This model was filed with the application to the U.S. Patent Office for Patent Number 185,390 issued to George H. Corliss of Providence, Rhode Island on December 19, 1876. The goal of the patent’s design was an efficient steam-driven water pump.
This patent was based in part upon his June 2, 1857 patent for the same purpose. That patent claimed a design for a steam pump that improved efficiency of fuel use while providing a well-regulated stream of pumped water. This was accomplished by multiple powered steam cylinders alternating with pump cylinders located around the circumference of a circular structure. Inlet and outlet water mains formed the framing of the structure. That design allowed for smooth and efficient pumping without the need for a flywheel. Corliss however desired to further improve the overall efficiency of the pump.
A principal goal of the Corliss design in Patent Number 185,390 was to provide for slow operation of the water pumps while allowing the steam engine driving the pump to work at high speed. It was known that slow pump motion was needed to allow the pump to fill and empty efficiently. However, steam engines could operate more efficiently when run faster and using the work from the expansion of steam in the cylinders.
The new patent improved upon the 1857 patent by eliminating the need for multiple steam-powered cylinders. A single steam cylinder, shown at the top of the image, was connected to a crankshaft that turned a small gear and a large flywheel at high speed. The small gear meshed with a larger gear plate upon which was mounted an offset crankpin that was connected to the pushrods for eight water pumps located around the circumference of the pump frame. The gearing allowed the goal of rapid steam cylinder and slow water pump speeds to be attained.
Corliss also made provisions in the patent design to drive the air-pump and feed-pump associated with a condensing type steam engine. The connection for the pumps was to the crankshaft for the small gear. A pushrod from that connection passed over the steam cylinder pushrod and operated a bell-crank on the engine framing. Rods at each end of the bell-crank operated the air and feed pumps which would be located below the primary pumping mechanism. The compact design of the pumping mechanism was claimed as another benefit that allowed installation in a small pumping-house. Corliss received a later patent which expanded upon the details of the air-pump mechanism.
The patent model is constructed of wood and metal. All of the key features of the invention are illustrated by the model to include the driving steam cylinder, pushrod, gearing, pump cylinders, and fly-wheel. The air-pump and feed pump pushrod is also shown, but not the bell-crank nor pump mechanisms. The details of the pump cylinder intake and outlet connections and valves are not modelled. Note that while the model shows a vertically mounted steam cylinder and pump frame, the intention of the patent was for horizontal mounting as can be seen in the patent application drawings. A full description of the invention along with complete diagrams of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.
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