Abstract: A sensor insertion device comprises a lower case and an upper case. A base holder and a needle holder are disposed in the lower case. A needle holder raising mechanism is disposed above the needle holder. A sensor base having a sensor unit is held by the base holder. When the upper case is pushed down, the base holder and the needle holder move toward an opening on the lower surface side of the lower case, and the needle holder is raised by the needle holder raising mechanism. A protrusion that holds the upper case on the lower case is provided to the upper case in a state in which the upper case has been pushed down until the opening on the lower surface side comes into contact with the skin.

Abstract: A system for injecting includes a cartridge body defining a proximal opening and a distal needle interface. The system also includes a plunger member defining a plunger interior and configured to be manually manipulated to insert a stopper member relative to the cartridge body. The plunger member includes a needle retention feature disposed in the plunger interior, an energy-storage member disposed in the plunger interior, and an energy-storage member latching member disposed in the plunger interior. The system further includes a needle hub assembly coupled to the distal needle interface of the cartridge body. The needle assembly includes a needle having a needle proximal end feature, a hub, and a needle latching member configured to couple the needle to the hub. The needle is retractable into plunger interior upon manipulation of the plunger member to actuate the energy-storage member latching member.

Abstract: Described is an actuation mechanism for a medicament delivery device having a needle with a distal tip. The actuation mechanism comprises an outer sleeve telescopically relative to the delivery device and an inner sleeve telescopically arranged relative to the outer sleeve. The outer sleeve is axially translatable relative to the delivery device, and the inner sleeve is axially translatable relative to the outer sleeve. In a first state, the inner sleeve protrudes distally from the outer sleeve and the outer sleeve protrudes distally from the delivery device. In a second state, the inner sleeve is contained within the outer sleeve. Movement of the outer sleeve proximally relative to the delivery device in the second state initiates delivery of a medicament in the delivery device.

Abstract: An aspiration and injection device is provided that can allow for ergonomic, safe, and precise aspiration of a target site and ejection of a medicament to the target site. The device can include a syringe barrel, a flange extender couplable to the barrel, and plunger that can be engaged by a hand and/or one or more finger of a user to perform aspiration and injection at a target site.

Abstract: There are provided a syringe filled with a resin composition and a storage method thereof. According to the syringe and the storage method, mixed air, which causes the resin composition to be intermittently discharged from the syringe, is suppressed. The syringe filled with the resin composition includes a syringe, a resin composition filling the syringe, and a plunger. The resin composition contains voids. The ratio of the volume of the voids relative to the volume of the resin composition is 1.0 ppm by volume to 520 ppm by volume. The voids have a maximum diameter of 2,500 ?m or less.

Abstract: A syringe including an injection syringe body and a syringe handle, configured to cooperate with one another in order to ensure a locking function between the injection syringe body and the syringe handle. The injection syringe body includes a longitudinal hub including at least one female or male retaining element, and a protective sheath moveable along said longitudinal hub and able to cover in a retracted position the at least one retaining element of the longitudinal hub. The syringe handle includes at least one male or female retaining element intended to cooperate with the at least one female or male retaining element of the longitudinal hub, ensuring a retaining function, the cooperation being named locking position. The syringe further includes at least one blocker, the at least one blocker ensuring a radial holding function when the retracted and the locking positions are both engaged.

Abstract: The present invention relates to an injector for preventing accidental needle sticks comprising:—a cylinder extending along a longitudinal axis, an inner wall and an outer wall, the cylinder having an outlet at an outlet end opposite an actuating end and a finger grip on the outer wall, which finger grip is positioned between the outlet end and the actuating end,—a piston having a piston body and a deformable sealing element, which deformable sealing element abuts the inner wall of the cylinder at an abutting interface and seals an annular gap between the piston body and the inner wall of the cylinder when the piston is inserted in the cylinder,—a needle guard for mounting on the outside of the cylinder from the outlet end or the actuating end, which needle guard comprises a barrel with a mounting end opposite an operating end, the barrel having a slot for receiving the finger grip of the cylinder when the needle guard is mounted on the cylinder, which slot extends from the mounting end towards the operating

Abstract: An electroporation device with a needle array removably attached thereto, the needle array having a body, a shroud movable with respect to the body between a rest position and one or more actuated positions, and an auto-lock assembly. Where the auto-lock assembly is adjustable between a locked configuration, where the shroud is not movable with respect to the body, and an unlocked configuration, where the shroud is movable with respect to the body, and where biasing the shroud from the rest position to the one or more actuated positions and back to the rest position adjusts the auto-lock from the unlocked configuration to the locked configuration.

Abstract: A pen needle assembly (10) includes a pen needle (12) with a hub body (16) having a needle shield (28) that covers a needle (26) and can be retracted to expose the needle during injection and return to the extended position after use and locked in the extended position. A spring (56) is provided to rotate the needle shield after use to a locked position. A locking member (84) can be provided on the needle shield that cooperates with the hub body (16) to prevent rotation after use. An attachment mechanism (38) for the pen needle provides a sensory indication when a needle-bearing hub body (16) is seated on a pen and limits further rotation of the pen needle relative to the delivery device.

Abstract: An injector including a syringe arranged along a longitudinal axis, a removable cover for removable engagement with the syringe and a cover removal assembly including an outer portion which is engagable by a user and is movable axially in a cover disengagement direction along an axial travel path with respect to the longitudinal axis and an inner portion which includes at least one engagement portion which is engagable with the removable cover, whereby axial movement of the inner portion in the cover disengagement direction removes the removable cover from the syringe, at least one of the outer portion and the inner portion being configured such as to provide an axially floating lost motion engagement between the outer portion and the inner portion.

Abstract: A method of securing an assembly of a drug delivery system, comprising: configuring at least a first component and a second component of the assembly in a closed configuration ready for placement into the drug delivery system; installing an assembly key including a locking element on the assembly to secure the assembly in said configuration; and, transporting the assembly with the assembly key installed.

Abstract: The invention provides a syringe assembly comprising a syringe barrel having an inside surface defining a chamber, an open proximal end, and a distal end having an opening therethrough. An elongated plunger rod extends between a first end and a second end, with a cap or guard disposed on the first end of the plunger rod. A plunger head extends within the chamber of the syringe barrel, and is adapted for slidable movement within the syringe barrel between the proximal end and the distal end, with the second end of the plunger rod connected with the plunger head through a pivotable connection. The plunger rod is adapted to pivot with respect to the plunger head between a first position in which the guard is adjacent the distal end of the syringe barrel and a second position in which the plunger rod is in general axial alignment with the syringe barrel, and is further adapted for axial movement so as to cause sliding movement of the plunger head through the syringe barrel to expel contents thereof.

Abstract: An aspiration and injection device is provided that can allow for ergonomic, safe, and precise aspiration of a target site and ejection of a medicament to the target site. The device can include a syringe barrel, a flange extender couplable to the barrel, and plunger that can be engaged by a hand and/or one or more finger of a user to perform aspiration and injection at a target site.

Abstract: A piston for use in an injector comprising a cylinder having a longitudinal axis and an inner wall, which piston has a deformable sealing element with a convex surface, which deformable sealing element when the piston is inserted in the cylinder abuts the inner wall of the cylinder at an abutting interface and seals an annular gap between the piston and the inner wall of the cylinder. The abutting interface and the deformable sealing element have axial dimensions parallel with the longitudinal axis. The ratio between the axial dimension of the abutting interface and the axial dimension of the deformable sealing element is in the range between 0.01 and 0.2. In another aspect, an injector includes the piston and is used in a disposable syringe of the piston. The piston can prevent refilling of a syringe.

Abstract: A syringe barrel including a tubular, barrel body operable to receive a syringe plunger at a proximal end thereof and a syringe needle at a distal end and sidewalls of said syringe body being flexible and elliptical in cross-section and opposing compression of said syringe barrel at opposite ends a major axis of said syringe barrel cross-section serving to operably flex the elliptical cross-section of said syringe body into a more circular cross-sectional configuration and increasing the volume of said syringe barrel body and concomitantly serving to create a relative vacuum within said syringe body as compared with the configuration of said syringe tubular, barrel body prior to application of said compression.

Abstract: The present disclosure relates to apparatus, assemblies, combinations, and methods for infusing fluids by hollow microneedles.

Abstract: A syringe holder for a motorized injection device, the syringe holder being adapted to receive a receptacle intended to contain a fluid or viscous substance, preferably a disposable refillable receptacle or a syringe, as well as being adapted to be mounted on the motorized injection device such that the motorized injection device enables a part or all of the fluid or viscous substance contained in said receptacle to be expelled. The syringe holder includes a first activator portion to control a predefined function of the motorized injection device. The syringe holder is distinguished in that it comprises a second activator portion to control said predefined function of the motorized injection device independently from the first activator portion.

Abstract: A syringe-type cosmetic container in which a push bar for moving a piston is integrally formed on an upper end of an over cap so as to provide both a sealing function of closing a discharge hole by the over cap and a function as a pressing unit that moves the piston, such that manufacturing time may be shortened and manufacturing costs may be reduced by decreasing the number of components.

Abstract: The present invention is directed to a pen-type injector equipped with a cartridge holder for a drug delivery device. The cartridge holder has a longitudinal axis and comprises a body for receiving a cartridge, wherein the body comprises at a proximal end engagement means for releasably coupling the cartridge holder to the drug delivery device, a latch member for releasably engaging a cap of the drug delivery device and an alignment element which is visual from the outer side of the body. The alignment element may be an aperture provided in the body and/or a lug which forms the latch member.

Abstract: A fluid injection device having a syringe body, a needle, and a needle protection device removable from the injection device and having a substantially flexible or deformable inner body and a substantially rigid outer body. In the stored position the inner body closes the dispenser orifice of the needle and the outer body co-operates with the injection device to fasten the protection device on the injection device. The protection device includes a protection system against accidental pricking, having protective flaps that are integral part of the outer body and movable between a covering position in which they cover the needle, and an open position in which the needle is uncovered. The protection system has a control ring that slides over the outer body so as to move the flaps from their covering position to their open position, before injection, and from their open position to their covering position, after injection.

Abstract: A protective sheath (100) for a cannula (210) arranged on a hub (200) which can be fitted onto a syringe (300), the sheath including female elements intended to cooperate with male elements (201) of the hub (200) for guiding thereof, and characterized in that the female elements include a retracted position before use RBU, a retracted position during use RU, and a retracted position after use RAU, wherein the whole length of the cannula (210) is inside the sheath (100), the female elements further include an ejection position E, wherein whole or part of the cannula (210) protrudes out of the sheath (100), and further characterized in that at least two of the RBU, RU, and RAU positions are substantially transversally aligned.

Abstract: A self-injection device (100, 200), including a pen body (108, 208) connectable to a pen needle (10), and a cap (104, 204) selectively connectable to the pen body (108, 208) in a first orientation with respect to the pen body (108, 208) to minimize the length or volume of the self injection device (100, 200), and in a second orientation to provide sufficient length or volume in an interior of the cap (104, 204) to house a pen needle (10) connected to the pen body (108, 208).

Abstract: A piston for use in an injector comprising a cylinder having a longitudinal axis and an inner wall, which piston has a deformable sealing element with a convex surface, which deformable sealing element when the piston is inserted in the cylinder abuts the inner wall of the cylinder at an abutting interface and seals an annular gap between the piston and the inner wall of the cylinder. The abutting interface and the deformable sealing element have axial dimensions parallel with the longitudinal axis. The ratio between the axial dimension of the abutting interface and the axial dimension of the deformable sealing element is in the range between 0.01 and 0.2. In another aspect, an injector includes the piston and is used in a disposable syringe of the piston. The piston can prevent refilling of a syringe.

Abstract: This disclosure relates to medical fluid delivery sets and related systems and methods. In some aspects of the invention, a medical fluid delivery set includes a syringe connected to a series of interconnected fluid lines. The syringe includes a medical fluid containment cylinder and a plunger assembly that can be axially moved relative to the medical fluid containment cylinder. The plunger assembly includes an inner plunger shaft including a seal that is slidably disposed within the medical fluid containment cylinder and an outer plunger shaft that at least partially surrounds the inner plunger shaft to form a space between an outer surface of the inner plunger shaft and an inner surface of the outer plunger shaft that is sized to receive a wall of the medical fluid containment cylinder therein.

Abstract: A pre-fill syringe with a receiver tube (1, 12, 21) with a nozzle (4, 20) positioned at the nozzle-side end of the receiving tube (1, 12, 21), the piston (2, 18) is to be formed in such a manner that it for a transport state at the nozzle-side end of the receiver tube (1, 12, 21) can be connected with the receiving tube.

Abstract: A syringe assembly including: (1) a syringe barrel defining a chamber; (2) a plunger mounted in the chamber and moveable with respect to the barrel; and (3) a cap holder assembly containing a cap and an absorbent material removably attached to the syringe.

Abstract: A needle assembly has distal and proximal ends. The needle assembly comprises a body element having distal and proximal ends, an attachment means configured to be attached to a medication delivery device, a button element which is movable from a first position to a second position, and a needle configured to move to the distal direction, when the button element is moved from the first position to the second position.

Abstract: A syringe having an integral ampule is disclosed. The syringe includes a barrel defining a reservoir configured to store a fluid and a plunger defining an inner cavity. The plunger includes an ampule within the inner cavity, where the ampule seals the fluid. The plunger also includes a cap at a proximal end of the plunger that is configured to move distally relative to the plunger, and a first one-way valve at the distal end of the plunger. The distal movement of the cap relative to the plunger causes an opening within the ampule. A method of injecting a fluid within a patient using a syringe having an integral ampule is also disclosed.

Abstract: According to the invention, an injection device (D) comprises a pre-filled syringe and a safety device. The pre-filled syringe comprises a barrel with an inner cavity in fluid communication with a hypodermic needle attached to a distal end of the pre-filled syringe and a piston fluid-tightly sealing a proximal end of the inner cavity. The safety device comprises a support body for retaining the pre-filled syringe therein, an outer body operably connected to the piston, a needle shield and a releasable retaining means (R). The retaining means comprises a radial projection and a longitudinal recess adapted to receive the radial projection. The radial projection is connected to or integral part of one of the support body or the outer body and a longitudinal recess formed into the other of the support body or the outer body. The needle shield, the support body and the outer body are telescopable relative to each other.

Abstract: A steroid delivery system including a mixing syringe having a first chamber and a second chamber and at least one hypodermic needle is provided. The first chamber of the mixing syringe contains a pre-measured volume of a local anesthetic and the second chamber contains a pre-measured volume of a corticosteroid. An improved mixing syringe and a method for treating pain using the steroid delivery system of the present invention is also provided herein. The improved syringe achieves mixing without the introduction or elimination of air and without puncturing or rupturing of a membrane, diaphragm or other material. The kit concept improves the speed of the procedure, sterility, accuracy of dosing, and immediate availability of disparate items to implement the procedure in a variety of medical practice settings.

Abstract: A portable medicament dispensing device having a mechanism which is not susceptible in jamming for dispensing the medication to a user. The device employs employs a coupling for coupling the relative motion between reciprocating body members housing the ancillary components and a barrel plunger associated with the syringe. One embodiment provides a pivoting coupling whereas an alternate uses a rack and pinion system. The advantage of simplifying such mechanisms results in a structure which has smooth unemcumbered motion with fewer parts to avoid mechanical jamming during use.

Abstract: The invention resides in a hand-held medicament delivery device which comprises a housing containing a first electrical circuit and a battery, a medicament delivery mechanism, and a protective cap releasably securable to the housing. The housing also includes a contactless switch and the cap a switch actuator. The switch is operable between an on state in which the first electrical circuit is connected to the battery and an off state in which the first electrical circuit is disconnected from the battery. The invention also resides in a method of controlling power in a hand held medicament delivery device comprising the steps of actuating a contactless switch in the housing by an actuator in a housing cap when the switch and actuator are in proximity, the actuation of the switch signalling to a microprocessor that the cap is on the housing, detecting the status of the device by the microprocessor, and only if the microprocessor determines the device is inactive, powering down the device.

Abstract: An injection device for aesthetic medicine, for administering a fluid material beneath the skin of a person by means of a syringe. The injection device includes a motor system with a motor configured to drive a first piston, and at least a syringe cover adapted to be mounted on the motor system and to accommodate a syringe comprising at least a syringe barrel for accommodating the filling material, a syringe needle and a second piston located in the syringe and drivable by the first piston for ejecting a quantity of fluid material out of the syringe. The motor system is cable-free and electrically actuated.

Abstract: A safety device having a tubular support for a needle mount end and a protective shield slidably mounted on the support from a set position, a retracted position and then to a locked position to covers the needle. A locking member mounted on the support, within the shield and a cam follower is engaged with a cam profile on the locking member. Forward axial movement of the support relative to the locking member causes the locking member to rotate relative to the support. The shield has a guide defining a shoulder towards its rearward end and an abutment on the locking member is receivable behind the shoulder when the shield is in its locked position. A spring acts such that when the locking member is turned to engage its abutment with the shoulder of the shield when the latter is in its locked position, so preventing subsequent rearward movement thereof.

Abstract: An injection device is provided. The device includes a housing having a first end defining a first opening. A plunger is received within the first opening of the housing to move between first and second positions. A cartridge is disposed in the housing and has an interior serving as a reservoir for a drug. A delivery needle is disposed within the housing and is in fluid communication with the reservoir via an interruptible fluid channel. A locking mechanism is disposed in the housing. In the first position of the plunger the delivery needle is enclosed by the plunger and in the second position of the plunger the delivery needle is placed in an injection position and the plunger activates the locking mechanism whereby when the plunger returns to the first position the locking mechanism prevents the needle from being placed in the injection position.

Abstract: A fluid syringe of the type used with fluid infusion devices is presented here. The fluid syringe generally includes a barrel, a piston, and a check valve seal. The barrel has an interior wall and a sealed main fluid chamber. The piston is slidably coupled within the barrel, and the piston has a piston seal forming an interference fluid seal against the interior wall. The check valve seal is coupled to the piston, and it is located between the piston seal and the main fluid chamber. The check valve seal forms an interference fluid seal against the interior wall when the piston is unloaded, and it disengages the interior wall to allow gas flow from the main fluid chamber toward the piston seal when the piston is loaded.

Abstract: The present invention concerns a prefilled injection device having a container and a dose setting mechanism encapsulated inside the housing. The housing is made from two parts which are locked together by a bayonet coupling: In addition to the bayonet coupling, the two parts are also provided with irreversible locking means locking the two parts permanently together.

Abstract: A cannula (1) for dispensing fluid products, particularly for vaginal and rectal applications, comprises: a tubular body (2) for containing a fluid product (P), having a first extremity (2a), at which a dispenser opening (3) is formed, and a second open extremity (2b), opposed to the first extremity (2a). A closing body (5) which is associable with the tubular body (2) to close the second extremity (2b). The closing body comprises a first element (6) at least partially insertable through the second extremity (2b) and suitable for acting as a sliding piston inside the tubular body (2), and a second annular body, that functions a tamper indication seal. A cover cap (4) which can be fitted on the tubular body (2) to close the dispenser opening (3) and which is made in a single body piece. Longitudinal score lines divide the cover cap into a plurality of first sections and a single second section. Fold lines extend longitudinally along the first sections.

Abstract: A device for administering a liquid preparation comprising a pharmaceutical agent, particularly a contrast agent, in the form of a bolus. The device comprises in particular a core cylinder and an external cylinder, the core cylinder comprising a conduit (107) and a cylindrical reservoir (108) cooperating with a respective plunger (109), wherein the plunger is modified in order to operatively engage with guiding means (300) provided on the external cylinder.

Abstract: The invention relates to an injection device (1, 100) configured to perform automatic priming upon removal of a protective cap (15, 115) from a cap receiving portion (9, 109) of a housing (2, 102). When mounted on the injection device (1, 100) the cap (15, 115) defines a first position for a drive member (10, 110) relative to the housing (2, 102), which drive member (10, 110) is capable of causing a piston rod (7, 107) to advance a piston (8, 108) in a reservoir (4, 104). Means (13, 120) are provided defining a second position for the drive member (10, 110) relative to the housing (2, 102). During removal of the cap (15, 115) from the cap receiving portion (9, 109) the drive member (10, 110) moves from the first position to the second position under the influence of a spring (11, 111), thereby causing the piston rod (7, 107) to pressurise the reservoir (4, 104).

Abstract: This document discloses, among other things, an air-powered auto-injector device for subcutaneous delivery of a rescue drug. The device is configured for self-administered treatment of anaphylactic shock. Air is compressed by relative movement of a piston and a cylinder and released to subcutaneously drive an hypodermic needle.

Abstract: An injection device is provided. The device includes a housing having a first end defining a first opening. A plunger is received within the first opening of the housing to move between first and second positions. A cartridge is disposed in the housing and has an interior serving as a reservoir for a drug. A delivery needle is disposed within the housing and is in fluid communication with the reservoir via an interruptible fluid channel. A locking mechanism is disposed in the housing. In the first position of the plunger the delivery needle is enclosed by the plunger and in the second position of the plunger the delivery needle is placed in an injection position and the plunger activates the locking mechanism whereby when the plunger returns to the first position the .locking mechanism prevents the needle from being placed in the injection position.

Abstract: A needle shroud assembly (10) comprises a barrel (16), a needle shroud (18) captively telescoped relative to the forward end of the barrel for movement between retracted and extended positions and is biased towards said extended position by a spring (25). A separate locking element (42) is mounted within the barrel moveable between a safe position (as seen in FIG. 5) in which it prevents or limits retraction movement of said needle shroud (18), and a live position in which it is clear of the rearward path of the needle shroud (18). The locking member is moved from its safe position to its live position by means of an externally operable actuating member (54), having a cam (52) which cooperates with a cam surface (46) on the locking element (42). The cam (52) is driven back to its original position by the rearward end of the shroud (18) as it moves to the fully retracted position.

Abstract: An injection device is provided. The device includes a housing having a first end defining a first opening. A plunger is received within the first opening of the housing to move between first and second positions. A cartridge is disposed in the housing and has an interior serving as a reservoir for a drug. A delivery needle is disposed within the housing and is in fluid communication with the reservoir via an interruptible fluid channel. A locking mechanism is disposed in the housing. In the first position of the plunger the delivery needle is enclosed by the plunger and in the second position of the plunger the delivery needle is placed in an injection position and the plunger activates the locking mechanism whereby when the plunger returns to the first position the locking mechanism prevents the needle from being placed in the injection position.

Abstract: This document discloses, among other things, an air-powered auto-injector device for subcutaneous delivery of a rescue drug. The device is configured for self-administered treatment of anaphylactic shock. Air is compressed by relative movement of a piston and a cylinder and released to subcutaneously drive an hypodermic needle.

Abstract: A cover for a syringe includes an elongated flexible envelope and an absorbent material. The elongated flexible envelope includes a body portion and a needle-receiving portion. The body portion has a first end that defines an opening and an opposite second end. The needle-receiving portion extends from the second end of the body portion and terminates in a distal end. The body portion and the needle-receiving portion define a cavity of sufficient size to allow the syringe to be placed therein. The cavity is in communication with the opening. The envelope is made of a material that is impervious to liquid. The absorbent material is disposed in the distal end of the needle-receiving portion.

Abstract: A radiation shielding syringe carrier comprising a top cap, a main body and a needle shield, all formed from a radiation dense material. The main body preferably includes a syringe shield shaped to be threadably engaged to the bottom of the carrier. Preferably a separate top cap and shipping cap are provided.

Abstract: Containers for automatic injectors and automatic injectors adapted for those containers are disclosed. The containers include structures adapted to retain and, optionally, cripple the needle of the automatic injector when the automatic injector is inserted into the container after use. Depending on the embodiment, an indicator may be included, either as part of the container or as part of the automatic injector, to indicate whether or not the automatic injector has been used. If the indicator is provided as a part of the automatic injector, a corresponding portion of the container may be formed of a light permeable material. The container may also include features, such as an eyelet over the closed end, designed to cushion the automatic injector. Cushioning and shock absorbing features may also be provided inside the container. A clip is also disclosed. The clip is designed to attach two or more containers together.

Abstract: An injection channel is produced in human or animal tissue by means of a pre-injection device for incorporating a medium which is to be injected. Said pre-injection device comprises a chamber which is used to receive a pre-injection medium, a nozzle which is provided for attachment to the skin and a pressure generating device which acts on the chamber in order to generate a high-pressure jet from the pre-injection medium exiting from the nozzle. Said type of needle-free pre-injection device is serially connected to a main injection device.

Abstract: An injection device is provided. The device includes a housing having a first end defining a first opening. A plunger is received within the first opening of the housing to move between first and second positions. A cartridge is disposed in the housing and has an interior serving as a reservoir for a drug. A delivery needle is disposed within the housing and is in fluid communication with the reservoir via an interruptible fluid channel. A locking mechanism is disposed in the housing. In the first position of the plunger the delivery needle is enclosed by the plunger and in the second position of the plunger the delivery needle is placed in an injection position and the plunger activates the locking mechanism whereby when the plunger returns to the first position the locking mechanism prevents the needle from being placed in the injection position.