U.S. patent application number 11/106196 was filed with the patent office on 2005-08-25 for corrugated hose assembly.
Invention is credited to Martucci, Norman S., Mathew, Boney A..
Application Number | 20050183786 11/106196 |
Document ID | / |
Family ID | 24543127 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050183786 |
Kind Code |
A1 |
Martucci, Norman S. ; et
al. |
August 25, 2005 |
Corrugated hose assembly
Abstract
According to the present invention, there is provided a hose
assembly with an inner fluoropolymer layer having a smooth inner
surface and an outer polyamide layer having an undulated
surface.
Inventors: |
Martucci, Norman S.;
(Madison Heights, MI) ; Mathew, Boney A.;
(Clarkston, MI) |
Correspondence
Address: |
KOHN & ASSOCIATES PLLC
30500 NORTHWESTERN HWY
STE 410
FARMINGTON HILLS
MI
48334
US
|
Family ID: |
24543127 |
Appl. No.: |
11/106196 |
Filed: |
April 15, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11106196 |
Apr 15, 2005 |
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10614300 |
Jul 3, 2003 |
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10614300 |
Jul 3, 2003 |
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09634277 |
Aug 9, 2000 |
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6641884 |
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Current U.S.
Class: |
138/137 ;
264/209.3; 264/210.1; 264/286; 428/36.91; 428/421 |
Current CPC
Class: |
B32B 2307/714 20130101;
Y10T 156/1016 20150115; B32B 27/08 20130101; B32B 27/322 20130101;
F16L 11/085 20130101; Y10T 156/1038 20150115; B32B 1/08 20130101;
B32B 3/26 20130101; Y10T 156/1018 20150115; Y10T 156/1002 20150115;
Y10T 156/1023 20150115; Y10T 428/3154 20150401; F16L 11/127
20130101; Y10S 138/01 20130101; F16L 11/11 20130101; Y10T 428/1393
20150115; B32B 27/34 20130101; Y10T 428/1362 20150115; B32B
2307/306 20130101; B32B 2597/00 20130101 |
Class at
Publication: |
138/137 ;
428/036.91; 428/421; 264/209.3; 264/210.1; 264/286 |
International
Class: |
F16L 011/00 |
Claims
1-13. (canceled)
14. A method of making a hose assembly including the steps of:
forming a smooth inner fluoropolymer layer; forming an outer
polyamide layer over the inner fluoropolymer layer while adhering
said outer and inner layers together; and corrugating said outer
polyamide layer.
15. A method as set forth in claim 14, said first forming a smooth
inner fluoropolymer layer.
16. A method as set forth in claim 14, forming step being further
defined as extruding the outer polyamide layer over the smooth
inner fluoropolymer layer.
17. The method as set forth in claim 14, further characterized by
depositing at least one braided layer between said inner and said
outer layers.
18. The method as set forth in claim 14, further characterized by
positioning an integral conductive strip in the inner layer which
is co-extensive for the length of the inner layer for conducting
electrical charges along the length of the inner layer.
19. The method as set forth in claim 14, said corrugating step
further defined as forming a spiral corrugation on the outer
polyamide layer.
20. The method as set forth in claim 14, said corrugation step
further defined as forming a circular corrugation on the outer
polyamide layer.
21. A hose assembly comprising: an inner fluoropolymer layer having
an entirely smooth non-corrugated inner surface; and an outer
polyamide layer extruded about said inner layer, said outer layer
having a corrugated outer surface, said hose assembly being used in
a fuel line.
22. An assembly as set forth in claim 21, further characterized by
including at least one braided layer disposed on said outer layer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention relates to a hose construction. More
specifically, the subject invention relates to a hose assembly
having an inner fluoropolymer layer with a polyamide outer layer
used in automotive, aeronautics and other environs for carrying
fluids, such as fuels.
[0003] 2. Description of Related Art
[0004] Hose assemblies for conveying fuels are well known in the
art. Such assemblies are exposed to a variety of fuel mixtures and
fuel additives in addition to extreme engine temperatures. Such
hose assemblies must be resistive to chemicals, as well as heat
resistant to degradation as a result of chemical and heat
exposure.
[0005] Fluoropolymer materials, such as polytetrafluoroethylene
possess the requisite chemical and temperature resistant properties
for most fuel hose applications. However, fluoropolymer materials
exhibit relatively poor tensile and hoop strengths. As a
consequence, such fluorinated materials are prone to kinking. Such
kinking remains permanent and provides a continual resistance to
fluid flow through the hose assembly. Moreover, as a result of the
fluorinated material low tensile strength, attachment of securing
or coupling members to the hose assembly is unreliable.
[0006] Various approaches have been described for offering
additional strength to a fluoropolymer layer. One approach involves
braiding fibers about the inner fluorocarbon layer. The braided
fibers offer additional strength for the fluorocarbon layer
resulting in a hose assembly that resists kinking. An example of
such an approach is disclosed in co-pending U.S. Ser. No.
08/535,734, filed Jun. 11, 1990, and assigned to the assignee of
the subject invention. A drawback of such braiding techniques,
however, is the extensive labor and time involved.
[0007] Additional examples for strengthening an inner fluorocarbon
layer with an outer layer are shown in U.S. Pat. No. 2,991,808 to
Sigmann, U.S. Pat. No. 4,104,095 to Shaw, and U.S. Pat. No.
4,800,109 to Washizo, all of which disclose the use of a
polytetrafluoroethylene inner layer supported with an outer is
layer.
[0008] Alternatively, some patents in the prior art utilize both an
outer layer and a braided layer for added strength as shown in U.S.
Reissue No. 35,527. However, there remains problems with the
bending capabilities of such tubing in conjunction with the outer
layer.
[0009] Furthermore, some patents in the prior art utilize
multi-layer hoses with corrugated outer surfaces for added strength
at the bending sites, as shown in the U.S. Pat. No. 5,305,799, to
Holmgren. However, these processes have not been utilized for hoses
having an inner fluoropolymer layer and an outer polyamide
layer.
[0010] Additionally, some patents in the prior art utilize machines
for creating corrugation, as shown in the U.S. Pat. No. 3,864,446,
to Maroschak. However, there remains problems in creating
corrugation without having to corrugate the entire hose
assembly.
[0011] It would therefore be useful to develop a hose which is
resistant to kinking when being bent without adding extensive labor
or time to the manufacturing process.
SUMMARY OF THE INVENTION
[0012] According to the present invention, there is provided a hose
assembly is with an inner fluoropolymer layer having a smooth inner
surface and an outer polyamide layer having an undulated surface. A
method is provided for making a hose assembly by forming a smooth
inner fluoropolymer layer without undulations and an outer
polyamide layer having undulations.
DESCRIPTION OF THE DRAWINGS
[0013] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0014] FIG. 1 is a prospective view partially broken away and in
cross section of the preferred embodiment of the subject
invention;
[0015] FIG. 2 is a prospective view partially broken away and in
cross section of an alternate embodiment of the subject
invention;
[0016] FIG. 3 is a prospective view partially broken away and in
cross section of an alternate embodiment of the subject
invention;
[0017] FIG. 4 is a schematic view, of a fuel system showing three
separate applications of the subject invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A hose assembly made in accordance with the present
invention is generally shown at 10 and FIGS. 1, 2, and 3. The
assembly 10 includes a tubular inner layer 12, an outer layer 14
disposed about the inner layer 12, an integral conductive strip 16
co-extensive with the length of the inner layer 12 coupling
mechanism 18 (FIG. 4) adapted to engage the end of the hose
assembly 10 and undulations or corrugations 42 on the outer surface
of the outer layer 14.
[0019] The tubular inner layer 12, as best shown in FIGS. 1, 2, and
3, is made from a fluoropolymer material resistant to both chemical
and heat degradation, allowing a variety of fluids, particularly
automotive fuels and fuel additives, e.g., detergents, alcohols,
etc., to pass through the inner layer 12 without corroding or
degrading the inner layer 12. The inner layer 12 is preferably
extruded using well-known melt or paste extrusion techniques and
has a wall thickness of between 0.001 and 0.120 inches.
[0020] Although the inner layer 12 may be made of any number of
fluoropolymer materials, the inner layer 12 is ideally made from a
polymer of the following: polytetrafluoroethylene (PTFE), the
homopolymer of tetrafluoroethylene sold under the trademark TEFLON
by DuPont; perfluorinated ethylene-propylene (FEP), the copolymer
of tetrafluoroethylene and hexafluoropropylene sold under the
trademark TEFLON FEP by DuPont; perfluoroalkoxy fluorocarbon resin
(PFA), the copolymer of tetrafluoroethylene-perfluorovinyl ethyl,
sold under the trademark TEFLON PFA by DuPont; or ethylene
tetrafluoroethylene (ETFE), the copolymer of ethylene and
tetrafluoroethylene sold under the trademark TEF-ZEL by DuPont PVDF
and THV. In addition to the aforementioned fluoropolymer materials,
polychlorotrifluoroethylene, the homopolymer of
chlorotrifluoroethylene, and polychlorotrifluoroethylene-e-
thylene, the copolymer of chlorotrifluoroethylene and ethylene may
also be used.
[0021] The outer layer 14, best shown in FIGS. 1, 2, and 3, is
disposed about the inner layer 12. The outer layer 14 is made up of
polyamide material for increasing strength of the hose assembly 10.
More specifically, the outer layer 14 allows the inner layer 12 to
bend without kinking. That is, the outer layer 14 provides strength
to the inner layer 12 upon bending. This is commonly referred to as
hoop strength. Thus, by disposing the outer layer 14 having
undulations 42 about the inner layer 12, the hoop strength of the
inner layer 12 is increased. Further, the outer layer 14 adds to
the working pressure of the hose. That is, the outer layer 14
provides strength to the inner layer 12 and allows the inner layer
12 to accommodate a fluid under pressure. Additionally, the outer
layer 14 adds to the tensile strength of the hose assembly 10. When
coupling members 18 (FIG. 6) are disposed at the ends of the hose
assembly 10, as described below, the outer layer 14 increases the
tensile strength of the hose assembly 10 sufficient to fixedly
connect the coupling member 18 (FIG. 4) to the hose assembly 10. By
disposing the outer layer 14 having undulations 42 about the inner
layer 12, the bend radius of the hose is increased.
[0022] Although the outer layer 14 may be made of any number of
polyamide materials, preferably the outer layer 14 is made from a
polyamide material selected from the following: nylon 6; nylon 6,6;
nylon 11; or nylon 12; or other nylon alloy. It should be noted
that the selection of a particular polyamide material should be
based upon the physical requirements of the particular hose
assembly application. For example, nylon 6 and nylon 6,6 offer
higher heat resistant properties than nylon 11 or nylon 12, whereas
nylon 11 and nylon 12 offer better chemical resistant properties
than nylon 6 or nylon 6,6. Thus, the ultimate selection of a
polyamide material should be based upon requirements of a
particular hose assembly application.
[0023] In addition to those polyamide materials previously
mentioned, other nylon materials such as: nylon 6,12; nylon 6,9;
nylon 4; nylon 4,2; nylon 4,6; nylon 7; and nylon 8 may also be
used. Ring containing polyamides including aliphatic-aromatic
polyamides e.g. nylon 6,T and nylon 6,I may also be used. Finally,
the outer layer 14 may also be made of various polyamide blends.
Again, it is noted that the selection of particular polyamide
material is dependent upon the specific physical requirements of a
particular hose assembly.
[0024] The outer layer 14 can be made of an expanded polyamide
material, as shown in FIGS. 1, 2, and 3. Alternatively, the outer
layer 14 can include an unexpanded polyamide material. Although
expanded and unexpanded polyamide outer layers 14 both offer the
hose assembly 10 increased tube and tensile strength, the expanded
polyamide is preferred. The expanded polyamide material offers the
hose assembly 10 substantially the same degree of strength as the
unexpanded material while significantly reducing the weight of the
hose assembly 10. That is, the expanded polyamide material is
significantly lighter in weight than the unexpanded polyamide
material due to the presence of void spaces therein formed during
the expansion process. The expansion process, commonly known in the
art as "foaming", generally takes place while extruding the outer
layer 14.
[0025] Such foaming processes generally require blowing agents such
as "CELOGEN HT 550.TM.", or exothermic blowing agent sold by
Uniroyal Chemicals or "ACTIVEX 537.TM.", or other endothermic
blowing agent sold by B.I. Chemicals. The blowing agent is
generally intermixed with a polyamide material during the extrusion
of the outer layer 14 and causes expansion of the polyamide by
producing gas, thereby forming void spaces within the outer layer
14.
[0026] The undulations or corrugations 42 on the outer layer 14,
provide additional bend radius to the hose assembly 10. There are
two specific types of undulations or corrugations that may be
present on the outer layer 14, there types are spiral (FIG. 2) or
circular (FIG. 3) undulation. Further, the entire is hose assembly
10 or portions thereof may be corrugated. This allows the
manufacturer to undulate or corrugate only those portions which
will be bent thereby only providing this additional support where
necessary.
[0027] There are a number of methods for fabricating the hose
assembly 10, one particular well known method involves a two part
extrusion process typically known as "cross-head" extrusion. The
typical "cross-head" extrusion method involves first extruding an
inner layer, such as the fluoropolymer inner layer 12, then
extruding an outer layer thereover, such as the polyamide or outer
layer 14. This method of fabrication is particularly effective when
utilizing an inner layer 12 comprising polytetrafluoroethylene.
Additionally, when utilizing thermoplastic fluoropolymer materials,
co-extrusion methods of fabricating may be applicable. As commonly
known in the art, co-extrusion methods involving utilizing two
extruders at once thereby forming both inner and outer layers
simultaneously.
[0028] After the hose assembly has been formed, the hose is sent
through a molding machine. The molding machine is made up of pairs
of presses 44 which form the corrugation or undulation on the outer
surface of the outer layer 14. The mold presses 44 are configured
to form undulations on the opposite sides of the hose 10 thus
creating the undulations about the entire outer surface of the
outer layer 14. This allows the manufacturer to either undulate or
corrugate the entire hose 10 or only portions thereof.
Additionally, the presses 44 are slidably attached to the molding
machine thus allowing the presses 44 to be moved thus enabling the
manufacturer to determine what part of the tubing will be
undulated. Also, there are two specific types of undulation that
may be present on the outer layer 14, these types are spiral (FIG.
2) or circular (FIG. 3) undulation. The type of undulations 42
depend upon the configuration of the mold presses 44 or pressure
forming the outside with internal mandrels or cross head extrusion
with an internal mandrel with pressure forming dies outside. Due to
the chemical inertness and general lubricious nature of
fluoropolymer materials, relative movement between the inner 12 and
outer 14 layers is often encountered. In hose applications which
require immobility between adjacent layers, the present hose
assembly 10 may be modified to eliminate such relative movement
between the inner 12 and outer 14 layers.
[0029] One embodiment for eliminating relative movement between the
inner 12 and outer 14 layers involves etching an outer surface 20
of the inner layer 12 prior to disposing the outer layer 14
thereabouts, as shown on FIG. 4. Etching techniques are well known
in the art and examples of common etching techniques include acid
treatment, plasma treatment, and mechanical scuffing and adhesive.
Subsequent to etching, the outer surface 20 of the inner layer 12
maintains an irregular configuration 22 as shown in FIG. 4.
Essentially, the irregular configuration 22 includes of rough
surface having a plurality of cavities and protuberances
therein.
[0030] Subsequent to etching the outer surface 20 of the inner
layer 12, the outer layer 14 is extruded thereover. During this
extrusion, an inner surface 24 of the outer layer 14 shapes into
mating engagement with the irregular configuration 22 of the outer
surface 20 of the inner layer 12, thereby resulting in a mechanical
and/or chemical bond therebetween. This mechanical bond prohibits
relative movement (rotational or longitudinal) between the inner 12
and outer 14 layers.
[0031] An alternative embodiment for eliminating relative movement
between the inner 12 and outer 14 layer is shown on FIG. 1. The
alternative embodiment includes disposing of at least one braided
layer between the inner 12 and outer 14 layers. More specifically,
the alternative embodiment includes a braided or woven layer 26
disposed in an inter-weaving fashion, or wrapped tightly about the
outer surface 20 of the inner layer 12. Preferably, the material
used for the braided layer 26 is a glass fiber. Glass fibers are
preferred due to relative low cost and superior heat resistant
properties.
[0032] The braided or woven fibers can be tightly wound or they may
be loosely wound about the inner layer 12, having wide gaps between
adjacent fibers. Subsequent to position of the braided layer 26
about the inner layer 12, the outer layer is extruded thereover.
During this extrusion, the inner surface 24 of the outer layer 14
shapes into mating engagement with the irregular configuration 31
of the intermediate coating 28 thereby resulting in mechanical
and/or the chemical bond therebetween, the chemical bond only
occurring when there are gaps between the braid. This mechanical
bond prohibits relative movement (rotational and longitudinal)
between a braided layer 26/intermediate coating 28 and outer layer
14.
[0033] Additionally, as fluid flows to the inner layer 12,
electrical charges tend to build throughout the length of inner
layer 12. In order to prevent these electrical charges from
accumulating, the inner layer 12 preferably includes an integral,
longitudinal conductive strip 16 co-extensive with the length of
the inner layer 12 for conducting electrical charge along the
length of the inner layer 12. Preferably the inner integral
conductive strip 16 includes of conductive strip 30 of carbon
black, as shown in FIG. 1. Alternatively, the integral conductive
strip 16 may include an inner layer 32 of carbon black positioned
adjacent an inner surface 33 of the inner layer 12 as shown in
FIGS. 2 and 3. Alternatively, the integral conductive strip 16 may
be interspersed throughout the inner layer 12 by intermixing carbon
black throughout the fluoropolymer material while the inner layer
12 is extruded. The braided layer 26, intermediate coating 28, and
outer layer 14 are all preferably electrically nonconductive. This
is important in that electrical charges applied to the exterior of
the hose assembly 10 will not be conducted along its length nor to
the fluid passing therethrough. It will be appreciative that the
integral conductive strip may include conductive material other
than carbon black.
[0034] The assembly 10 further includes a coupling mechanism 18 as
shown in FIG. 4. The coupling mechanism 18 is adapted to engage the
ends of the hose assembly 10 for interconnecting the hose assembly
10 to a flow of fluid, e.g. fluid flow 2 and from a fuel tank 35.
More particularly, the coupling mechanism 18 includes a coupler 18
or joint having an insert portion 34 for inserting into and
engaging the inner surface 33 (FIGS. 1 and 2) of the inner layer
12. The insert portion 34 may have a plurality of barbs 36 for
engaging the inner surface 33 (FIGS. 1 and 2) of the inner layer
12, as thus viewed in FIG. 4. The coupling mechanism 18 may also
include an engaging portion extending longitudinally from the
insert portion 34 for engaging a fitting. The engaging portion may
include a male threaded member or a female threaded member. The
engaging portion may include any configuration that will cooperate
with the member to which it is to be connected with. For example,
the engaging portion can include a socket to receive a mating ball
joint. Alternatively, in place of the engaging portion, the
coupling mechanism 18 can provide an additional insert portion 34
for inserting into the interior surface of the inner layer 12 of
another hose assembly 10 as shown in FIG. 4. Thus, the coupling
mechanism 18 can operate as a joint between independent hose
assemblies 10 thereby interconnecting them to allow fluid flow
therebetween. The coupling mechanism 18 is preferably made from
organic polymeric material and mechanically connected to the hose
assembly 10, as shown in FIG. 4. Alternatively, the coupling
mechanism 18 can be molded to the hose assembly.
[0035] A typical application of the present hose assembly 10 is
shown in FIG. 4. FIG. 4 discloses an engine 37, fuel tank 33, and
three distinct uses of the present hose assembly 10. A fuel line
for conveying fuel between a fuel rail 40 and the fuel tank 35 is
shown at 38. Coupling mechanism 18 as previously described,
interconnects the fuel line 38 with the fuel rail 40 fuel tank 35.
The fuel rail 40 provides a flow of fuel to a plurality of fuel
jumpers 42. Although not shown in FIG. 4, it will be appreciated to
those skilled in the art that a gas manifold and throttle body can
be substituted for the fuel tail 43. The fuel jumpers 42 are
interconnected to the fuel rail 40 by ways of the coupling
mechanism 18, as shown in FIG. 4, or alternatively, it may be
molded directly to the fuel rail 40. Fuel injections for injecting
fuel into individual fuel cylinders are shown on phantom at 44. The
fuel injectors 44 may include male supports 46 for inserting and
engaging the inner surface of the fuel jumper 42, in a similar
manner as the insert portion 34 of the coupling mechanism 18
engages the inner surface 33 of the inner layer 12.
[0036] Although the diameters of the fuel line 38, fuel rail 40,
and fuel jumper 42 may differ, all are made from the hose assembly
10 as described above. That is, each includes a fluoropolymer inner
layer 12 and a polyamide outer layer 14 having undulations 42. Due
to possible variances in diameter along each hose assembly 10,
i.e., fuel line 38, fuel rail 40, fuel jumper 42 and fuel filler
pipes, it will be understood that the insert portion 34 of the
coupling mechanism 18 used to interconnect each hose assembly 10
must vary correspondingly to accommodate each specific hose
assembly 10 diameter.
[0037] Although the present hose assembly has been described for
conveying fuels, it will be readily appreciated that the present
hose assembly 10 may be used for conveying a variety of fluids,
e.g., cooling fluids, lubricating fluids, etc.
[0038] Throughout this application, various publications, including
United States patents, are referenced by citation or number. All
citations for these publications are listed below. The disclosure
of these publications and patents in their entireties are hereby
incorporated by reference into the application in order to more
fully describe the state of the art to which this invention
pertains.
[0039] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description, rather
than of limitation.
[0040] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than is
specifically described.
* * * * *