This in turn operates the lever L through rod R and a bell-crank attachment, as shown in the right-hand view.
The car is drawn to the rear end of the track and held by the bell-crank lever A (Plate 23).
When in operation, the bell-crank is rotated in the direction of the arrow by the action of the wrist-plate and connecting-rod.
A short rope spliced round a thimble in the eye of the bell-crank, with a double wall-knot crowned at its end.
Referring to Fig. 23, A is a bell-crank which turns loosely upon the valve stem V.