On reading Wurlitzer patents
Drawing of a Wurlitzer 112 from a 1959 patent (2,881,650). As you can see, the Wurlitzer in this drawing has some significant differences from the Wurlitzer that made it to market.
What is a patent? A patent is a form of compromise. When you patent an invention, you must describe it in detail: specifically, enough detail that someone with a background in your industry would understand how to recreate your invention just by reading the patent application. In return for this valuable information, you are given the exclusive legal right to make and sell your product for a certain number of years. If someone else makes or sells your product during the time period covered by your patent, you have the power to sue them for patent infringement.
Before a patent is granted, an invention must meet three major requirements:
The invention must be novel
It must be useful
It must be non-obvious
In other words, you can only patent new technology that has some real-life purpose and isn’t too conceptually basic. Patenting an invention doesn’t obligate you to produce it, but according to the “usefulness” requirement, you can’t patent things that are strictly hypothetical or otherwise impossible to produce. And although your invention can build off a previous invention, you can’t patent an improvement that would be “obvious” to anyone familiar with the current state of the art in your industry.
There are also requirements to the patent application itself. In addition to the detailed description, most patents must be accompanied by at least one black-and-white drawing. Even today, photographs are only allowed in special situations (usually in the field of biology).
Parts of a patent
As a legal document, patents are pretty formulaic. They always including the following parts:
The drawing
Vintage patent drawings are highly detailed and often very beautiful. In contrast, today’s patent drawings are often extremely crude. From the beginning, patent artists started omitting more and more details from their drawings. For instance, an 1869 patent of a flying machine depicted a mustachioed man using the machine in so much detail that you could almost guess his life story. In contrast, the patent artist for Google Glass (2012) didn’t even bother to give its cartoon user a mouth.
Today, patent drawings are purely another communications tool: as long as they get the point across, they don’t have to look particularly stylish. This has its upsides. Since you don’t need to hire a specialized draftsman anymore, filing a patent is now that much cheaper and more accessible. But the illustrations in vintage patents definitely have a certain magic. Since they follow artistic trends of the period, looking at patents instantly immerses you in a particular historical moment in a way that other media cannot. So, admiring the drawings is a great reason to look up old patents.
The description of the invention
Each part of the drawing is numbered so that you can refer back to it when reading the description. It basically explains in words what you are looking at in the drawings. This part is admittedly dry, but you can find some interesting gems if you read it closely.
For instance, we often think about who the Wurlitzer was made for. Today, it is considered something of an offbeat instrument that creates a very characteristic, unusual sound. It is mostly beloved by professional musicians. Most beginners don’t know that much about them, because it isn’t as user-friendly or commonly available as a digital piano. Very few people learn on a Wurlitzer electronic piano in a classroom setting these days (although we are aware of exceptions, which is very cool).
However, we know that, at the time of their manufacture, Wurlitzer intended for their electronic pianos to be used by beginners. We know this because, first of all, there are specific “student models.” Even before the release of student models, however, there are photos of classrooms full of Wurlitzer 112 and 120 pianos. There is also a teacher command module that was marketed alongside the 120 and 140 models. It included a microphone and fit on top of the Wurlitzer’s lid, so that the teacher could easily address the class.
So, Wurlitzer designed electronic pianos for beginners — but did they consider that more advanced musicians might use them as well? Yes, there is certainly evidence for this. One piece of evidence is a 1959 patent (2,881,650), which contemplates that the invention may be used “simply as a piano, such as might be used by a student or in the home.” For these users, simple volume controls and non-variable filters were sufficient. However, the patent considers that “many persons, including those who would use such an instrument with a dance band, wish to obtain additional effects.” These effects include two (yes, two!) tremolo circuits: a “high pass” and a “low pass” tremolo, each with its own set of controls, each mounted on opposite sides of the name board.
For the 1950s, this is an extremely granular form of wave-shaping. (Remember that effects were few and far between at this point — fuzz hadn’t even been invented yet!) Why would they include these effects in the electronic piano? The patent explains: “For instance, by using a very slow tremolo in the bass, a bass viola can be simulated. In the treble, a very fast tremolo can be set up to simulate a celeste.” Wurlitzer called what would happen in the middle register “a chorus effect…controlled by the difference in frequency between the treble tremolo and the bass tremolo.” They continued: “The phasing effects of the two oscillators give various effects of build up and cancellation but can be controlled by the pianist, and the possible combinations are practically limitless.”
So, Wurlitzer was open to casting a pretty wide net in terms of its target audience. In this patent alone, they discuss features intended for students, home pianists, and “dance bands.” It is unclear who, exactly, these dance bands are. Presumably, they are not the kind fo band that would have a bass viola or celeste player already. However, it’s probably safe to assume that a “dance band” would be composed of experienced musicians, not beginners.
However, the two tremolo circuits were ultimately not included in the final product. You can see the vestiges of this idea in the odd little plug on the chassis of the Wurlitzer 112, which contains a simple filter. If the inventors of this patent had their way, you would be able to remove the plug and connect another plug with a different filter, or connect the dual tremolo. However, Wurlitzer never released plugs with different components inside, so the only plugs that were ever released are the ones that came stock with the 112 in the first place.
Beginners and experienced musicians have different needs, and it is difficult to market to both audiences at the same time. Focusing too much on beginners alienates professionals; focusing too much on professionals typically raises the price beyond the means of beginners. How to weigh these two markets was a challenge that Wurlitzer often grappled without throughout their history. The patent clearly demonstrates that they gave plenty of thought to the needs of experienced musicians. However, the release of the 112 proves that the company ultimately decided, in this case, to simply things, and focus more closely on the beginner and amateur market.
Note that a valid patent does not require the invention to be produced or brought to market. Even though Wurlitzer never released an electronic piano with two sets of tremolo controls, it still held the patent for the technology. The invention must be possible to produce, but it doesn’t literally have to be manufactured.
There are many reasons why a company might patent something that they do not intend on manufacturing. Patenting all the bells and whistles associated with your invention keeps your options open, so that you can release these variations in the future if you so choose. If you patent something really cool, the invention is protected, but any novel, non-obvious, and useful improvements on it are fair game. For instance, if a competitor patents an improvement you thought of but failed to patent yourself, you are blocked from releasing your invention with that improvement. Your competitor can’t release it either, unless you give him or her a license to manufacture the patented invention that the improvement is based upon. However, if you make the business determination that the improvement would increase sales of your product, your hands are tied unless you can negotiate a license with the competitor that holds the patent on the improvement.
So, it is possible that Wurlitzer never intended to manufacture the dual tremolo effect on the first round of 112s. However, patenting it gave them the freedom to use it later, if they so chose. This patent also protected their dual-tremolo idea from becoming co-opted by their competitors.
The claims
Legally, the claims are the most pertinent part of the patent. Here, the inventor lists the features of the invention that are patentable. The main, independent, claim is one sentence. The patent will also have several dependent claims that can elaborate on the independent claim.
This is the independent claim in the 1959 patent (2,881,650) that we discussed earlier:
The invention is hereby claimed as follows:
An electronic musical instrument of the type including vibrating reeds or the like with electrical pick-ups therefrom, an amplifier having an input operatively connected to said pick-ups and an output connected to a means for converting electric oscillations from said reeds into sound, said amplifier having circuits having at least two different wave shaping characteristics, and two tremulant generators of different phase shift characteristics, each of said tremulant generators being associated with a respective wave-shaping circuit.
This part is not written for readability. It is written strategically, in order to improve its odds of surviving any legal challenge that a competitor might bring.
Except from the patent claims in 2,881,650 (“Electronic Piano Amplifier,” granted in 1959).
There are rules about what kind of information can be found in independent or dependent claims. For instance, dependent claims can only discuss elements found in the independent claim. They also cannot introduce new features or make any claims that are more general than the independent claim. The purpose of dependent claims is to support the independent claim. If the independent claim is determined non-patentable in court, features of the dependent claim might come to the rescue and ensure that the invention remains at least partially patentable.
If we were inventors attempting to patent a product, and we needed to determine whether the patent supersedes our invention, our analysis would focus almost exclusively on the patent claims. For our purposes, though, the claims are pretty dry and less interesting than the specification section.
How to find Wurlitzer patents
Wurlitzer patents are listed on a metal serial plate, which is found on the back of the keyboard. In console and portable Wurlitzer 200 and 200a models, this serial plate is found on the outside of the piano, underneath the keybed. The specific patents listed change during the years, as new models are released.
Once you have a number, you can look up the patent on the U.S. Patent Office’s website. Wurlitzer also held several Canadian patents, which can be found in the Canadian Patent Database.
You can find more interesting patents inside the patent documents themselves. Often, patents will reference inventions described by earlier patents. All mentioned patents will be listed at the end of the patent document.
Further Reading
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