Method of determining current position data of a machining tool and apparatus therefor
AssigneeSirona Dental Systems GmbH
InventorFranz Basler
Life of this patent
Estimating the term…
Abstract
The current positioning data of a machining tool with regard to a reference surface of a workpiece or of a body connected to the workpiece, is determined. The tool and the workpiece to be machined are relatively moveable toward and away from one another, and the rotary speed of a drive motor for the tool is set to a starting rotary speed which is so low that, when the tool comes into contact with the reference surface, its rotary speed is measurably reduced, the reference surface is moved past the tool before the tool is in contact and while the tool is in contact. As a result, the braking moments in the bearings are increased, and the drive motor comes to a stop quicker.
Claims15
A method of determining current position data of a machining tool during machining with regard to a reference surface of a workpiece or a body connected to the workpiece, comprising the steps of:
- relatively moving the tool and the workpiece toward and away from one another along a feed axis;
- providing a drive motor for the tool and setting the rotary speed of the drive motor to a starting rotary speed which is so low that when bringing the tool into contact with the reference surface, the rotary speed is measurably reduced;
- wherein the reference surface is moved past the tool before the tool is in contact and while the tool is in contact.
An apparatus for determining current position data of a machining tool, comprising a feed device to effect relative movement of the tool and a workpiece toward and away from one another, a first spindle for accommodating the workpiece, at least one further spindle for accommodating the machining tool which can be set in rotation and has an end machining surface, the spindles being arranged and mounted in such a way that the machining tool and workpiece can be moved relatively toward and away from one another for the purpose of material removal at the workpiece, drive motors for adjusting the spindles and for the drive of the machining tool, at least one reference surface which is arranged on one of the workpiece, a work holder and a body connected to the workpiece and against which the end machining surface of the machining tool travels, a signal establishing the feed path of the tool being produced upon contact with the reference surface, which signal is used for determining the starting position of the machining tool, drive means being provided for moving the reference surface along the end machining surface of the machining tool during the contact produced by the feed, and a contact surface being formed with the reference surface by the end machining surface of the tool, the contact surface being asymmetrical and having direction components both in the feed direction and in the direction radial thereto, although only over a part of the circumference of the workpiece.
Dependencies are inferred from the claim text.