Change-speed mechanism

Claim 1

IN COMBINATION, A MOTORCYCLE HAVING A FRAME, MOTOR-DRIVEN TRANSMISSION MEANS SUPPORTED ON SAID FRAME AND INCLUDING A DRIVE SPROCKET, AN AXLE-MOUNTED REAR WHEEL INCLUDING A HUB CONNECTED WITH SAID FRAME, A FIRST PAIR OF SPROCKETS OF UNEQUAL DIAMETER, MEANS CONNECTING SAID PAIR OF SPROCKETS AND SPACED RELATION COAXIALLY WITH SAID REAR WHEEL, SAID MEANS INCLUDING A DRUM HAVING A DRUM FACE AND A CYLINDRICAL PERIPHERY, SAID DRUM FACE BEING INTERPOSED BETWEEN SAID WHEEL HUB AND THE SMALLER OF SAID FIRST PAIR OF SPROCKETS, THE LARGER OF SAID FIRST PAIR OF SPROCKETS BEING A RING SPROCKET MOUNTED ON SAID DRUM PERIPHERY, A HOUSING RIGIDLY CONNECTED WITH SAID FRAME, A SHAFT ROTATABLY JOURNALED IN SAID HOUSING AND EXTENDING THEREFROM, THREE ADDITIONAL SPROCKETS MOUNTED ON SAID SHAFT EXTERNALLY OF SAID HOUSING, A FIRST ENDLESS CHAIN CONNECTING THE INTERMEDIATE ONE OF SAID THREE ADDITIONAL SPROCKETS WITH SAID TRANSMISSION DRIVE SPROCKET, SECOND AND THIRD ENDLESS CHAINS CONNECTING THE OTHER TWO OF SAID ADDITIONAL SPROCKETS WITH SAID FIRST PAIR OF SPROCKETS, RESPECTIVELY, KEY MEANS MOVABLY MOUNTED ON SAID SHAFT IN ENGAGEMENT WITH SAID INTERMEDIATE SPROCKET FOR CONNECTING SAID INTERMEDIATE SPROCKET ALTERNATELY WITH SAID OTHER TWO ADDITIONAL SPROCKETS, RESPECTIVELY, AND MEANS ENCLOSED WITHIN SAID HOUSING FOR SELECTIVELY SHIFTING SAID KEY MEANS.