Dimarzio Patent Question: Airbucker Tapered Slugs and Spacer

WHAT ARE AIRBUCKERS?
Airbuckers are full-sized humbuckers that contain a gap or space between the magnet and the polepieces. The distance is quite small, and may be filled with nothing but air or by some non-magnetic material. The purpose of the gap is to lessen the magnetic field over the pickup, which in turn lets the string vibrate more freely. This results in a purer, more open sound and improved sustain.

The other purpose of the “air” design is to reliably reproduce the performance of vintage humbuckers (1950s and 60s), many of which contain magnets weakened by age and mishandling. Weakened or "aged" magnets are inherently unstable, and therefore cause unpredictable performance. Airbuckers utilize stable, full-strength magnets, yet the magnetic field is the same as produced by an "aged" magnet, thus offering the performance advantage without the unpredictability.

https://www.dimarzio.com/node/1725​

I've been lead to believe (I don't dissect pickups), that they accomplish this by using a spacer (I heard surgical tube) and tapered slugs. Obviously, you can't use the trademarked term airbuckers. But could other pickup winders use the same tech (covered by Patent which only lasts for several years) and not face patent issues? It's more a matter of curiosity as I don't wind pickups, but happen to like this approach in their pickups. Could I ask a custom winder to do it?

 

@Squier by Squier I think you may be confusing trademarks with patents. I don't know about other countries but in the US patents are good for only a few years and are technical in nature. Trademarks examples include :

Example Trademark Devices

• letters and words.
• logos.
• pictures.
• a combination of words and a logo.
• slogans.
• colors.
• product shapes.
• sounds.

 

Looks right. According to one site I found:

A U.S. utility patent, explained above, is generally granted for 20 years from the date the patent application is filed; however, periodic fees are required to maintain the enforceability of the patent. A design patent is generally granted protection for 14 years measured from the date the design patent is granted.

The patent you found was in 93 so it should be expired. Patents being held too long is considered to stifle innovation. I won't speak for other fields, but I work in software and often feel that patents stifle innovation.

 

Part of what you say also reminds me that few companies would have the resources to fight Dimarzio (if Dimarzio stole their design or Dimarzio claimed that their company used their patent). Big companies like Duncan could as would major guitar manufacturers. But a small company couldn't. I believe Chris Kinman lost by default in a lawsuit Dimarzio filed for this reason.

I would argue this issue is more general than just with guitar pickup patents though.