• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
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  • 优先权
    • 专利摘要:
    INSERTION EAR PROTECTOR. The present invention relates to an insert earplug (100) that includes an elongated core (110) and outer layer (120). The outer layer includes a sound attenuating portion (121) that has a first average density and a stem portion (122) that has a second average density, and the second average density is greater than the first average density.
    公开号:BR112015000590B1
    申请号:R112015000590-0
    申请日:2013-07-11
    公开日:2021-05-18
    发明作者:James P. Endle；Jeffrey L. Hamer；Alan R. Seville；Kenneth F. Teeters
    申请人:3M Innovative Properties Company；
    IPC主号:
    专利说明:

    technical field
    [0001] This invention relates to a hearing protection device, in particular an insert ear protector that has an elongated core produced from a first material, and an outer layer produced from a second material. Background
    [0002] The use of hearing protection and noise attenuation devices are known, and several types of devices have been considered. Such devices include earmuffs and semi-ear devices constructed partially or completely of foam or rubber materials that are inserted into or placed over a wearer's ear canal to physically obstruct the passage of sound waves into the inner ear.
    [0003] Compressible type or roll-down type earplugs generally comprise a compressible resilient body portion and can be produced from suitable slow recovery foam materials. The earplug can be inserted into the canal ear of a user by first winding it between the fingers to compress the body portion, then pushing the body portion into the ear canal, and subsequently allowing the body portion to expand to fill the ear canal.
    [0004] Insertion-type earmuffs have also been considered, and may include a compressible cushion portion and a hard portion extending from the cushion portion. To insert an insert-type earplug, the wearer grasps the hard portion and pushes the attenuating portion into the ear canal with an appropriate level of force. The attenuating portion compresses as it is accommodated in the ear canal. Insertion earmuffs can allow the earmuff to be quickly and easily inserted into an ear canal, and can promote hygiene by minimizing contact with the attenuating portion of the earmuff prior to insertion.
    [0005] Although insert earplugs exhibit desirable characteristics in many applications, they can be costly and can present difficult manufacturing challenges. Glossary Summary
    [0006] “Mold” means a hollow shape that may or may not impart a shape to a component placed in the hollow shape.
    [0007] "Thermally bonded" means a state in which molecules of two materials or surfaces have diffused into the material or surface of the other when in a molten phase so that a bond is formed. Chemical bonding is absent or does not provide the primary source of bonding between thermally bonded materials or surfaces.
    [0008] “Thermoplastic” means a polymer that can be repeatedly heated and reshaped and will retain its shape upon cooling.
    [0009] “thermoset” means a polymer that can be cured irreversibly.
    [0010] “Disabled” when referring to a foaming agent means that the foaming agent can be further activated to facilitate the formation of gases or cells in a material.
    [0011] In one embodiment of the present invention, an earmuff is disclosed, including an elongated core that includes a first material and that has first and second ends and an outer main surface, and an outer layer that includes a second material. and which covers at least a portion of the main outer surface of the elongated core. The outer layer includes a sound attenuating portion having a first mean density p1 and a stem portion having a second mean density p2, and |p2 > 1.2 p1|. In an exemplary embodiment, the outer layer is thermally bonded to at least a portion of the outer main surface of the elongated core, and an adhesive is not present between the outer main surface of the elongated core and the outer layer. The first material includes one or more of polypropylene and styrene-ethylene-butylene-styrene (SEBS), and the second material includes one or more of a thermoplastic, styrene-ethylene-butylene-styrene (SEBS), a thermosetting polymer, and a EPDM rubber. In a further embodiment, the first and second ends of the elongated core are at least partially exposed.
    [0012] In another embodiment of the present invention, an earmuff is disclosed, including an elongated core that includes a first material and that has first and second ends and an outer main surface, and an outer layer that includes a second material. and which covers at least a portion of the main outer surface of the elongated core. The second material includes thermoplastic spheres.
    [0013] In a further embodiment of the present invention, an earmuff is disclosed including an elongated core that includes a first material and that has first and second ends and an outer main surface, and an outer layer that includes a second material and thermally bonded to at least a portion of the outer main surface of the elongated core. The outer layer includes a sound attenuating portion having a first mean density p1 and a stem portion having a second mean density p2, and |p2 > 1.2 p1|. The outer layer is a contiguous layer and extends from the first end of the elongated core to the second end of the elongated core, and the outer layer includes thermoplastic spheres.
    [0014] Patent Application No. US 13/547,189 entitled Method of Making an Earplug and filed on July 12, 2012, concerns a method of producing personal protective equipment such as an insert earplug, and US Patent Application Serial No. 13/547,294 entitled Foamable Article and filed July 12, 2012, relates to an article for forming a device or component, and is incorporated herein by reference. Brief description of the drawings
    [0015] Figure 1 is a perspective view of an insert earplug according to the present invention.
    [0016] Figure 2 is a cross-sectional view of an insert earplug according to the present invention.
    [0017] Figures 3A to 3D are cross-sectional views of exemplary insert earplugs in accordance with the present invention showing sound attenuating portions having various exemplary shapes.
    [0018] Figure 4 is a perspective view of a preform that includes an elongated core and an outer layer in an intermediate state of an exemplary method of producing an earmuff.
    [0019] Figure 5 is a schematic representation of an exemplary manufacturing process according to the present invention.
    [0020] Figures 6A and B are cross-sectional views of an example of a mold used in an exemplary embodiment of the present invention.
    [0021] Figures 7A and B are cross-sectional views of an example of a mold used in an exemplary embodiment of the present invention.
    [0022] Figure 8 is a schematic representation of an exemplary manufacturing process according to the present invention. Detailed Description
    [0023] A earplug that provides hearing protection for a wearer, and a method of producing a earplug, is provided in the following description. An earmuff in accordance with the present invention includes a relatively stiff elongated core covered, directly or indirectly, by a relatively soft outer layer. The outer layer includes a compressible sound attenuating portion that can be inserted into a wearer's ear canal, and stem portion that can be gripped by a wearer to handle the earplug. Such an earplug can easily be inserted into an ear canal without first requiring the sound attenuating portion to be compressed or “rolled down”. The present invention further provides a method of producing an earplug that minimizes difficult and costly manufacturing techniques. The method can include the steps of covering a substrate, such as an elongated core, with an outer layer that includes a deactivated foaming agent, and activating the foaming agent so that at least a portion of the outer layer expands into a desired format.
    [0024] Figures 1 and 2 show an insert earplug 100 in accordance with the present invention. Earguard 100 includes an elongated core 110 made from a first material and having first and second ends 111 and 112, and an outer main surface 113. Earguard 100 additionally includes an outer layer 120 made to from a second material and connected, directly or indirectly, to at least one outer main surface portion 113 of elongated core 110. The outer layer 120 includes a sound attenuating portion 121 for at least partial insertion into a wearer's ear canal, for example, and a stem portion 122 that has a smaller diameter and greater average density than the sound attenuating portion 121. In some embodiments, a channel 115 extends completely or partially through an elongated core 110 between the first and second. ends 111 and 112.
    [0025] During insertion of the earplug 100, the stem portion 122 and the elongated core 110 serve as a handle that can be grasped by a user. The earplug 100, and specifically the sound attenuating portion 121, is placed in proximity to the wearer's ear and inserted into the ear canal. The sound dampening portion 121 compresses as it is positioned, and the elongated core 110 provides sufficient hardness to facilitate insertion. In use, the sound attenuating portion 121 is positioned substantially within an ear canal to block sound passage and the stem portion 122 extends outwardly from the ear canal to provide a cable for removing the earplug.
    [0026] The elongated core 110 provides a substrate on which the outer layer 120 can be covered, directly or indirectly, and facilitates the insertion of the earplug 100 into a wearer's ear canal. In an exemplary embodiment, elongated core 110 is produced from a first material that exhibits greater rigidity or hardness than outer layer 120, yet is soft enough to be comfortable and secure for a wearer. The elongated core 110 provides sufficient rigidity that the earmuff 100 can be positioned for use at least partially in a wearer's ear by pushing the sound attenuating portion 121 into the ear canal with an appropriate force. That is, a sufficiently stiff elongated core 110 combined with an appropriate outer layer 120 allows the earplug 100 to be positioned for use at least partially in a user's ear without the need to compress or "roll down" the attenuator portion first. 121. Direct insertion without the need to compress or “roll down” the sound attenuating portion 121 first, for example, promotes hygiene by limiting contact with the sound attenuating portion 121 before placing it in the ear. The elongated core 110 also exhibits an appropriate level of flexibility so that it can slightly deform the contours of the ear canal when positioned for use.
    [0027] The elongated core 110 is produced from one or more materials that can properly bond, and are otherwise compatible with the outer layer material 120 or one or more intermediate layers. In an exemplary embodiment, elongated core 110 is made from a blend of polypropylene and styrene-ethylene-butylene-styrene (SEBS), such as TUFPRENE available from S&E Specialty Polymers, LLC. of Lunenburg, Massachusetts. Other suitable materials include SANTOPRENE 101-90, available from Exxon Mobile Corporation, and other materials that exhibit appropriate hardness so that the attenuating portion 121 of the earplug 100 can be easily inserted into a wearer's ear canal.
    [0028] The elongated core 110 can be produced from one or more materials that have a specific hardness. In various exemplary embodiments, the hardness of at least one elongated core portion 110 is between 50 and 100 Shore A, or between 70 and 90 Shore A, or about 80 Shore A. A desired hardness may depend on the dimensions of the elongated core 110 so that the elongated core 110 exhibits a desired hardness.
    [0029] In an exemplary embodiment, the elongated core 110 has a circular cross-section that is substantially uniform anywhere between the first and second ends 111 and 112 so that the elongated core 110 exhibits a generally cylindrical shape. A circular cross-section can minimize edges that can cause discomfort from touching portions of a user's ear. In various other exemplary embodiments, the elongated core may have a triangular, square, or other suitable cross-section cross-section, or it may have a cross-section that varies along the length of the earplug 100. The surface Outer main 113 may have a serrated, grooved, or otherwise textured surface. Such a surface can increase the surface area that contacts the outer layer 120 or an intermediate layer so that a strong bond is created. In some exemplary embodiments, elongated core 110 includes multiple concentric layers, such as a layer to provide a desired hardness and a layer that facilitates a robust bond with the outer layer, or that provides other desired characteristics.
    [0030] In some exemplary embodiments, the elongated core 110 is hollow and is in the form of a tube defining a channel 115. The earplug 100 having a hollow elongated core 110 can be fabricated so that components of a reservoir or of a communication system can be attached to the ear protector. Alternatively or additionally, channel 115 can accommodate one or more filters or other passive auditory elements to provide an attenuation curve that has a desired shape. For example, filters placed on channel 115 can cause non-linear attenuation of high-level inserts produced by explosions, gunshots, or the like. Channel 115 may also provide a recess in which a lanyard can be attached so that the first and second earplugs can be joined, or the ends of a headband can be attached to a semi-aural hearing protector.
    [0031] Earmuff 100 additionally includes an outer layer 120 which substantially directly or indirectly covers the elongated core 110 and which includes the sound attenuating portion 121 and the stem portion 122. In an exemplary embodiment, the outer layer 120 substantially surrounds outer main surface 113 of elongated core 110 and extends from first end 111 to second end 112 of elongated core 110. In some embodiments, outer layer 120 is a contiguous layer such that portions of the sound attenuating portion 121 contact portions of the stem portion 122. The first and second ends 111 and 112 of the elongate core 110 may be at least partially exposed, and the elongate core 110 may be similarly or dissimilarly colored from the color. outer layer 120 to hide or display the presence of elongated core 110. Sound attenuating portion 121 is positioned near first end 111 of core 1 ongado 110 and is shaped to fit in a wearer's ear canal. In an exemplary embodiment, the sound attenuating portion 121 is substantially dome-shaped or spherical in shape, and has a diameter at its widest point that is greater than a diameter of the stem portion 122. In various other embodiments shown in Figures 3A through 3D, for example, the sound attenuating portions 125, 126, 127, 128, respectively, may be bullet-shaped, bell-shaped, cone-shaped, mushroom-shaped, or otherwise shaped to provide a desired fit or be compatible with a particular application.
    [0032] The outer layer 120 is produced from a soft, pliable foam, rubber, polymer, or other suitable material that can be comfortably positioned in a wearer's ear canal. In an exemplary embodiment, outer layer 120 is produced from a SEBS such as MONPRENE MP1900 available from Teknor Apex of Pawtucket, Rhode Island. Other suitable materials include plasticized polyvinyl chloride, ethylene propylene diene monomer (EPDM) rubber, styrene butadiene rubber (SBR), butyl rubber, natural rubbers, other thermoplastics, thermoset polymers, and other suitable materials as known in the art that can be formulated to exhibit an appropriate hardness range. In an exemplary embodiment, elongated core 110 and outer layer 120 materials are selected so that the primary source of bonding between elongated core 110 and outer layer 120, directly or indirectly, is thermal bonding. An additional adhesive is not required to bond elongated core 110 and outer layer 120, and such an adhesive is not present between elongated core 110 and outer layer 120 in an exemplary embodiment. In some exemplary embodiments, outer layer 120 includes multiple concentric layers, such as a layer to provide characteristics desired for contacting a wearer's ear canal and a layer that facilitates a robust connection with the elongated core, or layers that provide other desired features.
    [0033] The outer layer 120 material can be selected to control the friability of the outer layer 120 so that it cannot be easily broken or disintegrated during use. The friability of an earplug can be controlled in part by selecting a material that has an appropriate molecular weight, with a higher molecular weight generally resulting in a less friable earplug. In an exemplary embodiment, outer layer 220 includes a SEBS that has a molecular weight between 100,000 Daltons and 200,000 Daltons, as measured by gel permeation chromatography analysis as known in the art, such as in accordance with ASTM D6474 - 99.
    [0034] The density of outer layer 120 can be controlled during fabrication to provide a specific density as desired for a particular application. Outer layer 120 may exhibit a density that varies in thickness, for example, so that outer layer 120 has an integral outer skin that is denser than the balance of outer layer 120. Such skin may be present in one or both the sound attenuating portion 121 and the stem portion 122. Alternatively, the sound attenuating portion 121 or the stem portion 122 may have a substantially uniform density. In an exemplary embodiment, irrespective of the presence of an integral outer skin or varying densities within the sound dampening portion 121 or stem portion 122, the sound dampening portion 121 has a first average density pl and the stem portion has a second density average p2. The first and second average densities p1 and p2 can be ascertained by averaging the densities at each location of the sound attenuating portion 121 or stem portion 122. Without being limited by theory, the average density is believed to provide a indicating the ability of the sound attenuating portion 121 or stem portion 122 to compress or otherwise conform when subjected to an external force. The first average density p1 of the sound attenuating portion 121 is selected so that the sound attenuating portion can provide a comfortable fit conforming to a user's ear canal, while providing a desired level of sound attenuation. In various exemplary embodiments, the first average density p1 of a sound attenuating portion 121, comprising a foamed SEBS for example, is between 100 kg/m3 and 180 kg/m3, or 110 kg/m3 and 160 kg/m3, or may be about 125 kg/m3 The second mean density p2 of the shank portion 122 is greater than the first mean density p1, and in various exemplary embodiments is between 200 kg/m3 and 300 kg/m3, 225 kg/m3 and 275 kg/m3, or it can be about 250 kg/m3. Accordingly, in various exemplary embodiments, the second average density p2 of the stem portion 122 of the outer layer 120 is greater than 1.2, 1.5, 2 or more times the first average density p1 of the sound attenuating portion 121 of the layer. external 120.
    [0035] Earguard 100 can be formed in a multi-step process. In an exemplary embodiment, earplug 100 is formed in a process involving an intermediate state in which outer layer 120 is covered around elongated core 110, directly or indirectly, to result in a pre-formed hearing protection device. such as preform 130, but does not yet include sound dampening portion 121. In the intermediate state shown in Figure 4, outer layer 120 of preform 130 includes a deactivated foaming agent. In an exemplary embodiment, the deactivated foaming agent includes a sphere expandable foaming agent that includes thermoplastic spheres, for example, that include a housing that encapsulates a hydrocarbon or other suitable gas that expands when exposed to heat or other source. activation. The expansion of the thermoplastic housing results in an increased volume and reduced density of the outer layer material 120. The deactivated foaming agent can also be a chemical foaming agent that includes an expandable material that is a single piece or otherwise not. contained by an expandable sphere. Activation of such a foaming agent causes the expandable material to expand creating voids or gaps in the outer layer material. In an exemplary embodiment, outer layer 120 of preform 130 includes a deactivated expandable sphere foaming agent and a deactivated chemical foaming agent. Activation of the foaming agent or agents present in outer layer 120, and the associated expansion of outer layer 120, can be controlled to provide an earplug 100 having a sound attenuating portion 121 and stem portion 122 exhibiting a desired shape, density, hardness, and other desired characteristics. The presence of both an expandable sphere foaming agent and a chemical foaming agent can assist in providing sufficient structure and expansion so that the outer layer can be properly formed during activation, while reducing the hardness of the outer layer of a level that would otherwise result if only an expandable sphere foaming agent were used. Some or all of a gas generated by a chemical foaming agent may escape during activation so that some or all of the gas is not present in the outer layer after activation. Some or all of an expandable sphere foaming agent may remain on the outer layer of an end cap so that an end cap can include the thermoplastic spheres. In an exemplary embodiment, outer layer 120 of earplug 100 includes between 1% and 5% by weight, and may include approximately 3% by weight, of foaming agent or foaming agent remains.
    [0036] In the intermediate state shown in Figure 4, preform 130 can be cut to the desired length of earmuffs 100, can be cut to an extended length sufficient for subsequent formation of many earmuffs, or it may remain uncut so that activation of outer layer 120 occurs prior to cutting as described below with reference to Figure 8. Preform 130 having an extended length can facilitate handling for subsequent processing and activation of the foaming agent. In an exemplary embodiment, the preform 130 is cut to an extended length which can subsequently be cut and activated to produce a desired quantity of earplugs 100. An extended preform 130 may be spirally or otherwise shaped to facilitate shipping or handling.
    [0037] The present invention provides a method of producing personal protective equipment, such as the ear protector 100 described above. An exemplary method includes steps of covering a substrate with an outer layer, and applying heat to at least a portion of the outer layer so that at least a portion of the outer layer expands. The expansion of the outer layer occurs due to the activation of a foaming agent present in the outer layer material and can be controlled by placing at least a portion of the outer layer in a mold prior to expansion. Portions of the outer layer can be confined by the shape of the mold as the outer layer expands, or are heat protected to limit activation of the foaming agent.
    [0038] The method described in this document is suitable not only for manufacturing ear protectors, but also for manufacturing other types of hearing protection devices and components for other personal protective equipment, as well as other molded or shaped parts suitable for others applications. For example, the present method provides a process for producing a seal for a facepiece of a respiratory protection device that can be foamed to provide a desired shape and density. Other exemplary applications include the manufacture of earplugs, respirators, eyewear, other personal protective equipment, components of such personal protective equipment, and other applications.
    [0039] An exemplary method of producing an insert earplug according to the present invention includes the steps of covering an elongated core, directly or indirectly, with an outer layer comprising an inactivated foaming agent, and activating the foaming agent of at least a portion of the outer layer to form a sound dampening portion and a rod portion connected, directly or indirectly, to the elongated core.
    [0040] Figure 5 shows a schematic drawing of an exemplary method of producing an ear protector 200 in accordance with the present invention. An extended elongated core 210 is formed by extruding a first material through a first die 240 and extracting the first material to an appropriate diameter. As described above, the elongated core can be solid, or it can include a longitudinal channel that extends through all or a portion of the elongated core 210, and it can include one or more concentric layers that have diverging characteristics. The first material can be cooled so that it remains stable in subsequent steps in the manufacturing process. The magnitude of temperature change may depend on the materials used and the desired characteristics of the final product. In an exemplary embodiment, the elongated core 210 is cooled as needed so that it exhibits a temperature at a point prior to being covered by the second matrix 250 that is less than an activation or cure temperature of the outer layer 220. Before be covered, the elongated core 210 has an extended length and is not yet cut to the desired length for an earmuff.
    [0041] In the embodiment shown in Figure 5, the elongated core 210 is covered, directly or indirectly, with an outer layer 220 comprising a second material, by the second matrix 250. The second matrix 250 may be a coextrusion matrix or other matrix suitable as known in the art. In an exemplary embodiment, the second material comprises a thermoplastic and one or more deactivated foaming agents. The outer layer 220 is applied to the elongated core 210 while remaining at a temperature below an activation temperature of the deactivated foaming agents. In an exemplary embodiment, the second material includes SEBS and a foaming agent that has an activation temperature of between 100°C and 205°C, 120°C and 190°C, or about 170°C. Other suitable materials include plasticized polyvinyl chloride, ethylene propylene diene monomer rubber (EPDM), styrene butadiene rubber (SBR), butyl rubber, natural rubbers, other thermoplastics, thermoset polymer, and other suitable materials as known in the art . In embodiments in which the outer layer 220 includes a second material that has a thermoset rubber or polymer, the outer layer 220 may be applied at a temperature below a temperature of curing or curing the thermoset rubber or polymer. In such an embodiment, outer layer 220 may include a deactivated foaming agent and an uncured or partially cured rubber or thermoset polymer which may be subsequently activated and cured, respectively, with heat or other suitable activation or curing process.
    [0042] The weight percentage of foaming agent in the outer layer 220 when initially applied to the elongated core 210 can be selected based on the type of thermoplastic or other material used and the final shape, density, hardness, or other desired portion characteristics sound attenuator 221. In an exemplary embodiment, outer layer 220 has an initial composition of between 90% and 99.5% SEBS and between 10% and 0.5% of an appropriate deactivated foaming agent, or approximately 93. % SEBS and 7% of a deactivated expandable sphere foaming agent such as EXPANCEL 930 DU 120, EXPANCEL 920 DU 120, both available from Eka Chemicals AB of Sundsvall, Sweden. In other exemplary embodiments, outer layer 220 has an initial composition that includes a deactivated chemical foaming agent such as oxybis benzene sulfonyl hydrazide (OBSH) available from Biddle Sawyer Corp. of New York, New York. The presence of a chemical foaming agent such as an OBSH foaming agent can produce a sound dampening portion that has a lower hardness value than a sound dampening portion formed from an outer layer that includes a foaming agent. expandable sphere foam such as EXPANCEL as the only foaming agent. In an exemplary embodiment, outer layer 220 includes a deactivated expandable ball foaming agent and a deactivated chemical foaming agent. The presence of both an expandable sphere foaming agent and a chemical foaming agent can assist in providing sufficient structure so that the outer layer can be properly formed and that it may not be present with a chemical foaming agent alone, by reducing the hardness of the outer layer to a level that would otherwise result if only an expandable sphere foaming agent were used. Consequently, the combination of a chemical foaming agent and an expandable sphere foaming agent can result in an outer layer that has a level of hardness suitable for a desired application, such as for insertion into an ear canal. In an exemplary embodiment, outer layer 220 when initially applied may include between approximately 0.5% by weight and 3% by weight of a deactivated chemical foaming agent, or approximately 2% by weight of a chemical foaming agent , and between approximately 0.5% by weight and 9.5% by weight of a deactivated swellable ball foaming agent, or approximately 2% by weight of a deactivated swellable sphere foaming agent. Outer layer 220 may also include other suitable foaming agents, or various combinations of foaming agents from EXPANCEL, foaming agents from OBSH, and other suitable foaming agents. Outer layer 220 may additionally include pigment to impart a desired color, antioxidants, UV stabilizers, and oils or waxes to aid in extrusion and mold release as known in the art.
    [0043] In some exemplary embodiments, outer layer 220 is in a molten state when covered over elongated core 210. As a result, molecules of outer layer 220 and elongated core 210, or one or more intermediate layers, are believed to , diffuse into each other's material or surface and a thermal bond is formed. when materials or surfaces cool and solidify, outer layer 220 remains thermally bonded, directly or indirectly, to elongated core 210. In an exemplary embodiment, significant chemical bonding is absent so that the primary source of bonding between elongated core 210 and outer layer 220 is thermal bonding. In other exemplary embodiments, outer layer 220 contacts elongated core 210 or one or more intermediate layers when covered over elongated core 210 but no significant bond is formed between outer layer 220 and elongated core 210 or one or more layers. intermediate. Upon activation and/or curing of outer layer 220, a thermal bond can be formed, directly or indirectly, between outer layer 220 and elongated core 210.
    [0044] In other exemplary embodiments, the elongated core 210 may be covered with the outer layer 220, or one or more intermediate layers, by means of lamination, molding, spraying, dipping, or other suitable process as known in the art as an alternative or in addition to second die 250. Such steps may occur before or after elongated core 210 is cut to a desired length. Regardless of the process used, the temperature of the outer layer 220 must remain below the activation temperature of the foaming agent(s) so that the foaming agent(s) remains deactivated during the coating process. In the event that an uncured or partially cured material is included in the outer layer 220, such as an EPDM rubber or thermoset polymer, the temperature of the outer layer 220 must remain below the material's curing temperature.
    [0045] In an exemplary embodiment, elongated core 210 covered by outer layer 220 is cut to the length of a desired earplug with cutter 260. The result is preform 230 which has elongated core 210 and outer layer 220 at the which outer layer 220 includes a deactivated foaming agent which can be subsequently activated to create an earplug having a sound attenuating portion 221 and a stem portion 222.
    The cutter 260 can cut the preform 230 to a desired length of the earmuffs 200, or to an extended length sufficient for subsequent formation of many earmuffs. In an exemplary embodiment, the preform 230 is cut to an extended length which can be subsequently cut and activated, or vice versa, to produce a desired quantity of earmuffs 200. An extended preform 230 may be spirally wound. or otherwise shaped for ease of handling or transportation.
    [0047] In an exemplary embodiment, the deactivated foaming agent present in outer layer 220 includes thermoplastic spheres that encapsulate a hydrocarbon or other expandable material. Applying an appropriate amount of heat causes the thermoplastic housing and hydrocarbon to expand. In other exemplary embodiments, the foaming agent includes, alone or in combination with an expandable sphere foaming agent, an expandable material which is a single piece or otherwise unencapsulated, and which produces gas when exposed to heat or another source of activation. If left uncontained, activation of the foaming agent(s) creates cells in the outer layer 220, ultimately increasing the volume and decreasing the density of the outer layer 220. The expansion of outer layer 220 can be controlled by the thickness and composition of the outer layer 220, selectively applying heat, catalyst, or other source of activation, and/or placing at least a portion of preform 230 in a mold to limit expansion of outer layer 220 as the foaming agent is activated.
    [0048] In the exemplary method shown in Figures 6A and 6B, mold 270 is used to control the expansion of outer layer 220. Mold 270 includes a first cavity 271 in the form of a rod portion that receives a preform portion 230 Preform 230 can be cut to the length of a desired earmuff 200 before being placed in mold 270. Alternatively, preform 230 can be of an extended length and can be cut to length after being inserted into mold 270. Cutting the preform 230 after insertion into the mold 270 can facilitate handling and insertion. Heat is applied to the exposed portion of preform 230 to raise the temperature of outer layer 220 to at least an activation temperature of a foaming agent present in outer layer 220 and cause outer layer 220 to expand as shown in Figure 6B. The portion of the earmuff 200 positioned in the first cavity 271 can be effectively protected against heat so that the activation of the foaming agent is limited. Alternatively or additionally, first cavity 271 constrains outer layer 220 and substantially inhibits the expansion caused by activation of the foaming agent which would otherwise result in a larger volume and less dense outer layer. The elongated core 210 and outer layer 220 are subsequently cooled and extruded from the mold 270. The finished earplug 200 includes a sound attenuating portion 221 formed by the exposed outer layer that could expand freely and a stem portion 222 that has been partially restrained in mold 270 during activation of the foaming agent. Due to mold restriction and/or limited foaming agent activation, stem portion 222 may have a higher average density and/or greater hardness than sound dampening portion 221.
    [0049] In the exemplary embodiment of Figures 7A and 7B, mold 370 is used to control expansion of outer layer 320 of preform 330. Mold 370 includes a first cavity 371 in the form of a stem portion that receives a portion of preform 330. Mold 370 additionally includes a second cavity 372 in the form of a sound dampening portion. When preform 330 is initially placed in mold 370, a gap 375 exists between preform 330 and a perimeter of second cavity 372. In some embodiments, a small gap 376 may exist between preform 330 and a perimeter. of first cavity 371. Upon application of heat or other suitable activation source, a portion of outer layer 320 expands to fill gap 375 and substantially conforms to the shape of second cavity 372. The portion of earmuff 300 positioned in the first cavity 371 can be effectively protected from heat so that the activation of the foaming agent is limited. Alternatively or additionally, expansion of the outer layer 220 that would otherwise occur during activation of the foaming agent is restricted by the first cavity 371. In addition, as the application of heat it softens the outer layer 320 and the foaming agent. foam is activated, outer layer 320 may expand to fill first cavity 371 and a portion of outer layer 320 initially in first cavity 371 may flow to second cavity 372 to fill gap 375. In an exemplary embodiment, mold 370 includes small gas flows to allow excess gas to escape thus preventing the passage of any molten material.
    [0050] In an exemplary embodiment, mold 370 is oriented such that first cavity 371 is oriented above second cavity 372 during a portion or the entire activation process. Such an orientation can allow material to flow from the first cavity 371 to the second cavity 372 during activation. Furthermore, an orientation in which the first cavity 371 is oriented above the second cavity 372 may facilitate the formation of an integral skin in the sound attenuating portion 321 due to the fact that cells or gaps formed during activation of the foaming agent may tend to move up and away from a lower surface of cavity 372.
    The earplug 300 is subsequently cooled and extruded from the mold 370. The finished earplug 300 includes a sound attenuating portion 321 that is shaped like the second cavity 372 of mold 370, and a stem portion 322 that has the shape of the first cavity 371 of the mold 370. Due to the restriction of the first cavity 371 and/or limited activation of the foaming agent in the area of the first cavity 371, the stem portion 322 may have a medium density and/or greater hardness than than the sound attenuating portion 321.
    [0052] In the exemplary embodiment shown in Figures 7A and 7B, the earplug 300 is formed from preform 330 which has an overall length l in a longitudinal direction between approximately 15 mm and 40 mm, or of about 25.5 mm. mm. The outer layer 320 has an outer diameter d1 between approximately 2.5 mm and 6.5 mm, or about 4.5 mm, the elongated core 310 has an outer diameter d3 between approximately 1.5 mm and 3.5 mm. , or about 2.5 mm, and channel 315 has a diameter d4 between approximately 1.0 mm and 2.0 mm or approximately 1.5 mm. After activation of the outer layer 320 described above, as shown in Figure 7B, the final earmuff 300 has an overall length L in a longitudinal direction between approximately 15 mm and 40 mm, or approximately 25.5 mm, attenuating portion of sound 321 has an outside diameter D1 at its widest point between approximately 8 mm and 16 mm, or approximately 12.5 mm, stem portion 322 has a diameter D2 between approximately 3 mm and 10 mm, or approximately 6.5 mm, elongated core 310 has an outer diameter D3 between approximately 1.5 mm and 3.5 mm, or approximately 2.5 mm, and channel 115 has a diameter D4 between approximately 1.0 mm and 2.0 mm, or approximately 1.5 mm. The dimensions of preform 330 and finished earmuff 300 can be varied based on outer layer 320 and elongated core 310 materials, and as required to form a final earmuff 300 that has the desired characteristics for an application. particular.
    [0053] Figure 8 shows another exemplary method of producing an ear protector according to the present invention. The method includes a step of activating a foaming agent in outer layer 420 before cutting elongated core 410 and outer layer 420 to a desired length. Similar to the method described above with reference to Figure 5, a first material is extruded through the first die 440 and extracted to an appropriate diameter. The uncut extruded elongated core 410 is cooled and covered, directly or indirectly, with outer layer 420. In an exemplary embodiment, the elongated core 410 is covered with outer layer 420 by a second die 450. Alternatively, the elongated core 410 may be covered with outer layer 420 by laminating, molding, spraying, dipping or any other suitable process known in the art.
    [0054] The elongated core 410 and outer layer 420 can be subsequently cooled. Portions of uncut elongated core 410 and outer layer 420 are then positioned in mold 470 by, for example, joining two halves of mold 470 in uncut elongated core 410 and outer layer 420. With the mold properly positioned relative to the uncut elongated core 410 and outer layer 420, the foaming agent is activated by heat or another source of activation to cause outer layer 420 to expand. In embodiments in which outer layer 420 includes an uncured or partially cured material, the application of heat or other source of activation also causes outer layer 420 to cure. In an exemplary embodiment, mold 470 includes a first cavity 471 in the form of a stem portion and a second cavity 472 in the form of a sound dampening portion. upon application of heat or other suitable activation source, a portion of outer layer 420 expands to fill second cavity 472 and substantially conform to the shape of second cavity 472. The portion of earmuff 400 positioned in first cavity 471 can be effectively protected from heat so that activation of the foaming agent is limited. Alternatively or additionally, expansion of the outer layer 420 that would otherwise occur during activation of the foaming agent is substantially restricted by the first cavity 471. Furthermore, as the application of heat it softens the outer layer 420 and the foaming agent of foam is activated, a portion of the outer layer 420 initially in first cavity 471 may flow into second cavity 472. In an exemplary embodiment, mold 470 includes small gas flows to allow excess gas to escape while preventing the passage of any cast material.
    [0055] Elongated core 410 and activated outer layer 420 are then cooled, removed from mold 470, and cut to a desired length with cutter 460 to result in finished earplug 400. Finished earplug 400 includes a portion sound attenuator 421 which is shaped like the second cavity 472, and a stem portion 422. Due to the restriction of the first cavity 471 and/or the limited activation of the foaming agent in the area of the first cavity 471, the stem portion 422 it may have an average density and/or hardness greater than that of the sound attenuating portion 421.
    [0056] In another exemplary embodiment, only a portion of the uncut elongated core 410 and outer layer 420 are positioned in a mold cavity. The mold cavity may be in the form of a rod such that expansion of an outer layer portion 420 is substantially restricted to form rod portion 422, while the remaining portion of outer layer 420 may freely expand to form the attenuator portion of sound 421. Alternatively, the mold cavity may be in the form of a sound dampening portion such that expansion of an outer layer portion 420 is restricted and selectively activated to form sound dampening portion 421, while the remaining portion of the outer layer 420 is not activated, or is only partially activated, and forms the stem portion 422.
    [0057] An ear protector according to the present invention can also be produced according to variations of methods described herein and other methods. For example, an exemplary earplug can be produced by covering a relatively stiffer elongated core with an outer layer as a foaming agent is activated, or by covering a relatively stiffer elongated core with an outer layer that has previously been foamed. . The foamed outer layer can be subsequently cut, compressed, densified, or otherwise shaped to form an outer layer having a stem portion and a sound dampening portion.
    [0058] An earmuff and a method of producing an earmuff described in this document provide several benefits. The earmuffs described herein can be comfortably positioned in a wearer's ear canal to provide a desired level of hearing protection, and the presence of a stiffer elongated core promotes hygiene by eliminating the need to roll down an attenuator portion. of sound before insertion. The method described in this document allows an ear protector to be efficiently manufactured. A earplug that has an outer layer bonded, directly or indirectly, to an elongated core as described herein eliminates the cost and complexity of an additional step of joining a rigid component to a sound attenuating component required of many earplugs of the previous insert type. The elongated core and outer layer can be thermally bonded without the need for an additional adhesive or additional assembly step.
    [0059] The present invention has been described with reference to its various embodiments. The detailed description and examples given above are provided for clarity only. No unnecessary limitations should be implied from this. It will be apparent to those skilled in the art that many changes can be made in the described embodiments without departing from the scope of the invention. Thus, the scope of the present invention is not to be limited to the exact details and structures described herein, but rather by the structures described by the language of the claims and equivalents of those structures. Any feature or feature described with respect to any of the above embodiments may be incorporated individually or in combination with any other feature or feature and have been presented in the order and combinations above for clarity.
    权利要求:
    Claims (7)
    [0001]
    1. Ear protector (100, 200, 300) comprising: an elongated core (110, 210, 310) comprising a first material and having first and second ends (111, 112) and an outer main surface (113) ; and an outer layer (120, 220, 320, 420) comprising a second material and covering at least a portion of the outer main surface (113) of the elongated core (110, 210, 310); wherein the second material comprises expandable spheres that include thermoplastic housings that encapsulate a gas and the outer layer (120, 220, 320, 420) comprises a sound attenuating portion (121, 221, 321, 421), CHARACTERIZED by the fact that the sound attenuating portion having a first mean density p1 and a stem portion (122, 222, 322, 422) having a second mean density p2, and |p2 > 1.2 p11, and wherein still the second material of the stem portion (122, 222, 322, 422) comprises the expandable spheres that include the thermoplastic housings that encapsulate the gas.
    [0002]
    2. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that |p2 > 1.5 p1|.
    [0003]
    3. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that p1 is between 100 kg/m3 and 180 kg/m3.
    [0004]
    4. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that the second material comprises styrene-ethylene-butylene-styrene (SEBS).
    [0005]
    5. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that the outer layer (120, 220, 320, 420) is thermally bonded to at least a portion of the main outer surface ( 113) of the elongated core (110, 210, 310).
    [0006]
    6. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that the second material comprises a thermoset polymer.
    [0007]
    7. Ear protector (100, 200, 300), according to claim 1, CHARACTERIZED by the fact that the second material comprises an EPDM rubber.
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    同族专利:
    公开号 | 公开日
    EP2872084A1|2015-05-20|
    RU2015102519A|2016-08-27|
    BR112015000590A2|2017-06-27|
    JP6352257B2|2018-07-04|
    US10966867B2|2021-04-06|
    TR201909442T4|2019-07-22|
    US20140014121A1|2014-01-16|
    CN104470474A|2015-03-25|
    EP3517084A1|2019-07-31|
    RU2662889C1|2018-07-31|
    CN104470474B|2017-11-21|
    KR20150031332A|2015-03-23|
    AU2013290178A1|2015-02-05|
    JP2015527118A|2015-09-17|
    IL236623A|2019-11-28|
    IL236623D0|2015-02-26|
    US20170360615A1|2017-12-21|
    PL2872084T3|2019-09-30|
    RU2619996C2|2017-05-22|
    US9737439B2|2017-08-22|
    EP2872084B1|2019-04-17|
    KR102171662B1|2020-10-29|
    US10441471B2|2019-10-15|
    US20170181893A1|2017-06-29|
    AU2013290178B2|2016-08-04|
    WO2014011824A1|2014-01-16|
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    法律状态:
    2018-12-04| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-11-19| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-01-05| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2021-03-23| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-05-18| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 11/07/2013, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US13/547,177|US9737439B2|2012-07-12|2012-07-12|Push-in earplug|
    US13/547,177|2012-07-12|
    PCT/US2013/049994|WO2014011824A1|2012-07-12|2013-07-11|Push-in earplug|
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