On a recent session of setting conibear-type traps for marmots, and trying to fit some sets tight against buildings, I thought about past sets that were either difficult or impossible to make due to the spring arms being "in the way" or not having room for the springs to release. I encounter this frequently when trying to set the den openings of marmots, or pathways tight against buildings used by various critters.
That got me wondering why nobody has come out with a coil spring model of body grip trap using coils. I haven't put pencil to paper to see if it's plausible yet but am interested in what others think about the idea. As we all know, the coil spring foot hold trap was in many ways a gamechanger. The conibear-style trap springs haven't changed since the advent of that type of trap, (of course there have been many jaw design options out there for a while, now).
And there are several styles of coil spring out there besides the lateral type used in foot hold traps, such as circular springs that can be mounted in a vertical position.
Thoughts?

I'm picturing them being around the jaws like the spring eyes on a normal bodygrip. I'm sure the right engineer could design springs with a spring ratio that would make this work, although it would probably be difficult and likely they would have the jaws further apart when set than on a typical bodygrip (not a dealbreaker). But the real issue I would see would be for fur trapping, I see a real problem with fur getting caught in the coil springs and pulling out tufts of fur is not desireable. Not an issue for your use, but making a trap just for nuisance that isn't suitable for fur would really narrow your potential customer base. Stabilizing the trap when set, without the springs would also be harder, but easily doable.

Anybody that has used bodygrips "in the wild" rather than just in boxes, very much, has fought springs being "in the way". Just not sure there is an alternative that is as convenient and versatile in as many situations as the existing springs, and cost effective to produce.

Every invention started with a problem that needed solved. Get after it prefect the design and patent it. ( not like that will stop duke from copying it.)

So, you know, way back when I didn`t know that any better, I had the similar thoughts with 110`s for mink in pocket/elbow sets. I didn`t like the idea of one arm of the spring being against the rigid ground, the outside of the pocket. Plus I didn`t care for the trap being blatantly right at the entrance to the pocket for the people factor. So, fold the spring to the inside of the jaws, set the trap and go inside the pocket, not right out front right a sore thumb. It worked to some extent(most of us have heard about how slick a mink can be dodging trigger wires) and this automatically decreased the interior jaw spread of the trap. In Mn we have a three day check on this type of setup and if a guy or gal were to deploy this type of set around freeze up, they could get out a ton of traps that are pretty impervious to weather while trapping some of the best mink of the season.

I believe they tried that many years ago.
I dont know for sure but I believe they were kind of weak and difficult to set.
Maybe the design should be re visited with more modern options.

My thought is the real struggle would be getting the power over that long of travel. I would think you need that long of travel for the leverage advantage. To get that much power in a simple design at that much travel you would need a coil spring that would be very very strong at the set point. I know from a engineering perspective i didn't exactly word this correctly but I hope you get the idea. Not saying it cant be accomplished without an overly powerful coil spring but if it was to be done and kept the design reasonably simple in might be a harder design than one would think. And would there be enough market shares in today's trapping world to make it profitable???

I think the Bigelow trap used a coil spring set up but I have never had one.


Bigelow

There were/are some "tube" type traps that may work, I bought one years ago that was made by AMOS Mfg. It's long and has 4 springs and two sets of jaws I thought it is a real piece of enginering so I bought one! Cooper barrel traps and the "clutch" type traps made years ago could give you some ideas also!?

The Compensator.
How bout rotating the spring arms parallel to the buildings and using the ole Compensator?….. No rotating jaws……lol.

We need one of our resident machinist trappers which a good imagination to look into this.