Early Whitworth 6" lathe, complete with change wheels and contershaft

This 6-in workshop lathe made by Joseph Whitworth & Co will take work up to 39 in long. A four-speed cone, together with back-gearing, provides eight headstock speeds.

The controls for the saddle and tool slide are placed in the apron and include a lever for engaging a split nut with the lead-screw for screwcutting. Hand traversing is effected by a hand wheel and pinion which engages with a rack below the lathe bed. The cross-slide screw feed has a micrometer adjustment.

Both sliding and surfacing motions can be made self-acting by means of a drive taken from a slotted shaft at the back of the lathe bed. The shaft drives a worm wheel and a spur gear engaged with it, each of which drives a concentric cone, one connected with the traversing and the other with the surfacing motion. These cone clutches may be alternatively engaged by turning a handle at the front. This method of coupling, which was introduced by Shepherd, Hill 8 Co at the International Exhibition of 1862, can be adjusted to give way in the event of too heavy a cut being attempted, thus providing a factor of safety. The use of a separate driving shaft for the tool motions enables the lead-screw to be used for screwcutting only and preserves its accuracy.