US 3461463 A
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Description (OCR text may contain errors)
Aug. 19, 1969 F. P. BEGUIN 3,461,463
EAR PROTECTOR SUSPENSION DEVICES AND ,THE
COMBINATION WITH nmnema Filed June 9, 1967 INVENTOR.; FRED I? BEGUIN A T TORNE Y United States Patent 3,461,463 EAR PROTECT OR SUSPENSION DEVICES AND THE COMBINATION WITH HEADGEAR Fred P. Beguin, Sturbridge, Mass., assignor to American Optical Company, Southbridge, Mass., a corporation of Delaware.
Filed June 9, 1967., Ser. No. 644,884 Int. Cl. A42b 1/08; H04r 1/ 10 US. Cl. 2-3 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE lNVENTION Field of the invention Head safety equipment with particular reference to devices for suspending circumaural hearing protectors or phone cups from headgear and the combination with the headgear.
Description of the prior art Heretofore ear protectors with and without communication transducers have been suspended from safety helmets and similar headgear with various forms of devices usually offering reasonable latitude in their adjustment for locating the protectors geometrically over the wearers ears.
' These devices, however, have been found to be lacking in simplicity and lightness of construction, ease of manipulation and dependability in producing optimum or even the same fit of the protectors about the ears with each application thereof during a course of work not requiring their continued use and/or in instances where the equipment is required to be interchanged between personnel.
While much emphasis has been placed upon universality of adjustment in prior ear protector suspension devices, the art has been amiss in its consideration of equally important factors such as the avoidance of heavy and ungainly multijointed constructions, for example. This type of structure is subject to frequent misalignment and loosening of its interconnecting parts during use which, accordingly, become susceptible to mechanical vibration by resonance with ambient sound waves and tend to transmit such vibrations or those created by impact through the structure as noise in the ear.
Similarly inferior are prior art spring steel ear protector supporting bands and the like which are also highly resonant and transmissive to mechanical vibrations set up either in themselves or in the headgear to which they are attached. Furthermore, when such bands are adjusted to different lengths and laterally deflected by different amounts according to the requirements for fitting the ear protectors to different head sizes and/ or shapes, the force applied thereby to the ear protectors is usually correspondingly varied. Thus, there is the ever present chance of incurring either insufficient circumaural sealing against ambient noise or discomfort and irritation of the skin resulting from excessive pressure of the ear protectors against the head.
In other prior art constructions particularly of the type provided with multiple adjusting screws, slides and the like which require manipulation by the wearer in adjusting the tension of ear protectors against his head there is the disadvantage that he may through inadvertence not achieve proper circumaural fitting of the protector with the result of unknowingly subjecting himself to dangerous or irritating ambient noise. It has been determined that when given the opportunity to adjust ear protectors for tightness of fit, a user will tend to either sacrifice security against dangerous noise for the apparent comfort of a loose fit or turn to the other extreme of applying an undue force to the ear protectors thinking that such is necessary for optimum noise protection, which it usually is not.
The present invention avoids the aforesaid drawbacks in its field and others which may become apparent as this description progresses by providing simple, lightweight and exceptionally economical suspension devices for circumaural ear protectors, phone cups and the like which devices are minimally subject to the transmission of mechanical vibrations, simply and easily adjusted to and from a position of use and are especially designed to automatically apply an optimum sealing force against the head regardless of its size and shape and/or position of the ears thereon.
SUMMARY OF THE INVENTION The aforesaid objectives are achieved according to the present inventive concept by the provision of hearing protector suspension devices each comprising a lightweight main support member of wire. The wire is formed with a rectangular bight at its uppermost or proximal end from which oppositely disposed lengths thereof extend in spaced parallel and similarly curved relationship over a substantial distance to form a slide section. Thelengths of wire are then helically coiled preferably in directions toward each other to form a fiexure and again extended downwardly in adjacent parallel relationship a short distance whereupon they are arcuately forked to provide a generally semicircular yoke section adapted to freely pivotally receive an ear protector cup.
Ends of the forked lengths of wire are each hooked or looped within a washer or gudgeon of plastic or nylon which is channeled to receive the same and through which a pivot screw is extended into the ear protector cup to produce a trunnion permitting the cup to swivel within the yoke.
Attaching each of the preformed wire suspension components to a safety hat or the like intended to receive the same is a carriage bolt extended from the inside of the hat outwardly through a hole provided therefor. With the square shank of the carriage bolt preventing its rotation relative to the hat, a series of relatively large diameter washers are fitted over the outwardly disposed length of the bolt leaving its extremity exposed at least sufiiciently to fully receive a self-locking retaining nut. The first and last of the series of washers are each preferably relatively thin. The first is formed of a generally soft or compressible material such as rubber or its equivalent which forms a seat against which succeeding washers may be firmly clamped by the nut to prevent wobble of the mounting bolt. This washer also dampens mechanical vibrations tending to transfer from the hat to the suspension assembly during its use. The last washer preferably but not necessarily being formed of metal provides a seat against which the retaining nut is tightened. Remaining intermediate washers in the series being intended to produce a pivot for the suspension device are preferably formed of a relatively rigid plastic material such as nylon or an equivalent thereof which is noted for its excellence in providing bearing surfaces between moving parts. These washers are selected in number and thickness according to the length required of the assembly for positioning the wire support member clear of the brim of the hat during use thereof. The last in the series of nylon washers is slotted across one of its faces to receive, with a smooth sliding friction fit, the slide section of the wire ear protector support member. Thus the ear protector may be selectively universally adjusted up and down, i.e. toward and away from the hat brim, and pivoted toward and away from the face to a centered relationship over the ear whereupon, by swiveling in its supporting yoke, the rim of the ear protector will seat flatly circumaurally against the wearers head.
The fully assembled structure requires no loosening or tightening of its component parts by the user. It is merely grasped, pulled down or pushed up and swung laterally to the position of the ear and released. Thereupon, its coiled wire flexure automatically provides a predetermined optimum, essentially constant force of the protector against the face regardless of the extent of outward deflection normally required thereof in fitting different head sizes and shapes. In order to maintain the aforesaid constant force at all positions of vertical adjustment of the main wire support, its slide section is curved toward the head sufficiently to compensate for the effect of deflection of the slide section due to variations in the length of its extension from the washers. The coils of the spring wire structurealso allow the ear protector cups to be deflected outwardly sufliciently to clear the brim of the hat without surpassing the elastic limit of the wire when it is desired to pivot the structure upwardly thereover.
The present inventive concept and its advantages over the prior art will be more fully understood by reference to both the accompanying drawing and the following detailed description of an actual embodiment of the inven- FIG. 1 depicts in side elevation a headgear and one ear protector suspension device illustrating principles of the present invention, it being understood that a duplicate ear protector suspension device is normally mounted on the opposite side of the headgear;
FIG. 2 is a fragmentary front elevational view of the FIG. 1 embodiment of the invention;
FIGS. 3, 4 and are enlarged cross-sectional views taken along lines 3-3, 44 and 55 respectively of FIG. 1;
FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 3; and
FIG. 7 is an enlarged perspective view of a modification of a portion of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 there is illustrated, as an exemplary form of headgear, a hard hat or safety helmet 10 to which an ear protector suspension device 12 for the left ear is fitted, it being understood that, although not shown or described herein, a duplicate suspension device for the right car would be provided on the opposite side of helmet 10.
The expression headgear as used herein is intended to include the various recognized forms of headbands and harnesses as well as pith hats, crash helmets, hard shell safety hats and/or caps similar to helmet 10 which is illustrated. It may also include a single broad rigid band adatped to rest across the top of the head.
Suspension device 12 comprises a lightweight main support 14 constructed of a single wire 16. Wire 16 is formed with a rectangular bight 18 from which oppositely disposed lengths thereof extend in spaced parallel and similarly curved relationship to form slide section 20 of the support. The two lengths of wire are then helically coiled preferably, but not necessarily, in directions toward each other as represented by coils 22 (FIGS. 1 and 3).
From coils 22, the wire lengths again assume a substantial parallel relationship whereupon they are forked arcuately to form a generally semicircular yoke section 24 of the support (FIGS. 1 and 2) which is adapted to freely pivotally receive ear protector cup 26.
Cup 26 may be equipped with communication transducers and the usual hardware associated with earphones or it may be used without such equipment only as a defender against ambient noise. In either case, the rim of cup 26 is, in recognized fashion, provided with an annular cushion 28 (FIG. 2) adapted to fit circumaurally in continuous peripherally sealed relationship with the head when the cup is properly geometrically positioned over the ear under force applied thereto. Details of the design of cup 26, not being peculiar to the present inventive concept, are expected herein with the understanding that various commercially available or other recognized forms of ear phones, noise protector cups and similar ear defenders in general may be substituted for the presentlyillustrated embodiment thereof. One interested in details of a cupped ear phone may refer to US. Patent No. 3,160,717.
Cup 26 is trunnioned in yoke 24 by pins or screws 30. Washers 32 functioning as gudgeons are fixed against rotation on each of the distal ends of wire 16. These ends of the wire are hooked or looped, as best seen in FIG. 4, into washers 32 which are each provided with an internal groove 34- for receiving the Wire. Neck 34a of the groove fixes the washer against rotation of the wire. Shoulders 32a and 32b prevent undue rotation of cup 26 in yoke 24 by engaging stops 26a and 26b (FIG. 2) provided on the outer shell of the cup.
Wire support 14 is reinforced against distortion during use by rivet 36 extended through coils 22. Rivet 36 holds the coils in axially aligned relationship with each other while sleeve 38 (FIG. 3) of resilient plastic material maintains a continuous tight fitting relationship of rivet 36 in the coils thereby preventing its rattling. Sleeve 38 further serves to dampen mechanical vibrations occurring in the wire support or tending to be transmitted therethrough to protector cup 26 from helmet 10.
During the installation of rivet 36, bushing 40, preferably of plastic, is slipped over sleeve 38 between coils 22. Bushing 40 thus maintains a constant spaced relationship of the coils and alignment of the parallel lengths of wire 16 which make up slide section 20 of the structure.
As an added precaution against undue lateral and/ or torsional distortion of slide section 20 and/or yoke 24, a rigid metal clip 42 spanning the slide section and having its opposite ends wrapped tightly about each length of wire 16 may be applied immediately above coils 20 as shown in FIG. 1. Rectangular bight 18 maintains the desired parallel relationship of the slide wire lengths adjacent the upper or proximal end of slide section 20.
An alternate construction serving the purpose of rivet 36, bushing 40 and sleeve 38 is illustrated in FIG. 7. This comprises spacer 37 which is molded or turned from a single piece of a relatively rigid but resilient plastic material, preferably nylon. Spacer 37 has an enlarged cylindrical midsection 39 performing the function of bushing 40 and lateral extensions 41 which are insertable into coils 22. The assembly using spacer 37 in place of rivet 36, bushing 40 and sleeve 38 is made simply by sliding clip 42 upwardly on slide section 20 sufliciently to permit coils 22 to be spread apart enough to enter extensions 41 thereinto whereupon clip 42 is returned by sliding to the position shown in FIGS. 1, 2 and 7. Clip 42 thus locks spacer 37 in place.
Attaching wire support 14 to helmet 10 is pivot block 44 supported by carriage bolt 46 extended through hole 48 provided therefor in the helmet wall 50, see FIG. 3.
Bolt 46 is prevented from rotating in helmet 10 by its square shank 52. To this end, hole 48 may be made square to tightly receive shank 52 or, alternatively, a presently preferred arrangement (FIG. 3) not requiring that hole 48 be square may be employed. The latter arrangement utilizes a peripherally winged lock washer 54 having a square central opening fitting over shank 52 which renders the washer non-rotatable on bolt 46. Being radially slotted at spaced points about its periphery and bent inwardly toward wall 50 along the slots, sharp pointed wings 56 (one shown in FIG. 3) bite into wall 50 when bolt 46 is tightened thereagainst to prevent its rotation. Lock washer 54 is illustrative of only one of the many recognized varieties of such devices, any of which may be substituted for washer 54.
Outwardly of wall 50, a series of washers placed on bolt 46 make up block 44.
A first thereof (washer 58, FIG. 3) is formed of a pliable material such as rubber or its equivalent which is conformable to the outer contour shape of helmet 10. Washer 58 thus produces a seat against which the next washer 60 may be drawn tightly to prevent wobble of bolt 46 relative to the helmet. Also, in being pliable and deadening to sound, washer 58 dampens if not eliminates transmission of mechanical vibrations from helmet to wire support 14. Washer 60 having concave side 63 seats substantially only peripherally against washer 58 thereby keeping bolt 46 substantially tangentially perpendicular to the curvature of helmet wall 50.
The series of succeeding washers 64 are selected in number and/or thickness according to the spacing required to place who support 14 clear of the brim of helmet 10 when suspended from washer 66 (see FIGS. 2 and 3).
Washer 66 is provided with a pair of parallel grooves 68, (FIGS. 5 and 6) which receive slide section 20 of wire support 14 and provide a slideway therefor. Slide section 20 is curved in a direction corresponding to that of wall 50 of helmet 10 and grooves 68 are formed to such predetermined depth that corresponding lengths of wire 16 disposed therein will essentially make a three point frictional contact in block 44. This can be seen in FIG. 5 wherein the points of contact are x, y and z. Thus, the curvature of slide section 20 is not apprecially deformed nor is the friction sliding fit thereof in grooves 68 disturbed by tightening of nut 70 which is used to establish the integrity of block 44. Nut 70 is selected to be one of the self-locking types readily commercially available. It prevents loosening of the block 44 assembly during rotation thereof in use.
A backing washer '72 of metal (FIGS. 1 and 3) may be used, if desired, to provide a rigid seat for nut 70.
Washers 60, 64 and 66 are, however, preferably formed of nylon or an equivalent thereof which is noted for its excellence in providing smooth acting bearing surfaces between moving parts. Thus, by grasping ear cup 26 one may easily adjust the same up or down and forward or back to a proper position of use over the ear. The former adjustment being made by sliding wire support 14 in block 44 and the latter by pivoting the whole assembly about fixed bolt 46. The tension applied to nut 70 having no effect upon the frictional fit of slide section 20 in block 44 may be adjusted to any desired degree according to the freedom desired of the aforementioned pivotal action.
As shown in FIG. 1 by dot-dash outlines 12a and 12b, suspension device 12 may be swung forwardly or rearwardly respectively to an out-of-the-way position against the helmet proper for convenient storage of the combination and/or less cumbersome application or removal of the helmet prior to and following application of the protector cups to the ears.
Particular features of the present construction reside in coils 22 providing an essentially constant predetermined optimum force of cup 26 against the head regardless of the extent of normal deflection thereof in fitting different head sizes and shapes and the aforesaid curvature of slide section 20 rendering said force unaffected by vertical (length) adjustment of the main wire support 14. That is,
as slide section 20 is lowered thereby giving it a greater tendency to deflect outwardly when cup 26 is pulled in that direction, its lower end, i.e. adjacent coils 22, is brought closer to the head. In its uppermost position with less tendency to deflect outwardly, coils 22 are brought further from the head. Thus, the amount of deflection taking place in slide section 20 itself versus the position of coils 20 relative to the head is essentially constant at all times so that the force factor of pressure of cup 20 against the head is determined essentially entirely by the compliance of coils 22.
Under conditions where slide section 20 happens to deflect away from contact point z in grooves 68 (FIG. 5) no appreciable change in the frictional sliding action of support 14 is noted. This loss of frictional contact is compensated for by a slight addition of force against points x and y.
In the above-described assembly with helmet 10 no tightening or loosening or adjusting of nuts or other components is required by the wearer nor is such advised. With cup 26 brought to position over the ear, the force automatically applied to the head is preset by coils 22 for optimum sealing against ingress of ambient noise.
Coils 22 are considered herein as being flexure means and the term flexure as used in the appending claims is to be interpreted as including not only the coils 22 but other equivalencies such as, for example, one or more thinned or flattened sections of the length of wire 16.
Music wire is preferred for the structure of main support 14 for reason of its superior surface finish which lends extreme smoothness to the sliding action thereof in block 44. Ordinary stainless steel and other spring wire materials may, nevertheless, be used if desired.
Typical of sizes and dimensions of the above-described construction which were actually used and tested are:
Wire 16 .080" diameter music Wire. Grooves 68 (FIG. 6) .087" in depth. Radius of curvature A (FIG. 6 inches.
5) of slide section 20 inside diameter; Coils 20 pitch; 2 coils at each side Angle B (FIG. 2) when of spacer 40.
coils are relaxed 60.
1. An ear protector suspension device adaptable to headgear comprising:
a main supporting body of one piece construction having a proximal elongated slide section, a distally disposed yoke for receiving and supporting an ear protector cup and a flexure intermediately of said section and yoke for permitting lateral deflection of said yoke relative to said slide section, said supporting body being constructed of a length of wire having a bight intermediate its opposite ends with extensions thereof from said bight sized and shaped to form said slide section, fiexure and yoke and said flexure comprising a number of helical coils in each of said extensions; and
a mounting block on said slide section, said block being adapted for fixed attachment to an article of headgear and having a pivotable slideway in which said slide section of said main supporting body is received for sliding and pivotal adjustment relative to said article.
2. An ear protector suspension device as recited in claim 1 wherein said coils in each of said extensions of said wire are substantially coaxially aligned with each other and said device further includes spacer means fixedly spacing the coils in one of said extensions of said wire from those in the other of said extensions of wire a fixed distance apart, said fixed distance and said bight establishing a parallel relationship of said extensions of wire in said slide section.
3. An ear protector suspension device as recited in claim 2 wherein said extensions of wire in said slide section are curved.
7 8 a 4. The combination of an article of headgear and ear v References Cited protector suspension means comprising: UNITED STATES PATENTS a main support for an ear protector cup, said support being on one-piece construction having an elongated 1,616,491 2/1927 Green 179-156 slide section, a distally disposed yoke for receiving 2,408,720 10/1946 Alger and supporting an ear protector cup and a flexure in- 3,193,841 7/1965 Haluska termediately of said section and yoke for permitting 3506991 2/1967 Wood Y 179-156 lateral deflection of said yoke relative to said slide section, said support being constructed of a length of wire shaped to form said slide section, flexure and 10 yoke and said flexure comprising a number of C01lS FOREIGN PATENTS formed in said length of wire; V
a mounting block on said headgear, said block having HERBERT ROSS Pnmary Exammer a pivotable slideway member in which said slide sec- US CL X tion of said main support is received; and 15 2 209;
means for fixing said block to said headgear with allowance for pivoting of said slideway member.