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:
Apr. 30, 1985
Filed:
Jun. 01, 1982
David R McMurtry, Wotton-under-Edge, GB;
Renishaw Electrical Limited, Wotton-under-Edge, GB;
Abstract
A numerically controlled machine tool comprises a tool movable into engagement with a workpiece, means for generating a first signal being a measure of the distance between the tool and a datum surface provided on a relatively fixed part of the machine, a first closed loop system adapted to move the tool toward the workpiece and having the first signal as feedback, means for generating a second signal being a measure of the distance between the tool and the workpiece, a second closed loop system (33) having the second signal as feedback, and means responsive to the second-mentioned distance attaining a threshold value, while being moved under the control of the first system, for changing control of the tool movement from the first to the second system.