Note: Descriptions are shown in the official language in which they were submitted.
~04~3``9S8
"Injection Syringe with Sealed Needle Guard."
The invention relates to an injection syringe comprising a
cartridge which is provided with a needle mount with injection needle and
which may be disposed in a cartridge holder, a needle guard which is dis-
posed over the injection needle, which guard at one end is detachably
connected to the needle mount, the needle guard being provided with a
thickened portion or ridge at the side of the needle mount.
Such an injection syringe is known from Netherlands Patent
Specification 133,649.
At the location of the thickened portion or ridge the needle
guard is frictionally clamped onto a longitudinal sleeve which forms part
of the needle holder and in which the injection needle is secured. Thus, ;
a sterile sealing o~ the needle is achieved. mObviously, sterility of the
needle is an essential requirement when using the injection syringe. The
known injection syringe has the drawback that the user cannot satisfactorily
ascertain the sterility of the needle. More specifically, the user cannot
ascertain whether the needle guard has been removed previously or, for
example, has come loose during transit and has subsequently been replaced
in the original position. In fact, the user not assured of the sterility
of the injection needle. - -
The Applicant has developed an injection needle of the above-
mentioned type which does not have Qaid drawback. More specifically, the
injection syringe according to the invention has been desinged so that the
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user can at once establish visually whether the needle guard has been --
removed previously.
For this purpose the injection syringe according to the invention
comprises a safety member provided with a central bore which via the bore is
slipped over the needle guard and which is provided with breakage means
which connect the member detachably and irreversibly to the cartridge o~ -
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the cartridge holder, the smallest diameter of the bore ranging between the
diameter of the needle guard and that of the thickened portion or ridge.
When using the injection syringe according to the invention the
safety member is to be removed before the needle guard can be detached. The
safety member is removed by turning said member relative to the cartridge or
by exerting force on it which is directed away from the cartridge. As a
result of this, the means which connect the safety member to the cartridge
or cartridge holder are broken and the safety member which is thus released
may be slipped back over the needle guard and eventually removed.
Subsequently, the needle guard may be removed.
The use~ of the injection syringe according to the invention
can ascertain visuaIly whether the breakage means are still intact and
from this conclude whether the needle guard has been removed previously and
thus whether the sterility is affected.
The safety member may have different embodiments For example,
the safety member may be a cylindrical body provided with a central bore
of which the lower end engages with or substantially engages with the
ridge of ~he needle guard. The lower part of the cyl;ndrical body is
provided with breakage means, for exa~ple taking the form of strips which
by their free ends are secured to the cartridge or cartridge holder.
In a favourable embodiment the ~afety member is a hollow body
taking the form of a cap which is open at the lower end, ~which at said end
~, i9 proYided with the breakage means and at the top contains a central bore
;~ whose diameter ran~es between that of the needle guard and that of the
thickened portion or ridge~
In said favourable embodiment the ridge or protrusion is dis-
po~ed inside the cap of the safety member and the connection of the needle
guard to the needle holder is protected additionally.
r According to a further favourable embodiment the bottom of the
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cap has an outer diameter which corresponds to the outer diameter of the
part of the cartridge holder which faces the cap and is provided with break-
age means in the form of a shoulder, strips or wires which by their free ends
are secured to the part of the cartridge holder which faces the cap.
In said embodiment the dimensions of the cap are adapted to those
of the cartridge holder, so that the cap may be regarded as an exte~sion of
the holder. This ensures that external forces acting on the injection
syringe, for example in transit~ less easily give rise to damaging of the
breakage means and detachment of the cap.
The invention will be described in more detail~with references
to the drawing.
In the drawing~ Fig. 1 shows a longitudinal section of an embodi-
ment of an injection syringe according to the invention~ the safety mæmber
being connected to the cartridge;
- Fig. 2 shows a longitudinal section of a different emb~diment ~ -
of the injection syringe according to the invention, the safety member being
conneoted to the cartridge holder.
In the drawing the reference numeral 1 denotes a cartridge. The
cartridge 1 comprises a cyl;ndrical vial 2 which contains an injectioL~fluid `
5 between a stopper 3 at the front of the vial 2 and a plunger 4 at the rear
of the vial. At the front the vial is provided with a neck 6 having a flange
! 7. The cartridge 1 furthermore comprises a needle mount 8 which by a flange
portion 9 is clamped onto the front faee of the vial 2 by means of an -~
aluminum ring 10. The ring 10 fits around the~flange of the vial and the
needle mount~ a flange portion 11 of the stopper 3 being disposed between
the two other flanges. At the end which faces away from the stopper 3 the
needle mount is provided with a cylindrical sleeve 12 in which an injection
needle 13 which is bevelled at both ends is secured. A needle guard 14 -
tightlg fits around the injection needle 13 and is fr~;ctionally secured to
.
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104~958
the sleeve 12 of the needle mount 8 by means of a thickened portion or
ridge 15. Around the ne~dle guard a safety member 16 is disposed, which may
for example be made of a transparent synthetic material. The safety member
16 has the shape of a cap;l7 which is open at the bottom, whose side wall is
cylindrical and whose top surface 18 has a central bore 19. Through said
central bore 19 the part of the needle guard 14 which is disposed above the
ridge 15 extends. The diameter of the central b~re 19 is smaller than the
outer diameter of the ridge lS but greater than the outer diameter of the
; part of the needle guard 14 which is disposed above the ridge. The lower
side of the top ~ortion 18 of the cap 17 engages or substàntially engages
with the ridge 15. At the lower end of the cap 17 breakage means 20 zre
provided in the form of for example plastic strips which with their free ends
are attached to the ring 10 of the cartridge 1.
In Fig. 2 the reference .nu~erals 1-15 denote similar components
of the injection syringe of Fig. 1. The cartridge 1 shown in Fig. 2 is dis-
posed in a cartridge holder 21. The cartridge holder 21 corresponds to that
described in the previously cited Netherlands Patent ~pecification 133,649
and consists of a hollow cylinder 22 with a cross-piece 23. At its front
end the cylinder 22 terminates in a neck 24 whose internal diamet~r is
exactly such as to accomodate the ring 10 of cartridge 1 without friction. In
order to lock the cartridge 1 inside the cartridge holder 21 the front end of
the holder 21 is provided with cams 25. Around the needle guard a safety
member 26 is disposed which f~r example made of a transparent synthetic mater-
ial. The safety member 26 has the shape of a cap 27 which is open at the bot-
tom end, whose side wall is substantially conical and whose top portion 28 is
provided with a central bore 29. The part of the needle guard 14 which is
disposed above the ridge 15 extends through the central opening 29. The ~
diamter of the opening 29 is smaller than the outer diameter of the ridge ~ -
lS but greater than the outer diameter of the part of the needle guard 14 ~ -~
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104(3958 `
which is disposed above the ridge 15. The lower side of the top portion 28
of the cap 27 engages or substantially engages with the ridge 15. At the
bottom the cap 27 is provided with breakage means 30 in the form of for
example strips made of a transparent synthetic material w~ich by their free
ends are attached to the top of the cartridge holder 21. The diameter of
the cap 27 at the bottom corresponds to the diameter of the cartridge holder
21.
When using the injection syringe according to the invention, it
is first ascertained whether the breakage means 20,30 are still intact so as
to check the sterility. Subsequently, the safety member 16, 26 is rotated
manually~ the breakage means 20, 30 then breaking off or being torn off.
The safety member which is thus released is ~lipped back over the needle
guard 14 and removed. After removal of the needle guard 14 the injection
syringe is ready for application. For this, the needle is inserted into the
body of a patient and the plunger is pushed forward with the aid of a plun~
ger rod, not shown. The pressure then exerted on the injection liquid 5 c~
causes the central part 31 of the stopper 4 to bulge up and expand. When
the pressure suffices the central part 31 will burst either spontaneously or
after contact with the bevelled rear end of the needle~l3. A further dis-
placement of the plunger results in the injection liquid 5 being injected in-
to the body of the patient ~ia the needle 13.
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