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:
Jan. 17, 1978
Filed:
Apr. 13, 1976
Richard Gundelfinger, Oakland, CA (US);
Rheodyne Incorporated, Berkeley, CA (US);
Abstract
Several embodiments of a two-position rotary valve for injecting a liquid sample into a stream of solvent, flowing through a liquid chromatographic column, are disclosed. The valve is switchable between a Load position and an Inject position. The valve includes a needle cavity axially extending along the valve's rotor axis of rotation. The needle cavity is designed to accommodate a syringe needle from which a sample is loaded into one end of a sample loop which is externally connected to the valve, while the opposite end of the loop is vented to the atmosphere, when the valve is in the Load position. This facilitates the loading of the sample into the sample loop through the needle cavity at atmospheric pressure with a conventional syringe needle. In the Inject position solvent is made to flow through the sample loop in order to eject the sample from the loop and inject it onto the column. Sample ejection from the loop may take place from the same loop end through which the sample was loaded into the loop or from the loop's opposite end.