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:
Feb. 16, 1999
Filed:
Aug. 18, 1997
Osamu Shimizu, Kanagawa-ken, JP;
Akihiro Ushitora, Kanagawa-ken, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A vacuum valve controller for a vacuum sewer system having a suction pipe which is communicated with a vacuum system by opening a vacuum valve, and which is cut off from the vacuum system by closing the vacuum valve, so that soil water in a soil water basin is sucked through the suction pipe and sent to a predetermined place by opening said vacuum valve is disclosed. The vacuum valve controller comprises a vacuum valve actuating means movable between a first position and a second position for actuating the vacuum valve between an open position and a closed position, respectively, means for normally biasing the vacuum valve actuating means to the second position, a pressure sensing tube for converting a change in level of soil water in the soil water basin to a change in pressure, a first pressure chamber communicated with the pressure sensing tube and associated with the vacuum valve actuating means for moving the vacuum valve actuating means to the first position when a level in the soil water basin reach a predetermined level, and means for urging the vacuum valve actuating means to the second position while soil water is sucked through the suction pipe. The first pressure chamber is so associated with the vacuum valve actuating means that the pressure chamber is capable of moving the vacuum valve actuating means to the first position while being incapable of moving the vacuum valve actuating means to the second position. By this means, it is possible to prevent the vacuum valve from moving to the closed position while the soil water is sucked through the suction pipe even if a negative pressure is established in the first pressure chamber whereby any water-hammer may be prevented.