Abstract: A joint is described which has a pair of coaxially aligned elastic rings (5) of truncated conical form the respective vertices of which are directed in opposite ways and are engaged each between a central core (3) externally having an attachment surface (3a) of truncated conical form and an outer collar (4) internally having an attachment surface (4a) of truncated conical form converging towards a vertex (V) which is common to the converging vertex of the attachment surface (3a) of the core (3).Each elastic ring (5) comprises an inner layer made of elastomeric material (10) and an outer layer (11) made of elastomeric material between which a laminar insert piece of truncated conical form (12) is inserted, the inner (12a) and outer (12b) surfaces of which converge towards the common vertex (V) of the attachment surfaces (3a, 4a).The outer elastomeric layer (11) is greater in thickness that the inner elastomeric layer (10).The described joint (1) has an improved fatigue limit.

Abstract: A mounting to hang an engine to a frame, adapted to insulate the frame from predetermined high-frequency and small-amplitude vibrations. The mounting comprises an envelope, a cover in the form of an elastomeric diaphragm associated with the side walls of the envelope, a pin adapted to receive the engine weight, engagement parts connecting the envelope to the frame. The mounting is comprised of a rocking system consisting of two masses and three elastomeric bodies with rigidities K2, K3, K4. The two masses are connected to each other by one elastomeric body and are in parallel to the elastomeric diaphragm being connected to the pin and envelope by interposition of the two other elastomeric bodies. The diaphragm and the parallel system when high-frequency and small-amplitude vibrations occur, give rise to a dynamic rigidity defined by two peaks and a valley therebetween; one of the peaks has a lower height than the other.

Abstract: A variable strength spring includes a tubular body, at whose inner surface is coaxially provided a concave contact seat, a ring made of elastomeric material rigidly engaged in the tubular body and a connection tang rigidly engaged in the elastic ring. The elastic ring has a radial groove that defines, on the longitudinal length of the ring, a first portion rigidly engaged inside the tubular body opposite the contact seat, and a second portion slidably engaged in the tubular body. On the outer circumferential end of the second portion is situated a rigid rabbet edge positioned opposite to a stopping seat inside the tubular body.

Abstract: An element for supporting the suspension-springs of railway wagons including a bottom plate, an intermediate plate and a parallel adjacent supporting plate provided with the interposition of first and second elastic rings which are connected to the plates at their respective contacting surfaces. The second elastic ring has a greater rigidity compared to that of the first elastic ring. The greater rigidity is obtained by forming the second ring to have a lesser height (L") than that (L') of the first ring, or by use of an elastomeric material that is more rigid than the material which is used for forming the first ring.