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:
Aug. 08, 1989
Filed:
Jun. 16, 1988
Applicant:
Inventors:
Assignee:
Nitto Kohki Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417417 ; 92 8 / ;
Abstract
An electromagnetically reciprocating apparatus includes a piston assembly which is driven by an electromagnet repeating magnetization and demagnetization and a compression coil spring so as to reciprocate a front and rear pistons of the assembly in a front and rear cylinders. An air hole is formed in the rear cylinder to communicate a sealed inner space partitioned in the cylinder by the rear piston with an atmosphere. A valve is mounted on the air hole to adjust a resonance frequency of the vibration system of the apparatus.