Metering syringe

• US 5,318,544 A
• Filed: 10/20/1992
• Issued: 06/07/1994
• Est. Priority Date: 10/20/1992
• Status: Expired due to Term

• Current Assignee: KERR Manufacturing Company (Envista Holdings Corporation)
• Original Assignee: KERR Manufacturing Company (Envista Holdings Corporation)
• Inventors: Steele, Charles E., Drypen, John
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): Wilkens, Frank
• Application Number:
  US07/964,045
• Time in Patent Office: 595 Days
• Field of Search: 604/187, 604/207-211, 604/218, 604/224, 604/227
• US Class Current: 604/210
• CPC Class Codes: A61M 2005/3139 Finger grips not integrally formed with the syringe barrel, e.g. using adapter with finger grips
• CPC Class Codes: A61M 5/31505 Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit
• CPC Class Codes: A61M 5/3155 by rotational movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• 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 syringe for metering fluid in which a plunger contains a plurality of stop surfaces which contact a stop on a syringe tube. The stop surfaces are linearly displaced from each other along a longitudinal axis of the plunger by distances corresponding to predetermined volumes of fluid to be metered. The stop surfaces are also angularly displaced about the longitudinal axis of the plunger so that incremental rotation of the plunger permits successive stop surfaces to limit plunger motion, thereby effecting a precise metering of the fluid.

Claims

1. A syringe for metering fluid, said syringe comprising:

a syringe tube for holding the fluid and having an orifice at one end for discharging the fluid and a generally circular opening at an opposite end, said generally circular opening including a stop edge forming a chord across said generally circular opening; and

a plunger slidably located in said openings of said syringe tube, said plunger having a longitudinal axis and a plurality of stop surfaces approximately perpendicular to said longitudinal axis and angularly displaced about said longitudinal axis from adjacent stop surfaces, said plunger further having a plurality of flat relief surfaces approximately parallel to said longitudinal axis and extending between and intersecting adjacent stop surfaces, said plunger having a cross-sectional shape along said longitudinal axis substantially the same as said generally circular opening with said stop edge forming said chord across said generally circular opening.

2. The syringe of claim 1 wherein said syringe tube further includes a clip releasably connected to a flange at said opposite end of said syringe tube, said clip having said generally circular opening for receiving said plunger.

3. The syringe of claim 2 wherein said stop edge is flexibly attached to said clip and, said stop edge is biased against said plunger so that said stop edge contacts said stop and relief surfaces.

4. A syringe for metering fluid comprising:

a syringe tube for holding the fluid and having

an orifice at one end for discharging the fluid, and

a generally circular opening at an opposite end, said generally circular opening including a stop edge forming a chord across said generally circular opening, and

a plunger slidably located in said opening of said syringe tube, said plunger having

a longitudinal axis,

a plurality of stop surfaces approximately perpendicular to said longitudinal axis, said plurality of stop surfaces being angularly disposed from each other and equally spaced around said longitudinal axis, and

a plurality of flat relief surfaces approximately parallel to said longitudinal axis and extending between and intersecting adjacent stop surfaces, said plurality of flat relief surfaces being angularly displaced from each other and equally spaced around said longitudinal axis,

said stop surfaces and said flat relief surfaces being spaced with respect to said longitudinal axis to form a cross-sectional shape of said plunger along said longitudinal axis substantially the same as said generally circular opening with said stop edge forming said chord across said generally circular opening.

5. A syringe for metering fluid comprising:

a syringe tube for holding the fluid and having

an orifice at one end for discharging the fluid, and

a generally circular opening at an opposite end, said generally circular opening including a stop edge forming a chord across said generally circular opening, and

a plunger slidably located in said opening of said syringe tube, said plunger having

a longitudinal axis,

a plurality of stop surfaces approximately perpendicular to said longitudinal axis, said plurality of stop surfaces being angularly displaced from each other and successively, equally spaced around said longitudinal axis, and

a plurality of flat relief surfaces approximately parallel to said longitudinal axis and extending between and intersecting adjacent stop surfaces, said plurality of flat surfaces being angularly displaced from each other and successively, equally spaced around said longitudinal axis,

whereby one of said stop surfaces contacts said stop edge in response to a translation of said plunger thereby metering a predetermined volume of fluid from said syringe, and said one of said stop surfaces loses contact with said stop edge in response to a rotation of said plunger thereby permitting one of said relief surfaces to translate past said stop edge until an adjacent stop surface contacts said stop edge.