Title:
SYRINGE
United States Patent 3662753


Abstract:
A syringe assembly enabling mixed discharge of substances retained in separated condition until intended use, employing a plunger and barrel arrangement that retains the substances separated during storage, allows mixing thereof prior to discharge, and causes discharge of the mixed substances.



Inventors:
TASSELL KITCHENER B
Application Number:
05/040197
Publication Date:
05/16/1972
Filing Date:
05/25/1970
Assignee:
KITCHENER B. TASSELL
Primary Class:
International Classes:
A61M5/19; A61M5/34; A61M5/31; A61M5/315; A61M5/32; (IPC1-7): A61M5/00
Field of Search:
128/218D,218M,218P,218PA,218N,220,215
View Patent Images:
US Patent References:
3511239MULTI-CHAMBER SYRINGE1970-05-12Tuschhoff
3494359TWO COMPARTMENT SYRINGE WITH A SINGLE BARREL1970-02-10Zackheim
3477431COMBINED MIXING SYRINGE AND CONTAINER1969-11-11Walecka
3342180Disposable liquid-powder package and hypodermic syringe1967-09-19Sandhage et al.
3110309Plastic cartridge needle assembly1963-11-12Higgins
2390246Syringe1945-12-04Folkman



Primary Examiner:
Mancene, Louis G.
Assistant Examiner:
Weinhold D. L.
Claims:
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows

1. A syringe assembly capable of normally retaining two substances separated and of subsequently allowing mixing thereof, comprising: an elongated barrel having a discharge end for cooperation with a syringe needle means, and a plunger inlet end; a plunger having a plunger head in said barrel and a plunger shaft extending through said plunger inlet end and to a position externally of said barrel to enable said plunger head to be shifted along said barrel; said barrel having at least two portions of differing diameters extending along its length, the larger being toward said plunger inlet end and the smaller toward said discharge end; said plunger head having releasable seal means operative to form a seal with respect to said barrel when said plunger head is shifted in said barrel toward said discharge end, to release the seal when said plunger head is shifted away from said discharge end and into said larger diameter portion, allowing passage of one substance therepast for mixing of the substances, and to form a seal with respect to said barrel when said plunger head is shifted in said barrel toward said discharge end to discharge the mixed substances.

2. The syringe in claim 1 including a smooth transition zone between said portions of differing diameters to allow said plunger head to retain its seal to said barrel when shifted toward said discharge end.

3. The syringe in claim 1 wherein said plunger head has a flexible peripheral sealing lip extending radially outwardly and diagonally toward said discharge end into engagement with said barrel, to be forced by pressure into sealing engagement with said barrel when shifted toward said discharge end and to be flexed out of sealing engagement with said barrel by said one substance when shifted away from said discharge end.

4. The syringe in claim 1 wherein said barrel has a needle assembly fitting, is of a polymeric material, and includes an integral polymeric portion forming a puncturable closure at said discharge end for puncture thereof by a needle when attached to said fitting.

5. A syringe assembly capable of normally retaining two substances separate and of subsequently allowing mixing thereof, comprising: an elongated barrel having a discharge end for cooperation with a syringe needle means, and a plunger inlet end; a plunger having a plunger head in said barrel and a plunger shaft extending through said plunger inlet end and externally of said barrel to enable said plunger head to be shifted along said barrel; said plunger head having releasable seal means operative to form a seal with respect to said barrel to maintain substances separated in said barrel, to release the seal when said plunger head is shifted away from said discharge end to allow movement of a substance therepast for mixing of the substances, and to form a seal with respect to said barrel when said plunger head is shifted in said barrel toward said discharge end, to discharge the mixed substances.

6. A syringe assembly capable of normally retaining two substances separate and of subsequently allowing mixing thereof, comprising: an elongated barrel having a discharge end for cooperation with a syringe needle means, and a plunger inlet end; a plunger having a plunger head in said barrel and a plunger shaft extending through said plunger inlet end and externally of said barrel to enable said plunger head to be shifted along said barrel; said barrel having at least two portions of differing diameters extending along its length, the larger diameter being toward said plunger inlet end and the smaller diameter toward said discharge end; said plunger head having releasable seal means operative to form a seal with respect to said barrel to maintain substances separated in said barrel, to release the seal when said plunger head is shifted away from said discharge end to allow movement of a substance therepast for mixing of the substances, and to form a seal with respect to said barrel when said plunger head is shifted in said barrel toward said discharge end, to discharge the mixed substances.

7. The syringe as defined in claim 5 wherein said discharge end of said barrel includes a needle assembly fitting thereon having a section of reduced outer diameter for pressed fit locking engagement with a syringe needle means.

8. The syringe in claim 7 wherein said needle assembly fitting includes an internal integral membrane therein sealing said discharge end, said membrane forming a puncturable closure for puncture by a needle when attached to said fitting.

9. The syringe in claim 8 including a smooth transition zone between said portions of differing diameters to allow said plunger head to retain its seal with said barrel when shifted toward said discharge end.

Description:
BACKGROUND OF THE INVENTION

This invention relates to syringes, and more particularly to a syringe assembly for controlled mixing and discharge of substances stored in separated condition in the syringe assembly.

Many present day medicines to be injected with a syringe require last minute mixing of two substances, such as two liquids or a liquid and a solid, just prior to injection, because premature mixing causes loss of potency thereof or possibly even harmful results. Consequently, a variety of two chamber storage vials have been created wherein the substances are kept separated during storage by a frangible diaphragm or the like but enable mixing just prior to use. Normally such vials are made for cooperation with a conventional syringe which is used to withdraw the substances from the vial. Because of cost factors, necessity of manufacture of separate components, i.e., the special two chamber vial and the syringe, and certain complications of use resulting therefrom, efforts have been made heretofore to create a syringe assembly which itself would store the substances separately and allow mixing therein prior to use. Unfortunately, such efforts have resulted in highly complex devices which are very costly to manufacture, or extremely difficult for the doctor or nurse to arrange the parts and manipulate for use, and usually both. Consequently, pharmaceutical manufacturers have been understandably reluctant to market their products in these combination units.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a special syringe assembly that, while being capable of storing substances in separated condition, capable of enabling mixing thereof, and capable of discharge thereof in mixed condition, is actually relatively inexpensive to manufacture and moreover extremely simple to use. No careful manipulations and interchange or interfitting of components is required by the user. Rather, it is only necessary to pull the plunger for mixing, insert the needle, and push the plunger for discharge. Hence, no special training of the doctor, nurse, or other user is required. Loading of the novel unit by the pharmaceutical house is also relatively simple. This invention is characterized by the coupling of its effectiveness and its simplicity.

The syringe employs a releasable seal of the plunger head in the barrel, such that the plunger head retains the substances separated, allows mixing of the substances with plunger retraction, by releasing the seal, and reseals automatically with plunger advancement to allow full discharge.

The plunger head has a diagonally oriented peripheral seal lip, preferably cooperative with differing diameter barrel portions.

These and other objects, features, and advantages of this invention will become apparent from the specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional, side elevational view of the main components of the novel syringe assembly, particularly showing the first stage of assembly thereof with one component;

FIG. 2 is a side elevational view of the novel syringe assembly, with needle means, and particularly showing the second stage of assembly with loading of the second substance;

FIG. 3 is a side elevational sectional view of the syringe, showing particularly the step required by the user for mixing of the substances;

FIG. 4 is a side elevational sectional view of the syringe assembly, particularly showing needle puncturing of the seal on the discharge end; and

FIG. 5 is a side elevational sectional view of the novel syringe, showing the discharge step.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now specifically to the drawings, the syringe assembly 10 includes a barrel subassembly 12 with plug subassembly 18, a plunger subassembly 14, and is combined with a needle subassembly 16.

Barrel subassembly 12 has an elongated, generally cylindrical, hollow barrel member 20 with a discharge end 20a and a plunger insert end 20b. End 20a is capable of cooperatively receiving needle subassembly 16, while end 20b is capable of cooperatively receiving plunger subassembly 14 as well as plug subassembly 18.

Barrel 20 may be formed of transparent or translucent glass or polymeric material, preferably the latter, with end 20a preferably being an integral portion thereof. End 20a includes a hollow nose 20a' defining a cavity 20c at the inner end of which is a piercable diaphragm 20d integral with the barrel in the preferred form. If the barrel is made of glass, this diaphragm may be a suitable insert of rubber or other polymeric material. The inner end of the barrel chamber adjacent diaphragm 20d preferably has a convex configuration as at 20e correspondingly interfittable with the concave configuration of the inner end of plunger head 14a for complete exhaustion of the ejected substance from the syringe during use, in a manner to be described in detail hereinafter.

Barrel 20 has portions of differing diameter in its interior, with portion 20f toward the discharge end being of smaller diameter than portion 20g toward the plunger inlet end, there being a smooth tapered transitional zone 20h therebetween. This transition zone enables the special plunger head 14a to maintain a seal against the inner diameter wall surface of the barrel as the plunger is moved toward the discharge end in a fashion to be described.

Plunger subassembly 14 includes the plunger shaft 14b, on the inner end of which is secured plunger head 14a, and on the outer end of which is a knob 14c, i.e., externally of the barrel. Plunger head 14a is formed of a resilient material such as rubber or the equivalent and is specially constructed to have a releasable seal relative to the barrel. That is, when the plunger head is retracted away from the discharge end and toward the plunger insert end of the barrel, the seal is released to allow passage of a substance in portion 20g of the barrel past the plunger head and into mixing relationship with the substance in portion 20f of the barrel. Yet, when the plunger is shifted in the opposite direction, moving head 14a toward the discharge end, an effective seal is maintained. More specifically, plunger 14a includes a peripheral, releasable sealing lip 14d which projects diagonally, i.e., both radially outwardly and axially towards the discharge end of the barrel, thereby engaging the inner peripheral wall surface of the barrel. The core of the plunger head is smaller in diameter than the diameter of barrel portions 20f and 20g. The peripheral lip is larger in diameter than both barrel portions. It has a special relationship relative to portions 20f and 20g of the barrel in the storage, mixing, and ejection (discharge) stages as will be explained more fully hereinafter.

Open end 20b of the barrel subassembly allows insertion of the substances in controlled fashion into the assembly, and subsequently is closed by the plug subassembly 18. This plug is preferably formed of a resilient material such as the polymer employed for the barrel, forming a sealing inter-lock with the barrel. Specifically, the nose 18a of plug 18 is inserted into the open end of the barrel until the axial barrel end engages the radially outwardly extending flange 18b, at which position the units are inter-locked as by engagement of a radially inwardly extending rib 20i on the barrel into a radially inwardly extending correspondingly oriented and dimensioned peripheral groove 18c on the plug. An effective seal can be maintained between this plug and shaft 14b of plunger subassembly 14 during the sliding inter-relationship therebetween, as by a suitable O-ring 30 mounted in the inner diameter of the annular plug subassembly 18.

Needle subassembly 16 includes a needle 16a of typical hollow hypodermic type, surrounded by a sleeve which includes an enlarged portion 16b for cooperation with protective cap subassembly 32 (FIG. 3), and includes a nose interlocking portion 16c which is inserted into axially oriented end cavity 20c in body subassembly 12. This interlock may be achieved as by a radially inwardly extending locking rib 20j on the outer end of cavity 20c interfitting in a correspondingly shaped and dimensioned radially inwardly extending peripheral groove 16d on nose 16c when the needle subassembly is pushed into the interlocking engagement with body subassembly 12. Nose 16c also has a first peripheral indent 16e for engagement by rib 20j during the storage condition of the needle in the body, i.e., non-puncturing condition, adjacent to which is a tapered surface 16f to enable the nose to be further inserted into the body for puncturing as will be explained in detail hereinafter.

Assembly of the components of this device occurs during filling of the medicinal substances into it. Specifically, substance number one S1 here shown to be a powder but which could also be a liquid, or a semi-liquid material, is first placed into portion 20f of body 12 (FIG. 1) and then head portion 14a of plunger subassembly 14 is inserted into the barrel until the forwardly projecting peripheral sealing lip 14d has moved past the transitional area 20h into engagement with the smaller inner diameter of portion 20f. Thus substance number one is retained in this forward portion of the body. Next, substance number two, shown to be a liquid S2, (FIG. 2) is inserted into portion 20g of body 12, followed by insertion of plug 18 to seal the open end 20b of the body. When so filled, the assembly 10 can be stored in this fashion, separately from or connected to the needle subassembly 16. As a precautionary measure, to avoid premature movement of the plunger a suitable cylindrical stop member or the like (not shown) can be placed around the plunger shaft 14b between knob 14c and flange 18b of the plug. Normally, it is desirable to connect needle subassembly 16 to the unit for handy shipment in one compact package.

This needle subassembly 16 is preferably retained in the cap of the subassembly 32, with the outer periphery of portion 16b being in sealing engagement with the inner diameter of cap 32, and in abutment with radially inwardly protruding stop ribs 32a. This cap and needle assembly is attached to body 20 by insertion of nose 16c into opening 20c until rib 20j interengages groove 16e (FIG. 3). The unit is then placed in a suitable container and shipped to the ultimate user.

The user therefore receives this unit with the plunger, substances, and body as illustrated in the left part of FIG. 2, but normally with the needle attached as in the right part of FIG. 3. Alternatively, the user may attach the needle as indicated. To mix substances S1 and S2, it is only necessary that the plunger subassembly 14 be pulled to a withdrawn condition where plunger head 14a is adjacent plug 18 as shown in FIG. 3. When so doing, lip 14d is shifted past transition zone 20h and into the larger diameter portion 20g of body 20. The liquid substance S2 is thereby forced past the outer periphery of lip 14d, between it and the inner diameter of portion 20g, to allow it to be mixed with substance S1. If necessary, the unit may be shaken at this point for complete mixture, dissolving, or chemical reaction as appropriate. At this point, needle 16a is shifted inwardly to puncture diaphragm 20d. (FIG. 4) This is done by pressing cap subassembly 32 toward the body, using one hand on the body and one hand on the cap, such that ribs 32a pushing on sleeve 16b forces needle 16a axially through diaphragm 20d into intercommunication with the mixed substances. These components are pressed together until rib 20j interfits with groove 16d, at which time cap 32 may be removed from the needle subassembly without retracting the needle subassembly from the body. The unit is then ready for use.

To eject the mixed substances, it is then only necessary to aspirate it and insert the needle into the flesh tissue, in conventional fashion, and advance the plunger subassembly relative to the barrel in the manner illustrated in FIG. 5. When this plunger is advanced, the back pressure of the liquid forces peripheral lip 14d into complete peripheral engagement first with the large diameter wall of barrel portion 20g, then into sealing engagement with transitional zone 20h, and then into sealing engagement with the smaller diameter barrel portion 20f. By the nature of the plunger head, and particularly the diagonal peripheral sealing lip thereon, the greater the back pressure of the substances upon the plunger head, the more tightly this lip will be sealed against the inner diameter of the barrel.

Once the above description and drawings are understood, it will be readily appreciated that this device is extremely simple. Indeed, its very simplicity is a major factor of its uniqueness, coupled with its effectiveness, thereby enabling its replacement of highly complex and expensive devices proposed heretofore. It is conceivable that various additional advantages and minor structural modifications of the invention may be apparent to those in the art upon reviewing this disclosure. Hence, the invention is not intended to be limited directly to the specific embodiment disclosed as illustrative, but only by the scope of the appended claims, and the reasonably equivalent structures to those defined therein.