Pinion of 60 teeth will give two loops inwards, if the motions are similar, but, if the motions are contrary, it will produce an ellipse of any proportion from a straight line to a circle.
Other combinations will give circulating or overlaying loops.
By the different arrangements of wheels and pinions on the plates N, N any number of loops can be produced up to 2,592 in the circle.
On the opposite page we illustrate some work executed with this chuck by Mr. Plant.
[Fig. 3] is a side elevation of the chuck full size.
A, A, the foundation plate screwing on the nose of the mandrel, and carrying the whole of the other parts of the chuck.
B, C, the two driving wheels giving an independent motion to the chuck.
D, D, angular wheel moving freely on the wheel C, for the angular adjustment of the figures.
E, E, pinion of any number of teeth fitting on the shaft carrying C and D.
H, H, large wheel of 120 teeth, forming foundation of the second part, and driven from the pinion E by the wheels F, G, and T.