WO2006077417A2

WO2006077417A2 - Magnetic shield

Info

Publication number: WO2006077417A2
Application number: PCT/GB2006/000194
Authority: WO
Inventors: Hugh J. Stanbury
Original assignee: Corus Uk Limited
Priority date: 2005-01-21
Filing date: 2006-01-20
Publication date: 2006-07-27
Also published as: EP1852005A2; GB0501181D0; JP2008529266A; WO2006077417A3; GB2422384A

Abstract

A pre-fabricated magnetic shield comprising a laminate panel having at least two co-planar sheets having electromagnetic shielding properties, the sheets being arranged and connected in such a way as to be offset from each other so to provide an overlap along each sheet edge.

Description

MAGNETIC SHIELD

The present invention relates to a magnetic shield and a method of manufacture of such shield.

There are an increasing number of environments which need to be free of electromagnetic interference in order for an electronic system or subsystem to operate reliably without being impaired by electromagnetic disturbance. Magnetic shields are becoming an increasingly important feature in the construction of new buildings.

The present invention sets out to provide an improved magnetic shield.

In one aspect of the invention, there is provided a pre-fabricated magnetic shield comprising a laminate panel having at least two co-planar sheets having electromagnetic shielding properties, the sheets being arranged and connected in such a way as to be offset from each other so to provide an overlap along each sheet edge.

Preferably the panel comprises between two and five sheets. Preferably still, the panel comprises 3 sheets.

Preferably still, the sheets are made of a material that has high permeability properties. Preferably the sheets are made from high permeability silicon steel.

Preferably, the magnetic shield comprises a plurality of panels connected together in such a way that the edges of each sheet of one panel abut the corresponding edges of each sheet of an adjacent panel.

Preferably, the overlaps are butt joined. In a second aspect, there is provided a method of manufacturing a magnetic shielding panel comprising the steps of arranging at least two sheets having electromagnetic shielding properties in a co-planar relationship such that the sheets are offset from each other so to provide an overlap along each sheet edge, and connecting the sheets together.

One embodiment of the present invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which :-

Figure 1 is a plan view of a magnetic shield constructed in accordance with the present invention; and

Figure 2 is a plan view of a plurality of shields connected together.

Referring first to Figure 1, a magnetic shield comprises a panel 5 which itself comprises three sheets 1OA, 1OB, 1OC of material having electromagnetic shielding properties. The sheets lOA-C are preferably made from a high permeability, silicon steel.

The sheets lOA-lOC are approximately 1 mm thick but can be made to any desired thickness depending on their intended application. Sheets made from such a material are lightweight and consequently, the panel 5 constructed from the sheets is lightweight which is highly advantageous.

Although the embodiment described refers to a panel 5 comprising three sheets lOA-C, a panel 5 may be formed of any number of sheets to provide a desired overall thickness for the intended application. The applicant has found, to date, that the optimum range of sheets is between 2 and 5.

The steel may be grain oriented or non-grain oriented. It is clear that the sheets should not be limited to a specific material. Other metallic materials could, for example, be used such iron, cobalt or nickel. Depending on the characteristics of the electromagnetic field to be shielded, the sheets lOA-C could also include or consist of other materials such as aluminium, lead, copper or ceramic or polymeric material.

The top sheet 1OA may be dry-lined to provide an aesthetic appearance. The sheet 1OA may be coated with, or may otherwise include, an anti-corrosive or anti-bacterial compound.

The sheets lOA-lOC are connected together to form the panel 5 by spot-welding or similar technique. An example of the position of the spot welds 14 can be seen in Figure 1.

The sheets lOA-lOC could alternatively be connected together using mechanical fixtures and/or adhesive.

The sheets lOA-C may be connected directly together or may be arranged in the form of a sandwich with a material layer located therebetween to improve the shielding effect or provide further properties that may be advantageous to the shielding structure.

The offset arrangement of the panel 5 is such that, when number of panels 5 are located against one another with the top sheets 1OA of each panel 5 adjacent (see Figure 2), the overlaps 12 around the panel edges ensure a uniform thickness of shielding material is provided across the entire shield surface, including at the connections between each panel 5.

The overlaps 12 of the sheets lOA-lOC of each panel 5 are butt- joined to minimise leakage. In an alternative embodiment (not shown) the edges of each sheet are designed in such a way that the sheets lOA-C of each panel 5 are joined in a dovetail arrangement. Construction and installation of the magnetic shield is simple.

Pre-fabricated panels are bought to the site for installation. The panels 5 are attached to a wall using rivets (the head of the rivet being larger than the hole created). Panels 5 may be alternatively fixed to a framework consisting of plywood or wooden batons. The panels 5 can be bent or otherwise shaped to cover the wall to ceiling and/or wall to floor joints. Consequently, an entire room can have a magnetic shielding surround.

If necessary, more than one layer of panels 5 may be used to provide the required shielding

Magnetic shields comprising panels 5 constructed in accordance with the present invention find particular application in rooms containing MRI scanners and rooms requiring transformer and substation shielding, communications protection, or transducer shielding. Also, laboratory or industrial settings containing sensitive equipment and measuring devices which may otherwise be affected by magnetic shields.

The above described embodiment has been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the present invention.

Claims

1. A pre-fabricated magnetic shield comprising a laminate panel having at least two co-planar sheets having electromagnetic shielding properties, the sheets being arranged and connected in such a way as to be offset from each other so to provide an overlap along each sheet edge.

2. A panel according to claim 1, wherein the panel comprises between two and five sheets.

3. A panel according to claim 2, wherein the panel comprises 3 sheets.

4. A panel according to any preceding claim, wherein the sheets are made of a material that has high permeability properties.

5. A panel according to claim 4, wherein the sheets are made from high permeability silicon steel.

6. A panel according to any preceding claim, wherein the magnetic shield comprises a plurality of panels connected together in such a way that the edges of each sheet of one panel abut the corresponding edges of each sheet of an adjacent panel.

7. A panel according to any preceding claim, wherein the overlaps are butt joined.

8. A method of manufacturing a magnetic shielding panel comprising the steps of arranging at least two sheets having electromagnetic shielding properties in a co-planar relationship such that the sheets are offset from each other so to provide an overlap along each sheet edge, and connecting the sheets together.