GB2309998A

GB2309998A - Retaining device

Info

Publication number: GB2309998A
Application number: GB9700525A
Authority: GB
Inventors: Lee Patrick Mullins
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-02-06
Filing date: 1997-01-08
Publication date: 1997-08-13
Also published as: GB2309998A8; GB9700525D0

Abstract

A retaining device for retaining to itself, and possibly also to another member, a component or other article having an aperture therein, the device comprising a body (11) of elastomeric material having a retainer portion (12) and an action portion (13) to which force can be applied to cause narrowing of the retainer portion (12), to permit the device to be inserted into the aperture. Alternatively (fig 6B) a pushing force can be applied internally to stretch the device to cause narrowing either by using a tool (48) or by forming an elongate shank to extend from the inner face.

Description

RETAINING DEVICE DESCRIPTION The present invention relates to a retaining device, that is a device which is constructed and adapted to retain to itself, and possibly also to another member, a component or other article (hereinafter referred to generally as the "object to be retained" or the "retained object") having an aperture therein. Thus, the retaining device may function as a connecting device for connecting two or more objects to each other.

The retaining device of the present invention may be embodied in a variety of different forms adapted to respective different applications, but whose different forms, nevertheless, possess common technical features which lie at the heart of the concept of the present invention.

It is an object of the present invention to provide a retaining device that is convenient and easy to use, is effective in operation, and economic to manufacture and use in large quantities.

According to a first aspect of the present invention, a retaining device comprises a body of elastomeric material having a retainer portion and an action portion to which force can be applied to cause narrowing of the retainer portion.

According to a second aspect of the present invention, a retaining device comprises a body of elastomeric material having a retainer portion and a hollow interior having an interior end face against which force may be applied to cause narrowing of the retainer portion.

According to a third aspect of the present invention, a retaining device comprises a body of elastomeric material having a retainer portion of relatively larger diameter and a tail portion of relatively smaller diameter which, when subjected to tractive force, causes narrowing of the retainer portion.

Further, a retaining device according to a fourth aspect of the present invention comprises a body of elastomeric material having a retainer portion of larger nominal diameter intended to be received in an aperture of an object to be retained thereby, and an insertion portion of smaller diameter extending from the retainer portion and for facilitating insertion of the device into the aperture, the body being capable of lengthening and narrowing under tractive effort applied to the insertion portion to allow the retainer portion to pass into an aperture of a dimension smaller than the nominal diameter of the retainer portion.

A fifth aspect of the invention resides in a method of securing an apertured object to a retaining device having a body of elastomeric material affording a retainer portion having a dimension larger than a dimension of the aperture of the object, which method comprises temporarily causing narrowing of the retainer portion to allow it to pass into the aperture of the object to be retained.

Narrowing of the retainer portion may be caused by action to extend its length. Such action may be by applying tractive force (pulling) generally axially on an end region of the exterior surface of the retainer portion.

Alternatively, such action may be by pushing generally axially on a transverse interior surface of the retainer portion, for example by means of a separate tool inserted within a hollow interior of the retainer portion or by means of an integral shank extending from the interior surface and passing axially along a hollow interior of the retainer portion.

The method as above further comprises allowing the retainer portion to return towards its nominal size after its passage into the aperture, thereby trapping and retaining the object to the device.

In all five aspects of the invention defined above, the body of the retaining device may afford, on the retainer portion, a shoulder limiting the extent of insertion of the retainer portion into or through the aperture in the object to be retained.

Preferably, the body of the retaining device is chamfered at the insertion end of the retainer portion, in order to assist insertion thereof into the aperture of the object to be retained.

Preferably also, the elastomeric material of the retaining device is a flexible plastics, rubber, or rubber-like material.

Embodiments of a retaining device in accordance with the present invention, and their associated method of use, will now be described in greater detail, and by way only of example, with reference to the accompanying illustrative drawings in which: Figure 1 is a diagrammatic side view of a first embodiment of retaining device according to the present invention; Figures 2, 3, 4 and 5 are respective diagrammatic side views of second, third, fourth and fifth embodiments of retaining device according to the present invention; Figure 6 is a diagrammatic perspective view of a sixth embodiment of retaining device according to the present invention shown before, during and after passage into an aperture of an object to be retained; and Figures 7A and 7B are diagrammatic views of a seventh embodiment of retaining device according to the present invention, showing respective transverse and longitudinal sections.

Referring firstly to Figure 1 of the drawings, there is shown a first embodiment of retaining device comprising a body, generally indicated at 1, of an elastomeric material such as a silicone rubber or plastics material having the strength and flexibility necessary to function as will be described hereinafter.

The body 1 comprises a relatively large diameter retainer portion 2 and a relatively small diameter action portion in the form of a tail or insertion portion 3, preferably joined by a chamfered portion 4 to the retainer portion 2. Optionally, the body 1 further comprises another portion 5 of even larger diameter than the retainer portion 2 so as to define a stop face 6 at the junction of this further portion 5 and the retainer portion 2.

Also optionally, and as shown in Figure 1, the retaining device of this embodiment may be double ended in that it comprises a further retainer portion, chamfered portion, and insertion portion extending in axial alignment with the first-described such portions and at the opposite end of the body 1. It is however, not necessary for the retaining device to be double ended, as will be apparent from other embodiments to be described below.

In use of the retaining device, an object (not shown) to be retained and having therein an aperture whose internal diameter is smaller than the nominal external diameter of the retainer portion 2 of the retaining device, is brought up to the retaining device and the insertion portion 3 thereof passed into the aperture of the object. For present purposes, it is assumed that the aperture of the object has an internal diameter somewhat larger than the external diameter of the insertion portion 3, so that the latter may pass freely into, and through, the aperture whereby the object readily reaches the chamfered portion 4.

As further insertion of the retaining device into the aperture is attempted, resistance to such will develop as the relatively large diameter retainer portion 2 attempts to enter the somewhat smaller diameter aperture. At this juncture, tractive force is applied to the insertion portion 3 in order to extend it longitudinally in the direction of the arrow A, whilst the retainer portion 2 and/or the object to be retained is/are gripped and either held stationary or pulled in the opposite direction.

Due to the elastomeric nature of the material of the retaining device, such relative tractive force applied to the insertion portion 3 is transmitted to the retainer portion 2 and causes lengthening of both portions with concurrent narrowing of their diameters.

As soon as such narrowing is effective to reduce the external diameter of the retainer portion 2 to substantially, or just less than, the internal diameter of the aperture of the object to be retained, the latter will begin to pass on to the reduced diameter retainer portion 2 which passes relatively smoothly, albeit with some resistance, into and through the aperture of the object as far as is required and/or necessary.

In the case of a retaining device as shown in Figure 1, this depth of penetration of the retainer portion 2 into, and through, the aperture of the object to be retained will be only so far as the shoulder face 6 which prevents any further penetration. Then, as soon as the tractive force on the insertion portion 3 is ceased, the elastomeric property of the material of the retaining device attempts to return the retainer portion 2 to its original diameter, whereby it becomes a relatively tight fit within the aperture of the object and also expands, in those regions not contained within the confines of the aperture of the object, to a larger diameter than that of the aperture of the object, whereby the object is firmly retained in place upon the device.

As shown in partial cutaway detail of Figure 1, the enlarged portion 5 of the body 1 may, at its shoulder face 6, afford a peripheral lip or rim 7 capable of creating an effective seal between such face 6 and an abutting surface of the retained object.

The embodiment of retaining device shown in Figure 1 is particularly intended as a spacer device useful for retaining thereto, and spacing from each other, a pair of objects such as printed circuit boards. In this connection, a first printed circuit board is mounted to, and retained by, the retaining device in the manner hereinbefore just described, so as to abut one shoulder face 6 thereof. Subsequently a second printed circuit board is mounted to, and retained by the other end of the retaining device, in a similar manner. The enlarged portion 5 of the body 1 thus forms a spacer lying between, and spacing at a predetermined distance apart, the two printed circuit boards. Clearly, other identical or similar retaining devices may be arranged elsewhere between the printed circuit boards in order to hold them in spaced, parallel relationship.

After the object to be retained has been mounted to, and is retained by, the retaining device, any surplus length of the insertion portion 3 may be trimmed and removed, if required.

Turning now to Figures 2 to 5 of the drawings, alternative embodiments of the retaining device of the present invention will be seen, each one embodying the basic principle and concept of the invention as described above, but each adapted to a different application function.

With reference, therefore, to Figure 2, a retaining device of the second embodiment of the present invention is provided in the form of a device similar to a rivet, and generally indicated at 11, for use with brittle materials. The device 11 comprises an enlarged head 15 affording a shoulder face 16 at its junction with a relatively large diameter retainer portion 12 from whose end opposite the enlarged head 15 there extends a relatively small diameter insertion portion 13. A chamfer portion, similar to the chamfer portion 4 seen in Figure 1, may be provided between the insertion portion 13 and the retainer portion 12, if desired.

The retaining device 11 according to this embodiment functions similarly to that described above with reference to Figure 1, except that two or more apertured objects to be interconnected and retained on the retainer portion 12 have their apertures passed along the insertion portion 13 and on to the retainer portion 12 as far as permitted by the stop face 16.

The insertion portion 13 is of such length and strength as to enable the requisite tractive force to be applied longitudinally thereof in order to extend and narrow the retainer portion 12 sufficiently to pass into, and through, the apertures of the objects to be retained. With the objects to be retained suitably positioned on the retainer portion 12, the insertion portion 13 may be cut off, if required.

Figure 3 shows an embodiment of retaining device according to the present invention which is similar to the printed circuit board spacer device described with reference to Figure 1, except that it omits the chamfered portions 4. This form of retaining device may additionally, or alternatively, be used to fix printed circuit boards to an equipment chassis.

With reference to Figure 4 of the drawings, there is shown a fourth embodiment of retaining device according to the present invention in the form of a cable retainer. The cable retainer, generally indicated at 21, comprises an insertion portion 23, a retainer portion 22, and a head portion 25 formed with a pair of spring arms 26 affording a V opening insertion 26' and a retaining aperture 26''.

A cable or cables to be retained may be snapped into place within the retaining aperture 26'' by passing into the V insertion 26' while the spring arms 26 are moved slightly apart to allow passage. Either before or after the cable(s) to be retained have been passed into the retaining aperture 26'', the cable retaining device itself will be fixed and secured in place to any desired substrate to which the cables are to be secured. The securement of the cable retaining device 21 to such substrate will be by insertion into an aperture of the substrate of the insertion portion 23, followed, in the same manner as described above in relation to the foregoing embodiments, by passage of the retainer portion 22 into the aperture of the substrate. Subsequently, if desired, any excess length of the insertion portion 23 may be cut off.

With reference to Figure 5, there is shown a retaining device according to a fifth embodiment of the present invention and in which there is the relatively narrow diameter insertion portion 33, the relatively larger diameter retainer portion 32, and a relatively even larger head portion 35 affording a shoulder face 36. The head portion 35 is provided at its end region opposite the retainer portion 32, with a socket 38, optionally receiving a metallic female insert, into which a spigot of some other object may be inserted. The retaining device of this embodiment may mount, and retain on its retainer portion 32, one or more other objects in a manner similar to that described above in relation to the foregoing embodiments, and may receive at its socket 38, the spigot of another object.

A sixth embodiment of retaining device according to the present invention is shown in Figure 6, in which Figure 6A shows a perspective view of the device, Figure 6B shows a perspective view of the device during its installation, and Figure 6C shows a perspective view of the device after its installation.

The retaining device of this embodiment comprises an elongate hollow body of an elastomeric material such as silicone rubber or a plastics material having the strength and flexibility necessary to function as will be described hereafter.

The body comprises a retainer portion 42, here shown as having an external surface of a right circular cylinder. The body terminates at one end in a rounded nose 44 which functions similarly to the chamfered portion 4 described in the first embodiment.

The interior of the body has an axially extending hollow 47 which preferably extends the full length of the body so as to terminate at the interior wall of the nose 44. This interior wall thus forms an action portion of the retaining device, whose function will become clear from the following description of the mode of use of the retaining device of this embodiment.

As shown in Figures 6B and 6C, use of this embodiment of the retaining device is explained by illustrating its passage into, and partially through, an aperture 49' of a disc 49 forming an object to be retained on the retainer portion 42. The aperture 49' has a dimension smaller than the nominal external diameter of the retainer portion 42.

Initially the retaining device is brought up to the disc 49 so that its nose 44 is placed at the aperture 49'. An elongate tool shank 48, narrow enough to pass freely into the hollow 47 and through the aperture 49', is placed within the hollow 47 so that an enlarged blunt-ended tool head 48' comes to bear against the interior wall of the nose 44 of the retaining device.

Axial force is then exerted on the action portion formed by the interior wall of the nose 44 by pushing the tool shank 48 in the direction of the arrow A relative to the disc 49. This causes the nose 44 and body of the retaining device to be pushed into the aperture 49 and the body to stretch in the direction of the arrow A. As it stretches it narrows and begins to pass into and through the aperture 49'.

By this means, the disc 49 passes on to, and along, the retainer portion 42, as best seen in Figure 6B. Whilst axial force by the tool head 48' is continued to be applied to the interior wall of the nose 44, that region 42' of the retainer portion 42 which has already passed through the aperture 49' will be somewhat narrower than its nominal diameter.

Moreover, where the retainer portion 42 is confined within the aperture 49' it will have a narrow neck 42''.

When the disc 49 has passed along the retainer portion 42 to its desired extent, to reach a position at which it is to be retained, the tool 48,48' is withdrawn. That region 42' of the retainer portion 42 which has passed through the aperture 49' now returns to its nominal diameter. The retainer portion 42 is, then, of larger diameter at each side of the disc 49 then the narrow neck 42'' where the retainer portion is confined in the region of the aperture 49' of the disc. The disc 49 will, thus, be securely retained in position. The disc 49 is, of course, merely an example of a retained object which, in practice, may take any form.

If desired, another object to be retained may be passed on to the retainer portion 42 whereby the retaining device forms a connecting device connecting together the two retained objects. The two retained objects may be spaced apart along the retainer portion 42, or placed adjacent each other. If desired, an enlarged portion on the retainer portion 42 may provide a stop face to determine a final position of the retained object(s).

Alternatively, the retaining device may be mounted to a substrate. This may be by passing its retainer portion 42 through an aperture of the substrate, in a manner as described above, the substrate being considered a retained object in this instance. Alternatively, the retaining device may be fitted, by means of its hollow 47, on to a suitable post on the substrate. Whichever of these ways of mounting the retaining device to the substrate is used, an, or another, object to be retained may also be mounted to the retaining device by either insertion into the hollow 47 or passage on to the retainer portion 42, as the case may be.

A seventh embodiment for retaining device according to the present invention is shown in Figure 7, in which Figure 7A shows a transverse sectional view, and Figure 7B shows a longitudinal section view of the device.

The retaining device 51 of this embodiment has similarities with that of the sixth embodiment and comprises an elongate hollow body of an elastomeric material, such as a silicone rubber or a plastics material, having the strength and flexibility necessary to function as will be described hereafter.

The body comprises a retainer portion 52, here shown as having an external surface of a right circular cylinder. The body terminates at one end in a rounded nose 54 which functions similarly to the chamfered portion 4 described in the first embodiment.

The interior of the body has a co-axially extending bore 57 which preferably extends the full length of the body so as to terminate at the interior wall 56 of the nose 54. This interior wall 56 thus forms an action portion of the retaining device, whose function will become clear from the following description of the mode of use of the retaining device of this embodiment.

An elongate shank 58 extends axially within the hollow 57 and is integrally moulded with the interior of the nose 54 so as to form a reinforced, or thickened, region 55 which affords the aforementioned interior wall 56. Such a reinforced region 55 may, however, be omitted. The length of the shank 58 is such that a portion of it projects from the bore 57 at the rear end of the body.

Preferably, and as shown in Figures 7A and 7B, the shank 58 is a solid member and, whilst it is integrally moulded, it may be made of a different material from that of the remainder of the body so as to be relatively more rigid. The shank 58 may, thus, be grasped directly and pushed in order to insert the retaining device 51 in an aperture much as occurs in the sixth embodiment described earlier. It may also be pulled in order to remove the retaining device 51 from the aperture. When withdrawing the retaining device in this manner the retainer portion 52 may invert which may make withdrawal easier.

As an alternative, the moulded shank 58 could incorporate a pin (not shown) of metal or other rigid material. This could be moulded-in during moulding of the retaining device 51. Optionally, a load-spreading disc or washer, having a function similar to that of the enlarged tool head 48' of the sixth embodiment, may be included, for example by moulding-in, within the region 55 at the interior of the nose 54.

As another alternative, the shank 58 is moulded integrally with the remainder of the body and is of substantially the same material and composition thereat. In this case, whilst the shank 58 may still function to enable withdrawal of the retaining device 51 by pulling thereon as described above, it may be insufficiently rigid to enable it to be pushed upon to enable insertion of the retaining device 51. A rigid, hollow rod (not shown) may then be employed as an insertion tool; such a rod would be slid over and along the shank 58 to abut the interior wall 56.

Axial force is then exerted on the action portion formed by the interior wall 56 of the nose 54 by pushing on the hollow rod.

Whichever of the foregoing alternatives is used, pushing on the action portion at the interior of the retaining device causes the nose 54 and body of the retaining device to be pushed into an aperture in which it is to be inserted and the body to stretch axially. As it stretches it narrows and begins to pass into and through the aperture.

As described with reference to the sixth embodiment, by this means the retainer portion 52 passes into, and through, the aperture. Whilst axial force is continued to be applied to the interior wall of the nose 54, that region of the retainer portion 52 which has already passed through the aperture will be somewhat narrower than its nominal diameter.

Moreover, where the retainer portion 52 is confined within the aperture, it will have a narrow neck.

When the retainer portion 52 has been passed into, and through, the aperture to its desired extent, to reach a position at which it is to be retained, the pushing action is terminated and the hollow rod, if used, is withdrawn. That region of the retainer portion 52 which has passed through the aperture now returns to its nominal diameter. The retainer portion 52, is, then, of larger diameter at each side of the retained object than the narrow neck where the retainer portion 52 is confined in the region of the aperture. The object containing the aperture will, thus, be securely retained in position. The retained object may take any form.

If desired1 another object to be retained may be passed on to the retainer portion 52 whereby the retaining device forms a connecting device connecting together the two retained object. The two retained objects may be spaced apart along the retainer portion 52, or placed adjacent each other. If desired, an enlarged portion on the retainer portion 52 may provide a stop face to determine a final position of the retained object(s).

Alternatively, the retaining device may be mounted to a substrate in the same manner as the sixth embodiment and an, or another, object to be retained may also be mounted to the retaining device by either insertion into the bore 57 or passage on to the retainer portion 52, as the case may be.

In the sixth and seventh embodiments, the radiussed nose 44,54 could, alternatively, be bevelled or squared-off. Further features may be added, as desired. For example, a bevelled lip around the exterior of the opening of the hollow 47,57 could be provided to follow the contours of a countersink, or a squared lip could be provided to fit in a counterbore, or a radiussed lip could be provided to fit into a radiussed recess, in each case around the aperture into and through which the retainer portion 42,52 is passed.

The retaining device of the present invention may fulfil the ancillary function of preventing coating materials, or liquids, from reaching the edges of, and other areas around, an aperture in which the device is inserted.

Whilst, in the foregoing description of the different embodiments, the retainer portion of the retaining device has been implied, or explicitly described, as being of circular external crosssectional shape, this need not be so. Similarly, the aperture in an object to be retained need not be circular. Indeed, the shape of the aperture may differ from that of the cross-section of the retainer portion. The sole requirement is that, whatever the shape(s) of the cross-section of the retainer portion and/or of the aperture(s) in the object(s) to be retained, there must be a dimension of the crosssection of the retainer portion which is larger than a dimension of the or each aperture. Thus, for example, the aperture may be oval, with at least a minor diameter smaller than the diameter of a circular cross-sectional retainer portion.

Whilst the retaining device of the present invention has been described above in relation to currently preferred embodiments, it is not limited to the precise details thereof but extends to any such variants as are encompassed within the scope of the appended claims.

Claims

1. A retaining device comprising a body of elastomeric material having a retainer portion and an action portion to which force can be applied to cause narrowing of the retainer portion.

2. A retaining device comprising a body of elastomeric material having a retainer portion and a hollow interior having an interior end face against which force may be applied to cause narrowing of the retainer portion.

3. A retaining device comprising a body of elastomeric material having a retainer portion of relatively larger diameter and a tail portion of relatively smaller diameter which, when subjected to tractive force, causes narrowing of the retainer portion.

4. A retaining device comprising a body of elastomeric material having a retainer portion of larger nominal diameter intended to be received in an aperture of an object to be retained thereby, and an insertion portion of smaller diameter extending from the retainer portion and for facilitating insertion of the device into the aperture, the body being capable of lengthening and narrowing under tractive effort applied to the insertion portion to allow the retainer portion to pass into an aperture of a dimension smaller than the nominal diameter of the retainer portion.

5. A retaining device according any preceding to claim, wherein a shoulder face is provided for limiting the extent of passage of the retainer portion into, or through, an aperture of an object to be retained thereto.

6. A retaining device according to claim 3 or 4, wherein a transition portion of chamfered form is provided in the region where the retainer portion adjoins the tail or insertion portion, as the case may be.

7. A retaining device according to claim 1 or claim 2, wherein a chamfered or rounded nose portion is provided at one end of the retainer portion.

8. A retaining device according to any preceding claim, wherein an enlarged head portion is provided at the end of the retainer portion opposite the tail portion, insertion portion or nose portion, as the case may be.

9. A retaining device according to claim 8 when dependent on claim 5, wherein the shoulder face is provided as a step where the retainer portion adjoins the enlarged head portion.

10. A retaining device according to claim 8 or claim 9 when dependent on claim 1, 3 or 4, wherein the head portion affords a shoulder face at each of its two opposite longitudinal ends, and wherein a respective retainer portion adjoins the head portion at each said shoulder face.

11. A retaining device according to claim 10, constructed and adapted for use as a spacer device for retaining, and relatively spacing, two objects.

12. A retaining device according to claim 8 or claim 9 when dependent on claim 1, 3 or 4, wherein the head portion is rounded at its end region opposite from the retainer portion.

13. A retaining device according to claim 8 or claim 9 when dependent on claim 1, 3 or 4, wherein the head portion affords a grip for one or more cables.

14. A retaining device according to claim 13, wherein the grip comprises a pair of resilient arms biassed towards a gripping condition in which they are capable of gripping one or more cables when inserted between the arms of the grip.

15. A retaining device according to claim 14, wherein the arms afford a first pair of inner limbs each attached at one end to a main body of the head portion, and a second pair of outer limbs wherein each outer limb is attached to the other end of a respective one of the inner limbs; and wherein the other ends of the inner limbs closely approach each other to form an entrance to the grip, and the free ends of the outer limbs at a spacing from each other to form a widened mouth leading towards the entrance to the grip.

16. A retaining device according to claim 8 or any claim dependent on claim 8, wherein the head portion is formed, at its end opposite the retainer portion, with an end socket for receiving a spigot on another object.

17. A retaining device according to claim 16, wherein the socket includes a female insert.

18. A retaining device according to claim 5, or any of claims 6 to 17 when dependent on claim 5, wherein the or each shoulder face has a raised peripheral rim arranged to seal against an object when retained on the associated retainer portion.

19. A retaining device according to any preceding claim, wherein the retainer portion is of circular cross-sectional shape.

20. The combination of a retaining device according to claim 2, or any claim dependent on claim 2, and an elongate tool for insertion within the hollow interior for applying force against the interior end face.

21. A retaining device according to claim 2, wherein an elongate shank extends axially within the hollow interior and is integral with the interior end face.

22. A retaining device according to claim 21, wherein the shank is formed of elastomeric material and is moulded integrally with the body.

23. A retaining device according to claim 21 or claim 22, wherein the shank is reinforced, preferably internally, by a rigid member.

24. A retaining device according to claim 21, wherein the shank is formed of a relatively rigid material comoulded, or otherwise connected, with the interior end face.

25. A retaining device according to any of claims 21 to 24, wherein the interior face is afforded by a reinforced, or thickened, region at the interior of a nose of the body.

26. A retaining device according to any of claims 21 to 25, wherein a region of the interior face is exposed within the hollow interior and in annular surrounding relationship to the shank.

27. The combination of a retaining device according to claim 26 and an elongate hollow rod for insertion within the hollow interior and over and along the shank, so as to abut the interior end face, for applying force thereagainst.

28. A method of retaining an apertured object to a retaining device having a body of elastomeric material affording a retainer portion having a dimension larger than a dimension of the aperture of the object, comprising temporarily causing narrowing of the retainer portion to allow it to pass into the aperture of the object to be retained.

29. A method according to claim 28, wherein temporary narrowing of the retainer portion is caused by elongating said portion.

30. A method according to claim 28 or claim 29, wherein temporary narrowing of the retainer portion is caused by applying tractive force longitudinally of said portion to cause elongation thereof.

31. A method according to claim 28, 29 or 30, wherein the retainer portion has a hollow interior and temporary narrowing of the retainer portion is caused by applying force on an interior end face of the retainer portion by pushing on an axially extending elongate shank which extends within the hollow interior and is integral with the interior end face.

32. A method according to claim 28, 29 or 30, wherein the retainer portion has a hollow interior and temporary narrowing of the retainer portion is caused by applying force on an interior end face of the retainer portion by pushing thereon using a tool inserted in the hollow interior.

33. A method according to claim 32, wherein an elongate shank is integral with the interior end face and extends axially along the hollow interior, and the tool is an elongate hollow rod extending over and along the shank.

34. A method according to any one of claims 28 to 30, wherein the retainer portion is adjoined by a relatively narrow tail portion or insertion portion which may be pulled to cause narrowing of the retainer portion.

35. A method according to claim 34, wherein the tail portion or insertion portion is first passed into, and through, the aperture of the object to be retained, the tail or insertion portion is then pulled relative to the retainer portion to allow the object to pass on to the retainer portion, and the tail portion or insertion portion is then relaxed to allow the retainer portion to expand towards its original size to fill a dimension of the aperture of the object to retain the latter.

36. A method according to claim 35, wherein the tail portion or insertion portion is cut off or trimmed in length after the object has been retained.

37. A method according to any one of claims 28 to 36, applied to the retention of a printed circuit board relative to an equipment chassis, other printed circuit board, or other component.

38. A method according to any one of claims 20 to 30 and 34 to 36, applied to gripping of one or more cables and mounting it/them relative to a substrate to which the retaining device is retained.

39. A retaining device substantially as herein described with reference to Figure 1, or Figure 2, or Figure 3, or Figure 4, or Figure 5, or Figure 6, or Figure 7 of the accompanying drawings.

40. The combination of a retaining device and an elongate tool substantially as herein described with reference to Figure 6 or Figure 7 of the accompanying drawings.

41. A method of retaining an apertured object to a retaining device, or of mounting a retaining device to an aperture in a substrate, substantially as herein described with reference to Figure 1, or Figure 2, or Figure 3, or Figure 4, or Figure 5, or Figure 6, or Figure 7 of the accompanying drawings.