US2625683A - Crash helmet - Google Patents

Description

Jan. 20, 1953 H. H ET AL CRASH HELMET 3 Sheets-Sheet 1 Filed Dec. 8, 1947 Jan. 20, 1953 H. P. ROTH El'AL RASH HELMET 3 Sheets-s 2 Filed Dec. 8' 1947 MHN p, E07}, C'HHQLE5 F'- LUMBHQD INVENT'OQS Jan. 20, 1953 H. P. ROTH EI'AL CRASH HELMET 3 Sheets-Sheet 5 Filed Dec. 8, 1947 CHHQL 55' F1 LOMBQQD lN! 'ENTOPS Patented Jan. 20, 1953 CRASH Hermam'P;LRoth,,.Manhattan-Beach, and'lChamles I FaLombarigsouth Pasadena, Galifi, assignors= to Protection, Inca, Los Angeles,..Calif., acornoration oifv California.

Application December 8, 1947-,;SeriakNo;zJZ90,2563

.1-8Glaims.

This;..invent'ion; vrelatesszto 1 axtypeof helmet to:

protect .ithe .flyers head:ini case of. a. crashllandl ing, collision intflight, or. any; other accident. The? invention. also: resides :insrthetmethod iorsxmakin therhelmet.

.Anotherobject ottheiinventiomis to provide: ahehnet OflthlsitYpfiOf lightweight, and. which:' is'zso :constructedthat: any: impact for-ceacting: uponthe helmetpwillbeilargely abs'orbedand dis.- tributed before; the impact from the: force or. blow-is imparteditozthe flyers head.

Another "object .of I theiinventi'on is to provide? an integrated material composed of 7 an energy absorbing element and a; liner elementlinterlo cked or: keyedtogether to forma sheet material ca pables of: being used as an energy-absorbingpr-o tection for any. specific purpose; and to-provide': a'formlof. interlock between. the said two elements which will co-operateto combine lightness and flexibility. These qualities. particularly adapt thislintegratedmaterial-to function as a'n' inner wall for the outer shell .ofa'crash-helmet;

Another object of 'theinvention is to provide :a helmet of this type; h'aving means for mounting earphones in: the helmetin such a way that they willnotinterfere with-the placing-of the helmet onthefiyers head; while atthe same time, after the'ihelmet has beenput-in place, the phones will; lie: closely against the flyers ears, thereby enablingi th'em to operate-with their-usual efl'l'ci'ency;

Another object of the-invention iS-to provide a1 simple :method; the practice oi which will insure :that the helmet willlfit with substantial ac"- curacy to the: shape and'size of the -fiyersh'ead Another object of the invention is to-providQ-a composite materialwhich'isembo'died in-the constructioniof .th'e lhelmet, and which willoperate efficiently to absorbimpact energy, and -substantiallyaprevent their transmission within limits of. course, i to. theefiyerfsz head; also, to i provide efli cient:means; and a simple method for facilitating the placement;ofiazprotective wall of thiscimpactabsorbing ecompositionwithin the outer' shell of thepzhelmet.

Another; object l. of 1'. the inventionzis to provide a helmet of this .type'with means for effectively ventilating its :interior to prevent-overheating of the flyerslheadwhen wearingthe helmet:

The helmetroftheapresent;invention comprises a. rigid outer; shell, aulayer just within: the: outer shell, of energy-absorbingmaterial; and preferably includes-a second or-inner layer of resilient material. The function of the rigid outer shell is stantially, comple.t.e-..crushing.,

(Cll 2 -6).

21 to distribute any,- force .-app1iedlocally on tli'e outside. ofthe shell sortha't itlwiillact. .on-ask-largesane area as; possible; within,\the .-he1met., Rreviouslyli helmets have been constructed employing; avrel'ae t'ively rigid or hard outer shellas, acmeansriorl distributing locally applied forcelbut ltheselliel': mets have reliedeithen solely onvtheluse ofLsu-chi a hard-outer shellflori combinedsuoha hardfout'erl shell with an h inner lininglof resilientmaterial); suchassponge rubber. The helmet ohthapnesentl invention involves a new concept in themattr; of the energy-absorbing 1iner...or... the .rigidouter shell}, When ahelmettisnonstructed witmarrigid outer shell with N a. resilient: lining thearesilienti lining-functions merely,- to slightly :delay: .the :ape plicationloftheiorce of the impact-to ,thelheadof. the wearer by temporarily stormgwandlthenl-transe mitting the impacbenergy'n ThetpresentoinyentiOIIJiIIVOISIBS? the employment ofaa isubstanti-all yg rigidrouter 1 shell. and .an 1energy-absorbingilayen composed of a non-resilient material "whichrlis; capableof being; crushedunder-the action ofz-an impact force. This.:layenotmaterial; 11381011311 acteristics: that enabledt to beicrushedr-iwithinl limits) withouttransmitting the force; that crushes-it; EOl'xGXflIIlPl-Q; by; providingeaizlaiyeri 0.? material: between thezrigid shell and; a-lrelatively; thin resilientlinnenliningewornforicomfortibygthe wearer, ,the: energy oft-impactconf1thgiouter=zshelt isfirst a distributed. toithe-lim'nga ofi-crushable mae terialll Whentthe'. force oil-thegimpa'cttrisesito that necessary to 1 start crushing this; -layer,,. fur-thenrapid rise oft.thetresistanceato the impact-: force does not occur until the layer: undergoeelsuh In other: words, within limits, the:crushing;orce:;isiabsorbedaand' confinedinaits actionitozthe crushed oripartialht crushed. liner. this-(ways the layenoii crush:- able material within the helmet ot-thfe..;present invention. protects the; wearer: by absorbmgi :the impact; energy byrth'enwork-donie in) crushinggit; as. contrasted with :storing. and; passingaiti onjto the wearerschead; tasioccurszzwithia;resi1ient;liner;

Further. :objects; of theainventionwills appean hereinaftenz The inverrtiomconsistsjn dzhe novelssteps; comm:- bination of; steps, .-;an'd:.eatures:of: constructiomot the. helmet to. betdescribed hereinafter; ialhlof' which c-contribute to produce: an :efficientl crasli helmet iandLmethod :of producing. the same.

A preferredembodiment of th'e invention is delscribed. in the following: specification; whil the broad scope of 'tlie' invention is pointed out iirthe appended cl'aimsa- In the drawings:

Fig. l is a perspective illustrating a method which we prefer to employ in producing a molding shell which fits accurately to the fiyers head, and which is employed in embodying the protective wall within the outer shell of the helmet.

Fig. 2 is a" perspective of the outer shell of the helmet.

Fig. 3 is a section taken in the front and rear medial plane of the helmet, illustrating one of the steps in the method of producing the helmet, and utilizing the molding shell, which is illustrated in the act of being formed in Fig. i.

Fig. 4 is a vertical cross-section through the helmet, taken on the line 4--4 of Fig. 3, but illustrating the method at a further stage of progress in which the impact-absorbent wall is placed between the outer shell and the molding shell which is temporarily held within the same.

' Fig. 5 is a vertical cross-section taken in a transverse plane through the partially completed helmet. Theright half portion of this figure particularly illustrates the location of the inner liner, with respect to the impact-absorbing wall, togather with a flexible innermost lining that comes directly in contact with the fiyers head. The left portion of this figure shows this flexible lining broken away to illustrate particularly a preferred manner for effecting the ventilating of the helmet.

Fig. 6 is a view somewhat similar to Fig. 5, but particularly illustrating the two ear phone pockets or recesses that are formed in the outer shell. This view also illustrates the manner of applying flexible binding at the front and rear edges of the opening of the helmet.

' Fig. 7 is a perspective illustrating the helmet in an inverted position, as it is illustrated in Figs. 3 to-6, and showing the same before the flexible innermost lining is put in place.

- Fig. 8 is a cross-section in a transverse plane passing through the ear phone pockets or re cesses, and showing the helmet in its natural upright position, but in this view the flexible innermost lining is omitted so as to show the ventilating grooves or channels that are formed in the protective wall. In this view one of the ear phones is shown latched in its outermost position as it would be when the helmet is being applied to the flyers head, while the other ear phone is shown in its released position, which would enable it to hold itself in a yielding manner against the fiyers ear.

- Fig. 9 is a fragmentary section upon an enlarged scale illustrating the detail of the layers of material that are molded and formed to the desired shape in the fabrication of the outer shell of the helmet.

Fig. 10 is a fragmentary horizontal section taken about on the line I 0-! 0 of Fig. 8, and illustrating further details of the mounting for one of the ear phones, and the parts of the latch that we prefer to employ for holding the ear phones in an outer or withdrawn position at the timethe. helmet is being applied to the flyers head. This view also illustrates the electric cord connection through the outer shell of the helmet, and the connection for the ventilating hose through which cool air is supplied to the ventilating ducts in the interior of the helmet.

Fig. 11 is a section taken about on the line lI- ll of Fig. 8, illustrating a detail of the flexible or elastic trim for the edge of the opening of 4 the helmet through which the fiyers head is inserted; and this view illustrates how this trim is secured to the edge of the opening and covered with a flexible sheath.

Fig. 12 is a perspective of the complete helmet, illustrating the electrical cord, and ventilating connections to the helmet.

Fig. 13 is a fragmentary view, that is to say, it is a sectional view through the wall of a helmet, consisting of an integrated material composed of an outer element of an energy-absorbing material interlocked with an inner element having characteristic resilience.

Fig. 14 is a fragmentary plan view of a portion of the face of the energy-absorbing element before uniting the element that has characteristic resilience thereto.

Referring now particularly to Figs. 1 to 4, inclusive, in practicing this invention it is desirable, but not essential, to have the helmet fit closely to the size and shape of the fiyers head. For this reason it is preferable to use the head of the flyer who is to Wear the helmet, in the first step of our method in producing a molding shell that is employed in a later step of the method. This includes the placement of a protective wall within the outer shell of the helmet. .The preparation of this molding shell may be accompiished in any suitable manner, but if desired, it can be effected in the manner illustrated in Fig. 1, in which figure I indicates a strip of material that can be applied to the fiyers head, in a moist condition, in such a way as to fashion a skull cap on his head which preferably is protected by a close-fitting bathing cap. For this purpose we prefer to employ a material known as plaster bandage, and which is used by surgeons in forming casts around broken limbs, or in similar situations. The body of this bandage is saturated with a substance that will harden after the bandage has been applied to ones body. Although the illustration shows the bandage I being applied from a roll, in practice, this may be aceomplished by employing short pieces such as the short pieces 2 which are applied to the fiyers head at different points, and extending in any direction desired. In this way a thin rigid shell 3 is formed (see Fig. 4) after the material sets.

In accordance with our method we also employ an outer shell which may be formed in any well known desired manner. For our purposes we would employ an outer shell 4, which is of considerably larger dimension than the inner shell 3, but which has the same general form in cross-section in corresponding planes, together with other features hereinafter described. This shell 4 is preferably formed of a composite material consisting of a multiplicity of layers of fiber glass cloth, bonded together into a single wall structure by means of a thermally processed plastic material, which is preferably of thermosetting type. The fiber glass cloth is applied in a succession of layers on a form having a size and shape which will give the outer shell 4 the desired form. Before placement on the form, the fiber glass cloth is impregnated with the plastic material which is then in fluid state. After all the desired layers of glass cloth are in place, heat and pressure, suitable to the particular plastic material employed, are applied, with the result that the layers of cloth are compacted and, as the plastic material sets, adhere firmly together in a wall structure which possesses relatively high strength for a given weight of maerial.

egcasgese Intlie body "of outer" shell 4, we prefer to em--- ploy'approximately four layers ofthe fiber glass" cloth, and this thickness of wall is maintained downto the peripheral edgefi of thebody of thehelmet (see Figs. 3 and 4). The material below thisedge as-illustrated inFig. 2, is fashioned into two'ear lobes, or extensions 6 in which we prefer to employ aless number of layers of the fiber glass, for example, two-layers. This isindicated in Fig. 9, in' which we indicatetheapproximate has an inwardly disposed extension H), the lower edge ll of which widens out'below and merges into the peripheral edge of the helmet, already referred to.

The overall size of the outer shell 4 should be such that protective material, having sulficient minimum thicknesses in various locations, can be provided between the shell 3 and the head of the wearer. We prefer to provide a minimum of approximately one-half inch of protectivematerial between the outer shell 4 and the-back, sides and top of the Wearers head, but to increasethe protective'layer to approximately one inch in the frontal area; It is desirable that the space occupied by the protective material not exceed the thicknesses herein specifiedJoy more than approximately one-quarter inch, since otherwise'the helmet would tend to become undesirably cumbersome and heavy. It is there fore necessary, in order to provide anice fit for persons having various head dimensions, to provide for making outer shell l in several sizes; A suitable size is chosen for use in steps hereinafter described.

The two shells, namely, the inner shell 3 and the outer shell 4, are then set up as indicated in Fig. 4, the inner shell 3 being held approximately in a central position within the outer shell. This may-be accomplished in any suitable manner, but preferably-by means of one ormore screws or bolts I2 applied as indicated in Fig. 4.- The body of this bolt is surrounded by a short sleeve 13, which operates as a spacer or distance piece for holding the walls of the two shells spaced apart a desired amount to provide a wall space, or molding space is, as indicated in Fig. 3.

In this space id we place an energy-absorbing, or impact-absorbing, material. We do not limit ourselves in the practice of this invention to any particular material for this purpose, but it should be a material which hasa resistance to crushing which increases relatively little while the material is crushed to one-half or less of its original thickness under an impact orcompressive force. A. material having this characteristic is highly advantageous when used in this way, since it functions to absorb and dissipate energydelivered.

rialsuch-ascellular cellulose a'cetate;whosescellue lar structure will be destroyed whenever tliexcomepressive'f'orce developed during an impact blow exceeds the inherent. crushing strength of the'.

material, and which will consequently'absor'b and dissipate energy. For this. purpose'we may em-.

ploy polystyrene foam, or hard foam rubber;- However, cellular cellulose-acetate ispreferably employed in pieces, which should be as largea'sa possible, and they-should substantially cover 'th'e entire interior'surf'ace of the outer shell 4' except in'the space required for earphones, and'except for channels provided for ventilation. The pieces: of cellular cellulose-acetate maybe. formedaso that they fit and may be attached to the interior of the outer shell 4 by any convenient. means such as a suitable cement, and have theiryjine ward faces contoured so that after: application;

of cushioning and trim layers: hereinafter dee scribed, a comfortable fit for the head. of the wearer is assured. In practice, expenditure: of". considerable time, and use of rather complicated;

procedures, is required'in order to assure comforteable fit when the cellular cellulose-acetate.- is Since the;

employed in relatively large. pieces. desired mechanical characteristics of the cellular cellulose-acetate are substantially retained when. it is employed in the form of a'larger'number of" smaller pieces instead of a. fewer number: of. larger pieces, we prefer to employ this material. divided or diced into relatively small bodies; andv in order to facilitate their embodiment in aprotective wall within the outer shell 4, we prefer to employ a binder of suitable material, such as a thermosetting elastomer which maybe a synthetic resin.

However, the invention may be practicedby employing a cementitious material as the binder carrying small bodies of an energy-absorbent material, the cementitious material being of a character to solidify or set after a time, or of a character such that it could be caused to solidify,"

through some other agency or treatment.

In order to lighten the weight of this wall with.-

' out detracting materially fromjits impact-resistant characteristics, we prefer to admix a quantity of ammonium carbonate, which operates as a. foaming agentdeveloping occluded gases, which give a cellular form. tothebind'en. which. .co-operates with thecellular. structure of. thecellul-ose-acetate inmaintaininga low. specific. gravity. for the wall composition. The binder. with the cellulose-acetate bodiescarried in it,.'is. in. a fluid state havingmoreor less viscosity.,.and after. being poured into place, the. compositionshouldbe rammed down into the .moldingspace,

l4 and finished oif with. a flat surface. l5. near. (See.

the upper edge N5 of the molding shell 3. Fig. 4.)

The entire assembly shown in Fig. 4, is then.

heated to approximately 200 to 256 F. for about one hour. This will set the elastomensuch as any synthetic resin, or equivalent substance; which serves as the binder for the cellulose-acetatebodies, and will simultaneously cause opera:- tion of the foaming agent togive a. cellular.

foam-, or sponge, rubber. It may, be. secured.- tothe, inner: face of.v the. protective. wall 11 in: any;

suitable manner, for example, by cementing the two contacting faces together.

For ventilation purposes, to keep the interior of the helmet cool, and to provide channels for wires connected to the ear phones, if relatively large blocks of energy-absorbent material are employed, we space them apart to form a ventilating channel system. If we use small dice of energy-absorbent material in a binder, we prefor to cut a system of grooves I!) through the inner layer of rubber and the protective wall (1. If desired these grooves may include a transverse channel or groove Ilia (see Fig. 7) which may, if desired, be located about in line with the side lobes I for the flyers ears.

The ear phones 20 and 2| (see Fig. 8) are preferably mounted against the inner face of the outer shell 4, in such a way that after the fiyer has donned the helmet, they will press themselves yieldingly but with not too great force against the fiyers ears. And this construction should be such that when the helmet is being put on, the phones will hold themselves in a withdrawn position so as to permit them to be passed down over the flyers ears. In Fig. 8 the ear phone 28 is illustrated in this withdrawn relation in which it is latched back by means that will be presently described, while the other phone 21 is shown with the latch released to permit the phone to move inwardly. Each ear phone is preferably secured to a yoke 22, the middle portion of which is secured to the end of a leaf spring 23. the shank 24 of which is attached by suitable fastening means, such as rivets 25, to the outer shell, 4.

Near the position of the ear phones, latching means is provided, including a latching stem 26, which has an inclined end face 27 and notch 28 on its upper side. When the ear phone is disposed in its latched-out position as illustrated at the left of Fig. 8, this notch 28 engages the edge of an opening 29 in the latch plate 38. After the flyer has donned the helmet, he exerts a slight downward pressure on the projecting ends of the latching stems 26, and this releases their notches 28 from their latch plates 3*], whereupon the resiliency in the leaf springs 23 will swing the ear phones in against his ears.

When a fiyer takes off his helmet, he should push his ear phones outwardly to latch them in their withdrawn positions. When they are pushed out in this way, the inclined faces 21 engage the edges of the openings 29, and as this outward movement is completed, the notches 28 will snap over the edges of their openings.

The circuit connections to the phones are brought in through an insulated electric cord 3! (see Figs. 10 and 12), which passes through a hushed opening 32 in the outer shell 4. This opening 32 is located at any convenient point, but must communicate with the channel system. The connection between the two phones is effected through a channel such as channel 19a, by carrying the electric cord in an insulating sheath 33 (see Fig. 8).

As illustrated in Fig. 8, the ear phones are not attached directly to the leaf springs 23, but each ear phone is carried on a bracket 34, which bracket is secured to the end of its spring by a fastening or rivet 35, which may be formed on the inner end of the latch stem 25.

The peripheral edge of the body of the helmet, and the curved edges H under the lobes l, are provided with a trim 36, which is preferably formed of a cushion-like material such as sponge rubber of substantiall circular cross-section.

This trim is preferably in the form of a ring, which is cut longitudinally with a slot 31 into which the edge of the outer shell 4 is thrust. Fig. 11 illustrates a detail of this connection, and also shows a sheath 38 enveloping the trim. This sheath is in the form of a continuous strip that is wrapped around the side of the trim that is remote from the slot 37, and the edges 39 of the sheath are secured through the wall of the material by suitable fastening means 40.

When the helmet is being worn, if the weather is warm, the helmet can be ventilated by cool air delivered to it through a small flexible air hose 4| (see Figs. 10 and 12), the end of which is secured to a bushing 42. The inner end of this bushing should be located in line with one of the grooves of the groove system 19.

The cushioning layer It is preferably provided with a lining 43 of a soft material such as chamois, leather, or other suitable material. This is illustrated in Fig. 5, in which view ventilating openings 44 are shown in the chamois in line with one of the grooves of the ventilating channel system 19. Obviously, as many of these vents 44 as desired may be provided at other points on the lining 43. The sheathing for the trim 36, if desired, may be applied in four pieces, including the pieces 38 (see Fig. 11), which are two in number. These pieces, however, would not extend across the front and back, and at these points sheaths G5 would be employed, which would overlap the adjacent ends of the sheaths 38 (see Fig. 6), and the inner portions of these special sheaths 43 would be applied as an apron 46 extending over a portion of the inner face of the elastic cushioning layer [8.

If desired, the opening at which the bolt I2 is applied, can be left in the outer shell unplugged, and this opening can be located in line with one of the ventilating channels as illustrated in Fig. 5. This will give an outlet for some of the air that is circulated through the helmet.

While the manner of employing the energyabsorbing material 11 results in a crash helmet that will operate satisfactorily, we have originated an integrated composite sheet material which has the advantageous characteristics of the construction illustrated in figs. 5 and 6, but which has an additional characteristic of lightness; and this characteristic is very desirable in a crash helmet, and also may be very desirable when such material is employed in other situations. This composite material, and the manner of employing it, is illustrated in Figs. 13 and 14. Referring to these figures, the integrated composite material 58 is composed of two elements 38a and 28b, which are manufactured so that they are interlocked or keyed together. In order to accomplish this, we prefer to form a sheet 69, a portion of which is illustrated in Fig. 14. This sheet is composed of cellular cellulose-acetate, and after forming a sheet of that material, we prefer to form a plurality of relatively deep grooves 56 that pass a considerable distance into the sheet on one face thereof. After forming this sheet 39 with the grooves '58, which preferably are disposed in two sets with one set running transversely to the other set, we use the grooved face of this sheet as a side wall for a mold in which the inner sheet or element 482) is molded, and this sheet or element 48b is composed of foam rubber, or any other suitable material having resilient characteristics. This foam rubber therefore will extend into the deep grooves 58 and form tongues 51 filling the same; and

these tongues are of course integral with the .body 430 of this sheet. The presence of the grooves .50 extending as they do in directions transverse duo-each other, admirably adapts this composite :sheet-totaking compound-curved form, which the material must have when applied to the inner 'faceof --the outer wall or shell A of the "helmet. This adaptability is illustrated in Fig. 13, in which the-"roots of the tongues 5! become compressed and reduced in width by the relatively :uncompressible columns orpillars 52 of the celvlulose acetate 58a. This integrated material can also :be provided with ventilating channels such as the channel 53 illustrated in-Fig. 13, and of "course the channels 53 and the inner face of the *element 4-8b can be provided with a linerfi lsimilar to the liner described in connection with Figs. 6 and '7.

If, desired, sheets of small area of this, integrated material may be lined on the foamrubber sideo'f the, material, w ijth'leather, Chamois, or othersuitablelini ng material, after whichv these sheets or blocks can'be attached by cement, or otherwise, to the interior of the shell in a pavemen pattern resembling the pattern illustrated in Fig. 14. These blocks can be disposed with their edges apart so as to form ventilating grooves between them; or the lining material may be put in place after cementing the blocks in their proper position, and then punched with ventilating holes through the lining to communicate with the ventilating channels.

While this integrated composite sheet material illustrated in Figs. 13 and 14 is particularly well adapted for use in a crash helmet, it is obvious that this sheet material could be very useful in many other situations where the duty of the material is to absorb energy and reduce the concussion effect of a blow delivered against the cellular outer element of the sheet.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

We claim as our invention:

1. In a fiyers crash helmet, the combination of an outer shell, an outer layer inside and adjacent the outer shell of energy-absorbing substantially inelastic material capable on impact of deforming and oifering a resistance to such deformation, absorbing and dissipating a considerable impact force, and an inner layer lining the said outer layer composed of a material having considerable resiliency, said helmet having a cavity within the same constructed so as to fit substantially to the shape and size of the flyers head.

2. A flyers crash helmet according to claim 1 in which the said outer layer is composed of blocks of substantially inelastic energy-absorbent material dispersed in a molded thermosetting material.

3. A iiyers crash helmet according to claim 1 in which the said outer layer includes cellular bodies, and a bonding agent carrying the same.

4. A fiyers crash helmet according to claim 1 in which the said outer layer comprises small bodies of cellular cellulose-acetate packed in a thermosetting elastomer.

5. A flyers crash helmet according to claim 1 in which the said outer layer comprises small bodies of cellular cellulose-acetate in a thermosetting elastomer containing a foamingagent imparting cellular structure thereto.

6. A flyers crash helmet according to claim 1 in which thesaid outer layer comprises small bodies of' cellular structure carried in athermosetting elastomer containing ammonium .car- Lbonat'e.

'7. .A flyers crash helmetaccordin'g to claim 1 in which the surface of the inner layer adjacent including an innermost liner ofrelatively soft "flimsy material.

9. A 'llyers crash "helmet according to claim 1 in which the saidoutershll comprises adhering layers including .plastic material.

10. A 'flyers crash helmet according to claim 1 in which the-saidouter shellcomprises adhering layers. of fiber glass cloth. 7

11. A flyers helmetaccor'clin'g to claim '1 in which the said outer shell'comprises adhering layers including plastic material, 'there being fewer of said layers at the lower edges of .said shell-than in the upper portion thereof.

12. A flyers helmet according to claim '1 in which the said outer shell is formed with a recess at each side of the same for the flyers ears, in combination with ear phones mounted in said recesses, and means for yieldingly supporting said ear phones on said outer shell to permit the same to move toward or from the flyers ears.

13. A flyers helmet according to claim 1 in which the said outer shell is formed with a recess at each side of the same for the flyers ears, in combination with ear phones mounted in said recesses, means for yieldingly supporting said ear phones on said outer shell to permit the same to move toward or from the flyers ears, and means associated with said ear phones for latching the same in an outwardly disposed position to provide clearance for the flyers ears when the helmet is being placed on his head, and means for releasing the latching means to enable the ear phones to move substantially into contact with the flyers ears.

14. Protecting means for reducing the efiect of an impact force upon a portion of the human body, including a rigid wall and a liner within and adjacent the wall including a material functioning to crush, and deform under the action of said force, thereby limiting the transmitted force to an amount tolerable to the body, said material being substantially inelastic so that it will substantially maintain its deformed state, and thereby reduce said force; in combination with means for containing and enveloping said protecting means.

15. A protection device for protecting a portion of a human body from an impact force, which comprises a relatively hard outer shell and a layer of non-resilient, crushable, energyabsorbent material within the outer shell operating to maintain its deformed state after being subjected to the said force, and capable of limiting the transmitted force to an amount tolerable to the body.

16. A protection device for protecting a portion of a human body, which comprises a relatively hard outer shell and a layer of non-resilient, crushable, energy-absorbent material within the outer shell, and a lining of soft resilient material within the layer of crushable material.

17. A crash helmet for protecting a portion of a human head against impact, said crash helmet having a body including a substantially rigid shell, a layer inside and adjacent said shell including a material capable of disintegrating within the layer, and in disintegrating functioning to resist a force of suflicient magnitude to crush and partially deform the same, thereby limiting the transmitted force to an amount tolerable to the human head, said material being substantially inelastic so that it is incapable of storing up the said crushing force and transmitting it. l8. A crash helmet according to claim 17 in cluding a liner within said shell, said liner being of an elastic character to adapt itself to the shape of the wearers head.

HERMAN P. ROTH.

CHARLES F. LOMBARD.

REFERENCES CITED UNITED STATES PATENTS Name Date Levinson Jan. 15, 1918 Number Number Number 20 252,544 356,578 566,178

12 Name Date Timmons Oct. 5, 1920 Hart Feb. 19, 1924 Shaw Apr. 21, 1925 Reppa June 1, 1926 Turner Oct. 12, 1926 Emanuele Sept. 20, 1927 Routt Oct. 25, 1927 McQuire Dec. 20, 1941 Sturm et a1. Mar. 10, 1942 Brady Apr. 28, 1942 Oestrike Sept. 28, 1943 Seletz Aug. 1, 1944 Feman Aug. 28, 1945 Daly May 13, 1947 Daly July 1, 1947 FOREIGN PATENTS Country Date Italy Mar. 24, 1927 Great Britain Sept. 10, 1931 Germany Apr. 19, 1933

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