Pre-filled syringe and pre-filled cartridge having an improved plunger and plunger rod for reducing syringing force
First Claim
Patent Images
1. A syringe designed to be pre-filled and stored ready for injection comprising:
- (a) a barrel having an inner surface defining a cylindrical chamber for retaining an injectable fluid therein;
said barrel having distal end terminating in a tapered tip to which an injection needle can be attached; and
a proximal end for receiving a plunger;
(b) a cup-shaped plunger slideably mounted in said barrel and positioned close to the proximal end of the barrel to provide a seal with the inner surface of the barrel, said plunger comprising;
(1) a distal convex face which is to interface with the injectable fluid contained in the barrel;
(2) a proximal flat or concave face essentially parallel with the distal convex face;
(3) outside wall contiguous with the distal convex face having thereon;
distal ring, proximal ring and center ring extending radially outwardly and forming a slideable seal with the inner surface of the barrel;
(4) inside wall having female threads thereon;
(5) bottom rim which together with the inside wall defines a circular opening in the cup-shaped plunger through which a plunger rod can be inserted for engagement; and
(c) a plunger rod having distal and proximal ends, for engaging the lunger comprising;
(1) a plunger rod tip, located at the distal end of the plunger rod, having a semi-circular shape with convex face projecting in the direction of the plunger, the diameter of which is substantially smaller than the diameter of the plunger, and is designed to contact the proximal flat or concave inside face of the plunger at the center portion thereof;
(2) neck portion, contiguous with the plunger rod tip, designed to receive a slideable cylinder;
(3) slideable cylinder, positioned around the neck portion, comprising;
an inside wall and an outside wall, the inside wall defines a cylinder the diameter of which is smaller than the diameter of the plunger rod tip so as to prevent the slideable cylinder slipping off of the neck portion, the outside wall having male threads for engagement of female threads of the plunger when the plunger rod is inserted into the plunger for operation of the syringe.
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Accused Products
Abstract
Disclosed are pre-filled syringes equipped with an improved plunger and a plunger rod, characterized by a leak-proof seal and easy sliding property.
138 Citations
18 Claims
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1. A syringe designed to be pre-filled and stored ready for injection comprising:
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(a) a barrel having an inner surface defining a cylindrical chamber for retaining an injectable fluid therein;
said barrel having distal end terminating in a tapered tip to which an injection needle can be attached; and
a proximal end for receiving a plunger;(b) a cup-shaped plunger slideably mounted in said barrel and positioned close to the proximal end of the barrel to provide a seal with the inner surface of the barrel, said plunger comprising; (1) a distal convex face which is to interface with the injectable fluid contained in the barrel; (2) a proximal flat or concave face essentially parallel with the distal convex face; (3) outside wall contiguous with the distal convex face having thereon;
distal ring, proximal ring and center ring extending radially outwardly and forming a slideable seal with the inner surface of the barrel;(4) inside wall having female threads thereon; (5) bottom rim which together with the inside wall defines a circular opening in the cup-shaped plunger through which a plunger rod can be inserted for engagement; and (c) a plunger rod having distal and proximal ends, for engaging the lunger comprising; (1) a plunger rod tip, located at the distal end of the plunger rod, having a semi-circular shape with convex face projecting in the direction of the plunger, the diameter of which is substantially smaller than the diameter of the plunger, and is designed to contact the proximal flat or concave inside face of the plunger at the center portion thereof; (2) neck portion, contiguous with the plunger rod tip, designed to receive a slideable cylinder; (3) slideable cylinder, positioned around the neck portion, comprising;
an inside wall and an outside wall, the inside wall defines a cylinder the diameter of which is smaller than the diameter of the plunger rod tip so as to prevent the slideable cylinder slipping off of the neck portion, the outside wall having male threads for engagement of female threads of the plunger when the plunger rod is inserted into the plunger for operation of the syringe. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of delivering a liquid medium into a patient from a pre-filled syringe, said syringe comprising:
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(a) a barrel having an inner surface defining a cylindrical chamber for retaining an injectable fluid therein;
said barrel having distal end terminating in a tapered tip to which an injection needle can be attached; and
a proximal end for receiving a plunger;(b) a cup-shaped plunger slideably mounted in said barrel and positioned close to the proximal end of the barrel to provide a seal with the inner surface of the barrel, said plunger comprising; (1) a distal convex face which is to interface with the injectable fluid contained in the barrel; (2) a proximal flat or concave face essentially parallel with the distal convex face; (3) outside wall contiguous with the distal convex face having thereon;
distal ring, proximal ring and center ring extending radially outwardly and forming a slideable seal with the inner surface of the barrel;(4) inside wall having female threads thereon; (5) bottom rim which together with the inside wall defines a circular opening in the cup-shaped plunger through which a plunger rod can be inserted for engagement; and (c) a plunger rod having distal and proximal ends, for engaging the plunger comprising; (1) a plunger rod tip, located at the distal end of the plunger rod, having a semi-circular shape with convex face projecting in the direction of the plunger, the diameter of which is substantially smaller than the diameter of the plunger, and is designed to contact the proximal concave inside face of the plunger at the center portion thereof; (2) neck portion, contiguous with the plunger rod tip, designed to receive a slideable cylinder; and (3) slideable cylinder, position around the neck portion, comprising;
an inside wall and an outside wall, the inside wall defines a cylinder the diameter of which is smaller than the diameter of the plunger rod tip so as to prevent the slideable cylinder slipping off of the neck portion, the outside wall having male threads for engagement of female threads of the plunger when the plunger rod is inserted into the plunger for operation of the syringe;said method comprising the steps of; (i) engaging a hypodermic needle with the tapered tip of said barrel;
(ii) threading the slideable cylinder at the distal end of the plunger rod into the plunger;(iii) gaining entry into the desired injection site on the patient; (iv) exerting a slight pressure on the plunger rod to expel head gas from the barrel; (v) releasing the pressure applied on the plunger rod to create vacuum in the syringe and drawing a small amount of body fluid from the patient and into the distal end of the barrel; and (vi) exerting pressure on the plunger rod to move the plunger thereby delivering the liquid medium into the patient. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification