Patent ID: 8439379

Claim:
In a bicycle having a main frame, a rear wheel driven by a foot operated crank assembly, a front wheel, a front fork having an upper and lower end, said front wheel being rotatably journaled in the lower end of said front fork, the upper end of said front fork being rotatable relative to said frame for steering said bicycle, said bicycle comprising: a handle bar connected to the upper end of said front fork, said handle bar being rotatable along a generally horizontal axis whereby it is reciprocably movable in a forward and rear direction, said handle bar including first and second, downwardly extending struts having lower ends; a drive sprocket rotatably journaled in a subframe connected to said main frame forward of said fork, said drive sprocket being connected by an endless chain to a driven sprocket connected to said front wheel; a first linkage comprising first and second arms, said first arm being pivotally connected to a lower end of said first strut and pivotally connected to said second arm, said second arm being fixedly connected in driving relationship to said drive sprocket, said first arm being longer than said second arm; a second linkage comprising third, fourth and fifth arms, said third arm being pivotally connected to said lower end of said second strut and pivotally connected to said fourth arm, said fourth arm being pivotally connected to said fifth arm, said fifth arm being fixedly connected in driving relationship to said drive sprocket, said third arm being longer than said first arm, said fifth arm being intermediate in length between said first arm and said second arm, and said fourth arm being shorter than either of said first, second, third or fifth arm; and said first linkage serving primarily to drive said sprocket between first and second substantially over center positions in response to reciprocal movement of said handle bar, said second linkage serving to move said first linkage over center in said first and second over center positions in response to reciprocal movement of said handle bar.