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. 25, 2003
Filed:
Sep. 20, 2002
Kenji Hiraku, Chiyoda, JP;
Kenichiro Tokuo, Chiyoda, JP;
Yuzo Kadomukai, Ishioka, JP;
Kunihiko Takao, Tsuchiura, JP;
Hiroyuki Yamada, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In order to provide a method for high volume and high pressure operation of a variable delivery type single cylinder plunger pump, the displacement of the piezoelectric element is magnified by a hydraulic displacement magnifying mechanism comprising a large-diameter bellows a small diameter bellows and working fluid and an engaging member is displaced to control the time interval of opening and closing the intake valve The large-diameter bellows is used at all times in the state compressed in the direction of displacement transfer, thereby ensuring that the pressure of the working fluid is maintained at a positive value to prevent vapor from being generated. The thermal expansion of a casing is selected in such a way that the total thermal expansion of the piezoelectric element and hydraulic displacement magnifying mechanism in the direction of displacement transfer is approximately the same as the thermal expansion of the casing whereby highly efficient driving is provided.