drawbar

noun

1. An open-mouthed bar at the end of a car, which receives a coupling link and pin by which the car is drawn. It is usually provided with a spring to give elasticity to the connection between the cars of a train.
2. A bar of iron with an eye at each end, or a heavy link, for coupling a locomotive to a tender or car.

   “With multiple-unit electric trains one cannot quote figures of drawbar horsepower, because there is no drawbar, as such; […].”

3. A device to couple a powered road vehicle to a load to transfer tractive effort to the load, either as a push or as a pull.
4. A sliding bar on a Hammond organ, controlling the volume of a waveform.
5. A device for changing the tools on milling machines.