Note: Descriptions are shown in the official language in which they were submitted.
`~' 217q~
SAFETY HELMET ~lTH IMPROVED RETATNING ASSEMBLY
FIF.I .n OF T~lF. INVENTION
The invention relates generally to safety helmets, particularly
helmets that do not envelop the sides and back of the wearer' s head, and to
5 improving the manner in which such helmets are retained on a wearer' s head.
DF.~scRIpTIoN OF THF PRIOR ART
Safety helmets used in the construction industry have a rigid
plastic shell, a size adjustment band mounted within the shell, and a harness
fixed to the adjustment band that seats on the wearer's head. Such helmets are
10 fairly heavy and perch fairly high on the head as the harness spaces the shell
upward froln the head. A major problem is that such helmets tend to fall off
when the wearer bends forward. They also fall off when the wearer tilts his
head back. To improve retention, the shell has been formed with a pair of
apertured tabs or simple openings in opposite sides that permit laces or other
15 ties to be used to fasten the helmet below the wearer's chin. Retention is
somewhat improved but the ties are sufficiently ull~,ulllrul~lc that workers
tend not to use them. Another approach to enhancing retention of ~u~ lu~liull
helmet involves shaping a rear section of the size adjustment band so that it dips
down about the wearer's occipital ridge. The modifled size adjustment band is
20 intended to prevent the helmet from falling when the wearer bends forward butfails to do so. The a" .., l~r.l I Irl ~I does little to resist falling of the helmet when
the wearer tips his head back. The prior art does not appear to have provided anadequate solution to the problem.
Conventional bicycle helmets, like ..., .~1, ,1~ 1 i. ~1. safety helmets,
25 perch atop the wearer's head but chin straps are normally used. Such helmets
are normally lighter than UUII~ iUllal ~,OIIDUU~,~iUII helmets and usually have
foam liners that snugly fit the wearer's head. Such helmets thus have less
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tendency to fall forward than uu..~ ,ull~LIuuLiull helmets, but they do
tend to lift and rotate backwards if a cyclist is movmg at a significant speed,
which creates a very " . "., r", ~ f. sensatiûn~
l~l`<TF.F SUMMARY OF THE INVENTION
In one aspect, in a safety helmet with a rigid shell, the invention
provides a retaining assembly that improves retention of the helmet. The
retaining assembly includes a rigid resilient arcuate band whose ends are
connected to opposing sides of the helmet such that the band pivots either
through hinge action or elastic rlPfflrm~fif~n about a horizontal axis forward of
the front-to-rear center of the interior of the shell. Adjustment means permit
the effective length of the retaining band to be adjusted so that the band seatsbelow the occipital ridge of the wearer's head and Afcnmmf~' variations in
head shape. In a ~ù~Llu~iull helmet, which has a harness that positions the
shell high on the wearer's head, the invention effectively resists the tendency of
the helmet to fall forward. In a bicycle-type helmet, the ends of the band may
be fLxed against rotation to the shell with the retaining band oriented in a natural
or unstressed rest position in which it extends downward and rearward from the
helmet at a plr~l ~l acute angle relative to horizontal, preferably between
50-70 degrees. After initial adjustment of the band length, the band pivots
elastically to a position closer to the helmet in response to rl ~ ,,rl 1 1~ ~ 11 wi.fh the
top of the wearer's occipital ridge and then snaps into place below the occipital
ridge when the helmet is fully seated. The band then resists lifting and
backward rotation of the bicycle helmet.
In another aspect, the invention ~UIIVtilliGllLIy retrofits a
~u--~Llu~,Liull helmet to resist the tendency of such a helmet to fall forward.
Such helmets often have openings on opposite sides that are intended to receive
chin ties, as described above. These openings are normally positioned forward
of the front-to-rear center of the interior of the shell to facilitate tieing below the
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.~ ,
chin. A rigid resilient retaining band is provided which has a pair of elastically
separable jaws at either end. Each pair of jaws has a projection that extends
from at least one jaw toward the other and ultimately serves as a pivot pin. Thepaired jaws are spread to receive the shell portions defining the openings, and
5 the projections are located within the openings. An adjustment mrrh~niem,
which is between the band ends, allows proper seating of the band below the
wearer's occipital ridge.
For purposes of this ~ various terms should be
understood as having particular meanings. The terms "rigid" and "resilient"
10 should be understood Ic~ ly as tending to retain overall shape and as
being sufficiently elastic to return to a particular shape after defiection or
deformation, in ,~ " ~ ) to the qualities of laces or fabric ties. The term
"arcuate" as used in respect of a retaining band should be understood as
generally arched and ~ g optional bends to allow greater clearance,
15 for e~ample, for a wear 's ears. The "effective length" of a retaining band
should be understood as the distance along the band measured between points
of connection to the shell. The terms "front", "rear", "horizontal" and like
C~ should be understood with reference to the normal orientation of a
helmet on a wearer' s head when the wear is standing upright. The
20 "front-to-rear center" of the interior of a helmet shell should be understood as a
vertical plane perpendicular to the length of the helmet and dividing the interior
of the shell into a forward section and a rear section of substantially equal
volume.
Various aspects of the invention will be apparent from a
25 description below of preferred CllllOl'' ' and will be more specifically
defined in the appended claims.
DF..~CRIPTION OF T~E DRAWINGS
The invention will be better understood with reference to
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. .. _ . . _ , .. . . . . _ .. _ .. .. .. . . . ..... .. . . .. .. .
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drawings in which:
fig. I shows a bicycle helmet with a special ret~ining band;
fig. 2 is a .1;,.~, ,.""" ";1 view detailing the geometric I~I~LiullDlU~
between . l .. , .~ of the bicycle helmet essentially in a central vertical plane
from the front to the back of the helmet;
fig. 3 is a view along the lines 3-3 of fig. 1 illustrating an
adjustment mechanism that serves both to adjust the effective length of the bandand to secul-e the band in a fixed orientation relative to the helmet;
fig. 4 is an exploded view of the adjustment mechanism of fig.
3;
fig. S shows a ~UIIDLlU~,LiOll helmet with a special retaining band;
fig. 6 is an enlarged cross-sectional view in a vertical plane
transverse to the length of the ~,ullDLluuLiull showing how the retaining band
fastens to an apertured tab of the helmet; and,
fig. 7 is a fragmented perspective view of the retaining band of
the UOllDLlu~Liull helmet; and,
fig. 8 is a fragmented cross-section view of the adjustment
m~rh~ni~m of the retaining band of the uullDLluuLiull helmet.
DF.r~CRIPTION OF PREFERRED EMBODIMENTS
Reference is made to fig. 1 which shows a bicycle helmet 10 on
a wearer's head 12. The helmet 10 comprises a rigid plastic shell 14 with an
inner foam liner 16 (which is apparent in fig. 3). Conventional fabric straps
(not illustrated) are used to secure the helmet 10 below the chin. The helmet 10also has a rigid, resilient arcuate retaining band 20 which extends around the
2~ back of the wearer's head 12 and which has a plastic pad 22 that seats below the
wearer' s occipital ridge 24. The retaining band 20 has a pair of opposing end
portions that are fixed to opposing sides ûf the helmet 10 spaced apart along a
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hori~ontal axis 26 (indicated in figs. 2 and 3). Only one band end portion 28
and one side 30 of the helmet 10 have been shown in figs. 1-4.
Fig. 2 ~ A~ lly illustrates the geometric relationship
between various ~ ' - of the helmet 10. The axis 26 and points of
5 fixation to tlle helmet 10 are positioned forward of the front-to rear center 32 of
the interior of the shell 14. In the unstressed rest position 34 shown in fig. 2,
the band 20 extends downward and rear vard from the shell 14 at an acute angle
relative to horizontal. The effective length of the retaining band 20 can be
adjusted while preserving the particular angular orientation. To ensure that the10 retaining band 20 seats d,U~JlUl ' ly below the occipital ridge 24 and
adequately lesists both for~vard tipping and rearward rotation of the helmet 10,the angle is preferably in the range of 50-70 degrees, which a~vl....l '
most wearers. In fig. 2, the angle, which is designated 0, is roughly 60
degrees, which is the most preferred value. Once adjusted for proper seating,
the retaining band 20 engages the top of the occipital ridge 24 whenever the
helmet 10 is put on, pivoting and deflecting upward about the hori~ontal axis 26to a deflected position 36 shown in phantom outline in fig. 2, proximate to the
shell 14. The band 20 is then biased by its inherent elasticity to snap down
towards its rest position 34, seating below the occipital ridge 24.
An adjustment mechanism 38 associated with the retaining band
20 is showll in figs. 3 and 4. In this r~ , the adjustment m~nh~ni~m
38 performs two functions: it secures the one band end portion 28 to the helmet
10 in the desired angular orientation; and, it permits the effective length of the
retaining band 20 to be adjusted. The one band end portion 28 is formed with a
1(7n~ 1in~1 slot 40, and one face of the band end portion 28 is formed with a
set 44 of ratchet teeth oriented transverse to the length of the retaining band 20
and facing inward toward the interior of the shell 14. The adjustment
-' 38 includes a plastic guide 46 integrally molded with a pair of
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apertured tabs 48 and a post 50 extending from one face of the guide 46. The
apertured tabs 48 are located within a passage 52 that extending through the
shell 14 and the inner liner 16 into the interior. The post S0 extends through the
slot 40 in the band end portion 28 into another passage 54 through the shell 14
S and inner liner 16. The post S0 is secured to the rigid shell 14 with a
snap-fitting cup-shaped fastener 56. The band end portion 28 is located
between the guide 46 and the shell 14, and the apertured tabs 48 and posts
guide movement of the band end portion 28 along an axis (not shown) inclined
atthe~lrrlr~r"";"f~langleof60degreesrelativetohorizontal. AnothersetS8
of teeth project from a surface of the guide 46 between the apertured tabs 48 toengage the set 44 of ratchet teeth of the band end portion 28. A cam assembly
60 is provided to press the sets 44, 58 of teeth into firm ~ ". . ~I The cam
assembly 60 includes a cam or eccentric 62 mounted for rotation about a pivot
pin 64 supported between the apertured tabs 48 which serve as mounting
lS blocks, and a lever 66 which is accessible extemally of the shell 14. The lever
66 is shown in fig. 3 in a locking orientation in which the eccentric 62 pressesthe sets 44, 58 of teeth into firm rl l~ 11 fixing the length of the band 20.
The lever 66 can be displæed in the angular direction indicated with an alrow infig. 3 to an unlocking orientation (not shown) in which the eccentric 62 releases
the mating sets 44, 58 of teeth, allowing manual .1;~1,1,1. f,, Irl 1 l of the band 20
along the guide 46, loosening or tightening the band 20. The opposing end
portion (not shown) of the band 20 may be fixed to the opposing side (not
shown) of the helmet 10 with two posts and two cup-shaped retainers
~w~ l,lf~ to the those illustrated in fig. 4, at an angle of 60 degrees relative to
vertical, or with other l,~ ,llLiU~ fasteners.
In use, the retaining band 20 might initially be adjusted with the
helmet 10 off to what appears to be an appropriate size. The helmet 10 can then
be seated on the user' s head 12, the band 20 deflecting to its position 36 shown
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.~ .
in fig. 2 upon contact with the top of the wearer's occipital ridge 24 and then
snapping down below the occipital ridge 24 as the helmet 10 is fully seated. If
the pad 22 does not lodge snugly below the occipital ridge 24, the cam
assembly 60 can be operated and the effective length of the band 20 adjusted,
S while the helmet 10 is seated on the wearer's head 12 or by removing and
adjusting length. Thereafter, the helmet 10 can simply be installed without
adjustment. The orientation of the retaining band 20 relative to the shell 14
resists forward tipping of the helmet 10, when the wearer leans forward, and, ifthe length of the band 20 has been a~/~)lU~ y adjusted, pulls the front of the
10 helmet 10 towards the wearer's forehead, resisting backward rotation of the
helmet 10 during high-speed operation of a bicycle.
Reference is made to fig. S which shows a prior art nonclnln~irm
helmet 70 adapted to seat more positively on a wearer's head 72. The helmet 70
comprises a rigid shell 74, a UUII~ size adjustment band 76, and a
15 domed harness 78 (the general outline of which is shown in phantom outline)
fLYed to the size adjustment band 76 and normally bearing against the top of thewearer's head 72. The size adjustment band 76 includes a rear section 80 that
dips down~ardly about the occipital ridge, the prior art attempt to prevent sucha helmet 70 from falling off as the wearer bends forward or tilts his head bæk.
20 This particula m,Ulli~LI U-_liUll helmet 70 has a pair of identical apertured tabs
extending downwardly from a lower rim of the shell 74 and intended to receive
laces or straps for fastening below the wearer' s chin. Only one such apertured
tab 82 has been illustrated and is apparent in figs. 5 and 6.
This ~ JOdilU~ of the invention involves ~ull~ ly
25 retrofitting the prior art helmet 70 for better retention. It takes advantage of the
fact that the two apertured tabs are positioned forwardly of the front-to-rear
center of the interior of the shell 74 and aligned with a horizontal axis 83
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,~
(indicated in fig. 6). A retaining band 84 is connected to the apertured tabs ofthe helmet 70. In this rllll,O.1i,.,~ "1 of the invention, the retaining band 84 has
nO~ rlr,",;"r.lrestpositionandthusno~ ",i~,f~langularorientation
relative to the shell 74. Instead, the retaining band 84 pivots freely relative to
5 the shell 74 (except of course when worn).
The retaining band 84 is formed of a rigid resilient nylon that is
uulls;d~ly harder than the ,uu~.,.-Liul-~l ~)UI,~_ihyl~,llC typically forming the
shell 74. It has a two-piece construction, and its two band sections 86, 88 are
most apparent in fig. 7. Eæh band section 86 or 88 defines one end portion 90
or 92 of the retaining band 84. The band end portion 90, which is defined by
the band section 86 and shown in fig. 6, is typical. It is integrally molded with
a pair of opposing jaws 94 that can be elastically separated. Each jaw 94 has a
tooth 96 that projects towards the other jaw along a cornmon axis, which, in theview of fig. 6, is the horizontal axis 83. Outer surfaces (not numbered) of the
15 teeth 96 are beveled to facilitate installation about the apertured tab 82. The
material ~on~titll~in~ the band 84 is sufficiently resilient that the jaws 94 deflect
mf~mf nt~rily to allow the two teeth 96 to lodge in the aperture 100 of the tab 82
and then to snap back into the rest orientation shown in fig. 6. In the illustrated
orientation, the two teeth 96 effectively function as pivot or hinge pins allowing
20 the band end portion 90 to pivot about the horizontal axis 83. The depth of the
jaws 94 might typically be llu~if~ s to one-half inches. This provides
more clearance than actually required to receive the apertured tab 82 and similar
tabs on other types of prior art ~,ull~.l U~,~iUII helmets, but ~I,UIIIIII ' ' other
prior art helmets that are simply formed with aligned holes in opposing sides of25 their shells, proximate to the bottom of the shell 74, that have also been used to
receive chin straps. The other band 84 end section defines an identical pair of
jaws 102, shown in fig. 7, that allow fastening in an identical manner to the
other apertured tab (not shown) of the shell 74. The two sets of jaws 94, 102
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together with the two apertured tabs thus define a hinge mechanism allowing
hinge movement of the band about the axis 83.
The two band sections 86, 88 have proximate ends that are
integrally formed with UUlll~)U..~ of an adjustment mechanism 104 which is
5 similar to adjustment " Ir~ 1 IC used in conventional cord ties. One band
section 86 is terminated with a hollow rectangular housing 106 that contains a
toothed pawl 108. The other band section 88 has an end portion formed with
ratchet teeth 110 and received within the rectangular housing 106. The pawl
108 has a lever 112 that can be used to engage and disengage the pawl 108 from
10 the ratchet teeth 110, and is biased by appropriate molding and resilience of the
constituent material to engage the ratchet teeth 110 and lock the adjustment
mrrh~nism 104.
To put on the l.ull~lluuLioll helmet 70, the user simply positions
the helmet 70 above his head 72, letting the retaining band 84 assume a vertical15 orientation behind him and then seats the helmet 70 as usual. If the retaining
band 84 does not locate properly below his occipital ~idge, the user can simply
adjust the band 8~ while wearing the helmet 70 or remove the helmet 70 to
operate the adjustment mechanism 104 more easily. The l,UlI:~IlU~l.iUll helmet 70
perches high on the wearer's head 72, owing to the presence of the harness 78,
20 but the retaining band 84 is properly oriented to prevent the helmet 70 from
falling off when the wearer bends forward.
It will be appreciated that particular CUIll)Ud;~ t of the
invention have been described and that " ,~"I; r~ , ; may be made therein
without departing from the spirit of the invention or necessarily departing from25 the scope of the appended claims.
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