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:
Jan. 22, 1985
Filed:
Mar. 08, 1983
Takahiro Matsui, Uji, JP;
Kabushiki Kaisha Morita Seisakusho, Kyoto, JP;
Abstract
This disclosure relates to a rotation control device for an air-drive and air-journal type dental handpiece, wherein rotation control is made by applying a braking force to an air journaled turbine for a certain time by the use of compressed air operated air timer and a closing valve. When the braking force is applied to cut off drive air to the turbine, there is produced negative pressure in the bearing mechanism by the inertial rotation of the turbine, whereupon negative pressure causes the turbine to suck dirt thereinto. There is also a danger of the operator being hurt by idle rotation of the cutting tool which is rotated together with the turbine. The device of the invention prevents effectively this kind of sucking up dirt and injury to operators.