公开(公告)号：WO2023089295A1

公开(公告)日：2023-05-25

申请号：PCT/GB2022/052753

申请日：2022-11-01

Applicant: RENISHAW PLC

Inventor： STOCKILL, William David

IPC: B23Q17/24 ,  B23Q11/00 ,  G01V8/12

Abstract: A tool measurement apparatus for a machine tool includes a transmitter portion (100) including a light source (102) for generating a light beam (104) and a receiver portion (300) including a detector for detecting the light beam (104), the light beam being passed from the light source to the detector along an optical path. At least one of the receiver portion (300) and the transmitter portion (100) comprises a protection device including a gas expulsion aperture (108) configured to expel a bleed gas supplied from an external gas source. The optical path also passes through the gas expulsion aperture (108). The protection device further comprises a check valve (112; 200) located in the optical path. The bleed gas is supplied to the gas expulsion aperture (108) through the check valve (112; 200) and the flow of the bleed gas through the check valve (112; 200) causes the check valve to adopt an open configuration defining a passageway through which the light beam (104) can pass.