Abstract: An improved model railroad coupler includes a shank having a proximal end and a distal end. The proximal end is shaped to define a joining element for attaching the model railroad coupler to a unit of model railroad rolling stock and the distal end is shaped to define a head. A knuckle having a hook is mounted on the head for limited rotational movement between a closed position and an open position. A trip pin is mounted on the knuckle for rotating the knuckle from the closed position to the open position when urged to do so. A spring which is disposed inside the shank provides a force to the knuckle to bias the knuckle to pivot into a closed position. In one embodiment of the invention the shank is a one piece member and the spring is a leaf spring which is separate from the knuckle and the shank.