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

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

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 (
Currently not on view
Object Name
patent model, heater, friction
Object Type
Patent Model
patent date
Vera, Pedro
overall: 4 1/4 in x 2 7/8 in x 2 7/8 in; 10.795 cm x 7.3025 cm x 7.3025 cm
ID Number
catalog number
accession number
patent number
Patent Models
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Work and Industry: Mechanical and Civil Engineering
Patent Models
Engineering, Building, and Architecture
Data Source
National Museum of American History
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