Change speed gear mechanism for bicycles and the like vehicles

Claim 1

A CHANGE SPEED GEAR MECHANISM FOR A BICYCLE OR THE LIKE VEHICLE, COMPRISING A SUPPORT LUG FOR SUPPORTING THE MECHANISM ON THE VEHICLE, TWO IDENTICAL SUPPORTS EACH IN THE FORM OF A DOUBLE YOKE RESPECTIVELY CONSTITUTING UPPER AND LOWER SUPPORTS, SUBSTANTIALLY PARALLEL LEVERS EXTENDING BETWEEN SAID SUPPORTS, MEANS FREELY PIVOTING SAID LEVERS IN CORRESPONDING YOKES OF SAID SUPPORTS TO FORM AN ARTICULATED PARALLELOGRAM IN WHICH SAID SUPPORTS ARE MAINTAINED PARALLEL TO EACH OTHER BY SAID LEVERS, MEANS CONNECTING ONE OF SAID SUPPORTS TO SAID SUPPORT LUG FOR RESILIENT PIVOTAL MOVEMENT THEREABOUT, A CHAIN GUIDE ASSEMBLY ADAPTED FOR MOVING A CHAIN TRANSVERSELY FROM ONE SPROCKET TO ANOTHER, MEANS CONNECTING SAID CHAIN GUIDE ASSEMBLY TO THE OTHER OF SAID SUPPORTS FOR RESILIENT PIVOTAL MOVEMENT THEREABOUT SUCH THAT SAID SUPPORTS ARE EACH INDEPENDENTLY PIVOTAL ABOUT RESPECTIVE AXES, CONTROL MEANS OPERATIVELY COUPLED TO THE ARTICULATED PARALLELOGRAM FOR DISPLACING THE CHAIN GUIDE ASSEMBLY TRANSVERSELY IN A FIRST DIRECTION, RETURN SPRING MEANS OPERATIVELY COUPLED TO THE ARTICULATED PARALLELOGRAM FOR DISPLACING SAID CHAIN GUIDE ASSEMBLY TRANSVERSELY IN A DIRECTION OPPOSITE TO SAID FIRST DIRECTION, A FIRST STOP DEVICE FOR LIMITING PIVOTAL MOVEMENT OF SAID ONE SUPPORT RELATIVELY TO SAID SUPPORT LUG, A SECOND STOP DEVICE FOR LIMITING PIVOTAL MOVEMENT OF THE CHAIN GUIDE ASSEMBLY RELATIVELY TO SAID OTHER SUPPORT AND A THIRD STOP DEVICE FOR LIMITING ANGULAR DEFORMATION OF THE ARTICULATED PARALLELOGRAM IN BOTH DIRECTIONS DURING TRANSVERSE DISPLACEMENT OF THE CHAIN GUIDE ASSEMBLY, SAID THIRD STOP DEVICE INCLUDING MANUALLY ADJUSTABLE MEANS FOR PRE-DETERMINING THE LIMITS OF SAID ANGULAR DEFORMATION FOR ADJUSTING TRANSVERSE DISPLACEMENT OF SAID CHAIN GUIDE ASSEMBLY.