US3659749A - Intermixing syringe - Google Patents

Abstract

An intermixing syringe provides means for the isolated storage of two components prior to their being mixed which is usually just before injection of the product. This syringe has an outer barrel and a hollow plunger slidable therein with the barrel portion forward of the piston providing one chamber and the plunger providing the other chamber. The plunger is provided with a piston having spaced, ring-like sealing surfaces and a fluid passageway extending from the interior of the plunger to the outer piston surface. The barrel of this syringe is formed with a straight-bored inner surface and includes no undercuts. The forward most sealing surfaces or end of the plunger piston is disposed to be moved from a sealing condition into a fluid flow or conducting condition to permit flow into the forward portion of the barrel.

Description

United States Schwartz atet [54] INTERMIXING SYRINGE [72] Inventor: Boris Schwartz, 400 Park Avenue, Paterson, NJ. 07504 [22] Filed: Apr. 28, 1970 21 Appl. No.: 32,695

52 user ..222/l45,l28/2l8,222/386 s1 Int.C1 ..B67d5/l2 5s FieldofSearch ..222/129,145,213,387,389,

222/470, 490, 494, 491, 565, 386, 541, 495', 128/218 M, 218 NV, 220

[ 1 May 2,1972

FOREIGN PATENTS OR APPLICATIONS 1,491,785 10/1969 Germany ..128/2 1 8 M Primary Examiner-Robert B. Reeves Assistant Examiner-Norman L. Stack, Jr. Attorney-Ralph R. Roberts ABSTRACT An intermixing syringe provides means for the isolated storage of two components prior to their being mixed which is usually just before injection of the product. This syringe has an outer barrel and a hollow plunger slidable therein with the barrel portion forward of the piston providing one chamber and the plunger providing the other chamber. The plunger is provided with a piston having spaced, ring-like sealing surfaces and a fluid passageway extending from the interior of the plunger to the outer piston surface. The barrel of this syringe is formed with a straight-bored inner surface and includes no undercuts. The forward most sealing surfaces or end of the plunger piston is disposed to be moved from a sealing condition into a fluid flow or conducting condition to permit flow into the forward portion of the barrel.

13 Claims, 16 Drawing Figures Patented May 2, 1972 3,659,749

3 Sheets-Sheet l,

I N VENT 0R Bows 50H WAR r2 [3 Y Patented May 2, 1972 3 Sheets-Sheet 2 9 3 w 4 A 9"I I 5 3 "$1 9 9 INVENTOR. BORIS SCHWARTZ #WJLA A GE/VT.

Patented May 2, 1972 3 Sheets-Sheet 5 gL/ l/l l7 i INTERMIXING SYRINGE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the general class of Surgery and more particularly to the subclass of syringes.

2. Description of the Prior Art Syringes are well known in the general field of surgery and those for storing and intermixing various ingredients are represented in patents as to PIERICK, U.S. Pat. No. 3,279,654 of October, 1966; to BROWN, U.S. Pat. No. 2,591,046 of April, 1952, and to CAMBER, Great Britain, No. 746,057 of January 1959. These and other patents use gravity to induce a flow of one component from one chamber to another. This method of transfer is often uncertain and sometimes is incomplete. Many require an exact manipulation of the syringe by the user who may not have the required skill or training. The precise and exact mixing of the various components comprising some of the new medicants is an absolute necessity. Ease of mixing by a potential administrator of the medicant is necessary and desirable, and such a manipulative device is an object of this invention.

In my U.S. Pat. No. 3,464,412 which issued on Sept. 2, 1969, I used the principle of reduced pressure to draw the fluid from the hollow plunger to and through a fluid passageway in the side of the piston and then through an undercut or relief formed in the bore of the barrel. The forward sealing rings of the piston were rendered ineffective as sealing means as they were brought in way of the undercut portion or portions in the barrel and the fluid flowed past these rings to the forward compartment in the barrel. In the present invention, undercuts are not provided however, the forward sealing means is rendered selectively ineffective by designing the piston so that a determined level of reduced pressure, when developed in the forward portion of the barrel, causes the forward sealing means of the piston to be displaced inwardly sufficiently to permit fluid from the plunger to flow past the piston sealing means.

The syringe of the present invention provides a means for bringing the forward portion of the barrel of the syringe into a condition of reduced pressure. At a determined level of reduced pressure, a flow conducting portion of the piston of a hollow plunger is brought into a fluid passing condition so that fluid flows from the plunger. This fluid which is stored in the plunger is sucked from the plunger interior to flow past the piston into the forward housing chamber to provide a controlled mixing of the stored ingredients.

SUMMARY OF THE INVENTION This invention provides a syringe-type apparatus having an outer housing or barrel of generally tubular construction which is formed with an open rear end and a restricted forward end. This forward end has an aperture or passageway through which the mixed medicant or fluid and the like is expelled from the syringe, usually to and through a needle. The plunger is slidable in the bore of the barrel and is formed with a hollow interior. Its forward end is provided with a piston having a fluid-flow passageway extending from the outer surface of the piston to the interior of the piston and plunger. The inner surface of the barrel portion of the outer housing is a straight bore in which the piston is slidable. The forward end of the piston is provided with sealing rings or a one-way valve disposed to permit forward fluid flow from the pistonto the barrel but no rearward or reverse fluid flow. A fluid passageway from the interior of the plunger to and around at least one of the sealing rings or through a one-way valve to the foreportion of the housing permits the two stored components to be mixed. As a storage syringe the plunger may store a determined fluid supply which is transferred to the barrel for injection at the time of use.

In the embodiments of this invention the syringe is arranged primarily as an intermixing syringe with one ingredient stored in the foreportion of the barrel and another ingredient which LII is fluid is stored in the hollow plunger member of the syringe. The several embodiments all have pistons with ring-type sealing surfaces and in all but one embodiment one end of the fluid-flow passageway is through the piston wall rearwardly of the forward sealing ring of the piston. When the fluid-flow path is around the forward sealing ring, the arrangement of the sealing surfaces on the plunger piston is made so that when the forwardmost ring is brought into a fluid-flow condition at least some of the remaining sealing surfaces of the piston seal the housing bore of the barrel so as to prevent flow of fluid or atmosphere to and from the open end of the barrel to the plunger interior or to the foreportion of the barrel.

It is an object of this invention to provide an intermixing syringe assembly in which two medicants may be isolated for storage and which at a determined time and by manipulative action are mixed usually immediately prior to the use of the medicant. The intermixing of the components is accomplished when the plunger is manipulated to move the plunger and piston outwardly from a forward position so that the forward portion of the barrel is brought into a condition of reduced pressure. At a determined level of reduced pressure or position of the piston of the syringe a portion of the piston is brought into a fluid-passing condition so that the fluid stored in the plunger is caused to be sucked into the reduced pressure forward portion of the barrel whereat the components are mixed.

It is a further object of this invention to provide an intermixing syringe wherein two components of the medicant are isolated for storage and, at the time of mixing, the ingredients are brought into comingle relationship with each other by the passage of fluid from the plunger through a one-way valve formed in the forward wall portion of the piston.

INTENT OF THE DISCLOSURE There has been outlined rather broadly the most important features of the various embodiments of the syringe apparatus of this invention in order that the present contribution to the art may be more fully appreciated. Those persons skilled in this art will appreciate that the concept on which the present disclosure is based may be utilized to provide the basis for other syringe devices similarly carrying out the purposes of this invention. The chosen embodiments of the syringe are provided for the purposes of illustration and description of the principles of this invention and are shown in the accompanying drawings forming a part of the specification wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents a sectional view of a two-compartment intermixing syringe adapted to store two components in an isolated condition;

FIG. 2 represents the syringe of FIG. 1 with the two medicant components in a mixed condition in the barrel portion of the syringe;

FIG. 3 represents an enlarged sectional view of the piston end of the plunger of FIG. I and showing in detail the construction of the piston;

FIG. 4 represents a sectional end view of the piston and plunger of FIG. 1, the view taken on the line 4-4 of FIG. 3;

FIG. 5 represents an enlarged sectional side view of a syringe barrel and a filter member disposed therein;

FIG. 6 represents a sectional view of an alternate two-compartment intermixing syringe embodiment with the two medicant components stored in an isolated condition;

FIG. 7 represents the syringe of FIG. 6 with the two medicant components in mixed condition;

FIG. 8 represents a sectional view of an alternate or modified piston construction of the piston shown in FIG. 6;

FIG. 9 represents a sectional view of yet another alternate or modified piston construction of the piston of FIG. 6;

FIG. 10 represents a sectional view of yet another alternate piston construction in which a one-way valve is provided in the forward end or wall of the piston;

FIG. 11 represents a sectional view of the piston and outer barrel with the view taken on the line 11-I1 of FIG.

FIG. 12 represents a sectional view of yet another embodiment of a two-compartment syringe with the two medicant components stored in an isolated condition;

FIG. 13 represents the syringe of FIG. 12 but with the two medicants now in a mixed condition;

FIG. 14 represents a fragmentary sectional side view of yet another alternate construction of a piston end of a syringe similar to the piston of FIG. 12;

FIG. 15 represents a sectional side view of yet another twocompartment syringe construction with the two medicant components stored in an isolated condition, and

FIG. 16 represents a fragmentary sectional view of the syringe of FIG. 15 with the piston moved to a forwardly position to permit the fluid portion to flow to the forward compartment and the medicant components to become mixed.

In the following description and in the claims various details will be identified by specific names for convenience; these names, however, are intended to be generic in their application. Corresponding reference characters refer to like members throughout the several figures of the drawings.

The drawings accompanying, and forming part of, this specification disclose certain details of construction of the several syringes for the purpose of explanation of the broader aspects of the invention, but it should be understood that structural details may be modified in various respects without departure from the concept and principles of the invention and that the invention may be incorporated in other structural forms than shown.

DESCRIPTION OF THE SEVERAL EMBODIMENTS Syringe of FIGS. 1 through 4 Referring now to the syringe as shown in FIGS. 1 through 4 it is to be noted that this syringe assembly includes anouter barrel 20 having a restricted front end having ahub 22 which is adapted to receive and removably seat a needle not shown in these views. Through this end is provided a passageway which is plugged or closed to the passage of air and/or powder by a resilient stopper or plug 24. The open rear end of this outer barrel is provided with aflange 26 for gripping by the operator. A dust shield in the form of aflanged rubber diaphragm 28 is disposed to snugly grip theflange 26. In the center of the diaphragm there is formed an aperture through which ahollow plunger 30 is slidable. On the rear end of theplunger 30 there is formed aflange 32 which is gripped by the operator for moving the plunger in the barrel. Carried in the interior of the plunger is a slidable piston or plug 34 which is slidable along the full length of the interior bore 35 of the plunger.

Carried on the front end of theplunger 30 is apiston 36 which, in this embodiment, is formed so that its rear portion provides a pair of spaced circular sealing surfaces or ring portions 37a. The forward portion of this piston is also provided with close-spaced like-sized sealing surfaces orring portions 37b. At least onefluid aperture 38 is formed in and through the sidewall of thepiston 36 to provide passageway from the interior 40 to the outer surface of the piston. The forward end of theplunger 30 is provided with a sealed and reducedglass end 42 which is formed to also providewing members 43 and 44. These wing members are adapted to engagelugs 45 and 46 formed in thepiston interior 40, FIGS. 3 and 4. Ashoulder 48 formed on the glass end of theplunger 30 is sized to engage and retain anintumed collar portion 49 of the piston.

Use and Operation of the Syringe of FIGS. I 4

The two-compartment syringe in the assembled condition of FIG. 1 provides an isolated storage for apowdered medicant 50 which is retained in the forward end of theouter barrel 20. Afluid medicant 52 is stored within the bore of themoveable plunger 30. To intermix themedicant components 50 and 52 at the desired time of use, theplunger 30 is drawn from the stored condition of FIG. 1 outwardly or rearwardly to the position and condition of FIG. 2. Theplunger 30 at this outer condition is now rotated so that theend 42 within thepiston 36 is broken off when and as theflange portions 43 and 44 of the glass end are caused to engage thewing portions 45 and 46 of the piston. This breakage occurs as the glass end exceeds its limit, causing the end to be broken off and allowing the fluid 52 to pass fromplunger 30 to and throughpassageway 53 and into the interior 40 of the piston. As and when theplunger 30 is pulled from its position in FIG. 1 to its position in FIG. 2 the forwardinterior portion 50 of theouter barrel 20 comes to a condition of reduced pressure. The fluid inarea 40 of the piston flows through thepassageway 38 into the reduced pressure area of theouter barrel 20 whereupon the fluid and the powder are mixed.

Flow from the interior ofpiston 36 to theportion 50 of the barrel is accomplished by the novelty of design of the forward sealing portion of the piston. Theforward wall 56 of thepiston 36 is formed or molded so as to be bowed forwardly when a condition of reduced pressure is applied to the outer surface of this wall and tending to accentuate the bow of the wall. This reduces the ability of the sealing rings 37b to seal the bore of thebarrel 20. A small amount of deflection is sufficient to permit fluid to flow forwardly past these sealingrings 37b and into the barrel. Positive pressure rearwardly againstwall 56 tends to flatten thewall 56 and to urgerings 37b against the bore ofbarrel 20 as thepiston 36 is moved forwardly. When the fluid passageway is established thefluid medicant component 52 flows to the reduced pressure area ahead of the forward part of thepiston 36 and into theouter barrel 20. As the fluid 52 is drawn forwardly atmospheric pressure causes piston or plug 34 to slide forwardly to the forward end of thebore 35 of theplunger 30. Therubber diaphragm 28 provides a snugly engaging shield to insure that the outer surface ofplunger 20 is maintained in a sterile condition during and while it is in the stored forward position.

Filter of FIG. 5

Referring next to FIG. 5 it is to be noted that a filter in the fonn of a rubber diaphragm ordisc 60 is shaped so as to have an outerperipheral portion 61 sized to be a sliding fit in the bore of the barrel of the syringe. This filter is disposed in the barrel of the syringe so that the center portion of the diaphragm in its mounted condition is concave towards the forward end of the syringe. A circular, forwardly extendingrim portion 62 is formed on the diaphragm and is spaced at short distance from theouter periphery 61 of the filter member. In therim portion 62 there are formed a series ofscallops 63 providing a plurality of fluid passageways through which the fluid may pass by therim portion 62. In use, as the plunger and piston is pushed forwardly, the center concave portion 64 of thediaphragm 60 is caused to deflect inwardly causing a fluid passageway in the form of a thin gap adjacent the inner wall of the barrel to be provided. Through this thin gap the fluid will pass around theouter surface 61 and through thepassageways 63 thence to and through afluid passageway 65 formed in the forward end of the syringe and then out through aneedle 66 or the like.

Syringe of FIGS. 6 and 7 Referring next to the syringe of FIGS. 6 and 7 there is shown an alternate embodiment wherein asyringe 70 is similar in construction to the syringe of FIGS. 1 through 4 except that the piston is made as a complete rubber member. This piston provides the fluid seal between theouter barrel 20 and plunger. This piston has acollar portion 72 which is adapted to fit within a neck or intumed flanged end portion 74 of aplunger 75. Forward of the plunger, the piston portion 76 has aninterior chamber 77 which tapers forwardly and outwardly so that the forward portion of the piston tends to collapse as the plunger is drawn backwardly to cause a reduced pressure to be developed in the forward portion of thebarrel 20.Plug 24 insures that the forward end of the barrel is sealed to prevent unwanted air to enter the interior of the barrel.

Use and Operation of the Syringe of FIGS. 6 and 7 As theplunger 75 is drawn from the position of FIG. 6 to the position of FIG. 7 and withplug 24 is place, the pressure in the forward portion of barrel becomes reduced below atmospheric pressure. At a point near the position of FIG. 7 a limit condition is reached whereat the forward face or wall of the piston slightly collapses so thatring sealing members 78 and 79 no longer provide a fluid seal for the forward portion of the plunger. When this occurs the fluid 80 in the barrel portion 81 flows forwardly and passes throughrear passageway 82 of the piston intochamber 77 and then throughaperture 83 into the reduced pressure area in the barrel whereat it is mixed withpowdered medicant 84 stored in this forward portion of the barrel. As the fluid 80 flows from the plunger and into the forward barrel, the slidingpiston seal 34 as in FIG. 2 slides forwardly tocollar portion 72.

Piston of FIG. 8

An alternate embodiment and construction to the piston shown in FIGS. 6 and 7 is shown in FIG. 8 wherein the piston is formed with an interior larger than that in FIG. 6. As shown, a piston 90 has an interior area orchamber 92 whose diameter snugly engages aplunger 93 having an outwardly extending shoulder or collar 94. At least onetransverse fluid passageway 95 is formed within the sidewall of piston 90 so that as the plunger is drawn backwardly in anouter barrel 20, the reduced or negative pressure formed in the forward portion of thebarrel 20 causes the two forward sealing members or rings 96 and 97 of the piston to slightly collapse inwardly enough to permit fluid from the bore ofplunger 93 to pass by these forward sealing rings. After the fluid from within theplunger 93 passes through thepassageway 95 andpast rings 96 and 97 it flows turbulently into the forward portion of the barrel.

In the manner of the piston of FIG. 6 the use of a syringe having the piston 90 mounted on aplunger 93 contemplates that the forwardsealing ring portions 96 and 97 are collapsed by reduced pressure a sufficient amount to permit fluid to bypass these rings when and as the negative pressure in the barrel is sufficient to draw the forward end wall of the piston a small amount forwardly.

Piston of FIG. 9

An alternate embodiment of a piston construction is shown in FIG. 9 in which instead of theenlarged chamber area 77 of FIG. 6 a smallerinterior passageway 99 is formed inpiston 100. This passageway, as shown, is contemplated to be of a regular or straight diameter. Transverse fluid passageways 101 are formed in the sidewall of the piston at a position adjacent the inner end of thepassageway 99. The forward face portion of thepiston 100 is made concave so as to permit ready deformation of the sealingring portion 103 as the plunger and the mountedpiston 100 is drawn rearwardly. As and when thepiston 100 is moved forwardly the concave surface causes a thrust or outward pressure to be applied to the sealing surfaces 103 so that they are caused to more tightly engage the inner surface oftheouter barrel 20.

In the manner of the pistons of FIGS. 2, 6 and 8 as shown and described above, thepiston 100 of FIG. 9 contemplates that under the influence of reduced pressure the sealing surface rings 103 will be at least locally deflected to permit forward fluid bypass past these rings while in the reverse motion and no reduced pressure, the forward pushing ofpiston 100 and pressure against the concave face will cause therings 103 to be urged outwardly against the inner surface of thebarrel 20.

One-Way Valve of Piston of FIGS. 10 and 11 Referring next to the embodiment of the piston of FIG. 10 it is contemplated that a one-way valve is formed in the forward wall portion of the resilient piston. In this piston assembly there is provided a molded piston member having a passageway 111 formed in and through the forward wall. Aresilient plug 112 or seal member has a rear skirt orenlarged portion 113 which is slightly larger in diameter than the bore of passageway 11!. A series of flutes 114 are formed in the wall of the passageway 111 to provide conductors for flow of fluid from theinterior 115 of the piston to and past the forward face of thepiston 110. Therear skirt 113 only partially covers the fluted passageways 114, however, a forward button portion ofplug 112 has an outerthin rim portion 117 which is made sufficiently resilient so that it can be deflected outwardly to allow fluid to flow forwardly past it. This flow occurs when reduced pressure is produced in the barrel portion forwardly of the piston. However, when the pressure is applied to the forward button by movingpiston 110 forwardly in the syringe thethin portion 117 of the button is pushed tightly against the face of the piston and over the fluted portions 114 to seal the flutes from passage of the fluid.

Use and Operation of Piston of FIGS. 9 and 10 In use, the piston of FIGS. 9 and 10 as it is moved by and with the plunger is a one-way valve. When the piston is drawn rearwardly the forward portion of the barrel, with thestopper 24 in place as in FIG. 1, develops a reduced or negative pressure as in FIG. 1. At a certain limit of reduced pressure the ability of thethin portion 117 ofplug 112 to retain fluid from a forward flow is overcome and the fluid from interior 115 flows along the flutes 114 and around the deflectedthin portion 117 and into the forward portion ofouter barrel 20. After the medicant components and the like have been mixed, thestopper 24 is removed from the forward passageway of the barrel and after a needle is mounted on the hub the piston may be moved forward for ejection of the mixed components from the syringe. Thethin cover 117 as the piston moves forwardly covers the flutes and seals the piston against reverse flow through passageway I12.

Syringe of FIGS. 12 and 13 Referring next to FIGS. 12 and 13 it is to be noted that an outer housing orbarrel 120 carries aplunger 121 provided with theresilient piston 122 similar to thepiston 36 of FIG. 1. However, in this particular embodiment thelugs 45 and 46 are omitted. Inbore 123 formed in the forward end of plunger 12] is mounted aresilient plug 124 which is adapted to seal the passageway or bore 123 against any passage or flow of fluid. When a reduced pressure in the forward portion of thebarrel 120 is produced and reaches a determined limit, theplug 124 is drawn forward by this reduced pressure and is dislodged from thepassageway 123. The plug, as it is drawn forwardly, falls into the interior ofthe piston I22 as in FIG. 13.

Use of Piston of FIGS. 12 and I3 In the manner of the syringe of FIG. I, the syringe of FIG. 12 is manipulated to draw the piston and plunger rearwardly to develop a negative pressure in the forward barrel portion. As and when a determined negative pressure is developed the forward ring portions of the plunger permit a negative pressure to develop in the cavity of the piston and theplug 124 is drawn from bore I23 to fall into the interior of the piston. Withbore 123 now open the fluid flows from the plunger into the chamber of the piston, through the passageways in the sidewall and past the forward sealing rings and finally intobarrel 120 as in the manner of FIG. 1. It is also contemplated that ifplug 124 is not dislodged as planned, thepiston 34 may be urged forwardly to develop forward thrust on the plug.

Referring finally to the syringe of FIGS. 15 and 16 there is provided a syringe having an outer housing orbarrel 140 having a conventionally formedforward end 142 and aresilient stopper 144 fitted intopassageway 145 to make said passageway both fluid and airtight. In this forward end of this syringe adry medicant 146 may be stored.Outer housing 140 has a flanged rear end 148 and forwardly thereof is a reducedportion 150 formed so as to provide an inner diameter shoulder of a size which slidably guides the outer diameter of aplunger 156. The forward portion of this plunger has an extendedneck portion 158 with aninner diameter passageway 159 therethrough providing for a passage for fluid. This inner diameter passageway may be slightly tapered or have a rounded outer or forward end. This forward end also is formed with a shoulder or outwardly extendingflange portion 162. A rubber piston 170 is mounted on this forward end and is formed with an inwardly directedflange portion 172 sized so as to be slidable on the outer surface of theextended neck portion 158.

An outer ring-type seal 174 is formed on the rear portion of piston 170 while a short distance forwardly of this seal at least onepassageway 176 is formed in the sidewalls of the piston. A plug portion' 178 is formed on and attached to the inner end wall of this piston. This plug portion is tapered and has a rounded end adapted to slidably engage and seal thepassageway 159 when the piston is positioned in the condition of FIG. 15. When the fluid-carryingplunger 156 is drawn backwardly from the position of FIG. 15 theouter sealing portion 174 of the piston is disposed to engage the reducedportion 150 of the barrel. Theforward ring 180 provides a deflectable seal of the piston as in the manner of the other pistons above described.

Use and Operation of Syringe of FIGS. 15 and 16 It is contemplated that in operation as piston 170 is drawn rearwardly from the position of FIG. 15 to the position of FIG. 16, a condition of reduced pressure is produced in the forward portion of theouter barrel 140. This condition tends to draw the piston 170 from its sealing condition to the condition of FIG. 16 whereupon the piston slides forwardly upon the reducedneck portion 158 and opens the fluid passageway for fluid flow through 159 and then through thepassageway 176 and pastforward ring 180. If theplunger portion 178 is seated in thepassageway 159 too tightly or is not dislodged by the reduced pressure in the forward portion of the barrel, the engagement of theshoulder 174 with theshoulder 150 in the barrel insures that the piston 170 is removed to the condition of FIG. 16 asplunger 156 is pulled rearwardly.

It is to be further noted that after the fluid transfer fromplunger 156 to the fore portion ofbarrel 140 thestopper 144 is removed and a needle in the manner of FIG. is mounted on the hub. When the plunger is moved forwardly to expel the mixed medicant from the syringe the piston 170 moves rearwardly on the reducedneck portion 158 to the condition of or substantially the condition of FIG. whereupon the sealing action ofring 174 insures that the fluid is expelled by the piston 170 without fluid flow into the plunger orpassageway 159.

Although reducedportion 150 is shown as formed in the barrel body, this may be eliminated and instead a stop member disposed to positively engage theplunger ring 174 may be made as a separate member and be attached to the rear of the housing. It is only necessary that the piston be engaged and positively moved to the condition of FIG. 16 to efl'ect fluid flow.

It is further noted that although the above-described embodiments are primarily contemplated as being used for an intermixing syringe, the syringe may also be used as a fluid storage device. To avoid the necessity of shipping a syringe withthe barrel having a determined quantity of fluid stored therein and with the plunger extending great distance from the barrel the above-described syringes may be used as shown as fluid storage devices. When so used the plunger is filled ith fluid as shown but instead of a powder being stored in the fore portion of the barrel the piston is brought to the extreme forward position after which the stopper is mounted in the hub passageway. To transfer the fluid from the plunger to the barrel, the plunger is drawn rearwardly in the manner of an intermixing operation after which the fluid flows to the barrel from which it is expelled in the usual manner.

TERMS The work barrel" as above used is contemplated as being the outer housing of a syringe and as shown is of plastic, glass or other material compatible with the product being stored.

"Piston" as above shown is contemplated as being of rubber or other resilient material which will have sealing surfaces sized to resiliently and frictionally engage the bore of the barrel.

Plunger" as above used is a hollow tubular member of glass, plastic or other material compatible with the product being stored.

As cost is an essential consideration, the material used in the several components will be made to satisfy storage criteria, manufacturing and tooling cost and aesthetic appearance.

Terms such as up, down, "bottom," top," front," back," in," out and the like are applicable to the embodiments shown and described in conjunction with the drawings. These terms are merely for the purposes of description and do not necessarily apply to the position in which the several embodiments of the syringes may be constructed or used.

The conception of the intermixing syringe and its many applications is not limited to the specific embodiments shown but departures therefrom may be made within the scope of the accompanying claims and without sacrificing its chief advantages and protection is sought to the broadest extent the prior art allows.

What is claimed is:

1. An intermixing syringe for the isolated storage of at least two medicant portions and the like, the syringe including an outer housing in whose interior front end is stored one of the medicant portions and a hollow plunger in whose bore there is a slidable piston and in its hollow portion of the plunger is the isolated storage of the other stored medicant portion, the syringe including means whereby the medicant portion carried by the plunger may be transferred from the hollow plunger to the interior front end of the outer housing for the mixing of the portions in the front end of the outer housing, the syringe having means for bringing the stored medicant portion in the plunger into the front end of the outer housing and the front end of the same housing portion into a condition of reduced pressure, the syringe comprising: (a) an outer housing of generally tubular configuration having an open rear end extending into an inner bore of a generally constant cross section, the housing having a front partially closed other end with a discharge passageway therethrough; (b) removable means for closing the passageway of the partially closed front end of the housing so as to prevent the passage of air, fluids and the like; (c) a plunger having a main portion of generally tubular configuration and sized to easily move axially in the bore of outer housing without sealing of the bore of the housing; d) a movable piston providing for the closing of the rear end of the plunger and the hollow portion thereof to the passage of air, fluid and the like, said movable piston slidable within and through the length of an interior bore formed in the plunger and providing therewith a fluid-tight sealing means, and (e) a resilient piston adapted for mounting on and closing the front end of the plunger, said piston formed with a plurality of ringlike sealing surfaces sized so as to be slidable in the bore of the housing while engaging said bore in a fluid-flow sealing manner, the piston having at least one flow passageway formed therein with one end of the passageway open to the interior of the plunger and the other end terminating at the piston outer surface and between adjacent ring-like sealing surfaces, said piston further formed so that under the influence of a reduced pressure developed in the forward portion of the outer housing those ring-like sealing surfaces forward of the formed flow passageway are deflectable forwardly from a sealing condition to a fluid-flow forwardly condition permitting the fluid in the plunger to flow through said passageway and past those forward sealing surfaces and into the forward housing portion when said forward housing portion is brought to a condition of reduced pressure as developed by the rearward movement of the plunger in the outer housing.

2. An intermixing syringe as in claim 1 in which the piston is made of rubber with an interior chamber which is formed so as to taper forwardly and outwardly so that the forward portion of the piston will tend to collapse inwardly and forwardly under the influence of a small amount of pressure exerted on the rear of the piston.

3. An intermixing syringe as in claim 1 in which the piston is made of rubber with an enlarged interior portion terminating in a forward wall formed with a small forward bulge which is caused to collapse partly in its support of the forward sealing rings said collapse being induced by a small amount of pressure applied to said forward of the piston.

4 An intermixing syringe as in claim 1 in which the piston is made of rubber with its forward face made with a concave surface extending rearwardly causing the forward face to collapse in its support of the forward sealing rings under the influence of the flow of fluid past the rings.

5. An intermixing syringe as in claim 1 in which the forward end of the plunger is made with a small bore in which the medicant in the plunger is a fluid and there is provided a resilient plug adapted to seal the bore against fluid flow until the plug is displaced by a determined pressure from the fluid in the plunger and in which the piston is made with an enlarged interior sized to freely accept and retain the displaced plug.

6. An intermixing syringe as in claim 5 in which the plug is a cylindrical rubber member of determined length which is at least as long as the diameter ofthe plug.

7. An intermixing syringe as in claim 5 in which the plug is a rubber ball of determined diameter which is slightly larger than the forward bore in the plunger.

8. An intermixing syringe as in claim 1 in which the forward end of the plunger is made with a bore of determined reduced diameter extending through an extended neck portion formed to provide an outer cylindrical surface of determined extent which is temiinated at a forward flanged end, and in which the piston is a slidable member on the outer surface of the neck portion of the plunger, said piston being formed with a rear inwardly directed flange portion sized to be slidable on the cylindrical neck outer surface, said piston adjacent the inwardly directed flange portion having an enlarged inner bore of determined extent and slidable on the forward flanged end of the plunger neck, this forward end of the enlarged inner bore terminating in a wall in which there is formed a plug member which is sized and positioned to be a sealing fit in the reduced bore in the plunger neck when the slidable piston is moved to a rear position on the neck, and in which the plug is displaced from the bore to a fluid flow condition when the piston is moved to a forward position on the neck of the plunger.

9. An intermixing syringe as inclaim 8 in which the forward portion of the neck bore is tapered outwardly and in which the plug is also made with a similar taper.

10. An intermixing syringe as inclaim 8 in which the piston has an outer rear ring-like portion slidable in the bore of the housing and in which there is provided a reduced portion carried by the rear end of the housing, said reduced portion disposed to engage the outer rear ring-like portion of the piston as it is drawn rearwardly in the housing enabling the neck of the plunger to be drawn rearwardly in the piston until the forward flange of the piston becomes a stop to further movement of the plunger neck in the iston. 11. An rntermrxlng syringe as in 0 arm l in which the forward end of the plunger is sealed to prevent fluid flow until the plunger is rotated in the piston and in which interior of the piston is provided with inwardly extending wing portions disposed to cooperatively engage extending flange portions formed on the forward end of the plunger when the plunger is rotated to cause the flange portions to engage the wing portions and break the sealed forward end of the plunger.

12. An intermixing syringe as in claim 11 in which at least the plungers forward end is made of glass.

13. An intermixing syringe as in claim 11 in which the forwardmost portion of the housing is provided with a filter, said filter being made of a resilient material such as rubber and in which in its mounted condition in the housing the outer diameter is a light press fit against the bore until fluid pressure is exerted against a concave center portion whereupon the disc is bowed sufiiciently to cause the rim portion to be moved from its engagement with the wall to permit a fluid flow around at least a portion of the outer diameter and through the scallops in the rim portion.

Claims (13)

1. An intermixing syringe for the isolated storage of at least two medicant portions and the like, the syringe including an outer housing in whose interior front end is stored one of the medicant portions and a hollow plunger in whose bore there is a slidable piston and in its hollow portion of the plunger is the isolated storage of the other stored medicant Portion, the syringe including means whereby the medicant portion carried by the plunger may be transferred from the hollow plunger to the interior front end of the outer housing for the mixing of the portions in the front end of the outer housing, the syringe having means for bringing the stored medicant portion in the plunger into the front end of the outer housing and the front end of the same housing portion into a condition of reduced pressure, the syringe comprising: (a) an outer housing of generally tubular configuration having an open rear end extending into an inner bore of a generally constant cross section, the housing having a front partially closed other end with a discharge passageway therethrough; (b) removable means for closing the passageway of the partially closed front end of the housing so as to prevent the passage of air, fluids and the like; (c) a plunger having a main portion of generally tubular configuration and sized to easily move axially in the bore of outer housing without sealing of the bore of the housing; (d) a movable piston providing for the closing of the rear end of the plunger and the hollow portion thereof to the passage of air, fluid and the like, said movable piston slidable within and through the length of an interior bore formed in the plunger and providing therewith a fluid-tight sealing means, and (e) a resilient piston adapted for mounting on and closing the front end of the plunger, said piston formed with a plurality of ring-like sealing surfaces sized so as to be slidable in the bore of the housing while engaging said bore in a fluid-flow sealing manner, the piston having at least one flow passageway formed therein with one end of the passageway open to the interior of the plunger and the other end terminating at the piston outer surface and between adjacent ring-like sealing surfaces, said piston further formed so that under the influence of a reduced pressure developed in the forward portion of the outer housing those ring-like sealing surfaces forward of the formed flow passageway are deflectable forwardly from a sealing condition to a fluid-flow forwardly condition permitting the fluid in the plunger to flow through said passageway and past those forward sealing surfaces and into the forward housing portion when said forward housing portion is brought to a condition of reduced pressure as developed by the rearward movement of the plunger in the outer housing.

2. An intermixing syringe as in claim 1 in which the piston is made of rubber with an interior chamber which is formed so as to taper forwardly and outwardly so that the forward portion of the piston will tend to collapse inwardly and forwardly under the influence of a small amount of pressure exerted on the rear of the piston.

3. An intermixing syringe as in claim 1 in which the piston is made of rubber with an enlarged interior portion terminating in a forward wall formed with a small forward bulge which is caused to collapse partly in its support of the forward sealing rings said collapse being induced by a small amount of pressure applied to said forward of the piston.

4. An intermixing syringe as in claim 1 in which the piston is made of rubber with its forward face made with a concave surface extending rearwardly causing the forward face to collapse in its support of the forward sealing rings under the influence of the flow of fluid past the rings.

5. An intermixing syringe as in claim 1 in which the forward end of the plunger is made with a small bore in which the medicant in the plunger is a fluid and there is provided a resilient plug adapted to seal the bore against fluid flow until the plug is displaced by a determined pressure from the fluid in the plunger and in which the piston is made with an enlarged interior sized to freely accept and retain the displaced plug.

6. An intermixing syringe as in claim 5 in which the plug is a cylindrical rubber member of determined length which is at least as long as the diameter of the plug.

7. An interMixing syringe as in claim 5 in which the plug is a rubber ball of determined diameter which is slightly larger than the forward bore in the plunger.

8. An intermixing syringe as in claim 1 in which the forward end of the plunger is made with a bore of determined reduced diameter extending through an extended neck portion formed to provide an outer cylindrical surface of determined extent which is terminated at a forward flanged end, and in which the piston is a slidable member on the outer surface of the neck portion of the plunger, said piston being formed with a rear inwardly directed flange portion sized to be slidable on the cylindrical neck outer surface, said piston adjacent the inwardly directed flange portion having an enlarged inner bore of determined extent and slidable on the forward flanged end of the plunger neck, this forward end of the enlarged inner bore terminating in a wall in which there is formed a plug member which is sized and positioned to be a sealing fit in the reduced bore in the plunger neck when the slidable piston is moved to a rear position on the neck, and in which the plug is displaced from the bore to a fluid flow condition when the piston is moved to a forward position on the neck of the plunger.

9. An intermixing syringe as in claim 8 in which the forward portion of the neck bore is tapered outwardly and in which the plug is also made with a similar taper.

10. An intermixing syringe as in claim 8 in which the piston has an outer rear ring-like portion slidable in the bore of the housing and in which there is provided a reduced portion carried by the rear end of the housing, said reduced portion disposed to engage the outer rear ring-like portion of the piston as it is drawn rearwardly in the housing enabling the neck of the plunger to be drawn rearwardly in the piston until the forward flange of the piston becomes a stop to further movement of the plunger neck in the piston.

11. An intermixing syringe as in claim 1 in which the forward end of the plunger is sealed to prevent fluid flow until the plunger is rotated in the piston and in which interior of the piston is provided with inwardly extending wing portions disposed to cooperatively engage extending flange portions formed on the forward end of the plunger when the plunger is rotated to cause the flange portions to engage the wing portions and break the sealed forward end of the plunger.

12. An intermixing syringe as in claim 11 in which at least the plunger''s forward end is made of glass.

13. An intermixing syringe as in claim 11 in which the forwardmost portion of the housing is provided with a filter, said filter being made of a resilient material such as rubber and in which in its mounted condition in the housing the outer diameter is a light press fit against the bore until fluid pressure is exerted against a concave center portion whereupon the disc is bowed sufficiently to cause the rim portion to be moved from its engagement with the wall to permit a fluid flow around at least a portion of the outer diameter and through the scallops in the rim portion.

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