This invention relates to a vibration isolation device The vibration isolation device ot the invention has particular, but not exclusive, application tor mounting ot rails, such as mounting htt rails to the wall of a lift well

Rails on which rolling apparatus moves are often secured in position by the use ot mounting devices which provide mountings ot the rails at spaced locations along the iengths thereto It not infrequently occurs that substantial forces are transmitted trom the rails through the mounting devices to the surroundings supporting medium, and this may give rise to significant noise production In the case of elevators, the elevator cage may be provided with wheels which engage rails extending vertically through the lift well and the rails may be mounted to the wall ot the lift well by means of such mounting devices, with the consequence that substantial sideward movements ot the elevator cage occurring during operation will be transmitted to the tt well wall via the rails and the engaging wheels, and via the mounting devices This may give rise to significant vibration and consequent noise production The so produced noise is a significant problem in many situations, for example, in apartment buildings

In one aspect the invention provides a vibration isolation device comprising first and second components, and resilient interconnection means, the resilient interconnection means comprising: a resilient structure comprised of first and second resilient elements secured to the second component, the first resilient element being positioned between the first and second components and the second resilient element being positioned at a surtace of the second component facing away from the first component, and coupling means holding said resilient structure under compressive torce applied between opposite ends thereof, and the coupling means holding one said end ot the resilient structure against the first component and locating both said ends at a substantially fixed distance with respect to each other in the end to end direction of the resilient structure

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The resilient elements may have end to end extending openings therethrough with the coupling means extending through these openings and through an opening in the second component The coupling means may also extend through an opening in the first component, and/or may be tixed thereto

The coupling means may include a spacer element which is disposed between and in contact with a surtace ot said first component which faces the second component and with a stop surtace ot the coupling means disposed adjacent that end ot the second resilient element which is away trom the second component, or is otherwise arranged to limit the extent ot relative inwards movement which can occur as between the ends ot the resilient structure

The coupling means may turther include a bolt and nut or other coupling which extends through the components and the resilient elements and which has a sidewardly extending first portion, such as a bolt head or a nut. which bears directly or indirectly against the surtace ot the first component remote trom the second component, and a second substantially sidewardly extending portion, such as a nut or bolt, which bears directly or indirectly against the end of the second resilient element which is away trom the second component The nut may define the stop surtace or the stop surface may. tor example, be detined on a washer disposed between the nut and the second resilient element

In another aspect the invention provides a vibration isolation device comprising first and second components and a projecting member which is substantially fixed with respect to the first component and extends through an opening in the second component, a first resilient element being secured to and positioned between and m contact with facing opposed surfaces ot the first and second components, and a second resilient element being secured to the second component and positioned against the surtace ot the second component opposite the first component, means being provided tor holding said resilient elements in compression in the direction ot extent of the projecting member, between the first to the second component, and means being provided for maintaining the spacing between the ends ot the resilient elements which are away trom the second component substantially at a predetermined distance, said

opening being sized to permit limited movement of the projecting member therewithin in directions transverse to said direction of extent.

In a still further form the invention provides a vibration isolation device comprising first and second components and a resilient structure to which the second component is fixed. one end of the resilient structure being substantially fixed with respect to the first component and an opposite end of the resilient structure being held in substantially fixed relationship relative to said one end.

The tirst and second components may be generally planar and parallel

The vibration isolating devices of the invention may be arranged such that mechanical interconnection between the first and second components is maintained in the event ot destruction of the first and second resilient elements.

In a yet further form, the invention provides in combination a first member mounted with respect to a support surface by a mount incorporating any vibration isolation device as above described. In this case, the first member may comprise a rail or other elongate member and the vibration isolation device may be arranged with the end to end direction ot the resilient elements, or the direction of extent of the projecting member, or the direction ot spacing between the first and second components generally parallel to the direction of extent of the elongate member. Where the first and second components are generally parallel, they may be transverse to the first member.

The invention is further described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a side view of a rail mount incorporating a vibration isolation device constructed in accordance with the invention; and

Figure 2 is a partly sectioned end view of the rail mount of Figure 1 .

The rail mount 10 is arranged to connect between a rail 12 and the surtace 14a ot a htt well 14 Generally, there will be a number of mounts 10 arranged at spaced locations along the length of the rail These may be similarly formed, as next described.

The rail mount includes an isolation device 15 which comprises first and second components 16.18 interconnected by three resilient couplings 20 Component 18 is in the torm ot a rectangular plate, and component 16 has a rectangular plate portion 16a. ot approximately the same size as component 18. and an integral angled bracket portion 16b at one edge Portion 16b is in use mounted to surtace 14a by suitable means such as bolts or the like (not shown) so that portion 16a extends normally from the surface.

The components 16.18 are coupled together in substantially parallel relationship by the three resilient couplings 20.

A bracket 24 in the form of an elongate angle piece is affixed to component 18 so as to extend along a marginal portion of the component 18 remote trom that edge ot component 18 which is in use adjacent the surtace 14a. This bracket 24 is clamped in position on the component 18 by bolts 26 which pass through aligned openings in the bracket 24 and component 18, and by nuts 27 which are threadedly engaged with these. The openings in one or more of the component 18 and bracket 24. and through which bolts 26 pass, may be elongate as shown in Figure 1 to enable adjustment of the position of the bracket relative to the component 18.

Bracket 24 carries two clamp elements 28 which are bolted to the bracket 24 and which in use engage outstanding flange portions 12a.l2b (Figure 1) on rail 12 to hold the rail in position on the bracket 24 and thus to hold it in position relative to the remainder of the device 10. Component 16 may be suitably reinforced, such as by provision of the webs 30 shown which extend between portions 16a.16b thereof.

The resilient couplings 20 each comprise a resilient structure 25 tormed of two substantially trustoconical resilient elements 32.34 which are positioned one to either side ot the portion 16a ot component 16 with the larger diameter ends thereof each ad _j acent the portion 16a

The following description next describes one ot the couplings 20. the three couplings 20 being substantially identical Thus, elements 32.34 are arranged in coaxially aligned relationship They are secured to the portion 16a ot component 16 by bolts 60 and threadedly engaged nuts 62. the boits 60 passing through openings in the portion 16a disposed at sidewardlv extending flanges 64 at the larger diameter ends ot the elements 32.34 The flanges 64 are positioned against the side surfaces ot the portion 16a

Elements 32.34 have axial openings 42 therefJirough A bolt 38 extends trom the side ot component 18 remote trom component 16. through a washer 47. through an opening 45 in the component 18, coaxially through opening 42 in element 32. through an axially aligned opening 44 in component 16 and thence through opening 42 in element 34. to project trom the outer, smaller diameter, end ot element 34 and through a washer 49 disposed on the outer end ot the element 34 A nut 51 is threadedlv engaged on the outer end ot the bolt 38 The nut 51 is tightened on the bolt 38 so that the bolt head 38a bears against washer 47 and the nut 38b bears against washer 49 to apply compressive force to the elements 32,34

A hollow cylindrical spacer 40 is arranged coaxially on the shank ot bolt 38 and is disposed between components 32.34 and within bores 42 and extending through opening 44 Spacer 40 is ot somewhat larger diameter than openings 45 and the internal diameter ot washer 49 and. when nut 51 is tightened sufficiently, the ends of the spacer are brought into respective engagement with the inner surtace of the component 16 and with the washer 49. so limiting the degree ot compression of elements 32,34 That is. the washer 49 defines a fixed stop surface 49a which bears against the outer end ot the resilient element

In the tightened condition ot nut 51. the spacer 40 and bolt 38 and nut 51 provide an

interconnection between the components 16.18 at which the bolt, nut and spacer are rigidly coupled to the component 16 On the other hand, component 16 is fixedly connected to the inner ends of the resilient elements 32.34

5 The outer ends ot the resilient elements resiliently bear against the inner surtace ot component 16 and against washer 49 At these outer ends of the resilient elements, the openings 42 are provided with washers 75 which are moulded into the resilient elements and are arranged coaxially within these The openings 42 of the resihent elements 32.34 also have integral inwardly extending circular flanges 32a.34a at the outer ends, immediately

1 adjacent the washers 75 The internal diameter ot these washers 75 is only slightly greater than the external diameter ot the spacer 40 and the spacer passes through these with only small clearance, so limiting the movement of the outer ends of the elements 32.34 radially with respect to the axis of bolt 38. In this way. then, the outer ends of the elements 32.34 are substantially fixedly located relative to the bolt 38 and thus also with respect to component

1 18. spacer 40 and washer 49

The opening 44 is somewhat larger than the outside diameter of the spacer 40 and a degree ot relative movement transverse to the axis ot bolt 38 is therefore permitted as between the bolt 38 and the component 16. which movement is however limited by resilient 0 deformation of the elements 32,34 and consequently generated resilient forces. Some degree of axial relative movement of the component 16 relative to the bolt 38 is also possible, this being resisted by resilient axial compression or tension forces arising from the resultant resilient deformation of the elements 32.34.

25 Elements 32.34 have at the inner ends thereof embedded planar apertured members

77 which are coaxially arranged within openings 42 and assist in providing rigidity and in facilitating mounting of the elements 32.34 to the component 16. These members have sideward extensions with apertures through which bolts 60 pass and a central aperture which is coaxially arranged with respect to opening 42. As shown, openings 42 are, at least in the

30 compressed state of the resilient elements 32.34. somewhat trustoconicai in torm. varying in

diameter trom a larger diameter at the inner ends ot the resilient elements, to smaller diameters at the outer ends The larger diameter end ot the opening 42 is of diameter substantially equal to the central internal diameter ot member 77

^■ ^ It has been found that, in use. the described arrangement is particularly effective in reducing vibration and consequent noise The arrangement also has the advantage that in the event ot destruction ot the elements 32.34. such as by tire, the holding between the components 16.18 is not completely destroyed since the bolts 38 will still hoid the elements together, albeit somewhat looseh That is. if the elements 32.34 are not present the bolt 38 I d still extends through both components 16.18 and these are looselv held together since the washer 49 is of greater diameter than opening 44 in component 16

The mounting provided by the isolation device 15 is relatively stiff in the axial directions of bolts 38. but less so in directions transverse to the bolt axes, so providing

1 5 desirable mounting characteristics tor rail 12 In the particularly described arrangement, the planes ot the components 16.18 are transverse to the lengthwise direction ot extent of the rail 12 Thus, the direction in which the isolation device 15 exhibits greatest stiffness as between the components 16.18 is aligned with the direction ot extent ot the rail The stiffness prescribed in directions transverse to that direction is less 0

It has been found satisfactory to provide three resilient couplings 20. although greater or smaller numbers may be employed if desired In the arrangement shown, there are two resilient couplings 20 disposed close to the bracket 24 and with the axes ot these immediately outside the locations of bolts 265 (as viewed in Figure 1) and only slightly below an 5 imaginary line joining the axes of bolts 26 There is a single centrally located resilient coupling 20 disposed adjacent the portion 16a ot component 16 This arrangement is particularly effective In general it is desirable to have at least two resilient couplings, to limit relative movement between components 16.18 in the event ot destruction ot the resilient elements 32.34. and to position at least one resilient coupling close to the location ot the rail 0

The resilient elements may be formed ot relatively hard rubber composition, but any suitable resilient material may be employed.

The described arrangement has been advanced merely by way ot explanation and many modifications may be made thereto without departing trom the spirit and scope ot the invention as defined in the appended claims.