A safety razor is often said to be a razor with a guard. So a safety razor blade is therefore a blade for a safety razor. Or is it a razor blade with a guard. Is it, in fact, a safety-razor blade, or a safety razor-blade?
According to Alfred W Ferrara, it is the later. So lets us see what imaginary problem he sought to solve with his invention:
The efficiency of the safety razor blade, however, is restricted by the safety factor involved in positioning the blade near the guard. The closer the blade is located with respect to the guard, the less effective the razor will be; when the blade is located too great a distance from the guard, its efficiency is greatly improved, but it then resembles a straight-edge razor in the necessity of handling it with great care.From US patent 3,263,330
Another disadvantage of conventional safety razors lies in the fact that most of their bulk, weight and cost is taken up by parts that do not perform a cutting function. Thus, most of the parts of the conventional safety razors are supports, guards and holding means for the razor blade, the blade, itself, being light-weight, compact and relatively inexpensive compared to the remainder of the razor assembly. Although it is the blade, alone, that performs the cutting function, the other parts of the assembly are conventionally made of rust-resistant metal and so increase the cost of the entire assembly as to render it non-disposable after a single use.
So… get the blade closer to the skin, and simplify the razor. Let us see how Alfred sought to solve these issues.
Giving the average shaver an unprotected blade would be counterproductive. So if the blade should be brought closer to the skin, it needed to be protected. So Aldred came up with a guard mounted on the blade itself; two narrow combs made from a strip of metal. In the strips there would be a row of holes punched out. The strip would then be folded over and secured to the edges of a regular double edged blade – although there is no reason it couldn’t be done to a single edged blade.
Or, as the patent phrases it:
According to a preferred embodiment of my invention, the individual cutting edge portions of the blade are separated from each other by teeth in the form of strips of a material resistant to cutting by the cutting edge of the blade. These teeth are fixed to the blade body on either side of the cutting edge and extend across the cutting edge to divide the cutting edge into separate portionsFrom US patent 3,263,330
To utilise the safety razor blade he invented, Alfred proposed a modified safety razor – in short, a safety razor without a guard. An unsafe razor, if you prefer.
Shown in figure six on the patent drawing, the razor has a handle, a top cap and a bottom plate. The only real difference between Alfred’s unsafe razor and a regular safety razor is the lack of a guard.
Conceptually Alfred’s idea is similar to Perret’s 1762 patent, and Paul Zammat’s improved razor guard, his invention had a major obstacle to being adopted. While it would make the razor slightly cheaper, the more complex blade would be significantly more expensive.