Torsional dampers

A torsional damper for use in a friction clutch plate, said torsional damper comprising at least two coaxial parts mounted for relative rotation within a defined range of relative angular movement, circumferentially acting elastic means operatively disposed between said coaxial parts and resisting relative angular movement over at least part of said range of relative angular movement, said circumferentially acting elastic means comprising a circumferentially acting spring having one end in engagement with one of said coaxial parts and another end coupled to the other of said coaxial parts, said circumferentially acting spring being operative at the outset of relative angular movement, said circumferentially acting elastic means further comprising at least one elastically deformable arm, a support constrained to rotate with a first of said coaxial parts, a shoulder formed on a second of said coaxial parts, said elastically deformable arm extending in a substantially circumferential direction and attached at one end to said support, the other end of said elastically deformable arm having a shoulder being circumferentially spaced from said shoulder on said second coaxial part at the outset of relative angular displacement of said coaxial parts, whereby said shoulders come into engagement with each other and said elastically deformable arm becomes operative after a predetermined range of relative angular movement between said coaxial parts, said elastically deformable arm and said support are parts of a flange of one-piece construction, said first coaxial part comprising a hub and said support comprising a foot in engagement with said hub, said support further comprising an annular member having an internal perimeter from which said foot projects, radial clearance being defined between said elastically deformable arm and said annular member.

A torsional damper for use in a friction clutch plate, said torsional damper comprising at least two coaxial parts mounted for relative rotation within a defined range of relative angular movement, circumferentially acting elastic means operatively disposed between said coaxial parts and resisting relative angular movement over at least part of said range of relative angular movement, said circumferentially acting elastic means comprising a circumferentially acting spring having one end in engagement with one of said coaxial parts and another end coupled to the other of said coaxial parts, said circumferentially acting spring being operative at the outset of relative angular movement, said circumferentially acting elastic means further comprising at least one elastically deformable arm, a support constrained to rotate with a first of said coaxial parts, a shoulder formed on a second of said coaxial parts, said elastically deformable arm extending in a substantially circumferential direction and attached at one end to said support, the other end of said elastically deformable arm having a shoulder being circumferentially spaced from said shoulder on said second coaxial part at the outset of relative angular displacement of said coaxial parts, whereby said shoulders come into engagement with each other and said elastically deformable arm becomes operative after a predetermined range of relative angular movement between said coaxial parts, and there being two of said elastically deformable arms, said elastically deformable arms extending in circumferentially opposite directions and being formed in a one-piece flange together with said support therefor.