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US 4,850,968 AGranted
Self-blocking hypodermic syringe for once-only use, comprising a needle protection cap
AssigneeAR.MA.s.r.l.
InventorArmando Romano
Life of this patent
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AssigneeAR.MA.s.r.l.
InventorArmando Romano
Estimating the term…
The syringe according to the invention comprises elastic means for blocking the intake stroke of the plunger which are initially located in an inactive position and are transferred into an active position during the first syringe intake and injection operation. When in said active position the elastic means are disposed in a position secured to the cylindrical body of the syringe and interfering with the intake stroke of the plunger. The syringe of the invention also comprises a slidable cap coaxial to the syringe body and covering the body itself, and being provided at its front with an exit hole for the needle and having members for its fastening to the syringe body, and elastic thrust means. The cap when in its retracted position leaves the needle exposed and when in its advanced position covers the needle, the fastening members being moved into their released position by elastic means on the first forward movement of the plunger.
A self-blocking hypodermic syringe of the type wherein a plunger is withdrawn for an intake stroke of liquid before dispensing the liquid, with the syringe operable for once-only use comprising a cylindrical body which at its front end carries means for connection to a hypodermic needle and is open at its opposite end, a plunger which slides in a fluid-tight manner and is provided with a gripping rod, elastic means for blocking the intake stroke of the plunger which are initially located in an inactive position and are transferred into an active position during the first syringe intake and injection operation, and structure operable when the plunger is placed in said active position by a first intake stroke to dispose the elastic means in a detent position securing the elastic means to the cylindrical body of the syringe and operable to prevent a further plunger intake stroke.
A self-blocking hypodermic syringe for once-only use comprising a cylindrical body which at its front and carries means for connection to a hypodermic needle and is open at its opposite end, and contains a plunger which slides in a fluid-tight manner and is provided with a gripping rod, characterized by also comprising elastic means for blocking the intake stroke of the plunger which are initially located in an inactive position and are transferred into an active position during first syringe intake and injection operation, when in said active position the elastic means being disposed in a position secured to the cylindrical body of the syringe and interfering with the plunger intake stroke, said elastic means consisting of a split-ring which before the syringe is initially used embraces the minor diameter region of a frusto-conical portion of the rod of the plunger which converges in the direction in which the plunger is driven for injection, the minor diameter region of the frusto-conical portion having a diameter less than the diameter of the rod and the major diameter region having a diameter substantially equal or slightly less than the inner diameter of the cylindrical body, the syringe cylindrical body comprising an annular bulge which is able to receive the slit-ring when this drawn in front of it during the initial liquid intake stage, said bulge having an inner diameter greater than the diameter of the major diameter region of the frusto-conical portion plus the thickness of the slit-ring and being position at a distance from that end of the cylindrical body carrying the needle which exceeds the distance between the front end of the plunger and the rear surface of its frusto-conical portion, when its undeformed state the split-ring having an inner diameter less than the maximum diameter of the frusto-conical portion and an outer diameter greater than the inner diameter of the cylindrical body, and being elastically formable to widen out into the bulge under the action of the frusto-conical surface as the plunger is driven in.
A self-blocking hypodermic syringe for once-only use comprising a cylindrical body which at its front end carries means for connection to a hypodermic needle and is open at its opposite end, and contains a plunger which slides in a fluid-tight manner and is provided with a gripping rod, characterized by also comprising elastic means for blocking the intake stroke of the plunger which are initially located in an inactive position and are transferred into an active position during the first syringe intake and injection operation, when in said active position the elastic means being disposed in a position secured to the cylindrical body of the syringe and interfering with the plunger intake stroke, said hypodermic syringe being further characterized by comprising a slidable cap coaxial to the syringe body and covering the body itself, and being provided at its front with an exit hole for the needle, and further having members for its fastening to the syringe body, and elastic thrust means, said cap when in its retracted position leaving the needle exposed and when in its advanced position covering the needle, the fastening members being moved into their released position by release means associated with the first forward movement of the plunger.
Dependencies are inferred from the claim text.