1902-28763. Or, for those who can’t quite recall the patent numbers of the top of their heads, one of King Gillette’s earliest patents for the classic three piece Old Type Razor.
It wasn’t King Gillette’s earliest patent, nor his last. It is, as far as I am aware, the earliest of his patents showing the classic Old Style razor with the bottom knob. Both his early US patents – US 775,134 and US 775,135 – required the user to either unscrew the handle or use the whole handle as a knob.
1902-28763 was filed, unsurprisingly, in 1902. It was approved and published the year after. The main idea was to make a razor that was easy to use, and did not require much maintenance. In the words of the patent text:
The chief object of this invention is to produce a safety razor which may be kept in satisfactory condition for use without requiring any stropping or other sharpening by the user. According to this invention the blade of the razor is made of very thin sheet steel, which need be only thick enough to take a suitable cutting edge. This blade is detachably secured to a holder so constructed that it will retain the blade in proper position with respect to the guard and give it sufficient rigidity to make it operative for shaving. There is thus substituted for the thick rigid blade heretofore used, a thin, flexible blade made of so small an amount of material and capable of being sharpened so quickly and easily that it may be produced and sold in quantities at a very low price, so that when one of the blades becomes dull, it may be detached from the holder and thrown away, and replaced by a new, sharps blade at slight expense, the user being thus saved the time and trouble hitherto involved in keeping the razor blade sharp.From Great British patent 1902-28763
A can be seen from the drawing, the patent don’t deviate much from the “standard” Old Type razor. The most notable difference I can see is the inclusion of four short transverse extensions at the corners of the top cap, which served to protect the shaver from the corners of the blade. These were likely found unnecessary and deleted to make production easier.