Elastomeric mounting

An elastomeric mounting device for positioning between two plates fixed relatively to one another, said relatively fixed plates defining the maximum height of said mounting device, said device comprising:

• a pair of concentric rigid members arranged to define an annular space therebetween, one of said rigid member having means for securing it between said relatively fixed plates and the other rigid member having means for securing an article to be supported by said mounting,
• an annular element of elastomeric material which extends between and serves to interconnect said rigid members, the annular element being bonded to each of said rigid members at surface positions of the respective members which are longitudinally off-set when the elastomeric mounting is in an unstressed condition and one of said bonded surface portions being of a substantially cylindrical shape, the annular element of elastomeric material comprising between its inner and outer peripheries an annular section the thickness of which, as considered in said longitudinal direction, is less than the thickness of the element, in said direction, in at least one of the inner and outer peripheral regions and being of a shape which deforms by both shear and bending movements to exhibit a regressive stiffness characteristic in the event of relative longitudinal movement of the rigid members over a first working range of relative longitudinal positions of the rigid members,
• elastomeric axial buffer means operable at relative longitudinal positions of the rigid members which lie outside said first working range of relative longitudinal positions to provide outside of said first working range a resistance to relative longitudinal movement greater than that provided by the annular element of elastomeric material within said first working range of relative positions, said elastomeric axial buffer means comprising a pair of buffer elements, one arranged to restrict relative longitudinal movement in a second working range due to excess applied load and the other arranged to restrict relative longitudinal movement in a third working range due to excess rebound forces, one of said buffer elements being positioned to act between one of the relatively fixed plates and one of the rigid members and
• elastomeric transverse load bearing means secured relative to one only of said rigid members and arranged between said rigid members to resist relative movement of the rigid members in transverse directions perpendicular to the direction of said relative longitudinal movement, said transverse load bearing means comprising an annular body of elastomeric material secured to said one of said rigid members,
• said rigid members, said annular element and said buffer means being arranged so that no portion of said mounting device projects above or below said maximum height in any stage of operation of said mounting device.