Assembly and method for reducing foil wrinkles

Patent metadata

Field	Value
Publication number	US-9437389-B2
Application number	US-201113574515-A
Country	US
Kind code	B2
Filing date	Feb 1, 2011
Priority date	Feb 8, 2010
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

An assembly of a support plate and an exit window foil for use in an electron beam device. The support plate is designed to reduce wrinkles in said foil, which wrinkles may arise due to surplus foil arising in the assembly process. The foil is being bonded to the support plate along a closed bonding line bounding a substantially circular area in which the support plate is provided with apertures and foil support portions and in which area the foil is adapted to serve as a portion of a wall of a vacuum tight housing of the electron beam device. Another aspect involves a method for using the assembly in a filling machine, as well as a method of reducing wrinkles.

First claim

The invention claimed is:

1. An assembly of a support plate and an exit window foil for use in an electron beam device, said support plate being designed to reduce wrinkles in said exit window foil, which wrinkles may arise due to surplus foil arising in the assembly process, the assembly comprising, said exit window foil being bonded to the support plate along a closed bonding line bounding an area in which the support plate is provided with apertures and foil support portions and in which area the exit window foil serves as a portion of a wall of a vacuum tight housing of the electron beam device, the support plate, within said area, is provided with a pattern of apertures and foil support portions alternately, which pattern, when vacuum is created in the housing, forms a topographical profile of the exit window foil absorbing any surplus foil,
the exit window foil and support plate area, within the closed bonding line, being defined by a cylindrical coordinate system having an axial axis, a radial axis and an angular axis, said axial axis being aligned with an axial centre axis of the support plate, and said radial axis being aligned with a radius of the support plate within the closed bonding line, and the absorbing of surplus foil is made in such a way that in the apertures a dominant bending of the foil is created around either the radial axis or the angular axis,
the foil support portions of the support plate, within said area, being comprised of concentric rings connected to each other by radially directed spokes, the radially directed spokes each having an arc-shaped concave upper surface facing the exit window foil.

2. An assembly according to claim 1 , wherein the dominant bending is being created around the angular axis in that the foil support portions of the support plate, within said area, provide a variation in the axial direction along the radial axis.

3. An assembly according to claim 2 , wherein said variation in the axial direction along the radial axis is provided as a concentric waveform, and that, within said area, the support plate, along the angular direction, does not vary or varies an amount in the axial direction.

4. An assembly according to claim 1 , wherein the radially directed spokes and the concentric rings define the boundaries of the apertures.

5. An assembly according to claim 1 , wherein said concentric rings coincide with wave crests of a waveform.

6. An assembly according to claim 1 , wherein the closed bonding line is positioned on a plateau.

7. An assembly according to claim 1 , wherein the support plate comprises two members, a first support plate member designed to support a central portion of the foil, and a second plate member having the shape of a frame and provided with said closed bonding line.

8. A method for reducing wrinkles in an exit window foil of an electron beam device, which wrinkles may arise due to surplus foil arising in the assembly process, said exit window foil being bonded to a support plate along a closed bonding line bounding an area in which the support plate is provided with apertures and foil support portions and in which area the exit window foil serves as a portion of a wall of a vacuum tight housing of the electron beam device,
the method comprising:
providing, within said area, a pattern of apertures and foil support portions alternately in the support plate, which pattern, when vacuum is created in the housing, forms a topographical profile of the exit window foil absorbing any surplus foil,
the exit window foil and support plate area, within the closed bonding line, being defined by a cylindrical coordinate system having an axial axis, a radial axis and an angular axis, said axial axis being aligned with an axial centre axis of the support plate, and said radial axis being aligned with a radius of the support plate within the closed bonding line,
the absorbing of the surplus foil occurring by a dominant bending of the exit window foil in the apertures created around either the radial axis or the angular axis,
the foil support portions of the support plate, within said area, being comprised of concentric rings connected to each other by radially directed spokes, the radially directed spokes each having an arc-shaped concave upper surface facing the foil.

9. A method for sterilizing packaging containers in a filling machine, the method comprising using an electron beam generating device comprising an assembly according to claim 1 .

10. An electron beam generating device comprising:
a vacuum chamber configured to be connected to a vacuum source to create a vacuum in the vacuum chamber;
a filament positioned in the vacuum chamber and configured to emit electrons;
a control grid positioned in the vacuum chamber;
an electron exit window through which, electrons emitted by the filament, pass;
the electron exit window comprising an exit window foil and a support plate serving as a support for the exit window foil, the exit window foil being bonded to the support plate along a closed bonding line bounding an area, the support plate including apertures and foil support portions that alternate with one another and form, when the vacuum is created in the vacuum chamber, a topographical profile of the exit window foil absorbing any surplus foil; and
the foil support portions comprising concentric rings connected to each other by radially directed spokes, the radially directed spokes each having an arc-shaped concave surface extending between radially adjacent concentric rings and facing the foil.

11. The electron beam generating device according to claim 10 , wherein the exit window foil and the support plate area, within the closed bonding line, are defined by a cylindrical coordinate system having an axial axis, a radial axis, and an angular axis, the radial axis being aligned with a radius of the support plate within the substantially circular bonding line, and a dominant bending of the foil is created in the apertures around the radial axis or the angular axis to absorb the surplus foil.

12. The electron beam generating device according to claim 11 , wherein the apertures possess boundaries defined by the concentric rings and the radially directed spokes, and the concentric rings coincide with wave crests of a concentric waveform created by a variation in the foil support portions in the axial direction along the radial axis.

13. The electron beam generating device according to claim 10 , wherein the radially directed spokes in an interspace between two concentric rings are not aligned with the radially directed spokes in an immediately adjacent circumferential interspace.

Assignees

• Åberg Andreas
• Linné Ulrika
• Hostettler Urs
• Tetra Laval Holdings & Finance

Inventors

• Åberg Andreas
• Linné Ulrika
• Hostettler Urs

Classifications

• Y10T29/49002

  Electrical device making · CPC title

• H01J2237/00

  Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging · CPC title

• H01J5/18

  Windows permeable to X-rays, gamma-rays, or particles · CPC title

• B65B55/08

  by irradiation · CPC title

• G21K5/02

  having no beam-forming means · CPC title