F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
F16F1/00—Springs
F16F1/36—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers
F16F1/371—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers characterised by inserts or auxiliary extension or exterior elements, e.g. for rigidification
F16F1/3713—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers characterised by inserts or auxiliary extension or exterior elements, e.g. for rigidification with external elements passively influencing spring stiffness, e.g. rings or hoops