Here is information on Samuel E. Thomas’s “Process of Casting” patent from 1888.
The Invention
The patent, US386941A, granted to Samuel E. Thomas of Brooklyn, New York, on July 31, 1888, describes a novel process for joining a wrought-lead pipe to cast metal. This invention was designed to create a strong, durable, and leak-proof connection that would not fail from wear, rust, or weather.
The process consists of three main steps:
- Tinning the Pipe: The first step is to coat the end of the wrought-lead pipe with a thin film of molten tin. This is done by dipping the end of the lead pipe into molten tin.
- Placing in Mold: The tinned end of the pipe is then inserted into a prepared mold. In this setup, the pipe itself becomes part of the wall of the mold’s cavity.
- Casting: Finally, molten metal (preferably lead, but other metals can be used) is poured into the mold. The molten metal flows around the end of the pipe, and due to the tin coating, it quickly and permanently adheres to the lead pipe, forming a single, unified piece.
To prevent the lead pipe from melting during the casting process, Thomas recommends inserting a core of a rigid material like iron or stone into the pipe’s end. This core also helps the pipe maintain its shape as it cools.
Significance of the Invention and Inventor
Samuel E. Thomas’s patent, while focused on a very specific technical process, is a good example of the kind of practical, problem-solving innovations that were common in the late 19th century.
- Solving a Practical Problem: At the time, lead pipes were widely used for plumbing, especially for water-closet discharge pipes. The joint where a lead pipe connected to a cast-metal flange was a common point of failure, often leading to leaks. Thomas’s process provided a more reliable alternative to traditional soldering, creating a bond that was less susceptible to “wear, or rust, or by wear.” This was a significant improvement for public sanitation and plumbing reliability.
- A “Niche” Innovation: The patent’s focus on a single, specific process highlights a key characteristic of the era’s inventors. They often worked on highly specialized problems within an industry. Thomas’s solution was a direct response to a need in the plumbing and sanitation sector, showing how ingenuity was applied at a granular level to improve everyday technology.
- The Inventor’s Role: The patent indicates that Samuel E. Thomas assigned his invention to Fred. Adee & Co., a plumbing supply company in New York City. This was a common practice. Many inventors did not have the means to commercialize their own ideas and would sell or license their patents to companies that could manufacture and distribute the product. This demonstrates the symbiotic relationship between individual inventors and the growing industrial firms of the late 1800s.
