DISPOSABLE PLASTIC SYRINGE FOR USE IN COLORIMETRY

• US 3,732,079 A
• Filed: 02/03/1971
• Issued: 05/08/1973
• Est. Priority Date: 02/20/1969
• Status: Expired due to Term

• Current Assignee: Pymah Corp (3M Company)
• Original Assignee: Ward B. Davis
• Inventors: Davis, Ward B.
• Primary Examiner(s): Wolk, Morris O.
• Assistant Examiner(s): Reese, R. M.
• Application Number:
  US05/112,234
• Time in Patent Office: 825 Days
• Field of Search: 23/253,253TP,259 206/43,17.5,56AA 128/2R,231,232 116/114.19,114.20 73/425.4,425.4P,441,442,443,446 222/215
• US Class Current: 422/408
• CPC Class Codes: B01L 3/505 flexible containers not provided for above

Abstract

A disposable plastic syringe particularly for use in colorimetry is formed by embossing a sheet of transparent synthetic plastic, or otherwise forming in it, a bulbar cavity, and subsequently closing the cavity by adhering a plane synthetic plastic sheet over the cavity, the two sheets being either heated sealed or adhesively joined together at the margins around the cavity. The cavity is connected to the outside edge of the device by an embossed groove which when attached to the plane sheet forms a tubular inlet or outlet. The cavity is shaped as a truncated pyramid with a turret closing the top, this turret forming a finger-pressable '"'"''"'"''"'"''"'"'button'"'"''"'"''"'"''"'"' by which the syringe will draw in or expel liquid through the tubular connection to the margin of the device. The volume of liquid drawn into each specimen syringe is relatively accurately measured. A partial coating, such as a stripe or spot, inside the bulbar cavity using a color-changeindicator composition provides means for making a colorimetric determination of the acidity or the content of some individual constituent of the liquid drawn into the syringe device.

Claims

2. The syringe defined in claim 1 in which the color-changing indicator composition is applied as a printed spot on the inside of said cavity.

3. The syringe defined in Claim 1, in which at least a portion of the body is transparent.

4. The syringe defined In claim 3, in which said body comprises a plane backing sheet of plastic adhered to plane margins around a figure embossed in a second sheet of plastic, said figure consisting of an enlarged truncated rectangular pyramidal cavity, and a tubular cavity extending from said pyramidal cavity to the edge of said second sheet.

5. The syringe defined in claim 4 in which a rectangular turret is formed atop said pyramidal cavity, said turret having upright walls and being closed on top to provide a finger-pressable surface.

6. The syringe defined in claim 5, in which at least some of the upright walls of said turret are provided with vertical reinforcing flutes.