The US patent system has issued millions of patents. The overwhelming majority are unremarkable: a better valve seat, a slightly cheaper clip, a marginally faster sorting method. But somewhere in that pile sit documents so odd that they have become folklore among patent attorneys and examiners. What follows are real grants — not applications, not rumors — described rather than cited, because half the fun of these is finding them yourself. The closing section is the serious part, and it is the reason this list matters to anyone actually filing.
The ones involving animals
A method of exercising a cat. The claimed invention is pointing a handheld laser at the floor and moving the dot so the cat chases it. That is genuinely what issued. The specification is written in the flat, careful register of any mechanical patent, which is what makes it magnificent.
Ear protectors for long-eared dogs. A pair of soft tubes that slip over a spaniel's ears to keep them out of the food bowl. Unlike most items on this list, this one solves a problem that dog owners actually have, and versions of it are on sale today.
A diaper harness for pet birds. A garment that lets a parrot enjoy the run of the house without consequences.
The ones involving the human body
A method of concealing partial baldness. The comb-over, claimed as a process: divide the remaining hair into three sections, fold them across the scalp in a specified order, and fix them in place. It is a method claim on a hairstyle, and it issued.
A kissing shield. A thin membrane stretched over a frame with a handle, held between two faces so that affection can be exchanged without germs. Patented well before anyone had a public-health reason to want one.
A device for assisting childbirth by centrifugal force. A table that spins the mother at speed so that the resulting acceleration helps deliver the baby into a net. This is not a joke filing. It was granted, complete with engineering drawings of the restraint system.
A greenhouse helmet. A transparent dome worn over the head, containing plants, so that the wearer and the vegetation exchange carbon dioxide and oxygen in a closed loop. The drawings are exactly as unsettling as you are imagining.
A watch that counts down your remaining life. The user enters actuarial inputs, and the display runs backward toward an estimated expiration. Mechanically trivial, conceptually bleak, fully patented.
The ones that sound like party tricks
An apparatus for simulating a high five. A mounted lower arm and hand on a spring, so the user can slap it and receive the physical feedback of celebration without a second person present. There is a companion piece elsewhere in the record: a machine that delivers a congratulatory pat on the back.
A small umbrella that clamps to a beverage bottle. Sold under an obvious name, it shades your drink at the beach. The claims cover the clamp geometry, which is the sort of detail that makes patent attorneys respect the drafter even while laughing.
A motorized ice cream cone. The scoop rotates on a battery-driven turntable so that the user need only hold their tongue still. It reached retail, which is more than most patented inventions manage.
A Santa Claus detector. A decorative stocking containing a light source and a switch that illuminates when the stocking is disturbed, indicating a visit. Filed in complete earnest as a children's novelty and prosecuted like any other electromechanical device.
The ones that caused actual trouble
Two entries deserve separate treatment, because they did not stay funny.
A method of swinging on a swing. A patent attorney filed on behalf of his young son, claiming the technique of pulling alternately on the two chains to swing side to side rather than back and forth. It was examined and granted. The story ends well: the office reexamined it after the resulting publicity and cancelled the claims over prior art.
The sealed crustless sandwich. A large food company obtained claims covering a peanut butter and jelly sandwich with the crusts removed and the edges crimped together. The company then sent letters to small bakeries. The claims were eventually cut down badly on appeal, but not before real businesses spent real money responding.
There is a whole quieter genre of this in software and business methods — a patent on reserving an aircraft lavatory, a patent on scrolling a document by a page — where the invention is thin but the enforcement is not. Those are less amusing when the letter arrives at your address.
What these actually show about examination
It is tempting to read this list as evidence that the patent office is asleep. It is not, and the real lesson is more useful than that.
The statutory tests are novelty and non-obviousness, not merit. An examiner is not asked whether an invention is sensible, dignified, or commercially viable. They ask whether it is new, whether it would have been obvious to someone skilled in the field, and whether the application describes it adequately. A greenhouse helmet can clear all three. Our guide to non-obviousness covers the test that does most of the actual filtering.
Usefulness is a very low bar. The utility requirement asks only that the invention do something, not that anyone want it. Perpetual motion machines get rejected; useless-but-functional gadgets do not.
The prior art an examiner finds is limited by time. Examiners work under production quotas with a fixed number of hours per case. If the relevant prior art is a sixty-year-old playground practice that nobody ever wrote down, a keyword search will not surface it. This is precisely why a real prior art search before you file tells you something the examiner's search may not.
A grant is not validation. This is the point that costs inventors the most money. Holding a patent means the office found your claims novel over what it located; it does not mean anyone will buy the product, and it does not mean the claims would survive a serious challenge. The swing patent and the sandwich patent both show that a granted patent can be attacked and cut down. If you are weighing whether the filing is worth it in the first place, start with is a patent worth it for a simple product and with an honest read on whether the idea is actually good — two different questions that the grant notice answers neither of.
A pending application is not a patent. Many of the strangest documents floating around the internet are published applications that were never granted, which anyone can file for a modest fee. The distinction is explained in patent application vs granted patent. And a surprising share of the visually odd filings are design patents, which claim appearance only — a different instrument with different rules, covered in how to file a design patent.
The genuinely encouraging reading of this list is that the threshold is lower than most first-time inventors assume. If a spinning birthing table cleared examination, your unglamorous improvement to a bracket probably can too. Whether it should is a business question, not a legal one.
Projects House is a product development engineering firm, not a law firm. We take ideas — including the ones that sound strange out loud — and work out whether they can be built, what they would cost to make, and what the defensible engineering inside them really is, before anyone pays for a filing. Patent drafting and prosecution belong with a registered patent attorney. To get an engineering read on your idea, use the contact form.