Safety syringe abstract
A safety syringe having a cylindrical hollow barrel member of semi-elastic
material has a seal and stop device at the distal open end and a
first restraining stop device axially spaced a preselected distance
from the distal open end. A cylindrically shaped needle carrier
is initially positioned within the barrel member between the stop
device, the needle carrier having a centrally located recess device
at the proximal end thereof for receiving and holding a male piston
extension device. A piston rod having a piston is provided for drawing
fluid into the barrel and forcing fluid out of the barrel through
a longitudinal bore in the needle carrier and through an elongated
hollow needle attached to the needle carrier. The piston has a male
extension at the distal end for engagement with the female recess
of the needle carrier. The piston coacts with the first restraining
stop device so as to stretch the barrel to disengage the stop means
from the needle carrier and to permit subsequent longitudinal movement
of the assembled and locked piston and needle carrier in the proximal
direction relative to the barrel so as to withdraw the hollow needle
means totally within the barrel to prevent accidental contact of
the needle with an errant body part.
Safety syringe claims
The embodiments of an invention in which an exclusive property
or right is claimed are defined as follows:
1. A safety syringe comprising:
(a) a cylindrical hollow barrel member of semi-elastic material
adapted to contain a fluid, having a preselected normal unstretched
inner cylindrical surface defined by an inner diameter and distal
and proximal open ends, and said barrel member further comprising:
(i) a first restraining stop means projecting radially inwardly
a preselected distance from said inner cylindrical surface and axially
spaced a preselected distance from said distal open end;
(ii) a seal and stop means at said distal open end projecting radially
inwardly a preselected distance from said inner cylindrical surface;
(iii) first anti-rotation means positioned between said first restraining
stop means and said seal and stop means, and
(iv) flange means extending radially outward at said proximal open
end;
(b) a cylindrical shaped needle carrier having distal and proximal
ends and being positioned initially within said barrel member between
said first restraining stop means and said seal and stop means,
said needle carrier being further characterized by having:
(i) at said distal end thereof means for receiving and holding
an elongated hollow needle means;
(ii) a hollow longitudinally-extending bore throughout;
(iii) at said proximal end thereof centrally located female recess
means for receiving and holding piston extension means; and
(iv) second anti-rotation means on the outer surface thereof for
engagement with said first anti-rotation means to prevent rotation
of said needle carrier relative to said barrel member,
(c) an elongated piston rod means having a distal end adapted to
be positioned in said barrel member by insertion through said open
proximal end thereof and having at the distal end thereof a piston
means having a diameter preselected so as to snugly contact said
preselected normal unstretched inner cylindrical surface of said
barrel member, said piston rod means further comprising:
(i) piston extension means centrally positioned on the distal end
of said piston means extending axially a preselected distance, and
having locking means for engagement with and retention by said recess
means of said needle carrier; and
(ii) notch means on said piston rod means positioned at a preselected
location between the proximal end of said piston means and a proximal
end of said piston rod means; and
(d) piston rod movement limit means attached to said flange means,
adapted to engage said piston rod means and to engage said notch
means, upon partial withdrawal of said piston rod means from said
barrel member, to thereby lock said piston rod to said barrel member;
whereby said syringe is further characterized by said piston means,
when moved axially within and toward said distal end of said barrel
member, forcing fluid through said bore until contact therewith
said first restraining stop means, said piston means and said first
restraining stop means having co-acting means which function, upon
further axial movement of said piston means toward the distal end
of said barrel member, to force outward said first restraining stop
means and the adjacent section of said barrel member to permit the
engagement of and attachment to said piston extension means with
said recess means of said needle carrier, following which said piston
rod means with attached needle carrier may be moved in unison longitudinally
toward said proximal end of said barrel member sufficiently so that
an elongated hollow needle means attached to said needle carrier
would be entirely within said barrel member to thus prevent accidental
contact of said needle means with an errant body part; and
whereby said limit means would then be in engagement with said
notch means to lock said piston rod means to said barrel means to
thus prevent further relative axial movement of said piston rod
means and said barrel means.
2. Apparatus of claim 1 further characterized by (i) said seal
and stop means including an annular seal located on a proximal portion
thereof, and (ii) said needle carrier, at said distal end thereof,
having a planar surface positioned to engage said annular seal.
3. Apparatus of claim 1 further characterized by said coacting
means of said piston means and said first restraining stop means
comprising beveled surface means.
4. Apparatus of claim 1 further characterized by said needle carrier
centrally located female recess means having (i) a first portion
of a preselected diameter adjacent to said proximal end of said
needle carrier, and (ii) a second portion adjacent to and of a larger
diameter than said first portion.
5. Apparatus of claim 4 further characterized by said locking means
of said piston extension means having a male shape complimentary
to said needle carrier female recess means.
6. Apparatus of claim 1 further characterized by said piston rod
movement limit means comprising a U-shaped member having a bight
portion and attached at said bight portion to said flange means
and having a pair of opposed spaced resilient fingers straddling
said piston rod means at said proximal open end of said barrel member.
7. Apparatus of claim 1 further characterized by said first and
second anti-rotation means comprising complementary axially extending
protrusion and recess means.
8. Apparatus of claim 7 further characterized by said needle carrier
having a recess and said barrel member having a rib.
9. A safety syringe comprising:
(a) a cylindrical hollow barrel member of semi-elastic material
adapted to contain a fluid having a preselected normal unstretched
inner cylindrical surface defined by an inner diameter and distal
and proximal open ends, and said barrel member further comprising:
(i) a first restraining stop means projecting radially inwardly
a preselected distance from said inner cylindrical surface and axially
spaced a preselected distance from said distal open end;
(ii) a seal and stop means at said distal open end projecting radially
inwardly a preselected distance from said inner cylindrical surface;
and
(iii) first anti-rotation means positioned between said first restraining
stop means and said seal and stop means,
(b) a cylindrical shaped needle carrier having distal and proximal
ends and being positioned initially within said barrel member between
said first restraining stop means and said seal and stop means,
said needle carrier being further characterized by having:
(i) at said distal end thereof means for receiving and holding
an elongated hollow needle means;
(ii) a hollow longitudinally-extending bore throughout;
(iii) at said proximal end thereof centrally located recess means
for receiving and holding piston extension means; and
(iv) second anti-rotation means on the outer surface thereof for
engagement with said first anti-rotation means to prevent rotation
of said needle carrier relative to said barrel member; and
(c) an elongated piston rod means having a distal end adapted to
be positioned in said barrel member by insertion through said open
proximal end thereof and having at the distal end thereof a piston
means having a diameter preselected so as to snugly contact said
preselected normal unstretched inner cylindrical surface of said
barrel member, said piston rod means further comprising piston extension
means centrally positioned on the distal end of said piston means
extending axially a preselected distance, and having locking means
for engagement with and retention by said recess means of said needle
carrier; and whereby said syringe is further characterized by said
piston means when moved axially within and toward said distal end
of said barrel member, forcing fluid through said bore until contact
therewith said first restraining stop means, said piston means and
said first restraining stop means having co-acting means which function,
upon further axial movement of said piston means toward the distal
end of said barrel member, to force outward said first restraining
stop means and the adjacent section of said barrel means to permit
the engagement of and attachment to said piston extension means
with said recess means of said needle carrier, following which said
piston rod means with attached needle carrier may be moved in unison
longitudinally toward said proximal end of said barrel member sufficiently
so that an elongated hollow needle means attached to said needle
carrier would be entirely within said barrel member to thus prevent
accidental contact of said needle means with an errant body part.
10. A safety syringe comprising:
a) a cylindrical hollow barrel member of semi-elastic material
adapted to contain a fluid having a preselected normal unstretched
inner cylindrical surface defined by an inner diameter and distal
and proximal open ends, and said barrel member further comprising:
(i) a first restraining stop means projecting radially inwardly
a preselected distance from said inner cylindrical surface and axially
spaced a preselected distance from said distal open end; and
(ii) a seal and stop means at said distal open end projecting radially
inwardly a preselected distance from said inner cylindrical surface;
b) a cylindrical shaped needle carrier having distal and proximal
ends and being positioned initially within said barrel member between
said first restraining stop means and said seal and stop means,
said needle carrier being further characterized by having:
(i) at said distal end thereof means for receiving and holding
an elongated hollow needle means;
(ii) a hollow longitudinally-extending bore throughout; and
(iii) at said proximal end thereof centrally located recess means
for receiving and holding piston extension means; and
c) an elongated piston rod means having a distal end adapted to
be positioned in said barrel member by insertion through said open
proximal end thereof and having at the distal end thereof a piston
means having a diameter preselected so as to snugly contact said
preselected normal unstretched inner cylindrical surface of said
barrel member, said piston rod means further comprising: piston
extension means centrally positioned on the distal end of said piston
means extending axially a preselected distance, and having locking
means for engagement with and retention by said recess means of
said needle carrier; and whereby said syringe is further characterized
by said piston means, when moved axially within and toward said
distal end of said barrel member, forcing fluid through said bore
until contact therewith said first restraining stop means, said
piston means and said first restraining stop means having co-acting
means which function, upon further axial movement of said piston
means toward the distal end of said barrel member, to force outward
said first restraining stop means and the adjacent section of said
barrel member to permit the engagement of and attachment to said
piston extension means with said recess means of said needle carrier,
following which said piston rod means with attached needle carrier
may be moved in unison longitudinally toward said proximal end of
said barrel member sufficiently so that an elongated hollow needle
means attached to said needle carrier would be entirely within said
barrel member to thus prevent accidental contact of said needle
means of an errant body part.
Safety syringe description
BACKGROUND OF THE INVENTION
This invention relates to disposable syringes having an arrangement
which will shield the syringe needle after the syringe has been
used so as to thus prevent the sticking or pricking of a human person
handling the syringe. The needle stick hazard is a well known health
hazzard, regard being given to the possibility of transmitting infectious
diseases such as the HIV virus, hepatitis, and the like through
needles which have become contaminated through prior use.
Various prior art arrangements have been proposed. Representative
examples of prior art arrangements are the Chul 5256151 Haining
5342323 and Gloyer et al 4747830 and the several prior art references
cited in these patents.
While a number of prior art arrangements have been proposed, none
are as advantageous as the present invention.
SUMMARY OF THE INVENTION
The present invention provides a safety syringe comprising a cylindrical
hollow barrel member of semi-elastic material. The barrel has an
inner cylindrical surface having a preselected normal or unstretched
inner diameter and distal and proximal open ends. A first restraining
stop is provided in the barrel projecting radially inwardly a preselected
distance from said inner cylindrical surface and being axially spaced
a preselected distance from the distal open end of the barrel. The
barrel further has a seal and stop means at the distal open end
which projects radially inwardly a preselected distance from the
inner surface.
The cylindrical hollow barrel member may also include first anti-rotation
means positioned between said first restraining stop means and said
seal and stop means.
The syringe further includes a cylindrically shaped needle carrier
having distal and proximal ends and being positioned initially within
the barrel between the first restraining stop means and the seal
and stop means. The needle carrier has at the distal end thereof
means for receiving and holding an elongated hollow needle means.
The needle carrier also has a centrally located hollow longitudinally
extending bore throughout. In addition the needle carrier has, at
the proximal end thereof, a centrally located female recess means
for receiving and holding or retaining a piston extension means.
Finally the needle carrier may also include a second anti-rotation
means on the outer circumferential surface thereof for engagement
with the first anti-rotation means on the barrel so as to prevent
rotation of said needle carrier relative to the barrel member.
The syringe further includes an elongated piston rod means having
a distal end adapted to be positioned in the barrel member by insertion
through the open proximal end thereof. At the distal end of the
piston rod is a piston means having a diameter preselected so as
to snugly contact the normal unstretched inner cylindrical surface
of the barrel member. At the distal end of the piston means is a
male-like piston extension means centrally positioned and extending
axially a preselected distance and having locking means for engagement
with and retention by the female recess means of said needle carrier.
The syringe may also include a piston rod limit means which functions
to limit the extent of removal of the piston rod from the barrel
member. In the preferred embodiment, this includes a flange means
extending radially outward from the barrel member at the proximal
open end thereof; and a U-shaped member of resilient material attached
at the bight portion thereof to the flange means and having a pair
of opposed spaced fingers which straddle the piston rod at the proximal
open end of the barrel member. The locking arrangement further includes
notch means on the piston rod positioned at a preselected location
between the proximal end of the piston means and the proximal end
of the piston rod, the aforesaid opposed spaced fingers of the U-shaped
member snapping into said notch as the piston rod is removed from
the barrel member.
Prior art syringes have had several disadvantages. One disadvantage
is that, in some cases, connecting a hollow needle means to the
needle carrier could tend to cause rotation of the needle carrier
within the barrel of the syringe and could cause unseating of the
needle carrier with respect to the distal end of the barrel to thus
permit fluid leakage. In the present invention the needle carrier
is not held in place with respect to the barrel by means of threads,
such as threaded surfaces used in many prior art safety syringes;
therefore, the present invention is not prone to that problem. Furthermore,
the present invention may include cooperating anti-rotation means
on the circumferential surface of the needle carrier and the inner
wall of the barrel member so as to prevent relative rotation therebetween.
In the present invention the needle carrier is initially positioned
within the barrel member between the first restraining stop means
and the seal and stop means, this positioning being firm and positive
so that an attached elongated hollow needle means may be effectively
administered to a body part. Fluid within the barrel may be injected
into the body part by movement of the piston rod means within the
barrel in the distal direction. Once all of the fluid has been so
administered, then additional movement of the piston in the distal
direction will cause engagement between the male member on the distal
face of the piston with the female recess in the proximal end of
the needle carrier; this final movement of the piston in the distal
direction is permitted by the piston engaging the first restraining
stop means of the barrel member and stretching the barrel in that
region of the barrel from the normal unstretched inner diameter
to a somewhat larger diameter so as to permit the distal face of
the piston to engage or contact the proximal face of the needle
carrier. Thereafter, the piston rod means with the attached needle
carrier may be moved longitudinally within the syringe barrel member
toward the proximal end of the barrel. The invention is characterized
so that the aforesaid movement of the piston means with the attached
needle carrier is sufficient so that an elongated hollow needle
means attached to the needle carrier would be drawn totally within
the barrel member to thus prevent accidental contact of the needle
means with an errant human body part.
The optional piston rod movement limit means may be employed to
hold the piston rod means in the "safe position".
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric exploded view of the preferred embodiment
of the invention.
FIG. 2 shows a partial longitudinal cross-section of the syringe
shown in FIG. 1 with the needle carrier positioned within the barrel
member between a first restraining stop means and a seal and stop
means and with the piston means positioned within the barrel member
but spaced axially or longitudinally away from the first restraining
stop means.
FIG. 3 is a view similar to FIG. 2 except the piston rod means
with attached piston means has been moved completely in the distal
direction with the piston means engaging the first restraining stop
means and forcing it outwardly, thus stretching the barrel member
from its normal unstretched inner diameter to a larger diameter
and with the male extension on the piston means engaging the female
recess in the needle carrier.
FIG. 4 is a view of the apparatus shown in FIG. 2 as shown along
section lines 4--4.
FIG. 5 is another longitudinal cross-section of the device shown
in FIG. 1 after the piston rod means has withdrawn the needle carrier
with attached elongated hollow needle means and the piston rod means
has been locked with respect to any further longitudinal relative
movement with the barrel means.
FIG. 6 shows the apparatus shown in FIG. 5 as viewed along section
lines 6--6.
FIG. 7 is a longitudinal cross-section of the barrel member.
FIG. 8 is a longitudinal cross-section of the needle carrier.
FIG. 8A is a view of the proximal end of the needle carrier as
viewed along section lines 8A--8A.
FIG. 9 is a longitudinal view of the piston rod means.
FIG. 10 shows an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 reference numeral 10 designates a safety syringe with
the various components depicted in exploded fashion. The components
include a barrel member 20 a needle carrier 30 a piston rod means
40 an elongated hollow needle means 50 and a locking means 60.
The barrel member 20 is shown in larger scale in FIG. 7; it is
depicted as a cylindrical hollow barrel member of semi-elastic material
such as a plastic well known to those skilled in the art and adapted
to contain a fluid. The barrel member has an inner cylindrical surface
20A having a preselected normal or unstretched inner diameter and
distal and proximal open ends 20B and 20C respectively. The barrel
member further includes a first restraining stop means 21 comprising
an inwardly extending shoulder which projects radially inwardly
a preselected distance from said inner surface 20A and is axially
spaced a preselected distance from the distal open end 20B; the
stop means is shown with a sloped or beveled proximal surface 21A
and with an inner circumferential surface 21B.
The barrel member further includes a seal and stop means at the
distal end 20B identified by reference numeral 22. More specifically
the seal and stop means comprises a radially inwardly extending
shoulder 22B having at the proximal end thereof an annular axially
extending seal 22B. Other seal means such as an "O"-ring
may be used in place of seal 22B.
In the preferred embodiment of the invention the barrel member
further includes first anti-rotation means positioned between the
first restraining stop means and the seal and stop means 21 and
22 respectively. The first anti-rotation means comprises a protrusion
shown as a longitudinally extending rib 23 (see also FIG. 4) which
extends inwardly from the inner surface 20A of the barrel member.
The barrel member further includes a flange means 24 at the proximal
end 20C of the barrel.
The needle carrier 30 is best shown in FIGS. 8 and 8A; it has a
cylindrical shape having an outer circumferential surface 30A having
a diameter essentially the same as the inside diameter of the barrel
member 20. The needle carrier has distal and proximal ends 30B and
30C respectively and a hollow longitudinally extending centrally
located bore 30D throughout. At the distal end 30B the needle carrier
has a means 30E for receiving and holding an elongated hollow needle
means. Those skilled in the art will recognize that different needle
receiving and holding means may be used; the arrangement depicted
has an axial extension with internal threads for receiving a luer-type
elongated hollow needle means. A conically-shaped extension 30F
extends in the distal direction from the threaded hub 30E; elements
30E and 30F collectively providing an appropriate support for a
needle means 50 shown in FIGS. 1-3 and 5.
At the proximal end 30C of the needle carrier is centrally located
a female recess means 31 for receiving and holding a male piston
extension means 41. The female recess 31 is centrally positioned
and comprises a short bore 31A of a first preselected diameter which
opens into a larger diameter recess portion 31B as is clearly shown
in FIGS. 2 and 8.
The needle carrier further has second anti-rotation means on the
outer surface thereof for engagement with the first anti-rotation
means or protrusion 23 which is integral with the barrel member
20. More specifically, the second anti-rotation means on the needle
carrier is a longitudinally extending recess 33 shown in FIG. 8A.
Those skilled in the art will understand that other anti-rotation
means may be used.
As shown in FIG. 2 the needle carrier 30 is positioned initially
within the barrel member between the first restraining stop means
21 and the seal and stop means 22. The axial surface 30G (see FIG.
8) at the distal end of the needle carrier abutting the annular
seal 22A at the distal end 20B of the barrel.
The elongated piston rod means 40 is shown in detail in FIGS. 6
and 9; it has a distal end 40A and proximal end 40B and an elongated
body or rod portion 40C which may have a variety of cross-sections
but, in the preferred embodiment, has a cruciform-shape as shown
in FIG. 6. At the distal end 40A is a piston means 42 which includes
a piston 42A having a diameter preselected so as to snugly contact
the normal unstretched inner cylindrical surface 20A of the barrel
member 20. A beveled circumferencial surface 42A' is provided on
the distal face of the piston means 42. An O-ring recess 42B for
receiving an O-ring 42B', as shown in FIG. 3 may also be provided
on the circumferential surface of piston 42A, as is well understood
by those skilled in the art. As shown in FIG. 9 the elongated rod
portion 40C (having the cruciform cross-section) has a uniform dimension
except for an outer ramp or incline surface portion 40D terminating
close to but spaced from the piston means 42 so as to define a notch
40E therebetween. At the extreme proximal end of the rod portion
40C is an end piece or cap 44.
At the distal end of the piston rod means is a piston extension
means 41 which may also be termed the male portion of a locking
means so as to provide engagement with and retention by the female
recess 31 in the proximal end of the needle carrier 30. Referring
to FIGS. 2 and 9 it will be seen that the male extension 41 comprises
portions 41A and 41B which are shaped and dimensioned so as to compliment
the recesses 31B and 31A respectively of the recess 31 in the needle
carrier. The material selected for those portions of the plunger
and needle carrier which provide the interlocking action as aforesaid
are those well known to those skilled in the art such as resilient
plastic.
The piston rod movement limit means 60 is best shown in FIG. 6;
it comprises a U-shaped member of resilient material such as plastic
attached at its bight portion 60A to the flange means 24 of the
barrel by use of an appropriate pin or rivet means 61 having heads
or ends 61A and 61B as shown in FIG. 2. The U-shaped member 60 further
includes a pair of opposed spaced fingers 60B and 60C which straddle
the piston rod 40C at the proximal open end 20C of the barrel member.
As indicated, the member 61 is made of a resilient material so that
the fingers 60B and 60C maintain contact with the piston rod 40C
as the piston rod moves longitudinally with respect to the barrel
member 20. Thus, as the piston rod means 40 is moved out of the
barrel member the resilient fingers 60B and 60C will eventually
contact the inclined portions 40C and 40D of the piston rod and
yield enough so as to permit a slight amount of additional movement
of the piston rod to the point depicted in FIG. 5 wherein the fingers
60B and 60C are shown in the notch 40E to thereby lock the piston
rod with respect to the barrel member.
OPERATION
In use, as aforesaid, the needle carrier is initially positioned
between the first restraining stop means 21 and the seal and stop
means 22 and the rib 23 of the barrel is in engagement with the
recess 33 of the needle carrier. The distal end 40A of the piston
rod means 40 is positioned in the barrel member by insertion through
the open proximal end 20C thereof. The piston rod movement limit
means 60 may be attached to the flange 24 if the locking function
is desired. Typically the limit means 60 would be attached to the
flange prior to the insertion of the piston, the resilient fingers
60B and 60C to be spread permitting the insertion of the piston
rod means.
Once the syringe is in the hands of a professional, a needle means
50 of appropriate size would be attached to the needle carrier,
as shown, and then the syringe may be used to administer medications
or other fluids to a body. Thus fluid may be drawn into the barrel
by relative movement of the piston toward the proximal end 20C of
the barrel member following which, when the piston is moved axially
toward the distal end 20B of the barrel member, such fluid is forced
through the bore 30D of the needle carrier and through the hollow
needle means 50. The fluid flow continues until the male locking
means 41 is in engagement with the female recess 31. The locking
function is facilitated by the beveled surface 42A' on distal face
of the piston means 42 engaging the sloped or beveled surface 21A
of the first restraining stop means 21. As additional force is applied
to the piston rod, the barrel is stretched outwardly to a new diameter
Y as shown in FIG. 3 from the original diameter X, also shown in
FIG. 3 to thus unlock the needle carrier from its initial position.
FIG. 3 shows the engaged and locked piston rod means and needle
carrier; it is clear that the now assembled piston rod means and
needle carrier with attached needle may be withdrawn in the proximal
direction with respect to the barrel member 20 to a position such
as shown in FIG. 5 wherein the needle carrier with assembled needle
50 is totally withdrawn within the barrel member and, as aforesaid,
the limit means fingers 60B and 60C are lying within the notch means
40E of the piston rod so as to prevent any further relative axial
or longitudinal movement between the needle carrier and the barrel
member. The needle means 50 which may be contaminated, is thus
safely within the protective barrel 20 where accidental contact
of the needle with an errant human body part is prevented.
FIG. 10 shows an alternate arrangement of the invention. Instead
of using the limit means 60 the piston rod means of FIG. 10 identified
by reference numeral 140 has a cruciform cross-section 140C adapted
to be broken off as at 140C' after completion of the use of the
syringe for its intended purpose and subsequent withdrawal of the
needle within the barrel member as aforesaid. |