GB2213861A

GB2213861A - Magnetically secured adhesive fastener, and method

Info

Publication number: GB2213861A
Application number: GB8729274A
Authority: GB
Inventors: John Andrew Brian Hirst
Original assignee: Exotech Ltd
Current assignee: Exotech Ltd
Priority date: 1987-12-15
Filing date: 1987-12-15
Publication date: 1989-08-23
Anticipated expiration: 2007-12-15
Also published as: GB8729274D0; GB2213861B

Abstract

A fastener (13) is adhered to a body (10) comprised essentially of mild steel sheet. Whilst the adhesive (20) is setting, the fastener is held on the body by a magnet (18) incorporated in a head of the fastener. <IMAGE>

Description

Title:"Method of mounting a member, a fastener for use in the method and a structure ;ncorporating the fastener" Oescrlptlon of Invention According to a first aspect of the invention, there is provided a method of mounting a member on a body of magnetic material wherein the member is held by a magnetic field on a surface of the body with a layer of settable adhesive interposed between the body and the member and the adhesive is caused or permitted to set.

The magnetic field is preferably established by a magnet incorporated in the member to be mounted on the body. The magnet may be a permanent part of the member.

The description "magnetic" is used herein to refer to materials which are subjected to a relatively strong force, when placed in a magnetic field.

Generally, the body will be a substantially unmagnetised body of ferromagnetic material, for example a sheet of mild steel.

The member may be a fastener which is used in the mounting of a further member on the body. Such further member may be formed entirely of materials which are essentially non-magnetic.

According to a second aspect of the invention, there is provided a method of mounting a member on a body of magnetic material wherein there is formed a fastener having a magnetic field, the fastener is applied to a face of said body with a layer of settable adhesive between the fastener and the body, the magnetic field holds the fastener on said face whilst the adhesive sets and the fastener is then used to fasten the member to the body.

According to a third aspect of the invention, there is provided a fastener incorporating a magnet, the magnet being so disposed adjacent to a flat face of the fastener that there is a magnetic pole at said face.

An example of a structure incorporation a fastener embodying the third aspect of the invention and which is produced hy a method according to both the first and the second aspect of the invention will now be described, with reference to the accompanying drawing, which shows a digrommat;e illustration of a fastener mounted on a sheet, the fastener be;ng partly broken away to reveal internal parts.

The structure shown in the accompanying drawina comprises a body 10 of magnetic material. The body may be a sheet of mild steel and may have protective and!or decorative coatings (not shown). In the example illustrated, the body has opposed flat faces 11 and 12.

The structure further comprises a fastener 13 which includes an elongated shank 14 and a head 15 at one end of the shank. That face ló of the head which is remote from the shank 14 is flat, to conform the shape of the face I I of the body, and is perpendicular to a longitudinal axis 19 defined by the shank. The head extends from that axis a plurality of times further than does the shank. The head includes a relatively thick central portion and a peripheral flange 17 which is thin, as compared, with the central portion, the thickness being that dimension which extends in a direction along the shank.

The central portion of the head 15 incorporates a permanent magnet 18 which has a thickness, measured in a direction along the shank 1 4, substantially less than the thickness of the central portion of the head and preferably no more than one half of that thickness. The magnet 18 is preferably pre-formed and then inserted into a complementary recess defined by the remainder of the head 15. The remainder of the head may be integral with the shank 14. The magnet is preferably a press-fit in the recess and may be assembled with the remainder of the head without use of an adhesive or other fixing means. However, an adhesive may be interposed between the magnet and the remainder of the head. Alternatively, the magnet could be formed in the recess defined by the remainder of the head.

The magnet 18 lies at the centre of the face 16 of the head and preferably extends from the axis 19 a distance which is at least one quarter and is preferably no more than three quarters of the distance which the head extends from the axis 19. Typically, the head extends from that axis twice as far as the magnet extends from that axis. The face 16 of the head is preferably circular, in which case the magnet also is preferably circular.

The magnet 18 may be formed of known materials, for example magnetic particles in a matrix of a polymeric binder, and may comprise a ferrite.

In the example illustrated, the magnet 18 presents a central part of the flat face 16 of the head. It would be within the scope of the invention for the magnet to be covered by a further part of the head which presents the central part of the face 16.

There ;s interposed between the face I 0e of the fastener and the face l I of the body a layer 20 of adhesive which holds the fastener on the bodv 10.

The adhesive is applied to one or both of the body and the fastener in a settable condition and the fastener is mounted on the body whilst the adhesive is still in that condition. The fastener is then held in the intended relation to the body by magnetic forces which result from the magnetic field associated with the magnet 18. In a case where those parts of the head 15 which surround the magnet 18 are formed of magnetic material, there may be established a magnetic circuit interrupted only by the relatively thin laver of adhesive 20, there being substantial magnetic flux at that part of the face ló presented by the magnet !8 and also at that part of the face 16 presented by the remainder of the head.The magnet 18 is Dreferably arranged with one magnetic pole at the face I ló and the other pole of the magnet 18 remote from the face 16.

Suitable adhesives include that sold under the Trade Mark "LOCTITE".

The specific adhesive used may be selected according to the characteristics of the surface of the body 10 and of the surface of the fastener.

The adhesive may be applied to one or both of the fastener and the bodv 10 immediately prior to application of the fastener to the body. Alternatively, the adhesive may be applied a substantial period of time before the fastener is applied to the body, the adhesive being covered by a protective layer which protects the adhesive against premature curing and/or premature adhesion to other surfaces. Such protective covering may be peeled away before the fastener is applied to the body 10.

The shank 14 may be adapted to c-operate with a further fastener element or with a further member to be mounted on the body 10 by means of the fastener, such adaptation being the provision of barbs, ribs, a screw thread or other formation on the surface of the shank. Alternatively, the shank may be formed as a hook or otherwise adapted to support a member to be mounted on the body 10.

Whilst the invention will generally be applied to a fastener for use in mounting a further member on the body 10, it is within the scope of the invention to incorporate directly in a memher which is to be mounted on the body 10 a magnet and to adhere that member to the body 10 in the manner n which the fastener 13 is adhered to the body.

The features disclosed in the foregoing description or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAI CAS:-

1. A method of mounting a member on a body of magnetic material wherein the member is held by a magnetic field on a surface of the body with a layer of settable adhesive interposed between the body and the member and the adhesive is caused or permitted to set.

2. A method of mounting a member on a body of magnetic material wherein there is formed a fastener having a magnetic field, the fastener is applied to a face of said body with a layer of a settable adhesive between the fastener and the body, the magnetic field holds the fastener on said face whilst the adhesive sets and the fastener is then used to fasten the member to the body.

3. A fastener incorporating a magnet, the magnet being so disposed adjacent to a flat face of the fastener that there is a magnetic pole at said face.

4. A fastener according to Claim 3 wherein the fastener has a shank and a head at one end of the shank and wherein said face is presented by the head.

5. A fastener according to Claim 4 wherein said face is presented in a direction opposite to that in which the shank extends from the head.

6. A fastener according to Claim 4 or Claim 5 wherein the shank is elongated.

7. A fastener according to Claim 6 wherein the shank is provided with barbs, ribs or a screw thread.

8. A fastener according to any one of Claims 3 to 7 having a layer of settable adhesive on said face.

9. A fastener according to Claim 8 having a protective covering on said layer of adhesive so that the layer of adhesive is interposed between the protective covering and the fastener.

10. A structure comprisina a fastener according to any of Claims 3 to 7 and a body of magnetic material, wherein the fastener is held on a surface of the body by a layer of adhesive interposed between said flat face of the fastener and said surface of the body.

! 1. A fastener substantially as herein described with reference to tk.e accompanying drawing.

12. Any novel or novel combination of features disclosed herein or in the accompanying drawing.