Note: Descriptions are shown in the official language in which they were submitted.
CA 02793516 2012-10-30
HARD HAT SUSPENSION
FIELD
The present disclosure relates generally to protective equipment. More
particularly,
the present disclosure relates to a suspension for a hard hat.
BACKGROUND
Hard hats are commonly used as safety devices on construction sites and in
other
locations where it is desirable to protect a wearer's head from damage caused
by impact. A
hard hat includes a moulded hard plastic hat shell, which is inexpensive to
produce.
Most hard hats include a nylon web suspension for absorbing or
softening/spreading
forces transmitted through the hard hat shell to the wearer's head. The
suspension typically
includes a set of two flat crossing nylon straps, and optionally a small
square padding at the
intersection thereof. The suspension can also include a circumferential head
strap,
sometimes including brow and/or neck padding.
It is desirable to provide a suspension that provides an alternative approach
to impact
absorption, in a way that still addresses relevant safety issues.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present disclosure will now be described, by way of example
only, with reference to the attached Figures.
Fig. 1 is a plan view of an integrally formed suspension for a hard hat,
according to
one embodiment of the present disclosure.
Fig. 2 is a plan view of an integrally formed suspension for a hard hat,
according to
another embodiment of the present disclosure.
Fig. 3 is a plan view of an integrally formed suspension for a hard hat,
according to a
further embodiment of the present disclosure.
Fig. 4 is a perspective view of a suspension strap for a hard hat according to
one
embodiment of the present disclosure.
Fig. 5 depicts perspective, plan and elevated views of the strap of Figure 4.
Fig. 6 is a perspective view of a suspension strap according to another
embodiment
of the present disclosure.
Fig. 7 depicts perspective, plan and elevated views of the strap of Figure 6.
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Fig. 8 is a perspective view of a suspension strap according to a further
embodiment
of the present disclosure.
Fig. 9 depicts perspective, plan and elevated views of the strap of Figure 8.
DETAILED DESCRIPTION
A hard hat suspension is provided for a hard hat that protects a wearer's
head. The
hard hat comprises a rigid outer shell. The suspension comprises a central
portion for
resting on the wearer's head, and a plurality of resilient impact absorbing
corrugated strap
members depending from the central portion. At least some, or all, of the
strap members
comprise a corrugated segment and terminate in an uncorrugated attachment end
that is
configured for attachment to an inner surface of the rigid outer shell. The
suspension may be
of unitary construction or may be formed of separate strap members.
It is an object of the present disclosure to obviate or mitigate at least one
disadvantage of previous approaches. Any advantages stated herein may pertain
to certain
aspects or embodiments, and not necessarily to all aspects or embodiments.
In one embodiment, the present disclosure provides a hard hat suspension for
use in
a hard hat for protecting a wearer's head. The suspension includes a central
portion for
resting on the wearer's head, and a plurality of resilient impact absorbing
corrugated strap
members depending from the central portion. At least some of the plurality of
strap members
include a corrugated segment and terminate in an uncorrugated attachment end
that is
configured for attachment to the hard hat.
In some embodiments, each of the plurality of strap members comprises the
corrugated segment and terminates in the uncorrugated attachment end. The
plurality of
strap members can be distributed substantially equidistantly about the
perimeter of the
central portion of the suspension. The plurality of strap members can comprise
four strap
members positioned in a substantially X-shaped configuration. The strap
members can be
positioned to define a first pair of opposing obtuse angles within the X-
shape, and a second
pair of opposing acute angles within the X-shape. In such a configuration, the
four strap
members can comprise two pairs of diagonally opposing strap members, each
diagonally
opposing strap member being substantially parallel to the other strap member
in its pair.
In some embodiments, the central portion can be elongated in one dimension to
position the strap members for attachment to the rigid outer shell with
minimal stress. The
uncorrugated attachment end of each strap member can be angled with respect to
the
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corrugated segment of the strap member. The diagonally opposing strap members
can be
offset from one another.
In some embodiments, the corrugated segment of at least one of the strap
members
comprises two rows of corrugations. The two rows of corrugations can define an
aperture
therebetween. The corrugated segment of each of the strap members can comprise
ridges
which project towards the inner surface of the rigid outer shell. The ridges
can be separated
by flat spacer portions configured to comfortably abut the wearer's head.
In some embodiments, the central portion defines a central aperture for
weakening
the central portion and improving shock absorption. The central aperture can
be ovoid, or
any other suitable shape.
In some embodiments, the corrugated segment of the strap members comprises at
least three ridges. In other embodiments, the corrugated segment of the strap
members
comprises at least four ridges. In further embodiments, the corrugated segment
comprise
more than four ridges.
In some embodiments, the suspension is of unitary construction, for example
with the
central portion and the strap members of the suspension being integrally
formed.
The suspension can also comprise a plurality of strap members. In one
embodiment,
the plurality of strap members comprises four strap members, and suspension
comprises
first and second straps, each of the first and second suspension straps
comprising two of the
plurality of strap members, the first and second suspension straps each having
an
uncorrugated central section, the uncorrugated central sections of the first
and second
suspension straps overlapping with one another to form the central portion.
The
uncorrugated central section of the first suspension strap may be recessed
such that when it
overlaps with the uncorrugated central section of the second suspension strap,
the resulting
formed central portion is substantially flat and level with the rest of the
suspension straps.
The suspension may comprise a plurality of separate straps, wherein each of
the plurality of
separate straps comprises two of the plurality of strap members, the straps
each having an
uncorrugated central section, the uncorrugated central sections of the straps
overlapping
with one another to form the central portion.
In another embodiment, the present disclosure provides a hard hat for
receiving and
protecting a wearer's head, comprising a rigid outer shell and a suspension.
In such an
embodiment, the suspension comprises a central portion and a plurality of
resilient impact
absorbing strap members depending from the central portion. At least some of
the plurality
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of strap members comprise a corrugated segment and terminating in an
uncorrugated
attachment end that is configured for attachment to an inner surface of the
rigid outer shell.
The additional aspects described above, and in further detail later herein, in
relation to
optional features of the strap members and the central portion are equally
applicable to this
embodiment including the hard hat's rigid outer shell.
Other aspects and features of the present disclosure will become apparent to
those
ordinarily skilled in the art upon review of the following description of
specific embodiments in
conjunction with the accompanying figures.
In describing the suspension herein, a skilled person would readily understand
that
certain terminology has been adopted to describe the suspension prior to
installation in the
hard hat (e.g. as depicted in Figures 1 to 9 in a generally flat
configuration) and that some
terms used herein refer to the shape or configuration of the suspension and
its parts refer to
the substantially flat configuration. A skilled person would readily
understand that installation
of the suspension would result in curving of the straps, for instance, such
that what is
described as "flat" or "substantially flat" would be a curved flat surface
once installed in an
outer shell of a hard hat.
A "corrugated" portion or segment of a strap member means that at least a
portion of
the strap member is wavy, serpentine, or sinusoidal. The purpose of the
corrugated segment
is to impart resilience and absorb horizontal or vertical impact, thereby
cushioning and
protecting a wearer's head.
According to an example embodiment of the present disclosure, the flat nylon
straps
of known hard hat suspensions are replaced with injection moulded plastic
suspension
straps, or strap members. The injection moulded plastic straps of an example
embodiment
can be formed integral with the locking clips that clip into apertures in the
hat shell, to which
a circumferential head strap can be secured. The plastic suspension straps of
an example
embodiment include a serpentine shape or corrugated pattern, making them
strong enough
for the desired absorption, without breaking. During impact the corrugations
straighten out,
absorbing the energy to allow the hat to pass safety standards testing.
The straightening out of the corrugated injection moulded strap of example
embodiments of the present disclosure is a different approach than absorption
by the
stretching of a nylon strap, which is used in known approaches. A thin
uncorrugated strap,
as used in known approaches, will break under pressure; a thick uncorrugated
strap makes
the wearer's head absorb the energy, rather than the straps. Impact absorbing
corrugated
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strap members according to example embodiments of the present disclosure
include a
corrugated segment and an uncorrugated attachment end. While corrugations or
other
locking mechanisms are known for strap adjustment or securing the attachment
end of a
strap to a hard hat shell, only flat uncorrugated straps have been used for
the impact
absorbing portion of the strap.
The suspension is also a large contributor to the overall production expense
of the
hard hat, in terms of material and labour. At least some embodiments of the
present
disclosure provide a suspension that has a decreased cost of production
without decreased
performance.
Figure 1 depicts a hard hat suspension 100 of an example embodiment of the
present disclosure. The suspension comprises a central portion 110 for resting
on the
wearer's head, and a plurality of resilient impact-absorbing corrugated strap
members 122,
124, 126, 128 depending therefrom. In an embodiment, at least one strap member
comprises a corrugated segment. For example, at least some of a plurality of
strap members
comprise a corrugated segment. In the example embodiment of Figure 1, each
strap
member 122, 124, 126, 128 comprises a corrugated segment 132, 134, 136, 138
and
terminates in an uncorrugated attachment end 142, 144, 146, 148.
In the example embodiment depicted in Figure 1, the four strap members 122,
124,
126, 128 are placed in an X-shaped configuration, or a substantially X-shaped
configuration.
The strap members are positioned to define a first pair of opposing obtuse
angles 162 within
the X-shape, and a second pair of opposing acute angles 164 within the X-
shape. In another
embodiment, the plurality of strap members are distributed substantially
equidistantly about
the perimeter of the central portion of the suspension.
In the example embodiment of Figure 1, the four strap members 122, 124, 126,
128
comprise two pairs of diagonally opposing strap members 122, 126 and 124, 128,
with each
diagonally opposing strap member being substantially parallel to the other
strap member in
its pair. For example, 122 and 126 are substantially parallel, and 124 and 128
are
substantially parallel.
In the example embodiment of Figure 1, the uncorrugated attachment end 142,
144,
146, 148 of each strap member is angled at points 140 with respect to the
corrugated
segment of the strap member 132, 134, 136, 138. This configuration permits the
suspension
to be installed in a rigid shell of a hard hat with less stress, allowing
impact absorption to be
more uniformly distributed across each strap member.
CA 02793516 2012-10-30
In the example embodiment of Figure 1, each strap member has an attachment
segment 152, 154, 156, 158 defining attachment holes (exemplified by 150)
which may be
used for engaging a conventional hard hat headband, such as an adjustable
headband (not
shown). The suspension 100 may be of unitary construction, as depicted in
Figure 1. It may
be integrally formed, such as using injection molding.
Figure 2 depicts a suspension 200 in accordance with another embodiment of the
present disclosure in which the central portion is elongated and the strap
members are not
angled. The suspension 200 comprises dependent strap members 222, 224, 226,
228 each
having a corrugated segment 232, 234, 236, 238. Figure 2 also illustrates
attachment ends
242, 244, 246, 248, and attachment segments 252, 254, 256, 258 defining
attachment holes,
as exemplified by 250.
In the example embodiment of Figure 2, the strap members 222, 224, 226, 228
are in
an X-shaped configuration. The central portion 210 in Figure 2 is elongated in
one
dimension to position the strap members for attachment to the rigid outer
shell with minimal
stress. This permits impact absorption to be more uniformly distributed across
each strap.
In this embodiment, there is no angling of strap members 222, 224, 226, 228,
between the
attachments ends 242, 244, 246, 248 and the corrugated segments 232, 234, 236,
238, with
each strap member being substantially linear along its length, with optional
tapering as
shown.
In the example embodiment of Figure 2, diagonally opposing strap members are
offset from one another. For instance, although they are parallel, strap
member 222 is offset
from its diagonally opposed strap member 226, while strap member 224 is offset
from its
diagonally opposed strap member 228.
Figure 3 depicts a suspension 300 in accordance with another embodiment of the
present disclosure in which a central aperture is provided in the central
portion. The
suspension 300 comprises dependent strap members 322, 324, 326, 328 each
having a
corrugated segment 332, 334, 336, 338. Figure 3 also illustrates attachment
ends 342, 344,
346, 348, and attachment segments 352, 354, 356, 358 defining attachment
holes, as
exemplified by 350. In the example embodiment of Figure 3, the strap members
322, 324,
326, 328 are in an X-shaped configuration.
In this embodiment, the central portion 310 in Figure 3 is elongated in one
dimension
to position the strap members for attachment to the rigid outer shell with
minimal stress. This
permits impact absorption to be more uniformly distributed across each strap.
In the
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example embodiment of Figure 3, the central portion 310 defines a central
aperture 311 for
weakening the central portion to improve shock absorption. The central
aperture 311 in the
example embodiment of Figure 3 is ovoid, and the central aperture 311 has
relative
dimensions that are similar to the relative dimensions of the central portion
310 itself. In
another embodiment, the central portion and the central aperture defined
thereby are of
another shape. Examples of other shapes for the central portion in other
embodiments
include square, rectangular, triangular, diamond, and any other suitable
shape. In another
embodiment, the central aperture has relative dimensions that are dissimilar
to the
dimensions of the central portion.
In the example embodiment of Figure 3, as in Figure 2, there is no angling of
strap
members 322, 324, 326, 328, between the attachments ends 342, 344, 346, 348
and the
corrugated segments 332, 334, 336, 338, with each strap member being
substantially linear
along its length.
In the example embodiment of Figure 3, also as in Figure 2, diagonally
opposing
strap members are offset from one another. For instance, although they are
parallel, strap
member 322 is offset from its diagonally opposed strap member 326, while strap
member
324 is offset from its diagonally opposed strap member 328.
Figures 4 to 9 illustrate elements of other embodiments in which the
suspension
comprises a plurality of separate suspension straps each having an
uncorrugated central
section. One of these separate suspension straps is illustrated in each of
Figures 4 to 9, with
each suspension strap effectively combining two of the previously described
strap members.
These example embodiments illustrate and describe a suspension strap that is
used in a
suspension having two cooperating suspension straps. Other embodiments can
include
more than two cooperating suspension straps. The uncorrugated central sections
of the
suspension straps overlap with one another to form the central portion when
the suspension
is assembled. In one embodiment with two separate suspension straps, the
uncorrugated
central section of a first suspension strap is recessed such that when it
overlaps with a
central section of a second suspension strap, the resulting formed central
portion is
substantially flat and level with the rest of the straps.
Figures 4 and 5 depict a suspension strap 420 in accordance with an embodiment
of
the present disclosure. The suspension strap 420 comprises corrugated segments
432, 436
and attachment ends 442, 446 configured to be releasably secured in a hard hat
shell.
Attachment segments 452, 456 are also provided defining attachment holes, as
exemplified
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by 450, for engaging a hard hat headband. In an example embodiment, the
suspension
strap 420 is a functional equivalent of two diagonally opposite strap members
described in
Figures 1 to 3, with the diagonally opposite strap members joined together and
forming a part
of the central portion of the suspension.
In the example embodiment depicted in Figures 4 and 5, two corrugated segments
432, 436 are separated by a non-corrugated segment 410. In this embodiment,
each
corrugated segment 432, 436 comprises four ridges exemplified by 430, the
ridges projecting
towards the inner surface of the rigid outer shell (not shown). The ridges 430
are separated
by flat spacer portions exemplified by 431 configured to comfortably abut the
wearer's head.
In other embodiments, the corrugated segments comprise a different number of
ridges and
flat spacer portions.
Figures 6 and 7 depict a suspension strap 520 in accordance with another
embodiment of the present disclosure. The suspension strap 520 comprises
corrugated
segments 532, 536 comprising two rows of corrugations, each pair of rows
defining an
aperture exemplified by 533 therebetween. The aperture 533 serves to weaken
the adjacent
corrugated rows and improves overall shock absorption.
Attachment ends 542, 546 are configured to be releasably secured in a hard hat
shell. Attachment segments 552, 556 are also provided defining attachment
holes, as
exemplified by 550, for engaging a hard hat headband. In an example
embodiment, the
suspension strap 520 is a functional equivalent of two diagonally opposite
strap members
described in Figures 1 to 3, with the diagonally opposite strap members joined
together and
forming a part of the central portion of the suspension.
In the example embodiment depicted in Figures 6 and 7, two corrugated segments
532, 536 are separated by a non-corrugated segment 510. In this embodiment,
each
corrugated segment 532, 536 comprises three ridges exemplified by 530, the
ridges
projecting towards the inner surface of the rigid outer shell (not shown). The
ridges 530 are
separated by flat spacer portions exemplified by 531 configured to comfortably
abut the
wearer's head. In other embodiments, the corrugated segments comprise a
different number
of ridges and flat spacer portions. Figure 7 depicts and example embodiment in
which
aperture 533 includes rounded ends 535 which extend beyond the corresponding
corrugated
segment 532 in which the aperture is defined.
Figures 8 and 9 depict a suspension strap 620 in accordance with another
embodiment of the present disclosure, in which four ridges are provided in the
two rows of
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corrugations. The suspension strap 620 comprises corrugated segments 632, 636
and
attachment ends 642, 646 configured to be releasably secured in a hard hat
shell.
Attachment segments 652, 656 are also provided and define attachment holes, as
exemplified by 650, for engaging a hard hat headband. In an example
embodiment, the
suspension strap 620 is a functional equivalent of two diagonally opposite
strap members
described in Figures 1 to 3, with the diagonally opposite strap members joined
together and
forming a part of the central portion of the suspension.
In the example embodiment depicted in Figures 8 and 9, two corrugated segments
632, 636 are separated by a non-corrugated segment 610. In this embodiment,
each
corrugated segment 632, 636 comprises four ridges exemplified by 630, the
ridges projecting
towards the inner surface of the rigid outer shell (not shown). The ridges 630
are separated
by flat spacer portions exemplified by 631 configured to comfortably abut the
wearer's head.
In the example embodiment depicted in Figures 8 and 9, the corrugated segments
632, 636 comprise two rows of corrugations, each pair of rows defines an
aperture
exemplified by 633 therebetween. The aperture 633 serves to weaken the
adjacent
corrugated rows and improves overall shock absorption. Figure 9 depicts and
example
embodiment in which aperture 633 includes rounded ends 635 which extend beyond
the
corresponding corrugated segment 632 in which the aperture is defined.
A skilled person would appreciate that features depicted for the "separately
formed
strap" embodiments of Figures 4 to 9, such as specific number of corrugations,
rows of
corrugations defining an aperture therebetween, design parameters, etc., could
also be
employed in "unitary construction" embodiments depicted in Figures 1 to 3.
Conversely, a
skilled person would recognize that features pertaining to the configuration
of dependent
strap members in the "unitary construction" embodiments (angling, etc.) could
be applied to
the "separately formed strap" embodiments, since each separately formed strap
has two
opposite sides (flanking the central non-corrugated segment) which could
effectively be
taken as the equivalent of dependent strap members in the "unitary
construction"
embodiments.
Generally, features of the corrugations may be adjusted to provide different
or
improved shock absorption characteristics. For example, in some embodiments,
more
corrugations may be used.
In some embodiments, no headband would be required, and the above-described
attachment segments could therefore be omitted from such embodiments.
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Hard hats and suspensions according to some embodiments are capable of
absorbing horizontal and vertical impact force. In some embodiments, the hard
hat meets
safety standards, such as those set by the Canadian Standards Association
(CSA), and
which would be known to a skilled person.
Individual non-limiting advantages of some (but not necessarily all)
embodiments
include that they may be easier to manufacture, may be cheaper to manufacture,
may
reduce labour costs, may improve safety, may be more comfortable to the
wearer, and/or
may be cooler (e.g. better ventilated).
In the preceding description, for purposes of explanation, numerous details
are set
forth in order to provide a thorough understanding of the embodiments.
However, it will be
apparent to one skilled in the art that these specific details are not
required. The above-
described embodiments are intended to be examples only. Alterations,
modifications and
variations can be effected to the particular embodiments by those of skill in
the art without
departing from the scope, which is defined solely by the claims appended
hereto.
