Safety helmet

Abstract

A safety helmet includes an outer shell configured to surround a user's head, and an infrared reflective layer disposed within the outer shell. The infrared reflective layer is configured to reflect at least a portion of incident infrared radiation transmitted through the outer shell. The infrared reflective layer has an infrared reflectivity of at least 40%. The safety helmet may further have an evaporative cooling pad positioned within a cavity defined by the inner surface of the outer shell. A method of manufacturing the safety helmet is also disclosed.

Description

[0001] This application is a divisional application of the application filed on January 13, 2021, with a priority date of January 13, 2020, application number 202180016331.2, entitled "Safety Helmet".

[0002] Cross-reference to related applications This application claims priority to U.S. Provisional Application No. 62 / 960,415 entitled “Safety Helmet”, filed January 13, 2020, and U.S. Application No. 17 / 146,711 entitled “Safety Helmet”, filed January 12, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure generally relates to safety helmets for use in various situations and environments, and particularly to a safety helmet having a thermal management component configured to reduce the temperature of a user's head when the user wears the safety helmet. Background Technology

[0004] Safety helmets are widely used in a variety of environments. A safety helmet typically consists of a rigid outer shell to protect the user's head. The shell is usually made of thermoplastic material. Typically, thermoplastic materials are configured to transmit at least a portion of the infrared radiation emitted from the sun. When wearing such a safety helmet in warm environments with direct sunlight, the interior of the shell is usually warmer than the ambient temperature due to the transmittance of infrared radiation through the shell material. This increased temperature inside the safety helmet causes an increase in the temperature of the user's head, thus making the user uncomfortable when wearing the helmet in warm / hot weather.

[0005] Therefore, given these and other shortcomings of existing safety helmets, there is a need in the art for an improved safety helmet that can be easily and effectively worn by the user in a variety of environments, while improving user comfort by reducing the temperature of the user's head when wearing the safety helmet in warm / hot environmental conditions. Summary of the Invention

[0006] Generally, this disclosure provides an improved safety helmet that addresses and / or overcomes some or all of the defects associated with existing safety helmets. In some non-limiting embodiments or aspects, a safety helmet is provided that may have a shell configured to surround a user's head, and an infrared reflective layer disposed within the shell. The infrared reflective layer may be configured to reflect at least a portion of incident infrared radiation transmitted through the shell. The infrared reflective layer may have an infrared reflectivity of at least 40%.

[0007] According to some non-limiting embodiments or aspects, the infrared reflective layer may have an infrared reflectivity in the range of 83% to 89%. The infrared reflective layer may have a hemispherical emissivity of less than 0.2. The infrared reflective layer has an optical density of at least 2.0. The infrared reflective layer may have a thickness of 20 nm to 5 μm.

[0008] According to some non-limiting embodiments or aspects, the infrared reflective layer may have at least one of the following: aluminum, gold, silver, copper, and any combination thereof. The infrared reflective layer may also have at least one of the following: doped titanium dioxide, doped or undoped indium tin oxide, doped cerium oxide, doped manganese oxide, iron(III) oxide, cadmium sulfide, chromium trioxide, and any combination thereof.

[0009] According to some non-limiting embodiments or aspects, an infrared reflective layer is applied to an insert that is removably or non-removably attached to the housing. The insert may include a substrate made of a thermoplastic film.

[0010] According to some non-limiting embodiments or aspects, a safety helmet may include an outer shell configured to surround a user's head, and an infrared reflective layer on at least a portion of the inner surface of the outer shell. The infrared reflective layer may be configured to reflect at least a portion of incident infrared radiation transmitted through the outer shell. The helmet may further include an evaporative cooling pad positioned within a cavity defined by the inner surface of the outer shell. The evaporative cooling pad may include a top waterproof and breathable layer and a bottom waterproof and breathable layer defining the cavity therebetween. The outer surface of the bottom layer may be configured to contact the user's head. The evaporative cooling pad may further include a liquid-absorbing layer positioned within the cavity.

[0011] According to some non-limiting embodiments or aspects, the top and bottom layers may comprise nylon materials laminated with a waterproof and breathable material. At least one of the top and bottom layers may comprise polyurethane or polytetrafluoroethylene.

[0012] According to some non-limiting embodiments or aspects, the evaporative cooling pad may further include a sweat-absorbing fabric on the outer surface of the bottom layer. The evaporative cooling pad may further include an opening in at least one of the top and bottom layers, wherein the opening has a zipper. The evaporative cooling pad may further include a body portion having a first end and a second end, and a pair of wings extending laterally from the first end. The first end may be configured to contact the user's forehead. Each of the pair of wings may be configured to extend to the user's temple. The second end may be configured to extend to the top of the user's head.

[0013] According to some non-limiting embodiments or aspects, a method of manufacturing a safety helmet may include molding the outer shell of the safety helmet with a thermoplastic material; and applying an infrared reflective layer to at least a portion of the inner surface of the outer shell, or applying an infrared reflective layer to an insert that can be attached to the outer shell.

[0014] According to some non-limiting embodiments or aspects, the insert with the infrared reflective layer can be integrally formed with the housing during molding of the housing. The method may further include attaching the insert with the infrared reflective layer to the housing by at least one of the following: adhesive, one or more mechanical clips or fasteners, press-fit, ultrasonic bonding, and any combination thereof. The method may further include inserting an evaporative cooling pad into a cavity of the housing defined by an inner surface. The evaporative cooling pad may include a top waterproof and breathable layer and a bottom waterproof and breathable layer defining the cavity therebetween; a liquid-absorbing layer positioned within the cavity; and an opening in at least one of the top and bottom layers.

[0015] According to some non-restrictive embodiments or aspects, the features of a safety helmet may include one or more of the following: Clause 1: A safety helmet comprising: a shell configured to surround a user's head; and an infrared reflective layer disposed inside the shell, the infrared reflective layer being configured to reflect at least a portion of incident infrared radiation transmitted through the shell, wherein the infrared reflective layer has an infrared reflectivity of at least 40%.

[0016] Clause 2: The safety helmet according to Clause 1, wherein the infrared reflective layer has an infrared reflectivity in the range of 83% to 89%.

[0017] Clause 3: The safety helmet according to Clause 1 or 2, wherein the infrared reflective layer has a hemispherical emissivity of less than 0.2.

[0018] Clause 4: A safety helmet according to any one of Clauses 1 to 3, wherein the infrared reflective layer has an optical density of at least 2.0.

[0019] Clause 5: A safety helmet according to any one of Clauses 1 to 4, wherein the infrared reflective layer comprises at least one of the following: aluminum, gold, silver, copper, and any combination thereof.

[0020] Clause 6: A safety helmet according to any one of Clauses 1 to 5, wherein the infrared reflective layer comprises at least one of the following: doped titanium dioxide, doped or undoped indium tin oxide, doped cerium oxide, doped manganese oxide, iron(III) oxide, cadmium sulfide, chromium trioxide, and any combination thereof.

[0021] Clause 7: A safety helmet according to any one of Clauses 1 to 6, wherein the thickness of the infrared reflective layer is 20 nm to 5 μm.

[0022] Clause 8: A safety helmet according to any one of Clauses 1 to 7, wherein the infrared reflective layer is applied to an insert that is removably or non-removably attached to the shell.

[0023] Clause 9: A safety helmet according to any one of Clauses 1 to 8, wherein the insert comprises a base made of thermoplastic film.

[0024] Clause 10: A safety helmet comprising: an outer shell configured to surround a user's head; an infrared reflective layer on at least a portion of an inner surface of the outer shell, the infrared reflective layer being configured to reflect at least a portion of incident infrared radiation transmitted through the outer shell; and an evaporative cooling pad positioned within a cavity defined by the inner surface of the outer shell, the evaporative cooling pad comprising: a top waterproof and breathable layer and a bottom waterproof and breathable layer defining the cavity therebetween, wherein the outer surface of the bottom layer is configured to contact the user's head; and a liquid-absorbing layer positioned within the cavity.

[0025] Clause 11: The safety helmet as described in Clause 10, wherein the top layer and the bottom layer comprise nylon material laminated with a waterproof and breathable material.

[0026] Clause 12: A safety helmet as described in Clause 10 or 11, wherein at least one of the top and bottom layers comprises polyurethane or polytetrafluoroethylene.

[0027] Clause 13: A safety helmet according to any one of Clauses 10 to 12, wherein the evaporative cooling pad is further comprised of a sweat-absorbing fabric on the outer surface of the bottom layer.

[0028] Clause 14: A safety helmet according to any one of Clauses 10 to 13, wherein the evaporative cooling pad further includes an opening in at least one of the top and bottom layers, and wherein the opening has a zipper.

[0029] Clause 15: A safety helmet according to any one of Clauses 10 to 14, wherein the evaporative cooling pad comprises a main body portion having a first end and a second end, and a pair of wings extending laterally from the first end.

[0030] Clause 16: A safety helmet according to any one of Clauses 10 to 15, wherein the first end is configured to contact the user's forehead, wherein each of the paired wings is configured to extend to the user's temporal region, and wherein the second end is configured to extend to the top of the user's head.

[0031] Clause 17: A method of manufacturing a safety helmet, the method comprising: molding a shell of the safety helmet into a thermoplastic material; and applying an infrared reflective layer to at least a portion of an inner surface of the shell, or applying the infrared reflective layer to an insert that can be attached to the shell.

[0032] Clause 18: The method according to Clause 17, wherein the insert having the infrared reflective layer is integrally formed with the housing during the molding of the housing.

[0033] Clause 19: The method according to Clause 17 or 18 further comprises attaching the insert having the infrared reflective layer to the housing by at least one of the following: adhesive, one or more mechanical clips or fasteners, press fit, ultrasonic bonding, and any combination thereof.

[0034] Clause 20: The method according to any one of Clauses 17 to 19 further comprises inserting an evaporative cooling pad into a cavity of the housing defined by the inner surface, wherein the evaporative cooling pad comprises: a top waterproof and breathable layer and a bottom waterproof and breathable layer defining the cavity therebetween; a liquid-absorbing layer positioned within the cavity; and an opening in at least one of the top and bottom layers.

[0035] These and other features and characteristics of this disclosure, as well as the methods of operation, the functions of structurally related elements, the assembly of parts, and the economics of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, which form part of this specification, wherein like reference numerals denote corresponding portions in the various figures. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to be limiting of this disclosure. Therefore, specific dimensions and other physical characteristics relating to the various embodiments disclosed herein should not be considered limiting. Furthermore, it should be understood that this disclosure may take the form of various alternative variations and sequences of steps unless expressly specified otherwise. Attached Figure Description

[0036] Figure 1 This is a side view of a safety helmet according to some non-limiting embodiments or aspects of this disclosure; Figure 2 yes Figure 1 A side sectional view of a safety helmet; Figure 3A This is a bottom view of a safety helmet according to some non-limiting embodiments or aspects of this disclosure; Figure 3B This is a bottom view of a safety helmet according to some non-limiting embodiments or aspects of this disclosure; Figure 3CThis is a cross-sectional view of the outer shell of a safety helmet with an infrared reflective layer according to some non-limiting embodiments or aspects of this disclosure; Figure 3D This is a cross-sectional view of the outer shell of a safety helmet having an infrared reflective layer that exhibits infrared light reflective properties, according to some non-limiting embodiments or aspects of this disclosure; Figure 4 It is a graph showing the experimental results of the thermal performance of multiple helmets as a function of time; Figure 5 It is a graph showing the experimental results of the thermal performance of multiple helmets as a function of time; Figure 6A It is a graph showing the experimental results of the thermal performance of a control helmet and a safety helmet according to some non-limiting embodiments or aspects of this disclosure, wherein the graph shows the results of a first thermal test; Figure 6B It is a graph showing the experimental results of the thermal performance of a control helmet and a safety helmet according to some non-limiting embodiments or aspects of this disclosure, wherein the graph shows the results of a second thermal test; Figure 7 This is a top view of an evaporative cooling pad configured for use with a safety helmet, showing an evaporative cooling pad according to some non-limiting embodiments or aspects of this disclosure; and Figure 8 This is a cross-sectional view of the evaporative cooling pad shown in Figure 3.

[0037] exist Figures 1 to 8 Unless otherwise stated, the same markings refer to the same parts and components, as may be the case. Detailed Implementation

[0038] For the purposes described below, the terms “end,” “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and their derivatives shall be used in connection with this disclosure as it is oriented in the accompanying drawings. However, it should be understood that this disclosure may take various alternative variations and sequences of steps unless explicitly specified otherwise.

[0039] All figures and ranges used in the specification and claims should be understood to be modified in all cases by the term “about”. “About” means ±25% of the value, for example, ±10% of the value. However, this should not be regarded as a limitation on any analysis of the value under the doctrine of equivalence.

[0040] Unless otherwise stated, all ranges or ratios disclosed herein should be understood to encompass the starting and ending values, as well as any and all subranges or subratios included therein. For example, the specified range or ratio of “1 to 10” should be considered to include any and all subranges or subratios between the minimum value of 1 and the maximum value of 10 (inclusive); that is, all subranges or subratios begin at the minimum value of 1 or greater and end at the maximum value of 10 or less. The ranges and / or ratios disclosed herein represent averages with respect to the specified ranges and / or ratios.

[0041] The terms “first,” “second,” etc., are not intended to refer to any particular order or sequence, but rather to different conditions, properties, or elements.

[0042] The term "at least" is synonymous with "greater than or equal to".

[0043] As used herein, “at least one of…” is synonymous with “one or more of…”. For example, the phrase “at least one of A, B, or C” means any one of A, B, or C, or any two or more of A, B, or C. For example, “at least one of A, B, or C” includes: one or more of A only; or one or more of B only; or one or more of C only; or one or more of A and one or more of B; or one or more of A and one or more of C; or one or more of B and one or more of C; or one or more of all of A, B, and C.

[0044] As used herein, the terms “parallel” or “substantially parallel” mean (if extended to the theoretical intersection) the relative angle between two objects (e.g., elongated objects), including the reference line, i.e., 0° to 5°, or 0° to 3°, or 0° to 2°, or 0° to 1°, or 0° to 0.5°, or 0° to 0.25°, or 0° to 0.1°, including the values ​​mentioned.

[0045] As used herein, the term “perpendicular” or “nearly perpendicular” means that the relative angle between two objects at their actual or theoretical intersection is 85° to 90°, or 87° to 90°, or 88° to 90°, or 89° to 90°, or 89.5° to 90°, or 89.75° to 90°, or 89.9° to 90°, including the values ​​mentioned.

[0046] In this document, the word "exemplary" is used to mean "as an example, instance, or illustration." Any implementation or approach of this subject matter described herein as "exemplary" is not necessarily to be construed as preferred or superior to other implementations or aspects.

[0047] The terms “comprises”, “comprising”, or any other variations thereof are intended to cover non-exclusive inclusion, such that an arrangement, apparatus, or method that includes a list of components or steps may include not only those components or steps but also other components or steps not expressly listed or inherent to such arrangement, apparatus, or method. In other words, a system or apparatus that begins with “comprises…” does not exclude the presence of other components or additional elements in the system or method, unless further constraints are imposed.

[0048] The term "includes" ("including") or any other variation thereof is intended to cover non-exclusive inclusion, such that an arrangement, apparatus, or method that includes a list of components or steps includes not only those components or steps but may also include other components or steps not expressly listed or inherent to such arrangement, apparatus, or method. In other words, one or more elements in a system or apparatus that begins with "includes..." do not exclude the presence of other elements or additional elements in the system or method, unless further constraints are imposed.

[0049] Unless otherwise expressly stated, the terms "an embodiment," "embodiment," "embodiments," "the embodiment," "the embodiments," "one or more embodiments," "some non-limiting embodiments or aspects," and "one embodiment" mean "one or more (but not all) embodiments of this disclosure." The description of one embodiment with multiple interconnected components does not imply that all of these components are necessary. Rather, a variety of optional components are described to illustrate a variety of possible embodiments of this disclosure.

[0050] No aspect, component, element, structure, action, step, function, instruction, and / or similar element used herein shall be construed as critical or essential unless explicitly described as such. Furthermore, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more” and “at least one.” Furthermore, as used herein, the term “collection” is intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, and / or similar) and may be used interchangeably with “one or more” or “at least one.” The term “a” or similar terms are used where only one item is intended. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Furthermore, unless explicitly stated otherwise, the phrase “based on” is intended to mean “at least partially based on.” Unless explicitly stated otherwise, the term “some non-limiting embodiments or aspects” means “one or more (but not all) embodiments or aspects of this disclosure.” A description of some non-limiting embodiments or aspects with several interconnected or combined components does not imply that all of these components are required. Instead, a variety of optional components are described to illustrate a variety of possible implementations of this disclosure.

[0051] When this document describes a single device or item, it is obvious that more than one device / item (whether or not they cooperate) can be used in place of the single device / item. Similarly, when this document describes more than one device or item (whether or not they cooperate), it is obvious that a single device / item can be used in place of more than one device or item, or that a different number of devices / items can be used in place of the number of devices or programs shown. The functionality and / or features of a device can alternatively be embodied by one or more other devices that are not explicitly described as having such functionality / features. Therefore, other embodiments or aspects of this disclosure do not need to include the device itself.

[0052] As discussed herein, some operations can be performed, modified, or removed in a different order. Furthermore, steps can be added to the methods described herein and still conform to the described implementation scheme. Additionally, the operations described herein can occur sequentially, or some operations can be processed in parallel.

[0053] In the following detailed description of various embodiments of this disclosure, reference is made to the accompanying drawings, which form part of the embodiments, and which illustrate, by way of illustration, specific embodiments in which this disclosure may be practiced. However, it should be understood that this is not intended to limit this disclosure to the forms disclosed, but rather, this disclosure will cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. It should be understood that other embodiments may be utilized and changes may be made without departing from the scope of this disclosure. Therefore, the following description should not be construed as limiting.

[0054] Various embodiments or aspects of this disclosure relate to safety helmets having thermal management components configured to reduce the temperature of a user's head when the helmet is worn.

[0055] refer to Figure 1 A safety helmet 100 (hereinafter referred to as "helmet 100") is provided, having a rigid shell 102 configured to surround a user's head. The shell 102 has a generally hemispherical shape and a face opening 104 at the front end configured to be located above the user's face. The shell 102 includes a front portion 106 located above the face opening 104, an upper portion 108, and a rear portion 110 extending from the upper portion 108 to the back of the user's neck. Pairs of side portions 112 extend from the upper portion 108 on each side of the face opening 104.

[0056] In some non-limiting embodiments or aspects, the housing 102 is made of a thermoplastic material such as high-density polyethylene (HDPE) or polycarbonate. The housing 102 can be manufactured using, for example, injection molding. Some thermoplastic materials at least partially transmit infrared radiation (IR) from the sun (see...). Figure 3D Using this material, IR is neither absorbed nor reflected by the housing 102. Instead, IR is transmitted through the material of the housing 102. As used herein, IR refers to solar infrared radiation in the range of 700–1500 nm.

[0057] The helmet 100 may have an infrared reflective layer 200 configured to reflect at least a portion of the incident IR. For example, to prevent the interior of the shell 102 from becoming warmer due to IR transmission through the material of the shell 102, in some non-limiting embodiments or aspects, the infrared reflective layer 200 is at least disposed on the inner surface 120 of the shell 102. Figures 3A to 3B (as shown in the diagram) on a portion of the outer shell 102. For example, the infrared reflective layer 200 may be provided on up to 100% of the inner surface 120 of the outer shell 102. In some embodiments or aspects, one or more cutouts 206 may be formed on the infrared reflective layer 200 to correspond to one or more ventilation openings 114 on the outer shell 102 of the helmet 100.

[0058] Infrared reflective layer 200 is configured to reflect at least a portion of incident IR 150 into the thermoplastic material of housing 102 and away from the user's head (see [link]). Figure 3D By placing the infrared reflective layer 200 on the inner surface 120 of the housing 102, the appearance of the housing 102 can remain unchanged relative to a conventional safety helmet. For example, the exterior of the housing 102 can be made in any desired color and / or have any desired graphics or markings applied thereon.

[0059] In some non-limiting embodiments or aspects, the infrared reflective layer 200 may contain a material that reflects IR. For example, the infrared reflective layer 200 may include a pure metal, such as aluminum, gold, silver, or copper. In other non-limiting embodiments or aspects, the infrared reflective layer 200 may include an alloy of aluminum, gold, silver, copper, or any combination thereof. In some non-limiting embodiments or aspects, the infrared reflective layer 200 may contain at least 95% by weight aluminum. In further non-limiting embodiments or aspects, the infrared reflective layer 200 may be made of one or more of the following materials: doped titanium dioxide, doped or undoped indium tin oxide, doped cerium oxide, doped manganese oxide, iron(III) oxide, cadmium sulfide, chromium trioxide, or any combination thereof. The thickness of the infrared reflective layer 200 may be from approximately 20 nm to 5 µm, for example, 30 nm.

[0060] In some non-limiting embodiments or aspects, the infrared reflective layer 200 may be a coating sprayed onto at least a portion of the inner surface 120 of the housing 102. For example, the infrared reflective layer 200 may be applied to the inner surface 120 of the housing 102 as an atomized spray of atomized droplets of metallizing paint or ink. Techniques for applying paint or ink include spraying, inkjet printing, or pad printing. In further non-limiting embodiments or aspects, the coating may be applied using an infrared reflective material applied directly to the inner surface 120 of the housing 102 via a physical vapor deposition (PVD) or chemical vapor deposition (CVD) process. In further non-limiting embodiments or aspects, the infrared reflective layer 200 may be an infrared reflective film applied to at least a portion of the inner surface 120 of the housing 102.

[0061] In some non-limiting embodiments or aspects, the infrared reflective layer 200 may be formed in an insert 202 formed separately from the housing 102 (see...). Figure 3CThe insert 202 may be removably or non-removably attached to the housing 102. For example, an infrared reflective layer 200 may be formed on a substrate 204, which is co-molded with the housing 102 during its manufacture. In this way, the insert 202 having the infrared reflective layer 200 is integrally formed with the inner surface 120 of the housing 102. In some non-limiting embodiments or aspects, the infrared reflective layer 200 may be formed on the substrate 204, which is configured to be thermoformed together with the housing 102 (see [link to relevant documentation]). Figure 3C The substrate 204 may be high-density polyethylene (HDPE), polyethylene terephthalate (PET), or other thermoplastic films. Before bonding the substrate 204 to the inner surface 120 of the housing 102, the infrared reflective layer 200 may be vapor-deposited onto the substrate 204 (using CVD or PVD).

[0062] During the injection molding of the housing 102, the insert 202 can be placed on the core, and the housing 102 can be injection molded / formed over the insert 202. Techniques for molding the insert 202 together with the housing 102 include overmolding, insert molding, and co-molding. In this way, the insert 202 with the infrared reflective layer 200 is integrally formed with the inner surface 120 of the housing 102 without requiring the insert to be adhered to or clamped to the housing 102. In some embodiments or aspects, the insert 202 with the infrared reflective layer 200 can be secured to the inner surface 120 of the housing 102 using adhesives, ultrasonic welding, one or more mechanical clips or fasteners, or via press fitting. The insert 202 can be removably or non-removably secured to the inner surface 120 of the housing 102.

[0063] In some non-limiting embodiments or aspects, the infrared reflective layer 200 may have an infrared reflectivity greater than 40% in the 700-1400 nm region (i.e., the effectiveness of reflecting infrared radiation energy). In some non-limiting embodiments or aspects, the infrared reflectivity of the infrared reflective layer 200 may be 83%-89%. Furthermore, the infrared reflective layer 200 may have a hemispherical emissivity value less than 0.2. Hemispherical emissivity relates to the effectiveness of a material in emitting energy as thermal radiation. In some non-limiting embodiments or aspects, the emissivity value may be 0.06. In some non-limiting embodiments or aspects, the infrared reflective layer 200 may have an optical density (i.e., a measure of radiative energy absorptivity) of at least 2.0 (e.g., 3.5).

[0064] refer to Figure 4The graph shows the experimental results of the temperature difference between the outside and inside of the safety helmet as a function of time. The graph illustrates the experimental results for a control helmet without the infrared reflective layer 200 (line 400) and three other helmets with various infrared reflective layers 200. Figure 4 The test results for the first helmet (line 500) are shown, in which the inner surface of the helmet is coated with Rust-Oleum High Heat Ultra paint, and the helmet was placed under an IR lamp for 60 minutes. Results from three independent experiments using this helmet showed no significant temperature difference compared to the control helmet. Figure 4 The test results for a second helmet (Line 600) are also shown, in which the inner surface of the helmet is coated with Krylon Color Master metallic silver paint, and the helmet was placed under an IR lamp for 60 minutes. The results of three independent experiments conducted using this helmet showed a temperature difference of 10 °F to 15 °F compared to the control helmet. Figure 4 The test results for a third helmet (Line 700) are also shown, in which the inner surface has an infrared reflective layer deposited using chemical vapor deposition technology, and this helmet was placed under an IR lamp for 60 minutes. Results from a single experiment using this helmet showed a significant temperature difference compared to the control helmet.

[0065] refer to Figure 5 The chart shows the experimental test results used to evaluate pairs of safety helmets 100 with different infrared reflective layers 200 relative to a control safety helmet 100 without an infrared reflective layer 200. The experimental tests were conducted according to the solar radiation testing guidelines described in Method 505, Procedure I of MIL-STD-810G. The control safety helmet 100, as a black, non-breathable helmet, reached a maximum internal temperature of 143.8 °F. The first safety helmet 100 with an infrared reflective layer 200 in the form of a metallized PVD coating reached a maximum internal temperature of 132.3 °F. The second safety helmet 100 with an infrared reflective layer 200 in the form of an overmolded thermoformed insert reached a maximum internal temperature of 134.8 °F.

[0066] Figures 6A to 6B The difference between a safety helmet with an infrared reflective layer 200 and one without an infrared reflective layer 200 is shown. Figure 6A The comparison between the control helmet (without infrared reflective layer 200) and the test helmet (with infrared reflective layer 200) shows that approximately 600 W / m is achievable. 2 The assessment results of the solar irradiance at a distance. Figure 6BThe comparison between the control helmet (without infrared reflective layer 200) and the test helmet (with infrared reflective layer 200) shows that approximately 1000 W / m is achievable. 2 The assessment results at the distance of the solar irradiance value. Figures 6A to 6B The temperature displayed on the Y-axis of the chart represents the highest recorded inner shell temperature.

[0067] refer to Figure 2 The safety helmet 100 may have an evaporative cooling pad 300 positioned within an internal cavity 122 defined by the inner surface 120 of the outer shell 102. In some non-limiting embodiments or aspects, the cooling pad 300 may be removably or non-removably connected to at least a portion of a suspension device 124 connected to the inner surface 120 of the outer shell 102. In some non-limiting embodiments or aspects, the cooling pad 300 may be removably connected to the suspension device 124 via hook and loop fasteners, buttons, buckles, hooks, or other connecting mechanisms. As described herein, the evaporative cooling pad 300 may be configured to cool the user's head via a water evaporation process.

[0068] refer to Figure 8 The evaporative cooling pad 300 has a top layer 302, a bottom layer 304, and a cavity 306 defined therebetween. As described herein, the outer surface 305 of the bottom layer 304 is configured to contact the user's head. The top layer 302 and the bottom layer 304 may be made of a waterproof and breathable material sewn together or otherwise joined together to define the cavity 306 therebetween. In some non-limiting embodiments or aspects, the top layer 302 and the bottom layer 304 may be made of nylon material laminated with a waterproof and breathable material. In some non-limiting embodiments or aspects, the top layer 302 and the bottom layer 304 may be made of polyurethane or polytetrafluoroethylene. In some non-limiting embodiments or aspects, the top layer 302 and the bottom layer 304 may have a sweat-absorbing fabric 308 on their outer surfaces.

[0069] refer to Figure 8 The evaporative cooling pad 300 further includes a liquid absorption layer 310 positioned within a cavity 306, and an opening 312 disposed in at least one of the top layer 302 and the bottom layer 304. In some non-limiting embodiments or aspects, the opening 312 may be disposed in a seam between the top layer 302 and the bottom layer 304. In some non-limiting embodiments or aspects, the opening 312 may have a zipper or other closure mechanism for sealing the opening. The opening 312 may be configured to allow coolant (e.g., water) to be added to the cavity 306, such that the liquid permeates the liquid absorption layer 310. The top layer 302 and the bottom layer 304 are configured to allow coolant to pass in vapor form in a direction exiting the cavity 306, but not in liquid form.

[0070] refer to Figure 7 The evaporative cooling pad 300 may be generally T-shaped. For example, the evaporative cooling pad 300 may have a body portion 314 having a first end 316 opposite to a second end 318. Pairs of wings 320 extend laterally from the first end 316. In some non-limiting embodiments or aspects, the first end 316, the second end 318, and / or the wings 320 may have a circular shape. In use, the first end 316 is configured to contact the user's forehead, each of the pair of wings 320 is configured to extend to the user's temple, and the second end 318 is configured to extend to the top of the user's head.

[0071] The evaporative cooling pad 300 is configured to allow heat to be transferred from the user's head to the evaporative cooling pad 300, thereby evaporating the liquid in the cavity 306. The evaporating liquid provides a cooling sensation as it carries heat away from the head. By combining the infrared reflective layer 200 with the evaporative cooling pad 300 in the same helmet 100, the infrared reflective layer 200 enhances the efficiency of the evaporative cooling pad 300. In the case of cooler ambient air in the helmet 100 originating from the infrared reflective material, less coolant will evaporate due to the ambient air temperature and infrared radiation. Instead, the liquid will evaporate as it carries heat away from the user's head.

[0072] The terminology used in this specification has been chosen primarily for readability and guidance purposes and may not be intended to define or limit the subject matter of the invention. Therefore, the scope of this disclosure is not limited by this detailed description, but rather by any claims made on the application based thereon. Accordingly, the disclosure of various embodiments of this disclosure is intended to illustrate, and not limit, the scope of this disclosure as set forth in the appended claims.

[0073] Although this disclosure has been described in detail for illustrative purposes based on embodiments or aspects currently considered to be most practical and preferred, it should be understood that such detail is for that purpose only and that this disclosure is not limited to the disclosed embodiments or aspects, but rather is intended to cover modifications and equivalents within the spirit and scope of the appended claims. For example, it should be understood that this disclosure considers that, to the extent possible, one or more features of any embodiment or aspect may be combined with one or more features of any other embodiment or aspect.

Claims

1. A safety helmet comprising: A shell configured to surround the user's head; and An infrared reflective layer disposed inside the housing, the infrared reflective layer being configured to reflect at least a portion of the incident infrared radiation transmitted through the housing. The infrared reflective layer has an infrared reflectivity of at least 40%.

2. The safety helmet of claim 1, wherein the infrared reflective layer has an infrared reflectivity in the range of 83% to 89%.

3. The safety helmet of claim 1, wherein the infrared reflective layer has a hemispherical emissivity of less than 0.

2.

4. The safety helmet of claim 1, wherein the infrared reflective layer has an optical density of at least 2.

0.

5. The safety helmet of claim 1, wherein the infrared reflective layer comprises at least one of the following: aluminum, gold, silver, copper, or any combination thereof.

6. The safety helmet of claim 1, wherein the infrared reflective layer comprises at least one of the following: doped titanium dioxide, doped or undoped indium tin oxide, doped cerium oxide, doped manganese oxide, iron(III) oxide, cadmium sulfide, chromium trioxide, or any combination thereof.

7. The safety helmet of claim 1, wherein the thickness of the infrared reflective layer is 20 nm to 5 µm.

8. The safety helmet of claim 1, wherein the infrared reflective layer is applied to an insert that is removably or non-removably attached to the shell.

9. The safety helmet of claim 8, wherein the insert comprises a substrate made of a thermoplastic film.

10. A method of manufacturing a safety helmet, the method comprising: The outer shell of the safety helmet is molded from a thermoplastic material; and An infrared reflective layer is applied to at least a portion of the inner surface of the housing or to an insert that can be attached to the housing.

11. The method of claim 10, wherein the insert having the infrared reflective layer is integrally formed with the housing during the molding of the housing.

12. The method of claim 10, further comprising attaching the insert having the infrared reflective layer to the housing by at least one of the following: adhesive, one or more mechanical clips or fasteners, press fit, ultrasonic bonding, or any combination thereof.

13. The method of claim 10, further comprising inserting an evaporative cooling pad into a cavity of the housing defined by the inner surface, wherein the evaporative cooling pad comprises: The cavity is defined by a top waterproof and breathable layer and a bottom waterproof and breathable layer; The liquid absorption layer positioned within the cavity; and An opening in at least one of the top and bottom layers.

14. The method of claim 13, wherein the liquid absorption layer is configured to be permeated with coolant added to the cavity through the opening.

15. The method of claim 14, wherein the top waterproof and breathable layer and the bottom waterproof and breathable layer are configured to allow the coolant to pass through in the form of vapor in the direction away from the cavity, but not in the form of liquid.

16. The method of claim 14, wherein the evaporative cooling pad is configured to allow heat to be transferred from the user's head to the evaporative cooling pad, thereby evaporating the coolant in the cavity.

17. The method of claim 10, wherein the infrared reflective layer comprises at least one of the following: aluminum, gold, silver, copper, or any combination thereof.

18. The method of claim 10, wherein the infrared reflective layer comprises at least one of the following: doped titanium dioxide, doped or undoped indium tin oxide, doped cerium oxide, doped manganese oxide, iron(III) oxide, cadmium sulfide, chromium trioxide, or any combination thereof.

19. The method of claim 10, wherein the infrared reflective layer has an optical density of at least 2.

0.

20. The method of claim 10, wherein the infrared reflective layer has a hemispherical emissivity of less than 0.

2.

21. A safety helmet comprising: A housing configured to surround a user's head, the housing including one or more ventilation openings; An infrared reflective layer disposed inside the housing, the infrared reflective layer comprising one or more cutouts corresponding to the one or more vent openings, the infrared reflective layer being configured to reflect at least a portion of incident infrared radiation transmitted through the housing; and An evaporative cooling pad, positioned inside the housing and aligned with the one or more vent openings, comprises: A cavity is defined therebetween, consisting of a top waterproof and breathable layer and a bottom waterproof and breathable layer, wherein the outer surface of the bottom waterproof and breathable layer is configured to contact the user's head; and The liquid absorption layer is positioned within the cavity.

22. The safety helmet of claim 21, wherein the top waterproof and breathable layer and the bottom waterproof and breathable layer comprise nylon material laminated with a waterproof and breathable material.

23. The safety helmet of claim 21, wherein at least one of the top waterproof and breathable layer and the bottom waterproof and breathable layer comprises polyurethane or polytetrafluoroethylene.

24. The safety helmet of claim 21, wherein the evaporative cooling pad is further comprised of a sweat-absorbing fabric on the outer surface of the bottom waterproof and breathable layer.

25. The safety helmet of claim 21, wherein the evaporative cooling pad further includes an opening in at least one of the top waterproof and breathable layer and the bottom waterproof and breathable layer, and wherein the opening has a zipper.

26. The safety helmet of claim 21, wherein the evaporative cooling pad comprises a body portion having a first end and a second end, and a pair of wings extending laterally from the first end.

27. The safety helmet of claim 26, wherein the first end is configured to contact the user's forehead, wherein each of the paired wings is configured to extend to the user's temporal region, and wherein the second end is configured to extend to the top of the user's head.

28. The safety helmet of claim 21, further comprising a suspension device connected to the interior of the outer shell.

29. The safety helmet of claim 28, wherein the evaporative cooling pad is removably connected to the suspension device.

30. The safety helmet of claim 21, wherein the evaporative cooling pad further includes an opening in at least the outer surface of the bottom waterproof and breathable layer or the outer surface of the top waterproof and breathable layer.

31. The safety helmet of claim 30, wherein the opening is provided in the seam between the top waterproof and breathable layer and the bottom waterproof and breathable layer.

32. The safety helmet of claim 30, wherein the opening includes a zipper for sealing the opening.

33. The safety helmet of claim 30, wherein the liquid-absorbing layer is configured to be permeated with coolant added to the cavity through the opening.

34. The safety helmet of claim 33, wherein the top waterproof and breathable layer and the bottom waterproof and breathable layer are configured to allow the coolant to pass in vapor form in the direction away from the cavity, but not in liquid form.

35. The safety helmet of claim 33, wherein the evaporative cooling pad is configured to allow heat to be transferred from the user's head to the evaporative cooling pad, thereby evaporating the coolant in the cavity.

36. The safety helmet of claim 35, wherein the infrared reflective layer is configured such that a relative portion of the coolant is converted from evaporation caused by heat from the ambient air inside the safety helmet to evaporation caused by heat from the user's head.

37. The safety helmet of claim 29, wherein the evaporative cooling pad is connected to the suspension device by at least one of the following: hook and loop fasteners, buttons, buckles, hooks, adhesives, one or more mechanical clips or fasteners, other connecting mechanisms or any combination thereof.

38. The safety helmet of claim 29, wherein the evaporative cooling pad can be installed and / or replaced while the suspension device is assembled in the safety helmet.

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