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A variable wheelbase personal mobility vehicle is disclosed comprising a front wheel assembly and a rear wheel assembly. A front wheel is pivotably mounted relative to the front wheel assembly for controlling the direction of movement of the personal mobility vehicle. Plural drive wheels are mounted

A variable wheelbase personal mobility vehicle is disclosed comprising a front wheel assembly and a rear wheel assembly. A front wheel is pivotably mounted relative to the front wheel assembly for controlling the direction of movement of the personal mobility vehicle. Plural drive wheels are mounted relative to the rear wheel assembly for driving the personal mobility vehicle. A seat is connected to the rear wheel assembly for supporting an operator. A variable wheelbase mechanism varies the distance between the front wheel and the plural drive wheels.

대표청구항 ▼

A variable wheelbase personal mobility vehicle is disclosed comprising a front wheel assembly and a rear wheel assembly. A front wheel is pivotably mounted relative to the front wheel assembly for controlling the direction of movement of the personal mobility vehicle. Plural drive wheels are mounted

A variable wheelbase personal mobility vehicle is disclosed comprising a front wheel assembly and a rear wheel assembly. A front wheel is pivotably mounted relative to the front wheel assembly for controlling the direction of movement of the personal mobility vehicle. Plural drive wheels are mounted relative to the rear wheel assembly for driving the personal mobility vehicle. A seat is connected to the rear wheel assembly for supporting an operator. A variable wheelbase mechanism varies the distance between the front wheel and the plural drive wheels. al roller with the central window of the housing. 2. The drive module of claim 1, wherein said housing comprises: (a) a first housing segment to which the drive motor is mounted; and (b) a second housing segment selectably attachable to the first housing segment, wherein the second housing segment in cooperation with the first housing segment retains the roller assembly and the support bearings in engagement with the drive motor; whereby the roller assembly and the rotary bearings are removable from the drive module when the second housing segment is detached from the first housing segment. 3. The drive module of claim 1, wherein the arc diameter of the primary groove is substantially equal to a diameter of a length of coiled tubing supported by the roller assembly. 4. The drive module of claim 1, wherein the drive motor is a reversible hydraulic motor. 5. An individual drive module for use in a traction drive unit for imparting axial loads to tubing engaged by said traction drive unit, said drive module comprising: (a) an independent drive motor with an output shaft; (b) a roller having a circumferential annular groove, the roller supported by rotary bearings and driven by the output shaft of said drive motor; and (c) a housing having a first housing segment to which the drive motor is mounted and a second housing segment selectably attachable to the first housing segment, wherein the second housing segment in cooperation with the first housing segment retains the roller and the support bearings in engagement with the drive motor. 6. The drive module of claim 5, wherein the roller comprises an independently rotatable central roller section and two independently rotatable coaxial outer roller sections, one outer section on each side of the central roller section. 7. The drive module of claim 5, wherein the annular groove has an arc diameter substantially equal to an outer diameter of a tubing supported by the roller. 8. A traction drive unit for imparting axial loads to tubing, said drive unit comprising: (a) a pair of drive modules, each drive module comprising (i) a housing having a central window, (ii) an independent drive motor with an output shaft, and (iii) a roller having a circumferential annular groove aligned with the central window of the housing, the roller supported by rotary bearings and driven by the output shaft of said drive motor, wherein the rollers of the pair of drive modules are opposed and independently driven; and (b) biasing means for independently urging the roller of each drive module into engagement with a tubing supported by the opposed rollers. 9. The traction drive unit of claim 8, wherein the roller has a semi-toroidal annular groove with an arc diameter substantially equal to the outer diameter of the tubing supported by the roller. 10. The traction drive unit of claim 8, wherein the pair of opposed rollers are mounted in an alternating pattern 90° apart from adjacent pairs of opposed rollers along the axis of the tubing. 11. The traction drive unit of claim 8, wherein the drive motor is a reversible hydraulic motor. 12. A traction drive unit for imparting axial loads to tubing, said drive unit comprising: (a) a plurality of pairs of drive modules, each drive module comprising (i) a housing, (ii) an independent drive motor with an output shaft, and (iii) a bearing-supported roller in contact with a tubing, the roller driven by the output shaft of the drive motor, wherein each pair of drive modules have opposed and independently driven rollers and are mounted in an alternating pattern 90° apart from adjacent pairs of drive modules along the axis of the tubing; and (b) tensioning means for independently controlling the axial load applied to the tubing by each roller. 13. The traction drive unit of claim 12, wherein each roller comprises an independently rotatable central roller section and two independently rotatable coaxial outer roller sections, one out