Koken Attack Driver - updated design - weird O-Ring under striking cap

[Tool Using Animal]

A couple of days ago I bought a Koken Attack Driver on Amazon (directly from Amazon, not some 3rd party seller). It seems the design has been updated. It looks a bit different than the photos I can find online. The striking cap seems to be a separate part now and there is an O-Ring beneath it. Does anyone have any more info on what has changed/improved?

 

[tattooman]

I'm looking at it, and all I can think, is WTH ??

My guess is it has a purpose, I can't see Koken putting an O ring in any place without a purpose, but I'm not up on Koken personally, but I've been studying their excellent line of products of late. This will be interesting.

 

[merkyworks]

If it’s a legit Koken tool and not a knockoff. Strike cap is user replaceable if it becomes damaged/mushroom’d from repeated strikes. The oring is there to take up any manufacturing tolerances so the cap doesnt rattle.

 

[The Cobbler]

but the o ring would dampen blows, which , in my opinion, you don't want in that situation

 

[Fedwrench]

If it’s a legit Koken tool and not a knockoff. Strike cap is user replaceable if it becomes damaged/mushroom’d from repeated strikes. The oring is there to take up any manufacturing tolerances so the cap doesnt rattle.

This sounds plausible. I don't think the o ring itself would cause that much loss of impact force though.

If you're worried about a design change, I would contact Kokenusa.com and ask them about the redesign. It never hurts to ask. I couldn't find a picture of an attack driver with an O Ring online or in their 21/22 catalog.

 

[driftpin]

Is it possible that the O-ring is just there to keep any contaminants out? The cap has a zero-clearance fit to the body?

 

[seber]

The o'ring is not there to absorb anything. It is a dynamic lock ring. Static rings in this application would soon take a set and become worthless. Very thoughtful engineering by Koken.