Abstract: A dual-chamber safety hypodermic syringe. The syringe includes a barrel having a medicine chamber, a needle chamber, and a guide hole connected between the chambers. The needle assembly is moved in and out of the needle chamber between the extended position where an inlet on a neck of the needle assembly is disposed in communication with the guide hole for enabling liquid medicine to be squeezed out from the medicine chamber through the needle cannula of the needle assembly, and the received position where the needle assembly is safely received inside the needle chamber and kept from sight.

Abstract: A disposable hypodermic syringe comprises an outer barrel, an inner barrel slidingly disposable in the outer barrel, a hypodermic needle disposed axially at the front end of the outer barrel so as penetrate its front end wall and being held, at its rear end, by the front end wall of the inner barrel, and a plunger which is slidingly disposable in the inner barrel. The outer barrel includes elements for interlocking with the inner barrel when the inner barrel is in a fully inserted position. The plunger includes release elements for releasing the inner barrel from the outer barrel while interlocking with the inner barrel so as to allow the inner barrel and the plunger to be withdrawn in combination with the hypodermic needle for a distance sufficient to displace the needle into a space formed between the outer barrel and the inner barrel.

Abstract: A prefilled syringe has a tubular body which has an open front end and an open rear end. A front assembly is mounted on an outer periphery of a front end portion of the tubular body. A finger grip is mounted on an outer periphery of a rear end portion of the tubular body. A front sealing member is provided in the tubular body so as to be disposed forwardly of injection liquid and a rear sealing member is provided in the tubular body so as to be disposed rearwards of the injection liquid. A plunger rod is provided so as to be movable in the tubular body. A temporary stop member temporarily stops the plunger rod through retention of the temporary stop member by the finger grip such that the rear sealing member is temporarily stopped at a predetermined position of the tubular body. A retention canceling member cancels the retention of the temporary stop member by the finger grip without moving the plunger rod.

Abstract: A syringe comprises a barrel (1) having a plunger (7) in slidable and sealing engagement therewith. In order to provide an autodestruct system, so that the syringe can be used once only, being rendered disabled after one normal use, the barrel (1) has means interrupting the cylindrical surface of its inner wall in the form of grooves (10, 11) or a projection (29), and the plunger (7) has a locking means (17, 20) which operates on engagement with a groove (10, 11) or projection (29) on withdrawal of the plunger (7) to prevent further withdrawal movement. The locking means (17, 20) is provided on the head of the plunger (7) adjacent an elastomeric sealing cap (15). The locking means may comprise a pair of flukes (17) or a cross-shaped disc (20).

Abstract: A stabilizer for a piston that strengthens the piston when higher dispensing volumes and/or pressures are involved. The stabilizer intimately contacts the piston along the radius of the piston to prevent distortion of the piston thereby preventing the fluid being dispensed from flowing around the piston destroying repeatability, accuracy and contaminating the driving mechanisms. The stabilizer also prevents the piston from cocking that may make the dispensing inaccurate and non-repeatable. The stabilizer may be of substantially any material from metals to any of the plastics suitable for maintaining its structural integrity under the pressures and forces involved.

Abstract: A multi-use medication dispensing pen made of a plastic material that is recyclable after the contents of the medication cartridge have been exhausted. The pen is made of a minimal number of parts, which include a housing, a dial mechanism, a generally cylindrical button assembly located within the proximal end of the dial mechanism, an internally threaded nut, and an externally threaded leadscrew. The pen is arranged so that the dial mechanism must be rotated to the zero-dose position prior to setting a dose. The pen includes a lockout mechanism that prevents the dial mechanism from being inadvertently depressed during dosing. The pen further includes a mechanism that limits the maximum dosage that can be dialed up and a mechanism that prevents the user from dialing up a dosage greater than that remaining in the cartridge.

Abstract: A self-aligning reinforced plunger rod and a non-elastomeric plastic plunger insert assembly for use with an elastomeric plunger in a cartridge or syringe barrel, the plunger rod having a first, second, third and fourth sides, a distal end with an end disc, a proximal end with a thumb rest, a central reinforcing disc at the midpoint between the end disc and the thumb rest, and a plunger rod tip integral with the end disc and having a neck portion and a ball portion for engagement with a cavity in the non-elastomeric plastic plunger insert.

Abstract: A self-aligning plunger rod and a non-elastomeric plastic plunger insert assembly for use with an elastomeric plunger in a cartridge or syringe barrel for manual or power-assisted withdrawing of fluid from a site or expelling fluid from the cartridge or syringe barrel.

Abstract: Dimensionally stable plunger rod for use with a plunger in a cartridge or syringe barrel for manual or power-assisted withdrawal of fluid from a site or expelling fluid from the cartridge or syringe barrel having: a plunger rod body with a distal and a proximal end; an end disc at the distal end; a threaded member integral with the end disc designed to engage a plunger; a thumb rest at the proximal end; a central disc at the mid point between the end disc and the thumb rest to provide additional reinforcement to the plunger rod; four longitudinal radially extending rectangular vanes connected to the end disc at the distal end, to the central disc at the mid point, and to the thumb rest at the proximal end; two pairs of longitudinal radially extending reinforcing vanes forming two triangular configurations with one of the longitudinal radially extending rectangular vanes on one side of the plunger rod body; and two pairs of longitudinal radially extending reinforcing vanes forming two triangular config

Abstract: A single-use syringe assembly is provided and includes an elongated syringe barrel with a plunger assembly disposed therein. The plunger assembly includes an elongated plunger rod having a plunger tip located distally. The plunger tip contains a locking detent disposed a the distal end of the tip. The syringe barrel has a nozzle at the substantially closed distal end, the nozzle adapted to conform to the plunger tip. The distal end of the nozzle contains an annular inward biased ring adapted to mate with the locking detent of the plunger tip. Upon usage of the syringe and application of force to apply the liquid, the locking detent is irreversibly mated with the nozzle inwardly biased ring, thereby preventing reuse of the syringe assembly.

Abstract: A self-aligning reinforced plunger rod and a non-elastomeric plastic plunger insert assembly for use with an elastomeric plunger in a cartridge or syringe barrel, the plunger rod having a first, second, third and fourth sides, a distal end with an end disc, a proximal end with a thumb rest, and a plunger rod tip integral with the end disc and having a neck portion and a ball portion for engagement with a cavity in the non-elastomeric plastic plunger insert. Connecting the end disc and thumb rest there are: four longitudinal radially extending rectangular vanes spaced about 90.degree.

Abstract: A pre-filled injection device having a retractable needle with a sharpened tip for penetrating the skin of a patient for administering medicinal fluids is provided. The pre-filled injection device of the present invention allows the needle to be manually retracted, thereby reducing the risk of transmission of various pathogens, most notably human immune virus (HIV), to infected personnel, due to an inadvertent needle stick. The present pre-filled injection device has a hollow housing which receives a pre-filled cartridge containing medicinal fluids. A needle retainer initially holds a needle projecting forwardly from the hollow housing. The rear end of the needle pierces the pre-filled cartridge when sufficient pressure is applied to the end of the pre-filled cartridge to advance it in the forward direction. A plunger is slidably displaceable within the housing. A latch member is operable in a latched position to prevent forward movement of the plunger.

Abstract: An improved syringe plunger rod for a retracting needle syringe is illustrated having a plunger rod with inner and outer members and a retaining ring. The retaining ring restricts movement between the inner and outer members until the ring makes contact with the proximal end of the retracting needle syringe and further distal force is applied to the inner member. Once disengaged, the inner member moves relative to the outer member to activate the retractable needle syringe. One advantage of the improved plunger rod is that it reduces the probability of premature activation of the retractable needle syringe. In addition, the improved plunger rod assists in the prevention of re-use of the syringe.

Abstract: An injection device has a two part barrel. The forward part (10) telescopes into the rear part (3) and within the barrel a capsule (1) with a needle (2) at its forward end is initially held by a trigger (11) formed integrally with the forward part (10) so that the needle (2) does not project. The trigger (11) is inoperable at this stage, being inaccessible because of the telescopic overlap. A spring (20) acts on a plunger at the rear of the capsule. When the overlap is increased, the trigger (11) becomes accessible through a slot (7), and when it is operated the capsule (1) is released for the spring (20) to shoot it forwards and eject the dose through the now projecting needle (2). The capsule (1) may have a two part dose and its mixing may then be effected by the spring (20), fully compressed after the overlap increase, urging the plunger forwards.

Abstract: An assembly for the collection of a patient's blood specimen comprises an elongate needle holder, a blood collection tube, and a cap closing the blood collection tube. The needle holder supports a blood extracting needle through a closed end thereof. The blood collection tube is insertable into the interior of the needle holder so as to collect blood. The cap has a membrane which is puncturable by the needle upon insertion of the blood collection tube into the interior of the needle holder. The cap includes a deflectable member extending therefrom for engagement with the cylindrical wall of the needle holder so as to frictionally resist longitudinal movement of the tube within the tube holder.

Abstract: A closed delivery system is described for the handling of injectable biological products and vaccines used in the treatment and prevention of livestock diseases. This system embodies a multidose prefilled disposable cartridge and a metered pistolgrip syringe body. The cartridge is breech loaded into the syringe body and the product is dispensed from the cartridge by a unique drag link mechanism as a means for advancing the plunger rod and forcing the vaccine from the cartridge into the flesh of the animal being treated. Each prefilled cartridge is disposed of after it is emptied and no cleaning is required. A color coding system between the multidose, prefilled, disposable cartridges and the syringe bodies insure that proper dosages are given and that products are not mixed up or confused by the technicians administering the products.

Abstract: A retractable and destructible safety syringe including a syringe barrel, a plunger, a needle holder, a needle, capture elements formed on the needle holder or the plunger and a one-way movable detent formed on the plunger or the needle holder. When a piston of the plunger is fully depressed within the syringe barrel, the detent can be easily firmly engaged with the capture elements, whereby the needle holder and the needle can be together pulled back into the barrel. In addition, when the fully retracted plunger is depressed again, the tip of the needle is pressed against a shoulder section of the barrel, being bent and destroyed thereby. Sealing fixing rings are formed on outer wall of the needle holder and inner wall of the needle holder cavity, serving to sealably and separably engage the needle holder with the needle holder cavity. A latch plate is disposed between the barrel and the plunger to prevent the plunger from being pushed to latch the capture elements to the detent by mistake.

Abstract: A diagnostic syringe actuator device for use in combination with a syringe in the removal of tissue, fluid and/or cells for the diagnosis of pathological processes wherein the syringe includes a hollow syringe body having a longitudinally movable syringe plunger at least partially disposed therein with a probe needle attached to the distal end portion comprising a hollow retractor tube having a longitudinally movable retractable piston disposed therein, a longitudinally movable syringe plunger sabot disposed within the hollow retractor tube, a sabot lock mechanism selectively movable between a locked and unlocked position disposed to engage the syringe plunger sabot when in the locked position to maintain the syringe plunger and the syringe plunger sabot in the advanced position and to disengage the syringe is plunger sabot when moved to the unlocked position such that the syringe plunger sabot and the syringe plunger move from the advanced position when the retractable piston has been at least partially retr

Abstract: A single-use syringe assembly is provided and includes an elongated syringe barrel with a plunger assembly disposed therein. The plunger assembly includes an elongated plunger rod having a plunger tip located distally. The plunger tip contains a locking detent disposed a the distal end of the tip. The syringe barrel has a nozzle at the substantially closed distal end, the nozzle adapted to conform to the plunger tip. The distal end of the nozzle contains an annular inward biased ring adapted to mate with the locking detent of the plunger tip. Upon usage of the syringe and application of force to apply the liquid, the locking detent is irreversibly mated with the nozzle inwardly biased ring, thereby preventing reuse of the syringe assembly.

Abstract: The syringe for medicinal purposes features a syringe barrel (1), one end of which is formed as an adapter (2) for a cannula or a closure (3), e.g., in the form of a tip cap, and of a plunger (4), arranged within the syringe barrel (1), and movable by a piston rod (5). At the end of the syringe barrel (1) facing away from the adapter (2), a plunger brake (6) is arranged, which is formed by a rest piece surrounding the syringe barrel (1) and connected removably to it. The rest piece has a projection extending into the lumen of the syringe barrel (1), which forms a stop for the side of the plunger (4) away from the adapter (2).

Abstract: A syringe assembly has a hub body which can be inserted into a hub insertion hole and pulled out thereof into inside a syringe body. A chamfer portion is formed at the hub body, being capable of engaging with the hub insertion hole. A needle insertion hole capable of being inserted a needle therein is provided with an end face of the hub body in a direction of an axis center of the hub body. A flow hole is provided with the hub body such that the needle insertion hole and an inside of the syringe body are communicated with each other in the direction of the axis center. A piston engagement hole is provided on end face side of the hub body, so as to engage with the piston. A seal taper is annularly formed at the hub body, such that its outside diameter is made narrower for the end face side, so as to abut on and contact with an inner face of the hub insertion hole.

Abstract: A syringe comprising a tubular body (11) closed at one end (12) and open at the other end (13), a plunger (14) receivable in the body (11) to define a chamber (16) of variable volume, a needle support (24) adapted to support and accommodate a hollow needle, said needle support (24) being supported from or in the wall of the body (11) and being movable in a direction substantially parallel to the main axis of the body (11) between a first position at which the needles extends from the one end of the body (11) and the interior of the needle is in communication with the chamber (16), and a second position at which the outer end of the needle is in a retracted position, said needle support (24) having a protrusion (28) which is selectively engageable with the wall of the body (11) at the first and second positions to be able to be retained at said positions and receivable through the wall of the body (11) when at the second position to be engaged with the plunger (14) to prevent axial movement of both the needle

Abstract: A backstop device to prevent inadvertent withdrawal of a stopper or plunger rod from the open distal end of a flangeless syringe barrel. The backstop includes a retaining wall configured to engage at least a portion of the syringe barrel, and a finger plate at the proximal end of the retaining wall. The finger plate includes an aperture adjacent the open proximal end of the syringe through which a stopper may be inserted. If desired, a ridge may be formed around the periphery of the aperture which may engage with a portion of the syringe barrel. The aperture and, if present, the ridge present a smaller passageway than the inside diameter of the syringe, preventing inadvertent removal of the stopper from the syringe. The backstop can be placed on the syringe regardless of the presence or absence of the plunger.

Abstract: A backstop device to prevent inadvertent withdrawal of a stopper from the open distal end of a syringe barrel. The backstop, mounted to a syringe flange, includes a pair of spaced apart plates located on either side of the flange. Both plates include respective apertures accessible through lead openings formed through the plates. The bottom aperture is formed for snug contact with the syringe barrel, while the upper aperture includes a ridge engageable with the interior of the syringe barrel adjacent the open distal end. The top aperture and ridge together present a smaller passageway than the diameter of the stopper, preventing inadvertent removal thereof. The backstop can be placed on the syringe regardless of the presence or absence of the plunger.

Abstract: The applicator is assembled from an integral injection-molded part which includes an elongated flat strap from which a piston member projects at a right angle to one side and, at some distance therefrom, a cylinder member including a canula molded thereon projects at a right angle to the other side. The strap forms two spring arms of which the one, being bent by 180.degree., is first slid over the piston head with a recess. Subsequently, the cylinder is also fit onto the piston head, with the strap section that connects the piston to the cylinder head being also bent by 180.degree.. The piston head snaps in a rear position into the cylinder. The two biased spring arms always bias the piston in the direction of the rear end position, so that the applicator can be operated with one hand to take, for instance, blood from a container.

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 first object of the invention is to insure that medication filled syringe equipment can be kept sterile at all stages until use, is protected against malicious unauthorized use, can be packaged in a simpler way and can protect the medication to be in a stable form. A second object of the invention is to insure that an additional liquid such as an anesthetic, another medication in liquid form or a solubilizer can be aspirated by medication filled syringe equipment in an aseptic appropriate manner before injection. To attain these objects, the equipment of the invention comprises barrel 1, needle attaching portion 2 fitted with cap 11, plunger rod 22, and sealing device 31 as tube 32 of a heat-shrinkable film that is slipped over the area from the cap 11 through the barrel 1 to the basal head 23 of the plunger rod 22.

Abstract: A backstop device to prevent inadvertent withdrawal of a stopper or plunger rod from the open distal end of a flangeless syringe barrel. The backstop includes a retaining wall configured to engage at least a portion of the syringe barrel, and a finger plate at the proximal end of the retaining wall. The finger plate includes an aperture adjacent the open proximal end of the syringe through which a stopper may be inserted. If desired, a ridge may be formed around the periphery of the aperture which may engage with a portion of the syringe barrel. The aperture and, if present, the ridge present a smaller passageway than the inside diameter of the syringe, preventing inadvertent removal of the stopper from the syringe. The backstop can be placed on the syringe regardless of the presence or absence of the plunger.

Abstract: A non-reusable syringe with automatically actionable protective needle cover. The syringe consists of a syringe which locks the plunger in place after full injection, rendering it unusable. In addition an automatic needle cover is provided which aids as a clamping device and prevents pricking or leaking of a needle. the means of operating the needle cover also allows the needle to be visible for injection.

Abstract: The present invention is a self-destructive syringe that includes a cylindrical body with a hypodermic needle at one end, a breakable circle, and a retaining ring. The syringe has a piston with a sharp point at the front of the piston. When the piston reaches the lower end of the stroke, the sharp point on the piston perforates the breakable circle while the edges of the piston are encased in the retaining ring. The retaining ring has cutting edges which will damage the seal of the piston if the piston is returned for reuse. A seal, supported by flanges, is positioned at an opposite end of the syringe so as to prevent the piston from reaching the destructive end of the syringe.

Abstract: A syringe for administering medicines, pharmaceuticals, and other liquid or semi-liquid materials includes a movable scale which is automatically reset to a zero position after a preselected dosage of material has been discharged from the syringe. The scale is adjustable for selecting subsequent dosages to be discharged, which may be the same or different in quantity from the previously discharged dosage. The automatic zero reset feature of the scale enables a user to administer multiple dosages of material from the same syringe, and vary the quantity of each dosage if desired, without the need to make calculations or adjust the scale to compensate for either the quantity of material previously discharged from the syringe or the quantity of material currently remaining in the syringe.

Abstract: A safety syringe includes a means for retracting a used needle within the syringe, sealing the syringe and locking the plunger in a retracted position requiring only conventional syringe manipulation. Accidental contact with a used needle or syringe contents is thereby prevented such that the syringe can be safely discarded in a conventional manner. A needle clamp augmentation to the front surface of the syringe plunger is engageable with the needle head portion of a hollow needle releasingly mounted to the syringe. A sealant cavity formed proximate to the needle end of the syringe contains a sealing compound. A sealant cavity cover prevents migration of the sealing compound into the syringe cylinder. Fully depressing the plunger causes the needle clamp to engage the needle head portion. Retracting the plunger dislodges and retracts the needle, drawing a sealing means about the gap left by the retracted needle and preventing fluid leakage.

Abstract: A tubular barrel having an inner surface with threads at a front end ther receives a chuck having corresponding threads for engaging the chuck to the barrel, the chuck having additional threads in an opposite sense for engaging a needle hub thereto. A piston received slidably in the barrel engages the rear of the chuck and is fixed against rotation relative to the hub, whereby a piston stem protruding from the rear of the barrel can be used to engage the chuck to the front end of said barrel. Cams provided on the inside surface cooperate with flexible cam followers on the chuck to make disengagement of the chuck from the barrel more difficult than engagement. A circumferential rib provided on the inside surface at the rear of the barrel impedes withdrawal of the piston, the stem being frangible to prevent the reuse.

Abstract: One end of a hollow cylindrical tube is attached to a tubing positionable in a patient's body. A radial flange on the tube supports a collar in abutting relationship to one flange surface. Lugs extend integrally from the collar through the flange for disposition against the opposite flange surface. The collar extends radially past the tube's inner periphery and has slots at its inner periphery. Stops integral with the inner periphery of the collar are annularly displaced relative to the slots. Ramps on the collar lead to the stops. A piston in the tube along part of its length has, at the end within the tube, a sleeve in sealed relationship with the tube is inner periphery. Splines have grooves at spaced positions along their axial lengths at the radially outer ends of the splines. A handle at the piston axial end has an aperture to receive a user's finger for manual adjustment of the piston axially relative to the tube.

Abstract: A non-reusable, disposable syringe has a cylindrical barrel with a needle assembly on its forward end, and a needle trap for protecting the needle from contact. The needle trap includes a hollow plastic housing with a rearward end portion adapted to fit over the cylindrical barrel, and a generally cone-shaped forward end portion having a closed forward extremity. A locking member of generally hollow cylindrical shape is secured within the rearward end of the needle trap housing and has forwardly directed flexible, circumferentially spaced, inwardly tapering fingers that taper inwardly more rapidly than the forward end of the housing when the needle trap is placed over the barrel the fingers of the locking member flex outwardly to pass over the needle base and then flex inwardly to assume a locking position behind the needle base.

Abstract: A syringe tubular body forms a fluid receiving chamber having a restricted opening at one end for receiving a hollow needle and a wider opening at the other end for receiving a tubular plunger. The plunger has resilient fingers at its distal end which is inserted into the body chamber and an annular groove in one embodiment adjacent the proximal end. The fingers have inwardly extending hook-like projections. A piston assembly includes a body with an annular groove which releasably receives the projections for securing the piston assembly to the plunger during injection, the piston assembly including an elastomeric disc piston sealingly engaged with the tubular body chamber sides. A sleeve is external and movable along the body and is next adjacent the disc. The sleeve has an annular groove which is selectively engaged by the projections. The sleeve has an axial extent greater than that of the piston assembly body groove.

Abstract: Disclosed are pre-filled syringes equipped with an improved plunger, a plunger actuating cylinder and a plunger rod, characterized by a leak-proof seal and easy sliding property.

Abstract: A syringe (1) comprising a barrel (2) having an outer sheath (3) and an inner sheath (4). The outer sheath (3) has a nozzle (5) and the inner sheath also has a nozzle (6) which corresponds with and fits into, the nozzle (5). A needle (7) is attachable to the nozzle (6). A plunger (9) is located partly within the barrel (2) and is used to administer a drug. After the drug is administered the plunger (9) interlocks with the inner sheath (4) and as the plunger (9) is withdrawn, so too is the inner sheath (4), Hence the needle (7) is retracted to be within the outer sheath (3). After the needle (7) is retracted, the outer sheath (3) and inner sheath (4) are interlocked thus preventing the syringe (1) from being used again as well as locking the needle (7) in a safe retracted position within the outer sheath (3 ) thereby preventing "needle stick".

Abstract: A medical locking device securely fits onto finger grips of a syringe. The locking device is axially aligned with the syringe along a defined longitudinal axis wherein the syringe receives a plunger. The locking device includes a centrally positioned aperture which receives the shaft of the plunger. A retaining member is positioned around the aperture and receives the finger grips of the syringe by engaging at least three sides of the finger grips. This eliminates shifting of the medical locking device and there are opposed cutting members which are chordally positioned in the aperture. The cutting members taper as fine cutting edges for wedging into the plunger during execution of a locking position. To utilize the device, the user twists the plunger into a locking position so that the cutting members wedge into the plunger. This locking position eliminates and prevents any further plunger movement in either direction along the longitudinal axis.

Abstract: A surgical instrument for injecting/removing non-solid substances is diclosed. The instrument comprises a body formed from two legs (1, 2) pivotally articulated to each other at one of their ends, one of said legs (1) being provided with means (15,17) for receiving and retaining a syringe or squirt (16) while the other of said legs (2) is provided with means (20,22) for selectively retaining a plunger (19) which cooperates with said syringe or squirt, said legs being selectively pivotable between a first position wherein said plunger (19) is received within said syringe (16) and a plurality of positions wherein plunger (18) moves within syringe (16) in order to inject/remove a non-solid substance.

Abstract: A syringe for administering medicines, pharmaceuticals, and other liquid or semi-liquid materials includes a movable scale which is automatically reset to a zero position after a preselected dosage of material has been discharged from the syringe. The scale is adjustable for selecting subsequent dosages to be discharged, which may be the same or different in quantity from the previously discharged dosage. The automatic zero reset feature of the scale enables a user to administer multiple dosages of material from the same syringe, and vary the quantity of each dosage if desired, without the need to make calculations or adjust the scale to compensate for either the quantity of material previously discharged from the syringe or the quantity of material currently remaining in the syringe.

Abstract: A single-usage disposable hypodermic syringe in which the needle cover of the conventional syringe is replaced by a tubular housing which encloses from the tip of the needle cannula to the rear end of the barrel. An empty space is reserved inside the needle locking base for the positioning of a plug. When an arc segment of a projected member located at the front of the plunger is moved forward with the plunger, the plug with the channel is being pushed to the bottom of the empty space, allowing the plug to rotate and block off the opening of the needle cannula. The medication can no longer be given. A triangular plate installed in the rear portion of the Y-shaped plunger is used to restrict the movement of the projecting plate. Only when the projecting plate is rotated and swing away that the syringe is able to accept medication. The syringe cannot be reused and the tubular housing is used to cover the overall syringe for disposal.

Abstract: The present invention is a two-compartment syringe which may contain a medical substance, such as a freeze-dried powder, and a solvent separately. When used, the medical substance and solvent are mixed for injection. A silicone coating is used inside the syringe barrel. The syringe is further provided with finger hooks to enable use of the syringe with one hand.

Abstract: A syringe having a casing, a shiftable rod assembly, and a needle foot latched at a first end of the casing is disclosed. The syringe is equipped with a shiftable ring for limiting stroke length of the rod assembly in such a way to maintain the piston at a predetermined distance from the needle foot, and to increase the stroke length after a second outward shifting stroke of the piston for drawing in liquid, in such a way that upon a second inward shifting stroke of the piston for expulsion of the injection liquid, the piston will be coupled with the needle foot.

Abstract: A locking syringe is disclosed which comprises a plunger, a cylinder, and a cap. The plunger includes a proximal end and a distal end having a first set of annular ridges formed thereon. The cylinder comprises an open cylindrical passage and includes a needle attached in a conventional manner at the proximal end thereof. A plurality of annular ridges are formed inside the passageway at the distal end of the cylinder. The ridges in the cylinder engage the annular ridges on the plunger in a snap fit and prevent removal of the plunger from the cylinder after the syringe has been used. The cylinder also includes a plurality of annular ridges formed adjacent the needle. The ridges on the cylinder snap fit into mating annular ridges in the cap to prevent re-use of the needle once the syringe is discarded.

Abstract: A control syringe is provided for fine needle aspiration of biopsy tissue. An aperture through the barrel of the syringe is temporarily covered with a flexible impervious pressure sensitive adhesive tape. A low pressure created in the barrel by withdrawing the plunger is broken by peeling the tape from the barrel. Thereafter, the tape may be replaced over the aperture so that collected tissue may be discharged by moving the plunger forward. A ratchet and pawl arrangement on the syringe holds the plunger in its rearward position until released. One ratchet and pawl comprises a plurality of ratchet teeth along at least one rib of an X-shaped cross section of the plunger and a pawl on the rearward end of the barrel for engaging the ratchet teeth. Such a ratchet is released by rotating the plunger.

Abstract: A pre-filled hypodermic syringe includes a retractable needle and detachable plunger shaft so the syringe can be selectively rendered inoperable. A liquid held within the syringe is held in place by a elastomeric stop that surrounds the discharging tip of the needle. When the syringe is to be used, the needle stop is removed and the plunger is advanced within the syringe barrel until the liquid is displaced through the needle. When the plunger contacts the base of the needle within the syringe barrel, the plunger becomes capable of being rotated. The rotation of the plunger connects the plunger to the needle and the needle can be retracted into the syringe barrel with the plunger. Once fully retracted, the needle cants and the plunger shaft can be destructively disconnected from the plunger, rendering the syringe inoperable.

Abstract: A resilient material pressurizing plunger for syringes or like containers in which the plunger construction is such that on the initial insertion into the syringe by a first inserting member, the plunger is distortable thus allowing the gas pressure generated by the plunger insertion to escape. The plunger is also capable of pressurizing the chamber when further insertion occurs by use of a second insertion member which prevents the distortion.

Abstract: A syringe for injecting medicinal fluids into a patient or aspirating fluids or tissue from a patient, wherein the syringe incorporates a self-locking mechanism on the plunger thus preventing the plunger from being withdrawn back into the barrel by the action of a vacuum in the syringe barrel. The self-locking mechanism is independent of the relative rotational relationship of the plunger with respect to the barrel. Unlocking may be effected by simply squeezing the self-locking mechanism on the plunger, no rotational force being necessary.

Abstract: A locking device is capable of being retrofitted by insertion into a standard plastic syringe. The syringe is of the type having a cylindrical inner wall made of plastic material, a closed, distal end, and an open, proximal end for movement of a plunger therein. The plunger has a plunger stem made of plastic material with longitudinal ribs in an "X" shaped cross-section. The locking device has a clip-type body portion formed with a U-shaped channel for clipping onto one longitudinal rib, a first set of barbed points angled toward the plunger stem for engaging the plunger stem when it is depressed toward the distal end after a first retraction movement toward the proximal end of the syringe, and a second set of barbed points angled toward the inner wall of the syringe for engaging the inner wall in order to lock the plunger stem from a second retraction movement, thereby preventing reuse of the syringe.