вход по аккаунту


Патент USA US2123275

код для вставки
July 12, 1938.
Filed June 1, 1936
2 Sheets-Sheet 2
. 1o.
, WWI»
rzxru. :
wpvE/v CLOTH or
£046; 507401:
Patented July 12, 1938
_ 2,123,275’
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, ?remen,
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.
Various types of protective head-wear have been
made. Of these one of the most satisfactory is
the type disclosed in Patent No. 1,835,883 to J. M.
10 Lewis. That patent discloses safety headgear
comprising molded plastic material, ‘suitably
phenoL-formaldehyde resin, interiorly reinforced
by one or more layers of formable material in
sheet form, such as duck cloth or the like, mold
ably embedded in the plastic. In the manufac
ture of such molded plastic headgear it has not
been possible satisfactorily to use a unitary sheet
solute 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 soi
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 disadvan- lo
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 pro
vide 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
helmet crowns isv such that folds can not be . disadvantages encountered heretofore in the pro
20 avoided when the sheet is forced into a crown
duction of hats of this general type, and which are 20
forming mold. Such folds would be highly unde
of improved strength and resistance to mechani
sirable. Accordingly, all headgear of this type cal shock while embodying the desirable features
with which I am familiar have been reinforced heretofore had in such head-wear.
with small pieces of sheet fabric ?tted to form the
A further object is to provide a protective head
desired reinforcement, or, and more suitably, by gear of this type embodying strong and rigid por
sheet textile slotted inwardly from the edge to tions especially adapted to protect the head of the
provide sector-shaped pieces radiating from a wearer from indury by mechanical and electrical
small central portion. Such blanks and the sec
sources, and having a lower portion embodying a
tors are patterned to form a smooth crown when degree of resiliency for wearing comfort while re
of fabric because the contour of the cap, hat and
30 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
35 and sold, and they have afforded satisfactory pro
tection 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
40 encountered in the production of the headgear.
For instance, due to uneven drag of the reinforce
ment 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 op
erator having familiarity with the materials and
particular shape which is being made can judge
to some extent where this will occur, and the prac
tice ‘has been to place small extra pieces of fabric
50 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
55 experience the operator can not forecast with ab
taining 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 frag
mentary view of the blank shown in Figs. 1 and 2;
Fig. 5 a fragmentary sectional view showing, some
what schematically, the internal construction of
a headgear embodying the invention; Fig. 6 > a
view similar to Fig. 4 showing a modi?cation ; 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 modi?ed embodiment
of reinforcing element; Fig. 9 a fragmentary sec
tional view, on an enlarged scale, showing, some
what 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
discovery that the foregoing disadvantages en
countered in making molded plasticvhead-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 rein
force. I have discovered that such knit reinforc
ing blanks adapt themselves to being moldably
embedded in the plastic, which simplifies the mak
ing of such headgear and substantially improves
the product as compared with prior practice, as
will appear.
I have discovered further, and this is a par
ticularly important feature of the invention, that
15 especially desirable results ?ow from the use of
blanks of the type referred to which are so knit,
or woven, from textile fabric as to have ribs ra
diating from the center of the crown and extend
ing vertically of it. Such reinforcing blanks af
20 ford the foregoing advantages and additionally
provide improved resistance to shock due, as I
now believe, to the improved mechanical proper
ties in the direction of the ribs in the fabric.
In contrast with prior practice, therefore, there
25 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
30 cloth usually used heretofore. Since the rein
forcing element is knit to the general contour
of the crown, and since knit fabric embodies re
siliency, the blanks adapt themselves to the mold
and the mold movements so that formation of
35 resin pockets is substantially eliminated. This
renders the head-wear more uniform in its me
chanical properties. These unitary woven rein
forcing 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 opera
tions that have arisen from the use of ‘excess ma46 terial. In the practice of this invention the crown
can be molded completely to shape and substan
tially the only over?ow is an excess of plastic
which is brittle and can be removed readily with
out the expensive and wasteful trimming opera
A particular advantage of the hat, apart from
manufacturing features, ?ows from the use of rib
knit reinforcing elements in which the ribs radiate
from the center of the crown. The rib fabric pro
vides a structure which is more resistant to me
chanical 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
materials are initially plastic and moldable, but
after being subjected to heat and pressure they
become very hard, infusible, electrically non-con
ducting, 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 re
sulting from condensation of phenol and formal
dehyde, although other types may be used of
which the phenoi-furfural and urea-formalde 10
hyde 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 hand 15
woven from vegetable ?bers 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,"-rein
forcement 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 rein~
forcing element of the type described. The
structure is shown schematically in Fig. 5, the
blank B being moldably embedded in and rein
forcing the molded plastic l. /
The blank can of course be knit to any desired
thickness or quality of weave and it thus be
comes possible to make these headgear with a
single reinforcing element. If desired for any
reason, however, a plurality of such unitary, pre
shaped 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
the art. The mechanical properties are also more
it may be provided with a‘ continuous brim to
dependable because of the greater uniformity
which results from eliminating the resin pockets.
by attaching a suitable member to its base, as by
A variety of moldable plastics are known which
are suitable for use in the practice of this inven
tion. Among others reference may be made to
asphalts and plastics compounded from rubber,
10 casein, or cellulose compounds, numerous exam
ples of which are known and available for com
mercial use. Most suitably, however, the head
gear is made from moldable plastics of the type
comprising organic condensation products, com
monly termed synthetic resins, or resinoils. These
form a helmet, or with a visor to form a cap,
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 ?exibility between
the brim and the crown which is desired in some 70
In the preferred practice of- the invention,
however, the crown and brim, or visor, are in
tegrally formed. Such an embodiment of the
invention is illustrated in Fig. '7, which shows a
protective helmet having integrally molded crown
and brim portions ‘5 and 6, respectively, formed
in the manner just described. In the manufac
ture of such head-gear the woven and substan
tially pre-formed reinforcing blank is woven to
general crown contour, as described hereinabove,
and isfurther provided with a portion for form
ing the brim 6. This may be done in the weav
ing operation, or if desired for any reason an
10 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 por
‘tion 5a and brim portion Go for reinforcing the
‘crown 5 and brim 6 of the helmet shown in Fig.
15 '7. Preferably this blank is rib-knit to provide
ribs 3a disposed as described hereinabove.
In the manufacture of head-gear of this gen
' eral type a common practice has ‘been to sup
plement the reinforcementof the upper portion
20 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
for the making of helmets of the general shape
shown in Fig. 7. It comprises a woven brim
i'orming portion i3 which is continuous with a
tubular crown-forming body portion I4 having
at its upper end ?aps it which may be folded 5
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 im 10
pregnate the reinforcing element with the resin
prior to molding the hat or cap. This neces
sitates drying the impregnated blank, and by
using a tubular blank the drying can be ex
pedited since a current of air can be moved 15
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 ?aps ii are brought
together to form the closed crown, whereupon 20
molding proceeds as usual. Ordinarily it is ad
vantageous to overlap the ?aps somewhat, but
fabric with the ribs extending radially from the , experience has shown that this does not cause
25 center of the crown confers such improved resin pockets, apparently because ‘the woven
strength that for some purposes the use of an fabric is readily compressed and spaces are not 25
additional screen reinforcing element may be left for excess resin to accumulate.
dispensed with. However, should it ‘become
necessary to afford supplemental reinforcing the of the general type referred to be provided with
invention offers the further advantage that the external ribs projecting upwardly from the ex
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 reinforce
ment need extend only about three—fourths of
the distance downwardly from the top of the
crown. This is exempli?ed 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 mold
ably 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 reinforc
ing elements. Thus, Fig. 9 is a fragmentary sec
tion through a crown comprising a woven rein
forcing blank III of the type referred to herein
above, the upper portion being further reinforced
by a smaller wire-textile element Ii, as shown,
both being moldably embedded in plastic I2.
65 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
70 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.
75 Fig. 10 shows one such tubular blank adapted
_ terior surface of the crown.
This can be accom
plished simply in the practice of this invention ‘_
by the use of Woven, or knit, reinforcing elements
of the type just described. In this case ?aps
l5 are stitched together to provide thickened
seam portions l6, Fig. 11. The elements are then 35
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 reinforc 40
ing 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 reinforc
ing elements in the practice of the invention,
it will be observed that in this manner any de
sired 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 50
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-' 55
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 60
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 afore
said patents to Lewis and to Punton. and also in 65
Patent No. 1,935,204 to J. B. Dym. Other types
of lining‘ may, of course, be used.
In addition to the advantages described herein
above, a feature of the invention is that the
ribbed reinforcing elements which characterize 70
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 75
- 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 por
tions. This means that in the practice of the
invention all the rigidity and resistance to me
chanical shock that are necessary canvbe provided
in the upper portion of the crown, while the por
tion of the crown adjoining the brim can be less
heavily impregnated and thus made somewhat
10 ?exible.
This latter feature is desirable because
the presence of. some ?exibility in the region ad
joining the sweat-band makes the head-gear more
comfortable for the wearer. This has not been
attained heretofore, however, it being necessary
15 according to prior practice to make the crown
of the head-gear of substantially the same rigidity
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, ab
sence of resin pockets, and elimination of tearing
and splitting due to drag and folding in the mold
ing operations.
According to the provisions of the patent
statutes, I have explained the principle and con
struction 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 ap
pended claims, the invention may be practiced
otherwise than as speciflcally illustrated and de
I claim:
1. Molded safety head-gear comprising a rigid
crown portion composed of molded plastic ma
terial having moldably embedded therein at least‘
one knit fabric blank knit substantially to the
crown shape.
2. Molded safety-head-gear comprising inte
grally formed rigid crown and brim portions com
posed of molded plastic material having moldably
embedded therein and extending therethrough at 10
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 ma
terial having moldably embedded therein at least 15
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 ma 20
terial having moldably embedded therein at least
one rib-knit fabric blank having the ribs radiat
ing from the center of the crown and being free
from folds and overlaps.
5. Molded safety head-gear comprising inte 25
grally formed rigid crown and brim portions com
posed 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 30
6. Molded safety head-gear according to claim
5, said blank having wire knit in at least the
upper portion of the crown.
Без категории
Размер файла
710 Кб
Пожаловаться на содержимое документа