CATALOG OF THE MECHANICAL COLLECTIONS g]^ 



In this design a flyball governor operates to increase the throw 

 of the engine valve eccentric as the engine speed increases. It is^ 

 one of the earliest of the automatically controlled shifting eccentric 

 types of governor. 



A slotted eccentric disk is carried in guides on the face of a pulley 

 fixed to the engine shaft. A gear-driven setscrew causes the eccentric 

 to move in or out relative to the center of the shaft as the screw is 

 turned. A bevel gear at the end of the screw meshes with another 

 gear on the end of a small spindle, which is carried parallel to the 

 crankshaft. On the other end of the spindle a small spur gear 

 meshes with an annular ring gear fastened to a friction disk, which 

 is free to turn on the shaft. This friction disk is held against the 

 face of a pulley that turns on the crankshaft in the same direction 

 but slightly faster than the shaft. The tendency of this combination 

 is to turn the annular gear faster than the shaft, causing the spur 

 gear to turn and move the setscrew in the direction to decrease the 

 throw of the eccentric. However, the annular gear is also fastened 

 to a brake drum, the band on which is tightened by the governor as 

 the engine speed increases. The effect of this is to hold back the 

 annular gear and turn the spur gear in the opposite direction, with 

 the result that the throw of the eccentric would be increased. By 

 adjusting the tension on the brake band so that it would overcome 

 the friction on the disk just sufficiently to permit the annular gear 

 to turn at the same speed as the shaft, at the desired speed of the 

 engine, the action of the governor would maintain this speed. 



STEARNS AND HODGSON ENGINE GOVERNOR, 1852 



U.S.N.M. no. 251287; original patent model; transferred from the United States 

 Patent Office ; not illustrated. 



This model was submitted with the application for the patent is- 

 sued to George S. Stearns and William Hodgson, of Cincinnati, Ohio, 

 August 31, 1852, no. 9236. 



The feature of this governor is the use of toothed sectors on the 

 weight arms meshed with a cylindrical rack instead of the usual pin 

 and link mechanism to actuate the governed gear. Otherwise it is a 

 simple flyball governor of the old form. 



PORTER WEIGHTED ENGINE GOVERNOR, 1858 



Plate 19, Figxjee 1 



U.S.N.M. no. 2512S9; original patent model; transferred from tlie United States 

 Patent Office; photograph no, 30368. 



The model formed part of the application for the patent issued to 

 Charles T. Porter, of New York, N. Y. July 13, 1858, no, 20894; 

 reissued June 21, 1859, no. T40. 



