The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 21, 1978
Filed:
Oct. 31, 1975
William D Cornell, Ballwin, MO (US);
Sherwood Medical Industries Inc., St. Louis, MO (US);
Abstract
A blood collection tube useable with a needle holder for drawing blood from a body vessel. The tube has a rubber stopper with an annular axially extending portion in tight sealing engagement within the bore of the tube for maintaining a negative pressure in the tube. An annular groove in the annular portion of the stopper has a vacuum loss indicating member for providing a visual indication that the tube has or does not have a negative pressure therein. The vacuum loss indicating member may be cobalt chloride responsive to atmospheric moisture, a material including methylene blue that is sensitive to oxygen, or a closed-end manometer which has a quantity of liquid therein in a balanced position when normal negative pressure conditions exist in the tube and which moves within the manometer to visually indicate a loss of pressure when such occurs.