Sub-series 4. Patent Files, 1937-1972, undated

Arranged alphabetically by subject, this sub-series contains Betz Laboratories, Incorporated's patent files. They mainly pertain to the patenting of inventions conceived and developed by employees of Betz Laboratories and its corporate predecessor W.H. & L.D. Betz, including, but not limited to, Charles A. Noll and Louis J. Steffanelli. To a lesser extent, they also concern non-Betz patents that were of interest to the firm and its employees.

The Patent Files provide documentation of the legal processes through which Betz employees patented their inventions. They also contain technical information for the inventions represented in this series. From the Patent Files, one can also gain insights into the conception, research, and development work involved in bringing the represented inventions into being.

The contents of the Patent Files consist mainly of patents, legal documents, and correspondence. A few photocopied article pages, a photocopied article reprint, and a blueprint are preserved in this sub-series as well.