U.S. patent application number 09/729119 was filed with the patent office on 2002-06-20 for custom fitting assembly for helmet with protective hood.
Invention is credited to Epperson, William Lewis, Kuna, Francis J., Nattress, Robert Henry.
Application Number | 20020073479 09/729119 |
Document ID | / |
Family ID | 23975186 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020073479 |
Kind Code |
A1 |
Epperson, William Lewis ; et
al. |
June 20, 2002 |
CUSTOM FITTING ASSEMBLY FOR HELMET WITH PROTECTIVE HOOD
Abstract
A protective hood molded to the contours of the interior of an
aircrew helmet. The brow pad and a support panel are located within
the protective hood. The custom fitting system, that adjusts the
position of the support panel relative to the helmet, is located
outside the hood. The custom fitting system is pivotally connected
to the support panel, with the protective hood sealed around the
pivotal connection. The brow pad and support panel lift the hood
off the wearer's head, providing a gap to circulate ventilating
air.
Inventors: |
Epperson, William Lewis;
(Clarks Summit, PA) ; Kuna, Francis J.;
(Carbondale, PA) ; Nattress, Robert Henry;
(Shavertown, PA) |
Correspondence
Address: |
KEUSEY, TUTUNJIAN & BITETTO, P.C.
14 VANDERVENTER AVENUE, SUITE 128
PORT WASHINGTON
NY
11050
US
|
Family ID: |
23975186 |
Appl. No.: |
09/729119 |
Filed: |
December 4, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09729119 |
Dec 4, 2000 |
|
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09497032 |
Feb 2, 2000 |
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Current U.S.
Class: |
2/410 |
Current CPC
Class: |
A42B 3/12 20130101; Y10S
2/901 20130101; A42C 2/007 20130101; A62B 18/04 20130101 |
Class at
Publication: |
2/410 |
International
Class: |
A42B 001/06 |
Claims
What is claimed is:
1. A system for adjusting an enclosed support panel comprising: a
helmet having an interior; a protective hood lining said interior;
a support panel disposed within said protective hood; and a custom
fitting system disposed outside of said protective hood and
operationally coupled to said support panel through said protective
hood.
2. The system of claim 1, wherein said custom fitting system
adjusts the relative position between said support panel and said
helmet.
3. The system of claim 1, wherein said custom fitting system is
pivotably connected to said support panel and wherein said
protective hood is sealed around the pivotal connection.
4. The system of claim 3, wherein said custom fitting system
comprises: straps pivotally connected to said support panel; and
strap retaining clips mounted to said helmet.
5. The system of claim 1, wherein said support panel comprises a
nape panel.
6. The system of claim 5, wherein said custom fitting system
adjusts the front-to-back position of said nape panel relative to
said helmet.
7. The system of claim 1, further comprising a brow pad disposed
within said protective hood.
8. The system of claim 1, wherein said support panel comprises a
crown panel.
9. The system of claim 7, wherein said custom fitting system
adjusts the height of said crown panel relative to said helmet.
10. The system of claim 8, wherein said crown panel comprises
webbing strips with a gap formed therebetween.
11. The system of claim 10, comprising a crown duct equipped with
an exhaust vent directed toward the gap.
12. The system of claim 7, wherein said hood is sealed around said
crown duct.
13. The system of claim 8, wherein said crown panel creates a space
between said protective hood and a wearer's head.
14. The system of claim 13, comprising a crown duct equipped with
an exhaust vent directed toward the space.
15. The system of claim 14, wherein said hood is sealed around said
crown duct.
16. The system of claim 1, wherein said helmet includes a visor
having an interior surface and a periphery and said protective hood
is sealed to said visor periphery.
17. The system of claim 16, wherein said visor includes a visor
duct along at least a portion of said visor periphery, and wherein
said visor duct is equipped with vent holes directed toward the
interior surface of said visor.
18. The system of claim 16, further comprising a respiration system
including a stiff outer shell equipped with a breathing air supply
hose and an exhalation valve, wherein said outer shell overlies a
portion of said protective hood disposed below said visor.
19. The system of claim 18, wherein said protective hood seals
around said breathing air supply hose and said exhalation
valve.
20. The system of claim 1, further comprising a respiration system
including a stiff outer shell equipped with a breathing air supply
hose and an exhalation valve, wherein said outer shell overlies a
portion of said protective hood with said protective hood sealing
around said breathing air supply hose and said exhalation
valve.
21. The system of claim 20, wherein said respiration system
additionally includes an adjustable length strap removably coupled
between said outer shell and said helmet.
22. The system of claim 20, wherein said outer shell is equipped
with a microphone cable, wherein said protective hood seals around
said microphone cable.
23. The system of claim 20, wherein said outer shell is equipped
with a drink tube, wherein said protective hood seals around said
drink tube.
24. The system of claim 1, wherein said helmet includes earphones
having communications cables, wherein said earphones are disposed
within said hood and said hood is sealed around said communications
cables.
25. The system of claim 1, further comprising a respiration system
including a stiff outer shell and an inner facepiece adapted to
enclose a mouth and nose of a wearer, wherein said stiff outer
shell and said inner facepiece sandwich a portion of said
protective hood therebetween.
26. The system of claim 25, wherein said respiration system
includes a breathing air supply hose and an exhalation valve,
wherein said protective hood seals around said breathing air supply
hose and said exhalation valve.
27. The system of claim 1, wherein said protective hood has a lower
edge.
28. The system of claim 27, comprising an elastic neck dam
connected near said lower edge of said protective hood.
29. The system of claim 27, comprising a shoulder shroud connected
to said lower edge of said protective hood.
30. The system of claim 1, wherein said protective hood is made
from a chemical resistant and biological resistant material that is
molded to the shape of the helmet interior.
31. A fitting assembly for a helmet comprising: an inner helmet
positionable in a fore and aft direction and including interiorly a
front forehead dome and side sections; a rear panel adapted to
contact the wearer's nape and means coupling said rear panel to
said side sections for adjustably positioning said inner helmet in
the fore and aft direction; a contoured pad adapted to support the
dome on the wearer's forehead; and a protective hood lining the
interior of said inner helmet.
32. The assembly of claim 31, wherein said contoured pad comprises
a primary layer molded to the contours of the wearer's
forehead.
33. The assembly of claim 32, wherein said primary layer comprises
an expanding foam compound having an initial liquid state and a
final, cured solid state.
34. The assembly of claim 33, wherein said compound is introduced
in the initial liquid state into a gap formed between said dome and
the wearer's forehead and wherein said compound expands to
substantially occupy the gap in the final, cured solid state.
35. The assembly of claim 32, further comprising an inner layer of
compressible material disposed between said primary layer and the
wearer's forehead.
36. The assembly of claim 35, wherein said contoured pad further
comprises an outer impact absorbing layer disposed between said
primary layer and said dome.
37. The assembly of claim 36, wherein said inner and outer layers
cooperatively form a receptacle for containing said primary
layer.
38. The assembly of claim 34, wherein said contoured pad further
comprises a pouch made of a material adapted for skin contact,
wherein said pouch encases said primary layer, said inner layer and
said outer layer.
39. The assembly of claim 31, wherein said coupling means comprises
straps on said rear panel and retention clips on said inner
helmet.
40. The assembly of claim 39, wherein said rear panel straps are
pivotally connected to said rear panel.
41. The assembly of claim 40, wherein said rear panel comprises a
semi-rigid material.
42. The assembly of claim 41, wherein said rear panel straps pivot
to engage said clips and upon tightening, said rear panel straps
are adapted to flex said rear panel to the profile of the user's
nape.
43. The assembly of claim 31, further comprising a chin strap
attached to lower regions of said side sections, wherein said chin
strap and said contoured pad and said rear panel form a three-point
restraint which cooperatively resists forward rotation of the
helmet.
44. The assembly of claim 31, further comprising a breathing mask
attached to lower regions of said side sections, wherein said
breathing mask and said contoured pad and said rear panel form a
three-point restraint which cooperatively resists forward rotation
of the helmet
45. The assembly of claim 31, wherein said rear panel is disposed
within said protective hood.
46. The assembly of claim 31, wherein said contoured pad is
disposed within said protective hood.
47. The assembly of claim 31, wherein said rear panel coupling
means is disposed outside said protective hood.
48. The assembly of claim 31, further comprising: a crown pad
adapted to contact the wearer's crown, wherein said inner helmet in
additionally positionable in a vertical direction; and means
coupling said crown pad to said side sections for adjustably
positioning said inner helmet in the vertical direction.
49. The assembly of claim 48, wherein said coupling means comprises
straps on said crown pad and retention clips on said inner
helmet.
50. The assembly of claim 49, wherein said crown pad straps are
pivotally connected to said crown pad.
51. The assembly of claim 50, wherein said crown pad is made of a
semi-rigid material.
52. The assembly of claim 51, wherein said crown pad straps pivot
to engage said clips and upon tightening, said crown pad straps are
adapted to flex said crown pad to the profile of the user's
crown.
53. The assembly of claim 48, wherein said crown pad is disposed
within said protective hood.
54. The assembly of claim 48, wherein said crown pad coupling means
is disposed outside of said protective hood.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation-in-part of co-pending U.S. patent
application Ser. No. 09/497,032 filed Feb. 2, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a custom fitting assembly for a
helmet equipped with a protective hood. The system is particular
suited for use with helmet mounted devices which support military
air and ground operations.
[0004] 2. The Prior Art
[0005] In general, helmets are designed to meet requirements for
comfort, stability, and head impact protection during flight,
egress and ejection, and to fit an anthropometric range of heads.
With the advent of helmet mounted devices (HMDs) an increased
demand for optical stability was required to keep the HMD in the
operator's field of view. This created various designs of inner
liners and improved suspension systems to meet the comfort,
stability and weight bearing requirements of the many HMDs.
[0006] Improvements in electro-optics technologies promised to
transfer aircraft mounted head up displays and HMD imagery to the
inner surface of the helmets visor or to other optical display
combiner or device. With new Helmet Mounted Display (HMD)
technologies comes a new and even tighter requirement for optical
stability. Current helmets have been used to launch these new
technologies with little success. The weights and center of gravity
of new HMD systems displace the helmet out of the "eyebox" thereby
negating the HMD's operational effectiveness as well as causing
aircrew fatigue, neck strain, and during ejection possible severe
injury and death.
[0007] An example of a prior art design is described in U.S. Pat.
No. 5,584,073. A serious drawback with such platform is that to
achieve a high level of stability, the suspension had to be
tightened to the point of wearer discomfort. While the suspension
system was tight it still swayed under "G" loading with HMD
weights. Due to the narrow headband, the load bearing areas around
the head created numerous areas of discomfort, known as "hot
spots". Additionally, each HMD system requires exact and repeatable
placement of the image in front of the wearer's eyes, which must be
maintained during the entire mission and over many missions.
Designers concluded that meeting such criteria with existing
systems could not be practically achieved and would require an
impractical number of helmet sizes to properly fit a large
anthropometric head population.
[0008] Accordingly, it would be desirable to provide an inner
helmet assembly in just a few sizes which could be easily
custom-fitted to military personnel for use with various outer
helmet systems for a variety of modern combat applications. Such an
inner helmet would figuratively lock onto the wearer's head thereby
insuring reproducible alignment of the "eyebox" to the eventual
HMD.
SUMMARY OF THE INVENTION
[0009] It is therefore a primary object of the invention to provide
a helmet fitting assembly in one or two sizes with custom-fitted
inserts that can be adapted to various helmets.
[0010] It is a further object of the present invention to allow
easy positioning of the helmet with positive locking devices.
[0011] It is yet another object of the present invention to provide
an insert which is molded or formed in situ to conform to a portion
of the wearer's head.
[0012] It is still another object of the present invention to equip
the helmet with a hood that provides protection against chemical
agents and biological agent, as may occur during chemical or
biological warfare or industrial accidents.
[0013] These and other related objects are met by providing a
semi-rigid suspension system of independent components which
contacts the head over large surface areas. The system includes a
custom-contoured component and positive lock components which
cooperatively allow repeated engagement of the desired design eye
position.
[0014] The preferred embodiment of the system revolves around an
inner helmet comprising a front forehead dome and side sections. A
semi-rigid rear panel engages the wearer's nape and has adjusting
straps which extend generally forwardly to engage positive locking
clips located on the inner helmet side sections. The inner helmet
is positioned in the fore and aft directions by the rear panel
adjusting straps. A contoured pad then supports the forehead dome
on the user's forehead. The contoured pad includes an inner comfort
layer, a primary layer which is custom fitted in situ, and an outer
impact absorbing layer. Because the primary layer is essentially a
mold of the wearer's forehead it always seats in the same
position.
[0015] A semi-rigid crown pad has adjusting straps which extend
generally downward to engage positive locking clips located on the
inner helmet side panels. The inner helmet assembly is suspended
from the crown pad via the straps which are adjusted to bring the
inner helmet to the desired vertical position. The inner helmet is
restricted from upward movement by a chin strap or breathing
mask.
[0016] The components of the helmet fitting assembly are adjusted
along the horizontal and vertical axes to position the wearer's
eyes in the proper orientation and distance from the ultimate
display. In use the helmet fitting assembly also resists forward
rotation caused by the weight of the display systems located in
front of the wearer's forehead within the helmet. Forward rotation
is characterized by the forehead dome sliding down while the rear
portion of the helmet rides up. These forces are resisted by the
brow pad which is molded to a particular part of the forehead, the
nape panel, and by the chin strap or breathing mask which opposes
any tendency of the rear part of the helmet to pivot away from the
wearer's chin.
[0017] It can be seen that we have met the various objects of the
invention by providing a custom molded insert which complements the
positive lock components used for alignment. The semi-rigid crown
pad and nape panel are strong, lightweight and conformable to
individual sizes and shapes. All inserts are designed to distribute
weight and stresses over large surface areas avoiding sensitive
regions of the head. The inserts work in conjunction with the chin
strap or breathing mask and nape strap to resist pivoting forces
thereby locking the helmet in its desired position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In the accompanying drawings to which reference is made in
the instant specification and which are to be read in conjunction
therewith and in which like reference numerals are used to indicate
like parts in various views:
[0019] FIG. 1 is an exploded view of the preferred embodiment
showing an outer helmet separated from an embodiment of an inner
helmet which includes the fitting assembly according to the
invention.
[0020] FIG. 2A is a cross-sectional view of the inner helmet taken
along the line 2-2 from FIG. 1.
[0021] FIG. 2B is a cross-sectional view similar to FIG. 2A showing
the protective hood according to the invention.
[0022] FIG. 3A is an enlarged view of the front brow pad taken from
FIG. 2A.
[0023] FIG. 3B is a front side elevational view of the brow pad
illustrating a foaming operation for custom fitting the brow pad to
the wearer's forehead.
[0024] FIG. 3C is an enlarged view similar to FIG. 3A showing the
protective hood in relation to the brow pad.
[0025] FIG. 4A is an enlarged view of the nape strap taken from
FIG. 2A.
[0026] FIG. 4B is a front side elevational view of the nape
strap.
[0027] FIG. 4C is an enlarged view similar to FIG. 4A showing the
protective hood in relation to the pivotal connection of the
support panels.
[0028] FIG. 5 is a top plan view of the crown pad taken along the
line 5-5 from FIG. 2A.
[0029] FIG. 6A is a cross-sectional view of a retention clip
engaging a strap taken along the line 6a-6a from FIG. 2.
[0030] FIG. 6B is a further view cross-sectional view of the
retention clip taken along the line 6B-6B from FIG. 6A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Referring now in detail to drawings, and in particular FIG.
1, there is shown an outer helmet 10 separated from an inner helmet
20. Outer helmet 10 may, for example, be formed of ballistic
material of any suitable type known to the art to afford the wearer
protection against injury from flying fragments and the like. Outer
helmet 10 may consist of a basic protective helmet for infantry, a
standard helmet for air crew provided with visors, or an advanced
helmet for air crew provided with HMD technologies. Inner helmet 20
may be permanently attached within outer helmet 10, for example, by
screws or adhesives. Alternatively inner helmet 20 may be clipped,
latched or otherwise removable secured within outer helmet 10, for
example by an interchangeable latch assembly described in a
commonly-owned, copending patent application Ser. No. 09/640,442
filed on Aug. 17, 2000. Total weight for the inner helmet and on
HMD equipped outer helmet is in the order of 41/2 lbs.
[0032] Inner helmet 20 is a rigid frame made of a strong yet
lightweight material, for example, graphite or fiberglass. Inner
helmet 20 is characterized by a broad forehead dome 21, side
sections 22a and 22b, a rear panel 25 and a crown aperture 26. Side
section 22a includes a first pair of retention clips 23a and 23b
and a second pair of retention clips 23c and 23d. A similar set of
retention clips are mounted onto side panel 22b. A chin strap 19
extends between the lower portions of side panels 22a and 22b.
[0033] Referring now to FIG. 2A side panel 22b is shown with a
first pair of side panel slots 24a and 24b disposed immediately
rearwardly of the first pair of retention clips, and a second pair
of side panel slots 24c and 24d disposed immediately above the
second pair of retention clips. A crown pad 50, which will be
described in greater detail below, includes adjusting straps that
extend through slots 24c and 24d and into respective retention
clips. These adjusting straps permit vertical positioning of inner
helmet 20 relative to the crown of the wearer's head. A breathing
mask may be attached to side panels 22a and 22b via adjustable
length straps 27a. While not shown for the sake of clarity, the
central portion of each side panel may comprise a depression for
accommodating ear phones.
[0034] Adjacent the interior of forehead dome 21 is a brow pad 30
which will be discussed in greater detail below in connection with
FIGS. 3A and 3B. A rear pad 25a of impact absorbing material is
attached to the interior of rear panel 25. Interior of rear pad 25a
is a nape panel 40 which will be discussed in greater detail in
connection with FIGS. 4A and 4B. In use, the adjusting straps of
nape panel 40 are employed to set the fore and aft position of
inner helmet 20 with respect to the nape of the wearer's neck. Brow
pad 30 is subsequently fitted to the contours of the wearer's
forehead. Points within brow pad 30, nape panel 40 and chin strap
19 or breathing mask 27 form the apices of an imaginary triangle
28. Upon installation of brow pad 30, leg 28a of triangle 28
assumes a fixed length. When tightened, chin strap 19 or breathing
mask 27 essentially fixes the distance of legs 28b and 28c. The
significance of the fixed triangle geometry is as follows.
[0035] The straps of nape panel 40 and crown pad 50 may be adjusted
to establish a particular exit pupil distance for an outer helmet
mounted display (HMD). The position is retained by brow pad 30
which fills the entire space between forehead dome 21 and the
wearer's forehead. An outer helmet mounted display typically adds
significant weight to the front portion of the helmet. Such weight
is evenly distributed across large surface areas via brow pad 30
and crown pad 50. The moment of this forwardly-mounted weight
generally urges forehead dome 21 downwardly over the wearer's eyes.
Since leg 28a is of a fixed length, such movement would require
nape panel 40 to pivot counter-clockwise. However, since leg 28b is
of fixed length the torque applied to nape panel 40 is resisted by
chin strap 19.
[0036] FIG. 2B is another cross-sectional view showing a protective
hood 70 that is completely integrated with the components of the
custom fitting assembly. The hood forms a protective bubble around
the head. With the introduction of chemically- and
biologically-filtered breathing and ventilation air into the hood,
aircrew can safely operate, and exit their vehicles, in hostile
environments.
[0037] FIG. 2B illustrates the positioning of protective hood 70
with respect to the nape panel 40 and crown pad 50, both of which
shall be generically referred to as support panels. Brow pad 30 is
first fitted and then placed inside hood 70. Nape panel 40 and
crown pad 50 are also placed inside hood 70 with their straps
located outside hood 70. Hood 70 is sealed around the pivotal
connection between the support panels and their straps, as will be
described in further detail below. The straps are shown in dotted
line indicating that in the view of FIG. 2B they are behind hood
70.
[0038] To seal across the open front of the helmet, there is
provided a visor 74 having a visor periphery 74a. A visor duct 74b
is disposed within periphery 74a and is fed ventilating air through
the front or side of visor 74, for example, at a location 74c
outside the hood. Below the visor is a respiration system 76 having
the following conventional components: a stiff outer shell 76a; a
rubber inner facepiece 76b; a breathing air supply hose 76c; an
exhalation valve 76d; a microphone cable 76e; a drink tube 76f; and
adjustable length straps 27a and 27b removably coupling outer shell
76a to helmet side sections 22a and 22b. The hood is layered
between outer shell 76a and inner facepiece 76b. Components 76c,
76d, 76e and 76f pass through holes in the hood and are secured to
inner facepiece 76b, effectively clamping the hood between
facepiece 76b and outer shell 76a. Hose 76c and the tubular portion
of valve 76d may be secured to facepiece 76b with threaded nuts 76g
and 76h, for example. Any openings between the holes and the
components are filled with an appropriate sealant.
[0039] A pair of earphones 78 are placed inside the hood, whereby
the hood provides increased attenuation of external ambient noise
allowing improved communication. The earphones have a
communications cable 78a which passes through a hole in the hood.
Any opening between the hole and cable 78a is filled with an
appropriate sealant. Further down, hood 70 has a lower edge 70a
near which is attached a neck dam 70b. Optionally, a shoulder
shroud 70c may be attached onto lower edge 70a. Neck dam 70b is an
air barrier preventing exchange of air between the head cavity and
the atmosphere or the lower portion of a flight suit or other
garment. A dump valve 70d is located above neck dam 70b for
releasing excess pressure from within the head cavity. Shroud 70c
may be attached to the flight suit or other garment with a slide
fastener or simply tucked inside. Hood 70 is made from a chemically
resistant and biologically resistant material, like rubber or butyl
rubber. The hood is molded to the contours of the interior of the
helmet.
[0040] Referring now to FIGS. 3A and 3B, brow pad 30 is shown
comprising an outer pouch 31 equipped with a closeable flap 31a.
Pouch 31 is removably affixed to the inner surface of forehead dome
21, for example, by hook and loop fasteners or other suitable
means. Pouch 31 is made from a material which has characteristics
of durability and comfort when contacting the wearer's skin, e.g.
leather or other suitable materials. Within the pouch there is an
outer liner 32 made of an impact absorbing material, for example,
polystyrene, which conforms to the interior of forehead dome 21.
There is also an inner layer 34 made of compressible, comfort
material, for example, foam rubber. Once nape panel 40 and crown
pad 50 are adjusted to the proper exit pupil, the interior of pouch
31 is filled with a liquid foaming agent which expands and
solidifies to conform to the contours of the wearer's forehead and
the outer liner 32. As can be seen in FIG. 3B an expandable foam
may be used wherein the foaming agent in liquid form 33 is injected
or poured into the interior of pouch 31 and expands to fill the
cavity. A minimally exothermic polyurethane foam having a
relatively fast rise time may be used, for example, foams made from
polyether polyol resin combine with pre-reacted diphenylmethane
diisocyanate.
[0041] In FIG. 3C, protective hood 70 is shown between forehead
dome 21 and brow pad 30. Brow pad 30 is first fitted, as described
above, in the absence of hood 70. Brow pad 30 is then placed inside
hood 70 and attached with a hook and loop fastener to the hood 70
instead of forehead dome 21.
[0042] In FIG. 4A, nape panel 40 is shown comprising a semi-rigid
frame 41 made, for example, from a composite resin. Very thin,
flexible composite resin layers are laminated together resulting in
lightweight, yieldable panels. Interior of frame 41 is a comfort
layer 42 made from a compressible material, for example, foam
rubber. Further interior is a cover layer 43 made from a
comfortable, durable material, for example, leather. Cover layer 43
holds comfort layer 42 in place by extending through apertures 44
or around the outer perimeter where its edges are adhered on the
exterior side of frame 41. FIG. 4B shows apertures 44 along with
straps 46a, 46b, 46c and 46d which are attached respectively to
four quadrants of nape panel 40 via pivoting connection points 47a,
47b, 47c and 47d.
[0043] FIG. 4C shows the pivotal connection between the support
panels and their straps in detail. A portion of comfort layer 42 is
removed and a hole is formed in frame 41 to accommodate a threaded
female post 80 which terminates at its left side in a retention
plate 80a. Hood material 70 is fitted around post 80 with any
openings being filled by an appropriate sealant. Strap 46 is
pivotally connected to post 80 via screw 46e. Hence, the pivotal
connections for both support panels are maintained with the hood
material completely sealing the support panels therein. The benefit
of this configuration is that the support panels, as well as the
brow pad, serve to lift the hood material off the wearer's head
providing greater comfort. This configuration also maintains the
contact surfaces between the brow pad and the wearer as well as
between the support panels and the wearer. Therefore, the wearer's
head can be completely sealed against the environment while
maintaining the reproducible alignment of the eyebox, which is
critical for HMD systems.
[0044] Referring again to FIG. 2B, this lifting of the hood results
in a gap 50c between webbing strips 50a and 50b of the support
panel or a space 50d adjacent the support panel. A duct 90 having
an exhaust vent 90a directed toward gap 50c or space 50d is
provided. Duct 90 extends through a hole in the hood. Any spaces
around the hole are filled with an appropriate sealant. Ventilating
air is provided to duct 90 to cool the wearer's head.
[0045] As can be seen in FIG. 5 crown pad 50 has a similar
construction to nape panel 40 including a semi-rigid frame 51, a
comfort layer similar to 42 and a cover layer similar to 43. As can
be seen from this top plan view, the cover layer has edges 53a and
53b which extend through apertures 54 before being adhered on the
exterior surface of frame 51. Each of the quadrants 55a, 55b, 55c
and 55d includes a strap 56a, 56b, 56c and 56d pivotally attached
to frame 51 via screws 57a, 57b, 57c and 57d. The apertures create
web-like strips in panel 40 and pad 50 that extend from the
adjacent quadrants out to the strap connection points. This
web-like configuration allows each quadrant to conform to the
contours of the wearer's crown and nape as the straps bend to
extend through the side panel slots in the inner helmet. In other
words, the straps and the connection points of FIGS. 4B and have a
further independent degree of flexibility into and out of the
page.
[0046] FIG. 6A shows an exemplary bendable, plastic strap extending
initially through a side panel slot 24 formed within side panel 22a
or 22b and further through clip frame 60 made of rugged plastic.
Mounting screws 61 secure clip frame 60 to the exterior of side
panel 22. Extending outwardly from clip frame 60 is a cantilevered
retention arm 62 having a fixed end 62b and a free end 62c with
downwardly extending wedges 62a therebetween. Locking element 63,
as can be seen more clearly in FIG. 6B is slideably mounted to clip
frame 60. Locking element 63 is slideable in direction 62d from a
position adjacent rear stop 62e, over detent 62f, to a position
adjacent front stop 62g. Ordinarily the free end 62c of
cantilevered retention arm 62 is free to rise upwardly as wedges
62a ratchet over corresponding wedges 58 on the strap. Once the
final adjusted position is obtained, locking element 63 is slid to
its left most locking position whereby the free end 62c is
prohibited from riding upwardly to lock the strap in position. In a
practical embodiment, wedges 58 on the strap and arm were spaced 2
mm apart.
[0047] FIG. 2 shows a positioning fixture 29 with a reference point
29a. Positioning fixture 29 is dimensioned and configured to align
reference point 29a on the exact line of sight of the ultimate
display. The crown pad straps and nape panel straps are adjusted in
2 mm increments to locate reference point 29a directly in front of
the wearer's eyes at a predetermined distance. If a strap is
inserted too far through clip 60, free end 62c is raised and the
strap is retracted. Once aligned, locking elements 63 are moved to
their locking positions over free ends 62c. while maintaining the
aligned position on the wearer's head, brow pad 30 is filled with
the appropriate amount of foaming agent. The resulting foam 33
expands to fill the gap and press the head firmly against nape
panel 40. Brow pad 30 and nape panel 40 are generally diametrically
opposed. Accordingly, the inner helmet may be easily donned and
doffed while simultaneously reestablishing the exact eyebox
alignment every time. Upon tightening chin strap 19, the inner
helmet assembly becomes locked in position on the head. Centrifuge
testing was performed with head movements up to 4G and
forwardly-positioned stationery head positioning up to 9G. Overall
the approximately 41/2 lbs. complete inner/outer helmet was
displaced a maximum of 4 mm with the average for 10 aircrew between
1.5 and 3 mm.
[0048] It will be seen that we have provided a lightweight inner
helmet with conformable panels and a complementary contoured pad
that can be easily custom fitted to a large population. The helmet
fitting assembly effectively distributes weight and resists
displacement forces by locking the assembly to the head over large
surface areas. The positive lock retention system and molded brow
pad insure reproducible alignment to the eyebox thereby meeting
critical requirements for HMD utilization.
[0049] It will be understood that certain features and
subcombinations are of utility and may be employed without
reference to other features and subcombinations. This is
contemplated by and is within the scope of the claims. It is
further obvious that various changes may be made in details within
the scope of the claims without departing from the spirit of the
invention. It is, therefore, to be understood that the invention is
not to be limited to the specific details shown and described.
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