Apparatus for working materials by means of an electron beam

Claim 1

APPARATUS FOR WORKING MATERIALS BY MEANS OF AN ELECTRON GUN COMPRISING A BASE DISC; A CARRIER PLATE EXTENDING ACROSS AND SLIGHTLY SPACED FROM A SURFACE OF SAID BASE DISC; MEANS ROTABLY SUPPORTING SAID CARRIER SEAL ON SAID BASE DISC; FIRST SEALING MEANS BETWEEN THE ADJACENT SURFACE OF SAID BASE DISC AND CARRIER PLATE, SAID FIRST SEALING MEANS EXTENDING COMPLETELY AROUND THE BASE DISC ADJACENT TO BUT SPACED FROM THE EDGE OF THE BASE DISC; SAID BASE DISC HAVING AN ELECTRON GUN RECEIVING APERTURE AND A RELIEF PORT EXTENDING THERETHROUGH, SAID ELECTRON GUN RECEIVING APERTURE AND SAID RELIEF PORT BEING EQUALLY SPACED FROM THE AXIS OF ROTATION OF SAID CARRIER PLATE AND OPENING, INTO THE SPACE BETWEEN THE BASE DISC AND CARRIER PLATE WITHIN SAID FIRST SEALING MEANS; A SECOND SEALING MEANS BETWEEN THE ADJACENT SURFACES OF SAID BASE DISC AND CARRIER PLATE, SAID SECOND SEALING MEANS SURROUNDING THE ELECTRON GUN RECEIVING APERTURE; A THIRD SEALING MEANS BETWEEN THE ADJACENT SURFACES OF THE BASE DISC AND CARRIER PLATE, SAID THIRD SEALING MEANS SURROUNDING THE RELIEF PORT; SAID BASE PLATE DISC HAVING A PUMPING PORT EXTENDING THERETHROUGH AND OPENING INTO THE SPACE BETWEEN THE BASE DISC AND CARRIER PLATE WITHIN SAID FIRST SEALING MEANS AND OUTSIDE OF SAID SECOND AND THIRD SEALING MEANS, SAID PUMPING PORT ADAPTED TO BE CONNECTED TO MEANS FOR REDUCING THE PRESSURE IN THE SPACE BETWEEN THE BASE DISC AND CARRIER PLATE WHICH IS INSIDE FIRST SEALING MEANS AND OUTSIDE OF SAID SECOND AND THIRD SEALING MEANS; SAID CARRIER PLATE HAVING AN APERTURE THERETHROUGH SPACED FROM THE AXIS OF ROTATION OF SAID CARRIER PLATE A DISTANCE EQUAL TO THE SPACING OF EACH OF THE ELECTRON GUN RECEIVING APERTURE AND THE RELIEF PORT FROM SAID AXIS OF ROTATION, MEANS IN SAID CARRIER PLATE APERTURE FOR SUPPORTING THE MATERIAL TO BE WORKED; AND A CLOSURE PLUG REMOVABLY MOUNTED ACROSS SAID CARRIER PLATE APERTURE: SAID CARRIER PLATE BEING ROTATABLE WITH RESPECT TO SAID BASE DISC BETWEEN A FIRST POSITION IN WHICH THE CARRIER PLATE APERTURE IS OVER THE ELECTRON GUN RECEIVING APERTURE AND A SECOND POSITION IN WHICH THE CARRIER PLATE APERTURE IS OVER THE RELIEF PORT.