Sheet metal injector

Injectors can be complicated razors, even when meant to be simple. The forerunners of injectors were more complicated still. But today I have a nice find for you all; a very simple sheet metal injector. Patented by A William H Camfield in 1936, the patent was assigned to the Magazine Repeating Razor Co – the people behind the Schick Magazine Razors.1

The invention was touted as an improved and simplified form of safety razor and magazine, which also was cheap to manufacture.

Or, as the patent text states:

The present invention is an improvement in that the means for feeding a blade from the magazine and into the shaving head of the razor is simultaneous with a limited separation of parts of the shaving head, both operations being performed by a single means operated manually after the magazine and shaving head are joined.

This form of shaving device is not only of marked utility but is adapted for economical manufacture.

From US patent 2,050,244

And yes, the sheet metal injector is a lot simpler and will be much cheaper to manufacture. It don’t look nearly as nice as the earlier magazine razors though.

The razor was to be made from a single piece of sheet metal. This was stamped out, bent, and riveted. One end of the sheet metal acted as a top cap, and put tension on the blade. The other end acted as the bottom plate, or blade platform as the patent calls it. This part had a guard cut at one end, and blade stops to keep the blade from sliding forward.

The rear of the razor is where the magic happens. A recessed portion forms a channel, and a small ramp aids in the insertion of a metal finger affixed to the magazine.

For those of use used to injectors, the rest is self evident. The finger separates the top cap and bottom plate slightly. This released the pressure put on the old blade. The old blade can then be pushed out by the insertion of a new blade. And when the finger is withdrawn, the top cap clamps down on the new blade and secures it.

Patent drawing showing the sheet metal injecotr
Patent drawing from US patent 2,050,244

There is no reason why the sheet metal injector wouldn’t work. Where it probably failed is that it was too cheap – and would feel cheap to the prospective buyers. A looped sheet metal handle would he a significant downgrade compared to the earlier Magazine Repeaters. Which is probably why the company went for the Type E2 instead, after a short run of the Type D.3

The patent is, of course, long expired. But anyone who plans to take up manufacture of a sheet metal injector should probably spend some time coming up with a better design for the handle.

You can read the full text of the patent for the sheet metal injector at Google Patents, or over at


  1. I am still looking for a user grade and affordable Type C, by the way. ↩︎
  2. Which conceptually works like the sheet metal injector, but is a more refined design. ↩︎
  3. Which was mechanically interesting, but overly complicated. ↩︎

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