The History Of The Can Opener - Patent to Patent Progression

What came first, the can or the can opener? Based on the evolution of the can opener as tracked through the US patent database using Google Patents, I would have to say the can arrived first by nearly a half century, and then people started scratching their heads over how to open the thing. I remember when I was 20 years old, taking a bus down to some beach on the Sinai in the winter, with some water, pitas, and a can of sardines. When I took the sardines out of the box, it turned out there wasn't an pull-off tab, it required an opener. The best I could do, after quite a bit of searching, was a rusty piece of metal and a rock. Yum!

The first can opener seems to have been invented by William Lyman. Previously, cans were opened with whatever tools happened to be at hand, and a hammer was usually involved due to the thickness of the metal. The basic idea is to puncture the can at the center of the lid with the sharp tip, then to lower the cutting disc onto the lid and scribe out a circle. It worked better than a pocket knife, but only for the right size can!

Next came openers with circular blades made out of rolled sheet stock, which cut through some or all of the lid in one shot. The early one pictured below cut through about a third of the lid on being forced down, ie, the blade only filled a third of the circular groove in the wooden handle. the inventor comments that as soon as it gets wet, rust will help keep the blade in place. After the blade is punctures the can, the operator is supposed to twist the handle to cut through the rest. The trick that bedeviled this opener, and most other openers for years to come, was holding the can steady while trying to open it.

The next type is a bayonet style opener, versions of which are still in use today. It's stab, and move, and stab and move.

Here's the first really useful innovation on the 1870 patent I found. The cutter location in now variable, so the opener can be used on different sized (circular) cans and still cut right at the rim, which is both easier and more efficient for getting the food out.

Here's a 360 degree version of the sheet cutter. I have my suspicion that when you clammed this through the lid of the can, you got liquid all over the table, assuming the can didn't just collapse.

The operation of the can opener below is obvious, and I'm tempted to say, it's obvious it didn't work very well. The operator has no leverage, it's a tough bet whether the handle will twist off before your wrist.

As "Tim the Tool Man" would have said, what this machine needs is more power. Table mounted mechanical can openers became common in the 1880's, where a long handle gives the operator great leverage to force an otherwise inelegant solution to work. The can is held in place, the blade cuts through the lid, you reposition the can and do it again. Later versions of these table mounted can openers used a flat gear, which is a much more efficient way of translating a lever motion into a plunge.

The can opener below was the first scissors type I found, one that uses two handles with a pivot to force the cutting blade through the lid of the can. As there is no crank, I assume the operator simply keeps repositioning the cutting blade and working around the lid.

Another variation on the original can opener, this one allows infinite adjustment of the blade position, rather than using set screws for a limited number of sizes.

I think this table mounted machine is a significant advancement in the history of can openers because it uses a gear with sharpened teeth to turn the can as it cuts. It also features a flat gear to raise and lower the cutting mechanism for any height of can that can fit.

Another take on plunge openers that cut through the entire lid in one shot. This opener features dozens of little knives for the initial plunge, after which the operator has to turn the can opener to cut through all of the remaining shards.

While not precisely a can opener, the patent below shows a design for can lids. A groove is cut in the lid during the manufacturing stake, and a wire with a little ball on the end is soldered into the grove. Pulling on the ball pulls the wire out of the groove, and opens a large tab in the lid that you can pry up. The lead solder they used in those day poisoned more than a few people.

I included this patent for a pistol can opener, which probably did better as a gag gift than as a working opener. I wonder if anybody ever robbed a bank with one?

Fifty five years after the first can opener was inventor, we a quantum leap towards modern style can opener. It features a serrated gear or disc which is turned with one hand and forces the can up against a cutting disc. Turning the handle forces the can to turn in a circle, as with the gear on our earlier table top model, the scissors like handles drive the cutting disc through the side of the can and hold it tightly. The main difference between this opener and the modern can opener is that it cuts through the side of the can to remove the whole top. It's a hangover from the original opener, that left can opener inventors with the mindset that the opener moves in the same plane as the lid of the can.

Finally, we arrive at what I would call the modern can opener in 1931. These last two patents really define the two types of modern can openers, and both focus on the mechanism without defining the handles. The first is your basic low cost opener, that uses a crank key with gear or serrated disc under the outside edge of the can to hold and turn the can while a blade cuts through the top of the can along the inside edge. It uses the two handled squeeze to cut through the can lid and hold the can tight, with the pivot at the very front. A serrated disc or gear is driven by the turning handle, a rolling disc supports the bead of the lid from the outside, and a knife cuts along the bead on the inside, for any size can. It also bends over the edge as it cuts, in an attempt to render the can safe for handling.

The final patent is for the mechanism of the upscale can openers that most people use today. The two gears lock together to keep the cutting disc turning at the same rate as the finer toothed gear or disc that turns the can with pressure under the edge. If you're shopping for a can opener, make sure that the mechanism looks like this: