Railcar elastomeric spring

A cold formed railcar spring comprising:

• a spring member formed from a preform of thermoplastic polyester elastomer having a durometer hardness ranging between about 40 and about 45 on the Shore D scale, with said preform having a selected initial axial length and a generally cylindrical shape of a predetermined diameter between first and second axial ends thereof and defining an axial bore opening to said first and second ends, with said preform and said bore being substantially uniform in cross section perpendicular to a central axis, and wherein the elastomer of said preform is such that, upon being axially compressed at least 30% of the initial axial length of said preform, said elastomer will permanently retain a substantial portion of the length reduction after being compressed and whereby said preform is thereafter transmuted into said spring member for absorbing, dissipating and returning energy imparted thereto;
• and
• first and second metal plates adapted to be mechanically fastened at the first and second ends, respectively, of said preform, with each plate having a pair of generally parallel and planar surfaces defining a predetermined thickness therebetween and a generally centralized bore extending through each plate, with each plate further including a profiled periphery, and wherein each plate further includes a plurality of radially spaced mechanical fasteners formed as an integral part of each plate and extending at an acute angle relative to one planar surface on each plate, with each fastener being arranged in predetermined relation about a diameter of said preform at opposite ends thereof such that, upon axial compression of said preform, a portion of the elastomer of preform radially expands and presses into mechanically interlocking relation with a distal end of each fastener whereby fastening said plate to one end of said preform.

A cold formed railcar spring comprising:

• a spring member formed from a preform of thermoplastic polyester elastomer having a durometer hardness ranging between about 40 and about 45 on the D scale, with said preform having an initial axial length and a generally cylindrical shape of a predetermined diameter between first and second axial ends thereof and defining an axial bore opening to said first and second ends, with said preform and said bore being substantially uniform in cross section perpendicular to a central axis, and wherein the elastomer of said preform is such that, upon being axially compressed at least 30% of the initial axial length of said preform, said elastomer will permanently retain a substantial portion of the length reduction after being compressed and whereby said preform is thereafter transmuted into said spring member for absorbing, dissipating and returning energy imparted thereto;
• and
• first and second metal plates adapted to be mechanically fastened at the first and second ends, respectively, of said preform, with each plate having a pair of planar surfaces with a predetermined thickness therebetween and a generally centralized bore extending through each plate and defining a central axis which aligns with the central axis of said preform, with each plate further including a profiled periphery, and wherein each plate further includes a plurality of radially spaced fasteners formed as an integral part of each plate and having first and second generally parallel major surfaces extending generally normal to the planar surface on said plate, with each fastener being pressed axially into one end of said preform, upon axial compression of said preform, until one of said planar surfaces on said plate contacts with said preform so as to interlock one end of the preform with said plate, and with each fastener serving to inhibit radial expansion of said elastomeric spring during a working cycle of said spring.