U.S. patent number 3,805,783 [Application Number 05/293,620] was granted by the patent office on 1974-04-23 for hand powered hypodermic jet injector gun.
Invention is credited to Aaron Ismach.
United States Patent |
3,805,783 |
Ismach |
April 23, 1974 |
HAND POWERED HYPODERMIC JET INJECTOR GUN
Abstract
A hand powered hypodermic jet injector gun has a hollow housing
with a depending handle formed with a cavity containing a working
fluid. A first chamber in the housing receives the working fluid
from the cavity via a hand pump and one-way valves. A piston and
coil spring in the chamber are retracted by the working fluid
entering the chamber thus to cock the gun. A piston rod attached to
the piston is slidable in a muzzle to eject medicament from a
second chamber in the muzzle via a nozzle thereon. The muzzle is
slidably adjustable by a rotatable coupling ring on the housing of
the gun to adjust the volume of the second chamber. A trigger at
the hand operates another one-way valve for releasing the working
fluid from the first chamber allowing the spring to expand and move
the piston rod for ejecting the medicament from the second
chamber.
Inventors: |
Ismach; Aaron (Brooklyn,
NY) |
Family
ID: |
26812624 |
Appl.
No.: |
05/293,620 |
Filed: |
September 29, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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114871 |
Feb 12, 1971 |
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Current U.S.
Class: |
604/71;
222/283 |
Current CPC
Class: |
A61M
5/30 (20130101); A61M 5/204 (20130101) |
Current International
Class: |
A61M
5/30 (20060101); A61M 5/20 (20060101); A61m
005/30 () |
Field of
Search: |
;128/173H,215,218R,218L,218F ;222/323,283 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Dunne; G. F.
Attorney, Agent or Firm: Loveman; Edward H.
Parent Case Text
This is a continuation, Ser. No. 114,871, filed Feb. 12, 1971 now
abandoned .
Claims
The invention claimed is:
1. In a hydraulic powered jet injector instrument of the type
having a housing with a hydraulic chamber, a hydraulic piston
reciprocally mounted in said hydraulic chamber and rigidly
connected to a medicament piston and wherein a spring means biases
said hydraulic piston in one direction in said hydraulic chamber,
the improvement comprising:
a muzzle slidably mounted at one end thereof to said housing, and
extending partially within said hydraulic chamber, the second end
of said muzzle surrounding said medicament piston, said one end of
said muzzle extending sufficiently into said hydraulic chamber to
act as a stop for said hydraulic piston,
a nozzle means on the other end of said muzzle for ejecting said
medicament:
said nozzle means, said muzzle and said medicament piston defining
a medicament chamber, and
an adjustable coupling means operatively coupling said muzzle and
said housing for adjusting the volume discharged from said
medicament chamber.
2. In a hydraulic powered jet injector instrument as defined in
claim 1, wherein said adjustable coupling means comprising a
rotatable ring threadedly engaged on said housing and having an
internal first radial flange, said muzzle having an external second
radial flange engageable by said first radial flange, whereby the
axial position of said muzzle with respect to said housing is
determined by the rotational position of said ring.
3. A hand powered jet injector instrument comprising:
a hollow housing;
a handle depending from said housing, said handle being formed with
a cavity for containing a fluid, said housing being formed with a
first chamber communicating with said cavity for receiving said
fluid therefrom;
a hand operated pump on said housing arranged to pump said fluid
from said cavity into said chamber;
a piston movable axially in said chamber and retracted by fluid
pumped into said chamber;
a coil spring in said chamber adapted to be compressed by said
piston when said piston is retracted in said chamber;
a muzzle slidably mounted at one end thereof to said housing, and
extending partially within said chamber, said one end of said
muzzle extending sufficiently into said chamber to act as a stop
for said piston;
a piston rod attached to said piston and axially slidable in said
muzzle;
a nozzle means at the other end of said muzzle for ejecting a jet
of a medicament, said nozzle means piston rod and said muzzle
defining a second chamber for containing said medicament; and
adjustable coupling means operatively coupling said muzzle and said
housing and for adjusting the volume discharged from said second
chamber.
4. A hand powered jet injector instrument as defined in claim 3,
further comprising
a manually operable trigger carried by said housing; and
one-way valve means operated by said trigger, said valve means
controlling return of fluid from said first chamber to said cavity
to permit said spring to expand and move said piston and said
piston rod axially to eject said medicament from said chamber.
5. A hand powered jet injector instrument as defined in claim 3,
further comprising:
a container of medicament;
a support means for holding said container onto said muzzle;
said support means including a passage communicating with said
second chamber for passing said medicament from said container into
said second chamber.
6. A hand powered jet injector instrument as defined in claim 5
further comprising:
a manually operable trigger carried by said housing; and
one-way valve means operated by said trigger said valve means
controlling return of fluid from said first chamber to said cavity
to permit said spring to expand and move said piston and said
piston rod axially to eject said medicament from said second
chamber.
7. A hand powered jet injector instrument as defined in claim 3,
wherein said adjustable coupling means comprising:
a rotatable ring threadedly engaged on said housing and having an
internal first radial flange;
said muzzle having an external second radial flange engageable by
said first radial flange, whereby the axial position of said muzzle
with respect to said housing is determined by the rotational
position of said ring.
8. A hand powered jet injector instrument as defined in claim 7,
further comprising:
a container of medicament;
a support means for holding said container onto said muzzle;
said support means including a passage communicating with said
second chamber for passing said medicament from said container into
said second chamber.
9. A hand powered jet injector instrument as defined in claim 8
wherein said support means further comprises:
a bar having a saddle at one end engaged with said muzzle; and
guide means on said housing engageable with the other end of said
bar for preventing said muzzle from rotating with respect to said
housing.
10. A hand powered jet injector instrument as defined in claim 9
wherein said saddle includes a fitting engaged in said saddle and
having a passage communicating with said second chamber for passing
said medicament from said container into said second chamber.
11. A hand powered jet injector instrument as defined in claim 9,
further comprising a bracket on said bar adjustably engaging said
container to hold the same in place while passing said medicament
into said second chamber.
12. A hand powered jet injector instrument as defined in claim 11,
furthr comprising
a manually operable trigger carried by said housing; and
one-way valve means operated by said trigger, said valve means
controlling return of fluid from said first chamber to said cavity
to permit said spring to expend and move said piston and said
piston rod axially to eject said medicament from said second
chamber.
13. A hand powered jet injector instrument as defined in claim 12,
further comprising other one-way valve means in said handle and
said housing arranged to permit passage of said fluid from said
cavity to said first chamber when said pump is operated, said pump
comprising a further passage formed in said housing and a pump rod
axially slidable in said further passage, said further passage
extending between said first chamber under control of said other
one-way valve means.
Description
This invention concerns an improved hand powered hypodermic jet
injector and more particularly involves a medical injector having
improved means for adjusting the volume of dosage injected and for
ejecting the medicament.
Jet injectors heretofore known have generally employed an external
source of hydraulic pressure to eject the medicament, such as
described in my prior U.S. Pat. No. 3,057,349. The need has existed
for a hand powered jet injector which can be operated with a local
rather than an external source of hydraulic pressure, and one in
which the volume of dosage or quantity of medicament injected is
readily adjustable.
According to the invention, there is provided a hypodermic jet
injection gun which is well balanced and may be operated and
comfortably held by an operator in one hand, leaving the operator's
other hand free to swab or grasp the patient. The device is
noiseless and free from recoil and may be quickly and easily
disassembled, and efficiently sterilized by autoclaving or other
means. It can be readily serviced by use of conventional hand tools
without the need for specially adapted tools or devices. The device
is ideal for use in isolated areas, or places where a portable
instrument of this type is required and is easy to use, requiring
no particular skill, with relatively simple components which are
readily replaced if necessary. With this device only the
inoculating fluid goes below the skin level of the patient and thus
it is relatively easy to insure sterile operating conditions since
only the nozzle of the instrument contacts the skin of a
patient.
The hand powered hypodermic injection gun employs a hand operated
hydraulic pump which cocks the gun by retracting an ejection piston
and compressing a spring in the body of the gun. The handle of the
gun contains a reservoir of hydraulic fluid. A valve operating
trigger is operated to permit passage of the fluid from the cocking
chamber back to the reservoir while the spring expands and advances
the ejection piston. The ejection piston passes through a discharge
chamber containing the medicament which is discharged in a fine jet
from a nozzle. The volume of the discharge chamber is adjustable by
the setting of a rotatable coupling ring mounted on the barrel of
the gun. A scale inscribed on the barrel of the gun indicates the
volume of the discharge chamber. Also mounted on the barrel of the
gun and supported by a novel adjustable stand is a container of
fluid medicament which is fed automatically into the discharge
chamber. The stand is adjustable for supporting containers of
different sizes and for protecting the needle which punctures the
container.
Accordingly it is a principal object of the present invention to
provide a portable hypodermic jet injection device which may be
used in isolation without the use of an external power source.
It is another object of the present invention to provide a portable
hypodermic jet injection device wherein the dosage may be easily
adjustable.
It is still another object of the present invention to provide a
portable hypodermic jet injection device wherein the dosage is set
in a sterile manner by simply rotating a ring mounted on the barrel
of the gun.
These and other objects and many of the attendant advantages of
this invention will be readily appreciated as the same becomes
better understood by reference to the following detailed
description when considered in connection with the accompanying
drawings in which:
FIG. 1 is a front view of a hand powered hypodermic injection gun
embodying the invention;
FIG. 2 is a vertical tranverse sectional view taken along line 2--2
of FIG. 1;
FIG. 3 is a vertical, longitudinal sectional view taken along line
3--3 of FIG. 2; and
FIG. 4 is a top plan view of the gun.
Referring now to the drawings wherein like reference characters
designate like or corresponding parts throughout, there is
illustrated a hypodermic injection gun generally designated as
reference numeral 9 comprising a handle 10 in which is a cavity 12
(FIG. 2) defining a reservoir for oil or other hydraulic fluid 14.
The cavity 12 is closed by a plate 16 and a diaphram 18 and they
are secured by four screws 20 at one side 21 of the handle 10. The
diaphram 18 compensates for expansion or contraction of the fluid
14. A resilient pad 17 is secured to the bottom of the handle 10
and may be used to support the gun when the gun is cocked in a
manner to be hereinafter described.
The fluid can be pumped out of the reservoir 12 by a plunger or
piston rod 22 movable axially upwardly in a tubular chamber 24
formed in a side 23 of the handle 10 opposite the side 21. A
fitting 26 screwed into the upper end of a chamber 24 serves as a
guide for the piston rod 22 which carries a knob 27 adapted to be
grasped for reciprocating the rod 22 axially in the chamber 24. The
bottom end of the chamber 24 communicates with the cavity 12 via a
narrow passage 28 opening into a bore 30 containing a conventional
spring loaded ball check valve 32. A passage 34 in a valve core 35
is normally closed by the ball valve 32 and is in communication at
opposite ends respectively with the bore 30 and with a further
passage 38 which leads into the cavity 12.
The fluid 14 which is drawn into the chamber 24 passes into a
transverse bore 40 in the handle 10 when the piston rod 22 is moved
axially downwardly. The bore 40 is normally closed by a ball valve
42 and a spring 44 retained by a screw 46 in the side 21 of the
handle 10. A passage 47 for the hydraulic fluid 14 opens into the
side of bore 40 (FIG. 3) and in turn communicates with a chamber 48
in the gun 9 via a vertical passage 49. The chamber 48 extends
axially horizontal and slidably contains a piston 50. One end of a
massive coil spring 52 bears against the piston 50 and the other
end bears on a screw 54. The head 55 of the screw is exposed and
can easily be removed by hand or by a wrench when required. A
sealing ring 56 in a groove 58, around the piston 50 prevents
leakage of fluid 14 beyond the piston.
The piston 50 is integral with an axial shaft 60 having a central
threaded bore 62. The shaft 60 is slidably disposed in a bore 64
which communicates with the cylindrical chamber 48. An externally
threaded hollow nipple 66 is screwed into a threaded seat 68 at the
left end of the bore 64 to guide movement of the shaft 60. A radial
flange 72 of the nipple 66 bears against the left end of the handle
10. A sealing ring 74 engaged in a groove 75 around the shaft 60
seals the bore 64 against passage of the hydraulic fluid 14 beyond
the bore 64.
A piston rod 80 serves as an ejector for a liquid medicament 82
stored in a container 84. The piston rod 80 has a threaded right
end 83 which is screwed into the central bore 62, in the shaft 60.
A rear radial flange 85 on the rod 80 bears against the left end of
the shaft 60. The left end of the rod 80 extends into a cylindrical
muzzle 90 slidably engaged in the passage 70 of the nipple 66. A
sealing ring 86 in a groove 88 around the rod 80 seals the
medicament 82 in a chamber 100. The forward portion of the muzzle
90 is adapted to receive a closure member 102 which is held firmly
in place at the end of the muzzle 90 by a nozzle cap 104 which is
threadedly engaged to the exterior of the muzzle 90. The chamber
100 is defined as the volume between the closure member 102 and a
conical tip 106 of the rod 80 in the muzzle 90. A head 110 of the
rod 80 is smaller in diameter than a bore 112 of the muzzle 90
thereby providing a narrow circumferential clearance or passage 108
surrounding the head 110.
The closure member 102 is provided with a ball check outlet valve
101 and carries appropriate sealing rings. At its forward
extremity, the nozzle cap 104 carries a sapphire orifice insert 105
which is bored to a very close tolerance and which determines the
diameter of the jetstream of the medicament 82.
After the spring 52 is compressed and the gun is cocked as will
hereinafter be described, the volume of the chamber 100 can be
adjusted by means of a cylindrical coupling ring 114 rotatably
engaged on the externally threaded left end of the nipple 66. The
ring 114 has a circumferential radial flange 116 engaging a radial
flange 118 formed on the muzzle 90. Thus, by rotating the ring 114,
the muzzle 90 will be axially retracted or extended with respect to
the nipple 66, and will thereby vary the spacing between the tip
106 of the piston rod 80 and a corresponding conical wall 101 of
the closure member 102.
The muzzle 90 is prevented from rotating by a bracket 120 which
also serves as a support for the container 84. The vertical bracket
120 includes a flat horizontal bar or strip 122 screwed or welded
to a rectangular saddle 124 which bears on the muzzle 90. The
muzzle 90 has an integral internally threaded cup 126 into which is
screwed a fitting 128 which is centrally bored to carry a
medicament inlet ball valve 130 adapted to seat on a medicament
tube 131 leading to the medicament chamber 100 when the chamber 100
is being filled with medicament. When the medicament in chamber 100
is discharged the inlet ball valve 130 seals a seat 128a and
prevents the medicament from returning to the container 84. A screw
132 in the end of the saddle 124 bears against the fitting 128 to
secure it thereto. The right end of the bar 122 is bifurcated to
form a slot 134 defining a pair of fingers 136. A member such as a
screw 138 extends through the slot 134 between the fingers 136 and
is engaged in a threaded hole 140 in the top of the gun 9. By this
arrangement the screw 138 holds the bracket 120 in a vertical
position. The volume of the chamber 100 and hence the dosage is
determined by the relative positions of the muzzle 90 and the rod
80 and can be indicated by a scale 135 inscribed on top of the gun
(FIG. 4) near the end of the bar 122. If desired a window 133 may
be provided at the rear of the gun 9 and symbols such as those at
135 may be provided thereat whereby the position of the piston 50
with respect to the symbols would represent the dosage or volume of
the chamber 100.
The medicament 82 is drawn from the container 84 which may be a
cylindrical bottle having a neck 150 in which is a rubber stopper
151 held by a ring 152. The stopper 151 bears on the upper end of
the fitting 128. A tube assembly 154 extends upwardly from the
fitting 128 and is adapted to penetrate the stopper 151 by the
needle-like tip 155 extending above the tube 154. The tube 154
conveys air into the container 84 via an air hole 158 in the
fitting 128, which communicates with the atmosphere. A tube 156
smaller in height then the tube 155 passes the medicament 82 around
the inlet valve 130 through the medicament tube 131 via a series of
slots 129 at the rear end of the tube. The container 84 is
supported in axially vertical position by a generally U-shaped
bracket 166 having a vertical arm 168 engaged in a clamp 170 by a
screw 172. The clamp is carried by an upright bar 174 welded to the
top of the bar 122. A shorter hollow arm 176 of the bracket 166
carries a knob 180 which bears on the upper end of the inverted
container 84. The arm 176 and the arm 168 have a threaded socket
which is adapted to engage the screw tip 182a of an auxiliary
extension 182. The auxiliary arm extension 182 as shown in FIG. 3
is coupled to the arm 168, and in this position if a larger bottle
84 of medicament is to be used the bracket 166 may be raised by
opening the screw 172. Alternately, when the gun is not to be used
the extension arm 182 is threaded into the knob 180 and the bracket
assembly is then lowered such that the arm extension 182 covers the
tip 155 which is thereby protected (FIG. 1).
The discharge of medicament is effected by axial movement of the
rod 80 to the left as viewed in FIG. 3, by retracting a trigger 200
which is pivotally mounted to the gun just in front of the handle
10. A valve stem 202 is moved rearwardly by retraction of the
trigger 200. The stem 202 is slidably mounted in a valve insert 204
screwed into a valve fitting 206. The valve fitting is set in a
bore 208 and has a lateral passage 210 which communicates at one
end with the chamber 12 via a passage 214 in the handle 10. The
other end of the bore 208 communicates with a bore 216 in the
fitting 206. The valve stem 202 contacts a ball valve 218 biased
against the fitting 208 by a spring 220 in the bore 47. By this
arrangement the ball valve 218 normally blocks the passage 214 so
that no hydraulic fluid can pass from the chamber 48 and the
passage 49 to the chamber 12 via the passage 214. When the trigger
200 is retracted to the right or pivoted counterclockwise around
the pin 201 as viewed in FIG. 3, the valve stem 202 is retracted so
that the ball valve 218 clears the passage 49 and the hydraulic
fluid can pass around a narrow portion 202' of the stem 202 to the
passage 214.
In operation of the jet injector, the knob 27 is grasped and the
pump rod 22 reciprocated several times. This will draw the
hydraulic fluid 14 by suction out of the chamber 12 via the
passages 28, 34 and 38 to the passage 24. From passage 24 the fluid
14 is forced by reciprocation of the rod 22 into the chamber 48 via
the passages 40, 47 and 49. This causes retraction of the piston
50, the shaft 60 and the rod 80 and compression of the spring 52.
The amount that the piston 50 is retracted is determined by the
distance D shown in FIG. 3, i.e., the distance between the end 50a
of the piston 50 and the edge 54a of the screw 54 when the gun is
uncocked. By design this distance D is also the distance between
the rear edge 114a of the ring 114 and the front edge 72a of the
radial flange 72. As the piston 50 is retracted a gap appears
between the edge 90a of the muzzle 90 and the edges 85a of the
radial flange 85. Correspondingly, the distance D between the end
50a and the edge 54a decreases so that when the end 50a abuts the
edge 54a the distance between the edges 90a and 85a are at the
distance D and the gun is fully cocked. In addition as the piston
50 moves to the right (as viewed in FIG. 3) the medicament 84
freely flows into the slots 129 through the medicament tube 131 to
fill the chamber 100. The gun is now cocked. With the spring in the
cocked position, the gun may be easily primed and purged of air by
merely rotating the ring 114 in one direction and the other. That
is when the ring 114 is rotated so that the muzzle 90 moves
longitudinally to the right as viewed in FIG. 3 the volume of
chamber 100 is decreased thereby forcing any medicament therein to
be ejected through the nozzle cap 104. When the ring 114 is rotated
so that the muzzle 90 moves longitudinally to the left as viewed in
FIG. 3 the volume in chamber 100 increases and is filled with
medicament. After the gun is primed the dosage is set by rotating
the ring 114 so that the edge of the arms 136 is aligned with the
proper numeral on scale 135. After the gun has been fired the
dosage may also be checked at window 133 (FIG. 4) by observing the
alignment of the edge 50a with numerals of the scale. The gun may
now be cocked as hereinbefore described and the nozzle cap 104
placed in contact wtih the patient's body and trigger 200 may be
retracted. This will enable the release of the hydraulic fluid from
chamber 48 via passages 49, 47 and 214. The spring 52 will expand
and the rod 80 will be driven to the left to the position where the
edge 85A is stopped by the muzzle end 90A as shown in FIG. 3, while
the medicament is ejected forcibly in a fine jet via the nozzle cap
104.
Each time the jet injector gun is used, it is necessary to
reciprocate the pump rod 22 to cock the gun and in doing so the
chamber 100 is filled with medicament. That is, each time the
piston 50 is retracted thereby moving the piston rod 80 to the
right which creates a vacuum within the chamber 100 and causes the
medicament to be drawn into the chamber 100 in an amount
predetermined by the distance which the piston 50 and thus piston
80 is set to move. The medicament is withdrawn from the container
84 through the seat 128a and through the medicament tube 131 via
the slots 129. The check outlet valve 101 serves to prevent the
entry of any air or suck-back of any fluid during the loading cycle
of the medicament chamber with the spring pressure on this valve
sufficiently light to be easily overcome during the firing or
ejecting cycle. The aforementioned structure and operation of the
inlet valve 130, medicament tube 131, slots 129, closure member 102
and nozzle cap 104 are the same as those disclosed and described in
my aforementioned U.S. Pat. No. 3,057,349.
It will be noted that no external source of hydraulic power is
required since the jet injector gun is entirely hand powered. For
normal usage only nozzle cap 104 need be swabbed with a
disinfectant. Occasionally the entire gun can be taken apart for
cleaning and sterilization of parts. The gun requires no particular
skill to adjust, operate or assemble and disassemble. It should be
noted that whenever the dosage is changed, the change in the
medicament chamber (the volume between the conical walls 101 and
the tip 106 of the piston 80) is such that a minimum dead end space
is maintained, i.e., conical wall 101, is moved rather than moving
the tip of the piston 80 thereby providing easier priming (removal
of entrapped air) and also minimizing the amount of fluid remaining
in the chamber between strokes. It fulfills a long felt need in the
medical field for a reliable, portable, hand powered hypodermic jet
injector.
It should be understood that the foregoing relates to only a
preferred embodiment of the invention, and that it is intended to
cover all changes and modifications of the example of the invention
herein chosen for the purposes of the disclosure, which do not
constitute departures from the spirit and scope of the
invention.
* * * * *