Another word for coupling

There were no coupling rods.

While coupling or uncoupling vehicles..

In these the central bar which connects the two end links has screw threads cut upon it,;and by means of a lever can be turned so as either to shorten the coupling and bring the vehicles together till their buffers .are firmly pressed together, or to lengthen it to permit the end link to be lifted off the hook.

- Automatic Coupling for Freight Cars (U.S.A.).

The knuckle stands open until the coupling is pushed against another coupling, when the two hooks turn on their pivots to the position shown in fig.