Note: Descriptions are shown in the official language in which they were submitted.
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PROTECTIVE FACE SHIELD ASSEMBLY WITH REMOVABLE SHIELD OR VISOR
TECHNICAL FIELD
[0002] The present invention generally relates to a protective face
shield assembly with
a removable shield or visor, and more particularly relates to a protective
face shield assembly
suitable for use with protective hoods used in toxic environments. After use,
the shield or visor
may be removed from the protective face shield assembly and either cleaned and
reinstalled, or
replaced.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Protective hoods are used in combination with, or as an integrated
part of,
protective smock style tops or full-body suits, the purpose of which are to
shield or isolate
individuals from chemical, physical, and biological hazards that may be
encountered during
hazardous materials operations. Some protective suit designs contain several
components:
hoods, smock style tops, pants or coveralls, gloves, and boots. A protective
hood may be
designed to cover only the head, face, and shoulders, or it may form part of a
smock style top
worn with pants or coveralls, the smock style top covering the head, face,
arms, and torso. A
protective hood may also form part of a protective full-body suit.
[0004] Tritium suits protect a wearer against inhalation and skin
exposure of Hydrogen-
3, H-3, or 3H (a.k.a. tritium) in nuclear plants. Tritium is a radioactive
isotope of hydrogen that
contains one proton and two neutrons. It is a gas at standard temperature and
pressure.
Tritium is produced in nature and is also industrially produced as a by-
product in nuclear
reactors by neutron activation of Lithium-6 as well as in heavy water-
moderated reactors.
Tritium is difficult to contain; rubber, plastic, and some kinds of steel are
somewhat permeable
to tritium. The emitted electrons from small amounts of tritium cause
phosphors to glow; hence,
tritium is used to make self-illuminating devices, such as watches and exit
signs. Tritium is also
used in nuclear weapons.
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[0005]
Some current tritium hoods are made with a TYVEK QC fabric containing a thin,
ten millimeter LEXAN shield or visor which is affixed permanently to the
fabric. The visor
contains a ventilation opening which is closable by a flap, also made of the
visor material. This
flap is covered by an adhesive strip.
[0006] In the laundering of such tritium suit hoods, problems arise that
make the hoods
unusable and unsafe. During the laundering process the ten millimeter LEXAN
visor could
become distorted and possibly cracked. Also, the visor may dislodge from the
fabric.
Therefore, the tritium suit hoods are discarded rather than laundered and
reused.
[0007]
One attempt by the present inventor to address this drawback was to employ a
visor assembly with a tritium hood, which allowed for the visor to be press
fit into the visor
assembly for easy removal and replacement. This visor assembly is shown and
described in
U.S. Patent Application Publication No. US 2009/0100560 A1. Unfortunately, the
means for
attaching the visor to the hood was not sufficiently robust, the seal having a
tendency to open
up when the wearer moved around within the hood.
[0008] The present invention serves to address these drawbacks by providing
a
protective face shield assembly with removable shield or visor that is
suitable for use with hoods
used in toxic environments, the protective face shield assembly comprising:
an arcuate or bow-shaped frame member that defines an opening, the frame
member
being formed from similarly sized first and second arcuate frame members;
a shield or visor positioned within the opening defined by the arcuate frame
member and
between the first and second arcuate frame members, thereby forming an
assembly; and
means for holding the assembly in gas-tight, detachable engagement.
[0009] In
an exemplary embodiment, the first and second arcuate frame members have
a plurality of coextensive hollow protrusions of varying heights that extend
substantially
perpendicularly there through around a perimeter of the frame member. The
hollow protrusions
in the first arcuate frame member have slot-shaped internal cavities, and the
hollow protrusions
in the second arcuate frame member have substantially circular cross-sectional
shapes and
terminate at an upper face into a slot-shaped opening. These hollow
protrusions define mating
structures that are engagably secured together in the inventive assembly.
[0010] The means for holding the above-named assembly in gas-tight,
detachable
engagement in this exemplary embodiment are coupling devices in the form of
removable/re-
usable rivets or drive pins, and a continuous gasket that extends along an
inside surface of the
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first arcuate frame member around the opening formed by the arcuate frame
member. The
drive pins each have a head and a shank with an o-ring and a pair of side
wings located at a
distal end thereof. When the drive pins are inserted through the hollow
protrusions of the first
and second arcuate members and turned 90 degrees, the side wings of each drive
pin engage
below the upper face of the hollow protrusions of the second arcuate frame
member, retaining
the drive pins in place within the assembly. The coextensive hollow
protrusions or mating
structures are as a result engagably secured together. The resulting assembly
in which the
shield or visor and continuous gasket are sandwiched between the first and
second arcuate
frame members is thereby held together in gas-tight, detachable engagement
firmly and without
movement of one part relative to another.
[0011] The present invention also provides a reusable protective hood
alone and as part
of a reusable protective smock style top or full body suit for use in toxic
environments, wherein
the protective face shield assembly described above is detachably affixed to
the hood, the
affixed protective face shield assembly forming a gas-tight seal with the
hood.
[0012] In an exemplary embodiment of the reusable protective hood, the hood
is a
tritium hood that protects a wearer from inhalation of and skin exposure to
tritium in nuclear
plants.
[0013] In another exemplary embodiment of the reusable protective
hood, the hood
extends over the shoulders of the wearer. When in use, the hood would be
supplied with air
under pressure, which would cause the hood to become inflated, while
breathable air is supplied
to the wearer. The combination of air pressure and the feature of the hood
extending over the
shoulders of the wearer keep the hood in an upright position during use,
allowing free
movement of the wearer's head even while wearing a hard hat within the hood.
[0014] In an exemplary embodiment of the reusable protective smock
style top, the top
is provided with one or more zippers to facilitate ease of donning and doffing
of this garment.
[0015] The present invention further provides a method for laundering
a protective hood,
as described above, either alone or as part of a reusable protective smock
style top or full body
suit, the method comprising: removing the shield or visor from the protective
face shield
assembly of the protective hood; laundering the protective hood, smock style
top, or full body
suit; and either separately cleaning and reinstalling the shield or visor, or
replacing the shield or
visor.
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[0016] Other features and advantages of the invention will be apparent
to one of
ordinary skill from the following detailed description and accompanying
drawings.
[0017] Unless otherwise defined, all technical and scientific terms
used herein have the
same meaning as commonly understood by one of ordinary skill in the art to
which this invention
belongs. In case of conflict, the present specification, including
definitions, will control. in
addition, the materials, methods, and examples are illustrative only and not
intended to be
limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present disclosure may be better understood with reference
to the following
drawings. Components in the drawings are not necessarily to scale, emphasis
instead being
placed upon clearly illustrating the principles of the present disclosure.
[0019] Particular features of the disclosed invention are illustrated
by reference to the
accompanying drawings of the following exemplary embodiments of the present
invention:
FIG. 1 is an exploded plan view of an exemplary embodiment of the protective
face
shield assembly with removable shield or visor of the present invention;
FIG. 2 is an enlarged cross-sectional view, taken along line 2-2 of FIG. 3,
showing a
coupling device in the form of a removable/re-usable drive pin inserted
through the hollow
protrusions in the first and second arcuate frame members and turned 90
degrees, thereby
engaging the side wings of the drive pin below an upper face of the hollow
protrusion of the
second arcuate frame member, retaining the drive pin in place within the
assembly.
FIG. 3 is a frontal view of an exemplary embodiment of the reusable protective
smock
style top of the present invention, the protective face shield assembly
attached to, and forming a
gas-tight seal with a hood portion of the smock style top.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The protective face shield assembly of the present invention,
when used with a
protective hood, provides the wearer with full peripheral vision due to its
semi-annular or arcuate
shape, while allowing for the shield or visor to be removed for separate
cleaning, thereby
preserving the visual clarity and structural integrity of the shield or visor.
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[0021] Referring now to the drawings in detail, an exemplary
embodiment of the
protective face shield assembly with removable shield or visor of the present
invention is shown
in FIG. 1 generally at 10. The inventive assembly comprises an arcuate frame
member 12 that
defines an opening 14, and a shield or visor 16 removably held within the
opening 14.
[0022] The arcuate frame member 12 is formed from two similarly sized
structures, a
first arcuate frame member 18 and a second arcuate frame member 20. The size
and shape of
frame member 12 accommodates the face and field of view of the user. In this
exemplary
embodiment, the first and second arcuate frame members 18, 20 are
substantially rectangular
in overall shape having a degree of curvature ranging from greater than about
0 to less than
about 90 degrees, a maximum height extending from an upper edge to a lower
edge ranging
from about 30 to about 36 centimeters (cm), a maximum width extending from one
side edge to
an opposing side edge ranging from about 45 to about 54 cm, and a thickness
ranging from
about 0.6 to about 1.3 cm. Opening 14 measures from about 27 to about 31 cm in
total height,
and from about 43 to about 51 cm in total width.
[0023] In this exemplary embodiment, the first and second arcuate frame
members 18,
have a plurality of co-extensive hollow protrusions 22, 24, respectively, of
varying heights
that extend substantially perpendicularly there through around a perimeter of
the arcuate frame
member. The hollow protrusions in the first arcuate frame member 18 have slot-
shaped
openings 26, and the hollow protrusions in the second arcuate frame member 20
have
20 substantially circular cross-sectional shapes and terminate at an upper
face into a slot-shaped
opening 28.
[0024] As best shown in FIG. 2, the means for holding assembly 10 in
gas-tight,
detachable engagement in this exemplary embodiment are coupling devices in the
form of
removable/re-usable rivets or drive pins 30, and a continuous gasket 32 that
extends along an
inside surface of the first arcuate frame member 18 around the opening 14. The
drive pins 30
each have a head 34 and a shank 36 with an o-ring 38 and a pair of side wings
40a, 40b,
located at a distal end of the shank 36. When the drive pin 30 is inserted
through the hollow
protrusions 22, 24 of the first and second arcuate frame members 18, 20 and
turned 90
degrees, the side wings of each drive pin engage below the upper face of the
hollow protrusions
of the second arcuate frame member 20, retaining the drive pin in place within
the assembly 10.
The coextensive hollow protrusions or mating structures 22, 24 are as a result
engagably
secured together. The resulting assembly 10 in which the shield or visor 16
and the continuous
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gasket 32 are sandwiched between the first and second arcuate frame members
18, 20 is
thereby held together in gas-tight, detachable engagement firmly and without
movement of one
part relative to another.
[0025] The present inventor has found that twelve or more rivets or
drive pins positioned
around a perimeter of the arcuate frame member are needed to achieve a gas-
tight seal. Using
fewer than twelve rivets or pins results in unacceptable leakage. In a
preferred embodiment, a
total of twelve rivets or pins are used.
[0026] The first and second arcuate frame members 18, 20 may be made
from any
suitable material including, but not limited to, polymeric materials such as
polycarbonate,
polypropylene, and the like, as well as metal or metallic materials. In a
preferred embodiment,
frame members 18, 20 are made using polypropylene compounded with, for
example, glass or
similar additives.
[0027] Each frame member is preferably formed as a single solid piece
by injection
molding, computer numeric control (CNC) milling, or other suitable
manufacturing method.
[0028] The shield or visor 16 used with the inventive protective face
shield assembly 10
in this exemplary embodiment is flexible and has a size and shape that
accommodates or fills
the opening 14 formed by the first and second arcuate frame members 18, 20.
The visor 16 is
provided with a plurality of holes that extend there through around a
perimeter of the visor, the
holes lining up with the hollow protrusions 24 of the second arcuate frame
member 20, which
serve as alignment guides. Due to the flexibility of the visor 16, it readily
assumes the arcuate
shape of the first and second arcuate frame members 18, 20. The visor 16 may
also be
provided with a ventilation opening in the form of, for example, a taped flap.
[0029] The shield or visor 16 is made from a flexible, transparent
sheet-like material,
such as polycarbonate resin (e.g., LEXAN polycarbonate resin), polyvinyl
chloride (PVC), or
other flexible, transparent material, or combinations of materials through
which objects can be
readily and easily seen.
[0030] An exemplary embodiment of the reusable protective smock style
top of the
present invention is shown in FIG. 3 generally at 42. The protective top 42
comprises a hood
portion 44, which is sealably attached to the protective face shield assembly
46, and a body
portion 48.
[0031] The hood portion 44 is formed with an opening (not shown), the
size and shape
of which approximates the size and shape of the opening formed by the frame
assembly 46.
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The area surrounding the opening is provided with a plurality of holes (not
shown) that are
positioned to line up with the hollow protrusions of the first and second
arcuate frame members.
[0032] The protective face shield assembly 46 is sealably attached to
the reusable
protective smock style top 42 by positioning the second arcuate frame member
inside the hood
portion 44 of the protective smock style top 42, inserting the hollow
protrusions of the second
arcuate frame member through the holes of the hood portion 44, and through the
holes of the
shield or visor. The first arcuate frame member is then placed on the
assembled parts in mating
engagement. Drive pins are inserted through the hollow protrusions of the
first and second
arcuate frame members and each turned 90 degrees to engage the pins.
[0033] In the exemplary embodiment shown in FIG. 3, a pair of zippers 50a,
50b (or
other suitable device) are placed at opposing sides of the front portion of
the smock style top 42
to facilitate ease of donning and doffing of this garment.
[0034] The smock style top 42 may be made from any suitable material
including, but
not limited to, PVC, or other suitable material.
[0035] In a further exemplary embodiment, the reusable protective smock
style top is a
tritium protective top that protects a wearer from inhalation of and skin
exposure to tritium in
nuclear plants.
[0036] After being worn, the smock style top in this further exemplary
embodiment is
sent to a laundry where the visor is removed, and the top and visor washed and
decontaminated in separate operations using different means. As will be
readily appreciated by
those skilled in the art, the smock style top can be washed more vigorously
than the visor. The
visor is washed so as to remove any contaminants and to preserve the visual
clarity and
structural integrity thereof. The smock style top and visor are then rejoined
for subsequent use.
As noted above, the visor may also be replaced instead of cleaned and
reinstalled.
[0037] As also noted above, other features and advantages of the invention
will be
apparent to one of ordinary skill from the detailed description and drawings.
By way of example,
instead of drive pins, threaded screws, cam locks or other suitable fasteners
could be used to
hold the assembly in gas-tight, detachable engagement.
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