U.S. patent application number 11/888114 was filed with the patent office on 2008-02-28 for shrink tubing jacket construction, and method.
Invention is credited to Kip D. Weller.
Application Number | 20080048011 11/888114 |
Document ID | / |
Family ID | 39112434 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080048011 |
Kind Code |
A1 |
Weller; Kip D. |
February 28, 2008 |
Shrink tubing jacket construction, and method
Abstract
A shrink tubing jacket construction enables blade-free or
enhanced removal of shrink tubing from an underlying substrate,
such as a catheter construction. The shrink tubing jacket
construction comprises a length of shrink tubing and one or more
tear members located within the wall of the shrink tubing. The wall
of the shrink tubing has a certain first material strength and the
tear member has a certain second material strength, such that when
the tear member is in tension, the second material strength
functions to slice through the wall of the shrink tubing for
enabling blade-free removal of the same. Paired tear members may be
diametrically opposed such that when simultaneously tensioned in a
diametrical direction, the net stress on the underlying substrate
is minimized during the slicing action.
Inventors: |
Weller; Kip D.; (Saint
Charles, IL) |
Correspondence
Address: |
Meroni & Meroni, P.C.
P.O. Box 309
Barrington
IL
60011
US
|
Family ID: |
39112434 |
Appl. No.: |
11/888114 |
Filed: |
July 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60839991 |
Aug 24, 2006 |
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Current U.S.
Class: |
229/87.05 ;
206/497; 53/441 |
Current CPC
Class: |
A61M 25/0668 20130101;
A61M 25/0009 20130101 |
Class at
Publication: |
229/87.05 ;
206/497; 53/441 |
International
Class: |
B65D 65/26 20060101
B65D065/26; B65B 53/00 20060101 B65B053/00; B65D 65/00 20060101
B65D065/00 |
Claims
1. A shrink tubing jacket construction for enabling blade-free
removal of shrink tubing from an underlying substrate, the shrink
tubing jacket construction comprising: an axial length of shrink
tubing, the shrink tubing having an inner tubing diameter, an outer
tubing diameter, a tubing length, a tubing wall, and a first lumen,
the tubing wall being bound by the inner and outer tubing diameters
and the tubing length, the tubing wall having a tubing material
strength, the inner tubing diameter for receiving the underlying
substrate, the first lumen extending through the tubing wall
intermediate the inner and outer tubing diameters, the first lumen
having a lumen length at least equal to the tubing length; and a
first tear member, the first tear member being insertable through
the First lumen thereby being received within the tubing wall, the
first tear member having a member length and a member material
strength, the member length having a magnitude at least equal to
the lumen length, the member material strength being greater in
magnitude than the tubing material strength such that when the
first tear member is tensioned in a diametrical direction relative
to the shrink tubing, the first tear member slices through the
first lumen and tubing wall toward a select tubing diameter.
2. The shrink tubing jacket construction of claim 1 wherein the
first lumen is formed in the tubing wall closer to the inner tubing
diameter relative to the outer tubing diameter, the first tear
member being diametrically directed toward the outer tubing
diameter during slicing action thereby leaving a minimized material
membrane adjacent the inner tubing diameter, the minimized material
membrane being manually rupturable for manually removing the shrink
tubing from the underlying substrate.
3. The shrink tubing jacket construction of claim 1 comprising a
second lumen substantially identical to the first lumen, and a
second tear member substantially identical to the first tear
member, the second lumen being diametrically opposed to the first
lumen, the second tear member being insertable through the second
lumen, the first and second tear members for slicing through the
first and second lumens and the tubing wall in diametrically
opposite directions.
4. The shrink tubing jacket construction of claim 3 wherein the
first and second tear members are collinearly tensionable with
substantially equal tension for minimizing stress and strain on the
underlying substrate during slicing action.
5. The shrink tubing jacket construction of claim 1 comprising a
slotted jig, the slotted jig being constructed from a substantially
rigid material and comprising a slot and an inner jig diameter, the
inner jig diameter being greater in magnitude than the outer tubing
diameter for receiving the shrink tubing, the slot being orientable
in radially outward adjacency to the first lumen, the first tear
member being tensioned in a diametrical direction through the slot,
the rigid material of the slotted jig for minimizing stress and
strain on the underlying substrate during slicing action.
6. The shrink tubing jacket construction of claim 1 comprising tear
member-accessing means for enabling a user to more easily access
the tear member.
7. A shrink tubing jacket construction for enhancing removal of
shrink tubing from an underlying substrate, the shrink tubing
jacket construction comprising: shrink tubing, the shrink tubing
having an inner tubing diameter, an outer tubing diameter, and a
tubing wall, the tubing wall having a tubing material strength, the
inner tubing diameter for receiving the underlying substrate; and a
first tear member, the first tear member being located in the
tubing wall, the first tear member having a member material
strength, the member material strength being greater in magnitude
than the tubing material strength such that when the first tear
member is tensioned in a diametrical direction relative to the
shrink tubing, the first tear member slices through the tubing wall
toward a select tubing diameter.
8. The shrink tubing jacket construction of claim 7 wherein the
first tear member is located in the tubing wall in closer proximity
to the inner tubing diameter relative to the outer tubing diameter,
the first tear member being directed toward the outer tubing
diameter during slicing action thereby leaving a minimized material
membrane adjacent the inner tubing diameter, the minimized material
membrane being manually rupturable for manually removing the shrink
tubing from the underlying substrate.
9. The shrink tubing jacket construction of claim 7 comprising a
second tear member, the second tear member being opposed to the
first tear member, the first and second tear members for slicing
through the tubing wall in diametrically opposite directions.
10. The shrink tubing jacket construction of claim 9 wherein the
first and second tear members are collinearly tensionable for
minimizing stress and strain on the underlying substrate during
slicing action.
11. The shrink tubing jacket construction of claim 7 comprising a
slotted jig, the slotted jig being constructed from a substantially
rigid material and comprising a slot and an inner jig diameter, the
inner jig diameter being greater in magnitude than the outer tubing
diameter for receiving the shrink tubing, the slot being orientable
in adjacency to the first tear member, the first tear member being
tensioned in a diametrical direction through the slot, the rigid
material of the slotted jig for minimizing stress and strain on the
underlying substrate during slicing action.
12. The shrink tubing jacket construction of claim 7 comprising
tear member-accessing means for enabling a user to more easily
access the tear member.
13. A tear-removable jacket for enhancing removal of
sheath-protecting tubing from an underlying substrate, the jacket
comprising: tubing material, the tubing material having an inner
tubing diameter, an outer tubing diameter, and a tubing wall, the
tubing wall having a tubing material strength, the inner tubing
diameter for sheath-protecting the underlying substrate; and a tear
member, the tear member being extruded into the tubing wall, the
tear member having a member material strength, the member material
strength being greater in magnitude than the tubing material
strength such that when the tear member is tensioned in a
diametrical direction relative to the tubing material, the tear
member slices through the tubing wall toward a select tubing
diameter.
14. The tear-removable jacket of claim 13 wherein the tear member
is located in the tubing wall in closer proximity to the inner
tubing diameter relative to the outer tubing diameter, the tear
member being directed toward the outer tubing diameter during
slicing action thereby leaving a minimized material membrane
adjacent the inner tubing diameter, the minimized material membrane
being manually rupturable for manually removing the jacket from the
underlying substrate.
15. The tear-removable jacket of claim 13 comprising two tear
members, the two tear members being diametrically opposed for
slicing through the tubing wall in diametrically opposite
directions.
16. The tear-removable jacket of claim 15wherein the two tear
members are collinearly tensionable for minimizing stress and
strain on the underlying substrate during slicing action.
17. The tear removable jacket of claim 13 usable in combination
with a slotted jig, the slotted jig being constructed from a
substantially rigid material and comprising a slot and an inner jig
diameter, the inner jig diameter being greater in magnitude than
the outer tubing diameter for receiving the tubing material, the
slot being orientable in adjacency to the tear member, the tear
member being tensioned in a diametrical direction through the slot,
the rigid material of the slotted jig for minimizing stress and
strain on the underlying substrate during slicing action.
18. The tear-removable jacket of claim ______ comprising tear
member-accessing means for enabling a user to more easily access
the tear member.
19. A method for selectively outfitting a substrate with a shrink
jacket, the method comprising the steps of: locating a first tear
member intermediate an inner and outer tubing diameter through a
length of shrink tubing at a sheath-slicing depth; receiving an
underlying substrate within the inner tubing diameter; reducing the
inner tubing diameter for sheath-protecting the underlying
substrate; tensioning the first tear member in a diametrical
direction relative to the length of shrink tubing; and slicing
through the shrink tubing from the sheath-slicing depth toward a
select tubing diameter via the tensioned first tear member.
20. The method of claim 19 wherein the step of locating the first
tear member is defined by forming a member-receiving lumen
intermediate the inner and outer tubing diameter through the length
of shrink tubing at the sheath-slicing depth and inserting the
first tear member in the member-receiving lumen.
21. The method of claim 19 wherein the step of locating the first
tear member is defined by locating the tear member closer to the
inner tubing diameter relative to the outer tubing diameter, the
first tear member being directed toward the outer tubing diameter
during the step of tensioning the first tear member, the slicing
action leaving a minimized material membrane adjacent the inner
tubing diameter, the minimized material membrane being manually
rupturable for manually removing the shrink tubing from the
underlying substrate.
22. The method of claim 19 wherein the step of reducing the inner
tubing diameter is defined by heat-shrinking the shrink tubing.
23. The method of claim 19 comprising the step of locating a second
tear member diametrically opposed to the first tear member
intermediate the inner and outer tubing diameters through the
length of shrink tubing at the sheath-slicing depth, the first and
second tear members being collinearly tensionable for slicing
through the shrink tubing with minimized stress and strain on the
underlying substrate.
24. The method of claim 19 comprising the step of jig-enveloping
the shrink tubing while slicing through the shrink tubing, the
jig-enveloped shrink tubing for minimizing stress and strain on the
underlying substrate.
Description
PRIOR HISTORY
[0001] This non-provisional patent application claims the benefit
of U.S. Provisional Patent Application No. 60/839,991, filed in the
United States Patent and Trademark Office on Aug. 24, 2006.
BACKGROUND OF THE INVENTION
[0002] 2. Field of the Invention
[0003] The disclosed invention generally relates to a thermal
plastic tubing construction or heat-shrinkable tubing construction.
More particularly, the disclosed invention relates to a
heat-shrinkable tubing jacket or jacket assembly having a tear
member extruded therein for enabling users thereof to tear through
the wall of the jacket assembly to enable tubing or jacket release
from an underlying substrate.
[0004] 2. Description of the Prior Art
[0005] U.S. Pat. No. 4,138,457 ('457 Patent), which issued to Rudd
et al., discloses a Method of Making a Plastic Tube with Plural
Lumens. The '457 Patent teaches a plastic tube having a main lumen,
an auxiliary lumen, and an integral connector at one end for
connecting the main lumen in fluid communication with another
device. The auxiliary lumen extends longitudinally within the side
wall of the tube with the integral tube connector free of the
auxiliary lumen. The tube can be made by extruding thermoplastic
material through a die having a hollow main lumen die pin and a
hollow auxiliary lumen die pin adjacent the die outlet orifice. Air
under pressure is supplied to both die pins to produce tubing
extrudate having main and auxiliary lumens. The pressure of the air
supplied to the auxiliary lumen forming pin is reduced at
programmed intervals during the extrusion of the tubing so that
selected portions are free of an auxiliary lumen or have a lumen of
limited size. The tubing can be severed so that it has a selected
portion at one end that can serve as an end connector.
[0006] U.S. Pat. No. 5,226,899 ('899 Patent), which issued to Lee
et al., discloses a Catheter Tubing of Controlled in Vivo
Softening. The '899 Patent teaches a catheter tubing having a layer
of a hydrophobic stiffening polymer encapsulated by a layer of
hydrophilic thermoplastic base polymer. Preferred stiffening
polymers are polyesterpolyether block copolymers. Preferred base
polymers are thermoplastic polyetherurethanes. The encapsulated
layer may be a stripe or an annular layer having base polymer
layers laminated on both surfaces thereof.
[0007] U.S. Pat. No. 5,246,452 ('452 Patent), which issued to
Sinnott., discloses a Vascular Graft with Removable Sheath. The
'452 Patent teaches a porous graft having a non-porous coating or
sheath which does not adhere to the graft. After the graft is
implanted into the patient, circulation is restored through the
graft. The sheath is left in place temporarily while blood works
its way through the wall of the porous graft to the non-porous
sheath, where it is prevented from leaking. Clots form in the
graft, sealing it. After a few minutes, the sheath is removed. The
graft or the inside surface of the sheath can be pre-treated with a
coagulant to accelerate clotting. The sheath is applied to the
graft as a coating, e.g. by dipping or spraying, or as a separate
sleeve, e.g. heat-shrinkable tubing. The sheath can be removed by
cutting. Preferably, the sheath incorporates a string, strip, or
ribbon of material which is attached to the sheath. For removal,
the string is pulled, tearing the sheath which is removed with the
string.
[0008] U.S. Pat. No. 6,206,430 ('430 Patent), which issued to Pond
et al., discloses a Connector and Attachment Mechanism for a Lumen.
The '430 Patent teaches a fitting and attachment assembly including
a connector having a conventional proximal end and a distal end
having a barbed portion thereon; said distal end being mateable
with fluid delivery tubing. The mating end portion of said tubing
including a separable annular collar in abutting relationship with
the end of said tubing and a severable heat-shrinkable sleeve
positioned externally of said tubing. A mechanism is further
provided for severing said sleeve.
[0009] U.S. Pat. No. 6,938,645 ('645 Patent), which issued to
Duarte et al., discloses a Protective Sheath having a Longitudinal
Strip made of Flexible Material, and Method of Manufacturing such a
Sheath. The '645 Patent teaches an annulated tubular sheath having
a split down a longitudinal section thereof. According to the
invention, a longitudinal strip of the sleeve is made of a flexible
material and is disposed in an angular position of 5-180 degrees in
relation to the longitudinal section or is disposed in the region
of the sheath in which the longitudinal section is made.
Preferably, the flexible material is a thermoplastic elastomer. The
invention also relates to a method for producing a sleeve by
extruding a plastic material, a longitudinal strip made of a
flexible material obtained by co-extruding an elastomer material. A
device for carrying out said method comprises an extrusion head
provided with an insert for placing the co-extrusion in a stop
position on a die in order to block the flow of the extruded
plastic material and to enable the flow of elastomer material.
[0010] U.S. Pat. No. 6,976,991 ('991 Patent), which issued to
Hebert et al., discloses a Manipulatable Delivery Catheter for
Occlusive Devices. The '991 Patent teaches a delivery catheter with
a flexible, proximally-manipulated hinge or joint region. The
inventive catheter may have a balloon region. The catheter may have
a shaft of varying flexibility which contains several lumens. The
inner, or delivery, lumen generally may be used with a guide wire
to access target sites within the body via the flexible, small
diameter vessels of the body. The delivery lumen may be also used
for placement of occlusive materials, e.g., in an aneurysm.
Inflation of the micro-balloon, located near the distal tip of the
catheter, is effected using the inflation lumen. The push/pull wire
lumen contains a wire, which when manipulated, flexes the
catheter's distal tip. The push/pull wire tubing may have a
variable thickness to aid in adjusting the degree of flexibility.
Moreover, the delivery catheter may be capable of twisting in a
helical or corkscrew-like manner for traversing certain
vasculature. This may be accomplished by winding the push/pull wire
within the catheter and fixedly attaching it. The catheter may
further include an entry in the catheter wall to allow for the
insertion of a guide wire; this may facilitate the rapid exchange
of catheter devices as desired by the user.
[0011] United States Patent Application Publication No.
2005/0165366, authored by Brustad et al., teaches a medical tubing
adapted for insertion into a body tissue or cavity and method of
manufacturing different variations of the tubing along a length of
the tubing. The tubing comprises a plurality of individual,
discrete, generally ring-shaped elements arranged in series and
fused or bonded together forming a continuous tubular structure.
The ring-shaped elements may be formed of a thermoplastic or a
thermoset material. The ring-shaped elements may include plastic
rings, metallic rings, un-reinforced plastic rings and/or metal
reinforced plastic rings assembled along the length of the tubular
structure to provide variable flexibility and kink-resistance. The
tubular structure may have a cross-section of any geometric shape
and it may be bent, twisted or curved without kinking. The
ring-shaped elements may have different flexural modulus. The
ring-shaped elements may include a combination of flexible and
rigid ring-shaped elements assembled along different portions or
sections of the tubular structure. The ring-shaped elements may be
metallic and may be bonded with a resilient, flexible elastomeric
adhesive, wherein the ring-shaped elements may have different
lengths and may be fused closer or further apart to one another
depending on the characteristics of a portion or section of the
tubing. In another aspect of the invention, the medical tubing may
further comprise a secondary lumen and a pull wire to control the
tubular structure. The ring-shaped elements may be truncated to
provide a bending bias. In another aspect of the invention, the
ring-shaped elements may vary in diameter and/or composition in
different portions or sections of the tubular structure. In yet
another aspect of the invention, some of the ring-shaped elements
may be radiopaque, or the ring-shaped elements may comprise of
different colors to operate as indicators along the tubular
structure.
[0012] Arguably, the most pertinent of the foregoing disclosures
includes the '452 Patent and the '430 Patent. From an inspection of
the '452 Patent, it will be seen that the disclosed product is a
vascular graft with removable sheath. It will be further seen that
the outer sheath is optionally a heat-shrinkable coating or sleeve,
incorporating a string, strip, or ribbon of material thereunder,
which tear member is notably under the sheath, not incorporated or
extruded into the sheath. The purpose for the tubing of the '452
Patent is thus different than the purpose or object of the present
tubing construction. Notably, the pullable member of the '452
Patent is laid underneath the outer tubing directly contacting the
underlying substrate such as graft 10. Direct contact with the
underlying substrate, such as graft 10, oftentimes results in
damage to the substrate. Thus, the prior art perceived a need for a
heat-shrinkable tubing having a tear member extruded within the
wall of the outer sheath (i.e. intermediate the inner and outer
diameter of the outer sheath) for enabling removal thereof.
[0013] With regard to the '643 Patent, it will be seen that the
tear member is also situated in contacting superficial adjacency to
the inner substrate such as inner tubing 40. Situating the tear
member under (i.e. not within) the outer heat-shrinkable tubing,
while perhaps providing a superior sheath removal mechanism, also
promotes damage of the underlying substrate. Given the highly
sensitive nature of medical applications in which the constructions
of the '452 and '643 Patent(s), it is preferably to provide a
tubing construction comprising an outer heat-shrinkable tubing with
a tear member extruded intermediate the inner and outer diameters
so as to enable sheath removal, while protecting the underlying
substrate from damage.
[0014] For medical applications, such as catheter applications, it
is noted that oftentimes these devices typically comprise several
tubular layers of material, one over the other. A heat shrink
tubing is often utilized as a last step in the manufacture or as
the outermost sheath or layer. Often this tubing is FEP/Teflon
tubing but it could also be other materials. When this material is
shrunk over the underlying substrate(s), it causes the layer
immediately under it to melt and flow into the layers below and to
cause those layers to all meld or bond together. The final step,
then, involves stripping off that heat shrink tubing layer and
throwing it away. In this application the heat shrink tubing is
essentially being used as a tool or mechanical device. The current
/common method for removal (in devices not incorporating a tear
member) is to take a razor or sharp type of tool and to drag the
tool along the length of the device with the goal being to "score"
the shrink tubing or to cut part way through the wall. Ideally they
try to cut most of the way through the wall so that after the
scoring is done, on one or more sides, the heat shrink tubing can
be easily peeled away.
SUMMARY OF THE INVENTION
[0015] Accordingly, in an attempt to address the foregoing
shortcomings readily apparent in the prior art, the disclosed
thermoplastic tubing construction shrink tubing jacket assembly
essentially provides certain heat shrinkable tubing with a wire or
other tear member device built or extruded "into the wall" of the
tubing. Similar to state of the art garden hoses and the like,
which incorporate braided textile material into the tubing, the
tear member is not exposed at either the inner or outer diameter of
the tubing construction, but rather embedded within the wall
structure of the tubing.
[0016] For non medical applications, such as covering various
rollers, parts or other structures, this tubing can be used
allowing for ease of tubing or sheath removal at the user's
election. Further, in electrical applications, when conductors may
be covered with insulation to protect or insulate the underlying
conductor(s), and sheath removal may be required, the essence of
the present invention may be effectively practiced.
[0017] The method of sheath removal inherently taught by the
present invention is necessarily less "craft sensitive" than those
tubing constructions requiring lengthwise cutting to remove an
outer sheath. Inexperienced practitioners may well be able to
remove the sheaths, having been shown, where to pull. Further,
there is little chance of damaging the underlying substrate as, for
example, by cutting too deep.
[0018] In practice, the user may simply trim the ends of the tubing
to expose the tear member at both ends. After fixing one end
thereof (i.e. by clamping same), the other (free) end may be
pulled, outward (thereby slicing through the tubing wall) and
toward the first fixed end. The final removal is made easy by
simply pulling at the tubing and the tubing will tear in the region
where new weak structural lines have been created (i.e. that region
directly underlying the extrusion zone essentially forming a thin
easily penetrable or tearable membrane). In this last regard, it
should be noted that the wire or tear member is extruded closer to
the inner wall than the outer wall as the desire is to tear as much
wall material as possible during the wire pulling process. Ideally
this wire or tear member would be embedded in radial outward
adjacency to the inner wall or diameter of the tubing.
[0019] Notably, the end product on which the tubing construction of
the present invention is to be used, (for example, a catheter being
manufactured) will not differ as practiced under the currently
disclosed structure(s) and method(s). The resultant end product
will be the same. Foreseeable benefits of the tubing construction
herein contemplated include enhanced ease and speed of manufacture,
as well as a lessened scrap rate of relatively expensive base
component materials. Perhaps most notably, however, is a decrease
in stress and strain on the end product resulting in higher end
product reliability. It is further believed that commonly used
scoring techniques have limitations in terms of the sizes of
products with which they will work. In this regard, it is noted
that as catheters and the like become smaller in diameter it
becomes more and more difficult to properly score or scribe a
partial cut line along their surface. The construction of the
present invention may well be incorporated into almost any size of
heat shrink tubing, thus obviating the obstacle of difficult,
small-diameter tubing.
[0020] Other objects of the present invention, as well as
particular features, elements, and advantages thereof, will be
elucidated or become apparent from, the following description and
the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Other features of my invention will become more evident from
a consideration of the following brief description of patent
drawings:
[0022] FIG. 1 is a transverse cross-sectional type depiction of a
first preferred embodiment of the shrink tubing jacket construction
of the present invention showing a single tear member.
[0023] FIG. 2 is a transverse cross-sectional type depiction of a
second preferred embodiment of the shrink tubing jacket
construction of the present invention showing opposing tear
members.
[0024] FIG. 3 is a transverse cross-sectional type depiction of a
first alternative embodiment of the shrink tubing jacket
construction of the present invention showing a single
member-receiving lumen.
[0025] FIG. 4 is a transverse cross-sectional type depiction of a
second alternative embodiment of the shrink tubing jacket
construction of the present invention showing opposing
member-receiving lumens.
[0026] FIG. 5 is a lateral view type depiction of the second
preferred embodiment of the shrink tubing jacket construction of
the present invention with end portions broken to show the opposing
tear members.
[0027] FIG. 6 is an edge view type depiction of a pulley system for
mechanized tear member removal from the shrink tubing jacket
construction of the present invention.
[0028] FIG. 7 is a plan view type depiction of the pulley system
otherwise depicted in FIG. 6 for mechanized tear member removal and
shrink tubing jacket construction according to the present
invention.
[0029] FIG. 8 is a plan view type depiction of the pulley system
otherwise depicted in FIG. 7 removing tear members from the shrink
tubing jacket construction of the present invention.
[0030] FIG. 9 is a first longitudinal type depiction of a shrink
tubing jacket construction having a translucent tubing structure so
as to enable the user to visually perceive the tear member embedded
within the wall thereof.
[0031] FIG. 10 is a second longitudinal type depiction of a shrink
tubing jacket construction having trimmed ends so as to expose ends
of the tear member.
[0032] FIG. 11 is a third longitudinal type depiction of a shrink
tubing jacket construction having scored sections or pre-scored
ends so that the tear member ends may be more easily accessed by
manually ripping the tubing at the scoring.
[0033] FIG. 12 is a transverse cross-sectional type depiction of a
first embodiment of a single slotted jig formed of relatively rigid
material for enveloping the shrink tubing jacket construction for
aiding tear member removal (via the slotted portion).
[0034] FIG. 13 is a transverse cross-sectional type depiction of
the slotted jig otherwise depicted in FIG. 12 enveloping the first
preferred embodiment of the shrink tubing jacket construction of
the present invention, which jacket construction is
sheath-enveloping a catheter.
[0035] FIG. 14 is a transverse cross-sectional type depiction of a
second embodiment of a dual-slotted jig formed of relatively rigid
material for enveloping the shrink tubing jacket construction for
aiding tear member removal (via the slotted portions).
[0036] FIG. 15 is a transverse cross-sectional type depiction of a
prior art type substrate with a tear member interstitially
sandwiched between the substrate and a shrinkable tubing
jacket.
[0037] FIG. 16 is a transverse cross-sectional type depiction of a
prior art type jacketed catheter (with underlying substrate) with a
tear member interstitially sandwiched between the catheter and a
shrinkable tubing jacket.
[0038] FIG. 17 is a transverse cross-sectional type depiction of a
prior art type catheter (with underlying substrate) with a groove
or slot formed therein via heat shrinking action of the shrinkable
tubing jacket otherwise removed from the figure.
[0039] FIG. 18 is a transverse cross-sectional type depiction of an
arc length of tubing material.
[0040] FIG. 19 is a transverse cross-sectional type depiction of a
partially disassembled preliminary shrink tubing jacket
construction showing a tubing construction, a tear member in
radially inward adjacency thereto.
[0041] FIG. 20 is a transverse cross-sectional type depiction of
the shrink tubing jacket construction otherwise shown in FIG. 19 in
assembled relation with the arc length of tubing shown in FIG.
18.
[0042] FIG. 21 is a transverse cross-sectional type depiction of
the assembled shrink tubing jacket otherwise shown in FIG. 20
enveloping an underlying substrate in a pre-shrink state.
[0043] FIG. 22 is a transverse cross-sectional type depiction of
the structures otherwise depicted in FIG. 21 in a post-shrink
state.
[0044] FIG. 23 is a transverse cross-sectional type depiction of a
heat shrinkable tubing construction with a lumen formed in the wall
thereof.
[0045] FIG. 24 is a transverse cross-sectional type depiction of a
further alternative assembly of the present invention comprising an
inner slotted sleeve, and an outer shrink tubing jacket
construction.
[0046] FIG. 25 is a fragmentary perspective type depiction of a
shaft with an outer shrink tubing jacket layer with a tear member
inserted into the wall of the tubing jacket layer.
[0047] FIG. 26 is a fragmentary perspective type depiction of the
assembly otherwise depicted in FIG. 25 wherein the tear
member-bearing wall has a tear-through started as enabled via the
tear member.
[0048] FIG. 27 is a fragmentary longitudinal or side type view of
the assembly otherwise depicted in FIG. 26 wherein the tear member
of the tear member-bearing wall is pulled or torn through a
majority of the tubing length.
[0049] FIG. 28 is a fragmentary longitudinal or side type view of
the assembly otherwise depicted in FIG. 27 wherein the tear member
of the tear member-bearing wall is pulled or torn through the full
tubing length.
[0050] FIG. 29 is a fragmentary side view type depiction of a first
end of a common guiding catheter type construction outfitted with a
shrink tubing jacket outer layer and guiding an inner form-easing
mandrel.
[0051] FIG. 30 is a fragmentary side view type depiction of a
common guiding catheter type construction otherwise depicted in
FIG. 29 comprising inner and outer tubing layers with a braided
interstitial layer between the inner and outer tubing layers.
[0052] FIG. 31 is an expanded fragmentary side view type depiction
of the structures otherwise depicted in FIG. 29 showing the
multi-layered assembly from two ends.
[0053] FIG. 32 is a fragmentary side view type depiction of a shaft
type member with a shrink tubing jacket construction outer layer
and an inner mandrel.
[0054] FIG. 33 is a fragmentary side view type depiction of a group
of conductor members with an outer layer defined by a shrink tubing
jacket construction of the present invention.
[0055] FIG. 34 is a fragmentary side view type depiction of an
underlying substrate with a shrink tubing jacket construction as a
partial outer layer with a tear member extending from one end
thereof and as positioned adjacent a U.S. coin for sizing
perspective.
[0056] FIG. 35 is a first sequential, fragmentary perspective type
depiction of a shaft outfitted with a shrink tubing jacket
construction of the present invention wherein the tear member of
the tear member-bearing wall is pulled or torn through a majority
of the tubing length.
[0057] FIG. 36 is a second sequential, fragmentary perspective type
depiction of structures otherwise depicted in FIG. 35 wherein the
tear member of the tear member-bearing wall is nearly pulled or
torn through the entire tubing length.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0058] Referring now to the drawings, a first preferred embodiment
of the present invention concerns a shrink tubing jacket
construction 10 as generally illustrated and referenced in FIGS. 2,
5, 7, 8, and 9-11. Further depictions of the shrink tubing jacket
construction 10 are shown in FIGS. 4(a)-6(b). A second preferred
embodiment of the shrink tubing jacket construction 10(a) is
depicted and referenced in FIGS. 1, 13, 32, 33, 35, and 36. It will
be seen from an inspection of the noted figures that the primary
difference between the first preferred shrink tubing jacket
construction 10 and the second preferred shrink tubing jacket
construction 10(a) is the extrusion of two wires, monofilaments, or
other tear members 11 (in the first preferred embodiment) into the
wall 12 of heat shrink tubing 13 as compared to the extrusion of a
single wire, monofilament, or other tear member 11 into the wall 12
of certain heat shrink tubing 13 (in the second preferred
embodiment).
[0059] In the preferred embodiment, two tear members 11 are
situated 180 degrees from one another or along a common diameter at
opposite sides of tubing 13. Certain tear members 11 are
illustrated and referenced in FIGS. 1, 2, 5, 8, 9-11, 15, 16, 19,
20, 21-28, and 32-36; wall 12 is illustrated and referenced in
FIGS. 1-5, 13, 15, 16, 19, and 20-22; and tubing 13 is illustrated
and referenced in FIGS. 1-5, 7-11, 15, 16, 19-23, 25-29, and 31-36.
It is further contemplated that the teachings of the present
disclosure present a certain novel method of removing heat shrink
tubing 13 from an underlying substrate, such as a catheter 14,
which catheter or catheter construction 14 is generally illustrated
and referenced in FIGS. 13, 16, 17, 21, 22, and 29-31. Other
underlying substrates may include a shaft, roller or other similar
component 15 as illustrated and referenced in FIGS. 25-28, and
34-36; or a bundle of conductors or wires (to form a cable) as at
16 and illustrated and referenced in FIG. 33. In this last regard,
it is contemplated that ripping radially outward and lengthwise
through an outer shrink tubing jacket layer in order to remove the
same from an underlying substrate is novel methodology in the
art.
[0060] It will be understood from an inspection of the noted or
applicable figures, that the tear member(s) 11 are preferably
extruded or embedded within the wall 12 as close to the inner
diameter (as at 17) as possible so that the tear member 11 removal
(as generally depicted in FIGS. 8, 25-28, and 34-36)) will tear or
cut through as much wall 12 as possible making full removal of the
tubing 13 as easy as possible due to minimal remaining material (in
radially inward adjacency to tear member(s) 11 as referenced at 18
in FIG. 1 to tear or remove. It is contemplated that material 18
may be easily broken or torn (i.e. manually rupturable), the same
essentially being a minimized material membrane extending
intermediate the extruded tear member 11 and the inner diameter 17
of the tubing 13.
[0061] Further, it may be readily understood that that shrink
tubing jacket construction 10 preferably comprises two or paired
tear members 11 (each pair being 180 degrees apart). In this
regard, it is contemplated that dual or paired wires or tear
members 11 may be pulled in radially opposite directions so as to
input less bending stress on the substrate and also to make final
tearing of the tubing 13 easier. In other words, it is contemplated
that paired tear members 11 lying along a common diameter on
opposite sides of tubing 13 may well function to prevent undue
bending of the underlying substrate. In this regard, it is
contemplated that wire removal may be effected by a mechanized dual
pulley system as generally depicted in FIGS. 6-8, which pulley
system may well function to impart equal and opposite tensile
forces upon the tear members 11 for effecting a zero net bending
force on the underlying substrate to which the construction 10 is
attached.
[0062] From an inspection of FIG. 8, for example, it will be seen
that when two or paired tear members 11 are incorporated into the
design and harnessed to paired pulley assemblies 20, the tear
members 11 may be effectively engaged and pulled at common pull
rates with common tensile force. In other words, it is contemplated
that the assemblies 20 preferably function to rotate at a common
velocity in opposite directions for pulling the tear members 11
radially outward from the relaxed, extruded position (as generally
depicted in FIG. 5), thereby imposing material-tearing forces (as
imparted by pulley assemblies 20 and the inherent tensile strength
of the tear members 11), the material-tearing forces essentially
operating to impart substantially equalized forces as at vector
arrows 21 in FIG. 8, thereby resulting in reduced stress on the
underlying substrate. In other words, the net force on the
substrate would tend toward zero resulting in reduced stress and
strain. Notably, it is further contemplated that the mechanized
"ripping speed" can be relatively slow for controlled jacket
removals or spring-loaded for effecting rapid,
distortion-minimizing jacket removals.
[0063] From an inspection of FIGS. 3, 4, and 23, it may be further
understood that a certain tear member-receiving lumen 22 (or lumens
22) may be incorporated into the wall 12 of the tubing 13 of the
present invention. A fine wire or tear member 11 could be fed
through or received by the lumen 22, which tear member 11, after
being inserted into or received by the lumen 22, may well function
to enable the user to tear through wall 12 of tubing 13 for tubing
or jacket removal as generally depicted throughout the applicable
figures. In this regard, it is contemplated that a lumen 22 may be
formed in the wall 12 if extrusion or embedded placement of a wire
or tear member 11 is not possible given material requirements.
Notably, the lumen 22 could fulfill other useful purposes, as may
be gleaned from a general consideration of the state of the
art.
[0064] From an inspection of FIGS. 9-11, it may be noted that
certain means for accessing the tear member 11 are contemplated. In
this regard, it is contemplated that said means may, in a first
scenario, be defined by the translucent material construction of
the tubing 13. In other words, it is contemplated that the tubing
structure 13 may be constructed from translucent material(s) so as
to enable the user to visually perceive the tear member 11 embedded
within the wall 12 as generally depicted in all three figures.
Other means for accessing the tear member 11 may be defined by
exposed end(s) 23 of a tear member 11. In this regard, it is
contemplated that the ends 23 of tubing 13 may be trimmed away
thereby exposing ends 23 as generally depicted in FIG. 10. Further,
the ends 23 of tubing 13 may be pre-scored as at 24 in FIG. 11 so
that tear member ends 23 may be more easily accessed by manually
ripping tubing 13 at said scoring 24.
[0065] From an inspection of FIGS. 7(a) and 7(b), it will be seen
that other means for facilitating tubing removal may be utilized in
combination with tear member(s) 11, which means may be defined by
certain fixtures or jigs which function to provide shaft support
(and are thus preferably constructed from relatively rigid
materials) during tear member action. In this regard, it is
contemplated that slit metal or plastic tubing 25 may envelope
shrink tubing jacket constructions 10 or 10(a). It is contemplated
that the tubing may well function to facilitate removal of the tear
member 11 without bending or otherwise straining the underlying
substrate (e.g. a catheter 14). The underlying substrate or
catheter 14 could be placed inside such tubing 25 (sized for the
application) so that the tear member 11 is positioned in radial
inward adjacency to one or more slots 26 as further generally
depicted and referenced. Tear member 11 may then be pulled radially
outward through the slot 26 and then pulled, upward or against the
grain, toward the opposite end of tubing 13. Notably, this process
can be performed in a heated environment which eases the tearing
and slitting of the tubing 13 (optionally constructed from FEP heat
shrink type thermoplastic).
[0066] From an inspection of FIGS. 15 and 16, it may be seen that
certain prior art methodology has included attempts to overlay a
tear member 11 in contact with an underlying substrate (i.e. the
tear member 11 not being embedded in the wall 12 of tubing 13). In
other words, prior art tear members 11 have been loosely sandwiched
or interstitially situated intermediate the underlying substrate 27
and the tubing 13 as generally depicted in FIG. 15. While it is
noted that this type of prior art tear member 11 may effectively
function to tear through the overlying tubing 13 (whether in a
heated or chilled state), it is further noted that when heated and
driven against the outer diameter 28 of the underlying substrate 27
(such as a catheter 14), the tear member 11 often causes a
problematic longitudinal groove 29 to form in the outer diameter 28
as generally depicted in FIG. 17.
[0067] In this last regard, it should perhaps be further noted that
if the underlying substrate 27 is relatively thin thermoplastic on
a mandrel, the heated tear member 11 may cut through the outer
diameter 28 underlying substrate 27. Test results have suggested
the preferred manufacture of the removal jacket construction of the
present invention, the same being to embed or extrude the tear
member 11 within wall 12 so as to prevent direct contact
intermediate the tear member(s) 11 and the underlying substrate
27.
[0068] As earlier stated, and as further supported in FIG. 32, heat
shrink tubing 13 is often used as a temporary covering or
protective layer for a shaft, roller or other similar component 15.
Such tubing is often stripped off with a razor type cutting
implement. However, if underlying surface damage is to be avoided,
(e.g. for corrosion protection), an easily strippable jacket
construction such as construction 10 or 10(a) as taught by the
present invention may be effectively utilized. From an inspection
of FIG. 33, it may be further noted that heat shrink tubing 13 is
also often used to cover a group of conductors 16 to form the same
into a cable or to jacket and sheath-protect them. If damage occurs
or if an individual conductor 16 fails, or if added circuits become
required, it may become necessary to remove the jacket or outer
sheath. It may be difficult to remove the outer jacket with a
cutting implement such as a razor or knife. Having a tear member 11
in the outer tubing 13 makes outer sheath or jacket removal easy
and greatly reduces the chances of damaging the underlying
conductors 16.
[0069] As has been noted hereinabove, current and common methods
for removing shrink tubing jackets, and other plastic layers,
include scoring methods or mechanisms with certain depth control of
the scoring blade or blades. In the case of an underlying catheter
type substrate, it is common to make two score lines, lengthwise,
scoring most of the way through the outer shrink layer, normally
the two score lines being 180 degrees opposed or on opposite sides
of the shaft. This allows the tearing process to easily peel away
with the material giving way at the weakened score line. Pitfalls,
however, are experienced with this type of scoring method including
extreme difficulty with effectively accomplishing the task on
relatively small diameter shafts. Further, as walls become thinner
it is difficult to control a partial score in the wall without
cutting through the wall and damaging the substrate underneath.
Wall thickness, thus, should be consistent for this state of the
art methodology to be effective; if the substrate varies in
diameter then the shrink tubing layer will have a graduated
thickness, making a depth set blade less effective.
[0070] A buried "zip wire" or tear member 11, however, has proven
effective in outer heat shrink tubing jacket removal. The removal
of an outer tubing sheath and the like is clean and tends to
prevent damage to the underlying substrate. To prevent the wire or
tear member 11 from being pulled into the lumen when pulled from
the opposite end, the wire can be grabbed, fixtured, or attached
which will ensure the ability to pull with sufficient force to rip
through the tubing wall 12. Wall thickness can also be varied,
possibly adding thickness to the lumen areas to compensate for the
lessened material due to the lumen.
[0071] While the above description contains much specificity, this
specificity should not be construed as limitations on the scope of
the invention, but rather as an exemplification of the invention.
For example, as is described hereinabove, it is contemplated that
the present invention essentially discloses a shrink tubing jacket
construction for enabling blade-free removal of shrink tubing from
an underlying substrate. The shrink tubing jacket construction
according to the present invention may be said to comprise an axial
length of shrink tubing and an axial length of zip wire or similar
tear member. The shrink tubing has an inner tubing diameter, an
outer tubing diameter, a tubing length, a tubing wall, and an axial
lumen, which lumen functions to receive the tear member.
[0072] The tubing wall is bound by the inner and outer tubing
diameters as well as the tubing length. The tubing wall has a
certain tubing material strength. The inner tubing diameter
functions to receiving an underlying substrate and the axial lumen
extends through the tubing wall intermediate the inner and outer
tubing diameters. Notably, the axial lumen has a lumen length at
least equal to the tubing length. The tear member is insertable
through the lumen thereby being received within the tubing
wall.
[0073] The tear member has a member length and a member material
strength. The member length has a magnitude at least equal to the
lumen length, and the member material strength is greater in
magnitude than the tubing material strength such that when the tear
member is tensioned in a diametrical direction relative to the
shrink tubing, the tear member is able to slice through the axial
lumen and tubing wall toward a select tubing diameter, which may be
preferably defined by the outer tubing diameter.
[0074] The lumen may be preferably formed in the tubing wall
relatively closer to the inner tubing diameter as compared to the
outer tubing diameter such that when the tear member is directed
toward the outer tubing diameter, a minimized material membrane is
left behind adjacent the inner tubing diameter as a result of the
slicing action. The minimized material membrane is manually
rupturable for manually removing the shrink tubing from the
underlying substrate.
[0075] The shrink tubing jacket construction may comprise a second
axial lumen substantially identical to the first axial lumen, but
diametrically opposed thereto, and a second tear member
substantially identical to the first tear member may be inserted
into the second lumen. The first and second tear members may well
cooperate to slice through the first and second lumens and the
tubing wall in diametrically opposite directions. In this regard,
it is contemplated that the first and second tear members are
collinearly tensionable as generally depicted in FIG. 8 with
substantially equal tension for reducing the net stress on the
underlying substrate.
[0076] Further means for reducing the net stress on the underlying
substrate may be defined by a slotted jig, which slotted jig is
preferably constructed from a substantially rigid material and
essentially comprises a lengthwise slot and an inner jig diameter.
The inner jig diameter is greater in magnitude than the outer
tubing diameter for receiving the shrink tubing. The slot may be
oriented in radially outward adjacency to the lumen(s) and tear
member(s) such that when tensioned in a diametrical direction, the
tear member may be guided through the slot. It is contemplated that
the rigid material of the slotted jig may well function to reduce
the net stress and bending strain on the underlying substrate as
the tear member slices through the tubing wall.
[0077] Stated another way, the shrink tubing jacket construction
may be said to essentially comprise certain shrink tubing and with
an embedded or wall-located tear member. The shrink tubing has an
inner tubing diameter, an outer tubing diameter, a tubing length
and a tubing wall, which wall has a tubing material strength. The
inner tubing diameter functions to receive some type of underlying
substrate as specified hereinabove. The tear member is embedded in
the tubing wall and preferably has a member length and a member
material strength, which member length has a magnitude at least
equal to the tubing length, and which member material strength is
greater in magnitude than the tubing material strength such that
when the tear member is tensioned in a diametrical direction
relative to the shrink tubing, the tear member may well slice
through the tubing wall.
[0078] In addition to the novel jacket construction, the foregoing
specifications are thought to further support certain novel
methodologies, including a method for outfitting a shrink jacket
upon, and removing a shrink jacket from, an underlying substrate;
as well as certain method of manufacture. The method for outfitting
a substrate and removing the outfit from the substrate may be said
to essentially comprise the steps of locating a tear member
intermediate an inner and outer tubing diameter along a length of
shrink tubing at a sheath slicing depth as generally depicted in
the noted figures. The sheath-slicing depth may be defined by the
distance intermediate the member 11 and the outer diameter of the
tubing 13. After so locating the tear member, an underlying
substrate may be received within the inner tubing diameter
whereafter the inner tubing diameter may be reduced (as, for
example, by applying heat and heat-shrinking the tubing 13). This
latter action may well function to sheath-protect the underlying
substrate.
[0079] When the user wishes to remove the sheath-protecting outer
shrink rubbing jacket construction, as exemplified by the
foregoing, the tear member may be tensioned in a diametrical
direction relative to the length of shrink tubing, which action may
well function to slicing through the shrink tubing from the
sheath-slicing depth toward a select tubing diameter, which select
tubing diameter may be typically defined by the outer tubing
diameter for removing the shrink tubing jacket construction from
the underlying substrate.
[0080] The method may comprise certain additional steps including
forming a member-receiving lumen intermediate the inner and outer
tubing diameter through the length of shrink tubing at a
sheath-slicing depth and then inserting the first tear member in
the member-receiving lumen. Further, the step of locating the first
tear member may be defined by locating the tear member within the
tubing wall relatively closer to the inner tubing diameter as
compared to the outer tubing diameter. As earlier stated, the tear
member may then be directed toward the outer tubing diameter during
the step of tensioning the tear member for leaving a minimized
material membrane adjacent the inner tubing diameter. The minimized
material membrane is thought to be manually rupturable for enabling
manual removal the shrink tubing from the underlying substrate.
[0081] Certain methods for minimizing the stress/strain on the
underlying substrate include locating a second tear member
diametrically opposed to the first tear member intermediate the
inner and outer tubing diameters through the length of shrink
tubing at the sheath-slicing depth. The first and second tear
members are collinearly tensionable for slicing through the shrink
tubing for reducing the stress/strain on the underlying substrate.
Further, the shrink tubing may be jig-enveloped before or while
slicing through the shrink tubing. It is contemplated that the
jig-enveloped shrink tubing may well function to guide the slicing
action while also minimizing stress and strain on the underlying
substrate.
[0082] Although the invention has been described by reference to a
number of preferred and alternative embodiments, as well as a
number of different methods, it is not intended that the novel
devices and methods be limited thereby, but that modifications
thereof are intended to be included as falling within the broad
scope and spirit of the foregoing disclosure and the appended
drawings.
* * * * *