CA1326983C - Needleless drug delivery system - Google Patents
Needleless drug delivery systemInfo
- Publication number
- CA1326983C CA1326983C CA 609025 CA609025A CA1326983C CA 1326983 C CA1326983 C CA 1326983C CA 609025 CA609025 CA 609025 CA 609025 A CA609025 A CA 609025A CA 1326983 C CA1326983 C CA 1326983C
- Authority
- CA
- Canada
- Prior art keywords
- accumulator
- fluid
- injector
- casing
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61D—VETERINARY INSTRUMENTS, IMPLEMENTS, TOOLS, OR METHODS
- A61D7/00—Devices or methods for introducing solid, liquid, or gaseous remedies or other materials into or onto the bodies of animals
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/30—Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/20—Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically
- A61M5/204—Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically connected to external reservoirs for multiple refilling
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Veterinary Medicine (AREA)
- Engineering & Computer Science (AREA)
- Public Health (AREA)
- General Health & Medical Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- Anesthesiology (AREA)
- Hematology (AREA)
- Heart & Thoracic Surgery (AREA)
- Biomedical Technology (AREA)
- Vascular Medicine (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A relatively simple portable, needleless apparatus for injecting drugs into cattle, etc. includes a fluid actuated, pistol-type, manually operated injector for discharging a drug under pressure; and a portable drive mounted in a backpack for controlling operation of the injector, the drive including a hydraulic fluid reservoir, a pressure accumulator for receiving fluid from the reservoir, a DC motor and pump combination for pumping fluid from the reservoir through a one-way valve to the accumulator when the pressure therein reaches a predetermined level, a solenoid valve permitting the flow of fluid under pressure from the accumulator to the injector to operate the latter, and for returning fluid from the injector to the reservoir following an injection.
A relatively simple portable, needleless apparatus for injecting drugs into cattle, etc. includes a fluid actuated, pistol-type, manually operated injector for discharging a drug under pressure; and a portable drive mounted in a backpack for controlling operation of the injector, the drive including a hydraulic fluid reservoir, a pressure accumulator for receiving fluid from the reservoir, a DC motor and pump combination for pumping fluid from the reservoir through a one-way valve to the accumulator when the pressure therein reaches a predetermined level, a solenoid valve permitting the flow of fluid under pressure from the accumulator to the injector to operate the latter, and for returning fluid from the injector to the reservoir following an injection.
Description
1 326q83 This invention relates to a needleless injection apparatus, and in particular to a portable, needleless multi-dose injection apparatus.
The injection of drugs or other injectable fluids into large animals such as horses and cattle is usually performed with disposable needles.
~ he injection of drugs and other chemicals into farm animals is a common occurrence. Not only must the animals be treated for disease prevention and curing, but hormones are commonly used to increase meat and milk production.
Traditionally, injections are performed using the conventional needle and syringe. Quite often, a so-called disposable needle and syringe is used and re-used until the needle becomes too dull to penetrate the hide of an animal. Not only is there a certain amount of pain and trauma to the animal, but there is a danger of injection with a contaminated needle.
Moreover, the accumulation of used needles and syringes represent a serious environmental problem.
It is well established that needleless injectors represent a solution to the pain and trauma problems. A
needleless injector of the type described in applicant's Canadian Patent No. 1,178,503, issued November 27, 1984 makes a substantially smaller hole and inflicts much less pain than even the smallest needle. However, needleless injectors are high pressure devices, requiring systems for generating pressures sufficiently high to propel a drug through a small injection orifice at a high velocity.
Known multiple injection devices tend to be somewhat complicated or ill-suited for use in the field, e.g. by veterinarians wishing to inject drugs into a large herd of cattle, horses, sheep or goats. Multiple injection units are - ~
disclosed, for example by United States Patents Nos.
The injection of drugs or other injectable fluids into large animals such as horses and cattle is usually performed with disposable needles.
~ he injection of drugs and other chemicals into farm animals is a common occurrence. Not only must the animals be treated for disease prevention and curing, but hormones are commonly used to increase meat and milk production.
Traditionally, injections are performed using the conventional needle and syringe. Quite often, a so-called disposable needle and syringe is used and re-used until the needle becomes too dull to penetrate the hide of an animal. Not only is there a certain amount of pain and trauma to the animal, but there is a danger of injection with a contaminated needle.
Moreover, the accumulation of used needles and syringes represent a serious environmental problem.
It is well established that needleless injectors represent a solution to the pain and trauma problems. A
needleless injector of the type described in applicant's Canadian Patent No. 1,178,503, issued November 27, 1984 makes a substantially smaller hole and inflicts much less pain than even the smallest needle. However, needleless injectors are high pressure devices, requiring systems for generating pressures sufficiently high to propel a drug through a small injection orifice at a high velocity.
Known multiple injection devices tend to be somewhat complicated or ill-suited for use in the field, e.g. by veterinarians wishing to inject drugs into a large herd of cattle, horses, sheep or goats. Multiple injection units are - ~
disclosed, for example by United States Patents Nos.
2,928,390, which issued to A. Venditty et al on March 15, 1960 and 3,515,130, which issued to J. Tsujino on June 2, 1970.
While the Tsujino device is much simpler and presumably lighter than the Venditty et al device, Tsujino is concerned solely with reducing the weight of the hand held injector, i.e. the Tsujino device is not actually portable, it is only the injector itself which is portable. The hydraulic system used with the Tsujino device would be stationary or carried by a large vehicle.
It is readily apparent that a need still exists for a truly portable injection apparatus for making multiple injections.
The object of the present invention is to meet the above defined need by providing a relatively simple, inexpensive, lightweight portable, needleless injector, which can be used to make many quick injections.
Accordingly, the present invention relates to a portable, needleless injection apparatus comprising fluid actuated, needleless injector means for discharging a drug . . ,. ~ :. ~, , 1 326~83 under pressure; portable generator means for supplying fluid under pressure to said injector means, said generator means including casing means; reservoir means in said casing means for storing fluid; pressure accumulator means in said casing means; first valve means in said casing means for controlling the flow of fluid between said accumulator means and said injector means, and from said injector means to said reservoir means; and pump means in said casing means for pumping fluid from said reservoir means to said accumulator means when the pressure in said accumulator means drops below a predetermined level.
The use of a needleless injector with a truly portable, preferably battery operated, power source makes it possible to perform as many as one thousand subcutaneous injections per hour. With the apparatus of the present invention, the user can walk to each animal, carrying the power generator, rather than being tethered to a stationary bulky source of power. While the apparatus is primarily intended for veterinarians, it will be appreciated that farms with large herds of animals would benefit by owning such an apparatus.
The invention will be described in greater detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention, and wherein:
Figure 1 is a schematic, perspective view of an apparatus in accordance with the invention in the use position;
Figure 2 is a mainly sectioned, side view of an -injector for use with the apparatus of Fig. l;
Figure 3 is a mainly, sectional view of a disposable syringe used in the injector of Fig. 2;
Figure 4 is a mainly sectioned side view of a power generator used in the apparatus of Fig. l;
Figure 5 is a partly sectioned side view of a pump used in the power generator of Fig. 4;
Figure 6 is a front view of a wobble plate used in the pump of Fig. 5; and Figure 7 is a partly sectioned side view of a plunger and valve plate used in the pump of Fig. 5.
With reference to Fig. 1, the apparatus of the present invention which is generally indicated at 1 is designed to be portable. For such purpose the apparatus 1 is mounted in a backpack 2 with lugs 3 extending outwardly from the corners thereof for receiving straps 4. The straps 4 extend around a user's shoulders 5 and chest. The apparatus 1 is designed to inject a drug from a container 6 on the side of the backpack 2. The drug and hydraulic fluid are fed from the backpack 2 via lines 8 and 9 to a hand held pistol-style injector generally indicated at 10.
The injector 10 includes an elongated body 12 with a barrel 13 connected to one end thereof and a handle 14 ,.. : , . ~, . :: , -, extending downwardly from the other end thereof. The metal barrel 13 is releasably connected to the body 12 by a stepped, tubular coupler 15, with an annular shoulder 17 at one end for engaging an inwardly extending, annular flange 18 on one end of the body 12. The inner end 20 of the barrel 13 has interior threads for removably mounting the barrel on the coupler 15, and the outer end has an annular, inwardly extending flange 21 for engaging the stepped outer end 22 of a disposable syringe 24. The outer end of the barrel includes an annular row of teeth 25 to facilitate locating of the injector 10 on the skin.
As best shown in Fig. 3, the disposable syringe 24 includes a tubular barrel 26 with a thin skirt 27 defining one end thereof. The beaded free~end 28 of the skirt mates with an annular groove 30 in the coupler 15 to connect the syringe barrel 26 to the coupler when the barrel 13 is screwed onto the coupler. The other, discharge end 32 of the barrel 26 includes a shoulder 33, which acts as a stop for a separate cover 34. The end 32 is generally conical with three longitudinally extending passages 36 spaced equidistant apart through which liquid can be discharged. The passages 36 are normally closed by a one-way valve in the form of a tapering flexible rubber skirt 37, the beaded inner end 38 of which forms a seal between the barrel 26 and the cover 34. Liquid passing through the passages 36 is discharged from the syringe : '' . ' .., ' ~
. . , ' ' ' . . ', . ' : ~ . . ' ' through a central orifice 39 in the conical end 22 of the cover 34.
An elongated tubular plunger 40 is slidably mounted in the barrel 26. An O-ring 42 forms a seal between the barrel 26 and the plunger 40. The hollow front end of the plunger 40 receives a cylindrical insert 43 with a plurality of small longitudinally extending passages 44 therein. The front or outer ends of the passages 44 are normally closed by a rubber disc 46. The disc 46 is held on the insert by three small lugs 47 extending rearwardly from a generally conical, tubular head 49. Thus, liquid travelling through the plunger 26 enters a small chamber 50 behind the insert 43 and is discharged through the passages 44 and the head 49 into a chamber 52 formed between the plunger 40 and the barrel 26 during rearward movement of the plunger 40. The use of many small holes or passages 44 in the insert 43 prevents puncturing of the one-way valve disc 46 by liquid under high pressure. A tubular coupler 53 is provided at the inner end of the plunger. The coupler 53 includes a rearwardly extending bifurcated arm 55 with an enlarged frusto-conical head 56 for connecting the plunger to the small tubular end 57 of a piston 58 (Fig. 2). A tubular arm 59 perpendicular to the arm 55 includes a series of annular ridges for connecting the drug carrying line 8 to the interior of plunger 40. A
longitudinally extending slot 60 (Fig. 2) is provided in the coupler 15 so that the coupler 53 can pass therethrough when - ' ' ' , - ~: - ,:
.
the syringe 24 and the barrel 13 are being connected to the body 12 of the injector.
Referring again to Fig. 2, the piston 58 is generally cup-shaped with the tubular front end 57 for connecting the piston to the plunger 40. The piston 58 is biased rearwardly by three helical springs 61, and is sealed in the body 12 by an O-ring 62. The stroke of the piston 58 and consequently of the plunger 40 is determined by a tubular stop 64, which is slidably mounted in an extension 65 on the rear end of the body 12. The extension 65 is sealed in the body 12 by an O-ring 66, and the stop 64 is sealed in the extension 65 by an O-ring 67. Longitudinal movement of the stop 64 is effected by rotation of a screw 69 in the threaded interior of the stop. The screw 69 extends outwardly through the closed outer end 70 of the extension 65 to a short cylindrical handle 72 for manual rotation of the screw.
Rotation of the stop 64 is prevented by a pin 73 extending outwardly from the stop through a longitudinally extending slot 74 in the extension 65. A series of dosage lines (not shown) is provided on the extension 65 beside the slot 74 for indicating the stroke of the piston 58 and plunger 40, and consequently the dosage of the drug. An oil duct 76 extends from the body 12 through the handle 14 and is connected to the line 9 by a coupler 77. Operation of the injector 10 is controlled by a trigger defined by a pushbutton 78 in the handle 14. The button 78 is connected to the solenoid valve .
79 of a portable power generator (Fig. 4) by a wire 80 (Figs.
1 and 3) .
With reference to Fig. 4, the power generator is defined by a casing containing a hydraulic fluid reservoir generally indicated at 81 and a pressure accumulator generally indicated at 82.
The reservoir 81 is defined by a pair of tubular, coaxial casings 84 and 85, with a tubular diaphragm 86 sandwiched therebetween. An opening 88 in the outer casing 84 permits air to enter and exit the outer casing 84 for balancing pressure on the diaphragm 86. The hydraulic fluid is housed in the chamber defined by the inner casing 85, the diaphragm 86 and one side of the pressure accumulator casing 89. A DC motor 90 is mounted on a flange 92 on one end of a sleeve 93 using bolts 95 and nuts 96 (one shown). The sleeve 93 is connected to the casings 84 and 85, and to the accumulator casing 89 by bolts 97 (one shown), so that the various casings form one large housing or casing for mounting in a backpack 2. The motor shaft 99 is connected to a wobble plate pump shaft 100 by a coupler 101. The shaft 100 is rotatably mounted in bearings 103 in the casing 85, and a fluid seal 104 is provided at the motor end of the shaft. The shaft 100 carries an inclined wobble plate 105, i.e. a plate 105 with an inclined face 106 (Figs. 5 and 6), which reciprocates three plungers 107 (one shown) in a valve body 108 which closes the accumulator end of the casing 85.
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:
. .
: - . .
:
As best shown in Figs. 5 to 7, the inclined face 106 of the plate 105 includes a shallow arcuate recess 109 for receiving hydraulic fluid entering the pump casing 85 through an opening 110 (Fig. 4). During rotation, the face 106 of the plate 105 slides relative to three similar circular plates 112. Each plate 112 is maintained in position against the plate 105 by the hemispherical head 113 of the plunger 107 and a helical compression spring 114. The head 113 bears against the sides of a generally conical recess 115 (Fig. 7) in the outer end of the plate 112. Each of the plates 112 contains a central opening 116 permitting the passage of hydraulic fluid from the recess 109 into the plungers 107. A second passage 117 equalizes fluid pressure on each side of the plunger head 113. Each plunger 107 contains a longitudinally extending passage for feeding fluid through passages (one shown) 118 in the valve body 108.
The two-part valve body 108 is sealed in the casing 85 by an annular gasket 119 and in the accumulator casing 8g by an O-ring 120. During rotation of the plate 105, the plungers 107 reciprocate between open and closed positions of valves 121 ~one shown) normally closing the passages 118 containing the plungers 107 from a passage 123 through the valve body 108. ~he valves 121 are biased to the closed position by helical springs 124. The passage 123 is in fluid communication with a passage 125 in the pressure accumulator casing 89. A pressure sensor 126 is mounted in a passage 127 perpendicular to the passage 125.
The pressure accumulator includes a semispherical recess 128 with an internally threaded top end 129 for receiving an externally threaded, domed cover 130. A
diaphragm 131 divides the interior of the pressure accumulator into an upper gas chamber 132 and a lower oil chamber 133.
Compressed nitrogen is introduced into the chamber 132 through an opening 134 and a one way valve 135.
A metal insert 136 is provided in the diaphragm 131 for preventing damage to the diaphragm as it presses against one end of a passage 137 perpendicular to the passage 125.
The passage 137 contains a sleeve 138 carrying the plunger 139 of the solenoid valve 79. The valve is biased to the closed position by a helical spring 140 between the closed inner end 142 of the sleeve 138 and the inner end of the plunger 139.
The plunger 139 includes two shoulders 143 and 144 for closing openings 146 and 147, respectively in the sleeve 138. The opening 146 permits the flow of hydraulic fluid from the chamber 133 through the passage 137, the sleeve 138 and an opening 149 to the line 9. The opening 147 permits the return of hydraulic fluid from the line 9 through the opening 149, sleeve 138 a passage 150 in the casing 89, and around the pressure sensor 126 to a passage lSl and the reservoir 81.
The motor 90 is operated by portable, rechargeable batteries (not shown) mounted in the backpack 2. By turning ' ::: :
..
1 3269~3 the sleeve 72, the length of the piston stroke and consequently the dosage to be administered can be adjusted.
With the chamber 52 full of medicine, the trigger (button) 78 is depressed to actuate the solenoid valve 79. Thus, the plunger 139 is moved upwardly (Fig. 4) to open the flow path from the accumulator oil chamber 133 to the line 9. Oil flows into the body 12 of the injector forcing the piston 58 forwardly. Such forward piston movement pushes the plunger 40 forwardly to open the one-way valve (skirt) 37 and forces the drug from the chamber 52 through the orifice 39 under high pressure.
Once the drug has been discharged, the spring 140 returns the plunger 139 to the closed position (Fig. 4), and the springs 61 move the piston 58 to the rest position against the sleeve 64. Thus, the hydraulic oil returns through line 9, the sleeve 138, and passages 150 and 151 to the reservoir 81. At the same time, rearward movement of the plunger 40 creates a partial vacuum in the chamber 52. Drug is drawn through the line 8 and the insert 44 into the chamber 52. The injector is now ready for another injection.
When pressure in the accumulator 82 drops below a predetermined level as detected by the sensor 126, the motor 90 is started to operate the pump forcing hydraulic oil into the chamber 133 of the accumulator. Such pressurizing of the system can occur while the operator is walking from one animal to the next animal. By using the pressure accumulator 82, a 1 326q83 relatively small, battery operated DC motor can be used to power the pump.
- :- : , : -- ::
. , ., :. : :
,: : .. . :~ . ., , ,.. ;,.. :; ; .:
While the Tsujino device is much simpler and presumably lighter than the Venditty et al device, Tsujino is concerned solely with reducing the weight of the hand held injector, i.e. the Tsujino device is not actually portable, it is only the injector itself which is portable. The hydraulic system used with the Tsujino device would be stationary or carried by a large vehicle.
It is readily apparent that a need still exists for a truly portable injection apparatus for making multiple injections.
The object of the present invention is to meet the above defined need by providing a relatively simple, inexpensive, lightweight portable, needleless injector, which can be used to make many quick injections.
Accordingly, the present invention relates to a portable, needleless injection apparatus comprising fluid actuated, needleless injector means for discharging a drug . . ,. ~ :. ~, , 1 326~83 under pressure; portable generator means for supplying fluid under pressure to said injector means, said generator means including casing means; reservoir means in said casing means for storing fluid; pressure accumulator means in said casing means; first valve means in said casing means for controlling the flow of fluid between said accumulator means and said injector means, and from said injector means to said reservoir means; and pump means in said casing means for pumping fluid from said reservoir means to said accumulator means when the pressure in said accumulator means drops below a predetermined level.
The use of a needleless injector with a truly portable, preferably battery operated, power source makes it possible to perform as many as one thousand subcutaneous injections per hour. With the apparatus of the present invention, the user can walk to each animal, carrying the power generator, rather than being tethered to a stationary bulky source of power. While the apparatus is primarily intended for veterinarians, it will be appreciated that farms with large herds of animals would benefit by owning such an apparatus.
The invention will be described in greater detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention, and wherein:
Figure 1 is a schematic, perspective view of an apparatus in accordance with the invention in the use position;
Figure 2 is a mainly sectioned, side view of an -injector for use with the apparatus of Fig. l;
Figure 3 is a mainly, sectional view of a disposable syringe used in the injector of Fig. 2;
Figure 4 is a mainly sectioned side view of a power generator used in the apparatus of Fig. l;
Figure 5 is a partly sectioned side view of a pump used in the power generator of Fig. 4;
Figure 6 is a front view of a wobble plate used in the pump of Fig. 5; and Figure 7 is a partly sectioned side view of a plunger and valve plate used in the pump of Fig. 5.
With reference to Fig. 1, the apparatus of the present invention which is generally indicated at 1 is designed to be portable. For such purpose the apparatus 1 is mounted in a backpack 2 with lugs 3 extending outwardly from the corners thereof for receiving straps 4. The straps 4 extend around a user's shoulders 5 and chest. The apparatus 1 is designed to inject a drug from a container 6 on the side of the backpack 2. The drug and hydraulic fluid are fed from the backpack 2 via lines 8 and 9 to a hand held pistol-style injector generally indicated at 10.
The injector 10 includes an elongated body 12 with a barrel 13 connected to one end thereof and a handle 14 ,.. : , . ~, . :: , -, extending downwardly from the other end thereof. The metal barrel 13 is releasably connected to the body 12 by a stepped, tubular coupler 15, with an annular shoulder 17 at one end for engaging an inwardly extending, annular flange 18 on one end of the body 12. The inner end 20 of the barrel 13 has interior threads for removably mounting the barrel on the coupler 15, and the outer end has an annular, inwardly extending flange 21 for engaging the stepped outer end 22 of a disposable syringe 24. The outer end of the barrel includes an annular row of teeth 25 to facilitate locating of the injector 10 on the skin.
As best shown in Fig. 3, the disposable syringe 24 includes a tubular barrel 26 with a thin skirt 27 defining one end thereof. The beaded free~end 28 of the skirt mates with an annular groove 30 in the coupler 15 to connect the syringe barrel 26 to the coupler when the barrel 13 is screwed onto the coupler. The other, discharge end 32 of the barrel 26 includes a shoulder 33, which acts as a stop for a separate cover 34. The end 32 is generally conical with three longitudinally extending passages 36 spaced equidistant apart through which liquid can be discharged. The passages 36 are normally closed by a one-way valve in the form of a tapering flexible rubber skirt 37, the beaded inner end 38 of which forms a seal between the barrel 26 and the cover 34. Liquid passing through the passages 36 is discharged from the syringe : '' . ' .., ' ~
. . , ' ' ' . . ', . ' : ~ . . ' ' through a central orifice 39 in the conical end 22 of the cover 34.
An elongated tubular plunger 40 is slidably mounted in the barrel 26. An O-ring 42 forms a seal between the barrel 26 and the plunger 40. The hollow front end of the plunger 40 receives a cylindrical insert 43 with a plurality of small longitudinally extending passages 44 therein. The front or outer ends of the passages 44 are normally closed by a rubber disc 46. The disc 46 is held on the insert by three small lugs 47 extending rearwardly from a generally conical, tubular head 49. Thus, liquid travelling through the plunger 26 enters a small chamber 50 behind the insert 43 and is discharged through the passages 44 and the head 49 into a chamber 52 formed between the plunger 40 and the barrel 26 during rearward movement of the plunger 40. The use of many small holes or passages 44 in the insert 43 prevents puncturing of the one-way valve disc 46 by liquid under high pressure. A tubular coupler 53 is provided at the inner end of the plunger. The coupler 53 includes a rearwardly extending bifurcated arm 55 with an enlarged frusto-conical head 56 for connecting the plunger to the small tubular end 57 of a piston 58 (Fig. 2). A tubular arm 59 perpendicular to the arm 55 includes a series of annular ridges for connecting the drug carrying line 8 to the interior of plunger 40. A
longitudinally extending slot 60 (Fig. 2) is provided in the coupler 15 so that the coupler 53 can pass therethrough when - ' ' ' , - ~: - ,:
.
the syringe 24 and the barrel 13 are being connected to the body 12 of the injector.
Referring again to Fig. 2, the piston 58 is generally cup-shaped with the tubular front end 57 for connecting the piston to the plunger 40. The piston 58 is biased rearwardly by three helical springs 61, and is sealed in the body 12 by an O-ring 62. The stroke of the piston 58 and consequently of the plunger 40 is determined by a tubular stop 64, which is slidably mounted in an extension 65 on the rear end of the body 12. The extension 65 is sealed in the body 12 by an O-ring 66, and the stop 64 is sealed in the extension 65 by an O-ring 67. Longitudinal movement of the stop 64 is effected by rotation of a screw 69 in the threaded interior of the stop. The screw 69 extends outwardly through the closed outer end 70 of the extension 65 to a short cylindrical handle 72 for manual rotation of the screw.
Rotation of the stop 64 is prevented by a pin 73 extending outwardly from the stop through a longitudinally extending slot 74 in the extension 65. A series of dosage lines (not shown) is provided on the extension 65 beside the slot 74 for indicating the stroke of the piston 58 and plunger 40, and consequently the dosage of the drug. An oil duct 76 extends from the body 12 through the handle 14 and is connected to the line 9 by a coupler 77. Operation of the injector 10 is controlled by a trigger defined by a pushbutton 78 in the handle 14. The button 78 is connected to the solenoid valve .
79 of a portable power generator (Fig. 4) by a wire 80 (Figs.
1 and 3) .
With reference to Fig. 4, the power generator is defined by a casing containing a hydraulic fluid reservoir generally indicated at 81 and a pressure accumulator generally indicated at 82.
The reservoir 81 is defined by a pair of tubular, coaxial casings 84 and 85, with a tubular diaphragm 86 sandwiched therebetween. An opening 88 in the outer casing 84 permits air to enter and exit the outer casing 84 for balancing pressure on the diaphragm 86. The hydraulic fluid is housed in the chamber defined by the inner casing 85, the diaphragm 86 and one side of the pressure accumulator casing 89. A DC motor 90 is mounted on a flange 92 on one end of a sleeve 93 using bolts 95 and nuts 96 (one shown). The sleeve 93 is connected to the casings 84 and 85, and to the accumulator casing 89 by bolts 97 (one shown), so that the various casings form one large housing or casing for mounting in a backpack 2. The motor shaft 99 is connected to a wobble plate pump shaft 100 by a coupler 101. The shaft 100 is rotatably mounted in bearings 103 in the casing 85, and a fluid seal 104 is provided at the motor end of the shaft. The shaft 100 carries an inclined wobble plate 105, i.e. a plate 105 with an inclined face 106 (Figs. 5 and 6), which reciprocates three plungers 107 (one shown) in a valve body 108 which closes the accumulator end of the casing 85.
.
:
. .
: - . .
:
As best shown in Figs. 5 to 7, the inclined face 106 of the plate 105 includes a shallow arcuate recess 109 for receiving hydraulic fluid entering the pump casing 85 through an opening 110 (Fig. 4). During rotation, the face 106 of the plate 105 slides relative to three similar circular plates 112. Each plate 112 is maintained in position against the plate 105 by the hemispherical head 113 of the plunger 107 and a helical compression spring 114. The head 113 bears against the sides of a generally conical recess 115 (Fig. 7) in the outer end of the plate 112. Each of the plates 112 contains a central opening 116 permitting the passage of hydraulic fluid from the recess 109 into the plungers 107. A second passage 117 equalizes fluid pressure on each side of the plunger head 113. Each plunger 107 contains a longitudinally extending passage for feeding fluid through passages (one shown) 118 in the valve body 108.
The two-part valve body 108 is sealed in the casing 85 by an annular gasket 119 and in the accumulator casing 8g by an O-ring 120. During rotation of the plate 105, the plungers 107 reciprocate between open and closed positions of valves 121 ~one shown) normally closing the passages 118 containing the plungers 107 from a passage 123 through the valve body 108. ~he valves 121 are biased to the closed position by helical springs 124. The passage 123 is in fluid communication with a passage 125 in the pressure accumulator casing 89. A pressure sensor 126 is mounted in a passage 127 perpendicular to the passage 125.
The pressure accumulator includes a semispherical recess 128 with an internally threaded top end 129 for receiving an externally threaded, domed cover 130. A
diaphragm 131 divides the interior of the pressure accumulator into an upper gas chamber 132 and a lower oil chamber 133.
Compressed nitrogen is introduced into the chamber 132 through an opening 134 and a one way valve 135.
A metal insert 136 is provided in the diaphragm 131 for preventing damage to the diaphragm as it presses against one end of a passage 137 perpendicular to the passage 125.
The passage 137 contains a sleeve 138 carrying the plunger 139 of the solenoid valve 79. The valve is biased to the closed position by a helical spring 140 between the closed inner end 142 of the sleeve 138 and the inner end of the plunger 139.
The plunger 139 includes two shoulders 143 and 144 for closing openings 146 and 147, respectively in the sleeve 138. The opening 146 permits the flow of hydraulic fluid from the chamber 133 through the passage 137, the sleeve 138 and an opening 149 to the line 9. The opening 147 permits the return of hydraulic fluid from the line 9 through the opening 149, sleeve 138 a passage 150 in the casing 89, and around the pressure sensor 126 to a passage lSl and the reservoir 81.
The motor 90 is operated by portable, rechargeable batteries (not shown) mounted in the backpack 2. By turning ' ::: :
..
1 3269~3 the sleeve 72, the length of the piston stroke and consequently the dosage to be administered can be adjusted.
With the chamber 52 full of medicine, the trigger (button) 78 is depressed to actuate the solenoid valve 79. Thus, the plunger 139 is moved upwardly (Fig. 4) to open the flow path from the accumulator oil chamber 133 to the line 9. Oil flows into the body 12 of the injector forcing the piston 58 forwardly. Such forward piston movement pushes the plunger 40 forwardly to open the one-way valve (skirt) 37 and forces the drug from the chamber 52 through the orifice 39 under high pressure.
Once the drug has been discharged, the spring 140 returns the plunger 139 to the closed position (Fig. 4), and the springs 61 move the piston 58 to the rest position against the sleeve 64. Thus, the hydraulic oil returns through line 9, the sleeve 138, and passages 150 and 151 to the reservoir 81. At the same time, rearward movement of the plunger 40 creates a partial vacuum in the chamber 52. Drug is drawn through the line 8 and the insert 44 into the chamber 52. The injector is now ready for another injection.
When pressure in the accumulator 82 drops below a predetermined level as detected by the sensor 126, the motor 90 is started to operate the pump forcing hydraulic oil into the chamber 133 of the accumulator. Such pressurizing of the system can occur while the operator is walking from one animal to the next animal. By using the pressure accumulator 82, a 1 326q83 relatively small, battery operated DC motor can be used to power the pump.
- :- : , : -- ::
. , ., :. : :
,: : .. . :~ . ., , ,.. ;,.. :; ; .:
Claims (4)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A portable, needleless injection apparatus comprising fluid actuated, needleless injector means for discharging a drug under pressure; portable generator means for supplying fluid under pressure to said injector means, said generator means including casing means; reservoir means in said casing means for storing fluid; pressure accumulator means in said casing means; first valve means in said casing means for controlling the flow of fluid between said accumulator means and said injector means, and from said injector means to said reservoir means; and pump means in said casing means for pumping fluid from said reservoir means to said accumulator means when the pressure in said accumulator means drops below a predetermined level.
2. An apparatus according to claim 1, including pressure sensor means in said casing means for sensing pressure in said accumulator means and for actuating said pump means when the pressure in said accumulator means drops below the predetermined level.
3. An apparatus according to claim 2, including DC
motor means attached to said casing means for driving said pump means in response to a signal from said pressure sensor means.
motor means attached to said casing means for driving said pump means in response to a signal from said pressure sensor means.
4. An apparatus according to claim 2, including second, one-way valve means between said pump means and said accumulator means permitting the flow of fluid from said reservoir means to said accumulator means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 609025 CA1326983C (en) | 1989-08-22 | 1989-08-22 | Needleless drug delivery system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 609025 CA1326983C (en) | 1989-08-22 | 1989-08-22 | Needleless drug delivery system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1326983C true CA1326983C (en) | 1994-02-15 |
Family
ID=4140481
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 609025 Expired - Lifetime CA1326983C (en) | 1989-08-22 | 1989-08-22 | Needleless drug delivery system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1326983C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2006279244B2 (en) * | 2005-08-05 | 2011-09-15 | Cobbett Technologies Pty. Ltd. | Non-surgical mulesing applicator |
| CN102499787A (en) * | 2011-11-18 | 2012-06-20 | 陈凯 | Split type needle-free injection system used for animal injection |
| US8221347B2 (en) | 2004-12-01 | 2012-07-17 | Acushot, Inc. | Needle-free injector |
| USD919208S1 (en) | 2019-07-26 | 2021-05-11 | Kärcher North America, Inc. | Portable cleaning device |
-
1989
- 1989-08-22 CA CA 609025 patent/CA1326983C/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8221347B2 (en) | 2004-12-01 | 2012-07-17 | Acushot, Inc. | Needle-free injector |
| AU2006279244B2 (en) * | 2005-08-05 | 2011-09-15 | Cobbett Technologies Pty. Ltd. | Non-surgical mulesing applicator |
| CN102499787A (en) * | 2011-11-18 | 2012-06-20 | 陈凯 | Split type needle-free injection system used for animal injection |
| CN102499787B (en) * | 2011-11-18 | 2014-06-11 | 陈凯 | Split type needle-free injection system used for animal injection |
| USD919208S1 (en) | 2019-07-26 | 2021-05-11 | Kärcher North America, Inc. | Portable cleaning device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |
Effective date: 20110215 |