US2123275A - Protective headgear - Google Patents

Description

July 12, 1938. J. B. DYM 2,123,275

PROTECTIVE HEADGEAR Filed June 1, 1936 2 Sheets-Sheet 2 R/BBED FABRIC KNIT FRO/1 KNIT TE XT/LE' WIRE RIB KNIT TEXTILE man/c.

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Patented July 12, 1938 UNITED STATES PATENT OFFICE 2,123,275 I PROTECTIVE HEADGEAR Joseph B. Dym, Pittsburgh, Pa., assignor to Mine Safety Appliances Company, Pittsburgh,

Pa., a

corporation of Pennsylvania Application June 1, 1936, Serial No. 82,765

6 Claims.

This invention relates to protective, or safety, head-wear of the type worn by miners, firemen, mill and construction workers, and other persons for protection of the head against injury, as from falling objects, contact with exposed electrical ,wir-

.ing, or in other ways.

helmet crowns is such that folds can not be avoided when the sheet is forced into a crownforming mold. Such folds would be highly undesirable. Accordingly, all headgear of this type with which I am familiar have been reinforced with small pieces of sheet fabric fitted to form the desired reinforcement, or, and more suitably, by sheet textile slotted inwardly from the edge to provide sector-shaped pieces radiating from a small central portion. Such blanks and the sectors are patterned to form a smooth crown when the sectors are slightly overlapped in the mold.

Headgear of the type disclosed in the aforesaid Lewis patent has been satisfactory and successful, and large numbers of protective caps and helmets constructed in accordance with it have been made and sold, and they have afforded satisfactory protection to the users.

While such headgear is satisfactory from the standpoint of the quality of the headgear and the protection afforded by it, certain drawbacks are encountered in the production of the headgear. For instance, due to uneven drag of the reinforcement in the mold, and to the slight overlap of the sectors, pockets of excess plastic may occur. Such resin pockets cause the mechanical properties of the head-wear to lack uniformity. A skilled operator having familiarity with the materials and particular shape which is being made can judge to some extent where this will occur, and the practice has been to place small extra pieces of fabric in certain areas where the operator suspects that folding of fabric and resin pocketing may occur. This is not wholly satisfactory, however, because in some instances as many as twenty extra pieces must be placed in the mold, and despite extensive experience the operator can not forecast with absolute certainty just how or where the material will fold. Furthermore, such expedients increase production costs.

Also; when the male portion of the die drags the fabric into the female die there may be an uneven 5 tension exerted upon the fabric. To counteract this danger an excess of material is provided so that in the case of extreme side pull on one side enough material will be left to form the hat or cap.

From an operating standpoint this is disadvanlo tageous because it entails considerable waste of material as well as trimming operations which would be otherwise unnecessary.

It is among the objects of this invention to provide protective headgear which'can be made 15 readily and relatively cheaply, using apparatus now available for the manufacture of headgear of the foregoing type, which overcome or minimize disadvantages encountered heretofore in the production of hats of this general type, and which are 20 of improved strength and resistance to mechanical shock while embodying the desirable features heretofore had in such head-wear.

A further object is to provide a protective headgear of this type embodying strong and rigid portions especially adapted to protect the head of the wearer from indury by mechanical and electrical sources, and having a lower portion embodying a degree of resiliency for wearing comfort while retaining the safety features.

Other objects of the invention will appear from 30 the following description.

- The invention will be described with reference to the accompanying drawings in which Figs. 1 and 2 are eievational views of reinforcing blanks for making protective headgear in accordance with this invention; Fig. 3 a plan view of the blank shown in Fig. 2; Fig. 4 an enlarged fragmentary view of the blank shown in Figs. 1 and 2; Fig. 5 a fragmentary sectional view showing, somewhat schematically, the internal construction of a headgear embodying the invention; Fig. 6 a

view similar to Fig. 4 showing a modification Fig. '7 a side view of a helmet made according to the invention; Fig. 8 a view similar to Fig. 6, with resin 4 removed in parts to show a modified embodiment of reinforcing element; Fig. 9 a fragmentary sectional view, on an enlarged scale, showing, somewhat schematically, still another embodiment of reinforcing element; Fig. 10 an elevational view 50 of still another form of blank; Fig. 11 a plan view of one use of headgear blanks shown in Fig. 10; and Fig. 11a a fragmentary sectional view of the structure made from the blank of Fig. 11.

This invention is predicated in part upon my 55 countered in making molded plastic head-wear' are minimized or overcome by reinforcing the headgear with one or more members knit, or woven, to the general contour and size of the crown, or crown and brim, which they are to reinforce. I have discovered that such knit reinforcing blanks adapt themselves to being moldably embedded in the plastic, which simplifies the making of such headgear and substantially improves the product as compared with prior practice, as will appear.

I have discovered further, and this is a particularly important feature of the invention, that especially desirable results flow from the use of blanks of the type referred to which are so knit, or woven, from textile fabric as to have ribs radiating from the center of the crown and extending vertically of it. Such reinforcing blanks afford the foregoing advantages and additionally provide improved resistance to shock due, as I now believe, to the improved mechanical properties in the direction of the ribs in the fabric.

In contrast with prior practice, therefore, there is used a unitary reinforcing element instead of the slotted sheet fabric blanks or individual small pieces of sheet cloth, and in the preferred embodiment the blank is ribbed instead of being substantially smooth as in the case of the duck cloth usually used heretofore. Since the reinforcing element is knit to the general contour of the crown, and since knit fabric embodies resiliency, the blanks adapt themselves to the mold and the mold movements so that formation of resin pockets is substantially eliminated. This renders the head-wear more uniform in its mechanical properties. These unitary woven reinforcing elements initially formed to the general contour of the crown likewise repress the tendency to drag in the molding operation, and thereby it becomes possible to use blanks of approximately correct size, thus reducing the waste heretofore arising through the extensive trimming operations that have arisen from the use of excess ma-- terial. In the practice of this invention the crown can be molded completely to shape and substantially the only overflow is an excess of plastic which is brittle and can be removed readily without the expensive and wasteful trimming operations.

A particular advantage of the hat, apart from manufacturing features, flows from the use of ribknit reinforcing elements in which the ribs radiate from the center of the crown. The rib fabric provides a structure which is more resistant to mechanical shock applied in a direction generally longitudinal to the ribs than in the head-gear available heretofore, in which duck and the like smooth fabric have been used. The advantage of this improvement lies in the fact that by far the majority of shocks are applied in the direction of the ribs, as will be understood by those skilled in the art. The mechanical properties are also more dependable because of the greater uniformity which results from eliminating the resin pockets.

A variety of moldable plastics are known which are suitable for use in the practice of this invention. Among others reference may be made to asphalts and plastics compounded from rubber, casein, or cellulose compounds, numerous examples of which are known and available for commercial use. Most suitably, however, the headgear is made from moldable plastics of the type comprising organic condensation products, commonly termed synthetic resins, or resinoils. These materials are initially plastic and moldable, but after being subjected to heat and pressure they become very hard, infusible, electrically non-conducting, insoluble in organic solvents, dilute acids and alkalies, and inert to steam and oil. Of these materials the best known, and one which is particularly advantageous, is that resulting from condensation of phenol and formaldehyde, although other types may be used of which the phenoi-furfural and urea-formaldehyde resinoids are examples.

The blanks contemplated by the invention may be knit, or woven, in various ways and from various materials. Thus, for some purposes there may be used blanks of the type that are handwoven from vegetable fibers for blocking into dress hats of the Panama and like types. More suitably, however, the blanks are machine-knit from cotton or other prepared thread.

Where a reinforced crown only is desired, the blank may, and preferably will, assume the shape and size of the crown. Such a woven blank is shown at I, Fig. 1. More often, however,"-reinforcement of. the visor of a cap, or the brim of a hat or helmet is likewise provided, and in such instances the blank will assume a form suited to that end, as described more in detail hereinafter. Most advantageously this is so knit as to provide ribs 3, Fig. 4, which radiate outwardly and downwardly from the center of the blank.

In the preferred practice of the invention the blank is impregnated with plastic, such as the well-known phenolformaldehyde type, and the impregnated blank, after drying, is then disposed in the female part of a mold shaped to produce the desired form. The blank is then pressed in the mold by a complementary male die member to form and shape it under heat and pressure, all in the manner known in the art of plastic molding. Thus there is produced a crown of molded plastic reinforced interiorly by a reinforcing element of the type described. The structure is shown schematically in Fig. 5, the blank B being moldably embedded in and reinforcing the molded plastic l.

The blank can of course be knit to any desired thickness or quality of weave and it thus becomes possible to make these headgear with a single reinforcing element. If desired for any reason, however, a plurality of such unitary, preshaped reinforcing elements may be used. Thus, the use of two reinforcing elements B moldably embedded in resin la is shown in Fig. 6.

In the practice of the invention the crown of the headgear may be made as just described, and the crown may be provided with a brim or visor or the like ancillary structure in desired manner or of desired type. Or, if preferred, the entire headgear, i. e., crown or crown and brim. may be reinforced with a unitary woven fabric element as described.

Where the crown only is made in this manner it may be provided with a continuous brim to form a helmet, or with a visor to form a cap, by attaching a suitable member to its base, as by connecting a brim of rubber, leather, or other material. Or, if desired, there may be connected a molded plastic brim or visor portion. Such connections afford a degree of flexibility between the brim and the crown which is desired in some instances.

In the preferred practice ofthe invention, however, the crown and brim, or visor, are integrally formed. Such an embodiment of the invention is illustrated in Fig. '7, which shows a protective helmet having integrally molded crown and brim portions and 6, respectively, formed in the manner just described. In the manufacture of such head-gear the woven and substantially pre-formed reinforcing blank is woven to general crown contour, as described hereinabove, and isfurther provided with a portion for forming the brim 6. This may be done in the weaving operation, or if desired for any reason an annular brim-forming portion may be stitched to the bottom of the knit crown. Figs. 2 and 3 schematically show a blank having a crown portion 5a and brim portion Go for reinforcing the crown 5 and brim 6 of the helmet shown in Fig.

'7. Preferably this blank is rib-knit to provide ribs 3a disposed as described hereinabove.

In the manufacture of head-gear of this general type a common practice has been to supplement the reinforcementof the upper portion of the crown by a foraminous metallic element, such as one or more layers of woven wire screen, likewise moldably embedded in the hat. The added strength arising from the use of rib-knit fabric with the ribs extending radially from the center of the crown confers such improved strength that for some purposes the use of an additional screen reinforcing element may be dispensed with. However, should it become necessary to afford supplemental reinforcing the invention offers the further advantage that the woven and substantially preformed reinforcing element, whether of the ribbed or unribbed type, can be knit from textile thread and wire thread. For instance, the reinforcing element can be knit with cotton or other textile thread extending in one direction, and wire in another direction to afford those desired reinforcing properties. Thus one element embodies the functions for which two elements were used heretofore.

For most purposes the 'added wire reinforcement need extend only about threefourths of the distance downwardly from the top of the crown. This is exemplified in Fig. 8, showing a safety helmet I made in accordance with the invention and having integrally molded crown and brim portions reinforced by a rib-knit fabric member of the type described hereinabove moldably embedded in the plastic. Approximately the upper three-fourths of the crown portion consists of ribbed fabric 8 knit from textile and wire threads, the lower portion 8, likewise ribbed, being formed from textile fabric only.

The crowns of protective head-gear generally may be reinforced by such textile-wire fabric moldably embedded in the plastic, these elements being used to reinforce a portion of the crown, say three-fourths of the crown from its center downwardly, and with or without other reinforcing elements. Thus, Fig. 9 is a fragmentary section through a crown comprising a woven reinforcing blank III of the type referred to hereinabove, the upper portion being further reinforced by a smaller wire-textile element Ii, as shown, both being moldably embedded in plastic I2. Element ill may be omitted for some purposes, as where great shock resistance is not needed.

Although reference has been made to the use of blanks having the crown completely woven,-

it will be understood that if desired the blank may be woven in somewhat tubular form with one end adapted to be closed to form the top of the crown, these blanks being sized and contoured to effectively constitute the woven pre-formed blanks contemplated by the invention.

Fig. 10 shows one such tubular blank adapted for the making of helmets of the general shape shown in Fig. 7. It comprises a woven brimi'orming portion i3 which is continuous with a tubular crown-forming body portion I4 having at its upper end flaps it which may be folded over to close the top of the crown when the head-wear is being molded.

Such tubular blanks are advantageous for some purposes. For instance, in the plastic molding of articles of this type the practice is to impregnate the reinforcing element with the resin prior to molding the hat or cap. This necessitates drying the impregnated blank, and by using a tubular blank the drying can be expedited since a current of air can be moved through the impregnated blank, which can not be done with closed blanks. In the use of such blanks, the impregnated and dried blank is placed in the usual female mold and flaps ii are brought together to form the closed crown, whereupon molding proceeds as usual. Ordinarily it is advantageous to overlap the flaps somewhat, but experience has shown that this does not cause resin pockets, apparently because the woven fabric is readily compressed and spaces are not left for excess resin to accumulate.

For some purposes it is desired that head-wear of the general type referred to be provided with external ribs projecting upwardly from the explished simply in the practice of this invention by the use of Woven, or knit, reinforcing elements of the type just described. In this case flaps l5 are stitched together to provide thickened seam portions l6, Fig. 11. The elements are then disposed in a female mold having seam-receiving grooves disposed to position the external ribs as desired. When the element is forced into the die by the male member the seams are thus forced into the grooves with the production of reinforcing ribs l'l, Fig. 11a, projecting upwardly from the exterior of the crown. From what has been said relative to the use of a plurality of reinforcing elements in the practice of the invention, it will be observed that in this manner any desired number of upwardly projecting external reinforcing ribs I! can be formed by the use of a plurality of reinforcing elements so arranged that the seams are staggered in the separate layers for expulsion into grooves appropriately placed in the female die.

For simplicity of representation no attempt has been made to show in Fig. 11a the resin in which the blank is moldably embedded but it will be understood that the structure is like that de-' scribed hereinabove and shown in, for example, Figs. 5 and 6.

If desired, the edge of the brim or visor may bereinforced by a moldably embedded element, such. as rope, in the manner described and claimed in Patent No. 1,875,143 to C. W. Punton. Likewise, these head-gear may be provided with linings of which a variety are known to the art and examples of which are disclosed in the aforesaid patents to Lewis and to Punton. and also in Patent No. 1,935,204 to J. B. Dym. Other types of lining may, of course, be used.

In addition to the advantages described hereinabove, a feature of the invention is that the ribbed reinforcing elements which characterize the invention permit multiple-stage impregnation of the element. That is, the ratio of fabric to plastic in the different portions of the hat can be varied with the need. Ordinarily it is desired that the upper portion of the crown be the most rigid part of these head-gear, and to this end the woven textile fabric element may be more heavily impregnated in that portion than in other portions. This means that in the practice of the invention all the rigidity and resistance to mechanical shock that are necessary can be provided in the upper portion of the crown, while the portion of the crown adjoining the brim can be less heavily impregnated and thus made somewhat flexible. This latter feature is desirable because the presence of. some flexibility in the region adjoining the sweat-band makes the head-gear more comfortable for the wearer. This has not been attained heretofore, however, it being necessary according to prior practice to make the crown of the head-gear of substantially the same rigidity throu hout.

Other advantages will be understood from what has been said. Primarily, operating dimculties are minimized and the quality of the product is improved through the attainment of uniformity arising from uniform distribution of resin, absence of resin pockets, and elimination of tearin and splitting due to drag and folding in the molding operations.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as speciflcally illustrated and described.

I claim: 1. Molded safety head-gear comprising a rigid crown portion composed of molded plastic material having moldably embedded therein at least one knit fabric blank knit substantially to the crown shape.

2. Molded safety-head-gear comprising integrally formed rigid crown and brim portions composed of molded plastic material having moldably embedded therein and extending therethrough at least one\ knit fabric blank knit substantially to the crown shape.

3. Molded safety head-gear comprising a rigid crown portion composed of. molded plastic material having moldably embedded therein at least one knit fabric blank having wire thread knit in at least the upper portion of the crown portion,

and knit substantially to crown shape.

4. Molded safety head-gear comprising a rigid crown portion composed of molded plastic material having moldably embedded therein at least one rib-knit fabric blank having the ribs radiating from the center of the crown and being free from folds and overlaps.

5. Molded safety head-gear comprising integrally formed rigid crown and brim portions composed of molded plastic material having moldably embedded in the crown at least one rib-knit fabric blank knit to substantially crown shape and having the ribs radiating from the center of the crown.

6. Molded safety head-gear according to claim 5, said blank having wire knit in at least the upper portion of the crown.

. JOSEPH B. DYM.

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