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. 05, 1997
Filed:
Jun. 28, 1995
Katsunori Tsutsui, Chita-gun, JP;
Brother Kogyo Kabushiki Kaisha, Nagoya, JP;
Abstract
A threading apparatus is capable of eliminating a rise delay in the feed velocity due to friction resistance and can perform high-precision threading even in high-speed tapping. A feed servo amplifier is controlled to operate using one of a plurality of gains. A gain setter sets the plurality of gains, which include a high gain, which is high enough to overcome static friction resistance, and a normal gain. A gain changer selects one of the plurality of gains for the feed servo amplifier. In particular, the gain changer selects the high gain during a start period of tapping operation and then selects the normal gain after the start period. Therefore, a rise delay in the feed velocity due to friction resistance during the start period of the tapping operation can be compensated for. After the start period, the normal gain is selected. Thus, high-precision threading can be performed over the course of the tapping operation with no errors.