Method and device for cleaning and/or replacement of a laser window of a process chamber

Patent metadata

Field	Value
Publication number	US-2018345375-A1
Application number	US-201816001636-A
Country	US
Kind code	A1
Filing date	Jun 6, 2018
Priority date	Jun 6, 2017
Publication date	Dec 6, 2018
Grant date	—

Abstract

A device is provided for cleaning and/or replacement of a laser window of a process chamber, enclosed by an outer wall, containing a modified atmosphere, in particular a process chamber for layered printing of a 3D object by a technique such as Selective Laser Sintering (SLS), where this device features an opening in the outer wall that is fitted with the laser window and where this laser window allows a laser beam from a laser source located outside of the process chamber into the process chamber, where an external sealing ring is provided that extends between the outer wall and this laser window.
A method is also provided for cleaning and/or replacement of the laser window in the opening of the outer wall of the enclosed process chamber.

First claim

1 . Device with a laser window fitted on an outer wall of an enclosed process chamber containing a modified atmosphere, in particular a process chamber for layered construction of a 3D object by means of a laser,
where this outer wall features at least an opening that is fitted with a laser window and where this laser window lets a laser beam from a laser source located outside of the process chamber pass through the opening and into this process chamber to build the 3D object in layers, where an external sealing ring is provided that extends between the outer wall and the laser window, wherein the improvement comprises that the laser window ( 1 ) is movable with respect to the opening, where, moreover, a sealing plate is provided that extends into the process chamber and that is movable between an open position and a closed position, where, in the open position of the sealing plate, this sealing plate leaves the opening in the outer wall clear, and where in the closed position of the sealing plate: an internal sealing ring is provided that extends into the process chamber between the sealing plate and the outer wall, around the opening, the sealing plate, combined with the internal sealing ring, seals the opening of the process chamber, around the opening, a lock chamber is created that is bordered by at least the sealing plate, the internal sealing ring and the laser window, an inlet and an outlet extend into the lock chamber for supply of the modified atmosphere in this lock chamber.

2 . A device according to claim 1 , wherein the outlet is fitted with a pressure relief valve and/or where the outlet is connected to a vacuum pump for creating a vacuum in the lock chamber.

3 . A device according to claim 1 , wherein this contains an internal guide that guides the sealing plate between the open position and the closed position of the sealing plate, preferably primarily parallel to the opening and/or the outer wall.

4 . A device according to claim 1 , wherein this contains an external guide that guides the laser window between an open position and a closed position of the laser window.

5 . A device according to claim 1 , wherein the internal sealing ring and/or the external sealing ring contain an inflatable seal.

6 . A device according to claim 1 , wherein the laser window contains an adapter plate with one or more laser panes.

7 . A device according to claim 1 , wherein drive means are provided that drive the sealing plate to open the laser window and move it from an open position to a closed position in a first step, and in a subsequent second step, move the laser window with respect to the opening to the open position.

8 . A device according to claim 1 any of claims 1 , wherein the inlet and the outlet are made up of a single connecting pipe that alternates between serving as an inlet and outlet.

9 . A method for cleaning or replacement of a laser window of an enclosed process chamber containing a modified atmosphere, in particular a process chamber for layered construction of a 3D object by techniques such as Selective Laser Sintering (SLS), where an outer wall of the process chamber features at least an opening that is fitted with the laser window and where this laser window lets a laser beam from a laser source located outside the process chamber pass through the opening and enter this process chamber for layered construction of the 3D object, in which this method comprises the following steps:
placement of a sealing plate in the enclosed process chamber on an inner side of the laser window so that this fully covers the opening fitted with the laser window; creation of an enclosed lock chamber by closing an internal sealing ring around the opening with the laser window, between the outer wall and the sealing plate; movement of the laser window with respect to the opening in the outer wall; cleaning of the inner side of the laser window or replacement of this laser window by a new laser window; placement of the cleaned laser window or the new laser window over the opening of the outer wall; closure of an external sealing ring around the opening with the laser window, between the outer wall and the laser window; modification of the atmosphere in the lock chamber; removal of the sealing plate on an inner side of the laser window.

10 . A method according to claim 9 , in which modification of the atmosphere in the lock chamber is carried out by supplying an inert gas.

11 . A method according to claim 9 , in which modification of the atmosphere in the lock chamber is carried out by creating a vacuum in the lock chamber and then supplying an inert gas.

12 . A method according to claim 1 , in which placement and removal of the sealing plate is carried out by guiding this sealing plate over an internal guide.

13 . A method according to claim 12 , in which guidance of the sealing plate is carried out primarily in parallel to the outer wall, the opening and/or the laser window.

14 . A method according to claim 9 , in which closure of the internal sealing ring and/or the external sealing ring is carried out by inflating an inflatable seal.

15 . A method according to claim 9 , in which movement of the laser window with respect to the opening in the outer wall is carried out by guiding this laser window over an external guide.

Assignees

• 3D Systems Inc

Inventors

• Van Vaerenbergh Jonas
• Valkenborgs Brawley

Classifications

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B23K26/123 Primary

  in an atmosphere of particular gases · CPC title

• B22F10/32

  of the atmosphere, e.g. composition or pressure in a building chamber · CPC title

• B22F12/22

  Driving means · CPC title

• B08B15/02

  using chambers or hoods covering the area {(B08B15/002 takes precedence)} · CPC title