CH639265A5 - EAR PROTECTOR. - Google Patents

Description

The present invention generally relates to ear protection devices and, more particularly, it relates to an ear protector comprising an elastic headband having, fixed at its ends, a pair of organs in contact with the ear canal.

Ear protectors of the type comprising an elastic band headband of general U-shape having, fixed at its ends, a pair of organs directed inwards, in contact with the ear canal, are known per se. Compared to ear protectors of the ear cover type, such protectors generally have the advantages of being lighter and less bulky. However, they are often significantly less effective, when it comes to their essential purposes, reducing or attenuating noise, than ear cover type protectors.

Consequently, a main object of the present invention is to provide ear protectors of the type comprising an elastic headband band of general U-shape and members for contact with the ear canal fixed on the ends of the headband band which are significantly more effective in attenuating or reducing noise than similar protectors of the prior art.

Another object of the present invention is to provide ear protectors of the above-mentioned type which are comfortable to wear while having excellent noise dampening properties.

Another object of the present invention is to provide ear protectors of the aforementioned type having the qualities of being small, light and comfortable to wear while having excellent damping or noise reduction properties.

Another object of the present invention is to provide ear protectors of the aforementioned type in which the organs for contact with the ear canal adapt themselves to the ear canals of users.

Fig. 1 is a schematic front view, partially in dashes, of an ear protector according to the invention.

Fig. 2 is a schematic view in longitudinal section of an ear closure lug 20 of FIG. 1.

Fig. 3 is a schematic view in longitudinal section of another embodiment of the ear closure lug 20 of FIG. 1.

With reference to fig. 1 and 2, where the same reference numbers refer to identical structures, the ear protector of the invention generally comprises an elastic band U-shaped headband 1 having a tip (or thimble) obturation of the ear canal 20, directed inwards, fixed to each of the opposite ends 3 and 5 of the elastic band. The end caps for the ear canal 20 are fixed to said end portions 3 and 5 in an articulated manner so that the end pieces are free to pivot horizontally and vertically. Each of the end pieces (or lugs) 20 comprises a hollow capsular element,

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soft, smooth and deformable 22, of dimensions and shapes adapted to be partially introduced into the ear canal. Thanks to this combination of characteristics, the tips 20, under the influence of the elastic band headband, are partially pushed into the ear canals and establish sealing relationships therewith. Due to the articulated fixing of the tips 20 on the ends 3 and 5 of the headband, the tips 20 are free to pivot and adapt to the natural angles of the user's ear canals, which allows them to find inherently a seat inside with maximum shutter effect, without the user needing to adjust them from the outside. This is an important advantage of the ear protector of the invention, since the case often arises where the ear canals of an individual are not precisely bilaterally symmetrical. In addition, it has been found that the ear protectors of the prior art often require significant adjustments on the part of the user, who must adjust the organs of contact with the ear canals so as to obtain a sealing effect. maximum; these adjustments are often poorly made or made lightly, or are neglected, which does not provide the user with the maximum ear protection allowed by the protector. With the hearing protector of the present invention, however, these adjustments, which can be of a minute nature, are made automatically.

The main roles of the headband in the general shape of U 1 are, of course, to serve as carriers for the end pieces for closing the ear canals 20 and to act as a pushing device for pushing said end pieces 20 in relation to obturation with the ear canals. Therefore, keeping these criteria in mind, the design, construction and materials used in the manufacture of said headband 1 are obviously subject to considerable variation. The headband 1 may consist of a metal spring and may have a construction in one piece or in several pieces. For example, two curved flat spring elements can be maintained in sliding relation, interposed, thus defining a U-shaped structure adjustable in length. However, in the interest of obtaining a light construction and in one piece, it is preferable that the headband 1 is made to the mold in an appropriate manner with a stiff, elastic, polymeric material, preferably thermoplastic, such as polyvinyl chloride, rigid polyvinyl chloride or a polyacetal resin. Thus, this construction makes it possible to obtain a light headband 1, of simple manufacture, which at the same time has a sufficient permanent bending coefficient to enable it to establish and maintain the end pieces 20 in engagement with the shutters. ear canals throughout the life of the protector.

It has been found that the pushing force exerted by the elastic headband 1 on the endpieces 20 under conditions of use is significant, insofar as said pushing force must be sufficient for an effective sealing of the resulting in the ear canals while, at the same time, it should not cause discomfort to the user. By virtue of the construction of the end piece 20, it has been found that this pushing force need not be large, which greatly contributes to the comfort of the user provided by the ear protector of the invention . We have discovered, for example, that an appropriate thrust of the end pieces 20 is obtained when the headband has a construction and a composition such that, when its opposite free ends (as defined by the spheres 7 and 9 of the construction in Fig. 1) are kept spaced from each other at a spacing of 14.35 cm, there is a recovery thrust force directed inwards from 50 to 300 g (0, 49 to 2.94 N), and preferably from 100 to 200 g (0.98 to 1.96 N). The correct measurement of this recovery thrust force can be carried out in an appropriate manner by maintaining one end of the headband 1 in a fixed position while its other end is pulled to the specified distance by means of a spring. calibrated. Likewise, this measurement can also be carried out in an appropriate manner by maintaining one end of the headband 1 in a fixed position, while its other end is suspended under said fixed end and is loaded in increments with weights known until the specified spacing distance of 14.35 cm is reached. The recovery thrust force can be controlled by appropriate sizing of the headband 1, selection of its construction material, or combination of the two.

The construction of the end pieces for closing the ear canals 20 is of great importance in the invention, since it is necessary for the end pieces to be of dimensions and shapes suitable for partial introduction into the ear canals and at least these parts to be introduced into the ears comprise a hollow, smooth, soft and deformable capsular element 22. In view of these requirements, the capsular element 22 is composed of a soft, smooth and deformable elastomer or plastomer material, such as chloride plasticized polyvinyl, silicone rubber, ethylene / vinyl acetate co-polymer, styrene / butadiene block copolymers, ethylenepropylene rubber, neopropene rubber, polyurethane rubber, natural rubber and others . The hardness of the construction material of the capsular element 22, determined at room temperature by the Shore A durometer method described in ANSI / ASTN D 2240-75, can be in the range from 10 to 80, preferably in the range between 20 and 50.

Preferably, the capsular element 22 has a conical shape. In fact, with a conical-shaped capsular element 22, the small diameter end of the element constitutes the free end of the obturator tip 20 to be introduced into the ear canal, while its large diameter end defines the external end of attachment to the end 3 or 5 of the headband 1. The introduced angle defined by the conical-shaped capsular element 22 can be of the order of 15 ° to 45 °, the preferred range being 20 ° to 30 °. The small end of the conical-shaped capsular member 22 may have a diameter of 0.3 to 1.02 cm (0.120 to 0.4 in.), And it will preferably be in the range of 0, 51 and 0.76 cm (0 ^ 2 and 0.3 in.).

The space 24 defined by the hollow capsular element 22 can be left empty or, preferably, can be filled with an elastic or deformable filling material 26. If said capsular element 22 is hermetically closed, said filling material 26 can consist of a fluid such as water, oil or air. Preferably, the filling material 26 will be a solid or semi-solid, elastic or deformable, such as a silicone sealant or grease, a wadding of polyester fibers, polyurethane foam, polyvinyl chloride foam and the like. . A particularly useful material as filling material 26 in the ear protection device of the invention is an externally plasticized polyvinyl chloride foam, the nature and the concentration of the plasticizer being such that they give the finished foam characteristics of low speed. recovery of its deformation and a low recovery pressure exerted under deformation conditions.

The thickness of the wall of the capsular element 22 is subject to considerable variation and is normally not critical with regard to the realization of the advantages of the invention insofar as the deformability of the capsular element 22 is preserved . In general, said thickness will be between 0.0013 and 0.076 cm (0.0005 and 0.03 in.), Preferably in a range between 0.025 and 0.051 cm (0.01 and 0.02 in.).

Another essential object of the invention is that the closure end pieces 20 of the ear canals are articulated on the ends 3 and 5 of the headband 1, so that said end pieces 20 can pivot freely, at the same time horizontally and vertically, under the influence of the recovery pushing force produced by the elastic band headband 1. In general, any articulated fixing device which gives as a result the freedom of pivoting movements of the endpieces 20 mentioned above is suitable for the construction of the invention, and many

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devices of this type are known to those skilled in the art. For example, the end pieces 20 can be fixed to the ends 3 and 5 of the headband 1 by means of springs, joints, universal joints and the like. Preferably, however, the fixing device used will be such that the resulting articulation of each of the end pieces 20 will allow its pivoting so that its free end can describe an orbital trajectory, in a plane which is approximately normal to the plane defined by the tight band. -head 1. A suitable device for polymer articulations comprises a short flexible tail or rod, made of a polymer material such as polypropylene or silicone rubber, having one end fixed to an end part 3 or 5 of the strip. headband 1 and the other end fixed to the closure end piece 20 of the ear canal. Another suitable articulated fixing device comprises a low calibration spiral spring having one end fixed to an end part 3 or 5 and the other end being fixed to said end piece 20.

The preferred articulated fastener will include a ball joint as described in an accompanying drawing. In this device, the end parts 3 and 5 of the headband 1 are provided with end spheres 7 and 9, respectively. Said spheres 7 and 9 can be separate and distinct elements from the structure of the headband 1, or can be formed integrally with the latter. The outer end of each capsular end piece (or lug) 22 receives inside a closure member 28 having a socket located in the center 30 of a diameter suitable for receiving the sphere 7 or 9. Preferably, the central point of the articulated attachment of the end piece 20 on the end part 3 or 5 of the headband 1 will be on or inside, rather than outside of, the outer end of the 'tip 20. If we stick to this characteristic point of design mentioned recently, the tendency of the tip 20 to fold in on itself under the push of the headband 1 is reduced to a minimum. In the embodiment of the invention illustrated in FIG. 2, the geometric center of the sleeve 30 - in other words, the central point of the articulated attachment - is located on the plane defined by the outer end of the capsular element 22, and is therefore located at inside the outer end of the end piece 20. The passage 32 leading to said socket 30 is internally chamfered so as to define a conical stop surface 34 which, when brought into contact with the surface of the end part 3 or 5 of the headband 1 by pivoting the end piece 20, limits and prevents said end piece 20 from having a wider movement. The building material used in the manufacture of the closure member 29 preferably has sufficient elasticity to allow reception of the sphere 7 or 9 in the sleeve 30 simply by pressing the sphere 7 or 9 inside. For this reason, the closure member 28 of the end piece 20 is preferably formed of an elastic polymer material which, for reasons of convenience and compatibility, can generally be of the same type as that used in the manufacture of the capsular element 22.

It should be noted that, while the term headband is used here in connection with the structure having the reference number 1, this term is not intended to limit the specific manner in which said structure is used. For example, while the ear protector of the invention can, of course, be worn with its headband 1 positioned directly on the user's head, it can be used substantially as advantageously when said headband 1 is worn behind the neck or under the user's chin. Indeed, in certain cases, such as when the user must also wear bulky equipment on the head, a respirator or eye protection, it may be necessary to wear said headband 1 either behind the neck or under the chin .

Another embodiment of the invention is illustrated in FIG. 3. The nozzle 20, the capsular element 22, the space 24, the filling material 26 and the closure member 28 are illustrated therein. The closure member 28 comprises a connection part 36 and an attachment or assembly part 38. The connection part 36 allows the mentioned articulated fixing. The assembly part 38 serves to attach the capsular element 22. The connection part 36 and the attachment part 38 are separated by the section 40 and by the space 42. The space 42 allows the use of a member more flexible closure that can be gripped and inserted more comfortably and, therefore, to have a more comfortable mouthpiece. The connection part 36 and the assembly part 38 move in contact with each other when a tip is grasped and introduced into an ear canal.

Next are several examples of non-restrictive illustrations.

Example 1:

The external elements of the two end pieces 20 of the type illustrated in FIG. 2 are made in compression molds using two-part heat treated silicone rubber (Silastic Q-3-9591, manufactured by Dow Corning Corp., Midland, Michigan). The polymerization in the mold is carried out at a temperature of approximately 177 ° C (350 ° F) for approximately 10 min. The Shore A hardness of the polymerized material, at room temperature, was around 60. The essential dimensions of these external elements are as follows:

Capsular element 22

Length 2.6 cm (1.028 in.)

Diameter of small end 0.64 cm (0.250 in.)

Large end diameter 1.47 cm (0.580 in.)

Wall thickness 0.04 cm (0.015 in.)

25 ° insertion angle

Closing device 28

Length 1.37 cm (0.541 in.)

Sleeve diameter 30 0.64 cm (0.250 in.)

Introduced angle of the conical stop surface 34 60 °

The spaces 24 of the capsular elements 22 were each filled with a cylindrical plug having, in the unstressed state, a diameter of approximately 1.37 cm (0.54 in.) And a length of approximately 1.8 cm ( 0.7 in.), Said stopper consisting of a plasticized foam material, essentially polyvinyl chloride with closed cells. The plug is introduced by rolling it first between the fingers, introducing it into the space 24 and, then, letting the plug expand. Next, the closing member 28 is cemented on the capsular element 22 by means of a silicone rubber cement polymerized at room temperature.

The generally U-shaped headband of this construction consists of rigid polyvinyl chloride and is formed by injection molding of the resin in the form illustrated in fig. 1. The diameter of the resulting molded structure is 0.48 cm (• Kic in.). The radius of curvature of the upper part of the headband 1 is 6.35 cm (2.5 in.), The length of each of these sections of right side arms is approximately 8.76 cm (3 , 45 in.), And the end parts 3 and 5 are each folded inwards to form an angle of about 85 ° with respect to the corresponding right side arm section. The total length of the headband 1 is 16 cm (10.3 in.). The opposite ends of the headband formed are molded into integral spheres 7 and 9 each having a diameter of 0.64 cm (0.250 in.). Since the headband 1 is in the unstressed state, the free space between the spheres 7 and 9 is approximately 5.7 cm (2.25 in.). When the spheres 7 and 9 of this headband are separated up to a distance of 14.35 cm, the recovery thrust force produced has been found to be approximately 180 g (1.7 N).

The hearing protector of this example was then assembled by manually placing each of the spheres 7 and 9 in a socket 30 of one or the other of the end pieces.

The results of the test carried out using this construction of ear protectors are reported in Example 4.

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Example 2:

The elements 22 and 28 of the two end pieces 20 having essentially the same shapes and dimensions as those described in Example 1 are produced by compression molding of a plastic-polyvinyl chloride composition comprising the following ingredients:

Ingredient Parts by weight

PVC resin (inherent viscosity of 1.11). . . 100

Plasticizer 9775A®1 65

Di-n-octyl azalate 25

Calcium-zinc stabilizer (CZ-10) 2 2

Fluid silicone (Dow 200) 3 0.5

Epoxidized soybean oil (G-62) 4 12

1 Manufactured by Emery Industries, Inc., Cincinnati, Ohio.

2 Manufactured by Interstab Chemicals, Inc., New Brunswick, New Jersey.

3 Manufactured by Dow Corning Corp., Midland, Michigan.

♦ Manufactured by Rohm & Haas, Philadelphia, Pennsylvania.

The Shore A hardness value of the material produced was about 50. The spaces 24 of the capsular elements 22 were all filled with a plug of polyvinyl chloride foam of a type similar to that used in Example 1. Des capsular elements 22 were then cemented on the closure members 28 by means of a two-part polyurethane adhesive to complete and complete the constructions of the two end pieces 20.

The construction of the headband 1 of this example is essentially the same in shape and dimensions as that of Example 1. However, in the present example, the headband 1 is produced by injection molding a polyacetal resin (Delrin®, manufactured by EI DuPont de Nemours et Cie, Wil-mington, Delaware). When the ends of the headband were separated to a distance of 14.35 cm between the spheres 7 and 9, the resulting inward recovery recovery push force was determined to be approximately 142 g ( 1.4 N).

The construction of the ear protector was completed by manual assembly of the tips 20 on the headband 1, and the resulting construction was tested according to the method of Example 4.

Example 3:

Elements 22 and 28 of a pair of end caps 20 are manufactured by compression molding of a thermally polymerized silicone rubber SWS-7655, manufactured by SWS Silicones Corp., Adrian, Michigan. The mold polymerization in the mold took place for about 10 min and at a temperature of about 177 ° C (350 ° F). The Shore A hardness value of the polymerized silicone rubber was approximately 50. The spaces 24 of the capsular elements 22 were filled with a plug of polyvinyl chloride foam of the same type and in the same way as in the example. 1. The capsular elements 22 were then cemented on the closure members 28 using a silicone rubber cement polymerized at room temperature. The finished end pieces 20, having essentially dimensions identical to those of Examples 1 or 2, were then assembled on a headband 1 substantially the same size and geometry as those used in Examples 1 or 2. However, in the present example , said headband 1 was formed by injection molding of Celcone- resin, a highly crystalline acetal copolymer manufactured by Celanese Chemical Co., New York, NY This headband 1, when flared in opening it to distance or separate the spherical elements by a distance of 14.35 cm, gave a recovery thrust force of approximately 174 g (1.7 N).

The resulting structure of the ear protector was then tested according to the method described in Example 4.

Example 4:

The ear protectors of Examples 1 to 3 were subjected to tests of comparison with each other and with several ear protectors of the prior art, commercially available, of a generally identical type. Audiometric data was obtained, as well as comments from human test subjects regarding the comfort and ease of use of the hearing protectors used. Three human subjects were used to test, and the tests for each protector were repeated three times by each subject. Instructions were given to test subjects to adjust or adjust the shutters of the protectors as best they could, so as to minimize the noise for each protector. The audiometric test procedure was that of ANSI S3.19, modified only insofar as three human subjects, instead of the ten stipulated, were used. For practical reasons, the results of the audiometric analyzes are reported in Table I as single number noise reduction (NRR) assessments. The method for converting the results of the ANSI S3.19 audiometric tests into single-number NRR evaluations is fully described in the monograph “Single-number noise reduction measurements for hearing protectors”, Elliott H. Berger, EA-RLOG © , EAR Corporation, Indianapolis, Indiana, 1979. It should be noted that, in each of the ear protectors of the prior art, their elements for closing the ear canals were fixed to the element of the band headband in a manner not articulated.

Table I

Ear protectors

Headband band pressure at 14.35 cm

NRR '(dB)

Subject Comments

g

NOT

Prior art (T)

80

(0.78)

11

Seems to allow noise to enter despite manual adjustment

Prior art (W-20)

166

(1.63)

15

Difficult to adjust

Prior art (W-20)

216

(2.12)

15

Difficult to adjust

Prior art (MSB)

177

(1.73)

• 16

Difficult to install and adjust

Prior art (DSS)

248

(2.75)

14

Extremely uncomfortable

Example 1

180

(1.76)

22

Self-adjusting

Example 2

142

(1.39)

21

Self-adjusting

Example 3

174

(1.71)

24

Self-adjusting

Example 5:

Several ear protectors are manufactured using the PVC headband 1 of example 1 and the tips 20 of the type produced according to example 3. In the present example, several filler or filling materials 26 are used to fill the spaces 24 of the capsular elements 22. The constructions of the resulting protectors are tested audiometrically by a single subject, using the test apparatus and the ANSI S3.19 procedure. The results of these tests are reported in Table II below.

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Table II

Tip filler

Attenuation (dB) at various frequencies (Hz)

f =

125

250

500

1000

2000

3150

4000

6300

8000

PVC foam plug

28

28

28

30

32

36

36

38

41

Fast recovery polyurethane foam cap

28

26

27

27

26

40

46

45

43

Slow recovery polyurethane foam cap

25

26

29

30

29

40

39

41

41

Glass wool

27

28

27

27

28

38

41

43

41

Crazy silicone sealant

27

26

26

26

29

42

42

42

42

Air

25

24

24

25

32

43

45

46

46

Water

27

25

22

28

30

43

42

41

42

R

1 sheet of drawings

Claims (15)

639,265 2 1. Ear protector comprising an elastic band of general U-shaped headband having, fixed at each of its opposite ends, a member for contact with the ear canal, directed inwards, each of said members having a first end arranged for be pushed by said elastic headband according to a closure relation of the ear canal and a second end, opposite the first, having external dimensions sufficiently small to be surrounded by the external ear and to be directly connected to an opposite end corresponding of the headband, characterized in that the first end of each of these atrial contact members comprises a closure lug of dimension and shape adapted to be inserted partially into the atrial canal, at least this portion of said terminal which can be introduced into the ear canal comprising a hollow, smooth, soft and deformable capsular element, the the capsular element being at least partially filled with a soft, deformable or elastic filling material, and an articulated ball and socket attachment of each second end of the contact member on the corresponding end of the headband, thus allowing for the contact member to pivot on its articulated ■ fixing point and to conform to the ear under the pushing force of the headband. 2. Ear protector according to claim 1, characterized in that each opposite end of the headband is provided with a terminal sphere and that each terminal comprises a corresponding socket receiving the sphere by articulating therein. 3. Ear protector according to claim 2, characterized in that each terminal comprises an end closure member for its hollow capsular element and that this end closure member comprises a socket located in the center to receive the sphere. 4. Ear protector according to claim 3, characterized in that the passage path towards the sleeve comprises a chamfered surface, which thus makes it possible to delimit a conical abutment surface to limit the extent or the extent of the pivoting movement of the pod. 5. ear protector according to claim 1, characterized in that the closure lug of the ear canal has a conical shape, its end portion of small diameter being adapted to be introduced into the ear canal and its end of large diameter being fixed by articulation on the end of the headband. 6. Ear protector according to claim 5, characterized in that the angle at the top of the conical terminal is between 20 and 30 :. 7. Ear protector according to claim 1, characterized in that the construction material of the capsular element has a Shore A hardness of between 20 and 50. 8. ear protector according to claim 1, characterized in that the filling material is an externally plasticized po-lyvinyl chloride foam, the nature and concentration of the plasticizer are such that the foam is characterized by a slow recovery speed from its deformation and by a low recovery pressure exerted under deformation conditions. 9. Ear protector according to claim 1, characterized in that the space in the hollow capsular element is hermetically sealed and that it is at least partially filled with a fluid. 10. Ear protector according to claim 1, characterized in that the capsular element is composed of silicone rubber. 11. Ear protector according to claim 1, characterized in that the capsular element consists of polyvinyl chloride. 12. Ear protector according to claim 1, characterized in that the recovery thrust force directed inwards produced by the elastic band headband, with a spacing of 14.35 cm between its two opposite ends, is between 100 and 200 g. 13. Ear protector according to claim 1, characterized in that the headband consists of a rigid polyvinyl chloride resin. 14. Ear protector according to claim 1, characterized in that the headband consists of a polyacetal resin. 15. ear protector according to claim 1, characterized in that each terminal comprises a member for closing the hollow capsular element and that the closure member comprises a connection part for the implementation of the articulated fixing and a part junction or assembly to attach it to the capsular element, the connection part and the junction part being spaced and moving to come into contact with each other when a terminal is grasped and introduced into an ear canal.