Mini bike drive kit

Claim 2

A variable ratio drive apparatus adapted to be readily attached as by bolts or the like to, and wholly supported by, the engine of a mini bike or the like having an engine and a drive wheel with a drive sprocket fixed to the drive wheel, comprising a speed-responsive driver pulley mounted on the engine shaft, a mounting plate mounted on the side of the engine adjacent said driver pulley, independently of other support and affixed thereto by bolts or the like, a jackshaft supported by said mounting plate between the engine shaft and the drive wheel, in predetermined parallel spaced relation with the engine shaft, a torque-responsive driven pulley mounted on said jackshaft and connected to said driver pulley by a belt, and an output sprocket or the like on said jackshaft between the inner face of the driven pulley and the mounting plate, on the same side of the mini bike as said pulleys and in position for chain connection to said drive sprocket, said drive apparatus being thereby wholly supported by the engine and the jackshaft being located in predetermined relation with the engine power shaft independently of other minibike structure, so as to permit ready mounting of the drive apparatus and to thereby provide and maintain said predetermined shaft spacing.

Claim 3

A variable-ratio drive apparatus for a mini bike or the like having an engine which includes a projecting power shaft projecting from a side face thereof for the reception of a drive pulley or the like, comprising a mounting plate for mounting to said side face of the engine and including a jackshaft support for supporting a jackshaft in spaced parallel relation with the power shaft of the engine to which it is mounted, a jackshaft which mounts in said jackshaft support, variable-width driver and driven pulleys and a belt, for connecting said power shaft and jackshaft, said pulleys being asymmetric and each having a substantially flat fixed pulley flange at the inner side thereof to lie adjacent the mounting plate, and having a conical movable pulley flange at the outer side thereof, and means to move the movable pulley flanges oppositely toward and away from the fixed flanges to vary the relative effective diameters of the pulleys and thereby vary the drive ratio between them, an output sprocket or the like beween the inner side of the driven pulley and the jackshaft supPort, shroud mounting brackets on said mounting plate, and a shroud shaped to enclose said pulleys and belt and having means for mounting the same on said brackets.

Claim 4

A variable-ratio drive apparatus for a mini bike or the like having an engine which includes a projecting power shaft projecting from a side face thereof for the reception of a drive pulley or the like, comprising a mounting plate for mounting to said side face of the engine and including a jackshaft support for supporting a jackshaft in spaced parallel relation with the power shaft of the engine to which it is mounted, a jackshaft which mounts in said jackshaft support, variable-width driver and driven pulleys and a belt, for connecting said power shaft and jackshaft, said pulleys being asymmetric and each having a substantially flat fixed pulley flange at the inner side thereof to lie adjacent the mounting plate, and having a conical movable pulley flange at the outer side thereof, and means to move the movable pulley flanges oppositely toward and away from the fixed flanges to vary the relative effective diameters of the pulleys and thereby vary the drive ratio between them, an output sprocket or the like beween the inner side of the driven pulley and the jackshaft supPort, shroud mounting brackets on said mounting plate, and a shroud shaped to enclose said pulleys and belt and having means for mounting the same on said brackets.

Claim 5

A variable-ratio transmission kit adapted for ready installation on a minibike or the like in place of direct drive, by mounting the same on the engine of the minibike, the engine having a flat side face for the reception thereof and from which a power shaft projects, comprising a mounting plate adapted to be wholly supported by the engine, having a mounting end portion adapted to fit against said side face of the engine and to be fixed thereagainst as by bolts or the like, a jackshaft support fixed to said mounting plate for supporting a jackshaft in predetermined spaced parallel relation with the power shaft of the engine, and a jackshaft for support thereby in position to project outward from said mounting plate in said predetermined relation with the power shaft, asymmetric variable-width driver and driven pulleys which mount on said power shaft and jackshaft, said pulleys each having a substantially flat fixed pulley flange at the inner side thereof to lie adjacent the mounting plate and a conical movable pulley flange at the outer side thereof, a belt for connecting said pulleys, and means to move said movable pulley flanges oppositely inward and outward in contact with said belt to vary the effective diameters of the pulleys and the drive ratio between them, and an output sprocket or the like which mounts on said jackshaft adjacent the inner face of the driven pulley thereon, between said pulley and the mounting plate and is driven by said driven pulley to transmit drive therefrom, said mounting plate being thereby mountable to the engine by bolts or the like to fix the jackshaft in predetermined spaced parallel relation with the engine shaft independently of other support, the pulleys being mountable on said shafts close to the plane of the said side face of the engine and providing for operation of said belt at all ratios substantially in a fixed plane adjacent to the said side face, and said sprocket being thereby positioned to operate in a plane close to the plane of the said side face of the engine.

Claim 6

A variable-ratio transmission kit adapted for ready installation on a minibike or the like in place of direct drive, by mounting the same on the engine of the minibike, the engine having a flat side face for the reception thereof and from which a power shaft projects, comprising a mounting plate adapted to be wholly supported by the engine, having a mounting end portion adapted to fit against said side face of the engine and to be fixed thereagainst as by bolts or the like, a jackshaft support fixed to said mounting plate for supporting a jackshaft in predetermined spaced parallel relation with the power shaft of the engine, and a jackshaft for support thereby in position to project outward from said mounting plate in said predetermined relation with the power shaft, asymmetric variable-width driver and driven pulleys which mount on said power shaft and jackshaft, said pulleys each having a substantially flat fixed pulley flange at the inner side thereof to lie adjacent the mounting plate and a conical movable pulley flange at the outer side thereof, a belt for connecting said pulleys, and means to move said movable pulley flanges oppositely inward and outward in contact with said belt to vary the effective diameters of the pulleys and the drive ratio between them, and an output sprocket or the like which mounts on said jackshaft adjacent the inner face of the driven pulley thereon, between said pulley and the mounting plate and is driven by said driven pulley to transmit drive therefrom, said mounting plate being thereby mountable to the engine by bolts or the like to fix the jackshaft in predetermined spaced parallel relation with the engine shaft independently of other support, the pulleys being mountable on said shafts close to the plane of the said side face of the engine and providing for operation of said belt at all ratios substantially in a fixed plane adjacent to the said side face, and said sprocket being thereby positioned to operate in a plane close to the plane of the said side face of the engine.

Claim 7

A variable-ratio transmission kit as in claim 3 in which the means for moving the movable flange of the driver pulley is speed-responsive.

Claim 8

A variable-ratio transmission kit as in claim 4 in which the means for moving the movable flange of the driven pulley is torque-responsive, and acts to impose tension on the belt in opposition to that of the speed-responsive driver pulley.

Claim 9

A variable-ratio transmission kit as in claim 3 with the addition of shroud-mounting brackets on said mounting plate, a shroud shaped to enclose said pulleys and belt, and means for mounting the shroud on said brackets.

Claim 10

A variable ratio drive apparatus adapted to be readily attached as by bolts or the like to the engine of a minibike or the like, as in place of a direct-drive, for support by such engine and to provide a variable drive mechanism of narrow configuration and low overhang from the engine, said engine including a power shaft projecting from a side face of the engine, comprising a mounting plate adapted to be mounted as by bolts or the like against said side face of the engine, and to be wholly supported thereby, a jackshaft mounted on said mounting plate in position to project outward therefrom in predetermined spaced parallel relation with the power shaft of the engine, variable-width driver and driven pulleys respectively on said power shaft and jackshaft, and a belt connecting the two pulleys, said pulleys being asymmetric and each having a substantially flat fixed pulley flange at the inner side thereof, adjacent the mounting plate, and having a conical movable pulley flange at the outer side thereof, and means to move the movable pulley flanges oppositely toward and away from the fixed flat flanges to vary the relative effEctive diameters of the pulleys and thereby vary the drive ratio between them, and an output sprocket or the like on the jackshaft between the inner side of the driven pulley and the mounting plate, said drive apparatus being thereby wholly supported by said engine, said belt being disposed to operate at all ratios substantially in a fixed plane adjacent the face of the engine, and the sprocket lying between the belt plane and the mounting plate for chain connection to a wheel sprocket in a plane close to the plane of said engine side face.

Claim 11

A variable ratio drive apparatus adapted to be readily attached as by bolts or the like to the engine of a minibike or the like, as in place of a direct-drive, for support by such engine and to provide a variable drive mechanism of narrow configuration and low overhang from the engine, said engine including a power shaft projecting from a side face of the engine, comprising a mounting plate adapted to be mounted as by bolts or the like against said side face of the engine, and to be wholly supported thereby, a jackshaft mounted on said mounting plate in position to project outward therefrom in predetermined spaced parallel relation with the power shaft of the engine, variable-width driver and driven pulleys respectively on said power shaft and jackshaft, and a belt connecting the two pulleys, said pulleys being asymmetric and each having a substantially flat fixed pulley flange at the inner side thereof, adjacent the mounting plate, and having a conical movable pulley flange at the outer side thereof, and means to move the movable pulley flanges oppositely toward and away from the fixed flat flanges to vary the relative effEctive diameters of the pulleys and thereby vary the drive ratio between them, and an output sprocket or the like on the jackshaft between the inner side of the driven pulley and the mounting plate, said drive apparatus being thereby wholly supported by said engine, said belt being disposed to operate at all ratios substantially in a fixed plane adjacent the face of the engine, and the sprocket lying between the belt plane and the mounting plate for chain connection to a wheel sprocket in a plane close to the plane of said engine side face.

Claim 12

A variable-ratio drive apparatus as in claim 7 with the addition of a bearing sleeve fixed to said mounting plate and projecting inward therefrom, the jackshaft being rotatably mounted in said bearing sleeve and the driven pulley and output sprocket being fixed to the jackshaft.

Claim 13

A variable-ratio drive apparatus as in claim 7 in which said means to move the movable pulley flanges comprises speed responsive means at the outer side of said driver pulley, operative to control the position of the movable flange of said pulley to vary the effective diameter thereof, and torque-responsive means at the outer side of said driven pulley, operative to control the position of the movable flange of said pulley to vary the effective diameter thereof.