Nikola Tesla U.S. Patent 517,900 - Steam Engine Patent Wrapper Page 8

80 2 in which the piston is free to reciprocate, or in other words, is not connected with a fly wheel or other like device for regulating or controlling its speed. The drawing hereto annexed illustrates devices by means of which the invention may be carried out, Fig. 1 being a central vertical section of an engine embodying my invention, and Fig. 2 a similar view of a modification of the same. Referring to Fig. 1, A designstes a cylinder containing a reciprocating piston B secured to a rod C extending through one or both cylinder heads. DD' are steam ducts communicating with the cylinder at or near its ends and E is the exhaust chamber or passage located between the steam ports. The piston E is provided with the usual passages F F' which by the movements of the piston are brought altermately into COFHmunication with the exhaust port. I G designates a slide valve which when reciprocated admits the steam or the gas by which the engine is driven, from the pipe G' through the ducts D D' to the ends of the cylinder. 2 The parts thus described may be considered as exemplifying any cylinder, piston and slide valve with the proper ports controlled thereby, but the slide valve instead of being dependent for its movement upon the piston -3