Safety syringe abstract
The present invention relates to a disposable safety syringe (1)
including an automatically retractable needle (12) for preventing
said syringe from being reused, comprising a cylindric body (82)
defining, at one end thereof, a needle coupling end-piece (7) and
being opened at the other end portion thereof for introducing thereinto
a piston (4) having a scaling gasket (5). The main feature of the
invention is that on said piston are provided engaging means (23
24) for engaging and retracting the needle (12) after to the delivering
of the injection liquid.
Safety syringe claims
1. A disposable safety syringe including an automatically retractable
needle, said syringe comprising a syringe cylindric body defining,
at one end portion thereof, an end piece for coupling the syringe
needle and being opened, at the other end portion thereof, for receiving
a syringe plunger including a sealing gasket, characterized in that
said syringe needle is coupled to a barrel cylindric element including
two bottom resilient wings having, at their end portions, a tapering
portion adjoining a cut-out delimited by an abutment tooth element
in order to prevent said needle from being retracted, said abutment
tooth element being coupled to a locking abutment element, that
said syringe further comprises, on said syringe plunger, engaging
and retracting means for engaging and retracting said needle, after
having delivered the injection liquid, that said engaging and retracting
means comprise a nose housed inside an axial cavity formed on said
syringe plunger, said nose being adapted to be coupled to said syringe
needle and connected to a return spring arranged in an axial cavity,
and that at least one of the cut-outs defined on said resilient
wings is curved so as to cause said needle to be arranged with a
slanted orientation and for preventing said needle from exiting
again.
2. A disposable safety syringe, according to claim 1 characterized
in that said barrel element is housed inside a cap which can be
pressure coupled to an end piece and that said cap defines, in its
inside, a cylindric portion which can be tightly engaged with said
barrel element.
3. A disposable safety syringe, according to claim 1 characterized
in that said engaging and retracting means comprise a stop abutment
provided in an axial cavity and engageable with an abutment formed
by a nose including clamping elements which can be engaged with
resiliently yieldable wings.
4. A disposable safety syringe, according to claim 1 characterized
in that said nose projects from an opening defined by said plunger
gasket and that said spring is resiliently preloaded for retracting
said needle at the end of the injection liquid delivery operation
Safety syringe description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a disposable safety syringe,
including an automatically retractable needle, for preventing the
syringe from being reused.
[0002] As is known, a main problem of disposable syringes is that
deriving from a possibility of reusing said syringes and a possibility
that the syringe needle can accidentally prick the operator of the
syringe.
[0003] For solving the above mentioned problem, safety syringes
have been already constructed, in which are provided resilient means,
operating between the syringe body and plunger, so as to cause the
syringe needle to be automatically retracted, after having being
used, since the syringe plunger is resiliently withdrawn from the
syringe body.
[0004] Such a solution however, has not been found as practical,
since, during a regular use of the syringe, it is necessary to overcome
the resilient urging force provided by the spring, and which must
be of a comparatively high value, in order to assure a satisfactory
withdrawing of the needle but which actually hinders a proper use
by the operator.
SUMMARY OF THE INVENTION
[0005] Accordingly, the aim of the present invention is to overcome
the above mentioned drawbacks, by providing a disposable safety
syringe, including an automatically retractable needle, for preventing
the syringe from being reused, and allowing the syringe needle to
be automatically retracted into the syringe body by resilient means
which are inoperative during a regular use of the syringe.
[0006] Within the scope of the above mentioned aim, a main object
of the present invention is to provide such a disposable safety
syringe the needle of which can be retracted by very simple and
efficient retracting means.
[0007] Another object of the present invention is to provide such
a disposable safety syringe which, owing to its specifically designed
constructional features, is very reliable and safe in operation.
[0008] Yet another object of the present invention is to provide
such a disposable safety syringe which can be easily made starting
from easily available elements and materials and which, moreover,
is very competitive from a mere economic standpoint.
[0009] According to one aspect of the present invention, the above
mentioned aim and objects, as well as yet other objects, which will
become more apparent hereinafter, are achieved by a disposable safety
syringe including an automatically retractable needle, said syringe
comprising a syringe cylindric body defining, at one end portion
thereof, an end piece for coupling the syringe needle and being
opened, at the other end portion thereof, for receiving a syringe
plunger including a sealing gasket, characterized in that said syringe
further comprises, on said syringe plunger, engaging means for engaging
and retracting said needle, after having delivered the injection
liquid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further characteristics and advantages of the present invention
will become more apparent hereinafter from the following detailed
disclosure of a preferred, though not exclusive, embodiment of a
disposable safety syringe including an automatically retractable
needle for preventing the syringe from being reused, and being illustrated,
by way of an indicative but not limitative example, in the accompanying
drawings, where:
[0011] FIG. 1 is a schematic exploded view illustrating the disposable
safety syringe according to the present invention;
[0012] FIG. 2 is a cross-sectional view of the syringe illustrating
said syringe in a use condition thereof;
[0013] FIG. 3 is a schematic view illustrating the end step of
the injectable liquid delivering operation;
[0014] FIG. 4 illustrates, on an enlarged scale, the position assumed
by the needle and plunger of FIG. 2;
[0015] FIG. 5 illustrates, on an enlarged scale, the position of
the syringe needle and plunger or piston in the condition shown
in FIG. 3; and
[0016] FIG. 6 is a schematic view illustrating the retracting operation
for retracting the syringe needle being performed by resilient means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] With reference to the number references of the above mentioned
figures, the disposable safety syringe, including a retractable
needle, according to the present invention, which has been generally
indicated by the reference number 1 comprises a syringe cylindric
body 2 defining an inner chamber 3 in which a syringe piston or
plunger can slide, said syringe plunger or piston being indicated
by the reference number 4 and including a sealing front gasket 5
having a central opening 6 as it will become more apparent hereinafter.
[0018] Making now reference to the syringe constructional details,
the syringe cylindric body 2 is provided, at one end portion thereof,
with an end piece 7 thereon is applied a cap 8 housing in its
inside a barrel element 11 which, at one end thereof, is coupled
to a syringe needle 12 and, at the other end thereof, comprises
resiliently spreadable wings, generally indicated by the reference
number 13.
[0019] Said wings comprise a tapering portion 14 at their free
end, adjoining cut-outs 16 ending with a tooth element 17 abutting
against an abutment ring element 18 provided in the attachment region
of the end-piece 7.
[0020] On the outer surface of the end-piece 7 are provided a plurality
of slots 7a for improving the engagement of the cap 8.
[0021] Moreover, a further cut-out 16a is provided, which has a
curved configuration, so as to substantially prevent the syringe
needle from being re-engaged in the mentioned cap as it is withdrawn.
[0022] As shown, the cap 8 comprises a cylindric surface 19 therein
said barrel element 11 is engaged for providing the required sealing.
[0023] The syringe plunger 4 defines, according to a feature of
the invention, an axial cavity 20 which, at its portions thereat
said gasket 5 is arranged, comprises a stop abutment 21 engaging,
as the syringe is used, with an abutment element 22 defined by a
nose 23 having clamping elements 24 which can be engaged with the
mentioned resilient wings, as it will become more apparent hereinafter.
[0024] The nose 23 is coupled to recovering resilient means 30
housed in said axial cavity 20 and which, at the other end portion
thereof, engages with a pawl, which can be locked at the flanged
end portion 32 of the syringe plunger 30.
[0025] With the disclosed arrangement, the nose 23 projects from
said central hole or opening 6 and is restrained in a stop abutment
position by the stop abutment 21 engaging with the abutment 22.
[0026] As the syringe is used, and as shown in FIGS. 2 and 4 the
syringe plunger will perform its operating stroke to inject the
injection liquid.
[0027] Under such a condition, the syringe needle is firmly held
in its position due to the provision of the cap 8 and because of
the engagement of the engagement of the tooth elements 17 with the
locking abutment 18.
[0028] At the end of the injection, the clamping elements 24 of
the nose 23 by engaging with the tapering portions 14 will cause
the wings 13 to be radially contracted, thereby disengaging the
tooth elements 17 from the abutment 18 so as to allow the syringe
needle to be disengaged from the mentioned cap.
[0029] Moreover, the nose 23 can disengage from the stop abutments
21 under a pushing force, and owing to the provision of the return
spring 30 causing the needle to be immediately retracted, inside
the axial cavity 20 as is clearly shown in FIG. 6.
[0030] In such a condition, the syringe cannot be absolutely reused.
[0031] Moreover, the needle will be arranged at a protected region
thereby preventing any inuring to the syringe operator.
[0032] From the above disclosure it should be apparent that the
invention fully achieves the intended aim and objects.
[0033] In particular, it is pointed out that a safety disposable
syringe has been provided which, while having a very simple construction,
allows the syringe needle to be automatically retracted upon the
injection.
[0034] The invention, as disclosed, is susceptible to several modifications
and variations, all of which will come within the scope of the invention.
[0035] Moreover, all of the constructional details can be replaced
by other technically equivalent elements, depending on requirements. |