% 87.64% 490 nm 17.47% 60.00%
50.14% 42.28% 35.76% 87.67% 480 nm 7.97% 59.47% 49.93% 42.81%
35.13% 87.59% 470 nm 4.22% 59.07% 49.51% 41.47% 34.91% 87.44% 460
nm 2.37% 58.91% 48.80% 41.64% 34.27% 87.23% 450 nm 1.31% 57.91%
48.09% 40.37% 33.12% 87.00% 440 nm 0.82% 57.05% 47.07% 38.94%
32.11% 86.64% 430 nm 0.62% 55.94% 45.67% 38.19% 30.82% 86.25% 420
nm 0.50% 54.65% 44.04% 36.29% 28.99% 85.81% 410 nm 0.45% 52.89%
41.99% 33.67% 26.74% 85.30% 400 nm 0.46% 50.50% 39.35% 31.06%
24.12% 84.55%
[0039] The range of concentrations of antimony doped fin oxide with
dispersant in accord with the present invention as shown in this
fable correlates with the arc protective limits of the resulting
product. As this chart shows, faceshields of the present invention
provide substantially consistent light transmission across the
visible light spectrum which results in color acuity for the user
of such faceshields. Indeed, the present invention provides a
higher degree of light transmission at every visible wavelength
versus the example prior art "green" shield, which essentially
blocks shorter wavelength visible light (i.e., in the blue-violet
range) and therefore lacks the desired color acuity for use by
electricians and electrical workers. Furthermore, while the example
faceshield in accord with the present invention does not have tire
same level of light transmission as a "clear" faceshield, the
present invention, unlike the clear shield, has infrared radiation
absorption properties that enable its use in hazardous environments
having the potential for arc flash events. For instance, the
invention in the form of a faceshield and in the form of a hood
window has been subjected to arc testing according to the American
Society of Testing and Materials Test Method F2178. This test
method is used to quantify the level of protection provided by arc
resistant eyewear, faceshields and hoods. This test provides an are
rating value for face and head protective equipment such as
eyewear, faceshields and hoods equipped with hood windows, which,
in the case of the faceshields manufactured in accord with the
present invention have arc ratings of 4 to 40 cal/cm.sup.2, and in
the case of hoods equipped with hood windows manufactured in accord
with the present invention have an arc rating of 15 to 140
cal/cm.sup.2. The faceshields and hoods equipped with hood windows
that were tested also meet the requirements of the National Fire
Protection Association standard 70E. The faceshield 10 can further
optionally include a very thin gold coating on its surface to
reflect radiant heat in prolonged environmental exposures, such as
experienced by firefighters, smelters and the like. The gold
coating reflects a substantial portion of the radiant heat exposure
and the grey eyewear, faceshield and hood window absorb a
significant portion of the remaining infrared radiation that is not
reflected by the thin gold surface coating. As a further option,
the faceshield may have added to it selected amounts of a dye of a
color within the visible light spectrum. Thus, unlike traditional
green or orange tinted-faceshields, the present invention creates a
medium-density filter allowing visibility across the visible light
spectrum that also allows color acuity. Furthermore, for increased
ultraviolet radiation protection, it may be desirable to add up to
1% by weight of an ultraviolet radiation absorbing compound to the
eyewear, faceshield and hood window compositions.
[0040] The above description is not intended to limit the meaning
of the words used in the following claims that define the
invention. Rather, it is contemplated that future modifications in
structure, function or result will exist that arc not substantial
changes and that all such insubstantial changes in what is claimed
are intended to be covered by the claims. For instance, those of
skill will understand that the instance invention can also apply to
other forms eyewear beside spectacles, goggles, faceshields and
hood windows. Likewise, it will be appreciated by those skilled in
the art that various changes, additions, omissions, and
modifications can be made to the illustrated embodiments without
departing from the spirit of the present invention. All such
modifications and changes are intended to be covered by the
following claims.
* * * * *