Electromagnetic clutch

Claim 1

IN A DEVICE OF THE CLASS DESCRIBED, A SHAFT, AN ELECTROMAGNET MOUNTED ON SAID SHAFT, A COLLAR HAVING A RADIAL FLANGE MOUNTED ON SAID SHAFT, AN ARMATURE CARRIED BY SAID FLANGE AND DISPOSED WITH AN INITIAL AIR GAP WITH RESPECT TO SAID ELECTRO-MAGNET WHEN SAID ELECTRO-MAGNET IS DEENERGIZED, A FIRST RESILIENT MEANS FOR BIASING SAID ARMATURE TOWARD SAID FLANGE, A TOOTH RING CARRIED BY SAID ELECTROMAGNET, A TOOTH RING CARRIED BY SAID ARMATURE, A SECOND RESILIENT MEANS INTERMEDIATE SAID LATTER TOOTH RING AND SAID ARMATURE, WHEREIN SAID ARMATURE HAS RELATIVE LONGITUDINAL MOTION WITH RESPECT TO SAID LATTER TOOTH RING, SAID TOOTH RINGS BEING ENGAGEABLE WHEN SAID ARMATURE IS ATTRACTED TO SAID ELECTRO-MAGNET UPON ENERGIZATION THEREOF, SAID FIRST RESILIENT MEANS BEING STRESSED UPON INITIAL MOTION OF SAID ARMATURE TOWARD SAID ELECTRO-MAGNET, SAID SECOND RESILIENT MEANS BEING SUBSEQUENTLY STRESSED UPON ENGAGEMENT OF SAID TOOTH RINGS WHEN THE AIR GAP BETWEEN SAID ARMATURE AND SAID ELECTRO-MAGNET IS SUBSTANTIALLY LESS THAN SAID INITIAL AIR GAP, SAID SECOND RESILIENT MEANS HAVING A HIGH RESISTANCE TO STRESSING SO AS TO EFFECT AN INITIAL RAPID REVERSE MOVEMENT OF SAID ARMATURE IN WITHDRAWING FROM SAID ELECTRO-MAGNET UPON DE-ENERGIZATION THEREOF, SAID FIRST RESILIENT MEANS EFFECTING FINAL REVERSE MOVEMENT OF SAID ARMATURE TO THE POSITION OF SAID INITIAL AIR GAP, SAID FIRST RESILIENT MEANS HAVING LESS RESISTANCE TO STRESSING THAN SAID SECOND RESILIENT MEAN.