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. 09, 1994
Filed:
Feb. 17, 1993
Teruo Nakagawa, Shijonawate, JP;
Shigeki Fujiwara, Izumiotsu, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
In a precision drilling method for drilling a straight hole in a work with a drill, a drill unit for rotating the drill is supported to a housing in suspension by an electromagnetic force consisting of separately controllable restoring and damping elements. The drill unit is supported by first restoring and damping elements such that a positional displacement of the drill unit is permitted to relieve a contacting pressure applied to the drill unit when the drill comes into contact with the work. The positional displacement of the drill unit is monitored by sensors. When a force applied to the drill unit, which is determined according to thus monitored displacement, is greater than a critical value, the first restoring element is increased to give a relatively strong support capable of rapidly restoring the position of the drill unit, and preferably the first damping element is also increased to rapidly damp a vibration of the drill unit induced by the positional displacement. Subsequently, the straight hole is drilled in the work with the drill by feeding the housing toward the work. As a result, it is possible to form the straight hole precisely at a desired position in the work without causing a breakage of the drill.