A continuously adjustable transmission comprises a number of arms (18), one end of each of which is pivotably connected to a rotatably arranged driven first member (17) and of which the other end cooperates with a second rotatably arranged member (15). The axes of rotation (20) of the arms (18) are parallel to the axes of rotation of the members (15, 17) and are evenly distributed about a circle. The part of the second member (15) acted upon by the arms lies at a radial distance from the circle in which the axes of rotation (20) of the arms (18) are situated. Both members (15, 17) are movable in relation to each other between a concentric position in which the transmission ratio is 1:1 and an eccentric position for obtaining another transmission ratio. The arms (18) are situated in a common radial plane and the end of each arm which cooperates with the second member (15) has an elongated clamping member (19) pivotably connected with the arm (18) through an axially extending shaft (21). Each clamping member (19) is accommodated in a ring-shaped slot (22) in the second member (15). A spring (24) acts between each arm and the corresponding clamping member (19) in a direction such that opposite ends of the clamping member (19) will be urged to engage two opposite, substantially cylindrical walls (23) of the slot (22). The distance between the points where one clamping member (19) engages the opposite walls (23) is greater than the radial distance between the walls (23).

When an input shaft 6 is rotated by an external driving force, the resultant rotational force of the input shaft 6 is transmitted to an offset housing 21 of which rotational force in turn is transmitted to variable rings 39. If, at that time, angular volocities of the variable rings 39 are periodically varied relative to the angular velocity of the offset housing 21, the periodically varying angular velocities of the variable rings 39 are corrected to be substantially constant in a predetermined phase range, allowing only rotational forces having corrected angular velocities to be fetched from the variable rings 39 for transmission to an output shaft 7. Thus, by arbitrarily varying the angular velocities of the variable rings 39 relative to the angular velocity of the offset housing 21, the rotational speed of the output shaft 7 is steplessly varied relative to the rotational speed of the input shaft 7.

A vehicular drive system is presented which couples an infinitely variable automatic transmission to a constant speed electric motor. The drive system utilizes a battery powered DC motor having a no-load to full-load speed variation of less than 10 percent. The motor drives the input shaft of the transmission. The output of the transmission is coupled to drive the vehicle axle. Adjustment of the eccentricity of a cam plate within the transmission controls the speed and torque ratio between input and output shafts of the transmission. Eccentricity is varied as a function of tension on a spring in opposition to the forces developed on the cam plate by the transmitted torque. Spring tension is controlled by the pressure applied to an operator actuated accelerator pedal. The more the accelerator pedal is depressed, the greater will be vehicle acceleration and/or the steeper the hill that can be climbed.

The invention is a variable mechanical transmission for converting a rotary input into a rotary output. The transmission includes a spindle for mounting, allowing for rotation in response to the rotary input, a hub mounted on the spindle for rotation therewith, and a plurality of elongate arms. The arms are each pivotally mounted on the hub, with the pivoting axes of the arms being arranged about the spindle axis. Each arm carries at its outer end a clutched pinion which rotates in one direction only. The pinions engage the teeth of a gear. The gear is mountable on a frame for rotation about a gear axis paralleling the spindle axis and also for movement on a frame between concentric and extreme eccentric positions, at which the gear axis has a minimal and maximal displacement, respectively, from the hub axis. Also included in the transmission is shifting structure operable to shift the gear from its concentric toward its extreme eccentric position, and rotary output means coupled to the gear for rotation therewith about the gear axis, for producing a rotary output. The shifting structure may be controlled by an operator or shift responsively to a load on the transmission.