Safety medical syringe with retractable needle
First Claim
1. A safety syringe comprising:
- a hollow barrel for containing a fluid having a cylindrical wall, a rear end opening and a front end opening and a fluid chamber therein extending between said openings;
a hollow plunger mounted in the fluid chamber of the barrel and axially moveable back and forth within the barrel, for the intake and expulsion of fluid from the fluid chamber, the plunger containing an axial needle receiving chamber therein, used during needle retraction and the plunger having a rear end portion extending out of the rear end opening of the barrel and a front end portion positioned inside the barrel;
sealing means extending around the periphery of the plunger, engaging the inside surface of the wall of the barrel within the fluid chamber to prevent fluid from leaking out of the rear end of the barrel;
a first rupturable disc sealingly temporarily closing the needle receiving chamber of the plunger adjacent the front end thereof to prevent fluid from the fluid chamber from entering the needle receiving chamber;
a needle retaining member having a front end and rear end and having a second rupturable disc member at the rear end thereof sealingly attached to the barrel until fluid has been expelled from the fluid chamber;
a hollow needle sealingly mounted in the needle retaining member at the front end of the barrel and protruding therefrom, a rear end of the needle in communication with the fluid chamber to permit the flow of fluid from the fluid chamber through the needle;
a first annular punch type release means on the front end of the plunger and adapted to rupture the second disc member on the needle retaining means for releasing it from the barrel after the fluid has been expelled from the fluid chamber;
a second annular punch type release means extending rearwardly from the second disc member at the rear end of the needle retaining member to rupture the first rupturable disc and open the front end of the plunger to receive the needle and needle retaining member into the needle receiving chamber;
both the first and second punch type release means having a sharp leading edge inclined at an angle to both the rupturable discs, so that each leading edge, when penetrating its respective disk, creates a pointed force and shearing action to separate each rupturable disc respectively from either the barrel or the plunger; and
bias means within the barrel associated with the needle retaining member urging the needle and the needle retaining member rearwardly in the barrel and toward a retracted position in the interior of the needle receiving chamber.
4 Assignments
0 Petitions
Accused Products
Abstract
A syringe for giving medical injections which has an internal mechanism for releasing and retracting a needle into the syringe after the injection has been given and retaining the needle and a hollow plunger inside the barrel of the syringe to reduce the risk of accidental needle sticks. The interior of the hollow plunger is initially hydraulically sealed off by a plunger front end wall from the fluid chamber of the syringe to prevent fluid from entering the interior of the hollow plunger. After the plunger has been depressed to expel fluid from the barrel, further depression of the plunger causes cutting punch type members to sever a disc shaped flange portion of a stem type needle retaining member and the plunger front end wall thereby permitting the spring to propel the needle and needle retaining member into the hollow plunger thereby retracting the needle and retaining member inside the barrel.
118 Citations
45 Claims
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1. A safety syringe comprising:
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a hollow barrel for containing a fluid having a cylindrical wall, a rear end opening and a front end opening and a fluid chamber therein extending between said openings; a hollow plunger mounted in the fluid chamber of the barrel and axially moveable back and forth within the barrel, for the intake and expulsion of fluid from the fluid chamber, the plunger containing an axial needle receiving chamber therein, used during needle retraction and the plunger having a rear end portion extending out of the rear end opening of the barrel and a front end portion positioned inside the barrel; sealing means extending around the periphery of the plunger, engaging the inside surface of the wall of the barrel within the fluid chamber to prevent fluid from leaking out of the rear end of the barrel; a first rupturable disc sealingly temporarily closing the needle receiving chamber of the plunger adjacent the front end thereof to prevent fluid from the fluid chamber from entering the needle receiving chamber; a needle retaining member having a front end and rear end and having a second rupturable disc member at the rear end thereof sealingly attached to the barrel until fluid has been expelled from the fluid chamber; a hollow needle sealingly mounted in the needle retaining member at the front end of the barrel and protruding therefrom, a rear end of the needle in communication with the fluid chamber to permit the flow of fluid from the fluid chamber through the needle; a first annular punch type release means on the front end of the plunger and adapted to rupture the second disc member on the needle retaining means for releasing it from the barrel after the fluid has been expelled from the fluid chamber; a second annular punch type release means extending rearwardly from the second disc member at the rear end of the needle retaining member to rupture the first rupturable disc and open the front end of the plunger to receive the needle and needle retaining member into the needle receiving chamber; both the first and second punch type release means having a sharp leading edge inclined at an angle to both the rupturable discs, so that each leading edge, when penetrating its respective disk, creates a pointed force and shearing action to separate each rupturable disc respectively from either the barrel or the plunger; and bias means within the barrel associated with the needle retaining member urging the needle and the needle retaining member rearwardly in the barrel and toward a retracted position in the interior of the needle receiving chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A safety syringe comprising:
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a hollow barrel for containing a fluid having a cylindrical wall, a rear end opening and a front end opening and a fluid chamber therein extending between said openings; a hollow plunger mounted in the barrel and axially moveable back and forth within the barrel, for the intake and expulsion of fluid from the barrel, the plunger containing an axial needle receiving chamber therein, used during needle retraction; sealing means extending around the plunger, and slidably engaging an inside surface of the wall of the barrel to prevent fluid from leaking out of the rear end of the barrel; a severable front end wall sealingly temporarily closing the needle receiving chamber of the plunger adjacent the front end thereof to prevent fluid from the fluid chamber from entering the needle receiving chamber; a needle retaining assembly having an elongated tubular stem with a front end and rear end and having a severable disc member at the rear end thereof sealingly attached to the barrel; a hollow needle sealingly mounted in the stem at the front end of the barrel and protruding therefrom until fluid has been expelled from the fluid chamber, a rear end of the needle in communication with the fluid chamber to permit the flow of fluid from the fluid chamber through the needle when the plunger is depressed; a first annular cutting blade member on the front end of the plunger and adapted to sever the disc member on the needle retaining assembly for releasing it from the barrel after the fluid has been expelled from the fluid chamber; a second annular cutting blade member extending rearwardly from the disc member at the rear end of the needle retaining assembly to sever the front end wall of the plunger and open the front end of the plunger to receive the needle and needle retaining assembly into the needle receiving chamber of the plunger; both the first and second cutting blade members having a sharp leading edge inclined at an angle to both the front end wall and the severable disc member, so that each leading edge, when severing its respective wall or disc member creates a pointed force and a shearing action to respectively separate either the front end wall from the plunger or the disc from the barrel; and a compression spring within the barrel associated with the needle retaining assembly urging the needle and the needle retaining assembly rearwardly in the barrel and toward a retracted position in the interior of the needle receiving chamber. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A safety syringe comprising:
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a hollow barrel having a cylindrical wall, a rear end opening and a front end opening and a fluid chamber therein extending between said openings; a hollow plunger mounted in the barrel and axially moveable back and forth within the barrel, for the intake and expulsion of fluid from the barrel, the plunger containing an axial needle receiving chamber therein; sealing means extending around the plunger, and slidably engaging an inside surface of the wall of the barrel to prevent fluid from leaking out of the rear end of the barrel; a severable front end wall sealingly closing the needle receiving chamber of the plunger adjacent the front end thereof to prevent fluid from the fluid chamber from entering the needle receiving chamber; a needle retaining assembly having an axially extending stem member and having a severable disc member extending radially outwardly from the stem member and sealingly attached to the barrel; a hollow needle sealingly mounted in a needle hub member which is attached to the front end of the stem member and positioned at the front end of the barrel and protruding therefrom until fluid has been expelled from the fluid chamber, a rear end of the needle in communication with the fluid chamber to permit the flow of fluid from the fluid chamber through the needle when the plunger is depressed; a first annular cutting member on the front end of the plunger and adapted to sever the disc member on the needle retaining assembly for releasing it from the barrel after the fluid has been expelled from the fluid chamber; a second annular cutting member extending rearwardly from the disc member at the rear end of the needle retaining assembly to sever the front end wall of the plunger and open the front end of the plunger to receive the needle and needle retaining assembly into the needle receiving chamber of the plunger; both the first and second cutting members having a sharp leading edge inclined at an angle to both the front end wall and the severable disc member, so that each leading edge, when severing its respective wall or disc member creates a pointed force and a shearing action to respectively separate either the front end wall from the plunger or the disc from the barrel; and bias means within the barrel associated with the needle retaining assembly urging the needle and the needle retaining assembly rearwardly in the barrel and toward a retracted position in the interior of the needle receiving chamber. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37)
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38. A safety syringe comprising:
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a hollow barrel for containing a fluid having a cylindrical wall, a rear end opening and a front end opening and a fluid chamber therein extending between said openings; a hollow plunger mounted in the fluid chamber of the barrel and axially moveable back and forth between the front and rear end opening of the barrel, for the intake and expulsion of fluid from the fluid chamber, the plunger containing an axial needle receiving chamber therein and the plunger having a rear end portion extending out of the rear end opening of the barrel; a sealing means extending around the periphery of the plunger, engaging an inside surface of the wall of the barrel within the fluid chamber to prevent fluid from leaking out of the rear end of the barrel; a barrier means sealingly attached to the plunger adjacent the front end thereof to hydraulically separate the needle receiving chamber from the fluid chamber to prevent fluid from the fluid chamber from entering the needle receiving chamber; a needle retaining means sealingly attached temporarily to the barrel until fluid has been expelled from the fluid chamber; a hollow needle sealingly mounted in the needle retaining means and protruding from the front end of the barrel;
the fluid chamber being in communication with the interior of the hollow needle to permit fluid to flow from the fluid chamber through the needle when the plunger is moved toward the front end of the barrel;bias means within the barrel associated with the needle retaining means urging the needle and the needle retaining means rearwardly in the barrel and toward a retracted position in the interior of the needle receiving chamber; a first annular punch type release means on the front end of the plunger and adapted to rupture the needle retaining means for releasing it from the barrel to permit the bias means to move the needle and needle retaining means toward the needle receiving chamber after the fluid has been expelled from the fluid chamber; and a second annular punch type release means extending rearwardly from the rear end of the needle retaining means to rupture the barrier means and open the front end of the plunger to receive the needle and needle retaining means into the needle receiving chamber. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45)
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Specification