U.S. patent number 3,756,235 [Application Number 05/171,628] was granted by the patent office on 1973-09-04 for hypodermic syringe barrel and needle structure.
This patent grant is currently assigned to Burron Medical Products, Inc.. Invention is credited to George K. Burke, Kenneth Raines.
United States Patent |
3,756,235 |
Burke , et al. |
September 4, 1973 |
HYPODERMIC SYRINGE BARREL AND NEEDLE STRUCTURE
Abstract
A hypodermic syringe barrel and needle structure in which a
molded plastic barrel is formed with an integral tubular extension
having cannula and bonding material receiving bore surfaces
thereon, a separately molded plastic confining cap member having an
internal flange at its end is sonically welded or sealed to the
extension to form a permanent part thereof, a cannula is disposed
within the aperture defined by such flange and with the bore
surfaces of the extension and a bonding material composition is set
within the bore surfaces and beneath such flange and in intimate
bonding engagement with the outer surfaces of the cannula to retain
the cannula in fixed position relative to the extension and cap
member.
Inventors: |
Burke; George K. (Bethlehem,
PA), Raines; Kenneth (Bethlehem, PA) |
Assignee: |
Burron Medical Products, Inc.
(Bethlehem, PA)
|
Family
ID: |
22624523 |
Appl.
No.: |
05/171,628 |
Filed: |
August 13, 1971 |
Current U.S.
Class: |
604/240 |
Current CPC
Class: |
A61M
5/343 (20130101); A61M 5/349 (20130101) |
Current International
Class: |
A61M
5/34 (20060101); A61m 005/32 () |
Field of
Search: |
;128/218N,221,218R,216,220,215 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Claims
We claim:
1. A hypodermic syringe barrel and needle structure comprising a
one-piece molded plastic syringe barrel having a substantially
uniform internal diameter, a base and an integrally molded tubular
extension projecting outwardly from said base, said extension
including means defining a frangible portion outwards of the base,
and an internal surface including portions shaped to define a
cannula accommodating bore portion and an outwardly flaring bore
portion outwards of said cannula accommodating bore portion, a
separately molded plastic cap member shaped to fit on said
extension and spaced from said base of said barrel, said cap member
having an inwardly directed flange at its outer end, means bonding
said cap member to said extension, a cannula inserted within said
extension in abutting contact with at least a portion of one of
said bore portions of said extension, and a bonding composition
disposed in surrounding relationship to said cannula in intimate
engagement with and bonded to the outer surface thereof, said
bonding composition at least substantially filling the space
between said cannula and the surrounding bore portion and the inner
surface of said inwardly directed flange to retain said cannula in
fixed relation relative to said extension and cap member.
2. A hypodermic syringe barrel and needle structure as claimed in
claim 1 and said inner surface of said inwardly directed flange on
said cap member facing said outwardly flaring bore portion and
including a surface portion that extends laterally outwards of the
outer terminal end of said outwardly flaring bore portion.
3. A hypodermic syringe barrel and needle strucure as claimed in
claim 1 in which said integral tubular extension of said plastic
barrel member and said cap member have facing bonding surfaces.
4. A hypodermic syringe barrel and needle structure as claimed in
claim 3 and the means bonding said cap member to said tubular
extension comprising a sonically welded connection located at least
at said facing bonding surfaces so that said cap member is
effectively integrally combined with said tubular extension.
5. A hypodermic syringe barrel and needle structure as claimed in
claim 4 and the bonding surface of said tubular extension
comprising a laterally directed external shoulder surface located
outwards of said frangible portion of said extension and the
bonding surface of said cap member comprising a laterally directed
external flange surface at the inner end of said cap member.
6. A hypodermic syringe barrel and needle structure as claimed in
claim 5 and a pointed sonic energy directing means provided on and
integral with one of said bonding surfaces.
7. A hypodermic syringe barrel and needle structure as claimed in
claim 6 and said pointed sonic energy directing means comprising a
pointed annular bead extending from the laterally directed flange
surface at the inner end of said cap member.
8. A hypodermic syringe barrel and needle structure comprising a
molded polypropylene syringe barrel having a base and an integral
tubular extension projecting outwardly of said base, said extension
including a first portion extending outwardly of said base and
constituting a frangible portion for separating the extension from
said barrel member, said frangible portion being defined between a
first annular shoulder constituting a portion of said base and a
second annular shoulder formed on the inner surface of said tubular
extension, said shoulders being longitudinally offset from one
another, said tubular extension having an external shoulder
longitudinally offset from said second annular shoulder and
constituting a bonding face, said tubular extension having an outer
wall surface extending beyond said external shoulder and including
a first surface portion that is cylindrical and a second surface
portion extending from and beyond said first surface portion and
tapering inwardly to a terminal annular end surface on said
exension, said extension having an inner bore surface that tapers
inwardly to and merges with a transversely extending surface that
in turn merges with a frusto-conically shaped portion formed with
said tubular extension and that projects rearwardly into said bore,
said frusto-conically shaped portion having a bore therethrough
including a first, cylindrical surface portion for accommodating a
cannula and an adjoining outwardly flaring surface portion that
extends to said terminal annular end surface of said extension, a
separately molded polypropylene cap member having an external
flange at its inner end constituting a bonding surface and an
internal flange at its outer end, said internal flange defining an
opening substantially larger than the transverse dimensions of any
cannula to be inserted therethrough, said cap member having an
internal surface including joined portions complementary with said
first and second surface portions of the outer wall surface of said
extension, said external flange at the inner end of said cap member
having a pointed bead means of the plastic material of said cap
member constituting an energy director, said cap member being
sonically welded via said bonding surface and energy director
thereon to said bonding face on said extension to integrally unite
the cap member and extension, the longitudinal distance between
said bonding surface of said external flange and the inner surface
of said internal flange on said cap member being greater than the
longitudinal distance between said external shoulder and said end
surface of said extension so that said internal flange on said cap
member is spaced outwardly of said end surface of said extension, a
cannula extending through the opening defined by said internal
flange and operatively positioned relative to the bore surface of
said frusto-conically shaped portion of said extension and said
outwardly flaring bore surface portion, and a bonding material
composition set within said integrally united extension and cap
member in surrounding relation to said cannula and including an
annular set portion of said composition extending between said end
surface of said extension and the inner surface of said internal
flange whereby said cannula is maintained in permanently fixed
operative relation.
9. A hypodermic syringe barrel and needle structure as claimed in
claim 3 in which one of said facing bonding surfaces includes a
circumferentially extending bead and the other bonding surface
includes a cooperating circumferential groove to retain said cap
member in position on said tubular extension.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the art of disposable sterile
devices, such as hypodermic syringes and the like, which are
adapted to be destroyed after a single use.
Devices of this character are known in the art, such as in U. S.
Pat. No. 3,306,291, dated Feb. 28, 1967.
In general, the needle or cannula is mounted within a needle hub
that is connected to an extension or boss on the barrel of a
syringe or the needle can be fused within a glass extension of a
glass syringe barrel.
Since disposable syringes must be mass produced, it is desirable to
provide a syringe barrel and needle combination wherein the needle
is fixed in relation to the barrel.
Further, it is desirable to produce the syringe barrel from organic
plastic materials, such as polyethylene or polypropylene, and
certain difficulties arise in fixing a metal cannula within bores
provided in tubular portions molded from such materials.
Consequently, a constructional arrangement is desired in which a
metal needle can be readily fixed to a syringe barrel molded of
such plastic materials and wherein means are provided to lock the
needle in place so as to prevent removal thereof.
STATEMENT OF THE INVENTION
Thus, the invention provides a syringe barrel that is so molded of
the above-mentioned materials as to include an integral tubular
extension having a frangible portion outwards of the base of the
barrel and a needle accommodating bore and bonding material
receiving pocket as well as a bonding or interlocking surface
thereon to mate with a facing bonding or interlocking surface of a
plastic cap of the same material and which cap, after bonding or
interlocking with the tubular extension, permanently confines the
needle and its associated bonding material relative to the
pocket.
Particularly, the invention provides an integral tubular extension
from the base of the barrel that includes a needle and bonding
material accommodating internal shape, a frangible portion outwards
of the base and a lateral shoulder to receive a bonding or
interlocking surface on the end of a molded plastic cap and which
end has an energy directing bead or a series of pointed projections
thereon so that the cap can be effectively integrally bonded to the
tubular extension by sonic, i.e. ultrasonic, welding, and after
which a needle can be inserted within the extension and an epoxy
resin bonding composition introduced into the pocket to bond the
needle in place. Since the cap is now an integral part of the
extension, the needle and surrounding epoxy bonding composition are
permanently confined by the cap. In some instances, the material
from which the cap is made may not be the same as the syringe body
and, in such instances, the interior wall of the cap and the
exterior surface of the barrel extension may be provided with a
mating bead and groove construction to interlock the parts.
BRIEF DESCRIPTION OF THE DRAWINGS
Further and more specific features and advantages of the invention
will be more readily apparent from the following description taken
in connection with the accompanying drawings in which:
FIG. 1 is a fragmentary longitudinal sectional view of a molded
syringe barrel and the integral tubular extension thereof;
FIG. 2 is a longitudinal sectional view of a molded cap; and
FIG. 3 is a view similar to FIG. 1 illustrating the barrel and cap
in sonically bonded relation and with the needle and bonding
material confined by the cap.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
In the drawings, the syringe barrel A is formed of molded organic
plastic material, such as polyethylene or polypropylene, and
receives a plunger indicated at B, the arrangement being similar to
that of prior U.S. Pat. No. 3,306,291 mentioned hereinbefore.
During molding, the barrel is formed with a tubular extension C
that includes a frangible portion 100 defined between the outer or
annular shoulder surface 101 of the barrel and an internal annular
shoulder 102 on the extension. This formation of providing a
frangible portion is as in said U.S. Pat. No. 3,306,291. Thus, the
length of the frangible portion, which is an area of stress, should
have a length no more than twice its wall thickness. The outer wall
surface of the extension includes a cylindrical portion 103
extending from the external laterally extending shoulder 104 and an
inwardly tapered portion 103' that extends to the end surface 111
of the extension. The surface of shoulder 104 constitutes a bonding
surface. The extension is provided with an inner bore surface 105
that is slightly tapered inwardly from its juncture with shoulder
102 and via surface 106 joins with the outer surface 107 of a
generally frusto-conically shaped portion 108 formed within the
extension. The portion 108 has a bore surface 109 that merges with
a further surface 110 that flares outwardly toward the end surface
111 of the extension. The outwardly flaring surface defines a
bonding material receiving pocket. The bore surface can be slightly
tapered or straight and of a diameter to accommodate the outer
surface of an inserted needle or cannula D, FIG. 3.
The separately molded cap E includes an inwardly directed flange
112 that defines an opening in the outer end of the cap. The inner
surface 113 of this flange acts as a confining surface as explained
hereinafter. The other or inner end of the cap is shaped to provide
an outwardly directed flange 114. An annular pointed head 115 of
material is formed as a projection from surface 116 of flange 114.
The outer surface of the cap includes a cylindrical or straight
portion 118 extending beyond surface 117 of flange 114 and which
merges at 119 with an inwardly tapered surface portion 120. The
inner surface of the cap includes portions that are complemental
with the outer surface portions of the extension. The bead 115 is
an energy directing bead of plastic that effects the bonding and
sealing connection between the surface 116 of flange 114 of the cap
and the surface of shoulder 104 on the tubular extension when the
cap is assembled with the extension of the barrel and the assembly
is subjected to an ultrasonic field in a sonic welding
apparatus.
In producing the assembled components of the invention, the barrel
A and its integral extension C are injection molded from
polypropylene. The cap E, likewise injection molded from this
material, is placed over the extension with the tip of bead 115 in
contact with shoulder 104 of the extension. These parts are
subjected to ultrasonic welding so that the cap is permanently
integrally bonded and sealed to the extension generally as is shown
at X in FIG. 3.
A stainless steel needle or cannula D is then inserted within bore
surface 109 of the frusto-conically shaped portion 108 of the
extension and an epoxy resin bonding composition is introduced into
the space surrounding the cannula that is delimited by the
outwardly flaring bore surface 110, the end surface 111 of the
extension, the inner surface 113 of inwardly directed flange of the
cap E, and that inner wall surface portion 121 of the cap that is
between the end surface 111 and inner flange surface 113. Thus, the
epoxy resin bonding material, when set, forms into an annular
portion 122 so that outward pulling force applied on the needle is
resisted by the inner flange surface 113 of the cap which is
integrally united to the extension of the barrel.
In providing this effective epoxy resin receiving space, the
extension and cap are so dimensioned that the longitudinal distance
between the surface 116 of outwardly directed flange 114 and the
surface 113 of inwardly directed flange 112 is greater than the
distance between the shoulder 104 and the end surface of the
tubular extension.
After the cannula has been mounted and fixed to the now
interconnected extension and cap, a protective needle cover, not
shown, is positioned over the exterior of the cap.
Thus, this invention provides a hypodermic syringe barrel structure
of molded plastic material having an integral tubular extension
projecting beyond the base of the barrel. The extension includes a
frangible portion outwards of the base and an internal surface
shaped to provide a cannula accommodating bore portion and an
outwardly flaring portion extending beyond such bore portion. The
extension also includes a laterally directed bonding surface
adjacent the frangible portion and an outer cap accommodating
surface. A molded plastic cap having at one end an outwardly
directed flange constituting a bonding surface provided with a
shaped energy directing portion is effectively integrally bonded
and sealed to the extension and a cannula is bonded within the bore
by a quantity of an epoxy resin bonding composition that at least
fills the space surrounding that portion of the cannula that is
inwards of an inwardly directed flange on the other end of the
cap.
While the energy director, either a bead or a series of
projections, is preferably formed on the cap, the same could be
formed on the lateral shoulder of the tubular extension.
Additionally, it is to be understood that the bore surface in the
frusto-conical portion of the tubular extension is usually
dimensioned to accommodate a particular size cannula, however, a
larger diameter cannula can be utilized therein because the same
can be positioned with its end peripheral surface contacting the
outwardly flaring portion of the bore surface and the resin
utilized to retain the cannula in place.
Under certain circumstances, it may be desirable to form the cap
and syringe body from different materials and, therefore, the
ultrasonic sealing technique described above may not be practical
since the materials are not compatible. Thus, the external surface
of the barrel extension may be provided with a circumferential bead
125 and the internal surface of the cap E may be provided with a
complementary circumferential groove 126 to cooperate with the bead
125. The cap is interfitted with the extension and the bead and
groove snap together to effectively retain the cap in position on
said extension.
As this invention may be embodied in several forms without
departing from the spirit or essential characteristics thereof, the
present embodiment is therefore illustrative and not restrictive,
since the scope of the invention is defined by the appended claims
rather than by the description preceding them, and all changes that
fall within the metes and bounds of the claims or that form their
functional as well as conjointly cooperative equivalents, are
therefore intended to be embraced by those claims.
* * * * *