U.S. patent number RE37,324 [Application Number 09/227,037] was granted by the patent office on 2001-08-14 for method for making disposable tubular device.
Invention is credited to Bernard S. Esrock.
United States Patent |
RE37,324 |
Esrock |
August 14, 2001 |
Method for making disposable tubular device
Abstract
A method of making a disposable tubular device comprising
extruding a first material through a first die to form the tube and
moving the tube through the second die while extruding a second
material through the second die to form the tube-support structure.
The second material has a surface hardness which is greater than
the surface hardness of the first material.
Inventors: |
Esrock; Bernard S. (Frontenac,
MO) |
Family
ID: |
22830869 |
Appl.
No.: |
09/227,037 |
Filed: |
January 7, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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222109 |
Apr 4, 1994 |
5460619 |
|
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Reissue of: |
447894 |
May 23, 1995 |
05591389 |
Jan 7, 1997 |
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Current U.S.
Class: |
264/171.12;
156/244.15; 264/171.26; 264/172.1; 425/113; 425/131.1; 425/462;
425/467 |
Current CPC
Class: |
A61C
17/0217 (20130101) |
Current International
Class: |
A61C
17/02 (20060101); A61C 17/00 (20060101); B29C
047/06 () |
Field of
Search: |
;264/171.26,171.27,171.12,172.1 ;425/467,462,131.1,113 ;156/244.15
;604/280 ;433/80 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Silbaugh; Jan H.
Assistant Examiner: Eashoo; Mark
Attorney, Agent or Firm: Senniger, Powers, Leavitt &
Roedel
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of Ser. No. 222,109 U.S. Pat. No.
5,460,619, filed Apr. 4, 1994 .Iadd.now U.S. Pat. No.
5,460,619.Iaddend..
Claims
What is claimed is:
1. A method of making a disposable tubular device adapted for
releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument, the
instrument having a nipple for engagement with the tubular device,
the device comprising a pliable elongate tube of resilient material
and a tube-support structure having a stiffness greater than that
of the tube and extending substantially the entire length of the
tube, the tube and tube-support structure forming at least two
distinct passageways, a first of the two passageways being formed
by the tube and a second of the two passageways being formed by the
tube and the tube-support structure, the method comprising:
extruding a first material through a first die to form the tube,
the .Iadd.said first .Iaddend.material being sufficiently pliable
to form a seal around the nipple for sealing against fluid leakage
between the nipple and the tube;
moving the tube through a second die while extruding a second
material through the second die to form the tube-support
structure;
the second material having a surface hardness which is greater than
the surface hardness of the first material.
2. A method as set forth in claim 1 wherein the second die is
configured to form a sleeve around the tube.Iadd., .Iaddend.the
sleeve comprising the tube-support structure.
3. A method as set forth in claim 2 wherein the first die is
configured such that .Iadd.step of .Iaddend.extruding the first
material through the first die forms the tube with a fluted outer
surface having elongate flutes, the flutes extending along
substantially the entire length of the tube.
4. A method as set forth in claim 3 wherein the second die is
configured to form the sleeve in a friction fit over the tube, the
flutes and an inner surface of the sleeve defining a plurality of
fluid passageways.
5. A method as set forth in claim 1 wherein the first material is a
polyvinyl chloride having a durometer hardness reading between
approximately 80 Shore A and 90 Shore A.
6. A method as set forth in claim 5 wherein the second material is
a polyvinyl chloride having a durometer hardness reading of at
least approximately 60 Shore D.
7. A method of making a disposable tubular device adapted for
releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument, the device
comprising a pliable elongate tube of resilient material and a
tube-support structure having a stiffness greater than that of the
tube and extending substantially the entire length of the tube, the
tube and tube-support structure forming at least two distinct
passageways, the method comprising.Iadd.: .Iaddend.
extruding a first material .[.through a first die.]. to form the
tube, the first material having a durometer hardness reading
between approximately 80 Shore A and 90 Shore A;
moving the tube through a .[.second.]. die while extruding a second
material through the .[.second.]. die to form the tube-support
structure in a friction fit over the elongate tube, the second
material having a durometer hardness reading of at least
approximately 60 Shore D.
8. A method as set forth in claim 7 wherein the first material and
the second material are polyvinyl chloride.
9. A method as set forth in claim 7 wherein the .[.second.]. die is
configured to form a sleeve around the tube, the sleeve comprising
the tube-support structure.
10. A method as set forth in claim 9 wherein the .[.first die is
configured such that.]. .Iadd.step of .Iaddend.extending the first
material .[.through the first die.]. forms the tube with a fluted
outer surface having elongate flutes, the flutes extending along
substantially the entire length of the tube.
11. A method as set forth in claim 10 wherein the flutes and an
inner surface of the sleeve define a plurality of fluid
passageways.
12. A method for making a disposable tubular device adapted for
releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument, the
instrument having a nipple for engagement with the tubular device,
the device comprising a pliable elongate tube of resilient material
and a tube-support structure having a stiffness greater than that
of the tube and extending substantially the entire length of the
tube, the tube and tube-support structure forming at least two
distinct passageways, a first of the two passageways being formed
by the tube and a second of the two passageways being formed by the
tube and the tube-support structure, the method comprising:
extruding a first polyvinyl chloride material .[.through a first
die.]. to form the tube with a fluted outer surface having elongate
flutes extending along substantially the entire length of the tube,
the material being sufficiently pliable to form a seal around the
nipple for sealing against fluid leakage between the nipple and the
tube;
moving the tube through a .[.second.]. die while extruding a second
polyvinyl chloride material through the .[.second.]. die to form
the tube-support structure, the .[.second.]. die being configured
to form the tube-support structure in a friction fit over the
elongate tube;
the second polyvinyl chloride material having a surface hardness
which is greater than the surface hardness of the first polyvinyl
chloride material.
13. A method as set forth in claim 12 wherein the first polyvinyl
chloride material has a durometer hardness reading between
approximately 80 Shore A and 90 Shore A.
14. A method as set forth in claim 13 wherein the second polyvinyl
chloride material has a durometer hardness reading of at least
approximately 60 Shore D..Iadd.
15. A method of making a disposable tubular device adapted for
releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument, the
instrument having a nipple for engagement with the tubular device,
the device comprising a pliable elongate tube of resilient material
and a tube-support structure having a stiffness greater than that
of the tube and extending substantially the entire length of the
tube, the tube and tube-support structure forming at least two
distinct passageways, a first of said passageways being formed by
the tube and a second of said passageways being formed by the tube
and the tube-support structure, the method comprising the steps of
forming a first material into the tube and forming a second
material into the tube-support structure so the structure has a
friction fit with the tube, said first material being sufficiently
pliable to form a seal around the nipple for sealing against fluid
leakage between the nipple and the tube, said second material
having a surface hardness which is greater than the surface
hardness of the first material. .Iaddend..Iadd.
16. A method of making a disposable tubular device adapted for
releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument, the
instrument having a nipple for engagement with the tubular device,
the device comprising a pliable elongate tube of resilient material
and a tube-support structure having a stiffness greater than that
of the tube and extending substantially the entire length of the
tube, the tube and tube-support structure forming at least two
distinct passageways, a first of the two passageways being formed
by the tube and a second of the two passageways being formed by the
tube and the tube-support structure, the method comprising:
extruding a first material to form the tube, said first material
being sufficiently pliable to form a seal around the nipple for
sealing against fluid leakage between the nipple and the tube;
moving the tube through a die while extruding a second material
through the die to form the tube-support structure having a
friction fit with the tube;
the second material having a surface hardness which is greater than
the surface hardness of the first material. .Iaddend..Iadd.
17. A method as set forth in claim 16 wherein the die is configured
to form a sleeve around the tube, the sleeve comprising the
tube-support structure. .Iaddend..Iadd.
18. A method as set forth in claim 17 wherein the step of extruding
the first material forms the tube with a fluted outer surface
having elongate flutes, the flutes extending along substantially
the entire length of the tube. .Iaddend..Iadd.
19. A method as set forth in claim 16 wherein the first material is
a polyvinyl chloride having a durometer hardness reading between
approximately 80 Shore A and 90 Shore A. .Iaddend..Iadd.
20. A method as set forth in claim 19 wherein the second material
is a polyvinyl chloride having a durometer hardness reading of at
least approximately 60 Shore D. .Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates to disposable tubular devices of the type
used with medical instruments for delivering fluid to or evacuating
fluid from a patient.
Tubular devices for transporting fluids between a patient and a
medical instrument are typically used by medical professionals such
as physicians, dentists and dental technicians, and veterinarians
for suctioning fluid from or irrigating a part of a patient's body.
One such tubular device is a disposable syringe tip for an
air-water dental syringe.
A typical syringe tip has a central water passageway and at least
one passageway through which air may flow. The tip is typically
sealingly retained in a syringe hand-piece by a retaining collar
which compresses an O-ring against the tip to seal the connection
between the tip and the handpiece. Between uses of the syringe, the
tip must be removed from the hand-piece by wholly or partially
disengaging the retaining collar. The tip is then either sterilized
before reuse or discarded and replaced with a new syringe tip.
A disadvantage encountered with prior syringe tip designs is the
difficulty in having a quickly detachable tip which provides a
water-tight seal between the central water passageway of the tip
and a water conduit of the hand-piece. In some syringes, no
elastomeric seal is placed between the water conduit and the
central water passageway. In such syringes, water may leak between
the conduit and the tip. In other conventional syringes, O-rings
are positioned between the end of the tip and the water conduit of
the hand-piece. With these syringes, the O-ring is repeatedly used
until the O-ring fails, which may be at an inopportune time. Also,
unless the O-ring is squeezed between the hand-piece and the tip,
the O-ring will not prevent leakage. Further, the force of water
from the conduit tends to unseat the tip from the O-ring.
SUMMARY OF THE INVENTION
Among the several objects of this invention may be noted the
provision of an improved tubular device for conveying fluid between
a medical instrument and a patient; the provision of such a device
which is adapted for self-sealing to a fluid conduit of the medical
instrument; the provision of such a device which is easily attached
to and detached from the medical instrument; the provision of such
a device which is disposable; and the provision of such a device
which is of relatively simple and inexpensive construction.
Generally, a disposable tubular device of this invention is adapted
for releasable and sealing connection to a medical instrument for
transporting fluid between a patient and the instrument. The
instrument has a nipple with a fluid passageway therethrough. The
device comprises a generally pliable elongate tube of resilient
material extending substantially the entire length of the device
and a tube-support structure extending substantially the entire
length of the tube. The tube has a proximal end configured to be
slidably pushed onto the nipple of the medical instrument to a
position in which the nipple fits snugly inside the proximal end of
the tube, a distal end, and an elongate fluid passageway extending
through the tube from its proximal end to its distal end. The
elongate fluid passageway is adapted to communicate with the fluid
passageway of the nipple when the proximal end of the tube is on
the nipple. The tube is sufficiently pliable to expand radially
outwardly at its proximal end when the proximal end is pushed on
the nipple and is sufficiently resilient to form a continuous seal
around the nipple for sealing against the fluid leakage between the
nipple and the tube when fluid flows through the passageways. The
tube-support structure has a stiffness greater than that of the
tube and sufficient to maintain the tube in a selected operative
position.
Generally, a method of making a disposable tubular device in
accordance with the present invention comprises extruding a first
material through a first die to form the tube and moving the tube
through a second die while extruding a second material through the
second die to form the tube-support structure. The second material
has a durometer hardness reading which is greater than the
durometer hardness reading of the first material at such
temperature.
Other objects and features will be in part apparent and in part
pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a dental syringe of the
present invention, with portions broken away to show detail;
FIG. 2 is a side elevational view of a syringe tip of the syringe
of FIG. 1, with portions broken away to show detail;
FIG. 3 is an end elevational view of the syringe tip of FIG. 2
showing coaxial inner and outer tubes with a central water
passageway through the inner tube and a plurality of air
passageways defined by the inner and outer tubes;
FIG. 4 is a vertical sectional view taken along the plane of line
4--4 of FIG. 2;
FIG. 5 is an end elevational view a tubular device of the present
invention similar to the syringe tip of FIGS. 2-4 but having the
air passageways defined by coaxial intermediate and outer
tubes;
FIG. 6 is an end elevational view of a tubular device of the
present invention similar to the syringe tip of FIGS. 2-4 but
having the air passageways defined entirely by the outer tubes;
FIG. 7 is an end elevational view of a tubular device of the
present invention similar to the syringe tip of FIGS. 2-4 but
having only one air passageway which is generally annular in
cross-section and coaxial with the water passageway;
FIG. 8 is an end elevational view showing a tubular device of the
present invention similar to the syringe tip of FIGS. 2-4 but
having only a single fluid passageway;
FIG. 9 is an end elevational view showing a tubular device of the
present invention similar to the device of FIG. 8 but having three
side-by-side fluid passageways in the inner tube of the tubular
device; and
FIG. 10 is an end elevational view showing a tubular device of the
present invention similar to the device of FIG. 9 but having three
fluid passageways radially disposed in the inner tube of the
tubular device.
Corresponding reference numerals indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and first, more particularly to FIG.
1, a medical instrument of the present invention in the form of an
air-water dental syringe is indicated in its entirety by the
reference numeral 20. The dental syringe 20 comprises a
conventional hand-piece, generally designated 22, a disposable
syringe tip, generally designated 24, and a syringe tip coupler,
generally designated 26, connecting the syringe tip to the
hand-piece.
The hand-piece 22 includes a first fluid (water) conduit 28 for
directing a stream of water to a discharge end 30 of the hand-piece
and a second fluid (air) conduit 32 for directing an air stream to
the discharge end of the hand-piece. The hand-piece 22 further
includes a threaded bore 34 at its discharge end 30 for threadably
receiving the syringe tip coupler 26. The water and air conduits
28, 32, respectively, of the hand-piece 22 extend from pressurized
sources (not shown) to the bore 34 of the hand-piece and are in
fluid communication therewith.
The syringe tip 24 comprises a generally pliable elongate inner
tube 36 of resilient material extending substantially the entire
length of the tip and an outer tube 38, constituting an inner tube
support structure, extending substantially the entire length of and
surrounding the inner tube (FIG. 2). The inner tube 36 has a
proximal end 40, a distal end 42, and an elongate fluid passageway
44 extending through the inner tube from its proximal end to its
distal end. The inner tube has a fluted outer surface 45 with six
elongate flutes 46 equally spaced about the circumference of the
outer surface, and six elongate outer surface portions 48 each
between adjacent flutes. The flutes 46 and outer surface portions
48 extend the length of the inner tube 36. The inner tube 36 fits
snugly within the outer tube 38 and each elongate outer surface
portion 48 is in continuous contact with the inner surface 50 of
the outer tube generally along the entire length of the inner tube.
Preferably, the inner and outer tubes 36, 38, respectively, are
held together by a close friction fit between the outer surface
portions 48 of the inner tube and the inner surface 50 of the outer
tube. Alternatively, the tubes 36, 38 may be bonded together, e.g.,
by heat or with a suitable adhesive. The flutes 46 and the inner
surface 50 of the outer tube 38 define six elongate air passageways
52 circumferentially disposed about the elongate fluid passageway
44 (i.e., the central water passageway) and extending substantially
the length of the tube. Preferably, the inner and outer tubes 36,
38 have generally coterminous proximal and distal ends (FIG. 2).
Also preferably, the syringe tip 24 has a generally uniform
cross-section (FIG. 4) throughout its entire length and its
proximal end 40 (FIG. 3) is substantially the same as its distal
end 42. Although the flutes 46 in this embodiment are in the outer
surface 45 of the inner tube 36, it is to be understood that the
flutes may alternatively be formed on the inner surface 50 of the
outer tube 38 and still be within the scope of the present
invention.
The syringe tip coupler 26 comprises a cylindric stem 54 having
first and second externally threaded surface portions 56, 58,
respectively, adjacent opposite ends 60, 62 of the stem, and a
central bore 64 for receiving the syringe tip 24. The first
threaded surface portion 56 is threadably fitted within the
threaded bore 34 of the hand-piece 22. The second threaded surface
portion 58 receives a nut 66 which maintains the syringe tip 24 in
the central bore 64. The stem 54 further includes a forwardly
projecting nipple 65 within the central bore 64 for receiving the
proximal end 40 of the inner tube 36, a rearwardly projecting
nipple 68 aligned with the forwardly projecting nipple and
receivable within the water conduit 28 of the hand-piece 22, and a
longitudinal opening 70 through the nipples for passage of water
from the water conduit through the aligned nipples and into the
central water passageway 44 of the inner tube 36. The central bore
64 is in fluid communication with the air conduit 32 by way of a
radially directed opening 72 in the stem 54. A first O-ring 74 is
positioned generally between the stem 54 and the hand-piece 22
circumferentially about the rearwardly projecting nipple 68 for
sealing against water leakage between the water conduit 30 and the
stem.
The syringe tip 24 is adapted for releasable and sealing connection
to the stem 54. The proximal end 40 of the inner tube 36 is
configured to be slidably pushed onto the forwardly projecting
nipple 65 of the stem 54 so that the nipple fits snugly inside the
proximal end of the inner tube (FIG. 1). The elongate water
passageway 44 of the inner tube 36 communicates with the
longitudinal opening 70 of the nipple 65 when the proximal end of
the tube is positioned on the forwardly projecting nipple. To this
end, the inner tube 36 is sufficiently pliable so that its proximal
end 40 expands radially outwardly when pushed onto the nipple 65
and sufficiently resilient to form a continuous seal around the
nipple for sealing against fluid leakage between the nipple and the
inner tube when water flows through the passageways 30, 44. Because
the inner tube 36 seals against the nipple 65, it is unnecessary to
provide an O-ring between the inner tube and nipple.
As noted above, the syringe 24 is releasably secured to the syringe
tip coupler 26 of the medical instrument 20 by the nut 66. A second
O-ring 76 is circumferentially positioned over the outer surface 78
of the outer tube 38 and abuts a forward end 62 of the stem 54 to
prevent leakage of air between the tip 24 and stem. Tightening the
nut 66 urges a generally cone-shaped, split collar 82 against the
second O-ring 76 to hold the O-ring in place against the stem 54
and also squeezes the collar radially inwardly against the syringe
tip 24 to thereby hold the syringe tip in place. A third O-ring 84
is circumferentially positioned around the stem 54 generally
between the first and second threaded surface portions 56, 58,
respectively, and between the nut 66 and hand-piece 22 to prevent
leakage of air from between the stem and hand-piece. Preferably,
the coupler 26 is configured so that the syringe tip 24 may be
inserted into and removed from the stem 54 by loosening the nut 66
without the need to remove the nut.
The inner tube 36 of the syringe tip 24 is preferably made of a
pliant medical grade polyvinyl chloride or other suitable synthetic
resin having a durometer hardness reading between approximately 80
Shore A and 90 Shore A. Within this range, the inner tube is
sufficiently pliable to seal against water leakage and sufficiently
stiff to prevent the air passageways 52 from being pinched closed
when the inner tube engages the nipple 65 of the stem 54 or when
the syringe tip is bent to the degree shown in FIG. 2. The outer
tube 38 (i.e., the tube-support structure) is preferably made of a
stiffer medical grade polyvinyl chloride, having a durometer
hardness reading of at least approximately 60 Shore D (most
preferably 81 Shore D) and a flex modulus of at least approximately
10,000 psi (most preferably 12,000 psi). The outer tube 38 thus has
a stiffness greater than that of the inner tube 36 and sufficient
to maintain the entire syringe tip 24 in a selected operative
position. Preferably, the outer tube 38 is sufficiently flexible to
be capable of being bent by the operator to a selected operative
position (FIG. 2). The outer tube 38 is also sufficiently stiff
(i.e., resistant to bending) such that the force of the fluid
streams passing through the tip 24 during use do not substantially
alter the shape the angle of the bend) of the tip. Because of this
stiffness, a stream of air or water, or a mixed stream of both, can
be directed to the specified desired location. Because the inner
and outer tubes are both of polyvinyl chloride, there is an
inherent adhesion between the tubes which resists movement of the
inner tube relative to the outer tube. Although the tubes are
preferably formed of polyvinyl chloride, it is to be understood
that the tubes could be formed of other suitable resins without
departing from the scope of this invention.
A disposable tubular device of the present invention (e.g., the
syringe tip 24) is preferably made by a dual-extrusion method. A
first material is extruded through a first die to form an inner
tube 36. This die is configured such that extrusion of the first
material through the first die forms an elongate tube with elongate
flutes. The flutes extend along substantially the entire length of
the tube. The fluid tube is then passed longitudinally through a
second die while a second material is extruded through the second
die and around the inner tube. The extruded tubes are then cut to
length to form the tip 24. The second die is configured so that the
outer tube 38 (sleeve) so formed fits snugly over the inner tube
36. The sleeve 38 constitutes a tube-support structure for
maintaining the general overall shape of the inner tube 36. The
flutes 46 and a portion of an inner surface 50 of the sleeve 38
define a plurality of fluid passageways 52. The first and second
materials are selected so that the outer tube of the tip 24 is
stiffer than the inner tube at the typical operating temperatures
of the syringe (e.g., temperatures in the range of 50.degree. F. to
110.degree. F.).
In use, the syringe tip coupler 26 is mated with the hand-piece 22
of the dental syringe 20 as previously described. The syringe tip
24 is inserted into the central bore 64 of the coupler 26 and
slidably pushed onto the forwardly projecting nipple 65 of the
coupler 26 to releasably and sealably mount the tip of the medical
instrument 20. Preferably, the syringe tip 24 is provided to the
operator with a bend therein. The bend causes fluid to be sprayed
at an angle and also helps retain the inner tube within the outer
tube. The operator may vary the angle of the bend (or remove it
entirely) to facilitate the spraying of fluid at a different angle.
The relatively stiff outer tube 38 ensures that the force of the
fluid streams passing through the tip 24 during use does not
substantially alter the shape (e.g., the length of the bend) of the
tip. Because of this stiffness, a stream of air or water, or a
mixed stream of both, can be directed to the specified desired
location. The operator selects the fluid stream or combination of
fluid streams (e.g., air, water, or an air-water mixture) to be
delivered to the patient. The water stream, if selected, flows from
the pressurized source through the water conduit 28 of the
hand-piece into the longitudinal opening 70 of the stem 54. The
water then passes into the central water passageway 28 of the
syringe tip 24 mounted on the forwardly projecting nipple 65 at its
proximal end 40. The water is discharged from the distal end 42 of
the inner tube 36 at the desired location. The resilient inner tube
36 prevents water leakage between the forwardly projecting nipple
65 and the inner tube as long as part of the nipple is within the
inner tube. Thus, the inner tube will prevent leakage even if the
tip is not fully pushed onto the nipple. Also, because of the
resilient inner tube 36, the tip 24 seals against the nipple even
when the tip is not tightly held on the nipple. Thus, the tip may
be turned or rotated on the nipple without leakage. The air stream,
if selected, flows from the pressurized source through the air
conduit 32 of the hand-piece 22 into the central bore 64 of the
stem 54 by way of the radially directed opening 72 in the stem 54.
The pressurized air passes from the central bore 64 into the air
passageways 52 of the tip 24 which are in fluid communication with
the central bore. The air is discharged from the distal end 42 of
the syringe tip 24 to atomize the water discharged from the inner
tube 36.
After use, the syringe tip 24 is removed from the coupler 26 by
disengaging the tip from the nipple 65. This is done by simply
loosening the nut and pulling the tip 24 from the medical
instrument 20. The tip 24 is then discarded. A new syringe tip 24
can be inserted into the coupler 26 for the next use of the medical
instrument 20.
An alternative embodiment of a disposable syringe tip of the
present invention, generally designated 86, is shown in FIG. 5. The
tip 86 comprises an inner tube 88, an outer tube 90, and an
intermediate tube 92 positioned between the inner and outer tubes.
Preferably, all three tubes 88, 90, 92 have coterminous proximal
and distal ends and generally uniform cross-sections throughout the
entire length of the tip 86. The tip 86 has a central water
passageway 94 defined by the inner tube 88. The intermediate tube
92 has inner and outer surfaces 98, 100, respectively. The inner
surface 98 of the intermediate tube 92 opposes the outer surface
102 of the inner tube 88 and the outer surface 100 of the
intermediate tube opposes the inner surface 104 of the outer tube
90. The outer surface 100 of the intermediate tube 92 comprises a
fluted surface 106 similar to the flutes 46 of the inner tube 36 of
the tip in FIGS. 2-4. The flutes 106 of the intermediate tube 92
and a portion of the inner surface 104 of the outer tube 90 define
air passageways 108 extending the length of the intermediate tube.
In this embodiment, either or both the intermediate and outer tubes
90, 92 may be made of a generally stiff material and constitute the
tube-support structure, and the inner tube 88 comprises a generally
pliable elongate tube of resilient material (similar to inner tube
36) extending substantially the entire length of the tip 86. The
inner tube 88 fits snugly within the intermediate tube 92. The
outer surface portion 110 of the intermediate tube 92 is in
continuous contact with the inner surface 104 of the outer tube 90
generally along the entire length of the tip 86. It is to be
understood that the inner surface 98 of the intermediate tube 92
may be configured with the fluted surface 106, or that the outer
surface 102 of the inner tube 88 or inner surface 104 of the outer
tube 90 may be formed with the flutes and still be within the scope
of the present invention.
Referring now to FIG. 6, another embodiment of a syringe tip of the
present invention is generally designated 112. The tip 112
comprises an inner tube 114 and an outer tube 116 preferably having
coterminous proximal and distal ends and generally uniform
cross-sections throughout the entire length of the tip 112. A
central water passageway 122 is defined by the inner tube 114, and
three air passageways 124, disposed radially outwardly of the water
passageway, are defined entirely by the outer tube 116. Both the
water and air passageways 122, 124 of the tubes 114, 116 extend the
entire length of the tip 112. In this embodiment, the outer tube
116 is made of a generally stiff material and constitutes the
tube-support structure and the inner tube 114 comprises a generally
pliable elongate tube of resilient material. The inner tube 114
fits snugly within the outer tube 116 and the outer surface 126 of
the inner tube 114 is in continuous contact with the inner surface
128 of the outer tube 116 generally along the entire length of the
tip 114. Preferably, the inner and outer tubes 114, 116 are held
together by a close friction fit, and the materials of the tubes
are selected for providing an inherent adhesion of the inner tube
to the outer tube. Alternatively, the tubes 114, 116 may be bonded
together by heat or with a suitable adhesive.
Referring to FIG. 7, another embodiment of a syringe tip of the
present invention, generally designated 130, comprises an inner
tube 132 and an outer tube 134 preferably having coterminous
proximal and distal ends and generally uniform cross-sections
throughout the entire length of the tip. The tip 130 has a central
water passageway 140 defined by the inner tube 132 and an air
passageway 136 formed to be generally coaxial with respect to the
water passageway. To this end, the outer tube 134 is radially
spaced from the inner tube 132 to create an annulus (i.e., the air
passageway 136) between the inner and outer tubes extending the
length of the tip 130. The inner tube 132 is retained within the
outer tube 134 due to the syringe tip being bent at a region along
the length of the syringe tip. In this embodiment, the outer tube
134 constitutes the generally stiff tube-support structure and the
inner tube 132 comprises a generally pliable elongate tube of
resilient material.
In FIG. 8, another embodiment of a tubular device, generally
designated 142, comprises a generally pliable elongate inner tube
144 of resilient material and an outer tube 146 constituting the
tube-support structure. Preferably, the inner and outer tubes 144,
146 have coterminous proximal and distal ends and generally uniform
cross-sections throughout the entire length of the tip 142. The
inner tube 144 comprises a generally pliable elongate tube of
resilient material and is formed with a central single fluid
passageway 152. The inner tube 144 fits snugly within the outer
tube 146 which constitutes the generally stiff tube-support
structure. The outer surface 154 of the inner tube 144 is in
continuous contact with the inner surface 156 of the outer tube 146
generally along the entire length of the nip 142. The single
passageway embodiment 142 of the tubular device is particularly
useful for suctioning fluid from a patient.
As shown in FIGS. 9 and 10, other embodiments of the tubular device
for conveying one or more fluids comprise a multi-lumen inner tube
158 having a plurality of coextensive passageways 160 extending the
entire length of the tube. In one embodiment (FIG. 9), generally
designated 162, the passageways 160 are arranged side-by-side. In
the other embodiment (FIG. 10), generally indicated at 164, the
passageway 160 are circumferentially disposed in the inner tube
158. The inner tube 158 of each embodiment of the tubular devices
162, 164 comprises a generally pliable elongate tube of resilient
material and is surrounded by a generally stiff outer tube 166
which constitutes the tube support structure. The inner tube 158
fits snugly within the outer tube 166 and the outer surface 168 of
each inner tube 158 is in continuous contact with the inner surface
170 of each outer tube 166 generally along the entire length of the
tubular device 162, 164. The wall thickness of the inner tube 158
is sufficient to allow the inner tube 158 to adequately yield in
order to accept mating nipples of the medical instrument (not
shown) to which it connects. The multiple lumens may be used to
direct multiple fluids to a patient, or to direct fluid through one
lumen while evacuating fluid through another.
Although the tubular devices are described herein as being syringe
tips for dental syringes, it is to be understood that tubular
devices of the present invention may have uses in various other
aspects of the medical field.
In view of the above, it will be seen that the several objects of
the invention are achieved and other advantageous results
attained.
As various changes could be made in the above constructions without
departing from the scope of the invention, it is intended that all
matter contained in the above description or shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
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