US2960087A - Hypodermic injection apparatus - Google Patents

Description

Nov. 15, 1960 J. w. H. UYTENBOGAART 2,960,087

HYPQDERMIC INJECTION APPARATUS Filed Feb. 16, 1954 4 Sheets-Sheet 1 INVENTOR R ATTORNEY Nov. 15, 1960 J; w. H. UYTENBOGAART 2,960,037

HYPODERMIC INJECTION APPARATUS 4 Sheets-Sheet 2 Filed Feb. 16, 1954 Q Q w & Q a w E Q wWW lllll-llll I AN a N 3 3N T 3 w m ATTORNEYS Nov. 15, 1960 J. w. H. UYTENBOGAART HYPODERMIC INJECTION APPARATUS Filed Feb. 16, 1954 4 Sheets-Sheet 4 ATTORNEYS Jaw/mas @Fy/mqgaar/ m M... M M

United States HYPODERMIC INJECTION APPARATUS Johannes Wilhelmus Huybert Uytenbogaart, Wassenaar, Netherlands, assignor to Auguste Rooseboom, New York, N.Y.

Filed Feb. 16, 1954, Ser. No. 410,662

14 Claims. (Cl. 128-218) This invention relates to a structurally and functionally improved hypodermic injection apparatus.

By means of the present teachings, a mechanism is provided which may be used in connection with a relatively inexpensive ampule-needle assembly adapted to be readily incorporated in the apparatus as well as removed therefrom and which assembly after a one-time use, may be discarded. That assembly may be sterilized and filled by the pharmaceutical concern and will remain in properly uncontaminated condition up to the instant of use. At that time, and by suitable manipulation, it may be potentialized to give a hypodermic injection by operation of the apparatus. Accordingly, it Will not be necessary to clean and sterilize the entire apparatus at the time of each injection.

Still another object is that of furnishing a mechanism of this type in which a structure of improved design will be incorporated so that it is feasible to, in effect, achieve a mechanically operated cycle under which the main functions of needle penetration, medicament injection, and needle withdrawal will occur.

Still another object is that of incorporating in such an apparatus a function whereby aspiration will automatically occur. Therefore, the ultimate user will become fully cognizant of whether or not the needle which has penetrated the epidermis is or is not lodged in a vein. In the former event, the needle may be withdrawn and a new site of injection selected.

Among other objects are those of providing an apparatus which will include relatively few and rugged parts which are capable of economical manufacture and which parts may be assembled to furnish a unitary mechanism operating over long periods of time with freedom from all difficulties.

With these and other objects in mind, reference is had to the attached sheets of drawings illustrating practical embodiments of the invention and in which:

Fig. 1 is a front view;

Fig. 2 is a side elevation;

Fig. 3 is a sectional side view taken along the line 3-3 in the direction of the arrows as indicated in Fig. 1;

Figs. 4 and 5 are transverse sectional views taken respectively along the lines 4-4 and 55 in the direction of the arrows as indicated in Fig. 3;

Fig. 6 shows the needle-ampule assembly in association with the piston of the apparatus;

Fig. 7 is a view similar to Fig. 3 but illustrating the needle in fully projected position;

Fig. 8 is a somewhat enlarged fragmentary sectional side view illustrative of the aspiration and injection strokes of the apparatus;

Fig. 9 is a view similar to Fig. 3 but showing an alternative construction;

Fig. 10 is a fragmentary sectional side view of a still further form of apparatus; and

Fig. 11 is a fragmentary sectional view of an alternative form of ampule support.

Referring primarily to Figs. 1 and 2, the numeral 15 2,960,087 Patented Nov. 15, 1960 indicates a casing beyond the rear end of which the end reservoir may have its exposed end knurled as at 17 and contains a fluid capable of producing pressures such that a motor force is created. Conveniently, liquids such as Freon and methyl chloride are utilized. If such materials are employed, then the cartridge will have a capacity sufficiently great to assure its operation through a large number of cycles. These cartridges may be formed of any proper material and will involve only small cost. Additionally, by using Freon a gas will be produced which is practically odorless and which additionally is non-poisonous, non-inflammable, non-caustic and non-explosive.

A head portion '18 forms a part of the casing 15. A second casing 19 of tubular configuration is disposed adjacent casing 15 and parallel thereto. The two casing portions are connected in any suitable manner by, for example, being integral. The rear end of casing 19 is closed by a cover 20 which may be mounted by a bail 21 connected to an actuator 22. The latter is pivotally supported by casing 19 and embraces an arcuate portion conforming to the exterior of that casing. In the position illustrated in Fig. 2, the actuator has been moved past a dead-center position so that the cover 20 will not accidentally displace from the end of casing 19. A removable cap 23 covers the opposite end of casing 19 and is conveniently formed with a notch or slot 24.

That cap, when in seated position, has its inner edge bearing against the head of a bolt or screw 25 carried adjacent its forward end by casing 19. Likewise accommodated within this slot is the rear or inner end portion 26 of a lever 27 pivotally mounted adjacent the outer end of head 18 as at 28. The opposite end of the lever pivotally supports a second lever including an arcuate outer end 29 and an inner end 30 engageable with a surface of lever 27, in effect, provide a rigid extension thereof when part 29 is swung around its pivot in a clockwise direction as in Fig. 2. So extended, it furnishes a trigger for the mechanism in a manner hereinafter described.

Now considering the apparatus as illustrated in Figs. 3, 4 and 5, which show its interior structure, it will be noted that if a cartridge such as 16 is employed, this may have its inner end reduced to furnish a threaded neck portion 31. This enters into the threaded bore of a collar 32. A transverse partition 33 mounts this collar and additionally supports a piercing cannula 34. Therefore when cartridge 16 is rotated with respect to casing 15, the interengaging threads of the neck portion 31 and collar 32 will cause the pointed inner end of cannula 34 to penetrate a perforable seal 35 which initially closes the bore of neck 31. This cannula or parts adjacent thereto, provides a passage or restricted area. So constructed, it will function as an expansion valve to convert the liquid Freon" into a gas under pressure as such liquid flows therethrough.

In advance of partition 33, a chamber 36 is provided. The forward end of this chamber is bounded by a second partition 37. The latter is formed with a transverse bore which is defined on its opposite faces by valve seats 38. These are alternately engageable by valves 39 and 40 connected by a plunger 41 acted upon by a spring 42.-

Therefore, gas under pressure, may tflow into the bore of partition 37 and through passages 43 and 44 into the rear end of casing 18? which provides the power cylinder of the apparatus;

Within that cylinder, a piston is movable. Such piston may include a head portion 45 mounting a packing or ring 46 and also supporting a sleeve 4.7. That sleeve may be adjusted with respect to the head of the piston in the event a predetermined dosage of medicament is to be injected and: which is less than the complete capacity of the barrel or ampule as hereinafter described.

If no such provision is to be resorted to, then sleeve 47 may simply be fixed with respect to piston headv 45.

A rod 48 is secured to head 45 and terminates in a coupling portion 49. That rod on one of its faces furnishes an uninterrupted surface continued in the form of a series of ratchet teeth 50. On its opposite face or otherwise to one side of teeth 50, one or more undercut recesses 51 are formed in the rod. A collar 52 is slidably supported upon this rod and is provided with a detent in the form of a pivotally mounted spring-pressed tooth 53. This collar also supports by a pivot, a pawl 54 which is likewise spring-pressed. This pawl may be shifted against the action of the spring to a releasing position by means of a pin 55 which has its shank extending through to the outer face of collar 52 and preferably within a depression formed in the latter. Pawl 54 is aligned with and engages the teeth of the ratchet series 50. The detent element 53 is aligned with and may be disposed to lie within any one of the recesses 51 (if more than one of the same is provided).

As illustrated, for example, in Figs. 3 and 6, a onetime use injection assembly has been shown. It will be understood that one or all parts of the assembly might boot the type which could be used, cleaned and sterilized and refilled for subsequent use. In many respects, a discardable assembly is preferred which may includea hollow needle 56 protected by a sheath 57 afiixed to. an ampule or barrel 58 having a piston stopper 59. The barrel may be of glass and contains medicament. Stopper 59 includm a coupling part, for example in the form of a recess cooperable with coupling 49. The diameter of barrel 58 is preferably equal to that of collar 52. Accordingly, when collar 52 is shifted to the left as in Fig. 3, it will bear against the rear edge of :ampule 58. and move the latter.

It will be observed that casing 19 preferably has extending. outwardly from its face a subsidiary casing 60. Within 'the latter, a pivotally supported lever 61 is disposed. One end of this lever conveniently terminates in abutton 62 which extends through an opening in casing 60 and has a spring acting against it to normally maintain it in projected position. The opposite endof the lever providesa latch 63 which extends into .the casing bore and has its projection limited by a stop 64. A spring 65 has its rear end bearing against the inner face of piston head '45. Its opposite end bears against a flange or constriction 66 which may be recessed to receive and retain the end of spring 65. The diameter of this constricted portion is such that ampule or barrel 58 as well as collar 52 may pass through the same in guiding relationship. Conveniently beyond the flange 66, a further flange or rib 67 extends inwardly in to the bore of casing 19 to slidably contact the outer face of ampule 58 and guide the same inits movements. The outer end of casing 19 within cap 23 is preferably rounded, as shown, to provide a skin-contacting portion. [t is formed with an opening 68 through which cannula 56 may project.

At this time it is to be noted that sleeve 47 has a diameter such that it maybe projected through the space defined by the constriction or flange 66. As afore brought out, it may form a fixed part of head 45. However, if a structure limiting the amount of the injectable dosage is to be included in the apparatus, then a second sleeve or cylindrical portion 69 may form a fixed part of head 45 and rotatably support sleeve 47. As shown, a pin '70 will, under these circumstances, extend outwardly from member 69 and into a slot 71 in sleeve 47. This slot is formed with a series of recesses or notches 72 which selectively receive pin 70. As in Fig. 7, the outer face of sleeve 47 may, under these circumstances, be provided with indicia 73 adjacent each notch. These indicia will be indicative of the volume of medicament injectable as a consequence of positioning the pin within a selected notch.

Now considering the operation of this apparatus, attention is directed to all of Figures 1 to 8 inclusive. It will be assumed that the apparatus is unloaded. Therefore, as an initial step, the operator may shift actuator 22 past dead center to release bail 21 and cover 20. Under these circumstances, spring 65 will urge head 45 rearwardly. so that a part of this assembly may readily be grasped and the entire head and rod 48 together with collar 52 may be withdrawn from the bore of casing 19. An ampule-needle assembly is coupled to the end of rod 48 by operatively associating the coupling 49 with the piston stopper 59. In this. connection, it will be understood that any suitable form of coupling may be employed. Collar 52 is. shifted to the left as in Fig. 3. To this end, it may be necessary to release pawl 54 from engagement with teeth 50. This may be accomplished by exerting pressure on the pin 55. The shifting of collar 52 is continued until it bears against the rear edge of ampule or barrel 58. At that time, tooth 53 will be in line with the outermost of the undercut notches 51. Therefore, by manually shifting that tooth inwardly and then effecting a slight retraction of the collar 52 with respect to rod 48, it will lodge with-in the undercut zone of the notch and be retained therein as clearly shown in Fig. 3.

At this time, sheath 57 may be removed so as to expose needle 56. The latter is introduced into the bore of casing 19. Now by grasping the parts of the assembly adjacent piston head 45 and projecting them, the ampule will ride into position through the guiding portions 66 and 67 until the needle end is at a point immediately to the rear of opening 68. Cover 20 is shifted to a point Where it aligns with the rear end of casing 19 and actuator 22 is moved to the position shown in Fig. 2 so as to close and seal the rear end of casing 19. If, of course, it is desired to inject merely a portion of the medicament within the/barrel or ampule, then sleeve 47 may be rotated and axially moved with respect to sleeve 69 so that pin 70 is disposed within a notch 72 aligned with an indicium designation of proper value. With the parts in this position, the. forward end of the barrel or ampule 58 may be visible through the sight opening 74 formed in the side of the casing.

At this time, or else as a step preceding the steps just described, a cartridge or reservoir 16 is introduced into the bore of casing 15. If screw threads exist on collar 32 and neck portion 31, then a relative turning of the parts results in the piercing cannula penetrating the seal 35. Under these circumstances, gas under pressure will fill chamber 36 but will not flow beyond the same because of the seal provided by seat 38 cooperating with valve body 39 due to the action of spring 42. Prior to the insertion of the cartridge, cap 23 has preferably been mounted on the forward end of casing 19 with the head of bolt 25 introduced into slot 24 to the greatest extent possible. So disposed, the edge of this slot will lie adjacent the lower end or arm 26 of lever 27. in engagement with the cap edge, this arm will operate as a stop to prevent any operative shifting of the lever 27 and its trigger extension 29. Therefore, there will be no danger of valve 39 accidentally opening. If a hypodermic injection is to beresorted to, then cap 23 will be removed and the trigger extension 29 shifted to the position shown in Fig. 3 frornthat illustrated in,Figs. 1 and 2. A site of injection having been selected, the forward end of casing 19 is brought to bear against the tissues overlying this site and the axis of that casing is shifted to extend at the desired angle to efiect proper penetration.

If now the trigger '29 is actuated, stem or rod 41 will be shifted inwardly. Under these circumstances, valve 40 will engage with its seat to prevent an escape of gases through the bore which extends transversely of partition 37. Valve 39, having been unseated as a consequence of the triggering, it follows that gas will flow through passages 43 and 44 to the rear of the piston head 45. This will cause that head to be projected against the action of spring 65. So projected, it will correspondingly shift rod 48. That rod will not shift with respect to barrel or ample 58. This will be because the arm or tooth 53 is disposed within the undercut portion of the forward notch 51 and with this arm or finger carried by collar 52 and the latter bearing against the ampule or barrel, such shifting cannot occur. Therefore, the ampule-needle assembly will be projected as a unit, without the piston 59 shifting within the bore of barrel 58, to the position shown in Fig. 7. In that position needle 56 is fully projected.

In the latter View, it will be seen that collar 52 has moved through the orifice defined by flange 66 to a point where the forward end of the ampule lies immediately adjacent the inner face of casing 19 and adjacent the outer end of the latter. Under these circumstances, latch 63 will override collar 52 and prevent the latter from retracting even if the gas under pressure no longer acts against the piston head and seal 46. Of course, in Fig, 7, no interruption to the action of the gas against the piston head has been illustrated. Rather, valve 39 remains in open position.

The physician or other user will now release the pres sure upon the trigger 29 in that the needle has been plunged to the desired depth into the tissues. With such release, the valve parts actuated by the trigger will return to the positions shown in Fig. 3. Under these circumstances, the pressure within the cylinder to the rear of head 45 will be relieved by a return flow of gas through passages 44 and 43 through the bor of the transverse partition which accommodates the stem 41 and so out through the forward part of casing 15. With such release and as shown in Fig, 8, spring 65 will be free to shift piston head 45 rearwardly or to the right, carrying with it stem or rod 48. However, ampule or barrel 58 cannot retract because this is prevented by collar 52 being in engagement with latch 63. Therefore, rod 48 will move rearwardly, carrying with it th piston-stopper 59 to a point where the flange defining the rear end of coupling 49 will contact the forward edge of collar 52. In this connection, it will be observed that pawl 54 is clear of the successive series of teeth 50 and thus is not prevented from such rearward movement throughout this limited range of travel of the parts.

Obviously, if needle 56 has lodged in a vein, then an observer viewing the forward end of the ampule through the sight opening 74, will note that blood has been drawn into the barrel. In such event, the user will press against button 62. to release latch 63 and thus allow the entire syringe-ampule assembly to be retracted by spring 65 back to the position shown in Fig. 3. Thereupon, and after the parts have been reset, a new site of injection may be selected and the operation repeated Assuming that the aspirating action fails to reveal that the needle is lodged in a vein, then with the rearward movement of rod 48 (producing the aspirating action just described), tooth or finger 53, under the influence of its spring will move out of notch 51 as shown in Fig. 8. Now if the trigger 29 is again actuated, gas under pressure will once more flow to the rear of piston head 45 and project rod 48. At this time, the piston may move relatively to the barrel 58, because tooth or finger 53 no longer couples collar 52 for movement in unison with the rod. Accordingly, pison-stopper 59 will project through the bore of the ampule or barrel to expel medicament through the lumen of the needle and beyond the end of that needle. This action will continue until the pull upon trigger 29 is released. If that pull is not released, then the entire contents of the ampul will be injected. This is excepting only if mechanism of the type heretofore described at 47, 69, 70 et cetera is not employed. Also the operator, by sighting through opening 74 may, of course, arrest further projection of the piston stopper at any desired point aligned, for example, with indicating marks on the barrel 58 or the adjacent portions of casing 19. If this procedure is resorted to, either by way of sighting or an arrest of projection incident to the extension of sleeve 47, then the trigger will be released at the desired limit of the projection stroke.

Now by pushing against button 62, latch 63 will be retracted to permit collar 52 to be drawn rearwardly by the force of spring 65; the latter bearing against head 45 connected to rod 48 in turn coupled to collar 52 by a tooth 50 and pawl 54. Thereupon, the parts may be reset with, for example, the finger or arm 53 disposed in the second undercut notch 51 in the manner heretofore described; a second injection stroke preceded by penetration being effected in the next cycling of the apparatus to expel the balance of the medicament within the ampule. Of course, if sleeve 47 forms a fixed part of head 45 and all of the contents of the ampule be injected in a single stroke, then that sleeve will ride into position overlying the inner end of latch 63. Camming against the face of the latter, lever 61 will be swung to compress the spring within button 62. Under these circumstances, it will not be necessary to manually depress that button. Rather, upon releasing the trigger at the final stage of the cycling, spring 65 Will retact the needle into the casing thus withdrawing it from the patients flesh. Likewise, if an extensible sleeve 47 is employed, the latch 63 will be automatically retracted. Therefore, after the expulsion of the medicament from the ampule and a release of the trigger to vent thegas under pressure, spring 65 will retract the needle and ampule assembly to the position shown in Fig. 3.

Considering the illustrations in Figs. 3, 7 and 8 respectively, and in brief recapitulation, the first figure shows the parts ready for injection subject only to removal of the cap 23 from casing 19. With such removal, the trigger may be actuated. As actuation occurs, the ampule and needle will be projected to the position shown in Fig. 7 wherein the trigger is still actuated to assure a flow of gas under pressure to the rear of the piston within the cylinder or casing 19. Under these circumstances, latch 63 has moved into position to the rear of collar 52. Therefore, the latter may not be retracted and the ampule and needle will be maintained in fully projected positions. Accordingly, with release of the trigger and a venting of the gas under pressureas in the position of the valve part shown in Fig. 3-spring 65 will cause a limited retraction of rod 48; a stop structure functioning incident to pawl 53 abutting the rear flange portion of coupling 49. Therefore, piston 59 will be moved rearwardly within the bore of ampule 58 to assure an aspirating action. At the same time, the finger or pawl 53 will move out of notch 51. It follows that upon the next actuation of the trigger, gas under pressure will flow to the rear of head 45, thus projecting the piston 59 to the position shown in dot and dash lines in Fig. 8. Under such projection, pawl 54 will ride in engagement with a series of teeth 50 to prevent any retracting tendency on the part of rod 48. With the final stages of projection of the latter, sleeve 47 will ride past latch 63 to release the same. Accordingly, upon the pressure of the gas being relieved, the needle will be withdrawn to within casing 19.

Under certain circumstances, it might be desired to dispense with the aspirating step or function. Under these circumstances, by relatively slight changes in structure, the desired result could be achieved. For example, in Fig. 10, in which an apparatus in many respects identical with that shown in Figs. 1 to 8 inclusive has been illustrated, the structure has been modified so that the pawl 54 cooperating with the series of teeth 50, instead of riding on an uninterrupted initial surface adjacent the coupling 49, as in Fig. 3, engages at this zone with the last tooth 76 of the series. Likewise, the rod 48 is formed with notches 77 which are undercut to a lesser extent than notches 51. Therefore, with the initial projection of the parts occurring incident to the action of gas pressure to the rear of the piston head, the ampule-needle assembly will be projected in a manner heretofore described in connection with Fig. 7. However, when fully projected, pawl 54 will lie immediately to the rear of the most forward tooth or ratchet element '76 and be slightly spaced therefrom as shown in Fig. 10. Also, the rear flange portion of coupling 49 will be similarly spaced'from collar 52. Therefore, with the release of the gas pressure, spring 65 will be free to move the piston assembly rearwardly only to the small extent necessary to allow finger or arm 53 to swing clear of its notch 77; This rearward movement will not be sufficient to cause, in effect, a retraction of piston stopper 59 such that an aspirating action will occur. Therefore, all that will happen will be for finger 53 to disconnect from the piston rod after the parts are fully projected and maintained in that position by pawl 63. Accordingly, a subsequent actuation of the trigger causes a projection of the piston and an expulsion of the medicament from the ampule as heretofore described.

Attention is next invited to Fig. 9 in which an apparatus, which in function, generally corresponds to the mechanism shown in Figs. 1 to 8, has been, illustrated. It will be seen that the same general reference numerals have been used to indicate similar parts to those heretofore described. However, in this view, it will be noted that the numeral 78 indicates a piston head slidable within cylinder or casing 19 and which head is provided with a bored plug 79. The latter is formed with an opening 89 and is encircled by a sleeve 81 formed of rubber or similar material. Accordingly, a check valve structure is furnished by means of which fluid under pressure may flow from the rear of head 78 through port 80 and beyond sleeve 81 but may not return. A, rod 82 is connected to head 78 and is formed with a port 82, in proximity to port 80. This rod pivotally supports a lever, 83 within a slotted portion of its body and a spring 84 tends to move that lever into the boundary zones defined by the side faces of such rod.

The forward end of lever 83 terminates in a latch or engaging portion 83. This cooperates with a ledge or stop portion 85 forming a part of a collar, 86. Rod 82 slidably extends through the bore of this collar and terminates in a coupling portion 49, corresponding to the parts heretofore described under this reference numeral. A latch 87, correspondingin function to latch 63, is mounted to extend into the bore of casing 19 and has a cam face which may be engaged by collar 86 so that the latter may override the latch. Once moved to a position beyond the same, this latch, under the influence of spring 88, will prevent a retractionof collar 86. A button or actuator 82 spring-pressed as in 88, may act against that end of the lever opposite that which provides latch 87. Conveniently, a fluid-tight membrane 9% is interposed between button 89 and this lever.

It will be seen in this assembly that if the parts are properly grouped together with lever 83 in the position illustrated, then an actuation of trigger 29 will cause gas under pressure to flow to the rear of piston head 78. Therefore, that head will be projected together with rod 82 and collar 86. Thelatter, bearing against the rear edge of ampule 58, will cause needle $6 to be projected through opening 68 at the forward end of casing 19* and plunge the outer end of this needle into the tissues to the desired depth. 'Ihat depth will be conveniently established by the forward end of the ampule or barrel moving to a point adjacent the inner face of casing 19 at a point in proximity to the opening 68. With such movements of the parts, spring 91, which is interposed between collar 86 and flange 67, will be compressed.

Likewise, latch 87 will move to the rear of collar 86 and prevent a retraction of the latter under the influence of this spring.

Therefore, When trigger 29 is released and the compressed gas is vented, a further action of the parts will follow. In this connection, it will be understood that the .gas under pressure has flowed outwardly through port 89, pastthe check valve structure provided by sleeve 81 and thus exerts pressure in the space between head 78 and collar 86. The value of this gas pressure will be less than that which has been acting against the rear face of piston head 78. Accordingly, when trigger 29' is released, rod 82 will move rearwardly to a slight ex tent with respect to collar 86. Such rearward movement will result in a corresponding movement on the part of piston 59 and a consequent aspirating action within the barrel orampule 58. Likewise, it will result in the latch portion 83' of lever 83 clearing the supporting or engaging part 85. Therefore, under the influence of spn'ng 84, lever 83 will swing to a position aligned with the bore of collar 86.

Consequently, a further actuation of trigger 29 will cause head 78 to be projected with respect to collar 86. This will have the result that piston 59 moves within the bore of the barrel or ampule to expel the medicament contained therein. This expulsion may continue until the entire contents of the ampule have been injected. 0therwise, by sighting through opening 74 and observing the graduations or other indicia 92 in conjunction with piston 59, the forward movement of at any desired point resulting in only a partial injectionof the entiremedicament volume.

A partial injection is achieved 29 when piston 59 has been projected within ampule 58 to the desired extent. In advance of such projection, it will be appreciated that head 78, rod 82 and the collar or head 86 will have been shifted so that the needle extends beyond casing 19- as in Fig. 7. Under those circumstances, latch 87 will be in engagement with the rear surby releasing the trigger face of collar 86. Accordingly, the latter will not retract fore, the pressure between this member and collar 86 will cause the former to be retracted. This retraction will be sufficient to cause piston 59 to be shifted rearwardly within ampule 58 thereby causing an aspirating action as aforedescribed in connection with the structures of Figs. l to 8 inclusive. With this aspirating action, the engaging end portion 83' of lever 83 will override the ledge or flange 85. Accordingly, lever 83 will move substantially into axial alignment with rod 82.

It follows that a subsequent actuation of trigger 29 will cause head '78 as well as rod 82 to be projected while collar 86 remains stationary. Therefore, (the desired discharge of medicament from within the ampule or barrel 58 may occur. A partial discharge may, of course, be registered by releasing the trigger when piston 59 is in line with a desired indicating mark 92 associated with lever and compress spring 88. Therefore, when trigger rod 82 may be interrupted 29 is subsequently released, the latch will be inoperative and the entire ampule-needle assembly, under the influence of spring 91, will be retracted to the position shown in Fig. 9. If an earlier retraction is desired, then by pressing button 89, the latch may be released to secure this result. As is apparent, diaphragm or membrane 9i) prevents an escape of the gas through the opening provided for the passage of latch part 87.

In the event it is desired to stabilize the barrel or ampule in a position where it is perfectly aligned with the axis of casing 19, then a structure such as has been shown in Fig. 11 may be employed. It will be noted in that figure that collar 52 has been modified as at b to present a body portion mounting the pawl and finger as heretofore described. However, this collar is extended as at 96 to provide a sleeve. The latter slidably receives the barrel or ampule 58. Also, when (the parts are in the retracted position shown in Fig. 3, this sleeve will ride against the guiding flange or equivalent portion 67. Therefore, it follows that if the operator positions the ampule within the sleeve and the inserts the assembly as shown in Fig. 6 into casing 19, a relationship such as has been illustrated in Fig. 11 will follow. Accordingly, the needle 56 will always center with opening 68; the ampule remaining in alignment with the axis of rod 48.

As will be appreciated, the collar or equivalent unit together with its associated parts in all instances serves as a coupling mechanism to connect the reciprocal rod with the needle, barrel and piston assembly. More particularly, as in Fig. 3, element 53 disposed in one of the notches 51 will assure that the collar moves in synchronism with the rod as the latter is projected. When once projected, a small retraction of the rod with respect to the barrel of the assembly will cause a release of the aforementioned coupling between that rod and the collar. The latter during this retractive movement has been retained by the latch. This retraction is permitted in that pawl 54 will not have been in engagement with any of the teeth 50. Also, too great a retractive movement Will not occur because in an initial position of the parts this will have been prevented because of the contact which will be established between the rear flange of coupling 49 and collar 52;. In a partially projected or discharged position, this retractive movement will be limited by engagement of the pawl 54 with one of the teeth 50. The same co-action of the parts will occur in the structures as shown in Figs. and ll. In Fig. 9, of course, a retraction of the rod releases latch or pawl 83 from flange 85 of the collar 86 or its equivalent.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously numerous changes in construction and rearrangements of the pants might be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. An injection apparatus including in combination a hypodermic needle barrel and piston assembly, a casing to receive and movably mount said assembly, a rod reciprocal within said casing, a head arranged to move with said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, coupling means extending between said rod and collar ltO cause the same to project in synchronism, means for rendering said coupling means inoperative upon the head projecting and subsequently retracting to a predetermined extent whereby to disconnect said collar from movement with said rod and means tor urging said rod and head to a retracted position.

2. An injection apparatus including in combination a hypodermic needle barrel and piston assembly, a casing to receive and movably mount said assembly, a rod reciprocal within said casing, a head arranged to move with said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, coupling means extending between said rod and collar to cause the same to project in synchronism, means for rendering said coupling means inoperative upon the head projecting and subsequently retracting to a predetermined extent whereby to disconnect said collar from movement with said rod, means for urging said rod and head to a retracted position and a latch cooperating with said collar to prevent a retraction of the latter.

3. An injection apparatus including in combination a hypodermic needle barrel and piston assembly, a casing to receive and movably mount said assembly, a rod reciprocal Within said casing, a head arranged to move With said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, coupling means extending etween said rod and collar to cause the same to project in synchronism, means for rendering said coupling means inoperative upon the head projecting and subsequently retracting to a predetermined extent whereby to disconnect said collar from movement with said rod, means for urging said rod and head to a retracted position, a latch cooperating with said collar to prevent a retraction of the latter and means exposed upon the outer casing face to render said latch inoperative.

4. An injection apparatus including in combination a hypodermic needle barrel and piston assembly, a casing to receive and movably mount said assembly, a rod reciprocal within said casing, a head arranged to move. with said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, coupling means extending between said rod and collar to cause the same to project in synchronism, means for render-ing said coupling means inoperative upon the head projecting and subsequently retracting to a predetermined extent whereby to disconnect said collar from movement With said rod, means for urging said rod and head to a retracted position, a latch cooperating with said collar to prevent a retraction of the latter, and means to render said latch inoperative.

5. An injection apparatus including in combination an assembly comprising a hypodermic needle, a barrel mounting the same and a piston slidable within said barrel, a casing to receive and movably mount said assembly, a rod reciprocal within said casing, a head arranged to move with said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, coupling means extending between said rod and collar to cause the same to project in synchronism, means functioning upon such rod retracting to a predetermined extent to disconnect said collar from movement with said rod, a latch cooperating with said collar to prevent a retraction of the latter, means to render said latch inoperative, means forming a part of said apparatus whereby, with said collar and barrel maintained in projected positions, said rod and piston will be retracted to cause limited aspirating action in said barrel and means forming a part of said collar cooperating with said rod to prevent a complete aspirating retraction of the piston connected therewith.

6. An injection apparatus including in combination a hypodermic needle barrel and piston assembly, a casing to receive and movably mount said assembly, a rod reciprocal within said casing, a head arranged to move with said rod, means to connect said rod with the piston of said assembly, means acting against said head to project the latter, a collar engageable with the barrel of said assembly to project the same, a lever rockingly mounted by said rod and engageable with said collar to project the latter in synchronism with said rod, means for biasing said lever to assume a position substantially aligned with the bore of said collar to pass therethrough and allow a projection of said rod and the piston connected therewith independently of said collar, means for creating a reactive force between said head and collar to retract said rod and piston and means for limiting such retraction.

7. In a hypodermic injection apparatus in combination a casing having a forward end defining a space to receive a hypodermic needle, barrel and piston assembly, an actuating member within said casing and connectable to the piston of said assembly, means for projecting said member, a coupling mechanism cooperable with the barrel of said assembly for projecting the latter and the needle in response to a functioning of said projecting means, means forming a part of said mechanism for connecting the same with said actuating member in order that it will move in unison to project said assembly, means also forming a part of said mechanism to render said connecting means inoperative upon said actuating member being moved in a predetermined manner and latch means for retaining said coupling mechanism and the barrel cooperating therewith in projected positions.

8. In a hypodermic injection apparatus in combination a casing having a forward end defining a space to receive a hypodermic needle, barrel and piston assembly, an actuating member within said casing and connectable to the piston of said assembly, means for projecting said member, a coupling mechanism cooperable with the barrel of said assembly for projecting the latter and the needle in response to a functioning of said projecting means, means forming a part of said mechanism for connecting the same with said actuating member in order that it will move in unison to project said assembly, means also forming a part of said mechanism to render said connecting means inoperative upon said actuating member being moved in a predetermined manner and means for retracting said actuating member and the piston connected thereto with respect to the barrel to cause an aspiration of said assembly after the latter is projected.

9. In a hypodermic injection apparatus in combination a casing having a forward end defining a space to receive a hypodermic needle, barrel and piston assembly, an actuating member Within said casing and connectable to the piston of said assembly, means for projecting and means for retracting said member, said means for projecting adapted to be made operable and inoperable, a coupling mechanism cooperable with the barrel of said assembly for projecting the latter and the needle in response to a functioning of said projecting means, means forming a part of said mechanism for connecting the same with said actuating member in order that it will move in unison to project said assembly, means also forming a part of said mechanism to render said connecting means inoperative upon said actuating member being moved in a predetermined manner, latch means for retaining said coupling mechanism and the barrel cooper-ating therewith in projected positions and means for rendering said latch means inoperative so that said retracting means will function to return said assembly to an initial position when said projecting means is rendered inoperable.

10. In an injection apparatus a hypodermic needlebarrel assembly, a piston forming a part of said assembly and disposed in the barrel of the same, a reciprocal rod separate from said assembly, means connecting said rod to said piston, a coupling slidably mounted by said rod and engageable with the barrel, means forming a part of said coupling for functioning to project the barrel and needle as said rod is projected, means forming a part of said coupling to automatically disconnect the latter from said rod as the latter is retracted and latch means cooperating with said coupling for limiting the retraction of said rod.

11. In a hypodermic injection apparatus, in combination a casing having a forward end, an assembly comprising a barrel, a needle at one end thereof and a piston at its opposite end, said forward casing end being formed with an opening and said assembly being housed within said casing end, an actuating member movable within said casing and connected to the piston of said assembly, a coupling cooperable with the barrel of said assembly for projecting the latter to cause the needle to extend through said opening, means for connecting said coupling with said actuating member whereby they will move in unison, latch means for retaining said coupling and the barrel cooperating therewith in projected positions, said projecting means including a liquid-containing reservoir, an expansion valve interposed between said reservoir and casing space to convert the liquid within the reservoir into a gas, valve means for controlling the flow of that gas, and a further piston connected to the actuating member to move the latter.

12. A hypodermic injection apparatus as defined in claim 11, and a retracting means including a spring cooperating with said actuating means to normally urge the same toward a predetermined position.

13. In a hypodermic injection apparatus in combination a casing having a forward end defining a space to receive a hypodermic needle, barrel and piston asembly, an actuating member Within said casing and connectable to the piston of said assembly, means for projecting and means for retracting said member, said means for projecting being adapted to be made operable and inoperable, a coupling mechanism cooperating with the barrel of said assembly for projecting the latter and the needle in response to a functioning of said projecting means, means forming a part of said mechanism for connecting the same with said actuating member in order that it will move in unison to project said assembly, means also forming a part of said mechanism to render said connecting means inoperative upon said actuating member being moved in a predetermined manner, latch means for retaining such coupling mechanism and the barrel cooperating therewith in projected condition, said retracting means being operable after functioning of said latch means to cause a partial retraction of said actuating member and the barrel piston carried thereby when said projecting means is rendered inoperable, said actuating member being subsequently projectable to correspondingly project the piston within the barrel of the assembly when said projecting means is rendered operable.

14. In an injection apparatus as defined in claim 10, a member forming a part of said coupling and having a relatively recessed portion and a finger also forming a part of said coupling and extending into said recessed portion to engage a surface thereof.

References Cited'in the file of this patent UNITED STATES PATENTS 2,472,116 Maynes June 7, 1949 2,502,639 Blake Apr. 4, 1950 2,632,445 Kas Mar. 24, 1953 2,671,448 Hamish Mar. 9, 1954 FOREIGN PATENTS 1,014,881 France June 25, 1952 276,860 Switzerland Nov. 1, 1951 902,776 Germany Jan. 28, 1954

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