GB2212970A

GB2212970A - Disc centering device

Info

Publication number: GB2212970A
Application number: GB8826432A
Authority: GB
Inventors: Robert Gillbank
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-11-27
Filing date: 1988-11-11
Publication date: 1989-08-02
Also published as: GB8727827D0; GB8826432D0

Abstract

A device for centering a floppy disc within a sleeve before insertion into a disc drive comprises a generally square member 10 with a support surface 11, a peripheral wall 13 having an inward facing slope 14, and a centrally located boss 15 which is frusto-conical with a slope 16, a floppy disc in its sleeve being placed on the member 10 with boss 15 entering the central hole of the disc. The sleeve is positioned by the slope 14 and the disc by the slope 16. An edge cut-out 17 aids manipulation of the floppy disc. Snagging of the disc aperture edges by the disc drive cone is countered. <IMAGE>

Description

Disc Centering Device This invention relates to a device for centering discs, particularly flexible data storage discs used in computer systems, so-called 'Floppy Discs'.

The disc drive of a computer includes a cone which enters a circular aperture in the centre of the disc. Each disc is enclosed in a square sleeve, having a slot for access of refad and write heads to the sensitised area of the disc, and a central aperture for engagement of the drive cone with the disc. The sleeve is slightly larger than the disc so that the disc is carried in the sleeve with some play but none of the sensitised area of the disc is exposed by the central sleeve aperture, and is only exposed in the area of the read/write slot. Unlike sound recordings, the disc is never taken from the sleeve for insertion into the drive.

When a disc is inserted into a disc drive, its sleeve is located precisely by the edges of the insertion slot, but as there is play of the disc in the sleeve, the disc itself is not accurately centred with respect to the drive cone.

As a result, there is a tendancy for the drive cone to snag the edges of the central aperture of the disc. This does not cause any physical damage to the sensitised area of the disc such as might cause loss of data, but leads to mechanical wear and stress in the disc which tend to shorten disc life, thus requiring more frequent making of use copies from masters, and replacement in due course of masters themselves.

An object of this invention is to provide a device which will substantially avoid such damage to discs before insertion into the disc drive, by centering the disc accurately in the sleeve.

According to the invention, a device for centring discs in their sleeves comprises a support member, edge locating guides for receiving the edges of a disc cover, and a central locating boss, by means of which the disc may be placed on the support over the locating boss, and the edges of the sleeve located by the guides, thereby centering the disc in the sleeve.

The device may be made from a suitable plastics material, cast or injection or blow moulded as appropriate, and is preferrably formed from a single sheet of such material.

Obvious other materials such as sheet metal or wood could be used, but would be much more expensive. Such materials could be used for a 'Deluxe' or 'Executive' version for status rather than practical use.

The sleeve edge location guide may comprise a raised rim about the periphery of the generally square support surface, and preferrably has an inward slope, the position of the base of the slope defining the edge of the area to be occupied by the sleeve.

The central boss is preferrably a frusto-conical protrusion, and the support surface may have a bay cut-out to enable manipulation of a disc-sleeve combination.

A preferred embodiment of device according to the invention will now be described by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a plan view of the device, and Fig.2 is a cross-section on line Il-Il in Fig.1.

The device according to the invention shown in the drawings comprises a single piece of plastics blow or injection moulded sheet 10, which is substantially square in shape and has a major planar surface 11 which provides a support surface. The piece also has a peripheral wall 13 with an inner slope 14 which provides a guide or cam surface to enable a disc sleeve to be located on the surface 11, the base of the slope 14 defining the desired sleeve position.

A central frusto-conical boss 15 is also provided at the geometric centre of the support surface 11. The slope 16 of the boss allows a disc which is not correctly centered in its sleeve to be placed over the boss. Pushing the disc and sleeve onto the device automatically centres the disc using the slope of the boss as a cam, and the sleeve using the slope 14 of the peripheral wall. Discs can thus be centred correctly using the device before being placed in a disc drive so that the drive cone of the drive will not snag the edges of the central aperture of the disc, thereby reducing wear and tear on the disc and helping to prolong the useful life of the disc.

In order to facilitate manipulation of the disc using the sleeve edges, a bay 17 is cut out of one side of the surf surface 11. As the device is blow or injection moulded, or vacuum or press formed, the boss 15 and wall 13 are hollow.

The invention is not limited to this embodiment however, and other equivalent means or configurations may be provided to guide the sleeve and centre the disc. The underside may be provided with feet, or felt pads, or covered with felt or a foam plastics cushion, to avoid scratching of polished desk surfaces. Materials other than plastics may be used, such as metal sheet (aluminium alloy) or even carved from wood.

Claims

1. A device for centering floppy discs in their sleeves comprising a support member, edge locating guides for receiving the edges of a disc cover, and a central locating boss by means of which the disc may be placed on the support member over the locating boss and the edges of the sleeve located by the guides, thereby centring the disc in the sleeve.

2. A device according to Claim 1 wherein the edge locating guide comprises a raised rim about the periphery of the support member which is generally square and provides an upper support surface, said rim having an inward slope the position of the base of the slope defining the edge of the area to be occupied by the sleeve.

3. A device according to Claim 2 wherein the central boss is a frusto-conical protrusion with a slope which serves to centre the disc, and the support surface has a cut-out bay to enable manipulation of a disc-sleeve combination.

4. A device for centring floppy discs in their sleeves substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.