Note: Descriptions are shown in the official language in which they were submitted.
0
~EINFORCED STRIP AND FLExIBLE HOSES PRODUCED THEREWITH
The pr~sent invention is directed to strips for
use in forming flexible hoses. More particularly, the
present invention rel~tes to flexible hoses produced from
such strips, and to methods for producing flexible hoses
from helically wound strips.
It has been known for many years that ~lexible
plastic hoses can be produced by winding one or more
strips or elongated members formed from polymeric
materials into a helical structure. Upon winding
displaced portions of these strips on adjacent turns of
the helix, these adjacent turns, which have been referred
to as connecting portions, can then be secured together,
such as by the use of polymeric bonding material or hot
m~lt compositions. These molten bonding materials are
ordinarily applied to a connecting portion of such a
member as it is wound into the helical structure.
Such helically wound flexible hoses, as
disclosed for example in Richitelli, U.S. Patent NoO
3,199,541, have included both the use sf a single strip-
like member with a U-shaped channel on one edge and a
projection on the opposite edge, and a two-strip hose
produced ~rom a U-shaped channel member and a cap member
wound in alternating turns. The Richitelli patent also
includes the use of a reinforcing material 38, such as
that shown in FIGS. 6-11 thereof, which is said to be
substantially stiffer than the other hose materials, and
which is arranged on the radially extending walls of the
hose. This patent contends that the purposa o~ same is
u
to provide a stiff reinforcing element between the
convolutions of the hose. In some embodiments thereof, ths
reinforcing material, comprising polyethy].ene or polyethylene
copolymers i5 extruded and united with the basic strip
immediately after the extrusion process, and the reinforcing
material is exposed to the surface of the strip so that the
bond between adjoining strips may involve bonding of the
reinforcing material of one strip to the softer material of
an adjoining strip.
lG Another such strip material.is shown in Finley, U.S.
Patent No. 4,383,555, in ~hich the strips include a thin web
or membrane 21 of relatively soft material and a pair of
relatively rigid rib components extending alon~ the opposite
maryins of that web and co-extruded therewi~-h.
In addition, the applicant has discovered that such
spirally wound hoses can be produced with enhanced structural
strength and integrity., and still remain readily bondable by
fusing a buffer material which is more readily susceptible to
fusion under heat and/or pressure to a structural material
which is a relatively difficult to fuse polymeric material
having greater strength and rigidity. Molten polymeric
bonding material can then be used to bond these buffer
materials together.
In accordance with the present invention, the
deficiencies of the prior art helically wound flexible hoses
have now been overcome by the discovery of a strip material
.~
1 3 1 080~
-3
for use in forming a flexible hose from helically wound
convolutions of that strip.
According to the present invention then, there is
provided a strip for use in forming a flexible hose from
helically wound convolutions of the strip, the strip
comprising a substantially U~shaped body portion including a
pair of radially projecting, spaced-apart wall members
connected by a transverse portion, the body portion comprising
a first polymeric material having a predetermined Young's
modulus, substantially the entire surface of the body portion
comprising the polymeric material, whereby adjacent portions
of the body portion can be directly bonded together to form
the flexible hose upon the helical winding of the strip, the
spaced-apart wall members comprising first and second plate-
like support members embedded within th~ wall members, the
first and second plate-like support members comprising a
second polymeric material having a predetermined Youngls
modulus higher than the predetermined Young's modulus of the
first polymeric material of the body portion, whereby the
transverse portion is substantially free of the plate-like
support members, the plate-like support members thereby
reinforcing the wall members and permitting the body portion
to substantially retain its shape upon the application of
external force thereto.
~ he hose of the present invention comprlses a
helically wound strip defining a plurality of turns, the strip
comprising a substantially U-shaped body portion including a
~b
~ 3 1 ~8''1~
-4-
pair of radially projected spaced-apart wall members connected
by a transverse portion, the body portion comprising a first
polymeric material having a predetermined Young~s modulus,
substantially the entire surface of the body portion
comprising the polymeric material, whereby adjacent portions
of the plurality of turns of the strip can be directly bonded
together to form the hose, the pair of wall members comprising
first and second plate-like support members imbedded within
the pair of wall members, the first and second plate-like
support members being spaced apart by the transverse portion
and comprising a second polymeric material having a
predetermined Young's modulus higher than the predetermined
Young's modu~us of the first polymeric material of the body
portion, whereby the transverse portion is substantially free
of plate-like support members, the plate-like support members
thereby reinforcing the wall members and permitting the body
portion to substantially retain its shape upon the application
of external force thereto.
A method for making a flexible hose is also
provided~ comprising providing a stri.p comprising a
substantially U-shaped body portion including a pair of
radially projecting ~paced-apart wall members connect.ed by a
transverse portion, the body portion comprising a first
polymeric material having a predetermined Young's modulus,
substantially the entire surface of the body portion
comprising the polymeric material, and radially projecting
first and second plate-like support members imbedded in the
;~
IJI 08 G 0
--5--
pair of wall membersl the first and second plate-like support
members comprising a second polymeric material hav.ing a
predetermined Youngls modulus higher than th~ predetermined
Young's modulus of the first polymeric material of the body
portion, whereby the transverse portion is substantially free
of plate-like support members, the plate-like support members
thereby reinforcing the wall members and permitting the body
por~ion to substantially retain its shape upon the application
of external force thereto, winding the strip into a generally
helical configuration so that the strip forms a plurality of
turns, whereby displaced sections of the radially projecting
wall members are juxtaposed with one another, and directly
bonding the }uxtaposed sections of the wall members together
to form the flexi~)le hose.
In accordance with preferred embodiments of the
present invention, the method includes co-extruding the body
portion and the first and second plate-like support members
to produce the strip, and the plate like support members are
embedded within the body portion, and follow the shape of the
body portion for a predetermined portion thereof. In another
preferred embodiment, the plate-like support members are
radially projecting and are embedded in the wall members.
The present invention can be more fully appreciated
~: with reference to the following detailed description, which
refers to the attached drawings in which:
,~
, . ,
'
~ 3 1 ~ 8 0 ~
5a-
FIG. 1 is a schematic, sectional view showing
portions of a hose according to one embodiment of the present
invention;
FIG. 2 is a fragmentary view tiaken on an enlaryed
scale of a portion of the hose shown in FIG. l;
FIG. 3 is a si.de, sectional view of a portion of a
hose produced in accordance with another embodiment of the
present invention;
FIG. 4 is a side, sectional view of a portion of a
hose produced in accordance with another embodiment of the
present invention;
FIG. 5 is a side, sectional view of a portion of a
hose produced in accordance with another embodiment of the
present invention; and
FIG. 6 is a side, sectional view of a portion of a
hose produced in accordance with another embodiment of the
present invention.
:
~.~
-6- ~ 31 o~an
Referring next to the figures, in which like
numerals refer to like portions thereofl channel
member 10 employed in preparing a flexible hose in
accordance with the present invention is generally U-
shaped in section. Unless otherwise indicated, the
descriptions in this disclosure of the shape of an
elongated member or strip 'Jsection~ should be unders~ood
as referring to thP shape of the me~ber viewed in a
cross-section taken on a cut~ing plane transverse to its
direction of elongation. Ordinarily~ although not
necessarily, the elongated members are substantially
uniform in cross-sectional shape throughout their length.
Channel member 10 includes a transverse wall
portion 12 and a pair of radially projecting~
substantially parallel side wall portions 14 and 16.
Transverse wall portion 12 includes an inner surface 1~,
whil~ radially projecting side walls 14 and 16 include
inner sur~aces 20 and 22, respectively, which face
towards each other, thus creating inner space 24
therebetween. One side wall 14 terminates in
transversely extending end portion 26, which extends only
a short distance from the side wall 14. The other sids
: wall 16 terminates in longer transversely ex~ending side
portion 28, which includes a radially extending end
portion 30, thus forming a channel portion 31 (as can
best be seen on the left-hand side of FIG. 2) between the
radially extending side wall portion 16 and the radially
extending end portion 30. As will be explained in more
detail below, production of a flexible hosa from this
_7_ 1 3 ~ ù~
channel member or strip results from helical winding of
the strip so that the transversely extending end portion
26 at the end of wall portion 14 enters into the channel
portion 31 ~ormed between radially extending wall portion
16 and radially extending end portion 30. Furthermore,
production of such a 1exible hose also includes the
presence of bonding material 32 within channel portion
31, which assists in effecting a w~ld between the side
walls forming the channel portion 31 and the end portion
26 of the wall portion 14. The bonding material 32 can
best be seen on the righhand side of in FIG. 2 hereof.
Channel or strip member 10 itself is formed substantially
entirely of a readily fusible, low melting material, such
as ethylene ethyl acrylate (EE~), ethylene vinyl acetate
(EVA), and other such polymers having a low Young's
modulus, which are thus readily fusible in accordance
with the preparation of a hose in accordance herewith.
l'hese includ various other ethylene copolymers,
preferably with acrylic acid esters, or vinyl esters, so
that these copolymers have the overall physical
properties discussed above.
~ his material from which the channel or strip
member 10 is formed thus constitutes the entir~ outer
surface o~ strip 10. Thus, by merely interposing bonding
material 32 therebetween, direct welding of these
adjacent portions of the strip 10 can be effected, as
shown in the figure~, so as to produce th~ flexible hoses
of this invention. However, because o~ the nature of
these materials used to ~or~ the strip 10, they do not
! Jl ~8C 3
--8--
have the structural s~ability to resist subsequent
collapse, such as upon the exertion o~ external forces
created by vacuum and other pres~ures within the hose
which can be anticipated during use. Therefore, within
the strip itself, for example within and parallel to
radially projecting side walls 14 and 16, there are
included plate-like strips of rein~orcing material 34
and 36, respectively. These plate-like strips of
reinforcing material are formed from a relatively high
melting, but difficult to fuse structural material, such
as linear low density polyethylene (LLDPE), high density
polyethylene (HDPE~, a group of monomer resins sold under
the trademark SURLYN by E.I. DuPont de Nemours & Co., and
other such high Young~s modulus polymeric materials.
The reinforcing plate-like strips 34 and 36 can
be formed wi.thin the radially projectiny ~ide wall
members 14 and 16, respectively, in a coextrusion
process. As the process of coextrusion per se is
conventional and well Xnown to those skilled in the
plastic arts, this procPss need not be described in
detail herein. The coextrusion pxocess typically brings
each material to a liquid state and unites the flowing
liquid streams. In coextrusion, the heat and pressure
which may be applied to cause fusion o~ the two materials
are limited only by ~he degradation temperature of the
materials and the capacity o the equipment. ~ecause
conditions of heat and pressure far more severe than
those attainablé during the hose winding operation can be
applied during the coextrusion operation, the two
, ~ ~, . . .
9 1 3 1 ~u~
materials in question can be readily united during
coextrusion.
The thickness of the mat~rial forming the strip
10, including transverse wall me~ber 12 and radially
projecting wall portions 14 and 16, is generally between
about .020 and .060 inche~, and more praferably between
about .035 and .045 inch~s. The thi.cknsss of the ~upport
members 34 and 36, however, is g~nerally between about
.005 and .05C inches, and most preferably between about
.015 and ~030 inches.
As discussed above, and as can be shown more
clearly in FIG. 1, the channel or strip member 10 thus
described is wound on a generally cylindrical mandrel 50
having an axis 52 so that the strip member is formed into
a plurality of turns and hence into a helix extending
along axis 52. The side wall~ o neighboring turns of
strip member 10 are juxtaposed with one another, so that
the radially projecting side wall 14 of one ~urn of the
strip me~ber is juxtaposed with the radially projecting
side ~all 16 of the neighboring turn. More particularly,
these side walls are juxtaposed in a manner such that the
end portio~ 26 of radially projecting side wall member 14
enters into th~ channel 31 created between the radially
projecting wall member 16 ~nd radially extending end
portion 30 of the adjacent turn. Prior to winding of
each such turn, however, ~olten bonding material 32 is
deposited in channel 31. Thusj when molten bonding
material 32 is applied concomitantly with this winding
process, and is introduced into channel 31 æhortly before
-10~ o a
the next adjacent portion of the radially projecting side
wall member 14 enters the channel 31 in the helical
winding process, the bonding material 32 substantially
~ills channel 31, and the transversely extending end
portion 26 of radially projecting side wall portion 14
enters into that channel, and hence into the bonding
material 32 under the pr ssure exerted by the helical
winding process itsel~. The bonding material 32 then
progressively cools and solidifies, and bonds these edge
regions of these wall portions to one anothax. The
bonding material 32 itself consists primarily of
materials such as ethylene vinyl acetate (EVA) or
ethylene ethyl acrylate (EEA), which cannot only effect
the bonding discussed herein, but which are thus also
fully compatihle with the outer surfaces of the ~trip 10,
as discussed hereinbefore. The bonding material 32 is
itself desirably maintained at a temperature of between
about 350 and 500F when introduced into the channel 31.
The relevant portions o~ the strip 10 should be at least
at about room temperature when they contact the bonding
material 32. Also, the bonding material should be
introduced.into channel 31 no more than about two seconds
before that portion of the channel is engaged with the
transversely extending end portion 26 of the next winding
; of the radially projecting side wall portion 14.
Extraordinary bond strength is developed between the
bonding materi~l and the juxtaposed portion~ of the strip
in this manner. Thus, the finished hose is rugged and
1 3 ~ 0~3C)O
permits full exploitation of the strength created by the
overall s~ructure in accordance with this invention.
As will be readily appreciated, numerous
variations and combinations of the features described
above can be utilized. Thus, the siæe and relative
proportions of the members can be varied. Furthermore,
provision of the strllctural ~upport for t~.e strip 10 can
be made in other ways. For example, as shown in FIG. 3,
plate like rein~orcing material can be provided in the
transverse wall portion 12 by means o~ transversely
extending plate-like portion 36, and in addition smaller
plate-like portions 38 and 40 can be provided at the
arcuate end portions of the radially projecting side wall
portions 14 and 16, respectively, i.e., where the inner
ends of these side wall portions meet and extend into
transversly extending end portions 26 and 28,
respectively. In yet another embodiment shown in FI&. 4
hereof, the trip 10 again includes a transverse wall
portion 12, radially projecting side wall portions 14 and
16, as above, but in this case inwardly projecting side
wall portion 16 terminates at 42, while radially
projecting- side wall portion 14 extends into transverse
inner wall portion 44, which itsel~ te~minates in a short
radially projecting portion 46. Thus, upon helical
winding of this embodiment of strip 10, this short
radially projecting portion 46 enter~ into the channel
created within the U~shaped member created by radially
projecting side wall portions 14 and 16, and transverse
-12- 1 3 1 0~03
wall portion 12, which channel can th~n include the
bonding material 32 therein.
Referring next to FIG. 5, yet another
embodiment of strip lOa used to form the flexible hose of
the present invention is shown therein. In this
embodiment the strip member lOa includes a transverse
wall portion 12a, and radially projectin~ side wall
porticns 14a and 16a. These side wall portions 14a and
16a include edge portions 54 and 56, respectively, remote
from transverse wall portion 12a. ~he plate-liXe
reinforcing strips 34a and 36a in this case are embedded
in side wall portions 14a and 16a, respectively.
In the embodiment of FIG. 5, a U-shaped cap
member 58 is also employed, and acts as a second strip
for producing the flexible hoses h reof. Cap member 58
: has a crown wall 60 and lateral walls 62 and 64
;~ projecting generally co-directionally Erom the crown wall
60. The in~erior surfaces of the cap member 58 thus form
a trough 66. In this case the U-shaped cap member 58 is
29
again formed from the same lower melting buffer
materials, such as the EEA and EVA materials discussed
above.
After winding the strip member lOa of FIG. 5 on
generally cylindrical mandrel 50 in the manner shown in
FI~. 1 so that the side walls of neighboring turns of
strip member lOa axe ~uxtaposed with one another such
that the first side wall 14a of one turn of this strip
member i9 juxtaposed with the second side wall 16a of the
neighboring turn, each such pair oP juxtaposed strip
'' '
-13~ U ~
member side walls defines a projecting ridge extending
along the helix defined thereby. Cap member 5~ is then
wound onto the partially fo~med helix defined by the
strip member, i.e., so that the ridge defined by
neighboring turns o~ the strip me~er enter into the
trough 66 of cap member 58. As in the case in the other
embodiments of this invention, each portion of the cap
member 58 moves downstream on the helix and passes the
depositing station in which molten bonding material 32a
19 is deposited in trough 66. In this manner, the molten
bonding material 32a is applied concomitantly with the
winding process, and is introduced into each portion of
the cap member 58 shortly before that portion of the cap
member receives the side walls of the strip member lOa in
the helical winding process.
Referring next to FIG. 6, another embodiment of
the strip member lOb of the present invention is shown
therein. In this embodiment, the strip lOb has the same
general con~iguration as the strip lO shown in FIGS. l
and 2 hereof. However, in this case instead of the
reinforcing plate-like membars 34 and 36, reinforcement
is provided by inwardly pro~ecting members 68 snd 70
which extend within the inner surface of these U-shaped
members from ~he inner sur~aces of radially projecting
side wall portions 14b and 16b, respectively. Therefore,
upon the exertion of external force to the hose produced
~rom this strip member lOb, the projecting me~bers 68 and
70 will be forced together, and only a small amount of
di~tortion is pe~nitted, i.e., until these projecting
-14- l-7:l 0 ~ ~ 3
mam~ers cross the gap 72 initially therebetween (i.e.,
when it is in its relaxed state). Thereafter, their
contact substantially prevents further such distortion.
Although the invention herein has been
described with reference to particular embodiments, it is
to be understood that these e~bodiments are merely
illustrative of the principles and applications of the
present invention. It is therefore to be understood that
numerous modifications may be made to the illustrative
1o embodiments and that other arrangements may be devised
without departing from the spirit and scope of the
present invention as defined by the appended claims.
