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:
Apr. 14, 1981
Filed:
Apr. 02, 1979
Applicant:
Inventor:
Shiro Takahashi, Tokyo, JP;
Assignee:
Man Design Co., Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417417 ; 417550 ;
Abstract
In the construction of an electro-magnetic fluid pump such as an air pump in which a piston assembly carrying an armature is driven for reciprocal axial movement due to operational combination of magnetic attraction generated by a stator core and mechanical spring repulsion for cyclic discharge of the fluid out of its piston chamber, the piston assembly is postively supported on both axial sides of the stator core and a pneumatic spring is incorporated within the piston assembly. Biased movement of the piston assembly and bias in the magnetic attraction are both successfully prevented in order to minimize undesirable abrasion of the piston assembly and its related parts.