Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This is a divisional application of copending Canadian
Patent Application Serial No. 293,577, filed on December 21,
1977.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to welding helmets for pro- -
tecting the face and sides of a welder's head from being struck
by molten metal, sparks, ultra violet and other radiation and
other debris generated when a welding operation is taking place.
Normally, the helmet features a front piece with a light filter-
ing window so that the welder can watch the welding process
while at the same time his eyes are protected from the intense
light, including ultra violet and infra red radiation, generated
especially in an arc-welding operation. The front piece is
generally a continuation of two rearwardly extending sides
which serve to partially encircle the welder's head to protect
the sides of the head from flying debris.
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2. Description of the Prior Art
Except for the flexible ear portion covers, U.S. Patent
3,327,318 discloses a conventional welder's helmet or mask as
they are sometimes called. The conventional helmet includes a
head piece or cradle which fits over the welder's head and
supports the helmet (mask) in relation to the welder's head.
Normally, the helmet is held in a spaced relationship to the
welder's head so that air can circulate between the helmet and
the welder's head to prevent excessive perspiration and dis-
comfort due to heat.
Since there are adverse physiological conditions associated -
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with most welding operations, considerable effort has been
devoted to improving the welder's environment. The two major
adverse physiological conditions are excessive noise and air
pollution. In regard to the latter condition, U.S. Patents
2,354,502 and 3,535,707 demonstrate attempts to modify existing
welding helmets to provide means to control air pollution or
otherwise upgrade the atm~spheric conditions surrounding the
welder's head.
As noted above, one attempt at reducing noise pollution or
the adverse effects of noise is demonstrated by U.S. Patent
3,327,318, which discloses means for accommodating sound attenu-
ating ear muffs worn by the welder at the same time a welding
helmet is worn in position for welding. Conventionally, noise
abatement has followed the path of using ear muffs or sound
attenuating ear cups which firmly engage the sides of the head
while covering the ears.
In addition to the aforementioned patent, this method of
noise abatement is disclosed in U.S. Patent 3,621,488 in regard
to a crash helmet. The major efforts in this type of sound
attenuation have occurred in regard to crash helmets, and in
particular, to c:rash helmets or helmets worn by military air
craft personnel. Examples of such devices are shown in U.S.
Patents 2,619,639; 2,802,214; 2,867,~13; and 3,005,203.
It is well-known that the sound attenuating ear muffs are ~
effective and are used widely in industry. However, the largest ~ -
drawback of the sound attenuating ear muff is that it firmly -
grips the head of the wearer. Over long periods of time, e.g.
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~ eight hour work shift, these ear muffs can create severe
wearer discomfort from the physical pressure and from closing
of air circulation thus promoting perspiration in and around
the ears of the wearer.
SUMMARY OF THE INVENTION
In order to avoid some of the problems inherent in
prior art, safety helmets and welder's helmets that relied upon
the use af ear muff-type sound attenuating devices, it has
been discovered that a significant reduction in the noise level
presented to a welder's ear can be achieved by positioning sound -
absorbing devices on a welding helmet in spaced relation to
the welder's ear as set out in the foIlowing description.
In one particular aspect the present invention provides
ear protection device for use on a head protecting device of
the hard hat type comprising in combination: a first ear piece
and a second ear piece each having an outer surface and an inner
, surface lined with an acoustical sound absorbing medium; and ~ -
means to position said first and second ear pieces on the hard
hat so that each said ear piece and said sound absorbing medium
is spaced adjacent the wearer's ear but does without physically
touching the wearer's ear, head or face.
; BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a perspective view of the helmet according
to the present invention.
Figure 2 is a fragmentary section taken along the lines
2-2 of Figure 1.
Figure 3 is a rear view showing the helmet on the head
of welder/user in position for welding.
Figure 4 is a perspective view of a conventional welding
helmet having an ear protection device according to the
present invention fitted thereon.
Figure 5 is an exploded view of the ear protection
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device of Figure 4 shown removed from the helmet.
Figure 6 is a fragmentary section taken along
the line 6-6 of Figure 4.
Figure 7 is a partial side perspective view of
a conventional "hard ha-t" with noise attenuators according :
to the present invention.
Figure 8 is a partial bottom perspective view
of the device of Figure 7.
D _ ILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Figure 1 shows a welding helmet designated generally
as 10 which includes a face piece 12 formed of a hard and
durable fire
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retardant synthetic material such as plastic, fiberglass or fiber
reinforced synthetic sheet material. Face piece 12 is generally
molded by pressing from sheet stock or is otherwise formed as a
unitary structure having a generally cylindrical front section 14
having a window port or holder 16 including a shatter resistant
light filtering glass 18. Front section 14 protects the face of
the welder and provides means, through glass 18, whereby the
welder can view the weld in progress without damage to the eyes.
Window holder 16 can include means (not shown) for moving the
light filtering window 18 out of position thus revealing a clear
safety glass (not shown) so that eye protection is afforded to
the welder when not welding. Face piece 12 includes a crown
section 20 to protect the top forward portion of the welder's
head and a depending skirt portion 22 to protect the chin and
neck of the welder. Lastly, the face piece 12 includes rear-
wardly extending sides 26 and 28 for protecting each ear and the
side of the head of the welder/user.
Face piece 12 is~supported by head harness 30 which includes
a top of the head strap 32 and adjustable encircling strap 34.
The face piece 12 is caused to pivot in relation to the head
strap 30 by means of adjustable pivot members 36 and 38. Thus,
face piece 12 can be positioned in front of a welder's face
, (Fig. 3) for welding or moved away from the face thus allowing
¦ the welder an unobstructed view when the welding operation has
been halted or terminated.
Head encircling member 34 includes a ratchet-type adjustment;
and a snap-type adjustment (not shown) is included in strap 32 so
that harness 30 can be adjusted for different head sizes.
Adjustment of member 34 is accomplished by means of adjusting
knob 40.
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Formed in each side 26, 28 of face piece 12 of helmet 10 is
a forward extending recess such as 42 shown in relation to side
26 of face piece 12. Disposed within recess 42 is an ear protec-
tor 50 which has a peripheral shape in its forward portion 52
complementary to the recess 42 in face piece 12. Ear protector
50 extends rearwardly of the face piece 12 as shown by the numeral
54 of Figure 1. Ear protector 50 includes a rigid outer shell 50
and a complementary inner shell 58 having therein a large annular
opening 60 (Figures 2 and 3). Disposed within ear protector 50
10 is a noise attenuating material such as a noise absorption foam
manufactured and sold by the Composites Division of the Ferro
Corporation of Norwalk, Connecticut under the trademark CUSTIFOAM,
3-D. Ear protector 50 includes complementary spaced apart lips
62,'64 which trace the periphery of the sides 56, 58 so .that the
ear protector 50 can be affixed to the face piece 12 dS by a
- conventional cementing technique. Alternatively, rivets or ' -
other mechanical fasteners could be passed through the lips 62,
; 64 and the wall of face piece 12 to provide an intimate mechanical
bond.
As shown in Figure 3, when the helmet according to the
present invention is donned by a welder/user and the helmet 10 is
, in position for the welder to commence a welding operation, the
ear pieces 50 are positioned adjacent each ear of the welder, but
do not touch the ear of the welder. Provision is made in the .
construction of the helmet to adjust the width of the,"ear area".
This can be done by an adjustable band in the chin area (skirt ' :~
portion 22) of face piece 12 or around the back of the welder's
head by an additional adjusting strap (not shown). With the '~
; sound absorption material as close to .the user's ear as possible, -~ '-
without ~
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actually touching the earj maximum sound reduction at the ear is
achieved. Thus, the noise absorption material is positioned to
attenuate the noise that is presented to a welder's ear area
without pressing against the ear of the welder thus causing
discomfort due to pressure on the ear or excessive perspiration -
by preventing air from freely circulating around the ears of the
welder.
In particular, the welding helmet of Figures 1-3 is ideally
suited for use with the conventional air-carbon arc cutting and
gouging process developed by the Arcair Company of Lancaster,
Ohio. In the air-carbon arc cutting and gouging process, metal
cutting or grooving (preparation for subsequent weldingj is
achieved by using a torch which holds a carbon graphite electrode
so that the welder can strike an arc between the eIectrode and
the work piece to cause melting of the metal. At the same time,
a stream of compressed air is directed along the electrode to
"blow away" or remove the molten metal thus providing a cut or
groove in the metal work piece. The air-carbon arc cutting and
gouging process is inherently noisy, the noise generated by the
process coming essentially from a point source which the operator
faces. The helmet of the present invention was devised in an
attempt to reduce the level of noise present at the user's ear
without resorting to the conventional "ear-muff" type of ear
protector.
In the air-carbon arc cutting and gouging process, reducing
the noise level, measured 20 inches from the source by procedures
approved by the American Welding Society, present at the welder's -
ear by a factor of 10 to 15 decibels would result in significantly
improved operator comfort and lessen the tendency for-permanent
ear damage to operators using-equipment employing the process.
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Set forth in Table I is a summary of acoustical data measured
at the arc in the air-carbon arc cutting and gouging process and
at the welder's ear when the process is operating.
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From the foregoing l'able I, it is readily apparent that
there is a significant reduction in operating noise level when
the operator is wearing a helmet with noise attenuating ear
protectors such as shown in Figures 1-3 of the drawing. Even
when the process air pressure is reduced to reduce the operating
noise level, the improved helmet gives further beneficial reduc-
tions in the noise presented to a welder's ear.
Figure 4 shows a conventional welder's helmet 100 including
a head supporting harness 102 similar to the head supporting
harness 30 of the helmet of Figure 1, and a viewing port shown
generally as 104 closed by a light filtering window similar to
that of the helmet of Figure 1.
The helmet 100 has rearwardly extending sides, one of which
106 is shown in the drawing. The side 106 terminates in a gener-
ally vertically extending edge 108 which extends from the fore-
head protection portion 110 to the chin and neck protection
portion 112 of helmet 100. Fitted on either side of helmet 100
is an ear protection~device shown generally as 120. Referring to
Figure 5, the ear protection device 120 has a clam-like support
structure including a first half 122 in the shape of a dish with
a raised lip 124 having therein a plurality of apertures 126.
Hingedly connected to the first half 122 of ear protector 120 is
- a second support half 128 being a mirror image of section 122 of
ear protector 120. A large annular aperture 130 opens the bottom
of the dish-like portion of 128 to the atmosphere. Second half
128 includes a flat annular lip 132 and apertures 134 each of
which are complementary to apertures 126 of section 122. Dis-
posed within the dish-like portions 122 and 128 of ear protector
120 are a pair of foam pads 136, 138 of an acoustical absorbing
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material. This material can be the same foamed polymeric
material used in the device of Figures 1-3. The ear protector
120 is affixed to the helmet 100 by closing the halves 122,
128 (clam) to grip the respective sides of the helmet 100 such
as shown in Figure 4. The ear protector 120 is fastened to the
helmet 100 by passing a plurality of fasteners, e.g. rivets
140 through the mating apertures 126, 134 and through the
respective sidewall of'the helmet 100. Of course the ear pro-
tector 120 can be fastened to the helmet by a suitable adhesive
between the lip 124, 132 and the sidewall of the helmet. The
ear protector 120 is positioned so that the half of the pro-
tector 120 having the large aperture 130 is on the inside
surface of the helmet so that the acoustical sound absorbing
material is positioned adjacent the welder's ear in the manner ,
of the device shown in Figure 3. This apparatus of Figures
4-6 is a device that can be readily attached to existing weld-
ing helmets to provide the same type of noise reduction
experienced with the device of Figures 1-3. In point of fact,
a device was constructed according to that shown in Figures 4-
6 and the tests as set forth in Table II below confirmed almost -
identical noise level readings to those shown in Table I.
Figures 7 and 8 show.an appàratus according to the
invention~.as it can be applied to an ordinary safety helmet
(hard hat). The hard hat 150 is of the conventional type having
an outer shell 152 and inner head harness 154 (Figure 8) support
as is well known in the art. A face shield 156 is hingedly
fixea to hard hat 150 as by adjustable pivot,members, one of
which is shown as 158. Pivot member 158 is similar to pivot
members 36 and 38 of the device of Figures 1-3 and permits face
shield 156 containing tinted safety windo~.l57 to be moved into
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position in front of the wearer's face as welding takes place
or away from the wearer's face to facilitate material handling
and set-up before or after welding.
Ear protector device 160 consisting of two ear pieces 162
and 164 joined by a spacer or support 166 is fastened to hard
hat 150 by any convenient means, e.g. adhesive, ear protector
160 supports an inner lining of acoustical foam material
adjacent to but not in contact with the wearer's ear thus ,
ach~ieving the same noise attenuating characteristics found
with the devices of Figures 1 through 6.
Table II sets forth t~e r~sults of a series of tests run
with a device such as shown in Figures 7 and 8. The test data
shown in Table II show the device of Figures 7 and 8 to be
effective in reducing noise at the wearer's ear.
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In order to effect even more sound reduction, it would be
within the scope of the present invention to line the entire
interior surface, excluding the viewing port, of the welding
helmet with the sound absorbing material. Tests with this type
of helmet confirmed slightly better sound attenuating character-
istics with the full helmet lining.
It is within the scope of the present invention to mold the
ear protecting housing 56 of the apparatus of Figures 1-3 as an
integral unit with the helmet allowing for insertion of the
sound absorbing material after the molding operation.
It should be borne in mind that the object of the present
invention is to provide a welding helmet wherein the noise
level surrounding the user is not transmitted in total to his
ears. This is to be done while eliminating the need for the
"ear-muff" type sound blocking devices. It has been industry
experience that "ear-muff" type sound blocking devices are
uncomfortable especially when an operator is working in high
temperature environments because of the attendant perspiration
and irritation of the skin under the ear-muff. The ear-muff
device also represents another piece of equipment that must
be purchased and maintained, and use must be enforced to
prevent hearing damage. With the device of the ins~ant
invention, ear protection comes along with face and eye
protection which every welder must use.
The apparatus of the present invention does not interfere
with atmospheric circulation inside the welding helmet and
does not increase the welder discomfort since there is no
device exerting pressure on the ear of the user.
In summary, it should be noted that by using current mold-
ing techniques, the single unit welding helmet can be made
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light in weight and will provide in the same unit ear protection
whether or not the user wishes to have the same. Foreclosing,
the choice protects the user by reducing the ambient noise
level 10 to 15 dbA under the welding helmet.
It is also within the scope of the present invention to
include back and bottom flaps that can be caused to open or
close as the helmet is raised or lowered about the pivot points
to further protect the welder's ears from noise without contact-
ing the ears or the head around the ears of the welder/user.
Devices, according to the present invention, can be made
to be accessories which depend from conventional "hard-hats"
to effect noise protection in working environments.
The sound absorbing materials can be readily replaced
either because of wear, cleaning, or to use improved materials
as they are developed.
It is also possible to further minimize noise level by
sealing the viewing port area of the face shield with appropriate
gaskets so that noise does not filter in through gaps at the
g~ass to viewing port interface. The entire helmet and sound
absorbing materials are easily accessible for cleaning so that
the sound absorblng qualities will not be destroyed by the
material becoming filled with foreign particulate matter, or
vaporized or liquld materials.
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