The Invention
The patent, US387839A, granted to Granville T. Woods of Cincinnati, Ohio, on August 14, 1888, is for an improved galvanic battery. The invention focuses on creating a “simple, cheap, convenient, and durable” battery by optimizing the arrangement of its core components: a zinc electrode and a carbon electrode.
Key Features:
- Central Zinc, Outer Carbon: The battery’s design features a central zinc core (E), which is the positive electrode. This is surrounded by an open-ended cylinder of carbon strips or pencils (A), which act as the negative electrode.
- Insulating Cylinder: A key part of the invention is a thin, insulating cylinder (B) made of rubber or similar material. This cylinder is placed between the central zinc core and the outer carbon pencils.
- Forced Circulation of Fluid: The presence of the insulating cylinder forces the battery’s liquid electrolyte (exciting fluid) to circulate in a specific way. It must flow downward and upward around the bottom of the cylinder, rather than directly between the electrodes.
- Enhanced Performance: Woods explains that this unique circulation offers several advantages:
- It ensures a more thorough and uniform electrolytic action, as the fluid is constantly moving.
- It prevents “surface accumulations” or “short-circuiting” at the top of the fluid, which can weaken the battery’s power.
- It allows for a larger carbon surface area to be exposed, which compensates for any direct intensity lost by the presence of the cylinder and leads to a more “durable and constant action.”
- Modular Construction: The entire carbon element, including the strips and the insulating cylinder, is held together by a metal band clamp (C). This makes the carbon assembly a single, removable structure, which is convenient for cleaning and replacing parts.
Significance of the Invention and Inventor
Granville T. Woods was a pioneering African American inventor who made immense contributions to electrical technology. His patents, including this one, demonstrate his deep understanding of engineering and physics.
- Incremental Innovation: This patent isn’t about inventing a new type of battery chemistry, but rather about a significant mechanical improvement to an existing technology. By altering the physical arrangement of the electrodes, Woods made the battery more efficient, reliable, and easier to maintain. This type of incremental innovation was a major driver of technological progress in the 19th century.
- Solving Practical Problems: The invention solved several common problems with galvanic batteries of the time, such as inconsistent performance, rapid degradation of the zinc electrode, and the “short-circuiting” issue that reduced power output. These improvements were highly valuable for the rapidly expanding fields of telegraphy, telephony, and other applications that relied on portable power sources.
- A Prolific Legacy: This is just one of dozens of patents granted to Woods. He was a prolific inventor who made foundational contributions to railway telegraphy, telephone systems, and electric motors. Despite facing racial prejudice and legal challenges from rival inventors, his work was consistently validated and became the basis for modern technologies. This patent on galvanic batteries is another example of his genius in making fundamental technological improvements that were vital for the burgeoning electrical industry.
