Continuously variable transmission

A variable ratio transmission for transferring torque between an input port and an output port, the variable ratio transmission comprising:

• (a) a first transmission shaft rotatable about a first axis and configured to provide a first of the input and output ports;
• (b) a series of at least two conical gear wheels of different sizes and having different numbers of gear teeth, each of said conical gear wheels being mounted upon, and rotationally coupled to, said first transmission shaft in such a manner as to define a predefined range of angular motion through which said conical gear can turn relative to said first transmission shaft about said first axis, said series together being a conical external profile at an angle θ to said first axis;
• (c) a second transmission shaft rotatable about a second axis and configured to provide a second of the input and output ports, said second axis being disposed at an angle θ relative to said first axis;
• (d) a sliding gear wheel slidingly engaged with said second transmission shaft so as to rotate together with said second transmission shaft while being slidable in a direction parallel to said second axis, said sliding gear wheel being configured for driving engagement with any one of said conical gear wheels;
• and
• (e) an actuator associated with said sliding gear wheel and configured to displace said sliding gear wheel along said second transmission shaft parallel to said second axis between positions corresponding to selective engagement with each of said conical gears, thereby varying a drive ratio between said first and second transmission shafts.