Air chisel identification

[zjustin28]

Just bought an older air chisel at a pawn. It looks to have an old chicago pneumatic logo. Light metallic blue in color. Has a wierd knurled grip before the spring. Only other marking is b9855

 

[metaleltr]

 

[zjustin28]

Lol, i know, just at work, will have pics later.

 

[zjustin28]

Whats the silver knurled part for?

 

[machine_punk]

I don't have any air hammers, but I constantly use that tool's cousin...the air riveting hammer (which is generally built to have a little more control and accuracy. The phrase commonly used with a riveting hammer is a 'teasing trigger.')

The silver part looks a lot like the newer style of chisel retainer. I suspect it replaces the 'bee hive' spring already on the hammer--and holds the chisel on the hammer in use. It is supposed to be a lot quicker and easier than the spring. The full bee hive spring has to be completely removed and screwed back on each time you change chisels. The smaller 'quick change' style just has to be pushed to the side, while you change chisels (still not very easy, just quicker than completely unscrewing the spring). That style of holder you have (the silver, knurled piece) is supposed to be quicker than both styles of springs.

M_P