Hyd thumb definitions

[coopers]

Well, I posted this on the heavyequipmentforums but I'll do it here just in case. What is the difference between a direct link and a progressive linked hydraulic thumb? I know that some thumbs can close against the bucket even if the bucket is curled all the way out, and some won't. Our JD 120C's and 160C LC's do that but our 200C LC's don't do that, its thumb does not go all the way, it stops about 3/4 the way.

Blake
WA

 

[ScottAR]

Progressive has a linkage that looks like the bucket linkage allowing more arc travel. This allows the thumb to follow the same arc as the bucket.

The Direct thumb has the cylinder attached directly to the thumb. They typically don't travel all the way.

 

[coopers]

Okay, that makes sense. Thanks!

Blake
WA