CA2179139A1 - Safety helmet with improved retaining assembly - Google Patents

Abstract

A retaining assembly for a safety helmet with a rigid shell includes a rigid resilient arcuate band. The band is connected to opposing sidesof the helmet along an axis forward of the front-to-rear center of the helmet.
Ends of the band may be fixed to the shell against rotation with the band extending rearward and downward from the helmet at an angle at about 50-70 degrees relative to horizontal, and the band may pivot about the axis by elasticdeformation to allow seating and removal of the helmet. The band ends may alternatively be allowed to pivot by hinge action about the axis. To retrofit anexisting construction helmet, the band ends may be formed with elastically separable jaws carrying teeth that snap into apertured tabs moulded with the helmet shell or into apertures otherwise provided in opposing sides of the helmet.

Description

`~' 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 I

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 217~13~
.~ , 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 . .. _ . . _ , .. . . . . _ .. _ .. .. .. . . . ..... .. . . .. .. .

-- 2l7~l39 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 `-- 2179139 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 _ . .. . . . . , .. . _ .. ., .... _ .. ... . . ..

~ 21~39 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 217~t39 .~ .
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 2~7~t39 ,~
(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 ~ 7~9 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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Claims (15)

1. In a safety helmet comprising a rigid shell with an interior, a retaining assembly for preventing the helmet from falling from a wearer's head when the wearer bends forward, the retaining assembly comprising:
a rigid resilient retaining band comprising a pair of band end portions;
means connecting each of the band end portions to a different one of the sides of the shell such that the band pivots relative to the shell either by hinge action or elastic deformation of the band about a generally horizontal axis forward of the front-to-rear center of the interior of the shell; and, adjustment means permitting adjustment of the effective length of the retaining band such that the band seats below the occipital ridge of the wearer.

2. The safety helmet of claim 1 in which:
the connecting means fix the band end portions to the shell against relative rotation and orient the retaining band in a rest position in which the band extends downward and rearward at a predetermined acute angle relative to horizontal; and, the retaining band deflects elastically between the rest position and a deflected position closer to the shell;
whereby, during seating of the helmet on the head of the wearer, the retaining band is deflected by the occipital ridge to the deflected position and then snaps downwardly to its rest position below the occipital ridge.

3. The safety helmet of claim 2 in which the predetermined angle is between 50-70 degrees.

4. The safety helmet of claim 1 in which the connecting means define a hinge mechanism permitting the band end portions to rotate relative to the shell about the horizontal axis.

5. The safety helmet of claim 4 in which the hinge mechanism comprises a pair of apertured shell portions and each of the band end portions is associated with and pivotally connected to a different one of the apertured shell portions.

6. The safety helmet of claim 5 in which each of the band end portions comprises a pair of elastically separable opposing jaws that receive the associated shell portion therebetween and a projection extending from one ofthe jaws into the aperture of the received shell portion toward the other of thejaws.

7. The safety helmet of claim 1 in which the helmet comprises a size adjustment band connected to the shell and located at least partially within the interior and in which the retaining band is connected to the helmet separately from the adjustment band.

8. The safety helmet of claim 1 in which the adjustment means comprise:
a guide member attached to the shell and located within the interior, the guide member being shaped to guide movement of one of the band end portions along a predetermined axis, the guide member comprising mounting blocks that extend into a passage in the shell;
a cam assembly comprising a cam mounted on a pin supported by the mounting blocks and a lever attached to the cam and extending from the passage such the lever is accessible from externally of the shell, the lever pivoting about the pin between a locking orientation in which the cam presses the one band end portion against the guide member and an unlocking orientation in which the cam releases the one band end portion from the guide member.

9. The safety helmet of claim 1 in which the adjustment means further comprise a surface on the one band end portion shaped to interlock with a surface on the guide member when the cam presses the one band end portion against the guide member, thereby to resist displacement of the one band end portion relative to the guide member.

10. The safety helmet of claim 10 in which:
the one band end portion comprises a lengthwise slot;
the guide member comprises a post extending through the slot into another passage in the shell; and, a fastener engages the post externally of the shell to secure the guide member to the shell.

11. The safety helmet of claim 10 in which the surface of the one band end portion comprises a set of transverse teeth and the surface of the guide member comprises one or more teeth mating with the set of transverse teeth.

12. In a safety helmet that has a rigid shell comprising an interior and a pair of shell portions each formed with an aperture and each located on a different side of the helmet forward of the forward-to-rear center of the interior of the helmet, a rigid resilient retaining band that prevents the helmet from falling from a wearer's head when the wearer bends forward, the retaining band comprising:
a pair of elongate separable band sections, each of the band sections comprising a pair of elastically separable opposing jaws formed at one end of the band section and receiving one of the pair of shell portions, a projection extending from one of the jaws toward the other of the jaws, and a connector portion formed at the other end of the band section;
each of the band sections having its pair of jaws located about a different one of the shell portions with the projection of the one jaw extending into the aperture of the shell portion;
the connector portions of the band sections cooperating to define adjustment means for joining the band section and adjusting the length of the band.

13. The safety helmet of claim 12 in which the connector portion of one of the band sections comprises a housing and a pawl hinged to the housing and the other of the band section comprises ratchet teeth received within the housing and engaged by the pawl.

14. In a safety helmet comprising a rigid shell with an interior, a retaining assembly comprising:
a rigid resilient arcuate retaining band comprising a pair of band end portions, each of the band end portions being connected to a different one of the sides of the shell forward of the front-to-rear center of the interior of the shell such that the retaining band deflects elastically between a rest position in which the retaining band extends rearward and downward from the shell at a predetermined angle between about 50 and 70 degrees relative to horizontal and a deflected position closer to the shell; and adjustment means permitting adjustment of the effective length of the retaining band thereby permitting the retaining band to seat belowthe occipital ridge of the wearer.

15. The safety helmet of claim 14 in which the adjustment means are mounted to one of the sides of the shell and adapted to guide movement of one of the band end portion along an axis inclined at the predetermined angle within the interior of the shell.