Composite elastomeric spring

A method of making a composite elastomeric spring having a final torodial shape, comprising:

• providing a substantially elongate cylindrical interior block of elastomeric material defining an initial axial length between spaced ends and an exterior radial surface, said cylindrical block having a generally cylindrical core extending axially substantially through a center of said cylindrical block;
• forming an annular layer of elastomeric material circumferentially about said exterior radial surface of the interior block to define a generally cylindrically shaped preform composite spring member, said annular layer having a durometer hardness greater than that of said interior block, said annular layer having an initial axial length between spaced ends generally equal to said initial axial length of the interior block;
• applying an axial force to said preform composite spring member sufficient to simultaneously compress said interior block and annular layer a desired amount of their respective initial axial lengths, thereby reducing their initial axial lengths and changing the cylindrical shapes of said block and layer;
• and
• removing said axial force from and thereby allowing said preform composite spring member to transmute to the final torodial shaped said composite elastomer spring.

A composite elastomeric spring having a final shape, comprising:

• a first member of elastomeric material having a first durometer hardness and a ratio of plastic strain to elastic strain that is greater than 1.5 to 1, said first member having a molecular structure oriented in at least one direction and defining a transverse shape, and wherein said first elastomeric member has a first spring rate;
• and
• a second member of elastomeric material positioned adjacent and in circumferentially surrounding relation relative to a lateral surface of and in captured engagement with the first member, said second member having a second durometer hardness offering a second spring rate, said second member furthermore having a ratio of plastic strain to elastic strain that is greater than 1.5 to 1 and a molecular structure oriented in at least one direction;
• and
• wherein the captured relationship of said first and second members yielding a third spring rate to the final shape of the composite elastomeric spring effective in either compression or expansion modes of operation of said composite elastomeric spring, with said third spring rate being different than either said first or second spring rates.

A method of making an elastomeric spring having a symmetrically bulging final shape, comprising:

• providing a core of elastomeric material having a first durometer hardness, said core having an initial shape;
• providing a one-piece elongated member of elastomeric material having a second durometer hardness in circumferentially surrounding relation relative to said core to define a composite preform, said member being formed with an annular stress concentration area, said elongated member having a predetermined initial axial length divided in sections by said stress concentration area, each section having a lateral surface defining an initial shape;
• applying a compressive force to said composite preform sufficient to simultaneously compress and permanently change the initial shapes of said core and elongated member, said application of force causing said sections to bulge outwardly in substantially equal proportion as defined by the stress concentration area;
• and
• removing the compressive force from and thereby allowing said composite preform to transmute to the final shape of the elastomeric spring with the shapes of said sections being permanently expanded radially outwardly from their initial shapes.

A method of making an elastomeric spring having a symmetrically bulging final shape, comprising:

• providing a core of elastomeric material having a first durometer hardness, said core having an initial shape including an initial axial length;
• providing a one-piece cylindrical member of elastomeric material having a second durometer hardness in surrounding circumferential relation relative to said core to define a composite preform, said one-piece cylindrical member being formed with a plurality of equally spaced flanges extending radially outwardly therefrom and has a predetermined initial axial length divided in equal sections by said flanges, with each section having a lateral surface defining an initial shape;
• applying an axial force to said composite preform so as to simultaneously compress and permanently change the initial axial lengths of the cylindrical member and said core while thereby causing said sections to bulge outwardly in substantially equal proportion as defined by the flanges;
• and
• removing the axial force from and allowing said composite preform to transmute to the final shape of said elastomeric spring with the shapes of said sections being permanently expanded outwardly from their initial shapes.

A method of making an elastomeric spring having a symmetrically bulging final shape, comprising:

• providing a core of elastomeric material having a first durometer hardness, said core having an initial shape including an initial length;
• providing a one-piece cylindrical member of elastomeric material having a second durometer hardness in surrounding circumferential relation relative to said core to define a composite preform, said one-piece cylindrical member defining a plurality of equally spaced relief notches around a periphery thereof and has a predetermined initial axial length divided in sections by said notches, each section having a lateral surface defining an initial shape;
• applying an axial force to said composite preform so as to simultaneously compress and permanently change the initial axial lengths of the cylindrical member and said core while thereby causing said sections to bulge outwardly in substantially equal proportion as defined by the notches;
• and
• removing the axial force from and allowing said composite preform to transmute to the final shape of said elastomeric spring with the shapes of said sections being permanently expanded outwardly from their initial shapes.

A composite elastomeric spring having a symmetrically bulging final shape, comprising:

• a core of elastomeric material having a first durometer hardness and a ratio of plastic strain to elastic strain greater than 1.5 to 1, said core having a molecular structure oriented in an axial direction and defining an initial shape including an initial length, and wherein said elastomeric core has a first spring rate;
• a one-piece elongated member of elastomeric material positioned in circumferentially surrounding relation relative to said core such that said core and said elongated member are arranged in captured engagement with each other, said elongated member having a second spring rate with a ratio of plastic strain to elastic strain that is greater than 1.5 to 1 and a molecular structure oriented in an axial direction, with said elongated member being formed with at least one transverse stress concentration area thereon dividing the elongated member into sections, with each section having a lateral surface which bulges outwardly in substantial proportion as defined by the stress concentration area to define the symmetrically bulging final shape of said elastomeric spring;
• and
• wherein the captured engagement of said core and said elongated member provides said composite elastomeric spring with a third spring rate different from said first or second spring rates and effective in either compressive or expansive modes of operation of said composite elastomeric spring.

A symmetrically bulging composite elastomeric spring, comprising:

• a core of elastomeric material having a first durometer hardness and a ratio of plastic strain to elastic strain that is greater than 1.5 to 1, said core having a molecular structure oriented in an axial direction and having a first spring rate;
• a one-piece spring member of elastomeric material having a second spring rate;
• with said spring member being positioned in circumferentially surrounding relation relative to said core such that said core and said spring member are arranged in captured relationship relative to each other, with said spring member having a ratio of plastic strain to elastic strain that is greater than 1.5 to 1 and a molecular structure oriented in an axial direction, said spring member being formed with a plurality of equally spaced flanges extending radially outwardly therefrom to thereby divide the spring member into equal sections, each section having a lateral surface which bulges outwardly in substantial proportion as defined by the flanges to define the symmetrically bulging configuration of said elastomeric spring;
• and
• wherein the captured engagement of said core and said spring member provides said composite elastomeric spring with a third spring rate different from said first or second spring rate and effective in either compressive or expansive modes of operation of said composite elastomeric spring.

A symmetrically bulging composite elastomeric spring, comprising:

• a core of elastomeric material having a first durometer hardness and a ratio of plastic strain to elastic strain greater than 1.5 to 1, said core having a molecular structure oriented in an axial direction and has a first spring rate;
• a one-piece spring member of elastomeric material having a second spring rate, with said spring member being positioned in circumferentially surrounding relation relative to said core such that said core and spring member are arranged in captured relationship relative to each other, with said spring member further having a ratio of plastic strain to elastic strain that is greater than 1.5 to 1 and a molecular structure oriented in an axial direction, said spring member defining a plurality of equally spaced relief notches about a periphery thereof to thereby divide the spring member into equal sections, each section having a lateral surface which bulges outwardly in substantial proportion as defined by the relief notches;
• and
• wherein the captured relationship of said core and said spring member causing said spring member and said core to conjointly act at a third spring rate different from said first and second spring rate in response to loads acting on said elastomeric spring regardless of the direction said loads are applied to said composite elastomeric spring.