The Ratchet Socket Wrench: Turn the Nut Without Letting Go

In US 38,914 the handle A "may be of wood" and the metal shank B is made in two parts a and a′, screwed together. Their outer ends form eyes c in which two cylindrical bosses d, one on each side of the ratchet C, turn freely. Ratchet and bosses have a square opening e right through them, and into it fits a socket D with a square opening f and a flange g at one end. Two pawls, E and E′, sit on one pin h between the two parts of the shank: "One of these pawls, E, is a pulling one, and the other, E′, a pushing or shoving one." A spring F between them keeps both engaged. Swinging the handle one way (arrow 1) the pawls drive the teeth; the other way (arrow 2) they slip over them. "Several sockets, D, are used with the same wrench. These sockets are all of the same size externally, but the square openings f are of different dimensions to suit different-sized nuts." The patent names its purpose: cases where it would be "inconvenient or impossible, on account of a restricted space", to use an ordinary wrench.

Take the ratchet from a socket set, fit a socket on a nut clamped in the bench vise, and turn the handle one full revolution slowly, counting the clicks. Clicks per revolution is the number of positions the ratchet can take up; 360° divided by it is the smallest swing that gains ground. (Some ratchets use two offset pawls and click twice per tooth.) Now build a 'cramped corner': screw two offcuts of pine board to the bench either side of a hex bolt so that only a 30° swing is free. Try to run the nut down with a combination spanner, then with the ratchet. The spanner has to come off and be flipped at every stroke; the ratchet does not. Finally tighten the nut with the torque wrench to a set value and note how many ratchet strokes it took from finger-tight.

**J. J. Richardson** of Woodstock, Vermont, received US 38,914, dated 16 June 1863, for a ratchet wrench with a pulling pawl, a pushing pawl, a spring and interchangeable sockets. Its claim is the ratchet C with its two bosses turning in the eyes of the shank, combined with the pawls, spring and removable socket. **Honest limits.** Richardson's sockets had square openings, for square nuts. The tooth loads in the notebook are an example, not his dimensions. A ratchet is for running nuts; the highest torques are safer on a solid breaker bar.