Hearing Protector Mounting

Abstract

A hearing protector is mounted on a resilient headband by means of a stud passing loosely through a hole in the headband. Hemispherically shaped positioning pieces located on the stud on either side of the headband and held on the stud by a nut provide a free fitting support for the hearing protector.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to devices for preventing high levels of sound from reaching the ear of the wearer. In particular, it relates to a mounting for shell type hearing protectors.

2. Description of the Prior Art

In the development of headband supported hearing protector earcups, it has been found desirable to provide a large degree of adjustability between the earcup and the headband. Earcup adjustments about three axes, in some cases not mutually perpendicular, have been described. An additional useful adjustment of the longitudinal position of the earcup with respect to the headband has also been disclosed. In a form of hearing protector earcup well known at the present time, a sound barring seal is made between the ear cup and the wearer's head, comprising a hollow torroidally shaped seal member containing a pressure transmitting media. To be most effective, this form of hearing protector must press against the head of the wearer with sufficient force to cause the seal member to form a complete seal around the ear of the user. This requires that the headband is stiff enough to maintain the required pressure. Users find that it is desirable to have freedom in the angular location of the headband along an axis roughly parallel to the axis of the ear canal so that the band may be located say under the chin or alternately at the top of the head or at the nape of the neck. When the hearing protector is worn with a protective hat, the first or last positions are nearly mandatory.

Devices have been developed by which the required freedom of position of the earcup with relation to the headband can be obtained. Currently disclosed devices tend either to be unduly complex--requiring numerous parts--or when made with few parts failing to provide easy or sufficient adjustment. Many of the designs proposed make use of metal parts thus becoming a hazard in strong electrical fields.

SUMMARY OF THE INVENTION

A safety headband and mounting for the flexible and adjustable attachment of a hearing protector earcup thereto comprises a resiliant arcuate head encompassing member. Openings are located near each end thereof. The earcup for attaching to the headband includes a stud protruding more or less perpendicularly from the external surface of the earcup opposite to the ear opening thereof and at the approximate center of the earcup. A first positioning piece, in shape approximately a portion of a sphere with an axial hole therethrough is located on the stud. The base of the positioning piece faces and abutts the earcup. A second positioning piece of a shape similar to the first is likewise located on the stud in facing relationship to the first positioning piece and having its base facing away from the base of the first positioning piece. A nut, threaaded on the stud serves to maintain the positions of the two positioning pieces with respect to the stud and the earcup. The stud is also located in the opening in the headband with the first positioning piece on one side and the second positioning piece on the other. The opening in the end of the headband is greater than the diameter of the stud but less than the diameter of either of the two positioning pieces. The loose fit of the positioning pieces in the opening provides a desired freedom of position between earpiece and headband.

In a second embodiment of the invention, the openings in the two ends of the headband comprise a series of interconnected holes, the diameter of the several holes being less than the diameter of the base of either positioning piece and the opening between holes being greater than the diameter of the stud. The multiple openings provide adjustment between the earcup and the top of the headband.

It will be seen from this summary that the safety headband and mounting of the invention can be made from non-metallic parts so as to be non-conductive. The action of the spherical segments in the holes at the ends of the headband provide a complete freedom of angular movement within any chosen design limits and the location of the headband with respect to the wearers head is completely unrestricted. Further the mounting of the invention requires a minimum of parts. In particular, the first positioning piece may form a part of the earcup and the second may be formed as a part of the nut.

A further and purposeful feature of the mounting means of the invention is that by providing a suitable bearing ridge on the surface of the earcup, abnormal strains on the mounting studs due to handling of the ear protector can be alleviated.

DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts in isometric form the complete headband and mounting of the invention;

FIG. 2 depicts the cross section 2--2 of FIG. 1;

FIG. 3 depicts a second embodiment of the headband made with the invention; and

FIG. 4 depicts an embodiment of the invention to provide protection against over stressing of the earcup mounting stud.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 serves to show the assembly of a headband 10 and two hearing protector earcups 12 embodying the present invention. In FIG. 2 representing the cross section 2--2 of FIG. 1, 10 depicts the headband at a point defining the hole 14 therethrough. The earcup 12 comprises a shell as shown. a resilient torroidal member 16 attached to the open end 32 thereof forms a headseal for the earcup. A pressure transmitting fluid 18 fills the torroidal member 16 and serves to make the seal conform to any irregularities in the surface of the head of the wearer. A foam lining 20 serves to reduce certain echos, etc., within the ear containing portion of the shell 12. A threaded stud 30 passes through the shell approximately perpendicular to the surface ofthe open end of the shell 32 and at the approximate center of the shell.

A first positioning member 34 having an axial hole therethrough and having a convexedly curved surface is located on the stud 30 so that its base faces the shell and the curved surface faces away from the shell. The shape of the curved surface of the positioning member is approximately that of a portion of a sphere as shown. A second positioning member 36 of approximately the same shape as the first member 34 is also located on stud 30 in facing relationship to member 34 so that its curved surface faces the shell 12 and its base faces away from shell 12. A nut 38 serves to clamp the two positioning members 34 and 36 together. It is to be noted that the hole 14 is larger than the stud 30 but smaller than the largest diameter of the positioning members 34 and 36. This allows a complete freedom of movement of the protector relative to the headband within the limits set by the parameters of the hold 14 and the size positioning members 34 and 36. Thus, the protectors may take any angular position in the plane of the drawings as shown by double ended arrow 40 and in any other plane within the limits noted above. Because the positioning members are spherical in shape, there is no possibility of the headband jambing thereon as might happen if the member were conical, etc. Also, the headband 10 may take any angular position about the axis of the stud 30 as indicated by the double ended arrow 42 (FIG. 1).

In the design of FIG. 1 there is no provision for altering the distance from the axis of the users ears (approximately that of the studs 30) to the top of the bow of the headband 10. Adjustment may be provided by adding additional holes in the ends of headband 10. However, if this is done, the increments of adjustment must of necessity be fairly large. Also, in making the head height adjustment in such a design it would be necessary to completely remove the nut with the possibility of its loss. In the headband 44 of FIG. 3, a series of interconnected holes 46 are shown. The interconnected holes provide a single opening having sides of a roughly depressed scallop shape and roughly semicircular ends. It is to be noted that the distance 48 across the narrow sections of this opening should be greater than the diameter of the stud 30 and that the distance of greatest clear diameter 49 should be less than the greatest diameter of the positioning members. With this design of opening, the head length adjustment is made by loosening the nut until the positioning members clear the edges of the opening without having to unscrew the nut completely from the stud.

For purposes of definition it can be stated that the opening in the headband comprises at least one area having a minimum diameter greater than the diameter of the stud and less than an intermediate diameter, the intermediate diameter being smaller than the greatest diameter of the positioning members, the opening including at least two areas having a minimum diameter greater than the intermediate diameter and smaller than the largest diameter of the two positioning pieces.

With the design of FIG. 2 the entire torque of a twist of the shell about an axis perpendicular to the plane of the paper will be placed upon the stud. The stress on the stud can be considerably reduced by the construction shown in FIG. 4. In FIG. 4 a portion 50 of the shell in the vicinity of the stud 52 is raised in comparison to the design of FIG. 2. The shelf, or ring so formed on the shell is dimensioned so that the edge 54 of of the headband 56 engages the shell 50 when the shell 50 is twisted relative to the headband 56. In this case, the stress on stud 52 is now mostly tension rather than twist as found in the design of FIG. 2 and the forces which the stud 52 will withstand are correspondingly greater.

Although in the description above the two positioning members are described as being separate pieces, they may become parts of the shell and the nut. This construction is shown in FIG. 4. In FIG. 4, the positioning member 58 is shown as a part of shell 50 and positioning member 60 is shown as a part of nut 62.

The above description pertains to a principal concept of the invention. However, I desire to have it understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically illustrated and described.

Claims

We claim:

1. In a mounting for a hearing protector the hearing protector comprising at least one earcup the earcup comprising a shell with an ear opening and having a threaded mounting stud extending approximately perpendicularly from the side of the shell away from the ear opening near the center of the shell, and a resilient headband the improvement which comprises:

a. a first positioning member having a convexedly curved surface approximating a portion of a sphere, the positioning member defining a hole about the major axis thereof, the first positioning member being mounted on the stud with the convexedly curved surface facing away from the shell of the ear protector;

b. a second positioning member similar in shape to the first positioning member, located on the stud the convexedly curved surface of the second positioning member facing toward the convexedly curved surface of the first positioning member;

c. the headband being located between said first and second positioning members and defining near its end an opening, the opening being large enough to permit passage of the stud but not sufficient to permit passage of the first or second positioning members; and,

d. a nut, the nut defining a threaded opening mating with the thread of the stud, the nut located on the stud away from the convexedly curved surface of the second positioning member.

2. A hearing protector as defined in claim 1 wherein the earcup, the headband, the first and second positioning members, the stud and the nut are made of non-metallic materials.

3. A hearing protector as defined in claim 1 wherein the first positioning member is a part of the hearing protector shell and the second positioning member is a part of the nut.

4. A hearing protector as defined in claim 1 including a means forming a part of the shell for limiting angular motion of the shell with respect to the headband about all areas, except about the axis of the stud.

5. A hearing protector mounting as defined in claim 1 wherein the opening defined by the headband is an opening having sides of a roughly scallop shape and ends of a roughly semicircular shape, the opening having narrow sections and wider sections, the distance across the narrow sections being greater than the diameter of the stud and the greatest clear diameter across the wider sections being less than the greatest diameter of the positioning members.