US2578813A

US2578813A - Device for hypodermic injections

Info

Publication number: US2578813A
Application number: US792993A
Authority: US
Inventors: Kollsman Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-20
Filing date: 1947-12-20
Publication date: 1951-12-18
Anticipated expiration: 1968-12-18

Description

Dec. 18, 1951 P. KOLLSMAN 2,578,813

DEVICE FOR HYPODERMIC INJECTIONS Filed Dec. 20, 1947 INVENTOR. FZH UL KOLLSMRN H-o-M g. ATTORNEY Patented Dec. 18, 1951 2,578,813 DEVICE FOR HYPODERIWIC INJECTIONS rim! Kollsman, New York, N. Y.

I Application December 20, 1947, Serial No. 792,993 v referred to as 'injector ampules? They are convenient and practical devices oflering a great number of features and advantages over conventional syringes of the type requiring filling from a separate ampule. Injector ampules are usually designed for onetime use, to be discarded after discharge of the fluid therefrom. They are supplied by the menu-y facturer, for example a pharmaceutical laboratory, filled with a pre-determined volume of a medicinal composition and are ready for imme-' diate injection making it unnecessaryto prepare,

sterilize and fill a separate syringe.

Injector ampules aresterilized by the manufacturer before filling and all the parts coming in contact with the patients body are maintained sterile by appropriate means which form part of the subject matter of the present invention. In addition to maintaining sterility, it is, of course, necessary to maintain an absolutely tight seal of the contents to prevent accidental discharge of 4 I responding parts in the several figures of the fluid from the injector ampule.

It happens occasionally, particularly'ifinjector ampules are carelessly handled, that an injector ampule is dropped whereby a force is; exerted on 7 Claims. (Cl. 128-220) vantages and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with'the accompanying drawings forming a part of it in which Figure 1 is a cross-sectional side view of an injector ampule embodying the invention; .20

" modified form of device;

Figurev 2 is a cross-sectional side view of a j Figure 3 is a detailedcross-sectional side view on an enlarged scale of a multiple seal for the needle and front end of an injector ampule embodying the invention; and

Figure 4 is a detailed cross-sectional side view,

on an enlarged scale, of a preferred form of are intended to be generic in their application.

or the plunger, in a direction to discharge fiuid from the device. Relatively high pressuresare set up in the fiuid containing chamber'of the injector ampule tending to blow off the seal of the injector needle or, at least, disturb the seal sufliciently to make subsequent contamination likely.

This invention provides means, improvements and specific constructions for maintaining a secure seal of all vital portions of the injector ampule so that the device is maintained tightly sealed against fiuid discharge as well as tightly sealed against contamination even if dropped, excessively heated or cooled, or subjected to other conditions which would tend to disturb its essential properties. I

The aforementioned and various other fea- Corresponding reference characters refer to cordrawings. In the drawings accompanying and forming part of this application, 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 re- 20, 194?, discloses and claims a syringe designed for one-time use and so arranged that it cannot be reused.

Application Serial No. 792,994, flled December 120, 1947, discloses and claims a' springe having a narrow visible and optically enlarged passage leading to the inner end ofthe needle to facilitate observation, and expulsion of. gas bubbles in the syringe chamber.

Application Serial No. 792,995, filed December 20, 1947, discloses and claims an improved form of non-creeping plunger seal.

The injector ampule shown in Figure 1 comprises a barrel II in which a plunger I2 is telescopically movable. The plunger I2 is tightly sealed with respect to the interior surface I3 of the barrel by a gasket I4 which rests in a groove I5 of the plunger and frictionally engages the interior surface I3 of the barrel I I.

In the illustrated form of syringe, the rear surface I6 of the plunger forms a movable wall of a chamber II adapted to contain a charge of medicinal fluid confined between the barrel II and the plunger I 2.

'Ahollow injection needle I8, preferably of substantially uniform outer diameter is mounted in the plunger I2 and communicates with the chamber I'I through a hollow passage I9 extending through the plunger. The needle I8 projects from the front end surface of the plunger a distance d which may be made equal to the depth to which the needle is to be inserted into the body tissue. The front end surface 20 may be made substantially flat. and preferably has an area large enough to provide suflicient-resistance for the ejection of a medicinal composition from the injector ampule without causing discomfort to the patient when force is exerted against the barrel II in a direction to collapse the chamber II to expel its contents through the needle I8.

The injector ampule shown in Figure 1 is primarily designed for filling with a medicinal fluid composition at the plant or laboratory of the producer, the volume of the fluid being sufllcient for a single injection. After initial filling, the injector ampule'is sealed to prevent accidental discharge of the fluid from the chamber I1 and also to maintain its vital portions sterile, particularly the needle I8 itself and the portion immediately surrounding the needle so that the needle is not contaminated by removal of its seal.

According to the illustrated embodiment of the invention, a cavity or recess 2| is formed in the front surface 20 of the plunger I 2 immediately adjacent the needle. The side walls 22 of this cavity are preferably tapered to receive and tightly seal the end of a sealing cap 23 fitting over the needle I8.

The sealing cap 23 is preferably made of a relatively soft and elastic plastic material adapted to deform sufficiently to provide two seals, one at the tip of the needle and a'further seal at the front end surface of the plunger I2. For this purpose, the cap 23 is preferably provided with a pre-formed, for example pre-molded, bore including two portions of different diameters. A front portion 24 is preferably made of a diameter slightly less than the outside diameter of the needle so that the needle, upon being forced into the front portion of the cap, causes the cap to expand slightly and form a pressure-tight seal near the point of the needle.

A rear portion 25 of the interior space of the cap 23 preferably has a diameter slightly larger than the outside diameter of the needle in order to flt easily over the needle when the cap is being applied. The rearmost portion 26 of the cap 23 also may have an interior diameter slightly larger than the diameter of the needle. As the end of the cap is being forced into the cavity 2| of the plunger I2, the tapered side walls 22 of the cavity compress or deform the walls of the cap with the effect that the cap tightly engages boththe side walls 22 of the cavity as well as the shank of the needle.

The frictional engagement of the cap 23 with the front portion of the needle I8, with the side walls 22 of the cavity 2| and with the shank of the needle is suflicient to prevent the cap from being removed or blown off accidentally, for example by dropping of the injector syringe in a direction to cause reduction of the chamber volume II.

not sumcient to cause the frictionally held cap from being blown oif.

- into the body tissue.

The end of the cap 23 seating in the cavity 2| is maintined sterile and is protected against contamination by reason of its pressure tight seat in the plunger I2. When the cap 23 is removed from the needle I8 in order to prepare the injector ampule for use, the portion of the cap 23 which slides along the needle is the rear portion which was preserved sterile. In this manner contamination of' the needle is effectively prevented. Contact of the syringe with the patients skin immediately adjacent the needle is prevented by the recess 2| in the plunger surrounding the needle.

In sealed condition, the device serves as an ampule for storage of the medicinal fluidand may be readied for immediate use simply by removal of the sealin cap 23.

Small air bubbles accidentally trapped in chamber I1 may easily be removed by placing the fllled syringe in an upright position causing the bubbles to rise and collect near the passage I9. Slight telescoping movement of the plunger I2 with respect to the barrel II forces the bubbles out through the passage I9 and the needle I8.

The injector syringe may be used as follows: After removalof the sealing cap 23, the device is ready for use. It is preferably applied to the body of a patient by grasping it at the barrel II which provides a finger'grip surface or portion 21. The point of the needle I8 is placed on the patients skin and pressure is then exerted in the direction of the needle I 8 to force the needle This pressure does not cause any discharge from the syringe because of an initial considerable amount of friction between the plunger gasket I4 and the barrel surface I3, this friction being relatively great while the plunger is at rest and equivalent to a multiple of a force required for inserting the needle into the body tissue.

When the front end surface 20 of the plunger comes to rest on the patients skin, the pressure exerted at the barrel II is opposed by an equal pressure of the skin against the front surface 20. This opposing force is suflicient to overcome the friction of the gasket I4. The barrel II then moves telescopically over the plunger causing the fluid to be discharged through the passage I9 and the needle I8 into the patients body tissue.

Figure 2 illustrates a modified form of injector ampule comprising a barrel within which a plunger 3| is telescopically movable. The plunger has an enlarged finger operable grip portion 32 for convenient handling. A movable seal or membrane 33 which may be separate from the plunger 3| is telescopically movable in the barrel 80 and forms a seal for the fluid chamber 84 against the plunger 3|.

An injection needle 35 is mounted in the front end 36 of the barrel and is surrounded by a cavity or recess 31 having tapered walls 88.

A sealing cap 39 covers the needle 35. The cap 39 has a narrow bore front portion 40 tightly fitting over the point of the needle and a wider rear portion 4| of an interior diameter slightly larger than that of the needle. The rear portion 4| of the cap fits frictionally and tightly into the cavity or recess 31 with its end portion 42 usually sufficiently compressed by the tapered walls to engage the outside of the needle- 35, also. s

A modified form of sealing cap is illustrated on an enlarged scale in Figure 3 showing also the front end of an injector syringe. The sealing cap 45 is made of relatively soft resilient plastic material and has a front portion 45 tightly fitting over the front end of the needle 41, the outside diameter of the needle being preferably slightly larger than the inside diameter of the front portion 46 of the cap so that application of the cap over the needle causes the cap slightly to bulge at the portion where a tight seal. is effected as is also apparent from the drawings.

The rear portion 48 of the cap fits loosely over the needle and its end portion 49 is adapted to be frictionally and pressure-tightly held in a tapered hole 50 in the front end M of the injector ampule.

A long and slender rod 52, preferably of metal, for example a stainless steel wire, is molded or otherwise secured in the front portion 46 of the cap and extends through the channel or bore of the needle 41 into the chamber 53 of the injector ampule containing the medicinal fiuid.

The rod 52 serves a double purpose. It prevents the needle passage from clogging up by reason of contact of the medicinal fiuid with the metallic needle 41 so that clearance of the needle passage is insured after removal of the sealin cap 48 and the rod.

The rod 52 further constitutes a fiow resistance of considerable magnitude resulting in added sealing protection. If abnormally high pressures are built up in the chamber 53, for example by accidental dropping of the injector ampule, no appreciable pressure increase is experienced at the needle point during that brief period since pressure builds up only very slowly along the needle passage through which the rod 52 extends by reason of the great fiow resistance of the constricted passage. Thus, a low pressure seal at the needle point is sufficient to resist temporary high pressures in the chamber 53. The form of sealing cap illustrated in Figure 3 thus afiords triple protection. Two pressure tight seals are formed at the tip and at the base of the needle at 46 and 49, respectively, the latter seal also insuring sterility of the area immediately surrounding the needle and preventing contamination of the needle by removal of the sealing cap therefrom. In addition, the rod 52 virtually constitutes a seal in itself by reason of closing the needle passage almost entirely.

The tapered sealing surface in the front end 6 v. of the housing of .the injector ampule is also adapted to receive the nozzle of a filling duct through which the iniector syringe is first filled by forcing the medicinal fluid under pressure into the chamber 11, 84, .or 53, respectively, through the needle.

A specific form of construction for the sealing cap, preferred because ofv its simplicity and ease of manufacture, is shown in Figure 4.

The cap comprises atubular portion 54 of a suitable plastic material, preferably made in the form of tubing from which pieces of appropriate length are cut. The inner diameter of the tubing is slightly narrower than the outside diameter of the needle over which'it is intended to fit. For example, for a needle having an outside diameter of 0.035", tubing of approximately 0.032" inside diameter may be used, the yieldability and elasticity of the plastic material being such that the tubing may be slipped over the needle zwithout .an'undue application of force. A rod or stylus 55 extends inside thetubing, the outside diameter of the rod being" slightly less than the inside diameter of the needle passage. The rod 55 has an enlarged end or head 58 which fits tightly within the tubing 54 and seals its front end. The tubing may additionally be squeezed together and sealed at 51, either by application of a suitable adhesive or solvent, or by application of heat, such procedures of sealing metal to plastic being known to the art.

The sealing cap thus made is easy and inexpensive to manufacture and forms a reliable seal for injector ampules and syringes.

Obviously, the present invention is not restricted to the particular embodiments herein disclosed. Numerous modifications, additions, omissions, substitutions. and various other changes may be made, for example by making parts separate or integral, without departing 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 this disclosure and do therefore not involve a departure from the spirit and the teachings of the invention.

What is claimed is:

l. A combination ampule and syringe for stor ing and injecting a predetermined volume of a medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid; a hollow injection needle mounted in the front end of one of said members, said one member being shaped to provide a tapered sealing surface about said needle; a cap of plastic resillently deformable material sealing the point of said needle and seating pressure-tightly against said tapered sealing surface about said needle; and a rod in said cap extending through said hollow needle towards said chamber.

2. A combination ampule and syringe for storing and injecting a predetermined volume of medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fiuid; a hollow injection needle mounted in the front end of one of said members, said needle projecting from the front end surface of said one member, said one member being shaped to provide a tapered sealing surface about said needle; and a sealing cap pressure-tightly fitting on said sealin surface, said cap having a further sealing portion pressure-tightly engaging the point of said needle.

3. A combination ampule and syringe for storing and injecting a predetermined volume of medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid; a hollow injection needle mounted in the front end of one of said members, said needle projecting from the front end surface of said one member, said one member being shaped to provide a tapered internal sealing surface about said needle; and a sealing cap pressure-tightly fitting on said sealing surface, said cap having two portions of different internal diameter, a narrower portion adapted to engage and pressure-tightly seal said needle near its point, and a wider portion loosely fitting about the rearward portion of said needle.

4. A combination ampule and syringe for storing and injecting a predetermined volume of medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid; a hollow injection needle mounted in the front end of one of said members, said needle projecting from the front end surface of said one member, said one member being shaped to provide a tapered sealing surface about said needle; a sealing cap pressure-tightly fitting on said sealing surface, said cap having two portions of difierent internal diameter, a narrower portion adapted to engage and pressure-tightly seal said needle near its point, and a wider portion loosely fitting about the rearward portion of said needle; and a rod mounted in said cap adapted to extend through said hollow needle into said chamber.

5. A combination ampule and syringe for storing and injecting a predetermined volume of a medicinal fluid comprising, in combination, a barrel member; a plunger member telescopically fitting into said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of said members having a front end surface adapted to engage, and rest against, the body portion of a patient into which the fluid is to be injected; sealing means for sealing the plunger member with respect to the barrel member; a hollow injection needle mounted in one of said members communicating with said chamber, said needle projecting from said front end surface, said surface by resting against the body portion of the patient limiting the depth to which the needle is insertable, one of said members havin a fin- 6 ger grip portion for manual operation of the syringe by pressure exerted at said finger grip portion in the direction of said needle, said one member having a cavity in its front wall surrounding said needle; and a sealing cap pressuretightly seating in said cavity, said cap having two portions of different internal diameter, a narrower portion adapted to engage and pressuretightly seal said needle near its point, and a wider portion loosely fitting about the rearward portion of said needle.

6. A combination ampule and syringe for storin and injecting a predetermined volume of a medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid; a hollow injection needle mounted in the front end of one of said members, said one member being shaped to provide a tapered sealing surface about said needle; a tubular sealing member snugly fitting over said needle and seating pressure-tightly against said sealing surface; and a rod in said sealing member extending into said needle, said rod having an enlarged end portion tightly fitting into said tubular sealing member and closing the end of the sealing member adjacent the point of the needle;

7. A combination ampule and syringe for storing and injecting a predetermined volume of a medicinal fluid comprising, a barrel member; a plunger member movable in said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid; a hollow injection needle mounted in the front end of one of said members, said one member being shaped to provide a tapered sealing surface about said needle; a tubular sealing member of plastic material snugly fitting over said needle and also engaging said one member at said sealing surface; and a rod in said sealing member, said rod extending into the hollow passage of the needle and having an enlarged end portion tightly fitting into said tubular sealing member to close the other end of the sealing member adjacent the point of the needle.

PAUL KOLLSMAN.

REFERENCES CITED lhe following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,592,462 MacGregor July 13, 1926 1,848,711 Hall Mar. 8, 1932 1,943,120 Kabnick Jan. 9, 1934 2,388,323 Henderson Nov. 6, 1945 2,408,323 Lockhart Sept. 24, 1946 FOREIGN PATENTS 0 Number Country Date 51,542 Switzerland Nov. 1, 1910 632,883 Germany July 15, 1936