Abstract: A stepless automatic variable transmission with gears in a state of constant meshing which is operational without the need for disengaging or changing the gears such that the rotational output power can be varied to effect a neutral, low speed, medium speed, high speed, overdrive or reverse rotation by selecting a stepless automatic speed change method or a manual speed change method, and which includes a speed change system, an overdrive system and a speed change controlling system.The assembly of speed change system (10, 110, 310, 410, 510, 610), the overdrive system (50, 360, 660, 760) and the speed change controlling system (80, 180, 380, 680, 780) can vary with each of the systems combined to result in numerous stepless automatic variable transmissions. To effect speed changes low speed, medium speed, overdrive, and reverse rotation brake means are used. Also, either the manual speed change method or the automatic speed change method can be selected.

Abstract: A transmission having an input shaft with a sun gear (12), a medium speed shaft with a sun gear (14) rotatably mounted on the input shaft, a low speed shaft with a sun gear (16) rotatable mounted on the medium speed shaft and a reverse rotation shaft with a sun gear (18) rotatable mounted on the low speed shaft. A first carrier and a second carrier terminating in an output shaft are rotatably mounted on the reverse shaft and input shaft, respectively. Locking pins interconnect first and second carriers. Reverse rotation gear is integrally formed with an input gear and rotatable mounted on a locking pin. Each reverse rotation gear meshes with the reverse sun gear (18) and each input gear meshes with sun gear (12). Low speed gears are integrally formed with a medium speed gear and rotatable mounted on a locking pin. Each low speed gear meshes with sun gear (16) and each medium speed gear meshes with the input gear and the sun gear (14).