US3768472A - Fluid dispensing gun - Google Patents

Abstract

Apparatus for slowly and uniformly injecting fluids, such as liquid anesthesia, into a human or animal body, comprising a gunshaped body having handle and barrel portions, a piston extending axially through the barrel portion, fluid pressure means for selectively extending or retracting the piston, and adjustable damping means associated with the piston to permit controlled movement thereof; whereby when a syringe having a compressible cartridge is operatively connection to the apparatus, extension of the piston causes compression of the cartridge to effect the desired controlled dispensing from the syringe.

Description

ilnited States Patent [191 Hodosh et al'.

[111 3,768,472 Oct. 30, 1973 FLUID DISPENSING GUN [75] Inventors: Milton Illodosh, 145 Whitmarsh St.,

Providence, RI. 02906; Carl Cometta, East Providence, R1.

[73] Assignee: said Hodosh, by said Cometta [22] Filed: Feb. 7, I972 [21] Appl. No.: 223,873

[52] US. Cl...... 128/218 P, 128/173 H, 128/218 A, 2 222/389, 222/334 [51] Int. Cl A6lm 5/00 [58] Field of Search 222/386, 387 389, 222/309, 334, 326, 261, 262, 258; 128/173 H, 218 A, 218 R, 218 P, DIG. 1; 92/8, 9,10,

[56] References Cited UNITED STATES PATENTS 2,692,706 10/1954 Wiksten 222/334 X 2,717,804 9/1955 White, Jr. 239/373 X 3,413,894 12/1968 Kress et al. 91/422 X FOREIGN PATENTS OR APPLICATIONS 1,068,197 5/1967 Great Britain 92/12 Primary Examiner-Robert B. Reeves Assistant Examiner.loseph .I. Rolla Att0rneyEl1iot A. Salter et a1.

[57] ABSTRACT Apparatus for slowly and uniformly injecting fluids, such as liquid anesthesia, into a human or animal body, comprising a gun-shaped body having handle and barrel portions, a piston extending axially through the barrel portion, fluid pressure means for selectively extending or retracting the piston, and adjustable damping means associated with the piston to permit controlled movement thereof; whereby when a syringe having a compressible cartridge is operatively connection to the apparatus, extension of the piston causes compression of the cartridge to effect the desired controlled dispensing from the syringe.

4 Claims, 5 Drawing Figures PATENTEDUBT 30 ms SHEET 10F 2PATENTEUOBI 30 ms SHEET 2 BF 2 FLUID DISPENSING GUN BACKGROUND AND SUMMARY or THE INVENTION During certain surgical and dental procedures, and particularly the latter, it is common practice to administer an anesthetic, such as novocaine, in order to temporarily deaden sensitive nerves so that the patient will not be compelled to ensure undue pain. However, the administration of the anesthetic, in and of itself, is extremely unpleasant and somewhat painful to the patient, and it has been found that the primary cause of the pain and discomfort attendant to the administration of a liquid anesthetic, such as novocaine, is the fact that conventional injection apparatus administers the anesthetic too quickly and without sufficient uniformity. It has been found that if the anesthetic is administered slowly and uniformly, almost on a drop-by-drop basis, no pain or discomfort results. The same situation exists where during surgical or dental procedures liquid adhesives or polymers are being injected, such as during polymer implants, or where a sealant is being injected into a root canal.

Regardless of the specific nature ,of the injection, the fact of the matter is that there are numerous types of injections wherein for various reasons it is highly desirable to be able to make the injection on an extremely slow and uniform basis. Where such requirements exist, hand syringes, which depend upon the manual dexterity of the person administering same, have proven unsatisfactory; and while there have been previous attempts to provide apparatus for achieving the objectives of the present invention, for one reason or another such prior apparatus has not proven to be completely satisfactory. For example, applicants U.S. Pat. No. 3, 605, 745 dated Sept. 20, 1971, is concerned with this same problem, but the apparatus of this prior patent does not lend itself to a relatively small, compact, hand operated device, as does the present invention. Also, it has been found that effective and ready adjustability of the damping means that control movement of the piston that effects the dispensing operation is necessary and desirable in order to impart sufficient versatility to the apparatus.

It is therefore an object of the present invention to provide apparatus designed to receive a syringe having a compressible cartridge or ampule, the apparatus having means for slowly and uniformly compressing the cartridge to effect a slow and uniform dispensing of fluid therefrom.

Another object is the provision of apparatus of the character described that is relatively small, compact, and portable for easy hand operation, the apparatus preferably being in the form of a gun having handle and barrel portions.

Another object is the provision of apparatus of the character descnbed having means for quickly and effectively permitting adjustment of the dispensing means, whereby the rate of dispensing of the fluid from the cartridge may be readily selected and adjusted.

Another object of the present invention is the provision of apparatus of the character described wherein control of the dispensing means is effected by pressurized fluid which may either be self-contained within the apparatus or fed to the apparatus from an external source.

A further object is the provision of apparatus of the character described which is effective and durable in operation.

Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when considered. in connection with the accompanying illustrative drawings.

DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:

FIG. 1 is a side elevational view, in section, showing the present invention in its static position;

FIG. 2 is a fragmentary elevational view, in section, showing the apparatus in its retracted position;

FIG. 3 is an elevational view, in section, showing the apparatus in its extended or operative position;

FIG. 4 is an end view looking from the right with respect to FIG. 3; and

FIG. 5 is a fragmentary sectional view, taken on line 55 of FIG. 3.

DESCRIPTION OF THE INVENTION Referring to the drawings, there is shown generally at 10 fluid dispensing apparatus in the form of a handoperated gun comprising ahandle portion 12 and abarrel portion 14 removably connected thereto. More specifically, thebarrel portion 14 comprises a reducedportion 16 which fits snugly withinbore 18 in thebandle portion 12 and then is rigidly maintained in position therein by means of setscrew 20. At itsforward end 22,barrel portion 14 is provided with anend wall 24 from which extends a threadedattachment 26 adapted to threadedly receive asyringe 28 having a compressible ampule orcartridge 30 operatively connected to a needle 32, all in a well-known fashion. It will be understood that compression ofampule 30 by means of amovable piston 34 carried inbarrel portion 14 causes fluid from theampule 30 to be dispensed under pressure through needle 32. The basic object of the present invention is the provision of means for controlling movement ofpiston 34 so as to effect extremely slow and uniform dispensing of the fluid from theampule 30.

It will be understood that once thesyringe 28 has been used, it may easily be removed from theapparatus 10 by unscrewing it from theattachment 26, whereupon a new syringe may readily be substituted for subsequent u se of the apparatus. Also theentirebarrel portion 14 may be easily removed fromhandle portion 12 simply by loosening setscrew 20, whereupon a different barrel portion may readily be inserted, either if for reasons of disrepair it becomes necessary to replace thebarrel portion 14, or if it is desired to substitute a different barrel portion, such as where a different length operating stroke of the piston is desired for any reason, thus requiring a different length barrel.

Barrel portion 14 is divided by means of sealingwall 36 into an actuatingchamber 38 and adamping chamber 40. In turn,damping chamber 40 is divided intocompartments 42, 44 by means of sealingwall 46 fixedly secured topiston 34 for movement therewith. Likewise, actuatingchamber 38 is divided intocompartments 48, 50 by means of sealingwall 52 also secured topiston 34 for movement therewith. It will be understood thatpiston 34 slidably passes throughwall 36 in sealed relation thereto, and at its forward end thepiston 34 extends in sealed relation outwardly throughattachment 26 intosyringe 28 in order to engageampule 30 for compression of same.

As will be seen most clearly in FIGS. 1, 2 and 3,handle portion 12 of apparatus comprises an actuator in the form of atrigger member 54 pivotally mount as at 56. In FIG. 1, thetrigger 54 is shown in its off position, i.e., neither end of the trigger is depressed. In this position, theapparatus 10 is in a state of equilibrium, or expressed differently, thepiston 34 is stationary and is not compressing theampule 30. In FIG. 2, the upper end of thetrigger 54 has been depressed which, through a system hereinafter to be described in detail, causes retraction of thepiston 34. Conversely, in FIG. 3, the lower end oftrigger 54 has been depressed, which causes forward or extending movement ofpiston 34 into engagement withampule 30 to depress same, thus effecting the desired dispensing of fluid through needle 32. It will be understood that while the present invention is particularly adaptable and of value in connection with the injection of anesthesia, such as novocaine or the like, it is not limited to such use, and may be used to inject adhesives, polymers, sealants to root canals, etc. No matter what the use may be, however, the important feature of the present invention is the system now to be described whereby the fluid to be dispensed is dispensed at an extremely slow and uniform rate, practically on a drop-by-drop basis, if desired, in order to minimize discomfort and pain to the patient. More specifically, it has been found that the slow, uniform flow of fluid in advance of the needle functions as a cushion to reduce pain and shock to the patient and at the same time prevents balling up of the anesthesia, which sometimes occurs where the latter is introduced in spurts. Actually, it is within the scope of my invention to slowly and uniformly inject gaseous fluids, where the need for same exists as well as liquids of the type heretofore mentioned. It is also within the scope of my invention to use theapparatus 10 for aspiration purposes by havingpiston 34 connected toampule 30 so as to generate a negative pressure on the ampule while the piston is retracted. The invention may be used in this way to withdraw blood from a patient, for example.

As will be seen most clearly in FIG. I,handle portion 12 is provided with arecess 58 closed at its end by a threaded fitting 60 connected to a conduit 62 through which a pressurized gas, such as CO is introduced intorecess 58, it being noted that fitting 60 has an opening 64 extending therethrough through which the gas passes. In FIG. 3, a slightly modified form of the invention is shown wherein instead of introducing the CO from an outside source, a cartridge 66 is positioned inrecess 58 and is maintained therein by threadedfitting 60a. Abushing 68 with apin 70 extending downwardly therefrom is mounted at the upper extremity ofrecess 58, whereupon when cartridge 66 is inserted into position, the upper end of the cartridge will automatically be penetrated by the pin to permit the desired escape of the pressurized gas from the cartridge. Of course, where the pressurized gas is supplied from an outside source, as in FIG. 1, the bushing 68 andpin 70 perform no function. Whether the pressurized gas is selfcontained, as in FIG. 3, or whether it is supplied from an outside source, as in FIG. 1, it has been found to be beneficial to have the gas under reasonably high press sure, since this gives a firmer, more rigid movement of thepiston 34, rather than a soft, spongy type of motion, which is undesirable. Certainly, the pressurized gas is at a pressure considerably higher than atmospheric, and it has been found in practice that a pressure of around 90 lbs. per square inch is highly effective.

Referring again to FIG. 1, with thetrigger 54 in its off position, pressurized gas flows fromrecess 58 through conduit 72, conduit 74 and then upwardly throughconduit 76 to conduit 78 to conduit 80 toannular channel 82, then throughpassage 84 toannular chamber 86 and then finally throughpinhole 88 intodamping chamber 44. Since theaperture 88 is in the form of a pinhole, the pressurized gas, which maintains the pressure indamping chamber 44, flows, on demand, at an extremely low rate of flow. It will be understood that no matter what the position oftrigger 54, the low rate flow of pressurized gas intodamping chamber 44 always exists as long as make-up gas, because of leakage, is required. At the same time, pressurized gas fromconduit 76 flows throughconduit 90 to conduit 92 and then upwardly intospring chambers 94. Simultaneously, pressurized gas from conduit 74 flows throughconduit 96 toconduit 98 and then through lateral conduit 100 (FIG. 5) toconduit 102, then laterally back toconduit 104 intospring chamber 106. The fact that gas under equal pressure is being introduced intochambers 94 and 106 maintains theservo valve mechanisms 108, 110 therebetween in balanced, stationary position. In this position, pressurized gas is prevented from entering into either of theactuating chambers 48, 50, and hence the pressure within these chambers, which is at atmosphere, is balanced, whereuponpiston 34 remains stationary. It will be understood thatchamber 50 is in communication with atmosphere through port 1 12,annular chamber 114,passage 116, andannular chamber 118 which in turn communicates withconduit 120 which communicates with lateral passage 122 and then outwardly throughvent passage 124 to atmosphere. Likewise,chamber 48 is in communication with atmosphere throughport 126,annular chamber 128,passage 130, andannular chamber 132 which in turn communicates with conduit 134 which communicates with lateral passage 136 to ventpassage 124.

As will be seen in FIGS. 1, 2 and 3, thetrigger member 54 carries a pair ofplungers 138, 140 which, when the trigger is depressed, are adapted to engageball valves 142, 144, respectively, to dislodge the balls from their closed position, in which position they are normally maintained by the pressure in the system. More specifically, when thetrigger 54 is in the position illustrated in FIG. 1, neither of the balls are dislodged, and hence venting throughexhaust ports 146 and 148 is prevented. However, when the uppermost portion oftrigger 54 is depressed, as in FIG. 2,plunger 138 engagesball 142 to unseat same, thus exhausting pressurized gas fromspring chamber 94, throughexhaust port 146 whereupon the gas pressure inchamber 106 takes over and moves theservo valve parts 108, 110 to the right to the position shown in FIG. 2. With the parts in this position, pressurized gas passing upwardly throughconduit 76 is now free to flow around valve part 110 into communication with conduit 134 and then throughannular chamber 132,passage 130,annular chamber 128, and finally port 126 into thechamber 48. The introduction of pressurized gas intochamber 48forces piston 34, along withpiston walls 46 and 52 carried thereby, to move to the left to the positions illustrated in FIG. 2.Wall 46 carries a one-way ball-check-valve 150 which permits gas inchamber 44 to freely pass intochamber 42 as the piston is retracting, thus permitting relatively rapid movement of the piston as it retracts. It will, of course, be understood that the gas inchamber 50 is exhausted to atmosphere through the path previously described, aspiston wall 52 moves to its retracted position.

Referring now to FIG. 3, it will be seen that the lower portion oftrigger 54 has been depressed, thus causingplunger 140 to unseatball 144, while at the same time permitting theupper ball 142 to again move to its closed position. Withball 144 unseated, thus openingexhaust port 148, gas fromspring chamber 106 now exhausts throughconduits 104, 102, 100, 98 and then outwardly throughport 148. This causes the pressure inchamber 94 to now take over and move the servo valve parts to the left to the position illustrated in FIG. 3. In this position, the flow of pressurized gas tochamber 48 is shut off while simultaneously the pressurized gas now passes straight upwardly through conduit 72, whereupon it is free to pass aroundvalve part 108 into communication withconduit 120,annular channel 118,port 116,annular channel 114, and then throughport 112 intochamber 50, thus forcingpiston 34, andwalls 46 and 52 carried therewith, to move to the right to the position illustrated in FIG. 3, in which position thepiston 34 is extended into pressurized engagement withampule 30 to compress same and cause dispensing of the fluid therefrom through needle 32. Once again it will be understood that aspiston wall 52 moves from left to right, or from its retracted to its extended position, the gas inchamber 48 is exhausted to atmosphere through the path previously described. It is important to note, however, that as dampingwall 46 moves from its left-hand position of FIG. 2 to its right-hand position of FIG. 3, the one-way check valve 150 prevents air or gas in thechamber 42 from passing therethrough into thechamber 44. However, as an important part of my invention, novel means are provided for permitting an adjustable and regulated flow of air or gas to pass fromchamber 42 tochamber 44 during forward or extending movement ofpiston 34, in order to effect a controlled damping of said movement.

The damping means referred to above comprise anannular chamber 152 surrounding dampingchamber 40, whereupon when dampingwall 46 moves from left to right, i.e., from the position of FIG. 2 to that of FIG. 3, the air or gas inchamber 42 is forced intoannular chamber 152 since there is no seal betweenchamber 42 andannular chamber 152 at theend 154 of the former- Thus, as the air or gas inchamber 42 is compressed, it forces its way at theend 154 intoannular chamber 152 and then back through said chamber to end 156 at which point there is anannular passageway 158 which in turn communicates withpassage 160 which leads intochamber 44. It is important to note thatpassage 160 is defined bybeveled end 162 oftubular member 164, which beveled end cooperates with beveledannular portion 166 which is carried by the inner wall ofannular chamber 152. Thetubular member 164 is threadedly mounted as at 168 withbarrel portion 170, which barrel portion is maintained in fixed position by means of setscrew 20. Anend cap 172 having an innertubular portion 174 is secured totubular member 164 by any suitable means, such ascross pin 176; whereupon turning movement ofcap 172 causestubular portion 164 to threadedly move inwardly or outwardly with respect to fixedportion 170, depending upon the direction of turning movement of thecap 172. By turningend cap 172 so thattubular portion 164 moves inwardly, itsbeveled end 162 is caused to wedgingly engage more tightly withbeveled portion 166, thus decreasing the size of passage defined by these parts, thus slowing down the flow of air or gas fromchamber 42 tochamber 44. Conversely, by turningend cap 172 so as to threadedly movetubular portion 164 in an outward direction, the size ofpassage 160 is increased, thus proportionately increasing the rate of flow of air or gas from thechamber 42 to thechamber 44. It will thus be seen that by the simple medium of adjustingend cap 172, the rate of flow of air or gas fromchamber 42 tochamber 44 may readily be adjusted, thus controlling the damping action onpiston 34 andpiston wall 46 as the latter parts move in a forward direction.Suitable graduations 178 may be provided onend cap 172 to facilitate proper adjusting of the damping action.

It will be understood that only an extremely light load is required to press or actuate thetrigger 54, and in use a load of approximately five ounces has been found to be sufficient to depress the trigger. As previously stated, when thetrigger 54 is released, the compressed air or gas in the system automatically causes both ball valves to close, thus automatically maintaining the trigger in the off position illustrated in FIG. 1. Also as previously stated, any pressurized air or gas may be used in the system, although it is important that whatever medium be used, it must be relatively clean and free from dust or other dry particles in order to prevent clogging of any of the pressure lines. The apparatus is also capable of dispensing different vis-cosity fluids from thecartridge 30, simply by suitably regulating the gas pressure in the system.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.

What is claimed is:

1. Fluid dispensing apparatus comprising an elongated cylindrical housing, means on one end of said housing for mounting a compressible fluid-containing ampule exteriorly of said housing in axial alignment therewith, a piston in said housing and extending outwardly therefrom through said one end, means for moving said piston into engagement with said ampule to compress same and effect dispensing of fluid therefrom, said moving means comprising separate operating and damping chambers through which said piston movably extends, spaced sealing walls on said piston dividing each of the aforesaid chambers into separate compartments, fluid pressure means in communication with said operating chamber for effecting forward and reverse movement of said piston, a passage located inside of said housing and interconnecting said damping compartments for permitting a controlled flow of fluid from one damping compartment to the other during the sage and in the opposite direction increases the capacity of same.

3. in the apparatus of claim 1, said damping chamber being of larger diameter than said operating chamber.

4. In the apparatus of claim 1, said passage comprising an annular chamber extending around and along the exterior of said damping chamber.

Claims (4)

1. Fluid dispensing apparatus comprising an elongated cylindrical housing, means on one end of said housing for mounting a compressible fluid-containing ampule exteriorly of said housing in axial alignment therewith, a piston in said housing and extending outwardly therefrom through said one end, means for moving said piston into engagement with said ampule to compress same and effect dispensing of fluid therefrom, said moving means comprising separate operating and damping chambers through which said piston movably extends, spaced sealing walls on said piston dividing each of the aforesaid chambers into separate compartments, fluid pressure means in communication with said operating chamber for effecting forward and reverse movement of said piston, a passage located inside of said housing and interconnecting said damping compartments for permitting a controlled flow of fluid from one damping compartment to the other during the forward stroke of the piston, thus controlling the rate of movement of the piston during its forward stroke.

2. In the apparatus of claim 1, calibrated means for adjusting the permissible flow of fluid through said passage, whereby the rate of movement of the piston during its forward stroke is correspondingly adjusted, said adjusting means comprising an axially movable portion, movement of which in one direction restricts said passage and in the opposite direction increases the capacity of same.

3. In the apparatus of claim 1, said damping chamber being of larger diameter than said operating chamber.

4. In the apparatus of claim 1, said passage comprising an annular chamber extending around and along the exterior of said damping chamber.

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