Abstract: A disposable syringe includes a barrel with a bushing unit disposed on an inner surrounding surface thereof, a tubular grip unit in fluid-tight engagement with the bushing unit for holding a needle seat, a tubular plunger having a seal ring that is slidable on and in fluid-tight frictional engagement with the bushing unit so as to cooperate with the grip unit to define a medicament chamber, and a shield plug member in fluid-tight engagement with the grip unit and having a duct that communicates a needle cannula with the medicament chamber, thereby ensuring fluid-tightness of the medicament chamber.

Abstract: An intravenous catheter introducing device includes a barrel, a tubular grip member disposed to hold a needle seat in a position of use so as to permit a tip end of a needle cannula to extend forwardly of the barrel, a tubular plunger which is movable along a passage of the barrel, and a tubular receptacle which is retained in an accommodation compartment of the tubular plunger and which has socket and air-permeable ends and a flashback chamber. When the plunger is pressed forwardly to permit engagement of the socket end with a rear plug portion of the needle seat and to release the grip member from the barrel, a rearward movement of the needle seat by virtue of a biasing force of a biasing member will force the receptacle to move rearwardly so as to retract the needle cannula into the passage.

Abstract: An intravenous catheter introducing device includes a needle hub slidably inserted into a barrel and holding a needle cannula, a biasing member disposed to bias the needle hub to a rear position so as to retract the needle cannula in the barrel, and an easy release unit including an engaging wall segment which is attached to an outer surface of the barrel, two flexible squeezed wall segments which extend from the engaging wall segment and which is squeezable so as to move two latch members to steer clear of a retained end of the needle hub through an access hole in the barrel, thereby permitting the biasing member to bias the needle hub towards the rear position.

Abstract: A disposable syringe includes a pre-filled carpule which is retained in a barrel by means of a lunge member, a ring grip and a carrier unit. A retaining mechanism is disposed to guard the carrier unit against movement away from a locked position. A needle assembly is connected to the carpule. A plunger is engaged with a seal member of the carpule to cooperate with a tubular wall to define a sealed chamber that is communicated with the needle assembly. After the plunger is turned relative to the barrel to move the carrier unit to the unlocked position, the carpule can be pressed forwardly to force the carrier unit to release the ring grip from the lunge member such that the needle assembly and the carpule are biased by a biasing member rearwardly to retract the needle cannula into the barrel.

Abstract: A disposable syringe includes a barrel with a bushing unit disposed on an inner surrounding surface thereof, a tubular grip unit in fluid-tight engagement with the bushing unit for holding a needle seat, a tubular plunger having a seal ring that is slidable on and in fluid-tight frictional engagement with the bushing unit so as to cooperate with the grip unit to define a medicament chamber, and a shield plug member in fluid-tight engagement with the grip unit and having a duct that communicates a needle cannula with the medicament chamber, thereby ensuring fluid-tightness of the medicament chamber.

Abstract: An intravenous catheter introducing device includes a barrel, a tubular grip member disposed to hold a tubular member and a needle seat to permit a tip end of a needle cannula to extend forwardly of the barrel, a tubular plunger movable along a passage of the barrel, and a tubular receptacle retained in the plunger. Forward movement of the plunger permits engagement of a socket end of the receptacle with the rear plug portion of the tubular member and release of the grip member from the barrel such that the needle cannula can be retracted into the plunger. The tubular member has a pre-chamber so that flashback blood flowing thereinto is visible.

Abstract: A disposable syringe includes a barrel, a needle assembly, a plunger, a press-fitting unit, and a spacer. The plunger is movable in the barrel to a retraction initiating position, where a front open plunger end is coupled with the needle assembly for withdrawal of the needle assembly into the plunger. An endcap is disposed to cover a rear open plunger end of the plunger. The press-fitting unit is disposed between the plunger and an inner barrel surface of the barrel to permit press-fit engagement between the plunger and the barrel immediately after the plunger is moved to the retraction initiating position. The spacer includes front and rear abutment surfaces detachably engaged with the barrel and the endcap in a preuse position.

Abstract: A disposable syringe includes a barrel, a needle assembly, a plunger, and a spacer. A tubular catch extends rearwardly of the barrel to terminate at a peripheral edge. The needle assembly includes a needle cannula and a needle seat for securing the needle cannula. The plunger is movable in the barrel to a retraction initiating position, where a front open plunger end is coupled with the needle seat for withdrawal of the needle seat and the needle cannula into the plunger. An endcap is disposed to cover a rear open plunger end, and has a ring wall fittable in the catch. The spacer has front and rear abutment surfaces that detachably and respectively abut against the peripheral edge and a rim of the ring wall in a pre-use position to thereby prevent movement of the plunger to the retraction initiating position.

Abstract: A disposable syringe includes a barrel having a retaining region to retain a needle seat for carrying a needle cannula, and a friction diminishing region extending forwardly from the retaining region and terminating at a shoulder abutment, a plunger movable in the barrel toward the needle seat, and a coupling member biased by a biasing member and having a retained portion to frictionally engage the plunger, and an anchored portion to engage an anchoring portion of the needle seat such that when the needle seat is moved past the friction diminishing region to abut against the shoulder abutment, a subsequent pushing force applied to the plunger results in release of the retained portion from the plunger, thereby enabling the anchored portion to be moved into the plunger by means of the biasing member.

Abstract: An intravenous catheter introducing device includes a needle hub received in a barrel and holding a needle cannula. The barrel has a slotted path with starting and ending regions, and a docking port communicated with the starting region to form a docking shoulder. An engaging peg is disposed on the needle hub, and is anchored on the docking shoulder in use. The peg is slidable along the slotted path to the ending region for drawing the needle cannula into the barrel by means of a spring. A receptacle frame is disposed on the barrel, and defines a guide way for guiding movement of a guided body of an actuating unit such that a pushing body shoves the peg from the docking shoulder to the starting region. A stabilizing unit is disposed to keep the peg moving with the guided body.

Abstract: An intravenous catheter introducing device includes a needle hub slidably inserted into a barrel and holding a needle cannula, a biasing member disposed to bias the needle hub to a rear position so as to retract the needle cannula in the barrel, and an easy release unit including an engaging wall segment which is attached to an outer surface of the barrel, two flexible squeezed wall segments which extend from the engaging wall segment and which is squeezable so as to move two latch members to steer clear of a retained end of the needle hub through an access hole in the barrel, thereby permitting the biasing member to bias the needle hub towards the rear position.

Abstract: An intravenous catheter introducing device includes a barrel, a tubular grip member disposed to hold a needle seat in a position of use so as to permit a tip end of a needle cannula to extend forwardly of the barrel, a tubular plunger which is movable along a passage of the barrel, and a tubular receptacle which is retained in an accommodation compartment of the tubular plunger and which has socket and air-permeable ends and a flashback chamber. When the plunger is pressed forwardly to permit engagement of the socket end with a rear plug portion of the needle seat and to release the grip member from the barrel, a rearward movement of the needle seat by virtue of a biasing force of a biasing member will force the receptacle to move rearwardly so as to retract the needle cannula into the passage.

Abstract: A single-use syringe includes a barrel having front and rear passageways and a shoulder disposed there between, a plunger movable in the rear passageway, a carrier having a tail portion extending from a front end wall of the plunger, and pushing and retained regions formed forwardly of the tail portion, and a deformable sealing member in fluid-tight and slidable engagement with the barrel. The sealing member includes an inner surrounding wall surface with a yielding segment engaging the pushing region, and a retaining segment in frictional engagement with the retained region by a frictional force so as to confine a fluid-tight surrounding area. The frictional force is diminished when the yielding segment is depressed by the pushing region so as to facilitate release of the retained region from the retaining segment, thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable.

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: A disposable syringe includes a barrel, a seat member held by a grip member in the barrel such that a needle cannula extends through the seat member, a carpule configured to be fitted in a rear compartment of the barrel, and having front and rear seal members to confine a sealed chamber communicated with the needle cannula for holding liquid medicament, and a plunger operable to move the rear seal member forwardly to expel the liquid medicament through the needle cannula so as to bring the carpule in a used-up position, and to further move the front seal member from the used-up position so as to remove the grip member from the seat member to thereby bring the seat member to the disengaging position. A biasing member is disposed to bias the seat member together with the carpule rearwardly so as to retract the used needle cannula into the barrel.

Abstract: A disposable syringe includes a barrel, a needle assembly in fluid communication with the barrel, and a plunger movable in an accommodation chamber of the barrel. The needle assembly includes a needle seat sleeved on a small-diameter wall portion of the barrel, and a tubular insert extending axially into a duct of the needle seat and defining a fluid channel, and a needle cannula in fluid communication with the fluid channel. A space minimizing member is disposed to be in a fluid-tight engagement with an inner surface of the small-diameter wall portion, and has a tubular grip surface which defines a passageway fluidly communicated with the duct such that the insert is in a fluid-tight engagement with the grip surface to thereby communicate the channel with the chamber. Thus, the amount of residual medication fluid in the barrel after completion of an injection operation can be minimized.

Abstract: A single-use syringe includes a deformable sealing member which is in a fluid-tight and slidable engagement with a barrel wall, a plunger which is disposed to be movable along the barrel wall, a first coupling member which is secured to a front end wall of the plunger, and which has a first connected end disposed forwardly of the front end wall, and a second coupling member which is secured to a trail end wall of the sealing member, and which has a second connected end disposed rearwardly of the trail end wall. The second connected end confronts the first connected end in a radial direction, and is attached to the first connected end at a bonding region. Immediately after the second connected end stays put as a result of abutment of the sealing member against a shoulder of the barrel, a subsequent forward force applied to the plunger breaks the bonding region, thereby preventing operation of the plunger to move the sealing member rearward, and thereby rendering the syringe unreusable.

Abstract: A disposable syringe includes a plunger movable in a barrel relative to a needle seat that engages an inner surrounding barrel wall surface of the barrel by a resisting force. The plunger includes a plunger body and a coupling rod which is in frictional engagement with the plunger body and which has a central anchored area disposed to engage an anchoring portion of the needle seat by a holding force. As such, when the plunger body is moved to bring the central anchored area into engagement with the anchoring portion, the resisting force is overcome to permit disengagement of the needle seat from the barrel, and the coupling rod and the needle seat can be retracted into the plunger body by virtue of a biasing action of a biasing member.

Abstract: An intravenous catheter introducing device includes a needle cannula with a rear connecting end that is forced by a needle retracting member to displace relative to a barrel between a position of use to permit a needle tip to pierce a patient's vein, and a disposal position to permit retraction of the needle tip into the barrel. A tubular outlet member is disposed downstream of the rear connecting end, and is mounted radially and outwardly of the barrel. A flashback member can be connected to and in fluid communication with the tubular outlet member so as to permit the user to check whether a tubular catheter has been successfully introduced into a target vein of the patient. In addition, the flashback member can provide a blood drawing function to facilitate flow of blood into the flashback member.

Abstract: An intravenous catheter introducing device includes a needle assembly and a flashback member. The flashback member defines a flashback chamber having an accommodation space with a volume that is variable upon application of a manual force to the flashback chamber such that a reduced pressure is created in the accommodation space to place the flashback chamber in a ready position, where a tip end of the needle assembly can be brought to pierce a patient's skin for introducing a tubular catheter into the patient's vein, while a biasing force is generated to act on the flashback chamber. A pressure counteracting member is disposed to resist the biasing force such that the flashback chamber can be held in the ready position without application of any manual force once the tip end has pierced into the skin in search of the vein, and such that blood flow into the needle assembly is facilitated to enable the user to check the introduction of the catheter.