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:
Sep. 10, 2013
Filed:
May. 02, 2008
Edward Benjamin Egglestone, Hartlepool, GB;
Derek Marshall, Bristol, GB;
Benjamin Jason Merrifield, Bristol, GB;
Edward Benjamin Egglestone, Hartlepool, GB;
Derek Marshall, Bristol, GB;
Benjamin Jason Merrifield, Bristol, GB;
Renishaw PLC, Wotton-under-Edge, GB;
Abstract
A tool setting or tool analysis device for a machine tool comprises a light source for producing a light beam. A light receiver receives the light beam and produces a signal indicative of the amount of light received. This is analyzed by a main analysis circuit to generate a trigger signal to a machine controller when the beam is at least partially occluded. To provide fail-safe operation should the main circuit not recognize the tool, a back-up trigger signal is produced after a delay by a delay circuit. In one preferred form, the back-up trigger signal may oscillate, providing repeated edges which can ensure fail-safe operation even if the machine controller suffers from a blind window and therefore misses the initial trigger signal.