One-shot syringe

• US 5,380,285 A
• Filed: 12/02/1993
• Issued: 01/10/1995
• Est. Priority Date: 06/10/1992
• Status: Expired due to Fees

• Current Assignee: Robert W. Jenson
• Original Assignee: Robert W. Jenson
• Inventors: Jenson, Robert W.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US08/161,938
• Time in Patent Office: 404 Days
• Field of Search: 604/110, 604/187, 604/218, 604/219, 604/220, 604/222, 604/232, 604/230
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/3223 Means impeding or disabling repositioning of used needles at the syringe nozzle
• CPC Class Codes: A61M 2005/3224 Means to disalign the needle tip and syringe nozzle
• CPC Class Codes: A61M 2005/5033 by use of an intermediate blocking member positioned between the syringe barrel and the piston rod to prevent retraction of the latter, e.g. toothed clip placed on the piston rod
• CPC Class Codes: A61M 2005/5073 by breaking or rupturing the connection parts
• CPC Class Codes: A61M 2005/5093 including soluble mechanical parts
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: A61M 5/322 Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston devices for protecting guide needles in combination with catheters A61M25/0612
• CPC Class Codes: A61M 5/5013 Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe
• CPC Class Codes: A61M 5/508 Means for preventing re-use by disrupting the piston seal, e.g. by puncturing

Abstract

In a syringe with a hollow cylindrical barrel with one closed end, a plunger having a length longer than the barrel mounted in the barrel for reciprocation, a handle on the distal end of the plunger extending from the barrel and a piston mounted on the opposite end of the plunger in the barrel and a hypodermic needle mounted in the closed end of the barrel being in communication with the interior of the barrel, the improvement of including a hollow tapered section in the barrel adjacent to its closed end, which tapered section in cooperation with the piston end of the plunger is operable to disable the syringe as the piston commences traversing this tapered portion of the barrel.

A desired embodiment has the tapered section or portion formed by a separate sleeve slidably mounted in the barrel with the hypodermic needle mounted in this sleeve with means to engage the sleeve whereby withdrawing the plunger from the barrel after its piston end has entered this tapered section will pull the sleeve and the attached needle into the barrel thereby preventing persons from thereafter being "pricked" by the sharp end of the "used" needle.

Claims

1. In a disposable syringe having a hollow cylindrical barrel closed at one end, a plunger having a length longer than said barrel mounted in said barrel for reciprocation, said plunger having a handle on its end extending from the barrel and a piston mounted on the opposite end of said plunger received in said barrel and a hypodermic needle mounted in said closed end of said barrel being in communication with the interior of said barrel, the improvement comprising:

a tapered section formed in said barrel adjacent to its closed end which has a decreasing diameters from its central section to its closed end; and

disabling means associated with said piston end of said plunger operable to prevent re-use of said syringe once said disabling means has commenced traversing said tapered portion of said barrel, said disabling means including a collapsible piston core operable to be diminished in diameter by the tapered portion as the piston traverses said tapered portion of the barrel whereby said piston will not thereafter seal with the internal bore of said barrel if said piston is thereafter extracted from said tapered portion.

2. The improved syringe defined in claim 1 where the disabling means includes a joint between the piston and the plunger and a compressible means associated with said joint operable to separate said joint to disconnect said piston from said plunger when said compressible means commences traversing the tapered portion of the barrel.