US2699166A - Hypodermic injection unit - Google Patents

Description

Jn. 11, 1955 F. s. DlcKlNsoN, JR., ErAL 2,699,166

HYPODERMIC INJECTION UNIT Filed July 29, 1949 2 sheets-sheet 1 5 22 15 6 f 421 ZZ 4 T TNEYS Jan. 11, 1955 F. S. DICKINSON, JR., E'I'AL HYPODERMIC INJECTION UNIT Filed July 29. -1949 2 sheets-sheet 2 United States Patent O HYPDERMIC INJECTION UNIT Fairleigh S. Dickinson, Jr., Rutherford, and Albert E. Krug, Hawthorne, N. J., assignors to Becton, Dickinson and Company, Rutherford, N. J., a corporation of New Jersey This invention relates to a structurally and functionally improved hypodermic injection unit and especially a unit which will be used in an apparatus where the medicament is injected at velocities and in a suiciently fine stream such that no skin penetrating needle is employed.

It is an object of the invention to furnish a structure such that an ampule may be utilized as part of the as'- sembly, such ampule being filled or charged with a desired volume, grade and type of medicament. Accordingly a physician employing the unit will be assured that the injection will be precisely in accordance with his wishes.

It is a further object to furnish an assembly in which a glass ampule may be employed so that the injectable solution will remain stable and unaffected by the material of the ampule or cartridge. By means of this invention the danger of breakage of the ampule will be reduced to a minimum if not entirely eliminated despite the high pressures to which the parts must be subjected as an incident to velocity injection.

Still another object is that of providing an assembly which will include relatively few parts, each individually simple and rugged in construction, these parts having a long effective life and capable of being operated without especial skill.

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 sectional side View of the end portion of a hypodermic injection unit;

Fig. 2 is a simliar view but showing the parts after the injection operation has been completed;

Figs. 3 and 4 correspond to Figs. 1 and 2 respectively but show alternative forms of structure;

Fig. 5 is a sectional View similar to Fig. 1 but illustrating a still further form of unit;

Fig. 6 is a transverse sectional view taken along the lines 6 6 and in the direction of the arrows as indicated in Fig. 5;

Fig. 7 shows another alternative form of structure;

Fig. 8 is a transverse sectional view taken along the lines 8--8 and in the direction of the arrows as indicated in Fig. 7;

Fig. 9 is a fragmentary sectional end view of a still further form of assembly; and

Fig. l0 is a transverse sectional view taken along the lines 10--10 and in the direction of the arrows as indicated in Fig. 9.

As is Well understood by those conversant with the velocity injection art, different forms of mechanisms may be employed to cause the medicament to be injected at velocities and in sufficiently fine streams to produce the desired results. Certain of these mechanisms offer advantages over others of the same. It is preferred that the present teachings be employed with a mechanism of the general type shown in the prior application to George N. Hein, Jr., Serial Number 30,047, filed May 29, 1948, on Injection Assembly.

Therefore, in the several views the numeral indicates the end portion of such an apparatus or an extension thereof. In either event that part will preferably be in the form of a relatively heavy walled tube presenting a bore 16 through which liquid may ow. As taught in the aforementioned Hein application, suitable liquid is caused to ow under desired pressures and velocities to function as a piston. This ow is controlled by the operator who also potentializes the apparatus to Patented Jan. 11, 1955 assure that the desired pressures and other factors will n be present in such ow.

As shown in all figures with the exception of Figs. 5 and 6, an ampule 16 preferably in the form of a glass tube is employed and which has both of its ends unobstructed. As shown in Fig. 5, an ampule 17, also preferably of glass, may be utilized and which has its rear end closed. Where the rear end of the ampule is open, as in the first four figures, then a stopper 18 of the piston type may seal that end. This stopper is conveniently formed of rubber and may be suitably treated or impregnated so that it will be capable of axial movement through the bore of the ampule or medicament-containing cartridge. The forward ends of the ampules may be closed by relatively solid rubber stoppers 19 as in Figs. l and 2 or by stoppers 20 preferably having their inner faces formed with recesses as in the remaining iigures.

Considering now Figs. 1 and 2 it will be noted that body 15 mounts a retaining ring 21 conveniently by screw threads and this ring may similarly mount a loading cap 22. The latter retains an element 23 formed with an aperture 24 which will serve to define the medicament jet or column. In these views stoppers 19 are preferably provided with forwardly extending protuberances. The latter project into the elements 23 and engage with the inner face of the same. A bore 25 is formed through the stopper 19 and aligned with the aperture 24. As will be understood the diameter of the latter should preferably on the order of from .002 to .005 although in certain instances it may be substantially larger.

A sack denes the ampule-receiving chamber of the unit. Still referring to Figs. l and 2, this sack includes a cup-shaped body 26 formed of rubber and conveniently provided with a liange portion 27. The latter is engaged by adjacent surfaces of, for examples, the extension 15 and ring 21 so that a fluid tight seal is established. The internal diameter of the sack is' substantially equal to the external diameter of the ampule. The external diameter of that sack is less than the internal diameter of the chamber 23. Therefore, it is apparent that liquid may flow between the faces of that chamber and the sack.

In using an apparatus of the type shown in Figs. l and 2, loading cap 22 is dismounted. This exposes the bore of sack 26. Accordingly an ampule 16 may be pushed into that sack. Thereafter the loading cap is reapplied to the mounting ring and as afore brought out, the aperture 24 will, under these circumstances, align with bore 25. The mechanism controlled by the operator will now be actuated so that liquid under pressure will flow through bore 16. With such iow the pressure will be transmitted to the space intervening the sack and adjacent chamber walls 28. Therefore the walls of ampule 16 will be supported against collapse in an external or radial direction. Simultaneously the end or base of sack 26 will act against stopper 18. This will project the latter from the position shown in Fig. l to the position shown in Fig. 2 wherein all medicament intervening the stoppers 18 and 19 has been ejected through bore 25 Iand aperture 24. This will accomplish the desired injection.

Liquid being substantially incompressible it is thus apparent that the ampule is subjected both internally and externally to substantially equal pressures. Therefore, a shattering of the ampule in either an outward or an inward direction is prevented. After the completion of the injection the mechanism under the control of the operator is manipulated so that a second injection may be subsequently made. The liquid which has caused the parts to be supported and the medicament to be ejected will have a return ow through bore 16. Thereupon cap 22 may be dismounted and stopper 19, together with the ampule 16 and stopper 18 may be withdrawn and discarded. The sack will have returned to its' initial position as shown in Fig. l. Therefore, a new ampule may be introduced into the sack and the entire operation repeated.

In the form of structure shown in Figs. 3 and 4, the sack 29 is of a length substantially greater than the arnpule 16. It has its base portion turned in upon itself as at 30 in Fig. 3. In common with sack 26 a space exists between the inner face of the bore 16, or a chamber forming a continuation thereof, and the outer face of the sack. If the structure at the outer end of the unit does not follow the design as heretofore described in Figs. 1 and 2, then conveniently the cap 22 may mount an clement 31 formed with an aperture 32 corresponding to aperture 24. The aperture 32 has disposed in line with it a pointed cannula 33. Therefore, if a stopper such as 20 is employed, the inner end of the cannula will pierce into the recess of that stopper as the cap is mounted. Thereby communication will be established between the interior of the ampule and aperture 32 as the parts are properly assembled.

lf this assembly is as illustrated in Fig. 3, then it is obvious, upon an operator permitting a ow of liquid under pressure through the controlling portions of the mechanism, that the liquid will, under certain circumstances, compress the inturned end of the sack as shown in Fig. 4. Under these conditions, the pressure of the liquid may readily be transmitted to the space intervening the sack and the walls of the bore or chamber. Even if such compression is not effected to any marked extent, the flow will occur past the inner edge of the sack into this space. With such flow, inward pressure will be exerted on the outer face of the ampule. Simultaneously the internal pressure of the medicament within the latter will be increased so that the pressures will be substantially equalized. This will be because the inturned end portion Btl will have its base force stopper 18 inwardly from the position shown in full lines in Fig. 4 to the position shown in dot-dash lines in that figure. After the medicament has been ejected and a return ow of the hydraulic liquid has been completed, the sack will assume its normal position as shown in Fig. 3. Therefore, with a dismounting of cap 22 the spent arnpule Cguay removed and a new ampule or cartridge inserte ln the construction shown in Figs. and 6 the barrel or extension is conveniently formed with a shoulder portion 3:1'r providing a seat for the ampule 17. This shoulder portion is formed with a radial series of passages or slots 35. The chamber 36 has a diameter in excess of the Sack 37. Therefore a space exists through which liquid may ow to exert pressure on the outer face of the sack, the passages 35 providing communication with this space. The cap 43 is formed with a usual aperture 33 and a piercing cannula 39 may extend rearwardly in line with that aperture. This cannula projects beyond the end of a post or thrust portion 40 and an annular groove 41 defines this post portion and is of a dimension such that it may receive the major part of ampule 17. The base of this groove may mount a cushioning ring 42 and a vent opening is conveniently furnished at a point short of the ring.

When the mechanism is controlled by the operator to permit a flow of hydraulic liquid it is apparent that the liquid will fiow into the space intervening the sack and chamber 36 as afore described. Simultaneously the pressure of the medicament within the ampule will be substantially equalized because the base of the sack will shift that ampule to the right as viewed in Fig. 5. The stopper will have been previously perforated by the pointed inner end of cannula 39 as cap 43 is mounted by the retaining ring 44. The post 40 preventing movement of stopper 20, it follows that the body of the ampule will be projected into the groove 41. With such projection that stopper will function as a piston to express medicament through the bore of cannula 39 and aperture 38 at the desired velocity and pressures. A shattering of the ampule will not occur as it is squeezed to a point beyond the front end of the sack because as it so moves it will enter spaces subjected to substantial atmospheric pressures acting on both of its faces. Moreover, the cushioning ring will function to prevent a shattering engagement between the ampule edge and the face of the cap. The cap should not be removed together with the ampule. The sack will reestablish its normal position and the entire cycle may be repeated after an ampule is again positioned within the sack.

In the form of device shown in Figs. 7 and 8 the sack is not subjected to an inturning action; rather the sack 4S as shown in this gure has its flange portion 46 adjacent the inner end of the assembly and its edge and base extending outwardly towards the outer end of the CII same. This base may be thickened as indicated at 47 and the sack is maintained in position by conveniently employing a sleeve 48 of metal which has screw threaded engagement with an enlargement of the bore 16 and is also provided with an inner lip 48 which may bear against flange 46 to provide a leak-proof seal. The threads may be interrupted at a number of points as indicated at 49 to furnish passages for the fiow of liquid. These interruptions communicate with a space 50 from which passages 51 extend to the bore 16.

In this form of device a separate ampule-supporting sack 52 is provided. The inner flange 53 of the latter sack is engaged by a retainer 54 conveniently mounted by the same screw threads which mount the sleeve 48. This retainer clamps the flange 53 against the sleeve to furnish a leak-proof seal. The retainer 54 is formed with a series of thread interruptions 55 which communicate with the space intervening the outer edge of flange 53 of the passages 49. Therefore liquid under pressure may flow through grooves 55 into the chamber 56 existing beyond the sack 52 housing the ampule 16. A retaining ring 57 is mounted, for example, by threads upon the outer end of body 15. A gasket 58 may intervene the adjacent surfaces to provide a leak-proof seal. A clamping ring 59 is mounted upon ring 57 and bears against the outer flange portion 60 of sack 52, thus furnishing a leak-proof seal at that point. Cap 61 mounts an apertured element 62 with which a piercing cannula 63 is associated; the length of the latter being such that it may perforate the stopper 2t) as the cap is mounted.

ln using an apparatus of this type it is understood that with the cap removed ampule 16 is disposed within the bore defined by the tube or sack 52. As the cap is mounted communication is established with the medicament contained in the ampule. 1f the mechanism is controlied to permit a flow of hydraulic liquid as previously described, then that flow will cause a simultaneous establishment of pressure within chamber 56 and within the ampule. The latter result will obtain because of the elongation of sack 45 consequent to the hydraulic liquid acting upon the base of such sack to move stopper 18 inwardly. Incident to such inward movement the medicament will be expelled. By having the base portion 47 and the parts adjacent thereto somewhat thickened, ample material is provided even if substantially all of the extension or stretching of the sack occurs throughout this zone.

ln the form of construction shown in Figs. 9 and l0 the body 15 has coupled to it an extension 64 in the form of a tube. The inner end of this extension clamps the iiange 65 of the sack 66 against the surface of body 15 to establish a leak-proof seal. The outer end of the sack is turned upon itself to extend inwardly as at 67 and conveniently terminates in a flange portion 63. Body 15 may be continued within the bore of tube 64 in the form of a cup 69. The latter receives a cylinder 70 within which a piston 71 may reciprocate. This piston is preferably provided with a packing 72 and is continued in the form of a rod or plunger 73. The base of the cup 69 is formed with passages 73 communicating with the space defined by the sack or tube 66. The exterior of cylinder 70 may be threaded to engage corresponding threads on the inner face of cup 69. These same cylinder threads may mount a retaining ring 74 which bears against the face of ange 68 and forces it into sealing contact with the lip portion 75 provided at the outer end of, cylinder 70.

The extension 64 may mount, by screw threads, the cap 76. The latter supports an apertured element 77 from which a piercing cannula 73 extends rearwardly. Thus, in common with the construction described in connection with preceding figures, it is apparent that as the cap is mounted, communication will be established with the interior of the ampule 16.

With the parts assembled as shown, a control of the mechanism to permit liquid flow will result in the establishment of pressure within the chamber defined by the sack 66. This will exert pressure upon the outer face of the ampule. Simultaneously the hydraulic liquid will act against the head of piston 71. Consequently rod 73 will act against stopper 18 to establish substantially equal pressure conditions within the ampule. A continued flow will cause stopper 18 to be fully projected to a point where it contacts stopper 20. With a return ow of the hydraulic liquid, cap 76 is dismounted and the ampule may be withdrawn and replaced by a fresh ampule. The positioning of the latter will assure a complete retraction of rod 73 and the piston if this has not already occurred as a consequence of the reverse flow of the hydraulic liquid. With the cap again mounted, the parts are ready for a further operation.

In the forms of apparatus shown in Figs. l to 8 inclusive, itis apparent that the sack will, at all times, segregate the passages and spaces receiving the hydraulic liquid from the ampule-receiving space. Therefore, if the hydraulic system of the instrument has all air exhausted from it, no difficulties will be experienced as a consequence of air bubbles with resultant improper and partial operation of the apparatus. Moreover, when once charged, it will not be necessary to refill or replace hydraulic liquid in the passages of the instrument. Additionally, as afore brought out, in all forms of the apparatus the pressures both internally and externally of the ampule will be substantially equalized. Therefore, it becomes feasible to employ medicament-containing ampules of glass without fear of the cartridge collapsing or shattering. Also, in all forms of apparatus all that an operator will have to do is to remove the cap to withdraw the spent ampule and to replace the same with a fresh ampule. In the type of device shown in Figs, 7 and 8 the sack which assures a movement of the stopper 18 is merely extended when subjected to the thrust of the hydraulic liquid while, as in Figs. 1 to 4, parts of the sacks turn inwardly upon themselves. The former is desirable in many instances in that it assures a prevention of sack rupture. In the form illustrated in Figs. 9 and 10 leakage will be substantially prevented in that practically no escape will be possible past the packing of piston 71. In most instances it is desirable to have the hydraulic liquid act directly on the sack where structures such as are shown in Figs. 1 to 8 are employed. However, should it prove desirable to utilize a piston as in Figs. 9 and l0 this may be resorted to.

It will be understood that where an apparatus other than that disclosed in the aforementioned Hein application is employed, an operating fluid other than a hydraulic liquid might be employed. Therefore, except where otherwise indicated in the claims the expression liquid is to be used in an illustrative rather than a limiting sense. It is apparent in this connection that a compressible fluid such as a gas or air Would-under sufficient pressures-not alone tend to effect an expulsion of the medicament from the chamber but would also support the wall of the ampule against collapse incident to the constriction of sack or tube portions defining such chamber.

Thus, among others, the several objects of the invention as afore noted are achieved. Obviously numerous changes in construction and rearrangement of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

We claim:

1. A hypodermic injection unit including in combination a sack presenting side walls defining a bore and a base portion closing said bore, a rigid ampule disposed within said bore, a piston projectible relative to said ampule for expelling medicament therefrom, means for causing projection of said base to engage said piston and thus place medicament contained within said ampule under pressure and functioning simultaneously with the operation of piston projection to exert pressure on the outer face of said sack and subject the outer face of said ampule to a pressure corresponding to the medicament pressure within the same.

2. A hypodermic injection unit including in combination a sack presenting side walls defining a bore and a base portion closing said bore, a rigid ampule disposed within said bore, a piston projectible relative to said ampule for expelling medicament therefrom, means for causing projection of said base to engage said piston and thus place medicament contained within said ampule under pressure, means providing an enclosure spaced from the outer face of the sack side wall, said space being adapted to receive fluid and the latter being placed simultaneously with the operation of piston projection under pressure to thus cause the sack walls to bear in intimate contact with the outer face of said ampule to subject the latter to a pressure corresponding to the medicament pressure within the same.

References Cited in the file of this patent UNITED STATES PATENTS 921,130 Lockwood May 11, 1909 1,869,443 Stocklin Aug. 2, 1932 2,322,244 Lockhart lune 22, 1943 2,322,245 Lockhart June 22, 1943 2,380,534 Lockhart July 31, 1945 2,398,544 Lockhart Apr. 16, 1946 2,431,406 Lasersohn Nov. 25, 1947 2,514,575 Hein July 11, 1950 2,547,099 Smoot Apr. 3, 1951

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