legal rights and restrictions regarding after market parts

[Melvang]

As the title says, would there be any legal issues with attempting to develop aftermarket stems for MX wait he's?  I understand I can't just blatantly copy a current design, but I would like to change the portion of the stem that gives the feel, and possibly the material. 

But what I was thinking would be possibly UHMW for a stem material (though mkawa says this might pose issues).  Even with the issues with it UHMW has 15 times then abrasion resistance of carbon steel, and has a very low coefficient of friction. 

For a shape I was thinking something of a concave curve.  I thing this would give the feel of a progressive rate spring while still using standard springs.

Thoughts, comments, ideas?  I realize that molds would be significantly expensive, though I am very curious on what these would actually feel like.

[Grendel]

Hm, replacement sliders fro green/blue where the actuation point is moved to 1mm come to mind.

I don't think there would be a legal issue (patents are expired, right ?) and Cherry probably wouldn't mind as long these aren't sold in the millions.

[Melvang]

I don't want to go to the cost of those molds.  One piece stems only.  But after doing some quick internet research it seems that UHMW can't be injection molded.  It is actually pressed from a powder form and then heated. 

[jacobolus]

I’m guessing production of acceptable quality parts (i.e. hitting the tolerances you need, in a material that will withstand the abuse a switch part gets) in small batches is probably pretty steep in price. But there shouldn’t be any patent/etc. issues. [I’m sure replacing switch stems voids any warrantees though.]

[bcg]

I don't want to go to the cost of those molds.  One piece stems only.  But after doing some quick internet research it seems that UHMW can't be injection molded.  It is actually pressed from a powder form and then heated.

You are always allowed to do whatever you want with anything that you buy.  So if you buy switches, mod them, and resell them you are fine.

There could be patents on the mods that you do, but even to properly threaten a patent lawsuit is 10000-20000 USD.  Actually filing papers is like 50000 and following through with a suit is in the neighborhood of 250000 so probably don't need to worry if you are not working with those types of volume.

besides, if they were smart they would let you build up your business until you're a big enough target that they could get a payday, in which case you pay the vig and both go home fat and happy.

Just my two cents, don't take this as legal advice or even the ramblings of someone who remotely has a clue

[domoaligato]

Hm, replacement sliders fro green/blue where the actuation point is moved to 1mm come to mind.

I don't think there would be a legal issue (patents are expired, right ?) and Cherry probably wouldn't mind as long these aren't sold in the millions.

This would be awesome. Like jailhouse stems...

[dorkvader]

I believe a patent just means they can prevent you from selling your device. You can blatantly rip off whatever you want and use it all day long.

Of course, I am not a lawyer, etc.
hmm, I may be wrong; wikipedia says they can prevent you from using it!
http://en.wikipedia.org/wiki/United_States_patent_law

In the U.S., a patent is a right to exclude others from making, using, selling, offering for sale, exporting..., importing..., inducing others to infringe, offering a product specially adapted for practice of the patent...

[jacobolus]

Any patents on Cherry MX switches are long expired.

[HoffmanMyster]

I don't want to go to the cost of those molds.  One piece stems only.  But after doing some quick internet research it seems that UHMW can't be injection molded.  It is actually pressed from a powder form and then heated.

Sounds like a hot press.      I'm intrigued by the idea.  Mostly because it sounds like a fun challenge, but also partly because the properties seem interesting.

[bcg]

I believe a patent just means they can prevent you from selling your device. You can blatantly rip off whatever you want and use it all day long.

Of course, I am not a lawyer, etc.
hmm, I may be wrong; wikipedia says they can prevent you from using it!
http://en.wikipedia.org/wiki/United_States_patent_law

In the U.S., a patent is a right to exclude others from making, using, selling, offering for sale, exporting..., importing..., inducing others to infringe, offering a product specially adapted for practice of the patent...

Correct, that would be a violation of the law... I checked with a patent lawyer recently to verify this... its pretty appalling.  That's where the economics of enforcement come into play though.

[Melvang]

I don't think I would have an issue.  If you think about it, what I am wanting to so is no different than someone making aftermarket pistons for a car engine.

[jacobolus]

In general, it’s not a patent violation to replace one part of some device you own, and keep using the device as intended. But that depends slightly on what the patents are about. You’d have to read the relevant patents. For example, there might be a patent on the method of creating the part you are replacing.

But again, this is academic; Cherry MX is old enough that all the patents are expired.