Hypodermic syringe

• US 4,050,459 A
• Filed: 05/20/1976
• Issued: 09/27/1977
• Est. Priority Date: 05/23/1975
• Status: Expired due to Term

• Current Assignee: Anacleto Montero Sanchez
• Original Assignee: Anacleto Montero Sanchez
• Inventors: Sanchez, Anacleto Montero
• Primary Examiner(s): Yasko, John D.
• Application Number:
  US05/688,193
• Time in Patent Office: 495 Days
• Field of Search: 128/218 P, 128/218 PA, 128/218 R, 128/218 C, 128/215, 128/216, 128/234
• US Class Current: 604/210
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31595 Pre-defined multi-dose administration by repeated overcoming of means blocking the free advancing movement of piston rod, e.g. by tearing or de-blocking

Abstract

A hypodermic syringe for administering a plurality of measured doses, particularly to animals, comprises a barrel and a plunger movable in the barrel, the plunger having a track and the barrel a track follower. The track is made up of a plurality of stages each stage corresponding to a movement in the plunger which will expel from the syringe a single dose.

Claims

1. A hypodermic syringe comprising a barrel and a plunger slidably and rotatably received in said barrel, said barrel and plunger having cooperating cylindrical surfaces, one of said surfaces having track means comprising a circumferential section and two axially extendand radially off-set sections, adjacent terminal portions of said axial section being connected by said circumferential section and said axial sections extending in opposite axial directions from said circumferential section, and track follower means on the other of said surfaces, whereby said plunger may be moved axially in said barrel with said track follower means engaging a first axial section of said track and thereafter moved fruther axially with said track follower means engaging said other axial track section to dispense, sequentially, doses of a medication in amounts related to the lengths of said track sections, said track follower means comprising a ball engaging in said track and spring means urging said ball radially into engagement with said track.

3. A syringe as claimed in claim 1 wherein said track means further comprises a track section extending wholly axially along said surface and over a distance equal to that covered by said axial sections, whereby the entire contents of said syringe may be dispensed as a single dose by moving said track follower means within said wholly axially extending section.

4. A syringe as claimed in claim 1 wherein said track means comprises a step-like track formed as a groove in said surface of said plunger.

2. A hypodermic syringe comprising a barrel and a plunger slidably and rotatably received in said barrel, said barrel and plunger having cooperating cylindrical surfaces, one of said surfaces having step-like track means comprising circumferentially extending tread sections and axially extending riser sections and the other of said surfaces having track follower means engaging said track means to guide said plunger in step-like movement in said barrel, said track follower means comprising a ball engaging in said track and spring means urging said ball radially into engagement with said track.

5. A syringe as claimed in claim 2 wherein said track means extend around one-half of the circumference of said surface and said track follower means comprises two diametrically opposed elements, at least one of which always engages said track.