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:
Jun. 29, 2021
Filed:
Dec. 03, 2019
Okuma Corporation, Aichi, JP;
Motozumi Yura, Aichi, JP;
OKUMA CORPORATION, Aichi, JP;
Abstract
In a controller of a machine tool having a converter that converts an AC power supply to DC and a plurality of inverters that drive a feed axis and a spindle, a power outage preparation mode is judged when an AC power supply voltage becomes lower than a predetermined value, and power outage is judged when the power outage preparation mode continues for a time period exceeding a predetermined time period or when a DC voltage which is output from the converter becomes lower than V. During the power outage preparation mode, a threshold Vof a low voltage alarm provided at each inverter is changed to a value lower than V. In addition, when the power outage is judged, a stopping operation or a retracting operation of the feed axis is executed.