U.S. patent number 3,831,602 [Application Number 05/225,505] was granted by the patent office on 1974-08-27 for adjustable syringe assemblies.
This patent grant is currently assigned to Union Plastics Corporation. Invention is credited to Samuel Broadwin.
United States Patent |
3,831,602 |
Broadwin |
August 27, 1974 |
ADJUSTABLE SYRINGE ASSEMBLIES
Abstract
An adjustable syringe assembly capable of adjusting the extent
to which fluid is drawn into a syringe. A plunger of the syringe is
engaged by a pusher which is guided by a support releasably
connected with a barrel of the syringe. This support carries a stop
which is adjustably fixed to the support in the path of movement of
part of the pusher so as to adjust the extent to which the plunger
is displaced along its suction stroke.
Inventors: |
Broadwin; Samuel (New York,
NY) |
Assignee: |
Union Plastics Corporation
(Springfield, NJ)
|
Family
ID: |
22845153 |
Appl.
No.: |
05/225,505 |
Filed: |
February 11, 1972 |
Current U.S.
Class: |
604/210; 222/309;
604/186 |
Current CPC
Class: |
A61M
5/31548 (20130101); A61M 5/31591 (20130101); A61M
5/31578 (20130101); A61M 5/204 (20130101) |
Current International
Class: |
A61M
5/315 (20060101); A61M 5/20 (20060101); A61m
005/22 () |
Field of
Search: |
;128/218F,218C,218PA,215,218R ;222/309,340 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Attorney, Agent or Firm: Steinberg & Blake
Claims
What is claimed is:
1. A syringe assembly comprising an elongated barrel having one end
through which fluid enters into and discharges from said barrel and
an opposed open end distant from said one end, plunger means
extending through said opposed open end of said barrel into the
interior thereof for movement along a pressure stroke in the
interior of said barrel toward said one end thereof for discharging
fluid from said barrel and for movement in an opposite direction
away from said one end thereof along a suction stroke for sucking
fluid into said barrel, spring means engaging said barrel and
plunger means for urging the latter along said suction stroke
thereof, elongated support means extending longitudinally along
said plunger means beyond said opposed open end of said barrel and
having an end region situated adjacent the latter end of said
barrel, connecting means coacting with said elongated support means
and said barrel for releasably fixing said elongated support means
to said barrel at the region of said opposed open end thereof,
pusher means carried by said elongated support means for engaging
and pushing said plunger means in opposition to said spring means
along said pressure stroke for discharging fluid out of said barrel
through said one end thereof, said pusher means when released from
pushing said plunger means along said pressure stroke thereof being
returned by said spring means toward a starting position
simultaneously with retraction of said plunger means along said
suction stroke thereof by said spring means, and adjustable stop
means fixedly connectable to said elongated support means at a
selected location along the path of movement of said pusher means
when released, and mot moving with said pusher means, for limiting
the extent to which said pusher means is returned toward said
starting position by said spring means simultaneously with
retraction of said plunger means along said suction stroke, so that
in accordance with the selected location of said stop means along
said support means a predetermined amount of fluid will be sucked
into said barrel by said plunger means, said elongated support
means being of a tubular configuration having a hollow interior
receiving that part of said plunger means which extends beyond said
barrel, said tubular support means having an end distant from said
barrel through which said pusher means extends into the hollow
interior of said tubular support means into engagement with said
plunger means, and said tubular support means being formed with an
elongated slot extending longitudinally along said tubular support
means, said stop means extending through said slot and carrying a
releasable fixing means for releasably fixing said stop means to
said tubular support means at a selected location along said slot
thereof, and said pusher means having an end region in said tubular
support means engaging said plunger means and provided with a
projection extending through said slot between said stop means and
that end of said slot which is nearest to said barrel so that said
stop means will interrupt the movement of said projection of said
pusher means during expansion of said spring means for determining
the suction stroke of said plunger means, said projection of said
pusher means threadedly carrying an adjusting screw which engages
said stop means for providing fine adjustment of the suction stroke
of said plunger means.
2. A syringe assembly comprising an elongated barrel having one end
through which fluid enters into and discharges from said barrel and
an opposed open end distant from said one end, plunger means
extending through said opposed open end of said barrel into the
interior thereof for movement along a pressure stroke in the
interior of said barrel toward said one end thereof for discharging
fluid from said barrel and for movement in an opposite direction
away from said one end thereof along a suction stroke for sucking
fluid into said barrel, spring means engaging said barrel and
plunger means for urging the latter along said suction stroke
thereof, elongated support means extending longitudinally along
said plunger means beyond said opposed open end of said barrel and
having an end region situated adjacent the latter end of said
barrel, connecting means coacting with said elongated support means
and said barrel for releasably fixing said elongated support means
to said barrel at the region of said opposed open end thereof,
pusher means carried by said elongated support means for engaging
and pushing said plunger means in opposition to said spring means
along said pressure stroke for discharging fluid out of said barrel
through said one end thereof, said pusher means when released from
pushing said plunger means along said pressure stroke thereof being
returned by said spring means toward a starting position
simultaneously with retraction of said plunger means along said
suction stroke thereof by said spring means, and adjustable stop
means carried by said elongated support means at a selected
location along the path of movement of said pusher means when
released for limiting the extent to which said pusher means is
returned toward said starting position by said spring means
simultaneously with retraction of said plunger means along said
suction stroke, so that in accordance with the selected location of
said stop means along said support means a predetermined amount of
fluid will be sucked into said barrel by said plunger means,
wherein said elongated support means is of a tubular configuration
having a hollow interior receiving that part of said plunger means
which extends beyond said barrel, said tubular support means having
an end distant from said barrel through which said pusher means
extends into the hollow interior of said tubular support means into
engagement with said plunger means, and said tubular support means
being formed with an elongated slot extending longitudinally along
said tubular support means, said stop means extending through said
slot and carrying a releasable fixing means for releasably fixing
said stop means to said tubular support means at a selected
location along said slot thereof, and said pusher means having an
end region in said tubular support means engaging said plunger
means and provided with a projection extending through said slot
between said stop means and that end of said slot which is nearest
to said barrel so that said stop means will interrupt the movement
of said projection of said pusher means during expansion of said
spring means for determining the suction stroke of said plunger
means, and wherein said stop means includes a T-shaped member
having one leg situated in the interior of said tubular support
means extending transversely across and beyond said slot and a
second leg extending through said slot to the exterior of said
tubular support means and formed itself with a notch, a strap
extending across said notch and said slot of said tubular support
means and engaging the exterior surface of the latter, a screw
fixed to said T-shaped member and extending longitudinally along
said second leg thereof into said notch of the latter, said strap
being formed with an opening through which said screw extends, a
nut carried by said screw for releasably clamping said stop means
to said tubular support means at opposed edge regions of said slot
thereof, and wherein said tubular support means has at its exterior
a pair of ribs extending along opposite sides of said slot and
respectively formed with notches distributed along each rib with
the notches of one rib aligned with the notches of the other rib,
and all of said notches being located equidistantly from each
other, and said strap having a pair of relatively sharp edges
located in a pair of successive notches of each rib at a selected
position of adjustment of said stop means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to syringes.
In particular, the present invention relates to syringes which can
be adjusted for determining the extent to which fluid is sucked
into and discharged therefrom.
As is well known, a conventional syringe includes a barrel and a
plunger for drawing fluid into the barrel during a suction stroke
of the plunger and for discharging fluid from the barrel during a
pressure stroke of the plunger. The plunger must be very carefully
moved with respect to the barrel in order to make certain that the
desired amount of fluid is accurately drawn into the barrel. This
extreme care which must be exercised in connection with the
operation of a conventional syringe presents a great inconvenience.
This latter inconvenience becomes a very substantial drawback in
the case where a syringe must be used repeatedly in order to draw
precisely the same amount of fluid into the syringe at each stroke
of the plunger.
There are various situations encountered where a syringe is used
repeatedly under these conditions. For example, there are
situations where the same dose of a given fluid is to be repeatedly
injected into a number of patients, for example, so that a
physician, nurse or the like must repeatedly exercise the above
extreme care to make certain that precisely the right amount of
fluid is drawn into the syringe at each use thereof. In addition
there are situations where mechanical structures cooperate with a
syringe to operate the latter mechanically so as to provide cycles
during each of which a given amount of fluid is to be drawn into
the syringe from one container and expelled from the syringe into
another container. In this latter situation, it may be necessary,
for example, to add precisely determined amounts of liquid to a
number of individual containers, and manual operation of a syringe
under these conditions represents a great loss of time and
increased labor costs.
Moreover, the above situation is aggravated by the fact that during
one series of operations one amount of fluid may be required to be
repeatedly drawn into and expelled from a syringe while during a
following series of operations a different amount of fluid is to be
drawn in and expelled from a syringe. Under these latter
conditions, the changeover from the first amount which is
repeatedly drawn in and expelled to the second amount which is
repeatedly drawn in and expelled represents a further extreme
inconvenience which is encountered at the present time with
conventional syringes.
SUMMARY OF THE INVENTION
It is accordingly a primary object of the present invention to
provide a syringe assembly which will avoid the above
drawbacks.
In particular, it is an object of the present invention to provide
a syringe assembly which makes it possible to set the assembly in
such a way that once it is set it can be operated rapidly and
conveniently to repeatedly draw in a precisely determined amount of
fluid which is repeatedly expelled, so that the above inconvenience
is eliminated.
Furthermore, it is an object of the present invention to provide an
assembly of this type which can be readily adjusted so as to change
the precisely determined amount of fluid which is drawn into the
syringe.
Yet another object of the present invention is to provide a
structure of the above type which can be used with a conventional
syringe.
In particular, it is an object of the invention to provide a
relatively simple inexpensive structure which can be attached to a
conventional syringe so as to eliminate all of the drawbacks
referred to above.
Yet another object of the present invention is to provide an
inexpensive structure of this type which can be attached to
different types of conventional syringes for eliminating the above
drawbacks even though different types of syringes are used.
According to the invention the syringe assembly includes a barrel
having one end through which fluid is drawn into and expelled from
the barrel, this barrel having an opposed open end though which a
plunger means extends into the barrel for movement toward the one
end thereof during the pressure stroke while fluid is discharged
and in an opposite direction along a suction stroke in order to
draw fluid into the barrel. A spring means coacts with the plunger
means to urge the latter along its suction stroke. An elongated
support means is fixed by a releasable connecting means to the
barrel at the region of the opposed open end thereof referred to
above, and this elongated support means supports a pusher means for
movement along the axis of the barrel while engaging the plunger
means so as to push the latter along its pressure stroke in
opposition to the spring means, the pusher means being released to
permit the spring means to expand in order to retract the plunger
means along its suction stroke while returning the pusher means
toward a predetermined starting position thereof. An adjustable
stop means is carried by the support means to be located thereon at
a selected location in the path of movement of the pusher means so
as to determine the extent to which the plunger means is retracted
along its suction stroke by the spring means. Thus, by locating the
stop means at a selected location along the support means it is
possible to determine in a highly precise manner the suction stroke
of the plunger means when it is released from the pushing force of
the pusher means, and in this way precisely determined amounts of
fluid can be repeatedly drawn into the barrel to be susequently
expelled therefrom by the action of the pusher means.
BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by way of example in the accompanying
drawings which form part of this application and in which:
FIG. 1 is a front elevation of one possible syringe assembly
according to the present invention;
FIG. 2 is a longitudinal sectional elevation of the structure of
FIG. 1 taken along line 2--2 of FIG. 1 in the direction of the
arrows;
FIG. 3 is a transverse sectional plan view taken along line 3--3 of
FIG. 1 in the direction of the arrows;
FIG. 4 is a fragmentary partly sectional elevation showing a
variation of the structure of FIG. 2;
FIG. 5 is a transverse sectional plan view taken along line 5--5 of
FIG. 1 in the direction of the arrows;
FIG. 6 is a transverse sectional plan view showing a variation of
the structure of FIG. 5;
FIG. 7 is a partly sectional fragmentary elevation showing a
variation of the releasable connecting means of FIGS. 1 and 2,
and
FIG. 8 is a fragmentary elevation of a further embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1, the syringe assembly 10 of the present
invention which is illustrated therein includes an elongated barrel
12 which may be made of a transparent plastic carrying suitable
graduations 14, as is well known. This barrel 12 has a lower end 16
through which fluid is drawn into and discharged from the barrel
12. If desired this end 16 may be provided with the valve assembly
18. This assembly 18 has one-way valves 20 and 22 so that, for
example, through a flexible tubular member 24 fluid can be drawn
into the barrel 12 during a suction stroke of a plunger which moves
therein but cannot discharge through the valve 20, while during a
pressure stroke of the plunger fluid will discharge through the
valve 22 which does not permit fluid to be drawn in through the
valve 22. In this way through the tube 24 a fluid may be drawn out
of one container into the barrel 12 and then during the pressure
stroke of the plunger the fluid can be discharged through the valve
22 into another container.
The elongated barrel 12 has at its top end a flange 26 which has in
the illustrated example opposed curved side edges 28 (FIG. 3) and a
pair of opposed extensions 30 which project laterally from the
barrel at the top open end thereof, as viewed in FIGS. 1 and 2.
An elongated plunger means 32 extends into the barrel 12 through
the top open end thereof. This plunger means terminates at its
bottom end in a piston member 34 which has a slidable fluid-tight
engagement with the inner surface of the barrel as is well known.
From the piston member 34 the plunger means has an elongated shank
extending upwardly beyond the barrel 12 and formed in the
illustrated example by intersecting walls 36 which are
perpendicular to each other and which extend along the axis of the
barrel 12. These walls 36 which are perpendicular to each other are
connected at their top end to a flange 38 shown most clearly in
FIG. 2. This flange 38 extends beyond the outer edges of the fins
or mutually perpendicular intersecting walls 36 which form the part
of the plunger means 32 to which the piston 34 is fixed.
A spring means 40 coacts with the plunger means 32 for urging the
latter along its suction stroke which takes place when the piston
34 moves upwardly away from the lower end 16 of the barrel 12. This
spring means 40 is in the form of a coil spring which is coiled
about the intersecting walls 36 of the plunger means 32. The coil
spring has a top end engaging the flange 38 and a bottom end
engaging an upwardly directed surface at the top end of the barrel
12. This surface is surrounded by the flange which forms the
extensions 30 shown in FIG. 3. Thus, the spring 40 constantly seeks
to urge the plunger means 32 upwardly along its suction stroke.
In accordance with the present invention an elongated support means
42 is releasably connected with the barrel 12 at the region of its
top open end. This support means 42 is in the form of an elongated
tubular member which has a bottom end located at the region of the
top open end of the barrel 12. The tubular support means 42 may
have at its bottom end, in the example illustrated in FIGS. 1-3, a
pair of opposed notches 44 through which the extensions 30 at the
top end of the barrel can pass. The walls of the tubular support
means 42 between these notches, which extend axially from the
bottom end of the tubular support means 42, are formed with short
circumferential notches 46 which communicate with the noches 44 at
the top ends of the latter. Thus, once the extensions 30 are placed
in the notches 44, the barrel can be turned to locate portions of
the extensions 30 in the notches 46, and thus a bayonet connection
is made by this releasable connecting means between the bottom end
of the tubular support means 42 and the top end of the barrel
12.
The tubular support means 42 serves to support for movement along
the axis of the barrel 12 an elongated pusher means 48. This pusher
means 48 has a structure resembling that part of the plunger means
32 which extends upwardly beyond the piston 34. Thus, the pusher
means 48 itself is composed of a pair of intersecting walls 50 and
52 which are perpendicular to each other. The tubular support means
42 terminates at its top end in a top wall 54 which is formed with
a pair of intersecting slots through which the intersecting walls
50 and 52 slidably extend. The pair of intersecting walls 50 and 52
are fixed at their top ends to a transverse flange 56 which
provides a flat outer end surface for the pusher means. This
surface 58 can be manually engaged or it may be actuated by a
rotary cam, for example.
In the hollow interior of the tubular support means 42 the walls 50
and 52 of the pusher means 48 are fixed to a flange 60 which
extends across the interior of the tubular support means 42 and
which directly engages the top flange 38 at the top end of the
plunger means 32.
The elongated tubular support means 42 is formed with a
longitudinally extending slot 62 which extends substantially
through the length thereof, as is particularly apparent from FIGS.
1 and 2. The flange 60 at the bottom end of the pusher means has an
extension 64 which extends through and beyond the slot 62. In this
slot 62, above the projection 64 of the pusher means there is a
stop means 66 which is adjustable along the slot 62 and which is
situated at a selected location therealong by a releasable fixing
means. The stop means 66 includes a substantially T-shaped member
68 (FIG. 5) which has one leg in the interior of the tubular
support means 42 extending across the slot 62 and which has a
second leg extending through the beyond the slot 62. This second
leg of the T-shaped member 68 is itself formed with a horizontal
notch 70. In this notch 70 is located a strap 72 which extends
across the slot 62 at the exterior of the tubular support means 42.
The tubular support means 42 may be provided along the edges of the
slot 62 at the exterior of the tubular support means with a pair of
longitudinally extending lips 74, and the strap 72 may terminate at
its opposed ends in a pair of extensions 76 between which these
lips are located, as in most clearly apparent from FIG. 5.
The releasable fixing means for the adjustable stop means includes
an elongated screw member 78 fixed to the T-shaped member 68,
extending therefrom centrally through the notch 70 in the leg which
extends through and beyond the slot 62, and this screw 78 extends
through a central opening of the strap 72. Beyond the strap 72 the
screw 78 carries a nut 80 provided, for example, with the knurled
head so that the operator can conveniently turn this nut. Thus, by
loosening the nut 80 it is possible to loosen the strap 72 and
member 68 so that they can be shifted along the edges of the slot
62 to a desired location therealong, and once this location is
reached the nut 80 can be tightened so as to releasably fix the
stop means 66 at a selected location along the slot 62.
The above described structure operates as follows:
With the parts assembled as shown in FIGS. 1 and 2, the operator
can depress the pusher means 48 so as to move the piston 34
downwardly along its pressure stroke in opposition to the spring 40
which becomes compressed, the bottom end 60 of the pusher means 48
engaging the top end 38 of the plunger means so as to transfer
downward movement of the pusher means to the plunger means. In
order to render this movement convenient the support means 42 may
have a pair of extensions 82 at its top end suitably curved to be
engaged by the first and second fingers of the hand of the operator
while the thumb of the operator can engage the top surface 58 of
the pusher means 48. Thus, the entire pusher means will be
displaced downwardly along the interior of the tubular support
means 42, displacing the plunger means 32 downwardly in opposition
to the spring 40, and this movement is continued until the plunger
means reaches the bottom end of its pressure stroke when the piston
34 is located at its position closest to the discharge end 16 of
the barrel 12. Then the operator will simply release the pusher
means 42. The result is that the spring 40 will expand, returning
the parts toward their starting position such as that illustrated
in FIG. 2. The spring 40 will continue to expand, by displacing the
plunger means 32 along its suction stroke so as to draw fluid into
the barrel 12. This movement will continue until the projection 64
engages the stop means 66. Thus, by properly positioning the stop
means 66 a precisely determined amount of fluid will be drawn into
the barrel 12. Then during the next pressure stroke this fluid will
be expelled and upon release of the plunger means the spring 40
will again expand so as to repeat this operation. Therefore, by
properly positioning the stop means 66 it is possible to repeatedly
draw into the barrel 12 a precisely determined amount of fluid
which is subsequently expelled therefrom, and these operations can
be repeated as often as desired with a high degree of accuracy and
a minimum of inconvenience. As was pointed out above, instead of
operating the structure manually it is possible to adapt it for use
with a mechanically operating structure where a cam, for example,
will engage the surface 58 to displace the pusher means 48 in the
direction which pushes the plunger means 32 along its pressure
stroke, this cam then releasing the pusher means so that the spring
40 can expand to bring about the above operations in a mechanical
manner.
As is indicated in FIG. 4, the above-described structure may be
varied by mounting a rotary screw member 84 on the projection 64.
This screw member can simply be threaded through the projection 64
so that the top free end of the screw 84 can engage the lower
surface of the stop means 66. Thus, once the stop means 66 has been
placed in what is believed to be an accurate position, it is
possible by turning the screw 84 to provide an extremely fine
control of the extent to which fluid will be drawn into the barrel
12 during each suction stroke.
All of the above components may be conveniently made of plastic. As
is illustrated in FIG. 5, the tubular support means 42 may be made
of a pair of plastic components 42a and 42b having aligned ears 86
which engage each other and which are connected by rivets 88, so
that in this way the parts can be maintained in assembled
condition.
However, instead of such an arrangement it is possible to use an
arrangement as shown in FIG. 6 where the two components 42c and 42d
of the tubular support means 42 have interlocking projections for
assembling the components of the tubular support means. Thus, the
part 42c may have at its opposed side edges elongated tongues 90
which can snap into springy grooves 92 carried by the component
42d.
Furthermore, the exterior surface of the tubular support means 42
at the region of its lower end may be provided with exterior
threads 94, as shown in FIGS. 1 and 7. These exterior threads 94
are adapted to coact with the interior threads of a cap nut 96.
This cap nut 96 has a bottom circular flange 98 through which the
barrel 12 extends. With this construction the barrel 12 can
terminate at its top end in a simple circular flange 100 which
engages the bottom end surface of the tubular support means 42 with
the flange of the cap nut 96 engaging the flange 100 to press the
latter against the bottom end of the tubular support means 42, so
that with this arrangement by the addition of the simple cap nut 96
it is possible to utilize instead of the bayonet connection to
FIGS. 1-3 a threaded cap nut connection as shown in FIG. 7. In this
way the structure is adapted to be used with syringes of different
types. It is to be noted that the flange 100 can have a
considerable variation in its outer diameter while still being
capable of engaging the flange 98 and pressed against the bottom
end of the tubular support means 42, so that through a considerable
range of flange diameters it is still possible to use one
embodiment of the assembly structure of the invention which is used
in addition to the conventional syringe structure.
As may be seen from FIG. 8, the ribs 62' of this embodiment, which
otherwise is identical with that of FIG. 2, for example, are formed
with notches 100, and the notches of one of the ribs 62' are in
horizontal alignment with the notches of the other rib. The strap
72 is replaced by a strap 102 provided with relatively sharp edges
104 to be received in a pair of successive notches 100 of each rib
62'. In this way the stop means will be reliably held in a selected
position. In the event that it is desired to provide adjustments
between these positions, then an adjusting screw 84 as shown in
FIG. 4 may be used.
* * * * *