In a nutshell, I designed a water pump and I want to get a patent for that. I found that other patents have similarities of about 80% as my design. The main differences of my design is angle of blades is different, so the compression is different, internal volume is different, bearing fixed to the mid axis is different than other patented designs (but the bearing used is not a my invention). And the pump shape is slightly different. Material used is similar as I also use steel, iron, titanium and aluminium for internal parts. So, the basic idea is same. Same principles are used. But the machine is not identical to any of other patented machines. But after-all it will pump water like other patented machines. So in this case do patents cover the idea and basic principles? or the specific materials used or the technology such as slightly different shape, different blade angles etc?
Do the angle of the blades and the resulting different compression make a performance difference, or any other functional difference? Cost, ease of repair, reliability, etc. Does it achieve an unexpected result? Being different gets over the hurdle of novelty but just being different does not automatically get over the issue of obviousness.– George White ♦Dec 6, 2017 at 20:25
What George White says in his comment is very important. Optimization, by itself, usually isn't patentable. If you make some tweak and get an unexpected advantage, then it may be patentable. Also if the previous patents are still in force, you may not be able to manufacturer your pump depending on their claims.– Eric S ♦Dec 6, 2017 at 20:47
@GeorgeWhite: Thank you for the comment. No it does not make any unexpected result, it just pump water like other pumps. So if being different cannot be patented then how come there are thousands of camera manufacturers and they use the same principles for all of the cameras. such as, every camera has a lens and a sensor.– Pretty_Girl100Dec 7, 2017 at 8:35
@EricShain : Thank you for the comment. If optimization is cannot be patented how come some camera lens manufacturers put several layers of lenses lets say 8 lenses (in phone cameras etc) in a row and getting a patent as new type of camera. But it's basically the same (obvious) and many manufacturers do similar type ..– Pretty_Girl100Dec 7, 2017 at 8:39
Optical designs are really complicated. Certain configurations have been created that reduce imaging aberrations. Those specific designs have been patented. The patent isn’t on a new type of camera, it’s of a specific configuration of lenses. Computers have made this process a lot easier so fundamental new designs are now rare. Back 80 years ago. It could take hundreds of hours of hand calculation with a team to analyze a single configuration. That’s when the fundamental lens designs were more likely to be patented.– Eric S ♦Dec 7, 2017 at 13:40
A patent covers what the claims specify. In general, the claims aren't specific to a single implementation, but cover as broad a description of the novel idea as allowed by the examination process. You do sometimes see ranges specified for certain items, but not always and sometimes only in dependent claims. In order for your design to get patent protection, there needs to be something novel over the prior art. Merely tweaking some design aspect to optimize performance is likely not sufficient to obtain a patent. It would be considered "obvious" which means someone with ordinary skill in the field is likely to think of the change. If you make a change which results in an unexpected benefit, then you have a greater chance of getting the improvement patented.
I don't want to discourage you from trying to obtain a patent. I don't know enough about your design and the prior art to do that. What I would say it to focus on the specific improvements and try to patent those. For example, from your description is sounds like the impeller is more effective. If you can describe specific design differences with your impeller from what has been used previously, you may be able to get a patent on those differences. The trick is to not get so narrow with the claims that someone can avoid your patent with trivial design changes.
Patent claims can be broad or narrow. Sometimes, the basic concept, speaking very loosely, is so novel/non-obvious that one can get a broad claim. Other times you need to narrow and narrow to a specific embodiment to get a claim allowed. In that case the patent might not be worth much if someone can leave out a detail you needed to achieve patentability with little loss of customer appeal.