Disposable safety syringe having a retractable needle cannula and cannula lock
First Claim
1. A syringe comprising:
- a hollow cylinder having proximal and distal ends and containing a supply of fluid to be administered to a patient;
a double ended hypodermic needle cannula, a first end of said cannula extending into the interior of said cylinder, and the opposite end of said cannula extending outwardly from said cylinder for administering an injection;
means for supporting said cannula at the distal end of said cylinder;
a plug located at a relatively distal position within said cylinder so as to be separated from the first end of said cannula;
a piston located at a relatively proximal position within said cylinder in spaced axial alignment with said plug, whereby the fluid of said cylinder is received in the space between said plug and piston, said piston being movable distally through said cylinder and towards said plug for causing a corresponding distal movement of said plug, such that the first end of said cannula penetrates said plug and communicates with the fluid between said plug and said piston, andsealing means to form an air-tight seal between said piston and said plug to thereby fixedly attach said piston to said plug after said piston has been moved distally through said cylinder and into contact with said plug.
1 Assignment
0 Petitions
Accused Products
Abstract
A disposable safety syringe comprising a cylinder which is prefilled with fluid medication, a double ended hypodermic needle cannula, and a cannula lock by which the needle cannula is supported in an axially extended position so that an injection of the fluid medication may be administered. The cannula lock includes a clamp having a pair of oppositely disposed jaws between which the cannula is releasably retained. The fluid medication is carried within the syringe cylinder between piston and plug members, each of which members having respective suction heads which are arranged in spaced, face-to-face alignment with one another. The piston member is advanceable axially and distally through the syringe cylinder whereby to expulse the medication from the cylinder and move the suction head of the piston member into air-tight sealing engagement with the suction head of the plug member at the distal end of the cylinder. The needle cannula penetrates the sealed piston and plug members, such that a retraction of the piston member axially and proximally through the cylinder causes a corresponding withdrawal and relocation of the cannula from the jaws of the cannula lock to the interior of the cylinder, where said cannula is completely surrounded and shielded to prevent a reuse of the cannula and an accidental needle stick.
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Citations
20 Claims
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1. A syringe comprising:
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a hollow cylinder having proximal and distal ends and containing a supply of fluid to be administered to a patient; a double ended hypodermic needle cannula, a first end of said cannula extending into the interior of said cylinder, and the opposite end of said cannula extending outwardly from said cylinder for administering an injection; means for supporting said cannula at the distal end of said cylinder; a plug located at a relatively distal position within said cylinder so as to be separated from the first end of said cannula; a piston located at a relatively proximal position within said cylinder in spaced axial alignment with said plug, whereby the fluid of said cylinder is received in the space between said plug and piston, said piston being movable distally through said cylinder and towards said plug for causing a corresponding distal movement of said plug, such that the first end of said cannula penetrates said plug and communicates with the fluid between said plug and said piston, and sealing means to form an air-tight seal between said piston and said plug to thereby fixedly attach said piston to said plug after said piston has been moved distally through said cylinder and into contact with said plug. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A disposable safety syringe having a retractable needle cannula and comprising:
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a hollow cylinder having proximal and distal ends and containing a supply of fluid to be administered to a patient; a double ended hypodermic needle cannula, a first end of said cannula extending into the interior of said cylinder, and the opposite end of said cannula extending outwardly from said cylinder for administering an injection; means for releasably retaining said cannula at the distal end of said cylinder; a plug located within said cylinder to be positioned at the distal end thereof, such that the first end of said cannula penetrates said plug; a piston located at the proximal end of said cylinder in spaced axial alignment with said plug, whereby the fluid in said cylinder is received in the space between said piston and said plug; and means to move said piston distally through said cylinder and towards said plug to expulse the fluid from said cylinder via said cannula and to connect said piston to said plug, and to move said piston proximally through said cylinder to relocate said plug to a relatively proximal position within said cylinder and correspondingly withdraw said cannula from said retaining means for retraction completely within said cylinder. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A safety syringe having a retractable needle cannula and comprising:
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a hollow cylinder having proximal and distal ends and containing a supply of fluid to be administered to a patient; a double ended hypodermic needle cannula, a first end of said cannula extending into the interior of said cylinder, and the opposite end of said cannula extending outwardly from said cylinder for administering an injection; means for removably retaining said cannula at the distal end of said cylinder; a plug located at the distal end of said cylinder; a piston located at the proximal end of said cylinder in spaced axial alignment with said plug, whereby the fluid in said cylinder is received in the space between said piston and said plug; and means to move said piston axially and reciprocally through said cylinder, such that a distal movement of said piston through said cylinder and towards said plug expulses the fluid from said cylinder via said cannula and causes said plug and said piston to be penetrated by the first end of said cannula, and a proximal movement of said piston through said cylinder removes said cannula from said retaining means and relocates said cannula and the plug penetrated thereby towards the proximal end of said cylinder such that said cannula is withdrawn completely within said cylinder. - View Dependent Claims (18, 19, 20)
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Specification