Low profile size adjustable protective helmet

[57] ABSTRACT

A low profile protective helmet comprising a rigid shell lined with shock absorbing material, the shell being made up of separate front, center, and rear portions with the sides of the front and rear portions adjustably mounted in cantilever fashion on the sides of the center portion. The center portion is provided with a channel in its outer surface to receive the headband of a communications headset. The adjustable mounting enables the front and rear portions to be selectively mounted to provide a good fit over a range of head sizes and shapes. The front and rear edges of the center portion are provided with integral extensions which telescope with the adjacent edges of the front and rear portions to close the opening between the center portion and the front and rear portions throughout the range of adjustment. The shell may be formed of ballistic material or an outer shell of ballistic material may be worn over the helmet.

Claims, 5 Drawing Figures

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PATENTEDMAY30 1972

3,665,514

SHELF 1 OF 2

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PATENTED MAY 3 Ο 1972

3,665,514

SHEET 2 Gr 2

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3,665,514

LOW PROFILE SIZE ADJUSTABLE PROTECTIVE HELMET

BACKGROUND OF THE INVENTION

The invention relates to protective helmets for the human ³head and more particularly, to a helmet providing bump and ballistic protection for use in a confined space in conjunction with a communications headset.

Crewmen of combat vehicles used in military operations such as tanks and the like require some form of protection for ¹⁰their heads since they are frequently jostled about within a very confined space which includes numerous projections offering a potential bump hazard to the head. The operation of the vehicle and its related combat equipment cause a very high ambient noise level which requires that the crewmen use radio communications, both for internal and external communications. Further, because the crewmen may be required to leave the vehicle in a combat situation, it is desirable that their protective headgear also provide some degree of ballistic pro- 20 tection. Existing helmets for this purpose are of the same general type as those worn by football players and pilots. They comprise an oversize rigid shell with portions extending over the ears. They are supported on the head, either by an adjustable suspension system of fabric webbing, or by the use of 25 shock absorbing material and selected sizing pads. Communications equipment is mounted directly on the helmet with the ear pads supported by the portions of the helmet which cover the ears. Such helmets are extremely bulky because of the space required between the suspension system or sizing pads 30 and the shell to permit the accommodation of a reasonable range of head sizes and shapes and the space required within the. ear covering portions to accommodate ear pads and their supporting structure. The helmets are heavy and because the shell is spaced an appreciable distance from the head, they are 35 often unstable on the head. They also present a serious noise problem since the ear covering portions of the shell tend to aggravate the already serious ambient noise level by forming an echo chamber around the ears. The bulk of these helmets may seriously limit head movement by the crewmen in the very 40 confined space within the vehicle and, at best, presents difficult design problems in providing compatibility with various optical sighting devices which are located within the vehicle for use by the crewmen.

SUMMARY OF THE INVENTION

The invention comprises a helmet embodying a rigid shell lined with shock absorbing material, the shell being made up of separate portions which may be rigidly joined together in a jq plurality of relative positions to permit the helmet to be fitted closely to a range of head sizes and shapes. The shell portions are provided with integral extensions which telescope with adjacent portions to close the space between adjacent portions over the range of adjustment therebetween. The shell portions 55 are conformed to leave the ears of the wearer exposed such that a conventional communications headset may be worn in conjunction with the helmet and a channel is provided in the outer surface of the shell to receive the headband of such a headset. 60

Because of its adjustable features, the helmet provides a close fit with the head and thus an absolute minimum profile consistent with the amount of shock absorbing material required. The exposure of the ears not only eliminates noise attenuation problems caused by the ear covering portions of 65 prior art helmets, but permits the use of a separate conventional type headset without limiting the size of the ear pads which may be necessary for sound attenuation. The use of a separate headset permits ready removal of the headset with its additional weight and bulk during periods when it is not 70 needed. The close fit of the helmet minimizes the weight of the helmet itself, provides excellent stability of the helmet on the head, and in combination with the use of a separate headset, eliminates problems in attaining and maintaining optimal location of the ear pads on the head. 75

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevation of the helmet of the present invention in combination with a conventional communications headset.

FIG. 2 is a central longitudinal section of the helmet, with the communications headset removed, showing the shock absorbing material and the telescoping relationship between the separate portions of the helmet.

FIG. 3 is a partially exploded view of the helmet showing the details of the adjustable mounting system.

FIG. 4 is a vertical section taken along Line 4—4 of FIG. 3, showing the arrangement of shock absorbing material on the inside of the helmet shell.

FIG. 5 is a side elevation of the helmet with a ballistic overshell in place thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The protective helmet of the present invention, designated generally by numeral 10, comprises a helmet shell assembly 11 and a conventional releasable chin strap 12. The helmet is particularly adapted for use with a conventional communications headset 13 as seen in FIG. 1. The headset 13 comprises a head band 14 which extends over the top of the head and supports an earpad 15 mounted on each end thereof in firm engagement with the wearer’s head aroung the ears. The ears themselves are received within the earpad which carries a conventional earphone for transmitting sound to the ears. A microphone boom 16 may be mounted on the exterior of one of the earpads in a conventional manner.

The helmet shell assembly 11 is comprised of an outer shell 17 of a substantially rigid impact resistant material with a lining of shock absorbing material 18 fixed to the inner surface thereof in a manner to be described. The outer shell 17 is formed by three separate sections, a center or principal section 19, a front section 20 and a rear section 21. The center section 19 covers the central portion of the top of the wearer’s head from a point above the ear on one side of the head to a point above the ear on the other side of the head as best shown in FIGS. 1 and 3, The front section 20 is mounted in cantilever fashion on the sides of the center section 19 in a manner to be described and covers the upper frontal portion of the head. The rear section 21 is mounted on the sides of center portion 19 in similar fashion and covers the back of the head. The sides of all three sections are configured to provide a clear area around the ear of the wearer of the helmet to assure that the ear pads 15 of communications headset 13 can be maintained in firm contact with the area of the head around the ear while the helmet is being worn.

The outer surface of center section 19 is provided with a channel 22 therein as shown in FIG. 3 to receive the headband 14 of headset 13 as shown in FIG. 1. Channel 22 not only serves to locate and maintain the headset on the helmet shell assembly 11 but also minimizes the likelihood of jarring the headband out of position by catching it on objects within the vehicle as the wearer moves his head around. Accordingly, the depth of channel 22 should approximate the thickness of the headband 14.

The front and rear edges of the outer shell center section 19 are provided with integral extensions 23 and 24 which are slightly offset inwardly of the outer surface of the shell to engage under the rear edge of front section 20 and the forward edge of back section 21, respectively, in telescoping relationship therewith for a purpose to be described.

The side portions of center section 19 include integral front and rear extensions 25 as shown typically in FIG. 3. These extensions are provided in the sides of the front section 20, and also in the sides of the rear section 21. Thus, the hole 27 in the front section and rear section may be aligned with a pair of holes 26 in the respective extensions of the center section with the front section 20 and the rear section 21 in six different positions relative to the center section 22 and rigidly fastened in any of these positions by removable fasteners 28 engaging in the aligned holes.

3,665,514

A conventional threaded screw and flanged internally threaded socket may be used as fasteners 28 or other types of conventional fasteners may be used so long as they snugly engage in the aligned holes and are retained therein. In this regard it should be noted that size adjustment by changing the relative positions of the helmet sections should normally be required infrequently since a helmet is usually issued to a single individual and would be adjusted initially to fit his head. Thereafter the need for adjustment should be minimal unless the helmet is subsequently issued to another individual whereupon the size adjustment would be repeated.

The shock absorbing lining 18 is comprised of two layers of shock absorbing material over most of the inner surface of the outer shell 17 as best shown in FIG. 2. The outer layer 29 comprises a relatively firm shock absorbing material, for example, a substantially rigid crushable polystyrene bead material having a density of 4.5 pounds per cubic foot and a thickness of about ½ inch. The inner layer 30 comprises a relatively soft cushioning material such as a resilient polyurethane foam having a density of about 1 pound per cubic foot. The thickness of the inner layer 30 may be about three-eighths of an inch in those areas which are also covered by the outer layer and an inch or more in other areas as hereinafter described. The inside surface of the inner layer 30 of shock absorbing material is preferably covered with soft leather 31 or a similar material providing comfort and moisture absorption properties.

As best shown in FIG. 4, the outer layer 29 of shock absorbing material extends over the inner surface of the top portions of the outer shell only while the inner layer 30 extends over the outer layer 29 and also over the side portions of the outer shell. The thickness of the inner layer of shock absorbing material on the side portions is increased to at least the combined thickness of the outer and inner layers over the top portions of the shell and preferably somewhat greater than this combined thickness as shown in FIG. 4. This configuration of the shock absorbing lining allows the helmet to comfortably accomodate a reasonable range of head widths because of the compressability of the relatively soft cushioning material on the sides of the shell and in conjunction with the adjustability of the three shell sections extends the range of head sizes and shapes that may be accomodated by the helmet.

The outer layer 29 of shock absorbing material may be cemented to the inner surface of the outer shell and the inner layer 30 cemented to the outer layer 29. The side portions of the inner layer 30 may be movable or removable to provide access to the inner portion of fasteners 28 where the type of fastener used requires such access. This may be accomplished by forming the inner layer of one continuous piece as shown in FIG. 4 which is fixed in place by cementing only those portions which contact the inner surface of the outer layer of shock absorbing material leaving the side covering portions of the inner layer free to be displaced to provide access to the fasteners. It may also be accomplished by using separate side portions which are releasably mounted by means of hook and pile fasteners (not shown). For that matter, such hook and pile fasteners may be used to attach all of the shock absorbing material to the shell thereby permitting ready replacement of this material should it become damaged or soiled or when reissuing the helmet to another person.

As shown in FIG. 2, the shock absorbing material 18 does not cover the entire inner surface of the helmet shell sections since clearance must be provided for the telescoping or overlapping of the front section 20 and the rear section 21 with the extensions 23 and 24 on the front and rear edges of the center section 19 throughout the range of adjustment between the sections. In the embodiment shown in FIG. 2, this is accomplished by terminating the shock absorbing material a predetermined distance away from the rear edge of the front section 20 and from the front or forward edge of the rear section 21. It will also be apparent that the inner surfaces of the side portions of the front section 20 and rear section 21 must be free of shock absorbing material where they overlap the side portions of center section 19 for mounting purposes.

The rigid impact resistant material comprising the outer shell 17 may be a suitable thermoplastic such as polycarbonate which will provide the desired bump protection or may be a material which will provide both bump and ballistic protection such as a nylon fabric and resin laminate. Where bump protection only is provided by the outer shell material, an over shell 31 of suitable ballistic material may be provided for optional use when ballistic protection is desired as shown in FIG. 5. For example, within an armored vehicle only bump protection would normally be required but when the crewmen has to leave the vehicle under combat conditions the ballistic overshell could be added to the bump protective helmet. In this arrangement, the extra weight of the ballistic protective material would not have to be borne except when such protection was required. The ballistic protective overshell 31 is lined with a realtively soft resilient material such as the polyurethane foam material used in the inner layer 30 of the shock absorbing material within the helmet shell. This soft lining material permits the over shell to be properly fitted to the helmet shell over a range of size adjustments of the latter.

The invention described in detail in the foregoing specification is susceptible to changes in the details, materials, configuration, and arrangement of parts as may occur to persons skilled in the art and is not limited to the precise details of construction as shown and described herein. The terminology used in the specification is used for purposes of description and not of limitation, the scope of the invention being defined in the claims.