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:
May. 07, 2002
Filed:
Feb. 24, 2000
Brian M. Anderson, Sauk City, WI (US);
Other;
Abstract
A liquid pump for pumping groundwater samples from small diameter sub-terrain wells. The pump comprises a tubular casing having swaged ends and provided with inlet apertures on its side wall, a top cap and a bottom cap each provided with a bladder mandrel, a coil spring biasing the caps, a flexible bladder separating the interior of the pump into a liquid chamber and a gas chamber, and a pair of poppet valves preventing backflow of the pumped liquid. The pump is actuated by alternately pressurizing and de-pressurizing the actuating gas, preferably air, in the gas chamber causing the bladder to alternately contract and relax. The bladder is formed with reduced diameter ends that allows for an increased stroke volume of the pump. The pump is operated by a precision dual range controller, specifically adapted for “low flow” sampling.