Fractional patents exist in two basic types. The first type comprises the X-Patents, which were granted from 1790 to July 2, 1836. There are at least 50 fractional patents of the first type. The second type are those which were issued in the regular number series, which started with patent number 1 granted on July 13, 1836. This document will deal only with the second type.

Documents of the second type for which I have been able to identify and now have copies of are:

126 ½
RE 1,217 ½
RE 1,242 ½
2,712,152 ½
3,262,124 ½
D 90,793 ½

These documents do exist. These patents were granted and printed with the indicated numbers. Because the patent retrieval system is based upon a number system that does not make any provision for fractions these patents are not generally available to the public. In fact, officials in the PTO have had difficulty in obtaining copies, see attached file 1. Years ago I was advised that there were provisions made for indexing fractional patents within the system. However I know of no one who has been able to use the proposed system and thus I do not believe it was ever put into use.

Anyone familiar with the microfilm files knows that all of the patents which are available in the PTO are on the microfilm in sequential order in each of the separate classifications of regular utility patents, reissue utility patents design patents, name & date patents and additional improvement patents. Copies printed from microfilm are 25 cents each. Unfortunately, printed copies from the microfilm are generally not as good as the original printed copies. With a copy of the patents in hand one should be able to determine where in the patent classification system the originals and cross references might have been placed and thus original paper copies should be retrievable. However, because these anomalies may not have been included in reclassification projects or replacement copies could not be obtained and/or people who saw them thought that they might be interesting enough to remove the copy from the file; these fractional patents may not be available in the paper file. Years ago I had a good copy of the printed copy for number No. 2,712,152 ½, but as I have no time for organization it is somewhere in one of my many uncaptioned stacks of files. I have no time for research.

Patented files are maintained in storage and the older files are archived at National Archives. Ordering patent files is routine, except when they are fractional patents. The electronic ordering system has no provision for fractions and my attempts to have the files ordered manually have been fruitless. My contact at National Archives pulled the file for 126 ½ and advised me that there was a note indicating that the file had been lost but had been found just prior to the grant date. I have not had time to pursue the other original files.

I checked the July 19, 1966 Official Gazette for No. 3,262,124 ½ and found that this was the last patent issued on this date. Patent No. 2,712,152 ½ is interesting in that it is a Divisional of No. 2,712,152. I noted this later situation when I routinely checked the whole number for each of theses patents to see if there might be a connection.

This limited research has been undertaken on my own initiative and personal time. Even though a significant amount of time has been consumed no official government time has been involved. History may be of interest but apparently not important enough for any official recognition see attached file 2.

The first page of each of the listed documents are set forth in the attachments.