Spring coupling for an electromagnetic clutch

Claim 1

In an electromagnetic clutch including a first rotatable member having an axial end plate of magnetic material, a second rotatable member, an annular armature plate of magnetic material joined to said second rotatable member so that said annular armature plate is capable of limited axial movement, said annular armature plate facing said axial end plate of said first rotatable member with an axial air gap therebetween, and an electromagnetic means associated with said axial end plate for attracting said armature plate to said axial end plate so that rotation of said first rotatable member can be transmitted to said second rotatable member through said armature plate by the operation of said electromagnetic means, the improvement comprising: said second rotatable member including a drive shaft, a hub fastened to the end of said drive shaft and a radially extending flange mounted on said hub; a plurality of spring members coupling said annular armature plate to said radially extending flange, each of said spring members having first fitting means coupling said spring member to said annular armature plate and second fitting means coupling said spring member to said radially extending flange, said first and second fitting means being positioned opposite each other at a predetermined gap for preventing excessive bending of said spring members when the predetermined gap is closed by the initial rotation of said annular armature plate in response to the operation of said electromagnetic means and said first rotatable member, said excessive bending being prevented by said first and second fitting means contacting each other.