U.S. patent application number 10/625309 was filed with the patent office on 2005-04-07 for air filtration system including a helmet assembly.
Invention is credited to Diaz, Luis A., Henniges, Bruce D., Smit, Karen L., Wasserman, Mark A..
Application Number | 20050071909 10/625309 |
Document ID | / |
Family ID | 22646597 |
Filed Date | 2005-04-07 |
United States Patent
Application |
20050071909 |
Kind Code |
A1 |
Diaz, Luis A. ; et
al. |
April 7, 2005 |
Air filtration system including a helmet assembly
Abstract
An air filtration system and a helmet for use in the air
filtration system are disclosed and utilized to filter air between
a head and body of a user and an external environment. The air
filtration system and helmet include inner and outer shells that
define an air flow channel for channeling air about the user. A fan
module is mounted between the inner and outer shells and a scroll
housing is mounted adjacent the fan module. The scroll housing
includes an air inlet for drawing air into the air filtration
system and helmet, and at least one air outlet to distribute air
flow to the air flow channel. The helmet includes air exits at
front and rear sections that are in fluid communication with the
air flow channel and the air outlet or outlets. The air filtration
system includes a gown operating as a filter for filtering the
air.
Inventors: |
Diaz, Luis A.; (Yabucoa,
PR) ; Henniges, Bruce D.; (Kalamazoo, MI) ;
Wasserman, Mark A.; (Delton, MI) ; Smit, Karen
L.; (Kalamazoo, MI) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS, P.C.
THE PINEHURST OFFICE CENTER, SUITE #101
39400 WOODWARD AVENUE
BLOOMFIELD HILLS
MI
48304-5151
US
|
Family ID: |
22646597 |
Appl. No.: |
10/625309 |
Filed: |
July 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10625309 |
Jul 23, 2003 |
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10188656 |
Jul 2, 2002 |
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6622311 |
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10188656 |
Jul 2, 2002 |
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09764697 |
Jan 18, 2001 |
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6481019 |
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60176958 |
Jan 18, 2000 |
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Current U.S.
Class: |
2/171.3 ;
2/417 |
Current CPC
Class: |
A41D 13/11 20130101;
A41D 13/1153 20130101; A42B 3/286 20130101; A62B 18/045
20130101 |
Class at
Publication: |
002/171.3 ;
002/417 |
International
Class: |
A42C 005/04 |
Claims
What is claimed is:
1-107. (canceled)
108. A method for maintaining a constant volume of air flowing into
an air filtration system during the entire use of the air
filtration system, the air filtration system including a helmet
assembly adapted to be mounted on a head of a user and a gown for
covering the helmet assembly, wherein the helmet assembly of the
air filtration system includes a fan, motor, and power supply, said
method comprising the steps of: selectively activating and
deactivating the power supply at a first activation rate to
distribute a required voltage to the motor thereby establishing a
rotational speed for the fan that correlates to the constant volume
of air flowing into the air filtration system; monitoring the back
electromotive force of the motor of the helmet assembly to
determine the rotational speed of the fan and when the rotational
speed of the fan has stabilized for a predetermined period of time;
monitoring the voltage of the power supply after the rotational
speed of the fan has stabilized for the predetermined period of
time; and selectively activating and deactivating the power supply
at a second activation rate as the monitored voltage of the power
supply decreases thereby sustaining the required voltage being
distributed to the motor such that the constant volume of air
flowing into the air filtration system is maintained.
109-116. Cancelled
Description
RELATED APPLICATIONS
[0001] This patent application claims priority to and all
advantages of U.S. Provisional Patent Application No. 60/176,958
which was filed on Jan. 18, 2000.
BACKGROUND OF THE INVENTION
[0002] 1) Technical Field
[0003] The subject invention generally relates to an air filtration
system for filtering air between a head and body of a user and an
environment external to the user. The air filtration system is
utilized in the medical profession during surgical procedures. The
subject invention more specifically relates to a helmet assembly
and gown for use in the air filtration system.
[0004] 2) Description of the Prior Art
[0005] Air filtration systems and helmet assemblies utilized in the
air filtration systems are known in the art. As indicated above,
air filtration systems and helmet assemblies are worn by users
throughout the medical profession, such as surgeons, during
surgical procedures for filtering air between a head and body of
the surgeon and an external environment, such as a clean room.
[0006] Conventional air filtration systems and helmet assemblies
are deficient for one reason or another. For example, U.S. Pat. No.
5,592,936 to Thomas, Jr. et al. discloses an air filtration system
and helmet assembly that draws air through a filter medium into the
helmet assembly and through an intake grid where the air is then
channeled through an air flow channel over a face of the user. The
air filtration system and helmet assembly of this patent are
deficient in that air is not distributed completely about the head
of the user. That is, air is not distributed to a back of the head,
toward a neck, of the user. Further, the intake grid is deficient
in that the grid does not extend between a front and rear section
of the helmet assembly to maximize an effective intake area for the
filter medium.
[0007] A further example of a conventional air filtration system
and helmet assembly is disclosed in U.S. Pat. No. 5,054,480 to Bare
et al. This patent discloses an air filtration system and helmet
assembly that draws air into the helmet assembly via an intake fan,
and exhausts air from the air filtration system and helmet assembly
via an exhaust fan disposed at the rear section of the helmet
assembly spaced away from the neck of the user. The air filtration
system and helmet assembly of this patent is deficient in that they
are overly heavy due to the additional fan required to exhaust air.
Furthermore, the exhaust fan creates excessive strain, and
therefore fatigue, in the neck of the user because the exhaust fan
is spaced away from the neck of the user.
[0008] The conventional air filtration system and helmet assembly
disclosed in U.S. Pat. No. 5,711,033 to Green et al. is also
deficient. This patent discloses an air filtration system and
helmet assembly that draws air into the helmet assembly through an
intake fan and scroll housing disposed at a rear section of the
helmet assembly. The air filtration and helmet assembly of this
patent is deficient because the intake fan and scroll housing are
spaced away from the neck of the user. Further, the scroll housing
in this patent includes only one air outlet to distribute air about
the head of the user resulting in less balanced air flow throughout
the helmet assembly. Additional drawbacks of such an air filtration
system and helmet assembly including only one air outlet from the
scroll housing are excessive fog build-up and poorer heat
dissipation in the helmet assembly.
[0009] Other conventional air filtration systems and helmet
assemblies are also deficient for the following reasons. First,
these conventional air filtration systems and helmet assemblies do
not assist a single user in self-gowning as the surgeon maintains
sterility. That is, these air filtration systems and helmet
assemblies do not include a positioning and supporting system that
automatically centers a face shield over the helmet assembly and
that supports an entire weight of the gown and face shield.
Instead, the conventional air filtration systems and helmet
assemblies merely utilize hook-and-loop fasteners randomly places
around the helmet assembly to connect the face shield to the helmet
assembly in any orientation. Furthermore, randomly-placed
hook-and-loop fasteners do not automatically center the face shield
and do not support the entire weight of the gown and the face
shield as the surgeon self-gowns. Instead, as the user self-gowns,
he or she must repeatedly adjust the face shield in order to center
the face shield. This is time consuming and burdensome.
[0010] Secondly, it is generally understood that the amount of air
flowing into the helmet assembly is critical for anti-fogging and
heat control purposes. However, the air filtration systems and
helmet assemblies of the prior art do not assist the surgeon in
recognizing the amount, or volume, of air flowing into the helmet
assembly. That is, these air filtration systems and helmet
assemblies do not provide audible indication to the surgeon of the
volume of air flowing into the helmet assembly during any
particular surgical procedure.
[0011] Thirdly, as discussed above, it is ideal to position and
maintain any fans in the air filtration system and helmet assembly
as directly over, and not spaced from, the neck of the user as
possible in order to minimize strain and fatigue. The prior art air
filtration systems and helmet assemblies do not incorporate a strap
flexibly connected to the front section of the helmet assembly such
that the strap is pulled from the front section of the helmet
assembly and the weight of any fans is maintained over the user's
neck when the helmet assembly is adjusted to fit various sized
heads.
[0012] Due to the inefficiencies identified in such conventional
air filtration systems and helmet assemblies, it is desirable to
implement a novel air filtration system and helmet assembly that
utilizes a single fan to distribute air toward both the face and
the neck of the user and that includes a scroll housing that
includes at least two air outlets for complete balancing of the air
flow about the head of the user. It is also desirable to dispose
the fan in the helmet assembly such that it is not spaced away from
the neck of the user to minimize strain, and to include an intake
grid that extends between front and rear sections of the helmet
assembly to maximize the effective intake area for filtering the
air. Finally, it is desirable to implement an air filtration system
and helmet assembly that includes a positioning and supporting
system to assist the user in self-gowning, that includes audible
indication to the user of the volume of air flowing into the
helmet, and that includes a strap that can be adjusted to fit
different sizes of heads while maintaining the weight of the helmet
assembly over the neck of the user.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0013] An air filtration system for filtering air and a helmet
assembly for use in the air filtration system is disclosed. The air
filtration system and helmet assembly are utilized in the medical
profession during surgical procedures to filter air between a head
and body of a user, such as a surgeon, and an environment external
to the user. As appreciated by those skilled in the art, the
subject invention, in addition to air filtering, assists in
controlling carbon dioxide concentration, dissipating heat, and
anti-fogging within the helmet assembly. It is to be understood
that the subject invention can also be utilized in other situations
requiring filtered air including, but not limited to, the
manufacturing of semi-conductor chips and other computer components
in manufacturing clean rooms.
[0014] The air filtration system and helmet assembly include an
inner structural shell and an outer structural shell. The outer
structural shell extends from the inner structural shell to define
at least one air flow channel between the inner and outer shells
for channeling air about the head of the user. The helmet assembly
further includes a base section and a facial section extending from
the base section to define a facial opening.
[0015] A fan module is mounted to at least one of the inner and
outer shells, and a scroll housing is mounted adjacent the fan
module. More specifically, the fan module includes a fan and a
motor, and the scroll housing includes at least one air inlet and
at least one, preferably at least two, air outlets. The fan module,
including both the fan and the motor, is disposed at the rear
section of the base section. In operation, the fan module,
specifically the fan, draws air into the air inlet and distributes
air out of the scroll housing through the air outlet or outlets and
into the air flow channel.
[0016] The subject invention also incorporates at least two helmet
air exits, preferably a front and rear air helmet air exit for
distributing air from the air flow channel toward the head of the
user. More specifically, the front and rear air exits are disposed
at the front and rear sections of the helmet assembly,
respectively. The front and rear air exits are in fluid
communication with the air flow channel and the air outlets. The
front air exit distributes air from the air flow channel toward a
front, or face, of the head of the user, and the rear air exit
distributes air from the air flow channel toward a back, or neck,
of the head of the user. As such, a single fan is utilized to
distribute air toward both the face and the neck of the user. The
air outlet or outlets of the scroll housing completely balance the
air flow about the head of the user between the front and rear air
exits. Further, because the fan is disposed at the rear section of
the base section of the helmet assembly, the fan is not spaced away
from the user's neck and strain and fatigue in the user is
minimized.
[0017] The air filtration system further includes a gown having a
body portion and a head portion. The body portion covers at least a
portion of the body of the user and the head portion covers the
base section of the helmet assembly. The head portion of the gown
operates as a filter medium to filter air between the user and the
external environment. The gown also includes a skirt. More
specifically, the skirt is removably attached to the body portion
of the gown exclusively at a front of the gown. An intake grid is
mounted to the outer shell of the helmet assembly for user with the
gown. The intake grid is contoured to the outer shell between the
front section and the rear section of the base section to maximize
an effective intake area for the filter medium to filter air drawn
into the scroll housing.
[0018] The subject invention further includes a face shield mounted
to the head portion of the gown to cover the facial opening. As
such, the user can view through the head portion of the gown.
Depending on the particular embodiment of the subject invention,
the face shield includes either a mounting mechanism or a first
visual indicator. These will be described further below.
[0019] Also depending on the particular embodiment, the base
section of the helmet assembly includes either a mounting device or
a second visual indicator positioned, preferably centered, relative
to the facial opening. If the helmet assembly includes the mounting
device, the mounting device interlocks with the mounting mechanism
on the face shield. As such, the subject invention provides a
positioning and supporting system that automatically centers the
face shield over the facial opening and that preferably supports
the entire weight of the gown in order to assist the single user in
self-gowning as the user maintains sterility. On the other hand, if
the helmet assembly includes the second visual indicator, then the
second visual indicator aligns with the first visual indicator on
the face shield. As such, the subject invention provides a visual
positioning system that automatically centers the face shield over
the facial opening thereby assisting the single user is
self-gowning as the user maintains sterility.
[0020] The subject invention also includes a controller that
operates with a power supply to control the amount, or volume, of
air into the air filtration system and helmet assembly and to
provide audible indication of the volume of air to the user while
the user is wearing the air filtration system and helmet assembly
during the surgical procedure. Preferably, the power is integrally
disposed within the helmet assembly. The air filtration system and
helmet assembly of the subject invention also include a strap
flexibly connected to the helmet assembly such that the strap is
pulled from the front section of the helmet assembly. As a result,
the weight of the fan is maintained over the user's neck when the
helmet assembly is adjusted to fit various sized heads.
[0021] The subject invention further includes a method for
maintaining a constant volume of air flowing into an air filtration
system during the entire use of the air filtration system. The
method includes the steps of selectively activating and
deactivating the power supply at a first activation rate to
distribute a required voltage to the motor. This step establishes a
rotational speed for the fan that correlates to the constant volume
of air flowing into the air filtration system. Next, the method
monitors the back electromotive force of the motor of the helmet
assembly to determine the rotational speed of the fan as well as
when the rotational speed of the fan has stabilized for some
predetermined period of time. The voltage of the power supply is
monitored after the rotational speed of the fan has stabilized for
the predetermined period of time. Finally, the power supply is
selectively activated and deactivated at a second activation rate
as the monitored voltage of the power supply decreases. This step
sustains the required voltage that is distributed to the motor such
that the constant volume of air flowing into the air filtration
system is maintained throughout the entire use of the air
filtration system.
[0022] Accordingly, the subject invention provides an air
filtration system and helmet assembly that overcomes the
deficiencies in the prior art as identified above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0024] FIG. 1 is a perspective view of a helmet assembly mounted on
a head of a user of the assembly;
[0025] FIG. 2 is an exploded perspective view of the helmet
assembly;
[0026] FIG. 3 is a partially cross-sectional side view illustrating
a base section and a facial section of the helmet assembly and an
air flow channel and air exits within the helmet assembly;
[0027] FIG. 4 is a perspective view of a fan module and scroll
housing of the subject invention including at least one air outlet
from the scroll housing;
[0028] FIG. 5 is a perspective view of the scroll housing including
more than one air outlet from the scroll housing;
[0029] FIG. 6 is an exploded view of the fan module and scroll
housing;
[0030] FIG. 7 is a top view of the helmet assembly;
[0031] FIG. 8 is a side view of the helmet assembly and an air
filtration system including a gown and face shield;
[0032] FIG. 9 is a perspective view of the helmet assembly
illustration a positioning and supporting system including a
mounting clip supporting the face shield via an aperture in the
face shield;
[0033] FIG. 10 is a perspective view from a rear of the helmet
assembly illustrating an intake grid and first and second motor
controls extending at different heights from an outer shell of the
helmet assembly;
[0034] FIG. 11 is a perspective view from the rear of the helmet
assembly illustrating a rear support, strap, and adjustment knob to
facilitate a proper fit of the helmet assembly on various sized
heads of users;
[0035] FIG. 12 is an enlarged view of the rear support and the
adjustment knob;
[0036] FIG. 13 is an enlarged perspective view of an inner surface
of the adjustment knob illustrating a pinion and a plurality of
teeth; and
[0037] FIG. 14 is an enlarged perspective view of the rear support
illustrating a flexible support bar and a detent that mates with
the plurality of teeth on the adjustment knob.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Referring to the Figures, wherein like numerals indicate
like or corresponding parts throughout the several views, an air
filtration system and helmet assembly are generally disclosed at 10
and 12, respectively. Referring to FIG. 1, the air filtration
system 10 filters air between a head 14 and body 16 of a user and
an environment external to the user and includes the helmet
assembly 12 mounted to the head 14 of a user. The helmet assembly
12 distributes air about the head 14 of the user as will be
described below. More specifically, the helmet assembly 12
distributes air toward both a front of the head 14, i.e., the face,
of the user, and a back of the head 14, i.e., the neck, of the
user.
[0039] Referring now to FIGS. 2 and 3, the helmet assembly 12
includes an inner structural shell 18 and an outer structural shell
20. The inner shell 18 includes a cover surface 22 and a rear
facing 24 which extend to the outer shell 20. The cover surface 22
and rear facing 24 will be discussed further below. The outer shell
20 is spaced apart from the inner shell 18 and extends from the
inner shell 18 to define at least one air flow channel 26 between
the inner and outer shells 18, 20. It is to be understood that the
subject invention may include more than one discrete air flow
channel 26. However, the preferred embodiment includes a single
unitary air flow channel 26 and the subject invention will be
described below in terms of this air flow channel 26.
[0040] The air flow channel 26 channels air about the head 14 of
the user. The inner and outer shells 18, 20 form the air flow
channel 26 from a two-sheet thermoforming process which improves
the structural strength of the inner and outer shells 18, 20. More
specifically, each of the inner and outer shells 18, 20 include an
outer periphery 28, and in the two-sheet thermoforming process, the
inner and outer shells 18, 20 are pinched together at their outer
peripheries 28. The air flow channel 26 is subsequently
thermoformed between the pinched outer peripheries 28. As shown
best in FIG. 7, dissipation cavities 30 are disposed at opposite
lateral sides of the inner and outer shells 18, 20 to provide for
increased air release from the air flow channel 26 and from the
user out through the helmet assembly 12.
[0041] The helmet assembly 12 further includes a base section 32
having a front section 34 and a rear section 36. The inner and
outer shells 18, 20 extend between the front and rear sections 34,
36 to define the air flow channel 26. The cover surface 22 and the
rear facing 24 of the inner shell 18 extend to the outer shell 20
at the rear section 36 of the base section 32. Also, at the rear
section 36 of the base section 32, a mounting cavity 38 is formed
between the cover surface 22 of the inner shell 18 and the outer
shell 20. The mounting cavity 38 will be discussed further below.
The inner and outer shells 18, 20 form the base section 32. It is
understood that the base section 32 is the portion of the helmet
assembly 12 that is mounted over the head 14 of the user. As such,
it is also understood that the front section 34 of the base section
32 is at the face of the user as the user wears the helmet assembly
12, and the rear section 36 of the base section 32 is at the neck
of the user as the user wears the helmet assembly 12.
[0042] The helmet assembly 12 also includes a facial section 40
extending from the base section 32 to define a facial opening 42.
The facial section 40 of the helmet assembly 12 is a chin bar 44.
Preferably, the chin bar 44 is flexible and is formed of plastic.
The chin bar may also be formed of a polypropylene component. The
flexibility of the chin bar 44 protects the user's face and also
absorbs impact when the user contacts an external object with the
helmet assembly 12.
[0043] Referring to FIGS. 2 through 6, the air filtration system 10
and helmet assembly 12 further include a fan module 46 mounted to
at least one of the inner and outer shells 18, 20 and a scroll
housing 48 mounted in the helmet assembly 12 adjacent the fan
module 46. More specifically, both the fan module 46 and the scroll
housing 48 are disposed within the mounting cavity 38 at the rear
section 36 of the helmet assembly 12. Disposing the fan module 46
and the scroll housing 48 in the mounting cavity 38 is
space-saving, reduces the overall weight of the helmet assembly 12
because additional mounting connections are not required, and
minimizes strain and fatigue on the head 14 and the neck of the
user.
[0044] The fan module 46 includes a fan 50 and a motor 52 and is
disposed at the rear section 36 of the base section 32. The fan 50
includes a plurality of curved blades 54 and a hub portion 56. The
curved blades 54 of the fan 50 encourage air into the scroll
housing 48. The motor 52 includes an output 58, or drive shaft,
that is operatively connected to the fan 50 to drive the fan 50 at
a plurality of rotational speeds correlating to an amount, or a
volume, of air flowing into the air flow channel 26. As
appreciated, the rotational speeds of the fan 50 can be measured in
revolutions per minute (RPMs).
[0045] Referring primarily to FIGS. 4 and 5, the scroll housing 48
includes a base portion 60 and an outer wall 62 circumferentially
extending around the base portion 60. The scroll housing 48 further
includes at least one air inlet 64 and at least one air outlet 66.
In the most preferred embodiment of the subject invention, the
scroll housing includes a plurality of air outlets 66. That is, in
this embodiment the scroll housing includes at least two air
outlets 66. Other specific embodiments of the subject invention may
also only include the fan module 46 without the scroll housing 48.
In such embodiments, the at least one air inlet and the at least
one air outlet can be described as components of the fan module
46.
[0046] In operation, the motor 52 rotates the fan 50 to draw air
into the air inlet 64 of the scroll housing 48 and distributes air
out of the scroll housing 48 through the air outlet 66 or outlets
66 and into the air flow channel 26 where the air is distributed
about the head 14 of the user. The scroll housing 48 also includes
at least one air flow cutoff 68 which cuts the air as the fan 50
moves the air within the scroll housing 48. More specifically, as
shown in the Figures, the subject invention incorporates several
air flow cutoffs 68 in the scroll housing 48 to cut the air. A
power supply 70 is incorporated in the subject invention to power
the motor 52 to rotate the fan 50 via the motor output 58.
Preferably, the power supply 70 is a rechargeable DC battery. Also
preferred, the power supply 70 is disposed within, i.e., integrated
into, the helmet assembly 12. In such a case, the power supply 70
is referred to as an integral power supply 71 as shown in FIG. 3.
Alternatively, the power supply 70 can be mounted to the body 16 of
the user as shown in FIG. 8. The power supply 70 powers the motor
52 through pulse width modulation (PWM) which will be discussed
further below. The design of the scroll housing 48 provides more
efficient movement of air with less power being required from the
power supply 70 overall. Furthermore, in addition to such reduced
power requirements, the scroll housing 48 provides that sufficient
air flow can be maintained with overall less air velocity. This
results in a more quiet helmet assembly 12.
[0047] More specifically, the fan 50 of the fan module 46 is
rotatably mounted to the base portion 60 of the scroll housing 48
within the outer wall 62 of the scroll housing 48 to draw air into
the air inlet 64. As best shown in FIGS. 2 and 7, the air inlet 64
of the scroll housing 48 is integrally formed within the outer
shell 20 of the helmet assembly 12 for drawing air into the scroll
housing 48. However, it is to be understood that the air inlet 64
is not required to be integrally formed within the outer shell 20
of the helmet assembly 12. That is, in an alternative embodiment of
the subject invention, an external structure, not shown in the
Figures, can be mounted external to the helmet assembly 12 to
establish the air inlet 64 of the scroll housing 48 for drawing air
into the scroll housing 48. Referring now to FIGS. 4 through 6, the
scroll housing 48 further includes a support pedestal 72 protruding
from the base portion 60. As shown in the Figures, the support
pedestal 72 is integrally formed as a part of the scroll housing 48
to protrude from the base portion 60. Alternatively, it is also to
be understood that the support pedestal 72 can be a separate part.
That is, the support pedestal 72 can be a separate part that is
mounted or connected to the base portion 60 of the scroll housing
48 via connecting screws, snap-fit, and the like. The hub portion
56 of the fan 50 is rotatably mounted in the scroll housing 48 on
the support pedestal 72 by screws or other fasteners. The motor 52
of the fan module 46 is mounted within an underside 74 of the
support pedestal 72 between the support pedestal 72 and the cover
surface 22 of the inner shell 18 for space-saving purposes in the
helmet assembly 12. As appreciated, the underside 74 of the support
pedestal 72 is essentially hollow. The cover surface 22 of the
inner shell 18 operates as a motor cover to close the fan module 46
at the inner shell 18.
[0048] With respect to the at least two air outlets 66, the outer
wall 62 of the scroll housing 48 is partitioned to define the air
outlets 66. In the particular embodiment of the subject invention
having the at least two air outlets 66, it is to be understood that
the subject invention is not limited to at least two air outlets
66. That is, the subject invention may include, for example, three
or four air outlets 66. The air outlets 66 provide a complete
balance of air as the air is distributed from the scroll housing 48
about the head 14 of the user. To accomplish this, the helmet
assembly 12 includes at least two helmet air exits 76, 78. The air
outlets 66 are in fluid communication with the at least two helmet
air exits 76, 78 to distribute the air from the outlets 66, which
is in the air flow channel, toward the head of the user. In the
embodiments of the subject invention where the helmet assembly
includes the at least two helmet air exits 76, 78 it is not
critical that the scroll housing 48 include at least two air
outlets 66. To the contrary, the scroll housing, in these
embodiments, may only have at least one air outlet 66.
[0049] Preferably, the first 76 and second 78 air exits are
respectively front and rear air exits in that they are disposed at
the front and rear sections 34, 36 of the helmet assembly 12,
respectively, to effectively distribute air toward both the face
and neck of the user. However, in alternative embodiments, the
first and second air exits 76, 78 can be customized to distribute
air toward any portion of the user's head. For instance, the first
and second air exits 76, 78 can be side air exits such that air is
distributed toward the side of the user's head. For descriptive
purposes only, the subject invention will be described below only
in terms of the front 76 and rear 78 air exits and will be numbered
accordingly. More specifically, the front air exit 76 is disposed
at the front section 34 of the base section 32 for distributing air
from the air flow channel 26 toward the front of the head 14 of the
user, and the rear air exit 78 is disposed at the rear section 36
of the base section 32 for distributing air from the air flow
channel 26 toward the back of the head 14 of the user. The rear air
exit 78 is formed within the rear facing 24 for distributing air
from the air flow channel 26 toward the back of the head 14 of the
user.
[0050] As shown in FIG. 3, the air flow channel 26 defined between
the inner and outer shells 18, 20 terminates at the front section
34 with the front air exit 76 and at the rear section 36 with the
rear air exit 78. More specifically, the inner and outer shells 18,
20 converge toward the front section 34 of the base section 32 to
define the front air exit 76. The front air exit 76 has an air
deflection angle 80. The air deflection angle 80 is defined between
the outer shell 20 and the inner shell 18 wherein the outer shell
20 angles toward the inner shell 18 at the front air exit 76 for
proper deflection of air toward the front of the head 14 of the
user. As appreciated, the air deflection angle 80 between the outer
20 and inner 18 shell is greater than zero, preferably between
25-35 degrees. Additionally, referring to FIG. 7, the air flow
channel 26 diverges outwardly upon approaching the front air exit
76. The convergence and divergence of the air flow channel 26
maintains a balanced flow of air about the user's head 14.
Ultimately, this also has the effect of minimizing or even
completely eliminating noise within the helmet assembly 12 due to
the air flow.
[0051] As shown in FIG. 4, the subject invention incorporates at
least one air bleed valve 82 in the scroll housing 48 to influence
the amount, or the volume, of air flowing into the air flow channel
26 from each of the air outlets 66. It is to be understood that,
although there is only one air bleed valve 82 shown in FIG. 4, the
subject invention may alternatively incorporate more than one air
bleed valve. The air bleed valve 82 influences the volume of air
flowing to the rear air exit 78 thereby affecting the volume of air
flowing to the rear air exit 78 that is distributed primarily
toward the back of the head 14 of the user. To accomplish this, the
air bleed valve 82 includes a blade 84 that can be rotated to
cover, i.e., close, the air outlet 66 of the scroll housing 48
nearest the rear air exit 78. If covered or closed, more air is
moved to the front air exit 76 of the helmet assembly 12 and the
volume of air flowing is constant, not variable. As shown in the
Figures, the air bleed valve 82 is mechanically controlled by a
mechanical lever or knob 86 in order to manipulate the volume of
air flowing into the air flow channel 26 from each of the air
outlets 66. However, the air bleed valve 82 may alternatively be
electronically controlled to manipulate the volume of air. Also, it
is to be understood that the air bleed valve 82 is not required in
the subject invention.
[0052] Referring to FIG. 8, the air filtration system 10 includes a
gown 88 having a body portion 90 for covering at least a portion of
the body 16 of the user and a head portion, or hood, 92 for
covering the base section 32 of the helmet assembly 12, which
houses the head 14 of the user. More specifically, the body portion
90 can extend downward to cover any portion of the body 16 of the
user. For instance, the body portion 90 can extend downward to the
shoulders of the user, or to the waist of the user, or to the
ankles of the user. The head portion 92 of the gown 88 operates as
a filter medium 94 to filter air between the user and the external
environment. A skirt 93 is attached to the body portion 90 of the
gown 88 exclusively at a front, not numbered, of the gown 88.
Because the skirt 93, which is typically sterile in the industry,
is only attached at the front, i.e., does not encircle around a
back of the gown 88, cost can be saved. Also, the skirt 93 is
removably attached at the front of the body portion 90 of the gown
88 such that a particular user can decide whether to use the skirt
93 or not. The skirt 93 is attached to the gown 88 in any known
manner in the industry including, but not limited to, adhesive
tape. The facial section 40 of the helmet assembly 12, introduced
above, also operates to maintain the gown 88 away from the head 14
of the user.
[0053] The subject invention also includes a face shield 96 that
permits the user to view through the head portion 92 of the gown 88
and the facial opening 42 of the helmet assembly 12. As shown in
FIG. 9, the face shield 96 is mounted to the head portion 92 of the
gown 88 such that the face shield 96 covers the facial section 40
and the facial opening 42 of the helmet assembly 12 once the user
dresses into the air filtration system 10. More specifically, the
face shield 96 is sewn into the head portion 92 of the gown 88 to
maintain a complete barrier between the user and the external
environment. The facial opening 42 of the helmet assembly 12
essentially receives the face shield 96. Preferably, the facial
section 40 of the helmet assembly 12 includes a hook-and-loop
fastener 98 to further facilitate attachment of the face shield 96
to the facial section 40 for covering the facial opening 42.
[0054] The helmet assembly 12 further includes an intake grid 100
mounted to the outer shell 20. The intake grid 100 includes a top
surface 102 spaced from the outer shell 20 of the helmet assembly
12 to retain the filter medium 94 away from the outer shell 20 and
the fan 50. Furthermore, the intake grid 100 is contoured to the
outer shell 20 between the front section 34 and the rear section 36
of the base section 32. This improves the effective seal between
the gown 88 and the helmet assembly 12, and maximizes an effective
intake area 104 for the filter medium 94 to filter air drawn into
the scroll housing 48 by the fan 50.
[0055] Referring now to FIG. 9, the subject invention also-includes
a positioning and supporting system 106 for assisting a single user
in self-gowning as the user maintains sterility. As understood by
those skilled in the art, users `dress into` the air filtration
system 10 and helmet assembly 12 first by mounting the helmet
assembly 12 on their head 14. The gown 88, which includes an
interior and an exterior, is classified as not sterile on the
interior, and sterile on the exterior. As such, the user places
their arms partially into sleeves of the gown 88 and then, with
their arms partially in the sleeves, uses the sleeves of the gown
88 to grasp the head portion 92, including the face shield 96, and
bring the head portion 92 over the helmet assembly 12 and the head
14 of the user. It is understood that the user then attempts to
center the face shield 96 relative to the facial section 40 and
facial opening 42 of the helmet assembly 12. As discussed above, in
the prior art the user must repeatedly adjust the face shield 96 in
order to center the face shield 96. It is understood that this is
burdensome because the user has their hands partially in the
sleeves of the gown 88. Furthermore, in the prior art, sterility of
the user is sometimes compromised. Once centered, the user extends
their arms entirely through the sleeves of the gown 88, and an
assistant, such as a nurse, places sterile gloves on hands of the
user.
[0056] As the head portion, or hood, 92 of the gown 88 is brought
over the helmet assembly 12, the subject invention, to assist the
user in gowning without a need for outside assistance while
maintaining sterility, utilizes a mounting mechanism 108. Although
not required, which will be discussed below, the mounting mechanism
108 is preferably centered on the face shield 96. The mounting
mechanism 108 supports the face shield 96 on the helmet assembly
12. Preferably, the mounting mechanism 108 is an aperture 110
formed within the face shield 96. The function of the mounting
mechanism 108, the aperture 110, will be described further
below.
[0057] The subject invention also utilizes a mounting device 112
included on the base section 32 of the helmet assembly 12. More
specifically, the mounting device 112 is positioned on the helmet
assembly 12 relative to the facial opening 42. Although not
required, which will be discussed below, the mounting device 112 is
preferably centered on the helmet assembly 12 relative to the
facial opening 42. Preferably, the mounting device 112 is a single
mounting clip 114 connected to the helmet assembly 12 and that is
positioned, preferably centered, relative to the facial opening 42.
Of course, it is to be understood that the mounting device 112 can
alternatively include more than one mounting clip 114. For example,
the mounting device 112 can be defined to include two, three, four,
etc. mounting clips 114. In such cases, the helmet assembly 12 will
include a corresponding number of mounting mechanisms 108,
preferably apertures 110. As an example, if the mounting device 112
is defined to include two mounting clips 114, then the mounting
device 112, including the two mounting clips 114, is still
considered centered relative to the facial opening 42 even though
one of the two mounting clips 114 is disposed on the right-center,
and the other of the two mounting clips 114 is disposed on the
left-center. As implied above, it is not necessary that the
mounting mechanism 108 and the mounting device 112 be centered.
Instead, all that is required is that the mounting mechanism 108
and the mounting device 112 `function` to automatically center the
face shield 96 over the facial opening 42 as the user is
self-gowning. In other words, both the mounting mechanism 108 and
the mounting device 112 can be `off-center` and so long as the two
108, 112 align with one another during self-gowning, then the face
shield 96 and the attached gown 88 will be automatically centered
over the facial opening 42 of the helmet assembly 12.
[0058] As best shown in FIG. 3, the mounting clip 114 extends
upwardly from the base section 32 away from the facial opening 42
of the helmet assembly 12 to support the face shield 96. The
mounting clip 114 includes a distal edge 116 extending outwardly
from the base section 32 such that a portion 118 of the face shield
96 rests between the distal edge 116 and the base section 32 after
the face shield 96 is mounted to the mounting clip 114 to support
the gown 88. Preferably, as the face shield 96 is mounted to the
mounting clip 114, the mounting clip supports an entire weight of
the gown 88.
[0059] The mounting clip 114 interlocks with the aperture 110 that
is, in the preferred embodiment, centered on the face shield 96 to
automatically center the face shield 96 over the facial opening 42.
More specifically, the mounting clip 114 protrudes through the
aperture 110. As discussed above, the mounting clip 114 preferably
also supports an entire weight of the gown 88 and the face shield
96 to assist the single user is self-gowning while maintaining a
relative position between the gown 88 and face shield 96 and the
helmet assembly 12. Therefore, after the user places his or her
arms partially into the sleeves of the gown 88, the user can
self-gown by simply hanging the face shield 96, including the
aperture 110, and the head 14 portion on the mounting clip 114.
Because the mounting clip 114 and the aperture 110 are in the
centered relationships as described above, the face shield 96 is
automatically centered relative to the facial section 40 and the
facial opening 42 of the helmet assembly 12, and there is no need
for the user to repeatedly adjust the face shield 96. Instead, the
user simply brings or `rolls` the head portion 92 of the gown 88
over the helmet assembly 12 while maintaining sterility all the
while. The gown 88 then drapes completely over the helmet assembly
12 and the user's body 16. This is a simple process for the user
because the mounting clip 114 is also supporting the weight of the
face shield 96 and head portion 92 of the gown 88. As such, the
user is not required to support the face shield 96 and the head
portion 92 of the gown 88 as they bring the head portion 92 over
the helmet assembly 12. As described above, the positioning and
supporting system 106 allows the user, such as a surgeon, to dress
into the helmet assembly 12 and surgical gown 88 without the need
for an assistant.
[0060] Alternatively, the subject invention can include a visual
positioning system, disclosed by first 107 and second 109 visual
indicators in FIGS. 9 and 3, respectively. Although the visual
positioning system of the subject invention does assist the single
user in self-gowning while maintaining sterility, the visual
positioning system is different from the positioning and supporting
system, as described above, because the visual positioning system
does not support the weight of the gown 88 as the single user is
self-gowning. Instead, the visual positioning system includes the
first visual indicator 107 (refer to FIG. 9) disposed on the face
shield 96 which enables the user to visually align the face shield
with the helmet assembly. The first visual indicator 107 is a
marker or other suitable visual indicator for the user to look at
as he or she is self-gowning. The visual positioning system also
includes a second visual indicator 109 (refer to FIG. 3) that
compliments the first visual indicator 107. More specifically, the
second visual indicator 109 is a marker or other suitable visual
indicator that is positioned relative to the facial opening 42 of
the helmet assembly 12 for alignment with the first visual
indicator 107 on the face shield 96. As such, the visual
positioning system, including the first 107 and second 109 visual
indicators, automatically centers the face shield 96 over the
facial opening thereby assisting the single user is self-gowning
while maintaining the relative position between the gown and face
shield and the helmet assembly while maintaining sterility.
[0061] Although not required for overall centering, the first 107
and second 109 visual indicators are preferably centered on the
face shield 96 and on the helmet assembly 12, respectively.
Furthermore, the second 109 visual indicator is preferably disposed
on either one of the inner and outer shells 18, 20 of the helmet
assembly 12 in a suitable location for the user's eyes to pick up
or notice as he or she is self-gowning.
[0062] To maintain a constant volume of air flowing into the air
filtration system 10 during or throughout the entire use of the air
filtration system 10 by the user, the subject invention includes a
method. The method includes the step of selectively activating and
deactivating the power supply 90 at an activation rate, i.e., a
first activation rate. This step distributes a required voltage to
the motor 52 thereby establishing a rotational speed (RPMs) for the
fan 50 that correlates to the constant volume of air flowing into
the air filtration system 10. The back electromotive force (back
EMF) of the motor 52 is monitored by the controller 118 to
determine the rotational speed of the fan 50 as well as when the
RPMs of the fan 50 have stabilized, i.e., maintained constant RPMs
for a predetermined period of time (e.g. 10 seconds). After the
rotational speed of the fan 50 has stabilized for the predetermined
period of time, and optionally once the user has not manipulated
motor controls for the predetermined period of time, whatever this
period of time is, the controller 118 then monitors the voltage of
the power supply 70. As the voltage of the power supply decreases,
which inevitably occurs, the power supply 70 is selectively
activated and deactivated at a second activation rate, which is
higher than the first activation rate, to sustain the required
voltage being distributed to the motor 52. As such, the constant
RPMs for the motor 52 and the constant volume of air flowing into
air filtration system 10 is maintained. The selective activation
and deactivation of the power supply 70 is known in the art as
pulse width modulation or PWM and a specific example this method is
set forth in greater detail below.
[0063] In addition to controlling the volume of air flowing into
the air filtration system 10, the subject invention also provides
for audible indication of a minimum and a maximum volume of air to
the user such that the user recognizes when the minimum and maximum
volumes have been achieved. The ultimate object is to obtain
constant air flow throughout the air filtration system 10 and
helmet assembly 12. To accomplish this, the subject invention
incorporates a controller 118 that selectively activates and
deactivates the power supply 70 at the activation rate. This
activation rate has a frequency that is audible to the user for
providing audible indication of the minimum and the maximum volume
of air to the user. That is, the subject invention provides the
user with an audible `ping` upon reaching the minimum and maximum
volumes of air flowing into the helmet assembly 12.
[0064] The frequency at which the controller 118 selectively
activates and deactivates the power supply 70 when the minimum and
maximum volumes of air are flowing into the air filtration system
10 and helmet assembly 12 is preferably 1 kHz. However, it is to be
understood that the frequency may otherwise be within the
acceptable range of unaided human hearing (30 Hz-20 kHz) so long as
it provides the audible indication. The frequency of the activation
rate causes various components of the motor 52 of the fan module 46
to vibrate at the frequency thereby generating the audible
indication.
[0065] More specifically, the air filtration system 10 and helmet
assembly 12 include first 120 and second 122 motor controls that
extend from the outer wall 62 of the scroll housing 48, through an
opening in the helmet assembly 12, and then from the outer shell 20
of the helmet assembly 12. The motor controls 120, 122 are
electronically connected to the controller 118. The motor controls
120, 122 respond to manipulation by the user for increasing or
decreasing the rotational speed of the fan 50. As described above,
the rotational speed of the fan 50 correlates to the volume of air
flowing into the air flow channel 26. Therefore, increasing or
decreasing the rotational speed of the fan 50 adjusts the volume of
air flowing into the air flow channel 26. The first motor control
120 is responsive to manipulation by the user to increase the
rotational speed of the fan 50 and therefore to increase the volume
of air flowing into the air flow channel 26. The second motor
control 122 is responsive to manipulation by the user to decrease
the rotational speed of the fan 50 and therefore to decrease the
volume of air flowing into the air flow channel 26. Of course, an
opposite set-up of the first and second motor controls 120, 122
could be established.
[0066] As shown in the Figures, the first and second motor controls
120, 122 are preferably first and second push-buttons. As shown in
FIG. 10, the first and second push-buttons extend from the outer
shell 20 at a height that varies from the other of the first and
second push-buttons to assist the user, without looking, in
manipulating the push-buttons to increase or decrease the speed of
the fan 50 and the volume of air. While the user is wearing the
helmet assembly 12 and is dressed into the air filtration system
10, he or she can recognize `by touch` that the height of the
push-buttons varies. This facilitates ease of operation in
increasing and decreasing the volume of air flowing into the air
flow channel 26.
[0067] The plurality of rotational speeds at which the air
filtration system 10 and helmet assembly 12 drive the fan 50 is
defined to included a first rotational speed correlating to a first
volume of air, a second rotational speed correlating to a second
volume of air, a third rotational speed correlating to a third
volume of air, a penultimate rotational speed correlating to a
penultimate volume of air, and a last rotational speed con-elating
to a last volume of air. However, in the preferred embodiment of
the subject invention, the plurality of rotational speeds at which
the air filtration system 10 and helmet assembly 12 drives the fan
50 is further defined to include five distinct rotational speeds
for driving the fan 50. It is to be understood that the subject
invention may include any number of distinct rotational speeds for
driving the fan 50 without varying the scope of the subject
invention. In the preferred embodiment as set forth above, each of
the five rotational speeds for driving the fan 50 correlate to a
particular volume of air flowing into the air flow channel 26. For
instance, there is a first rotational speed correlating to a first
volume of air, a second rotational speed correlating to a second
volume of air, and so on up to a fifth rotational speed correlating
to a fifth volume of air. For descriptive purposes only, the first
volume of air is the minimum volume of air flowing into the air
flow channel 26, and the fifth volume of air is the maximum volume
of air flowing into the air flow channel 26. However, it is to be
understood that the opposite may be true. That is, the first volume
of air maybe the maximum volume of air, and the fifth volume of air
may be the minimum volume of air.
[0068] In the preferred embodiment of the subject invention, the
frequency of the activation rate is audible only in certain
instances. Specifically, the frequency of the activation rate is
only audible when the user manipulates the first motor control 120
to increase the rotational speed of the fan 50 from the fourth
rotational speed to the fifth rotational speed of the fan 50, and
when the user manipulates the second motor control 122 to decrease
the rotational speed of the fan 50 from the second rotational speed
to the first rotational speed of the fan 50.
[0069] As briefly discussed above, the power supply 70 powers the
motor 52 through PWM. It is understood in the art that in PWM, the
controller 118 instructs a switch to selectively activate and
deactivate the power supply 70 through pulse width modulation. This
ON (activated)/OFF (deactivated) scenario controls the RPMs of the
fan 50. As an illustrative example, at the fifth rotational speed
of the fan 50, the fan 50 rotates at 3800 RPM. To establish the
3800 RPM, the controller 118 selectively activates and deactivates
the power supply 70 in a 70:30 ratio. That is, the controller 118
turns the power supply 70 ON 70% of the time and OFF 30% of the
time. At the fourth rotational speed of the fan 50, the fan 50
rotates at 3350 RPM. To establish the 3350 RPM, the controller 118
selectively activates and deactivates the power supply 70 in a
60:40 ratio. That is, the controller 118 turns the power supply 70
ON 60% of the time and OFF 40% of the time. At the third rotational
speed of the fan 50, the fan 50 rotates at 2900 RPM. To establish
the 2900 RPM, the controller 118 selectively activates and
deactivates the power supply 70 in a 50:50 ratio. That is, the
controller 118 turns the power supply 70 ON 50% of the time and OFF
50% of the time. At the second rotational speed of the fan 50, the
fan 50 rotates at 2450 RPM. To establish the 2450 RPM, the
controller 118 selectively activates and deactivates the power
supply 70 in a 40:60 ratio. That is, the controller 118 turns the
power supply 70 ON 40% of the time and OFF 60% of the time.
Finally, in the illustrative example, at the first rotational speed
of the fan 50, the fan 50 rotates at 2000 RPM. To establish the
2000 RPM, the controller 118 selectively activates and deactivates
the power supply 70 in a 30:70 ratio. That is, the controller 118
turns the power supply 70 ON 30% of the time and OFF 70% of the
time.
[0070] In terms of the illustrative example and the preferred
embodiment, the controller 118 turns the power supply ON and OFF in
the 70:30 ratio (the fifth and maximum volume of air) and in the
30:70 ratio (the first and minimum volume of air) at the audible
rate of 1 kHz. On the other hand, in the other ratios, the
controller 118 turns the power supply 70 ON and OFF at an inaudible
rate, for example 25 kHz.
[0071] The above example is in no manner intended to limit the
breadth of the present invention as set forth in the appended
claims, but rather is provided to further illustrate the features
and numerous advantages of the invention.
[0072] It is to be understood that, in the preferred embodiment of
the subject invention, the controller 118 monitors the RPMs of the
output 58 of the motor 52. More specifically, as set forth in the
above method, the controller 118 monitors the voltage generated by
the motor 52 to receive the RPM information of the output 58 of the
motor 52. The controller 118 then converts the information from
analog to digital simply by changing the voltage generated by the
motor 52 into a digital value representative of the voltage. The
controller 118 incorporated into the subject invention also
recognizes a set point that is indicative of one of the plurality
of rotational speeds of the fan 50. It is to be understood that the
set point is indicative of the current rotational speed of the fan
50. As such, a memory is included into the controller 118 for
retaining the set point, i.e., the last rotational speed of the fan
50, when the power supply 70 is deactivated. The power supply 70 is
deactivated either when the voltage in the power supply 70 drops to
zero or the power supply 70 is disconnected and replaced. In other
words, if the battery drains, or is disconnected for any reason,
then a new battery can be used, and once connected the controller
118 will control the power supply 70 to rotate the fan 50 at the
last set point. It is understood that users may use the helmet
assembly 12 over a period of time that is longer than the life of
the battery, and that once the voltage of the battery drops below a
useful value, the batter is replaced with a new battery. As such,
when the new, i.e., fully charged, battery is installed, the
controller 118 read the available voltage of the battery and
instructs the switch to adjust, through PWM, the ON/OFF ratio to
the motor 52 to maintain the predetermined air flow throughout the
helmet assembly 12 that is established by the set point.
[0073] To assist in minimizing the strain on the head 14 and the
neck of the user, the air filtration system 10 and helmet assembly
12 of the subject invention include a front-adjustable support 128
for the helmet assembly 12. Strain and torque on the head 14 and
neck of the user is minimized by maintaining the weight of the fan
50 and motor 52 over the neck of the user even upon adjustment of
the helmet assembly 12 to fit various sized heads. The
front-adjustable support 128 includes a rear support 130 that
rigidly extends from the rear section 36 of the base section 32. It
is to be understood that the rear support 130 can be a separate
part that is connected to the helmet assembly 12 or can be an
integral part of the helmet assembly 12. The rear support 130
includes first and second rigid connectors 132 that connect the
rear support 130 to the rear section 36. In the preferred
embodiment, the rear support 130 is connected to and extends from
the rear section 36 of the inner shell 18 and will described below
in terms of the inner shell 18. However, it is to be understood
that the rear support 130 can connect to and extend from the rear
section 36 of the outer shell 20 without varying the scope of the
subject invention.
[0074] Referring to FIGS. 10 through 14, an adjustment segment 134
having first 136 and second 138 sides is disclosed. Although not
required, the rear support 130 preferably includes the adjustment
segment 134. That is, preferably the adjustment segment 134 is
integral to, or the same part as, the rear support 130. However,
the adjustment segment 134 can alternatively be a discrete
component that is simply mounted to the rear support 130. In either
situation, the adjustment segment 134 defines an adjustment
aperture 140. The subject invention also includes a strap 142
flexibly connected to and extending from the front section 34 of
the inner shell 18. The strap 142 includes a first end 144 disposed
within the first side 136 of the adjustment segment 134, and a
second end 146 disposed within the second side 138 of the
adjustment segment 134. More specifically, the adjustment aperture
140 defined by the adjustment segment 134 receives the first and
second ends 144, 146 of the strap 142. Preferably, the first end
144 is movably disposed within the first side 136 of the adjustment
segment 134, and preferably the second end 146 is movably disposed
within the second side 138 of the adjustment segment 134. However,
as will be understood from the explanation below, the first end 144
may be movably disposed within the first side 136 of the adjustment
segment 134 and the second end 146 may be fixedly disposed within
the second side 138 of the adjustment segment 134. Alternatively,
the first end 144 may be fixedly disposed within the first side 136
of the adjustment segment 134 and the second end 146 may be movably
disposed within the second side 138 of the adjustment segment
134.
[0075] The strap 142 further includes a frontal portion 148
disposed between its first and second ends 144, 146 and opposite
the adjustment segment 134 of the rear support 130. At least one
hinge 150 extends from the frontal portion 148 of the strap 142 to
flexibly connect the strap 142 to the front section 34 of the inner
shell 18. Preferably, there are two hinges 150 that extend from the
frontal portion 148 of the strap 142. In such a case, the two
hinges 150 are connected to the front section 34 of the inner shell
18 and to the frontal portion 148 of the strap 142 equidistant from
one another. A gap 152 exists between the frontal portion 148 of
the strap 142 and the front section 34 of the inner shell 18.
[0076] An adjustment device 154 is mounted to the adjustment
segment 134 of the rear support 130. The adjustment device 154 is
manipulated to pull the strap 142 from the front section 34 of the
inner shell 18 to maintain the weight of the fan 50 and motor 52
over the user's neck. This will described below. Referring to FIGS.
10 through 14, the adjustment device 154 is further defined as an
adjustment knob 156. The adjustment knob 156 is rotatably mounted
from and extends into the adjustment aperture 140 of the rear
support 130 to engage the first and second ends 144, 146 of the
strap 142. The adjustment knob 156 includes a pinion 158 extending
into the adjustment aperture 140. Further, the first end 144 of the
strap 142 includes a first rack 160 and the second end 146 of the
strap 142 includes a second rack 162. The pinion 158 of the
adjustment knob 156 extends into the adjustment aperture 140 to
engage and move the first and second racks 160, 162 upon rotation
of the adjustment knob 156.
[0077] The adjustment device 154 engages the first and second ends
144, 146 of the strap 142 to manipulate the first and second ends
144, 146 toward each other. This tightens the strap 142 and pulls
the strap 142 from the front section 34 as the rear support 130
remains fixed relative to both the rear section 36 and the strap
142. The adjustment device 154 also engages the first and second
ends 144, 146 of the strap 142 to manipulate the first and second
ends 144, 146 away from each other. This loosens the strap 142 and
pushes the strap 142 toward the front section 34 as the rear
support 130 remains fixed relative to both the rear section 36 and
the strap 142.
[0078] It is to be understood that all that is required is that the
adjustment device 154 function to manipulate the first and second
ends 144, 146 toward each other to tighten the strap 142 or away
from each other to loosen the strap 142. To manipulate the first
and second ends 144, 146 toward each other in the preferred
embodiment, both the first and second ends 144, 146 can move toward
each other. Alternatively, the subject invention may be `single-end
adjustable.` That is, it is also possible for the first and second
ends to be manipulated toward each other even if the first end 144
is fixed and the second end 146 is the only end of the strap 142
that is manipulated, i.e., moved, by the adjustment device 154, or
even if the second end 146 is fixed and the first end 144 is the
only end of the strap 142 that is manipulated, i.e. moved, by the
adjustment device 154.
[0079] In operation, as the strap 142 is tightened by the
adjustment device 154, the hinges 150 flex to increase the gap 152
between the frontal portion 148 of the strap 142 and the front
section 34 of the inner shell 18. Because the strap 142 only moves
relative to the front section 34 of the inner shell 18, the weight
of the fan module 46 and scroll housing 48 is maintained over the
neck of the user when the helmet assembly 12 is adjusted to fit a
smaller sized head 14. Alternatively, if the strap 142 is loosened,
the hinges 150 relax to decrease the gap 152. As such, the weight
of the fan module 46 and scroll housing 48 is maintained over the
neck of the user when the helmet assembly 12 is adjusted to fit a
larger sized head 14. In a sense, the helmet assembly 12 remains
stationary relative to the user's head 14 and neck upon adjustment,
only the strap 142 moves within the helmet assembly 12.
[0080] The adjustment knob 156 additionally includes an inner
surface 164 facing the rear support 130 of the helmet assembly 12.
The inner surface 164 includes a plurality of teeth 166. The teeth
166 form a ring around the inner surface 164. A flexible support
bar 168 is molded into and extends from the rear support 130. The
flexible support bar 168 includes at least one locking detent 170
mating with the teeth 166 of the adjustment knob 156 to lock the
strap 142 relative to the rear support 130. Of course, more than
one detent 170 can be utilized. As shown in FIG. 14, the preferred
embodiment of the subject invention includes two flexible support
bars 168 to lock the strap 142 relative to the rear support 130. In
operation, the flexible support bars 168 flex to disengage the
detent 170 from the teeth 166 of the adjustment knob 156 upon
manipulation of the adjustment knob 156 such that the strap 142 is
allowed to move relative to the rear support 130. The flexible
support bars 168 act like a spring and rebound to force the detent
170 back into engagement with the teeth 166.
[0081] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description rather than
of limitation.
[0082] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that reference numerals are merely for
convenience and are not to be in any way limiting, the invention
may be practiced otherwise than as specifically described.
* * * * *