[0001] This invention relates to an integral helmet, equipped with an air ejector device
fitted on the helmet's top apt to increase the air circulation in the helmet's interior.
[0002] Integral helmets are usually provided with vizors and almost always with a collar
which engages the wearer's jaw. In this way the various internal paddings create,
especially during the summer time an unbearable overheating of the wearer's head.
[0003] To improve the situation , front and/or side openings are provided on the helmets
to admit air into its interior, exploiting the running velocity of the vehicle, and
also channels within or between the paddings and related air discharges, to cause
air circulation into the helmet.
[0004] The provisions adopted to date are of limited efficiency as the inlet air quickly
loses its dynamic charge, with the result that the volume of air exchanged is quite
insufficient.
[0005] The object of this invention is to obviate these drawbacks by increasing the air
exchange volume at the level of the wearer's head by means of a device apt to increase
the extraction of the air itself, synergical with respect to the inlet air flow.
[0006] According to this invention, the shell of the helmet is provided with at least one,
preferably two holes, to discharge the ventilating air, said hole/holes being located
substantially on the vertical plane of symmetry of the helmet's shell, in a retracted
position with respect to the top of the helmet itself, said hole/holes being associated
with an ejector device apt to create a depression at the level of said discharge hole
or holes to favour exhaustion of the air, flowing through one or two ducts offset
with respect to said outlet hole/holes, provided in the helmet's shock absorber layer
and which lead/s to a chamber communicating with said air outlet holes.
[0007] The air outlet hole or holes are covered, in suitable position by an inclined flap
the opening of which faces the rear of the helmet, said flap being a fundamental part
of the ejector device, while the outlet holes can be closed or partially closed by
a sliding closure working substantially in contact with the outer surface of the helmet
shell.
[0008] The invention will now be described in conjunction with the drawings, which illustrate
the application of the present device to a helmet, by way of example only.
Fig. l is a side view of the helmet provided with the air extraction device according
to the invention.
Fig. 2 is a top view of the air extraction device showing the air outlet holes in
transparency
Fig. 3 is an elevation view of the device from direction >III of fig. 2 mounted on
the helmet, shown in cross section;
Fig. 4 is a view in cross section of the device taken on line X-X of fig. 2.
Fig. 5 is a diagram showing the flow path of the air exhaused from the helmet.
Fig. 6 is a schematic cross section of the helmet on its vertical symmetry plane to
define the position of the device longitudinally with respect to the helmet.
[0009] With reference to Fig. l, helmet l is equipped, in the known manner, with a vizor
2 which can be lifted by rotating on hinges 3, positioned symmetrically on the helmet's
sides.
The helmet according to the invention is provided, in a convenient position, ( to
be described infra ) , with an air ejector device 4 formed by a flap 6, provided with
lateral walls 7 and covering at least one, but preferably two outlet holes 8 for the
ventilating air, said holes being provided on the top part of shell l0, to discharge
externally the ventilating air entering the helmet either through a front grate ll
or some other laterally located air intake openings.
[0010] In fig. 2, holes 8 are symmetrically arranged with respect to vertical plane X-X
at a distance relative to their centers indicatively 30 to 50 mm., the diameter of
said holes being equal to approximately l0mm.
[0011] As it can be noted in figs 3 and 4 , said holes communicate with a chamber l2,obtained
by stamping, in the polyethylene shock absorber layer l4; said chamber l2 communicates
with the helmet's interior through at least one duct but preferably two ducts l6 offset
by about l0mm. with respect to the transversal position of outlet holes 8 so that
the holes themselves will not be aligned with said ducts l6.
[0012] The duct or ducts l6 outlet at the level of the innermost comfort padding l8 made
of open cell type foam material hence permeable to the passage of air, which takes
place as shown in fig. 5.
[0013] With reference to figs 4 and 3, outlet holes 8 are engaged by a plate 22 the ends
24 of which are restrained on two symmetrical fins 26 provided inside flap 6, and
which engages with the holes themselves through semi cylindrical projections 28 fitted
on opposite parts with hooks 30.
[0014] A slider 34 slides on plate 22; said slide is provided with a handle 36 and holes
38 which can coincide or not with holes 8 to open or close them at the wearer's will.
[0015] Ejector 4 made of plastic material, has its opening facing the rear of the helmet
and performs the dual function as air ejector and as protection against the infiltration
of water into holes 8.
[0016] With reference to Fig. 4, the angle α of inclination of surface 40 of said flap,
the extension of which is designated by letter Y, with respect to the tangent plane
of the helmet's surface, is comprised between 25° and 45°, preferably 30°.
[0017] With reference to Fig. l and particularly to Fig. 6, the longitudinal position of
device 4 , and substantially holes 8, with respect to the helmet is defined as follows
:
Taking meeting points K,Kʹ of the straight line determined by the intersection of
the vertical plane of symmetry of the helmet with the plane passing through the top
edge of vizor 2 and assuming center O of segment K,Kʹ the segment OP passing through
said point O and the transversal center line of holes 8 forms an angle β preferably
of 94° more or less 25° with the semi straight line OK.
[0018] Said variation will be as a function of the type of helmet and its dimensions.
[0019] To resume, angle β can vary between 69° and ll9°.
[0020] Tests conducted in the wind tunnel on a helmet equipped with a device according to
the invention proved that even with a single outlet hole 8,ten millimeters in diameter,
located in the optimal position above defined, the air extracted from the hole was
24 liters/min. without ejector and 42 liters/min with the ejector.
l) Integral helmet, particularly for motorcyclists, provided with vizor and internal
padding, consisting of a shock absorber liner adhering to the helmet shell and of
a internal comfort padding, in contact with the wearer's head, channels for air circulation
placed between said shock absorber liner and comfort padding, as well as apertures
for entry of the air, characterized in that the helmet shell (l0) is provided with
at least one hole, but preferably two outlet holes (8) for the ventilating air of
the helmet, located substantially on the vertical symmetry plane of the helmet itself
in a retracted position with respect to the summit of the shell, said hole or holes
being associated with an ejector device (4) apt to create a depression at the level
of said outlet hole or holes to improve extraction of the air, the flow of which,
coming from the comfort padding (l8) takes place through a duct or ducts (l6) provided
radially in the body of the shock absorber liner (l4) and which leads to a collecting
chamber (l2) communicating, in turn, with said outlet hole or holes (8)
2) Helmet according to claim l, characterized in that the radial duct or ducts (l6)
passing through the shock absorber liner (l4) of the paddinglead (s) the one side
to a collecting chamber (l2) in which open the outlet hole or holes (8) and on the
other side at the level of the inner comfort padding (l8) made a open cell foam material.
3) Integral helmet according to claims l and 2 characterized in that duct or ducts
(l6) and outlet hole or holes (8) are offset with respect to each other being in communication
with each other through collecting chamber (l2).
4) Integral helmet according to claims l thru 3, characterized in that in the outlet
hole or holes (8) are inserted hollow elastic projections (28) secured to a plate
(22) and provided, with respect to the centerline of the plate itself, with opposite
teeth (30) to engage on shell (l0) of the helmet, while said plate engages, in turn,
with its ends (24) with fins (26) secured internally to flap (6) of ejector device
(4).
5) Integral helmet according to claims l thru 4, characterized in that on plate (22)
slides a slider (34) equipped with a handle (36) and holes (38) which can be made
to coincide or not with outlet holes (8) to open, close or partially open or close
the air extracted from the helmet, at the user's will.
6) Integral helmet according to claims l thru 5, characterized in that the outer surface
(40) of flap (6) forming ejector device (4) is inclined with respect to the plane
tangent to the surface of the helmet at the point of application of the flap itself,
by an angle α varying between 25° and 45° , preferably about 30°.
7) Integral helmet according to claims l thru 6, characterized in that ejector device
(4) is housed across the vertical midline plane of the helmet in a retracted position
with respect to the summit of the helmet itself, defined by a tangential point on
its shell by a plane parallel to that substantially formed by its lower opening.
8) Integral helmet according to claims l-7 characterized in that,taking intersection
segment (K-K') with the shell of the straight line determined by the intersection
of the vertical symmetry of the helmet and of a plane coinciding with the top end
of vizor (2), the semi-straight line OP joining the mid point (O) of said segment
(K-Kʹ) with position (P) of outlet holes (8-8ʹ) forms an angle (β) of 94° ± 25° with
semi straight line (OK).