Safety syringe abstract
The present invention is an improved needle holder for safety syringe,
which is a needle holder formed through compounding two materials
in one-time, in which rubber convex ring of high coefficient of
deformation is formed on the step ring of holder, such that the
convex ring can properly compress the ring slot at the front part
of barrel. Further, a buckle ring is formed inside the holder, such
that the buckle head of plunger locks the buckle slot after injection,
and the holder as well as the needle are pulled back into the barrel
when the plunger is pulled, thus prevents the needle from exposure.
Safety syringe claims
1. An improved needle holder for safety syringe, the safety syringe
at least includes: a needle cap, a needle, a barrel, a holder, and
a plunger, which mainly applies the technology of compounding rubber
and plastic materials to the compressing structure of holder, which
features: A barrel, which is a hollow tube and a room is thus formed,
in which a height-drop ring slot of large diameter and a resist
ring are provided at the font end of the barrel, where the ring
slot is provided to be buckled by the needle base; a holder, which
is formed in one-time injection molding from compounding two materials,
in which a needle base and a step ring are formed, where a convex
ring is formed around the peripheral of step ring, and a hole is
provided at the center of needle base, while a ramp is provided
at the bottom of the hole, and a buckle ring is provided at the
opening edge of the ramp; a plunger, which is jointed to the buckle
base of the holder, where a buckle head and an enveloped rubber
head are provided at the end part; as the convex ring is formed
by rubber material, and the coefficient of deformation for rubber
material is large, the allowed range of inaccuracy is broadened,
the yield rate is thus significantly raised.
2. An improved needle holder for safety syringe as claimed in claim
1 wherein the buckle head of plunger can drop into buckle ring
of holder for buckling and joint, and forms a structure that allows
one-way pushing and buckling only whereas breaking away is not permitted.
3. An improved needle holder for safety syringe as claimed in claim
1 wherein the buckle head of plunger can be embodied into a shape
of cone or round.
4. An improved needle holder for safety syringe as claimed in claim
1 wherein the buckle head of plunger can provide a gap of minor
span at its center to increase the force of buckle between buckle
head and the holder.
5. An improved needle holder for safety syringe as claimed in claim
1 wherein the buckle ring can be embodied using rubber material
since the high coefficient of deformation for rubber material can
significantly raise the yield rate.
Safety syringe description
BACKGROUND OF THE INVENTION
[0001] 1) Field of the Invention
[0002] The present invention relates to an improved needle holder
for safety syringe. More specifically, it relates to the material
for locating as well as the structural design of a needle holder
for safety syringe, in which the technology of compounding plastic
and rubber materials is applied, such that the holder can be properly
compressed at the front end of barrel and thus relieves and retracts
from the font end of barrel.
[0003] 2) Description of the Prior Art
[0004] Conventional needle holder for safety syringe provides a
hook part at the front of plunger. When the plunger is pushed to
the end, the hook part hooks the needle holder, and the needle holder
along with the needle are retracted back to the barrel while the
plunger is pulled back, the contamination caused by careless piercing
is thus avoided.
[0005] The inventor of the present invention has strived for the
development of safety syringe over a long period of time, and he
has been granted numerous patents. Since the conventional needle
holder and the barrel are manufactured by multi-cavity plastic injection
molding, and as the injection environment and condition of different
cavities are not necessarily the same, while there generally exist
distinctions between multiple molds in mass production, it is difficult
to precisely control the sizes of respective needle holder and barrel
after injection forming. Consequently, it is hard to match each
other, and the manufacturers are upset by the resultant low yield
rate.
[0006] Therefore, based on the description in a previously submitted
application for Taiwan patent and the structure as well as the operation
principles of "needle holder for safety syringe", which
was a invention patent with grant number of 194836 the inventor
of the present invention herein further improves the two-piece needle
holder into a one-piece type. Besides, since the improved holder
can be embodied and inlaid into the preceding structure of components,
hence additional design of barrel or other component mold are unnecessary.
SUMMARY OF THE INVENTION
[0007] To meet the aforementioned requirements, the main purpose
of the improved needle holder for safety syringe according to the
present invention provides a holder that the technology of compounding
plastic and rubber materials to compound two materials is applied
and is formed in one-time process, such that the quantity of components,
cost, and manufacturing processes are all reduced. Besides, making
convex ring of holder from rubber material of high coefficient deformation,
the allowed range of inaccuracy certainly becomes broader, and the
yield rate is accordingly raised.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an exploded view of the present invention.
[0009] FIG. 2 is a 90 degree sectional view of the present invention.
[0010] FIG. 3 is a vertically sectional view of the present invention.
[0011] FIG. 4 shows the action of pushing the plunger forward according
to the present invention.
[0012] FIG. 5 shows that the needle and the holder are retracted
into the barrel according to the present invention.
[0013] FIG. 6A is another embodiment of the buckle head according
to the present invention.
[0014] FIG. 6B is another embodiment of the buckle head according
to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIGS. 1 and 2 the safety syringe is composed
of a needle cap 11 a needle 1 a barrel 2 a holder 3 and a plunger
4 in which the barrel 2 is a hollow tube and a room 21 is thus
formed. A height-drop ring slot 24 of large diameter is provided
on the upper side of inner wall 22 of the room 21 at the font end
of the barrel 2 while a resist ring 25 is formed in ring slot 24
and is neighbored to the low-inner wall 23 in which the diameter
of the low-inner wall 23 is larger than that of the up-inner wall
22 yet smaller than the diameter of ring slot 24. Ring slot 24 is
designed for supporting the compressing and buckling applied by
convex ring 33 of holder 3.
[0016] Further, a needle base 31 is formed on the holder 3 for
inserting and fixing needle 1 the lower side of needle base 31
is provided a height-drop to form a step ring 32 and the peripheral
of step ring 32 is formed a convex ring 33 in which the convex
ring is made from rubber material, and the holder 3 can be formed
in one-piece injection molding. As the rubber material has higher
coefficient of deformation, the resist ring 25 and ring slot 24
of barrel 2 can endure higher range of inaccuracy between each other,
and thus significantly raises the yield rate.
[0017] Moreover, a hole 30 is provided at the center of needle
base 31 such that medication can be injected into the needle 1.
A ramp 300 is provided at the bottom of hole 30 to meet the cone
of buckle head 41 in which a buckle ring 34 is provided at the
opening edge of the ramp 300 in order to be buckled to the buckle
head 41.
[0018] Besides, a cone buckle head 41 and an enveloped rubber head
42 are provided at the end part of the plunger 4 in which the buckle
head 41 is droppable into the buckle ring 34 of ramp 300 thus constructs
a structural design that allow one-way pushing only whereas breaking
away is not permitted. Consequently, after pushing the plunger 4
to the end, the buckle head 41 will not break away from the holder
3 once getting jointed with buckle ring 34.
[0019] Further, referring to FIGS. 3 and 4 during injection, plunger
4 is pushed forward in the room 21 of barrel 2 once the buckle
head 41 drops into buckle ring 34 the unbreakable joint is completed,
and the buckle head 41 is attached to the ramp 300 of the hole 30.
Such a design not only expects that the medication is injected completely,
but as well broaden the allowed error value when cone buckle head
41 contacts ramp 300 and firmly joints to the holder.
[0020] On the other hand, during the period of pulling plunger
4 as the buckle ring 34 is made from rubber material, the margin
of allowed deformation is large, and once the force of buckling
the buckle ring 34 and the buckle head 41 is greater than the compressing
of convex ring 33 to the ring slot 24 the plunger 4 is pulled back,
and the convex ring 33 is forced to break away from the resist of
ring slot 24 and resist ring 25 the holder 3 and needle 1 are integrally
retracted back to the room 21 of barrel 2. The operation of retracting
safety needle is thus completed, as shown in FIG. 5.
[0021] Furthermore, referring to FIGS. 6A and 6B, which show another
embodiment of the buckle head according to the present invention.
Considering that the force of buckling the buckle head 41 to the
buckle ring 34 should be larger than the compressing of convex ring
33 to the ring slot 24 to firmly and safely pull back the holder
3 as well as the needle 1 the size of lock 41 becomes critical,
thus this embodiment provide a gap 410 in buckle head 41 such that
the largest allowed error value to the diameter of the cone is increased.
[0022] As described in the background and main purpose of the present
invention, the holder 3 is a critical component of the whole safety
syringe. Since the assembly of installing the holder 3 to the barrel
2 significantly influences the yield rate of the whole safety syringe.
By way of the technology of compounding plastic and rubber materials
and applying the rubber material to embody the convex ring 33 of
the holder 3 on account of its high coefficient of deformation,
the holder 3 can be compressed properly at the front part of barrel
2 the allowed range of inaccuracy is thus raised, and the yield
rate is accordingly raised. |