GB2399154A

GB2399154A - Vibration damper

Info

Publication number: GB2399154A
Application number: GB0404916A
Authority: GB
Inventors: Andrew David Burton
Original assignee: SOFTSHOCK Ltd
Current assignee: SOFTSHOCK Ltd
Priority date: 2003-03-06
Filing date: 2004-03-05
Publication date: 2004-09-08
Anticipated expiration: 2024-03-05
Also published as: GB0404916D0; GB0305221D0; GB2399154B

Abstract

The damper includes a mounting 31 that is located on a U-shaped channel 15 having opposed re-entrant lips 19. The lips of the channel fit between internal 6A and external 6B portions of a resilient body. A fastening means 14 enables the resilient body to vibrationally isolate the U-shaped channel. The fastening means, such as a nut, may be attached to a threaded stud 3 that is moulded into or mounted through the resilient body. The resilient body may be an elastomeric polymeric material such as a natural or synthetic rubber composition. The mounting has an inner core made of a hard material and the internal portion 6A is wider than the mouth of the channel to prevent the mounting from pulling out of the channel under extreme loading. The mounting may be used to mount electronic signalling equipment to the walls of railway trackside cabins via bracket 13.

Description

2399 1 54

VIBRATION DAMPER

The present invention relates to a mounting device for securing equipment, electronic panelling and the like to a support so as to protect these items from structure-borne vibration that would otherwise be transmitted through their mountings. More particularly but not exclusively, it is concerned with a mounting for use where the support framework is constructed from IJ shaped channel.

In non-residential buildings and structures, internal frameworks are frequently constructed from [J-shaped channel to contain cabling and to support electrical or other equipment.

These frameworks will also carry any external vibration transmitted thereto through the structure ol the building. Typically, said equipment is fitted to the channelling by means of rigid fastenings as described below.

In many cases, the framework will comprise a generally IJ-shaped profile having a folded back lip as depicted in Figure lA or Figure lB. The folded-back lip 19 provides support for solid rigid fixing devices such as are conventionally used h1 the mounting of such equipment.

A British Standard, No. 6946:1988, "Metal channel cable support systems for electrical installations", covers the dimensions of such channels, including permissible ranges for lip dimensions and the separation between opposing lips. Channelling conforming to this standard is very widely used in the IJnited Kingdom. Equivalent standards are presumed to exist in other countries.

The general term "U-shaped channelling" will be used herein to refer to such channelling with re-entrantly folded lips. The term "British Standard channelling" will be used specifically to refer to channelling conforming to E3S 6946:1988 or equivalent standards.

The cross-sectional form of such channels provides support for the currently used rigid fixings, which hold the equipment securely in place. However, there is a need to fix certain components in a manner that gives protection from any structure-borne vibration.

While the invention relates mainly to the need to mount or fix items to this type of channelling in a manner that provides some vibration isolation, it is also desirable to ensure a fail-safe method oi fixing for the mounted equipment or components. For reasons of space, it would also be preferable to lit any vibration damping device substantially within the profile of the channel.

Although the invention has uses in many fields, it will be described with reference to its use in relation to the mounting of electronic equipment in a building that is subject to significant vibration either on an intermittent or constant basis, thus leading to a need for vibration protection. An example ol this would be a building with electronic equipment such as signalling equipment mounted on such channelling within the structure located beside a railway line, or major road, where passing trains, or heavy vehicles, could cause vibration that could result in the damage of delicate devices mounted to the channelling. This is an example only; the mountings ol' the invention would equally apply to many other situations.

The construction of buildings to house electronic or signalling equipment comprising many electronic or otherwise delicate devices, to be placed near to sources of external vibration, is often carried out using the channclling system referred to above. This provides a sturdy and versatile means of supporting a variety of cabling and fixings for control boxes, electronic equipment panels and the like. The framework cant in some cases, be subject to vibration from external sources. The current method of fixing the electronic equipment panels or devices to the channelling is to use a l'ixing nut and bolt and a rigid mounting, such as that shown in Figure 2 ensuring a ['inn, secure and direct fixing of the device, etc. to the channel.

However, this would lead to substantially all vibration transmitted to the frame being further transmitted directly to the electronic equipment panel or device, with the potential for damage to be done to any delicate equipment within the panel.

It is therel'ore an object of the present invention to provide a simple and efl'ective mounting to support a device or panel lo U-shaped channelling, particularly channelling conforming to BS 6946:1988 or a similar standard, whicl1 may act to damp out vibrations transmitted through the channelling, whilst ensuring that the mounted device is t'ixed in a manner that is safe under extreme loadings or in catastrophic situations such as fire damage.

According to the present invention, there is provided an anti-vibration mounting device for mounting to lipped U-shaped channelling' as defined herein, comprising a resilient body having resilient elements to grip each lip of the channelling resiliently between them with a first resilient element disposable within the channelling to contact each lip thereof and a second resilient element disposable externally of the channelling to contact each said lip, and fastening means mounted to the resilient body out of contact with the U-shaped channelling such that the fastening means is vibrationally isolated from the channelling.

The mounting device may be adapted to be mounted to British Standard channelling as hereinabove defined.

Preferably, said resilient elements are so configured as to grip each said lip of the channelling resiliently therebetween.

Advantageously, a surface ol' one or each said resilient element contactable with said lips may be provided with substantially rigid facing means.

Said facing means may be adapted to spread pressure exerted by said lips across the respective resilient element.

Said ['acing means may be adapted to protect a respective resilient element from abrasion or other damage.

Preferably, said resilient body comprises an elastomeric polymeric material.

Advantageously, said elastomeric material comprises a natural or synthetic rubber composition, optionally a l'illed vulcanised natural rubber composition.

Said fastening means may comprise a hard, rigid material, advantageously a metal, optionally steel.

Prel'erably, said fastening means comprises a threaded fastening element.

Advantageously, said fastening means comprises a male threaded fastening element extending outwardly from the resilient body, for example threaded stud means.

Said male fastening element may then be adapted to receive threaded nut means.

Alternatively, said fastening means may comprise a female threaded fastening element disposed within the resilient body, t'or example plate means with a threaded aperture extending therethrough.

Said female fastening element may then be adapted to receive threaded bolt means.

The l'astening means may be provided with selectively engageable means to oppose rotation thereof.

Said means to oppose rotation may for example be adapted to be gripped by a spanner, pliers, etc. or to receive a screwdriver head, a polygonalsection lacy, or the like.

The first, internal, resilient element of the device preferably has at least one dimension less than a separation of the lips of the corresponding U-shaped channelling, such that in a first disposition of the device it may be inserted therebetween.

The device may then be twistable into a second disposition aligned transversely to the first, in which the resilient elements contact the lips ol'the channelling grippingly therebetween.

Said internal clement may be so prol'iled as to facilitate said twisting through approximately a right angle but oppose further twisting.

Embodiments of the present invention will now be more particular described by way of example and with reference to the accompanying drawings in which: Figure IA and IB are typical cross-sections ol' channelling conforming to British Standard 6946: 19X8; Figure 2 is a cross-section of the channelling shown in I; igure IA with an existing form ol' rigid mounting in place; Figure 3 is a side elevation of a first mounting embodying the invention, comprising a threaded stud; Figure 4 is a side elevation of a second mounting embodying the invention, comprising a threaded hole; Figure 5 is a side elevation of a third, prel'erred mounting embodying the invention, also provided with a threaded stud; Figure 6 is a side elevation of a metal core of the mounting shown in Figure 5, isolated thercErom; Figure 7 is a plan view of a reinforcing element of the mounting shown in Figure 5, isolated therefrom; Figure 8 is a plan view from below of the mounting shown in Figure 5; Figure 9 is a schematic representation of insertion of any of the mountings shown in Figures 3, 4 and 5 into channelling; Figure 10 is a schematic view from above of either of the mountings shown in Figure 3 or Figure 4; Figure 11 is a side elevation ol' the mounting shown in Figure 3 with a bracket fixed thereto with a nut; Figure 12 is a side elevation of the mounting shown in Figure 4 with a bracket fixed thereto with a bolt; Figure 13 is a frontal elevation oi'an example of a wall panel, fitted to two parallel sections of channel by means oi'four mountings embodying the invention; Figure 14 is an elevation of a securing bracket for any of the mountings of the invention, separated therefrom; Figure 15 is an elevation ol'the securing bracket shown in Figure 14 holding the mount in channelling; and Figure 16 is a cross-sectional view of the securing bracket shown in Figure 14, fixed in position in the channelling, with the mounting not shown.

Referring now to the Figures, and to figures 1A and 1B in particular, channelling 15 conforming to British Standard 6946:1988 has a continuous cross-section comprising a generally U-shaped section with two opposed lips 19 folded back re-entrantly such that a rim of'the channelling 15 I:aces an interior there<-,!: The lips 19 provide inner location points for mountings, as shown below and also strengthen the channel 15. A mouth 8 extending between the lips 19 allows access to the interior of the channel 15.

Standardised dimensions have been set for the width of the mount 8 and for the width and depth of each lip 19. However, the exact profile of the lips 19 may vary, as shown, and the overall depth of the U-shaped section ol' the channel 15 can be specified separately Prom its width.

Figure 2 shows a conventional hard mounting 28 for use with U-shaped channelling 15, such as that conforming to BS 6946:1988. 'I'he hard mounting 28 comprises a metal bar with a threaded aperture 29 extending therethrough. 'I'he hard mounting 28 is provided with two locating grooves 30 configured to receive the rim 20 of each lip 19 of the channel 15.

Equipment is attached to the hard mounting 2X using a conventional threaded bolt (not shown) received engagingly in the aperture 29. Alternatively, a plain aperture 29 may be provided, in which case the bolt engages with a separate nut. As the bolt is tightened, the hard mounting 28 is drawn securely into contact with the rim 20.

There is thus a chain of direct metal-to-metal contacts, running from a structure to which the channelling 15 is mounted, through the channelling 15 and the mounting 28, to the equipment, along which vibrations may be transmitted.

Although it is possible to interpose vibration damping elements between the hard mounting 28 and the equipment, those significantly space the equipment away from the channelling, which may be undesirable. Such damping elements usually comprise rubber, plastics or the like, so in the case of fire may become burnt away, releasing the equipment from the channelling.

Each of a first mounting embodiment 31 and a second mounting embodiment 32 (depicted in Figures 3, 4 and 10) has a body 6 having three portions of different diameters and moulded from an elastomeric compound, such as a vulcanised natural or synthetic rubber formulation, providing resilience. As shown in Figures 11 and 12, the body 6 comprises an internal portion 6A locatable within an interior of the channelling 15 and an external portion 6B locatable externally of the channelling 15, connected by an intermediate portion 6C locatable between the lips 19 of the mount 8 of the channels.

leach mounting 31, 32 has an inner core manufactured from a hard, tough material such as steel. The inner core of the first mounting 31 (Figure 3) has an end portion 1 which is wider than the mouth 8 of the channel 15. ensuring that the mounting 31 will not pull out of the channel 15 even under extreme loadings, or in the case ol fire burning the elastomeric compound of the body 6 away. In the case of the second mount 32 (depicted in Figure 4) its end portion comprises a metal plate 10 with a threaded aperture 35 therethrough. In the same way, the plate 10 is wider/longer than the mouth 8 ol the channel 15 in one dimension.

The first embodiment of mounting 31, as shown in Figure 3, has a threaded stud 3 protruding outwardly from a shaft 34 passing through the body 6. It may be moulded into the elastomer of the body or may be a close fit within a correspondingly shaped aperture through the body.

At a distal end of the stud 3 is a means 7 of holding the mounting 31 against rotation when tightening a nut on the stud 3. This holding means 7 may be provided with two flats allowing a spanner grip, a slot for a screwdriver, a hexagonal recess, an external hexagon or square section knob or other means for allowing a grip to be achieved on the stud 3 when tightening the nut.

In this first embodiment of mounting 31 the core has a shoulder 2, since the shaft 34 has a greater diameter than the stud 3. This ensures that when a component being mounted thereto is fixed tightly, the compression of the body 6 of the mounting 31 is kept to a controlled minimum amount, in order to preserve the benefits of the vibration damping properties of the elastomeric compound and maintain the resilience of the mounting 31. It is advisable however, to place a washer over the stud 3 before applying the nut. This ensures that overtightening is avoided and also provides the correct compression of the mounting to grip the channel. The same el'l'ect is achieved in the case of the second embodiment of mounting 32 having an internal thread (Figure 4) by means of a hollow tube 9, moulded into its body 6, providing a stop to excessive compression.

A collar 4 is provided on each of' the first 31 and second embodiments of mountings 32, which performs the function ol'providing a hard location for the mounting 31, 32 against the rim 20 of the lips 19 of the channel 15, thus preventing tearing damage to the body 6 of the mounting and ensuring that the elastomeric body 6 performs by compression and distortion as a whole and not just locally to the rim 20 of the channel lips 19. A further "'unction of the collar 4 is to prevent fretting or damage to the body 6 where there would otherwise be contact with the (possibly rough or sharp) rim 20 of the channel 15. The collar 4 provides positive location and allows the elastomeric compound ol' the body 6 of the mounting 31, 32 to perform as a vibration isolator.

Each of the first 31 and second 32 embodiments of mounting has a recessed groove 5 on either side of the portion 6B of the body that is disposed externally to the channel 15. This feature, although not essential, is desirable from the point of view of location of the mounting. The recessed groove 5 will provide a positive "feel" when twisting the mounting 31, 32 into its desired position (see below) and help to ensure that the mounting 31, 32 remains in the correct orientation.

A third, preferred embodiment of mounting 33 is shown in Figure 5. While broadly similar to the first embodiment 31, it shows the use of several of the possible variations referred to above.

As for the first embodiment of mounting 31, the body 6 of the third embodiment of mounting 33 is a single moulding of elastomeric material, comprising an internal portion 6A, an external portion 6B and an intermediate portion 6C. (Each mounting 31,32,33 thus has a body 6 having a generally H-shaped profile.) An inner steel core comprises a cylindrical shaft 34 with a threaded stud 3 of lesser diameter extending axially from an end thereof, forming a shoulder 2 adjacent an externally-oriented (in use) face of the external portion 6B of the body 6. In this case, a washer 42 is bonded onto or into the external face of the body to ensure that use of a washer cannot be omitted, as is possible when it is a separate item.

However, as shown in more detail in Figure 6, the shaft 34 is provided with two diametrically-opposed wings 36, extending radially outwardly from adjacent an end of the shaft 34 remote from the stud 3. The overall width of the wings 36 and the shaft 34 is greater than the width of the mouth 8 ot' the channel 15. 'l'he wings 36 are thus equivalent to the end- portion I ol'the first mounting 31, similarly ensuring that the third mounting 33 cannot be directly pulled out of the channel 15 once in position. In this third embodiment, the shaft 34 is a separate item which can be inserted through an aperture in the body 6 either during manufacture or immediately prior to use. The aperture corresponds to the dimensions ol'the shaft to prevent its falling out before tightening.

Also, in place ol'the holding means 7 extending distally from the threaded stud 3 of the first mounting 31, the threaded stud 3 of the third mounting 33 is provided with a hexagonal section recess 37 extending axially inwardly from its distal end. This allows a standard hexagonal-section key to be inserted therein, to prevent rotation of the shaft 34 and the body 6 as a fastening nut is being tightened on to the stud 3 (shown unthreaded in Figure 5 for clarity).

The third embodiment ol' mounting 33 is provided, instead of the collar 4 of the first embodiment 31' with a reint'orcing plate 38 of steel or the like. This extends across substantially a whole of a face of the internal portion 6A of the body 6 opposed to the external portion 6B thereof. The reinforcing plate 38 thus spreads any load exerted on the internal portion 6A by the lips 19 of the channel 15, and protects the elastomer of the internal portion 6A from potential abrasion and tearing by the rim 2(), as t'or the collar 4. The reinforcing plate 38 may be flat, as is shown for the first and second embodiments, or alternatively, as shown in Figure 5 it may be contoured to locate the inner portion 6A with respect to the inner rim of the lips.

As shown in Figure 7 the reinforcing plate 38 is provided with a large elliptical aperture 40, through which the shalt 34 of the inner core ot'the mounting 33 passes. ['here is hence a considerable thickness ot' elastomer of the body 6 between the shaft 34 and an inner rim of the elliptical aperture 40, even at their point of closest approach. The shaft 34 thus remains vibrationally isolated from the reinforcing plate 38. The wings 36 ol' the shaft 34 extend beyond a widest diameter of the elliptical aperture 40. Thus, even should the elastomeric body 6 be burnt away, the wings 36 would be retained by the reinforcing plate 38, further ensuring that the inner core could not be pulled out of the channel 15.

A contact surface 39 of the external portion 6B of the third embodiment 33 is generally profiled to contact an external face of a respective lip 19 ol' the channel 15. IIowever, it is not provided with a specially conl'igured groove 5, as are the first and second embodiments 31, 32. This allows the third embodiment of mounting 33 to be used with a range of different channel 15 profiles with dil'ferently-profiled lips 19 (for example, that shown in Figure 1B).

The separation between the contact surface 39 and the reinforcing plate 38 is carefully selected such that a lip 19 of a channel 15 conforming to the specifications of BS 6946:1988 will be resiliently gripped therebetween.

The internal portion 6A of the third mounting 33 is preferably profiled as shown in Figure 8.

It is generally rectangular in section, with an end surface of the shaft 34 and wings 36 being substantially flush with a corresponding surface of the elastomeric internal portion 6A. Two opposed corners 41 of the rectangular profile are substantially right-angled, but the other two corners l l are rounded slightly asymmetrically as shown.

Figure I O shows the comparative profiles of different portions 6A, 6B, 6C of the body 6. As stated above, the profile of the portion 6A of the body that is disposed inside the channel 15 is generally rectangular but with two rounded corners 11. 'I'he shape of the profile shown in Figure 10 is one of several possible shapes that would perform this function. The rounded corners 11 are to allow the mounting 31, 32 to be twisted into position without interfering with the side walls of the channel 15, as indicated by the arrows of 1- igure 9. The two corners that do not have a rounded edge are to assist in locating the mounting 31, 32 once twisted into position, as well as preventing the mounting 31, 32, 33 from twisting too far.

As shown, the overall width 12 of the mounting 31, 32, 33 is less than the width of the channel mouth 8. This is desirable from the point of view of letting the mounting 31, 32, 33 where access to an open end of the channel 15 is not possible, so that it cannot be slid therealong.

Thus, as shown in Figure 9 the mounting 33 can be inserted through the mouth 8 ol the channel 15, or freely slid along the channel 15 from an open end thereof, then once it is in the correct position it is twisted through a quarter-turn. The rounded-off corners 11 of the inner portion 6/\ prevent it from fouling side-walls of the channel 15 as it is twisted, while the right-angled corners 41 would resist further twistings once in contact with the side-walls.

Figure 11 shows a cross section of the first embodiment of mounting 31 located into the channel 15 with a bracket 13 for electronic equipment, etc mounted thereto using a nut 14.

Figure 12 shows the same configuration for the second embodiment of mounting 32 with the mounted bracket 13 in this case being fitted thereto using a bolt 16.

In each case, the lips 19 ol the channel 15 fit between the internal 6A and external 6B portions of the body 6 of the mounting 31, 32, which maintain a firm, resilient grip thereon.

Figure 13 is a view of how an electronic equipment panel 17 could be mounted (for example to a wall) using four complete mount assemblies 1X located in two parallel sections of channel 15.

Each mounting 31, 32 would be initially located by inserting it into the channel 15 far enough to be able to twist the mounting 31, 32 to provide a positive location. The item to be mounted, namely the electronic equipment panel or other item, may then be offered up into position and fitted using either a nut 14 or bolt 16 (depending upon the choice of first (studded) or second (internally threaded) mounting 31, 32) to 1orm each mount assembly 18.

In the case ol a vertically extending channel, or in some cases even in a horizontal channel orientation, there will be a need to locate the mounting more firmly in position, such that it will not slide along the chamel 15. This may be achieved as shown in Figures 14, 15 and 16, although other arrangements are possible.

A securing bracket 21 has a rectangular location hole 22, configured to match the profile width 12 of a mount 31, 32, 33. A recess 24 is provided, having a hole 23 to receive a screw or bolt. Figure 15 indicates, in plan view, how the securing bracket 21 would locate around the mount 31, 32, 33 and be separately and firmly fixed to the channel 15 using a cap screw extending through the hole 23. I7igure 16 further illustrates this in cross section, showing the effect of the recess 24 in the bracket 21 allowing the head of the cap screw 25 to fall below the top ol the mounting 31, 32, 33 ensuring that there is no interference between the screw 25 and a mounted panel. A conventional method of fixing the screw 25 to a channel (i.c. a nut 27) is used to give a strong and secure location for the bracket 21. This, in turn, ensures that the mounting (not shown in Figure 16) is unable to move along the length of the channel 15.

As the bracket 21 only contacts the elastomeric body 6 ol'the mount 31, 32, 33 it does not affect its vibration damping properties.

An example of the use of these mountings would be in the construction of relocatable signalling buildings for backside use, where the buildings would contain a large amount of power supply and electronic equipment used for communication and signalling purposes. If the construction of the buildings involved the use of' the framework channelling referred to above, then there would he a requirement to support and mount equipment cabinets to the framework. The cabinets would be either floor mounted (thus also requiring a wall mounted support to prevent tilting) or wall mounted. There would he a need to isolate the equipment from the vibration caused by passing trains. 'I'he mountings of the present invention would provide the means to mount the cabinets directly to the framework and, due to the elastomeric compound used in the body ol the mountings, would provide a barrier to the structure-borne vibration associated with passing trains.

The mounting could be manufactured from a range of materials such as steel or aluminium and an elastomeric compound such as a natural or synthetic based rubber formulation.

In use, the mountings could be fitted into the channels either by sliding it along the channel from one end or by pushing the mounting into the slot and twisting it into position, allowing a bolt to be fitted through a bracket or device into the threaded hole in the mounting, fixing the device to the mount. Alternatively, where the mounting has been produced with a protruding threaded stud, instead of a threaded hole, the bracket or device can be fastened by means of a nut threaded onto the stud. In both conl'igurations, the mounting is constructed in such a manner that there is no metal-to-metal contact between the equipment mounted and the building framework.

A major benefit of this invention is that there is no need for additional brackets in order to create a secure position for an anti-vibration mounting located externally to the framework.

('I'his would be the current method of achieving vibration isolation). I\n additional advantage to this invention is that less space is required, the mountings being largely located inside the channel profile.

The mounting is constructed in such a manner that, should excessive force be applied to pull the mounted device from the channel, or in the event of fire, then the mount would successfully resist the force and maintain the fixing ensuring that the device would not come away from the support framework, causing unnecessary damage or injury. Mountings as shown have been tested to loads sufficient to cause del'ormation of the bolts/nuts used therewith, without the mounting itself giving way.

The mounting will provide resilient support for the component or device being located and therefore protect or isolate the device l'rom excessive vibration that would otherwise be transmitted through the structure' channel and solid fixing. There would be no requirement for additional fail-safe devices in the event of fire.

Claims

An anti-vibration mounting device for mounting to lipped U-shaped channelling, as defined herein, comprising a resilient body having resilient elements to grip each lip of the channelling resiliently between them with a first resilient element disposable within the channelling to-' contact each lip thereof and a second resilient element disposable externally of the channelling to contact each said lip, and fastening means mounted to the resilient body out ol' contact with the l. J-shaped channelling such that the l'astening means is vibrationally isolated from the channelling.
2. An anti-vibration mounting device as claimed in claim 1 wherein a surface of one or each said resilient element contactable with said lips is provided with substantially rigid ['acing means, adapted to spread pressure exerted by said lips across a respective resilient element and/or to protect a respective resilient element from abrasion or other damage.
3. An anti-vibration mounting device as claimed in either claim 1 or claim 2, wherein the resilient body comprises an elastomeric polymeric material.
4. An anti-vibration mounting device as claimed in claim 3, wherein said elastomeric material comprises a natural or synthetic rubber composition, optionally a filled vulcanized natural rubber composition.
5. An anti-vibration mounting device as claimed in any one of the preceding claims, wherein the fastening means comprises a hard, rigid material, advantageously a metal, optionally steel.
6. An anti-vibration mounting device as claimed in any one of the preceding claims, wherein the fastening means comprises a threaded fastening element.
7. An anti-vibration mounting device as claimed in claim 6, wherein the fastening means comprises a male threaded fastening element extending outwardly lrom the resilient body, for example threaded stud means, and adapted to receive threaded nut means.
8. An anti-vibration mounting device as claimed in claim 6, wherein the fastening means comprises a female threaded fastening element disposed within the resilient body, for example plate means with a threaded aperture extending therethrough, and adapted to receive threaded bolt means.
9. An anti-vibration mounting device as claimed in any one of the preceding claims, wherein the fastening means is provided with selectively engageable means to oppose rotation thereof
10. An anti-vibration mounting device as claimed in any one of the preceding claims wherein the first, internal, resilient element of the device has at least one dimension less than a separation of the lips of the corresponding U-shaped channelling, such that hi a first disposition of the device it may be inserted therehetween. 1
11. An anti-vibration mounting device as claimed in claim 10, wherein the first, internal, ; resilient element of the device has at least one dimension greater than a separation of the lips ol'the corresponding tJshaped channelling, so that the device is twistable into a second disposition aligned transversely to the first, in which the resilient elements contact the lips of the channelling grippingly therebetween.
12. An anti-vibration mounting device as claimed in claim 11, wherein said internal element is so profiled as to facilitate said twisting through approximately a right angle but to oppose further twisting.
13. An anti-vibration mounting device substantially as described herein with reference to any one of Figures 3 to 16 of the accompanying drawings.
14. An anti-vibration mounting device as claimed in any one of the preceding claims, adapted to be mounted to British Standard channelling as herein defined.
15. An anti-vibration mounting device as claimed in any one of the preceding claims, adapted to be mountable to channelling substantially as described herein with reference to either leisure 1 A or Figure 1 B ol' the accompanying drawings.