US2602447A - Device for hypodermic injection - Google Patents

Description

y 8, 1952 P. KOLLSMAN 2,602,447

DEVICE FOR HYPODERMIC INJECTIQNS Filed Dec. 20, 1947 4 INVENTOR. P QUL KOLLSMHN ATTORNEY Patented July 8, 1952 UNI D STATES? NT orrlcs This invention relates to improvements in devices for hypodermicor intra-muscular injection ofmedicinal fluids.

The invention has, particular application to so-called injector ampules, a novel device which, in eifect, is a combination of an ampuleand a syringe. An injection ampule contains a predetermined volume of fluidwhich maybe stored. in it in a similar manner as in a conventional ampule, and is equipped with a hypodermic needle so thatthe fluid may be, injected directly from the ampule without previous transfer to a separate syringe.

Injector ampules have numerous advantages over conventional injection syringes requiring filling froma separate ampule. One of the most important features is the immediate readiness of an injector ampule for injection, eliminating the necessity; of preparing, sterilizing, and filling an injection syringe, which is time consuming, requires a certain amount of skill and is dependent on the availability of sterilizing equipment. 7 I

Injector ampules are designed to be sterilized by the manufacturer before filling,- are sealed, and are furnished to the user in sterile condition requiring only removal, of a needle seal before actual use.

Injection ampules are relatively simple of con-' struction, are inexpensive to manufacture, and are primarily designed for one-time-use, the low production cost making refilling uneconomical.

The disposability, after use, of injector ampules brings with it further features of safety and convenience; a new sharp needle is available for each injection sincethe needle forms a permanent non-removable part of each device, the volume of the fluidis accurate, and the device is free from air or gasbubbles.

This invention is concerned with certain structural features and matters of design of importantelements of injector ampules.

Injector ampules basically consist of a barrel within which a plunger is telescopically movable, thus forming a variable volume chamber for the fluid. A hollow injection needle mounted in the device is in communication with the chamber. A movable seal is provided to seal the barrel with respect to -the plunger.

Movable seals of the type customarily employed in conventional injection syringes are generally not satisfactory for injector ampules because of certain inherent characteristics. Tightness of the, seal, for example, is far less critical in an ordinary syringe than it is in an injector ampule. A minor leak leading ,to the loss of a small amount of fluid is not fatal inan ordinary syringe since loss of fluid is the only detr mentalresult of the failure of the seal.v In an. n ector ampule, however, in which a predetermined 2Claims. (01.128-218) I 1 volume of fluid isstored over a substantial period of time, the tightness of the seal affects the sterility of the contents.

Experience has shown that seals of the con- 3 struction customarily formed in ordinary in-- jection syringes are not satisfactory in injector ampules. Attempts to: make the conventional seal tighter by a change indimensions likewisedonot bring satisfactory results. Seals are cus,

. tomarily made of an elastic material such as natural or synthetic rubber.

A tighter fit be-- tween the seal and. the wall, against which the seal acts, produced. by: an increase of the dimensions of the, seal results in an objectionable behavior of the seal which may be called creepsuited. for maintaining the contents of an 'in-- jector; ampule tightly enclosed in order to safeguard sterility, the seal being free from the objectionable tendency of creeping, so that after movement of the seal or plunger no enlargement of 'thechamber volume occurs, and no air is drawn in through the needle. In this manner, freedom from air of the contentsof'the injecto ampule is insured.

The-aforementioned and various other features, advantages and objects of the invention will appear more fully from the detailed description which follows accompanied by-drawings showing,

for the purpose of illustration, preferred embodiments of the invention. The invention also consists in certain new and original features of construction and combination of elements hereinafter set forth and claimed;

Although the features-characteristic ofthis invention which-'are'believed to be novel will be particularly pointed out inthe claims appended hereto, the invention itself, its objects" and advantages and themanner in which it may be carried out may-be better understood by referring to the following description taken in connection with the accompanying drawingsforming a part of this application in which:

Figure 1 is aside view'partly in cross-section of an-injector ampule embodying the invention; Figure 2 is a cross-sectional side view of the plunger seal of the injector ampule of Figure, 1;

Figure 3- tea cross-sectional side view of a form of plunger used in the injector ampule of Figure 1;

Figure 4 is an end view of the plunger shown in Figure 3;

Figure 5 is a side view, partly in section, of a modified form of injector ampule;

Figure 6 is a side view of the plunger seal of the injector ampule of Figure 5; and

Figure 7 is a section taken on line 'I-I of Figure 5. I

In the following description and in the claims,

various details will be identified by'specific names v The names, however, are in:

for convenience. tended to be generic in their application, Corresponding reference characters refer to corresponding parts in the several figures of the drawings. J

In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for the purpose of explanation of .broader aspects of the invention,'but it is understood that the details may be modified in various respects without departure from the principles of the invention and that the invention may be applied to other structures'than the ones shown.

The subject matter of this application is related to the subject matter of copending applications directed to devices of the general type disclosed herein.

Application Serial No. 792,991, filed December 20, 1947, now Patent No. 2,578,812 granted Dec. 18, 1951 discloses and claims a syringe in which the depth of insertion is automatically controlled and limited, and in which stop means are provided permitting measured partial discharge.

Application-Serial No. 792,992, filed December 20, 1947, disclosesand claims a syringe designed for one-time use and so arrangedthat it cannot be reused. I

Application Serial No. 792,993, filed December 20, 1947, now: Patent No. 2,578,813 granted Dec. 18, 1951 discloses, and claims a tubular needle seal for a syringe which prevents contamination of the needle and is blow-01f proof in that it will not blow off if the syringe fiuid is subjected to a sudden rise in pressure, for example by dropping thersyringe. y; r 1

Application Serial No. 792,994, filed December 20, 1947, now Patent No. 2,578,814 granted Dec. 18, 1951 discloses and claims a syringe having a narrow visible and optically enlarged passage leading to the inner end of the needle to facilitate observation,and expulsion of, gas bubbles in the syringe chamber.

The injector ampule shown in Figure 1 com prises a barrel II in which a plunger I2 is telesealing cap diagrammatically indicated at I8, the

precise construction of the sealing cap being no part of the subject matter of this invention.

The chamber I3- issealed against the lunger I2 by a sealing member or plug I9 shown in greater detail in cross section in Figure 2.

, 'Ifhe-sealing'plug I9 is preferably made of an elastic material such as natural or synthetic rubber and comprises a forward guiding portion 20 having a diameter sufficiently large to slide in the bore of the barrel I I substantially without compression of the guiding portion in the direction of the radius of the plug. A rearward sealing portion 2| has a diameter larger than the internal diameter of the bore of the barrel II to produce a liquid and pressuretight seal of relatively narrow width, the width of the sealing portion'2l being only a fraction of the Width of the guiding portion 20.

The forward surface 22 of the plug is preferably shaped to conform with the forward surface I! of the chamber I3.

A central stem 23 is frictionally insertable into, and is'lightly held in, an aperture 24 in the forward end of the plunger I2. The aperture 24 may be square to prevent formation of an airtight seal between the plunger I2 and the plug I9. The forward portion 25 of the plunger I2 is shaped to fit the substantially cone-shaped rear surface 26 of the sealing plug I9.

When the plug I9 is attached to the coneshaped forward end 25 of the plunger I2, the coneshaped end 25 forms a substantially rigid core resisting collapsing of the rearward portion of the plug in a radial direction.

The fiat forward surface 21 of the plunger I2 supports the rear surface 28 of the plug immediately adjacent the sealing portion 2| so that any deformation of the sealing portion 2| by reason of its tight fit in the barrel I2 is limited to radial compression. Deformation of the sealing plug in a direction parallel to its axis, the cause of objectionable creeping, is prevented.

The connection between the plug I9 and the plunger I2 by reason of insertion of the stem 23 into the aperture 24 is such as to provide for easy separation in the event the plunger is withdrawn, so that the position of the sealing plug is not disturbed by withdrawal of the plunger. The connection, however, is sufficiently firm to prevent the-plunger from dropping out of barrel II if the device is held in a vertical position. 7

The bodies ofthe barrel II and of the plunger I2 are conveniently shaped to permit fabrication of the bodies by molding them from synthetic plastic material requiring no further machining.

, The plug I9 is also of a shape which may be at the needle passage I6 where they are visible if the barrel housing I I is made from a clear, transparent plastic composition. Actuation of the plunger I2 forces the air bubbles out of the chamber I3 through the needle I4. The sealing plug I9 undergoes no deformation during this operation in a direction substantially parallel with the direction of travel, the sole deformation of the sealing portion 2| being in a radial direction, any tendency of deformation in an axial direction being opposed by the the plunger I2.

I6 until a predetermined volume is fiat forward surface 21 of:

When the sealing plug l9 comes to rest, it remains at rest and there is no tendency of creeping back so thatthe volume of the chamber is not enlarged and no air is drawn into the chamber through the needle I4.

A modified form of injector syringe is shown in Figure 5, details being illustrated in Figures 6 and 7. Primed reference numerals are employed to indicate elements corresponding to those of the device of Figure l.

A plunger i2 is telescopically movable in a barrel II in which a hollow injection needle I4 is mounted, communicating with the interior chamber l3 through a passage 16. A sealing plug I9 is movable in the bore of the barrel II and rests with its rear surface 28 against the forward surface 27' of the plunger l2.

The sealing plug [9 has a resiliently deformable central portion 29 adapted to be rearwardly deflected by pressure acting on the forward surface 22 of the plug. The plug has a peripheral guiding mrtion 29' and a sealing portion 2| lying immediately adjacent the forward surface of the plunger l2.

The plunger 12 is frictionally held in the bore of the barrel by reason of its forward end being slotted at 30. The slotted portion contains a resilient center plug 3| tending to force the slotted portions against the interior wall of the barrel ll whereby the plunger is frictionally held in whatever position it happens to be. The frictional engagement between the plunger l2 and the barrel I! however, is not so great as to interfere with the operation of the device, the friction just being suflicient to prevent the plunger l2 from becoming separated from the barrel when the device is being handled, for example held in a vertical position.

The injector ampule of Figure is preferably filled by forcing fluid under pressure into the chamber [3' through the needle M. It is used and operated in the same manner as the device shown in Figure l. The operation of the sealing plug 19', however, differs from that of the plug shown in Figures 1 and 2 in the following particulars.

When the plunger i2 is actuated in the direction to expel fluid from the chamber 13', a certain amount of pressure is set up in the chamber [3' by reason of the flow resistance of the narrow bore of the needle M. This pressure acts on the relatively thin central portion 29 of the plug and causes it to be deflected rearwardly as long as the pressure persists. When the plunger l2 comes to rest, the center portion 29 of the sealing plug tends to return to its original position by reason of its resiliency, causing an additional small volume of fluid to be expelled. This action of the plug compensates for any tendency of creeping so that, even if the sealing plug were to creep back, no air will be drawn into the chamber I3. I

The invention thus provides improved structural details for injection ampules insuring that the fluid charge of the injector ampules constructed in accordance with the invention is free from entrapped air or gas bubbles so that injector ampules may be used without previous checking or inspection for bubbles and without any preparation other than the removal of a needle seal applied by the manufacturer.

Obviously, the present invention is not re-- stricted to the particular embodiments of the in,

vention herein described and illustrated. Nu merous modifications, additions, omissions, substitutions and various other changes may be made without departure from the spirit and the essence of the invention as defined in the appended claims. All such changes will suggest themselves to persons skilled in the art after consideration of the disclosure and do, therefore, not involve a departure from the spirit and the teachings of this invention.

What is claimed is:

l. A combination ampule and injection syringe for forming and injecting a predetermined volume of medicinal fluid comprising, a barrel; a sealing plug of elastic material telescopically movable in said barrel for forming a variable volume chamber with said barrel adapted to contain a charge of fluid, said sealing plug having a forward guiding portion of a diameter sufficiently large to slide in said barrel substantially without compression of the guiding portion and a rearward sealing portion of a diameter larger than the inside diameter of said barrel; a hollow injection needle communicating with said chamber; and a plunger telescopically movable in said barrel, said plunger having a front surface adapted to engage the rear surface of said plug immediately adjacent said sealing portion to prevent elastic distortion of said sealing portion in the direction of travel of said plug in said barrel, said plunger further having a resiliently compressible portion of a diameter, measured unconstrained, larger than the internal diameter of the barrel for frictionally engaging the inner surface of said barrel thereby tending to arrest said plunger in said barrel.

2. A combination ampule and injection syringe for storing and injecting a predetermined volume of medicinal fluid comprising a barrel forming a chamber adapted to contain a charge of fluid; a hollow injection needle mounted in said barrel; a plunger member telescopically movable in'said barrel; a sealing member of elastic material, separate from said plunger member, said sealing member being telescopically movable in said barrel and having a guiding portion of a diameter sufiiciently large, to slide in said barrel substantially without compression, and a sealing portion of a diameter larger than the inside diameter of said barrel, one of said members being provided with a boss and the other of said members having a hole smaller than said boss for receiving and holding said boss in a compressed state, whereby said two members may be severably connected.

PAUL KOLLSMAN.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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