U.S. patent application number 10/214621 was filed with the patent office on 2003-02-13 for vibration damping corrugated flexible sleeving.
Invention is credited to Marks, Philip E..
Application Number | 20030030197 10/214621 |
Document ID | / |
Family ID | 23206250 |
Filed Date | 2003-02-13 |
United States Patent
Application |
20030030197 |
Kind Code |
A1 |
Marks, Philip E. |
February 13, 2003 |
Vibration damping corrugated flexible sleeving
Abstract
A flexible sleeve for damping vibrations and suppressing noise
is disclosed. The sleeve is corrugated for radial stiffness and
bending flexibility and has one or more damping layers of non-woven
felt adhered to a flexible, resilient tubular support layer. The
damping layers may be on both the inside and outside surfaces of
the support layer. The support layer defines an interior space for
receiving elongate substrates, the sleeve being slit to provide
access to the interior space. Manufacture of the sleeve is by
wrapping elongate multilayer strips combining the damping and
support layers helically around a convoluted mandrel and applying
heat and pressure to join the strips and force them to conform to
the convoluted shape of the mandrel.
Inventors: |
Marks, Philip E.; (Brighton,
MI) |
Correspondence
Address: |
John A. Chionchio, Esquire
Synnestvedt & Lechner LLP
Suite 2600
Philadelphia
PA
19107-2950
US
|
Family ID: |
23206250 |
Appl. No.: |
10/214621 |
Filed: |
August 8, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60311291 |
Aug 9, 2001 |
|
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|
Current U.S.
Class: |
267/136 |
Current CPC
Class: |
F16L 57/00 20130101;
Y10T 428/249986 20150401; Y10T 428/249958 20150401; F16L 3/26
20130101; H02G 3/0468 20130101; Y10T 156/1002 20150115; Y10T
428/249953 20150401 |
Class at
Publication: |
267/136 |
International
Class: |
F16M 001/00 |
Claims
What is claimed is:
1. A vibration damping sleeve adapted to receive and protect
elongate substrates, said sleeve comprising: an elongate tubular
support layer formed of a flexible, resilient polymeric material
and having circumferential corrugations providing radial rigidity
and bending flexibility, said support layer having an outwardly
facing surface and an inwardly facing surface surrounding and
defining an interior space adapted to receive the substrates; and a
damping layer of energy absorbing material positioned in facing
relationship with one of said surfaces of said support layer, said
damping layer being substantially co-extensive with said one
surface and having corrugations matching said corrugations of said
support layer.
2. A vibration damping sleeve according to claim 1, wherein said
damping layer is positioned on said outwardly facing surface of
said support layer.
3. A vibration damping sleeve according to claim 2, wherein said
damping layer is adhered to said support layer substantially
continuosly over said outwardly facing surface.
4. A vibration damping sleeve according to claim 2, wherein said
damping layer comprises an elongated strip of said energy absorbing
material adhered to an elongated strip of said support layer and
helically wrapped at a predetermined helix angle relatively to the
sleeve, the corrugations on the damping layer being oriented at an
angle to the helix angle sufficient to conform to the corrugations
on the support layer.
5. A vibration damping sleeve according to claim 2, wherein said
damping layer comprises a sheet of said energy absorbing material
cigarette wrapped around said support layer.
6. A vibration damping sleeve according to claim 1, wherein said
support layer is formed from a polymeric material selected from
among the group consisting of polyester, polypropylene and
nylon.
7. A vibration damping sleeve according to claim 1, wherein said
damping layer comprises a non-woven felt material.
8. A vibration damping sleeve according to claim 7, wherein said
felt material is selected from among the group consisting of
polyester, polypropylene and nylon.
9. A vibration damping sleeve according to claim 7, wherein said
damping layer is formed from substantially the same material as
said support layer.
10. A vibration damping sleeve according to claim 9, wherein said
damping layer and said support layer comprise polyester.
11. A vibration damping sleeve according to claim 2, further
comprising a second damping layer positioned between said inwardly
facing surface of said support layer and said interior space.
12. A vibration damping sleeve according to claim 11, wherein said
second damping layer is substantially co-extensive with said
inwardly facing surface and has corrugations matching said
corrugations of said support layer.
13. A vibration damping sleeve according to claim 12, wherein said
second damping layer is adhered to said support layer substantially
continuously over said inwardly facing surface.
14. A vibration damping sleeve according to claim 1, wherein said
damping layer comprises a foamed material.
15. A vibration damping layer according to claim 14, wherein said
damping layer comprises foam rubber.
16. A vibration damping layer according to claim 1, wherein an
elongated substrate is received within said interior space.
17. A vibration damping layer according to claim 1, wherein said
elongated substrate comprising a wiring harness.
18. A vibration damping sleeve adapted to receive and protect
elongate substrates, said sleeve comprising: a flexible resilient
elongate tubular support layer comprising polyester and having
circumferential corrugations providing radial rigidity and bending
flexibility, said support layer having an outwardly facing surface
and an inwardly facing surface surrounding and defining an interior
space adapted to receive the substrates; and a damping layer of
polyester felt positioned overlying one of said surfaces of said
support layer, said damping layer being substantially co-extensive
with said one surface and having corrugations matching said
corrugations of said support layer.
19. A vibration damping sleeve according to claim 18, wherein said
damping layer is adhered to said support layer substantially
continuously over said outwardly facing surface.
20. A vibration damping sleeve according to claim 19, further
comprising a second damping layer positioned between said inwardly
facing surface of said support layer and said interior space.
21. A vibration damping sleeve according to claim 20, wherein said
second damping layer is substantially co-extensive with said
inwardly facing surface and has corrugations matching said
corrugations of said support layer.
22. A vibration damping sleeve according to claim 21, wherein said
second damping layer is adhered to said support layer substantially
continuously over said inwardly facing surface.
23. A vibration damping sleeve according to claim 22, wherein said
second damping layer comprises polyester felt.
24. A method of making a vibration damping sleeve having a tubular
support layer formed of a flexible, resilient polymeric material
and a damping layer formed of a non-woven felt, said method
comprising the steps of: adhering a sheet of said felt to a sheet
of said polymeric material; cutting said adhered sheets into a
plurality of strips having longitudinal edges; wrapping said strips
helically around a mandrel having a plurality of corrugations while
positioning said edges in abutting relationship; and applying heat
and pressure to said strips thereby forcing them to conform to said
corrugations of said mandrel and causing said longitudinal edges to
adhere to one another and form a helical seam along said sleeve.
Description
RELATED APPLICATION
[0001] This application is based on and claims the benefit of U.S.
Provisional Application No. 60/311,291, filed Aug. 9, 2001.
FIELD OF THE INVENTION
[0002] This invention concerns sleeving for encasing and protecting
elongated substrates, such aspiring harnesses, and for reducing
rattle noise from such substrates when they are used in a high
vibration environment.
BACKGROUND OF THE INVENTION
[0003] Elongated substrates, such as wiring harnesses, fluid
conduits, such as brake lines and fuel lines, and optical fiber
bundles are often used in automotive, aerospace and marine
environments where they are subjected to significant ambient
vibration. In automotive applications, wiring harnesses in
particular are pernicious sources of unwanted "rattle noise" due to
their propensity to resonate in response to structure borne
vibration caused by engine operation or irregularities of the road
surface over which the vehicle is passing. Wiring harnesses
typically extend substantially throughout the vehicle's passenger
compartment where they distribute power and control signals from
the engine compartment to the dashboard instruments, interior
lights, radio, speakers, electric windows, electric door locks, the
window defogging element and on to the trunk to power the tail
lights and often an electric fuel pump which may be positioned in
the fuel tank. Although the harness is intermittently attached to
the vehicle structure, the lengths of the harness between
attachment points will often resonate and rattle against the
structure in response to relatively low-frequency vibrations within
the range of human hearing and provide a source of noise, which is
both annoying and a cause of concern to the vehicle occupants.
Aside from the noise annoyance, vibration of wiring harnesses will
cause fatigue failures of the wiring, solder joints or mechanical
connectors, leading to electrical malfunctions, such as short
circuits, which could result in a vehicle fire. The failure due to
vibration and fatigue of other elongate substrates, such as fuel
lines or brake lines, also has catastrophic potential. There is
clearly a need for a device which will help damp vibration of
elongated substrates and thereby reduce sympathetic vibration of
the substrates and its resultant rattle noise and associated
fatigue failures.
SUMMARY AND OBJECTS OF THE INVENTION
[0004] The invention concerns a vibration damping sleeve adapted to
receive and protect elongate substrates. The sleeve comprises an
elongate tubular support layer formed of a flexible, resilient
polymeric material, preferably polyester. The support layer has
circumferential corrugations providing radial rigidity and bending
flexibility. The support layer has an outwardly facing surface and
an inwardly facing surface surrounding and defining an interior
space adapted to receive the substrates. A damping layer of energy
absorbing material is positioned in facing relationship with one of
the surfaces of the support layer, the damping layer being
substantially co-extensive with the one surface and having
corrugations matching the corrugations of the support layer. The
damping layer is preferably a non-woven polyester felt positioned
on the outwardly facing surface of the support layer. The same
material, i.e., polyester, is preferred for both the support and
damping layers because it simplifies production of the sleeve and
recycling at the end of its life.
[0005] A second damping layer may be positioned between the
inwardly facing surface of the support layer and the interior space
to provide additional damping to the elongate substrates received
within the interior space. Preferably, the second damping layer is
substantially co-extensive with the inwardly facing surface and has
corrugations matching the corrugations of the support layer.
[0006] It is an object of the invention to provide a sleeve for
protecting elongate substrates from vibration.
[0007] It is another object of the invention to provide a
protective sleeve using a non-woven felt as a damping material.
[0008] It is yet another object of the invention to provide a
sleeve which is easy to manufacture and recycle.
[0009] It is again another object of the invention to provide a
sleeve having different components made from the same material.
[0010] These and other objects and advantages of the invention will
become apparent upon consideration of the following drawings and
detailed description of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a partial cut-away perspective view of an
embodiment of a sleeve according to the invention;
[0012] FIG. 2 is a cross-sectional view taken along lines 2-2 of
FIG. 1;
[0013] FIG. 3 is a partial cut-away perspective view of another
embodiment of the sleeve according to the invention; and
[0014] FIG. 4 is a flow chart describing a method of manufacture of
the sleeve according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] FIGS. 1 and 2 show a flexible protective sleeve 10 according
to the invention. Sleeve 10 has a flexible, resilient elongate
tubular support layer 12 with an outwardly facing surface 14 and an
inwardly facing surface 16. Inwardly facing surface 16 surrounds
and defines an interior space 18 adapted to receive elongate
substrates 20, which could be, for example, a wiring harness.
Support layer 12 has a slit 22 defined by adjacent sleeve edges 24
and 26, the slit providing access to the interior space 18. The
support layer 12 may be biased into a shape which normally closes
the slit by keeping the edges 24 and 26 in contact, or even in
overlapping relationship. The flexibility of the support layer,
however, allows the edges 24 and 26 to be easily separated and the
slit 22 opened to provide access to the interior space 18 for
inserting the elongated substrate 20, effecting repairs or
developing breakout branches.
[0016] Support layer 12 has circumferential corrugations 28 which
provide the sleeve with increased radial strength against collapse,
as well as relatively great bending flexibility. This enables the
sleeve to readily follow paths through the vehicle having
relatively sharp bends and compound curves as required to route the
harness or other substrate without kinking.
[0017] Support layer 12 is preferably formed of polymer sheet or
film, such as polyester, polypropylene or nylon. Such materials are
inexpensive, readily available and adaptable to a wide variety of
different manufacturing methods.
[0018] A damping layer 30 of energy absorbing material is shown
positioned in facing relation with the outwardly facing surface 14
of the support layer 12. The damping layer 30 is co-extensive with
the surface, having corrugations 32 matching those of the support
layer. Preferably, the damping layer 30 is adhered to the support
layer 12 substantially continuously over the entire outwardly
facing surface 14. By providing a corrugated damping layer, the
bending flexibility of the sleeve is not significantly altered as
it would be if the damping layer were smooth and only attached to
the crests of the corrugations. A smooth layer would increase the
bending stiffness, since the layer would resist expanding when the
sleeve was bent or curved.
[0019] Damping layer 30 is preferably formed from a non-woven felt
due to felt's excellent ability to absorb and dissipate vibration
energy. The preferred material for the damping layer 30 is a
polyester felt for its damping characteristics as well as its
durability and resistance to fire as well as to attack by molds,
mildew, bacteria and other agents of decay. Other felts, made of
materials such as polypropylene or nylon, are also feasible. It is,
however, preferred to make the damping layer 30 from the same
material (i.e., polyester) as the support layer 12. Using the same
materials simplifies production, since the layers are readily
compatible and may be adhered by a variety of different techniques
such as heat fusing by ultrasonic welding or by adhesives.
Recycling of the sleeve 10 is also simplified when the various
component layers are of the same material.
[0020] The damping layer 30 may also be made of other damping
materials such as foam rubber or foamed synthetic material, as well
as soft thermoplastic elastomers. Woven, braided or knitted fabrics
may also be used to provide an energy absorbing layer.
[0021] In one specific example of a sleeve according to the
invention, support layer 12 is a 0.24 mm thick polyester film to
which a damping layer 30 of non-woven flame-retardant polyester
fiber having an areal density of 7.25 ounces per square yard is
adhered.
[0022] As shown in FIG. 3, sleeve 10 may also include a second
damping layer 34 positioned between the inwardly facing surface 16
and the interior space 18. Damping layer 34 provides additional
protection to substrates 20, preventing them from rattling within
the support layer 12 and, thus, further reducing noise and damage
from mutual abrasion of the substrate and the sleeve. Preferably
damping layer 34 is substantially coextensive with and adhered to
the inwardly facing surface 16 and also has corrugations 36
matching the corrugations 28 of the support layer 12.
[0023] The second damping layer 34 is preferably a non-woven
polyester felt similar to the outer damping layer 30, although
other materials and configurations, such as foam rubber or foamed
synthetic material, as well as soft thermoplastic elastomers and
woven, braided or knitted fabrics, may also be used to provide an
energy absorbing layer.
[0024] As described in the flow chart of FIG. 4, the sleeve 10,
shown in FIG. 1, may be manufactured by first adhering a sheet of
the damping material (e.g., polyester felt) to a sheet of flexible,
resilient polymeric material (e.g., polyester film or sheet) to
form a single sheet having a damping layer adhered to a support
layer. Adherence of the sheets together is preferably by means of
adhesive but could also be by fusing via heat and pressure, for
example, by ultrasonic welding. The adhered sheets which will form
the support layer 12 and damping layer 30 of sleeve 10 are then cut
into strips, for example 51 mm wide and helically wrapped at a
predetermined helix angle around a shaped mandrel having
convolutions. The strips are wrapped so that their edges butt
against each other or even overlap. Heat and pressure are then
applied to the strips joining them along the abutting edges and
forcing the damping and support layers to conform to the
convolutions, thereby providing the corrugations 28 in the sleeve
10. Vestiges of strips 38 are indicated in FIG. 1 by their edges 40
which form a helical seam 42, characteristic of this particular
manufacturing method. Seam 42 describes a helix angle 44 measured
relative to the longitudinal axis 46 of the sleeve 10, the
corrugations 36 on the damping layer 30 being oriented at an angle
to the helix angle sufficient to conform to the corrugations 36 to
the corrugations 28 on the support layer 12.
[0025] In an alternate manufacturing process, the damping layer 30
is "cigarette wrapped" around a thin tubular polymer melt stream
which will become the support layer 12, thereby forming a
multilayer tubular feed stock which is then fed into a corrugating
machine. The term "cigarette wrapped" refers to a type of wrapping
wherein an elongated flat strip of sheet material is formed into a
tube by bringing the edges of the sheet together parallel to one
another forming a substantially straight seam lengthwise along the
length of the tube, much as cigarette paper is wrapped around
tobacco to form a cigarette. Such a seam 48 is shown in FIG. 3,
indicating the alternate method of manufacture for the embodiment
shown.
[0026] In yet another alternate forming process, corrugations are
added to a flat, multi-layer sheet material comprising a damping
layer and a polymer sheet layer. The flat, corrugated sheet is then
curled to a final tubular shape and heat set to permanently assume
the tubular shape.
[0027] The flexible protective sleeve according to the invention is
effective at reducing rattle noise of elongated substrates such as
wiring harnesses due to the noise and vibration damping
characteristics of the non-woven felt damping layer. When such a
layer contacts a neighboring structure, it tends to deaden any
sound that would normally be produced by the vibration of the
substrate against the structure. Energy of the vibration will also
be absorbed by the felt, thus, damping the vibration and increasing
the fatigue life of the items surrounded by the sleeve. Use of the
sleeve will result in decreased noise from sympathetic vibrations,
as well as decreased failures due to fatigue.
* * * * *