Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2180184
TITLE: T,AMTNATF: MATERIAL FOR PROTECTION
AGAINST SOFT X-RAYS
3ACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to occupational health and
safety, and in particular to a laminate for the
protection of personnel from the chronic and acute
health hazards of Soft X-rays. It also relates to the
protection of hearing within a welding helmet, and to
the protection of personnel from extreme heat.
Description of the Prior Art
Hitherto, it has been preferred for welding wear fabric
to consist of heavy leather g I ~:. covering inner
garments of some flame resistant fabric (FRF) such as
cotton. However, this protection is limited to arc light
from the ultraviolet region.
~Iowever, in the arc welding environment an electric
current flows from metal surface to another in order to
generate the heat required for fusion. The physica~ act
2 1 8~ 1 84
of striking a metal surface with a flow of electrons
liberates electrons from the outer shell of the metal
creating a form of radiation called Soft X-rays. Soft
X-rays are a form of radiation between ultraviolet
and X-ray radiation which have greater ability to
penetrate matter than ultraviolet but less
energy than X-rays. Soft X-rays can be defined as
having wavelengths greater than 0.1 Any ,~- but less
that 10 An~:,Lr ~ - . The essential characteristic of Soft
X-rays is they have a wavelength which is comparable to
the distance between electron shells and atomic nuclei.
In the arc welding environment, electric current flows
to force electrons against an exposed metal surface. The
result is a scattering of both electrons and photons in
the immediate vicinity. Electrons flowing outside a
contained electric current are frequently called beta
particles. Since both electrons and photons are neither
particle nor wave, and' each is in itself a logical
cull~LL~ ion ~ iqn~d for man to understand the
microscopic world in a macroscopic context, the term
Soft X-ray radiation will be used to delineate all forms
of energy, particulate and wave; electron, beta particle
and with a wavelength between 0.1 An~, - and 10
Ang~ ~L ~ - .
.
3- 21~0~84
Mathematically, Soft X-ray radiation should be produced
by a lOO volt arc. The gain in kinetic energy as the
electron accelerates equals the loss of potential
energy. 2
1/2mv = eV
v= 2eV/m = (2) (1.6xlO**-19C) (lOOV)/(9.lxlO**-31)kg
v= 5 . 9x10**6 m/s
--34
6.6 xlO J.s
=h/mv =
--31 6
(9.1 x 10 kg) (5.9xlOm/s)
--10
= 1.2 x lO m
These equations show that an electron accelerated across
an arc with a voltage of lOOv does so with wavelengths
that can approach 1. 2 An~LL in length, which is well
within the Soft x-ray region of the ele. LL gnDtiC
ff~e~;~L ~I~U. While these equations describe the electrons
within the arc and not the reflected beta particles or
the emitted photons, the equ;~tions d l_Lc~te a
substantial risk of occupational hazard from the welding
arc to both personnel health and weld quality as it
relates to manual dexterity during the welding process.
However, despite widespread concern of some unknown
health hazard in the arc welding environment,review of
the popular literature regarding welding processes has
found no consideration of Soft ~-ray radiation and a
21~3184
review of U.S. Patent 5,210,878, u.S. Patent 4,117,554,
U.S. Patent 4,445,232, U.S. Patent 5,222,257, U.S.
Patent 5,323,815 and U.S. Patent 5,172,426 has found no
measures taken to effectively shield against Soft X-ray
radiation .
Arc welding consists of numerous different processes
which utilize different ~ h1nDs. Flux Core Arc
Welding ( FCAW), Tungsten Inert Gas (TIG) welding Metal
Inert Gas (MIG) welding pose a greater risk than Stick
Metal Arc welding(SMAW). Welding in the vertical up
position poses a greater t:XpO~>ULe: to the chest than
other positions. Radiation risk is also determined by
voltage and <l~e of the current source. ~igh voltage
currents will create radiations of smaller wavelengths
while raising amperages will increase the amount of
radiation without altering the nature of the radiation.
It is also possible th~t other electrical devices and
other ele~;LI gnDtic envi~ L~ expose people to Soft
X-rays. Potential hazards include computer monitors,
televisions and other cathode ~ay tubes, electric
lighting and radio transmission equipment.
The medical effects of Soft X-rays are largely
undetDrmi necl, While the medical practice of chemotherapy
21 ~18~
~ --s--
has provided a wealth of knowledge regarding the effect
of X-ray radiation upon biological tissue, the study of
the effect of Soft X-rays upon biological tissue is less
advanced. Also, welding personnel suffer from symptoms
of premature aging which mimic non-lethal and chronic
doses of radiation injury such as chronic hair loss,
rP~ldPnin~ of the skin, increased thickness of the horny
layer of the skin and lung cancer. The similarity of
many of these symptoms to that of smoke inhalation may
have caused mi~rl;i~gno5i5. Soft X-rays pose a potential
health hazard in the welding environment.
If we assume that Soft X-ray radiation has biological
effects comparable to X-ray radiation then the areas of
the body most vulnerable to Soft X-rays would be those
which divide rapidly such a~i the skin, blood forming
organs, lungs, gonads and in~estines. Radiation injury
is not limited to the killing of radiosensitive cells
however. The initial injury leads to secon~ry
di~uLl,an~ es and reparative processes, often through
systemic - -ni Fm~ which modify the primary injury.
Radiation injury often simulates other injuries and is
neither unique or specific.
Soft X-ray radiation may reduce the quality of manual
21 ~01 ~4
welding. While large amounts of gamma radiation are
required to kill adult nerve cells, transitory
neurological effects can result from relatively small
doses. An intensive exposure to the brain of 50 Gy, or
50 joules / kilogram, of gamma radiation will
i n, S?ra~itate the nervous system and can lead to death in
minutes. It is possible then that Soft X-ray radiation
in the welding environment could lead to transitory
neurological dist~lrh~n~Ps which reduce weld quality
without leading to identif iable acute or chronic health
hazards. Reduced weld quality leads to increased
product cost, product failure, environmental spills need
for extensive testing.
The Process of manual arc welding exposes certain areas
of the body more than others due to- their closer
proximity to the welding arc ~ The hand, head and chest
area typically receive the greatest exposure to Soft X-
rays. The chest and throat area are perhaps the most
highly risked area since they are both exposed and
vulnerable. Also, people below'the age of thirty are
increasingly vulnerable.
One means of avoiding arc light radiation is the use of
oxyfuel welding processes which combine oxygen with a
C 7 218~184
fuel to create a high flame temperature. Since the only
radiation created is black~ody radiation, radiation
emitted from hot objects to the surrounding ai ~-re,
r~o Soft X-ray radiation is emitted. However, tr~ - ldoll-
heat in the form of infrared radiation limits the
usefulness of the technique due to discomfort of
personnel and distortion of work. E~--r i~- limitations
have limited the use of oxyfuel welding to small runs of
thin sheet.
Complete protection against any form of matter
penetrating radiation is i - - - i hle. It is only possible
to form a shield which removes a higher percentage of
the radiation. Matter can interfere with radiation by
reflection, absorption and diffraction. Any radiation
not affected by these three pL~,cesses travels through
the matter and is said to be~transmitted. once it has
been estimated what th~ n~c5 rémoves 509s of the
radiation, this thi~-kn~cc can be multiplied until the
radiation emitted is reduced to a reasonable level. A
secondary material of difreren~ composition is often
incorporated to alter the nature of the emitted
radiation .
All elements transmit narrow bands of ele~;LL ~ tic
-
C~ ~ 21801~4
radiation which are detr-nminPd the element's atomic
structure. The wavelengths of these are detPrmi nr-~ by
the electrons in the elements electron shells, with a
band created by each electron. The i nnF~ electron
shell, the K-shell, has two electrons which create an
emission band each. These two ~m1c~jrn bands are called
K-line emissions. The electrons of the second shell,
called the L shell, create L-line emissions. M-line and
N-line emissions also exist. K-line ~ qi ~nc are the
most intense and are from five to ten times greater than
L-line emissions. While these emission spectra are
generally considered to consist of photon tr~n-~i cci ~n
only, it is not known by the inventor at the time of
this application whether electrons are transmitted
through matter according to similaF emission spectra.
When the element is heated to a sufficient tr - c.Lu~,
the elements radiate pLotons at these same narrow bands
in a process called hl i~l~khody radiation. The
t-mL ~I.u~ ~s involved in arc welding generate enough
heat to generate bl~ckhody rad;ation in the ultraviolet
region but not in the Soft X-ray region.
Hitherto, welding personnel have had intense and
sometimes injurious quantities of heat applied to
218~184
their hands. u.S. patent 4,445,232 protects
against heat through the use of PVC foam, however, the
use of fibrous refractory material may yield greater
heat protection with less loss of flexibility. Fibers of
alumina mats have been made without the addition of
binders. These mats are made of alumina, otherwise
known as aluminum oxide and are highly effective as heat
shields and thermal barriers since the surface area of
these fibers is between 100 and 150 square meters per
gram. These fibrous mats of alumina are soft and
flexible, having a silky texture. Aluminum oxide
provides no unique protection against radiation in the
Soft X-ray region.
r
Hitherto, hearing protection has not been designed to
provide variable protection. Instead, conventional
protection of the ear canal has been designed to be on
or of f, so that the in'sulation that protects during long
periods of machine operation, etc. must be removed,
clumsily adjusted or overcome through the raising of
the voice during periods of co~versation. The use of
the conventional welding helmets also renders
conventional hearing protection muffs inap~ iate
since they do not fit within the helmet. Plugs fit
within the helmet but raise the risk of ear ~nfectlon.
-lo 2 1 8~1 8~
Prior attempts to protect people from soft X-ray
radiation have relied upon thick pieces of stationary
and heavy material such as concrete block or lead
plate. No known attempt has been made to produce
garments whihc shield from soft X-rays. Leather
garments have been used with the stated purpose of
shielding from ultraviolet radiation.
Prior attempts to protect hearing have relied upon ear
muffs, which can not fit within a welding helmet, or ear
plugs, which can raise the risk of ear infection. None
of the prior hearing protection is designed to be
variable .
Prior attempts to insulate personnel from heat have been
bulky and cumbersome for garments which require a high
degree of mobility and manual dexterity from the wearer.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a laminate
which gives i _.,v~d protection to personnel from the
chronic and acute effects of Soft X-rays within arc
light radiation in the welding environment, yet wh~ch is
--~t _
~ 2~8~1~4
light enough in weight and flexible enough to be worn.
It is an objective of this invention to provide garments
which will provide protection against Soft x-rays.
It is also an obj ect of this invention to provide a
method of variable hearing protection which can be worn
comfortably within a conventional welding helmet.
It is also an object of this invention to create a
laminate to provide greater insulation against heat in a
manner which can be comfortably worn.
It is an object of this invention to provide.for the
attenuation of soft x-rays while permitting the passage
of visible light.
r
It is an object of this invention to protect the ears
from the chafing effect of Velcro pads.
Accordingly, the present inven~ion providQs f or a
laminate material for use as protection against the soft
xray: , l. of ele~ nt~1 ir. radiation. ~he
laminate material comprises an outer layer of preferably
flame resistant material, an int~ -';Ate layer of
~ 21 ~0184
radiation shielding material and an inner layer of
preferably flame resistant material. While all matter
provides some protection against radiation, including
Soft X-rays, aluminum is generally the most efficient
due to its high density of reactive electrons. Aluminum
is so reactive on the microscopic scale that when in a
solid it forms a thin oxide layer on its external
surface to render the obj ect essentially inert on the
macroscopic scale. Yet the reactive electrons in the
interior of the metal are still able to interfere with
radiation. This rh~nl -n~n makes particular sense when
we consider radiation from beta particles, which are
essentially electrons travelling freely without a
nucleus. Because electrons repel each other; we would
expect the abundance of freely charged electrons within
aluminum solids to exert more stopping power than other
matter. As shown above, the arc welding environment is
theoretically known to~ generate beta particles with
wavelengths in the pe~ L-ting Soft X-ray of the
ele. ~L~ _ tic ~e~;~Lulu. It is not yet clear that any
photons from the Soft X-ray region are directly
generated by the arc welding process since blackbody
radiation will be confined to the ultraviolet region and
above. Photons may be indirectly created when electrons
collide, although they will have wavelengths greater
2 ~ 4
~ -B-
than that of the beta particles. However, any photons
generated by the arc welding environment also receive
increased interference from the higher electron density
of aluminum via the Compton effect or the photoelectric
effect. Aluminum is manufactured foils, sheets and
wires all of which can provide interference of Soft X-
ray radiation.
Like all elements aluminum has a characteristic emission
spectrum in the Soft X-ray region of the ele. ~L -tic
spectrum. Aluminum transmits radiation at 8 . 3392 A,
8.3367 A, 7.981 A and 169.8 A. The first three bands
are at the higher wavelength region of the Soft X-ray
spectrum while the last lies within the ultraviolet
region. The wavelengths of the emission bands tend to
decrease into the more dangerously penetrating regions
of the Soft x-ray spectrum as the atomic number of the
element increases. Absprption of the emission bands can
be effectively attained by the use of cloth and leather,
because they are essentially made from the element
carbon which has a single ~ inn band at 44 A.
Absorption of these bands is provided by the inner layer
of the laminate. In the particular case of the welding
environment, these emission bands will also be absorbed
by coveralls and street clothes which are worn beneath
~ -T4- 21 8~1 ~4
protective welding wear.
This invention has been developed and tested by the
inventor and found to give subjective evaluations of
increased weld quality with reduced symptoms acute
radiation injury. Such acute symptoms include lack of
concentration, eye strain, s ~ Ar tremors during
welding, irritability, fatigue and ;nfl: tion of the
throat. Elowever, further field testing will raise
ethical dilemma.
This invention provides lightweight protection from soft
x-rays in garment form through the incorporation of a
laminate with a central metallic aluminum la~yer. The
high electron density of aluminum gives it extraordinary
ability to interfere with soft x-rays, particularly when
the radiaition is in the form of beta particles.
This invention provides for the simultaneous
transmission of visible light and the protection from
soft x-rays by using a thick la,yer of material which is
transparent to visible light.
This invention provides for protection of hearing by
L-:ssing deformable foam rubber ear muffs again~t
2180~84
~ --~5--
the head by a prosthetic device which adjusts around
the neck in collar form.
This invention provides for the insulation from extreme
heat using a laminate with a central layer of heat
shielding and th~rr-l ly insulating refractory fibers
held between two lay~rs of impe ious fabric
r
2~0~84
-16-
DESCRIPTION OF THE DRAWINGS
Referring to the drawings, Figure l shows a
perspective drawing of the laminated material with
the bottom left hand corner ~ mi n;lted for
convenient viewing.
Figure 2 shows a section view of the laminated material.
Figure 3 shows a plain view of the head and shoulders of
the user while wearing the cap and neck cover, the veil
and W protecting safety goggles.
Figure 4 shows a plain view of the user from head to toe
while wearing the cap and neck cover, W protecting
safety goggles, the chest pad, the armlets, the gloves,
coveralls and work boots.
Figure 5 shows a plain view of the user from head to
toe while wearing the ~ of Figure 4 plus the
welding mask with acrylic viso~; plus the ~ront and
back apron.
Figure 6 shows a plain view of Figure 5 ~rom the side
view.
-17- 2180t84
.
Figure 7 shows a plain view of the front apron.
Figure 8 shows a plain view of the back apron.
Figure 9 shows a plain view of the chest pad.
Figure 10 shows a plain view of the users head while
wearing the cap and neck cover with hearing
protection muffs in place.
Figure 11 shows a plain view of the user' s head while
wearing hearing protection taken from the side view.
Figure 12 shows a plain view of the pattern for the cap
portion of the cap and neck cover.
Figure 13 shows a plairl view of the neck cover.
Figure 14 shows a plain view of the back of the glove.
Figure 15 shows a plain view of the front of the glove.
Figure 16 shows a plain view of the armlet for the
dominant arm.
-1~ 21~0~84
.
Figure 17 shows a plain view of the veil.
Figure 18 shows a plain view of the welding helmet with
acrylic visor and dark lens but no he;~lh~nrl assembly
taken from the side view.
Figure 19 shows a plain view of the hearing protection
muff .
Figure 20 shows a plain view of the hearing protection
muff taken from the side.
Figure 21 shows a plain view of the hearing protection
muff as it is, ~ ssed against the ear by the force of
the collar flap.
Figure 22 shows a plaip view of the relat;~n~h;r between
the ear and the hearing protection muf f when the chin is
thrust f orward .
Figure 23 shows a plain view of the relationship between
the ear and the hearing protection muf f when the head is
in the normal posture position.
-lg- 2 1 8~ 1 84
Figure 24 is a perspective of the acrylic visor inside
of the welding mask while the laminate of the welding
mask has been cut away to expose the laminate structure.
Figure 25 is a perspective of the ear chafing protector
with the upper right hand corner folded to reveal the
Velcro pad on the reverse side.
Figure 26 is a section view taken from Figure 15
showing the laminate construction of portions of the
glove, namely the back of the hand and the front of the
wrist .
DESCRIPTION OF THE ~ ;~su EMBODIMENT
The laminate of the present invention as shown in Figure
1 and Figure 2 is primarily comprised of three layers.
The exact composition ,of the laminate will very from
garment to garment. The outer layer 2 will vary between
heavy leather, 3.5 oz per square foot, and/or fire
resistant fabric(FRF). Weight and economy are the
factors detPl~n;n;n~ the outer layer for each garment.
The outer layer shields against sparks and flames while
diffracting radiation reflected ~rom the inner metal
layer. The leather and the FRF may be joined by a
-20- 2180184
~lexible adhesive such as poly vinyl acetate(PVA) 5. The
inner radiation shielding metal layer 1 will vary
~ler~n~in~ upon the extent of the radiation hazard, the
allowable weight det~rmi n~ by the distance of the
~abric from the body's centre of gravity and the
fleYibility requirements of the laminate. Possible forms
of the metal are metal sheets, foils and fibrous mats.
The metals will be adhered to each other and to fabric
or leather by both an adhesive such as contact cement 6,
and by stitching. The adhesive must be non-flammable
when dry. The inner layer 3 will be made of flame
resistant fabric (FRF~ such as denim cotton. When
leather and metal thickness are not prohibitive, the
three layers will also be joined by unbreakable thread
such as upholstery thread 4 . The edges o~ heavy sheet and
mat may be bordered by heavy stitching to keep them in
place .
The inner radiation chi~ldinq layer will preferably be
made from aluminum. While all matter provides some
radiation chi-~lrlinq, aluminum iS the preferred metal of
choice for general protection due to its high electron
density. Aluminum is so reactive on the microscopic
scale that as a pure, metal solid it is practically
inert on the macroscopic scale. ~etallic aluminum
2 1 ~01 84
--2:
reacts very quickly with oxygen 50 that a layer of oxide
protects atoms on the interior of the metal from
chemical reaction while allowing them to retain their
unbound electrons. When radiation penetrates the
aluminum in the form of beta particles, photons or
waves, these unbound electrons are able to have stopping
power above that of the bound electrons in other metals.
Aluminum also has a low number on the periodic table
which gives it a high number of electrons when compared
to its atomic weight. The availability and ductility of
aluminum also make it the best choice for general
protection against Soft X-ray radiation. It is possible
that the K-line and L-line discontinuities of aluminum
at approximately 8 and 170 An~ L : may coincide with
spectral peaks in the emission curves of arc light
environments or other ele~iLL tic environments.
While ele.;~L.Iuc.y.letic enviro~ments with such emission
curves are unknown at this time, their discovery may
necessitate the use of alternative metals, a flexible
f ibrous carbon material or very heavy leather either to
supplement or replace aluminum. Alternate metals are not
advised since their K-line emission spectra lie in the
higher energy low wavelength frequencies.
Figure 3, Figure 4, Figure 5 and Figure 6 show app~rel
2~8~8~
made from the laminate material o~ Figures 1 and 2 to
be worn by welders. The chest pad 9, the armlets 12 and
the gloves 11 are worn over the coveralls 23 which are
worn over street clothes and over the work boots 21.
Spats may also be worn to cover the work boots, although
these are not shown. The cap and neck cover 10 is worn
over the head and it attaches to the veil 13. Safety
goggles 19 are worn . Elearing muf f protectors 16 and ear
chafing protectors 17 are both available for use at the
user's discretion. The front apron 7 and the back apron
8 are worn over the chest pad. The welding mask 14,
complete with acrylic visor 15 and dark lens 20 attach
to the ho~lhs~nr7 assembly 18 to make the welding helmet
which is worn over the head while it is wearing the cap
and neck cover 10 and the safety goggles 19.
The front apron of Figure 7 is designed to provide
general light weight protection against the injurious
effects of Soft X-rays. It is comprised of 5 layers of
aluminum foil 1 held between two layers of f ire
resistant fabric(FRF) 2, 3 by çontact cement 6 and
stitching 4. It covers from the ~ho~ or blades to the
lower thigh. Lightweight aluminum sheet 26,
approximately 28 gauge, supplements the metal foil layer
1 in the region of the front apron which covers from the
~ 2lsals4
bottom of the ribcage to the upper thigh area. This
of fers increased protection to the intestinal and gonad
region without restricting body movement. The qho~ Dr
straps 27 on the front apron is wide to displace the
weight to the shoulders in a comfortable manner. A pair
of snaps 23 is placed at the rear of the qho~ Dr strap.
These allow the wearer to raise the level of the apron
to cover some of the neck, while allowing the shoulder
strap to create a hole large enough for the head to pass
through when putting the garment on. If a snap becomes
detached accidentally, the apron will continue to hang
in front of the body. As shown in Figure 8 A back apron
with five layers of aluminum foil 1 protects the back of
the body from radiation which is scattered b~ welding
booth walls. The back apron is essentially similar to
the front apron except for tailoring of the qhmll dDr
strap and the omission of increased intestinal
protection. The back apron attaches to the front apron
by four snaps 22, 28 placed along the front on the
chmll ~Drs. The back apron is readily removable for use
in hot environments. Snaps arç preferable to buttons or
studs since they do not permit the passage of sparks or
allow small holes through which radiation can pass.
They are also not prone to frayed edges. Side straps 25
attach through grommets 24 in the side of both front and
~ 21~01~4
back aprons to keep the aprons close to the body.
The chest pad as shown in Figure g drapes over the
shoulders. The front piece 33, which holds the
protective breastplate 29, attaches to the back piece 34
in the dorsal regions of the chest cavity using snaps
30. The front piece is stitched to the back piece along
the shoulders. The outer layer 2 is heavy leather and
FRF to provide the radiation and f ire protection of the
prior art. A metal breastplate an eighth of an inch
thick covers the rib cage to protect this exposed and
vulnerable area from Soft X-rays. The chest pad extends
below the ribcage with a covering of heavy leather 2 and
five layers of aluminum foil l to protect the intestinal
and gonad regions without impairing comfort or ease of
movement. Personnel with lower back problems may
consider some sort of girdlin~g belt to provide
prosthetic 6upport of llhe heavy breastplate 29. The
breastplate is held in place upon the chest pad by an
appropriately sized cloth of denim 3 and upholstery
thread 4 . Snaps at the deltoid ,and pectoral region 31 of
the ~ho~ r joint receive the armlet snaps as l/2" wide
velcro strips encircle the chest pad's two armlet
openings 3 2 .
21 ~01 ~4
The cap 35 and neck cover 36 laminate in Figure lo,
Figure 11, Figure 12 and Figure 13 is designed for
flexibility. The radiation shielding metal layer 1 is
comprised of f ive layers of aluminum foil . This
protection is PnhAncPd on the inner collar flap by a
plainly woven mat of one eighth inch diameter aluminum
wire 42. The neckcover snaps together at the front by
three snaps 3 9, 4 o to prevent spark entrance and ensure
radiation protection. The ear area of the neck cover is
covered by a four inch by four inch Velcro square 41 to
support the ear protection detailed in drawing 10. The
degree of ear protection provided is primarily set hy a
Velcro strap 43 on the collar of the neck cover. The
neck cover covers to the temple region to prevent the
blocking of peripheral vision. The male half of snaps 52
are placed at the temple of the cap to accept the female
portion of the veil snap 52 while avoiding the hPA~7hAn~
of the welding helmet.~ The cap portion utilizes 35 a
pattern similar to that of a standard welding cap. An
elasticized band 44 sown to the inner surface of the cap
portion ensures that the cap will cling snugly to the
head of the welding personnel.
As detailed in Figure 14 and Figure 15 the laminate for
the gloves is cut in a pattern similar to standard
26- 2180184
-
welding gloves. The radiation shielding metal layer 1
is comprised of a plainly woven mat of aluminum wire a
6ixteenth of an inch in diameter and is confined to the
back of the hand 45 and the front section of the wrist
~6 only, since these are the portions of the hand which
are exposed to radiation during welding and since
maximum flexibility is required for the inside of the
palm and fingers. To protect against the intense heat
flux which the back of the hand 45 and front of the
wrist receive, a heat shielding laminate is attached to
these areas as shown in Figure 26. The flexibility and
heat shielding abilities of the aluminum oxide fi~er 69
are utilized by containing the fibers within two layers
of 1. 0 oz per square foot glove leather 70 . ~he two
layers of leather are held close to each other by
stitching with upholstery thread to ~ ~ss the
naturally fluffy aluminum oxide fibers. To prevent the
escape of irritating aluminum oxide fibers, each layer
of 1. 0 oz . leather is adhered to another layer of 1. 0
oz. glove leather by a flexible adhesive such as PVA and
the laminate is sewn to the inner surface of the inner
layer 3.The inner surface of the fingers and of the palm
consist of heavy leather only, 3.5 oz per square foot,
to maintain the flexibility of the prior art.
_~7~ 3 0 ~ ~ 4
As detailed in Figure 16, the layer of metal foil in the
armlets consists of approximately ten layers aluminum
foil . This heavy foil provides a stif fness which permits
movement of the joint while providing a r7;7mrPninq action
to reduce fine q~~-71 ;7r tremors and spasms which
~7Ccn-~ny and deteriorate delicate welding procedures.
This metal foil layer is reduced to one layer of
foil in the elbow region 50 of the dominant arm. The
dominant arm is the right arm for right handers and the
left arm for left handers. This reduction in
the foil 7-hinknF,cc increases flexibility in this
ergonomically critical elbow area. The armlets are
attached to the chest pads by a ring of velcro straps 49
and snaps 47,48 at the deltoid and pectoral portions of
the shoulder joint. A Velcro strip ensures a close fit
of the sleeve to prevent spark entrance.
,.
The veil, as shown in ~igure 17, attaches to the cap
portion by a snap at each temple region 52. The outer
and inner layer of ~abric as well as the radiation
shielding metal layer are all thin for comfort and
flexibility. The veil's purpose is to protect against
small amounts of radiation which penetrate or scatter
behind the denser protection of the mask. The veil
drops below eye level to permit vision while extending
~ 21801~4
below the chin to protect the face. It is rec~ -nSad
that the veil not be used when the visor region of the
helmet is cold to prevent condensation of the breath
upon the visor.
The welding mask, as shown in Figure 18, is similar in
the shape of its design to conventional welding helmets
with a h~ Ahl?n-l assembly hole 53 which is identical in
size and position to the welding helmets of the prior
art. This will permit the utilization of accessory
hardware from the helmets of the prior art such as the
hf~;-rlh;~n~ assembly 18 and the dark lens assembly 20. It
utilizes a standard dark lens with clear covering lenses
and it requires W protecting safety goggles :to be worn
n~ rnaath. The mask however is made from an eighth of
an inch die cast aluminum 67 covered on both sides by
fiberglass 66, 68. This protects against soft X-rays and
against dangerous reflections of W from polished
aluminum surfaces. The inside of the helmet is painted
black to absorb stray light. The visor region of the
helmet is protected from soft X-rays by a one inch thick
piece of clear acrylic plastic 54. This acrylic lens is
held in place behind the helmet by a acrylic filter
holder which is shown in Figure 24. It is similar to
that of the other lenses for ease of cleaning and
2~ ~0 ~ ~4
.. ~ ~
replacement but is adhered to the new mask by either
adhesive or screws.
The ear pieces, as shown in Figure 19 and Figure 20 are
each comprised of two quarter inch thick pieces of foam
rubber 57, 58 surrounded by two layers of FRF 59, 60. To
the inner layer of FRF is sown a Velcro pad 61 to match
the Velcro pad on the neck cover in Drawing 4. The noise
insulation layer is made from two quarter inch thick
layers of foam rubber 57, 58 which is commonly used for
packing material. Both layers are a oval of two by three
inches, the layer closer to the ear 58 has a one inch
diameter circular hole in the centre. The two foam
layers are held together by adhesive.
The hearing muffs 16 are easily removable during periods
of conversation. As shown in Figure 25 drawing 11, five
inch sguare pads of soft cloth 62 with velcro 63
attached to one side are provided to cover the neck
cover's velcro pads and prevent chafing of the ears when
the hearing muffs are not in pl,ace. As shown in Figure
21, Figure 22 and Figure 23 when the muffs are in place,
the amount of hearing insulation is adjusted by both a
primary and a s~C~n~l~ry means. The amount of hearing
protection i9 prim~rily ~djusted by tte ve~r-r'~
~3~- 21 801 8~
positioning of the muffs upon the neckcover's Velcro pad
41 and by the positioning of the two inch wide Velcro
strap on the neck cover 43. By varying the positioning
of the neck covers Velcro strap, the neck cover offers
varying pressure against the ear muffs to vary the noise
insulation. The amount of hearing protection is
secondarily varied by the ergonomic position of the
head. Thrusting the chin forward of the neck will slide
the ears slightly from under the muffs, to decrease
hearing protection when in conversation or when
listening to a delicate welding operation. Due to the
variations in human anatomy and the eventual stretch of
fabric under tension, it is the responsibility of the
welding personnel and his tailor to ensure proper
adjustment of both ear muff location and neck collar
adjustment to ensure both adequate and variable hearing
protection .
The ear chafing protectors 17 of Figure 25 are soft
pieces of cloth with Velcro attached to one side of them
which matches the hearing muff ,Velcro pads of the neck
collar. When the hearing muffs are not in place it is
n~c~C5~ry to install the ear chafing protectors to
prevent chafing of the ears since the neck collar will
otherwise compress the Velcro pads against the ears.
-~1- 2l8ol~4
It will be appreciated that the above description is
related to the preferred ~ r~nt by way of example
only. Many variations on the invention will be obvious
to those in the f ield, and such obvious variations are
within the scope o~ the invention as described and
cl ~ d, wh-tll~r or n~t expresGI~ d~cri~ed.
