Abstract: A retracting needle safety syringe (2) includes a barrel (4) having a tip (10), to which a needle assembly (28) is mounted, and a plunger (6) including a stem (34) and a piston (40) at the distal end of the stem. The piston has a piston body (46) and a piston seal (58) which engages the barrel inner surface. The piston seal is detached from the piston, the piston body is secured to the tip, and the tip of the barrel is detached from the remainder of the barrel when the plunger is moved to its distal position. Pulling the plunger proximally from the distal position back towards a proximal position causes the piston body, the tip and needle assembly to be pulled into the interior (56) of the barrel, but without the piston seal sliding against the barrel. This retraction can take place manually or automatically.

Abstract: An ear piercing stud comprises a machined piercing post of titanium or other metal suitable for being in contact with flesh, a stud head of material capable of being gold plated and a shield of a material suitable for being in contact with pierced flesh. The shield lies against the stud head where the post meets the stud head to shield flesh from contact with the stud head in use. The post, shield and stud head are made separately and are assembled with part of the post passing through the shield and engaged in the stud head to hold the post, shield and stud head permanently.

Abstract: A one-piece syringe (2) includes an elongate frame (4) having front and back parts (6, 8) coupled by a hinge (10). A hollow barrel (12) extends from the front part and away from an outer surface (22). Plunger 14 has a pair of main bore gaskets 54 and an entrance bore gasket 56 at an outer end 32. Entrance bore gasket 56 is sized to matingly engage an entrance bore portion 52 while main bore gaskets 54 are sized to matingly engage a main bore portion 58 of bore 40. Main bore portion 58 has a smaller diameter than entrance bore portion 52. Sizing the gaskets in this manner permits syringe 2 to be shipped filled with an injectant 60 while keeping main bore gaskets from compression set during storage.

Abstract: A disposable syringe comprises a syringe cylinder and a syringe piston. The syringe cylinder is open at one end and at its other end has an end wall, which is closed with the exception of a region adjacent to a needle holder. The syringe piston comprises a piston skirt, which protrudes from the syringe cylinder, and a piston head, which is disposed within the syringe cylinder and provided with an annular seal. The annular seal is connected to the piston head by an annular peripheral flange.In order to provide a syringe which can easily be actuated and is nevertheless absolutely tight, the flange is frustoconical and flares toward the piston skirt. The radial distance from the inside peripheral surface of the hollow frustoconical flange to the piston skirt increases continuously. The flange is adjoined by the annular seal, which consists of a coaxial cylinder and freely protrudes on the side of the piston head.

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 safety syringe for preventing "needle stick" injury and/or reuse of the syringe includes a body (2), a plunger (4) mounted within the body, connection means (24) for connecting the plunger (4) to a needle holder (6) whereby subsequent retraction of the plunger (4) withdraws the needle holder (6) and the needle with a shielded position within the body (2) effected by a vacuum chamber (18) defined between the plunger (4) and the syringe body (2), vacuum being created within the chamber (18) by movement of the plunger (4) during the injection stroke and serving to withdraw the plunger (4), the needle holder (6) and needle after injection pressure is removed. The syringe may be provided with braking means (20) to control the rate of withdrawal of the needle and/or to prevent withdrawal until the injection stroke of the plunger (4) has been completed.

Abstract: In general, syringes for needleless injectors must be resonably accurately dimensioned, and the barrel of the injector must be formed of metal in order to prevent expansion of the syringe under pressure. A simple alternative is a syringe including an elongated tubular body with one open end and a closed end containing an injection orifice, and a plug slidable in the body with a prong at one end of the plug extending towards the orifice end of the body, the prong carrying an O-ring and an annular seal which prevents squeezing of the O-ring between the body of the syringe and the plug under injection pressures. An alternative form of syringe includes a pair of valves, one of which normally closes the injection orifice, and the other of which is mounted on the plug.

Abstract: A disposable syringe for injections has a cylindrical housing (1), which accommodates a piston (2) with a rod (3) and a needle fixing device. The piston (2) and the rod (3) are mechanically disengaged from each other and the rod (3) has an annular two-stepped slot (5), wherein provision is made for a lower-depth portion (6) and a higher-depth portion (7). A sealing cup (8) made of an elastic material is interference-fitted in the portion (6) of the slot (5), the width of the cup (8) being in excess of the clearance (b) between the bottom of the slot (5) in the portion (6) thereof and the inner surface of the housing (1).

Abstract: An operable syringe assembly comprises a barrel including a cylindrical body portion having a longitudinal axis. The body portion forms a side wall spaced from the axis defining a chamber for retaining fluid. The body portion includes an open proximal end and a distal end and further includes an inner barrel portion and an outer barrel portion surrounding and in spaced relationship with the inner barrel portion. The outer barrel portion is held in spaced relation with the inner barrel portion by at least one longitudinally oriented rib connecting the outer barrel portion and the inner barrel portion. A plunger including an elongate shaft portion having a proximal end, a distal end and a rigid piston at the distal end is provided. The piston has an outside diameter greater than the inside diameter of the inner barrel portion. The piston portion is slidably positioned in fluid-tight engagement inside the barrel.

Abstract: Apparatus for the delivery of light-curable composite dental filling material comprises a tubular composite reservoir, plunger and slider. The slider is free to move longitudinally along the reservoir but is matingly mounted to facets on the outside surface of the reservoir to prevent angular movement of the slider relative to the reservoir. The plunger consists of a shaft threaded to mate with the threaded inside diameter of the composite reservoir. The plunger also has a disk integrally formed to end of the shaft at one end and a male front piece at the other. The male front piece mates with a female fitting of a separate composite extrusion element.

Abstract: There are depicted two embodiments of an ambulatory disposable infusion delivery system in which fluid (drug) is fed to a substantially transparent receiving and retaining housing which has indicia markings conventionally applied to indicate quantity. The inflow of fluid causes an elastomeric member attached to a piston, which is slideable in a bore in this housing, to be moved, thus stretching this member. This tension provides an energy source (force) to push the fluid out of the bore when the connected tubing line is opened. The housing is provied with a discharge fluid conduit and a restrictor controlling the rate of flow. In both embodiments, the housing has a barrel with a substantially constant bore. The slideable piston in this bore has a resilient outer portion with at least two ribs providing sealing action while having a low coefficient of friction.

Abstract: Disposable syringe made of plastics, for medical purposes, consisting of a barrel (1), a piston (2) provided with a plunger shaft (3) guided at a distance from the barrel wall, and a closure cap (4), the piston (2) being releasably joined to the plunger shaft (3). The piston (2) is at least partially softly resilient due to the fact that on the piston periphery wall parts of greatly reduced wall thickness are present. The closure cap (4) contains a sufficiently long, stable slide bearing for the plunger shaft (3), so that deformation of the latter, arising out of off-center application of force in the retracted piston position, and out of the tendency of the relatively thin plunger shaft (3) to bow or buckle, will not be transferred to the piston (2).

Abstract: A piston for a precision dosing instrument includes a cylindrical core which may be made of glass, ceramic or metal, and a precision ground sleeve of polytetrafluorethylene disposed over the core. One end of the sleeve is closed while the core is open at both ends.

Abstract: A syringe having a barrel adapted to receive a plunger with a through passageway from the bottom wall of a groove in which an O-ring seal is positioned to the rear surface of the plunger. Upon insertion of the plunger into the barrel, the O-ring will move to a position adjacent a rear wall defining the groove over the passageway and allow air to escape from within the barrel through the passageway. When the pressure used to seat the plunger against material within the barrel is removed, the plunger will rebound slightly causing the plunger to move relative to the O-ring so that the O-ring makes an air tight seal between the plunger and the barrel. When pressure is again applied to the plunger to press the material out of the barrel, the plunger will again move relative to the O-ring to again position the O-ring over the passageway, however, the O-ring will seal the passageway sufficiently to restrict escape of a significant amount of the viscous material through the passageway.

Abstract: A device for taking specimens for laboratory analysis, specimens being of a fluid type such as body liquids or may be liquids of a different source. The device comprises a hollow body member with a closed end and an open end. The closed end has orifice therethrough which orifice is eccentric with respect to the longitudinal axis of the body member. A plunger having a plunger tip means is inserted into the body member for the purpose of accurately varying the internal volume of the device. The closed end is provided with an exteriorly mounted closure which may be of a rotatable type or a sliding plate type. The closure contains an orifice which may be aligned with the orifice in the closed end to take specimens into the device and then the closure may be moved with reference to the body member to misalign the orifices so that the orifice in the body member is closed and the specimen cannot be ejected from the device.

Abstract: A disposable syringe cartridge including a molded plastic cylinder having an open end and a closed end with inlet and outlet nipples integrally formed in the closed end, and a plastic piston head slidably received in the open end of the cylinder and pivotably connected to a plastic piston rod. The piston head utilizes a quad-type sealing ring providing a pair of adjacent sealing surfaces with the cylinder, and includes a square expansion flange rounded at each of its corners to conform in shape to the cylinder, with a rubber annular sealing boot extending between the open end of the syringe cylinder and the piston rod. A flange formed on the outer circumferential edge of the sealing boot is received over the open end of the cylinder and is captured by an annular cap that is ultrasonically welded to the cylinder, while a bead formed on the inner circumferential edge of the sealing boot is received in a groove defined by a pair of adjacent annular flanges formed on the piston rod.

Abstract: A piston for a precision dosing instrument includes a cylindrical core which may be made of glass, ceramic or metal, and a precision ground sleeve of polytetrafluorethylene disposed over the core. One end of the sleeve is closed while the core is open at both ends but the openings may have different diameters.

Abstract: A syringe, primarily for use with rapid hard setting viscous flowable material, has one or more passages in the piston whereby gas but not the viscous flowable material can escape to the rear of the piston.