MXPA97008067A - Eye protector with elastomeric covering does not perme - Google Patents

Abstract

The present invention relates to an ear foam plug to be received, at least partially, within an auditory channel, characterized in that it includes: a body portion formed of a plastic, elastic foam material having a structure of open multiple cells and having the size and shape for at least partial reception, within the ear canal, and a thin, external covering of a non-permeable elastomeric material different from the material that forms body portion and with the coating that forms a layer attached to the body portion, not permeable to air, at least in the area of body portion that is received within the ear canal to provide an increase in sound attenuation, compared to the attenuation of sound produced by the material plastic foam, elastic without thin coating of elastomeric material not impermea

Description

EAR PROTECTOR WITH NON-PERMEABLE ELASTOMERIC COVERING BACKGROUND OF THE INVENTION The present invention relates to a foam ear protector and more specifically to a foam ear protector with a non-permeable elastomeric coating. In the prior art, ear foam protectors have been manufactured from a slow recovery resilient foam material and such foam, slow recovery ear protectors have gained widespread acceptance. As an example, an ear protector, as shown and described in US Patent No. RE29 87, is used by compressing the ear protector to a small diameter and then inserting the ear protector compressed to the ear. The ear protector is then allowed to expand for a period of time, generally within a few seconds to as much as about one minute, to fill a substantial portion of the user's ear canal. Slow-recovery ear protectors can be made by a variety of techniques. One manufacturing method is to cut the cylindrical ear protectors of a sheet of slow recovery material. A second manufacturing method is to mold the earplugs into a cavity mold open or closed in a desired manner. As an example, a molded ear plug is shown in U.S. Patent No. 4,774,938. This patent also demonstrates that a molded ear protector will normally have smaller cells on the surface of the ear protector, since the molding process would tend REF: 25910 to compnmir the cells on the surface. Whether the ear protector is formed by cutting a blade or by molding it inside a cavity, the outer surface is porous and allows air to escape. In the prior art, there are also ear protectors that have been designed, which use a combination of an outer covering or bag and some kind of sound absorbing material, such as a cellular or fibrous material held within the cover or bag. . Examples of ear protectors having a relatively thick outer covering are shown in U.S. Patent Nos. 4,461, 290, 2,441,866 and 2,672,863. Examples of ear protectors having an outer cover are shown in U.S. Patent Nos. 4,160,449, 3,771,521 and 4,498,469. Some of these patents have the internal material that absorbs the sound formed by a foam or alveolar material and some by a fibrous material, but in both cases the outer bag or cover is formed as a separate element and does not have the characteristics of having a surface or tight intimate coating over the surface of the foam ear protector.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a foam ear protector, which has an elastomeric non-permeable outer coating adhered. The ear protector is formed by a body portion of foamed plastic material or resilient foam, having a multiple open cell structure and having a size and shape to be received at least partially within the wearer's ear canal. An external coating of a non-permeable elastomeric matepal forms a surface adhering to the body portion, which is not permeable to air at least in the area of the body portion that is received in the user's ear canal. This structure of a non-permeable elastomeric coating adhering to the outer surface of the foam ear protector provides a surprising increase in sound attenuation compared to the attenuation of sound produced by the same ear protector, constructed from the same plastic material as Resilient foam, without the thin adhesion coating of non-permeable elastomeric material. As a first method for manufacturing the ear protectors of the present invention, a mold is provided which has at least one, but usually a multitude of cavities, for the molding of the individual ear protectors Before the insertion of the foamable plastic material (which can be formed into foam), each cavity it is coated with the thin coating of the non-permeable elastomeric material. Then the plastic material in the form of foam is inserted into the coated cavities and after they are completely formed into foam the earplugs are removed and have the thin coating of the non-permeable matepal permanently attached to the alveolar ear protector. As indicated earlier, this structure provides a very beneficial result by increasing sound attenuation. A second method for producing the ear protector would be to mold the ear protectors in the cavities or cut them from a sheet in the normal way. Then the individual ear protectors could be sprayed or immersed into the coating of the non-permeable elastomeric material to adhere to the surface of the ear protector. The ear protector itself can be made of different types of foams and with a mode that uses a slow recovery foam. In this way, the ear protector can be compressed for insertion into the ear and then as the slow recovery ear protector regains its original shape, fills the ear canal and the non-permeable elastomeric coating is now in contact with the ear canal. the surface of the auditory canal. When such a slow recovery foam is used, the coating would not normally cover the back end of the hearing protector, so that air can escape out of a shield when compressed before insertion. Then the air can re-enter the protector through the trailing end as the slow recovery foam recovers. If the ear protector is a push type that does not have to be compressed before use, then the overlay would cover the entire ear protector, including the back end. The non-permeable elastomeric coating could be manufactured from a variety of elastomeric materials in which urethane, latex, etc. are included. A specific material which provides the non-permeable elastomeric coating is referred to as an "aliphatic urethane lacquer" and has a solvent base of toluene and the following physical properties: Solids by weight 7-10% Solids by volume 5-8% Tensile strength 387 Kg / cm2 (5,500 psi) Tear strength 500 PLI Elongation 350% Viscosity, Zahn # 2 14 -17 s Flammability temperature 0 5 - 2 8 ° C (33 - 37 ° F) This matepal can be used as either a pre-cast coating or a supepor coating by spraying and is generally used to produce a protective coating on the cellular materials. The suggested normal uses are in the automotpz field, the field of exercise equipment, in the field of office furniture and toys or sporting goods. The coating of the prior art is generally thick enough to provide a protective surface that can be cleaned and would not normally be used as a very thin coating as present with the ear protector of the present invention. It should also be appreciated that the foam ear protector of the present invention can take a variety of forms in which ear protectors are commonly included and inserted into the ear, as well as semi-audible devices. These are normally two ear protectors that are placed on the opposite ends of a band or headband which is constructed of plastic or metal. The band or headband retains the ear protectors under tension partially within the ear canal, although not as deep as a normai ear protector. Ear protectors would normally have the highest noise reduction rating and semi-audible headband devices would normally have a lower noise reduction rating. In any case, the use of the non-permeable elastomer coating produces a significant improvement by increasing the attenuation, to have a higher noise reduction rating, compared to similar devices without the coating. Although the exact reason for this increase in attenuation is not known, there seems to be a coordinated effect between the benefits of the alveolar material and the benefits of the thin non-permeable coating of elastomeric material. Several explanations have been postulated as to why the increase in attenuation occurs. These explanations include (1) the sound that travels through the open cell structure of the alveolar ear protector, which is not absorbed within the ear protector, is blocked by the non-permeable coating, (2) the sound that could leak through the open cell structure in contact with the ear canal is blocked by a more intimate contact of the non-permeable covering with the surface of the ear canal and (3) the sound passing through the ear protector It is blocked by the difference of materials that form a barrier layer where the coating and the foam ear protector come together. In any case, the increase in attenuation is significant and can fluctuate (depending on frequency) between 1 to 4 or more decibels higher than the attenuation level for devices without the coating. A clearer understanding of the invention will be had with reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an illustration of a foam ear protector of the prior art; Figure 2 is an illustration of a coated foam ear protector according to the present invention; Figure 3 is a cross-sectional view of the ear protector taken along lines 3-3 of Figure 2; Figure 4 is an illustration of a type of semiaudible headband of the hearing protector that uses the ear protector according to the present invention; Figure 5 is a cross-sectional view of the ear protectors, taken along lines 5-5 of Figure 4; Figure 6 is an illustration of a method for producing the ear protector of the present invention, which includes the use of a pre-cast coating; Figure 7 is an illustration of a first step of a method for manufacturing an ear protector of the present invention, which uses a top coating by spraying; and Figure 8 is an illustration of a step to provide a topcoat by spraying, which either completes the method of Figure 7 or can provide an additional step for the method of Figure 6. Figure 1 illustrates a shield for the ears 10 of the prior art, normally molded from a slow recovery foam material. As can be seen, the ear protector has a main body 12 of bullet shape, with a widened outer end 14. This type of ear protector would have the cells on the external surface of the normally smaller ear protector on the outer surface and with larger cells in the center of the ear protector. In this type of molded foam ear protector, since the surface of the ear protector has smaller cells, a more uniform configuration is generally formed on the outer cell surface than if the ear protector were formed at the same time. Cut the ear protector from a flat sheet. Although the ear protector 10 may have smaller cells on the outer surface, the molded ear protectors are all porous on the outer surface, although air may pass through the outer surface of the ear protector a little more. Slowly make it through the larger cells in the center of the hearing protector. A first embodiment of the present invention is illustrated in Figures 2 and 3. The present invention has an ear protector 100 which has an inner body 102 and an outer bonded surface 104. The ear protector 100 generally has the same shape as the prior art ear protector, having a bullet-shaped main body portion with a rear end enlarged. The internal body 102 can be constructed of the slow recovery foam or other types of resilient foams and the outer coating can be formed from a variety of non-permeable elastomeric materials in which urethane, latex, etc. are included. As indicated above, a suitable material is described as an aliphatic urethane lacquer and has the following physical properties: Solids by weight 7 - 10% Solids by volume 5 - 8% Tensile strength 387 Kg / cm2 (5,500 psi) Strength to tear 500 PLI Elongation 350% Viscosity, Zahn # 2 14 -17 s Flammability temperature 0.5 - 2.8 ° C (33 - 37 ° F) Other suitable non-permeable elastomeric coatings can also be used. The coating forms a thin surface which is intimately bonded to the foam ear shield itself and generally has a thickness between 0.00254 mm to 0.889 mm (0.1 to 35 mils). A preferred thickness would normally be 0.076 mm to 0.1016 mm (3 to 4 mils). When producing ear protectors with non-permeable elastomeric coating as shown in Figures 2 and 3, it has been shown that an increase of 1 to 4 or more decibels (depending on the frequency) in attenuation on the same ear protector composed only of foam material. This increase is significant considering the thin nature of the coating of the non-permeable elastomeric material. As indicated above, the exact reason for this increase in attenuation is unclear, but a number of possible explanations have been described above. Again, it is believed that there is some coordinated effect between the benefits of the foam material and the benefits of the thin non-permeable bonded layer of the elastomeric material. In addition to the form of the invention shown in Figures 2 and 3, it is also possible to have the ear protectors, such as the ear protectors 200, located at the ends of a headband 202 as shown in Figure 4 This type of device provides that the ear protectors 200 are partially inserted into the ear canal and are retained in the ear canal by the tension of the band 202. The band 202 can be constructed of either plastic or metal. As can be seen, the ear protectors 200 generally have a smaller insertable end 204 and a larger posterior portion 206 which would normally seal around the outside of the opening to the ear canal. Figure 5 is a cross-sectional view of one of the ear protectors, taken along lines 5-5 of Figure 4 and as can be seen, the ear protector is made of an inner honeycomb material 206 with an adhered outer coating of a non-permeable elastomeric material 208. Again, the elastomeric material can be any type of non-permeable material, such as urethane, latex, etc. and it may be the material described above as an aliphatic urethane lacquer. The production of the ear protector of the present invention can be done by the methods described with reference to figures 6 to 8. In figure 6, a mold member 300 is shown with multiple cavities 302, each having the shape of an earplug or ear protector, shown in Figures 2 or 4. When using the ear protector shown in Figure 2 as an example, the cavity would have a general bullet shape with a widened outer end. Then the mold 300 of the cavity is moved as shown by the arrow 304 and with a first spraying element 306 a pre-casting coating of a non-permeable elastomeric material 308 is applied to the interior of each cavity 302. The spray head 306 it can be actuated intermittently to ensure that each cavity is coated with the material 308 and without providing excess material to the exterior of the mold 300. After each cavity 302 is coated with the non-permeable elastomeric material 308, a nozzle 312 injector fills each cavity with 314 foamable plastic material to form the main body of the ear protector. Then, after the foamable plastic material is completely formed into foam, the ear protectors can be removed in the normal manner to produce the ear protector shown in Figure 2. If it is desired to have the ends of the protectors for the ears also coated with the non-permeable elastomeric coating, then the ends can be coated in a second stage. This can be accomplished by using the spray nozzle 306 before the ear protectors are removed from the cavity or after the ear protectors are separated from the cavities, as shown in Figure 8. In a second production method shown in Figure 7, the same molds 300 of cavities having the plurality of cavities 302 are used with the injection or nozzle 302 that supplies the foamable plastic material 314 to the interior of the cavities. After the foamable plastic material has been completely formed in foam, the ear protectors 318 can be removed and then placed on a conveyor belt 316 shown in Figure 8. Then the individual ear protectors 318 are sprayed with the spray head 306 with the non-permeable elastomeric material 308 to surface coat the 318 ear protectors with the coating.

Accordingly, the resulting ear protector has a body portion formed of resilient foam plastic material and a thin inner coating of a non-permeable elastomeric material to form the bonded surface on the body portion and with the combination having a attenuation greater than the attenuation of an ear protector formed only of molded resilient honeycomb plastic material. The coating thickness of the non-permeable elastomeric material can have a thickness in the range of 0.0025 mm to 0.899 mm (0.1 to 35 mils) and a preferred thickness of about 0.0762 mm to 0.1016 mm (3 to 4 mils). Although the invention has been described with reference to the particular embodiments, it will be appreciated that various modifications and adaptations can be made and the invention is only limited by the appended claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following

Claims (26)

1. Claims 1. An alveolar ear protector for receiving at least partially within the ear canal, characterized in that it includes: a body portion formed of resilient honeycomb plastic material having a multiple open cell structure and having a size and shape to be received at least partially within the ear canal, and a thin inner lining of a non-permeable elastomeric material and the liner forms a bonded surface on the body portion, not permeable to air, at least in the area of the ear portion. body received within the ear canal to provide an increase in sound attenuation compared to the attenuation of sound produced by the resilient alveolar plastic material without the thin coating of the non-waterproof elastomeric material.
2. 2. The hearing protector according to claim 1, characterized in that the resilient foamed plastic material is a slow recovery material and the surface, formed by the thin coating, does not cover the body portion in an area external to the portion of body received within the ear canal to allow air to escape when the ear protector is compressed for insertion into the ear canal and to subsequently recover when it is in the ear canal.
3. 3. The hearing protector according to claim 1, characterized in that the surface formed by the thin coating covers the entire body portion to prevent air from escaping when the ear protector is inserted into the ear canal.
4. 4. The hearing protector according to claim 1, characterized in that the body portion has a size and shape to be received substantially within the outer and inner portions of the ear canal.
5. 5. The hearing protector according to claim 1, characterized in that the body portion has a size and shape to be received only within an outer portion of the ear canal.
6. 6. The hearing protector according to claim 1, characterized in that the thin external coating of the non-permeable elastomeric material is a material defined as an aliphatic urethane lacquer.
7. 7. The hearing protector according to claim 1, characterized in that the thin external coating of the non-permeable elastomeric material has a thickness in the range of 0.00254 mm to 0.889 mm (0.1 to 35 thousandths of an inch).
8. 8. The hearing protector according to claim 1, characterized in that the thin outer coating of the non-permeable elastomeric material has a thickness of about 0.0762 mm to 0.1016 mm (3 to 4 mils).
9. 9. A method for manufacturing a foam ear protector having a thin surface of a non-permeable elastomeric material, characterized in that it includes the steps of: providing a mold having at least one cavity to form an ear plug having a size and shape to fit at least partially into an ear canal, providing a non-permeable elastomeric material, coating the interior of the cavity with the non-permeable elastomeric material, to form a thin surface on the inside of the cavity , providing a foamable plastic material, and placing the foamable plastic material within the coated cavity to foam the size and shape of the cavity to form a resilient honeycomb plastic ear protector, which has a thin surface adhered of non-permeable elastomeric material.
10. 10. The method according to claim 9, characterized in that the foamable plastic material consists of a foamable material, which has slow recovery.
11. 11. The method according to claim 9, characterized in that it includes the additional steps of removing the coated hearing protector from the cavity and covering any portion of the non-coated hearing protector by the non-permeable elastomeric material with additional non-permeable elastomeric material for form a protector for the ears that has all its external surface covered.
12. 12. The method according to claim 9, characterized p. or the cavity is provided with a size and shape to produce an ear protector that will be received substantially in the outer and inner portions of the ear canal.
13. 13. The method according to claim 9, characterized in that the cavity is provided with a size and shape to produce an ear protector to be received only within an outer portion of the ear canal.
14. 14. The method according to claim 9, characterized in that the non-permeable elastomeric material consists of a material defined as an aliphatic urethane lacquer.
15. 15. The method according to claim 9, characterized in that the coating of the non-permeable elastomeric material is at a thickness in the range of 0.00254 mm to 0.889 mm (0.1 to 35 thousandths of an inch).
16. 16. The method according to claim 9, characterized in that the coating of the non-permeable elastomeric material is at a thickness of about 0.0762 mm to 0.1016 mm (3 to 4 mils).
17. 17. The method according to claim 9, characterized in that the coating is applied by spraying.
18. 18. A method for manufacturing an alveolar ear protector, having a thin surface of a non-permeable elastomeric material, characterized in that it includes the following steps: providing a mold having at least one cavity to form an ear protector having an size and a shape to fit at least partially into an ear canal, provide a foamable plastic material, and place the foamable plastic material within the coated cavity to foam to the size and shape of the cavity to form an ear protector of resilient alveolar plastic, remove the ear protector from the cavity, provide a non-permeable elastomeric material, coat the ear protector with the non-permeable elastomeric material to adhere a thin surface on the outside of the elastomeric material ear protector not permeable.
19. 19. The method according to claim 18, characterized in that the foamable plastic material consists of a slow recovery foamable material.
20. 20. The method according to claim 18, characterized in that it includes the additional steps of covering the ear protector with a non-permeable elastomeric material to form an ear protector having its entire external surface coated.
21. 21. The method according to claim 18, characterized in that the cavity is provided with a size and shape to produce an ear protector to be received substantially inside the outer and outer portions of the ear canal.
22. 22. The method according to claim 18, characterized in that the cavity is provided with a size and shape to produce an ear protector to be received only within an outer portion of the ear canal.
23. 23. The method according to claim 18, characterized in that the non-permeable elastomeric material consists of a material defined as an aliphatic urethane lacquer.
24. 24. The method according to claim 18, characterized in that the coating of the non-permeable elastomeric material is at a thickness in the range of 0.00254 mm to 0.889 mm (0.1 to 35 thousandths of an inch).
25. 25. The method according to claim 18, characterized in that the coating of the non-permeable elastomeric material is at a thickness of about 0.0762 mm to 0.1016 mm (3 to 4 mils).
26. 26. The method according to claim 18, characterized in that the coating is applied by spraying.