To provide a safety-overload the connection between gearbox and feed shaft was by friction only through an ingenious and adjustable spring-loaded mechanism. It was also possible, if you trusted the set-up, to slacken the spring and use the device as an automatic "slip-stop" when machining up to a shoulder. The unit consisted of a cup (fitted to the output shaft from the box) with a flat bottom, parallel sides and an internal thread at the opening. On the end of the feed-shaft was a two-diameter boss with the larger, at the very end, fitting precisely into the cup and able to rotate freely within it. On the smaller diameter was a notched washer able to rotate on the boss, together with a spring to provide the necessary loading. A ring nut, with plenty of play on the inner part of the boss, screwed into cup's internal thread and pushed the components together. Passing through the wall of the cup was a round pin (visible in the photograph near the thread in the cup) that engaged with the notch in the washer and so transferred the cup's rotation to the feed-shaft. When the drive became overloaded, the washer would slide on the boss and the drive stop. To change the point at which the drive released it was only necessary to turn the ring nut and so alter the tension on the spring.

Simple, single-sided apron but well engineered with a decently long bronze leadscrew clasp nuts. The power cross-feed mechanism was built as a unit that bolted to the main structure. The feed was engaged by a keyed steel worm driving a worm wheel that formed one unit with a spur gear behind it - both in bronze. Note  the interlock arrangement to stop the feed and screwcutting being engaged simultaneously