Surgical needle abstract
The invention disclosed is a means of fastening flexible elastic
tubing, such as silicone rubber, to a rigid connector. The invention
allows for a liquid and gas tight, secure connection without the
use of any bonding materials between the tube and the connector
and without any external ribbing, threading, texturing, barbing,
etc. of any kind on the connector and without any external clamping
mechanism used to keep the tubing firmly attached to the rigid connector.
The invention allows for the rigid connector portion of a component,
such as a wound drainage surgical needle, to have a very smooth
cylindrical surface. The use of a smooth surface with no other adhering
mechanism to assist in making a secure connection that will not
easily pull off is contrary to what is taught in the art.
Surgical needle claims
I claim:
1. A cylindrical metal surgical needle for secure attachment to
flexible silicone tubing without the use of any bonding materials,
said needle comprising at one end a rigid, smooth cylindrical connector
portion having no external surface texturing and no additional mechanical
locking features, said connector portion having a diameter greater
than the inner diameter of the tubing to be attached to said connector
and wherein said connector has a semi-spherical contour on one end
which allows for easier engagement of the tubing to the connector
and a neck portion of smaller diameter and length protruding from
the opposite end of the connector and wherein said neck attached
the connector to a cylindrical body portion of the needle and wherein
said neck portion is a means of providing a relieved area permitting
the silicone tubing to relax to its original diameter, and wherein
the body portion has a diameter larger than the connector to allow
the outer diameter of the tubing to be substantially flush with
the cylindrical surface of the body of the needle and also to act
as a rigid stop means for the tubing to mate against.
2. A method of connecting silicone rubber tubing to a cylindrical
metal surgical needle without the use of any bonding materials,
said needle having at one end a rigid, smooth cylindrical connector
portion having no external surface texturing and no additional mechanical
locking features, said connector portion having a diameter greater
than the inner diameter of the tubing to be attached to said connector
and wherein said connector has a semi-spherical contour on one end
which allows for easier engagement of the tubing to the connector
and a neck portion of smaller diameter and length protruding from
the opposite end of the connector and wherein said neck attaches
the connector to a cylindrical body portion of the needle and wherein
said neck portion is a means of providing a relieved area permitting
the silicone tubing to relax to its original diameter, and wherein
the body portion has a diameter larger than the connector to allow
the outer diameter of the tubing to be substantially flush with
the cylindrical surface of the body of the needle and also to act
as a rigid stop means for the tubing to mate against, and comprising
the steps of:
(a) Sliding the silicone tubing onto the smooth, cylindrical connector
to mate against the rigid stop means; and
(b) Applying a longitudinal tensile force to the silicone rubber
tubing to cause elongation of the tube and reduce the diameter of
a portion of the tube, and thereby creating a firm no-slip adherence
of the silicone rubber tubing to the connector.
3. A method of firmly attaching and subsequently detaching silicone
rubber tubing to a cylindrical metal surgical needle without the
use of any bonding materials, said needle having at one end a rigid,
smooth cylindrical connector portion having no external surface
texturing and no additional mechanical locking features, said connector
portion having a diameter greater than the inner diameter of the
tubing to be attached to said connector and wherein said connector
has a semi-spherical contour on one end which allows for easier
engagement of the tubing to the connector and a neck portion of
smaller diameter and length protruding from the opposite end of
the connector and wherein said neck attaches the connector to a
cylindrical body portion of the needle and wherein said neck portion
is a means of providing a relieved area permitting the silicone
tubing to relax to its original diameter, and wherein the body portion
has a diameter larger than the connector to allow the outer diameter
of the tubing to be substantially flush with the cylindrical surface
of the body of the needle and also act as a rigid stop means for
the tubing to mate against, and comprising the steps of:
(a) Sliding the silicone tubing onto the smooth, cylindrical connector
to mate against the rigid stop means;
(b) Applying a longitudinal tensile force to the silicone rubber
tubing to cause elongation of the tube and reduce the diameter of
a portion of the tube, and thereby creating a firm no-slip adherence
of the silicone tubing to the connector; and when ready for detaching;
(c) Applying a longitudinal compressive force to the tubing against
said stop means to de-elongate the tubing and return the diameter
back to its original diameter; and
(d) Applying compressive pressure inwardly toward the rigid connector
on the portion of the tube covering the rigid connector on the portion
of the tube covering the rigid connector and simultaneously applying
force directed longitudinally to remove the tubing from the connector.
4. A method of connecting silicone rubber tubing to a cylindrical
metal surgical needle without the use of any bonding materials said
needle having at one end a rigid, smooth cylindrical connector portion
having no external surface texturing and no additional mechanical
locking features, said connector portion having a diameter greater
than the inner diameter of the tubing to be attached to said connector
wherein said method comprises the steps of:
(a) Sliding the silicone tubing onto the smooth, cylindrical connector
portion; and
(b) Applying a longitudinal tensile force to the silicone rubber
tubing to cause elongation of the tube and reduce the diameter of
a portion of the tube, and thereby creating a firm no-slip adherence
of the silicone rubber tubing to the connector.
5. A method of firmly attaching and subsequently detaching silicone
rubber tubing to a cylindrical metal surgical needle without the
use of any bonding materials said needle having at one end a rigid,
smooth cylindrical connector portion having a diameter greater than
the inner diameter of the tubing to be attached to said connector
wherein said method comprises the steps of:
(a) Sliding the silicone tubing onto the smooth, cylindrical connector
portion; and
(b) Applying a longitudinal tensile force to the silicone rubber
tubing to cause elongation of the tube and reduce the diameter of
a portion of the tube, and thereby creating a firm no-slip adherence
of the silicone tubing to the connector; and when ready for detaching;
(c) Applying a longitudinal compressive force to the tubing against
a stop means to de-elongate the tubing and return the diameter back
to its original diameter; and
(d) Applying compressive pressure inwardly toward the rigid connector
on the portion of the tube covering the rigid connector and simultaneously
applying force directed longitudinally to remove the tubing from
the connector.
Surgical needle description
BACKGROUND OF THE INVENTION
Throughout industry, it is found necessary to connect or otherwise
fasten flexible tubing to rigid components to make hook-ups for
the transfer of liquids and gases or to complete an assembly with
a termination or plug. This has been accomplished by utilizing various
configurations, depending upon the permanence and security of the
connection desired.
Temporary connections usually can be made by sliding the flexible
tubing over a smooth walled rigid component or tube with the component
outside diameter slightly larger than the tube inside diameter,
relying upon the dimensional interference of the two mating parts
to stretch the flexible tube radially. The resilience of the tube
then provides a gas or liquid tight seal while still providing the
ability to separate and reconnect the parts with relative ease.
Typically, this type of connection will disconnect with a minimal
longitudinal pulling force on the tubing.
Consequently, in order to provide for more secure connections or
permanent connections various additional design features were developed
to enhance the security of the connection. Often, the rigid component
will utilize a barbed, threaded, ribbed, textured, etc., configuration
for a mechanical interference or "bite" between the inner
wall of the flexible tube and the outer surface of the rigid part.
Such a connection makes separation of the two parts much more difficult,
and for total security the tubing can be clamped or bonded to the
rigid component.
These methods of making tubing connections to rigid connectors
are common in the medical industry, utilizing flexible tubing fabricated
of polyethylene, vinyl, polyurethane or latex.
However, with the rapidly increasing usage of flexible silicone
rubber tubing, particularly unique problems occur when making a
connection between the silicone tubing and a rigid connector. Because
of the extremely elastic nature of the material combined with the
lubricity of the surface of the material, it has been found that
connections made with barbed connectors, threaded connectors, etc.,
are not secure and are apt to separate when subjected to relatively
small tensile stresses. In order to provide secure connections between
silicone tubing and other rigid components, these connections are
normally bonded with additional silicone adhesive, resulting in
a permenent connection, which is expensive, labor consuming and
unsightly. Additionally, the only method of separating the silicone
tube from such a bonded joint is by cutting the tube from the connector,
making the rigid connector unsuitable for reconnection because of
the portion of tubing and adhesive remaining on the connector.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore, a principal object of the invention to provide
a means of securely connecting silicone rubber tubing to a rigid
connector without the use of silicone adhesive.
It is a further object of the invention to provide a means of securely
connecting silicone rubber tubing to a rigid connector without the
use of other mechanical locking means such as external texturing
on the connector and without the use of any external clamping device
over the tube and connector.
It is a still further object of the invention to provide a means
of easily separating the silicone tubing from the connector without
damage so the parts, both tubing and connector, can be reconnected
or connected to other components for additional use.
The present invention accomplishes all of the above objects of
invention. Because of the extreme elasticity of silicone rubber,
it has been found that subjecting the material to a tensile stress
causes a considerable reduction in the cross-sectional dimensions
of the material as it elongates. Additionally, when stretched, the
surface of the tubing looses some of its lubricity. Utilizing these
characteristics, it has been found that a very secure connection
can be formed by putting the silicone tubing over a very smooth
shank or tube or connector, which is contrary to normal practice.
The smoothness of the surface is critical to the security of the
connection, such that a highly polished surface will provide a much
more secure connection than a rough surface.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side elevational view of a portion
of a rigid connector and the silicone tubing prior to assembly.
FIG. 2 is a cross-sectional side elevational view of a portion
of the rigid connector and the silicone tubing after assembly and
before subjecting the joint to a tensile force.
FIG. 3 is a cross-sectional side elevational view of the joint
after subjecting the joint to a tensile force.
FIG. 4 is a cross-sectional side elevational view illustrating
a rigid flange at the end of the silicone tube.
FIG. 5 is a cross-sectional side elevational view illustrating
the expansion of the tubing by applying a compressive force.
FIG. 6 is a side elevational view of a surgical needle having a
certain connector embodiment attached to silicone tubing.
FIG. 7 is an enlarged fragmentary side elevational view of the
connector embodiment of FIG. 6.
FIG. 8 is an end view of the connector embodiment of FIG. 7.
FIG. 9 is an enlarged view of the connector portion of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a rigid component 1 and a piece of silicone
tubing 2 prior to assembly. The surface of the component 1 is a
very smooth polished surface. The component 1 is preferably made
of a metal material. It is necessary that the outside diameter 14
of the rigid component 1 be only slightly larger than the inside
diameter 13 of the silicone tubing 2. The elasticity of the silicone
tubing 2 allows the tubing 2 to slide onto the connecting end of
the component 1 as shown in FIG. 2. The dimensional interference
between the two parts causes a seal 3 to form.
FIG. 3 illustrates a longitudinal tensile force being applied to
the rubber tubing. The force is illustrated by the arrows in FIG.
3. Any tension applied to the silicone tubing 2 when located on
slightly larger component 1 results in an elongation of the silicone
tubing 2 causing a tightening of the silicone tubing 2 onto the
smooth connecting surface of the component 1 where it grips even
more securely because of the surface change of the silicone tubing
2. The elongation of the tubing 2 results in a decreased diameter
4 of the silicone tubing 2 increasing the security of the seal
3. Additionally, it has been found that this elastic deformation
of the silicone tubing 2 will be localized at the portion of the
tubing over the rigid component 1 and it will remain in a locally
deformed state after the tensile force is removed from the remainder
of the tube. Therefore, the tubing 2 can be stretched and pulled
after assembly to the rigid component 1 resulting in a more secure
grip even after releasing the tensile stress. With appropriate relative
sizing of the silicone tubing 2 and the rigid connector 1 the two
parts can be joined, in such a manner, so securely they cannot be
separated by manually pulling. Additional tensile force makes the
joint more secure.
This secure joint is formed using a connector component 1 with
a perfectly smooth surface, and utilizes no additional mechanical
locking or bonding means. The use of a plain smooth surface is contrary
to normal practice for forming a tight, secure connection.
In order to detach the silicone tubing 2 from the component 1
a longitudinally compressive force is applied to the tubing 2. The
force is illustrated by the arrows in FIG. 5. This force should
be applied against a stop means, to prevent the tubing 2 from sliding
farther onto the component 1. The longitudinally compressive force
causes tubing 1 to de-elongate and hence returns the tubing diameter
back to its original diameter prior to the elongation. The tubing
also regains its surface lubricity which it lost upon elongation
of the tubing 2.
Ones fingers can easily be used as a stop means by placing your
fingers at the end of the tubing 2 and then applying the compressive
force. Alternatively, a rigid flange 5 can be used as stop means
as shown in FIGS. 4 and 5.
The joint can then be easily separated by applying a compressive
force inwardly toward the axis of the rigid component 1 on the portion
of the tube 2 covering the rigid component 1. This can be easily
accomplished with one's fingers. Simultaneously with the inward
compressive force in the area stated, an additional longitudinally
directed force is also applied to the portion of the tube 2 covering
the rigid component 1 to effect removal of the tubing from the connector
component 1.
FIGS. 6 7 and 8 illustrate a particular embodiment of a cylindrical
surgical needle 8. The connector portion 9 of the needle 8 has a
semi-spherical contour 11 on one end which allows for easier engagement
of the tubing 2 to the connector 9. The needle 8 includes a neck
10 which protrudes from the opposite end of the connector 9. The
neck 10 has a smaller diameter than the connector 9. The neck 10
attaches the connector 9 to the body 15 of the needle 8. The necked
in portion 10 is a means of providing a relieved area permitting
the silicone tubing to relax to its original diameter. The body
15 has a larger diameter than either the connector 9 or neck 10.
This allows the outer diameter of the relaxed portion of the tubing
2 to be flush with the cylindrical body 15 of the needle. Therefore,
the end of the tubing does not protrude above the body portion.
The end surface 12 of the body 15 of the needle 8 acts as a flange
for the tubing 2 to mate against. Therefore, when removing the tubing
2 the longitudinally compressive force can be applied against this
flat end surface 12 to act as a stop means.
The invention described allows for a secure seal between silicone
tubing and a rigid component, such as a metal surgical needle, without
the using of a silicone adhesive or any other mechanical locking
means. The invention also allows both the tubing and connecting
component to be reused. While this invention has been described
and exemplified in terms of its preferred embodiment, those skilled
in the art can appreciate that modifications can be made without
departing from the spirit and scope of this invention.
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