Abstract: An injection device for injection of set doses of medicine from a cartridge has a nut that is screwed up along a threaded piston rod during a dose setting operation. The nut is screwed along the piston rod by rotating a dose setting member. A rotational coupling mechanism includes an axially displaceable coupling member which is rotated as a function of axial displacement. During dose setting, the nut is allowed to rotate relative to the coupling member. During injection, the coupling member is rotationally locked to the nut. This provides a dose setting and injection mechanism wherein the nut member is both rotated during dose setting and during injection.

Abstract: A hand-held remote for a medical fluid injector includes a syringe and a conduit which may be coupled to a pressure transducer on a control circuit of the injector. Movement of a plunger within a syringe body on the syringe creates a pressure which is sensed by the pressure transducer and the control circuit responds to the sensed pressure by causing fluid to be ejected from, or drawn into, a syringe mounted to the injector. The pressure developed by the remote provides tactile feedback to an operator for improved control over injections.

Abstract: The perivascular leak repair system, and method of using the same, of the present invention provides a sealant reservoir 102 with a repair catheter 104 operably attached; a flow control device 106 disposed between the sealant reservoir 102 and the repair catheter 104, and the flow control device 106 responsive to a flow control signal 108; a heart phase detector 114 generating a diastole phase signal 112; an injection switch 122 generating a injection signal 120; and a flow controller 110 responsive to the diastole phase signal 112 and the injection signal 120, and generating the flow control signal 108. A method of sealing a perivascular leak comprises identifying the perivascular leak 140; inserting a repair catheter to the perivascular leak 142; injecting sealant at the perivascular leak 144; and removing the repair catheter 146. The sealant can be injected when the heart is in diastole to sweep the sealant into the perivascular leak.

Abstract: An injection device for dispensing a dose of a substance, the device including a housing, a dispensing element which can be displaced relative to the housing and a locking element which can be coupled with the dispensing element during or after a substance dispensing operation so that after the dispensing element has effected a dispensing operation once, it can no longer be operated to dispense another dose, and a method of locking an injection device after a substance has been dispensed once, whereby a dispensing element operated to dispense the substance is locked or blocked before, during or after dispensing a set dose so that no more substance can be dispensed.

Abstract: The invention relates to a medical bag which is intended for the infusion of a medicament by means of gravity. The inventive bag comprises: at least two compartments, namely a first compartment (1) containing a medicament in the form of a solution and a second compartment (2) containing a rinsing solution; and means for separating/communicating the compartments, which prevent the rinsing solution from automatically entering the medicament compartment except at the end of the infusion period. The rinsing solution ends the infusion, by rinsing the medicament bag and the infusion line, such as to prevent any risk of contamination or leakage of residual medicament from the bag or line.

Abstract: A dosage device has a hollow barrel and a plunger slidable within the barrel, and a plurality of formations provided on the barrel and plunger and cooperating with one another to produce a sound signal and a pointed impulse, which corresponds to a predetermined dosage of fluid drawn into or displaced from the barrel. At least one of the barrel and plunger formations which are made of flexible material is configured to have a plurality of spaced-apart segments shaped and dimensioned to improve the quality of the sound signal.

Abstract: Apparatus for sealing a puncture communicating with a blood vessel includes a porous carrier formed from lyophilized hydrogel or other material. The plug may include at least first and second hydrogel precursors and a pH adjusting agent carried by the porous carrier in an unreactive state prior to exposure to an aqueous physiological environment. Once exposed to bodily fluids, the carrier expands as the lyophilized material hydrates to enhance and facilitate rapid hemostasis of the puncture. When the plug is placed into the puncture, the natural wetting of the plug by bodily fluids (e.g., blood) causes the first and second precursors to react and cross-link into an adhesive or “sticky” hydrogel that aids in retaining the plug in place within the puncture.

Abstract: A device for the dosed administration of an injectable product, including a housing with a receptacle for the product and a drive mechanism movable via a dosing element supported displaceably in the housing, wherein the drive mechanism includes engagement elements situated together in groups, the distance between the groups corresponding to a dosing amount of the injectable product and the distance between the engagement elements corresponding to a priming amount of the injectable product, and wherein the dosing element is coupled to the drive mechanism so that the dosing element at one time interacts with a group of engagement elements to administer the dosing amount and at another time interacts with an engagement element to release the priming amount.

Abstract: The invention relates to a medical bag which is intended for the infusion of a medicament by means of gravity. The inventive bag comprises: at least two compartments, namely a first compartment (1) containing a medicament in the form of a solution and a second compartment (2) containing a rinsing solution; and means for separating/communicating the compartments, which prevent the rinsing solution from automatically entering the medicament compartment except at the end of the infusion period. The rinsing solution ends the infusion, by rinsing the medicament bag and the infusion line, such as to prevent any risk of contamination or leakage of residual medicament from the bag or line.

Abstract: A dosing mechanism for use with an injection device to adjust a dose to be discharged from the injection device, the dosing mechanism including an adjusting element which can be moved relative to the dosing mechanism and including a coupling element for being releaseably coupled to a threaded bar associated with the injection device such that the adjusting element can be moved relative to the bar in one direction while a relative movement in the opposite direction is prevented, the dosing mechanism further including a retaining element with an engaging element for preventing the bar from being rotated in at least one direction, and a releasing element for uncoupling the adjusting element and bar.

Abstract: An injection device for injecting selectable amounts of a substance includes an activating mechanism including an axially moveable operating button which can rotated in a resting position only, a tubular drive element non-rotatably connected to the operating button, an axially fixed and non-rotatable guiding element, and an axially moveable driven member held non-rotatably in the device. A rotational grid is operationally between rotatable and non-rotatable components of the injection device such that the operating button can be moved two rotational directions when in the resting position whereby a selected amount of the substance to be injected can be selectively varied. For example, a dosage inadvertently selected too large by rotating the operating button too far in one direction can, in accordance with the present invention, be reduced by rotating the operating button in the opposite direction.

Abstract: An administering apparatus including a casing, a reservoir, a piston accommodated in the reservoir such that it can be shifted in an advancing direction, a piston rod which acts on the piston in the advancing direction and forms a first locking mechanism, a second locking mechanism which cannot be moved counter to the advancing direction, a lock element row formed by successively arranged first locking elements, extending in the advancing direction, and formed by one of the locking mechanisms, and a second lock element formed by the other locking mechanism and engaged with the lock element row, wherein it engages with a lock element gap of the lock element row, wherein the second lock element is moved out of engagement by a movement, against an elasticity force, of the piston rod in the advancing direction, but, when engaged, counteracts a movement of the piston rod counter to the advancing direction with a resistance force greater than the elasticity force to prevent the piston rod from moving counter to the

Abstract: A positive displacement flush syringe includes a barrel having a chamber for retaining fluid and an elongate tip extending distally therefrom having a passageway therethrough in fluid communication with the chamber. A plunger having a stopper which is slidably positioned in said chamber for driving fluid out of the chamber by movement of the stopper relative to the barrel is provided. Further, structure is provided to move fluid distally in the passageway after fluid has been delivered from the chamber and the stopper is in contact with the distal wall of the chamber.

Abstract: An injection device for administering a liquid product, the device including a drive mechanism, an engaging member and a catch including a number of latching elements, wherein at least one of the engaging member and the number of latching elements is relatively moveable to the other to generate a haptic and/or acoustic signal comprising a number of discrete signals during a relative movement, wherein one of the catch and the engaging member is coupled to the drive mechanism and the drive mechanism generates a variable drive speed during the relative movement, and wherein the latching elements are a distance (x0; x0??x) from each other such that a time interval between each of the number of discrete signals is constant. A method for generating a haptic and/or acoustic signal in use of an injection device is encompassed.

Abstract: Aspects of the present invention concern the discovery of a transdermal delivery composition that can deliver low, medium and high molecular weight pharmaceuticals and cosmetic agents. Embodiments include transdermal delivery compositions with therapeutic and cosmetic application, transdermal delivery devices for providing said transdermal delivery compositions to subjects in need thereof, and methods of making and using of the foregoing.

Abstract: A dosage device has a hollow barrel and a plunger slidable within the barrel, and a plurality of formations provided on the barrel and plunger and cooperating with one another to produce a sound signal, which corresponds to a predetermined dosage of fluid drawn into or displaced from the barrel. At least one of the barrel and plunger formations is configured to have a plurality of spaced-apart segments shaped and dimensioned to improve the quality of the sound signal.

Abstract: A threaded syringe provides a mechanism by which a clinician can deliver a viscous fluid through a relatively small lumen and can obtain tactile or audible feedback of delivery. The threaded syringe allows for delivery of more viscous fluids with less force and/or allows for more controlled delivery. The syringe includes a syringe barrel and a sliding member positioned on the proximal end of the syringe barrel. The sliding member has a first threaded hole and a second hole. The sliding member is slidable on the syringe barrel between a first position at which the first threaded hole is aligned with the syringe barrel for precise delivery of a material from the syringe and a second position at which the second hole is aligned with the syringe barrel for filling of the syringe or to stop bleed out.

Abstract: An injection device made up from a housing, a dose setting and injection mechanism, a dose setting member and an injection button is described. The dose setting and injection mechanism is made as a preassembled unit insertable into the housing. Both the dose setting member and the injection button is thereafter connected to the preassembled dose setting and injection mechanism inside the boundaries of the housing, while being accessible for a user from outside the housing. The same preassembled dose setting and injection mechanism can fit into a large variety of different houses making production of different variants of an injection device somewhat easier.

Abstract: A syringe assembly includes a barrel having a chamber for retaining fluid. The barrel has an open proximal end, a distal end and an elongated tip extending from the distal end having a passageway therethrough in fluid communication with the chamber. The tip has a diameter at its distal end of less than about 3.8 mm and a side wall tapered proximally outwardly at a taper of from 4% to 8%. A plunger rod includes an elongated body portion having a proximal end, a distal end and a stopper at the distal end. The stopper is slidably positioned in fluid-tight engagement in the barrel. An elongated projection extending distally from the distal end of the plunger rod is shaped to fit within the passageway of the elongated tip. Structure is provided for preventing proximal motion of the plunger rod with respect to the barrel after distal motion of the stopper to expel fluid through the passageway.

Abstract: An applicator gun for spraying a medically useful multiple component fluid to an area of interest. The handheld applicator gun functionally receives a commercially available or standardized multi-syringe applicator, and dispenses fluid from the multi-syringe applicator in a controllable manner. The handheld applicator gun further includes a return stop and a dispensing stop to limit the force exerted on the multi-syringe applicator.

Abstract: A safety syringe comprises a barrel having a retaining block disposed in the receiving hole, an initial stop portion and a final stop portion disposed in the end edge thereof, and a rotation resisting portion; a needle holder disposed in the barrel, and having a retaining groove and communicating with a port, a rotation stopping rod corresponding between the initial stop portion and the final stop portion of the barrel, overcoming portion capable of passing the rotation resisting portion of the barrel; and a plunger capable of catching and turning the needle holder. As the plunger is not engaged with the needle holder, the retaining groove of the needle holder confines the retaining block of the barrel.

Abstract: A system for automatically metering a predetermined dosage of a medicament from a cartridge. The system includes a tubular cartridge containing the medicament and a plunger which is movable in the cartridge to dispense the medicament through one end. The cartridge further includes an interior tab (e.g. a ring) for stopping forward movement of a detent carried by the trigger of a syringe body in which the cartridge is positioned. By limiting forward movement of the detent, forward movement of the plunger rod is also stopped, thereby controlling the amount of medicament dispensed from the cartridge.

Abstract: A device is provided for taking swab samples and sample dilution. The device has a plug made of a porous, absorbent material, which projects from a sleeve and is used to take a swab sample. The plug is located in one end of the sleeve. A piston, which can be moved in the sleeve by means of a piston rod, is located in the other end of the sleeve. A closure, which can be opened by means of pressure, is located between the piston and the plug, so that a liquid arranged between the piston and the plug moves through the closure to the plug and wets same on actuation of the piston rod.

Abstract: A medication delivery pen having a repeat-dose feature that is performed by using a pull-push operation. In particular, the medication delivery pen includes means for whether the medication delivery pen is armed and a variety of novel drive mechanisms. In addition, the medication delivery pen also includes a priming control mechanism that allows the user to easily prime medication delivery pen prior to arming the pen.

Abstract: A syringe assembly comprises a barrel having an inside surface describing a chamber for retaining fluid. The barrel includes an open proximal end and a distal end with an elongated tip extending therefrom having a passageway therethrough in fluid communication with the chamber. A plunger rod includes an elongated body portion having a proximal end, a distal end and a stopper at the distal end. The stopper is slidably positioned in fluid-tight engagement within the barrel. An elongated projection extends distally outwardly from the distal end of the plunger rod. The elongated projection is shaped to fit within the passageway of elongated tip. Structure is provided to prevent the removal of a needle assembly from the elongated tip of the syringe barrel. A locking element is provided to prevent the proximal motion of the plunger rod with respect to the barrel after initial distal motion of the stopper to expel fluid from the syringe barrel.

Abstract: A medication delivery pen having a repeat-dose feature that is performed by using a pull-push operation. In particular, the medication delivery pen includes means for determining whether the medication delivery pen is armed and a variety of novel drive mechanisms. In addition, the medication delivery pen also includes a priming control mechanism that allows the user to easily prime medication delivery pen prior to arming the pen.

Abstract: A locking syringe is disclosed which comprises a plunger, a cylinder, and a locking member for preventing the syringe to be used more than one time. The plunger includes an indention near its upper end into which a plunger locking member fits when the plunger is pushed and approaches the lower end of the cylinder to administer injections or remove bodily fluids and prevents re-use of the syringe by preventing removal of the plunger from the cylinder after the syringe has been used. The cylinder comprises an open cylindrical passage and includes a needle attached in a conventional manner at the end thereof.

Abstract: A cartridge-type syringe in which a cartridge, having liquid medicine or the like sealed therein, is inserted in a holder having a discharge needle at its distal end, and the cartridge is advanced to cause the discharge needle to pierce it, thereby injecting the liquid medicine or the like into an object, and when a piston rod of the cartridge is pushed to cause the discharge needle to pierce, the liquid medicine or the like will not be discharged in error in a large amount. In particular, there is provided a releaseable lock mechanism by which when a piston rod 15 is pushed, the piston rod 15 advances together with a tubular body 11 of a cartridge 10 without moving a piston 14 within the tubular body 11.

Abstract: A control syringe is provided for fine needle aspiration of biopsy tissue. An aperture through the barrel of the syringe is located at a rearward position of the barrel. A low pressure created in the barrel by withdrawing the plunger is broken by withdrawing the plunger past the aperture. Thereafter, the plunger may be pushed forward of the aperture so that collected tissue may be discharged by moving the plunger forward. A detent attached to the plunger holds the plunger in its rearward position until released. The detent comprises a plastic member with an outwardly biased shoulder for engaging the rearward end of the barrel. Such a detent is released by pressing it towards the plunger.

Abstract: A syringe instrument for particular use in medical balloon inflation procedures comprises a fluid chamber and a plunger arranged to displace fluid from the chamber for delivery to inflate the balloon, and incorporates control structure arranged to provide a series of releasible space limits for respective displacements of the plunger within the chamber. The control structure allows the fluid in the chamber to be pressurized at selective predetermined pressure levels governed by the releasable limits for the plunger displacements. A reverse drive structure is provided for reverse-displacement of the plunger from the fluid chamber to enable self-aspiration of fluid into the chamber from the balloon in order to simplify balloon deflation and removal from the patient. The reverse drive structure is manually activated with the same hand which depresses the plunger, for single handed operation of both the forward and reverse plunger motions.

Abstract: A cartridge-type syringe in which a cartridge, having liquid medicine or the like sealed therein, is inserted in a holder having a discharge needle at its distal end, and the cartridge is advanced to cause the discharge needle to pierce it, thereby injecting the liquid medicine or the like into an object, and when a piston rod of the cartridge is pushed to cause the discharge needle to pierce, the liquid medicine or the like will not be discharged in error in a large amount.In particular there is provided a releaseable lock mechanism by which when a piston rod 15 is pushed, the piston rod 15 advances together with a tubular body 11 of a cartridge 10 without moving a piston 14 within the tubular body 11.

Abstract: A device having a manually operable plunger slidably mounted within a container for orally administering liquid. The plunger operates to administer the liquid through an outlet, which is at least partially surrounded by a radially extending shield.

Abstract: The dual chamber syringe is employed for collecting blood samples. The syringe includes a plunger which is connected to a first piston which, in turn, is connected via a string to a second piston. A passageway is formed in the wall of the syringe barrel to communicate the duct at the forward end of the barrel with the chamber between the two pistons. Thus, upon withdrawal of the plunger from a barrel, fluid flows into the chamber created between the two pistons. Subsequent movement of the two pistons in unison causes a whole blood sample to be drawn into the foremost chamber within the barrel. The syringe can be subsequently connected with a vacutainer via a needle assembly so as to discharge the whole blood sample into the vacutainer for subsequent testing procedures. The discard fluid can be separately dispensed into another container.

Abstract: The present invention provides an improvement in injection syringes by providing for an end of dose indicator which is operatively associated with the dose knob of an injection syringe. The instant end of dose indicator works by providing a sound as an indication that the complete dose has been administered.

Abstract: A flexible, kink-resistant, introducer sheath for percutaneous vascular access. The introducer sheath includes a flat wire coil with uniform spacing between the turns, which is compression fitted about an inner, lubricous material polytetrafluoroethylene tube. The introducer sheath further includes an outer tube of a heat formable polyamide material which is heat formed and compressed through the spaces between the turns of the wire coil to mechanically connect to the roughened outer surface of the inner tube. The distal end of the outer tube is tapered in a mold with additional polyamide outer tube material. The proximal end of the sheath is flared for connection to a connector fitting. In another aspect of the introducer sheath, the flat wire coil has an inner diameter less than the outer diameter of the inner tube. The coil is then expanded and wrapped around the inner tube to form a compression fit.

Abstract: A syringe for controlling the amount of material or medical fluid in a syringe body which is expelled therefrom upon depression of a plunger in the syringe body. The syringe includes a syringe body having a chamber and a discharge end portion and an open opposite end portion, with a plunger received in the syringe body. A measuring ring having an inner thread in mesh with an outer thread on the plunger, with latch means for setting and holding the measuring ring and plunger and thus, permit an exact volume to be expelled from said chamber.

Abstract: A hypodermic syringe apparatus having a plunger with first and second sets of grooves, and a casing having first and second lock members, such that when the plunger is fully inserted or reinserted into the casing, the plunger is prevented from being withdrawn relative to the casing. The first and second sets of grooves of the plunger have stepped portions, such that the plunger can be withdrawn relative to the casing when the plunger is positioned (position A) in such a way that the first set of grooves interacts with the first lock member of the casing; and such that the plunger can be inserted or reinserted into the casing when the plunger is positioned (position B) in such a way that the second set of grooves interacts with the second lock member of the casing.

Abstract: A syringe for metering fluid in which a plunger contains a plurality of stop surfaces which contact a stop on a syringe tube. The stop surfaces are linearly displaced from each other along a longitudinal axis of the plunger by distances corresponding to predetermined volumes of fluid to be metered. The stop surfaces are also angularly displaced about the longitudinal axis of the plunger so that incremental rotation of the plunger permits successive stop surfaces to limit plunger motion, thereby effecting a precise metering of the fluid.

Abstract: A medication dispensing apparatus comprising a liquid container having an open end and a cap assembly engagably removable from the open end of the container. The cap assembly comprises an external cap having a lower end, an inner fixing element adapted to be fitted into the open end of the liquid container and connected to the lower end of the external cap. The cap assembly further comprises a dropper connected through the inner fixing element and having a fluid passageway and activation element for aspirating liquid from the container into the dropper.

Abstract: Hypodermic syringe with a blockable piston capable of preventing it recharge and reuse, comprising a cylindrical tubular body having a communicating container in its inlet end; a right-angled section piston rod; a first blocking means constituted by at least one member placed in abutment against rotation over the container bottom and opposed alternatively to on and the other of toothed intermediate sections of the piston rod; and a second blocking means slidingly mounted over the piston rod, placed in abutment with the first blocking means and urged in positional fastening by an elastic retention member constituting in turn, the lid of the container.

Abstract: A dosing assembly (80) is used to controllably fill a syringe (4), held within a syringe holder (50), from a vial (2) of the type including a piston (18) mounted within a container (14). The syringe holder (50) is threadably mounted (52, 36) to the vial with the needle cannula (72) piercing the piston to permit the syringe holder to be driven against the piston in a controlled manner to accurately meter the pharmaceutical introduced into the syringe. The dosing assembly includes a rotary drive (82, 88, 110, 118, 126) which rotates the syringe holder about the syringe holder axis, thus driving the syringe against the piston, as the syringe holder and syringe therewith are rotated about an axis situated 90.degree. from the syringe axis. This causes the pharmaceutical within the vial to be forced through the needle cannula and into the syringe; the amount of the dose in the syringe depends upon how far the user rotates the syringe holder using the rotary drive.

Abstract: A single-use, hypodermic syringe which disables itself during its initial application thereby preventing any subsequent use of the syringe. The working parts of the invention are designed to separate automatically when the syringe is oriented into the solution dispensing mode. These separated parts prevent subsequent aspiration of solutions into the syringe thereby rendering the syringe inoperable and unuseable after its initial use.

Abstract: A non-rechargeable, disposable hypodermic syringe for use with a needle includes a barrel, a retaining ring, and a plunger. The plunger has at least one annular notch formed therein. The barrel has at least one internal inwardly-flared tab formed therein which is oriented towards the forward end of the barrel. The tab is inwardly-biased, so that during rearward movement of the plunger, after delivery of the substance therein, the tab is received in the notch for annularly engaging in the notch, preventing the plunger's continued rearward movement and preventing the recharging of the syringe. In this manner, the syringe cannot be reused. The retaining ring is circumferentially disposed in the barrel between the plunger and the barrel. Cooperating ratchet teeth between the plunger and the ring coordinate the forward movement of the plunger with the ring, permitting the initial filling and aspiration of the syringe.

Abstract: A hypodermic syringe is provided which comprises a hollow barrel, a longitudinally slidable and axially rotatable plunger shaft, a sealing means, e.g., a self-resealing rubber cap or sealing gasket, and an integrally-joined cover which includes (i) a charging positioning means for longitudinally moving the shaft within the barrel, (ii) axial rotational means for rotating the shaft of about 180.degree. to a plurality of discharge positions, and (iii) discharging positioning means for longitudinally moving the shaft within the barrel. The hypodermic syringe can only be used once to inject a patient or user with a liquid.

Abstract: A disposable syringe for dispensing a metered dosage of a material includes a plunger rod which is axially movable within a syringe barrel for dispensing the material. The plunger rod includes a rail section located axially outside the syringe barrel, and a slidable stop member is secured to the rail section for adjusting the volume of material to be dispensed. The adjustable stop member includes a knife edge for embedding into a surface of the rail section of the plunger rod to lock the stop member in a desired position.

Abstract: The piston stem (6) of the non-reusable syringe carries radial ribs (7, 9) having a saw-tooth profile (20, 21) cooperating with a stop (19) fixed to the inner wall of the syringe body, for allowing the piston (1) to be moved in one direction only, so that the syringe can be used only once.

Abstract: An apparatus for dispensing a controlled dose of a liquid fluid such as a liquid medication includes a dispenser head which is snugly fitted over the needle-shaped end of a syringe filled with the liquid pharmaceutical and including a piston in fully retracted or drawn position. The syringe with its fully drawn piston is completely encased and protected by a tube which is connected to the dispenser head.

Abstract: In a discharging apparatus (1) for in particular a single use, the complete pump stroke (11) to be performed only once is subdivided into at least two partial strokes (12,13) by a limiting device (24) which, for the end of each partial stroke, has a stop (25) to be overcome in the manner of a resilient detent. All parts of the limiting device (24) are located in such a way that the guidance of pump piston (6) on thrust piston pump (4) on the piston running path (7) is in no way impaired. At the end of the last partial stroke (13) the pump cylinder (5) mountable as a separate vessel on pump piston (6) is positively locked with respect to the remaining discharging apparatus (1) by a removal preventing means (40), so that the interior of pump cylinder (5) is no longer accessible.

Abstract: The present invention resides in an improvement to a syringe having a syringe housing and a plunger slidably positioned therein and extendable therefrom, and includes a novel locking member mounted on the plunger externally of the housing and angularly movable thereon between a first position in which the locking member can move longitudinally along the plunger and a second position in which the locking member becomes engaged with the plunger to hold the members together in fixed condition for movement in concert. The locking member is also shaped to move into abutment with the syringe housing where the plunger is moved to limit movement of the plunger when in its locked position.

Abstract: A single use disposable medical syringe with the plunger shaft having first and second splines. The first spling co-acts with a first pawl to allow withdrawal only of the plunger. The plunger is then rotated to another position, wherein the second spline co-acts with a second pawl to permit insertion only of the plunger. The plunger may not then be withdrawn for re-use.