Energy & Power

• 

  Ericsson’s Patent Model of a Marine Steam Engine – ca 1858

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 20,782 issued to John Ericsson of New York, New York on July 6, 1858. The patent was for improvements in marine steam engines for powering a screw propeller. Mr. Ericsson’s goal was to maximize the power and compactness of the engine so that it could be located transversely and very low within a boat.

  His design consisted of two compact steam cylinders which were bolted together and mounted horizontally across the beam of the ship. They drove a single propeller shaft via a system of push rods and rocker arms. The design allowed for even application of power with reduced vibration and wear on engine parts and the frame of the ship.

  Mr. Ericsson was a prolific inventor; his inventions included many types of steam engines and associated apparatus as well as air engines. He was the designer of the USS Monitor for the North during the Civil War, and the engine for the Monitor was based on this patent.

  The patent model is made of brass and is mounted on a wood base representing a section of the hull of a ship. A brass plate on the base of the model is engraved “Screw Propeller Engine, J. Ericsson, Inventor.” All of the key elements of the patent are illustrated by the model which was provided with a crank on the propeller shaft to allow operation for demonstration. A full description of the operation of the engine along with complete diagrams can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1858

  patent date

  1858-07-06

  inventor

  Ericsson, John

  ID Number

  MC.251295

  catalog number

  251295

  patent number

  20,782

  accession number

  48865

  Data Source

  National Museum of American History

• 

  Merritt Propelling Apparatus, Patent Model

  Description

  This brass, steel, and wood patent model accompanied the patent application for Daniel S. Merritt's crank paddle, which claimed advancement over the common steamboat paddle wheel. The application received patent number 89,231 on April 20, 1869. Merritt, a resident of Mount Morris, Michigan, also held a patent for increasing the motion of an engine (no. 81,393; August 25, 1868).

  The principle of this invention is similar to that of other steamboat paddles patented in the nineteenth century. Sets of paddles are fastened to a common frame or bar. Using cranks, the paddles are plunged into the water, swept backward, and then lifted clear for another pass, in a manner similar to the action of oars. There is little in Merritt's design to set it apart from the others, except that the depth of his paddles in the water is adjustable, to suit variations in draft of the vessel. Merritt claimed that "no swell is caused by these paddles, rendering them particularly applicable to the propulsion of vessels upon canals," where swells tended to erode the canal banks.

  Location

  Currently not on view

  Date made

  1869

  patent date

  1869-04-20

  inventor

  Merritt, Daniel S.

  ID Number

  TR.308547

  catalog number

  308547

  accession number

  89797

  patent number

  89,231

  Data Source

  National Museum of American History

• 

  Carpenter Compound Hydraulic Engine, Patent Model

  Description

  The model was submitted to the U.S. Patent Office with the application for the patent issued to Oramill C. Carpenter, of Brooklyn, New York, December 17, 1878, no. 210915.

  The engine is essentially a hydraulic transmission, which takes motion from eccentric cams on a central shaft turned by a steam or other engine and transmits the motion to shafts on either side of and parallel to the central shaft. The inventor designed the engine to be applied to a streetcar, and the model is mounted in a miniature nickel-plated car truck.

  It is a 4-cylinder engine with opposed cylinders in groups of two. Single-acting plungers work in and out of the cylinders as the central shaft is turned. The head of each cylinder leads directly to another cylinder of reduced diameter in each of which a driven piston works through a longer stroke in time with the short stork of the driving piston. Valves for the relief of an excess pressure of liquid and spring-cushioned piston heads are described for smoother running.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1878

  patent date

  1878-12-17

  inventor

  Carpenter, Oramill C.

  ID Number

  MC.309252

  catalog number

  309252

  accession number

  89797

  patent number

  210,915

  Data Source

  National Museum of American History

• 

  Gilman’s Patent Model of a Valve for an Oscillating Steam Engine – ca 1851

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 7,871 issued to Samuel H. Gilman of Cincinnati, Ohio on January 1, 1851. Mr. Gilman’s patent was for an improvement in the design of valve gear for an oscillating steam engine. An oscillating steam engine differs from a standard engine in that the steam cylinder is pivoted on the engine frame and oscillates up and down about the pivot as its connecting rod operates the crankshaft of the engine. In a standard engine, the cylinder is fixed in orientation, and the piston rod moves fore and aft within a crosshead which allows the connecting rod to pivot independently as the crankshaft revolves.

  Mr. Gilman did not claim as new an entire design of such an engine. He limited his claim to a modification of the tube that guides the pushrod which controls the steam valve. He included threads at the bottom of the rod and shaped that portion so that it could clamp and secure the ball at the end of the pushrod. When threaded into the collar on the valve housing it allowed the pushrod to move slightly to conform to the motion of the valve house. He referred to his improvement as a “tubular nut.” The patent did not elaborate on exactly what Mr. Gilman claimed for improved function.

  The model as shown in the image illustrates all of the key elements of the patent. It is constructed of metal and mounted on a wooden base. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov).

  Location

  Currently not on view

  date made

  1851

  patent date

  1851-01-01

  inventor

  Gilman, Samuel H.

  ID Number

  ER.325617

  accession number

  249602

  catalog number

  325617

  patent number

  7,871

  Data Source

  National Museum of American History

• 

  Pitts’ and Gluyas’ Patent Model of a Steam Condenser – ca 1872

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 131,779 issued to Washington R. Pitts and George K. Gluyas of San Francisco, California, on October 1, 1872. The claim of the inventors was a new design for an improved high pressure condenser for a steam engine. The purpose was for the steam exhausted from the engine’s cylinder to be passed through the condenser and be converted back to water and returned to the boiler for reuse.

  The condenser design was intended for use on side-wheel steam boats. It would be located behind the paddle wheel where the water splashed up by the wheel would pass over the condenser and in the process cool the hot steam inside the condenser. The condenser consisted of a series of tubes passing between chambers at each end as shown in the image. Steam entered the condenser via an opening at the bottom left (not shown) and any remaining steam could be exhausted via the outlet pipe shown at the bottom right. This outlet had a valve that would cover it in normal operation since the goal was to have the steam converted to water prior to exiting. However, the engineer could open the valve as needed in operation to reduce any undue buildup of steam pressure within the condenser. The condense water exited via a series of tubes not shown at the back of the picture.

  Note, that the condenser was intended to be mounted with the steam exhaust up and to the right and the condense water outlet pipes on the bottom. The chambers at each end of the condenser were divided into compartments to cause the steam to travel back and forth two times prior to reaching the exhaust. The compartments were of decreasing volume with fewer tubes contained within them (seven rows of tubes in the first diminishing to four in the last) as can be seen by the grouping and gaps between tubes in the image. The intent was to balance the amount of condense water collected throughout the condenser.

  To control the flow of condense water and prevent steam pressure from blocking it, Pitts and Gluyas provided metal flanges over each of five exit holes for the water. The inventors did not claim as new the tubing, chambers and valves. Their claim was based primarily on two details. The first was division of the chambers at each into compartments having diminishing volumes. The second was the inclusion of the covers over the outlet pipes. Research of available trade literature and other sources has not revealed any commercial product that may have made use of this invention.

  The patent model is constructed of brass. The end plate is inscribed “Wash’n R. Pitts and Geo. K. Gluyas, San Fran’co.” The key features of the invention are illustrated by the model to include the end chambers, tubing, condense water outlet pipes, steam inlet, and the steam outlet with rubber valve. Diagrams showing the complete design can be found in the patent document online at www.uspto.gov.

  Location

  Currently not on view

  date made

  1872

  patent date

  1872-10-01

  inventor

  Pitts, Washington R.

  Gluyas, George K.

  ID Number

  ER.309239

  accession number

  89797

  catalog number

  309239

  patent number

  131,779

  Data Source

  National Museum of American History

• 

  Baldwin's Patent Model of a Flexible Beam Locomotive - ca 1842

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 2,759 issued to Matthias W. Baldwin on August 25, 1842. Baldwin’s invention was a design for a flexible beam truck for the driving wheels of a locomotive. The goal of the design was to increase the proportion of the engine’s total weight resting on driven wheels thus improving traction and thereby the ability of the engine to pull heavier loads. While then existing locomotives had multiple driven axles, their designs made them unsuitable for use on the tight curves that were common on American railroads at the time. Baldwin’s design allowed for multiple driving wheel axles to be coupled together in a manner that would allow each axle to move independently so as to conform to both to sharp curves and to vertical irregularities in the tracks. The “flexible beam” referred to heavy iron beams that were connected to each side of the engine’s frame with a vertical, spherical pin so that they could pivot horizontally and vertically in relation to the frame. The beams on each side of the frame moved independently of each other. At each end of the beams were journal boxes for the axles, and these boxes were constructed to an earlier Baldwin patent with cylindrical pedestals that allowed them to rotate vertically inside the beam. The result was that when rounding a curve one driving axle could move laterally in one direction while the other axle could move independently in the other direction thus adapting the wheels to the curve while at the same time keeping the axles parallel to each other. The coupling rods were made with ball-and-socket joints to allow them to adapt to the varying geometry due to lateral axle motion. While this geometry would also result in the coupling rod lengths varying as the axles moved laterally, in actual use the variation was very small – on the order of 1/32 of an inch – and was allowed for via a designed-in slackness in the bearings. The patent was applied by Baldwin to a large number of engines manufactured up until 1859 when the design was superseded by heavier and more advanced engines.

  The patent model is constructed of wood and metal and is mounted on rails attached to a wooden base. A brass plate attached to the boiler is inscribed with “M.W. Baldwin Philadelphia.” The boiler is painted wood as are the cylinders and coupling rods. The engine frame is steel, and the wheel rims are made of brass. The key element of the patent, the flexible beams are present on the front two axles. The beams and leaf springs are made of wood. The vertical pins appear to be made of steel. While the axle journal boxes are shown it appears the details of the cylindrical pedestals and other moving parts are not modelled.

  date made

  ca 1842

  ca. 1842

  patent date

  1842-08-25

  inventor

  Baldwin, Matthias W.

  ID Number

  TR.251274

  catalog number

  251274

  patent number

  2,759

  accession number

  48865

  Data Source

  National Museum of American History

• 

  Model for "Columbus Door"

  date made

  after 1858

  maker

  Peale, Titian Ramsay

  ID Number

  PG.66.21.26

  catalog number

  66.21.26

  accession number

  263060

  Data Source

  National Museum of American History

• 

  Corliss' Demonstration Model of a Steam Engine Valve Gear and Spring Dash Pot

  Description

  This is a crank-operated demonstration model of an early type of Corliss detachable rotary valve gear. The model is constructed of partially painted bronze and mounted on a walnut base. In the image the rotary valve is located in the wooden block at the upper left. The valve stem terminates in a short lever by which the valve is rotated. This lever is permanently connected to a plunger in a closed cylinder or dash pot located below the valve. A hook or latch is operated up and down in a position so that the hook engages with the lever on its upstroke and rotates the valve to open it. A stiff flat spring holds the hook against the lever while a bearing pin is located so that it will disengage the hook from the valve stem lever after the hook has raised it a determined amount. When the lever is freed a spring closes the valve. The dash pot prevents the too rapid closing of the valve.

  Corliss was a prolific inventor of steam technology in the middle 1800s and was the founder of the Corliss Steam Engine Company. His engines were used worldwide, and his designs were adopted by other engine manufacturers.

  ID Number

  MC.309816

  catalog number

  309816

  accession number

  109438

  Data Source

  National Museum of American History

• 

  Ericsson’s Patent Model of a Cross-Compound Steam Engine – ca 1849

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 6,844 issued to John Ericsson of New York, New York on November 6, 1849. The patent was titled “Arrangement of Engine for Using Steam Expansively.” In a common engine design of the time, high pressure steam from a boiler was introduced to the engine’s cylinder for only a portion of the stroke. The steam “cut-off” valve was then closed, and the steam’s expansive force did the remainder of the work for that stroke. This saved fuel because of the reduced need for continuous high-pressure steam.

  The goal of Mr. Ericsson’s invention was to improve the ability of an engine to use the expansive force of steam for efficiency while still providing uniform power throughout the stroke of the engine. In his design the resistance applied to the piston rod by the load on the engine decreased in the exact ratio of the decreasing pressure of the steam as it expanded in the cylinder. He achieved this by using two cylinders of differing sizes and exhausting the steam from the smaller cylinder into the larger. At the same time, steam pressure was balanced on both sides of the piston of the smaller cylinder. The relative sizes of the cylinders were carefully chosen to equalize the force on the engine’s crankshaft. The patent application claimed that this equal force was maintained even with the steam expanded by a factor of over twenty. This was a significant improvement over existing designs.

  Mr. Ericsson was a prolific inventor; his inventions included many types of steam engines and associated apparatus as well as air engines. He was the designer of the USS Monitor for the North during the Civil War and designed its engine as well as numerous other marine steam engines.

  The patent model as shown in the image is constructed of wood. All of the key elements of the patent are illustrated by the model including the arrangement of the crankshafts and the steam valves and their operating mechanisms. Diagrams showing the complete design of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1849

  patent date

  1849-11-06

  inventor

  Ericsson, John

  ID Number

  MC.251299

  catalog number

  251299

  accession number

  48,865

  patent number

  6,844

  Data Source

  National Museum of American History

• 

  Oceanarium, Coney Island

  Location

  Currently not on view

  date made

  1930s-1940s

  ID Number

  2013.0327.0480

  catalog number

  2013.0327.0480

  accession number

  2013.0327

  Data Source

  National Museum of American History

• 

  Fowler’s Patent Model of a Furnace Steam Boiler - ca 1856

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 15,803 issued to David H. Fowler of New Orleans, Louisiana on September 30, 1856. Mr. Fowler’s patent was for a new design for a boiler with both internal and external flues . The goal of the two flues was to increase the amount of boiler surface area exposed to the hot combustion gases from the furnace. His design called for a central boiler that was mounted above the furnace. The three supporting legs for the boiler surrounded the furnace and were tubes that allowed the introduction of water into the boiler via the legs. The internal flue passed through the center of the boiler and was surrounded by the water. Combustion gases flowed upward through this flue, transferring heat to the water. The external flue was implemented via a four inch space between the boiler’s side and the surrounding brickwork. This space ran around the entire circumference of the boiler. This allowed a portion of hot combustion gases to also heat the external wall of the boiler, significantly increasing the surface area of boiler metal being exposed to the gases. The external flue was capped at the top of the brickwork, and horizontal openings were provided at regular intervals around the circumference which communicated with the external flue. The chimney was located above the external flue, and a separate pipe connected the internal flue to the external. In 1861 Mr. Fowler advertised as a Steam Boiler Manufacturer in New Orleans. Research of available trade literature and other sources has not revealed any additional commercial use that may have made use of Mr. Fowler’s invention.

  The patent model is constructed of unpainted tinplate. It illustrates the central boiler and its internal and external flues as well as the brickwork surrounding the boiler. The aperture at the top for the external flue is present. The furnace door is modelled as are example apertures in the brickwork for ashes to be removed from the external flue. At the bottom of the boiler a single valve or cock for the introduction of water into the boiler via its three supporting legs is modelled. Diagrams showing the complete design can be found in the patent document online and are helpful in terms of understanding the orientation of the boiler and the surrounding brickwork (www.USPTO.gov/patents/process/search/index.jsp).

  Location

  Currently not on view

  date made

  ca 1856

  patent date

  1856-09-30

  inventor

  Fowler, David H.

  ID Number

  1997.0380.01

  catalog number

  1997.0380.01

  accession number

  1997.0380

  patent number

  15,803

  Data Source

  National Museum of American History

• 

  Corliss' Patent Model of a Steam Engine Cut-Off Valve – ca 1859

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 24,618 issued to George H. Corliss of Providence, Rhode Island on July 5, 1859. The patent was for an improved cut-off valve gear for steam engines. With this patent Corliss was seeking to improve the ability of the gear to operate at higher speeds than were possible with his earlier patent for a similar device. The patent represents the first valve gear to combine all the elements of what would become known as the typical, and very popular, Corliss engine. These include a detachable inlet valve link, variable timing wedge, a spring for closing the inlet valve, a dash pot to prevent jarring in closing the valves, and rotating valves.

  Corliss' design provided a means of adjusting the point in the power stroke of the engine’s piston at which high pressure steam being fed to the cylinder was cut off. This was desirable as power was extracted from the expansive force of the steam after the valve closed. This saved fuel by avoiding continuing use of high pressure steam.

  A primary feature of the patent is the mechanism shown at the top of the image of the model. It is the small steel piece of metal with a hook at its right end which engages a similar hook on the steam inlet valve stem extending to the right. The two hooks remain engaged by spring pressure until the valve stem is moved to the point that the inclined brass plate at the left overcomes the spring tension. The brass plate is moved laterally to change the point at which the toe and tooth disengage. As soon as they disengage another spring forces the inlet valve stem to close the valve.

  Corliss was a prolific inventor of steam technology in the middle 1800s and was the founder of the Corliss Steam Engine Company. His engines were used worldwide, and his designs were adopted by other engine manufacturers.

  The patent model is constructed of brass and mahogany. All of the key elements of the patent are illustrated by the model. In the image of the back of the model can be seen a hand crank for demonstrating operation of the valves which are also shown. Diagrams showing the complete design of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1859

  patent date

  1859-07-05

  inventor

  Corliss, George H.

  ID Number

  MC.308648

  catalog number

  308648

  accession number

  89797

  patent number

  24,618

  Data Source

  National Museum of American History

• 

  Benson’s Patent Model of a Steam Engine and Pump – ca 1847

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 5,185 issued to Benjamin S. Benson of Baltimore, Maryland on July 10, 1847. The patent was for an improved design for steam engines and pumps. It was a very early example of a “wobble disk” type of design, which has been used in many engine and pump designs.

  As seen in the image of the model, the engine consists of four single-acting cylinders placed around the axis of the shaft shown in the front right. A second shaft at the front left is connected to the piston rods of the cylinders via a crank arm and ball and socket joints. Ports located in the faceplate holding the cylinders admit and exhaust steam to each cylinder in turn as it rotates around the shaft axis. The angle between the two shafts causes the pistons’ lateral forces to be converted to rotational force as each piston is pushed out by the steam and then pulled back in due to atmospheric pressure.

  The third shaft seen at the rear of the model is coupled via bezel gears to the other two shafts and is used as the output shaft of the engine. Benson noted this was desirable to reduce stress on the piston rods and connecting arms. He noted that essentially the same mechanism could be used to pump fluids by applying external power to this shaft. The fluid would be pumped through the same valve mechanism as used for the engine.

  The patent model is constructed primarily of brass and steel and illustrates the important elements of Benson’s design. A full description of the operation of the engine 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.

  date made

  1847

  patent date

  1847-07-10

  inventor

  Benson, Benjamin S.

  ID Number

  MC.309197

  catalog number

  309197

  accession number

  89,797

  patent number

  5,185

  Data Source

  National Museum of American History

• 

  Corliss’ Patent Model of a Steam Pump - 1876

  Description

  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.

  Location

  Currently not on view

  date made

  1877

  1876

  patent date

  1876-12-19

  1877-05-22

  inventor

  Corliss, George H.

  ID Number

  ER.308694

  accession number

  89797

  catalog number

  308694

  patent number

  190,958

  185,390

  Data Source

  National Museum of American History

• 

  Ayer's Patent Model of a Refrigerator Car - 1876

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 184,029 issued to John M. Ayer on November 7, 1876. Ayer’s invention was a design for a railroad refrigerator car that would have improved insulation properties while also being lighter than other cars of the time. The ultimate goal of the improved design was to allow longer shipments of perishable goods without the cost and delay of ice replenishment. Ayer claimed that these goals were achieved without sacrifice in the strength or durability of the car. The basic idea of the patent was to create a double-walled car in which the inner and outer walls of the car were separated by air chambers. The roof of the car also had an air chamber between it and the inner ceiling. The air chambers were interconnected and vented to the outside air so as to permit circulation. This reduced the heating of the insulating air by prolonged contact with the exterior walls and roof when exposed to direct sun. The outer wall and roof were constructed of wood. The inner walls and ceiling were made from a layer of pasteboard (or similar paper product) and a layer of rubber . Both of these materials provided additional insulation, and the inner walls and ceiling were intended to be nearly air tight. The patent provided for double entry doors, and these were constructed of an outer layer of wood with an inner layer of the same pasteboard and rubber. The doors had beveled edges with the inner surfaces being smaller than the outer. The inner rubber surfaces were shaped to form a seal when the doors were secured thus adding to the airtightness of the car. Cars of Ayer’s design were constructed and used on railroads and were documented as still being used in 1903.

  The patent model is constructed of wood. There are two cut away sections, one on the side of the car and one on the roof. These show the essential elements of the patent - the air chambers and the inner wall and ceiling of the car. Double doors mounted in the side of the car are shown open to illustrate the seals and beveled edges.

  Location

  Currently not on view

  date made

  1876

  patent date

  1876-11-07

  inventor

  Ayer, John M.

  ID Number

  ER.325597

  accession number

  249602

  catalog number

  325597

  patent number

  184,029

  Data Source

  National Museum of American History

• 

  Benson's Patent Model of a Windmill - 1878

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 209,853 issued to Jesse Benson on November 12, 1878. Benson’s invention was an improved style windmill based on a turbine wheel. His claims included the advantages of simplicity, compactness, strength, and cost. He also claimed an improved and simpler governor mechanism. While most period windmills were simple fan designs with separate blades, other turbine wheel designs predated Benson’s patent. Benson’s improvements over earlier designs included simple and strong construction of the turbine wheel. It was based on a conical sheet metal frame that held six turbine blades, or flanges, that were narrow at the point of the conical frame and progressively broadened until they reached the rear of the frame. At that point the blades were bent so that they folded around the rear of the frame and served to strengthen the entire structure. The governor function was realized by bending a portion of the vane that projected beyond the rear of the turbine wheel. As the speed of the wind increased the bent portion of the vane applied force to the shaft of the turbine wheel so as to turn it to a shallower angle to the wind, thus spilling some of the force of the wind and keeping the windmill under control. Provisions were made for adjusting the amount of bend in the vane to accommodate varying local conditions of wind strength. A weighted cord attached to the vane's arm and extending to ground level allowed the user to lock the governor-vane at a 90 degree angle to the turbine wheel shaft. This would stop the windmill entirely.

  The patent model is constructed of wood and metal and is mounted on a wooden base. The model is painted red, white, and blue. The governor-fan is labelled “J. Benson.” The model illustrates the main elements of the patent including the turbine wheel and flange designs, the crankshaft, and the governor-fan. In its current condition, the model’s governor-fan has been straightened whereas a key element of the patent was the simple governor mechanism of bending the rear portion of the fan. The model also includes a thread representing the rope extending to the base of the windmill tower used to engage and disengage the windmill.

  Location

  Currently not on view

  date made

  1878

  patent date

  1878-11-12

  inventor

  Benson, Jesse

  ID Number

  MC.309133

  accession number

  89797

  patent number

  209,853

  catalog number

  309133

  Data Source

  National Museum of American History

• 

  White’s Patent Model of a Hot-Air Furnace - ca 1872

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 134,118 issued to Cyrus White of West Roxbury, Massachusetts on December 17, 1872. Mr. White’s patent was for improvements in the fresh air intake, ductwork, heat exchanger, and flue that would be used in conjunction with an overall furnace apparatus which was not a part of the patent. These components are shown in the accompanying image as upper and lower rectangular chambers interconnected by pipes. The drawings submitted as part of the patent application illustrate how a combustion chamber and a surrounding masonry structure would complete the overall heating installation. The drawings can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp). Fresh air entered the lower chamber via an opening on the right side. The cut out area at the left was the access for the combustion chamber which would have been located at the semi-circular metal collar shown above the air chamber. The upper chamber was the heat exchanger, the design of which White claimed as new in his patent. The exhaust gases from the combustion chamber entered via a hole located directly above the semi-circular collar previously mentioned. The exhaust was carried to a chimney through a hole at the right end of the heat exchanger. The hole seen at the left allowed access to the inside for cleaning and would have been closed by a door during operation. The vertical tubes seen in the image carried cold air upwards and through the outer casing of the heat exchanger where the air was heated. The heated air exited where these tubes reemerged from the heat exchanger on the top. White provided for additional heating to take place via smaller pipes that drew cold air from just outside of the heat exchanger. The inlets for these pipes can be seen just above where the larger pipes enter the heat exchanger. The smaller pipes communicated to a small chamber inside the outer heat exchanger case. Air heated in this chamber also exited at the top. White’s patent simply stated that the hot air exiting from the top could be conducted as desired to any apartments of the building. The other features claimed as new in the patent dealt with a set of “jet-holes” which were to be placed in a collar where the combustion chamber exhaust met the heat exchanger. The S-shaped tube seen between the cold air chamber and the heat exchanger provided fresh air to the jets. White claimed the resulting jets of air into the hot exhaust gases caused more complete combustion and better heating. White’s patent design led to the Cyrus White & Company, located in Jamaica Plain, MA. In 1888 it was noted that the company had been successful selling and installing White’s “Tropic” Furnaces.

  The patent model is constructed of unpainted tin plate and represents the key elements of the patent as shown in the image and described above.

  Location

  Currently not on view

  date made

  ca 1872

  patent date

  1872-12-17

  inventor

  White, Cyrus

  ID Number

  MC.251443

  accession number

  48890

  catalog number

  251443

  patent number

  134,118

  Data Source

  National Museum of American History

• 

  Corliss’s Patent Model of a Steam Engine – ca 1849

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 6,162 issued to George H. Corliss of Providence, Rhode Island on March 10, 1849, and reissued May 18, 1851. This is considered the first variable cut-off valve gear in which the point of the cut-off is determined by the engine governor. The patent was the first issued to George H. Corliss for steam engine improvements, and the model represents the original form of the Corliss steam engine.

  The patent is based on a walking beam steam engine, and the wooden patent model shown in the image represents the major features of such an engine. The crankshaft is at the left with the steam cylinder at the right. A small fly-ball governor can be seen to the left of the central column of the model. Steam inlet and exhaust valves are located at the top and bottom of the cylinder. The control rods for the upper set of valves are visible at the top left of the cylinder.

  The main feature of Corliss’ patent dealt with the operation and timing of the steam inlet valves. He provided a method for the governor to change the timing at which the high pressure steam was cut off during the stroke of the piston. If the engine speed increased beyond the desired speed, the movement of the governor caused a set of geared racks to disengage the control rods so as to close the inlet valves earlier. This caused the speed to decrease as engine power was reduced.

  Corliss was a prolific inventor of steam technology in the middle 1800s and was the founder of the Corliss Steam Engine Company. His engines were used worldwide, and his designs were adopted by other engine manufacturers.

  The patent model is constructed of wood with some metal parts. All of the key elements of the patent are illustrated by the model including the governor, the steam valves and their operating mechanisms. Diagrams showing the complete design of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1849

  patent date

  1849-03-10

  inventor

  Corliss, George H.

  ID Number

  MC.308646

  catalog number

  308646

  accession number

  89797

  patent number

  6,162

  Data Source

  National Museum of American History

• 

  Evaporating Salt Device Patent Model

  Description

  This patent model accompanied John Howarth’s patent application that received patent number 117,290 on July 25, The patent describes a process for extracting sulphate of lime (gypsum) from salt brine (concentrated sea water) by evaporating the brine and then superheating it.

  Location

  Currently not on view

  Date made

  1871

  patent date

  1871-07-25

  patentee

  Howarth, John

  inventor

  Howarth, John

  ID Number

  1999.0086.01

  catalog number

  1999.0086.01

  accession number

  1999.0086

  patent number

  117,290

  Data Source

  National Museum of American History

• 

  Hillson’s Patent Model of a Hot-Air Furnace - ca 1848

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 5,459 issued to Robert Hillson of Albany, New York on February 29, 1848. Mr. Hillson’s patent was for an improved design for hot air furnaces. Claimed advantages included the ability to circulate hot air via horizontal pipes to rooms on the same floor as the furnace; an improved design for air tight seals for doors entering into the furnace; the use of double-walled hot air ductwork to avoid heat loss and reduce the threat of fire; a fire grate design that prevented the coal from becoming packed and clogged; and an improved mechanism for dumping the cinders from the fire grate. The overall design of the furnace was a rectangular brick box mounted on a thick brick foundation. The upper portion of the furnace had double brick walls with four inches of space between the inner and outer. This provided channels for cold air to enter the furnace and circulate from its top to bottom. The interior of the furnace was a complicated series of brickwork chambers, flues and channels that circulated the hot gases from the firepot so as to expose large areas of hot surface to heat the air. The cylindrical fire pot and hot air chamber were mounted on a brick floor above the cold air chamber at the bottom of the furnace. The fire grate design, which Hillson claimed as new, was for a circular metal grate that had a semi-hemispherical raised section in the middle and a flat grate for the remainder of the area. Hillson claimed that this shape avoided the packing and clogging of the coal. Above the hot air chamber were located two doughnut-shaped compartments through which the hot gases from the combustion chamber passed. Air to be heated was in contact with the exterior of these compartments, and Hillson claimed the design offered greater heat radiating surfaces and better heating efficiency. A key claim made by Hillson was the ability to heat rooms on the same floor as the furnace via horizontal pipes. His idea was to draw the combustion air for his furnace from the rooms being heated. This produced a pressure differential between the furnace and the rooms thereby drawing the heated air from the furnace into the rooms. A review of available advertisements and trade literature of the period did not provide any information on the commercial development of Hillson’s patent. However, Hillson remained active in heating design until shortly before his death in 1888.

  The patent model is constructed of brass, lead, and painted wood. The model illustrates the various doors, air inlets, outlets, and flues as well as many of the interior details of the patent design including the grate, hot air chamber, air circular and smoke circular. The doors on the model have details of the tongue and groove seal that Hillson claimed added air-tightness to the furnace.

  Location

  Currently not on view

  date made

  ca 1848

  patent date

  1848-02-29

  inventor

  Hillson, Robert

  ID Number

  MC.251444

  accession number

  48890

  catalog number

  251444

  patent number

  5,459

  Data Source

  National Museum of American History

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