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:
May. 10, 1977
Filed:
Feb. 20, 1975
Toshimasa Nakanishi, Kanuma, JA;
Nakanishi Dental Mfg., Co., Ltd., Kanuma, JA;
Abstract
A dental handpiece of the present invention is provided with a head extending at substantially a right angle to said handpiece having a hollow therein. The head is also provided with a hollow vertically communicating with the hollow of the handpiece. A semispherical groove is cut into the hollow wall longitudinally and partially adjacent an orifice of the head. A cartridge having an elongated opening cut through at a mid-portion of a bottom thereof and also a small opening at a top wall near a lower orifice and at the same position as the semispherical groove is mounted into its hollow with a rotatable bushing through metal bearings inserted into a lower and upper orifices of the hollow. A gear is secured to the bushing at a position to form an entry into the elongated opening of the cartridge. Together with the spherical groove of the head and the small opening of the cartridge, a semispherical cavity cut into the lower metal bearing defines a spherical space for a metal ball. Accordingly, when the cartridge having a reamer is inserted into the head, the metal ball is fitted in a protruding fashion into the semispherical groove to prevent idling between the gear and metal bearings. The gear secured to the bushing can be easily adapted to mesh with a gear of the driving gear rotatably mounted within the handpiece, thus enabling the dentist to easily exchange the cartridge comprising the worn out parts.