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CN-122028826-A - Protective helmet equipped with improved goggles

CN122028826ACN 122028826 ACN122028826 ACN 122028826ACN-122028826-A

Abstract

The protective helmet (1) for sports or for use in motor vehicles according to the invention has a visor (3), the visor (3) being joined to the cap body (2) and comprising an at least partially transparent structural lens (41), a liquid crystal layer (43), and a protective layer (44) laminated to an inner face (432) of the liquid crystal layer (43). Innovatively, the helmet thus formed has the technical feature of aiming at optimally protecting the GH liquid crystal layer from unnecessary mechanical stresses that may impair its light transmittance uniformity.

Inventors

  • Roberto Ridge
  • Federico Rigi

Assignees

  • 奥特夫有限责任公司

Dates

Publication Date
20260512
Application Date
20241122
Priority Date
20231206

Claims (11)

  1. 1. Protective helmet (1) for sports or for use with a motor vehicle, said protective helmet (1) comprising: -a protective cap body (2) provided with a visible opening (23); -a visor (3), the visor (3) being engaged with the cap (2) to cover the opening (23), and the visor (3) comprising: -a structured lens (41), said structured lens (41) being at least partially transparent; -a liquid crystal layer (43), the liquid crystal layer (43) comprising at least two substrates (434) and a peripheral seal (438), the peripheral seal (438) defining an enclosed space containing a liquid crystal-containing mixture, the liquid crystal layer (43) being controlled by an electronic board (5), the liquid crystal layer (43) being positioned inside the structural lens (41), and the liquid crystal layer (43) being provided with an outer face (431) and an opposite inner face (432), the outer face (431) facing the structural lens (41); -a protective layer (44), said protective layer (44) being laminated to said inner face (432) of said liquid crystal layer (43).
  2. 2. Helmet (1) according to claim 1, wherein the protective layer (44) has a thickness comprised between 0.4 mm and 2mm.
  3. 3. Helmet (1) according to claim 1 or 2, wherein an opaque cover layer (416) is provided at the inner periphery of the visor (3) facing the cap body (3), the cover layer (416) also extending to cover the inner contour of the protective layer (44).
  4. 4. Helmet (1) according to any one of the previous claims, wherein the substrates (434) of the liquid crystal layer (43) are spaced apart from each other by a cylindrical or spherical spacer element (433).
  5. 5. Helmet (1) according to any one of the previous claims, wherein the cap body (2) is provided with a helmet seal (232) surrounding the opening (23), and wherein the peripheral seal (438) of the liquid crystal layer (43) extends between the base plates (434) and at least to below the projection of the contact line between the helmet seal (232) and the liquid crystal layer (43).
  6. 6. Helmet (1) according to claim 5, wherein the peripheral seal (438) of the liquid crystal layer (43) extends beyond the projection of the contact line between the helmet seal (232) and the liquid crystal layer (43).
  7. 7. Helmet (1) according to any one of the previous claims, wherein the liquid crystal layer (43) is of GH type.
  8. 8. Helmet (1) according to any one of the previous claims, wherein the visor (3) comprises a depolarizing layer (42) arranged between the structured lens (41) and the liquid crystal layer (43).
  9. 9. Helmet (1) according to any one of the previous claims, wherein the liquid crystal layer (43) is powered by a photovoltaic panel connected to the electronic board (5).
  10. 10. Helmet (1) according to any one of the previous claims, wherein, The structural lens (41) is surrounded by a frame (45) at the outer periphery of the structural lens (41), the frame (45) being obtained by overmoulding, The frame (45) protrudes vertically with respect to an inner surface (412) of the structural lens (41), And wherein the frame (45) defines a lens recess (413), both the liquid crystal layer (43) and the protective layer (44) being accommodated in the lens recess (413).
  11. 11. Helmet (1) according to any one of claims 1 to 9, wherein: The structural lens (41) has a lens recess (413) at an inner surface (412), both the liquid crystal layer (43) and the protective layer (44) being accommodated in the lens recess (413), and wherein a polymer filling material (415) fills free spaces between a side peripheral edge (414) of the lens recess (413) and the liquid crystal layer and between a side peripheral edge (414) of the lens recess (413) and the protective layer.

Description

Protective helmet equipped with improved goggles Technical Field The object of the invention is a protective helmet for sports and/or for use with motor vehicles, equipped with eye-goggles (visor), in particular with variable-transmittance (transmission) goggles. Background Protective helmets typically include eye protection goggles. In some cases, the goggles serve only to protect the eyes of the user from debris, dust intrusion, or only against wind. However, in other cases, goggles also provide protection against excessive light. Typically, light protection is achieved only by using pigments that allow the goggles to transmit only a small portion of the incident light. Such filters are typically graded from 0 to 4 in terms of progressively higher absorption levels. However, in many cases, the user needs to change the degree of light filtering according to different degrees of external brightness, such as in the case when a motorcyclist passes through a tunnel from an area where sunlight shines. Many techniques are known to find solutions to this problem. However, such known techniques have limitations that render them practically ineffective. Finally, lenses using liquid crystal layers are known and are only capable of responding quickly to changes in ambient light. However, such lenses have not been basically used due to the continuous existence of a number of problems including low maximum brightness of the filter, unnecessary polarization, interference with other transparent elements, and adverse reactions to mechanical stress. Therefore, the lens is applied in the field of a protective device for welding, in which a TN (twisted nematic) planar liquid crystal LC screen is widely used. However, the screen is not suitable for solar protection under normal conditions, because the screen is practically too dark in its maximum transmission state and has a very small field of view. Examples of lenses using liquid crystals are known from documents WO 2022/254349 A1 and US 2011/283431 A1. Device application techniques using GH (guest-host) liquid crystals are also known. This type of liquid crystal does not use a polarizing filter and therefore can achieve a light transmittance well above 50%, making this type of liquid crystal potentially more suitable for use in solar protection devices under conventional conditions. However, this type of lens also has a series of problems. In fact, GH-type LC filters react to mechanical stress, creating unnecessary non-uniformities in the light transmittance. Most existing helmet visors are made such that when a GH-type LC layer is applied to the helmet visor, the layer is subjected to deformation and mechanical stress, compromising the uniformity of the light transmittance of the layer. In addition, helmet visors are typically manufactured using an injection molding process that produces portions with residual internal stresses that interfere with the liquid crystal, thereby producing a birefringent effect commonly referred to as "rainbow," which causes visual discomfort. Furthermore, the opening and closing systems of helmet goggles often do not allow the application of a film to the entire inner surface of the visor without interfering with the seals that are commonly used to prevent the passage of water and air between the visor and the cap. Disclosure of Invention The object of the present invention is to solve the problems of the prior art in order to obtain a helmet equipped with variable transparency goggles that is truly effective and comfortable to use. In particular, it is an object of the present invention to provide helmets with variable transparency goggles provided with specific technical measures aimed at optimally protecting the GH liquid crystal layer from mechanical stresses that create undesired inhomogeneities within the transparency level. Said object is achieved by a protective helmet according to claim 1. The dependent claims disclose further advantageous embodiments of the invention. Drawings Features and advantages of the protective helmet according to the invention will become apparent from the following description of a non-limiting example given in accordance with the accompanying drawings, in which: Fig. 1 shows a perspective view of a protective helmet according to the invention in an exemplary embodiment; FIG. 2 shows an exploded schematic view of the structure of a lens assembly of a visor of a protective helmet in an exemplary embodiment; Fig. 3 shows a cross-sectional view of a protective helmet according to the invention in an exemplary embodiment; Fig. 4 shows a longitudinal cross-section of a protective helmet according to the invention in a further exemplary embodiment; Fig. 5 shows a longitudinal cross-section of a protective helmet according to the invention in a further exemplary embodiment; Figure 6 shows in detail a cross-sectional view of a lens assembly of a visor of a protective helmet according to the present invention in an