Flexible magnetic strip

Abstract: For holding together flexible materials, such as roll-up display screens, edge-to-edge, very thin and narrow flexible magnetic strip (3) is co-moulded edge-to-edge with non-magnetic flexible strip (4), one face (7 or 5) of the combined strip (1 or 2) being suitable for the application of an adhesive, e.g. in the form of double-adhesive tape (8, 9), and the other face (5 or 7) being provided with indicator means for the polarity of the magnetic portions (3) e.g. different colouring pigments in the non-magnetic portions (4) of co-acting combined strips, or impressions such as a single continuous groove (6) for N-polarity and a pair of grooves (10) for S-polarity.

Description: This invention relates to flexible magnetic strips, more particularly of the type having such attraction and holding power that comparatively very thin and narrow strips (e.g. width of the order of 3.0 mm and thickness of the order of 1.0 mm) can attract edge-to-edge. While it is evident that such flexible magnetic strips would be useful in many applications where both flexibility and holding power are of great advantage, e.g., in releasably holding together flexible materials, such as roll-up display screens, edge-to-edge, the problem is how to secure the strips to the flexible materials without creating too much stiffness and how to identify the respective polarities The object of the present invention is to provide a solution to these problems. According to the present invention, flexible magnetic strips which can attract edge-to-edge are characterized by very thin and narrow flexible magnetic strip portions co-moulded edge-to-edge with non-magnetic flexible strip portions, one face of each co-moulded strip being provided with indicator means for the polarity of the magnetic portion, and the other face being available for the application of adhesive means. Each non-magnetic strip portion may be of greater width than the respective magnetic strip portion, an example of a suitable width of non-magnetic strip portion being 5.0 mm. DE-A-2601439 discloses a sealing strip for lids and doors for refrigerators or automobiles, for example, consisting of a magnet strip and a soft flexible non-magnetic backing strip extruded together to form one piece along an edge or a surface. US-A-3191106 discloses a locking, sealing or holding material for door gaskets, particularly on refrigerators consisting of flexible magnetic strip to which is imported an acceptable colour by mixing with the binder for the magnetic particles aluminium powder coloured blue, yellow, or red or any other suitable colour. The adhesive means may be one side of double-adhesive tape applied to the co-moulded strip subsequent to extrusion from the mould. The indicator means may comprise colouring pigment in the non-magnetic strip portions of the co-moulded strips distinct from the colour of the magnetic strip portions; different colours being used to indicate the different polarities of the co-acting strips. WO-A-9741327 discloses a weather strip, in particular for window and door frames and the like, consisting of a band of magnetic material flexibly mounted on the frame and attracted face-to-face with a band of magnetic material round the window or door. Alternatively, the indicator means may comprise impressions in the non-magnetic strip portions of the co-moulded strips, such as continuous grooves formed during extrusion, for example, a single groove for N-polarity and a pair of grooves for S-polarity. Co-acting embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawing which is a greatly enlarged diagrammatic cross-section (not to scale) through co-acting strips. The drawing shows two flexible magnetic strips 1, 2 capable of attracting each other edge-to-edge and each co-moulded with a narrower strip portion 3 of flexible magnetic material and a wider strip portion 4 of non-magnetic flexible material. One face 5 of the portion 4 of strip 1 has a single groove 6 in it to identify its N-polarity, and the other face 7 of the strip 1 carries double-adhesive tape 8 whereby the strip 1 can be adhered to one side of, say, a roll-up display screen (not shown) after removal of a releasable cover strip 9. The other strip 2, on the other hand, has two grooves 10 in its face 7 to identify its S-polarity, and its face 5 carries double-adhesive tape 8 whereby the strip 2 can be adhered to one side of, say, another roll-up display screen (also not shown) after removal of its releasable cover strip 9, thus enabling the two strips 1, 2 to be used to hold together edge-to-edge the two screens. Alternatively, as mentioned above, identification of the polarities of the strips 1, 2 may be effected by incorporating different colour pigments in their respective wider portions 4; but the advantage in using grooves 6, 10 lies in being able to use a non-coloured binder such as that used in the magnetic portions of the co-mouldings.

Claims: Flexible magnetic strips (1, 2) which can attract edge-to-edge characterized by very thin and narrow flexible magnetic strip portions (3) co-moulded edge-to-edge with non-magnetic flexible strip portions (4), one face (5 or 7) of each co-moulded strip (1 or 2) being provided with indicator means (6 or 10) for the polarity of the magnetic portion, and the other face (7 or 5) being available for the application of adhesive means. Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in Claim 1, characterized in that each non-magnetic strip portion (4) is of greater width than the respective magnetic strip portion (3). Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in Claim 1 or Claim 2, characterized in that the adhesive means is one side of double-adhesive tape (8) applied to the co-moulded strip subsequent to extrusion from the mould. Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in any one of Claims 1 to 3, characterized in that the indicator means comprise colouring pigments in the non-magnetic strip portions (4) of the co-moulded strips (1, 2) distinct from the colour of the magnetic portions strip (3), and different colours being used to indicate the different polarities of the co-acting strips. Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in any one of Claims 1 to 3, characterized in that the indicator means comprise impressions (6, 10) in the non-magnetic strip portions (4) of the co-moulded strips. Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in Claim 5, characterized in that the indicator means comprise continuous grooves (6, 10) formed during extrusion. Co-moulded magnetic and non-magnetic flexible strips (1, 2) as in Claim 6 characterized by a single groove (6) for N-polarity and a pair of grooves (10) for S-polarity.

Inventors: BURTON MICHAEL ERIC, LEE SIMON JOHN, BURTON, MICHAEL ERIC, LEE, SIMON JOHN
Applicants: ANCHOR MAGNETS LTD, ANCHOR MAGNETS LIMITED
Application year: 2001
Main classification: H01F1
IPC codes: H01F1, H01F7