U.S. patent number 3,742,948 [Application Number 05/062,332] was granted by the patent office on 1973-07-03 for hypodermic syringe with radially movable blocking elements.
This patent grant is currently assigned to U.S. Philips Corporation. Invention is credited to Daniel Ong, Hendrik Alle Post.
United States Patent |
3,742,948 |
Post , et al. |
July 3, 1973 |
HYPODERMIC SYRINGE WITH RADIALLY MOVABLE BLOCKING ELEMENTS
Abstract
A hypodermic syringe comprising a liquid container and a needle
connected thereto at one end, which assembly is incorporated in a
housing, the liquid container being bounded at the other end by a
piston, and an operating mechanism being present to exert a force
on the piston, one or more blocking elements being present for
locking the operating mechanism or the piston against movement
relative to the liquid container, the housing showing a diameter
transition such that when the blocking elements pass along it, they
are moved radially so that the blocking is removed and the piston
penetrates into the liquid container so that the liquid flows out
through the needle.
Inventors: |
Post; Hendrik Alle (Emmasingel,
Eindhoven, NL), Ong; Daniel (Emmasingel, Eindhoven,
NL) |
Assignee: |
U.S. Philips Corporation (New
York, NY)
|
Family
ID: |
19807748 |
Appl.
No.: |
05/062,332 |
Filed: |
August 10, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Aug 25, 1969 [NL] |
|
|
6912969 |
|
Current U.S.
Class: |
604/139 |
Current CPC
Class: |
A61M
5/24 (20130101); A61M 5/2033 (20130101); A61M
2005/206 (20130101); A61M 2005/2073 (20130101); A61M
5/2459 (20130101) |
Current International
Class: |
A61M
5/24 (20060101); A61M 5/20 (20060101); A61m
005/20 () |
Field of
Search: |
;128/218R,218F,218A,218D,218P,218PA,218DA,215,216,217,173H |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Claims
What is claimed is:
1. A hypodermic syringe comprising a cylindrical liquid container,
a needle connected to one end thereof, a piston slidably fitting in
the other end of the liquid container, a medicament in the
container between the needle and piston, an elongate cylindrical
housing slidably carrying said container, a pressure member
slidably positioned in the housing adjacent the piston end of the
container, transversely movable positive blocking means engaging
the edge of the container at the piston end and controlling
relative movement of the container and the piston therein by the
pressure member, spring means for forcing the pressure member
toward the needle end of the housing, stop means on the needle end
of the housing, transition means on the inner surface of the
housing between said blocking means and said stop means for causing
the blocking means to move out of engagement with the container
whereby the pressure member will force the piston toward the needle
to eject the medicament in said container.
2. The invention as set forth in claim 1 and wherein the pressure
member has a head portion sized to slidably fit within the
container, the housing comprises an upper portion and a lower
portion of larger inner diameter and further wherein the
transversely movable positive blocking means comprises annular
elements bearing on the edge of the cylindrical container at the
piston end and in engagement with the inner wall of the upper
portion of the housing, the inner face of each annular element
sloping downwardly and inwardly and terminating inwardly of the
container wall to form a circular opening of smaller diameter than
the head portion of the pressure member, the head portion of said
pressure member engaging said inner faces whereupon movement of the
pressure head moves the cylindrical container toward the lower
housing portion, upon reaching the lower housing portion the
pressure head portion forces the blocking elements outwardly to
allow the pressure head to engage the piston and upon continued
movement eject the medicament from the container.
3. The invention as set forth in claim 1 and wherein the housing
comprises an upper portion and a lower portion, said lower portion
having a plurality of axial grooves in its inner wall, the
transversely movable positive blocking means comprising a plurality
of lugs extending radially from the pressure member and fitting in
the aforesaid grooves, said lugs each having a flat lower face
engaging the edge of the container adjacent the piston end and a
downwardly and inwardly sloping outer face, the lower end of each
of the grooves being provided with an inwardly and downwardly
sloping bevel termination, whereupon downward movement of the
pressure head the outer faces of the lugs engage the bevel
terminations and cause the lugs to move inwardly so as to force the
flat lower faces of the lugs off the container edge and allow the
lugs to be forced radially inwardly to slide within the container
and engage the piston to eject the medicament.
4. The invention as set forth in claim 1 and wherein the housing
comprises an upper portion and a lower portion having a plurality
of axial grooves in its inner wall, the transversely movable
positive blocking means comprising a plurality of lugs connected to
the piston and fitting in the aforesaid grooves, each lug having an
intermediate horizontal flat face engaging the edge of the
container adjacent the piston end, the upper portion of each lug
extending into its respective groove, the lower end of each of the
grooves being provided with an inwardly and downwardly sloping
bevel termination, whereupon downward movement of the pressure
member the upper portion of the lugs will engage the bevel
terminations and be forced inwardly removing the flat face lug
portion from the edge of the container and allowing the piston to
then be moved to eject the medicament.
Description
The invention relates to a hypodermic syringe comprising an
assembly of liquid container and a needle connected thereto at one
end, which assembly is incorporated in an elongate housing so as to
be movable, the other end being bounded by a piston fitting in said
container, the housing being bounded on the side of the needle by a
wall through which the needle can, but the liquid container cannot,
pass, an operating mechanism being furthermore present to exert a
force on the piston.
A hypodermic syringe of the above-described type is known from the
French Pat. specification No. 1,342,358. In this hypodermic syringe
a pressure is exerted on the piston by means of a pre-tensioned
spring after unlocking the operating mechanism. As a result of
this, the assembly of liquid container and needle is moved to the
outside while at the same time a diaphragm which separates the
liquid from the needle can be broken in that the liquid becomes
under pressure so that the liquid starts flowing out.
A drawback of this known hypodermic syringe is that the liquid can
already be pressed out of the liquid container before the needle
has penetrated sufficiently far into the part of the body to be
treated.
It is the object of the invention to mitigate this drawback and to
provide a hypodermic syringe in which the instant at which the
pressing-out of the liquid out of the liquid container begins is
determined unambiguously by the construction of the syringe.
In order to realize the end in view, the hypodermic syringe
according to the invention is characterized in that one or more
blocking elements are present which can be moved at right angles to
the longitudinal direction of the housing and which block the
operating mechanism or the piston against movement relative to the
liquid container, the wall of the housing showing, at least over
those parts of its circumference over which the blocking elements
extend, a diameter transition which is situated at a distance from
the upper edge of the liquid contained at most corresponding to the
length of the needle, all this in such manner that in passing said
transition the said elements move radially and the blocking is
removed, after which the piston can penetrate into the liquid
container and the liquid flows out through the needle.
Upon exerting a force by the operating mechanism in the hypodermic
syringe according to the invention, first the assembly of liquid
container and needle is moved over such a distance that the needle
has reached the desirable depth of penetration, after which, when
the transition edge provided in the housing is passed, the blocking
is removed and the piston presses the liquid out of the liquid
container. In this manner the instant of flowing-out of the liquid
is fully determined by the design of the housing.
The blocking elements may have a variety of constructions; one
example is constituted by pawl segments incorporated in a groove of
the piston or a pressure member cooperating therewith, said pawl
segments being forced by springs against the wall of the housing,
their configuration being such that upon passing the diameter
transition they are forced inwards over such a distance that they
become located inside the wall of the liquid container.
In a favorable embodiment of the hypodermic syringe according to
the invention the blocking elements are formed by annular segments
bearing individually on the upper edge of the liquid container and
engaging with their outer annular surface the wall of the housing,
the inner annular surface of said segments being at least partly
bevelled and having a smallest diameter smaller than the inside
diameter of the liquid container, the piston and a pressure member,
respectively, cooperating therewith of the operating mechanism
comprising a bevelled surface which bears against the bevelled
surface of the annular segments, the diameter at the said diameter
transition becoming larger so that the annular segments can move
outwards and are released from the piston and the pressure member,
respectively.
In a further favorable embodiment of the hypodermic syringe
according to the invention the blocking elements are constituted by
outwardly springing lugs which are connected to the piston or a
pressure member cooperating therewith and which face the liquid
container with their free end and in the untensioned condition have
a larger diameter than the wall of the liquid container, the piston
and the pressure member, respectively, having space for receiving
said lugs when they are compressed, said lugs comprising, on their
surface bearing on the edge of the liquid container, a collar which
falls within the liquid container and comprising a bevel on their
side facing the inner wall of the housing, the diameter of the
housing at the area of the said diameter transition becoming
smaller so that when the lugs move along said transition they are
forced inwards.
In another favorable embodiment of the hypodermic syringe according
to the invention the blocking elements are likewise formed by
outwardly springing lugs connected to the piston or the pressure
member, but in this embodiment their free end is remote from the
liquid container and which lugs, in the untensioned condition, have
a larger diameter than the wall of the liquid container, the piston
and the pressure member, respectively, having space for receiving
said lugs when they are compressed, said lugs comprising a surface
which bears on the edge of the liquid container, the part of the
lugs situated between said surface and their free end being
bevelled on the side facing the wall of the housing, the diameter
of the housing at the area of the said diameter transition becoming
smaller so that when said lugs are moved along it they are forced
inwards.
In the two last-mentioned embodiments the pressure member and the
piston and the lugs connected thereto, respectively, may be formed
as one assembly, for example, of a synthetic resin.
In order that the invention may be readily carried into effect, it
will now be described in greater detail, by way of example, with
reference to the accompanying drawings, in which
FIG. 1 diagrammatically shows a hypodermic syringe comprising a
pressure member provided with blocking lugs.
FIG. 2 diagrammatically shows a hypodermic syringe in which the
piston is provided with blocking lugs which with their free ends
are remote from the liquid container.
FIG. 3 diagrammatically shows a hypodermic syringe which comprises
separate blocking segments which can be moved radially.
Reference numeral 1 in FIG. 1 denotes a housing which is
constructed of two parts 2 and 3. An assembly of liquid container 4
and needle 5 connected thereto is arranged in said housing so as to
be movable. The lower side of the liquid container 4 is closed by a
diaphragm 6 which bursts when the liquid comes under pressure. The
upper side of the liquid container is closed by a piston 7. A
pressure member 8 constructed as a cup spring cooperates with the
piston 7. A compression spring 9 is present between the pressure
member 8 and the upper side of the part 3 of the housing. The
pressure member 8 is locked against movement by means of a locking
member 10 which is connected thereto and which comprises legs 11 on
its upper side. On their outside the legs 11 comprise a bevel 12
which bears on an edge of the part 3 of the housing with flat sides
13.
A slidable sleeve 14 which comprises a conical bore 15 which can
cooperate with the bevel 12 of the legs 11 is situated around the
part 3 of the housing. In order to prevent an unintentional
actuation of the syringe a pin 16 is present which projects in the
space between the legs 11 in such manner that said legs cannot be
compressed. The pin 16 is affixed to a cap 17 with which the pin
can be removed.
The pressure member 8 comprises resilient lugs 20 which bear on the
upper edge of the liquid container 4 with their free end 21. The
free end 21 comprises a collar 22 which falls within the liquid
container. From the free end 21 the lugs have a bevel 23. At the
area of the lugs 20 the part 3 of the housing comprises axial
grooves in which the lugs 20 are situated. These grooves extend up
to the position 24 where they change to a smaller diameter via a
bevel 50.
The operation of this hypodermic syringe is as follows: First of
all the cap 17 with pin 16 is removed. The housing 14 is then moved
downwards relative to the part 3 of the housing, the legs 11 being
squeezed by conical bore 15 so that the edges 13 are released and
the member 10 with pressure member 8 is forced downwards by the
spring 9. Since the pressure member 8 presses on the liquid
container 4 by means of the lugs 20, said container is also moved
downwards, the needle 5 penetrating the wall of the housing. At the
instant, the needle has substantially entirely left the housing,
the lugs 20 pass the diameter transition 24. Said lugs 20 are
forced inwards so that they are released from the edge of the
liquid container 4, and the pressure member forces the piston 7
downwards and the liquid is pressed out of the liquid container.
During the lowering of the liquid container 4 by means of the
pressure member 8, the lugs 20 exert no extra frictional force on
the wall of the part 3 of the housing because the lugs 20 with
collar 22 engage behind the edge of the liquid container 4 so that
the lugs 20 cannot move outwards.
In this manner a hypodermic syringe is obtained in which the
instant at which the pressing-out of liquid begins is determined
unambiguously by the position of the diameter transition bevel
50.
A seal 25 is present between the liquid container 4 and the part 2
of the housing, so that prior to use the compartment 26 in which
the needle 5 is present is fully closed so that the needle can be
stored in a sterile atmosphere.
FIG. 2 shows a hypodermic syringe which corresponds in general with
the syringe shown in FIG. 1 and in which therefore corresponding
components are referred to by the same reference numerals. The
difference from the syringe shown in FIG. 1 is that the piston 7 is
provided with lugs 30 which are remote from the liquid container
with their free end. A horizontal surface 31 of each of said lugs
30 bears on the edge of the liquid container 4, while from said
surface the lugs 30 extend upwards at an angle over a part 32. The
pressure member 8 is constructed so that it bears again against the
piston 7 and is furthermore provided with recesses in which the
lugs 30 will bear upon compression, In this manner it is achieved
that when the operating mechanism is actuated first the whole
assembly of liquid container 4 and needle 5 is moved. When the
bevel 50 of the grooves are passed, the lugs 30 are pressed inwards
so that the piston 7 in the liquid container starts moving and the
liquid is pressed out.
FIG. 3 shows again a hypodermic syringe as is shown in FIGS. 1 and
2 in which the blocking elements are formed by separate annular
segments 40 a horizontal surface 41 of which bears on the edge of
the liquid container 4. The outer annular surface of said segments
bears against the inner wall of the part 3 of the housing, while
the inner annular surface is provided with an inclined part 42
which has a smaller diameter than the inside diameter of the liquid
container. The pressure member 8 has a diameter which is slightly
smaller than that of the liquid container and, with a bevelled
surface 43, engages the surface 42 of the annular segments. At the
area 24 the part 3 of the housing changes into the part 2 of the
housing which has a slightly larger diameter. When actuating the
operating mechanism of this syringe also, first the liquid
container and the needle are moved by means of the pressure member
because the annular segments lock the pressure member and the
liquid container. When the annular segments 40 pass the edge 24
they are forced outwards as a result of the forces exerted on the
inclined surface 42 so that they are released from the pressure
member. The pressure member then presses on the piston so that the
liquid starts flowing out.
From the above it may be obvious that the invention provides a
hypodermic syringe in which the sequence of movement of the liquid
container with needle and piston is entirely determined by the
design of the housing and blocking elements cooperating
therewith.
* * * * *