Thank you for one of the best posts I've read in a long long time!
People needing legal advice should seek out an appropriate attorney.
Thank you, I've decided to do a fairly long post about this, so if any one does actually care, please listen up because this will be the only time that I will do this.
My background coming at this is from the large law firm (as in over 500 lawyers) and a corporate perspective.
Do not ask legal advice on the internet. You have no idea who you are talking to. You have no idea if I am a licensed attorney and registered to practice before the PTO or not. I'm not going to use my real name b/c I don't want it turning up on internet searches or the like.
I'm also not going to give specific legal advice and here is why I think that you should be very weary of any "attorney" that does. First, the internet is obviously interstate and international. I am licensed in a specific state and that is where I can legally practice law (along with a very specialized federal court). Ok, when someone from another state asks me a specific legal question, I can't give a specific legal opinion for a couple of reasons. First, it establishes an attorney-client relationship and that is bad for several reasons. One, practicing in a state in which I am not licensed is unethical, opens me to a malpractice claim and possible disbarment, and in most places is a crime. Two, establishing the A-C relationship brings up the ever-present problem of conflict of interest. All big law firms do extensive conflict of interest checks so they don't commit malpractice and more importantly, don't piss off a major corporate client and lose thousands (perhaps millions) of dollars of billable hours. It is hard to do a check when I don't even know who I am talking to. Now, most small law firms and solo practicioners don't do that because they do bread and butter stuff with individual clients and that problem doesn't arise.
Two, I don't need small clients, its not what I do. I will post very rarely on non law subjects and when people say something that is just so wrong that I can't help myself (which I am stopping actually).
So here is some advice. If you have questions, look for a local lawyer. You can google martindale hubbell and find local lawyers. You can call the state bar association, search their site, or call a local bar association. For patent lawyers and agents, google the PTO's Office of Enrollment and Discipline and do a search for a registered agent or lawyer in your area. Please don't ask internet lawyers for advice and put yourself and them in a difficult position. Go to a regular lawyer, even many big lawyers will do free consultations. You'll get specific advice for your situation and you will establish a confidential relationship which the vast majority of lawyers will not break. One of the bars to receiving a patent is prior publication, do you want to lose out b/c you effectively disclosed your invention over the internet or to a scam ad on tv?
And let me tell you a little about the legal profession- it is a business. There is a wide divide between a contingency fee lawyer taking any case that has a chance of making a profit and corporate lawyers who bill by the hour. Contigency fees are generally done by Plantiff's lawyers in personal injury cases, not in business law. PI lawyers take a lot of cases on contigency fees (which vary from maybe a third to a half), they take on all your car accidents, slip and fall, medmal, etc... What the lawyers know is that over 95% of lawsuits are settled out of court. PI cases are very straight forward, the lawyer sends a demand letter to the defendant, who sends it to his (or more likely his insurance company's) lawyer. The insurance company argues a bit, checks the policy to see what the coverage is, looks at the facts, fires off counteroffers, etc... What is going to happen is that the plantiff's lawyer has his paralegal fill in the blanks on a form demand letter, does maybe a few hours work, and the defendant settles for a few thousand or maybe a hundred thousand, which the plantiff, who many times doesn't make a whole lot of money, thinks is hitting the lottery jackpot. The plantiff's lawyer makes a pretty good profit for very little work, the defendant law firm, which bills by the hour, makes a decent amount on what is essential by the numbers type work and everyone is happy.
There is a huge leap between that and business and corporate law. Big law firms have big corporate clients that sue and are sued by other corporations. It is very, very expensive (have a look at the Blackberry patent suits) because there is a whole lot of corporate profit at stake. So patent law is in this realm. Most patents are done by major companies. These companies will have their own legal department with their own patent lawyers and agents who do the general slavery of patent prosecution. They hire outside counsel to do the heavy litigation. At this level, the companies have large R&D departments that spend a whole lot of money doing research in the hopes of making a profit from it, they pay their own set of researchers to do this.
Patent lawyers- it is something like 1.5% of all lawyers who are registered before the PTO. It takes a technical degree to be eligible and most lawyers are liberal arts majors. Usually these lawyers do very well in law school, are in at least the top 25% of their class, law review, great clerkships etc... Starting salaries at the major law firms start at $135,000 plus a bunch of bonuses and stuff to hit about $150K. Generally, these are very, very smart people who are very, very good at what they do.
So, in this light, while there are a lot of individuals who patent an invention, but there is a leap from doing that and either successfully marketing that invention yourself or selling it to a company. I am into entertainment law as well. Have a look at how many copyright lawsuits there are in New York and California by would be screenwriters and the major movie studios and tv networks. There are thousands of people who send scripts out unsolicited, but guess what? The studios have mailrooms full of people who very carefully slit open mail to see if it has an unsolicited script and will immediately send it back. They don't want to take the chance of an infringement suit. Companies are the same way, they pay their own scientists to invent and they don't want to take the chance of independently inventing something and having someone else sue them b/c that person sent them the invention unsolicited.
So, yes, you can sometimes be successful as a small private inventor, but you need money and connections, you need to get lucky and maybe find a small business or form your own, that will market your invention.
To the comment on doing prior art checks, you are right, while it is not a requirement to do so, a prudent lawyer or agent is going to do that for the reason you said, malpractice. Better to bill a thousand dollars of research time than $20K and 2 years of answering office actions and not getting the patent and getting sued. I would be very suspicious of someone who doesn't do that.
For the question about is it worth it- I can't answer that, is it worth it to you to be an inventor and have the certificate of the patent even if it isn't commercially viable? But there is this, to patent your inventions they need to be reduced to practice, you need a working invention, not just drawings. Find a patent lawyer and talk to him in person.
On the overall question of the thread- of course knife patents are worth it. I did a quick search on spyderco, I think it was 60 or more design and utility patents already issued. Do you think Mr. Glessar would spend that kind of money if it wasn't commercially worth it? Would he still be in business if not? Granted there are no publicly traded knife companies but if you do a cursory search you can find industry articles about how dealers are looking at 50% markups and profits on knife sales- the makers are probably looking at that kind of markup on dealer sales, so I would venture to guess that the major makers like Gerber, Leatherman, Benchmade, Cold Steel, Spyderco, etc... are probably making profits at least in the tens of millions of dollars. Hell, I've seen mom and pop bakeries and food related stores with one location that are grossing more than a million, even though the profit margins are much smaller.
So look at it this way- everyone had heard the adage that you have to spend money to make money. So, if you are serious, spend the time and money to hire a good lawyer to have a look at the process. You may spend $1000 but that is worth it when you consider the possibilities.
That is my opinion, probably disjointed because it is too early in the morning, but everyone may agree, disagree, or ignore me as they see fit.