Nikola Tesla U.S. Patent 511,916 - Electric Generator Patent Wrapper Page 16

( J 5ment of this object I have found it preferable to construct the engine so that it of itself controls the per iod, but as I have stated before, I may so modify the elements of the cambination that the electro-magnetic sy stem may exert a part ial or even complete control of the period. 40 In illustration of the manner in which the invention is carried out I now refer to the accompanying drawings: Fig. 1 is a central sectional view of an engine. and generator embodying the invention. Fig. 2 is a modi fi cation of the same. Referring to Figure 1 A is the main cylinder in which works a piston E. Inlet ports C C pass through the sides of the cylinder opening at the middle portion thereof and on opposite sides. Exhaust ports D D extend through the walls of the cylinder and are formed with branches that open into the interior of the cylinder on each side of the inlet ports and on opposite sides of the cylinder. The piston B is formed with two circunferential grooves E F which communicate through openings G in the piston with the cylinder on opposite sides of said piston respectively. The particular construction of the cylinder, the piston and the ports controlling it may be very much -723