Energy & Power

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  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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  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

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  Webster’s Patent Model of a Hot-Air Furnace - ca 1866

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 55,564 issued to Edward W. Webster of Hartford, Connecticut on June 12, 1866. Webster’s patent was for improvements in efficiency and the ability to provide adjustable amounts of heated air to various apartments of a building. The furnace was cylindrical in shape and consisted of an inner cylinder which was surrounded by a slightly larger cylinder. The outer cylinder was intended to reduce radiation of heat inside the furnace room. Cold air entered into a compartment which was the diameter of the outer cylinder and located at the base of the furnace. A damper was provided to allow mixing of outside air and return air from the rooms being heated. This cold air was allowed to pass upward through the space between the cylinders as well as through a series of air-tubes around the circumference of the inner cylinder. These ran between the top of the cold air compartment up and through a plate near the top of the furnace (just below where the furnace tapers to a smaller volume as shown in the image of the model). The fire-pot, grate, and ash pit were located just above the cold air compartment. The combustion chamber was closed at the top by the plate through which passed the air-tubes. Thus, the air-tubes were surrounded by the hot combustion gases. The entire inner cylinder was also exposed to the combustion gas. Outside and return air was thus heated and rose upwards into the conical shaped plenum at the top of the furnace and then to the heated rooms via the ductwork. Webster claimed as new or improved in his patent a means for adding humidity to the heated air via an “evaporating dish” filled with water and located at the top of the plenum. He also claimed as new or improved a means of providing for the exhaust of the combustion chamber to be downwards via a funnel in the bottom of the furnace and then to the flue. He claimed this provided for more complete and even heating of the air-tubes and inner cylinder. A review of available advertisements and trade literature of the period did not provide any information on the commercial development of Webster’s patent. However, he was active in additional patents until at least the 1880s.

  The patent model is constructed of painted tin plate and is highly detailed in terms of modeling the key elements of the patent. These include the air tubes, humidifier pot, ductwork carrying heated air to registers, return air ductwork, the several mixing dampers, the fire-pot and grate, and the down draft mechanism. In the image of the model the white colored box at the top of the ductwork is intended to represent a single air return register and two separate heat registers.

  Location

  Currently not on view

  date made

  ca 1866

  patent date

  1866-06-12

  inventor

  Webster, Edward

  ID Number

  MC.251442

  accession number

  48890

  catalog number

  251442

  patent number

  55,564

  Data Source

  National Museum of American History

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  Adam’s Patent Model of a Stove Drum - ca 1868

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 85,196 issued to John Adams of Findlay, Ohio on December 22, 1868. His patent was for a new and improved design for a Stove-Drum . A stove drum was the element of a heater or furnace which heated air via contact with a large, hot metal surface. It would be located between the combustion chamber of the stove and the chimney. Mr. Adam’s design consisted of two truncated cones interconnected by flues. The lower cone was the entry point for the hot combustion gases and had an inner truncated cone which included a damper at its bottom. With the damper open the hot gases would travel directly upwards through a pipe that ran through the middle of the lower and upper cones and thence to the chimney. This resulted in the minimal amount of metal surfaces being exposed to the gases and thus the least heat being provided to the room. It also allowed a more direct draft for lighting the fire. With the damper closed the hot gases flowed in the volume between the inside and outside lower cones. A plate at the top of these cones allowed the gases to flow into the five flues that interconnected the upper and lower cones. A key element of Adam’s patent was the division of each flue into two halves via vertical partitions. After coming up through the lower cones, the gases entered the outer compartment of the flues where it then entered the upper cone and heated its outside surface. The gases would then flow back downwards through the inner compartment of the flues and into the inner lower cone which communicated with the chimney via the vertical pipe previously mentioned. With the damper closed the entirety of the surface of the stove-drum would be heated by the combustion gases, and this provided the maximum heating for the room. Research of available trade literature and other sources has not revealed any commercial product that may have made use of this invention by Mr. Adams. He did have one additional patent for a furnace which appears to be based in part on the principles of this stove-drum patent.

  The model is constructed of unpainted tinplate and represented the key elements of Adam’s patent. The upper and lower truncated cones are shown as are the interconnecting flues, the inner lower cone, and the damper. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp).

  Location

  Currently not on view

  patent date

  1868-12-22

  inventor

  Adams, John

  ID Number

  MC.251502

  accession number

  48890

  catalog number

  251502

  patent number

  85,196

  Data Source

  National Museum of American History

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  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

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  Fickardt’s Patent Model of a Furnace – ca 1836

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 23 issued to Frederick A. Fickardt of Easton, Pennsylvania on September 8, 1836. His patent was for an improvement in furnaces for heating the upper rooms of a building. He claimed as new the use of an inner and outer chamber with insulating material on the outer chamber to reduce loss of heat into the furnace room. A gap of three to four inches was provided between the inner and outer chambers to further reduce loss of heat into the furnace room. The stove, or combustion chamber, was located within the inner chamber. Access to it for fueling and cleaning was via doors in both the inner and outer chambers. The inner chamber was open at the bottom allowing fresh air entry. The flue of the stove exited through this chamber via a sealed pipe. Heated air in the inner chamber was supplied to rooms above the furnace via a larger pipe, or duct, surrounding the flue of the stove. A sliding lid for the hot air duct was provided to stop cold or foul air entering the heated rooms from the cellar when the furnace was not in use. One of Fickardt’s claims was “Immediate heat, great heat, and economy of heat, and consequently economy of fuel, money, time, patience, and domestic comfort are the advantages which the subscriber hopes he is but reasonably led to anticipate by these improvements.” Research of available trade literature and other sources has not revealed any commercial use that may have made use of Mr. Fickardt’s invention.

  The patent model is constructed of painted tinplate. The central stove can be seen through access doors in the inner and outer chambers. The stove flue and hot air ductwork are shown at the top of the model. The sliding lid for the hot air duct is also shown. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp). The diagram submitted with the patent shows the shape of the furnace to be rectangular with a sloping top while the patent model submitted is cylindrical with a conical top.

  Location

  Currently not on view

  patent date

  1836-09-08

  inventor

  Fickardt, Frederick A.

  ID Number

  MC.251441

  catalog number

  251441

  accession number

  48890

  patent number

  23

  Data Source

  National Museum of American History

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  Vera’s Patent Model of a Friction Heater – ca 1869

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 86,046 issued to Pedro Vera of Bogota, United States of Colombia, on January 19, 1869. Mr. Vera’s patent was for improvements in machines designed to create heat by friction, for the purpose of generating steam or warming apartments. The main element of his design was a series of rotating disks in contact with stationary diaphragms. The friction between the disks and diaphragms produced heat which would be transferred to the water or air in contact with them. The alternating disks and diaphragms were mounted on shafts with the diaphragms being held stationary by four small rods along their diameters and running the length of the shafts. The rotating disks were keyed to the shafts. In the patent description, four shafts were mounted vertically inside a sealed cylinder that was intended to be water and steam-tight and strong enough to withstand the steam pressure of ordinary boilers. Springs were mounted between the tops of the shafts and the top of the cylinder in order to press the disk/diaphragm assemblies together to increase friction as desired. Each of the shafts exited the top of the cylinder via stuff-box seals and was topped with a pinion gear. The pinion gears were driven by a central gear on a shaft extending down through the cylinder. A pulley at the top of this shaft would be rotated via a belt by a source of power. The speed of the drive pulley would control the amount of heat generated by the device. Research of available trade literature and other sources has not revealed any commercial use that may have made use of Mr. Vera’s invention.

  The patent model is constructed of brass. It illustrates the sealed case containing the disk mechanisms, the stuffing-box seals for the shafts to exit, and the pulley and gearing arrangement to drive the disks. An access door is provided on the model to allow visibility of the disks, diaphragms, supporting rods, and shafts. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp).

  Location

  Currently not on view

  patent date

  1869-01-19

  inventor

  Vera, Pedro

  ID Number

  MC.88881.001

  catalog number

  88881.001

  accession number

  088881

  patent number

  86,046

  Data Source

  National Museum of American History

• 

  Sturtevant’s Patent Model of a Hot Air Furnace - ca 1869

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 95,281 issued to B. F. Sturtevant of Jamaica Plain, MA on September 28, 1869. Mr. Sturtevant’s patent involved recirculating the air being heated in a room or apartment. He had developed improved designs for rotary blowers in the past, initially to provide ventilating air in the work areas of his factory which made wooden pegs for shoes. In this patent he combined the rotary blower, which would be driven by a steam engine, with a heat exchanger through which passed the exhaust steam of the engine. The exhaust steam travelled through the vertical openings shown in the center of the image of the patent model. The air to be heated passed through several horizontal pipes inside the heat exchanger cylinder. The steam heated these pipes which in turn transferred heat to the air. The blower is at the left of the model. Its inlet air came via the return duct at the right after passing through the heat exchanger. Heated air was forced by the blower into the room at the lower left. The inventor claimed his design improved the efficiency of a furnace by continuously reheating the same air. Only a portion of the heat was lost in the room being heated, and a significant energy savings was claimed over heating cold outside air.

  Sturtevant was extremely successful with this and his many other patents relating to heating and ventilation. In 1860 he founded the B. F. Sturtevant Co. which was successful and long lived; Westinghouse bought the company in 1945, and operations continued at the Hyde Park, MA factory until its closing in 1989. The company’s equipment was installed in many private and public buildings including the U.S. Capitol and the “New National Museum, Washington, D.C” – now the Smithsonian National Museum of Natural History.

  The patent model is constructed of wood and metal. It represents the central duct work, heat exchanger, and rotary blower of Sturtevant’s patent. The air pipes are modelled inside the heat exchanger.

  Location

  Currently not on view

  date made

  ca 1869

  patent date

  1869-09-28

  inventor

  Sturtevant, B. F.

  ID Number

  ER.308677

  catalog number

  308677

  accession number

  89797

  patent number

  95,281

  Data Source

  National Museum of American History

• 

  Sturtevant’s Patent Model of a Heating and Ventilating Apparatus – ca 1870

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 100,211 issued to B. F. Sturtevant of Jamaica Plains, MA on February 22, 1870. The patent described a forced air heating system consisting of a steam producing boiler, a steam engine to drive a centrifugal wheel fan for circulating air, a heat exchanger to heat the air via the combustion products of the boiler, a condenser utilizing the circulating air to return the steam to water for reuse, and a series of duct work and valves. The patent model illustrates only the central duct work, heat exchanger and steam condenser. Diagrams showing the complete heating and ventilating apparatus design can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp). In the image the upper cylinder is the steam condenser. The cylinder at the bottom represents the heat exchanger. The opening at its front is where the combustion gases from the boiler would exit via a flue or chimney. Cold air entered at the ducts at the lower right. Two separate intakes are shown – the bottom was for fresh air from outside the building and the upper for recirculated air from heated rooms. A valve allowed engineers to regulate the ratio of outside to inside air. Hot air exited at the right side of the condenser via the ductwork which was connected to the engine-driven fan’s inlet. The heated, pressurized air exited from the fan into a series of ducts that would supply heat to various parts of the building. The patent also made provisions for domestic water heating by utilizing some of the condenser’s hot water for that purpose. Sturtevant claimed his design increased efficiency by making use of hot flue gases as the primary source to heat air but also by using the remaining energy of the steam in the condenser to further heat the air. Sturtevant was extremely successful with this and his other patents (no less than 10 patents dealing with heating and ventilation were granted to him on the same day as this patent). In 1860 he founded the B. F. Sturtevant Co. which was extremely successful and long lived; Westinghouse bought the company in 1945, and operations continued at the Hyde Park, MA factory until its closing in 1989. The company’s equipment was installed in many public and private buildings including the U.S. Capitol and the “New National Museum, Washington, D.C” – now the Smithsonian National Museum of Natural History.

  The patent model is constructed of brass and tin. It represents the central duct work, heat exchanger, and steam condenser of Sturtevant’s patent. The flue pipes are modelled inside the heat exchanger. The valves controlling the mixture of fresh and recirculated air are present within the inlet duct. A model of the pipe carrying exhaust steam to the condenser is also included.

  Location

  Currently not on view

  date made

  ca 1870

  patent date

  1870-02-22

  inventor

  Sturtevant, B. F.

  ID Number

  MC.308725

  catalog number

  308725

  accession number

  89797

  patent number

  100,211

  Data Source

  National Museum of American History

• 

  Handle from a Bed Warmer

  Description

  Turned wooden handle from a patent model (U.S. Patent No. 146,577) of a bed warmer, made by Job Crockett of Portsmouth, OH, and patented on January 20, 1874. No marks.

  Location

  Currently not on view

  patent date

  1874-01-20

  ID Number

  DL.251772

  catalog number

  251772

  accession number

  48890

  patent number

  146577

  Data Source

  National Museum of American History

• 

  Fireplace Patent Model

  Description

  Patent model of a freestanding, raised-hearth fireplace having a detachable oval firebox with removable, fully-enclosed, picketed chamber. Firebox rests atop central recess in hearth directly in front of a conforming concave back covered with embossed metallic-gold paper featuring a trumpeting winged angel next to a rayed sun. Flue at top back of firebox inserts into a corresponding slot in mantel that connects to a horizontal smoke pipe, oval in section, behind the frieze. Large rectangular opening in hearth front allows access to ashpit; diamond piercings at front corners and sides. Entire model japanned black with "THOMAS WHITSON'S / INVENTION" stenciled in yellow or metallic gold paint on mantel top and frieze. Soldered and riveted construction.

  Paper tags tied to hearth with red and purple (faded) wove ribbon are printed and handwritten with patent information for U.S. Patent No. 784, granted to Thomas Whiston of New York, NY, on June 14, 1838, for "Constructing the Flues of Open Fireplaces".

  Location

  Currently not on view

  date made

  ca 1838

  patent date

  1838-06-14

  inventor

  Whitson, Thomas

  ID Number

  DL.251497 [dup1]

  Data Source

  National Museum of American History

• 

  Hassock-Foot Warmer Patent Model

  Description

  Full-size patent model (U.S. Patent No. 219,572) of a combined hassock or cushion and foot warmer, made by J. Augustus Folsom of Boston, MA, and patented on September 16, 1879. Consists of an oval padded footrest covered in floral, Brussels or looped-pile carpeting with leather piping that has a shallow cavity or compartment for holding an oval piece of soapstone with a brass bail handle. Cushion interior also carpet-lined. No marks.

  Location

  Currently not on view

  patent date

  1879-09-16

  ID Number

  DL.251768

  catalog number

  251768

  accession number

  48890

  patent number

  219572

  Data Source

  National Museum of American History

• 

  Crocker’s Patent Model of a Hot-Air Furnace - 1874

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 163,050 issued to William O. Crocker on May 11, 1875. Crocker’s patent was for improvements in a hot-air furnace. The coal-fired furnace design provided an inner combustion chamber which was surrounded by an intermediate metal jacket. Cold air entered at the bottom of the furnace and was communicated via a set of holes in the base into the annular space between the combustion chamber and the intermediate jacket where it was heated. The diameter of the intermediate jacket increased from the base to top of the furnace. This allowed the heated air to expand efficiently into the air chamber at the top of the furnace where it was then conveyed via ducts to the building. The intermediate jacket was surrounded by an outer casing, the purpose of which was to increase efficiency by reducing radiation of heat from the hot intermediate jacket. Another design feature which claimed to increase efficiency was provision for both direct and indirect draft for the combustion chamber. The fire-pot had vertical partitions that extended from the top of the chamber three quarters of the way to the bottom. Two flues were provided, one near the top of the combustion chamber and one just above the fire-pot. The upper flue could be closed off so that the products of combustion would have to travel up into the combustion chamber and then back down behind the partitions through the fire-pot and back up its front to the lower flue exit. The object was to more evenly distribute the heated gases over the entire surface of the combustion chamber. A review of available advertisements and trade literature of the period did not provide any information on any commercial development of Crocker’s patent.

  The patent model is constructed of tin sheet. It illustrates the key design features of the patent: the outer casing, combustion chamber, and the intermediate jacket around the combustion chamber. The perforated openings at the base of the furnace which provide air circulation around the combustion chamber and intermediate jacket are clearly represented. The direct and indirect flues are also shown.

  Location

  Currently not on view

  date made

  1874

  patent date

  1875-05-11

  inventor

  Crocker, William O.

  ID Number

  MC.309281

  catalog number

  309281

  accession number

  89797

  patent number

  163,050

  Data Source

  National Museum of American History

• 

  Holley’s Patent Model of a Steam-Boiler Furnace – 1880

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 238,235 issued to Alexander Lyman Holley of Brooklyn, NY on March 1, 1881. Holley’s patent was for an improved gas-fueled steam-boiler for use in a furnace. Mr. Holley noted that past objections to the use of gas for fuel dealt with poor combustion of the gas due to incomplete mixing with combustion air. His invention related to a new way to mix the air and gas more completely prior to introduction into the combustion chamber. He provided for separate entry flues for the gas and air. These ran beneath the floor of the combustion chamber. Slots were cut into the floor perpendicular to the flues. Alternate slots were connected to either the gas flue or air flue. In his patent application drawing, he showed five slots – two for gas and three for air. He conceived that the pressure feeding the air and gas would create jets through the slots into the combustion chamber where mixture would occur and combustion take place. To facilitate this, he included a curved diaphragm as the top of the combustion chamber. The combustion gases would then be carried upwards through tubes in the boiler and thence to the exhaust. Research of available trade literature and other sources has not revealed any commercial product that may have made use of Mr. Holley’s invention. Mr. Holley was an engineer of great reputation in the steel making industry and was a founding member of the American Society of Mechanical Engineers.

  The patent model is constructed of wood and sheet metal. The boiler is sheet metal painted black. The wooden frame of the model is painted red with black lines to give it the appearance of being made of brick. The model conforms to the patent drawings and represents the major elements of the patent. The air and gas inlet pipes and flues are present. The burner is made of wood and has slots cut into it to represent the alternating gas air and gas ports. The model has a tag that includes the date (January 24, 1880) of the patent application.

  Location

  Currently not on view

  date made

  ca 1880

  patent date

  1881-03-01

  inventor

  Holley, Alexander L.

  ID Number

  MC.336506

  catalog number

  336506

  accession number

  1978.0318

  patent number

  29,007

  238,235

  Data Source

  National Museum of American History

• 

  Lawler's Patent Model of a Hot Water Heater - 1877

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 189,314 issued to Edward Lawler of Hartford, Connecticut on April 10, 1877. Mr. Lawler’s patent was for an improved water heater which would be fed from the normal water mains and which would have the ability to maintain a ready to use reservoir of hot water. He specifically noted its potential use in shops where hot drinks such as coffee were served. His design consisted of two cylindrical tanks made of cast iron. The hot water reservoir, the taller of the two tanks, was mounted on three legs elevating it over the shorter boiler and heating chamber located alongside it. Cold water from the mains entered via a pipe extending from the top of the reservoir to near the bottom. Hot water exited the reservoir through a hole and pipe at the very top. The boiler was connected to the reservoir via two pipes. The lower pipe received cold water from the bottom of the reservoir, and the upper pipe passed hot water into the reservoir where it entered well above the bottom of the pipe supplying cold water from the mains. The hot water, being of lesser density (specific gravity) than the cold, would rise to the top of the reservoir to be ready for dispensing. As hot water was drawn off for use, cold water would enter at the bottom to again fill the reservoir and pass into the boiler to be heated. Mr. Lawler’s design called for the boiler to sit atop a heating chamber of the same diameter which could be heated by gas or other fuels. Research of available trade literature and other sources has not revealed any commercial use that may have made use of Mr. Lawler’s invention.

  The patent model is constructed of copper. The reservoir and boiler are modelled along with the pipes interconnecting them as described in the patent. The cold and hot water connections are present at the top of the reservoir. Also shown at the bottom of the reservoir is a pipe that could be used for draining the system for cleaning. In its present condition the model does not include the heating chamber; however, the bottom of the boiler does model the flange described in the patent whereby the boiler would be secured atop the heating chamber. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov/patents/process/search/index.jsp).

  Location

  Currently not on view

  patent date

  1877-04-10

  inventor

  Lawler, Edward

  ID Number

  1997.0380.07

  catalog number

  1997.0380.07

  accession number

  1997.0380

  patent number

  189,314

  Data Source

  National Museum of American History

• 

  Gold and Foskett's Patent Model of a Steam Heating Apparatus - ca 1862

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 36,000 issued to Samuel F. Gold and William A. Foskett on July 29, 1862. Their patent was for a design for a steam radiator that warmed the air without excessive loss of humidity which was a disadvantage for then existing radiators. They sought an optimum temperature for the exterior surfaces of the radiator that would efficiently warm a room. Older designs allowed the surface temperature to approach that of the steam, and the designers claimed this damaged the air in the room by “….reason of the burning and decomposition of the extraneous matter in the air and the destruction of its moisture...” Their solution was to increase the surface area of the radiator elements and to distribute the steam within the radiator so as to uniformly and efficiently heat the elements. Each radiator element consisted of a long, thin chamber with many external conical projections. Steam entered the element in the center, and the center flanges were designed to allow multiple elements to be joined together with a single bolt. The interior of the chamber had a diaphragm that separated it in half horizontally so as to cause the steam to flow first outward to the end of the chamber and then return to the center where it exited the chamber. This controlled and even flow of steam on both sides of the central flanges had the advantage of producing an even thermal expansion across all parts thus avoiding leakage of steam at the joints. Another benefit of the open design was that there were no areas for steam to condense and become trapped in the form of water when the heat was turned off. This greatly avoided the chance of an explosion when the steam returned and obviated the need for a check valve common in other steam heat systems. A key design feature was that the conical projections on the surface of the elements were arranged differently on the front and rear of the chamber. Those on the rear were in rows and columns offset from those on the front by the diameter of the conical projections. This staggered the projections so air circulating among them would have maximum surface area to contact in its passage. The radiator design was made a part of the Union Steam and Water Heating Company steam heating system which was installed in many buildings including schools and homes . In 1891 the original patent was assigned to that company.

  The patent model is constructed of cast iron. It illustrates the design features of two truncated radiator elements joined at their center by the connecting bolt. The staggered conical projections are visible as are the separating diaphragms within each. The model is labeled “S.F. Gold & W.A. Foskett.”

  Location

  Currently not on view

  Date made

  ca 1862

  patent date

  1862-07-29

  inventor

  Foskett, William A.

  Gold, Samuel F.

  ID Number

  MC.336661

  catalog number

  336661

  accession number

  1978.0823

  patent number

  36,000

  Data Source

  National Museum of American History

• 

  Patent Model for Bellows

  Location

  Currently not on view

  date made

  ca 1880

  patent date

  1880-05-25

  inventor

  Smith, David B.

  ID Number

  DL.329541

  catalog number

  329541

  patent number

  228,131

  accession number

  88881

  Data Source

  National Museum of American History

• 

  Foot Warmer Patent Model

  Description

  Full-size patent model (U.S. Patent No. 35,532) of a foot warmer, made by Joseph Merrill and John H. Rowe of Boston, MA, and patented on June 20, 1862. Consists of a black wool-covered wooden box on four, compressed-ball feet containing two, removable, padded and woven fur-lined "foot-cases" or compartments for placing one's feet; springs on sides of compartments for a snug fit. Spring-upholstered top for using as a foot stool or kneeler. No marks.

  Location

  Currently not on view

  patent date

  1862-06-10

  Associated Date

  DELETE

  inventor

  Merrill, Joseph W.

  Rowe, John H.

  ID Number

  DL.251426

  catalog number

  251426

  patent number

  35,532

  accession number

  48890

  Data Source

  National Museum of American History

• 

  Wilson’s Patent Model of a Steam Radiator - ca 1859

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 24,897 issued to Charles A. Wilson of Cincinnati, Ohio on July 26, 1859. His patent was for a new and improved concept of stacking long, narrow boxes as elements for a steam radiator . The claimed benefit of this modular design was the ability to tailor the amount of radiator surface area in accordance with the amount of heating needed for a given room. And, this was made possible without changing the amount of floor space required for the radiator. His design called for the boxes, or modules, to be constructed of cast iron with corrugations at the top and bottom that allowed them to nest together tightly while still allowing for expansion and contraction with varying temperature. Each box had holes on the bottom at each end of the box. On the top of each box, nozzles projected upward and aligned with these holes allowing steam to pass from one section to the next. Two vertical screw bolts passed through the holes and nozzles to secure the stack of boxes together. Raised circular bumps surrounded each nozzle and provided a surface for a red lead or other gasket material to seal the joints. Steam entered and exited the radiator via two additional holes on the bottom of the lowest module. Research of available trade literature and other sources has not revealed any commercial product that may have made use of Mr. Wilson’s invention.

  The model is constructed of painted tinplate and consists of four modules, or boxes. Steam inlet/outlet holes are modeled at the bottom. The bosses between sections are also shown. The sections are held together with two screw bolts with nuts at the bottom. There is a small, rectangular access plate on the rear of the top section. The patent drawing shows this access; however, its purpose is not described.

  Location

  Currently not on view

  patent date

  1859-07-26

  inventor

  Wilson, Charles A.

  ID Number

  MC.251778

  accession number

  48890

  catalog number

  251778

  patent number

  24,897

  Data Source

  National Museum of American History

• 

  Stovepipe Drum Heater Patent Model

  Description

  Patent model (U.S. Patent No. 82,019) of a cylindrical heater or radiator that mounts vertically to a stovepipe, made by Henry Meyer of Richmond, IN, and patented on September 8, 1868. Drum-shaped body has molded bands near both ends and a scrollwork plaque on one side; circular, pivoting damper is held inside near top with eye-hook handle. Folded seams and riveted construction. Three paper tags tied to damper handle with red and purple wove ribbons are printed and handwritten with patent information and object numbers.

  Location

  Currently not on view

  Date made

  1868-09-08

  patent date

  1868-09-08

  ID Number

  DL.251501

  catalog number

  251501

  patent number

  82019

  accession number

  48890

  Data Source

  National Museum of American History

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