Dual rate jounce bumper and a vehicle comprising the same

A dual-rate jounce bumper for limiting a jounce travel between a first component and a second component of a vehicle, with the second component spaced from and moveable towards the first component along a jounce axis, said dual-rate jounce bumper comprising:

• a bumper having a first end for coupling to the first component and a second end spaced from said first end for contacting the second component, with said bumper compressible between the first component and the second component for limiting jounce, with said bumper radially expandable as said bumper is compressed, and
• an outer member, disposed about said bumper and capable of limiting the radial expansion of said bumper as said bumper is compressed, for increasing a stiffness of the bumper,
• wherein said outer member is obtained by overmolding stainless-steel with a thermoplastic polyurethane having a shore hardness ranging from a Shore D hardness of 50 to a Shore D hardness of 80, determined according to ASTM D2240-15e1,
• wherein the thermoplastic polyurethane is obtained by reacting:
• a polyol, an isocyanate, and optionally, a chain extender,
• wherein the polyol comprises a polyether polyol,
• wherein the polyether polyol has an average functionality in between 1.9 to 2.1 and a hydroxyl number in between 10 mg KOH/g to 500 mg KOH/g,
• wherein the isocyanate comprises an aliphatic isocyanate or an aromatic isocyanate, and
• wherein the aromatic isocyanate comprises methylene diphenyl diisocyanate and/or polymeric methylene diphenyl diisocyanate.