Liquid Dispenser And Method And Apparatus For Filling Same

Abstract

A liquid dispenser having a liquid containment barrel or body with a slidable sealing and dispensing-effecting plunger, the plunger having a self-sealing slit formed therein to enable filling therethrough of the dispenser barrel, the slit being formed at the bottom forwardly facing end of a threaded handle-connecting recess in the exposed rear portion of the plunger. A male fill member is employed, to be selectively inserted into and releasably open the plunger slit and to selectively fill the barrel with liquid, while venting past the male fill member through a vent eye formed in the opened slit as a result of insertion of the male fill member. An annular ring and grove on the rear end plunger and a lip shoulder stop on the rear end of the syringe barrel or body enable desired forward motion inhibiting action on the plunger during insertion and removal of the male fill member relative to the plunger slit.

Description

This invention relates to liquid dispensers, and a method and apparatus for filling such dispensers, and more particularly to a back-fillable liquid dispenser arrangement and a method and apparatus for filling such through the back or rear of the dispenser arrangement.

Syringes for use in dispensing fluids are well-known in the art, and normally consist of a barrel or cylinder body with a slidable plunger or piston in fluid-tight sealing engagement with the annular wall of a bore formed in the barrel for containment of liquid, and with exit port arrangements at the discharge or dispensing end of the barrel. In the prior art there have been various methods employed for filling such syringes with fluid. Syringes used for administration of drugs in liquid form, either orally or by injection with a needle or the dispensing end of the syringe, have conventionally been filled prior to use, by aspirating the liquid in through the forward or dispensing end of the syringe which is used subsequently for dispensing of the same fluid from the syringe. This method is slow, as it is often accomplished through a dispensing needle canula with a relatively small liquid flow bore, and as it depends on the pressure differential between a partially formed vacuum and the external atmospheric pressure, formed through manual rearward motion of the syringe plunger or piston while holding the dispensing end of the syringe within the body of liquid desired to be aspirated in. It is additionally hazardous to safety, as the dispensing end of the syringe is thereby contaminated with the liquid, as well as itself forming a possible contaminant source for the liquid being aspirated into the syringe.

There is a well-established need to fill syringes which are used to store liquid drugs or other pharmaceuticals for a significant length of time, and in hospital practice this is often done in pharmacies. Various methods have been utilized, including the aspiration of liquid through the forward dispensing end, as discussed above. In addition, it has been attempted to fill the syringe through the back or plunger end of the syringe, by sliding a needle along the interface between the rubber or other elastic plunger and the bore wall in the barrel, and in some instances a sharp-pointed beveled hollow needle or canula has been employed to pierce directly through the sold plunger. However, these prior art efforts at backfilling of a syringe have been less than fully desirable and successful, as both mentioned methods have substantial disadvantages. In the case where a fill needle is attempted to be slid past and between the plunger and the barrel bore wall, it will be appreciated that a relatively fine-sized needle is required as a practicality, and while such is feasible, the needles so employed have a required fill bore of such small size that desired injection molding of the fill needle is essentially impractical or impossible in production, as the injection molding core element becomes impractically too small to be effective for production processes, and in any event the needle is practically required to be so small as to render filling a relatively slow and tedious task, in addition to representing a tedious mechanical insertion problem in sliding the fill needle or canula between the plunger and the bore wall, and also providing substantial opportunities for contamination in the course of attempting to slide the fill needle between the plunger and the bore side wall. The other mentioned attempted method of fillinf, utilizing a sharp piercing and puncturing hollow fill needle or canula, also requires as a practical matter the employment of a small size needle, with resultant relatively slow filling of the syringe therethrough. In addition, such method has an accompanying serious and highly disadvantageous safety hazard, in potentially causing a core to be cut by the sharp piercing and puncturing forward end of the canula, which core will then be injected into the syringe in the course of filling, with subsequent potential harm to the patient upon dispensing of the liquid from the syringe. In addition, this method of filling poses a further disadvantage in that a fluid-tight seal is formed around the fill needle as a result of its puncture-piercing of the elastic plunger, thereby providing a venting problem during attempted insertion of liquid through the fill needle and into the syringe. While needles may be employed which have a secondary vent hole extending therethrough for connection with the atmosphere, such are necessarily more expensive and less desirable than a single bore tube for insertion of liquids.

It is an object and advantage of the present invention to provide a syringe or other dispenser or dispensing cartridge for liquids, which can be delivered to the desired place for filling in sterile and empty condition, and which may be fully assembled and may then be filled at the desired place of filling, easily and without disassembly or contamination. In effecting this object and advantage, the invention utilizes a backfilling arrangement and method, which enables simple, easy, fast and safe filling. By this simple, fast and safe arrangement and method for filling through the back or plunger end of the syringe or other dispenser, it is possible to employ various arrangements as may be desired at the dispensing or exit port end of the syringe, including various needles, valves, connectors, nozzles, caps, etc. which are permitted to remain intact and uncontaminated during filling.

It is a further object and feature of the invention to provide a backfilled dispenser arrangement which enables the utilization of a relatively large fill canula or fill needle, and which fill needle or canula desirably does not employ a sharp piercing end, but which is desirably blunt, and which fill needle or canula may have a relatively large fill bore extending therethrough.

Still a further feature of the invention is the provision of a backfilled dispenser arrangement and method and apparatus for filling such, which provides a self-forming natural air vent between a fill needle or canula and the surrounding insertion zone about the fill needle or canula, and which air vent is subsequently self-sealing after withdrawal of the fill needle or canula.

It is a further feature to provide a simple, safe, and efficient backfilled syringe or dispenser arrangement and method and apparatus for filling such, which enables various liquids, including thick and viscous liquids as well as thin or less viscous liquids, to be fed relatively easily through the back of the dispenser.

A further feature in carrying out the present invention is the relative ease of gauging the true quantity of liquid inserted into the dispenser, as air bubbles are substantially less likely to be injected into the syringe or other dispenser arrangement in utilizing the present invention that would be likely with aspirated front-end-filled syringes or other dispensers.

It will accordingly be appreciated that major advantages and features of this invention are provided in safety in filling, speed of filling, and the enablement of utilization of a simple and low-cost fill needle or canula arrangement for filling.

Still other objects, features and attendant advantages will become apparent to one skilled in the art from a reading of the following detailed description of a preferred and various other physical ambodiments constructed in accordance with the invention, taken in conjunction with the accompanying drawings, where:

FIG. 1 is an exploded view in perspective and with parts partially cut away for clarity of illustration, illustrating a preferred embodiment of a syringe dispenser, and fill apparatus for filling such according to the invention.

FIG. 2 is a longitudinal section view of the syringe dispenser of FIG. 1.

FIG. 3 is a perspective view of the fill member or fill needle of FIG. 1, being shown in enlarged view for clarity of illustration.

FIG. 4 is a longitudinal secton view of the fill member or fill needle of FIG. 3.

FIG. 5 is a fragmentary section view of the fill cylinder or syringe, fill needle, and fillable syringe dispenser, in assembled and interconnected position for filling of the syringe dispenser.

FIG. 5A is a view similar to FIG. 5, illustrating a further step at the conclusion of the filling operation and prior to withdrawal of the needle from the syringe plunger.

FIG. 6 is a perspective view of the radially elastically compressed and confined multipurpose syringe plunger within the syringe barrel, with fill needle positioned therein for filling and with the surrounding syringe body section shown in phantom for clarity of illustration.

FIG. 6A is a section view taken on line 6A--6A of FIG. 5.

FIG. 7 is a partially cut away section view of a forward seal member as utilized in the embodiment of FIGS. 1 and 2.

FIG. 9 is a fragmentary section view illustrating the attachment of a handle to the plunger, after filling of the syringe.

FIG. 9 is a partially cut away perspective view of a preferred plunger embodiment as employed in the syringe embodiment of FIGS. 1 and 2.

FIG. 10 is a partially cut away view in perspective of a modified form of plunger according to the invention.

FIG. 11 is a longitudinal section view of a modified and preferred form of back fillable slitted plunger according to the invention.

FIG. 12 is a fragmentary longitudinal section view of an assembly of a syringe with the modified plunger of FIG. 11 positioned therein in an optional alternative modified position and with a fill needle inserted therein during filling.

Referring now in detail to the figures of the drawings, in FIG. 1 there is illustrated a syringe dispenser 11 constructed in accordance with the invention, together with a fill member therefor in the form of a fill needle 61, a fill cylinder or syringe arrangement 71, and an attachable handle 51 for the syringe 11.

The syringe 11, which is more fully illustrated in enlarged form in FIG. 2, and its various parts and their functions in subsequent Figures, preferably takes the form of a glass tube body or barrel 13 having a forward dispensing nose end section 15 formed or secured thereon, and a finger grip section 17 formed or secured on the rear thereof. The glass tube body or barrel 13 may be formed of conventional glass tubing and has a cylindrical bore forming a liquid containment chamber 13a which is bounded at the rear by a multipurpose plunger 31 and in the illustrative embodiment is bounded at the forward end by a forward seal 41. The forward nose end section 15 is preferably formed with a reduced diameter tip or nose 15c having a dispensing mouth orifice 19. The nose or tip 15c may take various forms, as may be desired, depending upon the ultimate utility desired, as for instance such may be threaded or formed with a Luer taper for securing a needle unit thereto for injection purposes, or such may if desired be of a size and shape such that standard needle units may not be secured thereto, as in oral drug dispensing uses where it is desired to prevent the possibility of inadvertently and mistakenly securing an injection needle to the syringe and injecting the liquid into a human body when the drug is only for oral or other desired use.

Both the finger grip section 17 and the forward nose section 15 may be suitably formed of polypropylene, and may be slidably press-fit over the respective opposite ends of the glass tube body or barrel 13. Alternatively, it will be appreciated that the glass tube body 13 itself may be formed with an integral finger grip thereon at its rear section or otherwise as may be desired, and/or likewise the forward nose end section 15 may be integrally formed as a part of the glass tube body. Or, syringe body 13, 15, 17 may be formed of other material, either in separate parts or integrally, as may be desired and satisfactory for a given utilization and/or liquid L which may be desired to be dispensed. However, it will be appreciated that utilization of a glass tube body 13 is a preferred construction, as glass is a highly preferred material for containment of liquid drugs or other chemicals, in view of its various desirable properties such as low reactivity, low absorption and adsorption, and its transparency.

The forward seal 41 in the illustrative embodiment takes the form of a plug of elastic material, such as rubber, and serves as a pop-out bypass valve seal which is self-sealing with the bore wall in the compressed bore-retained position as shown in full lines in FIG. 2, and which is of a larger free size and shape to enable fluid bypass therearound and therepast from fluid chamber 13a through enlarged bypass chamber or cavity 16 and out through dispenser orifice or mouth 19 when such seal 41 is moved forward by columnar pressure thereon from rear plunger 31 through the contained fluid in the chamber 13a, thereby enabling initial sealing and subsequent dispensing of the liquid from within the syringe 11 after such is filled according to the invention and as will be subsequently described. In the illustrative embodiment, forward seal plug 41 has a cruciform ridge 43 formed on its forward and rearward surfaces, with face groobes 45, which insure full bypass fluid flow past the seal plug 41 after such has been ejected into the bypass chamber or cavity 16.

In lieu of the forward seal 41, the syringe 11 may employ other forward seal arrangements, such as a rupturable membrane, and in addition the tip or nose 15c may be capped, or may have a needle or canula unit attached thereto prior to use. Also, alternatively it is feasible to practice the basic and novel back-filling aspect of the invention, although not as desirable in most instances, without any seal or cover at the forward end of the syringe 11, as in the instance where the syringe has a conventional injection needle unit secured thereto and which itself sufficiently inhibits free liquid flow therefrom through its small bore and long length canula size as to enable effective filling of the syringe 11 essentially without loss of fluid through the dispensing mouth orifice notwithstanding the absence of a full seal or cover within or over the external forward end of the syringe 11. It will be appreciated that in most instances, and particularly in those instances where pharmacy or other intermediate stage filling is effected for subsequent use at another location, at least an external cover is desired over the tip or nose 15c or such other dispensing end on the syringe 11, and a preferred form also includes an internal forward seal, such as seal 41.

The elastic self-sealing plunger 31 disposed at the rear or back end of the syringe 11 for filling, takes the form in the preferred example, of a cup-shaped single-piece molded member having its bottom end wall facing forwardly within the bore of glass tube 13, and forming the rear wall of liquid containment chamber 13a. The rearwardly facing recess 35 of plunger 31 is threaded to accomodate a screw-threaded forward male end 53 of a conventional handle 51 which may be selectively inserted therein after filling the chamber 13a to enable manual manipulation of the plunger forwardly or rearwardly, for dispensing and/or aspiration action thereby, as may be desired. The elastic plunger 31 may be suitably formed of rubber or other suitable elastic material, although rubber is normally most preferred, the preferred form of construction being by molding of the rubber or other material. The annular external sealing surface of the plunger 31 has annular sealing ridges or rings 31 formed thereon with alternating annular grooves 34 therebetween, as is conventional practice, to aid in sealing and ease of sliding motion of the plunger 31 along the bore wall of the tube 13, the rearmost, or other selected and sufficiently suitable annular ring 33' as well as to some extent its adjoining annular groove 34', also serving a unique and important advantage in the back filling method and operation according to the invention, and as will be subsequently described.

The forward sealing wall 37 of plunger 31 has a slit 37a formed therein, preferably by cutting after molding of the plunger body 31 in a solid form without the slit. In the illustrative and preferred embodiment, the slit 37a is formed by progressively moving the plunger 31, after molding as noted above, past a stationary or rotating knife with the wall 37 extending toward and moving past the knife and sliding on a guide surface from which the knife protrudes. The knife, not shown, may take any desired form, and may have an inclined cutting edge progressively engaged by the plunger 31 as it moves therepast. The plunger 31 may preferably be confined in a suitably complementary slotted holder while it is moved past the knife edge, to assure desired cutting of the slit 37a, and it will be appreciated that the passage of the plunger 31 past the knife will effect cutting of a full slit 37a across the full forward extent of the plunger 31, including wall 37, to thereby form interfacing lips 37aa which self-sealingly engage in compressed relation against one another when the plunger 31 is compressed within the bore of glass cylinder 13. The preferred form of the slit 37a thus extends across the full extent of the forward face of the plunger 31, and through the full depth of the wall 37, although it will be appreciated that if so desired one may, although such is not preferred nor normally of any substantial advantage, and is in fact to a considerable extent disadvantageous, form the slit 37a slightly less than the thickness of wall 37, thereby leaving a thin relatively easily rupturable membrane at the base of the slit 37a, which membrane is of a thickness and strength such that it does not require pointed piercing or puncturing thereof to open it, but which will be opened through shearing action thereon as a result of stretching os such when the blunt-nosed fill member, subsequently to be described, is thrust forwardly thereagainst. This form is not preferred and is disadvantageous, in that it is difficult to control the precise size formation of the plunger and the precise thickness of such thin-walled membrane after cutting so as to be assured of sufficiently easy tensile shear rupture on moving the fill member thereagainst, and in addition it is possible for the membrane to tear off and separate during such tensile shear rupture, thereby providing a potential hazard of contaminating the liquid L with a piece or pieces of the plunger 31. The likelihood of such particulate separation of a piece of such tensile sheared thin membrane is considered greatly less than the likelihood of coring a much thicker wall, such as wall 37, with a piercing bevel sharpened hollow needle or canula, but is nevertheless considered hazardous in this respect and normally undesirable.

The syringe 11 may be manufactured and distributed to a desired place for filling, in the empty form as shown in FIG. 2, (or in a cartridge form without one or both finger grip 17 and nose section 15, if so desired) at which desired place of filling, the operator will utilize a fill member or needle including a male fill tube or canula which is inserted into the recess 35 and through the slit 37a to communicate between the exterior of syringe 11 and the interior of liquid containment chamber 13a. This fill member may, if desired, suitably take the form of a simple tube, of plastic, metal, or other suitable material, although plastic is simple to form and utilize and is preferred, and in such simple utilization form the fill member tube or canula may be simply inserted by pushing the tube end against and through the slit 37a. A more desirable fill member or needle is shown in FIGS. 3 and 4, and indicated by the reference numeral 61, this fill needle includes a connector body 63 having a bore 63b extending therethrough and connecting with a continuation bore 70a of smaller diameter in an insertion tube extension 70. The tube extension 70 extends from a base flange 67 which may be suitably secured to the body section 63 as by a heat seal at its peripheral intersection with the adjoining forward flange portion of the connector body section 63, or such may be otherwise suitably bonded or press-fit therein, or alternatively the entire fill needle 61 may be integrally formed as a single piece, as by injection molding of the entire body. Bore 63b may be straight walled along its length, or may be otherwise formed, as by forming a Luer taper at its rear end portion, as indicated at 63a. A conical tapered bore wall 67a is formed at the intersection between bore 63b and reduced diameter bore 70a. The Luer tapered bore section 63a enables ease of attachment of the fill needle 61 to a fill cylinder or syringe 71 having a Luer connector tip or nose 79 thereto, as shown in FIG. 5, for enabling filling of a desired liquid L through the fill needle 61 and into a syringe dispenser 11. It will be appreciated that other connector configurations may be utilized, as desired, in lieu of a Luer taper connection, such as a threaded connection, a bayonet connection, or other press-fit connection, or otherwise as may be desired, the simplest and easiest connection being a Luer or other tapered fit connection.

Fill needle 61 preferably has longitudinally extending spaced ribs 69 formed on the outer surface of tube extension 70 and extending from the forward face 65a of flange 65. These ribs 69 may serve a dual purpose of providing longitudinal vent slots therebetween, and also of providing a depth stop at the forward end during the filling operation, and will be subsequently described.

As will be seen from FIGS. 2 and 5, the plunger 31 is initially positioned within the rear or back end of the syringe barrel 13, with one or more of its sealing rings 33 extending rearwardly beyond an inwardly projecting annular lip detent 17b which engages with the next forwardly adjacent annular groove 34 on the plunger 31. It is preferred to position the rearmost sealing ring and an adjacent groove in this detention location, such being indicated by the reference numerals 33' and 34' respectively, as this affords quite ample plunger detention for enabling ease of fill tube insertion through the slit 372, and such also offers the advantage of greater lateral stability for the plunger 31 during the fill tube insertion and filling operation, next to be described, than would be provided with a shorter forwardly retained extent of the plunger within barrel 13 when employing the next forwardly adjacent or other forwardly disposed sealing ring and groove for this detention effect. However, primarily for illustrative purpose in this respect, FIG. 12 does illustrate a plunger initially detained through utilization of the penultimate or next forward succeeding sealing ring 233" and annular groove 234" in an also otherwise modified plunger arrangement, later to be described in more detail. In this respect, it will likewise be apprediated that, this modified plunger 231 may also be and is preferably, initially positioned with its rearmose annular sealing ring 233' and adjoining annular groove 234' in detaining engagement with the annular internally extending and protruding lip 17b at the rear of the syringe 11, in lieu of being utilized as shown for illustrative optional purposes in FIG. 12.

Referring now again to FIGS. 2 and 5, the syringe 11 is desirably furnished according to the invention, to the place of desired filling thereof, in the form shown in FIG. 2, with the plunger 31 positioned as shown and described above. In this position, the annular protruding lip 17b serves to resiliently inhibit both forward and rearward motion of the plunger 31 within the syringe barrel 13, thereby materially aiding in insertion and removal of the fill needle 61 with respect to slitted plunger 31. As has been previously noted, this initial resiliently detained positioning of the slitted plunger 31 is particularly advantageous in enabling direct and simple push insertion of a fill needle having a fill tube extension thereon, as in the case fill needle 61, or by simple utilization of a fill tube which is desirably generally blunt-nosed, as distinguished from being sharp-nosed with a piercing puncture point.

Referring now further to FIG. 5, the filling operation for a syringe 11 may be facilely effected by pushing the fill needle tube extension 70 against and through the slit 37a in the plunger 31, either before or after attaching the fill needle 61 to the connector tip 79 of fill cylinder 71. As shown in FIG. 5, it is desirable that the forward face 65a of fill needle body section 63 and associated flange 65 or a portion thereof, be rearwardly spaced behind the rear face 31r of plunger 31 during the filling operation, to assure venting between the faces 65a and 31r. In addition, it is not necessary or desirable that the flange 65 and itsforward face 65a be brought into contact with the rear face 31r of the plunger at this stage in the operation, for the additional reason that to do so might inadvertently result in pushing the plunger forwardly to move the rear annular sealing ring 33' past its external detaining connection with lip 17b. To this end, the operator will be expected to insert the needle 61 and associated tube 70 into the slit 37a so as to open the lips and provide a desired communication path along the bores 63b and 70a between chamber 13a and liquid L in fill syringe 71, without fully closing the interfacing surfaces 65a and 31r. The ribs 69 assist in enabling the operator to achieve this desired positioning of the fill needle 61, as their length may be desirably formed to be sufficiently longer than the depth of the recess 35 when the slitted wall 37 is opened by tube extension 70, to resiliently detain the face 65a in spaced relation behind the rear wall 31r of plunger 31, as generally indicated in FIG. 5. In such position, the longitudinal grooves extending between the tri-lobed ribs 69 also assure air venting from the vicinity of the slit rearwardly along the recess 35 to the zone between spaced faces 65a and 31r.

In the effectively opened condition of the slit 37a, the opposing lips 37aa engage with opposite sides of the external annular surface of tube 70, as generally illustrated in FIGS. 5, 6, and 6A. And as illustrated in FIGS. 6 and 6A, a natural cat eye vent 37ab will be formed on laterally opposite sides of the tube 70 between the two interengagement zones of the tube 70 and the slit lips 37aa. These cat eye vent openings 37ab enable full venting of the chamber 13a during filling of liquid L from the transfer or fill cylinder or syringe 71, into the chamber 13a, the desired full or partially filled quantity of liquid L being determined by the needs or desires for the indicated use. The cat eye vent openings 37ab will normally taper to a closed condition at their exterior opposite ends adjacent the interior bore wall of glass tube body or barrel 13, in view of the radially compressed and restrained condition of the plunger within the tube 13 the size of the eye vents 37ab being dependent on the relative size of the fill tube 70 and the plunger 31 and the elasticity and degree of confined compression of the plunger 31 within the bore of syringe barrel 13.

The filling of the liquid containment chamber 13a is effected by manually, or otherwise as may be desired,moving the push rod or handle 75 forward in the preferably downwardly extending fill cylinder or syringe 71, to move the plunger 77 forward in the barrel 73 and thereby expel the liquid L through the bore 79a in connector tip 79, and thereupon through fill needle bore 63b, 70a and into syringe chamber 13a. Venting of the syringe chamber 13a is effected by air passage through the natural vent eye openings 37ab.

After the desired extent of filling of the liquid containment chamber 13a in the syringe barrel 13 from fill cylinder or syringe 71, the plunger 31 is pushed forwardly so as to disengage ring 33' from its detaining engagement with the rear of the syringe barrel, and enable ease of effective subsequent connection of a manual plunger handle 51 therewith for operation of the plunger in dispensing liquid L from the syringe 11. This small extent of forward movement of the plunger 31 is easily effected by pushing the fill needle 61 and syringe 11 further toward one another to bring the flange 65 and its forward face 65a into pushing contact with the rear face 314 of the plunger 31, and continuing to push the fill needle 61 and syringe 11 together until the face 65a contacts the rear face of flange 17a and lip 17b on finger grip 17. Alternatively, such may be accomplished with other pusher means, such as a flat ended push rod pushing on surface 31r if a simple fill tube is employed in lieu of fill needle 61, such pushing being effected in such case after withdrawal of the fill tube. In either case, this will effectively move the piston 31 forward to an extent sufficient to move the groove 34' out of interlocking engagement with the annular lip 17b, and will position the elastic rearmost sealing ring 34' in a radially more compressed condition within and essentially radially confined by annular lip 17b. This effectively positions the piston 31 so as to enable ease of subsequent securement of the handle 51 thereto. This position is indicated in FIG. 5A. The fill cylinder 71 and fill needle 61 are thereupon removed from interengagement with plunger 31, or vice versa, through simply imparting relative opposite longitudinal motion between the fill needle 61 and syringe 11. The radially substantially compressed condition of the rearmost sealing ring 33' by the radial confinement thereof within annular lip 17b aids in the inhibition of reverse or rearward movement of the piston 31 during withdrawal of the fill needle 61, although such is not necessary in view of the relatively small resistance offered to removal of the tube 70 by the resiliently separated lips 37aa, as compared to the very substantial resistance to the opening of such in the forward direction during insertion of the relatively blunt-ended tube 70 therethrough for filling.

The removal of the fill needle 61, including its filled tube section, from the plunger 31 enables the slit 37a to be self-reclosed to full or effectively full interface contiguity between the interfacing slit lips 37aa. A handle 51 may thereupon be secured to the plunger 31, by placing such against the rear threaded recess section 35a, of the plunger 31, and effecting a slight forward motion of the plunger to move such past the lip 17b, and thereupon screwing the threaded forward male end 53 of the handle 51 into the threaded section 35a of piston 31. The handle 51 has a shoulder stop 54 which provides a positive forward stop for the handle 51 in its forward motion within plunger recess 35, thereby insuring against the possibility of inadvertently opening slit 37a by undesired screwing of the handle 51 too far into the recess 35. The handle 51 may thereupon be manipulated forwardly to move the plunger 31 and thereby effect movement of the liquid L within chamber 13a forwardly, thus enabling exerting of columnar acting force on forward seal 41 through the fluid in chamber 13a to cause the valve plug seal 41 to be popped out into the enlarged bypass chamber 16, after which the liquid L is thereupon expelled through the chamber 16 and out through dispenser mouth orifice 19 and such other connection as may be disposed thereon, such as a needle unit, etc., through continued forward motion of the plunger 31 by the manual or other handle 51. It has been found that the self-sealing action of the slit 37a is also effective against subsequent aspirating action, as by moving the handle 51 and plunger 31 rearwardly in the barrel 13, which may be necessary in some liquid dispensing operations, as when it is desired to determine whether an injection canula on the discharge end of the syringe is in a vein or other body member.

A modified form of plunger is shown in FIG. 10, being designated by the numeral 131. In this embodiment the plunger 131 has substantially the same body configuration as the previously described plunger 31, with annular seal rings and grooves along its longitudinal extent, and having a forward sealing wall 137, as well as a rear recess with screw threads formed therein for attachment of a handle 51 thereto. This embodiment differs from the plunger 31 in the formation of the slit 137a, in that the slit 137a does not extend across the full extent of the wall 137. However, the slit is formed to extend for a length greater than one-half the outer circumference of the fill needle tube section 70, so as to insure the formation of a natural cat eye vent at one or both of the opposite ends of the slit 137a when the fill needle tube 70 is inserted therethrough for filling. It will be appreciated that use of a fill tube with an effective outer circumference equal to or greater than twice the length of the effective transverse length will prevent the formation of the desired eye vent in the slit external of the fill needle tube, and thereby necessitate other substantially less desirable venting provisions, such as utilization of a much less desirable dual bore or other fill needle with its own internal self-venting characteristic.

A further and preferred modified piston construction is illustrated in FIG. 11, being indicated by the reference numeral 231. This piston is similar to piston 31 in its external configuration, having alternating annular sealing rings 233 and annular grooves 234 along its external length, and having a rear facing recess 235, with a threaded annular internal surface 235a along its rear extent. The sealing rings 233 and 234 are designated 233', 234', 233", 234", and 233'" respectively from the rear forwardly, for ease of explanation of a form of utilization of this plunger 231 or the plunger 31, in the filling mode as shown in FIG. 12 and subsequently described.

This modified and preferred plunger 231 differs particularly from the plunger 31 in its provision of a tapered internal forward wall surface 235b at the forward end recess 235, the slit 237a being cut across the apex of this tapered wall surface and extending rearwardly therefrom as shown in FIG. 11. The tapered wall surface 235b materially aids in guiding the fill needle tube or other blunt-nosed tube into centered engagement with the slit 237a for ease of insertion therethrough. The length of the threaded section 235a may be formed to accommodate the effective length of the threaded male section 53 on a desired handle 51, so as to position the shoulder stop 54 against the rear face of the plunger 231 in a stopped position when fully inserted, although there is substantially little if any possibility of opening the slit 237a by attempting to screw the handle threaded end 53 beyond the threads 235a in this embodiment, in view of the tapered forward end surface 235b and the forwardly spaced disposition of the rear extent of slit 237a beyond the end of the threaded section 235a.

Various other plunger constructions might be employed, such as a plunger utilizing a different sealing surface configuration along its longitudinal extent, or the plunger might be formed in two or more separate parts, such as by two interfitting longitudinally split halves which might have a tongue and groove or other interfit interengagement surface therebetween, so as to thereby form the slit in the forward wall without necessity for separate cutting after molding of the plunger, or the slit might be formed by other than cutting, although cutting is the preferred method of forming the slit, or other forms of slits might be utilized, although the greatly preferred and most advantageous form is the straight line diametral slit as employed in the embodiments of FIGS. 9 and 11.

As mentioned previously, FIG. 12 illustrates a modified, though substantially less preferred, positioning of a slitted plunger in the rear end of syringe 11, for and during filling. In this embodiment, the plunger embodiment of FIG. 11 is shown for illustrative purposes, it being appreciated that the plunger 31 or other plunger construction according to the invention might be suitably utilized to practice this modified mode according to the invention.

According to this modified mode of practice, the piston 231 (or 31, etc.) is positioned with the annular lip 17b engaging in the annular groove 234" between the mid-sealing ring 233" and the forward sealing ring 233"', in lieu of being an engagement in groove 234' between rear sealing ring 233' and mid-sealing ring 233". Longitudinal motive-inhibiting action on the piston 231 is thereby effected, similarly to the inhibiting action described in the preceding embodiments and mode of practice. However, it will be appreciated that as the greater extent of the piston 231 is in this mode external of the syringe barrel, such is less laterally stable, as compared to the mode as shown in FIGS. 2 and 5, and also, additional pushing effort and action is subsequently required on this less stable body to move such forwardly into a position comparable as shown in FIG. 5A, after completion of filling, and preparatory to removal of the fill needle 61 from the plunger 231 (or 31, etc.) and subsequent connection of a handle 51 thereto for operational manipulation of the plunger in the course dispensing the liquid L from the syringe 11.

While such is not illustrated, it is feasible to employ the invention in the form of a syringe body cartridge, without utilization of one or both of finger grip 17 and nose member 15, in which instance an annular or other suitable radially inwardly protruding detent may be provided on the cartridge barrel 13 either integrally or otherwise secured thereto, to serve the function of annular lip detent 17b. It will be appreciated that such a cartridge has multiple uses, including being usable to form a complete syringe as by securing a forward nose member 15 and a finger grip member 17 thereon, either before or after filling. Alternatively, a syringe body cartridge of this nature may be inserted into a syringe or syringe shell or other construction, which has a capability of utilization of cartridges.

It will further be appreciated that the forward seal 41 in any of the various constructions may be differently formed, as for instance by utilizing a conventional this rupturable membrane of rubber, suitably secured over or within the forward end of the tube body or barrel 13, as previously discussed, and as may be desired for a given utilization. Also, other selectively openable forward seal constructions may be employed in lieu of the seal 41, and/or an injection needle unit may be secured or formed on the forward end of barrel body 13, with or without a removable cover and/or seal thereover, as may be desired for a particular utilization.

It will be apparent to those skilled in the art that the embodiments illustrated and described are preferred and illustrative, and that various other modifications and improvements may be made without departing from the scope and spirit of the invention. For instance, while the illustrative and much preferred and advantageous embodiments and modes of practice according to the invention utilize an annular movement-inhibiting lip 17b in contact with annular sealing ring and groove surface on the backfillable plunger, other inhibiting detent arrangements might be utilized on either of both of the plunger and syringe barrel, as desired or appropriate. Accordingly, the invention is not to be limited by the particular illustrative and preferred embodiments, but only by the scope of the appended claims.

Claims

We claim:

1. A fillable liquid dispensing arrangement, comprising

a barrel having a liquid-holding chamber with a forward port end for dispensing of liquid therethrough,

said barrel having a rear end opening with a radially inwardly extending lip stop, and having a sealing plunger of elastic material and movably disposed therein at the rear end of said barrel and slidable in and along said chamber,

said plunger having a lip-engageable external surface protrusion thereon adjacent its rear end, and also having means for connecting a handle,

said plunger initially extending partially into said barrel through said rear end opening and extending partially rearwardly beyond said rear end opening,

said lip-engageable protrusion being disposed rearwardly of and adjacent said lip, to inhibit, but not prohibit, forward motion of said plunger within said rear end opening,

an openable pre-formed slit in said plunger and resiliently biased to a closed condition for enabling filling of said chamber with liquid from an external source and subsequent self-closure of said slit,

said plunger and its said slit being engageable through said rear end opening for filling therethrough and for externally manually controlled sliding motion of said plunger.

2. A liquid dispensing arrangement according to claim 1,

said plunger having a threaded external recess formed therein for threadedly connecting a manipulable handle thereto,

said slit being formed in a forward wall defining a forward extent of said recess.

3. A liquid dispensing arrangement according to claim 2,

said plunger being formed of elastic material in the zone of said slit.

4. A liquid dispensing arrangement according to claim 3,

said plunger being an integral molded unit of elastic material.

5. A liquid dispensing arrangement according to claim 4,

said plunger being formed of rubber.

6. A liquid dispensing arrangement according to claim 1,

said barrel comprising a syringe having a finger grip thereon adjacent said rear end, and having an orifice at its forward end for facilitating dispensing of liquids from said chamber.

7. A liquid dispensing arrangement according to claim 6,

said forward end of said barrel having a reduced diameter connector nose at its forward end,

said orifice being formed in said connector nose.

8. A liquid dispensing arrangement according to claim 6,

and a liquid-flow-inhibiting means adjacent the forward port end of said barrel for effectively substantially fully inhibiting liquid flow from said port end during rear end filling through said plunger.

9. A liquid dispensing arrangement according to claim 8,

and a selectively effectively openable closure element forming said liquid-flow-inhibiting means adjacent said forward end of said chamber.

10. A liquid dispensing arrangement according to claim 9,

said closure element comprising a removable cover.

11. A liquid dispensing arrangement according to claim 9,

said closure element comprising a valve seal.

12. A liquid dispensing arrangement according to claim 11,

said closure element comprising a movable by-pass valve seal.

13. A liquid dispensing arrangement according to claim 9,

said closure element being a slidable valve plug formed of elastic material engaging in sliding compressed and sealing relation within a forward end of said barrel,

said barrel having a forward enlarged by-pass chamber for selective forward movement of said valve plug thereinto, to enable selected dispensing of liquid from said chamber past said by-pass valve plug.

14. A liquid dispensing arrangement according to claim 1,

said slit extending across the full forward extent of said plunger.

15. A liquid dispensing arrangement according to claim 1,

said slit extending across a portion of and less than the full forward extent of said plunger.

16. A liquid dispensing arrangement according to claim 1,

said slit extending fully through a seal wall of said plunger.

17. A liquid dispensing arrangement according to claim 1,

said slit extending almost fully through a seal wall of said plunger and having a thin easily ruptured connecting web membrane which does not require pointed instrument puncture or piercing to be opened but which may be sheared upon and by stretching of said slit through insertion of said male fill member therein.

18. A liquid dispensing arrangement according to claim 1,

said plunger having an elastic annular sealing ring thereon forming said lip-engageable protrusion, and being radially compressibly movable past said lip stop and engageable in sliding sealing engagement with the wall of said liquid holding chamber for and during forward dispensing motion of said plunger after filling of said chamber through said slit.

19. A liquid dispensing arrangement according to claim 18,

and an annular outer groove formed on said plunger immediately forward of said elastic annular sealing ring and in releasably engagement with said lip stop.

20. A liquid dispensing arrangement according to claim 19,

said lip stop being an annular lip.

21. A fillable dispenser for fluids, comprising

a liquid-containment body having a bore therein and a dual function dispensing-effective and fill-enabling plunger extending only partially within the rear end of said bore and being selectively positively longitudinally movable along said bore to effect dispensing movement of fluid along said bore and from within said body,

said plunger having a radially elastically compressible motion inhibiting stop adjacent its rear end and extending rearwardly and radially beyond the effective rear end opening at the rear end of said body,

said plunger having a pre-formed self-sealing opening therein for enablement of filling of said liquid-containment body.

22. A fillable dispenser for fluids according to claim 21,

said plunger being a cup-shaped member formed of elastic material and having said opening formed in its bottom wall which extends forwardly in said body.

23. A fillable dispenser for fluids according to claim 22,

said opening being a self-closing slit having elastically deformable laterally interengageable and interfacing lip surfaces.

24. A fillable dispenser for fluids according to claim 23,

said plunger having an elastically compressible annular seal ring forming said motion-inhibiting stop, and an outer annular groove formed on said plunger and disposed forwardly of said seal ring, said groove in motion-inhibiting-aiding engaging relation with a radially inwardly extending portion of said body at and forming a part of the effective rear end opening at the rear end of said body.

25. A fillable dispenser for fluids according to claim 24,

said radially inwardly extending portion of said body comprising an annular lip extending radially inwardly beyond the adjacent wall surface forming said bore.

26. A fillable dispenser for fluids according to claim 23,

said slit extending across the full forward face of said plunger and along a partial rearward extent thereof.

27. A fillable dispenser for fluids according to claim 23,

said slit extending across less than the full forward extent of said plunger.

28. A fillable dispenser for fluids according to claim 21,

said body having an effectively sealed forward end which may be selectively unsealed to enable dispensing of liquid therefrom.

29. A fillable dispenser for fluids according to claim 28,

said body comprising a syringe body member with a cylindrical bore therein and forming the first mentioned said bore, and said bore having a liquid containment section thereof between the forward end of said plunger and said sealed forward end.

30. Liquid filling and dispensing apparatus, comprising

a liquid dispensing barrel having a selectively effectively openable closed dispensing end, a liquid receiving chamber and a slidable plunger for effecting dispensing of liquid from said chamber through said dispensing end,

said plunger extending only partially into said barrel preparatory to filling of said barrel,

said plunger having a normally closed pre-formed opening therein for selective external fluid communication with said chamber,

a transversely outwardly protruding compressible effective motion-inhibiting detent formed on and adjacent the rear end of said plunger and engaging with a rearwardly facing wall on the rear end of said barrel,

and a male fill member adapted to be inserted into and open said pre-formed opening and having a liquid flow passageway to enable filling of said chamber with liquid,

said pre-formed opening being greater in effective opened cross-sectional peripheral size than the corresponding effective cross-sectional peripheral size of said male fill member.

31. Liquid filling and dispensing apparatus according to claim 30,

said plunger being formed of self-recoverable elastic material adjacent and forming its said opening, said opening being a pre-formed self-closing slit.

32. Liquid filling and dispensing apparatus according to claim 31,

said slit extending across the full extent of the forward face of said plunger.

33. Liquid filling and dispensing apparatus according to claim 31,

said slit extending across a portion of the forward face of said plunger.

34. Liquid filling and dispensing apparatus according to claim 31,

said plunger having a screw-in threaded recess in its rear external surface, and said slit being formed in a forward wall of said plunger defining the forward extent of said recess.

35. Liquid filling and dispensing apparatus according to claim 34,

said fill member having a tubular male section engageable in opening relation with said pre-formed slit.

36. Liquid filling and dispensing apparatus according to claim 35,

said fill member having a longitudinally ribbed section extending rearwardly of the forward end of said fill member to assist in maintaining a vent opening along the zone of said threaded recess in said plunger.

37. Liquid filling and dispensing apparatus according to claim 30,

said fill member having connection means enabling connection thereof to a fill cylinder.

38. Liquid filling and dispensing apparatus according to claim 37, and a fill cylinder adapted to be connected to said fill member.

39. Liquid filling and dispensing apparatus according to claim 38,

said fill cylinder comprising a fill syringe having a Luer nose-end connector, and said fill member having a Luer connector complementary to said nose-end connector.

40. Liquid filling and dispensing apparatus according to claim 30,

said male fill member including a tube section having an outer circumference or periphery less than the effective opened cross-sectional peripheral size of said opening.

41. Liquid filling and dispensing apparatus according to claim 40,

said opening being a slit and being longer than one-half of the effective said outer circumference of periphery of said fill member tube section.

42. Liquid filling and dispensing apparatus according to claim 41,

said tube section having a relatively blunt forward end.

43. Liquid filling and dispensing apparatus according to claim 41,

said slit extending fully through a seal wall of said plunger.

44. Liquid filling and dispensing apparatus according to claim 41,

said slit extending almost fully through a seal wall of said plunger and having a thin relatively easily ruptured connecting web membrane which does not require pointed instrument puncture or piercing to be opened but which may be sheared upon and by stretching thereof through thrusting motion thereagainst in the course of insertion of said male fill member into said slit.

45. The method of filling a syringe body having a liquid-containment

chamber with a rearwardly bounding manually operable plunger and

a forward dispensing end spaced from the plunger, comprising

resiliently engaging an elastically radially compressible rearwardly and radially protruding portion of said plunger with a detent surface at the rear of said body and thereby resiliently elastically inhibiting forward motion of said plunger while opening a pre-formed self-closing valve in said plunger by insertion of a tubular member therein having a bore therethrough,

and passing liquid through said bore while enabling air venting from said chamber past said tubular member at other than said bore,

thereupon removing said tubular member from said valve and enabling the self-closure of said valve.

46. The method according to claim 45,

said valve being a pre-formed slit having opposing elastic lips which are biased into interengagement, and said opening of said valve being effected by insertion of said tubular member through said slit, to form an opening with a vent eye between said tubular member and the lips of said slit, said venting being effected through said vent eye.

47. The method according to claim 46,

and subsequently moving said plunger forwardly to radially compress said radially protruding portion of said plunger and to release said plunger for attachment of a handle thereto and selective liquid-moving motion thereof.

48. The method according to claim 47,

and connecting a handle to said plunger after filling therethrough, for dispensing of said liquid from said liquid-containment chamber and through said forward dispensing end.

49. The method according to claim 47,

said plunger having a rear facing threaded connector section, and said insertion of said tubular member therein being effected by rotating and threadedly engaging said tubular member with said threaded connector to impart relative longitudinal joining motion between said tubular member and said plunger through the camming effect imparted by said rotation and threaded engagement.

50. The method according to claim 49,

and subsequently connecting a handle to said plunger by threaded engagement with said threaded connector section.

51. The method according to claim 46,

said insertion of said tubular member being effected by axial thrusting of said tubular member through said slit.

52. The method according to claim 51,

and subsequently connecting a handle to said plunger for dispensing of said liquid from said liquid-containment chamber and through said forward dispensing end.

53. A male fill member for a liquid containment body having an elastic plunger with a screw-threaded recess therein the bottom wall having a slit formed therein, said fill member, comprising

a body having a blunt-nosed forward tube section,

said body having a laterally extending plunger pusher section disposed rearwardly of the blunt-nosed forward end of said forward tube section,

and spacer means having an effective stop shoulder surface facing toward the forward blunt-nosed end of said forward tube section and spaced between said plunger pusher section and said stop shoulder surface and engageable with said plunger bottom wall when said forward tube section is inserted in said slit to space said pusher section rearwardly of the effective rear surface of said plunger,

and a longitudinal vent recess extending past said stop shoulder surface.

54. A male fill member according to claim 54,

said spacer means comprising a plurality of longitudinally ribs formed along an extent of said tube section between said pusher section and said stop shoulder surface.

55. A male fill member according to claim 54,

said body having means thereon for connection thereof to a source of liquid for filling therethrough.

56. A slidable plunger for a dispenser, comprising

a cup-shaped body of elastic material having formed on its longitudinal external surface a plurality of annular sealing rings with an annular groove therebetween,

said cup-shaped body having an internal securing section and a forwardly and inwardly tapered internal bottom surface,

and a self-sealing slit formed in said conically tapered bottom.

57. A slidable plunger according to claim 56,

said internal securing section comprising a female threaded section.

58. A slidable plunger according to claim 56,

said slit extending fully across said bottom.

59. A slidable plunger according to claim 58,

said slit extending through a portion of said tapered bottom surface.