US Patent 7188853 Tricycle

A tricycle is comprised of a frame, a front wheel, a parallel four-bar linkage, two rear wheels, and two handlebars. The frame includes a stationary fork connected with the front wheel. The linkage is mounted at a rear section of the frame, having two side bars. The two rear wheels are rotatably mounted respectively to the two side bars. The two handlebars are fixed to the linkage and located beside bilateral sides of the seat cushion. The user can let the hands control the two handlebars to drive the tricycle to turn left or right and to enable the tricycle to lean sideward at the turning direction. While the tricycle runs faster, the turning steering can enable the tricycle to have “tail slide” effect.