Redesigned product - Patent infringement?

[richfloe]

In brief:
Very expensive piece of equipment which has a "control module" that fails every 10 years (give or take. the life of the product is probably expected to be 30 years or more). The control module simply turns a few things on and off and has a couple of delay timers to operate things in sequence.

Replacement module is a small metal box with a few connectors on it, contains a half dozen relays, transistors, diodes, resistors, capacitors, nothing exotic, probably $50 worth of parts. Replacement sells for $700 or so, only available from the company that made the original unit.

The typical user of the product would not have the expertise or desire to repair the device and there apparently has not been enough interest or volume to justify someone setting up a repair service or designing a more reliable and/or affordably priced replacement.

Well, I'm looking to get into either repairing them or designing a better unit (that would sell for less than $700).

If I were to fix the bad parts and send it back to the owner (or perhaps set up an exchange program), I can't see how there would be a problem. Unfortunately you have to use a saw to cut the cover off (intentionally made non-serviceable) and then figure out how to seal it back up. If I were to clone their unit and start making them, there could easily be a lawsuit (the parent company holds hundreds of patents for their various products).

What if I were to design a unit from scratch, perhaps with a microprocessor control (which would add some nice diagnostic features), that would plug into their wiring harness in place of the original part and perform the exact same functions? Could I be subject to a lawsuit?

Your comments or ideas are welcomed.
Any links to articles that may be useful would be appreciated.

Rich

[haklesup]

Since you are not a former employee of that company and are not working from schematics covered by an NDA you are essentially working in a "clean room" WRT patent law. To be totally above board, you would need to analyze the circuit you need and specify all its functions (without specifying the schematic) in a design spec from the POV of outside that black box. Then you would turn that over to another engineer who has never looked at the product to design a component or module to achieve that function. Even if that end result is exactly the same as the original, as long as the designer came up with it on their own from the specs and never saw the original, it is considered an original design and the fact that they match is just a coincidence and the design is considered "the way it is done".

In many cases a copyright mark on a PC board does not copyright the circuit but rather the artwork of the PCB itself. A patent protects the circuit inplementation but not necessarily its function, you would need to read the applicable patnets to know the difference. Many if not most circuit implementations are only protected by trade secret which is not legally enforcable unless those secrets are stolen from private property (like a company computer file stolen over the internet). Discovery of a trade secret through reverse engineering is legal and common. most IP these days is inside the IC chips, not around them. If this company is that old, many of those patents you're worried about may already be expired and in the public domain

Though you may win in a patent suite ultimately, an owner of such IP could make it very expensive for you to defend your design forcing you to quit through lack of an affordable lawyer. OTOH, that IP owner would likewise have to pay a lawyer to try and get you to stop. The typical strategy in that case is to make that lawyer work as hard as you can sending you letters and phone calls to which you reply vaguely denying any responsibility until the other guy gets sick of paying lawyer bills for no result.

Now you're not creating a complete product, just a repair module and there is plenty of precidence for this all over multiple markets. As long as you do not copy PCB layout artwork and document all the steps you took to discover the necessary function of this black box, you should be OK. In any case, I doubt the OEM considers the replacement module a profit center and will likely never notice your efforts. If you avoid reverse engineering the circuit layout (the easy way) and focus on specifying the electrical parameters outside the black box, you should be OK. Remember, there is always more than one way to do almost everything, If you substitute FETs for relays or a uController for a logic circuit, that would be plainly obvious that it is not a copy.

THey probably don't have patents on the subcircuit function, only its implementation in circuitry.

[Lenp]

Having been down this road in the past, I believe if you do independent design and do not 'reverse engineer', copy the circuitry or duplicate the OEM unit you will be home free. The world is full of aftermarket repair parts, like in the auto industry, that improve on the OEM's shortsighted design. If you add value by incorporating additional features, options, modes, or protections, that improves your position. There is a company I deal with that does very well making replacement parts for medical equipment. They are drop-in replacements with improved specs and performance, with a lower cost and better availability as a bonus.

I'm currently in the final stages of a product design that is right near the end of the path you are starting on. It is a replacement for an obsolete component that will have more enhanced features than the manufacturer's over priced 'replacement'. With CPU's and clever coding you can offer many features without large cost.

I'd be glad to lend a hand if needed

Len

[jimmy101]

Sounds like you are talking about the ignition circuit for a gas water heater, or some such similar appliance. The circuit has to turn on the glow igniter, verify it is on, turn on the gas, verify the flame lit, recycle if the flame signal is lost, etc. and do appropriate things when something doesn't do what it is supposed to do.

If you build and sell a replacement, or repair defective ones, then you are assuming liability. Since the lawsuit for blowing up someone's house could run into the millions of dollars I would strongly suggest incorporating to protect your personal assets (house, car ...).

[jwax]

richfloe wrote:

Could I be subject to a lawsuit?

Sure! We all are!
By that I mean you could build a device to match the performance of the original without being subject to an infringement lawsuit. However, if a lawyer desires, they could sue, but from what you described it would have to severely impact that companys revenue.
Without knowing more details, I'd be tempted to go for it. Most respectable patent lawyers will give you a free consultation to discuss your position. Be sure to select an attorney that knows the industry you're in.

[Dean Huster]

Building a true clone will be illegal. Just ask Hickok and Lavoie Labs how it worked for them when they cloned near-exact copies of the Tektronix 545 for undercutting Tek on military contracts. The lawsuit took a decade and the cloners are out of business.

I don't see how any suit could prevail if you designed a circuit that was totally different yet provided the same function. You don't ever see ?Goodyear suing Firestone or Yokahama for making replacement tires in the same sizes as Goodyear.

I don't see how any suit could prevail if you provided a repair service for the defective units, sealed and non-repairable or not. RCA never sued an independent TV repair shop because they repaired RCA TV sets. By the way, that's the only time you should be reverse-engineering the circuitry. Be sure to find a sure-fire way to reseal those units, especially if they're designed to operate in an explosive or corrosive atmosphere.

The suggestion to incorporate and have liability insurance to protect you in case your repair or new replacement product fails and causes damage is a good one.

By the way, homeowner's insurance will usually not cover claims on a home business regarding theft, fire or liability. That been a problem for a long time when one guy I read about found out that any insurance company with "state" somewhere in their name (and one of those is now renamed) were impossible to work with.

[richfloe]

Thanks for the comments!

I can see that liability is going to be my biggest problem. Insurance would likely be expensive considering the insurance company has no way to know what my skills are and would have to assume that I could screw up or cut corners and create a hazardous situation. I guess I had been more concerned with how to handle one of my repaired or replacement units that quit (from a customer satisfaction standpoint) than about the damage a malfunction could cause.

Jimmy101:
Have you been spying on me? This is the control module for a diesel-fired water heater. Upon call for heat, it turns on a motor that is both the combustion blower and fuel pump, turns on a sparker and fuel valve and uses a photo-sensor to detect flame. The timers provide for running the blower to purge the burner before and after operation.

A malfunction could be serious! I'll have to give this some further consideration before I proceed.

Thanks again

Rich

[haklesup]

WRT Liability: If you plan to make a lot of these and maybe other products then Incorporating is a good way to protect your personal assets. However you may still need to get business liability insurance.

If you just want to make a small bunch and sell direct over the internet or ebay, then a Personal Liability AKA "Umberella Policy" is advisable. You can get these from any reputable insurance company (like the one you get home and auto from already) and protects you up to a limit (usually $1M) for any kind of negligance you may get into whether that be a defective product or a stupid mistake. It can be pricy over time so you need to look at your profit capability vs these costs and the risk of a real problem (a failure that results in damage).

While the failure of a boiler can be serious, can this assembly cause that. If there are particular failure modes (like a stuck on relay) that can result in catestrophic failure then you need to look to engineer failsafe modes to force failure modes that only result in non operation or safe shutdown.