SERINGUE RETRACTABLE

RETRACTABLE SYRINGE

Abrégé anglais

A retractable syringe includes a barrel, one end of
which comprises a mounting collar. A needle carrier is releasably
mounted within the collar, and releasably supports a needle
cartridge. A hypodermic needle is mounted within the cartridge.
A sheath attaches at one end to the cartridge, and at the other
end to the collar. A plunger is telescoped into the barrel, and
includes a relatively hard piston sealingly engaging the barrel.
The piston includes a latch for engaging the carrier and releasing
it from the collar. A pocket in the carrier has a support member
in its center, and a pair of helical ribs for threadingly engaging
a pair of tabs on the cartridge. The cartridge sealingly receives
the support member. The collar has slots and inclined threads in
its bore wall for engaging lugs on the carrier. The inclined
threads have a friction bump near their blind ends. A retaining
pin prevents relative rotation between the carrier and collar
prior to desired retraction of the needle into the barrel.
Alternative embodiments include a barrel which may be resilient or
non-resilient and a hard or soft resilient piston, respectively,
having a plunger head secured therewithin and attached to the
plunger. A latch is attached to the plunger head, and is received
in a recess in the carrier to engage latch stops for rotating the
carrier to release it from the collar. Alternative embodiments
may include means for securing the plunger in the barrel after
retraction.

Revendications

CLAIM:
1. A retractable syringe for use with a hypodermic
needle cartridge comprising:
a barrel having a proximal end and a distal end, said
proximal end of said barrel including a mounting collar with a
bore having a wall;
a. piston plunger telescopingly received within said distal
end of said barrel, and having a sealing means, said sealing
means being adjacent to said mounting collar when said piston
plunger is fully inserted into said barrel, and wherein said
sealing means includes an expandable, elongated membrane
portion at a proximal end of said sealing means and a side,
said side having an annular indent formed therein;
a needle cartridge attachment means having a body, said
body having a proximal end and a distal end and an exterior
wall, said needle cartridge attachment means located at the
proximal end of the piston plunger;
means disposed on said body and engageable in contact with
correlatively shaped means disposed on said mounting collar for
releasably latching said body in said bore of said mounting
collar said distal end of said body having means engageable
with said sealing means for retracting said body into said
barrel.
2. Retractable syringe according to claim 1, wherein
said needle cartridge attachment means includes means for
threadingly engaging the hypodermic needle cartridge in sealed
relation thereto.
3. Retractable syringe according to claim 2, wherein the
hypodermic needle cartridge includes a cartridge body having a
proximal end and a distal end and an axially extending bore
57

therethrough, the proximal end of the cartridge body having a
hypodermic needle mounted therein, the distal end of the
cartridge body having a plurality of mounting tabs spaced apart
thereon, and wherein said needle cartridge attachment means
comprises an annular pocket having an outer wall and a pair of
axially spaced apart helical threads in said outer wall for
threadingly receiving the mounting tabs of the needle cartridge
body, and a needle cartridge support member disposed
substantially in the center of said pocket, said needle
cartridge support member being adapted to sealingly engage the
bore of the needle cartridge body when the needle cartridge
body is threaded into said pocket.
4. A retractable syringe for use with a hypodermic
needle cartridge, comprising:
a barrel having a proximal end and a distal end, said
proximal end of said barrel including a mounting collar with a
bore having a wall;
a piston plunger, having sealing means telescopingly
received within said distal end of said barrel;
a needle carrier having a body, said body having a
proximal end and a distal end and an exterior wall;
engagement means disposed on said body and engageable in
contact with correlatively shaped means disposed on said
mounting collar for releasably latching said body in said bore
of said mounting collar, said distal end of said body having
means engageable with said sealing means for retracting said
body into said barrel; and
wherein the engagement means are fractionally held in
engagement with said shaped means at two longitudinally
separated
58

59
positions.
5. The retractable syringe of claim 4, wherein said
engagement means includes threads and shoulders formed on
extensions of said engagement means,
said shaped means includes slots sized to admit threads,
bottom threads engageable with said threads and bottom shoulders
engageable with said shoulders.
6. The retractable syringe of claim 5, wherein said slots
are spaced laterally around collar.
7. The retractable syringe of claim 5, wherein said
shoulders are located in said barrel.
8. The retractable syringe of claim 5, wherein there is
further included a lip juxtaposed with said bottom threads having
means for containing said threads.

Description

70677-14D
'~ 4 7 6 31
BACKGROtJND OF THE INVENTION
The present invention relates generally to retractable
hypodermic syringes, and more particularly to a retrar_table
hypodermic syringe having a needle carrier adapted for releasably
attaching a needle cartridge thereto prior to use. The present
invention relates further to such a hypodermic syringe having
means for retarding the unlatching of the needle carrier from the
mounting collar of the syringe barrel during installation or
removal of a needle cartridge, and still further to an invertible
protective cover adapted at one end for sheathing the hypodermic
needle prior to use, and at the other end for releasably attaching
to and enclosing, or otherwise closing, a hub of the mounting
collar at an end of the syringe barrel in the absence of a needle
cartridge.
In the past, needle stick injuries suffered by medical
personnel anti others in the course of using hypodermic syringes
have presented a serious problem. Serious diseases such as
hepatitis and AIDS may be transmitted by needle stick injuries,
resulting in the needless suffering, and possibly even in the
death, of the unfortunate victims. Of late, the onslaught of AIDS
has resulted in needle stick injuries posing an even greater
health hazard because of the virtual certain death, at least
insofar as

- X107631
research to date indicates, of the injured person if he or she
contracts the disease.
In order to minimize the risk of needle stick injuries,
retractable syringes have been developed which enable the
retraction of the needle into the barrel of the syringe following
use and prior to disposal. The movement of the needle in the
retracted position is typically limited such that normally it will
not again protrude from the barrel, and normally will not again
come into contact with a health care worker or other person.
Retraction and retention of the possibly contaminated needle into
the barrel thus protectively isolates the needle and keeps it out
of further human contact under normal circumstances. Such a
retractable syringe is shown, for example, in U.S. patent
4,747,830, issued May 31, 1988, to Walter W. Gloyer and Frederick
G. Bright, also the inventors herein,.
At times, persons having a need to use a hypodermic syringe
will desire to select a particular size or shape of needle, such as
one relatively longer or shorter than others he or she typically
uses, or one having a larger or smaller diameter. Hypodermic
needle cartridges have been used in the past for nonretractable
syringes. It would be advantageous if a health care worker or
other such person could simply select a needle cartridge having a
needle of the desired size and shape and easily install it in a
commonly configured retractable syringe body. This would afford
the syringe user the flexibility of meeting his or her particular
A

-'- X107631
dical needs with a variety of needles but only a single inventory
of syringe bodies, as well as the safety and protection that a
retractable syringe provides against needle stick injuries, while
assuring reliability in connection. Since only one configuration
of syringe body need be manufactured for use with a virtually
unlimited selection of needle cartridges, the savings in tooling
and manufacturing costs would also be significant. Moreover, the
manufacture of a common syringe body without a needle permanently
attached would simplify the manufacturing process for the
retractable syringe, since the hypodermic needle would not have to
be installed during manufacture of the syringe body.
One type of hypodermic needle cartridge used in the past is
adapted for threaded engagement in a pocket disposed on the syringe
barrel. The pocket typically has a needle cartridge support member
disposed at or near its center, which is sealingly received in a
correlatively shaped bore in the body of the needle cartridge. The
body of the needle cartridge in one such prior art cartridge
arrangement is provided with a pair of diametrically opposed tabs
which threadedly engage a pair of axially spaced apart helical
threads in the pocket on the syringe barrel.
A hypodermic syringe needle typically is provided with a
protective sheath for covering the needle prior to use of the
syringe. With conventional non-retractable syringes, the
protective sheath may be reinstalled on the needle following use,
but such reinstallation also involves the inherent risk of a needle
stick injury from improper or~careless handling or the like of the
needle, the sheath, or both. Sometimes the person attempting to

o~~~ 1 g ,
:install the sheath may not be physically able to do so easily, as
might be the case, for example, if the person were to suffer from
arthritis, a nerve disorder, or other problem. Moreover, U.S.
Center for Disease Control guidelines now prohibit the recapping of
syringes with the needle covers after use.
Following use of a retractable syringe, there is no need to
reinstall the protective sheath, so the risk of a needle stick
arising from such reinstallation is eliminated.
There is another potential disease-causing contamination
problem, however, in that the syringe barrel is left open following
retraction of the needle, thereby permitting any excess fluid or
residue left in the syringe barrel to leak out into the
environment. For example, if the excess fluid or residue were to
be a contaminated fluid or residue, there is a risk of the
contaminating virus or bacteria contaminating other medical tools
or equipment in the area, possibly infecting persons who
subsequently come into contact with such tools or equipment or the
syringe. The needle sheaths typically used in the past for
covering the needles are incapable of being used to enclose the
barrels of retractable syringes following use and retraction of the
needles into the barrels, so as to prevent such leakage and
environmental contamination. Although sealable containers have
been used in the past into which used syringes can be placed for
disposal, such containers are typically completely separate items
which must be provided along with the syringes or kept on hand
somewhere close at hand. This. results in extra labor and materials
costs to manufacture such containers, extra shipping costs to

~ ~ o~s3-~-
pply them to the users, and extra storage and handling costs
on-site.
It is an object of the present invention to provide a
retractable syringe with a common barrel configuration which will
reliably accept a needle cartridge in which is mounted a needle of
virtually any desired size or shape. It is another object of the
present invention to provide such a retractable syringe with a
needle carrier releasably latched into a mounting collar of the
barrel and into which the needle cartridge is installed, and means
for preventing or retarding unlatching of the needle carrier from
the mounting collar during installation or removal of the needle
cartridge.
It is another object of the present invention to provide a
retractable syringe on which a needle cartridge may be securely
mounted such that the needle is firmly stabilized and supported in
the needle carrier, and the needle carrier is securely latched in
the mounting collar until such time as unlatching is desired.
It is another object of the present invention to provide a
retractable syringe with a protective cover that will both cover
the needle prior to use, and enclose the end of the barrel in which
the needle cartridge is mounted either prior to installation of a
needle cartridge in order to prevent contamination of the barrel,
or following use of the syringe and retraction of the needle in
order to prevent leakage of excess fluid or residue from the
barrel.
It is another object of the present invention to provide such
a syringe which is durable, reliable, and easy to use. It is still

7643-1D
X107631
another object of the present invention is to provide such a
syringe which is inexpensive and simple to manufacture.
SUMMARY OF THE INVENTION
In accordance with the present invention, these is
provided a retractable syringe for use with a hypodermic needle
cartridge comprising: a barrel having a proximal end and a
distal end, said proximal end of said barrel including a
mounting collar with a bore having a wall; a piston plunger
telescopingly received within said distal end of said barrel,
and having a sealing means, said sealing means being adjacent
to said mounting collar when said pistol plunger is fully
inserted into said barrel, and wherein said sealing means
includes an expandable, elongated membrane portion at a
proximal end of said sealing means and a side, said side having
an annular indent formed therein; a needle cartridge attachment
means having a body, said body having a proximal end and a
distal end and an exterior wall, said needle cartridge
attachment means located at the proximal end of the piston
plunger, means disposed on said body and engageable in contact
with correlatively shaped means disposed on said mounting
collar for releasably latching said body in said bore of said
mounting collar said distal end of said body having means
engageable with said sealing means for retracting said body
into said barrel.
In accordance with the present invention, there is
further provided a retractable syringe for use with a
hypodermic needle cartridge, comprising: a barrel having a
proximal end and a distal end, said proximal end of said barrel
including a mounting collar with a bore having a wall; a piston
plunger, having sealing means telescopingly received
s

~ 0731
within said distal end of said barrel; a needle carrier having
a body, said body having a proximal end and a distal end and
an exterior wall; engagement means disposed on said body and
engageable in contact with correlatively shaped means disposed
on said mounting collar for releasably latching said body in
said bore of said mounting collar, said distal end of said
body having means engageable with said sealing means for
retracting said body into said barrel; and wherein the
engagement means are fractionally held in engagement with said
shaped means at two longitudinally separated positions.
According to the preferred embodiment of the
invention, a retractable syringe includes a barrel, one end of
which comprises a needle carrier mounting collar. A needle
carrier is releasably mounted within the mounting collar, and
is adapted to releasably support therewithin a needle
cartridge. A hypodermic needle is mounted within the needle
cartridge. An invertible locking safety cover is adapted at
one end to be fractionally retained on the needle cartridge,
covering the needle, prior to use of the syringe, and at the
other end to be positively locked to a hub of the mounting
collar prior to installation of a needle cartridge into the
needle carrier, and after use of the syringe and retraction of
the needle into the barrel.
The needle carrier is sealingly mounted within the
mounting collar from within the barrel. The needle cartridge
is subsequently mounted to the proximal end of the needle
carrier from outside the barrel.
A needle cartridge receiving pocket extends axially
6a
70677-14D

t. ~ ~ 7 fi 31
part way through the main body of the needle carrier from its
proximal end. In the center of the pocket there is a needle
cartridge support member having an axial bore in fluid
communication with the interior of the needle carrier. The
pocket has a pair of helical threads around its outer wall,
forming a pair of lands which are a lure lock type thread upon
which a pair of tabs disposed on the
6b
70677-14D

107631 '
~tal end of the needle cartridge ride in removing or installing
the needle cartridge.
As with the other embodiments described below, the needle
cartridge includes a main body having the tabs on its upper end
adapted to be threadedly secured into the helically threaded pocket
of the needle carrier. The cartridge has a central axial bore
adapted to sealingly receive therewithin the needle cartridge
support member of the needle carrier. A hypodermic needle of
selected size and shape is mounted within the needle cartridge.
The mounting collar has a pair of axially extending slots in
its bore wall traversed by the lugs on the needle carrier when it
is installed into or removed from the mounting collar. The slots
intersect and communicate with a pair of inclined threads in the
bore wall of the mounting collar which extend part way around the
bore wall. When the lugs on the needle carrier are inserted into
the slots in the mounting collar and the needle carrier is then
rotated in the appropriate direction, the lugs travel along the
inclined threads into a position at the end of the inclined
threads. Rotation of the needle carrier in the opposite direction
passes the lugs along the inclined threads back to the slots for
removal of the needle carrier from the mounting collar.
An elongate plunger is telescoped into and carried within the
barrel. The plunger includes an injection piston attached at its
proximal end, disposed within and sealingly engaging the barrel.
The proximal face of the piston includes a stinger latch at or near
its center.

'~ 07s38~
The stinger latch is adapted to engage a seat in the recess of
the needle carrier in such fashion that rotation of the stinger
latch also rotates the needle carrier, and such that withdrawal of
the stinger latch into the barrel also withdraws the needle carrier
into the barrel. Rotation of the needle carrier until its lugs
traverse the inclined threads and are in alignment with the axial
slots permits withdrawal of the piston back into the barrel, along
with the needle carrier, needle cartridge, and needle.
The mounting collar includes a groove around the periphery of
its hub portion and adapted to receive an annular land disposed on
the larger end of the locking safety cover in order to secure the
cover to the hub, enclosing the barrel, when manufactured and prior
to installation of a needle cartridge onto the syringe, and after
retraction of the needle into the barrel.
The upper end of the barrel is provided with latching means
for catching the plunger in retracted position and securing the
needle safety within the barrel. The portion of the plunger
protruding from the barrel may be broken off substantially flush
with the end of the barrel. (The latching means for this
embodiment and the alternative embodiment below may also be only
the breaking off of the plunger in conjunction with the friction
between the barrel and the piston, but depending on tolerances may
not be reliable to hold the needle within the barrel.) The
protective cover may then be installed on the mounting collar hub
in order to enclose the barrel. The used syringe may then be
safely discarded without further danger of a needle stick injury.

~ o7s~
According to one alternative embodiment of the invention, a
retractable syringe includes a resilient barrel, one end of which
comprises a needle carrier mounting collar. A needle carrier is
releasably mounted within the mounting collar, and is adapted to
releasably support therewithin a needle cartridge. A hypodermic
needle is mounted within the needle cartridge. An invertible
locking safety cover is adapted at one end to be frictionally
retained on the needle cartridge, covering the needle, prior to use
of the syringe, and at the other end to be positively locked to a
hub of the mounting collar prior to installation of a needle
cartridge into the needle carrier, and after use of the syringe and
retraction of the needle into the barrel.
The needle carrier is sealingly mounted within the mounting
collar from within the barrel, and the needle cartridge is
subsequently mounted to the proximal end of the needle carrier from
outside the barrel. A plurality of radially outwardly extending
bayonet lugs are disposed on the exterior of the needle carrier.
A latch recess extends into the body of the needle carrier from its
distal end for receiving the stinger latch.
A needle cartridge receiving pocket extends axially part way
through the main body of the needle carrier from its proximal end.
In the center of the pocket there is a needle cartridge support
member having an axial bore in fluid communication with the latch
recess. The pocket has a pair of helical ribs around its outer
wall, forming a pair of lands upon which a pair of tabs disposed on
the distal end of the needle cartridge ride in removing or
installing the needle cartridge.

~ 8763'
The needle cartridge includes a main body having the tabs on
its upper end adapted to be threadedly secured into the helically
threaded pocket of the needle carrier. The cartridge has a central
axial bore adapted to sealingly receive therewithin the needle
cartridge support member of the needle carrier. A hypodermic
needle of selected size and shape is mounted within the needle
cartridge.
The mounting collar has a pair of axially extending slots in
its bore wall traversed by the lugs on the needle carrier when it
is installed into or removed from the mounting collar. The slots
intersect and communicate with a pair of inclined threads in the
bore wall of the mounting collar which extend part way around the
bore wall. The inclined threads each have a friction rise or
bump on their proximal surfaces near their blind ends. When the
lugs on the needle carrier are inserted into the slots in the
mounting collar and the needle carrier is then rotated in the
appropriate direction, the lugs travel along the inclined threads
into a secure, seated position between the friction rises and the
end walls of the inclined threads. Rotation of the needle carrier
in the opposite direction passes the lugs over the friction rises
and along the inclined threads back to the slots for removal of the
needle carrier from the mounting collar.
A retaining pin may be disposed in aligned holes in the needle
carrier and the mounting collar when they are fully assembled in
order to prevent relative rotation between them prior to desired
retraction of the needle into~the barrel.

- ~ ~~ 0763 1
An elongate plunger is telescoped into and carried within the
barrel. The plunger includes a relatively hard injection piston
attached at its proximal end, disposed within and sealingly
engaging the barrel. The proximal face of the piston includes a
stinger latch at or near its center.
The stinger latch is adapted to engage a seat in the recess of
the needle carrier in such fashion that upon removal of the
retaining pin, rotation of the stinger latch also rotates the
needle carrier, and such that withdrawal of the stinger latch into
the barrel also withdraws the needle carrier into the barrel.
Rotation of the needle carrier until its lugs traverse the inclined
threads and are in alignment with the axial slots permits
withdrawal of the piston back into the barrel, along with the
needle carrier, needle cartridge, and needle.
The mounting collar includes a groove around the periphery of
its hub portion and adapted to receive an annular land disposed on
the larger end of the locking safety cover in order to secure the
cover to the hub, enclosing the barrel, when manufactured and prior
to installation of a needle cartridge onto the syringe, and after
retraction of the needle into the barrel.
The upper end of the barrel is provided with latching means
for latching the plunger in retracted position and securing the
needle safely within the barrel. The portion of the plunger
protruding from the barrel may be broken off substantially flush
with the end of the barrel. (The latching means for this
embodiment and the other embodiments may also be only the breaking
off of the plunger in conjunction with the friction between the

-12-
6 1
1 7 3
barrel and the piston, but depending on tolerances may not be
reliable to hold the needle within the barrel.) The protective
cover may then be installed on the mounting collar hub in order to
enclose the barrel. The used syringe may then be safely discarded
without further danger of a needle stick injury.
According to another alternative embodiment of the invention,
an injection piston may be used with a non-flexible barrel. The
injection piston comprises a soft resilient member having a plunger
head secured therewithin and attached to the plunger. A latch
member is attached to the proximal end of the plunger head, and is
adapted to be received in a recess in the needle carrier and to
engage latch stops in the recess for rotating the needle carrier to
release it from the mounting collar.
A latching flange disposed on the upper end of the plunger
head engages hooks disposed on flexible arms attached to the barrel
when the plunger head is fully retracted into the barrel along with
the needle carrier, needle cartridge, and needle, thereafter
preventing movement of such members in a proximal direction and
latching them in safe, secure position for disposal.
In the preferred and this alternative embodiment, the plunger
latch may be covered by a thin resilient diaphragm, which
preferably will follow the latch member.
Otherwise, the second alternative embodiment is substantially
identical to the first alternative embodiment.
These and other objects and advantages of the invention will
become apparent from the following description of the preferred

~~ 0 7~ 31~y
emLOdiments when read in conjunction with reference to the
following drawings. ,
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding at the nature and objects of the
present invention, in conjunction to this specification, reference
should be had to the following drawings in which like parts are
given like reference numerals and wherein:
Figure 1 is an isometric view of one alternative embodiment of
a retractable syringe according to the present invention, the
syringe being shown in assembled condition and ready for use.
Figure 2 is a view partly in longitudinal section, partly
exploded, and partly in elevation of the retractable syringe of
Figure 1, showing the needle cartridge separated from the needle
carrier and the protective cover removed from the needle cartridge,
and showing the plunger latch disposed in the recess in the upper
end of the needle carrier.
Figure 3 is a vertical sectional view of the mounting collar
and needle carrier of the embodiment of Figure 1 in exploded
relation with the needle carrier in position to be inserted into
the mounting collar.
Figure 4 is a vertical sectional view of the assembled
mounting collar and needle carrier of the embodiment of Figure 1.
Figure 5 is a vertical sectional view of the assembled
mounting collar, needle carrier, and needle cartridge of the
embodiment of Figure 1.

~ '~0763~- ,
Figure 6 is an end view of the needle cartridge of both the
first and second alternative embodiments of the invention described
herein, taken along lines 6-6 of Figures 2 and 10.
Figure 7 is an end view of the needle carrier of both the
first and second alternative embodiments of the invention described
herein, taken along lines 7-7 of Figures 3 and 11.
Figure 8 is a vertical sectional view of the embodiment shown
in Figure 1, after use of the syringe and retraction of the needle
cartridge and needle into the syringe barrel.
Figure 9 is an isometric view of a second alternative
embodiment of a retractable syringe according to the present
invention, the syringe being shown in assembled condition and ready
for use.
Figure 10 is a view partly in longitudinal section, partly
exploded, and partly in elevation of the retractable syringe of
Figure 9, showing the needle cartridge separated from the needle
carrier and the protective cover removed from the needle cartridge,
and showing the plunger latch disposed in the recess in the upper
end of the needle carrier.
Figure 11 is a vertical sectional view of the mounting collar
and needle carrier of the embodiment of Figure 9 in exploded
relation with the needle carrier in position to be inserted into
the mounting collar.
Figure 12 is a vertical sectional view of the assembled
mounting collar and needle carrier of the embodiment of Figure 9.

~ ~ 1 U 7 6 3-~5_
Figure 13 is a vertical sectional view of the assembled
mounting collar, needle carrier, and needle cartridge of the
embodiment of Figure 9.
Figure 14 is a vertical sectional view of the embodiment shown
in Figure 9, after use of the syringe and retraction of the needle
cartridge and needle into the syringe barrel.
Figure 15 is an isometric view of the preferred embodiment of
a retractable syringe according to the present invention, the
syringe being shown in exploded view with three types of alternate
embodiment caps and without the syringe cartridge as in Figures 2
and 10.
Figure 16 is a longitudinal cross-sectional view of the
preferred embodiment of the barrel of the retractable syringe of
Figure 15.
Figure 17 is an end view of the barrel of Figure 16 taken
along section lines 17-17 of Figure 2.
Figure 18 is a cross-sectional view of Figure 16 taken along
section lines 18-18 of Figure 16.
Figure 19 is a detail view of the proximal end of the barrel
of Figure 16.
Figure 20 is a detail view of the distal end of the barrel of
Figure 16.
Figure 21 is a side view of the preferred embodiment of the
plunger of the retractable syringe of Figure 15.
Figure 22 is the distal end view of the plunger of Figure 21.
Figure 23 is the proximal end view of the plunger of
Figure 21.

10'631
70677-14
-16-
Figure 24 is a cross-sectional view of Figure 21 taken along
section lines 24-24 of Figure 21.
Figure 25 is a detail view of the proximal end of the plunger
of Figure 21. ,
Figure 26 is a partial cross-sectional view of the proximal
end of Figure 25 taken along sectian lines 26-26 of Figure 25.
Figure 27 is a proximal end view of the diaphragm of the
retractable syringe of Figure 15.
Figure 28 is a cross-sectional view of Figure 27 taken along
section lines 28-28 of Figure 27.
Figure 29 is a distal end view of the preferred embodiment of
the needle carrier of the retractable syringe of Figure 15.
Figure 30 is a proximal end view of the preferred embodiment
of the needle carrier of the retractable syringe of Figure 15.
Figure 31 is a longitudinal cross-section of the needle
carrier of Figure 29 taken along section lines 31-31 of Figure 29.
Figure 32 is a cross-sectional view taken along section lines
32-32 of Figure 31.
Figure 33 is a partial longit~~dinal cross-sectional view of
the needle carrier taken along section lines 33-33 of Figure 32.
Figure 34 is a partial longitudinal cross-sectional view of
the needle carrier taken along section lines 34-34 of Figure 32.
Figure 35 is a longitudinal cross-sectional view of one option
of the alternate embodiments of the cap of the preferred embodime'ht
of the retractable syringe of Figure 15.
Figure 36 is a detail view of the proximal end of the cap of
Figure 35.
r

4763 ~
~1
Figure 37 is a cross-sectional view of Figure 35 taken along
section lines 37-37 of Figures 35, 38 or 39.
Figure 38 is a longitudinal cross-sectional view of a second
alternative embodiment option of the cap of the preferred
embodiment of the retractable syringe of Figure 15.
Figure 39 is a longitudinal cross-sectional view of a third
alternative embodiment option of the cap of the preferred
embodiment of the retractable syringe of Figure 15.
Figure 40 is a longitudinal cross-sectional view of the
preferred embodiment of the cap of the retractable syringe of
Figure 15.
Figure 41 is an end view of the preferred embodiment of the
cap of the retractable syringe of Figure 15.
Figure 42 is a view in longitudinal section of the retractable
syringe of Figure 15, showing the assembly for normal operation.
Figure 43 is a view in longitudinal section of the retractable
syringe of Figure 15, showing the assembly retracted.
Figure 44 is a longitudinal cross-sectional view of an
alternate embodiment of the cap of the retractable syringe of
Fig. 15.
Figure 45 is a longitudinal cross-sectional view of another
preferred embodiment of the barrel of the retractable syringe of
Fig. 15.
Figure 46 is a longitudinal cross-sectional view of another
preferred cap of the preferred embodiment of the retractable
syringe of Fig. 15.

~ o~s3 ~
18 -
70677-14
Figure 47 is a longitudinal cross-sectional view of a
preferred embodiment of the needle holder of the retractable
syringe of Figure 15.
Figures 48A and 48B are a longitudinal cross-sectional
view and an end view, respectively, of the preferred embodiment
of the barrel of the preferred embodiment of the boll syringe of
Figure 15 corresponding to the needle holder of Figure 47.
Figures 49A and 49B are a longitudinal cross-sectional
view and an end view, respectively, of a preferred embodiment
of the piston of the retractable syringe of Figure 15.
DESCRIPTION OF THE PREFERRED EMBODIMENT AND
ALTERNATE EMBODIMENTS OF THE INVENTION
Referring intially to Figures 1 and 2, one alternate
embodiment of the retractable syringe of the present invention
is shown generally at 10.' Syringe 10 includes a resilient
barrel 12, the proximal end, that is, the end nearer the point
of the needle, of which comprises a needle carrier support or
mounting collar 14. A needle carrier 16, more particularly
described below and better shown in Figures 3-5 and 8, is mounted
within the needle carrier support or mounting collar 14. Needle
carrier 16 is adapted to support therewithin a needle cartridge
18 in which is mounted a hypodermic needle 20. An invertible
locking safety cover 22 is adapted at one end 24 to be
frictionally retained on needle cartridge 18, covering needle 20,
prior to use of syringe 10, and at the other end 26 to be
positively locked to the huh 28 of mounting collar 14 prior to
installation of a needle cartridge 18

~ o~s3 X19_
~..to needle carrier 16, and after use of syringe 10 and retraction
of needle 20 into barrel 12, as more particularly described below.
An elongate plunger member 30 is telescoped into and carried
within the barrel 12. Plunger member 30 includes a body portion
comprising a plurality of longitudinally extending ribs 32, a thumb
rest 34 formed at its distal end, that is, the end farther from the
point of the needle, and an injection piston 36 attached at its
proximal end, disposed within barrel 12. The proximal face of
piston 36 includes a longitudinally extending stinger latch 38 at
or near its center.
Plunger 30 including piston 36 may be made of a relatively
hard material such as, for example, high density polypropylene or
other suitable synthetic material. The outer circumferential
periphery of piston 36 is substantially smooth and rounded to
provide sealing engagement against the interior wall of barrel 12.
Barrel 12 may be made of a relatively resilient material such as
polyethylene or polypropylene, for example. The same material used
for barrel 12 may also be employed for protective cover or sheath
22. All materials should be of a grade and quality suitable for
human medical applications.
Piston 36 is of slightly larger diameter than the inside
diameter of barrel 12 so that in service, the barrel is slightly
stretched by the piston 36 as the piston traverses the barrel in
sealing relationship therewith. Piston 36 is sized and shaped to
serve as a liquid or fluid displacement means within barrel 12 for
withdrawing a liquid or fluid substance from another container, for
example, and subsequently injecting the substance through needle 20

~ 14~~32'~
_ .:o a subject being treated. Of course, syringe 10 may be used
for withdrawing liquid or fluid substances from a subject for
subsequent testing, or for other purposes. In short, the
retractable syringe l0 of the present invention may be used in any
clinical setting, under any medical conditions.
Referring now to Figures 3-5, needle carrier 16 is mounted
within mounting collar 14 of barrel 12 from within the barrel, and
needle cartridge 18 is subsequently mounted to the proximal end of
needle carrier 16 from outside barrel 12. Needle carrier 16 has a
generally circular conical main body 40 with a slight taper from
its distal end 42 to its proximal end 44. A radially outwardly
extending circumferential flange 46 is disposed around body 40 at
its distal end 42. A plurality of radially outwardly extending
bayonet lugs 48 are disposed on the exterior side wall of body 40
between flange 46 and proximal end 44. Preferably, there are two
such.lugs 48 which are diametrically opposed from one another. A
latch recess 50 extends into body 40 of needle carrier 16 from its
distal end 42. Latch recess 50 is shaped correlatively to stinger
latch 38, as is more fully set out below.
A substantially annular blind bore 52, comprising a needle
cartridge receiving pocket, extends longitudinally part way,
preferably about half way, through main body 40 from its proximal
end 44. In the center of pocket 52 there is disposed a needle
cartridge support member 54, which may be integral, for example,
with main body 40. Needle cartridge support member 54 extends from
the distal end wall 56 of pocket 52 beyond the plane of the
proximal end face 44 of main body 40, such that a substantial

-21
1073 _
~ximal end portion of member 54 protrudes out of the main body
40. Needle cartridge support member 54 is substantially circular
conical in configuration, and tapers slightly from its distal end
at end wall 56 to its proximal end 60. Needle cartridge support
member 54 has a longitudinally extending central axial bore 62
therein, in fluid communication with latch recess 50. Pocket 52
has a pair of relatively steeply pitched, raised, that is, radially
inwardly projecting, axially spaced apart helical ribs 64 around
its outer wall, forming a pair of lands upon which a corresponding
pair of tabs disposed on the distal end of the needle cartridge 18
ride in removing or installing the needle cartridge, as is more
fully set out below. The ribs 64 begin, or intersect the proximal
end face of main body 40, on diametrically opposed sides thereof as
is best shown in Figure 7.
Mounting collar 14 includes a hub portion 28 extending from
the proximal end 70 thereof to a relatively thick-walled needle
carrier retaining portion 72 of barrel 12, forming an annular
shoulder 74 therebetween. The hub portion 28 and needle carrier
retaining portion 72 of barrel 12 have a substantially circular
conical bore 76 therethrough, shaped correlatively to the outer
profile of main body 40 of needle carrier 16. Between the upper or
distal end of bore 76 in needle carrier retaining portion 72 and
the interior wall 78 of barrel 12 against which piston 36 is
sealingly engaged, is disposed a circular counterbore 80. Flange
46 of needle carrier 16 is received in counterbore 80 when the
needle carrier 16 is locked in~place in mounting collar 14. Flange

076321
~1
is somewhat resilient, so that it will sealingly engage
counterbore 80 when carrier 16 is locked into place in collar 14.
Mounting collar 14 has a pair of diametrically opposed,
substantially longitudinally extending slots 82 in the wall of bore
76, extending in a proximal direction from the interface between
bore 76 and counterbore 80. Slots 82 intersect and communicate
with a pair of inclined recesses or threads 84 in the wall of bore
76 which extend part way, for example 90° or less, around the
inside wall of bore 76 and are inclined toward the proximal end 70
of hub portion 28. Threads 84 as shown are right-hand threads, but
left-hand threads could be used, as desired. Threads 84 each have
a friction rise or bump 86 on their proximal surfaces near their
blind ends. Slots 82 are adapted to receive bayonet lugs 48 on
needle carrier 16, and when the needle carrier is so inserted into
collar 14 and rotated in the proper direction, preferably 90° or
less, lugs 48 traverse the buttresses of threads 84 until they
bottom out at the blind ends of the threads. Due to the inclined
nature of threads 84, rotation of the needle carrier to the right
(for a right-hand thread 84) will tend to draw the needle carrier
16 more tightly into the mounting collar 14, and will tend to
energize the seal between flange 46 and counterbore 80.
Somewhat more force is required to pass lugs 48 over friction
rises or bumps 86 in either direction than is required simply to
rotate needle carrier 16 in collar 14 with the lugs traversing the
threads 84 between slots 82 and the friction rises or bumps.
Accordingly, when the lugs 48 are fully seated in the blind ends of
threads 84, bounded on one side by the blind end walls of the

-23- r
1 x7631
veads 84 and on thother side by the friction rises or bumps 86,
the lugs 48 will be relatively securely seated in the blind ends of
threads 84, and the needle carrier 16 will in turn be relatively
securely latched into the mounting collar 14. Bumps 86 thus act as
anti-rotation means between mounting~collar 14 and needle carrier
16. Bumps 86 may not be necessary, however, if sufficient
frictional forces exist between needle carrier 16 and mounting
collar 14 to prevent relative rotation between them during
installation and/or removal of a needle cartridge as discussed
further below.
Figure 4 illustrates the needle carrier 16 fully seated and
latched into collar 14. Such installation and latching occurs
within barrel 12 as the syringe 10 is being assembled prior to use.
Figure 4 shows the needle carrier 16 in the same position depicted
in Figure 3, but the mounting collar 14 has been rotated,
preferably, as stated above, 90° or less. As can be seen in Figure
4, needle carrier 16 has a transversely disposed hole 90 extending
through the side wall of main body 40 into pocket 52. Mounting
collar 14 has a transversely disposed hole 92 extending through the
side wall of hub portion 28. Holes 90, 92 are in register with one
another when the needle carrier 16 is fully latched into the
mounting collar 14. Hole 92 in collar 14 is substantially circular
cylindrical in configuration, but hole 90 in needle carrier 16 is
preferably somewhat elongated in a circumferential direction in
order to ensure alignment of holes 90, 92 in the event needle
carrier 16 is not fully seated~in collar 14. A retaining pin 94 is
disposed in holes 90, 92, and fractionally secured in hole 92, when

-24-
_._ _ _ _ _
. zdle carrier 16 is fully mounted'in collar 14 in order to prevent
relative rotation between members 14, 16 in service, e.a. , prior to
and during use of syringe 10 to withdraw and/or inject fluids or
liquid substances, and prior to desired retraction of needle 20
into barrel 12. Pin 94, when in place in holes 90, 92, thus serves
to prevent needle carrier 16 from being accidentally or prematurely
released or unlatched from collar 14 and retracted into barrel 12.
A tab 96 is provided on the end of pin 94 for an operator to grasp
for easy removal of pin 94 when it is desired to retract the needle
carrier 16, and hence the needle 20, into barrel 12 after use of
syringe 10. It should be understood that retaining pin 94, and
thus bores 90, 92, may not be necessary in the event that
sufficient frictional forces exist between needle carrier 16 and
mounting collar 14 to prevent relative rotation of such members
during installation and/or removal of a needle cartridge.
Mounting collar 14 further includes a circumferentially
extending groove 98 around the periphery of hub portion 28 and
adapted to receive 'a correlatively shaped ridge or land 100
disposed on locking safety cover 22, as more fully described
hereinafter.
Referring now particularly to Figures 2, 5, 6, and 8, the
needle cartridge 18 of the present invention is shown in more
detail. Needle cartridge 18 includes an elongate, generally
conical, hollow main body 102 which tapers slightly from its upper
or distal end 104 to its lower or proximal end 106. Main body 102
of needle cartridge 18 has a-tapered, longitudinally extending,
central axial bore 108 which has a taper substantially the same as

~107~531
t taper of the outside surface of needle cartridge support member
54, so as to form a close fit therewith when installed on syringe
10. Bore 108 is in fluid communication with bore 62 in needle
cartridge support member 54. Needle cartridge 18 also includes a
substantially circular cylindrical extension portion 110 extending
in a proximal direction from proximal end 106 of main body 102. A
plurality of substantially longitudinally extending stiffening ribs
112 are disposed on main body 102 and extension portion 110 along
their outer sides, there being preferably four (4) such ribs 112
disposed at substantially 90° to one another. Cylindrical
extension 110 of needle cartridge 18 has a central axial bore
therethrough, which is in fluid communication with bore 108 of main
body 102. A hypodermic needle 20 of selected size and shape is
mounted within the central axial bore in cylindrical extension 110.
Needle 20 has a longitudinally extending bore therethrough of
selected diameter, which bore is in fluid communication with bore
108 and, hence, bore 62 in needle cartridge support member 54.
The upper or distal end 104 of needle cartridge 18 includes a
pair of diametrically opposed, outwardly extending tabs or ears 114
(Figure 6). When the distal end 104 of needle cartridge 18 is
inserted longitudinally axially into needle carrier 16 from the
proximal end thereof and rotated to the right (for a right hand
thread 64; to the left for a left-hand thread), each of tabs 114
engages and travels along one of the helical threads 64, which
draws needle cartridge 18 onto needle cartridge support member 54
and forces the needle cartridge into secure, stable, sealed
relationship with the needle cartridge support member. The tight

~ ~ ~ S 36~
1
iLictional engagement of tabs 114 against the walls of pocket 52
provides additional lateral stability and support for needle
cartridge 18 when mounted in needle carrier 16. When needle
cartridge 18 is rotated or screwed into locked position in needle
carrier 16, anti-rotation pin 94 prevents needle carrier 16 from
rotating in mounting collar 14 and becoming unlatched therefrom.
In order to remove needle cartridge 18 from needle carrier 16, for
example, to replace it with a different shaped or sized needle, as
desired, the needle cartridge is rotated to the left (for a
right-hand thread 64; to the right for a left-hand thread) , and
tabs 114 travel along threads 64 until they are released therefrom
at or near proximal end 44 of main body 40. Again, anti-rotation
pin 94 prevents relative rotation between members 14, 16 when
removing needle cartridge 18 from needle carrier 16. It should be
understood, however, that depending upon whether threads 64, 84 are
right-hand, left-hand or one of each, either the removal of needle
cartridge 18 from needle carrier 16 or the installation of needle
cartridge 18 onto needle carrier 16, will tend to rotate the
members 14, 16 with respect to one another in a direction so as to
further engage lugs 48 into threads 84.
Referring now particularly to Figures 2, 5, and 8, stinger
latch 38 of piston 36 has a main body 39 of generally conical
configuration with a retaining lip 116 around its upper periphery.
Stinger latch 38 also includes a pair of rotational lugs 118
extending longitudinally axially from below lip 116 to the proximal
end or apex of main body 39. Rotational lugs 118 are disposed on
diametrically opposed sides of stinger latch 38. Stinger latch 38

-27 1
._ X10 7631
~5 adapted to stretch an inner shoulder 120 of the resilient flange
46 and to descend into recess 50 formed in the distal end of needle
carrier 16 when plunger 30 is advanced to the proximal end of its
stroke. Stinger latch 38 is thus stabbed into engagement with a
tapered latch seat 122 in recess 50. Recess 50 has correlatively
shaped grooves 124 extending longitudinally axially on opposite
sides of latch seat 122 for receiving rotational lugs 118. When
stinger latch 38 is pushed into the recess 50 of needle carrier 16
in substantially random angular orientation with respect thereto,
latch 38 may be rotated slightly one way or the other in order to
bring lugs 118 into engagement with grooves 124 of recess 50. When
lugs 118 have so engaged grooves 124, further rotation of plunger
member 30 will rotate piston 36, stinger latch 38, needle carrier
16, needle cartridge 18, and needle 20. Rotation of needle carrier
16 in mounting collar 14 will be prevented, however, if retaining
pin 94 remains in aligned bores 90, 92. Rotation of needle carrier
16 in mounting collar 14 will be further retarded by friction bumps
86 following removal of pin 94.
When retaining pin 94 is removed from bores 90, 92, further
rotation of the plunger member 30 and injection piston 36 in the
appropriate direction also rotates the needle carrier 16 and its
lugs 48 along the threads 84 until the lugs are in alignment with
slots 82, whereupon withdrawal of the piston 36 back into the
barrel 12 also withdraws the needle carrier 16, needle cartridge
18, and needle 20 as a unit back into the barrel 12, eliminating
the possibility of a needle stick injury.

~~ 107~3.~2$-
The upper or distal end of barrel 12 has an annular area or
land 130 of reduced inside diameter. An annular latching groove
132 is formed in land 130 near its proximal end, adjacent to an
annular latching rib 134 disposed proximally of latching groove
132. The latching groove 132 is of about the same inside diameter
as the barrel 12 below land 130. Like land 130, the annular
latching rib 134 has an inside diameter smaller than the inside
diameter of barrel 12 below land 130; the inside diameter of rib
134 may, for example, be about the same as land 130. When piston
36 is withdrawn into barrel 12 in order to retract needle 20 into
the barrel, and as the piston is pulled against the rib 134, the
rib will stretch and permit the rounded edge of the piston to pass
over it into seated position in latching groove 132. Since the
thickness of rib 134 is greater than that of the wall of barrel 12
below the rib, considerably greater force is required to stretch
the rib outwardly than is required to stretch the barrel wall.
Accordingly, somewhat greater force is required to pull the piston
36 over the rib 134 than is required to withdraw the piston through
the barrel. Once seated in latching groove 132, piston 36 is
substantially resistant to movement in either direction. Although
it is preferred to provide rib 134 and groove 132 to hold piston 36
in retracted position within barrel 12, the rib and groove may be
omitted, and the frictional force due to the stretch of land 130
around piston 36 relied upon instead to hold the piston in place.
Further, all of the rib, groove, and land may be omitted, because
with the breaking off of the plunger, infra, the friction of the

~ '~ 0 7 ~ 391
:rel against the piston may be sufficient to latch the needle in
retracted position in the barrel.
Plunger member 30 is provided with perforations 136 in ribs 32
at a location such as to be substantially flush with the distal end
of barrel 12 when piston 36 is seated in groove 132. Lateral force
may then be applied to the distal end of plunger 30 to break off
the plunger at the perforations 136, leaving the remainder of the
plunger disposed inside barrel 12 with its distal end substantially
flush with the distal end of the barrel 12. Figure 8 illustrates
the plunger being broken off in this manner.
The syringe 10 is delivered to the person who will use it
either in the assembled configuration shown in Figure 1, or in a
similar configuration but without a needle cartridge and needle
mounted thereon. If the syringe 10 is delivered in the assembled
configuration shown in Figure 1, the operator may proceed to use it
as is, or he or she may choose to remove the needle cartridge and
needle supplied with the particular syringe and replace it with
another needle cartridge and needle. Such a situation might arise,
for example, if the operator wishes to use a needle of a different
shape, such as longer or shorter, or of a different size, such as
with a larger or smaller diameter and/or bore. If the operator
wishes to replace the needle cartridge and needle, he or she grasps
the needle cartridge firmly around the main body 102 and ribs 112
and rotates it in the appropriate direction to unscrew the
cartridge 18 from the needle carrier pocket 52. Preferably, during
this removal and replacement procedure a locking safety cover 22
remains on the needle cartridge being removed and on the needle

~ lo~s3°~
.rtridge being installed in its place. Locking safety covers 22
at this stage of the procedure will have their smaller ends 24
frictionally retained around the proximal ends of main bodies 102
and ribs 112 of needle cartridges 18, with needles 20 being safely
received in tapered blind bores 138 of covers 22 (Figure 2). After
removing the supplied needle cartridge, the operator then installs
the desired needle cartridge by grasping it firmly, preferably with
its cover 22 in place, inserting its distal end into pocket 52 with
member 54 entering bore 108, and rotating it in the appropriate
direction to screw it securely into place as shown, for example, in
Figures 5 and 8, so that it is integral.
If the syringe 10 were to be supplied with no needle cartridge
18 installed thereon, the operator simply has to install a desired
needle cartridge as set out above so that it is integral. In order
to ensure that a syringe 10 supplied without a needle cartridge is
not contaminated prior to the time a needle cartridge is installed,
it is preferred that a locking safety cover 22 be installed on the
hub 28 of mounting collar 14, as shown, for example, in Figure 8,
when the syringe 10 is manufactured so as to protectively enclose
the barrel. For this purpose the larger end 26 of cover 22 is
provided with an axially extending blind bore 140 of a shape
correlative to that of hub 28 and a diameter slightly smaller than
the outside diameter of the hub, so that when the cover is forced
over the hub, the cover will stretch slightly and sealingly engage
the hub. Annular locking ridge or land 100 of cover 22 will engage
and seat in annular groove 98 around hub 28 in order to positively
retain cover 22 on hub 28. A fluid barrier 142 between blind bore

-31 ~ h
X10763
0 and tapering bore 138 of cover 22 prevents fluid communication
between the bores.
During the time that a needle cartridge is either removed or
installed, i.e., prior to use of the syringe, the retaining pin 94
remains in place in bores 90, 92 in order to prevent needle carrier
16 from rotating in mounting collar 14. When the desired needle
cartridge is fully installed and in place in needle carrier 16,
syringe 10 is ready for use. Piston 36 is free to be moved by
plunger 30 from below rib 134 to a position just short of latching
engagement between stinger latch 38 and needle carrier 16. The
operator may then remove cover 22 from needle cartridge 18 and
needle 20, and proceed to either draw a liquid or fluid substance
from a container through needle 20 into barrel 12 and inject it
into a subject, or insert the needle 20 into a subject with barrel
12 empty and withdraw blood or other fluids from the subject for
depositing into a container for testing or the like.
After the syringe 10 has been used, plunger member 30 is
pushed firmly in a proximal direction until latch 38 of piston 36
is forced into recess 50 in needle carrier 16, and the plunger is
rotated slightly one way or the other, if necessary, so that lugs
118 of latch 38 seat in grooves 124 of recess 50. Engagement of
latch 38 in recess 50 is shown, for example, in Figure 2. Pin 94
is then removed from needle carrier 16 and hub 28, and the plunger
30 is rotated in the appropriate direction to move lugs 48 along
threads 84 into register with slots 82. Since lugs 48 will
initially be relatively securely seated between friction rises 86
and the ends of threads 84 prior to rotation of needle carrier 16,

~ ~ a~s~ ~
__.newhat greater force will be necessary to rotate the lugs over
the friction rises than will be required to continue rotating the
lugs over the remainder of the threads 84 to slots 82.
The plunger head 34 is then pulled in a distal direction to
pull needle carrier 16, needle cartridge 18, and needle 20 into
barrel 12 until piston 36 travels over rib 134 and seats in groove
132. Whether or not groove 132 is used, the distal portion of the
plunger member 30 is broken off at perforations 136 and discarded,
leaving the broken end of the plunger substantially flush with the
end of the barrel and if groove 132 is used, the remainder of the
plunger securely latched within the barrel 12. The needle
cartridge 18 and needle 20 are thus securely retained and
immobilized in protective isolation within the barrel, as shown in
Figure 8. The protective cover 22 may then be installed on the hub
28 of collar 14 as shown in Figure 8 in order to prevent excess
fluids or residue remaining in the syringe 10 from leaking out of
the syringe. The used syringe may then be safely discarded without
further danger of a needle stick injury.
Referring now to Figures 9 and 10, another alternate
embodiment of the retractable syringe of the present invention is
shown generally at 210. Syringe 210 includes a barrel 212, which
may be non-resilient, the proximal end of which comprises a needle
carrier support or mounting collar 214. A needle carrier 216, more
particularly described below and better shown in Figures 11-13, is
mounted within mounting collar 214. Needle carrier 216 is adapted
to support therewithin a needle cartridge 218 in which is mounted
a hypodermic needle 220. An invertible locking safety cover 222 is

3
apted at one end 224 to be fractionally retained on needle
cartridge 218, covering needle 220, prior to use of syringe 210,
and at the other end 226 to be positively locked to the hub 228 of
mounting collar 214 prior to installation of a needle cartridge 218
into needle carrier 216, and after use of syringe 210 and
retraction of needle 220 into barrel 212, as more particularly
described below.
The needle cartridge 218, needle 220, protective cover 222,
and mounting collar 214 of syringe 210 are substantially identical
to the corresponding parts of the syringe 10, i.e, needle cartridge
18, needle 20, protective cover 22, and mounting collar 14, and
thus will not be described again in detail in connection with the
second embodiment.
An elongate plunger member 230 is telescoped into and carried
within the barrel 212. Plunger member 230 includes a body portion
comprising a plurality of longitudinally extending ribs 232, a
thumb rest 234 formed at its distal end, and an inwardly facing
latching flange 235 and plunger head (not shown) attached at its
proximal end, disposed within barrel 212. The plunger head may be
of any suitable shape, such as, for example, a pair of conical
frustums attached end to end at their smaller circular faces and
coaxially disposed with respect to the plunger body, and is
disposed within and retains thereon an injection piston 236. A
plunger latch 238 (Figures 10 and 14) is attached to the plunger
head at or near the center of its proximal end. Piston 236 is
preferably made of a soft resilient material such as soft rubber,
butyl, latex, or the like, and is of a shape and size to serve as

~ ~0~~31
liquid or fluid substance displacement piston sealed by its
elastomer type deformation within barrel 212 for the same purposes
as piston 36 described above.
Referring now to Figures 11-13, needle carrier 216 is mounted
within mounting collar 214 of barrel 212 from withiz~ the barrel,
and needle cartridge 218 is subsequently mounted to the proximal
end of needle carrier 216 from outside barrel 212. Except for the
manner and structure in and by which the needle carrier 216 is
engaged by the plunger latch 238 to release the needle carrier from
the mounting collar 214, needle carrier 216 is substantially the
same as needle carrier 16. For the sake of clarity and brevity,
the manner and structure in and by which the needle carrier 216 is
mounted in and released from collar 214, and the needle cartridge
218 is mounted in and released from needle carrier 216, will not be
described again in detail in connection with the second embodiment;
suffice it to say that these matters are substantially identical to
the manner and structure in and by which the needle carrier 16 is
mounted in and released from collar 14, and the needle cartridge 18
is mounted in and released from needle carrier 16.
A latch recess 250 extends into the body 240 of needle carrier
216 from its distal end 242. Latch recess 250 is a generally
rectangular cavity into which projects a pair of oppositely facing
plunger latch stops 252 formed in body 240 near the distal
extremity of cavity 250 and spaced apart so as to form rotational
stops at 180° from one another. An opening 254 in the distal end
of needle carrier 216, smaller~than cavity 250, communicates cavity
250 with the distal end surface of body 240 and forms a shoulder

-3 5- r
X10 76 31
'5 therebetween. A circular counterbore 280 of mounting collar
214 sealingly receives an annular resilient flange 246 of needle
carrier 216 when the needle carrier 216 is locked in place in
mounting collar 214.
Figure 12 illustrates the needle carrier 216 fully seated and
latched into collar 214. Such installation and latching occurs
within barrel 212 as the syringe 210 is being assembled prior to
use. Figure 12 shows the needle carrier 216 in the same position
depicted in Figure 11, but the mounting collar 214 has been
rotated, preferably 90° or less. As can be seen in Figure 12, a
retaining pin 294 is disposed in aligned holes 290, 292 in needle
carrier 216 and collar 214, respectively, and is frictionally
secured in hole 292, when needle carrier 216 is fully mounted in
collar 214 in order to prevent relative rotation between members
214, 216 in service, ela., prior to and during use of syringe 210
to withdraw and/or inject fluids or liquid substances, and prior to
desired retraction of needle 220 into barrel 212. Pin 294 is
substantially identical to pin 94, and when in place in holes 290,
292, thus serves to prevent needle carrier 216 from being
accidentally or prematurely released or unlatched from collar 214
and retracted into barrel 212. A tab 296 is provided on the end of
pin 294 for an operator to grasp for easy removal of pin 294 when
it is desired to retract the needle carrier 216, and hence the
needle 220, into barrel 212 after use of syringe 210. As in the
case of the first embodiment described above, pin 294 may not be
necessary if sufficient antirotational forces exist between needle
carrier 216 and mounting collar 214 when assembled.

13~ 76 31~
Mounting collar 214 further includes a circumferentially
extending groove 298 around the periphery of hub portion 228 of
collar 214 and a~apted to receive a correlatively shaped ridge or
land 299 disposed on locking safety cover 222, as more fully
described hereinafter.
The proximal end of piston 236 may be formed as a thin
diaphragm 240 (Figure 9) which covers the plunger latch 238 in
sealed relation during the time the piston is used to draw liquids
or fluid substances into barrel 212 or to force such liquids or
f luid substances out of barrel 212 , as discussed above with respect
to the first embodiment of the present invention. Alternatively,
the piston 236 may be made with the neck of the plunger latch 238
protruding from the proximal end of the piston at all times. If
the diaphragm 240 is present, the plunger latch 238 is pushed to
stretch and distend the diaphragm into recess 250 formed in needle
carrier 216, and the plunger member 230 is rotated to rotate the
plunger latch 238 into engagement with plunger latch stops 252.
Diaphragm 240 may be ruptured at times. If diaphragm 240 is not
present, plunger latch 238 is simply pushed into recess 250 and
rotated into engagement with plunger latch stops 252. Further
rotation of the plunger head and latch 238 also rotates the needle
carrier 216 and its lugs 248 along the threads 256 until the lugs
are in alignment with slots 258, whereupon withdrawal of the
plunger head back into the barrel 212 also withdraws the needle
carrier 216 and needle cartridge 218 along with needle 220 as a
unit back into the barrel, eliminating the possibility of a needle
stick injury. As the plunger 230 is pulled away from the distal

~ 0~631~
1
:nd of the barrel 212, the plunger head and the piston 236 are also
pulled along as a connected unit.
Latch flange 235 comprises a body of generally hollow circular
cylindrical side wall configuration with a radially inwardly
extending, downwardly and inwardly tapering, annular frustoconical
latch flange 260 disposed around its upper inner periphery. The
upper end of barrel 212 is provided with recessed pockets 262 which
accommodate at least two latch hooks 264 carried on latch arms 266
(Figure 10) . Piston 236 is inserted into the barrel 212 as the
syringe 210 is assembled. Latch arms 266 carry the latch hooks 264
out into a position where the latch flange 260 will flex the arms
266 inwardly in moving in a distal direction past hooks 264, then
will engage the hooks 264 to prevent movement of the piston 236 in
a proximal direction back toward support collar 214. Thus, when
piston 236 is retracted, and when the plunger head has carried the
needle carrier 216, needle cartridge 218, and needle 220 back into
the protected position within barrel 212, the hooks 264 are latched
onto the flange 260. Thereafter, the needle carrier 216 and
plunger head are prevented from return movement. The plunger may
also be broken off, with or without use of the hooks 264 system,
for use as in the first embodiment to fix the needle location.
The syringe 210 is delivered to the person who will use it
either in the assembled configuration shown in Figure 9, or in a
similar configuration but without a needle cartridge and needle
mounted thereon. If the syringe 210 is delivered in the assembled
configuration shown in Figure ~9, the operator may proceed to use it
as is, or he or she may choose to remove the needle cartridge and

~ 107~~~
needle supplied with the particular syringe and replace it with
another needle cartridge and needle, for reasons set out above in
connection with the description of the first embodiment, for
example. If the operator wishes to replace the needle cartridge
and needle, he or she follows the same procedure set out above in
connection with the first embodiment. It should be noted again
that preferably, during this removal and replacement procedure a
locking safety cover 222 remains on the needle cartridge being
removed and on the needle cartridge being installed in its place.
If the syringe 210 were to be supplied with no needle
cartridge 218 installed thereon, the operator simply has to install
a desired needle cartridge as set out above. In order to ensure
that a syringe 210 supplied without a needle cartridge is not
contaminated prior to the time a needle cartridge is installed, it
is preferred that a locking safety cover 222 be installed on the
hub 228 of mounting collar 214, as shown, for example, in Figure
14, when the syringe 210 is manufactured so as to protectively
enclose the barrel. Annular locking ridge or land 299 of cover 222
will engage and seat in annular groove 298 around hub 228 in order
to positively retain cover 222 on hub 228.
During the time that a needle cartridge is either removed or
installed, i.e., prior to use of the syringe, the retaining pin
294, if employed, remains in place in bores 290, 292 in order to
prevent needle carrier 216 from rotating in mounting collar 214.
As stated above, friction bumps 270, like bumps 86, also serve as
anti-rotation means between collar 214 and needle carrier 216.
When the desired needle cartridge is fully installed and in place

~ ~ 0763
in needle carrier 216, syringe 210 is ready for use. Piston 236 is
free to be moved by plunger 230 from below pockets 262 to a
position before the diaphragm 240, if present, is stretched or
punctured (although this is not desirable without further sealing),
or otherwise before latch 238 is engaged into recess 250. The
operator may then remove cover 222 from needle cartridge 218 and
needle 220, and proceed to either draw a liquid or fluid substance
from a container through needle 220 into barrel 212 and inject it
into a subject, or insert the needle 220 into a subject with barrel
212 empty and withdraw blood or other fluids from the subject for
depositing into a container for testing or the like.
After the syringe 210 has been used, plunger member 230 is
pushed firmly in a proximal direction into engagement with needle
carrier 216 sufficiently to stretch or rupture the diaphragm 240,
if present, and force the latch 238 of piston 236 into recess 250
in needle carrier 216 (Figure 10). Plunger 230 is then rotated in
the appropriate direction until latch 238 engages latch stops 252,
whereupon further rotation of the plunger head and latch against
stops 252 will also rotate needle carrier 216 when retainer pin 294
is removed from bores 290, 292. Engagement of latch 238 in recess
250 is shown, for example, in Figure 10. Pin 294 is then removed
from needle carrier 216 and hub 228, and the plunger 230 is rotated
further in the appropriate direction to move lugs 248 along threads
256 into register with slots 258. Since lugs 248 will initially be
relatively securely.seated between friction rises 270 and the ends
of threads 256 prior to rotation of needle carrier 216, somewhat
greater force will be necessary to rotate the lugs 248 over the

40
X10763
Friction rises than will be required to continue rotating the lugs
248 over the remainder of the threads 256 to slots 258.
The plunger head 234 is then pulled in a distal direction to
pull needle carrier 216, needle cartridge 218, and needle 220 into
barrel 212 until latch flange 260 has become latched to hooks 264
(Figure 14). Plunger member 230 may also be provided with
perforations in ribs 232 so that the distal portion of the plunger
member may be broken off at the perforations and discarded, leaving
the broken end of the plunger substantially flush with the end of
the barrel and the remainder of the plunger securely latched within
the barrel 212. The needle cartridge 218 and needle 220 are thus
securely retained and immobilized in protective isolation within
the barrel, as shown in Figure 14. The protective cover 222 may
then be installed on the hub 228 of collar 214 as shown in Figure
14 in order to prevent excess fluids or residue remaining in the
syringe 210 from leaking out of the syringe. The used syringe may
then be safely discarded without further danger of a needle stick
injury.
Referring initially to Figure 15, the preferred embodiment of
the retractable syringe of the present invention is shown generally
at 400. Syringe 400 includes a barrel 212, the proximal end of
which comprises a needle carrier support or mounting collar 214.
The distal end of barrel 212 includes a set of finger stops 413
having equally spaced grooves 415 formed therein to prevent finger
skid.
A needle carrier 216, more particularly described below and
better shown in Figures 29-34, when assembled as in the other

4~1076~31
e.abodiments is mounted within needle carrier support or mounting
collar 214. Needle carrier 216 is adapted to support therewithin
a needle cartridge 218 in which is mounted a hypodermic needle 220.
An invertible locking safety cover 423, or alternatively 418, 420,
or 422, is adapted at one end 224 (Figures 35, 38, 39) to have a
mechanism in the preferred embodiment 423 to be frictionally
retained on the hub 428 of mounting collar 214 prior to
installation of a needle cartridge 18 into needle carrier 216, or
alternatively for covers 418, 210, 422 to be frictionally retained
on needle cartridge 218, covering needle 20, prior to use of
syringe 400, and at the other end 226 to be positively locked to
the hub 428 of mounting collar 214 after use of syringe 400 and
retraction of needle 220 into barrel 212, as more particularly
described below (Figure 43).
An elongate plunger member 230 is telescoped into and carried
within the barrel 212 when assembled. Plunger member 230 includes
a body portion comprising a plurality of longitudinally extending
ribs 232 (Figure 24) and a thumb rest 234 (Figure 22) formed at its
distal end. Thumb rest 234 includes grooves 427 to inhibit thumb
slippage on thumb rest 234.
A retraction mechanism 421 (Figure 25) is attached near the
proximal end of plunger member 230, disposed within barrel 212 when
assembled. The proximal face of retraction mechanism 421 includes
a longitudinally extending retractor or stinger latch 238 at or
near its center.
For retraction mechanism~421, stinger latch 238 is mounted on
a mounting post 430 which extends from retractor pedestal 432.

X07631
- 42 - 70677-14
Retractor pedestal 432 is supported by mounting rim 434 seated on
mounting base 436. Mounting base 436 terminates at flange 438.
At the distal end of flange 438 there is located a sheer intent
440.
Attached to the proximal end of retractor mechanism
421 there is mounted an injection piston 236~(as shown in
Figures 27 and 28 or in Figures 49A and 49B), which is also
disposed within barrel 212 when assembled. Injection piston 236
includes an entry port 442. Proximal to entry port 442 is an
expandable, distortable (Figure 43), mounting collar 444 that
distorts so that port 442 abuts to the retractor pedestal 432
with the entry port 442 contacting the retractor pedestal 432
when assembled after the stinger latch 238 has passed through
entry port 442 to disengage needle carrier 216 from mounting
collar 214 as discussed below (Figure 43). At the proximal end
of mounting collar 444 is located the leading edge or proximal
end 446 of injection piston 236 which includes an outer thick
membrane portion 448 and an interior thin membrane portiorn 450,
forming an interior detent 452 because of the differences in
thickness. Detent 452 is sized to receive stinger latch 238
therein. Injection piston 236 is typically made of the same
;.
materials as set out above, having a rubber durometer of forty.
Thus, membrane 450 is expandable as impinged upon by stinger
latch 238 and should not rupture under the action described
below. Thus, injection piston 236 maintains a liquid seal
between the plunger 230 and the interior wall of barrAl 212
during all stages of motion of the plunger 230 within the barrel
212.

~~ n 76 31
_. - 42a -
70677-14
Plunger 230 and barrel 212 may be made of a relatively
hard material such as, for example, high density polypropylene
or other

0631 ~
'~
suitable synthetic material. Barrel 212~may also be made of a
relatively resilient material such as polyethylene or
polypropylene, for example. The same material used for barrel 212
may also be employed for protective cover or sheath 418, 420, 422.
All materials should be of a grade and quality suitable for human
medical applications.
Piston 236 is usually of slightly larger diameter than the
inside diameter of barrel 212 so that in service, the barrel
telescopically receives the piston 236 as the piston traverses the
barrel with the piston 236 deforming to stay in sealing
relationship therewith. Piston 236 is sized and shaped to serve as
a liquid or fluid displacement means within barrel 212 for
withdrawing a liquid or fluid substance from another container, for
example, and subsequently injecting the substance through needle
220 into a subject being treated. Of course, syringe 400 may be
used for withdrawing liquid or fluid substances from a subject for
subsequent testing, or for other purposes. In short, the
retractable syringe 400 of the present invention may be used in any
clinical setting, under any medical conditions.
Referring now to Figures 29-34, 42 and 43, needle carrier 216
is mounted within mounting collar 214 of barrel 212 from within the
barrel, and needle cartridge 218 is subsequently mounted to the
proximal end of needle carrier 216 from outside barrel 212. Needle
carrier 216 has a generally circular conical main body 240 with a
slight taper from its distal end 242 to its proximal end 244 to be
contained in mounting collar-214 which is similarly tapered. A
radially outwardly extending circumferential flange 246 is disposed

~~'o~s3 ~
pound body 240 at its distal end 242. The distal surface 450 of
flange 246 is slanted toward its center to facilitate insertion of
the piston 236 therein and to continue the fluid path past surface
452 to channel 454. A plurality of radially outwardly extending
bayonet lugs 248 are disposed on the exterior side wall of body 240
between flange 246 and proximal end 244. Preferably, there are two
such lugs 248 which are diametrically opposed from one another. A
latch recess 250 extends into body 240 of needle carrier 216 from
its distal end 242. Latch recess 250 is shaped correlatively to
stinger latch 238, as is more fully set out below.
A substantially annular blind bore or pocket 451, comprising
a needle cartridge receiving pocket, extends longitudinally part
way, preferably about half way, through main body 240 from its
proximal end 244. In the center of pocket 451 there is disposed a
needle cartridge support member 54, which may be integral, for
example, with main body 240. Needle cartridge support member 54
extends from the distal end wall 456 of pocket 451 beyond the plane
of the proximal end face 244 of main body 240, such that a
substantial proximal end portion of member 54 protrudes out of the
main body 240. As discussed above, needle cartridge support member
54 is substantially circular conical in configuration, and tapers
slightly from its distal end at end wall 456 to its proximal end
60. This provides a pressure friction fit to receive the interior
of needle cartridge 218. Needle cartridge support member 54 has a
longitudinally extending central axial bore 62 therein, in fluid
communication with latch recess 250 by channel 454.

-45-
s
Pocket 451 has a pair of relatively steeply pitched, raised,
that is, radially inwardly projecting, axially spaced apart ribs
464 around its outer wall, forming a pair of lands upon which a
corresponding pair of tabs disposed on the distal end of the needle
cartridge 218 ride in removing or installing the needle cartridge,
as is more fully set out below. The ribs 464 begin, or intersect,
the proximal end face of main body 240, on diametrically opposed
sides thereof as is best shown in Figure 31. These ribs form what
is commonly referred to as a lure lock thread.
Mounting collar 214 includes a hub portion 428 extending from
the proximal end 470 thereof to a relatively thick-walled needle
carrier retaining portion 472 of barrel 212, forming an annular
shoulder 474 therebetween. The hub portion 428 and needle carrier
retaining portion 472 of barrel 212 have a substantially circular
conical bore 476 therethrough, shaped correlatively to the outer
profile of main body 240 of needle carrier 216. Between the upper
or distal end of bore 276 in needle carrier retaining portion 472
and the interior wall 478 of barrel 212 against which piston 236 is
sealingly engaged, is disposed a circular counterbore 480. Flange
246 of needle carrier 216 is received in counterbore 480 when the
needle carrier 216 is locked in place in mounting collar 214.
Flange 246 is somewhat resilient, so that it will sealingly engage
counterbore 480 when carrier 216 is locked into place in collar
214.
Mounting collar 214 has a pair of diametrically opposed,
substantially longitudinally~extending slots 482 in the wall of
bore 476, extending in a proximal direction from the interface

~4'~~1763~
Between bore 476 and counterbore 480. Slots 482 intersect and
communicate with a pair of inclined recesses or threads 484 in the
wall of bore 476 which extend part way, for example 90° or less,
around the inside wall of bore 476 and are inclined toward the
proximal end 470 of hub portion 428. Threads 484 as shown are
right-hand threads, but left-hand threads could be used, as
desired. Threads 484, unlike the embodiment of Figure 11 even
though the mounting collar 214 is the same numbered item in both,
does not have a friction rise or bump on their proximal surfaces
near their blind ends. Slots 482 are adapted to receive bayonet
lugs 248 on needle carrier 216, and when the needle carrier is so
inserted into collar 214 and rotated in the proper direction,
preferably 90° or less, lugs 248 traverse the buttresses of threads
484 until they bottom out at the blind ends of the threads. Due to
the inclined nature of threads 484, rotation of the needle carrier
to the right (for a right-hand thread 484) will tend to draw the
needle carrier 216 more tightly into the mounting collar 214, and
will tend to energize the seal between flange 246 and counterbore
480.
Unlike the embodiment of Figure 11, no additional force is
required to pass the lugs 248 along threads 484 for there are no
friction rises or bumps in either direction. Accordingly, when the
lugs 248 are fully seated in the blind ends of threads 484, they
are bounded only on one side by the blind end walls of the threads
484, but the lugs 248 will still be relatively securely seated in
the blind ends of threads 484, and the needle carrier 216 will in
turn be relatively securely latched into the mounting collar 214.

-4~-10631
Imps are not necessary, however, because sufficient frictional
forces exist between needle carrier 216 and mounting collar 214 to
prevent relative rotation between them during installation and/or
removal of a needle cartridge as discussed further below.
Figure 42 illustrates the needle carrier 216 fully seated and
latched into collar 214. Such installation and latching occurs
within barrel 212 as the syringe 400 is being assembled prior to
use. Figure 42 shows the needle carrier 216 in the same position
depicted in Figure 3, but the mounting collar 214 has been rotated,
preferably, as stated above, 90° or less. It should be understood
that a retaining pin, and corresponding bores, may not be necessary
because sufficient frictional forces exist between needle carrier
216 and mounting collar 214 to prevent relative rotation of such
members during installation and/or removal of a needle cartridge.
Mounting collar 214 further includes a circumferentially
extending extension groove 498 around the periphery of hub portion
428 (unlike groove 298 in the other like numbered collar 214 of
Figure 11) and adapted to receive a correlatively shaped ridge or
land 500 disposed on locking safety cover 423, or alternatively
418, 420, 422, as more fully described hereinafter.
Referring now particularly to Figures 10, 42 and 43, the
needle cartridge 218 of the present invention is shown in more
detail. Needle cartridge 218 includes an elongate, generally
conical, hollow main body 502 which tapers slightly from its upper
or distal end 504 to its lower or proximal end 506. Main body 502
of needle cartridge 218 has ~a tapered, longitudinally extending,
central axial bore 508 which has a taper substantially the same as

~~87s31c
she taper of the outside surface of needle cartridge support member
54, so as to form a close fit therewith when installed on syringe
400. Bore 508 is in fluid communication with bore 454 in needle
cartridge support member 54. Needle cartridge 218 may also include
a substantially circular cylindrical extension portion extending in
a proximal direction from proximal end 506 of main body 502 as in
the other embodiments. A plurality of substantially longitudinally
extending stiffening ribs may be disposed on main body 502 and the
extension portion along their outer sides. If this is so, there
would be preferably four (4) such ribs disposed at substantially
90° to one another. If there is a cylindrical extension of needle
cartridge 218 it would have a central axial bore therethrough,
which is in fluid communication with bore 508 of main body 502. A
hypodermic needle 220 of selected size and shape is mounted within
the central axial bore and if there is a cylindrical extension, in
the cylindrical extension. Needle 220 has a longitudinally
extending bore therethrough of selected diameter, which bore is in
fluid communication with bore 508 and, hence, bore 454 in needle
cartridge support member 54.
The upper or distal end 504 of needle cartridge 218 includes
a pair of diametrically opposed, outwardly extending tabs or ears
514 (Figure 42). When the distal end 504 of needle cartridge 218
is inserted longitudinally axially into needle carrier 216 from the
proximal end thereof and rotated to the right (for a right-hand
thread 464 to the left for a left-hand thread), each of tabs 514
engages and travels along one of the helical threads 464, which
draws needle cartridge 218 onto needle cartridge support member 54

d forces the needle cartridge into secure, stable, sealed
relationship with the needle cartridge support member. The tight
frictional engagement of tabs 514 against the walls of pocket 52
provides additional lateral stability and support for needle
cartridge 218 when mounted in needle carrier 216. In order to
remove needle cartridge 218 from needle carrier 216, for example,
to replace it with a different shaped or sized needle, as desired,
the needle cartridge is rotated to the left (for a right-hand
thread 464; to the right for a left-hand thread), and tabs 514
travel along threads 464 until they are released therefrom at or
near proximal end 244 of main body 240. It should be understood,
however, that depending upon whether threads 464, 484 are right-
hand, left-hand or one of each, either the removal of needle
cartridge 218 onto needle carrier 216, will tend to rotate the
members 214, 216 with respect to one another in a direction so as
to further engage lugs 248 into threads 484.
Referring now particularly to Figures 23, 25 and 26, stinger
latch 238 of plunger 230 has a main body 239 of generally conical
configuration with a retaining lip 516 around its upper periphery.
Stinger latch 238 also includes a pair of rotational lugs 518
extending longitudinally axially from below lip 516 to the proximal
end or apex of main body 239. Rotational lugs 518 are disposed on
diametrically opposed sides of stinger latch 238. Stinger latch
238 is adapted to stretch an inner shoulder 442 of the resilient
flange or piston 236 and to descend into recess 250 formed in the
distal end of needle carrier -216 when plunger 230 is advanced to
the proximal end of its stroke. Stinger latch 238 is thus stabbed

-S~~o~sc~ ~
_.nto engagement with a tapered latch seat 452 in recess 250.
Recess 250 has correlatively shaped grooves 453 extending
longitudinally axially on opposite sides of latch seat 452 for
receiving rotational lugs 518. When stinger latch 238 is pushed
into the recess 250 of needle carrier 216 in substantially random
angular orientation with respect thereto, latch 238 may be rotated
slightly one way or the other in order to bring lugs 518 into
engagement with latch seat 452 and thus grooves 453 of recess 250.
When lugs 518 have so engaged grooves 453, further rotation of
plunger member 230 will rotate piston 436, stinger latch 238,
needle carrier 216, needle cartridge 218, and needle 220.
Rotation of the plunger member 230 and injection piston 436 in
the appropriate direction which rotates the needle carrier 216 and
its lugs 248 along the threads 484 until the lugs are in alignment
with slots 482, whereupon withdrawal of the plunger 230 back into
the barrel 212 also withdraws the needle carrier 216, needle
cartridge 218, and needle 220 as a unit back into the barrel 212,
eliminating the possibility of a needle stick injury.
The upper or distal end of barrel 212 has an annular area or
land 530 of reduced inside diameter and with sloping distal end 531
and vertical proximal end 533. An annular latching groove 532 is
formed at the proximal end of land 530, adjacent to an annular
latching rib 534 disposed proximally of latching groove 532. The
latching groove 532 is of about the same inside diameter as the
inner diameter of barrel 212 below land 530. Like land 530, the
annular latching rib 534 has an inside diameter smaller than the
inside diameter of barrel 212 below land 530; the inside diameter

-51-
~~ o ~s ~ ~
rib 534 may, for example, be smaller than land 530. When
plunger 230 is withdrawn into barrel 212 in order to retract needle
220 into the barrel, and as the piston 236 is pulled against the
rib 534, the rib wall is slanted to permit the rounded edge of the
piston 236 to pass over it into seated position in latching groove
532. Since the thickness of rib 534 is greater than that of the
wall of barrel 212 below the rib, considerably greater force is
required to force the rib outwardly. Accordingly, somewhat greater
force is required to pull the piston 236 over the rib 534 than is
required to withdraw the plunger 230 through the barrel. Once
seated in latching groove 532, piston 236 is substantially
resistant to movement in either direction. Although it is
preferred to provide rib 534 and groove 532 to hold piston 236 in
retracted position within barrel 212, the rib and groove may be
omitted, and the frictional force to overcome the surface 533 may
be relied upon instead to hold the piston in place. Further, all
of the rib, groove, and land may be omitted, because with the
breaking off of the plunger 230, infra, the friction of the barrel
against the piston 236 may be sufficient to latch the needle in
retracted position in the barrel.
Plunger member 230 is provided with shear indent 440 in ribs
232 at a location such as to be substantially flush with the distal
end of barrel 212 when piston 236 is seated in groove 532. Lateral
force may then be applied to the distal end of plunger 230 to break
off the plunger at the shear indent 440, leaving the remainder of
the plunger disposed inside barrel 212 with its distal end
substantially flush with the distal end of the barrel 212.

-52-
~7~3~1
The syringe 400 is delivered to the person who will use it
either in the assembled configuration shown in Figure 42, or in a
similar to the configuration shown in Figure 42. The operator may
proceed to use it as is, or he or she may choose to remove the
needle cartridge and needle supplied with the particular syringe
and replace it with another needle cartridge and needle. Such a
situation might arise, for example, if the operator wishes to use
a needle of a different shape, such as longer or shorter, or of a
different size, such as with a larger or smaller diameter and/or
bore. If the operator wishes to replace the needle cartridge and
needle, he or she grasps the needle cartridge firmly around the
main body 502 and rotates it in the appropriate direction to
unscrew the cartridge 218 from the needle carrier pocket 451.
Preferably, during this removal and replacement procedure a locking
safety cover such as alternative embodiments 419, 420, 422 or the
carrier supplied with the needle cartridges 218 remains on the
needle cartridge being removed and on the needle cartridge being
installed in its place. Locking safety covers at this stage of the
procedure will have their longer ends 224 frictionally retained
around the proximal ends of main bodies 502 of needle cartridges
218, with needles 220 being safely received in tapered blind bores
538 of the covers (Figures 35, 38, 39). After removing the
supplied needle cartridge, the operator then installs the desired
needle cartridge by grasping it firmly, preferably with its cover
in place, inserting its distal end into pocket 451, and rotating it
in the appropriate direction ~to screw it securely into place as
shown, for example, in Figure 42, so that it is integral.

r -~ ~ o ~ s ~~
Should the operator wish to prefill the barrel with a dosage
and thus no needle cartridge is initially provided, an alternate
cap 600 may be used (Fig. 44). Such a cap has flanges 610
corresponding to the lure lock thread formed by ribs 464. An
internal cylindrical body 615 extends from end 620 and is
dimensionsed to extend such that as the flanges 610 move into the
lure lock thread of ribs 464, the end 625 of body 615 sealingly
abuts the end 60 of member 54.
If the syringe 400 were to be supplied with no needle
cartridge 218 installed thereon, as is preferable, the operator
simply has to install a desired needle cartridge as set out above
so that it is integral. In order to ensure that a syringe 400
supplied without a needle cartridge is not contaminated prior to
the time a needle cartridge is installed, it is preferred that a
locking safety cover 423 be installed on the hub 428 of the
mounting collar 214, as shown, for example, in Figure 40, when the
syringe 400 is manufactured so as to protectively enclose the
barrel. For this purpose the larger end 226 of cover 423 is
provided with an axially extending blind bore 540 of a shape
correlative to that of hub 428 and a diameter slightly smaller than
the outside diameter of the hub, so that when the cover is forced
over the hub, the cover will stretch slightly and sealingly engage
the hub. As shown in the alternate embodiments of Figures 35, 38
and 39, annular locking ridge or land 500 of cover 418, 420, 422
will engage and seat in annular groove formed on the distal side of
protrusion 498 around hub 428.in order to positively retain cover
418, 420, 422 on hub 428. Otherwise friction as in the preferred

~ 5'~ 076 1
.~bodiment of Figure 40 will hold the cover 423 on hub 428. A
fluid barrier 542 between blind bore 540 and bore 538 of any of the
covers prevents fluid communication between the bores.
When the desired needle cartridge is fully installed and in
place in needle carrier 216, syringe 400 is ready for use. Piston
436 is free to be moved by plunger 230 from below rib 534 to a
position just short of latching engagement between stinger latch
238 and needle carrier 216. The operator may then remove the
needle cover from needle cartridge 218 and needle 220, and proceed
to either draw a liquid or fluid substance from a container through
needle 220 into barrel 212 and inject it into a subject, or insert
the needle 220 into a subject with barrel 212 empty and withdraw
blood 'or other fluids from the subject for depositing into a
container for testing or the like. As discussed above, if the
barrel 212 is prefilled, when the needle carrier 216 is attached,
syringe 400 is ready for use.
After the syringe 400 has been used, plunger member 230 is
pushed firmly in a proximal direction until stinger 238 is forced
into recess 450 in needle carrier 216, and the plunger is rotated
slightly one way or the other, if necessary, so that lugs 518 of
stinger 238 seat in grooves 524 of recess 450. Engagement of
stinger 238 in recess 450 is shown, for example, in Figure 43. The
plunger 30 is then rotated in the appropriate direction to move
lugs 248 along threads 484 into register with slots 482.
The plunger head 434 is then pulled in a distal direction to
pull needle carrier 216, needle cartridge 218, and needle 220 into
barrel 212 until piston 236 travels over rib 534 and seats in

~ 5~ ~?s3~
groove 532. When or not groove 532 is used, the distal portion of
the plunger member 230 is broken off at shear indent 440 and
discarded, leaving the broken end of the plunger substantially
flush with the end of the barrel and if groove 532 is used, the
remainder of the plunger securely latched within the barrel 212.
The needle cartridge 218 and needle 220 are thus securely retained
and immobilized in protective isolation within the barrel, as shown
in Figure 43. The protective cover 423 may then be installed on
the hub 428 of collar 214 in order to prevent excess fluids or
residue remaining in the syringe 400 from leaking out of the
syringe. The used syringe may then be safely discarded without
further danger of a needle stick injury.
As best seen in Fig. 45, threads 484 do not require slots 482.
Friction bump 270 is supplied in thread 484. In addition, a
lip 650 is located at the proximal end of mounting collar 214.
This will further restrain the proximal end of needle holder 216 as
lugs 248 are inserted in threads 484.
As seen in Fig. 46, another embodiment of the cap 656 is
shown. This cap is similar to the cap of Fig. 40, except it does
not have the end 224.
As shown in Fig. 47, needle holder 660 is substantially
identical to the needle holder 216, except for certain lugs as
discussed below. Instead of lugs 248 as shown in Fig. 31, needle
holder 660 is supplied with incline threads 665 and with
extensions 670 on the same portion of needle holder 660 as
threads 665. Extensions 670 have shoulders 675. Corresponding to
needle holder 660, a modified mounting collar 214 as shown in

~~0363~
g. 48. Mounting collar 214 is shown in Fig. 48. Mounting
collar 214 as shown in Fig. 48 includes slots 700 on opposite sides
of mounting collar 214, and bottom threads 710 disposed at a 90°
angle laterally around mounting collar 214. In addition,
shoulder 720 is provided in the interior of barrel 212 spaced apart
approximately the distance that should 675 is spaced apart from
threads 665. Thus, as threads 665 are inserted into slots 700 and
needle holder 660 is rotated, threads 665 ride up threads 710 in
frictional engagement until shoulders 675 engaged shoulder 720.
Lip 650 supplies additional containment, thereby making a secure
engagement of the threads 665, 710.
As shown in Fig. 49, a modified piston or seal 236 has an
elongated indent 800, as well as section 450 being more elongated,
eliminated section 448. This permits rotation of section 450
opposite to that of the piston 236 shown in Fig. 28, which only has
an internal indentation 444.
While preferred and alternative embodiments of the invention
have been shown and described, many modifications thereof may be
made by those skilled in the art without departing from the spirit
of the invention. Therefore, the scope of the invention should be
determined in accordance with the following claims.

Dessin représentatif