[0001] The invention relates to a visor for safety helmets, particularily for safety helmets
for persons working in an environment rich in light, airbourne, medium-size airborne
particles, comprising a shield assembly including a substantially transparent shield
mounted in a frame, and further comprising attaching means for attaching the visor
to a safety helmet.
[0002] Visors of the above-mentioned kind are preferentially used in situations where light
particles of medium size, that is, particles with a diameter of between about 0,3
to about 3,0 mm, constitute a major fraction of total airborne material. In the present
context, the combination of "light" and "airborne" denotes particles that are being
kept airborne for a while, especially when supported by moderate air movements or
turbulence. Such partices will generally have a specific weight or, if of a porous
or similar nature, an appearent specific weight of less than 1. Saw dust is a good
example for a material rich in such particles.
[0003] Visors protecting the eyes against particles of the aforementioned kind comprise
a substantially transparent shield made of a close-meshed net arranged within a frame.
Under most working conditions, the meshes of the net do not substantially impede the
view of the bearer. This, however, does not hold true for certain conditions, for
example conditions with lighting by a light source placed above and slightly in front
of the bearer. Under such conditions, light reflection by the net becomes a nuisance
that may be aggravated by other factors, such as rainy weather or humid conditions
in general, light reflection by a wet shield net being substantially larger than by
a dry one. Humidity also promotes adherence of particles to the net and, thus, further
reduces visibility.
[0004] The object of the present invention is to provide an improved visor for safety helmets
of the aforementioned kind that substantially reduces light-reflection problems.
[0005] According to the invention, this object is met by a visor for safety helmets of the
aforementioned kind, which visor comprises an essentially non-transparent shield holder
to which the shield assembly is removably attached, said holder comprising an interconnecting
portion having essentially the horzontal extension of a portion of a circular band,
a frontal bill portion projecting generally forwardly from the interconnecting portion,
a rear bill portion projecting generally backwardly from the interconnecting portion,
and two supporting arms, one each joined to and extending from either end of the interconnecting
portion, said supporting arms being arranged for hinged and removable attachment to
a safety helmet provided with a frontal guard portion extending in an essentially
horizontal plane, whereby the visor is arranged movably between a protecting position
and a non-protecting position and temporarily can be held in either position, the
rear bill portion of the holder essentially superimposing the bill portion at close
distance when in the protecting position.
[0006] It is preferred for the supporting arms to be arranged in planes essentially perpendicular
to the plane defined by the rims of the front bill portion and the rear bill portion,
respectively, the planes of the essentially flat front bill portion and rear bill
portion being tilted in relation to each other, and the shield having essentially
the configuration of a portion of a cylinder mantle, the axis of the corresponding
cylinder being arranged about perpendicular to the plane defined by the rims of the
front bill portion and the rear bill portion.
[0007] It is further preferred for the interconnecting portion to comprise gripping means,
particularly gripping means of the snap-in closure type, for gripping and holding
the top portion of the shield frame. It is also preferred for the shield to be removably
and exchangeably mounted in a frame.
[0008] According to an advantageous feature of the present invention, the rim of the rear
bill portion of the holder fits the surface of the helmet both in the protecting and
the non-protecting position.
[0009] According to another advantageous feature of the invention, the means for attaching
the visor to the helmet and the hinge means comprise anchoring elements arranged between
the respective supporting arm and the respective side wall of the helmet and removably
fixed to both, the hinge means also comprising means for temporarily locking the visor
in a protecting position and a non-protecting position.
[0010] It is also preferred for the means for attaching the visor to the helmet to comprise
tongue means of the respective anchoring element for insertion into horizontal slots
arranged at the respective lateral wall of the helmet, the tongue means preferably
being provided with the male part of snap-in locking means cooperating with a corresponding
female part arranged on the inside of the helmet.
[0011] According to a particularily advantageous aspect of the invention, the hinge and
locking means comprise a wedge-shaped bearing tap portion arranged at an essentially
flat lateral surface of the respective supporting arm near the free end of the supporting
arm and being fitted into a bearing ring portion having a triangular opening with
rounded corners adapted to receive and to hold said bearing tap portion, said bearing
ring portion forming part of the anchoring element.
[0012] According to another advantageous aspect of the invention, the bearing tap portion
includes a circumferential groove for receiving and holding the bearing ring portion.
[0013] According to a particularly advantageous aspect of the invention, the shield assembly
consists of a mesh of metallic wire or polymer material in a frame.
[0014] It is furthermore preferred for the shield assembly to include a curved sheet of
translucent plastic material.
[0015] Other objects, features, and advantages of the invention will be apparent from a
preferred but not limiting embodiment, by reference to which the invention will explained
in more detail, said embodiment being illustrated by a drawing in which is shown by
- Fig. 1
- a schematic top view of the visor, with only a portion of the supporting arms shown,
- Fig. 2
- a schematic sectional view of the visor shown in Fig. 1, perpendicular to line A -
A,
- Fig. 3
- a part of Fig. 2, enlarged, showing the interlocking mechanism between shield and
shield holder,
- Fig. 4
- a schematic partial sectional view of the visor similar to that in Fig. 2, the visor
being shown in a protecting position (H) and a non-protecting position (G), in relation
to the safety helmet,
- Fig. 5
- the hinge and locking means of the right supporting arm, in side view and in a protecting
position,
- Fig. 6
- the means shown in Fig. 5, in an intermediate position,
- Fig. 7
- the means shown in Fig. 5, in a non-protected position,
- Fig. 8
- the hinge and locking means in the position shown in Fig. 7, in a sectional view M
- M.
- Fig. 6
- the hinge means of Fig. 6, disassembled.
[0016] A visor for a safety helmet 1 comprises a shield assembly 2 consisting of a shield
3 made of a net of metallic wire with a mesh width (diagonal) of about 1,5 mm embedded
in a quadrilateral plastic frame 4 surrounding the net shield 3 and having rounded
lower corners, the shield 3 together with the frame 4 having a spatial configuration
approximating that of a portion of a cylinder mantle, and a shield holder 5 to which
the shield is removably mounted.
[0017] Part of the circumference of the helmet 1 is indicated by point-dashed lines D (Fig.
1).
[0018] The shield holder 5 is made of a hard but resilient polymer material and is rougly
half-moon shaped with an outer rim 51 and an inner rim 52 extending between tips 53
and 54, and, except for what is said below, has a predominantly planar extension which
is best approximated by the plane P (Fig. 2) defined by rims 51 and 52. On the underside
of the shield holder 5 two parallel flanges 56, 57, essentially perpendicular to the
plane defined by the rear bill portion of the holder 5 and with a narrow grove between
them, extend between the tips 53 and 54. The flanges 56, 57 divide the shield holder
into a larger frontal bill portion 20 and the smaller rear bill portion 21 and, together
with the portion of the holder extending in-between them, define a interconnecting
portion 22 joined to the bill portions 20, 21. A mirror plane perpendicular to line
A - A in Fig. 1 divides the visor into two symmetric halves.
[0019] By designing their respective profiles according to the known snap-in closure principle,
as shown in Fig. 3, the two parallel and resilient flanges 56, 57 are arranged for
gripping contact with the upper frame rim portion 24 of the shield assembly 2. The
upper rim 24 fits into the groove between the flanges 56 and 57. Upon insertion into
the groove the rim 24 is locked in place by the locking cooperation of the flanges
56, 57 and the rim 24 profile, as evident from Fig. 3.
[0020] The respective upper surfaces of the inner bill portion 21, including that of the
interconnecting portion 22, and the outer bill portion 20 are slightly tilted in respect
of each other, the tilting angle α being in the order of 5 to 15°; said surfaces meet
at a ridge 28 at about center of the shield holder 5.
[0021] At its end regions 62, 63 extending for a distance of about 3 cm from the tips 53,
54 the holder 5 is provided with supporting arms 60, 61 extending backwards from the
holder 5 and rigidly attached, preferably by moulding the holder 5 and the arms 60,
61 in one single piece, to it at said end regions 62, 63 where the holder 5 has fortified
portions B and C, respectively (indicated by point-dashed lines in Fig. 1), the supporting
arms 60, 61 with their respective exterior lateral surfaces tangentially joining the
outer rim 51. The supporting arms 60, 61 are essentially straight and of moderate
width (a few mm) (Fig. 1). For stability reasons their extension (Figs. 5 and 6) in
a plane about perpendicular to the plane P defined by the rims 51 and 52 is considerably
larger. At their free ends the supporting arms 60, 61 are provided with hinge and
locking means (Figs. 5 - 8) arranged for pivoting movement of the visor between a
protecting position (G, Fig. 4) and a non-protecting position (H, Fig. 4), and for
temporarily locking the visor in the respective position.
[0022] Only the hinge and locking means of the right supporting arm 61 is shown in more
detail in Figs. 5 to 8. It consists of a bearing tap portion 75 forming part of the
free-end portion the supporting arm 61 and of a bearing ring portion 77, 80, 81 forming
part of an anchoring element 71. The opening 76 of the bearing ring portion 77, 80,
81 is about triangular in form and defined by a longer sidewall 77 and two shorter
sidewalls 80, 81 of equal length. The corners formed by the longer sidewall 77 and
the shorter sidewalls 80, 81 are well rounded.
[0023] The wedge-formed bearing tap 75 portion is joined to the flat outer surface at the
end region of supporting arm 60 from which it protrudes. It has a flat top surface
parallel to the flat surface of supporting arm 60 from which it raises by a few mm.
When seen in a direction perpendicular to said flat outer surface of the supporting
arm 60, the tap portion 75 has about the form of two hemicircles of different diameter
arranged at a distance from each other and symmetrical in respect to a line connecting
their centers and with their greatest distance at their intersections with this central
line and connected by side lines tangentially joining the respective hemicircle. The
smaller hemicircle end of the tap portion 75 is arranged close to the free end of
the supporting arm 60 and with said center line having an extension parallel to the
edges of the supporting arm. As shown in Fig. 8, the lateral wall of the tap portion
75 is provided with a circumferential groove 79, the inner lateral wall of which coincides
with the surface of the supportiong arm portion 60 to which the tap portion 75 is
joined.
[0024] The width of the groove 79 is slightly larger than the thickness of the bearing ring
portion 77, 80, 81. The hinge and locking means is assembled by inserting the bearing
tap portion 75 in the opening 76 of bearing ring portion 77, 80, 81 and turning the
tap portion 75 until it snaps into one of the two stable positions illustrated in
Figs. 5 and 7. The hemicurcular (center at point 85) end of the tap portion 75 with
the smaller radius will then be fitted into the corner between the shorter sidewalls
80, 81 and the other end of the tap portion 75 will assume a position close to one
of the rounded corners (rounded with a radius slightly larger than that of the larger
one of the two hemicircles of the tap portion 75) between the shorter sidewalls 80,
81 and the longer sidewall 77, in which position it will be locked. By applying an
upward lateral force to the supporting arm 60 either directly or indirectly, e.g.
by lifting the visor, the tap portion 75 will turn around the center 85 of the smaller
circle defining the wedge tip end of the tap portion 75. This will lead to lateral
displacement of the longer sidewall 77 resisting that displacement by a resilient
force. When this resilient force has been overcome, the tap portion 75 will be in
the unstable position indicated in Fig. 6, that is, with its wedge top end at the
center of the longer sidewall 77. Pushing a little further in the aforesaid direction
will make it assume the other stable position illustrated in Fig. 7, in which it will
be locked.
[0025] In a mounted state, the locking and hinge means 70 thus can occupy either of the
two stable positions shown in Figs. 5.
[0026] The comparatively flat anchoring element 71 is provided with a rectangular tongue
72 for mounting it in a horizontal slot 73 of a vertical pocket (not shown) arranged
in the lower part of the right lateral wall of the helmet 1. By adapting the with
and the depth of the pocket to the shape of the tongue 72 and by providing the tongue
72 and and the pocket 74 with a snap-in design, the visor can be removably fixed to
the helmet. Preferably, the tongue 72 is adapted to function as the male part and
the pocket 74 to function as the female part of the snap-in connection.
[0027] Supporting arm 62 is provided with corresponding hinge and fixation means not shown,
mirroring the arrangement illustrated in Figs. 5 - 7.
[0028] In Fig. 4 the visor holder 5, (the supporting arms 60, 61 having been excluded for
the sake of clarity) is shown in positional relation to the on safety helmet 1 on
which it is mounted, the helmet 1 having a front bill portion 11 and being borne by
a person with the head in a normal, upright position. In the protecting position G,
the inner bill 21 of the visor overlaps the front bill portion 11 of the helmet, thereby
preventing airborne particles or light to enter from above between the shield and
the face of the bearer. Entrance of water between the bills 11 and 21 can be avoided
by arranging a sealing element (not shown) made of, for example, spongy polyurethane
rubber, at the underside of bill 21 and parallel to rim 52, thus closing the gap between
the bills 11 and 21. Figure 4 also shows that the outer bill 22 is tilting downwards
in the protecting position G. As is explained in more detail in connection with the
description of the hinge and locking means, a moderate upward pressure on the shield
holder 5 or the shield 2 assembly suffices for moving the visor from the protecting
position G to the non-protecting position H and to lock it in the latter, each part
of the holder and the shield thereby being displaced along circular paths having their
center at point 85.
[0029] To provide for a good but not abutting fit the negative curved shape of the inner
rim 52 of the shield holder 5 is made to correspond about to the positive curved shape
of the frontal profile of the helmet 1, the hinge means 70, as well as the corresponding
hinge means for the left supporting arm 60, being positioned (center of rotation 85
in Fig. 4) for maintaining said fit in the protecting position G and in the non-protecting
position H, thereby minimizing the dimensions of the supporting arms 60, 61 necessary
to provide a reliable and safe connection of the visor to the helmet 1.
1. Visor for safety helmets, particularily for safety helmets for persons working in
an environment rich in light, airborne particles of a particle size between 0,3 to
3,0 mm and an apparent specific weight of less than 1, comprising a substantially
transparent shield assembly (2) consisting of a shield (3) mounted in a frame (4),
and further comprising attaching means for attaching the visor to a safety helmet,
characterized in that the visor comprises an essentially non-transparent shield holder (5) to which
the shield assembly (2) is removably attached, said holder (5) comprising an interconnecting
portion (22) having essentially the extension of a portion of a circular band, a frontal
bill portion (20) projecting generally forwardly from the interconnecting portion
(22), a rear bill portion (21) projecting generally backwardly from the interconnecting
portion (22), and two supporting arms (60, 61), one each joined to and extending from
either end of the interconnecting portion (22), said supporting arms (60, 61) being
arranged for hinged and removable attachment to a safety helmet (1) provided with
a frontal bill portion (11) extending in an essentially horizontal plane, whereby
the visor is arranged movably between a protecting position (G, Fig. 4) and a non-protecting
position (H, Fig. 4) and temporarily can be held in either position, the rear bill
portion of the holder (22) essentially superimposing the bill portion (11) at close
distance when in the protecting position (G, Fig. 4).
2. Visor according to claim 1, characterized in that the supporting arms (60, 61) are arranged in planes essentially perpendicular
to the plane defined by the rims (51, 52) of the front bill portion (20) and the rear
bill portion (21), respectively, the planes of the essentially flat front bill portion
(20) and rear bill bill portion (21) being tilted in relation to each other, and the
shield assembly (2) having essentially the configuration of a portion of a cylinder
mantle, the axis of the corresponding cylinder being arranged about perpendicular
to the plane defined by the rims (51, 52) of the front bill portion (20) and the rear
bill portion (21).
3. Visor according to claim 1 or 2, characterized in that the interconnecting portion (22) comprises gripping means (24, 56, 57), particularly
gripping means of the snap-in closure type, for gripping and holding the top portion
of the shield frame (4).
4. Visor according to any of claims 1 - 3, characterized in that the rim (52) of the rear bill portion (21) of the holder (5) approaches the
surface of the helmet (1) both in the protecting (G, Fig. 4) and the non-protecting
(H, Fig. 4) position to retain a good fit.
5. Visor according to claim 4, characterized in that the means for attaching the visor to the helmet (1) and the hinge means comprises
anchoring elements (71) arranged between the respective supporting arm (61) and the
respective side wall of the helmet (1) and removably fixed to both, the hinge means
also comprising means for temporarily locking the visor in a protecting position and
a non-protecting position.
6. Visor according to claims 4 or 5, characterized in that the means for attaching the visor to the helmet comprises tongue means (72)
of the respective anchoring element (71) for insertion into horizontal slots (73)
arranged at the respective lateral wall of the helmet (1), the tongue means (72) being
provided with the male part of snap-in locking means cooperating with a corresponding
female part arranged on the inside of the helmet (1).
7. Visor according to claim 5 or 6, characterized in that the hinge and locking means comprise a wedge-shaped bearing tap portion (75)
arranged at an essentially flat lateral surface of the respective supporting arm (61)
near the free end of the supporting arm (61) and being fitted into a bearing ring
portion (77, 80, 81) having a triangular opening with rounded corners adapted to receive
and to hold said bearing tap portion (75), said bearing ring portion (77, 80, 81)
forming part of the anchoring element (71).
8. Visor according to claim 7, characterized in that the bearing tap portion (75) includes a circumferential groove (79) for receiving
and holding the bearing ring portion (77, 80, 81).
9. Visor according to any of the preceding claims, characterized in that it comprises a shield (3) consisting of a mesh of metallic wire or polymer
material in a frame (4).
10. Visor according to any of the preceding claims, characterized in that it comprises a shield (3) including a curved sheet of translucent plastic
material.