Abstract: A safety shield system for a needle cannula of a pen needle injector or similar device, wherein the safety shield may be retracted from a first position enclosing the needle to a second position exposing the needle for injection. The safety shield system permits retraction of the safety shield during use, but extends the shield enclosing the needle in a locked position following use. The shield system is utilized with a pen needle injector having a double ended needle cannula mounted in a hub received on the open end of the pen needle injector. The assembly is disposed of by removing the assembly and needle cannula hub and storing the assembly in the cup-shaped cap enclosing the exposed end of the needle cannula within the cap. The cap includes internal radial ribs preventing retraction of the shield prior to removing the cap preventing inadvertently piercing the cap during assembly.

Abstract: A pneumatic retractable syringe has a plunger having an interior retraction lumen. The plunger and syringe barrel have cooperating locking elements so that the plunger is locked after use within the syringe barrel. After injection of medicament is completed, the needle is retracted into the lumen by compressed gas that is released from a gas cell within the syringe when the gas cell is ruptured just before the plunger reaches the end of its downstream path of travel.

Abstract: An improved assembly of plunger and needle hub for a safety syringe needle device is disclosed, which comprises a syringe barrel, a needle hub and a plunger. The syringe barrel is shaped as a tube and has an interior periphery thereof shaped as a straight tube. The needle hub is inserted into the syringe barrel and has an integrated combining ring, which is bent inward as a hook and has a crease whereon the combining ring is bent inward. The needle hub has a nozzle jutting out of the syringe barrel for connecting a needle. The plunger comprises a plug for being fitly received by the syringe barrel and a front end thereof can be pierced through and coupled with the combining ring.

Abstract: A safety needle device and method of supplying fluid to a vascular access port is described. The device may include a base member, a handle member, and a compressible member positioned between the handle member and a compression plate. The compressible member is coupled to a proximal end of a needle. Following the delivery of fluid to a vascular access port, the needle is removed by moving the handle member away from the base member, which collapses the compressible member, flushing fluid into the vascular access port to substantially replace a volume of the needle.

Abstract: A safety injector comprises a needle hub attached by a needle, a hollow barrel for engaging with the needle hub and guiding the needle hub to retract into the hollow barrel, and a plunger combination settled in the hollow barrel. The plunger combination comprises a retractable plunger and a hollow plunger partially telescoped with the retractable plunger, wherein at least one raised portion is formed on an outer wall of the retractable plunger and at a telescoping portion for engaging at least one depression formed on an inner wall of the hollow plunger so that when the plunger combination continuously receives a pushing force after the safety injector is used to perform the injection operation, the retractable plunger can smoothly retract into the hollow plunger. Consequently, a space in the hollow barrel can be spared for accommodating the retracted needle hub.

Abstract: A bowel extension device implantable into a body for treatment of short bowel syndrome. The bowel extension device comprises a housing and a displaceable member coupled to the housing. The bowel extension device is configured to apply a tensile force sufficient to promote bowel growth without causing damage to the bowel. In some embodiments, the bowel extension device can be completely contained with the body.

Abstract: A safety syringe includes an outer barrel, a needle unit, an outer barrel plug, an inner barrel, an inner barrel plug, a needle clamper, and a vacuum generating device. The needle unit is disposed within the front end of the outer barrel. The outer barrel plug is disposed within the outer barrel; the outer barrel plug is connected with the needle unit so as to fix the needle unit. The inner barrel plug is disposed within the front end of the inner barrel. The needle clamper is connected with the inner barrel plug. The needle clamper is able to clamp a rear opening of the needle unit. The vacuum generating device is disposed within the inner barrel, and the needle unit can be retracted into the inner barrel by the low pressure which is generated by the vacuum generating device.

Abstract: The present invention provides a device for injection of formulations into a patient. In one embodiment the injection is sub-cutaneous. The device is convenient for injecting viscous formulations that would otherwise clog conventional injection devices, for example formulations containing microspheres, suspensions, and other viscous substances. Generally, the device features a needle for piercing the skin, an internal chamber for holding and transmitting fluid, a plunger for applying pressure to the internal chamber, a switch for triggering withdrawal of the needle, a sheath at least partially encompassing the needle and having a flow path within the sheath, and a spring that expands when the switch is triggered, and which thereby at least partially withdraws the needle from the sheath.

Abstract: A syringe includes a piston (16) that is slidably guided in a casing (10), and a needle (20) adapted to be withdrawn into the casing. The piston (16) and the needle (20) are connected by a coupling (22; 22?) which is adapted to assume three states: a releasable coupling state in which the needle (20) can be moved towards the front end of the casing (10) together with the piston (16), an uncoupled state in which the piston (16) can be moved back in the casing (20) separately from the needle (20), and a permanent coupling state in which the needle (20) can be withdrawn into the casing (10) by the piston (16).

Abstract: A safety hypodermic syringe is disclosed to includes a barrel, which has a spiral tear groove on the front wall around a tubular neck that holds a needle assembly and a race for enabling the front wall of the barrel to be broken and carried with the needle assembly inside the barrel by a plunger after the service of the safety hypodermic syringe, and a support ring sleeved onto the tubular neck and stopped against the front wall of the barrel between the tubular neck and the race to prevent breaking of the spiral tear groove accidentally during transportation.

Abstract: A safety needle device and method of supplying fluid to a vascular access port is described. The device may include a base member, a handle member, and a compressible member positioned between the handle member and a compression plate. The compressible member is coupled to a proximal end of a needle. Following the delivery of fluid to a vascular access port, the needle is removed by moving the handle member away from the base member, which collapses the compressible member, flushing fluid into the vascular access port to substantially replace a volume of the needle.

Abstract: A device for expelling a fluid through a needle mounted on a hub includes an elongated luer member that has a distal portion dimensioned to engage the needle hub to provide fluid communication between the luer member and the needle. An adapter anchors the luer member within the device. Slidingly mounted on the adapter is a cylindrical-shaped inverted plunger that is movable thereon between an advanced position and a withdrawn position. A needle guard is biased by a biasing member to extend distally from the luer member when the plunger is in the advanced position. The guard is selectively engageable with the plunger to be retracted to expose the distal portion of the luer member for fluid engagement with the needle hub when the plunger is moved to the withdrawn position.

Abstract: A medical device for delivering a medicament to a patient. The device includes a syringe barrel with a plunger having a hollow front end and a stopper positioned over the plunger front end to seal the plunger front end. The stopper is movably inserted in the barrel to expel medicament in the barrel. A needle cannula is fixed to a needle cannula hub and is movable between an initial position in which the forward tip of the needle cannula is exposed and a retracted position in which the forward tip is contained within the medical device. A plug seal releasably secures the needle cannula hub to an end of the barrel, and a hub adapter secures the plug seal to the barrel end. A cutter positioned on the plunger pierces the stopper when the stopper is pressed against the plug seal to open the hollow front end of the plunger. The plunger also engages the plug seal to allow the needle cannula hub to move, via an urging member, to the retracted position through the front end of the plunger.

Abstract: This invention of a prepacked automatic retractable safety syringe comprises a needle hub with a needle tube and a rubber washer, a cap, a barrel, a spring, a vial, and a retractable plunger. To prevent or reduce injuries of needle stab and protect medical staffs, a forward action of the vial plus the needle hub compressed by the retractable plunger can drive a sliding movement between slides on the needle hub and snap hooks on the barrel via the spring's force to complete automatic retraction of the needle hub as well as the vial when an injection is finished.

Abstract: A device for expelling fluid from a pre-filled vial includes a hollow needle that is axially mounted on a syringe body. A guard, also mounted on the syringe body, is moveable between a first position wherein it is held to expose a distal portion of the needle and a second position wherein, after being released, it covers the distal portion. In operation, the vial is engaged in fluid communication with the needle, and it is then advanced on the syringe body. During this advancement, fluid is expelled from the vial through the needle, and the vial releases the guard for its movement from the first to the second position.

Abstract: An injection device (110) comprises a housing (112) having a syringe (114) with a discharge nozzle (118). The syringe is movable between a retracted position in which the discharge nozzle is contained within the housing and an extended position in which the discharge nozzle extends from the housing. There is syringe cap (180) for enclosing the discharge nozzle. The syringe cap is removable from the syringe by rotation to the syringes. A syringe carrier (150) in the housing is adapted to restrain rotation of the syringe relative to the housing as the cap is removed.

Abstract: An injection device (110) comprises a housing (112) defining a first axis (101). A drive (120) acts upon a syringe when released by a trigger (114). The trigger is rotatable from a rest position in which the drive is retained to an active position in which it no longer causes the drive to be so retained. The trigger is pivotally mounted and has a surface (201) shaped such that a user can apply a force in a direction substantially parallel to the first axis to rotate the trigger from its rest position to its active position. Such an injection device provides improved handling and ease of operation.

Abstract: A disposable syringe having a double hook element (9), causing, after a piston stroke toward the end of the socket element (4) of the needle, allowing retraction within the reservoir (1) during the reverse stroke of the piston (2). A spring (8) between the double hook element (9) and the end of a reservoir lip, when compressed, maintains the double hook element (9) in its position, and when extended, acts to cause the return of the needle (5) within the reservoir (1).

Abstract: A retractable needle safety syringe is provided having a braking mechanism. The braking mechanism may be disposed at a proximal portion of a syringe body of the syringe. The braking mechanism may comprise split brake members which are traversable between a braking position and a released position. At the braking position, fingers of the split brake member frictionally engage an outer surface of the shaft of a plunger of the syringe. The frictional engagement counterbalances a retraction force that urges a piston of the syringe toward a retracted position. When the split brake members are traversed to the released position, the fingers do not press against the outer surface of the shaft. As such, the retraction force may traverse the piston toward the retracted position and traverse a needle and needle holder into the body of the syringe.

Abstract: A needle gradually auto-retractable safety medical syringe includes a hollow barrel, a plunger provided in the barrel, a piston provided on the head of the plunger, a hub provided on the head of the barrel. The hub includes an elastic connecting hub providing with a needle and a hub sheath for fixing the elastic connecting hub, the elastic connecting hub may be disengaged with the head of the barrel and retracted with the effect of a spring after having finished the injection, a regually retractable bracket which are integrated with each other, the regually retractable bracket forms with at least two elastic supporting claws engaged to the inner wall of the pushing tube of the front end of the plunger after the injection finished, the elastic connecting hub allows the regually retractable device to retract in the barrel with the effect of the spring, and allows the needle to be drawn into the barrel.

Abstract: A safety needle assembly is disclosed which includes a housing, a needle extending distally from the housing, a slide member positioned within the housing and configured to move distally about the needle and at least one actuation member. The actuation member is supported on the housing and has a proximal end secured to the housing, a distal end obstructing distal movement of the slide member and a centrally located fulcrum. A biasing member is positioned within the housing to advance the slide member distally along the needle. A cover member is operably connected to the slide member and is configured to enclose a distal end of the needle. The actuation member is configured such that actuation of the actuation member pivots the distal end of the actuation member to facilitate distal movement of the slide member.

Abstract: Intelligent needles comprise a needle for insertion into the skin to deposit a substance that causes plumping of the skin. The penetration depth of the needle may be adjusted automatically in conjunction with a sensor mechanism that determines a depth the needle can penetrate without contacting blood vessels. Methods of making and using the same for acupuncture and subcutaneous injection are also provided.

Abstract: A blood collection device comprises an open ended syringe like housing into which a vacutainer can be inserted. The front of the device contains a needle holder and a double ended needle. The needle holder is attached to the device in a special manner that enables the needle holder to be decoupled and retracted into the device but only after the vacutainer has been removed and a separate needle retraction device has been inserted into the open end of the housing and pushed against the inner end of the needle holder. The needle retraction device comprises a hollow body which is under vacuum and which has an open end closed by a piston. The piston is of a special design that functions to decouple the needle holder from the blood collection device and to lock to the needle holder and at the same time to be decoupled from the hollow body the result of which is that the piston containing the needle holder and the attached contaminated needle is sucked back into the hollow body to render the needle safe.

Abstract: A disposable injection syringe for allowing a comfortable injection at a low injury risk of the user. The syringe includes an injection needle, a tubular cylinder having a free opening at a first end, an end part with a through hole for slidably accommodating the injection needle at an opening of a second end of the tubular cylinder opposite the free opening, a piston reciprocally accommodated in the cylinder, a piston rod attached to the piston and extending into the cylinder through the free opening of the cylinder, a coupling for interlocking the piston and the injection needle at least in the reverse direction of the injection piston stroke. The coupling has two coupling parts, one of which is attached to the piston and the other of which is attached to the injection needle. The coupling parts are spaced from each other during at least part of the injection stroke and interlock during withdrawal.

Abstract: Embodiments of the present invention include a device comprising a substantially planar housing defining a reservoir; a plunger disposed at least partially within said reservoir and movable between a first position and a second position; a liquid dispensing needle coupled to said plunger, said needle comprising a channel in fluid communication with said reservoir, said needle contained within said housing when said plunger is in said first position; and a spring adapted to resist movement of said plunger. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope of the invention.

Abstract: A medical device having a main body, an actuator and a needle, the needle able to be retracted into the main body, the main body having a chamber which is under reduced pressure or can be placed under reduced pressure, the needle attached or attachable to a retraction member movable between a forward position with the needle extending from the main body and a retracted position with the needle within the main body, the retraction member additionally movable between a held position preventing retraction and a release position where rotation of the actuator allows the retraction member to be retracted into the vacuum chamber by the reduced pressure of the chamber.

Abstract: A needle tip protective device for use with percutaneous entry needles. In one embodiment, the needle tip protective device includes a needle guard slidably mounted on a hypodermic needle, the latter having a needle tip located at the distal end thereof, and a change of profile formed medially there along. The needle guard is movable along the hypodermic needle and engageable with the change in profile formed thereon. The engagement with the change in profile is configured to correspond with the ability of the needle trap to entrap the needle tip once the needle trap has advanced the sufficient distance distally along the hypodermic needle. In further refinements, the needle trap may be biased toward the distal needle tip of the needle.

Abstract: An insertion device for inserting an infusion device at least partially into skin for subcutaneous infusion can comprise a sleeve having a lower surface that is configured to engage the skin, a shuttle or carriage to carry the infusion device between a retracted position and an advanced position; at least a first biasing member to urge the shuttle or carriage toward the advanced position, and an actuator to cause the first biasing member to urge the carriage from the retracted position to the advanced position. In some embodiments, the insertion device can further comprise a hub and at least a second biasing member to urge the hub away from the shuttle or carriage. In some embodiments, the insertion device can further comprise a needle attached to the hub. Methods for inserting an infusion device and various other features that can be comprised by an insertion device are also disclosed.

Abstract: A packing sleeve for use with a safety needle that automatically covers a tip of a needle following removal of the needle from a patient includes a generally hollow body having a longitudinal axis and a distal end and an open proximal end. The body surrounds at least a portion of the safety needle and has at least one track having an activation leg and a releasing leg. The at least one track is in sliding engagement with at least one member of the safety needle such that the motion of a portion of the safety needle relative to the body is dictated by a path the at least one member follows along the respective at least one track. The safety needle is in an initial position when the at least one member is proximate a first end of the activation leg and in an intermediate position when the at least one member is proximate a second end of the activation leg.

Abstract: A retractable needle device to be attached to the forward end of a syringe. The device has a forward end with a needle assembly that is urged into the body of the device so that when the syringe and device are to be discarded, the needle is located internally of the body of the device to inhibit needles stick injuries.

Abstract: A medical syringe has a needle shoot back mechanism which can be triggered to shoot the used needle back into the safety of the syringe body and is of a special design to allow the needle to be replaced without affecting the efficiency of the shoot back mechanism. A rotatable cover member is also available which is relatively large and which can be more easily gripped and turned to remove the needle from the syringe.

Abstract: A safety syringe assembly includes an elongated, generally cylindrical barrel having a hollow interior forming a hollow nozzle located at a distal end of the barrel and opening into the interior of the barrel. A plunger is slidably mounted in the barrel and has a longitudinal open channel. A needle holder mounts a needle at a distal end thereof and is slidably mounted in the longitudinal open channel of the plunger for movement between an advanced position in which the needle on the distal end of the needle holder projects from a distal end of the nozzle, and a retracted position in which the needle is retracted within the barrel. A compression spring is mounted inside of the barrel, and a spring retainer element has a spring support portion extending from the interiorly of the barrel to a portion for mounted within the barrel and supporting a distal end portion of the spring against expansion. The spring urges the needle holder toward its retracted position.

Abstract: The medical needle device of the present invention includes: a shield 4 including a substantially cylindrical portion 4a; a tube 13; a first hub 2 that is inserted into an inner bore of the shield movably in an axial direction, whose rear end is connected with the tube 3; a rigid needle 1 that is fixed to a front end portion of the first hub; and a hub movement controlling member 14 that is attached to the shield detachably, wherein the hub movement controlling member 14 includes: a stopper portion 14a that can be inserted from the rear end side of the shield into an inner bore of the shield exsertably, and has a front end that can be in contact with the first hub in a state of reaching a movement end on the front end side of the inner bore of the shield; and a holding portion that can maintain a state where a front end of the stopper portion 14a is in contact with the first hub 2 reaching the movement end on the front end side.

Abstract: A medication administration system is provided whereby a user can administer medication via intravenous, intramuscular, or subcutaneous routes from a single device in a safe and controlled manner, and without the danger of a needle-stick injury. The system essentially consists of a syringe-like device that is a closed system having an aseptic fluid path.

Abstract: A safety syringe that includes syringe assembly retained within a hollow tubular shell, whereby a retaining member is utilized for retaining the syringe assembly in an operative position such that it is available for administering a shot. After the safety syringe is used, a retracting assembly retracts the syringe assembly into the shell and locks it in place thereby preventing any accidental pricks.

Abstract: A no leak syringe has: a syringe body having a front portion and an open rear end portion, a plunger having a front and a rear and which is slideable along the barrel from a retracted position where the front of the plunger is in the rear portion of the barrel to a extended position where the plunger has been slid along the barrel towards the front of the barrel, a pierceable self healing seal extending over the front of the plunger and through which the needle can pierce when the needle is retracted, the seal being substantially closed after the needle has passed through the seal, a needle holder which is positioned in the front of the barrel, a needle attached to the needle holder, a triggering mechanism to enable the needle to be retracted into the syringe body and/or the plunger body, a plunger lock mechanism to lock the plunger against retraction when the needle has been retracted, a thumb pad on the rear of the plunger, and a seal on the thumb pad that seals against the open rear end portion of the s

Abstract: A novel hub design that enables removal of nozzle core for disposal while the hub is retained for reuse. The reusable hub provides a cost advantage over a one-piece metal design, enabling the use of a dispensing system that is of high quality and low cost to proliferate the use of the technology in the industry. Using this method, a nozzle hub dispensing system has a very favorable impact on the environment, 90% less hazardous waste with a reusable hub system, as only the lightweight cores are disposed. This nozzle hub provides a positive locking, tool-less mechanical connection of nozzle core to hub, which offers a financial advantage over competitive products.

Abstract: The present invention provides an improved barrel type plunger for use with a needle-retractable safety syringe, comprising a barrel, a needle retracted trigger and a supporting member. A front portion of said barrel is fitted over a sealing rubber pad, a slotted hole is provided at a wall of the front portion of said barrel, a bearing piece is provided in said slotted hole, and one end of said bearing piece is connected to the front side wall of said slotted hole. Said barrel and said supporting member are provided with a snap-in structure, respectively, which make supporting member releasably engaged in said barrel. After having released from said barrel, said supporting member is able to translate backwards under the action of a needle retraction force so that said bearing piece can be returned to such a position that said needle can be retracted backwards to the interior of said barrel. The present invention further provides a syringe comprising the above-mentioned barrel type plunger.

Abstract: Means to control the retraction of an auto-retractable safety syringe to minimise splashback or splatter is disclosed. The end of a hollow plunger (11) is covered by a sealing member (14) that, upon retraction, is dislodged so that the needle assembly and seal enters the hollow plunger. Three methods by which the auto-retraction is controlled are disclosed. Firstly there is provided a taper within the inside of the hollow plunger which creates varying resistance of movement to the sealing member. Secondly there is provided a bleed hole (15) at the upper end of the plunger, whereby the air is allowed to escape. Thirdly, there is provided on or more grooves (16) in the periphery of the plunger seal so that air is allowed to be released, thereby reducing the pressure in the plunger and hence the possibility of splashback.

Abstract: A safety syringe includes a flexible holder-supporting seat that is sleeved around and that clamps a needle holder within a front end portion of a syringe barrel. A flexible sealing member seals an open front end of a plunger so as to define a vacuuming chamber in the plunger. When the plunger moves within the barrel to a front limit position, a holder-retaining front portion of the sealing member engages and retains the needle holder thereon. The plunger pushes the holder-supporting seat to separate from the needle holder such that the sealing member and the needle holder mover rearward within the syringe barrel due to negative pressure produced in the plunger, thereby retracting a needle into the syringe barrel.

Abstract: An improved cartridge for the packaging of a pharmaceutical, and preferably a radiopharmaceutical, comprising a low UV-absorbing plastic barrel, closed at one end by a cap and at the other end by a piston.

Abstract: The present invention relates to a disposable safety syringe (1) including an automatically retractable needle (12) for preventing said syringe from being reused, comprising a cylindric body (82) defining, at one end thereof, a needle coupling end-piece (7) and being opened at the other end portion thereof for introducing thereinto a piston (4) having a scaling gasket (5). The feature of the invention is that on said piston are provided engaging means (23, 24) for engaging and retracting the needle (12) after the delivering of the injection liquid.

Abstract: A hypodermic syringe includes a barrel with a plunger slidably extending therein. The plunger includes an outer plunger element and an inner plunger element telescoping together. A plunger cap may be advanced after injection to rotate the plunger. A resistance lock retains the cap and plunger indexed until actuation. The rotation actuates latches and locking fingers on the luer hub to engage a probe axially and rotationally on the seal end of the plunger and disengage the slots in the barrel, respectively. The rotation disengages the seal stop to release the annular seal and finally releases the engagement between the outer plunger element and inner plunger element. The foregoing provides for the retraction of the luer hub and associated needle into the barrel.

Abstract: A retractable needle assembly for use in medical procedures comprising a needle assembly including a hub, a hollow needle passing through the hub and projecting from the posterior end of the hub. A tubular sheath having a longitudinal slot extending along a portion of its length A post attached to the hub and positioned to project through said longitudinal slot such that the needle and hub assembly may slide along the length of the sheath from a position exposing said needle to a retracted position within said sheath. A means for reversibly locking the needle assembly in the retracted position, a means for reversibly locking the needle in the in the exposed position and means for permanently locking the needle in the retracted position. Several different embodiments for locking the needle assembly in position both reversibly or permanently are disclosed.

Abstract: A needle-bearing device for injecting medicinal fluid from a pre-filled vial is provided. After use, the needle is retracted into the body of the device to prevent inadvertent contact with the sharpened end of the needle. In one embodiment, the invention provides a manually actuable button that effectuates retraction of the needle after use. In another embodiment, retraction is effectuated automatically after the injection is complete.

Abstract: The invention provide a cylindrical pushrod for the syringe needle-retracting safety injector, comprising an outer cylinder, an inner cylinder, a push pole, an underpinned piece and a seal gasket; the push pole is set at the front end of chamber of outer cylinder, its front end appears as a tubular shape or projects partially in the longitudinal direction, the back end of push pole is supported on the underpinned piece; the underpinned piece is set at the front end of the chamber of outer cylinder and supports the push pole; the cylinder wall of the inner cylinder supports the underpinned piece; a clamping structure is set at the tail of this cylindrical pushrod. With the safety injector with the cylindrical pushrod according to the invention, the medical personnel can control the time of the needle retraction as desired, and is not necessary to change their habitual injection practice, and thereby the safety injector is easy to operate.

Abstract: A disposable syringe includes a tubular needle seat inserted into a barrel for fixing a needle cannula. The needle seat has an axially extending cavity with a radially yieldable catch disposed therein. A plunger is movable in the barrel, and has an engaging head defining a rearwardly facing shoulder wall which is retained by the catch when the engaging head is extended into the cavity by a pushing force applied to the plunger. The barrel defines friction diminishing regions such that when the needle seat is moved past the friction diminishing regions to be placed to a disposal position, friction between the needle seat and the barrel is diminished, thereby facilitating a subsequent pulling action of the plunger for retracting the needle cannula into the barrel.

Abstract: Pre-filled injection ampoules for administering a readily-available dose of fluid medication, are provided with a retractable needle. The needle is held in a projecting configuration from a barrel against a rearward bias exerted on the needle by a spring located within a spring housing. A piston is positioned within the barrel for expelling the fluid medication therefrom. The piston is configured to release the needle after completion of an injection stroke and to receive the needle in an internal cavity. In alternative embodiments, a retractable-needle injection device includes a housing for receiving a pre-filled medication cartridge of the type having a slidable piston positioned therein. A stationary plunger is located within the housing for maintaining the piston at a fixed location as the cartridge is urged into the housing to administer an injection. After the end of an injection stroke, the cartridge is further urged into the housing to release a effectuate retraction.

Abstract: An improved assembly of plunger and needle hub for a safety syringe needle device is disclosed, which comprises a syringe barrel, a needle hub and a plunger. The syringe barrel is shaped as a tube and has an interior periphery thereof shaped as a straight tube. The needle hub is inserted into the syringe barrel and has an integrated combining ring, which is bent inward as a hook and has a crease whereon the combining ring is bent inward. The needle hub has a nozzle jutting out of the syringe barrel for connecting a needle. The plunger comprises a plug for being fitly received by the syringe barrel and a front end thereof can be pierced through and coupled with the combining ring.

Abstract: A multi-use safety syringe has a retractable needle that retracts only when the user wants to retract the needle. The safety syringe has an internal moveable carriage that locks to an end cap with releasable locking elements. The safety syringe guards against premature retraction of the needle by requiring the simultaneous release of two releasable locking elements by the user. When the locking elements are released, the carriage is released. The released carriage slides backward within the barrel, retracting the needle within the barrel.