Sub-series 3. United States Patent Applications, 1935-1946, undated

Arranged alphabetically by subject, this sub-series contains Ernst Berl’s United States patent application files. These files mainly, but not exclusively, concern inventions for which Ernst Berl was not awarded patents by the United States Patent Office. The files in this sub-series provide detailed primary documentation of the legal process through which Ernst Berl applied for patents in the United States. They also contain technical information for the inventions represented in this series.

From the United States Patent Applications files, one can learn much about the research and development work carried out by Berl to bring the represented inventions into being. They also provide information as to why Berl did not receive United States patents for some of his inventions. Legal work carried out by Ernst Berl’s younger son and patent attorney Herbert Berl is well documented in this sub-series as well.

The contents of this sub-series consist mainly of files for individual inventions for which Ernst Berl was not awarded patents in the United States, which mostly contain copies of patents, legal documents, and correspondence, but also include a few drawing reproductions and notes. Also found in this sub-series are fourteen files of Ernst Berl’s notarized declarations for inventions he conceived over the course of his career, which concern both successful and unsuccessful United States patent applications. A partial list of Ernst Berl’s United States patent applications, which lists both successful and unsuccessful applications, is preserved in this sub-series as well.