Note: Descriptions are shown in the official language in which they were submitted.
lhe inv~ntion rel~es gener~lly to nOldæ ~indow ga6ket6 ~nd to
the ~eactlon in~ec*ion Dold~ng of ~uch srtlcles from a ~lti-con6tituent
~aterial in a ~old c~vity. ~Dre p~rticul~rly, the ~nvention rel~tes to
such g~çkets sr autorotive applicatlons and to equipment and methods of
reaction ~njec~ion ~old~ng of B~Ch article~, wherein the elastomeric
wlndow gaskets are integrally n~lded onto o ~indow Eanel of gl~s or other
transparent ~ateri~l.
It has been knswn ~n the past to fab~ic~te nrticlefi ~uch a6
ncdul~r windww ga~kets for vehicular in6tallations from materi~l~ 6uch a6
polyvinylchlorlde (PVC~ u6ing conventional compre~sion or injection
snolding techniques. Some of 6uch window ga~kets h~ve been lnjection
mold~d di~ectly onto the windcw panel, ~h~ch i6 made o~ glass or other
6ub~tantially transparent naterlnl. Ihe w~ndow and gasket assemblies have
~hen been in~talled in a vehicle or other window frame wlth adhesives
and/or with integrally molded f~6tener protru~ions, ~8 disclosed, for
example, in ~nited States Patent ~08. ~,072,34D and 4,139,234. It ha~
been found, however, that windvw panel breakage has been unacceptably
hi~l in 6uch prlor processes because of the hlgh pressu~e5 re~uired in the
injection molding pr~ce~ses and becau6e ~f the hardne~s and rigidity o~
~he mold structure6 involved. ~dditionally, becau6e of the type6 of
material6 previously used ln molding the gasket6, such a~ subber or
polyvinylchlorlde (YVC~, it ha~ been found Lhat proper a~hesion of BUCh
gasketE to m~tnl body panel~ and to glass wlndc~ ~anel~ ha~ been difficult
2~ to atta~n, thereby resulting ~n water ~eak6, wind noise, and other related
problems, aG well n6 requiring the use of medhanical fa6te~er~ to secure
the a~emblie6 to the body pDnels.
~, x~ 3
This applica-tion is a division of commonly owned Canadian
Pa-tent AppLication Serial No. 448,329 filed February 277 1984.
In accordance with the present invention, improved
apparatuses of reac-tion injection molding articles such as vehicular
window gaskets are provided in order to overcome the above-discussed
disadvan-tages. Such appara-tus allows window gaskets to be reaction
injec-tion molded from multi-constituent liquid materials, such a~
urethane, for example, and to be molded at relatively low pressures
directly on-to -the glass or other transparent window panels. The gasket
and window panel assemblies can then be mounted directly into a wlndow
opening in a body panel and secured thereto with adhe~ives withou-t the
need for mechanical fastener devices~ thereby 8implifying the
installa-tion process and making i-t be-tter suited for robotic or other
automa-ted equipment. All or a portion of the gasket can also be coa-ted
wi-th a pigment decorative ma-terial in the mold cavity if desired.
The gaskets as produced by the apparatus of this invention
may also be fabrica-ted wi-th a lower cross-sectional profile, thereby
providing for a smooth aerodynamically advantageous fit between the
window assembly and the body panel. Such lower ~rofile also re(luire~
less offset or other forming of the body panel area surrounding the
window opening, thus simplifying the body panel fabrication and
increasing the design flexibility for such body panels. Also, because
the gaske-t and window assembly is preferably bonded and secured to the
body panel substantially con-tinuously around the window opening
periphery, the localized stress concentrations caused by spaced,
discrete mechanical fasteners are substantially avoided and the bonding
LCM:mls
~J~
and securing forces are more evenly distribu-ted. Thig allows the
window panel -to effectively contribute to the s-truc-tural integrity of
the installation, and also to allow for a recluction in window panel
thickness and weight.
In a preferred embodiment of the present invention, an
aftermixer appara-tus for use in a reaction in~ectlon molding system
includes a mixing
l,CM: mls
3~
body having at lea6t one co~mon inlet pa~ageway for receiving a
~ulti-oon~tituent ~aterial in a F~e~r;urized fl~able ~tate. qhe ap~r~tu~
lnclud~fi ~ n~ber of ni~ing pa~age~ay~ ~dapk~ to ~ceive the m~terial
from U~e common inlet pas~ageway and separate it into ~ corr~ponding
number of raterlal flow ~tream~ A ~ommon mixing cavity ~1 fluid
ccnmunicatiun wi~h the ~ixing pa~ageway~ reunlte~ the 6eparated flow
6treæm~ hnd convey~ the material ~nto ~ yating device for introduction
lnto the mold cavity. Adju~tment mean6 ls provided for 6electively
altering the Bize vf the oommon ~ixing cavity and the size of it~ inlets
1~ ln order to ~electlvely alter the back-pressure e~erted on the ma~erial
flowing ~lerethrough. Such ~dju~tment feature ~llows or the nptinlzation
of ~.e back-pressure ~nd thus the internlxing of the oonstituent~ of the
naterial for ~ given flow rate and inlet pres~ure thereof. Preferably,
the mixing pas6ageway6 each extend along a generally ~epentlne path
incl~ding at least cne bight portion adapted to cause the n~terial flowing
there~lro~gh to sub6tantially rever6e ~ts directi~n of ilc~ in order to
increase turbulence and e~)ance the nlxing ~f the material constituent6.
At least a portion of the preferred mold cavity of the reaction
injection molding cy6tem includes one or more elongated elastomeric
n~mber~ positioned generally adjacent ~he peripheral edge of ~le ld
cavity for 6upportingly e~ngaging the mold menber6 and the window panel.
n~e fle~ible elongated elactomeric member~ are preferably seated in
grooves in one or the other of the mold n~n~ers and are further adapted to
6ubstantially minimize or prevent fla~ling of the gasket material o~t of
the ~old cavity and al60 serve to acca,~date variations in the ~,ape of
the win~ow panels.
Additional o~jects, advantage~ ~nd feature~ of ~le present
invention will beccme apparent ~om the ~oll~wing description and appended
clains, taken in conjunction with the acccn~anying draw1ng~.
3 ~
Figure 1 lllustIate~ ~ portion of rn exemplary v~hlcular window
n66e~bly, partially ln cro6s-6ection, having a window ga6ket m~mber
lntegrally ~o7ded onto n tranEE~rent ~indcw panel in accordance with the
present lnvention.
Figure 2 ic h r~ ematic diagr~m illustr~ting ~ reaction injection
~olding Ey6tem for fabricatLng ~he ga6ket ~nd window panel assen'oly of
Figure 1.
~igure 3 1~ a partial cros6-6ectionAl view of a mold a~paratus
lo for t-he lding 6yste~ illustrated in Figure 2.
Figure 4 i~ a per~pective view of ~n aftermixer and gating
apparatus for a reac~ion injection molding apparatu~ in accordance with
~e present mvention.
Figure 5 i~ ~ cross-sectional view taken along line 5-5 of Figure
4.
P~hEP P~S5RJE~IL~L Q_~E~_PR~F~R~P J~D~2I~3~i
In Figure6 1 through 5, exemplary embodiment~ of the present
invention are illustrated for the reaction ~njection molding of
integrally-molded vehicular windcw panel gaskets onto their a~sociated
glass or other transparent ~indow panel~. One skilled in ~le art will
readily recognize rom the following di6cus6ion, however, that the
prinsiples of the invention are egually applicable to re~ction injection
molding of item~ o~)er than vehicular window gaskets, as ~ell ~s being
~L~licable to apparatu6 other Lhan the react~on injectioin molding 6ystem
sh~wn in the drawing6.
In ~igure 1, ~ vehicular window assembly 10 generally ~ncludes ~
vehicle body or other panel 12 having n reces~ed portian 14 ~rrounding an
opening for reoeiving a sub6t~ti~11y tfan~parent window panel therein.
In the exempl~ry ~indow ~6~emb1y 10 illustr~ted in Figure 1, n tran~parent
~indow panel 16, ~hich i6 prefer~bly gla~6, hn~ a window ga6ket ~e~ber 18
integrally molded ~herecn, with an edge porti~n 17 of the ~induw panel
~ub6tantially ~mbedded ~n the ga6ket member 18. Ihe gasket and wlndow
p~nel a66embly i6 6ecured to the recessed portion 14 by ~ean6 of an
s~)e6ive material 20 without the need for ~echanical fastener6 pro~rudLng
throu~l aperture6 ~n ~he body panel. Ey elimlnating the need for such
fastener~, the cro6s-6ectional profile of the ga6ket nember 1~ Day be
m m imlzed ln Drder to provide a anooth relatively unobtru6ive fit with the
body panel 12, thereby red~cing the aerodynamic drag on ~he vehicle.
A1BO, becau6e ~he gasket member ~nd window panel ~6semb1y 16 6ecured and
bonded Eubstantially continuou61y around it6 periFhery, the window panel
effectively beccne6 part of the b~dy 6tructure and i6 not 6ubjected to ~he
localized 6tress ooncentration6 cau6~d by discrete mechanical fa6tener6.
Ihus the windcw panel 16 can be thinner And lighter in weight than those
previously used. Optionally, however, lf direct bonding between the body
panel 12 and the ~in~cw panel 16 i6 defiired, the ~indow gafiket n~ber 18
may optionally be formed with a channel-6haped opening 24 e~tending
the~e~,rough in order to ~llow ~ r~uitable adhesive to bond the windcw
panel 16 directly to the recefified portion 14. Such optional
c~lannel-r~aped openins 24 ~ay consi6t of either ~ 6ingle opening extu ding
ç~ntinuou61y througho~t the entire w~ndrhw gasket member 18, or A 6erle6 of
discrete channel-shapr~ openings at ~Faced locati~l6 throughout the window
gasket Ir~er.
As will becx~le apparent from ~he discussion below, ~he window
gazket nlember 18 may al60 ~ptionAlly include e coatlng of pigmented
n~terlal either on lt6 entire exterior surface, or on ~ p~edetermined
portion thereof, a6 ~luzt~ated by referen oe numeral 26. ~uch coating of
.~_J~ 3 ~
plgmented m~terlal c~n be applied to the window g~ket member 18 dur~ng
the molding pr~ces~ ln order to provide a decorative etripe on lt6
exterior surface, or to color the window ,ga6ket member ln order to
oomplement the color Ech~me cf the vehicle~
The window ga6ket ~ember 18 i6 preferably molded from a
multi-constituent materialr BUCh a~ liquid ure~hane material for ex~mple.
~uch urethane naterial ~y be oompc6ed, for example, of a polyol re~in
constituent, an i~ocyanate constituent, ~nd a c~taly6t. Example~ of
ccnnercially-avall~ble polyol res m~ ~re nanufactured by Ihe DCW Chemical
Curpany under ~le tradama~k voR~NoL and by Texaoo Chenical CbTpany under
the trademark q3L~NaL SF-65~3. Examyles of commerci~ ocyanates are
produced by The ~pjohn Cbmpany under the trade~ark6 ISCN~IE 143L, ISaNAlE
181, ISCNAl~ 191 and ls~rE 240, ~nd al60 by ~cbay Chemical Gorporation
under the trademark~ MONLUR PF anæ MaNDUR CD. An example of a 6uitab1e
catalyst for ~ch urethane materinl ir~ marketed ~y Wltco Chenlcal Cbn~any
under the k ademark WlTCO ~OMRE~ ULr2B.
A6 illu~trated ~ematically by the reaction injection molding
6ystem 30 in Figure 2, the oon~tltuent6 of windcw gasket material are
injected from two or more constituent 60urces 32 and 34 ~nto a
Zo h~gh-pressure mixing apparatu6 36 by way of the respective metering
device~ 38 and 40. ~he oon6tituent~ of the material nre mixed ~n the
high-pre~fiure mixing appara~u6 36 at pre66ure6 in the rhnge of
approximately 2000 p.~.l.g. to approximately 3000 p.~.i.g. and are conveyed
to an a~termixer and ga~ing apparatus ~2. A~ di6cu~sed below, the
atermixer and gating apparatus ~2 further n~xe~ the con~tituent~ of Lhe
gasket material and reduce6 lt6 pre6~u~e to A range of approximately
30 p.6.i.g. to ~pproximately 100 p.6.i.g.~ and preferably approxi~ately 50
p.~.i.g., before introducing ~he material lnto a mold cavity 44 of a mold
a~ratu~ 46.
--6--
~S,J~
Prior to the lnjection of the ~ultl--aon~tituent gaGket n~terial
lnto the mold ~pparatu~ 46, the ~ld c~vity iE; preferably coated with ~ly
of n number of known mold relen6e agents, which typ~cally confii~ of
low-nælting point wa~es or ~ilioon 0116, for ex~mple. Ccmmerclal example~
of ~old relea6e agent6 are F~oducrd by Contour Chenucal Cbmpany under the
tradmark ~Rrxo 1711, EXI~T lI, l~ULEA6E 125, LIFFI ~n~ NCNSTICKENSTUFFE,
by Frekote Inc. under ~he trademarks ~REXCTE 34, FREK~TE 34H, F~ERCrE 31,
~nd FREXoTE 31~, ~nd by Palk Chemical Comçary under the t~ademark PRC7B9.
The volatile moJd release agent ~6 then all~wed to at lea~t partially
flaEh off of the n~ld spparatu6 which is typic~lly at ~ temperature ~n the
range of approximately 110~ ~o approximately 160F.
If desired, all of the mold cavity ~urface, or A predetermined
portion thereof, may be coated with a pigmented materlAl 60 that the
pign~nted material will be transferred ln the mold to the desired 6urface
or 6urfa oe s of the g36ket or other molded article during the reaction
injection molding proces6. An exa~ple of 6uch piymented material coating
i6 n~nufactured ~y S}lerwin Williams Cbmpany under the trademark PULA~E.
~fter the pig~ented naterial coating ha6 been ~llowed to flash off, the
window panel 16 is po6itioned in the mold and the mold ~ n~ers 48 and 50
of ~,e mold apparatus 46 are closed, sub6tanti~11y in mu~ual engagement
with one another. ~e oonstituent6 of the gasket ~aterial are injected
into the 6ystem~ mixed and introduced int~ the mold cav~ty 44 as described
above, and the window panel 16 with the window gaske~ 18 integrally m~lded
thereon i6 then renloved.
AS i6 known to tho6e 6killed in the reaction in~ection ~olding
~rt, the lntermixed con6tituent~ of ~he ~olding raterial underqo ~ rapid
And hig~ly exoLhermic reaction ln the mold cavity and are approx~mately
70% cured wi~hin ~ very ~hort time, generally les~ th~n one to ~lx
~ninute6, depending upon the cataly~t employed. After ~uch time, the
,~ 3~
Dolded article nay be remcved frQ~ the ld~ng ~pp~ratu~ ~nd ~llw ed to
cool ~t ~mbient ~amperatureL.
~ illustrated ln Figure 3, ~t le~6t one, and preferably both, of
the mold nenber~ 4~ nnd YO include an elongated el~fitomeric bead nember 56
oompres6ingly seated within a corre6ponding groo~e 5B~ qhe grocve6 58 are
po6itioned gener~lly ~djacent the peripher~l edye~ of the nlold cavity 44
60 that the ela6tomæric member~ 56 ou~prec6ingly engage and Eealingly
6upport either the opposite nold nember or the window panel 16 and al60
6ubs~anti~11y prevent or nini~lze fla~hing of ~he lding n~teriAl out
fro~ t})e mold c~vity ~4. When the mold apparatus i6 open, the ela~toleric
~anber6 56 preferably protrude slightly from thelr as60ciated grooves 58
so ~hat the ~orce required to hold the mold member6 48 and 50 together ~n
a ~ealing engagement i6 6ub~tanti~11y reduced from the force that would be
nece~6ary if the mold member6 were required to be fo~ced into direct
contact with one another. SLmilarly, s 61gnificantly reduced pres~ure i6
exeIted on the window panel 16 and consequently ~le frequency of breakage
of the window panels i6 r~ub6tanti~11y minimized or eliminated. Such
reduction in the force required to hold the mold n~3nber6 together i6 al~o
6ignificantly less than that required in oonventional oallpres6ion and
injection molding processe6. Additionally, the ela6to~erlc members 56 are
6ufficiently flexible to allow for minor variation~ ln the 6hape and
contour of the windcw panels and thereby sealingly i~olate the mold cavity
44 regardlec6 of ~ch minor window panel variations.
Figure6 4 and 5 illu6trate ~n improved atermixer and gating
aE~aratu~ 42, genernlly including an arter~ixer block or body 64 and a
gating block or boay 66 po~ition in one or the ot21er of the ~old menbers 4B
or 50 for further mixlng the congtituent6 of the gasket material and
a~nittLng the materi~l to the ~old cavity 44.
The Altermixer body 64 lnclude6 at least one con~on inlet
~ 3~ ~ ~3
pafi6a9eW~y 68 for r~oeiving tbe gAfiket ~teri~l from the hl~-prefifiure
~lx~ng appalatus 3~ ~t a pre~etenmlned flo~ rate ~nd prefifiUre. The gafiket
materinl fiows through the inlet pafifiageway 6B into nt le~fit a pair of
curvilinear mlxing pas6agewayfi 72 ~nd 74 ~here it i6 ~eparated into D
correfiponding number of flow ~tream6. ~uch ~eparation lncrea~e6 the
turbulence of the gafiket material flow ~nd accordingly enhance6 the
internlxiny of lt6 oonfitituentfi. ~e mlxing pafisageways 72 and 74 include
a divider wall 76 therein, ~hich fonm ~ generally serpentLne path in the
mlxing pa~sageway6. Such EærFentine path includefi at leafit one bight
portion 78 in the mlxing passageway 72 ~n~ a similar bight portlcn 82 ln
the nlxing pas~ageway 74. ~uch bight portions CaUBe the gasket material
to 6ub~tantially reverse it~ direction of flow, ~ indicated by the flc~
arrows 8q ~nd 86, re6pectively, in order to i~crease the turbulence of
each of the gasket material flow streams and enhance the inter~ixing of
the constituents therein.
~)ce the gasket material flow6 through the mixing pa6sageway6 72
and 74, it enters a corresponding number of respective inlet openings 88
and 90 of at least ane cxr,lmon mixing cavity 92. The flow streams from the
rixing passageways are reunited in the mlxing cavlty 92, which again
reverses the flow directions of the flow stream6, incrense~ their
turbulence, and enhances the lntermlxing of the gasket material
conStituents. The reunited and intermixed gasket material fram the mixing
cavity is received by the inlet pHssageway 94 in the gating body, wherein
it i6 conveyed through ~ diverging fan-gate passageway g6 to the mold
cavity 44.
~ he aftermixer body 64 preferably i~cludes n ~tepped or ofset
porticn 102 adapked ~o slidLngly engage n preferably corresponding ~tepped
or offEet portion 104 on the gating bo~y 66, guch ~hat ~he altermlxer body
64 and the gating bo~y 66 nay be slidably ~nd adjustably moved toward or
~way from one ~no~.er n~ lndic~ted by tbe arruw% 106 and 108. nle gating
b¢dy 66 ~l~o lnclude~ ~n integrrlly-fon~ed tongue portlon 110 in ~hich the
gating inlet pn~6ageway 94 i& for~ed. ~he tongue portion 110 1~ rlidably
~eceived in ~ ~lot 112 in the ~ftenml~er body 64 for elld~ble and
ndju6t~ble ~ove~ent thereln ~B the ~ftermi~er ~nd gating bodie5 are
~d~u~tably noved ~s descri~ed ~bvve. ~e ena portlon 114 of the tcngue
portion 110 def~ne~ tbe e~it portion of the mixing cnvity 92 ~uch that
6slective nL~ement of the tongue pcrt~on 110 in the ~lot 112 all~w6 the
6ize6 of the mi~ing cavity 92 and it6 inlet openingc ~8 Dnd 90 to be
eelectively ~ltered e8 the aften2ixer ~nd gating bodie6 are 6~1ectively
and ~dju6tably moved. Ihu6 the slze6 of the mixing savity snd lts inlet
openings may be Eelectively ~nd ~dju6tab1y increa~ed a8 the aftermixer and
gating bodie6 are ~oved apart from one another, ~nd corre6pondingly 6uch
6izes may be 6electively and ~dju6tably decreased a~ the aftermixer ~nd
gating bodies a~e ~oved toward one another. In order to fill the
unoccupied gap in the slot 112 ln the aftermixer body 64 after the
aftermixer body has been adju6tab1y moved away from the gating body 66,
one or more shim rembers 120 are removably ln6e!table into the 610t
adjacent the end portion 114 of the tongue 110.
The aftermixer body 64 16 preferably provided with one or more
elonga~ed opening6 124 the~ethrough for receiving ~ threaded fastener 126
extel)ding therethrough. The threaded fa6tener i6 adapted to threadably
engage a threaded aperture 12B in the gating body 66 and cerves a~ a
locking ~eans for fixing a pre6elected po6ition of the tongue portion 110
ln the 610t 112. Preferably, the a~tenmixer body 64 i6 al60 prov~ded wlth
c~unter6unk portion~ 13D for ~llo~ing the head portlon6 132 of the
a~tener6 126 ~n ~ rece66ed relatlon6hip wlth the 6urface 134 of the
aftelmi~er body 64.
The above-de~crlb~d select~ve ad~u~tment6 to ~he 6i~e ~f the
^r~
~lxing CAVity ~2 ~nd lts ~nlet vpening6 94 ~nd 96 allow for the ~elective
alter~tion of t~e back-pre~sure e~erte~ by tbe rfter~lxer 3nd gating
~pparatus 42 on t~e ga~ket material flcwlng therethrough. ~u~ alteration
thereby ~llcw~ for ~le 0ælectlve optimization of the intermlxing of the
con~tituent6 of the ga6ket ~ateri~l for ~ predetermined flow rate ~nd
pre~sule of the n~terial from the high-pre~ure mixin~ ~pparatu6 36 Ehown
~ematic~lly in Figure 2. ~y ~uch adju~bments, ~lerefore, the u6er of
the reaction injection molding ~ystem may ~fine-tuner the proce~6 to
nchieve optimum lntermixing and reaction of the constituent~ of the
lding materi~l a6 well a6 achieving greater control over the pre~6ure at
whidh the ~olding material i6 introduced into the mold cavlty~
m e foregolng di6cu66ion discloses ~nd describe~ ~xemplary
embodin~nt6 of ~le pre6ent invention. One Ekilled in ~he art will readily
reoognize from 6udh di6cussion that various dhanges, rcdifications and
vari~tion6 ~ay be made therein without departing fram the 6pirit and ~cope
of the invention as defined in the following claim60
