Safety syringe abstract
A safety syringe having a hollow barrel member with first and second
open ends and female threads on the inside surface of the first
end. A special cylindrically shaped needle holder body is positioned
inside the first end of the barrel. The holder body has male threads
on the curved outer surface thereof adapted to coact with the female
threads, and a needle receiving member on one end for receiving
and holding a standard hollow needle. The special holder also has
a recess in the other end, a first torque transmitting member located
in the recess, and a central bore. An elongated piston rod has at
one end a piston having, at the distal end, an integral central
axially extending protrusion adapted to fit within the recess of
said needle holder body, the protrusion having a second torque transmitting
member adapted to coact with said first torque transmitting member,
and a locking member adapted to coact with said body.
Safety syringe claims
I claim:
1. A safety syringe comprising:
(a) a cylindrical hollow barrel member adapted to contain a fluid
and having first and second open ends and a female thread on the
inside surface of said first end, said female thread being preselected
to mate with a male thread on a needle holder body;
(b) a cylindrically shaped needle holder body having a longitudinal
axis, first and second axial ends and further comprising:
(i) a male thread on the curved outer surface thereof and being
preselected to mate with said female thread,
(ii) means on said first axial end for receiving and holding the
hub of an elongated hollow needle,
(iii) a recess in said second axial end extending axially along
said longitudinal axis to a depth part way toward said first axial
end,
(iv) first means for transmitting rotational torque integral with
said body and located in said recess, and
(v) a central bore extending through said holder body along said
longitudinal axis;
(c) an elongated hollow needle including a hub, said hub exclusively
held by said hub receiving and holding means;
(d) an elongated piston rod; and
(e) a piston having inner and outer axial ends and further comprising:
(i) means connecting said inner axial end thereof to one end of
said piston rod,
(ii) an integral central axially extending protrusion on said outer
axial end thereof constructed to fit within said recess of said
needle holder body, and including;
(1) second means for transmitting rotational torque integral with
said protrusion and constructed to coact with said first rotational
torque transmitting means,
(2) snap locking means on said protrusion and said holder body
for snap locking said protrusion to said holder body;
whereby said needle holder body may be initially positioned in
said hollow barrel member with said female thread engaging said
male thread, and said piston on said piston rod may be inserted
into said second open end of said barrel member so that, upon relative
axial displacement therebetween, fluid within said barrel is pumped
through said central bore of said needle holder body and said hollow
needle exclusively held thereon, and
whereby, upon said piston being inserted, as aforesaid, and axially
displaced, relative to said barrel member, to a position whereat
said piston central axially extending protrusion is positioned within
said recess of said body with said second rotational torque transmitting
means thereon engaged with said first rotational torque transmitting
means of said body and with said snap locking means locking said
protrusion with said body, then upon rotational torque being applied
to said piston rod, said torque is transmitted via said protrusion
to said body to cause rotation of said body relative to said barrel
member to thereby release said male thread from said female thread
following which axial movement of said locked protrusion and said
body relative to said barrel member is facilitated, said last mentioned
axial movement being sufficient to withdraw said needle completely
within said first open end of said barrel member, thus preventing
accidental contact of said needle means by an errant body part.
2. Apparatus of claim 1 further characterized by said first and
second rotational torque transmitting means being a plurality of
longitudinally extending ribs, the ribs on said body extending radially
inward and the ribs on said piston central protrusion extending
radially outward.
Safety syringe description
BACKGROUND OF THE INVENTION
This invention relates to hypodermic syringes of the disposable
type and to a syringe which will shield the syringe needle from
sticking or pricking persons handling the syringe after the syringe
has been used.
In the medical field, a health hazard known as "needle stick"
exists because a "standard" hypodermic syringe does not
have the safety features as would prevent a used syringe from accidently
sticking (puncturing) the flesh of medical, clean up, and/or other
personnel before the syringe is finally discarded.
The needle stick hazard, of course, incurs the possibility of transmitting
infectious diseases such as Hepatitis, AIDS and the like through
needles which have become contaminated.
Various prior art arrangements have been proposed but none are
as advantageous as the present invention.
SUMMARY OF THE INVENTION
A syringe utilizing the present invention includes a cylindrical
hollow barrel member having first and second open ends, and first
female thread means on the inside surface of said first end. Also
provided is a cylindrically shaped needle holder body having a longitudinal
axis, first and second axial ends and further comprising: (i) first
male thread means on the curved outer surface thereof and adapted
to coact with said first female thread means, and (ii) means on
said first axial end for receiving and holding an elongated hollow
needle means. The needle holder body additionally has a first recess
in said second axial end extending axially along said longitudinal
axis to a depth part way toward said first axial end, said first
recess having a stoppage protrusion means extending radially inwardly;
a second recess in said second axial end extending along said longitudinal
axis a depth less than said depth of said first recess, said second
recess having a radial extent greater than said first recess; a
central penetrating bore extending through said holder body long
said longitudinal axis; and first ratational torque transmitting
means connected to said body and located in said second recess.
Other components of the syringe are an elongated piston rod; and
a piston means having inner and outer axial ends and further comprising:
(i) means connecting said inner axial end to one end of said piston
rod, (ii) an integral central axially extending protrusion on said
outer axial end adapted to fit within said first recess of said
needle holder body, and including a stoppage means adapted to coact
with said stoppage protrusion means of said first recess so as to
lock said piston means to said needle holder body, and (iii) second
rotational torque transmitting means on said outer axial end and
adapted to coact with said rotational torque transmitting means.
All of the aforementioned items or components are characterized
whereby said needle holder body may be initially positioned in said
hollow barrel member with said first female thread means engaging
said first male thread means, said piston means being insertable
into second open end of said barrel member and, upon axial relative
movement therebetween, to cause the flow of fluid through said central
penetrating bore of said needle holder body and attached hollow
needle means, and whereby upon said piston means being inserted,
as aforesaid, and axially displaced, relative to said barrel member,
to a maximum depth whereat (i) said piston axially extending protrusion
is positioned and locked within said first recess of said body with
said piston stoppage means engaged with said body stoppage protrusion
means, and (ii) said first and second rotational torque transmitting
means are engaged, so that, upon rotational torque being applied
to said piston rod, said torque is transmitted via said piston means
to said body to cause rotation of said body relative to said barrel
member and release of said first male thread means from said first
female thread means following which axial movement of said locked
piston means and said body relative to and into said barrel member
is facilitated, said last mentioned axial movement being sufficient
to withdraw a needle means on said body, as aforesaid, completely
within said first open end of said barrel member, thus preventing
accidental contact of said needle means by an errant body part.
The syringe may be further characterized by said means on said
first axial end of said needle holder body being a second female
thread means; by said first and second rotational torque transmitting
means being coacting longitudinally extending protrusions on said
body and said piston means; and/or by said barrel member and said
piston rod having coacting locking means permitting insertion of
said piston into said barrel and locking said piston rod so as to
prevent removal of said piston means and attached body.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view, in cross section, of the cylindrical hollow barrel
with the needle holder body positioned in one end of the barrel,
FIG. 2 and FIG.3 show the entire syringe in longitudinal, cross
section. FIG. 2 shows the piston within the barrel but spaced longitudinally
or axially from the needle holder body while FIG. 3 shows the piston
in locked relationship with said body,
FIGS. 4 and 5 show details of the syringe on an enlarged basis,
FIG. 6 shows the syringe with the needle withdrawn into the barrel,
and
FIG. 7 shows a modified needle attachment means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Referring to the figures, the reference numeral 1 generally depicts
the improved syringe and the reference numeral 2 designates the
hollow cylindrical barrel member having first and second open ends.
First female thread means 8 are provided on the inside curved surface
7 of the first end of the hollow barrel. A cylindrically shaped
needle holder body 4 has a longitudinal axis and first and second
axial ends and further comprises first male thread means 15 on the
curved outer surface thereof which are adapted to coact with said
first female thread means 8. The body also has means on said first
axial end thereof for receiving and holding an elongated hollow
needle means, more specifically, an annular recess extending axially
from the first axial end with second female thread means 13 disposed
in the outer surface 14 of said annular recess. A standard holder
3 for a standard needle 11 and having a radially extending shoulder
12 at one end thereof is adapted to be threaded into the annular
recess through the coaction of the shoulder 12 and the female threads
13.
The second axial end of the body has a first recess 17 extending
longitudinally to a depth partway toward said first axial end of
the body. The body has a stoppage protrusion means in the form of
an annular shoulder 16 extending radially inwardly in recess 17
toward the longitudinal axis as most clearly shown in FIG. 1. The
shoulder 16 extends around the body's longitudinal axis and is sloped
from its inner tip toward the second open end of the barrel; the
other surface of the protrusion is radially away from the longitudinal
axis thus forming a shoulder which is normal to the longitudinal
axis.
The body has a second recess in said second axial end extending
along the longitudinal axis a depth less than the depth of recess
17 but having a greater radial extent measured from the longitudinal
axis than recess 17.
The body also has a central bore 19 extending therethrough along
the longitudinal axis. the body further has first rotational torque
transmitting means 18 shown as longitudinal extending rib portions
shown clearly in FIGS. 1 2 and 4-7. The ribs extend radially toward
the longitudinal axis a preselected distance and longitudinally
a preselected distance.
An elongated piston rod 5 is provided consisting of a plurality
of laterally extending flutes 24 emanating from the longitudinal
axis and having at one end thereof an end piece 23 integral therewith
so as to provide a means for moving the piston rod 5 in and out
of the hollow barrel 2 along the longitudinal axis and further to
permit the application of rotational torque to the piston rod by
manual rotation of the piston (relative to the barrel about the
longitudinal axis.
A piston means 6 is affixed to the other end of the piston rod
5; it has a generally circular cross-section and a relatively short
axial or longitudinal extent thus defining an inner axial end which
is adapted to be attached to or integral with the piston rod 5 and
an outer axial end or face from which depends a centrally located
axially extending protrusion, shown in all figures but expecially
well (in phantom form) in FIG. 1 wherein it is seen that the said
protrusion is shaped in a complementary form with respect to the
recess 17 and its associated larger diameter recess including a
circumferential groove 20 adapted to coact with annular shoulder
16. The piston 6 further has a circumferencial flexible gasket 22
of a diameter selected so that when the piston 6 with the gasket
22 mounted thereon is positioned within the barrel 2 as shown in
the figures, there will be a tight sliding fit between the piston
assembly and the barrel to permit, when desired, the forcing or
pumping of liquid within the barrel 2 out through the passageway
19 and the connected needle 11 or, in the other mode of operation,
to pull fluid from an external source through the needle 11 passageway
19 and into the barrel 2.
The piston assembly further includes second rotational torque transmitting
means 21 on said outer axial end of the piston 6 which are adapted
to coact with said first rotational torque transmitting means 18.
The specific means shown are a plurality of longitudinally extending
and also radially inwardly extruding ribs arranged around the periphery
of the piston assembly protrusion. The ribs 21 are dimensioned to
coact with the ribs 18 upon a preselected rotational relationship
between the piston assembly 6 and the body 4; when this relationship
is established, then the piston assembly may be moved axially toward
the body so as to be in complete engagement with the body as is
depicted in FIGS. 2-7. Once such total engagement is reached, the
inwardly extending annular shoulder 16 will be "snapped"
into position in the notch 20 of the piston assembly.
The piston assembly further includes a notch 25 in one or more
of the fins or flutes 24 of the piston assembly; two such notches
25 are shown in FIGS. 2-7. The notches 25 are adapted to coact with
radially inwardly extending shoulders or latch means 9 with the
cooperating surfaces being beveled to permit the piston assembly
to move inwardly into the barrel 2 but the shoulder 9 serves as
a latch by catching notches 25 to prevent the piston assembly from
being withdrawn any further than the latch position as is depicted
in FIG. 6 where the piston assembly, latched to the body 4 with
the associated needle holder 3 and needle 11 has been withdrawn
within the barrel a sufficient longitudinal extent so that the sharp
pointed tip on the needle 11 is within the open end of the barrel.
Thus in practice the barrel 2 and body 4 would be preassembled
at the factory; the piston assembly would also be, in the usual
case, already positioned within the barrel 2 as shown in FIG. 2.
When medical personnel intend to use the syringe, then the needle
holder 3 and needle 11 would be connected to the body 4 as is shown
in FIGS. 2-7. At this point the syringe can be used, as is well
understood, either to inject fluid from within the syringe into
a patient or to withdraw a fluid sample, e.g., blood, from a patient
and collect it in the barrel.
Upon completion of the use of the syringe as intended, then in
order to render the syringe safe from an accidental stick, the piston
assembly is then forced longitudinally up into engagement with the
body 4 by having the protrusion on the piston assembly placed into
full engagement with the corresponding recess 17 of the body 4
all as aforesaid. In this position the firs and second rotational
torque transmitting means 18 and 21 are in operative engagement
so that, when rotational torque is applied to the handle piece 23
of the piston assembly of the correct sense, and the barrel 2 is
held, then the body 4 is unthreaded and released from the barrel
2 the body 4 being carried along with the piston assembly due to
the locking action of elements 16 with 20. Once the threads 8 and
15 have become disengaged, then the piston assembly may be further
moved in a longitudinal direction away from the first end of the
barrel to a point where it is latched through the coaction between
the shoulder 9 and the notches 25; at this point the dangerous sharp
tip to the needle 11 is out of harms way by being completely within
the first open end of the barrel member, an accidental contact of
said point on the needle means by an errant body part being thus
prevented.
In FIG. 1 the reference numeral 26 depicts a standard protective
outer cap which may be used to safeguard the needle until actual
use of the syringe is intended.
FIG. 7 shows an alternative embodiment wherein the needle holder
3 fits tightly on a central extension 27 of the body instead of
coacting with the threads 13 on the inside surface 14 of the body
4 as described above.
Referring again to the embodiment shown in FIGS. 1-6 the preferred
amount of threaded engagement between the male threads 15 on the
body 4 and the female threaded portion 8 of the hollow barrel 2
is approximately one-fourth to one turn. It may be assumed, by way
of example, that it takes a relative clockwise rotation of the body
4 with respect to the barrel 2 to have the threaded engagement of
the body with the barrel as is depicted, for example, in FIGS. 1-6.
After completion of the usage of the syringe, as described above,
then the rotational torque applied to element 23 of the piston assembly
will apply a relative counter clockwise rotation or torque to the
body 4 with respect to the barrel 2 thus disengaging the body,
as aforesaid, from the barrel 2 to permit the subsequent withdrawal
of the needle assembly within the barrel as is clearly depicted
in FIG. 6. |