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. 27, 2001
Filed:
Sep. 15, 1999
Hisami Nagai, Shizuoka, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a vibration motor assembly for use in, e.g., a portable phone, a weight is mounted on the output shaft of a motor and has a hermetically closed bore filled with a magnetic fluid. A magnetic body is disposed in the bore in the vicinity of the center of rotation of the weight. When the motor is not energized, the weight is held in a halt together with the shaft of the motor. In this condition, magnetic particles included in the magnetic fluid adhere to the magnetic body due to a magnetic force acting between the particles and the body. That is, all the magnetic particles are positioned in the vicinity of the center of rotation of the weight. Consequently, even a small torque, i.e., a small current can cause the motor to start rotating. When a centrifugal force acting on the particles overcomes a magnetic force acting between the particles and the magnetic body due to an increase in rotation speed, the particles move outward away the center of rotation of the weight within the bore and reach the inner periphery of the weight. This shifts the center of gravity of the weight and thereby increases the eccentricity of the weight and therefore vibration.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile