FLUID TESTING APPARATUS

• US 3,802,843 A
• Filed: 05/28/1971
• Issued: 04/09/1974
• Est. Priority Date: 05/28/1971
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: Jae Chang Kim
• Inventors: Kim, Jae Chang
• Primary Examiner(s): Wolk, Morris O.
• Assistant Examiner(s): Serwin, R. E.
• Application Number:
  US05/147,955
• Time in Patent Office: 1,047 Days
• Field of Search: 23/23B,259,292,253
• US Class Current: 422/71
• CPC Class Codes: B01D 33/01 with translationally moving filtering elements, e.g. pistons B01D33/04 - B01D33/327 take precedence
• CPC Class Codes: B01L 3/5082 Test tubes per se
• CPC Class Codes: Y10S 436/804 Radioisotope, e.g. radioimmunoassay
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

A fluid testing apparatus which is particularly suitable for isotope testing of human serum includes an elongated cylindrical tube having a closed lower end which telescopingly receives an elongated plunger. The plunger includes a generally cylindrical lower end which is relatively snugly received by the tube and a central portion having a transverse cross sectional area which is less than the cross sectional area of the tube interior so that fluid can flow in the space between the central portion of the plunger and the tube. The end portion of the plunger includes a cylindrical side wall and a transverse top wall which is provided with a central opening for communicating the bottom end of the plunger with the flow area between the central portion of the plunger and the tube. A mesh screen is held against the top wall of the end portion in covering relation with the central opening by an annular plug which is frictionally retained within the end portion, the central opening of the plug being aligned with the opening through the top wall.

Claims

2. The apparatus of claim 1 in which the plunger includes a cap portion extending transversely outwardly from the central portion for engagement with the upper end of the side wall of the tube, the cap portion including spout means whereby fluid can be poured from the tube through the spout means when the cap portion engages the upper end of the side wall.

3. The apparatus of claim 2 in which the cap portion includes a transversely extending generally planar closure portion engageable with the upper end of the side wall and a spout portion extending upwardly from the planar portion whereby the spout portion is spaced from the upper end of the side wall when the closure portion engages the side wall.

4. The apparatus of claim 1 in which the central portion of the plunger includes a plurality of ribs extending radially outwardly from the longitudinal axis of the plunger, the opening through the end portion extending along the longitudinal axis of the plunger.

5. The apparatus of claim 4 in which the radius of the ribs is less than the inner radius of the tube along most of the length of the ribs, the ribs projecting radially outwardly adjacent the upper end of the plunger to a radius substantially the same as the radius of the end portion whereby the plunger is maintained in substantial coaxial alignment with the tube when the end portion and the outwardly projecting rib portions are positioned within the tube.

6. The apparatus of claim 1 in which the end portion is provided with a recessed lower end, the screen means comprising a mesh screen received in the recess, a plug received in the recess and retaining the screen therein, the plug having a central opening therethrough communicating with the opening in the end portion.

7. The apparatus of claim 1 in which the end portion includes a generally cylindrical side wall and a top wall defining a generally cylindrical recess, the opening through the end portion being provided through the top wall along the axis of the plunger, the screen means comprising a generally planar mesh screen received by the recess and positioned below the opening, an annular plug received by the recess and frictionally retained therein, the plug retaining the screen adjacent the top wall of the end portion.

8. The apparatus of claim 7 in which the annular plug includes a longitudinally extending generally cylindrical side wall having a radially outwardly extending perimetric rib received in a circumferentially extending groove in the inner surface of the side wall of the end portion whereby the plug is removably secured within the recess.

9. The apparatus of claim 1 in which the upper end of the side wall of the tube is externally threaded and is adapted to be threadedly engaged with an end cap when the plunger is withdrawn from the tube.

10. An apparatus for testing fluids comprising an elongated tube having a generally cylindrical side wall defining a longitudinally extending bore, a bottom wall closing the bore, and an open top, an elongated plunger telescopingly received in the tube, the plunger including an end portion, a cap portion and a central portion between the end and the cap portions, the central portion including a plurality of ribs extending radially outwardly from the longitudinal axis of the plunger, the end portion including a generally cylindrical side wall and a transversely extending top wall defining a generally cylindrical recess, the side wall of the end portion having an outer diameter slightly less than the inner diameter of the tube and the top wall having a central opening therethrough, a generally planar mesh screen received by the recess and positioned below the opening, an annular plug received by the recess and frictionally retained therein, the plug retaining the screen adjacent the top wall of the end portion and having a central opening therethrough aligned with the opening in the top wall, the cap portion of the plunger including a transversely extending planar portion engageable with the upper end of the side wall of the tube and a spout portion extending upwardly from the planar portion whereby the spout portion is spaced from the upper end of the side wall when the closure portion engages the side wall.

11. The apparatus of claim 10 in which the radius of the ribs is less than the inner radius of the tube along a portion of the length of the ribs, the ribs projecting radially outwardly adjacent the upper end of the plunger to a radius substantially the same as the radius of the end portion of the plunger whereby the plunger is maintained in substantial coaxial alignment with the tube when the end portion and the outwardly projecting rib portions are positioned in the tube.

12. The apparatus of claim 10 in which the annular plug includes a longitudinally extending generally cylindrical side wall having a radially outwardly extending perimetric rib received in a circumferentially extending groove in the inner surface of the side wall of the end portion whereby the plug is removably secured within the recess.

13. The apparatus of claim 10 in which each of the ribs is provided with a notch above the opening in the top wall of the end portion.