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:
Jun. 08, 1976
Filed:
Sep. 02, 1975
Richard Gundelfinger, Oakland, CA (US);
Other;
Abstract
A two-position rotary valve for injecting a liquid sample into a stream of solvent flowing through a liquid chromatographic column, without interrupting solvent flow is disclosed. The valve is switchable between a load position and an inject position. Associated with the valve is a sample loop whose downstream end is connected to a needle cavity axially extending along the valve rotor. In the load position the upstream end of the sample loop is vented to the atmosphere. This facilitates the loading of the sample into the sample loop through the needle cavity at atmospheric pressure with a conventional syringe needle. After sample loading the syringe needle is replaced by a wire-like plug which together with a compressible seal are capable of withstanding high pressure in the needle cavity when the latter is switched to the inject position. In this position solvent flows through the sample loop and the needle cavity from the solvent source to the column, forcing the previously loaded sample onto the column.