I can see you are not familiar with wood stove emissions testing/EPA approved methods, which we can discuss in another thread. The very fact that off the shelf springs (as you noted have been around forever) do not allow for the precision, response time and lag time to hit the precise kg/h burn rates mandated within each of the test methods. We MUST make our own springs. There are mfg's, many my friends that have worked very hard to replicate our designs. They tell me so. Only to find the spring does not allow for the air adjustment needed and in the time frame needed to not have a test run ruled invalid.
As for the prior selling of springs to others, it wasn't proprietary, we just got lucky I guess and they like buying from us. (We try to be nice)
BKVP
So you are saying BK, a company barely more than 40 years old, has cornered the market on the most accurate of bi-metal springs available? Suggesting companies 100 years old haven’t been able to produce and are still in business? There’s actually more than one or two companies who produce these last time I looked. Then BK only sell springs to 5-6 other stove companies and no other companies in various industries? I might come closer to believing that if they provided springs to companies in other industries...and they may as far as I know.
Please, I was being a little sarcastic above, but I’m not a guru, or know it all, and I don’t mean to sound impolite. Just trying to put some pieces of a puzzle together. That being, it seems using a bi-metal spring would not infringe on any BK patents, as they were not the first to use them. However, how the spring is implemented...the box design BK uses to place the spring in likely is patented. Obviously, Hitzer and DS stoves use a spring on their stoves but it is implemented in a different manner than that of BK. Perhaps it is possible BK may even produce their springs.
I’m just trying to make the point that extremely accurate temperature springs is a very old concept. Use in stoves in general not so old, but older than BK as a company.
That little box on the back of BK may be patented and unique in how BK stove company uses it for burning wood on their stoves by modern standards, but the springs use themselves is not new to stoves in general and the accuracy of the springs by companies 100 years old and still in business speaks for itself. To say they couldn’t produce such springs seems a stretch. To say no other industry needs extremely accurate springs as a wood stove company also seems a stretch.
It’s entirely a different matter for a company to produce their own springs perhaps for their needs, but that too seems cost prohibitive let alone considering the learning curve a younger company would need to go through just to produce them, let alone the tooling set-up and costs associated with their production. Not to mention there are other applications where they are used that far out number wood stove production i.e.; highly accurate wall thermostats for furnaces just being one. I assume there are more furnaces in homes than wood stoves. Perhaps I am wrong and this wouldn’t be the first time. LOL!
Please understand I am not debating BK perfecting their use on wood stoves nor emissions and EPA test results using them, but rather stoves in general.
Maybe not the first stove to use them, but Locke Stove company used them on their Warm Morning stoves as early as 1941 and fulfilled stove contracts for the US military using bi-metallic thermostats on many of these stoves during that time period...some 40 years before BK was ever thought of or ever produced a stove, let alone produced a bi-metallic spring thermometer. It could be that they may have been used on WM stoves as early as the 1930’s since Locke was building stoves at that time though not in mass production.
I’m sure you may be aware of some of this and maybe you could provide even more information in that regard. I’m certainly not the guru, but I do know they have been accurate enough for use on stoves for a long time. Sort of hard to quantify and qualify them on the same level in regards to EPA and emissions testing when neither existed when these springs were first implemented on stoves to make them more efficient....burning coal or wood.
