HYPODERMIC SYRINGE WITH RADIALLY MOVABLE BLOCKING ELEMENTS

• US 3,742,948 A
• Filed: 08/10/1970
• Issued: 07/03/1973
• Est. Priority Date: 08/25/1969
• Status: Expired due to Term

• Current Assignee: Daniel Ong, Hendrik Alle Post
• Original Assignee: Daniel Ong, Hendrik Alle Post
• Inventors: Post, Hendrik Alle, Ong, Daniel
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): McGowan, J. C.
• Application Number:
  US05/062,332
• Time in Patent Office: 1,058 Days
• Field of Search: 128/218R,218F,218A,218D,218P,218PA,218DA,215,216,217,173H
• US Class Current: 604/139
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/2459 upon internal pressure increase, e.g. pierced or burst A61M5/2429 takes precedence

Abstract

A hypodermic syringe comprising a liquid container and a needle connected thereto at one end, which assembly is incorporated in a housing, the liquid container being bounded at the other end by a piston, and an operating mechanism being present to exert a force on the piston, one or more blocking elements being present for locking the operating mechanism or the piston against movement relative to the liquid container, the housing showing a diameter transition such that when the blocking elements pass along it, they are moved radially so that the blocking is removed and the piston penetrates into the liquid container so that the liquid flows out through the needle.

Claims

1. A hypodermic syringe comprising a cylindrical liquid container, a needle connected to one end thereof, a piston slidably fitting in the other end of the liquid container, a medicament in the container between the needle and piston, an elongate cylindrical housing slidably carrying said container, a pressure member slidably positioned in the housing adjacent the piston end of the container, transversely movable positive blocking means engaging the edge of the container at the piston end and controlling relative movement of the container and the piston therein by the pressure member, spring means for forcing the pressure member toward the needle end of the housing, stop means on the needle end of the housing, transition means on the inner surface of the housing between said blocking means and said stop means for causing the blocking means to move out of engagement with the container whereby the pressure member will force the piston toward the needle to eject the medicament in said container.

2. The invention as set forth in claim 1 and wherein the pressure member has a head portion sized to slidably fit within the container, the housing comprises an upper portion and a lower portion of larger inner diameter and further wherein the transversely movable positive blocking means comprises annular elements bearing on the edge of the cylindrical container at the piston end and in engagement with the inner wall of the upper portion of the housing, the inner face of each annular element sloping downwardly and inwardly and terminating inwardly of the container wall to form a circular opening of smaller diameter than the head portion of the pressure member, the head portion of said pressure member engaging said inner faces whereupon movement of the pressure head moves the cylindrical container toward the lower housing portion, upon reaching the lower housing portion the pressure head portion forces the blocking elements outwardly to allow the pressure head to engage the piston and upon conTinued movement eject the medicament from the container.

3. The invention as set forth in claim 1 and wherein the housing comprises an upper portion and a lower portion, said lower portion having a plurality of axial grooves in its inner wall, the transversely movable positive blocking means comprising a plurality of lugs extending radially from the pressure member and fitting in the aforesaid grooves, said lugs each having a flat lower face engaging the edge of the container adjacent the piston end and a downwardly and inwardly sloping outer face, the lower end of each of the grooves being provided with an inwardly and downwardly sloping bevel termination, whereupon downward movement of the pressure head the outer faces of the lugs engage the bevel terminations and cause the lugs to move inwardly so as to force the flat lower faces of the lugs off the container edge and allow the lugs to be forced radially inwardly to slide within the container and engage the piston to eject the medicament.

4. The invention as set forth in claim 1 and wherein the housing comprises an upper portion and a lower portion having a plurality of axial grooves in its inner wall, the transversely movable positive blocking means comprising a plurality of lugs connected to the piston and fitting in the aforesaid grooves, each lug having an intermediate horizontal flat face engaging the edge of the container adjacent the piston end, the upper portion of each lug extending into its respective groove, the lower end of each of the grooves being provided with an inwardly and downwardly sloping bevel termination, whereupon downward movement of the pressure member the upper portion of the lugs will engage the bevel terminations and be forced inwardly removing the flat face lug portion from the edge of the container and allowing the piston to then be moved to eject the medicament.