Frank J. Ferrell’s patent for a “Valve,” No. 467,796, is a further refinement of his previous inventions, focusing on an improved visual indicator. Patented on January 26, 1892, this patent describes a mechanism that provides an accurate, easy-to-read display of a valve’s position.
The invention’s core is a unique intermittent gear system:
- Toothed Disk: A small disk with a single tooth is secured to the valve stem.
- Grooved Disk: A larger, grooved disk is attached to the indicator plate. The grooves are designed to mesh with the tooth on the smaller disk. The spaces between the grooves have a concave shape that fits the smooth surface of the small disk, effectively locking the indicator in place.
As the valve stem turns, the small disk rotates. The tooth briefly engages a groove on the large disk, causing it to turn a specific amount. For the rest of the rotation, the concave surfaces hold the large disk still. This ensures that the indicator only moves to specific, marked positions (e.g., “open,” “closed,” quarter-turn).
Societal Impact
Ferrell’s inventions, including this one, played a crucial role in improving the efficiency and safety of industrial and plumbing systems in the late 19th century.
- Improved Control and Efficiency: The valve indicator provided a simple, compact, and highly accurate way for operators to know the exact position of a valve. This was a significant improvement over relying on “feel” or estimation, allowing for more precise control of fluid flow and reducing waste. This was particularly important in industrial settings like factories and steam plants.
- Practical Innovation: The design’s genius lies in its simplicity. It could be easily added to existing valves, making it a highly practical and marketable invention. This highlights how an inventor could make a significant impact through a refinement of existing technology.
- The Inventor’s Legacy: Frank J. Ferrell was a prolific African American inventor and machinist who specialized in steam-powered devices and their components. His patents, which also include steam traps and other valve designs, demonstrate his expertise and his contributions to the technological infrastructure that powered the American economy. Ferrell’s work serves as a powerful reminder of the vital role that Black innovators played in the industrial progress of the United States.
