Hi, this is Wayne again with a topic “Make: Inventions | Can Opener”.
Necessity, as they say, is the mother of invention, but sometimes necessity takes the long way around. For example, canned food was invented about 1800, but it was nearly 50 years before the first dedicated can opener was created. Of course, cans were opened in the meantime, since the first wide scale use of canned food was for napoleon’s army, a bayonet was commonly if dangerously used other suggested methods include a hammer and chisel or even a rock. I don’t have a bayonet, but i do have a sharp rock and it’s even kind of clean. It works about as well as you might expect. A hammer and chisel are an improvement, but is still far from ideal and i’m not sure my chisel is any cleaner than my rock. As canned food found its way from the battlefield to the kitchen.
There came a flood of hopefully helpful inventions. The first dedicated can opener was patented by british inventor robert yates. In 1855., i’ve been unable to get my hands on the original patent, but i did discover this image, which is almost enough to go on a blade on the straight side cuts the can. While the blunt side is used for leverage as usual, there are no measurements, so i pick a size that looks comfortable in the hand.
I transfer the basic outlines to some mild steel and cut out the general shape i make up for my lack of cutting torch skills by refining the shape with various grinding tools. The blunt end is made separately with the application of heat and a hammer. It’S attached to the main body with a couple of rivets that i made by cutting ordinary nails to length after sharpening the blade and giving it a polish with a wire brush. I wipe it down with oil to prevent rust.
The handle is made from a scrap of mahogany. I use the metal part as a template, then cut it to shape with a saw and refine it with a rasp and sandpaper. When i’m happy with the shape. I finish it with several coats of tongue oil and then complete the assembly with binding posts, time to try it out not as easy or as safe as modern can openers.
It’S certainly better than a hammer and chisel and undoubtedly safer than a bayonet. But after a 50-year wait is this: the best that an inventor could come up with ezra warner has the first american patent on a can opener from the year 1858. It has a replaceable blade and a curious bit at the end that rotates the steps to make.
One are similar, though, it’s a bit easier for me since there’s less cutting steel and more bending it according to the patent, the blade is supposed to be replaceable, so i won’t use what looks like a weld. Instead, i make the blade with a lap joint at the end and hold it in place with a pair of screws. The rotating part has an interesting shape. That’S not explained, but it’s not too difficult to make. The handle is also much simpler in this version.
It’S just a single piece of wood with a hole in the bottom. It’S held in place with friction it’s more difficult to use than the yates model. Starting. The cut is much more difficult and it’s harder to continue it.
I still don’t know what the rotating part is supposed to do. In fact, it works well enough without it, the replaceable blade is a nice improvement over the yates model, but overall it doesn’t get high marks. Both of these are pretty fiddly to use. Didn’T somebody invent something that didn’t require as much coordination. Well from the 1850s onwards, the patent office received thousands of new proposals for can openers in particular this one. Although its function is pretty obvious, it has a subtlety that belies its appearance.
The teeth are arranged different heights, so they progressively cut into the can theoretically making it easier to cut through the tin. It says in the patent that it was intended to be cheap and easy to make. So, let’s give it a try, i lucked out with this patent, since it has a template for the pointy bits, though i picked a somewhat arbitrary diameter.
It is simpler to make cutting out. The blade is a bit of work, but it would easily be stamped out in a factory. The handle is just a steel rod and bending a hook on one end is simple enough: the only detailed work is sharpening the blade and cutting the threads on one end. For the retaining nuts, the theory doesn’t seem to match up with reality. Although the blades were pretty sharp, i could barely scratch the can just using hand pressure applying a mallet eventually got results, even if that result was soup spraying everywhere.
On the upside, it leaves a less jagged edge than the others, but it only makes one size of whole, which might be a problem. It’S at least as dangerous. As it looks, i managed to cut myself a couple times while building it making it both dangerous and hard to use. Advances in manufacturing in the 20th century made cans easier to open and can openers more sophisticated while the circle of blades didn’t catch on the pivot and blade style.
Robert yates pioneered has had a much longer life, folding versions are standard military issues and you can still buy similar models today and while pop tops invented by hermle freys in 1959 are becoming more common. The old-fashioned can and their openers are here to stay. I’M steve hofer for make conventions.
You .