AU751702B2

AU751702B2 - A releasable retention device

Info

Publication number: AU751702B2
Application number: AU93271/98A
Authority: AU
Inventors: David Llewellyn
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-11-21
Filing date: 1998-11-19
Publication date: 2002-08-22
Anticipated expiration: 2018-11-19
Also published as: AU9327198A

Description

P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT 0 000 0 0 0 60000 00 0 a0 0 0 00 0 0 0*0:

ORIGINAL

Name of Applicant: Actual Inventor: Address for service in Australia: Invention Title: David Llewellyn David Llewellyn CARTER SMITH BEADLE Level 10, 189 Kent St Sydney, NSW, 2000 Australia A RELEASABLE RETENTION DEVICE Details of Associated Provisional Application: PP0489 filed 21 November 1997 The following statement is a full description of this invention, including the best method of performing it known to us -2- A RELEASABLE RETENTION DEVICE The present invention relates to a releasable retention device and, more particularly, to such a device particularly, although not exclusively, adapted to releasably retain compact discs and like devices to a base material.

BACKGROUND

Various kinds of releasable retention devices are known. One such category of device utilises an interference fit between the object to be •0 releasably retained and the device for performing this function.

000 ~In practice problems arise including, for example, wear between the 0 components so that the interference fit is eroded over time to the point where releasable retention is no longer effective.

With reference to Fig 1 a particular form of such a prior art device is illustrated. Because of the problem referred to above the unitary post illustrated in Fig 1 is made of extended length in order to provide alternative interference fit positions along the length once initial positions are worn away.

A creep problem also arises with this form of interference fit arrangement whereby relative movement between the object retained on the post and the post itself tends to cause the object to "walk" up or down the post.

It is an object of the present invention to address or ameliorate the abovementioned disadvantages, at least during the working life of the device to be retained.

#29442 fpp:ew 19 November 1998 -3- BRIEF DESCRIPTION OF INVENTION In this specification "releasable retention" refers to the behaviour of an object to be retained with respect to the releasable retention device. A relationship involving the ability to push an object onto the releasable retention device and to subsequently pull it off is included within the definition.

In one aspect the present invention consists in a retention device for releasable retention of a disc having an aperture in substantially fixed relationship to a base, said device comprising a retention member having a longitudinal axis parallel to an axis of movement required to effect engagement of said disc through said aperture, wherein said retention member comprises a first layer of material superposed by a second layer of material wherein said second layer overhangs said first layer.

Preferably said second layer is adhered to said first layer.

~Preferably said first layer and said second layer are substantially cylindrical in shape.

Preferably said retention device comprises a third layer.

Preferably said third layer is a double sided tape attached to an exposed face of said first layer. Alternatively, said third layer is an adhesive material for attaching said second layer to said base.

Preferably said third layer is of the same dimension as said second layer.

Preferably said third layer is of the same composition as said second layer.

Preferably said first layer is comprised of expanded polystyrene

(EPS).

#29442 fpp:ew 19 Novembr 1998 -4- Preferably said second layer is of paper.

Preferably said second layer is substantially thinner than said first layer.

Preferably the thickness of said first layer is slightly greater than the thickness of said disc.

BRIEF DESCRIPTION OF DRAWINGS Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:

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Fig 1 is a perspective view of a prior art releasable retention arrangement applied to a compact disc holder.

Fig 2 is a perspective view of a retention device according to a first embodiment of the invention,

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Fig 3 is a perspective view of the retention device of Fig 2 applied to 0 •releasably retain compact discs within a compact disc folder, and *So 0*0: 0 Fig 4 is a perspective view of a retention device according to a second embodiment of the invention.

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DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Fig 1 illustrates a particular application of a prior art releasable retention device comprising a unitary post 10 supported on a base 11. The diameter of the post 10 is such as to provide an interference fit with a center aperture 12 of a compact disc 13.

#29442 fpp:cw 19 November 1998 Fig 2 is a perspective view of a retention device 14 according to a first embodiment of the invention.

In this instance the retention device 14 is of substantially cylindrical shape. The device 14 includes a first layer 15 surmounted by a second layer 16. As best seen in the inset, in this instance, the first layer 15 is adhered to second layer 16 by an adhesive layer 17.

Also, in this instance, second layer 16 overhangs first layer 15 by dimension D.

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In this embodiment first layer 15 is made entirely from expanded polystyrene (EPS) and marketed under the trade mark "PLIX" by Carter Holt S. l5 S. Harvey Pty Limited of New Zealand.

0•9@ In this instance second layer 16 is made entirely from a durable paper.

So Typical longitudinal dimension L1 for the first layer 15 is around 3mm.

Typical longitudinal dimension L2 for the second layer 16 is in the range 4 thousand of an inch to 10 thousand of an inch.

In this particular example it is preferred that second layer 16 be relatively thin so as to allow flexibility of this layer, particularly at the overhanging portion 18.

The outside dimension of first layer 15 will be such as to provide an interference fit with an aperture in an object which is to releasably retained on the retention device 14. The outside dimension of second layer 16 will be selected to be a little greater than the outside dimension of first layer 15. In the case of the arrangement shown in Fig 2 the increase in dimension is given by the dimension D. It follows that as the aperture of an object to be releasably retained is passed over the second layer 16, deflection of the #29442 fpp:ew 19 November 1998 -6overhanging portion 18 must take place. Second layer 16 is of sufficient resilience that after the aperture of the object to be releasably retained has passed over the second layer 16 and has reached first layer 15 whereby deflecting force of the overhanging portion 18 is removed that the overhanging portion 18 will return to its undeflected state. The overhang D thereby assists in retention of the object on first layer The retention device of this first embodiment may have an adhesive on face 23 to allow the retention device to be adhered to any suitable planar base, such as brochures, magazine or book covers or the like made of materials such cardboard, durable paper, plastic etc.

The retention device of the first embodiment may have an adhesive on Sthe face 23 to allow the retention device to be adhered to any suitable planar base, such as a brochure, magazine or book cover or the like.

S0 .With reference to Fig 3 an example of utilisation of the retention device 14 of Fig 2 is provided.

0 In this example the retention device 14 of Fig 2 is adhered to a planar 0000 base 19. The base is of sufficient dimension that it extends beyond the 00: periphery of a compact disc 13. A cover 20 is hingedly connected to one edge of base 19 and adapted to close over the compact disc 13 when S releasably retained on retention device 14 in the manner previously described.

With this embodiment it is possible to releasably retain the compact disc 13 on a retention device 14 of total height not much greater than the height of the disc 13, thereby permitting convenient and total closure of cover over and about disc 13.

#29442 fpp:cw 19 November 1998 -7- It will be observed that the manner of loading the disc 13 onto the retention device 14 requires that the disc 13 travel along an axis of movement in line with a central, longitudinal axis of the retention device 14, as indicated by the double headed arrows in Fig 3.

Typical dimensions for this application include a central disc aperture of approximately 1.5cm. It follows that the outside diameter of first layer 15 in this application will be this same dimension, or fractionally larger, but with the possibility that wear, over time, will reduce the dimension to that of the aperture 12 of the disc 13.

0 Sqo- The outside diameter of second layer 16 in this application will be slightly greater that the diameter of the central aperture 12, providing a o typical overhang D of 0.01mm.

0000 In use a disc 13 is caused to approach aligned with and along the central longitudinal axis of the retention device 14 so that aperture 12 passes over and passed second layer 16 and settles on and around first layer where releasable retention is provided by an interference fit of around "0.01mm as previously described. Even if the interference fit is worn away overtime the second layer 16 is not exposed to the same amount of wear and therefore continues to provide retention capability for the disc 13 on retention device 14 by way of overhanging portion 18.

Disc 13 is removed by reversal of the above procedure.

Fig 4 illustrates a third embodiment of the retention device 14, in this instance including a third layer 21 of the same dimension and composed of the same material as that of second layer 16. Third layer 21 is similarly attached to the first layer 15 by means of an adhesive.

#29442 fpp:cw 19 November 1998 -8- This arrangement permits the attachment of, for example, double sided tape 22 to the outer face of third layer 21. The remaining, exposed face of the double sided tape 22 can then be adhered to any convenience surface so as to attach retention device 14 thereto in a convenient manner.

The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto without departing from the scope and spirit of the present invention.

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0400 be Ce 0 0**40 fc #29442 fpp:ew 19 November 1998

Claims

1. A retention device for releasable retention of a disc having an aperture in substantially fixed relationship to a base, said device comprising a retention member having a longitudinal axis parallel to an axis of movement required to effect engagement of said disc through said aperture, wherein said retention member comprises a first layer of material superposed by a second layer of material wherein said second layer overhangs said first layer.

2. A retention device as claimed in claim 1 wherein said second layer is adhered to said first layer. S', 6

3. A retention device as claimed in claim 1 or claim 2 wherein said first layer and said second layer are substantially cylindrical in •6••shape.

4. A retention device of any of the preceding claims further °comprising a third layer.

A retention device as claimed in claim 4 wherein said third layer is attached to an exposed face of said first layer.

6. A retention device as claimed in claim 5 wherein said third layer is of the same dimension as said second layer.

7. A retention device as claimed in claim 6 wherein said third layer is of the same composition as said second layer. #29442 fpp:cw 19 November 1998

8. A retention device as claimed in any one of the preceding claims wherein said first layer is comprised of expanded polystyrene (EPS).

9. A retention device as claimed in any one of the preceding claims wherein said second layer is of paper.

A retention device as claimed in any one of the preceding claims wherein said second layer is substantially thinner than said first layer. 0

11. A retention device as claimed in any one of the preceding le claims wherein the thickness of said first layer is slightly greater S* than the thickness of said disc.

12. A retention device as claimed in any one of claims 1 to 3 wherein an exposed face of said first layer is provided with an adhesive for attaching said second layer to said base.

13. A retention device as hereinbefore described and with reference to Figures 2 to 4. S** 0 5 DATED: 19 November 1998 CARTER SMITH BEADLE Patent Attorneys for the Applicant: DAVID LLEWELLYN #29442 fpp:ew 19 November 1998