Thread twister

This machine was designed by Leonardo to automate the operation of twisting thread. This is the phase coming after the doubling of the thread, where the textile fibers are twisted to give more resistance to the thread. The innovative device, probably conceived for work at home, was to function without the spinner’s having to feed the machine by hand, and without accumulation of thread on the bobbin.
The large wheel, driven by the crank, is connected by a belt to a shaft on which the reel of doubled thread is fixed. When this thread passes through another small wheel, it is twisted and then wraps around the larger bobbin. To provide a uniform distribution of the spun thread, the bobbin also performs a back-and-forth movement owing to an ingenious system for transforming the rotary motion of the principal wheel into alternating motion.