A little while back β because four years is nothing β I wrote a little piece on the Rally dry shaver. And now, while aimlessly poking through online patent texts, I found the patent for it.
Filed in the US and Germany by a Swede, the Rally was, as I mentioned, a lawnmower for your face. A handy way to get rid of that five oβclock shadow. A great gift that would likely be used twice and then put in a drawer.
So what was Jonas Γ ke Gregorius Malmberg trying to achieve? Well, mostly to improve on improving rolling drum dryshavers, apparently. By making the blades replaceable. Which makes a lot of sense, when you think about it. To quote the patent:
The present invention relates to an improvement in such shaving-apparatus having a finely slitted rotatably mounted drum and a fixed knife applied inside and in the longitudinal direction of the said drum, and the object of the invention is to obtain an effective operating and durable shaving apparatus of this type, the invention being chiefly characterized by an open-ended casing provided with a longitudinal slot and arranged inside the drum for the purpose of guiding the same and connected with a handle, the one of the longitudinal edges of the slot in the casing being provided with a longitudinal groove for inserting an exchangeable knife, and movable locking means which in the locking position cooperate with the ends of the knife in order to keep the knife fixed in the longitudinal direction and also crosswise. This arrangement thus renders it possible to use exchangeable knives which, after being inserted in the groove in the one edge of the slotted casing is firmly locked by the locking means.
The way the Ralley works can be worked out from the text and drawings.
Patent drawings for US patent 2,637,902 (and German patent 830,305)
The user would roll the finely slotted drum over his stubble. The stubble would β hopefully β enter the thin slots. The movement of the drum would bring the stubble to the blade, which would β hopefully β cut it.
One end of the Rally could swing up to access the interior of the drum. This both allowed the interior to be cleaned, and the blade to be replaced. The folding drum covers acted as the handle, as can be seen in the photo in my previous post. And the whole thing could fit in a pocket.
I can see a couple of ways to improve the Rally roller razor. The most obvious one would be a second blade. By mirroring the placement in the drum, the user would be able to roll it both ways. As Jonas drew and β likely β manufactured the Rally, it would only cut when rolled in one direction.
If it would cut much at all, that is. After all, the idea is that your stubble should somehow enter the slots β and not slip out again. So if your stubble is too stiff, or too thick, or too bendy, or too thinβ¦ the Rally would work less good.
You can read the full patent text for the Rally rolling razor over at Google Patents.