Abstract: Techniques for extinguishing a plasma arc in a blowback plasma torch are provided. The plasma arc can be extinguished by bringing the electrode into contact with the nozzle and out of contact with the nozzle while the power supply and flow of gas are left on. In particular, while current is flowing through the electrode, the electrode may be brought into contact with the nozzle to extinguish the plasma arc.

Abstract: Techniques for extinguishing a plasma arc in a blowback plasma torch are provided. The plasma arc can be extinguished by bringing the electrode into contact with the nozzle and out of contact with the nozzle while the power supply and flow of gas are left on. In particular, while current is flowing through the electrode, the electrode may be brought into contact with the nozzle to extinguish the plasma arc.

Abstract: A retractable safety syringe may have a needle, a syringe body, a shaft seal, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a shaft coupled to a piston. The shaft may have at least one non-engaging portion and at least one engaging portion. The plunger assembly is movable between a storage position and working positions. In the storage position, little or no force is exerted on the shaft seal by the non-engaging portion. In the working positions, the engaging portion is in sealing engagement with the shaft seal to seal the vacuum chamber. Stopper movement of the retractable safety syringe may be reduced or eliminated if the retractable safety syringe is prefilled.

Abstract: A retractable safety syringe may have a ferrule and needle which are selectively removeable from a distal end of a syringe body. In particular, the ferrule may have an annular flange. A wedge element may be frictionally engaged to the ferrule and a distal end of the syringe body. To retract the needle into the syringe body, a punch of a piston displaces the wedge element off of an annular flange of the ferrule. At about the same time, longitudinally offset tabs engage an annular flange and retract the needle into the syringe body via a retraction force created by a variable vacuum compartment or tension member. Alternatively, the ferrule and needle may be temporarily fixed to the distal end of the syringe body via a detent and/or o-ring which engages a lower undercut groove and an upper undercut groove of the ferrule. An annular ring of the piston may have longitudinal offset tabs which engage an annular ring of the ferrule.

Abstract: A safety syringe may define a variable fluid chamber and detached needle assembly. The variable fluid chamber may be hermetically sealed off from the environment or ambient air until the needle assembly is attached to a syringe body of the safety syringe. A proximal end of the variable fluid chamber is sealed off from the environment via a seal between a piston and syringe body. The distal end of the variable fluid chamber may be sealed off from the environment via a barrier covering the distal end of the syringe body. The barrier may be punctured to allow fluid to through tberethrough at or about the same time when the needle assembly is attached to the distal end portion of the syringe body.

Abstract: A safety syringe may define a variable fluid chamber and detached needle assembly. The variable fluid chamber may be hermetically sealed off from the environment or ambient air until the needle assembly is attached to a syringe body of the safety syringe. A proximal end of the variable fluid chamber is sealed off from the environment via a seal between a piston and syringe body. The distal end of the variable fluid chamber may be sealed off from the environment via a barrier covering the distal end of the syringe body. The barrier may be punctured to allow fluid to through therethrough at or about the same time when the needle assembly is attached to the distal end portion of the syringe body.

Abstract: A retractable safety syringe may have a needle, a syringe body, a shaft seal, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a shaft coupled to a piston. The shaft may have at least one non-engaging portion and at least one engaging portion. The plunger assembly is movable between a storage position and working positions. In the storage position, little or no force is exerted on the shaft seal by the non-engaging portion. In the working positions, the engaging portion is in sealing engagement with the shaft seal to seal the vacuum chamber. Stopper movement of the retractable safety syringe may be reduced or eliminated if the retractable safety syringe is prefilled.

Abstract: A retractable safety syringe may have a ferrule and needle which are selectively removeable from a distal end of a syringe body. In particular, the ferrule may have an annular flange. A wedge element may be frictionally engaged to the ferrule and a distal end of the syringe body. To retract the needle into the syringe body, a punch of a piston displaces the wedge element off of an annular flange of the ferrule. At about the same time, longitudinally offset tabs engage an annular flange and retract the needle into the syringe body via a retraction force created by a variable vacuum compartment or tension member. Alternatively, the ferrule and needle may be temporarily fixed to the distal end of the syringe body via a detent and/or o-ring which engages a lower undercut groove and an upper undercut groove of the ferrule. An annular ring of the piston may have longitudinal offset tabs which engage an annular ring of the ferrule.

Abstract: A retractable safety syringe may have a needle, needle holder, syringe body, a shaft seal, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a shaft coupled to a piston. The shaft may have at least one non-engaging portion and at least one engaging portion. The plunger assembly is movable between a storage position and working positions. In the storage position, little or no force is exerted on the shaft seal by the non-engaging portion. In the working positions, the engaging portion is in sealing engagement with the shaft seal to seal the vacuum chamber. Stopper movement of the retractable safety syringe may be reduced or eliminated if the retractable safety syringe is prefilled.

Abstract: A safety syringe may define a variable fluid chamber and detached needle assembly. The variable fluid chamber may be hermetically sealed off from the environment or ambient air until the needle assembly is attached to a syringe body of the safety syringe. A proximal end of the variable fluid chamber is sealed off from the environment via a seal between a piston and syringe body. The distal end of the variable fluid chamber may be sealed off from the environment via a barrier covering the distal end of the syringe body. The barrier may be punctured to allow fluid to through therethrough at or about the same time when the needle assembly is attached to the distal end portion of the syringe body.

Abstract: A retractable safety syringe may have a needle, needle holder, syringe body, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a distal piston and a proximal piston, with an intermediate chamber disposed between the two plungers. A vent through the syringe body pneumatically connects ambient air and the intermediate chamber allowing air to escape out of the intermediate chamber when a plunger assembly traversed toward the engaged position and allow air to be introduced into the intermediate chamber. A retraction force may be created by the vacuum chamber by traversing the plunger assembly to the engaged position. At the engaged position, the distal piston may engage the needle holder and the retraction force may retract the needle holder and needle into the syringe body to prevent accidental needle pricking and needle reuse.

Abstract: A retractable safety syringe may comprise a needle, needle holder, syringe body, and a plunger. A proximal portion of the body and a piston of the plunger may define a variable vacuum compartment. A through hole pneumatically connecting ambient air and the variable vacuum compartment may be formed through a thumb platform and rigid shaft of the plunger for allowing air to escape out of the variable vacuum compartment when a piston of the plunger is traversed toward the retracted position and allow air to be introduced into the variable vacuum compartment when the piston is traversed toward the engaged position. A retraction force may be created by the variable vacuum compartment by covering an entrance of the through hole and traversing the piston to the engaged position. At the engaged position, the piston may engage the needle holder and the retraction force may retract the piston, needle holder and needle into the syringe body to prevent accidental needle pricking and needle reuse.

Abstract: A retractable safety syringe may have a ferrule and needle which are selectively removeable from a distal end of a syringe body. In particular, the ferrule may have an annular flange. A wedge element may be frictionally engaged to the ferrule and a distal end of the syringe body. To retract the needle into the syringe body, a punch of a piston displaces the wedge element off of an annular flange of the ferrule. At about the same time, longitudinally offset tabs engage an annular flange and retract the needle into the syringe body via a retraction force created by a variable vacuum compartment or tension member. Alternatively, the ferrule and needle may be temporarily fixed to the distal end of the syringe body via a detent and/or o-ring which engages a lower undercut groove and an upper undercut groove of the ferrule. An annular ring of the piston may have longitudinal offset tabs which engage an annular ring of the ferrule.

Abstract: A retractable safety syringe may have a needle, needle holder, syringe body, a shaft seal, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a shaft coupled to a piston. The shaft may have at least one non-engaging portion and at least one engaging portion. The plunger assembly is movable between a storage position and working positions. In the storage position, little or no force is exerted on the shaft seal by the non-engaging portion. In the working positions, the engaging portion is in sealing engagement with the shaft seal to seal the vacuum chamber. Stopper movement of the retractable safety syringe may be reduced or eliminated if the retractable safety syringe is prefilled.

Abstract: A retractable safety syringe may have a needle, needle holder, syringe body, and a plunger assembly. A proximal portion of the body and a piston of the plunger may define a vacuum chamber. The plunger assembly may comprise a distal piston and a proximal piston, with an intermediate chamber disposed between the two plungers. A vent through the syringe body pneumatically connects ambient air and the intermediate chamber allowing air to escape out of the intermediate chamber when a plunger assembly traversed toward the engaged position and allow air to be introduced into the intermediate chamber. A retraction force may be created by the vacuum chamber by traversing the plunger assembly to the engaged position. At the engaged position, the distal piston may engage the needle holder and the retraction force may retract the needle holder and needle into the syringe body to prevent accidental needle pricking and needle reuse.

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 a brake member which is traversable between a braking position and a released position. At the braking position, the brake member frictionally engages 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 brake member is traversed to the released position, the brake member does 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 retractable safety syringe may have a ferrule and needle which are selectively removeable from a distal end of a syringe body. In particular, the ferrule may have an annular flange. A wedge element may be frictionally engaged to the ferrule and a distal end of the syringe body. To retract the needle into the syringe body, a punch of a piston displaces the wedge element off of an annular flange of the ferrule. At about the same time, longitudinally offset tabs engage an annular flange and retract the needle into the syringe body via a retraction force created by a variable vacuum compartment or tension member. Alternatively, the ferrule and needle may be temporarily fixed to the distal end of the syringe body via a detent and/or o-ring which engages a lower undercut groove and an upper undercut groove of the ferrule. An annular ring of the piston may have longitudinal offset tabs which engage an annular ring of the ferrule.

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 a brake member which is traversable between a braking position and a released position. At the braking position, fingers of the 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 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 retractable safety syringe may have a ferrule and needle which are selectively removeable from a distal end of a syringe body. In particular, the ferrule may have an annular flange. A wedge element may be frictionally engaged to the ferrule and a distal end of the syringe body. To retract the needle into the syringe body, a punch of a piston displaces the wedge element off of an annular flange of the ferrule. At about the same time, longitudinally offset tabs engage an annular flange and retract the needle into the syringe body via a retraction force created by a variable vacuum compartment or tension member. Alternatively, the ferrule and needle may be temporarily fixed to the distal end of the syringe body via a detent and/or o-ring which engages a lower undercut groove and an upper undercut groove of the ferrule. An annular ring of the piston may have longitudinal offset tabs which engage an annular ring of the ferrule.

Abstract: A safety syringe may define a variable fluid chamber and detached needle assembly. The variable fluid chamber may be hermetically sealed off from the environment or ambient air until the needle assembly is attached to a syringe body of the safety syringe. A proximal end of the variable fluid chamber is sealed off from the environment via a seal between a piston and syringe body. The distal end of the variable fluid chamber may be sealed off from the environment via a barrier covering the distal end of the syringe body. The barrier may be punctured to allow fluid to through therethrough at or about the same time when the needle assembly is attached to the distal end portion of the syringe body.