U.S. patent application number 10/354249 was filed with the patent office on 2004-07-29 for tube connection joint and method of forming same.
This patent application is currently assigned to SCIMED Life Systems, Inc.. Invention is credited to Benning, Christopher A., Li, Changqing, Sundheimer, Herbert Alan.
Application Number | 20040146341 10/354249 |
Document ID | / |
Family ID | 32736303 |
Filed Date | 2004-07-29 |
United States Patent
Application |
20040146341 |
Kind Code |
A1 |
Sundheimer, Herbert Alan ;
et al. |
July 29, 2004 |
Tube connection joint and method of forming same
Abstract
A connection joint (20) is described that is formed by inserting
a plastic connector (10) into the end of a silicone tube (14). The
connector includes a plurality of barbs (12). A reinforcing agent
(16) is placed between each of the barbs (12) of the connector
(10). An adhesive (18) is injected between the tube (14), the
reinforcing agents (16) and the connector (10). The adhesive (18)
is then cured at a predetermined temperature for a predetermined
time in order to solidify the connection joint (20).
Inventors: |
Sundheimer, Herbert Alan;
(Ellettsville, IN) ; Benning, Christopher A.;
(Ellettsville, IN) ; Li, Changqing; (Ellettsville,
IN) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
SCIMED Life Systems, Inc.
|
Family ID: |
32736303 |
Appl. No.: |
10/354249 |
Filed: |
January 28, 2003 |
Current U.S.
Class: |
403/270 |
Current CPC
Class: |
B29C 66/112 20130101;
B29C 66/71 20130101; B29C 66/534 20130101; B29C 66/114 20130101;
B29C 66/71 20130101; Y10T 403/55 20150115; A61M 39/12 20130101;
Y10T 403/52 20150115; B29C 66/1162 20130101; B29C 65/4865 20130101;
F16L 33/34 20130101; Y10T 403/477 20150115; B29C 65/4835 20130101;
F16B 11/008 20130101; B29K 2083/00 20130101; Y10T 403/559 20150115;
B29C 65/48 20130101; B29L 2023/007 20130101; B29K 2023/065
20130101; A61M 2039/1027 20130101 |
Class at
Publication: |
403/270 |
International
Class: |
F16B 012/04; B25G
003/34 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A connection joint comprising: a female receptacle; a male
connector having a groove defined therein, the male connector
inserted into the female receptacle, wherein one of the female
receptacle and the male connector is made of plastic and the other
is made of silicone; a reinforcing agent placed in the groove; and
a silicone adhesive injected into the groove surrounding the
reinforcing agent.
2. The connection joint of claim 1, wherein the male connector
comprises a first end and a barb and wherein the groove of the male
connector is defined between the barb and the first end of the
connector.
3. The connection joint of claim 2, wherein the reinforcing agent
is placed in the groove between the barb and the first end of the
connector.
4. The connection joint of claim 1, wherein the male connector
comprises a plurality of barbs and wherein a groove is defined
between each pair of barbs.
5. The connection joint of claim 4, wherein a reinforcing agent is
placed in a groove between at least one pair of barbs.
6. The connection joint of claim 1, wherein a durometer of the
reinforcing agent is about greater than or equal to a durometer of
the adhesive.
7. The connection joint of claim 6, wherein the reinforcing agent
is made of silicone.
8. A connection joint comprising: a tube; a connector having a
plurality of barbs inserted into the tube; a reinforcing agent
placed between at least one pair of the barbs; and an adhesive
injected in between the tube, the connector and the reinforcing
agent.
9. The connection joint of claim 8, wherein the durometer of the
reinforcing agent is greater than or equal to about that of the
adhesive.
10. The connection joint of claim 9, wherein the reinforcing agent
is of a durometer greater than about 70 shore A.
11. The connection joint of claim 10, wherein the durometer of the
adhesive is less than about 60 shore A.
12. The connection joint of claim 9, wherein the reinforcing agent
comprises an O-ring.
13. The connection joint of claim 9, wherein the reinforcing agent
comprises a plurality of particles suspended in the adhesive
injected in between the tube, the connector, and the reinforcing
agent.
14. The connection joint of claim 9, wherein the reinforcing agent
and the adhesive are made of silicone.
15. The connection joint of claim 8, wherein a reinforcing agent is
placed between each pair of the barbs.
16. A method for connecting a tube to a connector having a
plurality of barbs, the method comprising: placing a reinforcing
agent between at least two of the barbs of the connector; inserting
the connector into the tube; and injecting an adhesive between the
tube, the connector, and the reinforcing agent.
17. The method of claim 16, further comprising curing the adhesive
at a predetermined temperature for a predetermined period of
time.
18. The method of claim 17, wherein a durometer of the reinforcing
agent is greater than or equal to about that of the adhesive.
19. The method of claim 18, wherein the reinforcing agent is made
of silicone.
20. A connection joint comprising: a tube; a connector inserted
into the tube, the connector having a first end and a barb spaced
apart from the first end; a reinforcing agent placed between the
barb and the first end of the connector; and a adhesive injected
between the tube, the connector, and the reinforcing agent.
21. The connection joint of claim 20, wherein the connector further
comprises a plurality of barbs spaced apart from each other.
22. The connection joint of claim 21, wherein the reinforcing agent
is placed between at least two of the barbs.
23. The connection joint of claim 20, wherein the reinforcing agent
comprises a plurality of particles suspended in the adhesive
injected between the silicone tube, the connector, and the
reinforcing agent.
24. The connection joint of claim 20, wherein the reinforcing agent
comprises an O-ring.
25. The connection joint of claim 20, wherein the reinforcing agent
is of a durometer greater than or equal to a durometer of the
adhesive injected between the tube, the connector, and the
reinforcing agent.
26. The connection joint of claim 20, wherein the reinforcing agent
is of a durometer greater than about 70 shore A.
27. The connection joint of claim 20, wherein the adhesive is of a
durometer of less than about 60 shore A.
28. The connection joint of claim 25, wherein the reinforcing agent
is made of silicone.
29. The connection joint of claim 25, wherein the adhesive is a
silicone adhesive.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a connection joint formed
between a tube and connector, and more particularly to a connection
joint formed between a silicone tube and a plastic connector.
BACKGROUND OF THE INVENTION
[0002] A large number and variety of medical devices use silicone
tubing to deliver fluids and gases to patients. Often, these
silicone tubes must be connected to another component of the
medical device in order to serve its intended purpose. For example,
in an enteral feeding delivery system, a silicone tube is used to
deliver nutritional and other fluids to a patient through the
stomach wall. The silicone tube is coupled via a plastic connector
to a dialator which facilitates the insertion of the silicone tube
through an incision in the stomach. In order to properly insert the
dialator and position the silicone tube, the physician is often
required to pull on the silicone tube. The connection joint between
the silicone tube and the dialator must be able to withstand such
forces in order to avoid physical injury to the patient or
malfunction of the device. Unfortunately, silicone does not bond
particularly well to other materials, such as plastic, which is
commonly used in medical devices. Consequently, such connection
joints separate at an unacceptable rate. Accordingly, a connection
joint is needed that creates a bond with silicone having a
sufficient tensile strength to withstand the pulling forces
commonly experienced in medical or other applications.
SUMMARY OF THE INVENTION
[0003] In accordance with the present invention, a connection joint
is provided having increased tensile strength. The connection joint
is formed from a connector having a plurality of barbs inserted
into a tube. To further reinforce this connection, a reinforcing
agent is placed between at least one pair of the barbs and an
adhesive is injected between the tube, the connector and the
reinforcing agent. The adhesive is then cured at a predetermined
temperature for a predetermined time in order to solidify the
connection joint.
[0004] In accordance with yet other aspects of the present
invention, the durometer of the reinforcing agent is greater than
or equal to about that of the adhesive injected between the tube,
the connector and the reinforcing agent. In one embodiment, the
reinforcing agent is of a durometer greater than about 70 shore A,
while the durometer of the adhesive is less than about 60 shore A.
Although the reinforcing agent may take a variety of forms, in one
embodiment of the present invention, the reinforcing agent
comprises an O-ring. In another embodiment the reinforcing agent
comprises a plurality of particles suspended in the adhesive
injected between the tube, the connector and the reinforcing
agent.
[0005] In accordance with yet other aspects of the present
invention, the reinforcing agent may be placed between at least one
pair of barbs in the connector, between more than one pair of barbs
in the connector or between each pair of barbs in the connector. In
yet other embodiments, the connection joint may be formed between a
female receptacle (i.e., not necessarily a tube) and male
connector. The male connector may include at least one groove
defined therein, into which the reinforcing agent is placed and the
adhesive is injected. Finally, in yet other embodiments of the
present invention, a method for forming the connection joint
described above is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
becomes better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0007] FIG. 1 is a cross-section view of a connection joint formed
in accordance with the present invention; and
[0008] FIG. 2 is a perspective, exploded view of the connection
joint shown in FIG. 1.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0009] FIG. 1 illustrates a connection joint 20 formed in
accordance with the present invention. The connection joint 20 is
formed by inserting a plastic connector 10 into the open end of a
silicone tube 14. The connector 10 comprises a first end 22 and an
arm 24 protruding therefrom. A plurality of barbs 12 extend
radially from the arm 24. In the illustrated embodiment, the
connector 10 includes three barbs. However, those skilled in the
art will appreciate that the connector 10 may include any number of
barbs 12 deemed suitable for establishing a sufficient connection
joint 20. Accordingly, the connector 10 may include as little as
one barb. Prior to inserting the connector 10 into the open end of
the tube 14, a reinforcing agent 16 is placed between each of the
barbs 12 of the connector 10, as well as between the first end 22
of the connector 10 and the barb 12 closest to it. In the
embodiment of the present invention illustrated in FIGS. 1 and 2,
the reinforcing agent 16 is an O-ring placed between the barbs 12
of the connector 10. Once the reinforcing agents 16 and the barbs
12 of the connector 10 have been inserted in the open end of the
tube 14 (or, stated another way, once the tube 14 has been pushed
over the reinforcing agents 16 and barbs 12 of the connector 10),
an adhesive 18 is injected between the tube 14, the reinforcing
agents 16, and the connector 10. More specifically, the adhesive 18
is injected in the spaces left between the barbs 12, the
reinforcing agent 16, and the tube 14. The adhesive 18 is then
cured at a predetermined temperature for a predetermined time, as
will be described in more detail below, in order to solidify the
connection joint 20.
[0010] In one embodiment of the present invention, the adhesive
injected between the tube 14, the reinforcing agents 16 and the
connector 10 is a silicone adhesive that, when cured, solidifies
into a silicone rubber. A silicone adhesive with a higher durometer
is used in an effort to further increase the tensile strength of
the connection joint 20. In one embodiment of the present
invention, the silicone adhesive 18 is of a durometer of greater
than about 40 shore A and less than about 60 shore A. Once the
silicone adhesive 18 is injected into the connection joint 20 it is
cured at a predetermined temperature for a predetermined duration
of time. As those skilled in the art shall appreciate, the lower
the curing temperature is, the longer the curing time required and
vice versa. In one embodiment, the minimum practical curing
temperature is as low as room temperature (although lower curing
temperatures are theoretically possible), while the maximum curing
temperature is limited by the melting point of the plastic of the
connector 10. Further, the curing time is of a duration necessary
to ensure sufficient rubberization of the silicone adhesive 18. In
one embodiment of the present invention, the connector 10 is made
of high-density polyethelene having a melting point of 200.degree.
F. Accordingly, the silicone adhesive 18 is cured for approximately
three hours at 190.degree. F. This temperature is lower than the
melting temperature of the plastic connector 10, yet high enough to
produce a relatively short curing time. Although theoretically, a
curing time as low as eleven minutes could be used at a curing
temperature of 190.degree. F., additional curing time is used in
order to fully ensure sufficient rubberization of the silicone
adhesive in accordance with manufacturing requirements. Those
skilled in the art will recognize, however, that the curing times
and temperatures may vary depending on the type of plastic used for
the connector 10, the type or durometer of the silicone adhesive 18
used and the manufacturing requirements present. Further, those
skilled in the art will appreciate the other types or compositions
of adhesives may be used without departing from the spirit and
scope of the present invention.
[0011] Although silicone adhesive 18 does bond to the tube 14 and
the connector, the present invention further strengthens that bond.
More specifically, it has been discovered that the greater the
durometer of the silicone between the barbs 12 of the connector 10,
the greater the tensile strength of the connection joint 20, i.e.,
the greater pulling force the connection joint 20 can withstand
without separating. However, there is often an upper limit to the
durometer of silicone adhesive that can be injected due to
manufacturing requirements, type of silicone adhesive used, cost,
etc. Accordingly, to increase the durometer of the silicone between
the tube 14 and connector 10, a reinforcing agent 16 having a
durometer greater than or equal to the silicone adhesive 18 is
placed between the barbs 12. The reinforcing agent 16 reinforces
the adhesive 18 which surrounds it, creating a stronger bond
between the connector 10 and the tube 14 than the adhesive 18 would
have formed alone. Accordingly, the tensile strength of the
connection joint 20 is increased. Use of such a reinforcing agent
has advantages over other techniques for reinforcing the bond of
the connection joint such as adding heat shrink to the outside
diameter of the tube 14 or tying a suture around the outside
diameter of the tube 14 between the barbs 12.
[0012] In the embodiment of the connection joint 20 depicted in
FIGS. 1 and 2, the reinforcing agent 16 is an O-ring made of
silicone and having a durometer greater than about 70 shore A and
less than about 90 shore A. However, as noted above, the
reinforcing agent 16, e.g., an O-ring, may be of any durometer
greater than or equal to about that of the surrounding adhesive 18.
Those skilled in the art will also appreciate that the reinforcing
agent 16 may take a variety of different forms and be made of a
variety of different materials without departing from the spirit
and scope of the present invention. For example, the reinforcing
agent 16 may take the form of silicone particles or polymeric
bodies suspended in the adhesive 18. Said particles or bodies can
be injected along with the adhesive 18 between the tube 14 and
connector 10, or they can be placed between the tube 14 and the
connector 10 prior to injecting the adhesive. Said reinforcing
agent 16 can be made of silicone or of any other material suitable
for reinforcing the bond between the connector 10 and the tube 14,
such as metal. In addition, those skilled in the art will
appreciate that the reinforcing agent 16 may comprise a ring having
an "O" shape or any other shape suitable for either fully or
partially surrounding the arm 24 of the connector 10 between the
barbs 12. Those skilled in the art will also appreciate that in
other embodiments of the present invention, different types of
reinforcing agents 16 may be placed between the barbs 12 of the
connector 10. For example, an O-ring may be used between one pair
of barbs while particles may be suspended between others. In yet
other embodiments, an O-ring may be used along with other particles
between the same pair of barbs 12. Finally, it will be appreciated
that in some embodiments, a reinforcing agent 16 is not placed
between each pair of barbs 12 of the connector 10.
[0013] While certain embodiments of the invention have been
illustrated and described, those skilled in the art will appreciate
that various changes can be made without departing from the spirit
and scope of the invention. For example, the connector 10 may be
made of any material, e.g., plastic, metal, etc., deemed suitable
for the particular application of the connection joint 20. In one
embodiment of the present invention, the connector 10 is made of
high-density polyethylene, which does not impact the curing
reaction of the silicone adhesive 18. In yet other embodiments of
the present invention, the connection joint 20 may be formed
between a female receptacle (i.e., not necessarily a tube 14) and a
male connector 10. The male connector 10 may include at least one
groove defined therein, e.g., the space defined between a pair of
barbs, into which a reinforcing agent 16 is placed and an adhesive
18 is injected. Finally it will be appreciated that either the
female receptacle or the male connector may be made of plastic
while the other is made of silicone.
* * * * *