US 3430261 A
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Description (OCR text may contain errors)
March 4, 1969 c. E. BENNER 3,430,261
I SOUND ATTENUATOR ATTACHMENT FOR A PROTECTIVE HELMET Filed Iarch 1, 1967 Sheet 0:2
lNVENTOR so By CHARLES E. BENNER 60 22 ATTORNEY MKQMK i March 4, 1969 c. E. BENNER SOUND ATTENUATOR ATTACHMENT FOR A PROTECTIVE HELMET Filed March 1, 1967 Sheet m N m ms 5 m 5 m m W \msr ATTORNEY United States Patent Office 3,430,261 Patented Mar. 4, 1969 ABSTRACT OF THE DISCLOSURE An attachment for a protective helmet, providing sound attenuating ear muffs swivelled on horizontal pivots removably attached to the brim of the helmet, the muffs being spring-pressed to the ears of the wearer when in use, and rotatable about the pivots between an operative position to an inoperative position according to whether or not the wearer desires ear protection.
BACKGROUND OF THE INVENTION Field of the invention The invention relates to protective helmets, and more particularly to a readily removable atachment for protecting the wearer from sounds and noises of dangerously high intensity, with provision for placing a sound attenuator either in position for use or in a storage position when its use is not desired.
Description of the prior art The prior art discloses various removable attachments for safety helmets, and it discloses sound attenuators attached to a protective helmet. The means provided for attaching the sound attenuators to the helmet have been a cause of potentially lessening the protective properties of the helmet against hazards other than intense sounds or have introduced inherent new hazards to the wearer.
SUMMARY OF THE INVENTION The invention resides in a combination of support means detachably fastened to the brim of the helmet, a horizontal pivot attached to the said support means upon which pivot a spring member is swivelled, the spring member in turn supporting a sound attenuator and comprising two spring elements of unequal stiffness operable in mechanical shunt relationship to each other, the element of greater stiffness mainly determining the pressure of the attenuator against the ear of the wearer, and the element of lesser stiffness allowing withdrawal of the attentuator from the car a sufficient distance to facilitate rotation of the attenuator about the pivot into a storage position.
The invention avoids any necessity for providing a hole in the helmet, particularly in the crown thereof, for the fastening of an attachment, thereby avoiding the weakening of the helmet at the hole and the resultant lessening of protection against mechanical forces. The invention also avoids a hazard to the wearer which may arise from the use of a mounting bolt on the hole, which bolt may be driven accidentally into the head of the wearer. Furthermore, the avoidance of a bolt on the inside of the helmet avoids reducing the electrical insulating Value of the helmet.
BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a front elevational view of a safety helmet embodying the invention, in place on the head of a wearer, with sound attenuating means in place upon the ears of the wearer;
FIGURE 2 is a side elevational view, partly broken away, corresponding to the front view shown in FIGURE DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, 20 is a protective helmet, comprising usually a completely rigid shell, but at least having a rigid brim 22. Various safety and comfort features may be provided inside the helmet in accordance with the state of the art, but such interior arrangements are not involved in the present invention. A channelshaped support member 24 is provided which surrounds preferably about one-half the circumference of the brim 22 and engages the brim within the channel of the support member. For purposes of illustration, the member 24 is attached to the rear portion of the brim, although it might in some cases be attached to the front portion.
At each side of the support member 24, at a position adjacent to the ear of the wearer, there is attached a bracket 26. The attachment of the bracket 26 may be rigid, or there may be provided a restricted freedom of rotation about a vertical axis,- as illustrated, in which case stops 28 and 30 are provided to limit this rotation.
The bracket 26 comprises a vertical portion 36 supporting a substantially horizontal pivot 38 extending substantially radially outward from the member v24. The pivot 38 is preferably non-rotatable with respect to the portion 36 of the bracket 26 and threaded at the end remote from the bracket 26. On the pivot 38 there are provided in order a large fiat washer 42 for providing a good bearing between the bracket 26 and the next mounted part, which is one end of a generally U-shaped spring bracket arm 44 for supporting a sound attenuator, or ear mutf 46. Next to the arm 44 there is assembled on the pivot another flat washer 48 and then a compression coil spring 50. Against the outward end of the spring 50 there is assembled an interference fit nut 52. which is used to adjust the tension of the coil spring 50 as well as to secure the entire assembly to the pivot. A gimbal 34, rotatably supporting the ear muff 46 is attached to the end of the spring bracket arm 44- remote from the pivot, preferably by means of a swivel joint 54.
The portion 32 of the U-shaped member to which the gimbal 34 is attached may comprise a slip joint 64 for permitting vertical adjustment of the ear muff 46 relative to the ear. The parts of the slip joint 64 may bear upon a leaf 66 of electrically insulating, friction increasing material.
A similar assemblage of parts is provided for mounting a second ear muff on the other side of the helmet from the first. Due to the symmetry of parts on the two sides it is not necessary to repeat the description for the second side.
The coil spring 50 and the U-shaped spring bracket arm 44 are seen to be mechanically coupled so as to act as a unit in exerting pressure of the ear muff 46 against the ear of the wearer. The amount of pressure so obtained is adjustable by turning the nut 52.
When not wanted, the ear muff 46 may be rotated about the pivot 38 to a storage position, for example above the brim of the helmet and pressing against the side of the crown of the helmet, as shown in FIG. 4.
To facilitate the rotation of the ear muif by the wearer of the helmet, the ear muff may be pulled away from the ear a suitable distance before the rotation is started. To facilitate the removal of the ear muff to a sufficient distance, the coil spring 50 is made less stiff than the U-shaped spring bracket arm 44. The mechanical coupling of the two spring members 50 and 44 is such that there is a mechanical shunt relationship between them. This may be verified by noting that either member 50 or member 44 may be extended or compressed while the other member is held in a fixed position, and a force applied to the ear muff 46 in a direction to pull the ear muff away from the head will be observed to flex the U-shaped arm 44 toward a less bent form while simultaneously compressing the coil spring 50.
By makingthe U-shaped spring 44 considerably stiffer than the coil spring 50, the spring 44 is mainly the cause of the pressure of the ear muff against the ear of the wearer, but this pressure is adjustable by adjusting the compression of the coiled spring 50. However, when the wearer pulls the ear mufi away from his ear, the coiled spring 50'is readily compressed due to its lesser stiffness with the application of a moderate amount of additional force applied by the wearer. If it were not for the resilience of the coiled spring 50, a much greater force would be required to extend the stiffer spring 44 the required amount.
The helmet brim fits into the U-shaped channel of the support member 24 for the full length of the member 24, and the support member 24 is held in position in engagement with the rim by means of a coil extension spring 56 having its ends attached to the extremities of the member 24.
The coil extension spring 56 will operate to hold the channel-shaped member 24 to the brim of the helmet, but a clip 58 may also be provided, preferably permanently looped around the spring 56 at one end and having a hook 60 at the other end to engage the brim.
When it is desired to use the helmet without the sound attenuating equipment attached, the hook 60 is readily unhooked from the brim and the spring 56 slipped back over the top of the helmet, enabling the channel-shaped support member 24 to be removed from the brim of the helmet along with the sound attenuating equipment permanently attached thereto.
The sound attenuating equipment is equally readily attached to the helmet when needed, by engaging the brim of the helmet with the channel-shaped member 24, drawing the coil spring 56 forward over the top of the helmet, and fastening the book 60 over the edge of the brim.
Because of the sound attenuating equipment is easily and completely removable from the helmet, the latter remains standard equipment, whereas, if the sound attenuating equipment is permanently attached to the helmet, the combination becomes a single purpose unit.
Additional means for holding the spring 56 in place may comprise bosses 62 over which the spring 56 may be slipped while attaching or detaching the sound attenuating equipment. The bosses 62 may form sockets inside the shell of the helmet and these sockets can serve for attaching and holding appliances provided inside the shell.
It will be noted that the addition of the sound attenuating equipment to the helmet in the manner disclosed herein requires no modification of the helmet, such as the drilling of. holes. Furthermore, the sound at enuating equipment is quickly attached and detached Without the use of tools, and even without tightening or loosening a knurled nut. Also, the use of the compound spring with resilient member prevents unintentional removal of the helmet from the head by the operation of a too stiff spring during; the process of rotating the ear muffs from the operative to the inoperative position.
1. In combination with a protective helmet having a rigid brim, a support member adapted to partially surround said helmet and to be attached to said brim, said support member including portions adjacent to the ears of the wearer, a horizontal pivot attached to said support member and extending substantially radially outward with respect to said helmet in a position adjacent to an ear of the wearer, a sound attenuator, and compound spring means rotatably mounted upon said pivot at one end and attached to said attenuator at the other end, said spring means comprising two elements of unequal stiffness operable in mechanical shunt relationship to each other, the element of lesser stiffness engaging said pivot and pressing the element of greater stiffness in pressure contact with said support member, said element of greater stifi'ness applying pressure of the said attenuator against the ear, and the said element of lesser stiffness allows horizontal withdrawal of the attenuator from the car a sufficient distance to facilitate rotation of the attenuator about said pivot into a storage position.
2. 'Apparatus according to claim 1, in which said support member is channel-shaped and adapted to engage said brim within the channel of said support member.
3. Apparatus according to claim 1, together with detachable means for securing said support member to said helmet.
4. Apparatus according to claim 3, in which said support member surrounds substantially one-half the circumference of the said brim, extending from a position adjacent one ear of the wearer to a position adjacent to the other ear, and in which said detachable securing means loops around substantially the remainder of the circumference of the helmet.
5. Apparatus according to claim 4, in which the said support member surrounds substantially the rear half of the circumference of the said brim.
6. Apparatus according to claim 4, in which said securing means comprises an extension spring member having its ends attached to the extremities of the said support member.
References Cited UNITED STATES PATENTS 1,729,051 9/1929 Parker 22O9 X 2,855,604 10/1958 Austin 2-3 2,963,708 12/1960 Herbine et a1 28 3,193,841 7/1965 Haluska 23 3,273,164 9/1966 Thomas 2209 X 3,332,086 7/ 1967 Simpson et al 2-8 2,631,286 3/1953 Bowers 2-8 2,904,790 9/1959 Ruggiero 28 2,915,756 12/ 1959 Rex et a1 2--8 HERBERT F. ROSS, Primary Examiner.
US. Cl. X.R.