During the last few years I've spent many hours on the United States Patent and Trademark Office (USPTO) web site researching old patents concerning electric lamps and similar things of interest. One of the great things about the USPTO site is the ability to query their patent database. Maybe you have noticed a patent number on a light bulb's packaging, or even noticed the little patent label in the glass stem of many turn of the century carbon filament bulbs. Thanks to the USPTO site, these numbers are no longer a mystery. Patent numbers not only give us a good estimate of an object's age, they also provide us with the history of how and why a particular object came into existence. The focus of this patent collection mirrors my own interest: early light bulbs and similar things of interest.
Contained here is a listing of patent numbers that I have discovered, some by famous inventors, some by not-so-famous names. They are included here to help others study the history of electric lighting, primarily incandescent and gaseous lamps. Patents relating to the hardware of early electric lighting are also included, switches and sockets for example. Various patent numbers were discovered by reading books and other material on the subject but many were discovered by simply querying the USPTO site. This list is not intended to be a "master list" of all patents on the subject, it is merely a list that I think will be interesting to collectors and historians, conveniently grouped together by subject. I will continue to add to this collection as I discover more patent numbers. I also welcome your input regarding interesting patents that you wish to share.
The patent collection is divided into four primary categories: incandescent lamps, gaseous lamps, hardware, and miscellaneous. The documents are compatible with Adobe Acrobat Reader version 5 and 6. To download the latest version of Acrobat Reader please visit Adobe's website. Upon clicking the category links below, a preview page will appear showing small images of each patent's mosaic page. By default, the patents are sorted in chronological order by patent number with the oldest patents appearing first.
An example is shown at the left of this page illustrating patent #466,400 by Thomas A. Edison for a Cut-Out for Incandescent Lamps assigned to the Edison Electric Light Company on January 5th, 1892. Further sorting of patents is achievable by clicking on the inventor's name and the assignor. For example, clicking on "THOMAS A. EDISON" will query all patents by Edison. Clicking on "EDISON ELECTRIC LIGHT COMPANY" will return a page showing all patents (by any inventor) assigned to this company. For a deeper search of the patent database, the text of most patents is searchable using the search box located near the top of this page, but use with caution. Because of the limitations of OCR technology, the original patent text does not always translate correctly. The results are spelling errors that would just take too much time to correct by hand (hundreds of documents!)
Please note that if you are searching for Edison's patents then you should visit Rutger's Edison site shown below. Only a small number of Edison's electric lighting patents appear in the BulbCollector database. Moreover, this collection highlights the inventors that chose to compete with Edison's work.
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