l^Q BULLETIN 173, U. S. NATIONAL MUSEUM 



This invention relates to a design of pump valves so controlled by 

 spindles and guides that the necessity of central bearings in the valve 

 seat is avoided, leaving a clear circular opening for the passage of the 

 fluid being pumped. 



The model represents a valve chest of a pump cylinder equipped 

 with four valves arranged in pairs, in which one valve is located above 

 the other. In each pair the valve stem of the upper valve projects 

 upward into a hollow plug in the top of the valve chest and downward 

 into a socket in the lower valve. The socket of the lower valve ex- 

 tends downward into a hollow plug or guide in the bottom of the valve 

 chest. Both valves are spring closed and the lower valve is free to 

 move independently of the upper valve. 



KNOWLES STEAM PUMP, 1879 



Plate 29, Figtjbe 1 



U.S.N.M. no. 309250 ; original patent model ; transferred from the United States 

 Patent Office ; photograph no. 32644C. 



This model was filed with the application for the patent issued to 

 Lucius J. Knowles, of Worcester, Mass., April 1, 1879, no. 213823. 



The model represents the steam cylinders of a duplex pump fitted 

 with what the inventor calls auxiliary engines to operate the valves 

 of each cylinder when it is desired to use one cylinder of a duplex 

 pump without the other. Actually the piston of the auxiliary en- 

 gine is the valve of the main cylinder and the invention is in effect 

 a one cylinder or "simplex" pump with steam-actuated valve. This 

 is one of the earliest uses of the steam-actuated valve for steam 

 pumps. 



The auxiliary cylinder forms the steam chest and valve ports of the 

 main cylinder while the auxiliary piston acts as the valve. The 

 auxiliary piston has its own valve system, which consists of ports in 

 the auxiliary cylinder wall connected to the main steam passages and 

 so located that they will register with openings in the auxiliary piston 

 when the auxiliary piston is given a slight twist at the end of the 

 main piston's stroke. These openings connect to passages in the 

 auxiliary piston that direct the steam pressure to the proper end of 

 the auxiliary cylinder to cause the auxiliary piston to move to the 

 other end of the cylinder and so reverse the stroke of the main piston. 



Lucius James Knowles (July 2, 1819-February 26, 1884) origi- 

 nated and developed the Knowles Steam Pump Co. and the L. J. 

 Knowles & Brother Loom Works at Warren, Mass., and Worcester, 

 Mass., both of which became leading organizations in their respective 

 fields. The Knowles steam pump was one of the best known of the 



