U.S. patent number 3,714,668 [Application Number 05/114,538] was granted by the patent office on 1973-02-06 for protective helmet.
This patent grant is currently assigned to Angelica Corporation. Invention is credited to Anthony C. Mirabella.
United States Patent |
3,714,668 |
Mirabella |
February 6, 1973 |
PROTECTIVE HELMET
Abstract
This invention relates to a new and improved helmet comprising
an outer shell and an advanced helmet suspension system supported
therein. Also provided are adjusting means for fitting the
suspension system to the exact head size required, including
separate adjustments for the forehead, nape, and top of the head as
well as for correctly positioning the suspension system within the
shell.
Inventors: |
Mirabella; Anthony C.
(Hartford, CT) |
Assignee: |
Angelica Corporation (St.
Louis, MO)
|
Family
ID: |
22355851 |
Appl.
No.: |
05/114,538 |
Filed: |
February 11, 1971 |
Current U.S.
Class: |
2/419; 2/909 |
Current CPC
Class: |
A42B
3/145 (20130101); Y10S 2/909 (20130101) |
Current International
Class: |
A42B
3/04 (20060101); A42B 3/14 (20060101); A42b
003/00 () |
Field of
Search: |
;2/3,5,6,9,10 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Boler; James R.
Claims
What is claimed is:
1. A protective helmet comprising a protective shell, a sling
suspension assembly for supporting the shell on the head, the
suspension assembly having a circumferential strap and top straps
extending from the circumferential strap over the top of the head,
left and right side mounting brackets, means associated with the
left side of the circumferential strap for adjustably mounting the
suspension assembly to the left side mounting bracket, means
associated with the right side of the circumferential strap for
adjustably mounting the suspension assembly to the right side
mounting bracket, the mounting brackets being sufficiently flexible
to conform to the general contour of the circumferential strap when
mounted thereto, but sufficiently rigid to support and maintain the
shape of the suspension assembly, and means for releasably mounting
the left and right side mounting brackets to the left and right
inside wall portions, respectively, of the shell so that the shell
is suspended on the suspension assembly with the inner surface of
the shell spaced from the outer surfaces of the suspension
assembly.
2. The helmet of claim 1 wherein the left and right side mounting
brackets are interchangeable.
3. The helmet of claim 1 wherein the means for adjustably mounting
the suspension assembly to the left and right side mounting
brackets includes a plurality of mounting straps attached and
spaced along the left and right side portions of the
circumferential strap, and for each mounting strap a pair of slots
in the mounting bracket adjacent thereto through which the mounting
strap is adjustably threaded.
4. The helmet of claim 3 including means associated with the
mounting brackets for suspending the shell at four points around
the circumference of the shell.
5. The helmet of claim 4 wherein the means for releasably mounting
the left and right side mounting brackets to the shell includes a
pair of keyhole slots in each mounting bracket, the keyhole slots
being at substantially opposite ends of the bracket, each keyhole
slot having a large aperture portion and a narrower slot portion
extending away from the large aperture portion toward the nearest
end of the bracket, a pair of spaced pins mounted to the interior
surface at each side of the shell, each pin having a head that
passes through the large aperture portion of the keyhole slot but
not the narrower slot portion, the location and spacing of the pins
being such that the heads of a pin pair pass through the large
aperture portions of the associated keyhole pair with the mounting
bracket held straight, but remain engaged in the narrower slot
portions when the bracket is allowed to curve to the general
contour of the circumferential strap, thereby providing a
four-point quick release mount of the shell on the suspension
assembly.
6. The helmet of claim 4 including a chin strap assembly having a
strap extending under the chin, with means for supporting one end
of the strap from one mounting bracket, and means for adjustably
supporting its other end from the other mounting bracket.
7. The helmet of claim 6 wherein the last two named supporting
means includes a yoke between each end of the chin strap and the
corresponding mounting bracket.
8. A protective helmet comprising a protective shell, a sling
suspension assembly for supporting the shell on the head, the sling
suspension assembly including a left suspension assembly and a
right suspension assembly, each having a side strap portion with a
nape strap extending rearwardly therefrom, a forehead strap
extending forwardly therefrom, and a plurality of top straps
extending upwardly therefrom, mating connector means associated
with each of the nape, forehead, and top straps for adjustably
attaching each strap of the left suspension assembly to its
corresponding strap of the right suspension assembly, and means for
suspending the shell on the suspension assembly so that the inner
surface of the shell is spaced from the outer surfaces of the
suspension assembly.
9. The helmet of claim 8 wherein each of the left and right
suspension assemblies are patterned from a buildup of flat sheets
of material selected in accordance with the protection requirements
of the helmet.
10. The helmet of claim 8 wherein the mating connector means
associated with each of the nape, forehead and top straps are hook
and pile pads to provide continuous and independent size adjustment
over a wide range of sizes for each of the nape, forehead and top
straps.
11. The helmet of claim 11 wherein each of the forehead, nape and
top straps is curved to fit the contour of the head.
12. The helmet of claim 8 wherein the nape straps are curved
downward to fit at the back of the head below the perimeter of
maximum circumference of the head, the side straps, forehead
straps, and nape straps of the left and right suspension assemblies
combining to define a circumferential strap extending around the
head, whereby the helmet can be first donned with only the nape
straps separated, and then the nape straps adjustably attached in
the back of the head, placing the circumferential strap below the
head perimeter of maximum circumference.
13. The helmet of claim 8 including quick release means for
suspending the shell on the suspension assembly, whereby the
suspension assembly can be fitted to the head before the shell is
suspended thereon.
14. The helmet of claim 13 including means for suspending the shell
at four points spaced around the circumferential strap to provide a
stable four-point suspension system.
15. The helmet of claim 8 wherein the means for suspending the
shell on the suspension assembly includes means for adjusting the
location of the entire suspension assembly in the shell.
16. The helmet of claim 8 including left and right side mounting
brackets, means associated with the side strap portion of the left
suspension assembly for adjustably mounting the left suspension
assembly to the left side mounting bracket, means associated with
the side strap portion of the right side suspension assembly for
adjustably mounting the right suspension assembly to the right side
mounting bracket, the mounting brackets being sufficiently flexible
to conform to the general contour of the helmet shell when mounted
therein, but sufficiently rigid to support and maintain the shape
of the suspension assembly, and means for releasably mounting the
left and right side mounting brackets in the left and right inside
wall portions, respectively, of the shell so that the shell is
suspended on the suspension assembly with the inner surface of the
shell spaced from the outer surfaces of the suspension
assembly.
17. The helmet of claim 16 including means associated with the
mounting brackets for suspending the shell at four points around
the circumference of the shell.
18. The helmet of claim 8 wherein the top straps are substantially
parallel as they lay over the top of the head.
Description
BACKGROUND OF THE INVENTION
The invention herein described was made in the course of or under a
contract with the Department of the Army.
The primary function of any helmet suspension system is to act as a
wearable support to which the protective helmet shell is mounted.
In the early evolution of helmet designs, the helmet suspension
systems consisted of bits of leather or cord laced together to
provide some degree of adjustability. Recently, helmet suspension
designs have become more specialized in an effort to optimize the
overall performance of the helmet. The resultant designs fall into
two basic categories: conformal suspension systems and sling
suspension systems.
The conformal systems consist generally of a thick layer of foam or
other shock-absorbing medium bonded directly to the inner surface
of the helmet shell and molded or configured to fit snugly around
the head. The disadvantages of the conformal systems are high cost
resulting from the need for multiple basic shell sizes, difficulty
in attaining exact fit, high weight, and poor helmet ventilation.
The helmet of this invention is not of the conformal type.
The sling suspension system is the other basic category. With the
sling system, the weight of the helmet shell is supported through
attachment points around the circumference of the shell rather than
through pads bonded to its inner surface as with the conformal
system. Slings generally consist of a circumferential sweat band
and over-the-head straps, webbing or netting.
The advantages of the sling systems are their size adjustability,
light weight, good helmet ventilation, and mechanical flexibility.
By mechanical flexibility is meant that the relatively simple
design of the sling permits the selection of materials from either
fabrics, plastics, or metals depending on the exact mechanical
properties of the system desired. Conversely, with conformal
systems, there are relatively few materials which can be used in
their construction.
Unfortunately, there are certain disadvantages to the prior art
helmet suspension systems which include inadequate adjustment
provisions, improper location of suspension members, minimal
contact area with the head, and inherent design deficiencies
placing the helmet center of gravity too high.
The sling-type helmet suspension system of this invention obviates
the problems associated with the prior art systems to provide a
helmet design which offers vast improvements in the areas of sizing
and fit, comfort, stability, and protection over the prior art.
SUMMARY OF THE INVENTION
The advanced helmet suspension system of this invention is of the
sling type and includes generally a protective shell of suitable
material, such as metal or plastic, supported on the head by a
sling suspension assembly. The suspension assembly generally
includes a right suspension assembly and a left suspension
assembly, each adjustably supported by right and left side mounting
brackets, respectively. Each mounting bracket has a base or
circumferential strap made to extend from the side of the head
forward over the forehead and rearward under the nape of the neck,
and two substantially parallel straps extending from the base strap
at the side of the head over the top of the head. The forehead,
nape and top straps of the right and left suspension assemblies are
aligned so that each of these straps of one side suspension
assembly overlaps the corresponding strap of the other side
suspension assembly with each having appropriate connection means
for providing independent size adjustment for the forehead, nape
and top of the head. The adjustable nape straps are curved slightly
downward to provide a snug fit under the nape of the neck.
The combination of these independent strap adjustments together
with the adjustable means for mounting the right and left
suspension assemblies to the mounting brackets provide a total
adjustment to fit the sling to any size head, as well as to
position the sling within the helmet shell as desired by the
wearer.
Other features include left and right chin strap yokes and a chin
strap and cup assembly. These yokes are adjustably mounted to the
left and right mounting brackets, respectively, to provide supports
for the chin strap which is adjustably connected to the lower ends
of the yokes.
This suspension assembly design includes several unique features.
It permits the fabrication of the straps from a buildup of
materials selected in accordance with the protection requirements
of the helmet. Also the key to achieving stability in suspension
system design is to make the diameter of the circumferential strap
smaller than the maximum diameter of the head and to locate the
plane of the circumferential strap below the plane of the maximum
head diameter. This objective is achieved in this advanced helmet
suspension system by incorporating an adjustable nape strap as an
integral part of the circumferential strap allowing adjustment of
the nape strap with the helmet in place.
These and other features of the invention are described in detail
in the description to follow.
DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a side elevational view of the helmet of this invention
shown in the donned position with the protective shell shown in
dashed lines to illustrate the sling suspension assembly
therein;
FIG. 2 is a front elevational view of the sling suspension
assembly;
FIG. 3 is a left-side elevational view of the sling suspension
assembly of FIG. 1 with the right end of the chin strap
disconnected;
FIG. 4 is a plan view of the helmet of FIG. 1 on an enlarged scale
with the protective shell shown in dashed lines to illustrate the
sling suspension assembly therein;
FIG. 5 is an enlarged view in section taken along the line 5--5 of
FIG. 4;
FIG. 6 is an enlarged view in section taken along the line 6--6 of
FIG. 4;
FIG. 7 is an enlarged view in section taken along the line 7--7 of
FIG. 4;
FIG. 8 is an inside elevational view of the mounting bracket of
this invention;
FIG. 9 is an inside elevational view of the left suspension
assembly shown in its flattened position; and
FIG. 10 is an outside elevational view of the right suspension
assembly shown in its flattened position.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT:
Referring primarily to FIGS. 1 through 4, there is shown the
protective helmet 20 of this invention including generally a
protective shell 22 of metal, plastic or other suitable material to
provide a protective outer shield, and supporting the shell 22, a
sling suspension assembly 24.
The shell 22 is supported by the sling suspension assembly 24 by
means of left and right side mounting brackets 26 and 28,
respectively, the sling assembly 24 generally including a left
suspension assembly 30, a right suspension assembly 32, a left chin
strap yoke 34, a right chin strap yoke 36 and a chin strap and cup
assembly 38.
The left and right mounting brackets 26 and 28 are identical, and
shaped generally as shown in FIGS. 1, 2, 3 and 8, each having
keyhole slots 40 and 42 located generally at opposite ends of the
bracket. Associated with each keyhole slot are a large aperture
portion 43 and narrower slot portion 44 having a recess 45 to
receive the head of a mounting pin. The slot portion 44 extends
away from the large aperture portion 43 toward the closest end of
the mounting bracket. Hence, associated with the keyhole slot 40
are pairs of elongated slots 46, 48 and 50, and associated with the
keyhole slot 42 are pairs of elongated slots 52, 54 and 56. As will
be described, the purpose of these slots is to adjustably support
the remaining portions of the sling assembly.
As best shown in FIGS. 1, 4 and 6, pins 60 and 62 are rigidly
secured to the wall of the helmet shell on the left side, and pins
64 and 66 are rigidly secured to the wall of the shell on the right
side. Each of the pins 60, 62, 64 and 66 has a shank 69 and a head
70, the head 70 being small enough to pass through the large
aperture portion 43 of the appropriate keyhole in the appropriate
mounting bracket, but too large to be removed from the keyhole when
its shank is located in the keyhole slot 44.
The keyholes 40 and 42 are spaced such that the distance between
their large aperture portions 43 is equal to the distance between
the mounting pins 60 and 62, or 64 and 66 with the mounting
brackets held flat.
Holding the mounting brackets in the generally flat position, the
mounting bracket 26 is mounted inside the left wall portion of the
helmet shell 22 by placing the large aperture portions 43 of the
keyholes 40 and 42 over the pins 60 and 62, respectively. Due to
forces acting on the mounting brackets by the sling assembly 24, as
will be hereinafter explained, the brackets 26 and 28 are caused to
curve to the general contour of the head after they are released,
in turn causing the heads 70 of the mounting pins to engage the
recesses 45 of the keyhole slots 40 and 42 thereby securing the
brackets to the helmet shell.
The mounting brackets 26 and 28 represent a unique feature of this
invention in that they are fabricated from any suitable material,
such as plastic; are identical and therefore interchangeable with
their unique design requiring only a four-point mount to the helmet
shell thus permitting instant installation and removal of the
suspension system from the shell; and additionally through their
elastic strength provide support for and maintain the shape of the
assembled suspension system.
The left and right side suspension assemblies 30 and 32,
respectively, are basically similar as shown in FIGS. 9 and 10.
Referring to FIG. 9, the left side suspension assembly 30 generally
includes a side strap portion 80 having extending therefrom a nape
strap 81, a forehead strap 82, a foretop strap 83, and an aft top
strap 84. The straps 81 through 84 are curved as shown in the
drawing to conform to the contours of the head when the assembly 30
is assembled with the other components of the sling, as will be
hereinafter described. Mounting straps 85, 86, 87 and 88 are
affixed to the side strap portion 80 by any suitable means such as
stitching 89. The mounting straps 85 through 88 are of any suitable
material such as nylon web, and of a width approximately equal to
the length of the slots 46, 48, 52 and 54 of the left side mounting
bracket 26.
As best shown in FIG. 4, the mounting strap 85 is threaded through
the slots 52, the mounting strap 86 is threaded through the slots
54, the mounting strap 87 is threaded through the slots 48, and the
mounting strap 88 is threaded through the slots 46.
In like manner, the right side suspension assembly 32 generally
includes a side strap portion 90 having extending therefrom a nape
strap 91, a forehead strap 92, a foretop strap 93, and an aft top
strap 94. The straps 91 through 94 are curved as shown in FIG. 11,
just as are the straps 81 through 84 of the left side suspension
assembly 30, to conform to the contour of the head. Also, like the
left side assembly 30, the right side assembly 32 includes mounting
straps 95, 96, 97 and 98 affixed to the side strap portion 90, by
stitching 99 or other suitable means, for adjustably attaching the
right side assembly 32 to the right side mounting bracket 28.
Hence, the mounting strap 95 is threaded through the slots 46, the
mounting strap 96 is threaded through the slots 48, the mounting
strap 97 is threaded through the slots 54, and the mounting strap
98 is threaded through the slots 52.
As will be described in more detail, the threading of the mounting
straps into the slots of the mounting brackets provides adjustment
means for positioning the sling 24 within the helmet shell.
In this described embodiment, the straps 81 through 84 of the left
side suspension assembly 30 are made to overlie the straps 91
through 94, respectively, of the right side suspension assembly 32,
although, of course, the right side assembly could be made to
overlie the left side assembly, if desired.
A pad 100 of pile, such as the pile used in Velcro hook and pile,
is attached, such as by stitching, to substantially the full length
of the inner surface of each of the straps 81 through 84 of the
left side suspension assembly 30, and a pad 101 of tiny hooks, such
as those used in Velcro hook and pile, is attached such as by
stitching, to substantially the full length of the outer surface of
each of the straps 91 through 94 of the right side suspension
assembly 32. WIth the straps 81 through 84 of the left side
suspension assembly 30 made to overlie the straps 91 through 94 of
the right side suspension assembly 32, the hook pads 101 engage the
pile pads 100 to securely attach the right and left assemblies
together. The hook and pile provides nearly limitless adjustability
between maximum and minimum head sizes. While other forms of
connectors could be used, such as a series of snap connectors, none
offer the range of size adjustment and ease of connection that the
hook and pile provides.
The left and right suspension assemblies are a unique feature of
this invention. Because the sling is comprised of left and right
members, each of which can be made to lie flat, they can be
fabricated from a buildup of materials cut from a pattern. In this
manner, the materials may be selected to fit the specific
requirements of the sling. For example, as best shown in FIGS. 5
through 7, each of the straps 81 through 84 of the left side
assembly 30 includes a double thickness of heavy woven fabric 105
held together by stitching 106. The pile padding 100 is attached to
the inside surface of the fabric 105 by appropriate stitching. Each
of the straps 91 through 94 of the right side assembly 32 is also
comprised of a double thickness of heavy woven fabric 110 with the
hook pads sewn on the outside surfaces of the straps. Because the
straps of the right side assembly 32 are next to the head, it may
be preferable, depending on the shock requirements of the sling, to
include between the fabric layers 110 a layer of padding 111 of
foam or other suitable padding material. Also, as shown in FIG. 7,
a leather sweat band 115 is sewn to the inside surface of the
forehead strap 92.
As can be seen, this pattern design offers great selectivity in the
types of materials and number of layers used in fabricating the
sling.
Referring to FIGS. 1, 2 and 3, the left side yoke 34 includes a
fore-suspension strap 120 having one end threaded through the slots
56 of the left mounting bracket 26, and an aft suspension strap 121
having one end threaded through the slots 50 of the left mounting
bracket 26. The other ends of the straps 120 and 121 are joined by
a triangular piece 122 of heavy woven fabric or other suitable
material. Because the inside surface of the triangular piece 122
contacts the face, a similar triangular piece 123 of leather or
other perspiration-absorbing material is sewn to the inside of the
piece 122 with the lower ends of the straps 120 and 121 sandwiched
therebetween. A snap connector 124 is mounted in the triangular
piece 122.
Referring to FIG. 1, the right side yoke 36 is very similar to the
left side yoke 34. The yoke 36 consists of a fore suspension strap
126 having one end threaded through the slots 50 of the right side
mounting bracket 28, and an aft suspension strap 127 having one end
threaded through the slots 56 of the right side mounting bracket
28. Like the straps 120 and 121 of the yoke 34, the other ends of
the straps 126 and 127 of the yoke 36 are joined by a triangular
piece 128 of heavily woven fabric or other suitable material,
except that the end of the suspension strap 127 extends slightly
below and beyond the lower edge of the triangular piece 128 and is
adapted to support a rectangular ring 130. A similar triangular
piece 131 of leather or other perspiration-absorbing material is
sewn to the inside of the piece 128 with the lower ends of the
straps 126 and 127 sandwiched therebetween.
As noted in connected with the mounting strap adjustments for the
left and right side suspension assemblies 30 and 32, suspension
strap adjustments for the left and right yokes 34 and 36 afford
great versatility in size adjustment.
A chin strap assembly 38 includes a strap 134 of nylon or other
suitable material extending from the lower end of the left yoke 34
under the chin to the lower end of the right yoke 36. A snap
connector 135, that mates with the snap connector 124 mounted on
the triangular piece 122, is mounted to the left end of the strip
134 for connection to the lower end of the left yoke 34. At the
right end 137 of the strap 134 is a small pile pad 138 sewn to the
outer surface of the strap 134. Spaced some distance from the pile
pad 138, a hook pad 140 is sewn to the exterior surface of the
strap 134.
With the left end of the strap 134 snapped to the lower end of the
yoke 34, the strap 134 is held in place under the chin by threading
the end 137 outwardly through the ring 130, pulling the strap 134
taut, and folding the end 137 back with the pile pad 138 engaging
the appropriate portion of the hook pad 140. The lengths of the
pads 138 and 140 and the space therebetween are selected in
accordance with the size adjustment requirements.
Also included in the chin strap assembly 38 is a strap 150 which
extends across the front of the chin with its ends stitched to form
loops 151 and 152 around the strap 134 on either side of the face.
The loops 151 and 152 make it possible to adjust the strap 150 by
sliding it along the strap 134.
ASSEMBLY, SIZING AND DONNING PROCEDURES
As heretofore described, the left and right side suspension
assemblies 30 and 32 are attached together preferably by means of
hook and pile, such as Velcro hook and pile, to form the basic
suspension unit. The unit attaches to each of the suspension
mounting brackets 26 and 28 by means of the mounting straps 85, 86,
87, 88, 95, 96, 97 and 98, the mounting brackets 26 and 28 in turn
being mounted to the helmet shell 22 by means of keyhole slots 40
and 42 and mounting pins 60, 62, 64 and 66. The chin strap yokes 34
and 36 attach to the mounting brackets 26 and 28 by means of the
slots 50 and 56; the chin strap assembly 38 attaches to the yoke
assemblies by means of the snap connectors 124 and 135, the
rectangular ring 130 and the hook and pile 138 and 140 on the strap
134.
Generally, the helmet height or offset is controlled by adjustment
of the fore and aft top straps 83, 84, 93 and 94 made prior to
installation of the suspension assembly in the shell; the sling
circumference and fore and aft positioning of the sling within the
helmet shell is controlled by appropriate positioning of the eight
mounting straps 85 through 88 and 95 through 98 in the mounting
bracket slots; circumferential tension is controlled by adjustment
of the nape straps 81 and 91; and the chin strap length and tension
is controlled by the combined adjustment of the chin strap yokes 34
and 36 in the mounting bracket slots 50 and 56 and the strap 134 in
the rectangular ring 130.
INITIAL ASSEMBLY AND SIZING
To assemble and size the helmet of this invention, the wearer
places the left side suspension assembly 30 on a table in front of
him with the pile pads 100 facing up and the nape strap 81
extending to the left. The right side suspension assembly 32 is
placed to the right of the left side assembly 30 with the leather
sweat band 115 facing up and the nape strap 91 extending to the
right. With the left and right suspension assemblies 30 and 32 so
positioned, the forehead strap 92 is attached to the forehead strap
82 by overlapping the hook pad 101 of the forehead strap 92 on the
pile pad 100 of the forehead strap 82. For most head sizes this
overlapping should be such that the hook pad completely overlaps
the pile pad. By grasping the nape strap 81 in the left hand and
nape strap 91 in the right hand, the nape straps are brought
together behind the head with the forehead pressed against the
sweat band 115. The circumference of the sling assembly is then
adjusted to fit snugly around the head by adjusting the nape straps
81 and 91 just below the back of the head by means of the hook and
pile pads. Normally, the height of the sling is correct where there
is approximately a 1/4 inch clearance between the ears and the
sling. Next the foretop straps 83 and 93 and the aft top straps 84
and 94 are fastened together to fit snugly against the top of the
head by means of the hook and pile pad.
With the head straps of the sling correctly adjusted, the sling is
removed, the position of each strap marked, and the left and right
suspension assemblies 30 and 32 disassembled to facilitate further
assembly.
The procedure for attaching the left and right side suspension
assemblies 30 and 32 to the mounting brackets 26 and 28 is
basically identical so that only one need be explained in
detail.
The right sling assembly 32 is placed on the table with the
mounting straps 95 through 98 facing up and the nape strap 91
extending to the left. The mounting bracket 28 is held above the
assembly 32 with the slots 46 directly above the strap 95, the
slots 48 above the strap 96, the slots 54 above the strap 97 and
the slots 52 above the strap 98. Referring to FIG. 4, the strap 95
is threaded through the slots 46 in the manner shown in the drawing
so that the strap 95 is pulled flush with the mounting bracket 28.
Next the strap 96 is threaded through the slots 48 as shown in the
drawing, so that it is very close to lying flat on the mounting
bracket 28 with little or no slack. Next the strap 97 is threaded
through the slots 54 allowing slack in accordance with the head
size adjustment desired. The following table gives slack adjustment
for either the strap 87 of the left sling assembly 30 or the strap
97 of the right sling assembly 32 for large, medium and small head
sizes:
Head Size Head Circumference Strap 87 or 97 Position Large Greater
than 23 in. flush with mounting bracket Medium 22-23 inches 1/2
inch slack Small Less than 22 in. 1/2 inch slack
Next the strap 98 is threaded through the slots 52 allowing slack
in accordance with the head size adjustment desired. The following
table gives slack adjustment for either the strap 88 of the left
sling assembly 30 or the strap 98 of the right sling assembly 32
for large, medium and small head sizes:
Head Size Head Circumference Strap 88 or 98 Position Large Greater
than 23 in. 1 1/4 inch slack Medium 22-23 inches 1/2 inch slack
Small Less than 22 in. 1/2 inch slack
As shown in FIG. 4, the adjustment of the strap 98 causes the
mounting bracket to curve.
The same procedure is followed for mounting the left side
suspension assembly 30 with the strap 85 corresponding to the strap
95 and threaded through the slots 52; the strap 86 corresponding to
the strap 96 and threaded through the slots 54; the strap 87
corresponding to the strap 97 and threaded through the slots 48;
and the strap 88 corresponding to the strap 98 and threaded through
the slots 46.
With the left suspension assembly 30 attached to the left mounting
bracket 26 by means of the mounting straps 85 through 88, and the
right suspension assembly 32 attached to the right mounting bracket
28 by means of the mounting straps 95 through 98, each of the strap
81 through 84 of the left assembly 30 is attached to its
corresponding strap 91 through 94 of the right assembly 32 as
previously marked. Next, the entire suspension assembly 24 is
mounted in the helmet shell 22 by holding the left and right side
mounting brackets 26 and 28 straight and placing the large aperture
portions 43 of the keyhole slots 40 and 42 over the pins 60, 62, 66
and 64. When the mounting brackets are released and allowed to
curve as shown in FIG. 4, the narrow slot portions 44 of the
keyhole slots 40 and 42 slide over the shanks of the mounting pins,
thereby holding the sling in the shell.
The assembly and sizing procedure heretofore described is meant by
way of example only, it being understood that the forehead straps
82 and 92 need not completely overlap, but can be appropriately
adjusted just as the other head straps to fit a particular size
head. Additionally, the mounting straps can be adjusted to more
exact tolerances than set forth in the above tables to fit any size
head, and to position the sling assembly 24 up and down or fore and
aft in the shell 22.
DONNING PROCEDURE
To don the helmet 20, the helmet is held upside down with the front
of the helmet toward the body. The nape straps 81 and 91 are
separated, the nape strap 81 held open with the thumb of the left
hand while grasping the left side of the helmet, and the nape strap
91 held open with the thumb of the right hand while grasping the
right side of the helmet. The helmet is then rotated over the head
and pulled down on the head by means of the nape straps. The nape
straps 81 and 91 are then fastened below the back of the head for a
snug fit.
CHIN STRAP ASSEMBLY INSTALLATION AND ADJUSTMENT
The chin strap assembly 38 is optional, the helmet being perfectly
functional for certain applications, such as protection from
falling objects, without the chin strap assembly. However, the chin
strap assembly is recommended where impact might jar the helmet
from the head.
With the suspension assembly 24 removed from the shell 22, the left
yoke 34 is attached to the left mounting bracket 26 by threading
the end of the strap 120 through the slots 56 and the end of the
strap 121 through the slots 50, and the yoke 36 is attached to the
right mounting bracket 28 by threading the strap 126 through the
slots 50 and the strap 127 through the slots 56, as best shown in
FIGS. 1 and 3. The yokes should be threaded loosely at first until
final adjustment is made of the chin strap assembly 38. Next the
snap connector 135 of the chin strap assembly 38 is connected to
the connector 124 on the left yoke 34. The strap 134 is extended
under the chin with the strap 150 positioned over the front of the
chin. The end 137 is threaded through the rectangular ring and
folded back with the pile pad 138 pressed on the hook pad 140 so
that the chin strap assembly is held snugly in place. Exact
adjustment of the chin strap is accomplished with the combined
adjustment of the straps 120, 121, 126 and 127 of the yokes 34 and
36 and the strap 134 of the chin strap assembly 38.
Various changes and modifications may be made within this invention
as will be readily apparent to those skilled in the art. Such
changes and modifications are within the scope and teaching of this
invention as defined by the claims appended hereto.
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