Motorcycle snowmobile conversion unit

Claim 1

In combination with a portion of a motorcycle that has a chassis that includes a frame having a forked rearward portion, a seat, an engine supported on said frame, a forked pivotally movable forward portion, handlebars for pivoting said forward portion, and a circular driving sprocket driven by said engine, an assembly that cooperates with said motorcycle to provide a snowmobile, which assembly includes: a. a first frame having forward and rearward ends; b. two laterally spaced, parallel skis disposed under said forward ends; c. first means pivotally supporting said skis from said first frame; d. second means operatively associated with said first means to cause said skis to pivot in unison when said second means is actuated; e. third means for pivotally connecting said forward forked portion to said second means to permit said skis to be pivoted by manipulation of said handlebars; f. a protective hollow body assembly to protect the user of said snowmobile, said body mounted on said first frame and extending upwardly therefrom; g. a second frame having forward and rearward ends, said second frame including pairs of parallel laterally spaced outer side members and inner side members, and forward and rearward transverse shafts rotatably supported from said forward and rearward ends of said pairs of outer and inner side members; h. two laterally spaced, transversely aligned brackets secured to said pair of inner side members; i. a third transverse shaft rotatably supported by said brackets; j. a driven sprocket rigidly secured to said third shaft; k. a first endless chain belt connecting said driven sprocket to said driving sprocket; l. first and second longitudinally aligned sprockets secured to said third shaft and rearward shaft respectively; m. a second endless chain belt connecting said first and second sprockets; n. fourth means for connecting said forked rearward frame portion to said second frame, with said first and second frames longitudinally aligned; o. first and second pairs of longitudinally aligned sprockets secured to both said forward and rearward shafts; p. first and second pairs of endless chain belts that engage said first and second pairs of said sprockets on said forward and rearward shafts; and q. first and second endless exteriorly cleated belts of substantial width, with the interior surfaces of said first and second belts secured to said first and second pairs of endless chain belts respectively, and said cleated belts when rotated driving said snowmobile over a desired terrain on which it is guided by the position in which said skis are disposed.