초록 ▼

A three wheeled vehicle comprises a front subframe having a front wheel journaled thereto and a seat for a rider mounted thereon, and a rear subframe having a pair of rear wheels journaled thereto. The front subframe is journaled to the rear subframe at a kingpin axis, which defines a caster angle w

A three wheeled vehicle comprises a front subframe having a front wheel journaled thereto and a seat for a rider mounted thereon, and a rear subframe having a pair of rear wheels journaled thereto. The front subframe is journaled to the rear subframe at a kingpin axis, which defines a caster angle with respect to the vertical. The kingpin axis is spaced by a trail dimension from the rear axle axis. The caster angle and trail dimension, together with the wheelbase dimension between the front and rear axle axes and the track dimension across the rear wheels, are chosen cooperatively to define the desired handling characteristics of the vehicle.

대표청구항 ▼

1. A vehicle, comprising: a front subframe; a seat for a rider fixed to said front subframe; a front wheel, journaled to said front subframe at a front axle axis; a rear subframe; a pair of rear wheels spaced transversely from one another by a track dimension on either side of said rear subfr

1. A vehicle, comprising: a front subframe; a seat for a rider fixed to said front subframe; a front wheel, journaled to said front subframe at a front axle axis; a rear subframe; a pair of rear wheels spaced transversely from one another by a track dimension on either side of said rear subframe, and journaled for rotation about a rear axle axis spaced by a wheelbase dimension from said front axle axis; wherein said rear subframe is journaled to said front subframe at a kingpin axis behind said seat by a freely-pivoting journaled connection, such that said vehicle is steered by leaning said front subframe in the desired direction of turning, said kingpin axis being inclined to the vertical by a caster angle, and said kingpin axis being spaced from the rear axle axis by a trail dimension, said wheelbase, track, and trail dimensions and said caster angle being chosen cooperatively to provide desired handling characteristics to said vehicle, such that the vehicle is stable in operation. 2. The vehicle of claim 1, wherein when said caster angle is approximately 28° and said track dimension is at least approximately 50% of said wheelbase dimension, said trail dimension is at least 20% of said wheelbase dimension. 3. The vehicle of claim 1, wherein said rear subframe is journaled to said front subframe by cooperating coaxial members defining said kingpin axis. 4. The vehicle of claim 1, further comprising a pair of pedals journaled with respect to said front subframe and adapted to receive the feet of the rider and transmit torque therefrom to said front wheel to propel said vehicle. 5. The vehicle of claim 4, wherein said rear wheels are journaled for free rotation about said rear axle axis. 6. The vehicle of claim 1, wherein said seat for a rider comprises a seat portion and a back rest portion, and both seat portion and said back rest portion are fixed to said front subframe. 7. The vehicle of claim 6, further comprising a pair of handgrips fixed to said front subframe. 8. The vehicle of claim 1, wherein said trail dimension is at least about 24% of said wheelbase dimension. 9. The vehicle of claim 1, wherein said front and rear subframes are molded plastic members defining said front and rear axle axes and said kingpin axis. 10. A vehicle, comprising: a front subframe; a seat for a rider fixed to said front subframe; a front wheel, journaled to said front subframe at a front axle axis; a rear subframe; a pair of rear wheels spaced transversely from one another by a track dimension on either side of said rear subframe, and journaled for rotation about a rear axle axis spaced by a wheelbase dimension from said front axle axis; wherein said rear subframe is journaled to said front subframe at a kingpin axis behind said seat by a freely-pivoting journaled connection, said kingpin axis being inclined to the vertical by a caster angle, and said kingpin axis being spaced from the rear axle axis by a trail dimension, and wherein when said caster angle is approximately 28° and said track dimension is at least approximately 50% of said wheelbase dimension, said trail dimension is at least 20% of said wheelbase dimension, such that the vehicle is stable in operation.