Torsional vibration dampening device

A torsional vibration dampening device for a clutch to transmit torque between driving (2) and driven (4, 6, 7) members, absorbing torsional vibrations, comprising:

• a plurality of circumferentially extending spring receiving portions (15, 21) defined in both a torque-input member (9, 13, 14) and a torque-output member (10);
• a plurality of damper spring sets operatively accommodated in said respective spring receiving portions (15, 21), so that said torque-input and torque-output members are coupled with each other resiliently in their rotational directions via said damper spring sets;
• each of said damper spring sets consisting of a plurality of compression springs (11, 11) serially arranged with each other;
• a floating spring separator (23) being rotatable relatively to both said torque-input member and said torque-output member and having a plurality of arms (25) interposed between adjacent damper springs (11, 11) in a damper spring set, and a connecting member (24) adapted to integrally connect said plurality of arms (25) to each other through said connecting member;
• and
• said torque-input member including a clutch piston plate (9) adapted to engage the driving member (2) and a plurality of circumferentially equi-distantly spaced spring-holder plates (14) corresponding in number to said damper spring sets and secured to said clutch piston plate (9) and axially aligned with said damper spring sets,
• wherein said connecting member (24) is cylindrical in shape and arcuately and rotatably accommodated in an essentially cylindrical axially circumferentially extending aperture (d) defined between an outer peripheral surface of said spring-holder plates (14) and an inner peripheral wall surface of a cylindrical outer flanged portion of said piston plate (9), and
• wherein said plurality of arms (25) project radially and inwardly from said cylindrical connecting member (24).