How long do patents last?

[Eric Sedletzky]

Just wondering about an old US divers back pack design probably from 1964 ish?
It's one of those Kam "EZ" Paks made out of plastic with the stainless tank band with the cam lever.

The reason I ask is because a fellow vintage diver had one roll off the bed of his truck and hit the ground one day as we were gearing up for a dive. The impact shattered the lower corner of the pack and so we had to Jerry rig it (no pun intended, the guys name really is Jerry). He used it to dive that day but was heatbroken that the pak was trashed. So I told him not to frett because I could make him an identical one out of fiberglass.

The first thing I did after I got home was crazy glued all the pieces back together so I would have something to go off, then I made a mould from the old pack and then used the mould to cast a new pak out of fiberglass. The result was a perfect replica of the pak but much stronger. I drilled the holes where they needed to be and cut in all the slots in the same exact locations then transfered all the original hardware and it all fits perfect.

I did it for no money as a favor so there was no profit involved.

Am I infringing on any patents here since I'm not selling them and the one I made was technically a repair or replacement.
Is the patent still even valid?
I know Aqualung hasn't made these things for years, probably since the late 70's.

 

[VooDooGasMan]

If it is fiberglass it is not the same, so I would think your in the clear any how.

 

[Paladin]

Patents filed before 1995 lasted 17 years. Patents filed after 1995 last 20 years.

http://www.inventionstatistics.com/Patent_Protection_Time_Periods.html

 

[Akimbo]

There is/was a special class of patent called a Design Patent and only lasted 10 years… from the filing, not the issued date, if I remember correctly. Their primary value was to prevent copying by unsophisticated manufacturers since they had very little legal protection as long as you could make some minor improvements, practical or not.

I suspect that the patent in this case was a Design Patent or a cross licensing deal due to its similarity the Voit Snug Pack that first appeared in their 1960 catalog. The Sportways metal pack may have been earlier, I’m just not sure.

Simply providing slots for two cam bands would almost certinally protect you from losing a patent suit… if you could afford to fight it. In any case, you are good to go due to the age.

Save this photo for your “Prior Art” file in case you come up with something patentable.

 

[Luis H]

There were many similar packs made back then.

The US Divers plastic ones used to be notorious for cracking. The plastic was too brittle and if you lay the rig on the pack or if it fell on it, they would crack on the bottom where the inside strap slot is located.


Your friend is either lucky or he has been very careful, since his has lasted this long.

If I remember correctly, Dacor made a similar looking pack, but made out of aluminum. Those were fairly rugged.

There were also some very similar packs made by Nemrod and White Stag that were made out of a much more resilient plastic (I have one Nemrod and a couple of White Stag ones). These models have a slot for a continuous metal tank band. I have replaced the metal band with a modern metal cam (Scubapro style) tank band and they are very comfortable.


My point is that I would not worry about copying the geometry. There were plenty of similar packs made in the 70’s.


My understanding is also that patents only last 20 years max unless the owner extends it by making modifications/ improvements to it.

 

[Eric Sedletzky]

OK, thanks guys I'm not going to worry about it.

I will make one for myself off the mold I already have, then I think I will design my own with two cam slots and the ability to use a wing on it. It won't be hard to do and composite is light so it would be good for me use for travel.
If I could find carbon fiber I would use that but it is expensive and hard to find these days.

 

[Thalassamania]

I believe design patents are now 14 years and utility patents are 20 years. In either case, you're in the clear ... clone away.

 

[tyesai]

My take on it in a one minute video.

Copying Is Not Theft - Official Version - YouTube

 

[herman]

From a different point of view, considering no one currently makes these BPs and haven't in 30+ years there is on incentive to stop you, plus it would cost them a lot of cash to stop you from making it even if it was a patent infringement. A nasty letter from a lawyer would most likey be the most effort they would expend and you just stop making them at that point.

Now, if you intend to make a few, I am interested, they are my prefered BP...,,ooooohhhh how about one in Voit blue?? I have a reg in mind to color coordinate with.

 

[mrfixitchapman]

OK, thanks guys I'm not going to worry about it.

I will make one for myself off the mold I already have, then I think I will design my own with two cam slots and the ability to use a wing on it. It won't be hard to do and composite is light so it would be good for me use for travel.
If I could find carbon fiber I would use that but it is expensive and hard to find these days.

I use these guys

Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc.

DC