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:
Nov. 01, 1994
Filed:
Dec. 10, 1992
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E02F / ; E02B / ;
U.S. Cl.
CPC ...
405 52 ; 1372361 ; 210170 ; 405 37 ; 405 80 ;
Abstract
An underground drainage facility including a drainage pump adapted to be operated if an inflow water channel is constructed as a closed channel. Overflow weirs in water channels such as rivers or the like on an inflow side are less than a maximum water level. A vertical-shaft multi-stage adjustable-vane impeller is used as a drainage pump. Consequently, even a drainage pump of a high pressure head and large capacity can perform a waiting running and accommodate a variation in a quantity of inflowing water to the drainage facility.