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:
Feb. 19, 2008
Filed:
Jun. 23, 2004
Yasuhiko Kikkawa, Yamanashi, JP;
Haruyuki Shiraishi, Yamanashi, JP;
Masahiro Maeda, Yamanashi, JP;
Naoya Sumita, Yamanashi, JP;
Kunio Yamaguchi, Yamanashi, JP;
Yasuhiko Kikkawa, Yamanashi, JP;
Haruyuki Shiraishi, Yamanashi, JP;
Masahiro Maeda, Yamanashi, JP;
Naoya Sumita, Yamanashi, JP;
Kunio Yamaguchi, Yamanashi, JP;
Makino Milling Machine Co., Ltd., Tokyo, JP;
Abstract
A hollow portion of a spindle through which a draw bar and a disc spring assembly are inserted has a closed chamber structure and constitutes an oil pool chamber in which a lubricating oil is filled. The bearing portions that support the draw bar in the oil pool on both sides have the same inner diameter so that the volume of the oil pool chamber does not change when the draw bar is moved forward and backward. As a result, the lubricating oil is not pushed out of the oil pool chamber. Thus, a spindle unit can be provided in which a clamping device including the draw bar and the disc spring assembly for clamping a tool or a workpiece pallet at the forward end of the spindle can be reliably lubricated, so that the friction on and the breakage of the clamping device is reduced and that the service life of the unit is lengthened.