Self protected shaving device having multiple cutting edges… Try saying that three times fast.

A couple of days ago I posted about a razor that was all edge and no point. One of the patents that cited that one is Donald J Yellon’s self protected shaving device having multiple cutting edges. So lets see what that actually is, and means.

But first, lets see what imaginary problem Donald was trying to solve with his invention. To quote:

The ordinary razor or instrument used for shaving usually consists of a hardened steel blade made with an extremely fine sharp edge and fitted into a handle, by means of which the blade may be manipulated with the sharp edge in contact with the skin of the user.
Since the razor is considered a dangerous instrument, many attempts have been made to improve the construction and operation thereof. At the beginning of this century, the principle of the safety razor was introduced, wherein a guard is physically interposed between the skin and the cutting edge of the razor blade, so that the guard permits the edge to pass over the uneven surface of the part to be shaved, removing the hair without cutting the skin.
Other types of safety devices have also been devised. However, such modifications have usually retained the general form of an ordinary razor, while rendering it safer for use by fitting suitable guards to the blade of the ordinary razor, or by substitution of a holder carrying an adjustable blade of the strip-steel type.

From US patent 2,989,804

So… A razor has a sharp blade, which despite the presence of a guard may cut you. Not really a big problem if the user pays a tiny little bit of attention? But enough of a problem that Donald invented a solution.

Much like the all edge and no point razor, Donal did away with the traditional blade with an edge on the outside. Instead he went with a blade that had holes or slots, each one sharpened on the inside.

As can be seen from the drawing, Donal came up with several ways to make this new blade. The holes could be of various shapes, and the cutting edge could be at the top, middle, or bottom of the blade. He also depicted two different ways to mount the blade – a threaded post, and arms gripping the edges.

Did Donald achieve what he set out to do? If we judge by the title of the patent, yes he did.

There is no guard, or need for one. The small, interior edges would be near impossible to cut yourself on, so it is self protected.

It is certainly a… device. That you could try to shave with. So shaving device is correct.

And it does indeed have a multitude of cutting edges.

So yes, Donald did manage to invent a self protected shaving device having multiple cutting edges.

The patent goes into a fair bit of detail, but the long and the short of it is that the patent don’t offer enough of a benefit over normal safety razors be a contender. Or, arguably, any benefit at all over a normal safety razor. As I can tell it never made it into production, nor did Donald file any more patents.

The full patent can be read at Google patents.