Chain-type speed reducer

Claim 1

A SPEED REDUCER OF THE CHARACTER DESCRIBED, COMPRISING A FIXED CASING, A DRIVE SHAFT AND A DRIVEN SHAFT BOTH ROTATABLE IN SAID CASING, TWO LARGE DIAMETER SPROCKETS, TWO SMALL DIAMETER SPROCKETS, THE LATTER SPROCKETS BEING ARRANGED IN DIRECT ALIGNMENT WITH SAID LARGE DIAMETER SPROCKETS, CHAINS OPERATIVELY ENGAGING THE ALINED SPROCKETS, ONE LARGE DIAMETER SPROCKET BEING FIXED TO THE CASING, THE DRIVE SHAFT ROTATING IN SAID FIXED SPROCKET, THE OTHER LARGE DIAMETER SPROCKET ACTUATING SAID DRIVEN SHAFT AND HAVING A LESS NUMBER OF TEETH THAN THE TEETH IN SAID FIXED SPROCKET, A LEVER MEMBER AT THE INNER END OF SAID DRIVE SHAFT AND HAVING A HUB ARRANGED BETWEEN AND SPACING SAID LARGE DIAMETER SPROCKETS, SAID MEMBER BEING ACTUATED BY SAID DRIVE SHAFT, SAID SMALL DIAMETER SPROCKETS HAVING THEREBETWEEN A BEARING SUPPORT IN ONE END OF SAID LEVER MEMBER SAID BEARING SUPPORT BEING OF THE SAME WIDTH AS SAID HUB IN MAINTAINING SAID SPROCKET ALINEMENT, THE OPPOSED END OF SAID LEVER MEMBER SUPPORTING A COUNTERWEIGHT ARRANGED BEYOND THE PERIPHERY OF SAID LARGE DIAMETER SPROCKETS AND OF GREATER WIDTH THAN SAID HUB, SAID SMALL DIAMETER SPROCKETS BEING ROTATED IN THE CASING CIRCUMFERENTIALLY AROUND THE LARGE DIAMETER SPROCKETS IN MOVEMENT OF SAID FLEXIBLE CHAINS AROUND THE TEETH OF THE LARGE DIAMETER SPROCKETS IN THE SPEED REDUCTION DRIVE OF THE DRIVEN SHAFT BY SAID DRIVE SHAFT, AND MEANS SUPPORTED ON AND MOVABLE WITH SAID LEVER MEMBER BETWEEN THE HUB AND SAID BEARING SUPPORT FOR APPLYING TIGHTENING TENSION TO ONE OF SAID CHAINS.