Machine pour la fabrication d'engrenages coniques

1,223,827. Gear cutting. GLEASON WORKS. 1 Oct., 1969 [1 Oct., 1968], No. 48236/69. Heading B3K. A device provided in a gear cutting machine for checking that a previously cut workpiece 408 is properly oriented and fully seated on a work spindle, e.g. for finish cutting, comprises a pivotal arm 404 having an air passage 412 and port 413 adapted to be blocked by the workpiece if properly disposed. The arm 404 carries a projecting element 410 arranged to enter a previously cut groove so that if the workpiece is correctly oriented and fully seated on the work spindle the port 413 is blocked by a heel portion 414 of the workpiece and pressure builds up in the passage 412 to operate a pressure-sensitive switch 430 controlling the operation of the machine through a motor 434. The arm 404 may be moved into its operative checking position by an hydraulic cylinder and piston 418, 416 and retracted by spring-loaded means 420, 422 in suitably timed relation with the operation of the machine.