Note: Descriptions are shown in the official language in which they were submitted.
1077~f~3
The present invention relstes to boots useful in aquatic
activities, p~rticularly in underwater diving arld also concerns a
method of meking 3~me.
Such boots are normally made from a sock rising to just aooue
the ankle, with the sock heving an outsole of rubber. The sock itself
is normally made by ctitching together piece~ of cellular ela~to~er,
pr6fsrably covered by one Or two piec8~ of fabric, of nylon or eimil~r
synthetic yarn. A rubber outoole i~ then adhered to the bottom of
; the sock. One known type of outsole i~ a precut piecs which i8
cemented and ~titched to the sock all around the edge of the outsole.
In such a known construction, in order for the out~ole to be stitchs~
to the sock, it must be made of low grade flexible and soft rubber and
the latter, together with the otitching itself, can be easlly torn away
from the sock during use. Another known type Or outsole con~ist8 of a molded
rubbér piecs whlch is cemented to the aock. It has been found that such
conventionsl divers' boots do not lsst very long.
It i8 sn object Or the invention to provide a boot, which
obviates the above-noted disodvantage~ in that the rubber out~ole is
directly molded and vulcanized in ~itu and adheres to the sock without
any stitching.
~ore specirically, the boot of the prssent invention compri~eJ a
sock mada of a cellular elostom0ric material, including an in~ole and
an upper, and an outsole a~mbly consisting sub~tantially of a non-cellular
rubber composition coverlng the insole and the adjacent p~rt of the upper
all arDund the insole, said outoole eseembly bsing vulcanized in oitu
; and adh3ring to the sock.
Ths pre~ent invention also resides in a method of making such
a boot, which method comprise~ the steps of forming a sock including a
aole portion and un upper, fro~ a sheet of cellular elastomeric material;
adhering an outole aaesmbly including unvulcanized non-cellular rubber
composition to sQid sole portion and to the adJacent part of the upper
all around the 301e portion; plscing the re~ulting unit in an oven snd
vulcanizing under pressure ~aid out~ole a3sembly in situ on ~aid ~ock
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at a maximum temperature belew the degrading tempsrature of th~ ~ellular
elastomeric material of the 8eck
Preferably, s~id elastomeric material i8 cellul~r neoprene~ end
~; the rubber composition of the outsole assembly iA natural rubb~r
A pre~erred embodiment of the pre~ent invention will be
hereinofter described with reference to the accompanying drawing~, whe~ein
; Figure 1 io ~ per~pective vlew of ~ boot in accordance
with the invention;
` Figure 2 is a side elevatlon of the s~me;
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Figure 3 io a perspectivo vlew of the sock proper, the
upper portion being cut away;
Figure 4 is a longitudinal section of the boot, taken along
line 4-4 of Figure 1; snd
~ igure 5 is a cross-section, taken along line 5-5 of Flgure 2
In the drawlng~, like reterence charscters indicote lik0 ~lements
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1 throughout.
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A~ illustrated in the drawlng~, the boot comprises a sock 1, covered
in p rt by an outoole aosembly; generally indicated at 2, and made of rubber.
The outsole assembly more pecitloally includeo an outsole proper~ indlcated
~1 20 at 3, a toe-cap 4 covering the toe portion o- the sock 1, a back stay 5
;~ covering the heel portion ot the ock 1 snd e oxing 6 surrounding the
,1 entire lower edge ot the ~ock 1 nd ~ormlng -n lntegral unlt with the outsole
3, the toe-cap 4 and the back 5.
The sock 1 1~ made`trom at lea6t one plece of flexible and heat-
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insulating material, properly cut nd stltched to form the sock. In the
example shown, two pieceo are u~ed; they are stltched together by the line
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of otitching 7~extsndlng ln the centr-l vertical plane of the sock. Thu~
the in~ulating material is msde ot a layer 8 of cellular oynthetic elaatomer,
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;~ such ao celluler neoprene. Layer 9 may be uoed as is, or one or both faces
3û of which can be covered by a t-bric ot synthetlc yarn, such as nylon, sdhering
to layer ~. The drowings show an lnolde fabric 9 and an outside fabric 10
As an example, thickness ot the ~ock may vary trom 5 to ? millimeters and
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it has a high thermol insulation prope~ty, is highly flexible and absorbs
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water, a maximum ot about five percent by w~ight of the materisl,
Th~ sock is made in a conuentional m~nner in the making
of the boot. Once the sock ha~ been prepared, a metal laEt i8 insertsd
therein to impart to the sock ths sh~pe of a bo~t with ~ sole surfac~.
The underside ~nd the lower ~dges of the sock aru th~n co~red with a
first coat of a neoprene bHse cement which adh~res to cellular neoprene
layer ~ by being absorbed through the fabric 10 and which also adheres
to the outside fabric 10, the latter being gen~rally ~adl of nylon. Then,
a ~econd coat of cement, namely a netural rubber ba~e cement, i8 applied
on the first co~t. The second co0t adheres to the fir~t coat and also to
the outsole assflmbly 2~ since the latter is made of natural rubber, The
Various rubber part~ are th~n applied to the cement^coated 80C~. First,
a filler 11 ia applied and adhered to the so~e surface; filler 11 consists
of a rabric impregnsted with natural unvolcanized rubber and Or about 45
thou~ahdths Or an inoh thick; uovulcanlzed natursl rubber parts including
the' toe-cap 4, the back atay S and the foxing 6 ere then applied and
adhered tn the sock 1 and to the ~iller abrlc 11 ln their proper posltion.
The outsole 3 i8 then applied and adhered to the sock, and the entlre
~' asembly i8 th'en placed in sn autoclsve subjected to he~t and pre~sure
t~ vulcanize the outsole as~embly 2 in sltu. The vulcsnlzation, or curing
cycle, 1~ ~uch that the natural rubber components sre progresslvely
bro ught to ~ temper~turn Or a moxlmum Or 240~ during one hour and then
cured'for another three hour- at 24ûF, ~uch temperature belng chosen
80 as not to degrade the ela~tomeric property Or the sock materisl. The
autoclave i~ then opened and the resulting boot has it~ proper shspe
and has its out~ole assembly vulcanized in situ and ~ odhering
to the sock. No stitchlng whatever i~ needed to Qttsch the outsole
aseembly to the sook. Since nb atitching i~ requir0d, high grade natural
rubber parts are ssle~ to make the outsole assembly.
It is to bs noted that it is important not to exceed the
degrading temperature ot the oock material in the vulcanlzation step.
In this re~pect, a vulcanizing cycle of 1-3/4 hour at 3û pound-pressure
with a curlng cycle of fir~t one-half hour with 8 temper~turs rising
up to 270F and with a turther 1-1/4 hour wlth a temperature rsmaining at
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1077Z~i3
270F~ has been tried. ~owaver, in that experiment, it wa~ nated that
the temperature and vulcanizing cycle used caused a gre~t red~ction in
th~ thickne~s of the foam of the sock~ which would have resulted in a
great 1098 in the heat-in81ulsting property of the ~aterial of the 80ck.
In the vulcanizing cycle u8ad~ it is to be noted that a lower
temperature than 240F could be used; but then with a longer curing -
cycle. In fact, room tempereture could be used for vulcanization; but
the curing cycle would last one weak, which is not prsctical.
The pre88ure used during vulcanization i8 normally 30 pounds~
lû but could be as low 89 10 pounds per square inch.
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